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/module.h>
47 #include <linux/slab.h>
48 #include <linux/highmem.h>
49 #include <linux/bitops.h>
50 #include <linux/kthread.h>
51 #include <asm/atomic.h>
54 #include <linux/raid/bitmap.h>
60 #define NR_STRIPES 256
61 #define STRIPE_SIZE PAGE_SIZE
62 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
63 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
64 #define IO_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
84 #define RAID5_PARANOIA 1
85 #if RAID5_PARANOIA && defined(CONFIG_SMP)
86 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
88 # define CHECK_DEVLOCK()
91 #define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x)))
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)));
102 static inline int raid6_next_disk(int disk
, int raid_disks
)
105 return (disk
< raid_disks
) ? disk
: 0;
108 static void return_io(struct bio
*return_bi
)
110 struct bio
*bi
= return_bi
;
112 int bytes
= bi
->bi_size
;
114 return_bi
= bi
->bi_next
;
117 bi
->bi_end_io(bi
, bytes
,
118 test_bit(BIO_UPTODATE
, &bi
->bi_flags
)
124 static void print_raid5_conf (raid5_conf_t
*conf
);
126 static void __release_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
)
128 if (atomic_dec_and_test(&sh
->count
)) {
129 BUG_ON(!list_empty(&sh
->lru
));
130 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
131 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
132 if (test_bit(STRIPE_DELAYED
, &sh
->state
)) {
133 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
134 blk_plug_device(conf
->mddev
->queue
);
135 } else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
136 sh
->bm_seq
- conf
->seq_write
> 0) {
137 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
138 blk_plug_device(conf
->mddev
->queue
);
140 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
141 list_add_tail(&sh
->lru
, &conf
->handle_list
);
143 md_wakeup_thread(conf
->mddev
->thread
);
145 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
146 atomic_dec(&conf
->preread_active_stripes
);
147 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
148 md_wakeup_thread(conf
->mddev
->thread
);
150 atomic_dec(&conf
->active_stripes
);
151 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
152 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
153 wake_up(&conf
->wait_for_stripe
);
154 if (conf
->retry_read_aligned
)
155 md_wakeup_thread(conf
->mddev
->thread
);
160 static void release_stripe(struct stripe_head
*sh
)
162 raid5_conf_t
*conf
= sh
->raid_conf
;
165 spin_lock_irqsave(&conf
->device_lock
, flags
);
166 __release_stripe(conf
, sh
);
167 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
170 static inline void remove_hash(struct stripe_head
*sh
)
172 PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh
->sector
);
174 hlist_del_init(&sh
->hash
);
177 static inline void insert_hash(raid5_conf_t
*conf
, struct stripe_head
*sh
)
179 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
181 PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh
->sector
);
184 hlist_add_head(&sh
->hash
, hp
);
188 /* find an idle stripe, make sure it is unhashed, and return it. */
189 static struct stripe_head
*get_free_stripe(raid5_conf_t
*conf
)
191 struct stripe_head
*sh
= NULL
;
192 struct list_head
*first
;
195 if (list_empty(&conf
->inactive_list
))
197 first
= conf
->inactive_list
.next
;
198 sh
= list_entry(first
, struct stripe_head
, lru
);
199 list_del_init(first
);
201 atomic_inc(&conf
->active_stripes
);
206 static void shrink_buffers(struct stripe_head
*sh
, int num
)
211 for (i
=0; i
<num
; i
++) {
215 sh
->dev
[i
].page
= NULL
;
220 static int grow_buffers(struct stripe_head
*sh
, int num
)
224 for (i
=0; i
<num
; i
++) {
227 if (!(page
= alloc_page(GFP_KERNEL
))) {
230 sh
->dev
[i
].page
= page
;
235 static void raid5_build_block (struct stripe_head
*sh
, int i
);
237 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int pd_idx
, int disks
)
239 raid5_conf_t
*conf
= sh
->raid_conf
;
242 BUG_ON(atomic_read(&sh
->count
) != 0);
243 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
246 PRINTK("init_stripe called, stripe %llu\n",
247 (unsigned long long)sh
->sector
);
257 for (i
= sh
->disks
; i
--; ) {
258 struct r5dev
*dev
= &sh
->dev
[i
