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->bm_write is the number of the last batch successfully written.
31 * conf->bm_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 bm_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/async_tx.h>
49 #include <linux/seq_file.h>
59 #define NR_STRIPES 256
60 #define STRIPE_SIZE PAGE_SIZE
61 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
62 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
63 #define IO_THRESHOLD 1
64 #define BYPASS_THRESHOLD 1
65 #define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
66 #define HASH_MASK (NR_HASH - 1)
68 #define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
70 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
71 * order without overlap. There may be several bio's per stripe+device, and
72 * a bio could span several devices.
73 * When walking this list for a particular stripe+device, we must never proceed
74 * beyond a bio that extends past this device, as the next bio might no longer
76 * This macro is used to determine the 'next' bio in the list, given the sector
77 * of the current stripe+device
79 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
81 * The following can be used to debug the driver
83 #define RAID5_PARANOIA 1
84 #if RAID5_PARANOIA && defined(CONFIG_SMP)
85 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
87 # define CHECK_DEVLOCK()
95 #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
97 #if !RAID6_USE_EMPTY_ZERO_PAGE
98 /* In .bss so it's zeroed */
99 const char raid6_empty_zero_page
[PAGE_SIZE
] __attribute__((aligned(256)));
103 * We maintain a biased count of active stripes in the bottom 16 bits of
104 * bi_phys_segments, and a count of processed stripes in the upper 16 bits
106 static inline int raid5_bi_phys_segments(struct bio
*bio
)
108 return bio
->bi_phys_segments
& 0xffff;
111 static inline int raid5_bi_hw_segments(struct bio
*bio
)
113 return (bio
->bi_phys_segments
>> 16) & 0xffff;
116 static inline int raid5_dec_bi_phys_segments(struct bio
*bio
)
118 --bio
->bi_phys_segments
;
119 return raid5_bi_phys_segments(bio
);
122 static inline int raid5_dec_bi_hw_segments(struct bio
*bio
)
124 unsigned short val
= raid5_bi_hw_segments(bio
);
127 bio
->bi_phys_segments
= (val
<< 16) | raid5_bi_phys_segments(bio
);
131 static inline void raid5_set_bi_hw_segments(struct bio
*bio
, unsigned int cnt
)
133 bio
->bi_phys_segments
= raid5_bi_phys_segments(bio
) || (cnt
<< 16);
136 static inline int raid6_next_disk(int disk
, int raid_disks
)
139 return (disk
< raid_disks
) ? disk
: 0;
142 static void return_io(struct bio
*return_bi
)
144 struct bio
*bi
= return_bi
;
147 return_bi
= bi
->bi_next
;
155 static void print_raid5_conf (raid5_conf_t
*conf
);
157 static int stripe_operations_active(struct stripe_head
*sh
)
159 return sh
->check_state
|| sh
->reconstruct_state
||
160 test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
) ||
161 test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
164 static void __release_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
)
166 if (atomic_dec_and_test(&sh
->count
)) {
167 BUG_ON(!list_empty(&sh
->lru
));
168 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
169 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
170 if (test_bit(STRIPE_DELAYED
, &sh
->state
)) {
171 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
172 blk_plug_device(conf
->mddev
->queue
);
173 } else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
174 sh
->bm_seq
- conf
->seq_write
> 0) {
175 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
176 blk_plug_device(conf
->mddev
->queue
);
178 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
179 list_add_tail(&sh
->lru
, &conf
->handle_list
);
181 md_wakeup_thread(conf
->mddev
->thread
);
183 BUG_ON(stripe_operations_active(sh
));
184 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
185 atomic_dec(&conf
->preread_active_stripes
);
186 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
187 md_wakeup_thread(conf
->mddev
->thread
);
189 atomic_dec(&conf
->active_stripes
);
190 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
191 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
192 wake_up(&conf
->wait_for_stripe
);
193 if (conf
->retry_read_aligned
)
194 md_wakeup_thread(conf
->mddev
->thread
);
199 static void release_stripe(struct stripe_head
*sh
)
201 raid5_conf_t
*conf
= sh
->raid_conf
;
204 spin_lock_irqsave(&conf
->device_lock
, flags
);
205 __release_stripe(conf
, sh
);
206 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
209 static inline void remove_hash(struct stripe_head
*sh
)
211 pr_debug("remove_hash(), stripe %llu\n",
212 (unsigned long long)sh
->sector
);
214 hlist_del_init(&sh
->hash
);
217 static inline void insert_hash(raid5_conf_t
*conf
, struct stripe_head
*sh
)
219 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
221 pr_debug("insert_hash(), stripe %llu\n",
222 (unsigned long long)sh
->sector
);
225 hlist_add_head(&sh
->hash
, hp
);
229 /* find an idle stripe, make sure it is unhashed, and return it. */
230 static struct stripe_head
*get_free_stripe(raid5_conf_t
*conf
)
232 struct stripe_head
*sh
= NULL
;
233 struct list_head
*first
;
236 if (list_empty(&conf
->inactive_list
))
238 first
= conf
->inactive_list
.next
;
239 sh
= list_entry(first
, struct stripe_head
, lru
);
240 list_del_init(first
);
242 atomic_inc(&conf
->active_stripes
);
247 static void shrink_buffers(struct stripe_head
*sh
, int num
)
252 for (i
=0; i
<num
; i
++) {
256 sh
->dev
[i
].page
= NULL
;
261 static int grow_buffers(struct stripe_head
*sh
, int num
)
265 for (i
=0; i
<num
; i
++) {
268 if (!(page
= alloc_page(GFP_KERNEL
))) {
271 sh
->dev
[i
].page
= page
;
276 static void raid5_build_block(struct stripe_head
*sh
, int i
);
277 static int stripe_to_pdidx(sector_t stripe
, raid5_conf_t
*conf
, int previous
);
279 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int previous
)
281 raid5_conf_t
*conf
= sh
->raid_conf
;
284 BUG_ON(atomic_read(&sh
->count
) != 0);
285 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
286 BUG_ON(stripe_operations_active(sh
));
289 pr_debug("init_stripe called, stripe %llu\n",
290 (unsigned long long)sh
->sector
);
294 sh
->disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
296 sh
->pd_idx
= stripe_to_pdidx(sector
, conf
, previous
);
300 for (i
= sh
->disks
; i
--; ) {
301 struct r5dev
*dev
= &sh
->dev
[i
];
303 if (dev
->toread
|| dev
->read
|| dev
->towrite
|| dev
->written
||
304 test_bit(R5_LOCKED
, &dev
->flags
)) {
305 printk(KERN_ERR
"sector=%llx i=%d %p %p %p %p %d\n",
306 (unsigned long long)sh
->sector
, i
, dev
->toread
,
307 dev
->read
, dev
->towrite
, dev
->written
,
308 test_bit(R5_LOCKED
, &dev
->flags
));
312 raid5_build_block(sh
, i
);
314 insert_hash(conf
, sh
);
317 static struct stripe_head
*__find_stripe(raid5_conf_t
*conf
, sector_t sector
, int disks
)
319 struct stripe_head
*sh
;
320 struct hlist_node
*hn
;
323 pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector
);
324 hlist_for_each_entry(sh
, hn
, stripe_hash(conf
, sector
), hash
)
325 if (sh
->sector
== sector
&& sh
->disks
== disks
)
327 pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector
);
331 static void unplug_slaves(mddev_t
*mddev
);
332 static void raid5_unplug_device(struct request_queue
*q
);
334 static struct stripe_head
*
335 get_active_stripe(raid5_conf_t
*conf
, sector_t sector
,
336 int previous
, int noblock
)
338 struct stripe_head
*sh
;
339 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
341 pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector
);
343 spin_lock_irq(&conf
->device_lock
);
346 wait_event_lock_irq(conf
->wait_for_stripe
,
348 conf
->device_lock
, /* nothing */);
349 sh
= __find_stripe(conf
, sector
, disks
);
351 if (!conf
->inactive_blocked
)
352 sh
= get_free_stripe(conf
);
353 if (noblock
&& sh
== NULL
)
356 conf
->inactive_blocked
= 1;
357 wait_event_lock_irq(conf
->wait_for_stripe
,
358 !list_empty(&conf
->inactive_list
) &&
359 (atomic_read(&conf
->active_stripes
)
360 < (conf
->max_nr_stripes
*3/4)
361 || !conf
->inactive_blocked
),
363 raid5_unplug_device(conf
->mddev
->queue
)
365 conf
->inactive_blocked
= 0;
367 init_stripe(sh
, sector
, previous
);
369 if (atomic_read(&sh
->count
)) {
370 BUG_ON(!list_empty(&sh
->lru
));
372 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
373 atomic_inc(&conf
->active_stripes
);
374 if (list_empty(&sh
->lru
) &&
375 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
377 list_del_init(&sh
->lru
);
380 } while (sh
== NULL
);
383 atomic_inc(&sh
->count
);
385 spin_unlock_irq(&conf
->device_lock
);
390 raid5_end_read_request(struct bio
*bi
, int error
);
392 raid5_end_write_request(struct bio
*bi
, int error
);
394 static void ops_run_io(struct stripe_head
*sh
, struct stripe_head_state
*s
)
396 raid5_conf_t
*conf
= sh
->raid_conf
;
397 int i
, disks
= sh
->disks
;
401 for (i
= disks
; i
--; ) {
405 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
407 else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
412 bi
= &sh
->dev
[i
].req
;
416 bi
->bi_end_io
= raid5_end_write_request
;
418 bi
->bi_end_io
= raid5_end_read_request
;
421 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
422 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
425 atomic_inc(&rdev
->nr_pending
);
429 if (s
->syncing
|| s
->expanding
|| s
->expanded
)
430 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
432 set_bit(STRIPE_IO_STARTED
, &sh
->state
);
434 bi
->bi_bdev
= rdev
->bdev
;
435 pr_debug("%s: for %llu schedule op %ld on disc %d\n",
436 __func__
, (unsigned long long)sh
->sector
,
438 atomic_inc(&sh
->count
);
439 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
440 bi
->bi_flags
= 1 << BIO_UPTODATE
;
444 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
445 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
446 bi
->bi_io_vec
[0].bv_offset
= 0;
447 bi
->bi_size
= STRIPE_SIZE
;
450 test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
451 atomic_add(STRIPE_SECTORS
,
452 &rdev
->corrected_errors
);
453 generic_make_request(bi
);
456 set_bit(STRIPE_DEGRADED
, &sh
->state
);
457 pr_debug("skip op %ld on disc %d for sector %llu\n",
458 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
459 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
460 set_bit(STRIPE_HANDLE
, &sh
->state
);
465 static struct dma_async_tx_descriptor
*
466 async_copy_data(int frombio
, struct bio
*bio
, struct page
*page
,
467 sector_t sector
, struct dma_async_tx_descriptor
*tx
)
470 struct page
*bio_page
;
474 if (bio
->bi_sector
>= sector
)
475 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
477 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
478 bio_for_each_segment(bvl
, bio
, i
) {
479 int len
= bio_iovec_idx(bio
, i
)->bv_len
;
483 if (page_offset
< 0) {
484 b_offset
= -page_offset
;
485 page_offset
+= b_offset
;
489 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
490 clen
= STRIPE_SIZE
- page_offset
;
495 b_offset
+= bio_iovec_idx(bio
, i
)->bv_offset
;
496 bio_page
= bio_iovec_idx(bio
, i
)->bv_page
;
498 tx
= async_memcpy(page
, bio_page
, page_offset
,
503 tx
= async_memcpy(bio_page
, page
, b_offset
,
508 if (clen
< len
) /* hit end of page */
516 static void ops_complete_biofill(void *stripe_head_ref
)
518 struct stripe_head
*sh
= stripe_head_ref
;
519 struct bio
*return_bi
= NULL
;
520 raid5_conf_t
*conf
= sh
->raid_conf
;
523 pr_debug("%s: stripe %llu\n", __func__
,
524 (unsigned long long)sh
->sector
);
526 /* clear completed biofills */
527 spin_lock_irq(&conf
->device_lock
);
528 for (i
= sh
->disks
; i
--; ) {
529 struct r5dev
*dev
= &sh
->dev
[i
];
531 /* acknowledge completion of a biofill operation */
532 /* and check if we need to reply to a read request,
533 * new R5_Wantfill requests are held off until
534 * !STRIPE_BIOFILL_RUN
536 if (test_and_clear_bit(R5_Wantfill
, &dev
->flags
)) {
537 struct bio
*rbi
, *rbi2
;
542 while (rbi
&& rbi
->bi_sector
<
543 dev
->sector
+ STRIPE_SECTORS
) {
544 rbi2
= r5_next_bio(rbi
, dev
->sector
);
545 if (!raid5_dec_bi_phys_segments(rbi
)) {
546 rbi
->bi_next
= return_bi
;
553 spin_unlock_irq(&conf
->device_lock
);
554 clear_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
556 return_io(return_bi
);
558 set_bit(STRIPE_HANDLE
, &sh
->state
);
562 static void ops_run_biofill(struct stripe_head
*sh
)
564 struct dma_async_tx_descriptor
*tx
= NULL
;
565 raid5_conf_t
*conf
= sh
->raid_conf
;
568 pr_debug("%s: stripe %llu\n", __func__
,
569 (unsigned long long)sh
->sector
);
571 for (i
= sh
->disks
; i
--; ) {
572 struct r5dev
*dev
= &sh
->dev
[i
];
573 if (test_bit(R5_Wantfill
, &dev
->flags
)) {
575 spin_lock_irq(&conf
->device_lock
);
576 dev
->read
= rbi
= dev
->toread
;
578 spin_unlock_irq(&conf
->device_lock
);
579 while (rbi
&& rbi
->bi_sector
<
580 dev
->sector
+ STRIPE_SECTORS
) {
581 tx
= async_copy_data(0, rbi
, dev
->page
,
583 rbi
= r5_next_bio(rbi
, dev
->sector
);
588 atomic_inc(&sh
->count
);
589 async_trigger_callback(ASYNC_TX_DEP_ACK
| ASYNC_TX_ACK
, tx
,
590 ops_complete_biofill
, sh
);
593 static void ops_complete_compute5(void *stripe_head_ref
)
595 struct stripe_head
*sh
= stripe_head_ref
;
596 int target
= sh
->ops
.target
;
597 struct r5dev
*tgt
= &sh
->dev
[target
];
599 pr_debug("%s: stripe %llu\n", __func__
,
600 (unsigned long long)sh
->sector
);
602 set_bit(R5_UPTODATE
, &tgt
->flags
);
603 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
604 clear_bit(R5_Wantcompute
, &tgt
->flags
);
605 clear_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
606 if (sh
->check_state
== check_state_compute_run
)
607 sh
->check_state
= check_state_compute_result
;
608 set_bit(STRIPE_HANDLE
, &sh
->state
);
612 static struct dma_async_tx_descriptor
*ops_run_compute5(struct stripe_head
*sh
)
614 /* kernel stack size limits the total number of disks */
615 int disks
= sh
->disks
;
616 struct page
*xor_srcs
[disks
];
617 int target
= sh
->ops
.target
;
618 struct r5dev
*tgt
= &sh
->dev
[target
];
619 struct page
*xor_dest
= tgt
->page
;
621 struct dma_async_tx_descriptor
*tx
;
624 pr_debug("%s: stripe %llu block: %d\n",
625 __func__
, (unsigned long long)sh
->sector
, target
);
626 BUG_ON(!test_bit(R5_Wantcompute
, &tgt
->flags
));
628 for (i
= disks
; i
--; )
630 xor_srcs
[count
++] = sh
->dev
[i
].page
;
632 atomic_inc(&sh
->count
);
634 if (unlikely(count
== 1))
635 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
,
636 0, NULL
, ops_complete_compute5
, sh
);
638 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
639 ASYNC_TX_XOR_ZERO_DST
, NULL
,
640 ops_complete_compute5
, sh
);
645 static void ops_complete_prexor(void *stripe_head_ref
)
647 struct stripe_head
*sh
= stripe_head_ref
;
649 pr_debug("%s: stripe %llu\n", __func__
,
650 (unsigned long long)sh
->sector
);
653 static struct dma_async_tx_descriptor
*
654 ops_run_prexor(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
656 /* kernel stack size limits the total number of disks */
657 int disks
= sh
->disks
;
658 struct page
*xor_srcs
[disks
];
659 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
661 /* existing parity data subtracted */
662 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
664 pr_debug("%s: stripe %llu\n", __func__
,
665 (unsigned long long)sh
->sector
);
667 for (i
= disks
; i
--; ) {
668 struct r5dev
*dev
= &sh
->dev
[i
];
669 /* Only process blocks that are known to be uptodate */
670 if (test_bit(R5_Wantdrain
, &dev
->flags
))
671 xor_srcs
[count
++] = dev
->page
;
674 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
675 ASYNC_TX_DEP_ACK
| ASYNC_TX_XOR_DROP_DST
, tx
,
676 ops_complete_prexor
, sh
);
681 static struct dma_async_tx_descriptor
