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
;
527 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
528 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
531 atomic_inc(&rdev
->nr_pending
);
534 /* We have already checked bad blocks for reads. Now
535 * need to check for writes.
537 while ((rw
& WRITE
) && rdev
&&
538 test_bit(WriteErrorSeen
, &rdev
->flags
)) {
541 int bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
542 &first_bad
, &bad_sectors
);
547 set_bit(BlockedBadBlocks
, &rdev
->flags
);
548 if (!conf
->mddev
->external
&&
549 conf
->mddev
->flags
) {
550 /* It is very unlikely, but we might
551 * still need to write out the
552 * bad block log - better give it
554 md_check_recovery(conf
->mddev
);
556 md_wait_for_blocked_rdev(rdev
, conf
->mddev
);
558 /* Acknowledged bad block - skip the write */
559 rdev_dec_pending(rdev
, conf
->mddev
);
565 if (s
->syncing
|| s
->expanding
|| s
->expanded
)
566 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
568 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
570 bi
->bi_bdev
= rdev
->bdev
;
571 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
572 __func__
, (unsigned long long)sh
->sector
,
574 atomic_inc(&sh
->count
);
575 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
576 bi
->bi_flags
= 1 << BIO_UPTODATE
;
580 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
581 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
582 bi
->bi_io_vec
[0].bv_offset
= 0;
583 bi
->bi_size
= STRIPE_SIZE
;
585 generic_make_request(bi
);
588 set_bit(STRIPE_DEGRADED
, &sh
->state
);
589 pr_debug("skip op %ld on disc %d for sector %llu\n",
590 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
591 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
592 set_bit(STRIPE_HANDLE
, &sh
->state
);
597 static struct dma_async_tx_descriptor
*
598 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
599 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
602 struct page
*bio_page
;
605 struct async_submit_ctl submit
;
606 enum async_tx_flags flags
= 0;
608 if (bio
->bi_sector
>= sector
)
609 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
611 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
614 flags
|= ASYNC_TX_FENCE
;
615 init_async_submit(&submit
, flags
, tx
, NULL
, NULL
, NULL
);
617 bio_for_each_segment(bvl
, bio
, i
) {
618 int len
= bvl
->bv_len
;
622 if (page_offset
< 0) {
623 b_offset
= -page_offset
;
624 page_offset
+= b_offset
;
628 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
629 clen
= STRIPE_SIZE
- page_offset
;
634 b_offset
+= bvl
->bv_offset
;
635 bio_page
= bvl
->bv_page
;
637 tx
= async_memcpy(page
, bio_page
, page_offset
,
638 b_offset
, clen
, &submit
);
640 tx
= async_memcpy(bio_page
, page
, b_offset
,
641 page_offset
, clen
, &submit
);
643 /* chain the operations */
644 submit
.depend_tx
= tx
;
646 if (clen
< len
) /* hit end of page */
654 static void ops_complete_biofill(void *stripe_head_ref
)
656 struct stripe_head
*sh
= stripe_head_ref
;
657 struct bio
*return_bi
= NULL
;
658 struct r5conf
*conf
= sh
->raid_conf
;
661 pr_debug("%s: stripe %llu\n", __func__
,
662 (unsigned long long)sh
->sector
);
664 /* clear completed biofills */
665 spin_lock_irq(&conf
->device_lock
);
666 for (i
= sh
->disks
; i
--; ) {
667 struct r5dev
*dev
= &sh
->dev
[i
];
669 /* acknowledge completion of a biofill operation */
670 /* and check if we need to reply to a read request,
671 * new R5_Wantfill requests are held off until
672 * !STRIPE_BIOFILL_RUN
674 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
675 struct bio
*rbi
, *rbi2
;
680 while (rbi
&& rbi
->bi_sector
<
681 dev
->sector
+ STRIPE_SECTORS
) {
682 rbi2
= r5_next_bio(rbi
, dev
->sector
);
683 if (!raid5_dec_bi_phys_segments(rbi
)) {
684 rbi
->bi_next
= return_bi
;
691 spin_unlock_irq(&conf
->device_lock
);
692 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
694 return_io(return_bi
);
696 set_bit(STRIPE_HANDLE
, &sh
->state
);
700 static void ops_run_biofill(struct stripe_head
*sh
)
702 struct dma_async_tx_descriptor
*tx
= NULL
;
703 struct r5conf
*conf
= sh
->raid_conf
;
704 struct async_submit_ctl submit
;
707 pr_debug("%s: stripe %llu\n", __func__
,
708 (unsigned long long)sh
->sector
);
710 for (i
= sh
->disks
; i
--; ) {
711 struct r5dev
*dev
= &sh
->dev
[i
];
712 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
714 spin_lock_irq(&conf
->device_lock
);
715 dev
->read
= rbi
= dev
->toread
;
717 spin_unlock_irq(&conf
->device_lock
);
718 while (rbi
&& rbi
->bi_sector
<
719 dev
->sector
+ STRIPE_SECTORS
) {
720 tx
= async_copy_data(0, rbi
, dev
->page
,
722 rbi
= r5_next_bio(rbi
, dev
->sector
);
727 atomic_inc(&sh
->count
);
728 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_biofill
, sh
, NULL
);
729 async_trigger_callback(&submit
);
732 static void mark_target_uptodate(struct stripe_head
*sh
, int target
)
739 tgt
= &sh
->dev
[target
];
740 set_bit(R5_UPTODATE
, &tgt
->flags
);
741 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
742 clear_bit(R5_Wantcompute
, &tgt
->flags
);
745 static void ops_complete_compute(void *stripe_head_ref
)
747 struct stripe_head
*sh
= stripe_head_ref
;
749 pr_debug("%s: stripe %llu\n", __func__
,
750 (unsigned long long)sh
->sector
);
752 /* mark the computed target(s) as uptodate */
753 mark_target_uptodate(sh
, sh
->ops
.target
);
754 mark_target_uptodate(sh
, sh
->ops
.target2
);
756 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
757 if (sh
->check_state
== check_state_compute_run
)
758 sh
->check_state
= check_state_compute_result
;
759 set_bit(STRIPE_HANDLE
, &sh
->state
);
763 /* return a pointer to the address conversion region of the scribble buffer */
764 static addr_conv_t
*to_addr_conv(struct stripe_head
*sh
,
765 struct raid5_percpu
*percpu
)
767 return percpu
->scribble
+ sizeof(struct page
*) * (sh
->disks
+ 2);
770 static struct dma_async_tx_descriptor
*
771 ops_run_compute5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
773 int disks
= sh
->disks
;
774 struct page
**xor_srcs
= percpu
->scribble
;
775 int target
= sh
->ops
.target
;
776 struct r5dev
*tgt
= &sh
->dev
[target
];
777 struct page
*xor_dest
= tgt
->page
;
779 struct dma_async_tx_descriptor
*tx
;
780 struct async_submit_ctl submit
;
783 pr_debug("%s: stripe %llu block: %d\n",
784 __func__
, (unsigned long long)sh
->sector
, target
);
785 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
787 for (i
= disks
; i
--; )
789 xor_srcs
[count
++] = sh
->dev
[i
].page
;
791 atomic_inc(&sh
->count
);
793 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
, NULL
,
794 ops_complete_compute
, sh
, to_addr_conv(sh
, percpu
));
795 if (unlikely(count
== 1))
796 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
798 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
803 /* set_syndrome_sources - populate source buffers for gen_syndrome
804 * @srcs - (struct page *) array of size sh->disks
805 * @sh - stripe_head to parse
807 * Populates srcs in proper layout order for the stripe and returns the
808 * 'count' of sources to be used in a call to async_gen_syndrome. The P
809 * destination buffer is recorded in srcs[count] and the Q destination
810 * is recorded in srcs[count+1]].
812 static int set_syndrome_sources(struct page
**srcs
, struct stripe_head
*sh
)
814 int disks
= sh
->disks
;
815 int syndrome_disks
= sh
->ddf_layout
? disks
: (disks
- 2);
816 int d0_idx
= raid6_d0(sh
);
820 for (i
= 0; i
< disks
; i
++)
826 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
828 srcs
[slot
] = sh
->dev
[i
].page
;
829 i
= raid6_next_disk(i
, disks
);
830 } while (i
!= d0_idx
);
832 return syndrome_disks
;
835 static struct dma_async_tx_descriptor
*
836 ops_run_compute6_1(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
838 int disks
= sh
->disks
;
839 struct page
**blocks
= percpu
->scribble
;
841 int qd_idx
= sh
->qd_idx
;
842 struct dma_async_tx_descriptor
*tx
;
843 struct async_submit_ctl submit
;
849 if (sh
->ops
.target
< 0)
850 target
= sh
->ops
.target2
;
851 else if (sh
->ops
.target2
< 0)
852 target
= sh
->ops
.target
;
854 /* we should only have one valid target */
857 pr_debug("%s: stripe %llu block: %d\n",
858 __func__
, (unsigned long long)sh
->sector
, target
);
860 tgt
= &sh
->dev
[target
];
861 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
864 atomic_inc(&sh
->count
);
866 if (target
== qd_idx
) {
867 count
= set_syndrome_sources(blocks
, sh
);
868 blocks
[count
] = NULL
; /* regenerating p is not necessary */
869 BUG_ON(blocks
[count
+1] != dest
); /* q should already be set */
870 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
871 ops_complete_compute
, sh
,
872 to_addr_conv(sh
, percpu
));
873 tx
= async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
875 /* Compute any data- or p-drive using XOR */
877 for (i
= disks
; i
-- ; ) {
878 if (i
== target
|| i
== qd_idx
)
880 blocks
[count
++] = sh
->dev
[i
].page
;
883 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
884 NULL
, ops_complete_compute
, sh
,
885 to_addr_conv(sh
, percpu
));
886 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
, &submit
);
892 static struct dma_async_tx_descriptor
*
893 ops_run_compute6_2(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
895 int i
, count
, disks
= sh
->disks
;
896 int syndrome_disks
= sh
->ddf_layout
? disks
: disks
-2;
897 int d0_idx
= raid6_d0(sh
);
898 int faila
= -1, failb
= -1;
899 int target
= sh
->ops
.target
;
900 int target2
= sh
->ops
.target2
;
901 struct r5dev
*tgt
= &sh
->dev
[target
];
902 struct r5dev
*tgt2
= &sh
->dev
[target2
];
903 struct dma_async_tx_descriptor
*tx
;
904 struct page
**blocks
= percpu
->scribble
;
905 struct async_submit_ctl submit
;
907 pr_debug("%s: stripe %llu block1: %d block2: %d\n",
908 __func__
, (unsigned long long)sh
->sector
, target
, target2
);
909 BUG_ON(target
< 0 || target2
< 0);
910 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
911 BUG_ON(!test_bit(R5_Wantcompute
, &tgt2
->flags
));
913 /* we need to open-code set_syndrome_sources to handle the
914 * slot number conversion for 'faila' and 'failb'
916 for (i
= 0; i
< disks
; i
++)
921 int slot
= raid6_idx_to_slot(i
, sh
, &count
, syndrome_disks
);
923 blocks
[slot
] = sh
->dev
[i
].page
;
929 i
= raid6_next_disk(i
, disks
);
930 } while (i
!= d0_idx
);
932 BUG_ON(faila
== failb
);
935 pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
936 __func__
, (unsigned long long)sh
->sector
, faila
, failb
);
938 atomic_inc(&sh
->count
);
940 if (failb
== syndrome_disks
+1) {
941 /* Q disk is one of the missing disks */
942 if (faila
== syndrome_disks
) {
943 /* Missing P+Q, just recompute */
944 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
945 ops_complete_compute
, sh
,
946 to_addr_conv(sh
, percpu
));
947 return async_gen_syndrome(blocks
, 0, syndrome_disks
+2,
948 STRIPE_SIZE
, &submit
);
952 int qd_idx
= sh
->qd_idx
;
954 /* Missing D+Q: recompute D from P, then recompute Q */
955 if (target
== qd_idx
)
956 data_target
= target2
;
958 data_target
= target
;
961 for (i
= disks
; i
-- ; ) {
962 if (i
== data_target
|| i
== qd_idx
)
964 blocks
[count
++] = sh
->dev
[i
].page
;
966 dest
= sh
->dev
[data_target
].page
;
967 init_async_submit(&submit
,
968 ASYNC_TX_FENCE
|ASYNC_TX_XOR_ZERO_DST
,
970 to_addr_conv(sh
, percpu
));
971 tx
= async_xor(dest
, blocks
, 0, count
, STRIPE_SIZE
,
974 count
= set_syndrome_sources(blocks
, sh
);
975 init_async_submit(&submit
, ASYNC_TX_FENCE
, tx
,
976 ops_complete_compute
, sh
,
977 to_addr_conv(sh
, percpu
));
978 return async_gen_syndrome(blocks
, 0, count
+2,
979 STRIPE_SIZE
, &submit
);
982 init_async_submit(&submit
, ASYNC_TX_FENCE
, NULL
,
983 ops_complete_compute
, sh
,
984 to_addr_conv(sh
, percpu
));
985 if (failb
== syndrome_disks
) {
986 /* We're missing D+P. */
987 return async_raid6_datap_recov(syndrome_disks
+2,
991 /* We're missing D+D. */
992 return async_raid6_2data_recov(syndrome_disks
+2,
993 STRIPE_SIZE
, faila
, failb
,
1000 static void ops_complete_prexor(void *stripe_head_ref
)
1002 struct stripe_head
*sh
= stripe_head_ref
;
1004 pr_debug("%s: stripe %llu\n", __func__
,
1005 (unsigned long long)sh
->sector
);
1008 static struct dma_async_tx_descriptor
*
1009 ops_run_prexor(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1010 struct dma_async_tx_descriptor
*tx
)
1012 int disks
= sh
->disks
;
1013 struct page
**xor_srcs
= percpu
->scribble
;
1014 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1015 struct async_submit_ctl submit
;
1017 /* existing parity data subtracted */
1018 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1020 pr_debug("%s: stripe %llu\n", __func__
,
1021 (unsigned long long)sh
->sector
);
1023 for (i
= disks
; i
--; ) {
1024 struct r5dev
*dev
= &sh
->dev
[i
];
1025 /* Only process blocks that are known to be uptodate */
1026 if (test_bit(R5_Wantdrain
, &dev
->flags
))
1027 xor_srcs
[count
++] = dev
->page
;
1030 init_async_submit(&submit
, ASYNC_TX_FENCE
|ASYNC_TX_XOR_DROP_DST
, tx
,
1031 ops_complete_prexor
, sh
, to_addr_conv(sh
, percpu
));
1032 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1037 static struct dma_async_tx_descriptor
*
1038 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
1040 int disks
= sh
->disks
;
1043 pr_debug("%s: stripe %llu\n", __func__
,
1044 (unsigned long long)sh
->sector
);
1046 for (i
= disks
; i
--; ) {
1047 struct r5dev
*dev
= &sh
->dev
[i
];
1050 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
1053 spin_lock_irq(&sh
->raid_conf
->device_lock
);
1054 chosen
= dev
->towrite
;
1055 dev
->towrite
= NULL
;
1056 BUG_ON(dev
->written
);
1057 wbi
= dev
->written
= chosen
;
1058 spin_unlock_irq(&sh
->raid_conf
->device_lock
);
1060 while (wbi
&& wbi
->bi_sector
<
1061 dev
->sector
+ STRIPE_SECTORS
) {
1062 if (wbi
->bi_rw
& REQ_FUA
)
1063 set_bit(R5_WantFUA
, &dev
->flags
);
1064 tx
= async_copy_data(1, wbi
, dev
->page
,
1066 wbi
= r5_next_bio(wbi
, dev
->sector
);
1074 static void ops_complete_reconstruct(void *stripe_head_ref
)
1076 struct stripe_head
*sh
= stripe_head_ref
;
1077 int disks
= sh
->disks
;
1078 int pd_idx
= sh
->pd_idx
;
1079 int qd_idx
= sh
->qd_idx
;
1083 pr_debug("%s: stripe %llu\n", __func__
,
1084 (unsigned long long)sh
->sector
);
1086 for (i
= disks
; i
--; )
1087 fua
|= test_bit(R5_WantFUA
, &sh
->dev
[i
].flags
);
1089 for (i
= disks
; i
--; ) {
1090 struct r5dev
*dev
= &sh
->dev
[i
];
1092 if (dev
->written
|| i
== pd_idx
|| i
== qd_idx
) {
1093 set_bit(R5_UPTODATE
, &dev
->flags
);
1095 set_bit(R5_WantFUA
, &dev
->flags
);
1099 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
1100 sh
->reconstruct_state
= reconstruct_state_drain_result
;
1101 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
1102 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
1104 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
1105 sh
->reconstruct_state
= reconstruct_state_result
;
1108 set_bit(STRIPE_HANDLE
, &sh
->state
);
1113 ops_run_reconstruct5(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1114 struct dma_async_tx_descriptor
*tx
)
1116 int disks
= sh
->disks
;
1117 struct page
**xor_srcs
= percpu
->scribble
;
1118 struct async_submit_ctl submit
;
1119 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
1120 struct page
*xor_dest
;
1122 unsigned long flags
;
1124 pr_debug("%s: stripe %llu\n", __func__
,
1125 (unsigned long long)sh
->sector
);
1127 /* check if prexor is active which means only process blocks
1128 * that are part of a read-modify-write (written)
1130 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
1132 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
1133 for (i
= disks
; i
--; ) {
1134 struct r5dev
*dev
= &sh
->dev
[i
];
1136 xor_srcs
[count
++] = dev
->page
;
1139 xor_dest
= sh
->dev
[pd_idx
].page
;
1140 for (i
= disks
; i
--; ) {
1141 struct r5dev
*dev
= &sh
->dev
[i
];
1143 xor_srcs
[count
++] = dev
->page
;
1147 /* 1/ if we prexor'd then the dest is reused as a source
1148 * 2/ if we did not prexor then we are redoing the parity
1149 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
1150 * for the synchronous xor case
1152 flags
= ASYNC_TX_ACK
|
1153 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
1155 atomic_inc(&sh
->count
);
1157 init_async_submit(&submit
, flags
, tx
, ops_complete_reconstruct
, sh
,
1158 to_addr_conv(sh
, percpu
));
1159 if (unlikely(count
== 1))
1160 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
, &submit
);
1162 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
, &submit
);
1166 ops_run_reconstruct6(struct stripe_head
*sh
, struct raid5_percpu
*percpu
,
1167 struct dma_async_tx_descriptor
*tx
)
1169 struct async_submit_ctl submit
;
1170 struct page
**blocks
= percpu
->scribble
;
1173 pr_debug("%s: stripe %llu\n", __func__
, (unsigned long long)sh
->sector
);
1175 count
= set_syndrome_sources(blocks
, sh
);
1177 atomic_inc(&sh
->count
);
1179 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_reconstruct
,
1180 sh
, to_addr_conv(sh
, percpu
));
1181 async_gen_syndrome(blocks
, 0, count
+2, STRIPE_SIZE
, &submit
);
1184 static void ops_complete_check(void *stripe_head_ref
)
1186 struct stripe_head
*sh
= stripe_head_ref
;
1188 pr_debug("%s: stripe %llu\n", __func__
,
1189 (unsigned long long)sh
->sector
);
1191 sh
->check_state
= check_state_check_result
;
1192 set_bit(STRIPE_HANDLE
, &sh
->state
);
1196 static void ops_run_check_p(struct stripe_head
*sh
, struct raid5_percpu
*percpu
)
1198 int disks
= sh
->disks
;
1199 int pd_idx
= sh
->pd_idx
;
1200 int qd_idx
= sh
->qd_idx
;
1201 struct page
*xor_dest
;
1202 struct page
**xor_srcs
= percpu
->scribble
;
1203 struct dma_async_tx_descriptor
*tx
;
1204 struct async_submit_ctl submit
;