];
260 if (dev
->toread
|| dev
->towrite
|| dev
->written
||
261 test_bit(R5_LOCKED
, &dev
->flags
)) {
262 printk("sector=%llx i=%d %p %p %p %d\n",
263 (unsigned long long)sh
->sector
, i
, dev
->toread
,
264 dev
->towrite
, dev
->written
,
265 test_bit(R5_LOCKED
, &dev
->flags
));
269 raid5_build_block(sh
, i
);
271 insert_hash(conf
, sh
);
274 static struct stripe_head
*__find_stripe(raid5_conf_t
*conf
, sector_t sector
, int disks
)
276 struct stripe_head
*sh
;
277 struct hlist_node
*hn
;
280 PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector
);
281 hlist_for_each_entry(sh
, hn
, stripe_hash(conf
, sector
), hash
)
282 if (sh
->sector
== sector
&& sh
->disks
== disks
)
284 PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector
);
288 static void unplug_slaves(mddev_t
*mddev
);
289 static void raid5_unplug_device(request_queue_t
*q
);
291 static struct stripe_head
*get_active_stripe(raid5_conf_t
*conf
, sector_t sector
, int disks
,
292 int pd_idx
, int noblock
)
294 struct stripe_head
*sh
;
296 PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector
);
298 spin_lock_irq(&conf
->device_lock
);
301 wait_event_lock_irq(conf
->wait_for_stripe
,
303 conf
->device_lock
, /* nothing */);
304 sh
= __find_stripe(conf
, sector
, disks
);
306 if (!conf
->inactive_blocked
)
307 sh
= get_free_stripe(conf
);
308 if (noblock
&& sh
== NULL
)
311 conf
->inactive_blocked
= 1;
312 wait_event_lock_irq(conf
->wait_for_stripe
,
313 !list_empty(&conf
->inactive_list
) &&
314 (atomic_read(&conf
->active_stripes
)
315 < (conf
->max_nr_stripes
*3/4)
316 || !conf
->inactive_blocked
),
318 raid5_unplug_device(conf
->mddev
->queue
)
320 conf
->inactive_blocked
= 0;
322 init_stripe(sh
, sector
, pd_idx
, disks
);
324 if (atomic_read(&sh
->count
)) {
325 BUG_ON(!list_empty(&sh
->lru
));
327 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
328 atomic_inc(&conf
->active_stripes
);
329 if (list_empty(&sh
->lru
) &&
330 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
332 list_del_init(&sh
->lru
);
335 } while (sh
== NULL
);
338 atomic_inc(&sh
->count
);
340 spin_unlock_irq(&conf
->device_lock
);
344 static int grow_one_stripe(raid5_conf_t
*conf
)
346 struct stripe_head
*sh
;
347 sh
= kmem_cache_alloc(conf
->slab_cache
, GFP_KERNEL
);
350 memset(sh
, 0, sizeof(*sh
) + (conf
->raid_disks
-1)*sizeof(struct r5dev
));
351 sh
->raid_conf
= conf
;
352 spin_lock_init(&sh
->lock
);
354 if (grow_buffers(sh
, conf
->raid_disks
)) {
355 shrink_buffers(sh
, conf
->raid_disks
);
356 kmem_cache_free(conf
->slab_cache
, sh
);
359 sh
->disks
= conf
->raid_disks
;
360 /* we just created an active stripe so... */
361 atomic_set(&sh
->count
, 1);
362 atomic_inc(&conf
->active_stripes
);
363 INIT_LIST_HEAD(&sh
->lru
);
368 static int grow_stripes(raid5_conf_t
*conf
, int num
)
370 struct kmem_cache
*sc
;
371 int devs
= conf
->raid_disks
;
373 sprintf(conf
->cache_name
[0], "raid5-%s", mdname(conf
->mddev
));
374 sprintf(conf
->cache_name
[1], "raid5-%s-alt", mdname(conf
->mddev
));
375 conf
->active_name
= 0;
376 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
377 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
381 conf
->slab_cache
= sc
;
382 conf
->pool_size
= devs
;
384 if (!grow_one_stripe(conf
))
389 #ifdef CONFIG_MD_RAID5_RESHAPE
390 static int resize_stripes(raid5_conf_t
*conf
, int newsize
)
392 /* Make all the stripes able to hold 'newsize' devices.
393 * New slots in each stripe get 'page' set to a new page.
395 * This happens in stages:
396 * 1/ create a new kmem_cache and allocate the required number of
398 * 2/ gather all the old stripe_heads and tranfer the pages across
399 * to the new stripe_heads. This will have the side effect of
400 * freezing the array as once all stripe_heads have been collected,
401 * no IO will be possible. Old stripe heads are freed once their
402 * pages have been transferred over, and the old kmem_cache is
403 * freed when all stripes are done.
404 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
405 * we simple return a failre status - no need to clean anything up.
406 * 4/ allocate new pages for the new slots in the new stripe_heads.
407 * If this fails, we don't bother trying the shrink the
408 * stripe_heads down again, we just leave them as they are.