*
682 ops_run_biodrain(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
684 int disks
= sh
->disks
;
687 pr_debug("%s: stripe %llu\n", __func__
,
688 (unsigned long long)sh
->sector
);
690 for (i
= disks
; i
--; ) {
691 struct r5dev
*dev
= &sh
->dev
[i
];
694 if (test_and_clear_bit(R5_Wantdrain
, &dev
->flags
)) {
697 spin_lock(&sh
->lock
);
698 chosen
= dev
->towrite
;
700 BUG_ON(dev
->written
);
701 wbi
= dev
->written
= chosen
;
702 spin_unlock(&sh
->lock
);
704 while (wbi
&& wbi
->bi_sector
<
705 dev
->sector
+ STRIPE_SECTORS
) {
706 tx
= async_copy_data(1, wbi
, dev
->page
,
708 wbi
= r5_next_bio(wbi
, dev
->sector
);
716 static void ops_complete_postxor(void *stripe_head_ref
)
718 struct stripe_head
*sh
= stripe_head_ref
;
719 int disks
= sh
->disks
, i
, pd_idx
= sh
->pd_idx
;
721 pr_debug("%s: stripe %llu\n", __func__
,
722 (unsigned long long)sh
->sector
);
724 for (i
= disks
; i
--; ) {
725 struct r5dev
*dev
= &sh
->dev
[i
];
726 if (dev
->written
|| i
== pd_idx
)
727 set_bit(R5_UPTODATE
, &dev
->flags
);
730 if (sh
->reconstruct_state
== reconstruct_state_drain_run
)
731 sh
->reconstruct_state
= reconstruct_state_drain_result
;
732 else if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
)
733 sh
->reconstruct_state
= reconstruct_state_prexor_drain_result
;
735 BUG_ON(sh
->reconstruct_state
!= reconstruct_state_run
);
736 sh
->reconstruct_state
= reconstruct_state_result
;
739 set_bit(STRIPE_HANDLE
, &sh
->state
);
744 ops_run_postxor(struct stripe_head
*sh
, struct dma_async_tx_descriptor
*tx
)
746 /* kernel stack size limits the total number of disks */
747 int disks
= sh
->disks
;
748 struct page
*xor_srcs
[disks
];
750 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
751 struct page
*xor_dest
;
755 pr_debug("%s: stripe %llu\n", __func__
,
756 (unsigned long long)sh
->sector
);
758 /* check if prexor is active which means only process blocks
759 * that are part of a read-modify-write (written)
761 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_run
) {
763 xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
764 for (i
= disks
; i
--; ) {
765 struct r5dev
*dev
= &sh
->dev
[i
];
767 xor_srcs
[count
++] = dev
->page
;
770 xor_dest
= sh
->dev
[pd_idx
].page
;
771 for (i
= disks
; i
--; ) {
772 struct r5dev
*dev
= &sh
->dev
[i
];
774 xor_srcs
[count
++] = dev
->page
;
778 /* 1/ if we prexor'd then the dest is reused as a source
779 * 2/ if we did not prexor then we are redoing the parity
780 * set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
781 * for the synchronous xor case
783 flags
= ASYNC_TX_DEP_ACK
| ASYNC_TX_ACK
|
784 (prexor
? ASYNC_TX_XOR_DROP_DST
: ASYNC_TX_XOR_ZERO_DST
);
786 atomic_inc(&sh
->count
);
788 if (unlikely(count
== 1)) {
789 flags
&= ~(ASYNC_TX_XOR_DROP_DST
| ASYNC_TX_XOR_ZERO_DST
);
790 tx
= async_memcpy(xor_dest
, xor_srcs
[0], 0, 0, STRIPE_SIZE
,
791 flags
, tx
, ops_complete_postxor
, sh
);
793 tx
= async_xor(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
794 flags
, tx
, ops_complete_postxor
, sh
);
797 static void ops_complete_check(void *stripe_head_ref
)
799 struct stripe_head
*sh
= stripe_head_ref
;
801 pr_debug("%s: stripe %llu\n", __func__
,
802 (unsigned long long)sh
->sector
);
804 sh
->check_state
= check_state_check_result
;
805 set_bit(STRIPE_HANDLE
, &sh
->state
);
809 static void ops_run_check(struct stripe_head
*sh
)
811 /* kernel stack size limits the total number of disks */
812 int disks
= sh
->disks
;
813 struct page
*xor_srcs
[disks
];
814 struct dma_async_tx_descriptor
*tx
;
816 int count
= 0, pd_idx
= sh
->pd_idx
, i
;
817 struct page
*xor_dest
= xor_srcs
[count
++] = sh
->dev
[pd_idx
].page
;
819 pr_debug("%s: stripe %llu\n", __func__
,
820 (unsigned long long)sh
->sector
);
822 for (i
= disks
; i
--; ) {
823 struct r5dev
*dev
= &sh
->dev
[i
];
825 xor_srcs
[count
++] = dev
->page
;
828 tx
= async_xor_zero_sum(xor_dest
, xor_srcs
, 0, count
, STRIPE_SIZE
,
829 &sh
->ops
.zero_sum_result
, 0, NULL
, NULL
, NULL
);
831 atomic_inc(&sh
->count
);
832 tx
= async_trigger_callback(ASYNC_TX_DEP_ACK
| ASYNC_TX_ACK
, tx
,
833 ops_complete_check
, sh
);
836 static void raid5_run_ops(struct stripe_head
*sh
, unsigned long ops_request
)
838 int overlap_clear
= 0, i
, disks
= sh
->disks
;
839 struct dma_async_tx_descriptor
*tx
= NULL
;
841 if (test_bit(STRIPE_OP_BIOFILL
, &ops_request
)) {
846 if (test_bit(STRIPE_OP_COMPUTE_BLK
, &ops_request
)) {
847 tx
= ops_run_compute5(sh
);
848 /* terminate the chain if postxor is not set to be run */
849 if (tx
&& !test_bit(STRIPE_OP_POSTXOR
, &ops_request
))
853 if (test_bit(STRIPE_OP_PREXOR
, &ops_request
))
854 tx
= ops_run_prexor(sh
, tx
);
856 if (test_bit(STRIPE_OP_BIODRAIN
, &ops_request
)) {
857 tx
= ops_run_biodrain(sh
, tx
);
861 if (test_bit(STRIPE_OP_POSTXOR
, &ops_request
))
862 ops_run_postxor(sh
, tx
);
864 if (test_bit(STRIPE_OP_CHECK
, &ops_request
))
868 for (i
= disks
; i
--; ) {
869 struct r5dev
*dev
= &sh
->dev
[i
];
870 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
871 wake_up(&sh
->raid_conf
->wait_for_overlap
);
875 static int grow_one_stripe(raid5_conf_t
*conf
)
877 struct stripe_head
*sh
;
878 sh
= kmem_cache_alloc(conf
->slab_cache
, GFP_KERNEL
);
881 memset(sh
, 0, sizeof(*sh
) + (conf
->raid_disks
-1)*sizeof(struct r5dev
));
882 sh
->raid_conf
= conf
;
883 spin_lock_init(&sh
->lock
);
885 if (grow_buffers(sh
, conf
->raid_disks
)) {
886 shrink_buffers(sh
, conf
->raid_disks
);
887 kmem_cache_free(conf
->slab_cache
, sh
);
890 sh
->disks
= conf
->raid_disks
;
891 /* we just created an active stripe so... */
892 atomic_set(&sh
->count
, 1);
893 atomic_inc(&conf
->active_stripes
);
894 INIT_LIST_HEAD(&sh
->lru
);
899 static int grow_stripes(raid5_conf_t
*conf
, int num
)
901 struct kmem_cache
*sc
;
902 int devs
= conf
->raid_disks
;
904 sprintf(conf
->cache_name
[0], "raid5-%s", mdname(conf
->mddev
));
905 sprintf(conf
->cache_name
[1], "raid5-%s-alt", mdname(conf
->mddev
));
906 conf
->active_name
= 0;
907 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
908 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
912 conf
->slab_cache
= sc
;
913 conf
->pool_size
= devs
;
915 if (!grow_one_stripe(conf
))
920 #ifdef CONFIG_MD_RAID5_RESHAPE
921 static int resize_stripes(raid5_conf_t
*conf
, int newsize
)
923 /* Make all the stripes able to hold 'newsize' devices.
924 * New slots in each stripe get 'page' set to a new page.
926 * This happens in stages:
927 * 1/ create a new kmem_cache and allocate the required number of
929 * 2/ gather all the old stripe_heads and tranfer the pages across
930 * to the new stripe_heads. This will have the side effect of
931 * freezing the array as once all stripe_heads have been collected,
932 * no IO will be possible. Old stripe heads are freed once their
933 * pages have been transferred over, and the old kmem_cache is
934 * freed when all stripes are done.
935 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
936 * we simple return a failre status - no need to clean anything up.
937 * 4/ allocate new pages for the new slots in the new stripe_heads.
938 * If this fails, we don't bother trying the shrink the
939 * stripe_heads down again, we just leave them as they are.
940 * As each stripe_head is processed the new one is released into
943 * Once step2 is started, we cannot afford to wait for a write,
944 * so we use GFP_NOIO allocations.
946 struct stripe_head
*osh
, *nsh
;
947 LIST_HEAD(newstripes
);
948 struct disk_info
*ndisks
;
950 struct kmem_cache
*sc
;
953 if (newsize
<= conf
->pool_size
)
954 return 0; /* never bother to shrink */
956 err
= md_allow_write(conf
->mddev
);
961 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
962 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
967 for (i
= conf
->max_nr_stripes
; i
; i
--) {
968 nsh
= kmem_cache_alloc(sc
, GFP_KERNEL
);
972 memset(nsh
, 0, sizeof(*nsh
) + (newsize
-1)*sizeof(struct r5dev
));
974 nsh
->raid_conf
= conf
;
975 spin_lock_init(&nsh
->lock
);
977 list_add(&nsh
->lru
, &newstripes
);
980 /* didn't get enough, give up */
981 while (!list_empty(&newstripes
)) {
982 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
984 kmem_cache_free(sc
, nsh
);
986 kmem_cache_destroy(sc
);
989 /* Step 2 - Must use GFP_NOIO now.
990 * OK, we have enough stripes, start collecting inactive
991 * stripes and copying them over
993 list_for_each_entry(nsh
, &newstripes
, lru
) {
994 spin_lock_irq(&conf
->device_lock
);
995 wait_event_lock_irq(conf
->wait_for_stripe
,
996 !list_empty(&conf
->inactive_list
),
998 unplug_slaves(conf
->mddev
)
1000 osh
= get_free_stripe(conf
);
1001 spin_unlock_irq(&conf
->device_lock
);
1002 atomic_set(&nsh
->count
, 1);
1003 for(i
=0; i
<conf
->pool_size
; i
++)
1004 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
1005 for( ; i
<newsize
; i
++)
1006 nsh
->dev
[i
].page
= NULL
;
1007 kmem_cache_free(conf
->slab_cache
, osh
);
1009 kmem_cache_destroy(conf
->slab_cache
);
1012 * At this point, we are holding all the stripes so the array
1013 * is completely stalled, so now is a good time to resize
1016 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
1018 for (i
=0; i
<conf
->raid_disks
; i
++)
1019 ndisks
[i
] = conf
->disks
[i
];
1021 conf
->disks
= ndisks
;
1025 /* Step 4, return new stripes to service */
1026 while(!list_empty(&newstripes
)) {
1027 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
1028 list_del_init(&nsh
->lru
);
1029 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
1030 if (nsh
->dev
[i
].page
== NULL
) {
1031 struct page
*p
= alloc_page(GFP_NOIO
);
1032 nsh
->dev
[i
].page
= p
;
1036 release_stripe(nsh
);
1038 /* critical section pass, GFP_NOIO no longer needed */
1040 conf
->slab_cache
= sc
;
1041 conf
->active_name
= 1-conf
->active_name
;
1042 conf
->pool_size
= newsize
;
1047 static int drop_one_stripe(raid5_conf_t
*conf
)
1049 struct stripe_head
*sh
;
1051 spin_lock_irq(&conf
->device_lock
);
1052 sh
= get_free_stripe(conf
);
1053 spin_unlock_irq(&conf
->device_lock
);
1056 BUG_ON(atomic_read(&sh
->count
));
1057 shrink_buffers(sh
, conf
->pool_size
);
1058 kmem_cache_free(conf
->slab_cache
, sh
);
1059 atomic_dec(&conf
->active_stripes
);
1063 static void shrink_stripes(raid5_conf_t
*conf
)
1065 while (drop_one_stripe(conf
))
1068 if (conf
->slab_cache
)
1069 kmem_cache_destroy(conf
->slab_cache
);
1070 conf
->slab_cache
= NULL
;
1073 static void raid5_end_read_request(struct bio
* bi
, int error
)
1075 struct stripe_head
*sh
= bi
->bi_private
;
1076 raid5_conf_t
*conf
= sh
->raid_conf
;
1077 int disks
= sh
->disks
, i
;
1078 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1079 char b
[BDEVNAME_SIZE
];
1083 for (i
=0 ; i
<disks
; i
++)
1084 if (bi
== &sh
->dev
[i
].req
)
1087 pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n",
1088 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1096 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1097 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1098 rdev
= conf
->disks
[i
].rdev
;
1099 printk_rl(KERN_INFO
"raid5:%s: read error corrected"
1100 " (%lu sectors at %llu on %s)\n",
1101 mdname(conf
->mddev
), STRIPE_SECTORS
,
1102 (unsigned long long)(sh
->sector
1103 + rdev
->data_offset
),
1104 bdevname(rdev
->bdev
, b
));
1105 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1106 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1108 if (atomic_read(&conf
->disks
[i
].rdev
->read_errors
))
1109 atomic_set(&conf
->disks
[i
].rdev
->read_errors
, 0);
1111 const char *bdn
= bdevname(conf
->disks
[i
].rdev
->bdev
, b
);
1113 rdev
= conf
->disks
[i
].rdev
;
1115 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1116 atomic_inc(&rdev
->read_errors
);
1117 if (conf
->mddev
->degraded
)
1118 printk_rl(KERN_WARNING
1119 "raid5:%s: read error not correctable "
1120 "(sector %llu on %s).\n",
1121 mdname(conf
->mddev
),
1122 (unsigned long long)(sh
->sector
1123 + rdev
->data_offset
),
1125 else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
1127 printk_rl(KERN_WARNING
1128 "raid5:%s: read error NOT corrected!! "
1129 "(sector %llu on %s).\n",
1130 mdname(conf
->mddev
),
1131 (unsigned long long)(sh
->sector
1132 + rdev
->data_offset
),
1134 else if (atomic_read(&rdev
->read_errors
)
1135 > conf
->max_nr_stripes
)
1137 "raid5:%s: Too many read errors, failing device %s.\n",
1138 mdname(conf
->mddev
), bdn
);
1142 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1144 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
1145 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
1146 md_error(conf
->mddev
, rdev
);
1149 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1150 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1151 set_bit(STRIPE_HANDLE
, &sh
->state
);
1155 static void raid5_end_write_request(struct bio
*bi
, int error
)
1157 struct stripe_head
*sh
= bi
->bi_private
;
1158 raid5_conf_t
*conf
= sh
->raid_conf
;
1159 int disks
= sh
->disks
, i
;
1160 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1162 for (i
=0 ; i
<disks
; i
++)
1163 if (bi
== &sh
->dev
[i
].req
)
1166 pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n",
1167 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
1175 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
1177 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
1179 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1180 set_bit(STRIPE_HANDLE
, &sh
->state
);
1185 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
);
1187 static void raid5_build_block(struct stripe_head
*sh
, int i
)
1189 struct r5dev
*dev
= &sh
->dev
[i
];
1191 bio_init(&dev
->req
);
1192 dev
->req
.bi_io_vec
= &dev
->vec
;
1194 dev
->req
.bi_max_vecs
++;
1195 dev
->vec
.bv_page
= dev
->page
;
1196 dev
->vec
.bv_len
= STRIPE_SIZE
;
1197 dev
->vec
.bv_offset
= 0;
1199 dev
->req
.bi_sector
= sh
->sector
;
1200 dev
->req
.bi_private
= sh
;
1203 dev
->sector
= compute_blocknr(sh
, i
);
1206 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1208 char b
[BDEVNAME_SIZE
];
1209 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
1210 pr_debug("raid5: error called\n");
1212 if (!test_bit(Faulty
, &rdev
->flags
)) {
1213 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1214 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1215 unsigned long flags
;
1216 spin_lock_irqsave(&conf
->device_lock
, flags
);
1218 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1220 * if recovery was running, make sure it aborts.
1222 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1224 set_bit(Faulty
, &rdev
->flags
);
1226 "raid5: Disk failure on %s, disabling device.\n"
1227 "raid5: Operation continuing on %d devices.\n",
1228 bdevname(rdev
->bdev
,b
), conf
->raid_disks
- mddev
->degraded
);
1233 * Input: a 'big' sector number,
1234 * Output: index of the data and parity disk, and the sector # in them.
1236 static sector_t
raid5_compute_sector(raid5_conf_t
*conf
, sector_t r_sector
,
1238 int *dd_idx
, int *pd_idx
)
1241 unsigned long chunk_number
;
1242 unsigned int chunk_offset
;
1243 sector_t new_sector
;
1244 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1245 int raid_disks
= previous
? conf
->previous_raid_disks
1247 int data_disks
= raid_disks
- conf
->max_degraded
;
1249 /* First compute the information on this sector */
1252 * Compute the chunk number and the sector offset inside the chunk
1254 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
1255 chunk_number
= r_sector
;
1256 BUG_ON(r_sector
!= chunk_number
);
1259 * Compute the stripe number
1261 stripe
= chunk_number
/ data_disks
;
1264 * Compute the data disk and parity disk indexes inside the stripe
1266 *dd_idx
= chunk_number
% data_disks
;
1269 * Select the parity disk based on the user selected algorithm.