1208 pr_debug("%s: stripe %llu\n", __func__
,
1209 (unsigned long long)sh
->sector
);
1212 xor_dest
= sh
->dev
[pd_idx
].page
;
1213 xor_srcs
[count
++] = xor_dest
;
1214 for (i
= disks
; i
--; ) {
1215 if (i
== pd_idx
|| i
== qd_idx
)
1217 xor_srcs
[count
++] = sh
->dev
[i
].page
;
1220 init_async_submit(&submit
, 0, NULL
, NULL
, NULL
,
1221 to_addr_conv(sh
, percpu
));
1222 tx
= async_xor_val(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
1223 &sh
->ops
.zero_sum_result
, &submit
);
1225 atomic_inc(&sh
->count
);
1226 init_async_submit(&submit
, ASYNC_TX_ACK
, tx
, ops_complete_check
, sh
, NULL
);
1227 tx
= async_trigger_callback(&submit
);
1230 static void ops_run_check_pq(struct stripe_head
*sh
, struct raid5_percpu
*percpu
, int checkp
)
1232 struct page
**srcs
= percpu
->scribble
;
1233 struct async_submit_ctl submit
;
1236 pr_debug("%s: stripe %llu checkp: %d\n", __func__
,
1237 (unsigned long long)sh
->sector
, checkp
);
1239 count
= set_syndrome_sources(srcs
, sh
);
1243 atomic_inc(&sh
->count
);
1244 init_async_submit(&submit
, ASYNC_TX_ACK
, NULL
, ops_complete_check
,
1245 sh
, to_addr_conv(sh
, percpu
));
1246 async_syndrome_val(srcs
, 0, count
+2, STRIPE_SIZE
,
1247 &sh
->ops
.zero_sum_result
, percpu
->spare_page
, &submit
);
1250 static void __raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1252 int overlap_clear
= 0, i
, disks
= sh
->disks
;
1253 struct dma_async_tx_descriptor
*tx
= NULL
;
1254 struct r5conf
*conf
= sh
->raid_conf
;
1255 int level
= conf
->level
;
1256 struct raid5_percpu
*percpu
;
1260 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1261 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
1262 ops_run_biofill(sh
);
1266 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
1268 tx
= ops_run_compute5(sh
, percpu
);
1270 if (sh
->ops
.target2
< 0 || sh
->ops
.target
< 0)
1271 tx
= ops_run_compute6_1(sh
, percpu
);
1273 tx
= ops_run_compute6_2(sh
, percpu
);
1275 /* terminate the chain if reconstruct is not set to be run */
1276 if (tx
&& !test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
))
1280 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
1281 tx
= ops_run_prexor(sh
, percpu
, tx
);
1283 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
1284 tx
= ops_run_biodrain(sh
, tx
);
1288 if (test_bit(STRIPE_OP_RECONSTRUCT
, &ops_request
)) {
1290 ops_run_reconstruct5(sh
, percpu
, tx
);
1292 ops_run_reconstruct6(sh
, percpu
, tx
);
1295 if (test_bit(STRIPE_OP_CHECK
, &ops_request
)) {
1296 if (sh
->check_state
== check_state_run
)
1297 ops_run_check_p(sh
, percpu
);
1298 else if (sh
->check_state
== check_state_run_q
)
1299 ops_run_check_pq(sh
, percpu
, 0);
1300 else if (sh
->check_state
== check_state_run_pq
)
1301 ops_run_check_pq(sh
, percpu
, 1);
1307 for (i
= disks
; i
--; ) {
1308 struct r5dev
*dev
= &sh
->dev
[i
];
1309 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1310 wake_up(&sh
->raid_conf
->wait_for_overlap
);
1315 #ifdef CONFIG_MULTICORE_RAID456
1316 static void async_run_ops(void *param
, async_cookie_t cookie
)
1318 struct stripe_head
*sh
= param
;
1319 unsigned long ops_request
= sh
->ops
.request
;
1321 clear_bit_unlock(STRIPE_OPS_REQ_PENDING
, &sh
->state
);
1322 wake_up(&sh
->ops
.wait_for_ops
);
1324 __raid_run_ops(sh
, ops_request
);
1328 static void raid_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
1330 /* since handle_stripe can be called outside of raid5d context
1331 * we need to ensure sh->ops.request is de-staged before another
1334 wait_event(sh
->ops
.wait_for_ops
,
1335 !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING
, &sh
->state
));
1336 sh
->ops
.request
= ops_request
;
1338 atomic_inc(&sh
->count
);
1339 async_schedule(async_run_ops
, sh
);
1342 #define raid_run_ops __raid_run_ops
1345 static int grow_one_stripe(struct r5conf
*conf
)
1347 struct stripe_head
*sh
;
1348 sh
= kmem_cache_zalloc(conf
->slab_cache
, GFP_KERNEL
);
1352 sh
->raid_conf
= conf
;
1353 #ifdef CONFIG_MULTICORE_RAID456
1354 init_waitqueue_head(&sh
->ops
.wait_for_ops
);
1357 if (grow_buffers(sh
)) {
1359 kmem_cache_free(conf
->slab_cache
, sh
);
1362 /* we just created an active stripe so... */
1363 atomic_set(&sh
->count
, 1);
1364 atomic_inc(&conf
->active_stripes
);
1365 INIT_LIST_HEAD(&sh
->lru
);
1370 static int grow_stripes(struct r5conf
*conf
, int num
)
1372 struct kmem_cache
*sc
;
1373 int devs
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
1375 if (conf
->mddev
->gendisk
)
1376 sprintf(conf
->cache_name
[0],
1377 "raid%d-%s", conf
->level
, mdname(conf
->mddev
));
1379 sprintf(conf
->cache_name
[0],
1380 "raid%d-%p", conf
->level
, conf
->mddev
);
1381 sprintf(conf
->cache_name
[1], "%s-alt", conf
->cache_name
[0]);
1383 conf
->active_name
= 0;
1384 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
1385 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
1389 conf
->slab_cache
= sc
;
1390 conf
->pool_size
= devs
;
1392 if (!grow_one_stripe(conf
))
1398 * scribble_len - return the required size of the scribble region
1399 * @num - total number of disks in the array
1401 * The size must be enough to contain:
1402 * 1/ a struct page pointer for each device in the array +2
1403 * 2/ room to convert each entry in (1) to its corresponding dma
1404 * (dma_map_page()) or page (page_address()) address.
1406 * Note: the +2 is for the destination buffers of the ddf/raid6 case where we
1407 * calculate over all devices (not just the data blocks), using zeros in place
1408 * of the P and Q blocks.
1410 static size_t scribble_len(int num
)
1414 len
= sizeof(struct page
*) * (num
+2) + sizeof(addr_conv_t
) * (num
+2);
1419 static int resize_stripes(struct r5conf
*conf
, int newsize
)
1421 /* Make all the stripes able to hold 'newsize' devices.
1422 * New slots in each stripe get 'page' set to a new page.
1424 * This happens in stages:
1425 * 1/ create a new kmem_cache and allocate the required number of
1427 * 2/ gather all the old stripe_heads and tranfer the pages across
1428 * to the new stripe_heads. This will have the side effect of
1429 * freezing the array as once all stripe_heads have been collected,
1430 * no IO will be possible. Old stripe heads are freed once their
1431 * pages have been transferred over, and the old kmem_cache is
1432 * freed when all stripes are done.
1433 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
1434 * we simple return a failre status - no need to clean anything up.
1435 * 4/ allocate new pages for the new slots in the new stripe_heads.
1436 * If this fails, we don't bother trying the shrink the
1437 * stripe_heads down again, we just leave them as they are.
1438 * As each stripe_head is processed the new one is released into
1441 * Once step2 is started, we cannot afford to wait for a write,
1442 * so we use GFP_NOIO allocations.
1444 struct stripe_head
*osh
, *nsh
;
1445 LIST_HEAD(newstripes
);
1446 struct disk_info
*ndisks
;
1449 struct kmem_cache
*sc
;
1452 if (newsize
<= conf
->pool_size
)
1453 return 0; /* never bother to shrink */
1455 err
= md_allow_write(conf
->mddev
);
1460 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
1461 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
1466 for (i
= conf
->max_nr_stripes
; i
; i
--) {
1467 nsh
= kmem_cache_zalloc(sc
, GFP_KERNEL
);
1471 nsh
->raid_conf
= conf
;
1472 #ifdef CONFIG_MULTICORE_RAID456
1473 init_waitqueue_head(&nsh
->ops
.wait_for_ops
);
1476 list_add(&nsh
->lru
, &newstripes
);
1479 /* didn't get enough, give up */
1480 while (!list_empty(&newstripes
)) {
1481 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1482 list_del(&nsh
->lru
);
1483 kmem_cache_free(sc
, nsh
);
1485 kmem_cache_destroy(sc
);
1488 /* Step 2 - Must use GFP_NOIO now.
1489 * OK, we have enough stripes, start collecting inactive
1490 * stripes and copying them over
1492 list_for_each_entry(nsh
, &newstripes
, lru
) {
1493 spin_lock_irq(&conf
->device_lock
);
1494 wait_event_lock_irq(conf
->wait_for_stripe
,
1495 !list_empty(&conf
->inactive_list
),
1498 osh
= get_free_stripe(conf
);
1499 spin_unlock_irq(&conf
->device_lock
);
1500 atomic_set(&nsh
->count
, 1);
1501 for(i
=0; i
<conf
->pool_size
; i
++)
1502 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1503 for( ; i
<newsize
; i
++)
1504 nsh
->dev
[i
].page
= NULL
;
1505 kmem_cache_free(conf
->slab_cache
, osh
);
1507 kmem_cache_destroy(conf
->slab_cache
);
1510 * At this point, we are holding all the stripes so the array
1511 * is completely stalled, so now is a good time to resize
1512 * conf->disks and the scribble region
1514 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1516 for (i
=0; i
<conf
->raid_disks
; i
++)
1517 ndisks
[i
] = conf
->disks
[i
];
1519 conf
->disks
= ndisks
;
1524 conf
->scribble_len
= scribble_len(newsize
);
1525 for_each_present_cpu(cpu
) {
1526 struct raid5_percpu
*percpu
;
1529 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
1530 scribble
= kmalloc(conf
->scribble_len
, GFP_NOIO
);
1533 kfree(percpu
->scribble
);
1534 percpu
->scribble
= scribble
;
1542 /* Step 4, return new stripes to service */
1543 while(!list_empty(&newstripes
)) {
1544 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1545 list_del_init(&nsh
->lru
);
1547 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1548 if (nsh
->dev
[i
].page
== NULL
) {
1549 struct page
*p
= alloc_page(GFP_NOIO
);
1550 nsh
->dev
[i
].page
= p
;
1554 release_stripe(nsh
);
1556 /* critical section pass, GFP_NOIO no longer needed */
1558 conf
->slab_cache
= sc
;
1559 conf
->active_name
= 1-conf
->active_name
;
1560 conf
->pool_size
= newsize
;
1564 static int drop_one_stripe(struct r5conf
*conf
)
1566 struct stripe_head
*sh
;
1568 spin_lock_irq(&conf
->device_lock
);
1569 sh
= get_free_stripe(conf
);
1570 spin_unlock_irq(&conf
->device_lock
);
1573 BUG_ON(atomic_read(&sh
->count
));
1575 kmem_cache_free(conf
->slab_cache
, sh
);
1576 atomic_dec(&conf
->active_stripes
);
1580 static void shrink_stripes(struct r5conf
*conf
)
1582 while (drop_one_stripe(conf
))
1585 if (conf
->slab_cache
)
1586 kmem_cache_destroy(conf
->slab_cache
);
1587 conf
->slab_cache
= NULL
;
1590 static void raid5_end_read_request(struct bio
* bi
, int error
)
1592 struct stripe_head
*sh
= bi
->bi_private
;
1593 struct r5conf
*conf
= sh
->raid_conf
;
1594 int disks
= sh
->disks
, i
;
1595 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1596 char b
[BDEVNAME_SIZE
];
1597 struct md_rdev
*rdev
;
1600 for (i
=0 ; i
<disks
; i
++)
1601 if (bi
== &sh
->dev
[i
].req
)
1604 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1605 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1613 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1614 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1615 rdev
= conf
->disks
[i
].rdev
;
1618 "md/raid:%s: read error corrected"
1619 " (%lu sectors at %llu on %s)\n",
1620 mdname(conf
->mddev
), STRIPE_SECTORS
,
1621 (unsigned long long)(sh
->sector
1622 + rdev
->data_offset
),
1623 bdevname(rdev
->bdev
, b
));
1624 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1625 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1626 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1628 if (atomic_read(&conf
->disks
[i
].rdev
->read_errors
))
1629 atomic_set(&conf
->disks
[i
].rdev
->read_errors
, 0);
1631 const char *bdn
= bdevname(conf
->disks
[i
].rdev
->bdev
, b
);
1633 rdev
= conf
->disks
[i
].rdev
;
1635 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1636 atomic_inc(&rdev
->read_errors
);
1637 if (conf
->mddev
->degraded
>= conf
->max_degraded
)
1640 "md/raid:%s: read error not correctable "
1641 "(sector %llu on %s).\n",
1642 mdname(conf
->mddev
),
1643 (unsigned long long)(sh
->sector
1644 + rdev
->data_offset
),
1646 else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
1650 "md/raid:%s: read error NOT corrected!! "
1651 "(sector %llu on %s).\n",
1652 mdname(conf
->mddev
),
1653 (unsigned long long)(sh
->sector
1654 + rdev
->data_offset
),
1656 else if (atomic_read(&rdev
->read_errors
)
1657 > conf
->max_nr_stripes
)
1659 "md/raid:%s: Too many read errors, failing device %s.\n",
1660 mdname(conf
->mddev
), bdn
);
1664 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1666 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1667 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1668 md_error(conf
->mddev
, rdev
);
1671 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1672 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1673 set_bit(STRIPE_HANDLE
, &sh
->state
);
1677 static void raid5_end_write_request(struct bio
*bi
, int error
)
1679 struct stripe_head
*sh
= bi
->bi_private
;
1680 struct r5conf
*conf
= sh
->raid_conf
;
1681 int disks
= sh
->disks
, i
;
1682 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1686 for (i
=0 ; i
<disks
; i
++)
1687 if (bi
== &sh
->dev
[i
].req
)
1690 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1691 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1699 set_bit(WriteErrorSeen
, &conf
->disks
[i
].rdev
->flags
);
1700 set_bit(R5_WriteError
, &sh
->dev
[i
].flags
);
1701 } else if (is_badblock(conf
->disks
[i
].rdev
, sh
->sector
, STRIPE_SECTORS
,
1702 &first_bad
, &bad_sectors
))
1703 set_bit(R5_MadeGood
, &sh
->dev
[i
].flags
);
1705 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1707 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1708 set_bit(STRIPE_HANDLE
, &sh
->state
);
1713 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
);
1715 static void raid5_build_block(struct stripe_head
*sh
, int i
, int previous
)
1717 struct r5dev
*dev
= &sh
->dev
[i
];
1719 bio_init(&dev
->req
);
1720 dev
->req
.bi_io_vec
= &dev
->vec
;
1722 dev
->req
.bi_max_vecs
++;
1723 dev
->vec
.bv_page
= dev
->page
;
1724 dev
->vec
.bv_len
= STRIPE_SIZE
;
1725 dev
->vec
.bv_offset
= 0;
1727 dev
->req
.bi_sector
= sh
->sector
;
1728 dev
->req
.bi_private
= sh
;
1731 dev
->sector
= compute_blocknr(sh
, i
, previous
);
1734 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1736 char b
[BDEVNAME_SIZE
];
1737 struct r5conf
*conf
= mddev
->private;
1738 unsigned long flags
;
1739 pr_debug("raid456: error called\n");
1741 spin_lock_irqsave(&conf
->device_lock
, flags
);
1742 clear_bit(In_sync
, &rdev
->flags
);
1743 mddev
->degraded
= calc_degraded(conf
);
1744 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1745 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1747 set_bit(Blocked
, &rdev
->flags
);
1748 set_bit(Faulty
, &rdev
->flags
);
1749 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1751 "md/raid:%s: Disk failure on %s, disabling device.\n"
1752 "md/raid:%s: Operation continuing on %d devices.\n",
1754 bdevname(rdev
->bdev
, b
),
1756 conf
->raid_disks
- mddev
->degraded
);
1760 * Input: a 'big' sector number,
1761 * Output: index of the data and parity disk, and the sector # in them.
1763 static sector_t
raid5_compute_sector(struct r5conf
*conf
, sector_t r_sector
,
1764 int previous
, int *dd_idx
,
1765 struct stripe_head
*sh
)
1767 sector_t stripe
, stripe2
;
1768 sector_t chunk_number
;
1769 unsigned int chunk_offset
;
1772 sector_t new_sector
;
1773 int algorithm
= previous
? conf
->prev_algo
1775 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1776 : conf
->chunk_sectors
;
1777 int raid_disks
= previous
? conf
->previous_raid_disks
1779 int data_disks
= raid_disks
- conf
->max_degraded
;
1781 /* First compute the information on this sector */
1784 * Compute the chunk number and the sector offset inside the chunk
1786 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1787 chunk_number
= r_sector
;
1790 * Compute the stripe number
1792 stripe
= chunk_number
;
1793 *dd_idx
= sector_div(stripe
, data_disks
);
1796 * Select the parity disk based on the user selected algorithm.
1798 pd_idx
= qd_idx
= -1;
1799 switch(conf
->level
) {
1801 pd_idx
= data_disks
;
1804 switch (algorithm
) {
1805 case ALGORITHM_LEFT_ASYMMETRIC
:
1806 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1807 if (*dd_idx
>= pd_idx
)
1810 case ALGORITHM_RIGHT_ASYMMETRIC
:
1811 pd_idx
= sector_div(stripe2
, raid_disks
);
1812 if (*dd_idx
>= pd_idx
)
1815 case ALGORITHM_LEFT_SYMMETRIC
:
1816 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
);
1817 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1819 case ALGORITHM_RIGHT_SYMMETRIC
:
1820 pd_idx
= sector_div(stripe2
, raid_disks
);
1821 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1823 case ALGORITHM_PARITY_0
:
1827 case ALGORITHM_PARITY_N
:
1828 pd_idx
= data_disks
;
1836 switch (algorithm
) {
1837 case ALGORITHM_LEFT_ASYMMETRIC
:
1838 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1839 qd_idx
= pd_idx
+ 1;
1840 if (pd_idx
== raid_disks
-1) {
1841 (*dd_idx
)++; /* Q D D D P */
1843 } else if (*dd_idx
>= pd_idx
)
1844 (*dd_idx
) += 2; /* D D P Q D */
1846 case ALGORITHM_RIGHT_ASYMMETRIC
:
1847 pd_idx
= sector_div(stripe2
, raid_disks
);
1848 qd_idx
= pd_idx
+ 1;
1849 if (pd_idx
== raid_disks
-1) {
1850 (*dd_idx
)++; /* Q D D D P */
1852 } else if (*dd_idx
>= pd_idx
)
1853 (*dd_idx
) += 2; /* D D P Q D */
1855 case ALGORITHM_LEFT_SYMMETRIC
:
1856 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1857 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1858 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1860 case ALGORITHM_RIGHT_SYMMETRIC
:
1861 pd_idx
= sector_div(stripe2
, raid_disks
);
1862 qd_idx
= (pd_idx
+ 1) % raid_disks
;
1863 *dd_idx
= (pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1866 case ALGORITHM_PARITY_0
:
1871 case ALGORITHM_PARITY_N
:
1872 pd_idx
= data_disks
;
1873 qd_idx
= data_disks
+ 1;
1876 case ALGORITHM_ROTATING_ZERO_RESTART
:
1877 /* Exactly the same as RIGHT_ASYMMETRIC, but or
1878 * of blocks for computing Q is different.