409 * As each stripe_head is processed the new one is released into
412 * Once step2 is started, we cannot afford to wait for a write,
413 * so we use GFP_NOIO allocations.
415 struct stripe_head
*osh
, *nsh
;
416 LIST_HEAD(newstripes
);
417 struct disk_info
*ndisks
;
419 struct kmem_cache
*sc
;
422 if (newsize
<= conf
->pool_size
)
423 return 0; /* never bother to shrink */
425 md_allow_write(conf
->mddev
);
428 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
429 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
434 for (i
= conf
->max_nr_stripes
; i
; i
--) {
435 nsh
= kmem_cache_alloc(sc
, GFP_KERNEL
);
439 memset(nsh
, 0, sizeof(*nsh
) + (newsize
-1)*sizeof(struct r5dev
));
441 nsh
->raid_conf
= conf
;
442 spin_lock_init(&nsh
->lock
);
444 list_add(&nsh
->lru
, &newstripes
);
447 /* didn't get enough, give up */
448 while (!list_empty(&newstripes
)) {
449 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
451 kmem_cache_free(sc
, nsh
);
453 kmem_cache_destroy(sc
);
456 /* Step 2 - Must use GFP_NOIO now.
457 * OK, we have enough stripes, start collecting inactive
458 * stripes and copying them over
460 list_for_each_entry(nsh
, &newstripes
, lru
) {
461 spin_lock_irq(&conf
->device_lock
);
462 wait_event_lock_irq(conf
->wait_for_stripe
,
463 !list_empty(&conf
->inactive_list
),
465 unplug_slaves(conf
->mddev
)
467 osh
= get_free_stripe(conf
);
468 spin_unlock_irq(&conf
->device_lock
);
469 atomic_set(&nsh
->count
, 1);
470 for(i
=0; i
<conf
->pool_size
; i
++)
471 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
472 for( ; i
<newsize
; i
++)
473 nsh
->dev
[i
].page
= NULL
;
474 kmem_cache_free(conf
->slab_cache
, osh
);
476 kmem_cache_destroy(conf
->slab_cache
);
479 * At this point, we are holding all the stripes so the array
480 * is completely stalled, so now is a good time to resize
483 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
485 for (i
=0; i
<conf
->raid_disks
; i
++)
486 ndisks
[i
] = conf
->disks
[i
];
488 conf
->disks
= ndisks
;
492 /* Step 4, return new stripes to service */
493 while(!list_empty(&newstripes
)) {
494 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
495 list_del_init(&nsh
->lru
);
496 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
497 if (nsh
->dev
[i
].page
== NULL
) {
498 struct page
*p
= alloc_page(GFP_NOIO
);
499 nsh
->dev
[i
].page
= p
;
505 /* critical section pass, GFP_NOIO no longer needed */
507 conf
->slab_cache
= sc
;
508 conf
->active_name
= 1-conf
->active_name
;
509 conf
->pool_size
= newsize
;
514 static int drop_one_stripe(raid5_conf_t
*conf
)
516 struct stripe_head
*sh
;
518 spin_lock_irq(&conf
->device_lock
);
519 sh
= get_free_stripe(conf
);
520 spin_unlock_irq(&conf
->device_lock
);
523 BUG_ON(atomic_read(&sh
->count
));
524 shrink_buffers(sh
, conf
->pool_size
);
525 kmem_cache_free(conf
->slab_cache
, sh
);
526 atomic_dec(&conf
->active_stripes
);
530 static void shrink_stripes(raid5_conf_t
*conf
)
532 while (drop_one_stripe(conf
))
535 if (conf
->slab_cache
)
536 kmem_cache_destroy(conf
->slab_cache
);
537 conf
->slab_cache
= NULL
;
540 static int raid5_end_read_request(struct bio
* bi
, unsigned int bytes_done
,
543 struct stripe_head
*sh
= bi
->bi_private
;
544 raid5_conf_t
*conf
= sh
->raid_conf
;
545 int disks
= sh
->disks
, i
;
546 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
547 char b
[BDEVNAME_SIZE
];
553 for (i
=0 ; i
<disks
; i
++)
554 if (bi
== &sh
->dev
[i
].req
)
557 PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n",
558 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
566 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
567 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
568 rdev
= conf
->disks
[i
].rdev
;
569 printk(KERN_INFO
"raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
570 mdname(conf
->mddev
), STRIPE_SECTORS
,
571 (unsigned long long)sh
->sector
+ rdev
->data_offset
,
572 bdevname(rdev
->bdev
, b
));
573 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
574 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
576 if (atomic_read(&conf
->disks
[i
].rdev
->read_errors
))
577 atomic_set(&conf
->disks
[i
].rdev
->read_errors
, 0);
579 const char *bdn
= bdevname(conf
->disks
[i
].rdev
->bdev
, b
);
581 rdev
= conf
->disks
[i
].rdev
;
583 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