1271 switch(conf
->level
) {
1273 *pd_idx
= data_disks
;
1276 switch (conf
->algorithm
) {
1277 case ALGORITHM_LEFT_ASYMMETRIC
:
1278 *pd_idx
= data_disks
- stripe
% raid_disks
;
1279 if (*dd_idx
>= *pd_idx
)
1282 case ALGORITHM_RIGHT_ASYMMETRIC
:
1283 *pd_idx
= stripe
% raid_disks
;
1284 if (*dd_idx
>= *pd_idx
)
1287 case ALGORITHM_LEFT_SYMMETRIC
:
1288 *pd_idx
= data_disks
- stripe
% raid_disks
;
1289 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1291 case ALGORITHM_RIGHT_SYMMETRIC
:
1292 *pd_idx
= stripe
% raid_disks
;
1293 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
1296 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
1302 /**** FIX THIS ****/
1303 switch (conf
->algorithm
) {
1304 case ALGORITHM_LEFT_ASYMMETRIC
:
1305 *pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
1306 if (*pd_idx
== raid_disks
-1)
1307 (*dd_idx
)++; /* Q D D D P */
1308 else if (*dd_idx
>= *pd_idx
)
1309 (*dd_idx
) += 2; /* D D P Q D */
1311 case ALGORITHM_RIGHT_ASYMMETRIC
:
1312 *pd_idx
= stripe
% raid_disks
;
1313 if (*pd_idx
== raid_disks
-1)
1314 (*dd_idx
)++; /* Q D D D P */
1315 else if (*dd_idx
>= *pd_idx
)
1316 (*dd_idx
) += 2; /* D D P Q D */
1318 case ALGORITHM_LEFT_SYMMETRIC
:
1319 *pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
1320 *dd_idx
= (*pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1322 case ALGORITHM_RIGHT_SYMMETRIC
:
1323 *pd_idx
= stripe
% raid_disks
;
1324 *dd_idx
= (*pd_idx
+ 2 + *dd_idx
) % raid_disks
;
1327 printk(KERN_CRIT
"raid6: unsupported algorithm %d\n",
1334 * Finally, compute the new sector number
1336 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
1341 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
)
1343 raid5_conf_t
*conf
= sh
->raid_conf
;
1344 int raid_disks
= sh
->disks
;
1345 int data_disks
= raid_disks
- conf
->max_degraded
;
1346 sector_t new_sector
= sh
->sector
, check
;
1347 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1350 int chunk_number
, dummy1
, dummy2
, dd_idx
= i
;
1354 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
1355 stripe
= new_sector
;
1356 BUG_ON(new_sector
!= stripe
);
1358 if (i
== sh
->pd_idx
)
1360 switch(conf
->level
) {
1363 switch (conf
->algorithm
) {
1364 case ALGORITHM_LEFT_ASYMMETRIC
:
1365 case ALGORITHM_RIGHT_ASYMMETRIC
:
1369 case ALGORITHM_LEFT_SYMMETRIC
:
1370 case ALGORITHM_RIGHT_SYMMETRIC
:
1373 i
-= (sh
->pd_idx
+ 1);
1376 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
1381 if (i
== raid6_next_disk(sh
->pd_idx
, raid_disks
))
1382 return 0; /* It is the Q disk */
1383 switch (conf
->algorithm
) {
1384 case ALGORITHM_LEFT_ASYMMETRIC
:
1385 case ALGORITHM_RIGHT_ASYMMETRIC
:
1386 if (sh
->pd_idx
== raid_disks
-1)
1387 i
--; /* Q D D D P */
1388 else if (i
> sh
->pd_idx
)
1389 i
-= 2; /* D D P Q D */
1391 case ALGORITHM_LEFT_SYMMETRIC
:
1392 case ALGORITHM_RIGHT_SYMMETRIC
:
1393 if (sh
->pd_idx
== raid_disks
-1)
1394 i
--; /* Q D D D P */
1399 i
-= (sh
->pd_idx
+ 2);
1403 printk(KERN_CRIT
"raid6: unsupported algorithm %d\n",
1409 chunk_number
= stripe
* data_disks
+ i
;
1410 r_sector
= (sector_t
)chunk_number
* sectors_per_chunk
+ chunk_offset
;
1412 check
= raid5_compute_sector(conf
, r_sector
,
1413 (raid_disks
!= conf
->raid_disks
),
1415 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| dummy2
!= sh
->pd_idx
) {
1416 printk(KERN_ERR
"compute_blocknr: map not correct\n");
1425 * Copy data between a page in the stripe cache, and one or more bion
1426 * The page could align with the middle of the bio, or there could be
1427 * several bion, each with several bio_vecs, which cover part of the page
1428 * Multiple bion are linked together on bi_next. There may be extras
1429 * at the end of this list. We ignore them.
1431 static void copy_data(int frombio
, struct bio
*bio
,
1435 char *pa
= page_address(page
);
1436 struct bio_vec
*bvl
;
1440 if (bio
->bi_sector
>= sector
)
1441 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
1443 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
1444 bio_for_each_segment(bvl
, bio
, i
) {
1445 int len
= bio_iovec_idx(bio
,i
)->bv_len
;
1449 if (page_offset
< 0) {
1450 b_offset
= -page_offset
;
1451 page_offset
+= b_offset
;
1455 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
1456 clen
= STRIPE_SIZE
- page_offset
;
1460 char *ba
= __bio_kmap_atomic(bio
, i
, KM_USER0
);
1462 memcpy(pa
+page_offset
, ba
+b_offset
, clen
);
1464 memcpy(ba
+b_offset
, pa
+page_offset
, clen
);
1465 __bio_kunmap_atomic(ba
, KM_USER0
);
1467 if (clen
< len
) /* hit end of page */
1473 #define check_xor() do { \
1474 if (count == MAX_XOR_BLOCKS) { \
1475 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
1480 static void compute_parity6(struct stripe_head
*sh
, int method
)
1482 raid5_conf_t
*conf
= sh
->raid_conf
;
1483 int i
, pd_idx
= sh
->pd_idx
, qd_idx
, d0_idx
, disks
= sh
->disks
, count
;
1485 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1488 qd_idx
= raid6_next_disk(pd_idx
, disks
);
1489 d0_idx
= raid6_next_disk(qd_idx
, disks
);
1491 pr_debug("compute_parity, stripe %llu, method %d\n",
1492 (unsigned long long)sh
->sector
, method
);
1495 case READ_MODIFY_WRITE
:
1496 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1497 case RECONSTRUCT_WRITE
:
1498 for (i
= disks
; i
-- ;)
1499 if ( i
!= pd_idx
&& i
!= qd_idx
&& sh
->dev
[i
].towrite
) {
1500 chosen
= sh
->dev
[i
].towrite
;
1501 sh
->dev
[i
].towrite
= NULL
;
1503 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1504 wake_up(&conf
->wait_for_overlap
);
1506 BUG_ON(sh
->dev
[i
].written
);
1507 sh
->dev
[i
].written
= chosen
;
1511 BUG(); /* Not implemented yet */
1514 for (i
= disks
; i
--;)
1515 if (sh
->dev
[i
].written
) {
1516 sector_t sector
= sh
->dev
[i
].sector
;
1517 struct bio
*wbi
= sh
->dev
[i
].written
;
1518 while (wbi
&& wbi
->bi_sector
< sector
+ STRIPE_SECTORS
) {
1519 copy_data(1, wbi
, sh
->dev
[i
].page
, sector
);
1520 wbi
= r5_next_bio(wbi
, sector
);
1523 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1524 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1528 // case RECONSTRUCT_WRITE:
1529 // case CHECK_PARITY:
1530 // case UPDATE_PARITY:
1531 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1532 /* FIX: Is this ordering of drives even remotely optimal? */
1536 ptrs
[count
++] = page_address(sh
->dev
[i
].page
);
1537 if (count
<= disks
-2 && !test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1538 printk("block %d/%d not uptodate on parity calc\n", i
,count
);
1539 i
= raid6_next_disk(i
, disks
);
1540 } while ( i
!= d0_idx
);
1544 raid6_call
.gen_syndrome(disks
, STRIPE_SIZE
, ptrs
);
1547 case RECONSTRUCT_WRITE
:
1548 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1549 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1550 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1551 set_bit(R5_LOCKED
, &sh
->dev
[qd_idx
].flags
);
1554 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1555 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1561 /* Compute one missing block */
1562 static void compute_block_1(struct stripe_head
*sh
, int dd_idx
, int nozero
)
1564 int i
, count
, disks
= sh
->disks
;
1565 void *ptr
[MAX_XOR_BLOCKS
], *dest
, *p
;
1566 int pd_idx
= sh
->pd_idx
;
1567 int qd_idx
= raid6_next_disk(pd_idx
, disks
);
1569 pr_debug("compute_block_1, stripe %llu, idx %d\n",
1570 (unsigned long long)sh
->sector
, dd_idx
);
1572 if ( dd_idx
== qd_idx
) {
1573 /* We're actually computing the Q drive */
1574 compute_parity6(sh
, UPDATE_PARITY
);
1576 dest
= page_address(sh
->dev
[dd_idx
].page
);
1577 if (!nozero
) memset(dest
, 0, STRIPE_SIZE
);
1579 for (i
= disks
; i
--; ) {
1580 if (i
== dd_idx
|| i
== qd_idx
)
1582 p
= page_address(sh
->dev
[i
].page
);
1583 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1586 printk("compute_block() %d, stripe %llu, %d"
1587 " not present\n", dd_idx
,
1588 (unsigned long long)sh
->sector
, i
);
1593 xor_blocks(count
, STRIPE_SIZE
, dest
, ptr
);
1594 if (!nozero
) set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1595 else clear_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1599 /* Compute two missing blocks */
1600 static void compute_block_2(struct stripe_head
*sh
, int dd_idx1
, int dd_idx2
)
1602 int i
, count
, disks
= sh
->disks
;
1603 int pd_idx
= sh
->pd_idx
;
1604 int qd_idx
= raid6_next_disk(pd_idx
, disks
);
1605 int d0_idx
= raid6_next_disk(qd_idx
, disks
);
1608 /* faila and failb are disk numbers relative to d0_idx */
1609 /* pd_idx become disks-2 and qd_idx become disks-1 */
1610 faila
= (dd_idx1
< d0_idx
) ? dd_idx1
+(disks
-d0_idx
) : dd_idx1
-d0_idx
;
1611 failb
= (dd_idx2
< d0_idx
) ? dd_idx2
+(disks
-d0_idx
) : dd_idx2
-d0_idx
;
1613 BUG_ON(faila
== failb
);
1614 if ( failb
< faila
) { int tmp
= faila
; faila
= failb
; failb
= tmp
; }
1616 pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1617 (unsigned long long)sh
->sector
, dd_idx1
, dd_idx2
, faila
, failb
);
1619 if ( failb
== disks
-1 ) {
1620 /* Q disk is one of the missing disks */
1621 if ( faila
== disks
-2 ) {
1622 /* Missing P+Q, just recompute */
1623 compute_parity6(sh
, UPDATE_PARITY
);
1626 /* We're missing D+Q; recompute D from P */
1627 compute_block_1(sh
, (dd_idx1
== qd_idx
) ? dd_idx2
: dd_idx1
, 0);
1628 compute_parity6(sh
, UPDATE_PARITY
); /* Is this necessary? */
1633 /* We're missing D+P or D+D; build pointer table */
1635 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1641 ptrs
[count
++] = page_address(sh
->dev
[i
].page
);
1642 i
= raid6_next_disk(i
, disks
);
1643 if (i
!= dd_idx1
&& i
!= dd_idx2
&&
1644 !test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1645 printk("compute_2 with missing block %d/%d\n", count
, i
);
1646 } while ( i
!= d0_idx
);
1648 if ( failb
== disks
-2 ) {
1649 /* We're missing D+P. */
1650 raid6_datap_recov(disks
, STRIPE_SIZE
, faila
, ptrs
);
1652 /* We're missing D+D. */
1653 raid6_2data_recov(disks
, STRIPE_SIZE
, faila
, failb
, ptrs
);
1656 /* Both the above update both missing blocks */
1657 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx1
].flags
);
1658 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx2
].flags
);
1663 schedule_reconstruction5(struct stripe_head
*sh
, struct stripe_head_state
*s
,
1664 int rcw
, int expand
)
1666 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
;
1669 /* if we are not expanding this is a proper write request, and
1670 * there will be bios with new data to be drained into the
1674 sh
->reconstruct_state
= reconstruct_state_drain_run
;
1675 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
1677 sh
->reconstruct_state
= reconstruct_state_run
;
1679 set_bit(STRIPE_OP_POSTXOR
, &s
->ops_request
);
1681 for (i
= disks
; i
--; ) {
1682 struct r5dev
*dev
= &sh
->dev
[i
];
1685 set_bit(R5_LOCKED
, &dev
->flags
);
1686 set_bit(R5_Wantdrain
, &dev
->flags
);
1688 clear_bit(R5_UPTODATE
, &dev
->flags
);
1692 if (s
->locked
+ 1 == disks
)
1693 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
1694 atomic_inc(&sh
->raid_conf
->pending_full_writes
);
1696 BUG_ON(!(test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
) ||
1697 test_bit(R5_Wantcompute
, &sh
->dev
[pd_idx
].flags
)));
1699 sh
->reconstruct_state
= reconstruct_state_prexor_drain_run
;
1700 set_bit(STRIPE_OP_PREXOR
, &s
->ops_request
);
1701 set_bit(STRIPE_OP_BIODRAIN
, &s
->ops_request
);
1702 set_bit(STRIPE_OP_POSTXOR
, &s
->ops_request
);
1704 for (i
= disks
; i
--; ) {
1705 struct r5dev
*dev
= &sh
->dev
[i
];
1710 (test_bit(R5_UPTODATE
, &dev
->flags
) ||
1711 test_bit(R5_Wantcompute
, &dev
->flags
))) {
1712 set_bit(R5_Wantdrain
, &dev
->flags
);
1713 set_bit(R5_LOCKED
, &dev
->flags
);
1714 clear_bit(R5_UPTODATE
, &dev
->flags
);
1720 /* keep the parity disk locked while asynchronous operations
1723 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1724 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1727 pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
1728 __func__
, (unsigned long long)sh
->sector
,
1729 s
->locked
, s
->ops_request
);
1733 * Each stripe/dev can have one or more bion attached.
1734 * toread/towrite point to the first in a chain.
1735 * The bi_next chain must be in order.
1737 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
1740 raid5_conf_t
*conf
= sh
->raid_conf
;
1743 pr_debug("adding bh b#%llu to stripe s#%llu\n",
1744 (unsigned long long)bi
->bi_sector
,
1745 (unsigned long long)sh
->sector
);
1748 spin_lock(&sh
->lock
);
1749 spin_lock_irq(&conf
->device_lock
);
1751 bip
= &sh
->dev
[dd_idx
].towrite
;
1752 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
1755 bip
= &sh
->dev
[dd_idx
].toread
;
1756 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
1757 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
1759 bip
= & (*bip
)->bi_next
;
1761 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
1764 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
1768 bi
->bi_phys_segments
++;
1769 spin_unlock_irq(&conf
->device_lock
);
1770 spin_unlock(&sh
->lock
);
1772 pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
1773 (unsigned long long)bi
->bi_sector
,
1774 (unsigned long long)sh
->sector
, dd_idx
);
1776 if (conf
->mddev
->bitmap
&& firstwrite
) {
1777 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
1779 sh
->bm_seq
= conf
->seq_flush
+1;
1780 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
1784 /* check if page is covered */
1785 sector_t sector
= sh
->dev
[dd_idx
].sector
;
1786 for (bi
=sh
->dev
[dd_idx
].towrite
;
1787 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
1788 bi
&& bi
->bi_sector
<= sector
;
1789 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
1790 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
1791 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
1793 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
1794 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
1799 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
1800 spin_unlock_irq(&conf
->device_lock
);
1801 spin_unlock(&sh
->lock
);
1805 static void end_reshape(raid5_conf_t
*conf
);
1807 static int page_is_zero(struct page
*p
)
1809 char *a
= page_address(p
);
1810 return ((*(u32
*)a
) == 0 &&
1811 memcmp(a
, a
+4, STRIPE_SIZE
-4)==0);
1814 static int stripe_to_pdidx(sector_t stripe
, raid5_conf_t
*conf
, int previous
)
1816 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1818 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
1819 int disks
= previous
? conf
->previous_raid_disks
: conf
->raid_disks
;
1821 raid5_compute_sector(conf
,
1822 stripe
* (disks
- conf
->max_degraded
)
1823 *sectors_per_chunk
+ chunk_offset
,
1830 handle_failed_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
,
1831 struct stripe_head_state
*s
, int disks
,
1832 struct bio
**return_bi
)
1835 for (i
= disks
; i
--; ) {
1839 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1842 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
1843 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
1844 /* multiple read failures in one stripe */
1845 md_error(conf
->mddev
, rdev
);
1848 spin_lock_irq(&conf
->device_lock
);
1849 /* fail all writes first */
1850 bi
= sh
->dev
[i
].towrite
;
1851 sh
->dev
[i
].towrite
= NULL
;
1857 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1858 wake_up(&conf
->wait_for_overlap
);
1860 while (bi
&& bi
->bi_sector
<
1861 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1862 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1863 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1864 if (!raid5_dec_bi_phys_segments(bi
)) {
1865 md_write_end(conf
->mddev
);
1866 bi
->bi_next
= *return_bi
;
1871 /* and fail all 'written' */
1872 bi
= sh
->dev
[i
].written
;
1873 sh
->dev
[i
].written
= NULL
;
1874 if (bi
) bitmap_end
= 1;
1875 while (bi
&& bi
->bi_sector
<
1876 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1877 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1878 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1879 if (!raid5_dec_bi_phys_segments(bi
)) {
1880 md_write_end(conf
->mddev
);
1881 bi
->bi_next
= *return_bi
;
1887 /* fail any reads if this device is non-operational and
1888 * the data has not reached the cache yet.