1880 pd_idx
= sector_div(stripe2
, raid_disks
);
1881 qd_idx
= pd_idx
+ 1;
1882 if (pd_idx
== raid_disks
-1) {
1883 (*dd_idx
)++; /* Q D D D P */
1885 } else if (*dd_idx
>= pd_idx
)
1886 (*dd_idx
) += 2; /* D D P Q D */
1890 case ALGORITHM_ROTATING_N_RESTART
:
1891 /* Same a left_asymmetric, by first stripe is
1892 * D D D P Q rather than
1896 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1897 qd_idx
= pd_idx
+ 1;
1898 if (pd_idx
== raid_disks
-1) {
1899 (*dd_idx
)++; /* Q D D D P */
1901 } else if (*dd_idx
>= pd_idx
)
1902 (*dd_idx
) += 2; /* D D P Q D */
1906 case ALGORITHM_ROTATING_N_CONTINUE
:
1907 /* Same as left_symmetric but Q is before P */
1908 pd_idx
= raid_disks
- 1 - sector_div(stripe2
, raid_disks
);
1909 qd_idx
= (pd_idx
+ raid_disks
- 1) % raid_disks
;
1910 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1914 case ALGORITHM_LEFT_ASYMMETRIC_6
:
1915 /* RAID5 left_asymmetric, with Q on last device */
1916 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
1917 if (*dd_idx
>= pd_idx
)
1919 qd_idx
= raid_disks
- 1;
1922 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
1923 pd_idx
= sector_div(stripe2
, raid_disks
-1);
1924 if (*dd_idx
>= pd_idx
)
1926 qd_idx
= raid_disks
- 1;
1929 case ALGORITHM_LEFT_SYMMETRIC_6
:
1930 pd_idx
= data_disks
- sector_div(stripe2
, raid_disks
-1);
1931 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1932 qd_idx
= raid_disks
- 1;
1935 case ALGORITHM_RIGHT_SYMMETRIC_6
:
1936 pd_idx
= sector_div(stripe2
, raid_disks
-1);
1937 *dd_idx
= (pd_idx
+ 1 + *dd_idx
) % (raid_disks
-1);
1938 qd_idx
= raid_disks
- 1;
1941 case ALGORITHM_PARITY_0_6
:
1944 qd_idx
= raid_disks
- 1;
1954 sh
->pd_idx
= pd_idx
;
1955 sh
->qd_idx
= qd_idx
;
1956 sh
->ddf_layout
= ddf_layout
;
1959 * Finally, compute the new sector number
1961 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
1966 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
, int previous
)
1968 struct r5conf
*conf
= sh
->raid_conf
;
1969 int raid_disks
= sh
->disks
;
1970 int data_disks
= raid_disks
- conf
->max_degraded
;
1971 sector_t new_sector
= sh
->sector
, check
;
1972 int sectors_per_chunk
= previous
? conf
->prev_chunk_sectors
1973 : conf
->chunk_sectors
;
1974 int algorithm
= previous
? conf
->prev_algo
1978 sector_t chunk_number
;
1979 int dummy1
, dd_idx
= i
;
1981 struct stripe_head sh2
;
1984 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
1985 stripe
= new_sector
;
1987 if (i
== sh
->pd_idx
)
1989 switch(conf
->level
) {
1992 switch (algorithm
) {
1993 case ALGORITHM_LEFT_ASYMMETRIC
:
1994 case ALGORITHM_RIGHT_ASYMMETRIC
:
1998 case ALGORITHM_LEFT_SYMMETRIC
:
1999 case ALGORITHM_RIGHT_SYMMETRIC
:
2002 i
-= (sh
->pd_idx
+ 1);
2004 case ALGORITHM_PARITY_0
:
2007 case ALGORITHM_PARITY_N
:
2014 if (i
== sh
->qd_idx
)
2015 return 0; /* It is the Q disk */
2016 switch (algorithm
) {
2017 case ALGORITHM_LEFT_ASYMMETRIC
:
2018 case ALGORITHM_RIGHT_ASYMMETRIC
:
2019 case ALGORITHM_ROTATING_ZERO_RESTART
:
2020 case ALGORITHM_ROTATING_N_RESTART
:
2021 if (sh
->pd_idx
== raid_disks
-1)
2022 i
--; /* Q D D D P */
2023 else if (i
> sh
->pd_idx
)
2024 i
-= 2; /* D D P Q D */
2026 case ALGORITHM_LEFT_SYMMETRIC
:
2027 case ALGORITHM_RIGHT_SYMMETRIC
:
2028 if (sh
->pd_idx
== raid_disks
-1)
2029 i
--; /* Q D D D P */
2034 i
-= (sh
->pd_idx
+ 2);
2037 case ALGORITHM_PARITY_0
:
2040 case ALGORITHM_PARITY_N
:
2042 case ALGORITHM_ROTATING_N_CONTINUE
:
2043 /* Like left_symmetric, but P is before Q */
2044 if (sh
->pd_idx
== 0)
2045 i
--; /* P D D D Q */
2050 i
-= (sh
->pd_idx
+ 1);
2053 case ALGORITHM_LEFT_ASYMMETRIC_6
:
2054 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
2058 case ALGORITHM_LEFT_SYMMETRIC_6
:
2059 case ALGORITHM_RIGHT_SYMMETRIC_6
:
2061 i
+= data_disks
+ 1;
2062 i
-= (sh
->pd_idx
+ 1);
2064 case ALGORITHM_PARITY_0_6
:
2073 chunk_number
= stripe
* data_disks
+ i
;
2074 r_sector
= chunk_number
* sectors_per_chunk
+ chunk_offset
;
2076 check
= raid5_compute_sector(conf
, r_sector
,
2077 previous
, &dummy1
, &sh2
);
2078 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| sh2
.pd_idx
!= sh
->pd_idx
2079 || sh2
.qd_idx
!= sh
->qd_idx
) {
2080 printk(KERN_ERR
"md/raid:%s: compute_blocknr: map not correct\n",
2081 mdname(conf
->mddev
));
2089 schedule_reconstruction(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2090 int rcw
, int expand
)
2092 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
2093 struct r5conf
*conf
= sh
->raid_conf
;
2094 int level
= conf
->level
;
2097 /* if we are not expanding this is a proper write request, and
2098 * there will be bios with new data to be drained into the
2102 sh
->reconstruct_state
= reconstruct_state_drain_run
;
2103 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2105 sh
->reconstruct_state
= reconstruct_state_run
;
2107 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2109 for (i
= disks
; i
--; ) {
2110 struct r5dev
*dev
= &sh
->dev
[i
];
2113 set_bit(R5_LOCKED
, &dev
->flags
);
2114 set_bit(R5_Wantdrain
, &dev
->flags
);
2116 clear_bit(R5_UPTODATE
, &dev
->flags
);
2120 if (s
->locked
+ conf
->max_degraded
== disks
)
2121 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2122 atomic_inc(&conf
->pending_full_writes
);
2125 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
2126 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
2128 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
2129 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
2130 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
2131 set_bit(STRIPE_OP_RECONSTRUCT
, &s
->ops_request
);
2133 for (i
= disks
; i
--; ) {
2134 struct r5dev
*dev
= &sh
->dev
[i
];
2139 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
2140 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2141 set_bit(R5_Wantdrain
, &dev
->flags
);
2142 set_bit(R5_LOCKED
, &dev
->flags
);
2143 clear_bit(R5_UPTODATE
, &dev
->flags
);
2149 /* keep the parity disk(s) locked while asynchronous operations
2152 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
2153 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2157 int qd_idx
= sh
->qd_idx
;
2158 struct r5dev
*dev
= &sh
->dev
[qd_idx
];
2160 set_bit(R5_LOCKED
, &dev
->flags
);
2161 clear_bit(R5_UPTODATE
, &dev
->flags
);
2165 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
2166 __func__
, (unsigned long long)sh
->sector
,
2167 s
->locked
, s
->ops_request
);
2171 * Each stripe/dev can have one or more bion attached.
2172 * toread/towrite point to the first in a chain.
2173 * The bi_next chain must be in order.
2175 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
2178 struct r5conf
*conf
= sh
->raid_conf
;
2181 pr_debug("adding bi b#%llu to stripe s#%llu\n",
2182 (unsigned long long)bi
->bi_sector
,
2183 (unsigned long long)sh
->sector
);
2186 spin_lock_irq(&conf
->device_lock
);
2188 bip
= &sh
->dev
[dd_idx
].towrite
;
2189 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
2192 bip
= &sh
->dev
[dd_idx
].toread
;
2193 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
2194 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
2196 bip
= & (*bip
)->bi_next
;
2198 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
2201 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
2205 bi
->bi_phys_segments
++;
2208 /* check if page is covered */
2209 sector_t sector
= sh
->dev
[dd_idx
].sector
;
2210 for (bi
=sh
->dev
[dd_idx
].towrite
;
2211 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
2212 bi
&& bi
->bi_sector
<= sector
;
2213 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
2214 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
2215 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2217 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
2218 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
2220 spin_unlock_irq(&conf
->device_lock
);
2222 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
2223 (unsigned long long)(*bip
)->bi_sector
,
2224 (unsigned long long)sh
->sector
, dd_idx
);
2226 if (conf
->mddev
->bitmap
&& firstwrite
) {
2227 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
2229 sh
->bm_seq
= conf
->seq_flush
+1;
2230 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
2235 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
2236 spin_unlock_irq(&conf
->device_lock
);
2240 static void end_reshape(struct r5conf
*conf
);
2242 static void stripe_set_idx(sector_t stripe
, struct r5conf
*conf
, int previous
,
2243 struct stripe_head
*sh
)
2245 int sectors_per_chunk
=
2246 previous
? conf
->prev_chunk_sectors
: conf
->chunk_sectors
;
2248 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
2249 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
2251 raid5_compute_sector(conf
,
2252 stripe
* (disks
- conf
->max_degraded
)
2253 *sectors_per_chunk
+ chunk_offset
,
2259 handle_failed_stripe(struct r5conf
*conf
, struct stripe_head
*sh
,
2260 struct stripe_head_state
*s
, int disks
,
2261 struct bio
**return_bi
)
2264 for (i
= disks
; i
--; ) {
2268 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2269 struct md_rdev
*rdev
;
2271 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2272 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2273 atomic_inc(&rdev
->nr_pending
);
2278 if (!rdev_set_badblocks(
2282 md_error(conf
->mddev
, rdev
);
2283 rdev_dec_pending(rdev
, conf
->mddev
);
2286 spin_lock_irq(&conf
->device_lock
);
2287 /* fail all writes first */
2288 bi
= sh
->dev
[i
].towrite
;
2289 sh
->dev
[i
].towrite
= NULL
;
2295 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2296 wake_up(&conf
->wait_for_overlap
);
2298 while (bi
&& bi
->bi_sector
<
2299 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2300 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2301 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2302 if (!raid5_dec_bi_phys_segments(bi
)) {
2303 md_write_end(conf
->mddev
);
2304 bi
->bi_next
= *return_bi
;
2309 /* and fail all 'written' */
2310 bi
= sh
->dev
[i
].written
;
2311 sh
->dev
[i
].written
= NULL
;
2312 if (bi
) bitmap_end
= 1;
2313 while (bi
&& bi
->bi_sector
<
2314 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2315 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2316 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2317 if (!raid5_dec_bi_phys_segments(bi
)) {
2318 md_write_end(conf
->mddev
);
2319 bi
->bi_next
= *return_bi
;
2325 /* fail any reads if this device is non-operational and
2326 * the data has not reached the cache yet.
2328 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
2329 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2330 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
2331 bi
= sh
->dev
[i
].toread
;
2332 sh
->dev
[i
].toread
= NULL
;
2333 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2334 wake_up(&conf
->wait_for_overlap
);
2335 if (bi
) s
->to_read
--;
2336 while (bi
&& bi
->bi_sector
<
2337 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2338 struct bio
*nextbi
=
2339 r5_next_bio(bi
, sh
->dev
[i
].sector
);
2340 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2341 if (!raid5_dec_bi_phys_segments(bi
)) {
2342 bi
->bi_next
= *return_bi
;
2348 spin_unlock_irq(&conf
->device_lock
);
2350 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2351 STRIPE_SECTORS
, 0, 0);
2352 /* If we were in the middle of a write the parity block might
2353 * still be locked - so just clear all R5_LOCKED flags
2355 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2358 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2359 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2360 md_wakeup_thread(conf
->mddev
->thread
);
2364 handle_failed_sync(struct r5conf
*conf
, struct stripe_head
*sh
,
2365 struct stripe_head_state
*s
)
2370 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 0);
2371 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2373 /* There is nothing more to do for sync/check/repair.
2374 * For recover we need to record a bad block on all
2375 * non-sync devices, or abort the recovery
2377 if (!test_bit(MD_RECOVERY_RECOVER
, &conf
->mddev
->recovery
))
2379 /* During recovery devices cannot be removed, so locking and
2380 * refcounting of rdevs is not needed
2382 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2383 struct md_rdev
*rdev
= conf
->disks
[i
].rdev
;
2385 || test_bit(Faulty
, &rdev
->flags
)
2386 || test_bit(In_sync
, &rdev
->flags
))
2388 if (!rdev_set_badblocks(rdev
, sh
->sector
,
2393 conf
->recovery_disabled
= conf
->mddev
->recovery_disabled
;
2394 set_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
);
2398 /* fetch_block - checks the given member device to see if its data needs
2399 * to be read or computed to satisfy a request.
2401 * Returns 1 when no more member devices need to be checked, otherwise returns
2402 * 0 to tell the loop in handle_stripe_fill to continue
2404 static int fetch_block(struct stripe_head
*sh
, struct stripe_head_state
*s
,
2405 int disk_idx
, int disks
)
2407 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
2408 struct r5dev
*fdev
[2] = { &sh
->dev
[s
->failed_num
[0]],
2409 &sh
->dev
[s
->failed_num
[1]] };
2411 /* is the data in this block needed, and can we get it? */
2412 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2413 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2415 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2416 s
->syncing
|| s
->expanding
||
2417 (s
->failed
>= 1 && fdev
[0]->toread
) ||
2418 (s
->failed
>= 2 && fdev
[1]->toread
) ||
2419 (sh
->raid_conf
->level
<= 5 && s
->failed
&& fdev
[0]->towrite
&&
2420 !test_bit(R5_OVERWRITE
, &fdev
[0]->flags
)) ||
2421 (sh
->raid_conf
->level
== 6 && s
->failed
&& s
->to_write
))) {
2422 /* we would like to get this block, possibly by computing it,
2423 * otherwise read it if the backing disk is insync
2425 BUG_ON(test_bit(R5_Wantcompute
, &dev
->flags
));
2426 BUG_ON(test_bit(R5_Wantread
, &dev
->flags
));
2427 if ((s
->uptodate
== disks
- 1) &&
2428 (s
->failed
&& (disk_idx
== s
->failed_num
[0] ||
2429 disk_idx
== s
->failed_num
[1]))) {
2430 /* have disk failed, and we're requested to fetch it;
2433 pr_debug("Computing stripe %llu block %d\n",
2434 (unsigned long long)sh
->sector
, disk_idx
);
2435 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2436 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2437 set_bit(R5_Wantcompute
, &dev
->flags
);
2438 sh
->ops
.target
= disk_idx
;
2439 sh
->ops
.target2
= -1; /* no 2nd target */
2441 /* Careful: from this point on 'uptodate' is in the eye
2442 * of raid_run_ops which services 'compute' operations
2443 * before writes. R5_Wantcompute flags a block that will
2444 * be R5_UPTODATE by the time it is needed for a
2445 * subsequent operation.
2449 } else if (s
->uptodate
== disks
-2 && s
->failed
>= 2) {
2450 /* Computing 2-failure is *very* expensive; only
2451 * do it if failed >= 2
2454 for (other
= disks
; other
--; ) {
2455 if (other
== disk_idx
)
2457 if (!test_bit(R5_UPTODATE
,
2458 &sh
->dev
[other
].flags
))
2462 pr_debug("Computing stripe %llu blocks %d,%d\n",
2463 (unsigned long long)sh
->sector
,
2465 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2466 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2467 set_bit(R5_Wantcompute
, &sh
->dev
[disk_idx
].flags
);
2468 set_bit(R5_Wantcompute
, &sh
->dev
[other
].flags
);
2469 sh
->ops
.target
= disk_idx
;
2470 sh
->ops
.target2
= other
;
2474 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2475 set_bit(R5_LOCKED
, &dev
->flags
);
2476 set_bit(R5_Wantread
, &dev
->flags
);
2478 pr_debug("Reading block %d (sync=%d)\n",
2479 disk_idx
, s
->syncing
);
2487 * handle_stripe_fill - read or compute data to satisfy pending requests.
2489 static void handle_stripe_fill(struct stripe_head
*sh
,
2490 struct stripe_head_state
*s
,
2495 /* look for blocks to read/compute, skip this if a compute
2496 * is already in flight, or if the stripe contents are in the
2497 * midst of changing due to a write
2499 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
2500 !sh
->reconstruct_state
)
2501 for (i
= disks
; i
--; )
2502 if (fetch_block(sh
, s
, i
, disks
))
2504 set_bit(STRIPE_HANDLE
, &sh
->state
);
2508 /* handle_stripe_clean_event
2509 * any written block on an uptodate or failed drive can be returned.
2510 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2511 * never LOCKED, so we don't need to test 'failed' directly.