1890 if (!test_bit(R5_Wantfill
, &sh
->dev
[i
].flags
) &&
1891 (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
1892 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
))) {
1893 bi
= sh
->dev
[i
].toread
;
1894 sh
->dev
[i
].toread
= NULL
;
1895 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1896 wake_up(&conf
->wait_for_overlap
);
1897 if (bi
) s
->to_read
--;
1898 while (bi
&& bi
->bi_sector
<
1899 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1900 struct bio
*nextbi
=
1901 r5_next_bio(bi
, sh
->dev
[i
].sector
);
1902 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1903 if (!raid5_dec_bi_phys_segments(bi
)) {
1904 bi
->bi_next
= *return_bi
;
1910 spin_unlock_irq(&conf
->device_lock
);
1912 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
1913 STRIPE_SECTORS
, 0, 0);
1916 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
1917 if (atomic_dec_and_test(&conf
->pending_full_writes
))
1918 md_wakeup_thread(conf
->mddev
->thread
);
1921 /* fetch_block5 - checks the given member device to see if its data needs
1922 * to be read or computed to satisfy a request.
1924 * Returns 1 when no more member devices need to be checked, otherwise returns
1925 * 0 to tell the loop in handle_stripe_fill5 to continue
1927 static int fetch_block5(struct stripe_head
*sh
, struct stripe_head_state
*s
,
1928 int disk_idx
, int disks
)
1930 struct r5dev
*dev
= &sh
->dev
[disk_idx
];
1931 struct r5dev
*failed_dev
= &sh
->dev
[s
->failed_num
];
1933 /* is the data in this block needed, and can we get it? */
1934 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
1935 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1937 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
1938 s
->syncing
|| s
->expanding
||
1940 (failed_dev
->toread
||
1941 (failed_dev
->towrite
&&
1942 !test_bit(R5_OVERWRITE
, &failed_dev
->flags
)))))) {
1943 /* We would like to get this block, possibly by computing it,
1944 * otherwise read it if the backing disk is insync
1946 if ((s
->uptodate
== disks
- 1) &&
1947 (s
->failed
&& disk_idx
== s
->failed_num
)) {
1948 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
1949 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
1950 set_bit(R5_Wantcompute
, &dev
->flags
);
1951 sh
->ops
.target
= disk_idx
;
1953 /* Careful: from this point on 'uptodate' is in the eye
1954 * of raid5_run_ops which services 'compute' operations
1955 * before writes. R5_Wantcompute flags a block that will
1956 * be R5_UPTODATE by the time it is needed for a
1957 * subsequent operation.
1960 return 1; /* uptodate + compute == disks */
1961 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
1962 set_bit(R5_LOCKED
, &dev
->flags
);
1963 set_bit(R5_Wantread
, &dev
->flags
);
1965 pr_debug("Reading block %d (sync=%d)\n", disk_idx
,
1974 * handle_stripe_fill5 - read or compute data to satisfy pending requests.
1976 static void handle_stripe_fill5(struct stripe_head
*sh
,
1977 struct stripe_head_state
*s
, int disks
)
1981 /* look for blocks to read/compute, skip this if a compute
1982 * is already in flight, or if the stripe contents are in the
1983 * midst of changing due to a write
1985 if (!test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) && !sh
->check_state
&&
1986 !sh
->reconstruct_state
)
1987 for (i
= disks
; i
--; )
1988 if (fetch_block5(sh
, s
, i
, disks
))
1990 set_bit(STRIPE_HANDLE
, &sh
->state
);
1993 static void handle_stripe_fill6(struct stripe_head
*sh
,
1994 struct stripe_head_state
*s
, struct r6_state
*r6s
,
1998 for (i
= disks
; i
--; ) {
1999 struct r5dev
*dev
= &sh
->dev
[i
];
2000 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2001 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2002 (dev
->toread
|| (dev
->towrite
&&
2003 !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2004 s
->syncing
|| s
->expanding
||
2006 (sh
->dev
[r6s
->failed_num
[0]].toread
||
2009 (sh
->dev
[r6s
->failed_num
[1]].toread
||
2011 /* we would like to get this block, possibly
2012 * by computing it, but we might not be able to
2014 if ((s
->uptodate
== disks
- 1) &&
2015 (s
->failed
&& (i
== r6s
->failed_num
[0] ||
2016 i
== r6s
->failed_num
[1]))) {
2017 pr_debug("Computing stripe %llu block %d\n",
2018 (unsigned long long)sh
->sector
, i
);
2019 compute_block_1(sh
, i
, 0);
2021 } else if ( s
->uptodate
== disks
-2 && s
->failed
>= 2 ) {
2022 /* Computing 2-failure is *very* expensive; only
2023 * do it if failed >= 2
2026 for (other
= disks
; other
--; ) {
2029 if (!test_bit(R5_UPTODATE
,
2030 &sh
->dev
[other
].flags
))
2034 pr_debug("Computing stripe %llu blocks %d,%d\n",
2035 (unsigned long long)sh
->sector
,
2037 compute_block_2(sh
, i
, other
);
2039 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2040 set_bit(R5_LOCKED
, &dev
->flags
);
2041 set_bit(R5_Wantread
, &dev
->flags
);
2043 pr_debug("Reading block %d (sync=%d)\n",
2048 set_bit(STRIPE_HANDLE
, &sh
->state
);
2052 /* handle_stripe_clean_event
2053 * any written block on an uptodate or failed drive can be returned.
2054 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
2055 * never LOCKED, so we don't need to test 'failed' directly.
2057 static void handle_stripe_clean_event(raid5_conf_t
*conf
,
2058 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
2063 for (i
= disks
; i
--; )
2064 if (sh
->dev
[i
].written
) {
2066 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2067 test_bit(R5_UPTODATE
, &dev
->flags
)) {
2068 /* We can return any write requests */
2069 struct bio
*wbi
, *wbi2
;
2071 pr_debug("Return write for disc %d\n", i
);
2072 spin_lock_irq(&conf
->device_lock
);
2074 dev
->written
= NULL
;
2075 while (wbi
&& wbi
->bi_sector
<
2076 dev
->sector
+ STRIPE_SECTORS
) {
2077 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2078 if (!raid5_dec_bi_phys_segments(wbi
)) {
2079 md_write_end(conf
->mddev
);
2080 wbi
->bi_next
= *return_bi
;
2085 if (dev
->towrite
== NULL
)
2087 spin_unlock_irq(&conf
->device_lock
);
2089 bitmap_endwrite(conf
->mddev
->bitmap
,
2092 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
2097 if (test_and_clear_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2098 if (atomic_dec_and_test(&conf
->pending_full_writes
))
2099 md_wakeup_thread(conf
->mddev
->thread
);
2102 static void handle_stripe_dirtying5(raid5_conf_t
*conf
,
2103 struct stripe_head
*sh
, struct stripe_head_state
*s
, int disks
)
2105 int rmw
= 0, rcw
= 0, i
;
2106 for (i
= disks
; i
--; ) {
2107 /* would I have to read this buffer for read_modify_write */
2108 struct r5dev
*dev
= &sh
->dev
[i
];
2109 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2110 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2111 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2112 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2113 if (test_bit(R5_Insync
, &dev
->flags
))
2116 rmw
+= 2*disks
; /* cannot read it */
2118 /* Would I have to read this buffer for reconstruct_write */
2119 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
2120 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2121 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2122 test_bit(R5_Wantcompute
, &dev
->flags
))) {
2123 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2128 pr_debug("for sector %llu, rmw=%d rcw=%d\n",
2129 (unsigned long long)sh
->sector
, rmw
, rcw
);
2130 set_bit(STRIPE_HANDLE
, &sh
->state
);
2131 if (rmw
< rcw
&& rmw
> 0)
2132 /* prefer read-modify-write, but need to get some data */
2133 for (i
= disks
; i
--; ) {
2134 struct r5dev
*dev
= &sh
->dev
[i
];
2135 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
2136 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2137 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2138 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2139 test_bit(R5_Insync
, &dev
->flags
)) {
2141 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2142 pr_debug("Read_old block "
2143 "%d for r-m-w\n", i
);
2144 set_bit(R5_LOCKED
, &dev
->flags
);
2145 set_bit(R5_Wantread
, &dev
->flags
);
2148 set_bit(STRIPE_DELAYED
, &sh
->state
);
2149 set_bit(STRIPE_HANDLE
, &sh
->state
);
2153 if (rcw
<= rmw
&& rcw
> 0)
2154 /* want reconstruct write, but need to get some data */
2155 for (i
= disks
; i
--; ) {
2156 struct r5dev
*dev
= &sh
->dev
[i
];
2157 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
2159 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2160 !(test_bit(R5_UPTODATE
, &dev
->flags
) ||
2161 test_bit(R5_Wantcompute
, &dev
->flags
)) &&
2162 test_bit(R5_Insync
, &dev
->flags
)) {
2164 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2165 pr_debug("Read_old block "
2166 "%d for Reconstruct\n", i
);
2167 set_bit(R5_LOCKED
, &dev
->flags
);
2168 set_bit(R5_Wantread
, &dev
->flags
);
2171 set_bit(STRIPE_DELAYED
, &sh
->state
);
2172 set_bit(STRIPE_HANDLE
, &sh
->state
);
2176 /* now if nothing is locked, and if we have enough data,
2177 * we can start a write request
2179 /* since handle_stripe can be called at any time we need to handle the
2180 * case where a compute block operation has been submitted and then a
2181 * subsequent call wants to start a write request. raid5_run_ops only
2182 * handles the case where compute block and postxor are requested
2183 * simultaneously. If this is not the case then new writes need to be
2184 * held off until the compute completes.
2186 if ((s
->req_compute
|| !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
)) &&
2187 (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
2188 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)))
2189 schedule_reconstruction5(sh
, s
, rcw
== 0, 0);
2192 static void handle_stripe_dirtying6(raid5_conf_t
*conf
,
2193 struct stripe_head
*sh
, struct stripe_head_state
*s
,
2194 struct r6_state
*r6s
, int disks
)
2196 int rcw
= 0, must_compute
= 0, pd_idx
= sh
->pd_idx
, i
;
2197 int qd_idx
= r6s
->qd_idx
;
2198 for (i
= disks
; i
--; ) {
2199 struct r5dev
*dev
= &sh
->dev
[i
];
2200 /* Would I have to read this buffer for reconstruct_write */
2201 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
2202 && i
!= pd_idx
&& i
!= qd_idx
2203 && (!test_bit(R5_LOCKED
, &dev
->flags
)
2205 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
2206 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2208 pr_debug("raid6: must_compute: "
2209 "disk %d flags=%#lx\n", i
, dev
->flags
);
2214 pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
2215 (unsigned long long)sh
->sector
, rcw
, must_compute
);
2216 set_bit(STRIPE_HANDLE
, &sh
->state
);
2219 /* want reconstruct write, but need to get some data */
2220 for (i
= disks
; i
--; ) {
2221 struct r5dev
*dev
= &sh
->dev
[i
];
2222 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
2223 && !(s
->failed
== 0 && (i
== pd_idx
|| i
== qd_idx
))
2224 && !test_bit(R5_LOCKED
, &dev
->flags
) &&
2225 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2226 test_bit(R5_Insync
, &dev
->flags
)) {
2228 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2229 pr_debug("Read_old stripe %llu "
2230 "block %d for Reconstruct\n",
2231 (unsigned long long)sh
->sector
, i
);
2232 set_bit(R5_LOCKED
, &dev
->flags
);
2233 set_bit(R5_Wantread
, &dev
->flags
);
2236 pr_debug("Request delayed stripe %llu "
2237 "block %d for Reconstruct\n",
2238 (unsigned long long)sh
->sector
, i
);
2239 set_bit(STRIPE_DELAYED
, &sh
->state
);
2240 set_bit(STRIPE_HANDLE
, &sh
->state
);
2244 /* now if nothing is locked, and if we have enough data, we can start a
2247 if (s
->locked
== 0 && rcw
== 0 &&
2248 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
2249 if (must_compute
> 0) {
2250 /* We have failed blocks and need to compute them */
2251 switch (s
->failed
) {
2255 compute_block_1(sh
, r6s
->failed_num
[0], 0);
2258 compute_block_2(sh
, r6s
->failed_num
[0],
2259 r6s
->failed_num
[1]);
2261 default: /* This request should have been failed? */
2266 pr_debug("Computing parity for stripe %llu\n",
2267 (unsigned long long)sh
->sector
);
2268 compute_parity6(sh
, RECONSTRUCT_WRITE
);
2269 /* now every locked buffer is ready to be written */
2270 for (i
= disks
; i
--; )
2271 if (test_bit(R5_LOCKED
, &sh
->dev
[i
].flags
)) {
2272 pr_debug("Writing stripe %llu block %d\n",
2273 (unsigned long long)sh
->sector
, i
);
2275 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
2277 if (s
->locked
== disks
)
2278 if (!test_and_set_bit(STRIPE_FULL_WRITE
, &sh
->state
))
2279 atomic_inc(&conf
->pending_full_writes
);
2280 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2281 set_bit(STRIPE_INSYNC
, &sh
->state
);
2283 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2284 atomic_dec(&conf
->preread_active_stripes
);
2285 if (atomic_read(&conf
->preread_active_stripes
) <
2287 md_wakeup_thread(conf
->mddev
->thread
);
2292 static void handle_parity_checks5(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2293 struct stripe_head_state
*s
, int disks
)
2295 struct r5dev
*dev
= NULL
;
2297 set_bit(STRIPE_HANDLE
, &sh
->state
);
2299 switch (sh
->check_state
) {
2300 case check_state_idle
:
2301 /* start a new check operation if there are no failures */
2302 if (s
->failed
== 0) {
2303 BUG_ON(s
->uptodate
!= disks
);
2304 sh
->check_state
= check_state_run
;
2305 set_bit(STRIPE_OP_CHECK
, &s
->ops_request
);
2306 clear_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
);
2310 dev
= &sh
->dev
[s
->failed_num
];
2312 case check_state_compute_result
:
2313 sh
->check_state
= check_state_idle
;
2315 dev
= &sh
->dev
[sh
->pd_idx
];
2317 /* check that a write has not made the stripe insync */
2318 if (test_bit(STRIPE_INSYNC
, &sh
->state
))
2321 /* either failed parity check, or recovery is happening */
2322 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
2323 BUG_ON(s
->uptodate
!= disks
);
2325 set_bit(R5_LOCKED
, &dev
->flags
);
2327 set_bit(R5_Wantwrite
, &dev
->flags
);
2329 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2330 set_bit(STRIPE_INSYNC
, &sh
->state
);
2332 case check_state_run
:
2333 break; /* we will be called again upon completion */
2334 case check_state_check_result
:
2335 sh
->check_state
= check_state_idle
;
2337 /* if a failure occurred during the check operation, leave
2338 * STRIPE_INSYNC not set and let the stripe be handled again
2343 /* handle a successful check operation, if parity is correct
2344 * we are done. Otherwise update the mismatch count and repair
2345 * parity if !MD_RECOVERY_CHECK
2347 if (sh
->ops
.zero_sum_result
== 0)
2348 /* parity is correct (on disc,
2349 * not in buffer any more)
2351 set_bit(STRIPE_INSYNC
, &sh
->state
);
2353 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2354 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2355 /* don't try to repair!! */
2356 set_bit(STRIPE_INSYNC
, &sh
->state
);
2358 sh
->check_state
= check_state_compute_run
;
2359 set_bit(STRIPE_COMPUTE_RUN
, &sh
->state
);
2360 set_bit(STRIPE_OP_COMPUTE_BLK
, &s
->ops_request
);
2361 set_bit(R5_Wantcompute
,
2362 &sh
->dev
[sh
->pd_idx
].flags
);
2363 sh
->ops
.target
= sh
->pd_idx
;
2368 case check_state_compute_run
:
2371 printk(KERN_ERR
"%s: unknown check_state: %d sector: %llu\n",
2372 __func__
, sh
->check_state
,
2373 (unsigned long long) sh
->sector
);
2379 static void handle_parity_checks6(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2380 struct stripe_head_state
*s
,
2381 struct r6_state
*r6s
, struct page
*tmp_page
,
2384 int update_p
= 0, update_q
= 0;
2386 int pd_idx
= sh
->pd_idx
;
2387 int qd_idx
= r6s
->qd_idx
;
2389 set_bit(STRIPE_HANDLE
, &sh
->state
);
2391 BUG_ON(s
->failed
> 2);
2392 BUG_ON(s
->uptodate
< disks
);
2393 /* Want to check and possibly repair P and Q.
2394 * However there could be one 'failed' device, in which
2395 * case we can only check one of them, possibly using the
2396 * other to generate missing data
2399 /* If !tmp_page, we cannot do the calculations,
2400 * but as we have set STRIPE_HANDLE, we will soon be called
2401 * by stripe_handle with a tmp_page - just wait until then.
2404 if (s
->failed
== r6s
->q_failed
) {
2405 /* The only possible failed device holds 'Q', so it
2406 * makes sense to check P (If anything else were failed,
2407 * we would have used P to recreate it).