2513 static void handle_stripe_clean_event(struct r5conf
*conf
,
2514 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2519 for (i
= disks
; i
--; )
2520 if (sh
->dev
[i
].written
) {
2522 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2523 test_bit(R5_UPTODATE
, &dev
->flags
)) {
2524 /* We can return any write requests */
2525 struct bio
*wbi
, *wbi2
;
2527 pr_debug("Return write for disc %d\n", i
);
2528 spin_lock_irq(&conf
->device_lock
);
2530 dev
->written
= NULL
;
2531 while (wbi
&& wbi
->bi_sector
<
2532 dev
->sector
+ STRIPE_SECTORS
) {
2533 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2534 if (!raid5_dec_bi_phys_segments(wbi
)) {
2535 md_write_end(conf
->mddev
);
2536 wbi
->bi_next
= *return_bi
;
2541 if (dev
->towrite
== NULL
)
2543 spin_unlock_irq(&conf
->device_lock
);
2545 bitmap_endwrite(conf
->mddev
->bitmap
,
2548 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2553 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2554 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2555 md_wakeup_thread(conf
->mddev
->thread
);
2558 static void handle_stripe_dirtying(struct r5conf
*conf
,
2559 struct stripe_head
*sh
,
2560 struct stripe_head_state
*s
,
2563 int rmw
= 0, rcw
= 0, i
;
2564 if (conf
->max_degraded
== 2) {
2565 /* RAID6 requires 'rcw' in current implementation
2566 * Calculate the real rcw later - for now fake it
2567 * look like rcw is cheaper
2570 } else for (i
= disks
; i
--; ) {
2571 /* would I have to read this buffer for read_modify_write */
2572 struct r5dev
*dev
= &sh
->dev
[i
];
2573 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2574 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2575 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2576 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2577 if (test_bit(R5_Insync
, &dev
->flags
))
2580 rmw
+= 2*disks
; /* cannot read it */
2582 /* Would I have to read this buffer for reconstruct_write */
2583 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2584 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2585 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2586 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2587 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2592 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2593 (unsigned long long)sh
->sector
, rmw
, rcw
);
2594 set_bit(STRIPE_HANDLE
, &sh
->state
);
2595 if (rmw
< rcw
&& rmw
> 0)
2596 /* prefer read-modify-write, but need to get some data */
2597 for (i
= disks
; i
--; ) {
2598 struct r5dev
*dev
= &sh
->dev
[i
];
2599 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2600 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2601 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2602 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2603 test_bit(R5_Insync
, &dev
->flags
)) {
2605 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2606 pr_debug("Read_old block "
2607 "%d for r-m-w\n", i
);
2608 set_bit(R5_LOCKED
, &dev
->flags
);
2609 set_bit(R5_Wantread
, &dev
->flags
);
2612 set_bit(STRIPE_DELAYED
, &sh
->state
);
2613 set_bit(STRIPE_HANDLE
, &sh
->state
);
2617 if (rcw
<= rmw
&& rcw
> 0) {
2618 /* want reconstruct write, but need to get some data */
2620 for (i
= disks
; i
--; ) {
2621 struct r5dev
*dev
= &sh
->dev
[i
];
2622 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2623 i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
&&
2624 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2625 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2626 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2628 if (!test_bit(R5_Insync
, &dev
->flags
))
2629 continue; /* it's a failed drive */
2631 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2632 pr_debug("Read_old block "
2633 "%d for Reconstruct\n", i
);
2634 set_bit(R5_LOCKED
, &dev
->flags
);
2635 set_bit(R5_Wantread
, &dev
->flags
);
2638 set_bit(STRIPE_DELAYED
, &sh
->state
);
2639 set_bit(STRIPE_HANDLE
, &sh
->state
);
2644 /* now if nothing is locked, and if we have enough data,
2645 * we can start a write request
2647 /* since handle_stripe can be called at any time we need to handle the
2648 * case where a compute block operation has been submitted and then a
2649 * subsequent call wants to start a write request. raid_run_ops only
2650 * handles the case where compute block and reconstruct are requested
2651 * simultaneously. If this is not the case then new writes need to be
2652 * held off until the compute completes.
2654 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2655 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2656 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2657 schedule_reconstruction(sh
, s
, rcw
== 0, 0);
2660 static void handle_parity_checks5(struct r5conf
*conf
, struct stripe_head
*sh
,
2661 struct stripe_head_state
*s
, int disks
)
2663 struct r5dev
*dev
= NULL
;
2665 set_bit(STRIPE_HANDLE
, &sh
->state
);
2667 switch (sh
->check_state
) {
2668 case check_state_idle
:
2669 /* start a new check operation if there are no failures */
2670 if (s
->failed
== 0) {
2671 BUG_ON(s
->uptodate
!= disks
);
2672 sh
->check_state
= check_state_run
;
2673 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2674 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2678 dev
= &sh
->dev
[s
->failed_num
[0]];
2680 case check_state_compute_result
:
2681 sh
->check_state
= check_state_idle
;
2683 dev
= &sh
->dev
[sh
->pd_idx
];
2685 /* check that a write has not made the stripe insync */
2686 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2689 /* either failed parity check, or recovery is happening */
2690 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2691 BUG_ON(s
->uptodate
!= disks
);
2693 set_bit(R5_LOCKED
, &dev
->flags
);
2695 set_bit(R5_Wantwrite
, &dev
->flags
);
2697 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2698 set_bit(STRIPE_INSYNC
, &sh
->state
);
2700 case check_state_run
:
2701 break; /* we will be called again upon completion */
2702 case check_state_check_result
:
2703 sh
->check_state
= check_state_idle
;
2705 /* if a failure occurred during the check operation, leave
2706 * STRIPE_INSYNC not set and let the stripe be handled again
2711 /* handle a successful check operation, if parity is correct
2712 * we are done. Otherwise update the mismatch count and repair
2713 * parity if !MD_RECOVERY_CHECK
2715 if ((sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) == 0)
2716 /* parity is correct (on disc,
2717 * not in buffer any more)
2719 set_bit(STRIPE_INSYNC
, &sh
->state
);
2721 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2722 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2723 /* don't try to repair!! */
2724 set_bit(STRIPE_INSYNC
, &sh
->state
);
2726 sh
->check_state
= check_state_compute_run
;
2727 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2728 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2729 set_bit(R5_Wantcompute
,
2730 &sh
->dev
[sh
->pd_idx
].flags
);
2731 sh
->ops
.target
= sh
->pd_idx
;
2732 sh
->ops
.target2
= -1;
2737 case check_state_compute_run
:
2740 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2741 __func__
, sh
->check_state
,
2742 (unsigned long long) sh
->sector
);
2748 static void handle_parity_checks6(struct r5conf
*conf
, struct stripe_head
*sh
,
2749 struct stripe_head_state
*s
,
2752 int pd_idx
= sh
->pd_idx
;
2753 int qd_idx
= sh
->qd_idx
;
2756 set_bit(STRIPE_HANDLE
, &sh
->state
);
2758 BUG_ON(s
->failed
> 2);
2760 /* Want to check and possibly repair P and Q.
2761 * However there could be one 'failed' device, in which
2762 * case we can only check one of them, possibly using the
2763 * other to generate missing data
2766 switch (sh
->check_state
) {
2767 case check_state_idle
:
2768 /* start a new check operation if there are < 2 failures */
2769 if (s
->failed
== s
->q_failed
) {
2770 /* The only possible failed device holds Q, so it
2771 * makes sense to check P (If anything else were failed,
2772 * we would have used P to recreate it).
2774 sh
->check_state
= check_state_run
;
2776 if (!s
->q_failed
&& s
->failed
< 2) {
2777 /* Q is not failed, and we didn't use it to generate
2778 * anything, so it makes sense to check it
2780 if (sh
->check_state
== check_state_run
)
2781 sh
->check_state
= check_state_run_pq
;
2783 sh
->check_state
= check_state_run_q
;
2786 /* discard potentially stale zero_sum_result */
2787 sh
->ops
.zero_sum_result
= 0;
2789 if (sh
->check_state
== check_state_run
) {
2790 /* async_xor_zero_sum destroys the contents of P */
2791 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
2794 if (sh
->check_state
>= check_state_run
&&
2795 sh
->check_state
<= check_state_run_pq
) {
2796 /* async_syndrome_zero_sum preserves P and Q, so
2797 * no need to mark them !uptodate here
2799 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2803 /* we have 2-disk failure */
2804 BUG_ON(s
->failed
!= 2);
2806 case check_state_compute_result
:
2807 sh
->check_state
= check_state_idle
;
2809 /* check that a write has not made the stripe insync */
2810 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2813 /* now write out any block on a failed drive,
2814 * or P or Q if they were recomputed
2816 BUG_ON(s
->uptodate
< disks
- 1); /* We don't need Q to recover */
2817 if (s
->failed
== 2) {
2818 dev
= &sh
->dev
[s
->failed_num
[1]];
2820 set_bit(R5_LOCKED
, &dev
->flags
);
2821 set_bit(R5_Wantwrite
, &dev
->flags
);
2823 if (s
->failed
>= 1) {
2824 dev
= &sh
->dev
[s
->failed_num
[0]];
2826 set_bit(R5_LOCKED
, &dev
->flags
);
2827 set_bit(R5_Wantwrite
, &dev
->flags
);
2829 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
2830 dev
= &sh
->dev
[pd_idx
];
2832 set_bit(R5_LOCKED
, &dev
->flags
);
2833 set_bit(R5_Wantwrite
, &dev
->flags
);
2835 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
2836 dev
= &sh
->dev
[qd_idx
];
2838 set_bit(R5_LOCKED
, &dev
->flags
);
2839 set_bit(R5_Wantwrite
, &dev
->flags
);
2841 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2843 set_bit(STRIPE_INSYNC
, &sh
->state
);
2845 case check_state_run
:
2846 case check_state_run_q
:
2847 case check_state_run_pq
:
2848 break; /* we will be called again upon completion */
2849 case check_state_check_result
:
2850 sh
->check_state
= check_state_idle
;
2852 /* handle a successful check operation, if parity is correct
2853 * we are done. Otherwise update the mismatch count and repair
2854 * parity if !MD_RECOVERY_CHECK
2856 if (sh
->ops
.zero_sum_result
== 0) {
2857 /* both parities are correct */
2859 set_bit(STRIPE_INSYNC
, &sh
->state
);
2861 /* in contrast to the raid5 case we can validate
2862 * parity, but still have a failure to write
2865 sh
->check_state
= check_state_compute_result
;
2866 /* Returning at this point means that we may go
2867 * off and bring p and/or q uptodate again so
2868 * we make sure to check zero_sum_result again
2869 * to verify if p or q need writeback
2873 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2874 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2875 /* don't try to repair!! */
2876 set_bit(STRIPE_INSYNC
, &sh
->state
);
2878 int *target
= &sh
->ops
.target
;
2880 sh
->ops
.target
= -1;
2881 sh
->ops
.target2
= -1;
2882 sh
->check_state
= check_state_compute_run
;
2883 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2884 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2885 if (sh
->ops
.zero_sum_result
& SUM_CHECK_P_RESULT
) {
2886 set_bit(R5_Wantcompute
,
2887 &sh
->dev
[pd_idx
].flags
);
2889 target
= &sh
->ops
.target2
;
2892 if (sh
->ops
.zero_sum_result
& SUM_CHECK_Q_RESULT
) {
2893 set_bit(R5_Wantcompute
,
2894 &sh
->dev
[qd_idx
].flags
);
2901 case check_state_compute_run
:
2904 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2905 __func__
, sh
->check_state
,
2906 (unsigned long long) sh
->sector
);
2911 static void handle_stripe_expansion(struct r5conf
*conf
, struct stripe_head
*sh
)
2915 /* We have read all the blocks in this stripe and now we need to
2916 * copy some of them into a target stripe for expand.
2918 struct dma_async_tx_descriptor
*tx
= NULL
;
2919 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2920 for (i
= 0; i
< sh
->disks
; i
++)
2921 if (i
!= sh
->pd_idx
&& i
!= sh
->qd_idx
) {
2923 struct stripe_head
*sh2
;
2924 struct async_submit_ctl submit
;
2926 sector_t bn
= compute_blocknr(sh
, i
, 1);
2927 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
2929 sh2
= get_active_stripe(conf
, s
, 0, 1, 1);
2931 /* so far only the early blocks of this stripe
2932 * have been requested. When later blocks
2933 * get requested, we will try again
2936 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
2937 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
2938 /* must have already done this block */
2939 release_stripe(sh2
);
2943 /* place all the copies on one channel */
2944 init_async_submit(&submit
, 0, tx
, NULL
, NULL
, NULL
);
2945 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
2946 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
2949 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
2950 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
2951 for (j
= 0; j
< conf
->raid_disks
; j
++)
2952 if (j
!= sh2
->pd_idx
&&
2954 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
2956 if (j
== conf
->raid_disks
) {
2957 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
2958 set_bit(STRIPE_HANDLE
, &sh2
->state
);
2960 release_stripe(sh2
);
2963 /* done submitting copies, wait for them to complete */
2966 dma_wait_for_async_tx(tx
);
2972 * handle_stripe - do things to a stripe.
2974 * We lock the stripe and then examine the state of various bits
2975 * to see what needs to be done.
2977 * return some read request which now have data
2978 * return some write requests which are safely on disc
2979 * schedule a read on some buffers
2980 * schedule a write of some buffers
2981 * return confirmation of parity correctness
2983 * buffers are taken off read_list or write_list, and bh_cache buffers
2984 * get BH_Lock set before the stripe lock is released.
2988 static void analyse_stripe(struct stripe_head
*sh
, struct stripe_head_state
*s
)
2990 struct r5conf
*conf
= sh
->raid_conf
;
2991 int disks
= sh
->disks
;
2995 memset(s
, 0, sizeof(*s
));
2997 s
->syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
2998 s
->expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2999 s
->expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3000 s
->failed_num
[0] = -1;
3001 s
->failed_num
[1] = -1;
3003 /* Now to look around and see what can be done */
3005 spin_lock_irq(&conf
->device_lock
);
3006 for (i
=disks
; i
--; ) {
3007 struct md_rdev
*rdev
;
3014 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
3015 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
3016 /* maybe we can reply to a read
3018 * new wantfill requests are only permitted while
3019 * ops_complete_biofill is guaranteed to be inactive
3021 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
3022 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
3023 set_bit(R5_Wantfill
, &dev
->flags
);
3025 /* now count some things */
3026 if (test_bit(R5_LOCKED
, &dev
->flags
))
3028 if (test_bit(R5_UPTODATE
, &dev
->flags
))
3030 if (test_bit(R5_Wantcompute
, &dev
->flags
)) {
3032 BUG_ON(s
->compute
> 2);
3035 if (test_bit(R5_Wantfill
, &dev
->flags
))
3037 else if (dev
->toread
)
3041 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
3046 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3047 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
3050 is_bad
= is_badblock(rdev
, sh
->sector
, STRIPE_SECTORS
,
3051 &first_bad
, &bad_sectors
);
3052 if (s
->blocked_rdev
== NULL
3053 && (test_bit(Blocked
, &rdev
->flags
)
3056 set_bit(BlockedBadBlocks
,
3058 s
->blocked_rdev
= rdev
;
3059 atomic_inc(&rdev
->nr_pending
);
3062 clear_bit(R5_Insync
, &dev
->flags
);
3066 /* also not in-sync */
3067 if (!test_bit(WriteErrorSeen
, &rdev
->flags
)) {
3068 /* treat as in-sync, but with a read error
3069 * which we can now try to correct
3071 set_bit(R5_Insync
, &dev
->flags
);
3072 set_bit(R5_ReadError
, &dev
->flags
);
3074 } else if (test_bit(In_sync
, &rdev
->flags
))
3075 set_bit(R5_Insync
, &dev
->flags
);
3076 else if (sh
->sector
+ STRIPE_SECTORS
<= rdev
->recovery_offset
)
3077 /* in sync if before recovery_offset */
3078 set_bit(R5_Insync
, &dev
->flags
);
3079 else if (test_bit(R5_UPTODATE
, &dev
->flags
) &&
3080 test_bit(R5_Expanded
, &dev
->flags
))
3081 /* If we've reshaped into here, we assume it is Insync.
3082 * We will shortly update recovery_offset to make
3085 set_bit(R5_Insync
, &dev
->flags
);
3087 if (rdev
&& test_bit(R5_WriteError
, &dev
->flags
)) {
3088 clear_bit(R5_Insync
, &dev
->flags
);
3089 if (!test_bit(Faulty
, &rdev
->flags
)) {
3090 s
->handle_bad_blocks
= 1;
3091 atomic_inc(&rdev
->nr_pending
);
3093 clear_bit(R5_WriteError
, &dev
->flags
);
3095 if (rdev
&& test_bit(R5_MadeGood
, &dev
->flags
)) {
3096 if (!test_bit(Faulty
, &rdev
->flags
)) {
3097 s
->handle_bad_blocks
= 1;
3098 atomic_inc(&rdev
->nr_pending
);
3100 clear_bit(R5_MadeGood
, &dev
->flags
);
3102 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3103 /* The ReadError flag will just be confusing now */
3104 clear_bit(R5_ReadError
, &dev
->flags
);
3105 clear_bit(R5_ReWrite
, &dev
->flags
);
3107 if (test_bit(R5_ReadError
, &dev
->flags
))
3108 clear_bit(R5_Insync
, &dev
->flags
);
3109 if (!test_bit(R5_Insync
, &dev
->flags
)) {
3111 s
->failed_num
[s
->failed
] = i
;
3115 spin_unlock_irq(&conf
->device_lock
);
3119 static void handle_stripe(struct stripe_head
*sh
)
3121 struct stripe_head_state s
;
3122 struct r5conf
*conf
= sh
->raid_conf
;
3125 int disks
= sh
->disks
;
3126 struct r5dev
*pdev
, *qdev
;
3128 clear_bit(STRIPE_HANDLE
, &sh
->state
);
3129 if (test_and_set_bit_lock(STRIPE_ACTIVE
, &sh
->state
)) {
3130 /* already being handled, ensure it gets handled
3131 * again when current action finishes */
3132 set_bit(STRIPE_HANDLE
, &sh
->state
);
3136 if (test_and_clear_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
)) {
3137 set_bit(STRIPE_SYNCING
, &sh
->state
);
3138 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3140 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3142 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
3143 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
3144 (unsigned long long)sh
->sector
, sh
->state
,
3145 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->qd_idx
,
3146 sh
->check_state
, sh
->reconstruct_state
);
3148 analyse_stripe(sh
, &s
);
3150 if (s
.handle_bad_blocks
) {
3151 set_bit(STRIPE_HANDLE
, &sh
->state
);
3155 if (unlikely(s
.blocked_rdev
)) {
3156 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
3157 s
.to_write
|| s
.written
) {
3158 set_bit(STRIPE_HANDLE
, &sh
->state
);
3161 /* There is nothing for the blocked_rdev to block */
3162 rdev_dec_pending(s
.blocked_rdev
, conf
->mddev
);
3163 s
.blocked_rdev
= NULL
;
3166 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
3167 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
3168 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
3171 pr_debug("locked=%d uptodate=%d to_read=%d"
3172 " to_write=%d failed=%d failed_num=%d,%d\n",
3173 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
3174 s
.failed_num
[0], s
.failed_num
[1]);
3175 /* check if the array has lost more than max_degraded devices and,
3176 * if so, some requests might need to be failed.
3178 if (s
.failed
> conf
->max_degraded
) {
3179 sh
->check_state
= 0;
3180 sh
->reconstruct_state
= 0;
3181 if (s
.to_read
+s
.to_write
+s
.written
)
3182 handle_failed_stripe(conf
, sh
, &s
, disks
, &s
.return_bi
);
3184 handle_failed_sync(conf
, sh
, &s
);
3188 * might be able to return some write requests if the parity blocks
3189 * are safe, or on a failed drive
3191 pdev
= &sh
->dev
[sh
->pd_idx
];
3192 s
.p_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->pd_idx
)
3193 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->pd_idx
);
3194 qdev
= &sh
->dev
[sh
->qd_idx
];
3195 s
.q_failed
= (s
.failed
>= 1 && s
.failed_num
[0] == sh
->qd_idx
)
3196 || (s
.failed
>= 2 && s
.failed_num
[1] == sh
->qd_idx
)
3200 (s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
3201 && !test_bit(R5_LOCKED
, &pdev
->flags
)
3202 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
3203 (s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
3204 && !test_bit(R5_LOCKED
, &qdev
->flags
)
3205 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
3206 handle_stripe_clean_event(conf
, sh
, disks
, &s
.return_bi
);
3208 /* Now we might consider reading some blocks, either to check/generate
3209 * parity, or to satisfy requests
3210 * or to load a block that is being partially written.
3212 if (s
.to_read
|| s
.non_overwrite
3213 || (conf
->level
== 6 && s
.to_write
&& s
.failed
)
3214 || (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
3215 handle_stripe_fill(sh
, &s
, disks
);
3217 /* Now we check to see if any write operations have recently
3221 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
3223 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
3224 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
3225 sh
->reconstruct_state
= reconstruct_state_idle
;
3227 /* All the 'written' buffers and the parity block are ready to
3228 * be written back to disk
3230 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
3231 BUG_ON(sh
->qd_idx
>= 0 &&
3232 !test_bit(R5_UPTODATE
, &sh
->dev
[sh
->qd_idx
].flags
));
3233 for (i
= disks
; i
--; ) {
3234 struct r5dev
*dev
= &sh
->dev
[i
];
3235 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
3236 (i
== sh
->pd_idx
|| i
== sh
->qd_idx
||
3238 pr_debug("Writing block %d\n", i
);
3239 set_bit(R5_Wantwrite
, &dev
->flags
);
3242 if (!test_bit(R5_Insync
, &dev
->flags
) ||
3243 ((i
== sh
->pd_idx
|| i
== sh
->qd_idx
) &&
3245 set_bit(STRIPE_INSYNC
, &sh
->state
);
3248 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3249 s
.dec_preread_active
= 1;
3252 /* Now to consider new write requests and what else, if anything
3253 * should be read. We do not handle new writes when:
3254 * 1/ A 'write' operation (copy+xor) is already in flight.
3255 * 2/ A 'check' operation is in flight, as it may clobber the parity
3258 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
3259 handle_stripe_dirtying(conf
, sh
, &s
, disks
);
3261 /* maybe we need to check and possibly fix the parity for this stripe
3262 * Any reads will already have been scheduled, so we just see if enough
3263 * data is available. The parity check is held off while parity
3264 * dependent operations are in flight.
3266 if (sh
->check_state
||
3267 (s
.syncing
&& s
.locked
== 0 &&
3268 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
3269 !test_bit(STRIPE_INSYNC
, &sh
->state
))) {
3270 if (conf
->level
== 6)
3271 handle_parity_checks6(conf
, sh
, &s
, disks
);
3273 handle_parity_checks5(conf
, sh
, &s
, disks
);
3276 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
3277 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3278 clear_bit(STRIPE_SYNCING
, &sh
->state
);
3281 /* If the failed drives are just a ReadError, then we might need
3282 * to progress the repair/check process
3284 if (s
.failed
<= conf
->max_degraded
&& !conf
->mddev
->ro
)
3285 for (i
= 0; i
< s
.failed
; i
++) {
3286 struct r5dev
*dev
= &sh
->dev
[s
.failed_num
[i
]];
3287 if (test_bit(R5_ReadError
, &dev
->flags
)
3288 && !test_bit(R5_LOCKED
, &dev
->flags
)
3289 && test_bit(R5_UPTODATE
, &dev
->flags
)
3291 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
3292 set_bit(R5_Wantwrite
, &dev
->flags
);
3293 set_bit(R5_ReWrite
, &dev
->flags
);
3294 set_bit(R5_LOCKED
, &dev
->flags
);
3297 /* let's read it back */
3298 set_bit(R5_Wantread
, &dev
->flags
);
3299 set_bit(R5_LOCKED
, &dev
->flags
);
3306 /* Finish reconstruct operations initiated by the expansion process */
3307 if (sh
->reconstruct_state
== reconstruct_state_result
) {
3308 struct stripe_head
*sh_src
3309 = get_active_stripe(conf
, sh
->sector
, 1, 1, 1);
3310 if (sh_src
&& test_bit(STRIPE_EXPAND_SOURCE
, &sh_src
->state
)) {
3311 /* sh cannot be written until sh_src has been read.
3312 * so arrange for sh to be delayed a little
3314 set_bit(STRIPE_DELAYED
, &sh
->state
);
3315 set_bit(STRIPE_HANDLE
, &sh
->state
);
3316 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
,
3318 atomic_inc(&conf
->preread_active_stripes
);
3319 release_stripe(sh_src
);
3323 release_stripe(sh_src
);
3325 sh
->reconstruct_state
= reconstruct_state_idle
;
3326 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3327 for (i
= conf
->raid_disks
; i
--; ) {
3328 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3329 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
3334 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
3335 !sh
->reconstruct_state
) {
3336 /* Need to write out all blocks after computing parity */
3337 sh
->disks
= conf
->raid_disks
;
3338 stripe_set_idx(sh
->sector
, conf
, 0, sh
);
3339 schedule_reconstruction(sh
, &s
, 1, 1);
3340 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
3341 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3342 atomic_dec(&conf
->reshape_stripes
);
3343 wake_up(&conf
->wait_for_overlap
);
3344 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3347 if (s
.expanding
&& s
.locked
== 0 &&
3348 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3349 handle_stripe_expansion(conf
, sh
);
3352 /* wait for this device to become unblocked */
3353 if (conf
->mddev
->external
&& unlikely(s
.blocked_rdev
))
3354 md_wait_for_blocked_rdev(s
.blocked_rdev
, conf
->mddev
);
3356 if (s
.handle_bad_blocks
)
3357 for (i
= disks
; i
--; ) {
3358 struct md_rdev
*rdev
;
3359 struct r5dev
*dev
= &sh
->dev
[i
];
3360 if (test_and_clear_bit(R5_WriteError
, &dev
->flags
)) {
3361 /* We own a safe reference to the rdev */
3362 rdev
= conf
->disks
[i
].rdev
;
3363 if (!rdev_set_badblocks(rdev
, sh
->sector
,
3365 md_error(conf
->mddev
, rdev
);
3366 rdev_dec_pending(rdev
, conf
->mddev
);
3368 if (test_and_clear_bit(R5_MadeGood
, &dev
->flags
)) {
3369 rdev
= conf
->disks
[i
].rdev
;
3370 rdev_clear_badblocks(rdev
, sh
->sector
,
3372 rdev_dec_pending(rdev
, conf
->mddev
);
3377 raid_run_ops(sh
, s
.ops_request
);
3381 if (s
.dec_preread_active
) {
3382 /* We delay this until after ops_run_io so that if make_request
3383 * is waiting on a flush, it won't continue until the writes
3384 * have actually been submitted.
3386 atomic_dec(&conf
->preread_active_stripes
);
3387 if (atomic_read(&conf
->preread_active_stripes
) <
3389 md_wakeup_thread(conf
->mddev
->thread
);
3392 return_io(s
.return_bi
);
3394 clear_bit_unlock(STRIPE_ACTIVE
, &sh
->state
);
3397 static void raid5_activate_delayed(struct r5conf
*conf
)
3399 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3400 while (!list_empty(&conf
->delayed_list
)) {
3401 struct list_head
*l
= conf
->delayed_list
.next
;
3402 struct stripe_head
*sh
;
3403 sh
= list_entry(l
, struct stripe_head
, lru
);
3405 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3406 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3407 atomic_inc(&conf
->preread_active_stripes
);
3408 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3413 static void activate_bit_delay(struct r5conf
*conf
)
3415 /* device_lock is held */
3416 struct list_head head
;
3417 list_add(&head
, &conf
->bitmap_list
);
3418 list_del_init(&conf
->bitmap_list
);
3419 while (!list_empty(&head
)) {
3420 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3421 list_del_init(&sh
->lru
);
3422 atomic_inc(&sh
->count
);
3423 __release_stripe(conf
, sh
);
3427 int md_raid5_congested(struct mddev
*mddev
, int bits
)
3429 struct r5conf
*conf
= mddev
->private;
3431 /* No difference between reads and writes. Just check
3432 * how busy the stripe_cache is
3435 if (conf
->inactive_blocked
)
3439 if (list_empty_careful(&conf
->inactive_list
))
3444 EXPORT_SYMBOL_GPL(md_raid5_congested
);
3446 static int raid5_congested(void *data
, int bits
)
3448 struct mddev
*mddev
= data
;
3450 return mddev_congested(mddev
, bits
) ||
3451 md_raid5_congested(mddev
, bits
);
3454 /* We want read requests to align with chunks where possible,
3455 * but write requests don't need to.
3457 static int raid5_mergeable_bvec(struct request_queue
*q
,
3458 struct bvec_merge_data
*bvm
,
3459 struct bio_vec
*biovec
)
3461 struct mddev
*mddev
= q
->queuedata
;
3462 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3464 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3465 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3467 if ((bvm
->bi_rw
& 1) == WRITE
)
3468 return biovec
->bv_len
; /* always allow writes to be mergeable */
3470 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3471 chunk_sectors
= mddev
->new_chunk_sectors
;
3472 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3473 if (max
< 0) max
= 0;
3474 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3475 return biovec
->bv_len
;
3481 static int in_chunk_boundary(struct mddev
*mddev
, struct bio
*bio
)
3483 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3484 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
3485 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3487 if (mddev
->new_chunk_sectors
< mddev
->chunk_sectors
)
3488 chunk_sectors
= mddev
->new_chunk_sectors
;
3489 return chunk_sectors
>=
3490 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3494 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3495 * later sampled by raid5d.
3497 static void add_bio_to_retry(struct bio
*bi
,struct r5conf
*conf
)
3499 unsigned long flags
;
3501 spin_lock_irqsave(&conf
->device_lock
, flags
);
3503 bi
->bi_next
= conf
->retry_read_aligned_list
;
3504 conf
->retry_read_aligned_list
= bi
;
3506 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3507 md_wakeup_thread(conf
->mddev
->thread
);
3511 static struct bio
*remove_bio_from_retry(struct r5conf
*conf
)
3515 bi
= conf
->retry_read_aligned
;
3517 conf
->retry_read_aligned
= NULL
;
3520 bi
= conf
->retry_read_aligned_list
;
3522 conf
->retry_read_aligned_list
= bi
->bi_next
;
3525 * this sets the active strip count to 1 and the processed
3526 * strip count to zero (upper 8 bits)
3528 bi
->bi_phys_segments
= 1; /* biased count of active stripes */
3536 * The "raid5_align_endio" should check if the read succeeded and if it
3537 * did, call bio_endio on the original bio (having bio_put the new bio
3539 * If the read failed..
3541 static void raid5_align_endio(struct bio
*bi
, int error
)
3543 struct bio
* raid_bi
= bi
->bi_private
;
3544 struct mddev
*mddev
;
3545 struct r5conf
*conf
;
3546 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3547 struct md_rdev
*rdev
;
3551 rdev
= (void*)raid_bi
->bi_next
;
3552 raid_bi
->bi_next
= NULL
;
3553 mddev
= rdev
->mddev
;
3554 conf
= mddev
->private;
3556 rdev_dec_pending(rdev
, conf
->mddev
);
3558 if (!error
&& uptodate
) {
3559 bio_endio(raid_bi
, 0);
3560 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3561 wake_up(&conf
->wait_for_stripe
);
3566 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3568 add_bio_to_retry(raid_bi
, conf
);
3571 static int bio_fits_rdev(struct bio
*bi
)
3573 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3575 if ((bi
->bi_size
>>9) > queue_max_sectors(q
))
3577 blk_recount_segments(q
, bi
);
3578 if (bi
->bi_phys_segments
> queue_max_segments(q
))
3581 if (q
->merge_bvec_fn
)
3582 /* it's too hard to apply the merge_bvec_fn at this stage,
3591 static int chunk_aligned_read(struct mddev
*mddev
, struct bio
* raid_bio
)
3593 struct r5conf
*conf
= mddev
->private;
3595 struct bio
* align_bi
;
3596 struct md_rdev
*rdev
;
3598 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3599 pr_debug("chunk_aligned_read : non aligned\n");
3603 * use bio_clone_mddev to make a copy of the bio
3605 align_bi
= bio_clone_mddev(raid_bio
, GFP_NOIO
, mddev
);
3609 * set bi_end_io to a new function, and set bi_private to the
3612 align_bi
->bi_end_io
= raid5_align_endio
;
3613 align_bi
->bi_private
= raid_bio
;
3617 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3622 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3623 if (rdev
&& test_bit(In_sync
, &rdev
->flags
)) {
3627 atomic_inc(&rdev
->nr_pending
);
3629 raid_bio
->bi_next
= (void*)rdev
;
3630 align_bi
->bi_bdev
= rdev
->bdev
;
3631 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3632 align_bi
->bi_sector
+= rdev
->data_offset
;
3634 if (!bio_fits_rdev(align_bi
) ||
3635 is_badblock(rdev
, align_bi
->bi_sector
, align_bi
->bi_size
>>9,
3636 &first_bad
, &bad_sectors
)) {
3637 /* too big in some way, or has a known bad block */
3639 rdev_dec_pending(rdev
, mddev
);
3643 spin_lock_irq(&conf
->device_lock
);
3644 wait_event_lock_irq(conf
->wait_for_stripe
,
3646 conf
->device_lock
, /* nothing */);
3647 atomic_inc(&conf
->active_aligned_reads
);
3648 spin_unlock_irq(&conf
->device_lock
);
3650 generic_make_request(align_bi
);
3659 /* __get_priority_stripe - get the next stripe to process
3661 * Full stripe writes are allowed to pass preread active stripes up until
3662 * the bypass_threshold is exceeded. In general the bypass_count
3663 * increments when the handle_list is handled before the hold_list; however, it
3664 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3665 * stripe with in flight i/o. The bypass_count will be reset when the
3666 * head of the hold_list has changed, i.e. the head was promoted to the
3669 static struct stripe_head
*__get_priority_stripe(struct r5conf
*conf
)
3671 struct stripe_head
*sh
;
3673 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3675 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3676 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3677 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3679 if (!list_empty(&conf
->handle_list
)) {
3680 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3682 if (list_empty(&conf
->hold_list
))
3683 conf
->bypass_count
= 0;
3684 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3685 if (conf
->hold_list
.next
== conf
->last_hold
)
3686 conf
->bypass_count
++;
3688 conf
->last_hold
= conf
->hold_list
.next
;
3689 conf
->bypass_count
-= conf
->bypass_threshold
;
3690 if (conf
->bypass_count
< 0)
3691 conf
->bypass_count
= 0;
3694 } else if (!list_empty(&conf
->hold_list
) &&
3695 ((conf
->bypass_threshold
&&
3696 conf
->bypass_count
> conf
->bypass_threshold
) ||
3697 atomic_read(&conf
->pending_full_writes
) == 0)) {
3698 sh
= list_entry(conf
->hold_list
.next
,
3700 conf
->bypass_count
-= conf
->bypass_threshold
;
3701 if (conf
->bypass_count
< 0)
3702 conf
->bypass_count
= 0;
3706 list_del_init(&sh
->lru
);
3707 atomic_inc(&sh
->count
);
3708 BUG_ON(atomic_read(&sh
->count
) != 1);
3712 static void make_request(struct mddev
*mddev
, struct bio
* bi
)
3714 struct r5conf
*conf
= mddev
->private;
3716 sector_t new_sector
;
3717 sector_t logical_sector
, last_sector
;
3718 struct stripe_head
*sh
;
3719 const int rw
= bio_data_dir(bi
);
3723 if (unlikely(bi
->bi_rw
& REQ_FLUSH
)) {
3724 md_flush_request(mddev
, bi
);
3728 md_write_start(mddev
, bi
);
3731 mddev
->reshape_position
== MaxSector
&&
3732 chunk_aligned_read(mddev
,bi
))
3735 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3736 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
3738 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
3740 plugged
= mddev_check_plugged(mddev
);
3741 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
3743 int disks
, data_disks
;
3748 disks
= conf
->raid_disks
;
3749 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
3750 if (unlikely(conf
->reshape_progress
!= MaxSector
)) {
3751 /* spinlock is needed as reshape_progress may be
3752 * 64bit on a 32bit platform, and so it might be
3753 * possible to see a half-updated value
3754 * Of course reshape_progress could change after
3755 * the lock is dropped, so once we get a reference
3756 * to the stripe that we think it is, we will have
3759 spin_lock_irq(&conf
->device_lock
);
3760 if (mddev
->delta_disks
< 0
3761 ? logical_sector
< conf
->reshape_progress
3762 : logical_sector
>= conf
->reshape_progress
) {
3763 disks
= conf
->previous_raid_disks
;
3766 if (mddev
->delta_disks
< 0
3767 ? logical_sector
< conf
->reshape_safe
3768 : logical_sector
>= conf
->reshape_safe
) {
3769 spin_unlock_irq(&conf
->device_lock
);
3774 spin_unlock_irq(&conf
->device_lock
);
3776 data_disks
= disks
- conf
->max_degraded
;
3778 new_sector
= raid5_compute_sector(conf
, logical_sector
,
3781 pr_debug("raid456: make_request, sector %llu logical %llu\n",
3782 (unsigned long long)new_sector
,
3783 (unsigned long long)logical_sector
);
3785 sh
= get_active_stripe(conf
, new_sector
, previous
,
3786 (bi
->bi_rw
&RWA_MASK
), 0);
3788 if (unlikely(previous
)) {
3789 /* expansion might have moved on while waiting for a
3790 * stripe, so we must do the range check again.
3791 * Expansion could still move past after this
3792 * test, but as we are holding a reference to
3793 * 'sh', we know that if that happens,
3794 * STRIPE_EXPANDING will get set and the expansion
3795 * won't proceed until we finish with the stripe.
3798 spin_lock_irq(&conf
->device_lock
);
3799 if (mddev
->delta_disks
< 0
3800 ? logical_sector
>= conf
->reshape_progress
3801 : logical_sector
< conf
->reshape_progress
)
3802 /* mismatch, need to try again */
3804 spin_unlock_irq(&conf
->device_lock
);
3813 logical_sector
>= mddev
->suspend_lo
&&
3814 logical_sector
< mddev
->suspend_hi
) {
3816 /* As the suspend_* range is controlled by
3817 * userspace, we want an interruptible
3820 flush_signals(current
);
3821 prepare_to_wait(&conf
->wait_for_overlap
,
3822 &w
, TASK_INTERRUPTIBLE
);
3823 if (logical_sector
>= mddev
->suspend_lo
&&
3824 logical_sector
< mddev
->suspend_hi
)
3829 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
3830 !add_stripe_bio(sh
, bi
, dd_idx
, rw
)) {
3831 /* Stripe is busy expanding or
3832 * add failed due to overlap. Flush everything
3835 md_wakeup_thread(mddev
->thread
);
3840 finish_wait(&conf
->wait_for_overlap
, &w
);
3841 set_bit(STRIPE_HANDLE
, &sh
->state
);
3842 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3843 if ((bi
->bi_rw
& REQ_SYNC
) &&
3844 !test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3845 atomic_inc(&conf
->preread_active_stripes
);
3848 /* cannot get stripe for read-ahead, just give-up */
3849 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3850 finish_wait(&conf
->wait_for_overlap
, &w
);
3856 md_wakeup_thread(mddev
->thread
);
3858 spin_lock_irq(&conf
->device_lock
);
3859 remaining
= raid5_dec_bi_phys_segments(bi
);
3860 spin_unlock_irq(&conf
->device_lock
);
3861 if (remaining
== 0) {
3864 md_write_end(mddev
);
3870 static sector_t
raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
);
3872 static sector_t
reshape_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
)
3874 /* reshaping is quite different to recovery/resync so it is
3875 * handled quite separately ... here.
3877 * On each call to sync_request, we gather one chunk worth of
3878 * destination stripes and flag them as expanding.
3879 * Then we find all the source stripes and request reads.
3880 * As the reads complete, handle_stripe will copy the data
3881 * into the destination stripe and release that stripe.