2409 compute_block_1(sh
, pd_idx
, 1);
2410 if (!page_is_zero(sh
->dev
[pd_idx
].page
)) {
2411 compute_block_1(sh
, pd_idx
, 0);
2415 if (!r6s
->q_failed
&& s
->failed
< 2) {
2416 /* q is not failed, and we didn't use it to generate
2417 * anything, so it makes sense to check it
2419 memcpy(page_address(tmp_page
),
2420 page_address(sh
->dev
[qd_idx
].page
),
2422 compute_parity6(sh
, UPDATE_PARITY
);
2423 if (memcmp(page_address(tmp_page
),
2424 page_address(sh
->dev
[qd_idx
].page
),
2425 STRIPE_SIZE
) != 0) {
2426 clear_bit(STRIPE_INSYNC
, &sh
->state
);
2430 if (update_p
|| update_q
) {
2431 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2432 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2433 /* don't try to repair!! */
2434 update_p
= update_q
= 0;
2437 /* now write out any block on a failed drive,
2438 * or P or Q if they need it
2441 if (s
->failed
== 2) {
2442 dev
= &sh
->dev
[r6s
->failed_num
[1]];
2444 set_bit(R5_LOCKED
, &dev
->flags
);
2445 set_bit(R5_Wantwrite
, &dev
->flags
);
2447 if (s
->failed
>= 1) {
2448 dev
= &sh
->dev
[r6s
->failed_num
[0]];
2450 set_bit(R5_LOCKED
, &dev
->flags
);
2451 set_bit(R5_Wantwrite
, &dev
->flags
);
2455 dev
= &sh
->dev
[pd_idx
];
2457 set_bit(R5_LOCKED
, &dev
->flags
);
2458 set_bit(R5_Wantwrite
, &dev
->flags
);
2461 dev
= &sh
->dev
[qd_idx
];
2463 set_bit(R5_LOCKED
, &dev
->flags
);
2464 set_bit(R5_Wantwrite
, &dev
->flags
);
2466 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2468 set_bit(STRIPE_INSYNC
, &sh
->state
);
2472 static void handle_stripe_expansion(raid5_conf_t
*conf
, struct stripe_head
*sh
,
2473 struct r6_state
*r6s
)
2477 /* We have read all the blocks in this stripe and now we need to
2478 * copy some of them into a target stripe for expand.
2480 struct dma_async_tx_descriptor
*tx
= NULL
;
2481 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2482 for (i
= 0; i
< sh
->disks
; i
++)
2483 if (i
!= sh
->pd_idx
&& (!r6s
|| i
!= r6s
->qd_idx
)) {
2484 int dd_idx
, pd_idx
, j
;
2485 struct stripe_head
*sh2
;
2487 sector_t bn
= compute_blocknr(sh
, i
);
2488 sector_t s
= raid5_compute_sector(conf
, bn
, 0,
2490 sh2
= get_active_stripe(conf
, s
, 0, 1);
2492 /* so far only the early blocks of this stripe
2493 * have been requested. When later blocks
2494 * get requested, we will try again
2497 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
2498 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
2499 /* must have already done this block */
2500 release_stripe(sh2
);
2504 /* place all the copies on one channel */
2505 tx
= async_memcpy(sh2
->dev
[dd_idx
].page
,
2506 sh
->dev
[i
].page
, 0, 0, STRIPE_SIZE
,
2507 ASYNC_TX_DEP_ACK
, tx
, NULL
, NULL
);
2509 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
2510 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
2511 for (j
= 0; j
< conf
->raid_disks
; j
++)
2512 if (j
!= sh2
->pd_idx
&&
2513 (!r6s
|| j
!= raid6_next_disk(sh2
->pd_idx
,
2515 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
2517 if (j
== conf
->raid_disks
) {
2518 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
2519 set_bit(STRIPE_HANDLE
, &sh2
->state
);
2521 release_stripe(sh2
);
2524 /* done submitting copies, wait for them to complete */
2527 dma_wait_for_async_tx(tx
);
2533 * handle_stripe - do things to a stripe.
2535 * We lock the stripe and then examine the state of various bits
2536 * to see what needs to be done.
2538 * return some read request which now have data
2539 * return some write requests which are safely on disc
2540 * schedule a read on some buffers
2541 * schedule a write of some buffers
2542 * return confirmation of parity correctness
2544 * buffers are taken off read_list or write_list, and bh_cache buffers
2545 * get BH_Lock set before the stripe lock is released.
2549 static bool handle_stripe5(struct stripe_head
*sh
)
2551 raid5_conf_t
*conf
= sh
->raid_conf
;
2552 int disks
= sh
->disks
, i
;
2553 struct bio
*return_bi
= NULL
;
2554 struct stripe_head_state s
;
2556 mdk_rdev_t
*blocked_rdev
= NULL
;
2559 memset(&s
, 0, sizeof(s
));
2560 pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
2561 "reconstruct:%d\n", (unsigned long long)sh
->sector
, sh
->state
,
2562 atomic_read(&sh
->count
), sh
->pd_idx
, sh
->check_state
,
2563 sh
->reconstruct_state
);
2565 spin_lock(&sh
->lock
);
2566 clear_bit(STRIPE_HANDLE
, &sh
->state
);
2567 clear_bit(STRIPE_DELAYED
, &sh
->state
);
2569 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
2570 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2571 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2573 /* Now to look around and see what can be done */
2575 for (i
=disks
; i
--; ) {
2577 struct r5dev
*dev
= &sh
->dev
[i
];
2578 clear_bit(R5_Insync
, &dev
->flags
);
2580 pr_debug("check %d: state 0x%lx toread %p read %p write %p "
2581 "written %p\n", i
, dev
->flags
, dev
->toread
, dev
->read
,
2582 dev
->towrite
, dev
->written
);
2584 /* maybe we can request a biofill operation
2586 * new wantfill requests are only permitted while
2587 * ops_complete_biofill is guaranteed to be inactive
2589 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
&&
2590 !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
))
2591 set_bit(R5_Wantfill
, &dev
->flags
);
2593 /* now count some things */
2594 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
2595 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
2596 if (test_bit(R5_Wantcompute
, &dev
->flags
)) s
.compute
++;
2598 if (test_bit(R5_Wantfill
, &dev
->flags
))
2600 else if (dev
->toread
)
2604 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
2609 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2610 if (blocked_rdev
== NULL
&&
2611 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
2612 blocked_rdev
= rdev
;
2613 atomic_inc(&rdev
->nr_pending
);
2615 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
2616 /* The ReadError flag will just be confusing now */
2617 clear_bit(R5_ReadError
, &dev
->flags
);
2618 clear_bit(R5_ReWrite
, &dev
->flags
);
2620 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
2621 || test_bit(R5_ReadError
, &dev
->flags
)) {
2625 set_bit(R5_Insync
, &dev
->flags
);
2629 if (unlikely(blocked_rdev
)) {
2630 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
2631 s
.to_write
|| s
.written
) {
2632 set_bit(STRIPE_HANDLE
, &sh
->state
);
2635 /* There is nothing for the blocked_rdev to block */
2636 rdev_dec_pending(blocked_rdev
, conf
->mddev
);
2637 blocked_rdev
= NULL
;
2640 if (s
.to_fill
&& !test_bit(STRIPE_BIOFILL_RUN
, &sh
->state
)) {
2641 set_bit(STRIPE_OP_BIOFILL
, &s
.ops_request
);
2642 set_bit(STRIPE_BIOFILL_RUN
, &sh
->state
);
2645 pr_debug("locked=%d uptodate=%d to_read=%d"
2646 " to_write=%d failed=%d failed_num=%d\n",
2647 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
,
2648 s
.failed
, s
.failed_num
);
2649 /* check if the array has lost two devices and, if so, some requests might
2652 if (s
.failed
> 1 && s
.to_read
+s
.to_write
+s
.written
)
2653 handle_failed_stripe(conf
, sh
, &s
, disks
, &return_bi
);
2654 if (s
.failed
> 1 && s
.syncing
) {
2655 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
2656 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2660 /* might be able to return some write requests if the parity block
2661 * is safe, or on a failed drive
2663 dev
= &sh
->dev
[sh
->pd_idx
];
2665 ((test_bit(R5_Insync
, &dev
->flags
) &&
2666 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2667 test_bit(R5_UPTODATE
, &dev
->flags
)) ||
2668 (s
.failed
== 1 && s
.failed_num
== sh
->pd_idx
)))
2669 handle_stripe_clean_event(conf
, sh
, disks
, &return_bi
);
2671 /* Now we might consider reading some blocks, either to check/generate
2672 * parity, or to satisfy requests
2673 * or to load a block that is being partially written.
2675 if (s
.to_read
|| s
.non_overwrite
||
2676 (s
.syncing
&& (s
.uptodate
+ s
.compute
< disks
)) || s
.expanding
)
2677 handle_stripe_fill5(sh
, &s
, disks
);
2679 /* Now we check to see if any write operations have recently
2683 if (sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
)
2685 if (sh
->reconstruct_state
== reconstruct_state_drain_result
||
2686 sh
->reconstruct_state
== reconstruct_state_prexor_drain_result
) {
2687 sh
->reconstruct_state
= reconstruct_state_idle
;
2689 /* All the 'written' buffers and the parity block are ready to
2690 * be written back to disk
2692 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[sh
->pd_idx
].flags
));
2693 for (i
= disks
; i
--; ) {
2695 if (test_bit(R5_LOCKED
, &dev
->flags
) &&
2696 (i
== sh
->pd_idx
|| dev
->written
)) {
2697 pr_debug("Writing block %d\n", i
);
2698 set_bit(R5_Wantwrite
, &dev
->flags
);
2701 if (!test_bit(R5_Insync
, &dev
->flags
) ||
2702 (i
== sh
->pd_idx
&& s
.failed
== 0))
2703 set_bit(STRIPE_INSYNC
, &sh
->state
);
2706 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2707 atomic_dec(&conf
->preread_active_stripes
);
2708 if (atomic_read(&conf
->preread_active_stripes
) <
2710 md_wakeup_thread(conf
->mddev
->thread
);
2714 /* Now to consider new write requests and what else, if anything
2715 * should be read. We do not handle new writes when:
2716 * 1/ A 'write' operation (copy+xor) is already in flight.
2717 * 2/ A 'check' operation is in flight, as it may clobber the parity
2720 if (s
.to_write
&& !sh
->reconstruct_state
&& !sh
->check_state
)
2721 handle_stripe_dirtying5(conf
, sh
, &s
, disks
);
2723 /* maybe we need to check and possibly fix the parity for this stripe
2724 * Any reads will already have been scheduled, so we just see if enough
2725 * data is available. The parity check is held off while parity
2726 * dependent operations are in flight.
2728 if (sh
->check_state
||
2729 (s
.syncing
&& s
.locked
== 0 &&
2730 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
) &&
2731 !test_bit(STRIPE_INSYNC
, &sh
->state
)))
2732 handle_parity_checks5(conf
, sh
, &s
, disks
);
2734 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
2735 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
2736 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2739 /* If the failed drive is just a ReadError, then we might need to progress
2740 * the repair/check process
2742 if (s
.failed
== 1 && !conf
->mddev
->ro
&&
2743 test_bit(R5_ReadError
, &sh
->dev
[s
.failed_num
].flags
)
2744 && !test_bit(R5_LOCKED
, &sh
->dev
[s
.failed_num
].flags
)
2745 && test_bit(R5_UPTODATE
, &sh
->dev
[s
.failed_num
].flags
)
2747 dev
= &sh
->dev
[s
.failed_num
];
2748 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
2749 set_bit(R5_Wantwrite
, &dev
->flags
);
2750 set_bit(R5_ReWrite
, &dev
->flags
);
2751 set_bit(R5_LOCKED
, &dev
->flags
);
2754 /* let's read it back */
2755 set_bit(R5_Wantread
, &dev
->flags
);
2756 set_bit(R5_LOCKED
, &dev
->flags
);
2761 /* Finish reconstruct operations initiated by the expansion process */
2762 if (sh
->reconstruct_state
== reconstruct_state_result
) {
2763 sh
->reconstruct_state
= reconstruct_state_idle
;
2764 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
2765 for (i
= conf
->raid_disks
; i
--; ) {
2766 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
2767 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2772 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
) &&
2773 !sh
->reconstruct_state
) {
2774 /* Need to write out all blocks after computing parity */
2775 sh
->disks
= conf
->raid_disks
;
2776 sh
->pd_idx
= stripe_to_pdidx(sh
->sector
, conf
, 0);
2777 schedule_reconstruction5(sh
, &s
, 1, 1);
2778 } else if (s
.expanded
&& !sh
->reconstruct_state
&& s
.locked
== 0) {
2779 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2780 atomic_dec(&conf
->reshape_stripes
);
2781 wake_up(&conf
->wait_for_overlap
);
2782 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
2785 if (s
.expanding
&& s
.locked
== 0 &&
2786 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
2787 handle_stripe_expansion(conf
, sh
, NULL
);
2790 spin_unlock(&sh
->lock
);
2792 /* wait for this device to become unblocked */
2793 if (unlikely(blocked_rdev
))
2794 md_wait_for_blocked_rdev(blocked_rdev
, conf
->mddev
);
2797 raid5_run_ops(sh
, s
.ops_request
);
2801 return_io(return_bi
);
2803 return blocked_rdev
== NULL
;
2806 static bool handle_stripe6(struct stripe_head
*sh
, struct page
*tmp_page
)
2808 raid5_conf_t
*conf
= sh
->raid_conf
;
2809 int disks
= sh
->disks
;
2810 struct bio
*return_bi
= NULL
;
2811 int i
, pd_idx
= sh
->pd_idx
;
2812 struct stripe_head_state s
;
2813 struct r6_state r6s
;
2814 struct r5dev
*dev
, *pdev
, *qdev
;
2815 mdk_rdev_t
*blocked_rdev
= NULL
;
2817 r6s
.qd_idx
= raid6_next_disk(pd_idx
, disks
);
2818 pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
2819 "pd_idx=%d, qd_idx=%d\n",
2820 (unsigned long long)sh
->sector
, sh
->state
,
2821 atomic_read(&sh
->count
), pd_idx
, r6s
.qd_idx
);
2822 memset(&s
, 0, sizeof(s
));
2824 spin_lock(&sh
->lock
);
2825 clear_bit(STRIPE_HANDLE
, &sh
->state
);
2826 clear_bit(STRIPE_DELAYED
, &sh
->state
);
2828 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
2829 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2830 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2831 /* Now to look around and see what can be done */
2834 for (i
=disks
; i
--; ) {
2837 clear_bit(R5_Insync
, &dev
->flags
);
2839 pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
2840 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
2841 /* maybe we can reply to a read */
2842 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
) {
2843 struct bio
*rbi
, *rbi2
;
2844 pr_debug("Return read for disc %d\n", i
);
2845 spin_lock_irq(&conf
->device_lock
);
2848 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
2849 wake_up(&conf
->wait_for_overlap
);
2850 spin_unlock_irq(&conf
->device_lock
);
2851 while (rbi
&& rbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
2852 copy_data(0, rbi
, dev
->page
, dev
->sector
);
2853 rbi2
= r5_next_bio(rbi
, dev
->sector
);
2854 spin_lock_irq(&conf
->device_lock
);
2855 if (!raid5_dec_bi_phys_segments(rbi
)) {
2856 rbi
->bi_next
= return_bi
;
2859 spin_unlock_irq(&conf
->device_lock
);
2864 /* now count some things */
2865 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
2866 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
2873 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
2878 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2879 if (blocked_rdev
== NULL
&&
2880 rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
2881 blocked_rdev
= rdev
;
2882 atomic_inc(&rdev
->nr_pending
);
2884 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
2885 /* The ReadError flag will just be confusing now */
2886 clear_bit(R5_ReadError
, &dev
->flags
);
2887 clear_bit(R5_ReWrite
, &dev
->flags
);
2889 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
2890 || test_bit(R5_ReadError
, &dev
->flags
)) {
2892 r6s
.failed_num
[s
.failed
] = i
;
2895 set_bit(R5_Insync
, &dev
->flags
);
2899 if (unlikely(blocked_rdev
)) {
2900 if (s
.syncing
|| s
.expanding
|| s
.expanded
||
2901 s
.to_write
|| s
.written
) {
2902 set_bit(STRIPE_HANDLE
, &sh
->state
);
2905 /* There is nothing for the blocked_rdev to block */
2906 rdev_dec_pending(blocked_rdev
, conf
->mddev
);
2907 blocked_rdev
= NULL
;
2910 pr_debug("locked=%d uptodate=%d to_read=%d"
2911 " to_write=%d failed=%d failed_num=%d,%d\n",
2912 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
2913 r6s
.failed_num
[0], r6s
.failed_num
[1]);
2914 /* check if the array has lost >2 devices and, if so, some requests
2915 * might need to be failed
2917 if (s
.failed
> 2 && s
.to_read
+s
.to_write
+s
.written
)
2918 handle_failed_stripe(conf
, sh
, &s
, disks
, &return_bi
);
2919 if (s
.failed
> 2 && s
.syncing
) {
2920 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
2921 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2926 * might be able to return some write requests if the parity blocks
2927 * are safe, or on a failed drive
2929 pdev
= &sh
->dev
[pd_idx
];
2930 r6s
.p_failed
= (s
.failed
>= 1 && r6s
.failed_num
[0] == pd_idx
)
2931 || (s
.failed
>= 2 && r6s
.failed_num
[1] == pd_idx
);
2932 qdev
= &sh
->dev
[r6s
.qd_idx
];
2933 r6s
.q_failed
= (s
.failed
>= 1 && r6s
.failed_num
[0] == r6s
.qd_idx
)
2934 || (s
.failed
>= 2 && r6s
.failed_num
[1] == r6s
.qd_idx
);
2937 ( r6s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
2938 && !test_bit(R5_LOCKED
, &pdev
->flags
)
2939 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
2940 ( r6s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
2941 && !test_bit(R5_LOCKED
, &qdev
->flags
)
2942 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
2943 handle_stripe_clean_event(conf
, sh
, disks
, &return_bi
);
2945 /* Now we might consider reading some blocks, either to check/generate
2946 * parity, or to satisfy requests
2947 * or to load a block that is being partially written.