3883 struct r5conf
*conf
= mddev
->private;
3884 struct stripe_head
*sh
;
3885 sector_t first_sector
, last_sector
;
3886 int raid_disks
= conf
->previous_raid_disks
;
3887 int data_disks
= raid_disks
- conf
->max_degraded
;
3888 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
3891 sector_t writepos
, readpos
, safepos
;
3892 sector_t stripe_addr
;
3893 int reshape_sectors
;
3894 struct list_head stripes
;
3896 if (sector_nr
== 0) {
3897 /* If restarting in the middle, skip the initial sectors */
3898 if (mddev
->delta_disks
< 0 &&
3899 conf
->reshape_progress
< raid5_size(mddev
, 0, 0)) {
3900 sector_nr
= raid5_size(mddev
, 0, 0)
3901 - conf
->reshape_progress
;
3902 } else if (mddev
->delta_disks
>= 0 &&
3903 conf
->reshape_progress
> 0)
3904 sector_nr
= conf
->reshape_progress
;
3905 sector_div(sector_nr
, new_data_disks
);
3907 mddev
->curr_resync_completed
= sector_nr
;
3908 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
3914 /* We need to process a full chunk at a time.
3915 * If old and new chunk sizes differ, we need to process the
3918 if (mddev
->new_chunk_sectors
> mddev
->chunk_sectors
)
3919 reshape_sectors
= mddev
->new_chunk_sectors
;
3921 reshape_sectors
= mddev
->chunk_sectors
;
3923 /* we update the metadata when there is more than 3Meg
3924 * in the block range (that is rather arbitrary, should
3925 * probably be time based) or when the data about to be
3926 * copied would over-write the source of the data at
3927 * the front of the range.
3928 * i.e. one new_stripe along from reshape_progress new_maps
3929 * to after where reshape_safe old_maps to
3931 writepos
= conf
->reshape_progress
;
3932 sector_div(writepos
, new_data_disks
);
3933 readpos
= conf
->reshape_progress
;
3934 sector_div(readpos
, data_disks
);
3935 safepos
= conf
->reshape_safe
;
3936 sector_div(safepos
, data_disks
);
3937 if (mddev
->delta_disks
< 0) {
3938 writepos
-= min_t(sector_t
, reshape_sectors
, writepos
);
3939 readpos
+= reshape_sectors
;
3940 safepos
+= reshape_sectors
;
3942 writepos
+= reshape_sectors
;
3943 readpos
-= min_t(sector_t
, reshape_sectors
, readpos
);
3944 safepos
-= min_t(sector_t
, reshape_sectors
, safepos
);
3947 /* 'writepos' is the most advanced device address we might write.
3948 * 'readpos' is the least advanced device address we might read.
3949 * 'safepos' is the least address recorded in the metadata as having
3951 * If 'readpos' is behind 'writepos', then there is no way that we can
3952 * ensure safety in the face of a crash - that must be done by userspace
3953 * making a backup of the data. So in that case there is no particular
3954 * rush to update metadata.
3955 * Otherwise if 'safepos' is behind 'writepos', then we really need to
3956 * update the metadata to advance 'safepos' to match 'readpos' so that
3957 * we can be safe in the event of a crash.
3958 * So we insist on updating metadata if safepos is behind writepos and
3959 * readpos is beyond writepos.
3960 * In any case, update the metadata every 10 seconds.
3961 * Maybe that number should be configurable, but I'm not sure it is
3962 * worth it.... maybe it could be a multiple of safemode_delay???
3964 if ((mddev
->delta_disks
< 0
3965 ? (safepos
> writepos
&& readpos
< writepos
)
3966 : (safepos
< writepos
&& readpos
> writepos
)) ||
3967 time_after(jiffies
, conf
->reshape_checkpoint
+ 10*HZ
)) {
3968 /* Cannot proceed until we've updated the superblock... */
3969 wait_event(conf
->wait_for_overlap
,
3970 atomic_read(&conf
->reshape_stripes
)==0);
3971 mddev
->reshape_position
= conf
->reshape_progress
;
3972 mddev
->curr_resync_completed
= sector_nr
;
3973 conf
->reshape_checkpoint
= jiffies
;
3974 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
3975 md_wakeup_thread(mddev
->thread
);
3976 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
3977 kthread_should_stop());
3978 spin_lock_irq(&conf
->device_lock
);
3979 conf
->reshape_safe
= mddev
->reshape_position
;
3980 spin_unlock_irq(&conf
->device_lock
);
3981 wake_up(&conf
->wait_for_overlap
);
3982 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
3985 if (mddev
->delta_disks
< 0) {
3986 BUG_ON(conf
->reshape_progress
== 0);
3987 stripe_addr
= writepos
;
3988 BUG_ON((mddev
->dev_sectors
&
3989 ~((sector_t
)reshape_sectors
- 1))
3990 - reshape_sectors
- stripe_addr
3993 BUG_ON(writepos
!= sector_nr
+ reshape_sectors
);
3994 stripe_addr
= sector_nr
;
3996 INIT_LIST_HEAD(&stripes
);
3997 for (i
= 0; i
< reshape_sectors
; i
+= STRIPE_SECTORS
) {
3999 int skipped_disk
= 0;
4000 sh
= get_active_stripe(conf
, stripe_addr
+i
, 0, 0, 1);
4001 set_bit(STRIPE_EXPANDING
, &sh
->state
);
4002 atomic_inc(&conf
->reshape_stripes
);
4003 /* If any of this stripe is beyond the end of the old
4004 * array, then we need to zero those blocks
4006 for (j
=sh
->disks
; j
--;) {
4008 if (j
== sh
->pd_idx
)
4010 if (conf
->level
== 6 &&
4013 s
= compute_blocknr(sh
, j
, 0);
4014 if (s
< raid5_size(mddev
, 0, 0)) {
4018 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
4019 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
4020 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
4022 if (!skipped_disk
) {
4023 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
4024 set_bit(STRIPE_HANDLE
, &sh
->state
);
4026 list_add(&sh
->lru
, &stripes
);
4028 spin_lock_irq(&conf
->device_lock
);
4029 if (mddev
->delta_disks
< 0)
4030 conf
->reshape_progress
-= reshape_sectors
* new_data_disks
;
4032 conf
->reshape_progress
+= reshape_sectors
* new_data_disks
;
4033 spin_unlock_irq(&conf
->device_lock
);
4034 /* Ok, those stripe are ready. We can start scheduling
4035 * reads on the source stripes.
4036 * The source stripes are determined by mapping the first and last
4037 * block on the destination stripes.
4040 raid5_compute_sector(conf
, stripe_addr
*(new_data_disks
),
4043 raid5_compute_sector(conf
, ((stripe_addr
+reshape_sectors
)
4044 * new_data_disks
- 1),
4046 if (last_sector
>= mddev
->dev_sectors
)
4047 last_sector
= mddev
->dev_sectors
- 1;
4048 while (first_sector
<= last_sector
) {
4049 sh
= get_active_stripe(conf
, first_sector
, 1, 0, 1);
4050 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
4051 set_bit(STRIPE_HANDLE
, &sh
->state
);
4053 first_sector
+= STRIPE_SECTORS
;
4055 /* Now that the sources are clearly marked, we can release
4056 * the destination stripes
4058 while (!list_empty(&stripes
)) {
4059 sh
= list_entry(stripes
.next
, struct stripe_head
, lru
);
4060 list_del_init(&sh
->lru
);
4063 /* If this takes us to the resync_max point where we have to pause,
4064 * then we need to write out the superblock.
4066 sector_nr
+= reshape_sectors
;
4067 if ((sector_nr
- mddev
->curr_resync_completed
) * 2
4068 >= mddev
->resync_max
- mddev
->curr_resync_completed
) {
4069 /* Cannot proceed until we've updated the superblock... */
4070 wait_event(conf
->wait_for_overlap
,
4071 atomic_read(&conf
->reshape_stripes
) == 0);
4072 mddev
->reshape_position
= conf
->reshape_progress
;
4073 mddev
->curr_resync_completed
= sector_nr
;
4074 conf
->reshape_checkpoint
= jiffies
;
4075 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4076 md_wakeup_thread(mddev
->thread
);
4077 wait_event(mddev
->sb_wait
,
4078 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
4079 || kthread_should_stop());
4080 spin_lock_irq(&conf
->device_lock
);
4081 conf
->reshape_safe
= mddev
->reshape_position
;
4082 spin_unlock_irq(&conf
->device_lock
);
4083 wake_up(&conf
->wait_for_overlap
);
4084 sysfs_notify(&mddev
->kobj
, NULL
, "sync_completed");
4086 return reshape_sectors
;
4089 /* FIXME go_faster isn't used */
4090 static inline sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
4092 struct r5conf
*conf
= mddev
->private;
4093 struct stripe_head
*sh
;
4094 sector_t max_sector
= mddev
->dev_sectors
;
4095 sector_t sync_blocks
;
4096 int still_degraded
= 0;
4099 if (sector_nr
>= max_sector
) {
4100 /* just being told to finish up .. nothing much to do */
4102 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
4107 if (mddev
->curr_resync
< max_sector
) /* aborted */
4108 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
4110 else /* completed sync */
4112 bitmap_close_sync(mddev
->bitmap
);
4117 /* Allow raid5_quiesce to complete */
4118 wait_event(conf
->wait_for_overlap
, conf
->quiesce
!= 2);
4120 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
4121 return reshape_request(mddev
, sector_nr
, skipped
);
4123 /* No need to check resync_max as we never do more than one
4124 * stripe, and as resync_max will always be on a chunk boundary,
4125 * if the check in md_do_sync didn't fire, there is no chance
4126 * of overstepping resync_max here
4129 /* if there is too many failed drives and we are trying
4130 * to resync, then assert that we are finished, because there is
4131 * nothing we can do.
4133 if (mddev
->degraded
>= conf
->max_degraded
&&
4134 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
4135 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
4139 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
4140 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
4141 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
4142 /* we can skip this block, and probably more */
4143 sync_blocks
/= STRIPE_SECTORS
;
4145 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
4149 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
4151 sh
= get_active_stripe(conf
, sector_nr
, 0, 1, 0);
4153 sh
= get_active_stripe(conf
, sector_nr
, 0, 0, 0);
4154 /* make sure we don't swamp the stripe cache if someone else
4155 * is trying to get access
4157 schedule_timeout_uninterruptible(1);
4159 /* Need to check if array will still be degraded after recovery/resync
4160 * We don't need to check the 'failed' flag as when that gets set,
4163 for (i
= 0; i
< conf
->raid_disks
; i
++)
4164 if (conf
->disks
[i
].rdev
== NULL
)
4167 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
4169 set_bit(STRIPE_SYNC_REQUESTED
, &sh
->state
);
4174 return STRIPE_SECTORS
;
4177 static int retry_aligned_read(struct r5conf
*conf
, struct bio
*raid_bio
)
4179 /* We may not be able to submit a whole bio at once as there
4180 * may not be enough stripe_heads available.
4181 * We cannot pre-allocate enough stripe_heads as we may need
4182 * more than exist in the cache (if we allow ever large chunks).
4183 * So we do one stripe head at a time and record in
4184 * ->bi_hw_segments how many have been done.
4186 * We *know* that this entire raid_bio is in one chunk, so
4187 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
4189 struct stripe_head
*sh
;
4191 sector_t sector
, logical_sector
, last_sector
;
4196 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
4197 sector
= raid5_compute_sector(conf
, logical_sector
,
4199 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
4201 for (; logical_sector
< last_sector
;
4202 logical_sector
+= STRIPE_SECTORS
,
4203 sector
+= STRIPE_SECTORS
,
4206 if (scnt
< raid5_bi_hw_segments(raid_bio
))
4207 /* already done this stripe */
4210 sh
= get_active_stripe(conf
, sector
, 0, 1, 0);
4213 /* failed to get a stripe - must wait */
4214 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4215 conf
->retry_read_aligned
= raid_bio
;
4219 set_bit(R5_ReadError
, &sh
->dev
[dd_idx
].flags
);
4220 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
4222 raid5_set_bi_hw_segments(raid_bio
, scnt
);
4223 conf
->retry_read_aligned
= raid_bio
;
4231 spin_lock_irq(&conf
->device_lock
);
4232 remaining
= raid5_dec_bi_phys_segments(raid_bio
);
4233 spin_unlock_irq(&conf
->device_lock
);
4235 bio_endio(raid_bio
, 0);
4236 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
4237 wake_up(&conf
->wait_for_stripe
);
4243 * This is our raid5 kernel thread.
4245 * We scan the hash table for stripes which can be handled now.
4246 * During the scan, completed stripes are saved for us by the interrupt
4247 * handler, so that they will not have to wait for our next wakeup.
4249 static void raid5d(struct mddev
*mddev
)
4251 struct stripe_head
*sh
;
4252 struct r5conf
*conf
= mddev
->private;
4254 struct blk_plug plug
;
4256 pr_debug("+++ raid5d active\n");
4258 md_check_recovery(mddev
);
4260 blk_start_plug(&plug
);
4262 spin_lock_irq(&conf
->device_lock
);
4266 if (atomic_read(&mddev
->plug_cnt
) == 0 &&
4267 !list_empty(&conf
->bitmap_list
)) {
4268 /* Now is a good time to flush some bitmap updates */
4270 spin_unlock_irq(&conf
->device_lock
);
4271 bitmap_unplug(mddev
->bitmap
);
4272 spin_lock_irq(&conf
->device_lock
);
4273 conf
->seq_write
= conf
->seq_flush
;
4274 activate_bit_delay(conf
);
4276 if (atomic_read(&mddev
->plug_cnt
) == 0)
4277 raid5_activate_delayed(conf
);
4279 while ((bio
= remove_bio_from_retry(conf
))) {
4281 spin_unlock_irq(&conf
->device_lock
);
4282 ok
= retry_aligned_read(conf
, bio
);
4283 spin_lock_irq(&conf
->device_lock
);
4289 sh
= __get_priority_stripe(conf
);
4293 spin_unlock_irq(&conf
->device_lock
);
4300 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
4301 md_check_recovery(mddev
);
4303 spin_lock_irq(&conf
->device_lock
);
4305 pr_debug("%d stripes handled\n", handled
);
4307 spin_unlock_irq(&conf
->device_lock
);
4309 async_tx_issue_pending_all();
4310 blk_finish_plug(&plug
);
4312 pr_debug("--- raid5d inactive\n");
4316 raid5_show_stripe_cache_size(struct mddev
*mddev
, char *page
)
4318 struct r5conf
*conf
= mddev
->private;
4320 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
4326 raid5_set_cache_size(struct mddev
*mddev
, int size
)
4328 struct r5conf
*conf
= mddev
->private;
4331 if (size
<= 16 || size
> 32768)
4333 while (size
< conf
->max_nr_stripes
) {
4334 if (drop_one_stripe(conf
))
4335 conf
->max_nr_stripes
--;
4339 err
= md_allow_write(mddev
);
4342 while (size
> conf
->max_nr_stripes
) {
4343 if (grow_one_stripe(conf
))
4344 conf
->max_nr_stripes
++;
4349 EXPORT_SYMBOL(raid5_set_cache_size
);
4352 raid5_store_stripe_cache_size(struct mddev
*mddev
, const char *page
, size_t len
)
4354 struct r5conf
*conf
= mddev
->private;
4358 if (len
>= PAGE_SIZE
)
4363 if (strict_strtoul(page
, 10, &new))
4365 err
= raid5_set_cache_size(mddev
, new);
4371 static struct md_sysfs_entry
4372 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
4373 raid5_show_stripe_cache_size
,
4374 raid5_store_stripe_cache_size
);
4377 raid5_show_preread_threshold(struct mddev
*mddev
, char *page
)
4379 struct r5conf
*conf
= mddev
->private;
4381 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
4387 raid5_store_preread_threshold(struct mddev
*mddev
, const char *page
, size_t len
)
4389 struct r5conf
*conf
= mddev
->private;
4391 if (len
>= PAGE_SIZE
)
4396 if (strict_strtoul(page
, 10, &new))
4398 if (new > conf
->max_nr_stripes
)
4400 conf
->bypass_threshold
= new;
4404 static struct md_sysfs_entry
4405 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
4407 raid5_show_preread_threshold
,
4408 raid5_store_preread_threshold
);
4411 stripe_cache_active_show(struct mddev
*mddev
, char *page
)
4413 struct r5conf
*conf
= mddev
->private;
4415 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
4420 static struct md_sysfs_entry
4421 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
4423 static struct attribute
*raid5_attrs
[] = {
4424 &raid5_stripecache_size
.attr
,
4425 &raid5_stripecache_active
.attr
,
4426 &raid5_preread_bypass_threshold
.attr
,
4429 static struct attribute_group raid5_attrs_group
= {
4431 .attrs
= raid5_attrs
,
4435 raid5_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
4437 struct r5conf
*conf
= mddev
->private;
4440 sectors
= mddev
->dev_sectors
;
4442 /* size is defined by the smallest of previous and new size */
4443 raid_disks
= min(conf
->raid_disks
, conf
->previous_raid_disks
);
4445 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
4446 sectors
&= ~((sector_t
)mddev
->new_chunk_sectors
- 1);
4447 return sectors
* (raid_disks
- conf
->max_degraded
);
4450 static void raid5_free_percpu(struct r5conf
*conf
)
4452 struct raid5_percpu
*percpu
;
4459 for_each_possible_cpu(cpu
) {
4460 percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4461 safe_put_page(percpu
->spare_page
);
4462 kfree(percpu
->scribble
);
4464 #ifdef CONFIG_HOTPLUG_CPU
4465 unregister_cpu_notifier(&conf
->cpu_notify
);
4469 free_percpu(conf
->percpu
);
4472 static void free_conf(struct r5conf
*conf
)
4474 shrink_stripes(conf
);
4475 raid5_free_percpu(conf
);
4477 kfree(conf
->stripe_hashtbl
);
4481 #ifdef CONFIG_HOTPLUG_CPU
4482 static int raid456_cpu_notify(struct notifier_block
*nfb
, unsigned long action
,
4485 struct r5conf
*conf
= container_of(nfb
, struct r5conf
, cpu_notify
);
4486 long cpu
= (long)hcpu
;
4487 struct raid5_percpu
*percpu
= per_cpu_ptr(conf
->percpu
, cpu
);
4490 case CPU_UP_PREPARE
:
4491 case CPU_UP_PREPARE_FROZEN
:
4492 if (conf
->level
== 6 && !percpu
->spare_page
)
4493 percpu
->spare_page
= alloc_page(GFP_KERNEL
);
4494 if (!percpu
->scribble
)
4495 percpu
->scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4497 if (!percpu
->scribble
||
4498 (conf
->level
== 6 && !percpu
->spare_page
)) {
4499 safe_put_page(percpu
->spare_page
);
4500 kfree(percpu
->scribble
);
4501 pr_err("%s: failed memory allocation for cpu%ld\n",
4503 return notifier_from_errno(-ENOMEM
);
4507 case CPU_DEAD_FROZEN
:
4508 safe_put_page(percpu
->spare_page
);
4509 kfree(percpu
->scribble
);
4510 percpu
->spare_page
= NULL
;
4511 percpu
->scribble
= NULL
;
4520 static int raid5_alloc_percpu(struct r5conf
*conf