2949 if (s
.to_read
|| s
.non_overwrite
|| (s
.to_write
&& s
.failed
) ||
2950 (s
.syncing
&& (s
.uptodate
< disks
)) || s
.expanding
)
2951 handle_stripe_fill6(sh
, &s
, &r6s
, disks
);
2953 /* now to consider writing and what else, if anything should be read */
2955 handle_stripe_dirtying6(conf
, sh
, &s
, &r6s
, disks
);
2957 /* maybe we need to check and possibly fix the parity for this stripe
2958 * Any reads will already have been scheduled, so we just see if enough
2961 if (s
.syncing
&& s
.locked
== 0 && !test_bit(STRIPE_INSYNC
, &sh
->state
))
2962 handle_parity_checks6(conf
, sh
, &s
, &r6s
, tmp_page
, disks
);
2964 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
2965 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
2966 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2969 /* If the failed drives are just a ReadError, then we might need
2970 * to progress the repair/check process
2972 if (s
.failed
<= 2 && !conf
->mddev
->ro
)
2973 for (i
= 0; i
< s
.failed
; i
++) {
2974 dev
= &sh
->dev
[r6s
.failed_num
[i
]];
2975 if (test_bit(R5_ReadError
, &dev
->flags
)
2976 && !test_bit(R5_LOCKED
, &dev
->flags
)
2977 && test_bit(R5_UPTODATE
, &dev
->flags
)
2979 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
2980 set_bit(R5_Wantwrite
, &dev
->flags
);
2981 set_bit(R5_ReWrite
, &dev
->flags
);
2982 set_bit(R5_LOCKED
, &dev
->flags
);
2984 /* let's read it back */
2985 set_bit(R5_Wantread
, &dev
->flags
);
2986 set_bit(R5_LOCKED
, &dev
->flags
);
2991 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
2992 /* Need to write out all blocks after computing P&Q */
2993 sh
->disks
= conf
->raid_disks
;
2994 sh
->pd_idx
= stripe_to_pdidx(sh
->sector
, conf
, 0);
2995 compute_parity6(sh
, RECONSTRUCT_WRITE
);
2996 for (i
= conf
->raid_disks
; i
-- ; ) {
2997 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2999 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
3001 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
3002 } else if (s
.expanded
) {
3003 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3004 atomic_dec(&conf
->reshape_stripes
);
3005 wake_up(&conf
->wait_for_overlap
);
3006 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
3009 if (s
.expanding
&& s
.locked
== 0 &&
3010 !test_bit(STRIPE_COMPUTE_RUN
, &sh
->state
))
3011 handle_stripe_expansion(conf
, sh
, &r6s
);
3014 spin_unlock(&sh
->lock
);
3016 /* wait for this device to become unblocked */
3017 if (unlikely(blocked_rdev
))
3018 md_wait_for_blocked_rdev(blocked_rdev
, conf
->mddev
);
3022 return_io(return_bi
);
3024 return blocked_rdev
== NULL
;
3027 /* returns true if the stripe was handled */
3028 static bool handle_stripe(struct stripe_head
*sh
, struct page
*tmp_page
)
3030 if (sh
->raid_conf
->level
== 6)
3031 return handle_stripe6(sh
, tmp_page
);
3033 return handle_stripe5(sh
);
3038 static void raid5_activate_delayed(raid5_conf_t
*conf
)
3040 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
3041 while (!list_empty(&conf
->delayed_list
)) {
3042 struct list_head
*l
= conf
->delayed_list
.next
;
3043 struct stripe_head
*sh
;
3044 sh
= list_entry(l
, struct stripe_head
, lru
);
3046 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3047 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
3048 atomic_inc(&conf
->preread_active_stripes
);
3049 list_add_tail(&sh
->lru
, &conf
->hold_list
);
3052 blk_plug_device(conf
->mddev
->queue
);
3055 static void activate_bit_delay(raid5_conf_t
*conf
)
3057 /* device_lock is held */
3058 struct list_head head
;
3059 list_add(&head
, &conf
->bitmap_list
);
3060 list_del_init(&conf
->bitmap_list
);
3061 while (!list_empty(&head
)) {
3062 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
3063 list_del_init(&sh
->lru
);
3064 atomic_inc(&sh
->count
);
3065 __release_stripe(conf
, sh
);
3069 static void unplug_slaves(mddev_t
*mddev
)
3071 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3075 for (i
=0; i
<mddev
->raid_disks
; i
++) {
3076 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
3077 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) && atomic_read(&rdev
->nr_pending
)) {
3078 struct request_queue
*r_queue
= bdev_get_queue(rdev
->bdev
);
3080 atomic_inc(&rdev
->nr_pending
);
3083 blk_unplug(r_queue
);
3085 rdev_dec_pending(rdev
, mddev
);
3092 static void raid5_unplug_device(struct request_queue
*q
)
3094 mddev_t
*mddev
= q
->queuedata
;
3095 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3096 unsigned long flags
;
3098 spin_lock_irqsave(&conf
->device_lock
, flags
);
3100 if (blk_remove_plug(q
)) {
3102 raid5_activate_delayed(conf
);
3104 md_wakeup_thread(mddev
->thread
);
3106 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3108 unplug_slaves(mddev
);
3111 static int raid5_congested(void *data
, int bits
)
3113 mddev_t
*mddev
= data
;
3114 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3116 /* No difference between reads and writes. Just check
3117 * how busy the stripe_cache is
3119 if (conf
->inactive_blocked
)
3123 if (list_empty_careful(&conf
->inactive_list
))
3129 /* We want read requests to align with chunks where possible,
3130 * but write requests don't need to.
3132 static int raid5_mergeable_bvec(struct request_queue
*q
,
3133 struct bvec_merge_data
*bvm
,
3134 struct bio_vec
*biovec
)
3136 mddev_t
*mddev
= q
->queuedata
;
3137 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
3139 unsigned int chunk_sectors
= mddev
->chunk_size
>> 9;
3140 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
3142 if ((bvm
->bi_rw
& 1) == WRITE
)
3143 return biovec
->bv_len
; /* always allow writes to be mergeable */
3145 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
3146 if (max
< 0) max
= 0;
3147 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
3148 return biovec
->bv_len
;
3154 static int in_chunk_boundary(mddev_t
*mddev
, struct bio
*bio
)
3156 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
3157 unsigned int chunk_sectors
= mddev
->chunk_size
>> 9;
3158 unsigned int bio_sectors
= bio
->bi_size
>> 9;
3160 return chunk_sectors
>=
3161 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
3165 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
3166 * later sampled by raid5d.
3168 static void add_bio_to_retry(struct bio
*bi
,raid5_conf_t
*conf
)
3170 unsigned long flags
;
3172 spin_lock_irqsave(&conf
->device_lock
, flags
);
3174 bi
->bi_next
= conf
->retry_read_aligned_list
;
3175 conf
->retry_read_aligned_list
= bi
;
3177 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3178 md_wakeup_thread(conf
->mddev
->thread
);
3182 static struct bio
*remove_bio_from_retry(raid5_conf_t
*conf
)
3186 bi
= conf
->retry_read_aligned
;
3188 conf
->retry_read_aligned
= NULL
;
3191 bi
= conf
->retry_read_aligned_list
;
3193 conf
->retry_read_aligned_list
= bi
->bi_next
;
3196 * this sets the active strip count to 1 and the processed
3197 * strip count to zero (upper 8 bits)
3199 bi
->bi_phys_segments
= 1; /* biased count of active stripes */
3207 * The "raid5_align_endio" should check if the read succeeded and if it
3208 * did, call bio_endio on the original bio (having bio_put the new bio
3210 * If the read failed..
3212 static void raid5_align_endio(struct bio
*bi
, int error
)
3214 struct bio
* raid_bi
= bi
->bi_private
;
3217 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3222 mddev
= raid_bi
->bi_bdev
->bd_disk
->queue
->queuedata
;
3223 conf
= mddev_to_conf(mddev
);
3224 rdev
= (void*)raid_bi
->bi_next
;
3225 raid_bi
->bi_next
= NULL
;
3227 rdev_dec_pending(rdev
, conf
->mddev
);
3229 if (!error
&& uptodate
) {
3230 bio_endio(raid_bi
, 0);
3231 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3232 wake_up(&conf
->wait_for_stripe
);
3237 pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
3239 add_bio_to_retry(raid_bi
, conf
);
3242 static int bio_fits_rdev(struct bio
*bi
)
3244 struct request_queue
*q
= bdev_get_queue(bi
->bi_bdev
);
3246 if ((bi
->bi_size
>>9) > q
->max_sectors
)
3248 blk_recount_segments(q
, bi
);
3249 if (bi
->bi_phys_segments
> q
->max_phys_segments
)
3252 if (q
->merge_bvec_fn
)
3253 /* it's too hard to apply the merge_bvec_fn at this stage,
3262 static int chunk_aligned_read(struct request_queue
*q
, struct bio
* raid_bio
)
3264 mddev_t
*mddev
= q
->queuedata
;
3265 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3266 unsigned int dd_idx
, pd_idx
;
3267 struct bio
* align_bi
;
3270 if (!in_chunk_boundary(mddev
, raid_bio
)) {
3271 pr_debug("chunk_aligned_read : non aligned\n");
3275 * use bio_clone to make a copy of the bio
3277 align_bi
= bio_clone(raid_bio
, GFP_NOIO
);
3281 * set bi_end_io to a new function, and set bi_private to the
3284 align_bi
->bi_end_io
= raid5_align_endio
;
3285 align_bi
->bi_private
= raid_bio
;
3289 align_bi
->bi_sector
= raid5_compute_sector(conf
, raid_bio
->bi_sector
,
3294 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
3295 if (rdev
&& test_bit(In_sync
, &rdev
->flags
)) {
3296 atomic_inc(&rdev
->nr_pending
);
3298 raid_bio
->bi_next
= (void*)rdev
;
3299 align_bi
->bi_bdev
= rdev
->bdev
;
3300 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
3301 align_bi
->bi_sector
+= rdev
->data_offset
;
3303 if (!bio_fits_rdev(align_bi
)) {
3304 /* too big in some way */
3306 rdev_dec_pending(rdev
, mddev
);
3310 spin_lock_irq(&conf
->device_lock
);
3311 wait_event_lock_irq(conf
->wait_for_stripe
,
3313 conf
->device_lock
, /* nothing */);
3314 atomic_inc(&conf
->active_aligned_reads
);
3315 spin_unlock_irq(&conf
->device_lock
);
3317 generic_make_request(align_bi
);
3326 /* __get_priority_stripe - get the next stripe to process
3328 * Full stripe writes are allowed to pass preread active stripes up until
3329 * the bypass_threshold is exceeded. In general the bypass_count
3330 * increments when the handle_list is handled before the hold_list; however, it
3331 * will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
3332 * stripe with in flight i/o. The bypass_count will be reset when the
3333 * head of the hold_list has changed, i.e. the head was promoted to the
3336 static struct stripe_head
*__get_priority_stripe(raid5_conf_t
*conf
)
3338 struct stripe_head
*sh
;
3340 pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
3342 list_empty(&conf
->handle_list
) ? "empty" : "busy",
3343 list_empty(&conf
->hold_list
) ? "empty" : "busy",
3344 atomic_read(&conf
->pending_full_writes
), conf
->bypass_count
);
3346 if (!list_empty(&conf
->handle_list
)) {
3347 sh
= list_entry(conf
->handle_list
.next
, typeof(*sh
), lru
);
3349 if (list_empty(&conf
->hold_list
))
3350 conf
->bypass_count
= 0;
3351 else if (!test_bit(STRIPE_IO_STARTED
, &sh
->state
)) {
3352 if (conf
->hold_list
.next
== conf
->last_hold
)
3353 conf
->bypass_count
++;
3355 conf
->last_hold
= conf
->hold_list
.next
;
3356 conf
->bypass_count
-= conf
->bypass_threshold
;
3357 if (conf
->bypass_count
< 0)
3358 conf
->bypass_count
= 0;
3361 } else if (!list_empty(&conf
->hold_list
) &&
3362 ((conf
->bypass_threshold
&&
3363 conf
->bypass_count
> conf
->bypass_threshold
) ||
3364 atomic_read(&conf
->pending_full_writes
) == 0)) {
3365 sh
= list_entry(conf
->hold_list
.next
,
3367 conf
->bypass_count
-= conf
->bypass_threshold
;
3368 if (conf
->bypass_count
< 0)
3369 conf
->bypass_count
= 0;
3373 list_del_init(&sh
->lru
);
3374 atomic_inc(&sh
->count
);
3375 BUG_ON(atomic_read(&sh
->count
) != 1);
3379 static int make_request(struct request_queue
*q
, struct bio
* bi
)
3381 mddev_t
*mddev
= q
->queuedata
;
3382 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3383 unsigned int dd_idx
, pd_idx
;
3384 sector_t new_sector
;
3385 sector_t logical_sector
, last_sector
;
3386 struct stripe_head
*sh
;
3387 const int rw
= bio_data_dir(bi
);
3390 if (unlikely(bio_barrier(bi
))) {
3391 bio_endio(bi
, -EOPNOTSUPP
);
3395 md_write_start(mddev
, bi
);
3397 cpu
= part_stat_lock();
3398 part_stat_inc(cpu
, &mddev
->gendisk
->part0
, ios
[rw
]);
3399 part_stat_add(cpu
, &mddev
->gendisk
->part0
, sectors
[rw
],
3404 mddev
->reshape_position
== MaxSector
&&
3405 chunk_aligned_read(q
,bi
))
3408 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3409 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
3411 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
3413 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
3415 int disks
, data_disks
;
3420 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
3421 if (likely(conf
->expand_progress
== MaxSector
))
3422 disks
= conf
->raid_disks
;
3424 /* spinlock is needed as expand_progress may be
3425 * 64bit on a 32bit platform, and so it might be
3426 * possible to see a half-updated value
3427 * Ofcourse expand_progress could change after
3428 * the lock is dropped, so once we get a reference
3429 * to the stripe that we think it is, we will have
3432 spin_lock_irq(&conf
->device_lock
);
3433 disks
= conf
->raid_disks
;
3434 if (logical_sector
>= conf
->expand_progress
) {
3435 disks
= conf
->previous_raid_disks
;
3438 if (logical_sector
>= conf
->expand_lo
) {
3439 spin_unlock_irq(&conf
->device_lock
);
3444 spin_unlock_irq(&conf
->device_lock
);
3446 data_disks
= disks
- conf
->max_degraded
;
3448 new_sector
= raid5_compute_sector(conf
, logical_sector
,
3451 pr_debug("raid5: make_request, sector %llu logical %llu\n",
3452 (unsigned long long)new_sector
,
3453 (unsigned long long)logical_sector
);
3455 sh
= get_active_stripe(conf
, new_sector
, previous
,
3456 (bi
->bi_rw
&RWA_MASK
));
3458 if (unlikely(conf
->expand_progress
!= MaxSector
)) {
3459 /* expansion might have moved on while waiting for a
3460 * stripe, so we must do the range check again.
3461 * Expansion could still move past after this
3462 * test, but as we are holding a reference to
3463 * 'sh', we know that if that happens,
3464 * STRIPE_EXPANDING will get set and the expansion
3465 * won't proceed until we finish with the stripe.
3468 spin_lock_irq(&conf
->device_lock
);
3469 if (logical_sector
< conf
->expand_progress
&&
3470 disks
== conf
->previous_raid_disks
)
3471 /* mismatch, need to try again */
3473 spin_unlock_irq(&conf
->device_lock
);
3479 /* FIXME what if we get a false positive because these
3480 * are being updated.
3482 if (logical_sector
>= mddev
->suspend_lo
&&
3483 logical_sector
< mddev
->suspend_hi
) {
3489 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
3490 !add_stripe_bio(sh
, bi
, dd_idx
, (bi
->bi_rw
&RW_MASK
))) {
3491 /* Stripe is busy expanding or
3492 * add failed due to overlap. Flush everything
3495 raid5_unplug_device(mddev
->queue
);
3500 finish_wait(&conf
->wait_for_overlap
, &w
);
3501 set_bit(STRIPE_HANDLE
, &sh
->state
);
3502 clear_bit(STRIPE_DELAYED
, &sh
->state
);
3505 /* cannot get stripe for read-ahead, just give-up */
3506 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
3507 finish_wait(&conf
->wait_for_overlap
, &w
);
3512 spin_lock_irq(&conf
->device_lock
);
3513 remaining
= raid5_dec_bi_phys_segments(bi
);
3514 spin_unlock_irq(&conf
->device_lock
);
3515 if (remaining
== 0) {
3518 md_write_end(mddev
);
3525 static sector_t
reshape_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
)
3527 /* reshaping is quite different to recovery/resync so it is
3528 * handled quite separately ... here.
3530 * On each call to sync_request, we gather one chunk worth of
3531 * destination stripes and flag them as expanding.
3532 * Then we find all the source stripes and request reads.
3533 * As the reads complete, handle_stripe will copy the data
3534 * into the destination stripe and release that stripe.
3536 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3537 struct stripe_head
*sh
;
3539 sector_t first_sector
, last_sector
;
3540 int raid_disks
= conf
->previous_raid_disks
;
3541 int data_disks
= raid_disks
- conf
->max_degraded
;
3542 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
3545 sector_t writepos
, safepos
, gap
;
3547 if (sector_nr
== 0 &&
3548 conf
->expand_progress
!= 0) {
3549 /* restarting in the middle, skip the initial sectors */
3550 sector_nr
= conf
->expand_progress
;
3551 sector_div(sector_nr
, new_data_disks
);
3556 /* we update the metadata when there is more than 3Meg
3557 * in the block range (that is rather arbitrary, should
3558 * probably be time based) or when the data about to be
3559 * copied would over-write the source of the data at
3560 * the front of the range.