)
4523 struct page
*spare_page
;
4524 struct raid5_percpu __percpu
*allcpus
;
4528 allcpus
= alloc_percpu(struct raid5_percpu
);
4531 conf
->percpu
= allcpus
;
4535 for_each_present_cpu(cpu
) {
4536 if (conf
->level
== 6) {
4537 spare_page
= alloc_page(GFP_KERNEL
);
4542 per_cpu_ptr(conf
->percpu
, cpu
)->spare_page
= spare_page
;
4544 scribble
= kmalloc(conf
->scribble_len
, GFP_KERNEL
);
4549 per_cpu_ptr(conf
->percpu
, cpu
)->scribble
= scribble
;
4551 #ifdef CONFIG_HOTPLUG_CPU
4552 conf
->cpu_notify
.notifier_call
= raid456_cpu_notify
;
4553 conf
->cpu_notify
.priority
= 0;
4555 err
= register_cpu_notifier(&conf
->cpu_notify
);
4562 static struct r5conf
*setup_conf(struct mddev
*mddev
)
4564 struct r5conf
*conf
;
4565 int raid_disk
, memory
, max_disks
;
4566 struct md_rdev
*rdev
;
4567 struct disk_info
*disk
;
4569 if (mddev
->new_level
!= 5
4570 && mddev
->new_level
!= 4
4571 && mddev
->new_level
!= 6) {
4572 printk(KERN_ERR
"md/raid:%s: raid level not set to 4/5/6 (%d)\n",
4573 mdname(mddev
), mddev
->new_level
);
4574 return ERR_PTR(-EIO
);
4576 if ((mddev
->new_level
== 5
4577 && !algorithm_valid_raid5(mddev
->new_layout
)) ||
4578 (mddev
->new_level
== 6
4579 && !algorithm_valid_raid6(mddev
->new_layout
))) {
4580 printk(KERN_ERR
"md/raid:%s: layout %d not supported\n",
4581 mdname(mddev
), mddev
->new_layout
);
4582 return ERR_PTR(-EIO
);
4584 if (mddev
->new_level
== 6 && mddev
->raid_disks
< 4) {
4585 printk(KERN_ERR
"md/raid:%s: not enough configured devices (%d, minimum 4)\n",
4586 mdname(mddev
), mddev
->raid_disks
);
4587 return ERR_PTR(-EINVAL
);
4590 if (!mddev
->new_chunk_sectors
||
4591 (mddev
->new_chunk_sectors
<< 9) % PAGE_SIZE
||
4592 !is_power_of_2(mddev
->new_chunk_sectors
)) {
4593 printk(KERN_ERR
"md/raid:%s: invalid chunk size %d\n",
4594 mdname(mddev
), mddev
->new_chunk_sectors
<< 9);
4595 return ERR_PTR(-EINVAL
);
4598 conf
= kzalloc(sizeof(struct r5conf
), GFP_KERNEL
);
4601 spin_lock_init(&conf
->device_lock
);
4602 init_waitqueue_head(&conf
->wait_for_stripe
);
4603 init_waitqueue_head(&conf
->wait_for_overlap
);
4604 INIT_LIST_HEAD(&conf
->handle_list
);
4605 INIT_LIST_HEAD(&conf
->hold_list
);
4606 INIT_LIST_HEAD(&conf
->delayed_list
);
4607 INIT_LIST_HEAD(&conf
->bitmap_list
);
4608 INIT_LIST_HEAD(&conf
->inactive_list
);
4609 atomic_set(&conf
->active_stripes
, 0);
4610 atomic_set(&conf
->preread_active_stripes
, 0);
4611 atomic_set(&conf
->active_aligned_reads
, 0);
4612 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4613 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
4615 conf
->raid_disks
= mddev
->raid_disks
;
4616 if (mddev
->reshape_position
== MaxSector
)
4617 conf
->previous_raid_disks
= mddev
->raid_disks
;
4619 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4620 max_disks
= max(conf
->raid_disks
, conf
->previous_raid_disks
);
4621 conf
->scribble_len
= scribble_len(max_disks
);
4623 conf
->disks
= kzalloc(max_disks
* sizeof(struct disk_info
),
4628 conf
->mddev
= mddev
;
4630 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4633 conf
->level
= mddev
->new_level
;
4634 if (raid5_alloc_percpu(conf
) != 0)
4637 pr_debug("raid456: run(%s) called.\n", mdname(mddev
));
4639 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4640 raid_disk
= rdev
->raid_disk
;
4641 if (raid_disk
>= max_disks
4644 disk
= conf
->disks
+ raid_disk
;
4648 if (test_bit(In_sync
, &rdev
->flags
)) {
4649 char b
[BDEVNAME_SIZE
];
4650 printk(KERN_INFO
"md/raid:%s: device %s operational as raid"
4652 mdname(mddev
), bdevname(rdev
->bdev
, b
), raid_disk
);
4653 } else if (rdev
->saved_raid_disk
!= raid_disk
)
4654 /* Cannot rely on bitmap to complete recovery */
4658 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
4659 conf
->level
= mddev
->new_level
;
4660 if (conf
->level
== 6)
4661 conf
->max_degraded
= 2;
4663 conf
->max_degraded
= 1;
4664 conf
->algorithm
= mddev
->new_layout
;
4665 conf
->max_nr_stripes
= NR_STRIPES
;
4666 conf
->reshape_progress
= mddev
->reshape_position
;
4667 if (conf
->reshape_progress
!= MaxSector
) {
4668 conf
->prev_chunk_sectors
= mddev
->chunk_sectors
;
4669 conf
->prev_algo
= mddev
->layout
;
4672 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4673 max_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4674 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4676 "md/raid:%s: couldn't allocate %dkB for buffers\n",
4677 mdname(mddev
), memory
);
4680 printk(KERN_INFO
"md/raid:%s: allocated %dkB\n",
4681 mdname(mddev
), memory
);
4683 conf
->thread
= md_register_thread(raid5d
, mddev
, NULL
);
4684 if (!conf
->thread
) {
4686 "md/raid:%s: couldn't allocate thread.\n",
4696 return ERR_PTR(-EIO
);
4698 return ERR_PTR(-ENOMEM
);
4702 static int only_parity(int raid_disk
, int algo
, int raid_disks
, int max_degraded
)
4705 case ALGORITHM_PARITY_0
:
4706 if (raid_disk
< max_degraded
)
4709 case ALGORITHM_PARITY_N
:
4710 if (raid_disk
>= raid_disks
- max_degraded
)
4713 case ALGORITHM_PARITY_0_6
:
4714 if (raid_disk
== 0 ||
4715 raid_disk
== raid_disks
- 1)
4718 case ALGORITHM_LEFT_ASYMMETRIC_6
:
4719 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
4720 case ALGORITHM_LEFT_SYMMETRIC_6
:
4721 case ALGORITHM_RIGHT_SYMMETRIC_6
:
4722 if (raid_disk
== raid_disks
- 1)
4728 static int run(struct mddev
*mddev
)
4730 struct r5conf
*conf
;
4731 int working_disks
= 0;
4732 int dirty_parity_disks
= 0;
4733 struct md_rdev
*rdev
;
4734 sector_t reshape_offset
= 0;
4736 if (mddev
->recovery_cp
!= MaxSector
)
4737 printk(KERN_NOTICE
"md/raid:%s: not clean"
4738 " -- starting background reconstruction\n",
4740 if (mddev
->reshape_position
!= MaxSector
) {
4741 /* Check that we can continue the reshape.
4742 * Currently only disks can change, it must
4743 * increase, and we must be past the point where
4744 * a stripe over-writes itself
4746 sector_t here_new
, here_old
;
4748 int max_degraded
= (mddev
->level
== 6 ? 2 : 1);
4750 if (mddev
->new_level
!= mddev
->level
) {
4751 printk(KERN_ERR
"md/raid:%s: unsupported reshape "
4752 "required - aborting.\n",
4756 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4757 /* reshape_position must be on a new-stripe boundary, and one
4758 * further up in new geometry must map after here in old
4761 here_new
= mddev
->reshape_position
;
4762 if (sector_div(here_new
, mddev
->new_chunk_sectors
*
4763 (mddev
->raid_disks
- max_degraded
))) {
4764 printk(KERN_ERR
"md/raid:%s: reshape_position not "
4765 "on a stripe boundary\n", mdname(mddev
));
4768 reshape_offset
= here_new
* mddev
->new_chunk_sectors
;
4769 /* here_new is the stripe we will write to */
4770 here_old
= mddev
->reshape_position
;
4771 sector_div(here_old
, mddev
->chunk_sectors
*
4772 (old_disks
-max_degraded
));
4773 /* here_old is the first stripe that we might need to read
4775 if (mddev
->delta_disks
== 0) {
4776 /* We cannot be sure it is safe to start an in-place
4777 * reshape. It is only safe if user-space if monitoring
4778 * and taking constant backups.
4779 * mdadm always starts a situation like this in
4780 * readonly mode so it can take control before
4781 * allowing any writes. So just check for that.
4783 if ((here_new
* mddev
->new_chunk_sectors
!=
4784 here_old
* mddev
->chunk_sectors
) ||
4786 printk(KERN_ERR
"md/raid:%s: in-place reshape must be started"
4787 " in read-only mode - aborting\n",
4791 } else if (mddev
->delta_disks
< 0
4792 ? (here_new
* mddev
->new_chunk_sectors
<=
4793 here_old
* mddev
->chunk_sectors
)
4794 : (here_new
* mddev
->new_chunk_sectors
>=
4795 here_old
* mddev
->chunk_sectors
)) {
4796 /* Reading from the same stripe as writing to - bad */
4797 printk(KERN_ERR
"md/raid:%s: reshape_position too early for "
4798 "auto-recovery - aborting.\n",
4802 printk(KERN_INFO
"md/raid:%s: reshape will continue\n",
4804 /* OK, we should be able to continue; */
4806 BUG_ON(mddev
->level
!= mddev
->new_level
);
4807 BUG_ON(mddev
->layout
!= mddev
->new_layout
);
4808 BUG_ON(mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
);
4809 BUG_ON(mddev
->delta_disks
!= 0);
4812 if (mddev
->private == NULL
)
4813 conf
= setup_conf(mddev
);
4815 conf
= mddev
->private;
4818 return PTR_ERR(conf
);
4820 mddev
->thread
= conf
->thread
;
4821 conf
->thread
= NULL
;
4822 mddev
->private = conf
;
4825 * 0 for a fully functional array, 1 or 2 for a degraded array.
4827 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4828 if (rdev
->raid_disk
< 0)
4830 if (test_bit(In_sync
, &rdev
->flags
)) {
4834 /* This disc is not fully in-sync. However if it
4835 * just stored parity (beyond the recovery_offset),
4836 * when we don't need to be concerned about the
4837 * array being dirty.
4838 * When reshape goes 'backwards', we never have
4839 * partially completed devices, so we only need
4840 * to worry about reshape going forwards.
4842 /* Hack because v0.91 doesn't store recovery_offset properly. */
4843 if (mddev
->major_version
== 0 &&
4844 mddev
->minor_version
> 90)
4845 rdev
->recovery_offset
= reshape_offset
;
4847 if (rdev
->recovery_offset
< reshape_offset
) {
4848 /* We need to check old and new layout */
4849 if (!only_parity(rdev
->raid_disk
,
4852 conf
->max_degraded
))
4855 if (!only_parity(rdev
->raid_disk
,
4857 conf
->previous_raid_disks
,
4858 conf
->max_degraded
))
4860 dirty_parity_disks
++;
4863 mddev
->degraded
= calc_degraded(conf
);
4865 if (has_failed(conf
)) {
4866 printk(KERN_ERR
"md/raid:%s: not enough operational devices"
4867 " (%d/%d failed)\n",
4868 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
4872 /* device size must be a multiple of chunk size */
4873 mddev
->dev_sectors
&= ~(mddev
->chunk_sectors
- 1);
4874 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
4876 if (mddev
->degraded
> dirty_parity_disks
&&
4877 mddev
->recovery_cp
!= MaxSector
) {
4878 if (mddev
->ok_start_degraded
)
4880 "md/raid:%s: starting dirty degraded array"
4881 " - data corruption possible.\n",
4885 "md/raid:%s: cannot start dirty degraded array.\n",
4891 if (mddev
->degraded
== 0)
4892 printk(KERN_INFO
"md/raid:%s: raid level %d active with %d out of %d"
4893 " devices, algorithm %d\n", mdname(mddev
), conf
->level
,
4894 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
4897 printk(KERN_ALERT
"md/raid:%s: raid level %d active with %d"
4898 " out of %d devices, algorithm %d\n",
4899 mdname(mddev
), conf
->level
,
4900 mddev
->raid_disks
- mddev
->degraded
,
4901 mddev
->raid_disks
, mddev
->new_layout
);
4903 print_raid5_conf(conf
);
4905 if (conf
->reshape_progress
!= MaxSector
) {
4906 conf
->reshape_safe
= conf
->reshape_progress
;
4907 atomic_set(&conf
->reshape_stripes
, 0);
4908 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
4909 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
4910 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
4911 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
4912 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
4917 /* Ok, everything is just fine now */
4918 if (mddev
->to_remove
== &raid5_attrs_group
)
4919 mddev
->to_remove
= NULL
;
4920 else if (mddev
->kobj
.sd
&&
4921 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
4923 "raid5: failed to create sysfs attributes for %s\n",
4925 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
4929 /* read-ahead size must cover two whole stripes, which
4930 * is 2 * (datadisks) * chunksize where 'n' is the
4931 * number of raid devices
4933 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
4934 int stripe
= data_disks
*
4935 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
4936 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
4937 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
4939 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
4941 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
4942 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
4944 chunk_size
= mddev
->chunk_sectors
<< 9;
4945 blk_queue_io_min(mddev
->queue
, chunk_size
);
4946 blk_queue_io_opt(mddev
->queue
, chunk_size
*
4947 (conf
->raid_disks
- conf
->max_degraded
));
4949 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
4950 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
4951 rdev
->data_offset
<< 9);
4956 md_unregister_thread(&mddev
->thread
);
4957 print_raid5_conf(conf
);
4959 mddev
->private = NULL
;
4960 printk(KERN_ALERT
"md/raid:%s: failed to run raid set.\n", mdname(mddev
));
4964 static int stop(struct mddev
*mddev
)
4966 struct r5conf
*conf
= mddev
->private;
4968 md_unregister_thread(&mddev
->thread
);
4970 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
4972 mddev
->private = NULL
;
4973 mddev
->to_remove
= &raid5_attrs_group
;
4977 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
4979 struct r5conf
*conf
= mddev
->private;
4982 seq_printf(seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
,
4983 mddev
->chunk_sectors
/ 2, mddev
->layout
);
4984 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
4985 for (i
= 0; i
< conf
->raid_disks
; i
++)
4986 seq_printf (seq
, "%s",
4987 conf
->disks
[i
].rdev
&&
4988 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
4989 seq_printf (seq
, "]");
4992 static void print_raid5_conf (struct r5conf
*conf
)
4995 struct disk_info
*tmp
;
4997 printk(KERN_DEBUG
"RAID conf printout:\n");
4999 printk("(conf==NULL)\n");
5002 printk(KERN_DEBUG
" --- level:%d rd:%d wd:%d\n", conf
->level
,
5004 conf
->raid_disks
- conf
->mddev
->degraded
);
5006 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5007 char b
[BDEVNAME_SIZE
];
5008 tmp
= conf
->disks
+ i
;
5010 printk(KERN_DEBUG
" disk %d, o:%d, dev:%s\n",
5011 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
5012 bdevname(tmp
->rdev
->bdev
, b
));
5016 static int raid5_spare_active(struct mddev
*mddev
)
5019 struct r5conf
*conf
= mddev
->private;
5020 struct disk_info
*tmp
;
5022 unsigned long flags
;
5024 for (i
= 0; i
< conf
->raid_disks
; i
++) {
5025 tmp
= conf
->disks
+ i
;
5027 && tmp
->rdev
->recovery_offset
== MaxSector
5028 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
5029 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
5031 sysfs_notify_dirent_safe(tmp
->rdev
->sysfs_state
);
5034 spin_lock_irqsave(&conf
->device_lock
, flags
);
5035 mddev
->degraded
= calc_degraded(conf
);
5036 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5037 print_raid5_conf(conf
);
5041 static int raid5_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5043 struct r5conf
*conf
= mddev
->private;
5045 int number
= rdev
->raid_disk
;
5046 struct disk_info
*p
= conf
->disks
+ number
;
5048 print_raid5_conf(conf
);
5049 if (rdev
== p
->rdev
) {
5050 if (number
>= conf
->raid_disks
&&
5051 conf
->reshape_progress
== MaxSector
)
5052 clear_bit(In_sync
, &rdev
->flags
);
5054 if (test_bit(In_sync
, &rdev
->flags
) ||
5055 atomic_read(&rdev
->nr_pending
)) {
5059 /* Only remove non-faulty devices if recovery
5062 if (!test_bit(Faulty
, &rdev
->flags
) &&
5063 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
5064 !has_failed(conf
) &&
5065 number
< conf
->raid_disks
) {
5071 if (atomic_read(&rdev
->nr_pending
)) {
5072 /* lost the race, try later */
5079 print_raid5_conf(conf
);
5083 static int raid5_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
5085 struct r5conf
*conf
= mddev
->private;
5088 struct disk_info
*p
;
5090 int last
= conf
->raid_disks
- 1;
5092 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
5095 if (has_failed(conf
))
5096 /* no point adding a device */
5099 if (rdev
->raid_disk
>= 0)
5100 first
= last
= rdev
->raid_disk
;
5103 * find the disk ... but prefer rdev->saved_raid_disk
5106 if (rdev
->saved_raid_disk
>= 0 &&
5107 rdev
->saved_raid_disk
>= first
&&
5108 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
5109 disk
= rdev
->saved_raid_disk
;
5112 for ( ; disk
<= last
; disk
++)
5113 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
5114 clear_bit(In_sync
, &rdev
->flags
);
5115 rdev
->raid_disk
= disk
;
5117 if (rdev
->saved_raid_disk
!= disk
)
5119 rcu_assign_pointer(p
->rdev
, rdev
);
5122 print_raid5_conf(conf
);
5126 static int raid5_resize(struct mddev
*mddev
, sector_t sectors
)
5128 /* no resync is happening, and there is enough space
5129 * on all devices, so we can resize.
5130 * We need to make sure resync covers any new space.
5131 * If the array is shrinking we should possibly wait until
5132 * any io in the removed space completes, but it hardly seems
5135 sectors
&= ~((sector_t
)mddev
->chunk_sectors
- 1);
5136 md_set_array_sectors(mddev
, raid5_size(mddev
, sectors
,
5137 mddev
->raid_disks
));
5138 if (mddev
->array_sectors
>
5139 raid5_size(mddev
, sectors
, mddev
->raid_disks
))
5141 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5142 revalidate_disk(mddev
->gendisk
);
5143 if (sectors
> mddev
->dev_sectors
&&
5144 mddev
->recovery_cp
> mddev
->dev_sectors
) {
5145 mddev
->recovery_cp
= mddev
->dev_sectors
;
5146 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
5148 mddev
->dev_sectors
= sectors
;
5149 mddev
->resync_max_sectors
= sectors
;
5153 static int check_stripe_cache(struct mddev
*mddev
)
5155 /* Can only proceed if there are plenty of stripe_heads.
5156 * We need a minimum of one full stripe,, and for sensible progress
5157 * it is best to have about 4 times that.
5158 * If we require 4 times, then the default 256 4K stripe_heads will
5159 * allow for chunk sizes up to 256K, which is probably OK.
5160 * If the chunk size is greater, user-space should request more
5161 * stripe_heads first.