3561 * i.e. one new_stripe forward from expand_progress new_maps
3562 * to after where expand_lo old_maps to
3564 writepos
= conf
->expand_progress
+
3565 conf
->chunk_size
/512*(new_data_disks
);
3566 sector_div(writepos
, new_data_disks
);
3567 safepos
= conf
->expand_lo
;
3568 sector_div(safepos
, data_disks
);
3569 gap
= conf
->expand_progress
- conf
->expand_lo
;
3571 if (writepos
>= safepos
||
3572 gap
> (new_data_disks
)*3000*2 /*3Meg*/) {
3573 /* Cannot proceed until we've updated the superblock... */
3574 wait_event(conf
->wait_for_overlap
,
3575 atomic_read(&conf
->reshape_stripes
)==0);
3576 mddev
->reshape_position
= conf
->expand_progress
;
3577 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
3578 md_wakeup_thread(mddev
->thread
);
3579 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
3580 kthread_should_stop());
3581 spin_lock_irq(&conf
->device_lock
);
3582 conf
->expand_lo
= mddev
->reshape_position
;
3583 spin_unlock_irq(&conf
->device_lock
);
3584 wake_up(&conf
->wait_for_overlap
);
3587 for (i
=0; i
< conf
->chunk_size
/512; i
+= STRIPE_SECTORS
) {
3590 sh
= get_active_stripe(conf
, sector_nr
+i
, 0, 0);
3591 set_bit(STRIPE_EXPANDING
, &sh
->state
);
3592 atomic_inc(&conf
->reshape_stripes
);
3593 /* If any of this stripe is beyond the end of the old
3594 * array, then we need to zero those blocks
3596 for (j
=sh
->disks
; j
--;) {
3598 if (j
== sh
->pd_idx
)
3600 if (conf
->level
== 6 &&
3601 j
== raid6_next_disk(sh
->pd_idx
, sh
->disks
))
3603 s
= compute_blocknr(sh
, j
);
3604 if (s
< mddev
->array_sectors
) {
3608 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
3609 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
3610 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
3613 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3614 set_bit(STRIPE_HANDLE
, &sh
->state
);
3618 spin_lock_irq(&conf
->device_lock
);
3619 conf
->expand_progress
= (sector_nr
+ i
) * new_data_disks
;
3620 spin_unlock_irq(&conf
->device_lock
);
3621 /* Ok, those stripe are ready. We can start scheduling
3622 * reads on the source stripes.
3623 * The source stripes are determined by mapping the first and last
3624 * block on the destination stripes.
3627 raid5_compute_sector(conf
, sector_nr
*(new_data_disks
),
3628 1, &dd_idx
, &pd_idx
);
3630 raid5_compute_sector(conf
, ((sector_nr
+conf
->chunk_size
/512)
3631 *(new_data_disks
) - 1),
3632 1, &dd_idx
, &pd_idx
);
3633 if (last_sector
>= mddev
->dev_sectors
)
3634 last_sector
= mddev
->dev_sectors
- 1;
3635 while (first_sector
<= last_sector
) {
3636 sh
= get_active_stripe(conf
, first_sector
, 1, 0);
3637 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3638 set_bit(STRIPE_HANDLE
, &sh
->state
);
3640 first_sector
+= STRIPE_SECTORS
;
3642 /* If this takes us to the resync_max point where we have to pause,
3643 * then we need to write out the superblock.
3645 sector_nr
+= conf
->chunk_size
>>9;
3646 if (sector_nr
>= mddev
->resync_max
) {
3647 /* Cannot proceed until we've updated the superblock... */
3648 wait_event(conf
->wait_for_overlap
,
3649 atomic_read(&conf
->reshape_stripes
) == 0);
3650 mddev
->reshape_position
= conf
->expand_progress
;
3651 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
3652 md_wakeup_thread(mddev
->thread
);
3653 wait_event(mddev
->sb_wait
,
3654 !test_bit(MD_CHANGE_DEVS
, &mddev
->flags
)
3655 || kthread_should_stop());
3656 spin_lock_irq(&conf
->device_lock
);
3657 conf
->expand_lo
= mddev
->reshape_position
;
3658 spin_unlock_irq(&conf
->device_lock
);
3659 wake_up(&conf
->wait_for_overlap
);
3661 return conf
->chunk_size
>>9;
3664 /* FIXME go_faster isn't used */
3665 static inline sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
3667 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3668 struct stripe_head
*sh
;
3669 sector_t max_sector
= mddev
->dev_sectors
;
3671 int still_degraded
= 0;
3674 if (sector_nr
>= max_sector
) {
3675 /* just being told to finish up .. nothing much to do */
3676 unplug_slaves(mddev
);
3677 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
3682 if (mddev
->curr_resync
< max_sector
) /* aborted */
3683 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
3685 else /* completed sync */
3687 bitmap_close_sync(mddev
->bitmap
);
3692 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
3693 return reshape_request(mddev
, sector_nr
, skipped
);
3695 /* No need to check resync_max as we never do more than one
3696 * stripe, and as resync_max will always be on a chunk boundary,
3697 * if the check in md_do_sync didn't fire, there is no chance
3698 * of overstepping resync_max here
3701 /* if there is too many failed drives and we are trying
3702 * to resync, then assert that we are finished, because there is
3703 * nothing we can do.
3705 if (mddev
->degraded
>= conf
->max_degraded
&&
3706 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
3707 sector_t rv
= mddev
->dev_sectors
- sector_nr
;
3711 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
3712 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
3713 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
3714 /* we can skip this block, and probably more */
3715 sync_blocks
/= STRIPE_SECTORS
;
3717 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
3721 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
3723 sh
= get_active_stripe(conf
, sector_nr
, 0, 1);
3725 sh
= get_active_stripe(conf
, sector_nr
, 0, 0);
3726 /* make sure we don't swamp the stripe cache if someone else
3727 * is trying to get access
3729 schedule_timeout_uninterruptible(1);
3731 /* Need to check if array will still be degraded after recovery/resync
3732 * We don't need to check the 'failed' flag as when that gets set,
3735 for (i
=0; i
<mddev
->raid_disks
; i
++)
3736 if (conf
->disks
[i
].rdev
== NULL
)
3739 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
3741 spin_lock(&sh
->lock
);
3742 set_bit(STRIPE_SYNCING
, &sh
->state
);
3743 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3744 spin_unlock(&sh
->lock
);
3746 /* wait for any blocked device to be handled */
3747 while(unlikely(!handle_stripe(sh
, NULL
)))
3751 return STRIPE_SECTORS
;
3754 static int retry_aligned_read(raid5_conf_t
*conf
, struct bio
*raid_bio
)
3756 /* We may not be able to submit a whole bio at once as there
3757 * may not be enough stripe_heads available.
3758 * We cannot pre-allocate enough stripe_heads as we may need
3759 * more than exist in the cache (if we allow ever large chunks).
3760 * So we do one stripe head at a time and record in
3761 * ->bi_hw_segments how many have been done.
3763 * We *know* that this entire raid_bio is in one chunk, so
3764 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3766 struct stripe_head
*sh
;
3768 sector_t sector
, logical_sector
, last_sector
;
3773 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3774 sector
= raid5_compute_sector(conf
, logical_sector
,
3775 0, &dd_idx
, &pd_idx
);
3776 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
3778 for (; logical_sector
< last_sector
;
3779 logical_sector
+= STRIPE_SECTORS
,
3780 sector
+= STRIPE_SECTORS
,
3783 if (scnt
< raid5_bi_hw_segments(raid_bio
))
3784 /* already done this stripe */
3787 sh
= get_active_stripe(conf
, sector
, 0, 1);
3790 /* failed to get a stripe - must wait */
3791 raid5_set_bi_hw_segments(raid_bio
, scnt
);
3792 conf
->retry_read_aligned
= raid_bio
;
3796 set_bit(R5_ReadError
, &sh
->dev
[dd_idx
].flags
);
3797 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
3799 raid5_set_bi_hw_segments(raid_bio
, scnt
);
3800 conf
->retry_read_aligned
= raid_bio
;
3804 handle_stripe(sh
, NULL
);
3808 spin_lock_irq(&conf
->device_lock
);
3809 remaining
= raid5_dec_bi_phys_segments(raid_bio
);
3810 spin_unlock_irq(&conf
->device_lock
);
3812 bio_endio(raid_bio
, 0);
3813 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3814 wake_up(&conf
->wait_for_stripe
);
3821 * This is our raid5 kernel thread.
3823 * We scan the hash table for stripes which can be handled now.
3824 * During the scan, completed stripes are saved for us by the interrupt
3825 * handler, so that they will not have to wait for our next wakeup.
3827 static void raid5d(mddev_t
*mddev
)
3829 struct stripe_head
*sh
;
3830 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3833 pr_debug("+++ raid5d active\n");
3835 md_check_recovery(mddev
);
3838 spin_lock_irq(&conf
->device_lock
);
3842 if (conf
->seq_flush
!= conf
->seq_write
) {
3843 int seq
= conf
->seq_flush
;
3844 spin_unlock_irq(&conf
->device_lock
);
3845 bitmap_unplug(mddev
->bitmap
);
3846 spin_lock_irq(&conf
->device_lock
);
3847 conf
->seq_write
= seq
;
3848 activate_bit_delay(conf
);
3851 while ((bio
= remove_bio_from_retry(conf
))) {
3853 spin_unlock_irq(&conf
->device_lock
);
3854 ok
= retry_aligned_read(conf
, bio
);
3855 spin_lock_irq(&conf
->device_lock
);
3861 sh
= __get_priority_stripe(conf
);
3865 spin_unlock_irq(&conf
->device_lock
);
3868 handle_stripe(sh
, conf
->spare_page
);
3871 spin_lock_irq(&conf
->device_lock
);
3873 pr_debug("%d stripes handled\n", handled
);
3875 spin_unlock_irq(&conf
->device_lock
);
3877 async_tx_issue_pending_all();
3878 unplug_slaves(mddev
);
3880 pr_debug("--- raid5d inactive\n");
3884 raid5_show_stripe_cache_size(mddev_t
*mddev
, char *page
)
3886 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3888 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
3894 raid5_store_stripe_cache_size(mddev_t
*mddev
, const char *page
, size_t len
)
3896 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3900 if (len
>= PAGE_SIZE
)
3905 if (strict_strtoul(page
, 10, &new))
3907 if (new <= 16 || new > 32768)
3909 while (new < conf
->max_nr_stripes
) {
3910 if (drop_one_stripe(conf
))
3911 conf
->max_nr_stripes
--;
3915 err
= md_allow_write(mddev
);
3918 while (new > conf
->max_nr_stripes
) {
3919 if (grow_one_stripe(conf
))
3920 conf
->max_nr_stripes
++;
3926 static struct md_sysfs_entry
3927 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
3928 raid5_show_stripe_cache_size
,
3929 raid5_store_stripe_cache_size
);
3932 raid5_show_preread_threshold(mddev_t
*mddev
, char *page
)
3934 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3936 return sprintf(page
, "%d\n", conf
->bypass_threshold
);
3942 raid5_store_preread_threshold(mddev_t
*mddev
, const char *page
, size_t len
)
3944 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3946 if (len
>= PAGE_SIZE
)
3951 if (strict_strtoul(page
, 10, &new))
3953 if (new > conf
->max_nr_stripes
)
3955 conf
->bypass_threshold
= new;
3959 static struct md_sysfs_entry
3960 raid5_preread_bypass_threshold
= __ATTR(preread_bypass_threshold
,
3962 raid5_show_preread_threshold
,
3963 raid5_store_preread_threshold
);
3966 stripe_cache_active_show(mddev_t
*mddev
, char *page
)
3968 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3970 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
3975 static struct md_sysfs_entry
3976 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
3978 static struct attribute
*raid5_attrs
[] = {
3979 &raid5_stripecache_size
.attr
,
3980 &raid5_stripecache_active
.attr
,
3981 &raid5_preread_bypass_threshold
.attr
,
3984 static struct attribute_group raid5_attrs_group
= {
3986 .attrs
= raid5_attrs
,
3989 static int run(mddev_t
*mddev
)
3992 int raid_disk
, memory
;
3994 struct disk_info
*disk
;
3995 int working_disks
= 0;
3997 if (mddev
->level
!= 5 && mddev
->level
!= 4 && mddev
->level
!= 6) {
3998 printk(KERN_ERR
"raid5: %s: raid level not set to 4/5/6 (%d)\n",
3999 mdname(mddev
), mddev
->level
);
4003 if (mddev
->chunk_size
< PAGE_SIZE
) {
4004 printk(KERN_ERR
"md/raid5: chunk_size must be at least "
4005 "PAGE_SIZE but %d < %ld\n",
4006 mddev
->chunk_size
, PAGE_SIZE
);
4010 if (mddev
->reshape_position
!= MaxSector
) {
4011 /* Check that we can continue the reshape.
4012 * Currently only disks can change, it must
4013 * increase, and we must be past the point where
4014 * a stripe over-writes itself
4016 sector_t here_new
, here_old
;
4018 int max_degraded
= (mddev
->level
== 5 ? 1 : 2);
4020 if (mddev
->new_level
!= mddev
->level
||
4021 mddev
->new_layout
!= mddev
->layout
||
4022 mddev
->new_chunk
!= mddev
->chunk_size
) {
4023 printk(KERN_ERR
"raid5: %s: unsupported reshape "
4024 "required - aborting.\n",
4028 if (mddev
->delta_disks
<= 0) {
4029 printk(KERN_ERR
"raid5: %s: unsupported reshape "
4030 "(reduce disks) required - aborting.\n",
4034 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4035 /* reshape_position must be on a new-stripe boundary, and one
4036 * further up in new geometry must map after here in old
4039 here_new
= mddev
->reshape_position
;
4040 if (sector_div(here_new
, (mddev
->chunk_size
>>9)*
4041 (mddev
->raid_disks
- max_degraded
))) {
4042 printk(KERN_ERR
"raid5: reshape_position not "
4043 "on a stripe boundary\n");
4046 /* here_new is the stripe we will write to */
4047 here_old
= mddev
->reshape_position
;
4048 sector_div(here_old
, (mddev
->chunk_size
>>9)*
4049 (old_disks
-max_degraded
));
4050 /* here_old is the first stripe that we might need to read
4052 if (here_new
>= here_old
) {
4053 /* Reading from the same stripe as writing to - bad */
4054 printk(KERN_ERR
"raid5: reshape_position too early for "
4055 "auto-recovery - aborting.\n");
4058 printk(KERN_INFO
"raid5: reshape will continue\n");
4059 /* OK, we should be able to continue; */
4063 mddev
->private = kzalloc(sizeof (raid5_conf_t
), GFP_KERNEL
);
4064 if ((conf
= mddev
->private) == NULL
)
4066 if (mddev
->reshape_position
== MaxSector
) {
4067 conf
->previous_raid_disks
= conf
->raid_disks
= mddev
->raid_disks
;
4069 conf
->raid_disks
= mddev
->raid_disks
;
4070 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
4073 conf
->disks
= kzalloc(conf
->raid_disks
* sizeof(struct disk_info
),
4078 conf
->mddev
= mddev
;
4080 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
4083 if (mddev
->level
== 6) {
4084 conf
->spare_page
= alloc_page(GFP_KERNEL
);
4085 if (!conf
->spare_page
)
4088 spin_lock_init(&conf
->device_lock
);
4089 mddev
->queue
->queue_lock
= &conf
->device_lock
;
4090 init_waitqueue_head(&conf
->wait_for_stripe
);
4091 init_waitqueue_head(&conf
->wait_for_overlap
);
4092 INIT_LIST_HEAD(&conf
->handle_list
);
4093 INIT_LIST_HEAD(&conf
->hold_list
);
4094 INIT_LIST_HEAD(&conf
->delayed_list
);
4095 INIT_LIST_HEAD(&conf
->bitmap_list
);
4096 INIT_LIST_HEAD(&conf
->inactive_list
);
4097 atomic_set(&conf
->active_stripes
, 0);
4098 atomic_set(&conf
->preread_active_stripes
, 0);
4099 atomic_set(&conf
->active_aligned_reads
, 0);
4100 conf
->bypass_threshold
= BYPASS_THRESHOLD
;
4102 pr_debug("raid5: run(%s) called.\n", mdname(mddev
));
4104 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
4105 raid_disk
= rdev
->raid_disk
;
4106 if (raid_disk
>= conf
->raid_disks
4109 disk
= conf
->disks
+ raid_disk
;
4113 if (test_bit(In_sync
, &rdev
->flags
)) {
4114 char b
[BDEVNAME_SIZE
];
4115 printk(KERN_INFO
"raid5: device %s operational as raid"
4116 " disk %d\n", bdevname(rdev
->bdev
,b
),
4120 /* Cannot rely on bitmap to complete recovery */
4125 * 0 for a fully functional array, 1 or 2 for a degraded array.