5163 struct r5conf
*conf
= mddev
->private;
5164 if (((mddev
->chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5165 > conf
->max_nr_stripes
||
5166 ((mddev
->new_chunk_sectors
<< 9) / STRIPE_SIZE
) * 4
5167 > conf
->max_nr_stripes
) {
5168 printk(KERN_WARNING
"md/raid:%s: reshape: not enough stripes. Needed %lu\n",
5170 ((max(mddev
->chunk_sectors
, mddev
->new_chunk_sectors
) << 9)
5177 static int check_reshape(struct mddev
*mddev
)
5179 struct r5conf
*conf
= mddev
->private;
5181 if (mddev
->delta_disks
== 0 &&
5182 mddev
->new_layout
== mddev
->layout
&&
5183 mddev
->new_chunk_sectors
== mddev
->chunk_sectors
)
5184 return 0; /* nothing to do */
5186 /* Cannot grow a bitmap yet */
5188 if (has_failed(conf
))
5190 if (mddev
->delta_disks
< 0) {
5191 /* We might be able to shrink, but the devices must
5192 * be made bigger first.
5193 * For raid6, 4 is the minimum size.
5194 * Otherwise 2 is the minimum
5197 if (mddev
->level
== 6)
5199 if (mddev
->raid_disks
+ mddev
->delta_disks
< min
)
5203 if (!check_stripe_cache(mddev
))
5206 return resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
5209 static int raid5_start_reshape(struct mddev
*mddev
)
5211 struct r5conf
*conf
= mddev
->private;
5212 struct md_rdev
*rdev
;
5214 unsigned long flags
;
5216 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
5219 if (!check_stripe_cache(mddev
))
5222 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5223 if (!test_bit(In_sync
, &rdev
->flags
)
5224 && !test_bit(Faulty
, &rdev
->flags
))
5227 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
5228 /* Not enough devices even to make a degraded array
5233 /* Refuse to reduce size of the array. Any reductions in
5234 * array size must be through explicit setting of array_size
5237 if (raid5_size(mddev
, 0, conf
->raid_disks
+ mddev
->delta_disks
)
5238 < mddev
->array_sectors
) {
5239 printk(KERN_ERR
"md/raid:%s: array size must be reduced "
5240 "before number of disks\n", mdname(mddev
));
5244 atomic_set(&conf
->reshape_stripes
, 0);
5245 spin_lock_irq(&conf
->device_lock
);
5246 conf
->previous_raid_disks
= conf
->raid_disks
;
5247 conf
->raid_disks
+= mddev
->delta_disks
;
5248 conf
->prev_chunk_sectors
= conf
->chunk_sectors
;
5249 conf
->chunk_sectors
= mddev
->new_chunk_sectors
;
5250 conf
->prev_algo
= conf
->algorithm
;
5251 conf
->algorithm
= mddev
->new_layout
;
5252 if (mddev
->delta_disks
< 0)
5253 conf
->reshape_progress
= raid5_size(mddev
, 0, 0);
5255 conf
->reshape_progress
= 0;
5256 conf
->reshape_safe
= conf
->reshape_progress
;
5258 spin_unlock_irq(&conf
->device_lock
);
5260 /* Add some new drives, as many as will fit.
5261 * We know there are enough to make the newly sized array work.
5262 * Don't add devices if we are reducing the number of
5263 * devices in the array. This is because it is not possible
5264 * to correctly record the "partially reconstructed" state of
5265 * such devices during the reshape and confusion could result.
5267 if (mddev
->delta_disks
>= 0) {
5268 int added_devices
= 0;
5269 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
5270 if (rdev
->raid_disk
< 0 &&
5271 !test_bit(Faulty
, &rdev
->flags
)) {
5272 if (raid5_add_disk(mddev
, rdev
) == 0) {
5274 >= conf
->previous_raid_disks
) {
5275 set_bit(In_sync
, &rdev
->flags
);
5278 rdev
->recovery_offset
= 0;
5280 if (sysfs_link_rdev(mddev
, rdev
))
5281 /* Failure here is OK */;
5283 } else if (rdev
->raid_disk
>= conf
->previous_raid_disks
5284 && !test_bit(Faulty
, &rdev
->flags
)) {
5285 /* This is a spare that was manually added */
5286 set_bit(In_sync
, &rdev
->flags
);
5290 /* When a reshape changes the number of devices,
5291 * ->degraded is measured against the larger of the
5292 * pre and post number of devices.
5294 spin_lock_irqsave(&conf
->device_lock
, flags
);
5295 mddev
->degraded
= calc_degraded(conf
);
5296 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
5298 mddev
->raid_disks
= conf
->raid_disks
;
5299 mddev
->reshape_position
= conf
->reshape_progress
;
5300 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5302 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
5303 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
5304 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
5305 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
5306 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
5308 if (!mddev
->sync_thread
) {
5309 mddev
->recovery
= 0;
5310 spin_lock_irq(&conf
->device_lock
);
5311 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
5312 conf
->reshape_progress
= MaxSector
;
5313 spin_unlock_irq(&conf
->device_lock
);
5316 conf
->reshape_checkpoint
= jiffies
;
5317 md_wakeup_thread(mddev
->sync_thread
);
5318 md_new_event(mddev
);
5322 /* This is called from the reshape thread and should make any
5323 * changes needed in 'conf'
5325 static void end_reshape(struct r5conf
*conf
)
5328 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
5330 spin_lock_irq(&conf
->device_lock
);
5331 conf
->previous_raid_disks
= conf
->raid_disks
;
5332 conf
->reshape_progress
= MaxSector
;
5333 spin_unlock_irq(&conf
->device_lock
);
5334 wake_up(&conf
->wait_for_overlap
);
5336 /* read-ahead size must cover two whole stripes, which is
5337 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
5339 if (conf
->mddev
->queue
) {
5340 int data_disks
= conf
->raid_disks
- conf
->max_degraded
;
5341 int stripe
= data_disks
* ((conf
->chunk_sectors
<< 9)
5343 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
5344 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
5349 /* This is called from the raid5d thread with mddev_lock held.
5350 * It makes config changes to the device.
5352 static void raid5_finish_reshape(struct mddev
*mddev
)
5354 struct r5conf
*conf
= mddev
->private;
5356 if (!test_bit(MD_RECOVERY_INTR
, &mddev
->recovery
)) {
5358 if (mddev
->delta_disks
> 0) {
5359 md_set_array_sectors(mddev
, raid5_size(mddev
, 0, 0));
5360 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
5361 revalidate_disk(mddev
->gendisk
);
5364 spin_lock_irq(&conf
->device_lock
);
5365 mddev
->degraded
= calc_degraded(conf
);
5366 spin_unlock_irq(&conf
->device_lock
);
5367 for (d
= conf
->raid_disks
;
5368 d
< conf
->raid_disks
- mddev
->delta_disks
;
5370 struct md_rdev
*rdev
= conf
->disks
[d
].rdev
;
5372 raid5_remove_disk(mddev
, rdev
) == 0) {
5373 sysfs_unlink_rdev(mddev
, rdev
);
5374 rdev
->raid_disk
= -1;
5378 mddev
->layout
= conf
->algorithm
;
5379 mddev
->chunk_sectors
= conf
->chunk_sectors
;
5380 mddev
->reshape_position
= MaxSector
;
5381 mddev
->delta_disks
= 0;
5385 static void raid5_quiesce(struct mddev
*mddev
, int state
)
5387 struct r5conf
*conf
= mddev
->private;
5390 case 2: /* resume for a suspend */
5391 wake_up(&conf
->wait_for_overlap
);
5394 case 1: /* stop all writes */
5395 spin_lock_irq(&conf
->device_lock
);
5396 /* '2' tells resync/reshape to pause so that all
5397 * active stripes can drain
5400 wait_event_lock_irq(conf
->wait_for_stripe
,
5401 atomic_read(&conf
->active_stripes
) == 0 &&
5402 atomic_read(&conf
->active_aligned_reads
) == 0,
5403 conf
->device_lock
, /* nothing */);
5405 spin_unlock_irq(&conf
->device_lock
);
5406 /* allow reshape to continue */
5407 wake_up(&conf
->wait_for_overlap
);
5410 case 0: /* re-enable writes */
5411 spin_lock_irq(&conf
->device_lock
);
5413 wake_up(&conf
->wait_for_stripe
);
5414 wake_up(&conf
->wait_for_overlap
);
5415 spin_unlock_irq(&conf
->device_lock
);
5421 static void *raid45_takeover_raid0(struct mddev
*mddev
, int level
)
5423 struct r0conf
*raid0_conf
= mddev
->private;
5426 /* for raid0 takeover only one zone is supported */
5427 if (raid0_conf
->nr_strip_zones
> 1) {
5428 printk(KERN_ERR
"md/raid:%s: cannot takeover raid0 with more than one zone.\n",
5430 return ERR_PTR(-EINVAL
);
5433 sectors
= raid0_conf
->strip_zone
[0].zone_end
;
5434 sector_div(sectors
, raid0_conf
->strip_zone
[0].nb_dev
);
5435 mddev
->dev_sectors
= sectors
;
5436 mddev
->new_level
= level
;
5437 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5438 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
5439 mddev
->raid_disks
+= 1;
5440 mddev
->delta_disks
= 1;
5441 /* make sure it will be not marked as dirty */
5442 mddev
->recovery_cp
= MaxSector
;
5444 return setup_conf(mddev
);
5448 static void *raid5_takeover_raid1(struct mddev
*mddev
)
5452 if (mddev
->raid_disks
!= 2 ||
5453 mddev
->degraded
> 1)
5454 return ERR_PTR(-EINVAL
);
5456 /* Should check if there are write-behind devices? */
5458 chunksect
= 64*2; /* 64K by default */
5460 /* The array must be an exact multiple of chunksize */
5461 while (chunksect
&& (mddev
->array_sectors
& (chunksect
-1)))
5464 if ((chunksect
<<9) < STRIPE_SIZE
)
5465 /* array size does not allow a suitable chunk size */
5466 return ERR_PTR(-EINVAL
);
5468 mddev
->new_level
= 5;
5469 mddev
->new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5470 mddev
->new_chunk_sectors
= chunksect
;
5472 return setup_conf(mddev
);
5475 static void *raid5_takeover_raid6(struct mddev
*mddev
)
5479 switch (mddev
->layout
) {
5480 case ALGORITHM_LEFT_ASYMMETRIC_6
:
5481 new_layout
= ALGORITHM_LEFT_ASYMMETRIC
;
5483 case ALGORITHM_RIGHT_ASYMMETRIC_6
:
5484 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC
;
5486 case ALGORITHM_LEFT_SYMMETRIC_6
:
5487 new_layout
= ALGORITHM_LEFT_SYMMETRIC
;
5489 case ALGORITHM_RIGHT_SYMMETRIC_6
:
5490 new_layout
= ALGORITHM_RIGHT_SYMMETRIC
;
5492 case ALGORITHM_PARITY_0_6
:
5493 new_layout
= ALGORITHM_PARITY_0
;
5495 case ALGORITHM_PARITY_N
:
5496 new_layout
= ALGORITHM_PARITY_N
;
5499 return ERR_PTR(-EINVAL
);
5501 mddev
->new_level
= 5;
5502 mddev
->new_layout
= new_layout
;
5503 mddev
->delta_disks
= -1;
5504 mddev
->raid_disks
-= 1;
5505 return setup_conf(mddev
);
5509 static int raid5_check_reshape(struct mddev
*mddev
)
5511 /* For a 2-drive array, the layout and chunk size can be changed
5512 * immediately as not restriping is needed.
5513 * For larger arrays we record the new value - after validation
5514 * to be used by a reshape pass.
5516 struct r5conf
*conf
= mddev
->private;
5517 int new_chunk
= mddev
->new_chunk_sectors
;
5519 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid5(mddev
->new_layout
))
5521 if (new_chunk
> 0) {
5522 if (!is_power_of_2(new_chunk
))
5524 if (new_chunk
< (PAGE_SIZE
>>9))
5526 if (mddev
->array_sectors
& (new_chunk
-1))
5527 /* not factor of array size */
5531 /* They look valid */
5533 if (mddev
->raid_disks
== 2) {
5534 /* can make the change immediately */
5535 if (mddev
->new_layout
>= 0) {
5536 conf
->algorithm
= mddev
->new_layout
;
5537 mddev
->layout
= mddev
->new_layout
;
5539 if (new_chunk
> 0) {
5540 conf
->chunk_sectors
= new_chunk
;
5541 mddev
->chunk_sectors
= new_chunk
;
5543 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
5544 md_wakeup_thread(mddev
->thread
);
5546 return check_reshape(mddev
);
5549 static int raid6_check_reshape(struct mddev
*mddev
)
5551 int new_chunk
= mddev
->new_chunk_sectors
;
5553 if (mddev
->new_layout
>= 0 && !algorithm_valid_raid6(mddev
->new_layout
))
5555 if (new_chunk
> 0) {
5556 if (!is_power_of_2(new_chunk
))
5558 if (new_chunk
< (PAGE_SIZE
>> 9))
5560 if (mddev
->array_sectors
& (new_chunk
-1))
5561 /* not factor of array size */
5565 /* They look valid */
5566 return check_reshape(mddev
);
5569 static void *raid5_takeover(struct mddev
*mddev
)
5571 /* raid5 can take over:
5572 * raid0 - if there is only one strip zone - make it a raid4 layout
5573 * raid1 - if there are two drives. We need to know the chunk size
5574 * raid4 - trivial - just use a raid4 layout.
5575 * raid6 - Providing it is a *_6 layout
5577 if (mddev
->level
== 0)
5578 return raid45_takeover_raid0(mddev
, 5);
5579 if (mddev
->level
== 1)
5580 return raid5_takeover_raid1(mddev
);
5581 if (mddev
->level
== 4) {
5582 mddev
->new_layout
= ALGORITHM_PARITY_N
;
5583 mddev
->new_level
= 5;
5584 return setup_conf(mddev
);
5586 if (mddev
->level
== 6)
5587 return raid5_takeover_raid6(mddev
);
5589 return ERR_PTR(-EINVAL
);
5592 static void *raid4_takeover(struct mddev
*mddev
)
5594 /* raid4 can take over:
5595 * raid0 - if there is only one strip zone
5596 * raid5 - if layout is right
5598 if (mddev
->level
== 0)
5599 return raid45_takeover_raid0(mddev
, 4);
5600 if (mddev
->level
== 5 &&
5601 mddev
->layout
== ALGORITHM_PARITY_N
) {
5602 mddev
->new_layout
= 0;
5603 mddev
->new_level
= 4;
5604 return setup_conf(mddev
);
5606 return ERR_PTR(-EINVAL
);
5609 static struct md_personality raid5_personality
;
5611 static void *raid6_takeover(struct mddev
*mddev
)
5613 /* Currently can only take over a raid5. We map the
5614 * personality to an equivalent raid6 personality
5615 * with the Q block at the end.
5619 if (mddev
->pers
!= &raid5_personality
)
5620 return ERR_PTR(-EINVAL
);
5621 if (mddev
->degraded
> 1)
5622 return ERR_PTR(-EINVAL
);
5623 if (mddev
->raid_disks
> 253)
5624 return ERR_PTR(-EINVAL
);
5625 if (mddev
->raid_disks
< 3)
5626 return ERR_PTR(-EINVAL
);
5628 switch (mddev
->layout
) {
5629 case ALGORITHM_LEFT_ASYMMETRIC
:
5630 new_layout
= ALGORITHM_LEFT_ASYMMETRIC_6
;
5632 case ALGORITHM_RIGHT_ASYMMETRIC
:
5633 new_layout
= ALGORITHM_RIGHT_ASYMMETRIC_6
;
5635 case ALGORITHM_LEFT_SYMMETRIC
:
5636 new_layout
= ALGORITHM_LEFT_SYMMETRIC_6
;
5638 case ALGORITHM_RIGHT_SYMMETRIC
:
5639 new_layout
= ALGORITHM_RIGHT_SYMMETRIC_6
;
5641 case ALGORITHM_PARITY_0
:
5642 new_layout
= ALGORITHM_PARITY_0_6
;
5644 case ALGORITHM_PARITY_N
:
5645 new_layout
= ALGORITHM_PARITY_N
;
5648 return ERR_PTR(-EINVAL
);
5650 mddev
->new_level
= 6;
5651 mddev
->new_layout
= new_layout
;
5652 mddev
->delta_disks
= 1;
5653 mddev
->raid_disks
+= 1;
5654 return setup_conf(mddev
);
5658 static struct md_personality raid6_personality
=
5662 .owner
= THIS_MODULE
,
5663 .make_request
= make_request
,
5667 .error_handler
= error
,
5668 .hot_add_disk
= raid5_add_disk
,
5669 .hot_remove_disk
= raid5_remove_disk
,
5670 .spare_active
= raid5_spare_active
,
5671 .sync_request
= sync_request
,
5672 .resize
= raid5_resize
,
5674 .check_reshape
= raid6_check_reshape
,
5675 .start_reshape
= raid5_start_reshape
,
5676 .finish_reshape
= raid5_finish_reshape
,
5677 .quiesce
= raid5_quiesce
,
5678 .takeover
= raid6_takeover
,
5680 static struct md_personality raid5_personality
=
5684 .owner
= THIS_MODULE
,
5685 .make_request
= make_request
,
5689 .error_handler
= error
,
5690 .hot_add_disk
= raid5_add_disk
,
5691 .hot_remove_disk
= raid5_remove_disk
,
5692 .spare_active
= raid5_spare_active
,
5693 .sync_request
= sync_request
,
5694 .resize
= raid5_resize
,
5696 .check_reshape
= raid5_check_reshape
,
5697 .start_reshape
= raid5_start_reshape
,
5698 .finish_reshape
= raid5_finish_reshape
,
5699 .quiesce
= raid5_quiesce
,
5700 .takeover
= raid5_takeover
,
5703 static struct md_personality raid4_personality
=
5707 .owner
= THIS_MODULE
,
5708 .make_request
= make_request
,
5712 .error_handler
= error
,
5713 .hot_add_disk
= raid5_add_disk
,
5714 .hot_remove_disk
= raid5_remove_disk
,
5715 .spare_active
= raid5_spare_active
,
5716 .sync_request
= sync_request
,
5717 .resize
= raid5_resize
,
5719 .check_reshape
= raid5_check_reshape
,
5720 .start_reshape
= raid5_start_reshape
,
5721 .finish_reshape
= raid5_finish_reshape
,
5722 .quiesce
= raid5_quiesce
,
5723 .takeover
= raid4_takeover
,
5726 static int __init
raid5_init(void)
5728 register_md_personality(&raid6_personality
);
5729 register_md_personality(&raid5_personality
);
5730 register_md_personality(&raid4_personality
);
5734 static void raid5_exit(void)
5736 unregister_md_personality(&raid6_personality
);
5737 unregister_md_personality(&raid5_personality
);
5738 unregister_md_personality(&raid4_personality
);
5741 module_init(raid5_init
);
5742 module_exit(raid5_exit
);
5743 MODULE_LICENSE("GPL");
5744 MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
5745 MODULE_ALIAS("md-personality-4"); /* RAID5 */
5746 MODULE_ALIAS("md-raid5");
5747 MODULE_ALIAS("md-raid4");
5748 MODULE_ALIAS("md-level-5");
5749 MODULE_ALIAS("md-level-4");
5750 MODULE_ALIAS("md-personality-8"); /* RAID6 */
5751 MODULE_ALIAS("md-raid6");
5752 MODULE_ALIAS("md-level-6");
5754 /* This used to be two separate modules, they were: */
5755 MODULE_ALIAS("raid5");
5756 MODULE_ALIAS("raid6");