4127 mddev
->degraded
= conf
->raid_disks
- working_disks
;
4128 conf
->mddev
= mddev
;
4129 conf
->chunk_size
= mddev
->chunk_size
;
4130 conf
->level
= mddev
->level
;
4131 if (conf
->level
== 6)
4132 conf
->max_degraded
= 2;
4134 conf
->max_degraded
= 1;
4135 conf
->algorithm
= mddev
->layout
;
4136 conf
->max_nr_stripes
= NR_STRIPES
;
4137 conf
->expand_progress
= mddev
->reshape_position
;
4139 /* device size must be a multiple of chunk size */
4140 mddev
->dev_sectors
&= ~(mddev
->chunk_size
/ 512 - 1);
4141 mddev
->resync_max_sectors
= mddev
->dev_sectors
;
4143 if (conf
->level
== 6 && conf
->raid_disks
< 4) {
4144 printk(KERN_ERR
"raid6: not enough configured devices for %s (%d, minimum 4)\n",
4145 mdname(mddev
), conf
->raid_disks
);
4148 if (!conf
->chunk_size
|| conf
->chunk_size
% 4) {
4149 printk(KERN_ERR
"raid5: invalid chunk size %d for %s\n",
4150 conf
->chunk_size
, mdname(mddev
));
4153 if (conf
->algorithm
> ALGORITHM_RIGHT_SYMMETRIC
) {
4155 "raid5: unsupported parity algorithm %d for %s\n",
4156 conf
->algorithm
, mdname(mddev
));
4159 if (mddev
->degraded
> conf
->max_degraded
) {
4160 printk(KERN_ERR
"raid5: not enough operational devices for %s"
4161 " (%d/%d failed)\n",
4162 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
4166 if (mddev
->degraded
> 0 &&
4167 mddev
->recovery_cp
!= MaxSector
) {
4168 if (mddev
->ok_start_degraded
)
4170 "raid5: starting dirty degraded array: %s"
4171 "- data corruption possible.\n",
4175 "raid5: cannot start dirty degraded array for %s\n",
4182 mddev
->thread
= md_register_thread(raid5d
, mddev
, "%s_raid5");
4183 if (!mddev
->thread
) {
4185 "raid5: couldn't allocate thread for %s\n",
4190 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
4191 conf
->raid_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
4192 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
4194 "raid5: couldn't allocate %dkB for buffers\n", memory
);
4195 shrink_stripes(conf
);
4196 md_unregister_thread(mddev
->thread
);
4199 printk(KERN_INFO
"raid5: allocated %dkB for %s\n",
4200 memory
, mdname(mddev
));
4202 if (mddev
->degraded
== 0)
4203 printk("raid5: raid level %d set %s active with %d out of %d"
4204 " devices, algorithm %d\n", conf
->level
, mdname(mddev
),
4205 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
4208 printk(KERN_ALERT
"raid5: raid level %d set %s active with %d"
4209 " out of %d devices, algorithm %d\n", conf
->level
,
4210 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
4211 mddev
->raid_disks
, conf
->algorithm
);
4213 print_raid5_conf(conf
);
4215 if (conf
->expand_progress
!= MaxSector
) {
4216 printk("...ok start reshape thread\n");
4217 conf
->expand_lo
= conf
->expand_progress
;
4218 atomic_set(&conf
->reshape_stripes
, 0);
4219 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
4220 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
4221 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
4222 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
4223 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
4227 /* read-ahead size must cover two whole stripes, which is
4228 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4231 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
4232 int stripe
= data_disks
*
4233 (mddev
->chunk_size
/ PAGE_SIZE
);
4234 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
4235 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
4238 /* Ok, everything is just fine now */
4239 if (sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
4241 "raid5: failed to create sysfs attributes for %s\n",
4244 mddev
->queue
->unplug_fn
= raid5_unplug_device
;
4245 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
4246 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
4248 mddev
->array_sectors
= mddev
->dev_sectors
*
4249 (conf
->previous_raid_disks
- conf
->max_degraded
);
4251 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
4256 print_raid5_conf(conf
);
4257 safe_put_page(conf
->spare_page
);
4259 kfree(conf
->stripe_hashtbl
);
4262 mddev
->private = NULL
;
4263 printk(KERN_ALERT
"raid5: failed to run raid set %s\n", mdname(mddev
));
4269 static int stop(mddev_t
*mddev
)
4271 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
4273 md_unregister_thread(mddev
->thread
);
4274 mddev
->thread
= NULL
;
4275 shrink_stripes(conf
);
4276 kfree(conf
->stripe_hashtbl
);
4277 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
4278 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
4279 sysfs_remove_group(&mddev
->kobj
, &raid5_attrs_group
);
4282 mddev
->private = NULL
;
4287 static void print_sh(struct seq_file
*seq
, struct stripe_head
*sh
)
4291 seq_printf(seq
, "sh %llu, pd_idx %d, state %ld.\n",
4292 (unsigned long long)sh
->sector
, sh
->pd_idx
, sh
->state
);
4293 seq_printf(seq
, "sh %llu, count %d.\n",
4294 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
));
4295 seq_printf(seq
, "sh %llu, ", (unsigned long long)sh
->sector
);
4296 for (i
= 0; i
< sh
->disks
; i
++) {
4297 seq_printf(seq
, "(cache%d: %p %ld) ",
4298 i
, sh
->dev
[i
].page
, sh
->dev
[i
].flags
);
4300 seq_printf(seq
, "\n");
4303 static void printall(struct seq_file
*seq
, raid5_conf_t
*conf
)
4305 struct stripe_head
*sh
;
4306 struct hlist_node
*hn
;
4309 spin_lock_irq(&conf
->device_lock
);
4310 for (i
= 0; i
< NR_HASH
; i
++) {
4311 hlist_for_each_entry(sh
, hn
, &conf
->stripe_hashtbl
[i
], hash
) {
4312 if (sh
->raid_conf
!= conf
)
4317 spin_unlock_irq(&conf
->device_lock
);
4321 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
4323 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
4326 seq_printf (seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
, mddev
->chunk_size
>> 10, mddev
->layout
);
4327 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
4328 for (i
= 0; i
< conf
->raid_disks
; i
++)
4329 seq_printf (seq
, "%s",
4330 conf
->disks
[i
].rdev
&&
4331 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
4332 seq_printf (seq
, "]");
4334 seq_printf (seq
, "\n");
4335 printall(seq
, conf
);
4339 static void print_raid5_conf (raid5_conf_t
*conf
)
4342 struct disk_info
*tmp
;
4344 printk("RAID5 conf printout:\n");
4346 printk("(conf==NULL)\n");
4349 printk(" --- rd:%d wd:%d\n", conf
->raid_disks
,
4350 conf
->raid_disks
- conf
->mddev
->degraded
);
4352 for (i
= 0; i
< conf
->raid_disks
; i
++) {
4353 char b
[BDEVNAME_SIZE
];
4354 tmp
= conf
->disks
+ i
;
4356 printk(" disk %d, o:%d, dev:%s\n",
4357 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
4358 bdevname(tmp
->rdev
->bdev
,b
));
4362 static int raid5_spare_active(mddev_t
*mddev
)
4365 raid5_conf_t
*conf
= mddev
->private;
4366 struct disk_info
*tmp
;
4368 for (i
= 0; i
< conf
->raid_disks
; i
++) {
4369 tmp
= conf
->disks
+ i
;
4371 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
4372 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
4373 unsigned long flags
;
4374 spin_lock_irqsave(&conf
->device_lock
, flags
);
4376 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
4379 print_raid5_conf(conf
);
4383 static int raid5_remove_disk(mddev_t
*mddev
, int number
)
4385 raid5_conf_t
*conf
= mddev
->private;
4388 struct disk_info
*p
= conf
->disks
+ number
;
4390 print_raid5_conf(conf
);
4393 if (test_bit(In_sync
, &rdev
->flags
) ||
4394 atomic_read(&rdev
->nr_pending
)) {
4398 /* Only remove non-faulty devices if recovery
4401 if (!test_bit(Faulty
, &rdev
->flags
) &&
4402 mddev
->degraded
<= conf
->max_degraded
) {
4408 if (atomic_read(&rdev
->nr_pending
)) {
4409 /* lost the race, try later */
4416 print_raid5_conf(conf
);
4420 static int raid5_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
4422 raid5_conf_t
*conf
= mddev
->private;
4425 struct disk_info
*p
;
4427 int last
= conf
->raid_disks
- 1;
4429 if (mddev
->degraded
> conf
->max_degraded
)
4430 /* no point adding a device */
4433 if (rdev
->raid_disk
>= 0)
4434 first
= last
= rdev
->raid_disk
;
4437 * find the disk ... but prefer rdev->saved_raid_disk
4440 if (rdev
->saved_raid_disk
>= 0 &&
4441 rdev
->saved_raid_disk
>= first
&&
4442 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
4443 disk
= rdev
->saved_raid_disk
;
4446 for ( ; disk
<= last
; disk
++)
4447 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
4448 clear_bit(In_sync
, &rdev
->flags
);
4449 rdev
->raid_disk
= disk
;
4451 if (rdev
->saved_raid_disk
!= disk
)
4453 rcu_assign_pointer(p
->rdev
, rdev
);
4456 print_raid5_conf(conf
);
4460 static int raid5_resize(mddev_t
*mddev
, sector_t sectors
)
4462 /* no resync is happening, and there is enough space
4463 * on all devices, so we can resize.
4464 * We need to make sure resync covers any new space.
4465 * If the array is shrinking we should possibly wait until
4466 * any io in the removed space completes, but it hardly seems
4469 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4471 sectors
&= ~((sector_t
)mddev
->chunk_size
/512 - 1);
4472 mddev
->array_sectors
= sectors
* (mddev
->raid_disks
4473 - conf
->max_degraded
);
4474 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
4476 if (sectors
> mddev
->dev_sectors
&& mddev
->recovery_cp
== MaxSector
) {
4477 mddev
->recovery_cp
= mddev
->dev_sectors
;
4478 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
4480 mddev
->dev_sectors
= sectors
;
4481 mddev
->resync_max_sectors
= sectors
;
4485 #ifdef CONFIG_MD_RAID5_RESHAPE
4486 static int raid5_check_reshape(mddev_t
*mddev
)
4488 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4491 if (mddev
->delta_disks
< 0 ||
4492 mddev
->new_level
!= mddev
->level
)
4493 return -EINVAL
; /* Cannot shrink array or change level yet */
4494 if (mddev
->delta_disks
== 0)
4495 return 0; /* nothing to do */
4497 /* Cannot grow a bitmap yet */
4500 /* Can only proceed if there are plenty of stripe_heads.
4501 * We need a minimum of one full stripe,, and for sensible progress
4502 * it is best to have about 4 times that.
4503 * If we require 4 times, then the default 256 4K stripe_heads will
4504 * allow for chunk sizes up to 256K, which is probably OK.
4505 * If the chunk size is greater, user-space should request more
4506 * stripe_heads first.
4508 if ((mddev
->chunk_size
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
||
4509 (mddev
->new_chunk
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
) {
4510 printk(KERN_WARNING
"raid5: reshape: not enough stripes. Needed %lu\n",
4511 (mddev
->chunk_size
/ STRIPE_SIZE
)*4);
4515 err
= resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
4519 if (mddev
->degraded
> conf
->max_degraded
)
4521 /* looks like we might be able to manage this */
4525 static int raid5_start_reshape(mddev_t
*mddev
)
4527 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4530 int added_devices
= 0;
4531 unsigned long flags
;
4533 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
4536 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
4537 if (rdev
->raid_disk
< 0 &&
4538 !test_bit(Faulty
, &rdev
->flags
))
4541 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
4542 /* Not enough devices even to make a degraded array
4547 atomic_set(&conf
->reshape_stripes
, 0);
4548 spin_lock_irq(&conf
->device_lock
);
4549 conf
->previous_raid_disks
= conf
->raid_disks
;
4550 conf
->raid_disks
+= mddev
->delta_disks
;
4551 conf
->expand_progress
= 0;
4552 conf
->expand_lo
= 0;
4553 spin_unlock_irq(&conf
->device_lock
);
4555 /* Add some new drives, as many as will fit.
4556 * We know there are enough to make the newly sized array work.
4558 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
4559 if (rdev
->raid_disk
< 0 &&
4560 !test_bit(Faulty
, &rdev
->flags
)) {
4561 if (raid5_add_disk(mddev
, rdev
) == 0) {
4563 set_bit(In_sync
, &rdev
->flags
);
4565 rdev
->recovery_offset
= 0;
4566 sprintf(nm
, "rd%d", rdev
->raid_disk
);
4567 if (sysfs_create_link(&mddev
->kobj
,
4570 "raid5: failed to create "
4571 " link %s for %s\n",
4577 spin_lock_irqsave(&conf
->device_lock
, flags
);
4578 mddev
->degraded
= (conf
->raid_disks
- conf
->previous_raid_disks
) - added_devices
;
4579 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
4580 mddev
->raid_disks
= conf
->raid_disks
;
4581 mddev
->reshape_position
= 0;
4582 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
4584 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
4585 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
4586 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
4587 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
4588 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
4590 if (!mddev
->sync_thread
) {
4591 mddev
->recovery
= 0;
4592 spin_lock_irq(&conf
->device_lock
);
4593 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
4594 conf
->expand_progress
= MaxSector
;
4595 spin_unlock_irq(&conf
->device_lock
);
4598 md_wakeup_thread(mddev
->sync_thread
);
4599 md_new_event(mddev
);
4604 static void end_reshape(raid5_conf_t
*conf
)
4606 struct block_device
*bdev
;
4608 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
4609 conf
->mddev
->array_sectors
= conf
->mddev
->dev_sectors
*
4610 (conf
->raid_disks
- conf
->max_degraded
);
4611 set_capacity(conf
->mddev
->gendisk
, conf
->mddev
->array_sectors
);
4612 conf
->mddev
->changed
= 1;
4614 bdev
= bdget_disk(conf
->mddev
->gendisk
, 0);
4616 mutex_lock(&bdev
->bd_inode
->i_mutex
);
4617 i_size_write(bdev
->bd_inode
,
4618 (loff_t
)conf
->mddev
->array_sectors
<< 9);
4619 mutex_unlock(&bdev
->bd_inode
->i_mutex
);
4622 spin_lock_irq(&conf
->device_lock
);
4623 conf
->expand_progress
= MaxSector
;
4624 spin_unlock_irq(&conf
->device_lock
);
4625 conf
->mddev
->reshape_position
= MaxSector
;
4627 /* read-ahead size must cover two whole stripes, which is
4628 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4631 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
4632 int stripe
= data_disks
*
4633 (conf
->mddev
->chunk_size
/ PAGE_SIZE
);
4634 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
4635 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
4640 static void raid5_quiesce(mddev_t
*mddev
, int state
)
4642 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
4645 case 2: /* resume for a suspend */
4646 wake_up(&conf
->wait_for_overlap
);
4649 case 1: /* stop all writes */
4650 spin_lock_irq(&conf
->device_lock
);
4652 wait_event_lock_irq(conf
->wait_for_stripe
,
4653 atomic_read(&conf
->active_stripes
) == 0 &&
4654 atomic_read(&conf
->active_aligned_reads
) == 0,
4655 conf
->device_lock
, /* nothing */);
4656 spin_unlock_irq(&conf
->device_lock
);
4659 case 0: /* re-enable writes */
4660 spin_lock_irq(&conf
->device_lock
);
4662 wake_up(&conf
->wait_for_stripe
);
4663 wake_up(&conf
->wait_for_overlap
);
4664 spin_unlock_irq(&conf
->device_lock
);
4669 static struct mdk_personality raid6_personality
=
4673 .owner
= THIS_MODULE
,
4674 .make_request
= make_request
,
4678 .error_handler
= error
,
4679 .hot_add_disk
= raid5_add_disk
,
4680 .hot_remove_disk
= raid5_remove_disk
,
4681 .spare_active
= raid5_spare_active
,
4682 .sync_request
= sync_request
,
4683 .resize
= raid5_resize
,
4684 #ifdef CONFIG_MD_RAID5_RESHAPE
4685 .check_reshape
= raid5_check_reshape
,
4686 .start_reshape
= raid5_start_reshape
,
4688 .quiesce
= raid5_quiesce
,
4690 static struct mdk_personality raid5_personality
=
4694 .owner
= THIS_MODULE
,
4695 .make_request
= make_request
,
4699 .error_handler
= error
,
4700 .hot_add_disk
= raid5_add_disk
,
4701 .hot_remove_disk
= raid5_remove_disk
,
4702 .spare_active
= raid5_spare_active
,
4703 .sync_request
= sync_request
,
4704 .resize
= raid5_resize
,
4705 #ifdef CONFIG_MD_RAID5_RESHAPE
4706 .check_reshape
= raid5_check_reshape
,
4707 .start_reshape
= raid5_start_reshape
,
4709 .quiesce
= raid5_quiesce
,
4712 static struct mdk_personality raid4_personality
=
4716 .owner
= THIS_MODULE
,
4717 .make_request
= make_request
,
4721 .error_handler
= error
,
4722 .hot_add_disk
= raid5_add_disk
,
4723 .hot_remove_disk
= raid5_remove_disk
,
4724 .spare_active
= raid5_spare_active
,
4725 .sync_request
= sync_request
,
4726 .resize
= raid5_resize
,
4727 #ifdef CONFIG_MD_RAID5_RESHAPE
4728 .check_reshape
= raid5_check_reshape
,
4729 .start_reshape
= raid5_start_reshape
,
4731 .quiesce
= raid5_quiesce
,
4734 static int __init
raid5_init(void)
4738 e
= raid6_select_algo();
4741 register_md_personality(&raid6_personality
);
4742 register_md_personality(&raid5_personality
);
4743 register_md_personality(&raid4_personality
);
4747 static void raid5_exit(void)
4749 unregister_md_personality(&raid6_personality
);
4750 unregister_md_personality(&raid5_personality
);
4751 unregister_md_personality(&raid4_personality
);
4754 module_init(raid5_init
);
4755 module_exit(raid5_exit
);
4756 MODULE_LICENSE("GPL");
4757 MODULE_ALIAS("md-personality-4"); /* RAID5 */
4758 MODULE_ALIAS("md-raid5");
4759 MODULE_ALIAS("md-raid4");
4760 MODULE_ALIAS("md-level-5");
4761 MODULE_ALIAS("md-level-4");
4762 MODULE_ALIAS("md-personality-8"); /* RAID6 */
4763 MODULE_ALIAS("md-raid6");
4764 MODULE_ALIAS("md-level-6");
4766 /* This used to be two separate modules, they were: */
4767 MODULE_ALIAS("raid5");
4768 MODULE_ALIAS("raid6");