584 atomic_inc(&rdev
->read_errors
);
585 if (conf
->mddev
->degraded
)
586 printk(KERN_WARNING
"raid5:%s: read error not correctable (sector %llu on %s).\n",
588 (unsigned long long)sh
->sector
+ rdev
->data_offset
,
590 else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
592 printk(KERN_WARNING
"raid5:%s: read error NOT corrected!! (sector %llu on %s).\n",
594 (unsigned long long)sh
->sector
+ rdev
->data_offset
,
596 else if (atomic_read(&rdev
->read_errors
)
597 > conf
->max_nr_stripes
)
599 "raid5:%s: Too many read errors, failing device %s.\n",
600 mdname(conf
->mddev
), bdn
);
604 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
606 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
607 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
608 md_error(conf
->mddev
, rdev
);
611 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
612 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
613 set_bit(STRIPE_HANDLE
, &sh
->state
);
618 static int raid5_end_write_request (struct bio
*bi
, unsigned int bytes_done
,
621 struct stripe_head
*sh
= bi
->bi_private
;
622 raid5_conf_t
*conf
= sh
->raid_conf
;
623 int disks
= sh
->disks
, i
;
624 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
629 for (i
=0 ; i
<disks
; i
++)
630 if (bi
== &sh
->dev
[i
].req
)
633 PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n",
634 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
642 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
644 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
646 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
647 set_bit(STRIPE_HANDLE
, &sh
->state
);
653 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
);
655 static void raid5_build_block (struct stripe_head
*sh
, int i
)
657 struct r5dev
*dev
= &sh
->dev
[i
];
660 dev
->req
.bi_io_vec
= &dev
->vec
;
662 dev
->req
.bi_max_vecs
++;
663 dev
->vec
.bv_page
= dev
->page
;
664 dev
->vec
.bv_len
= STRIPE_SIZE
;
665 dev
->vec
.bv_offset
= 0;
667 dev
->req
.bi_sector
= sh
->sector
;
668 dev
->req
.bi_private
= sh
;
671 dev
->sector
= compute_blocknr(sh
, i
);
674 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
676 char b
[BDEVNAME_SIZE
];
677 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
678 PRINTK("raid5: error called\n");
680 if (!test_bit(Faulty
, &rdev
->flags
)) {
681 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
682 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
684 spin_lock_irqsave(&conf
->device_lock
, flags
);
686 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
688 * if recovery was running, make sure it aborts.
690 set_bit(MD_RECOVERY_ERR
, &mddev
->recovery
);
692 set_bit(Faulty
, &rdev
->flags
);
694 "raid5: Disk failure on %s, disabling device."
695 " Operation continuing on %d devices\n",
696 bdevname(rdev
->bdev
,b
), conf
->raid_disks
- mddev
->degraded
);
701 * Input: a 'big' sector number,
702 * Output: index of the data and parity disk, and the sector # in them.
704 static sector_t
raid5_compute_sector(sector_t r_sector
, unsigned int raid_disks
,
705 unsigned int data_disks
, unsigned int * dd_idx
,
706 unsigned int * pd_idx
, raid5_conf_t
*conf
)
709 unsigned long chunk_number
;
710 unsigned int chunk_offset
;
712 int sectors_per_chunk
= conf
->chunk_size
>> 9;
714 /* First compute the information on this sector */
717 * Compute the chunk number and the sector offset inside the chunk
719 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
720 chunk_number
= r_sector
;
721 BUG_ON(r_sector
!= chunk_number
);
724 * Compute the stripe number
726 stripe
= chunk_number
/ data_disks
;
729 * Compute the data disk and parity disk indexes inside the stripe
731 *dd_idx
= chunk_number
% data_disks
;
734 * Select the parity disk based on the user selected algorithm.
736 switch(conf
->level
) {
738 *pd_idx
= data_disks
;
741 switch (conf
->algorithm
) {
742 case ALGORITHM_LEFT_ASYMMETRIC
:
743 *pd_idx
= data_disks
- stripe
% raid_disks
;
744 if (*dd_idx
>= *pd_idx
)
747 case ALGORITHM_RIGHT_ASYMMETRIC
:
748 *pd_idx
= stripe
% raid_disks
;
749 if (*dd_idx
>= *pd_idx
)
752 case ALGORITHM_LEFT_SYMMETRIC
:
753 *pd_idx
= data_disks
- stripe
% raid_disks
;
754 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
756 case ALGORITHM_RIGHT_SYMMETRIC
:
757 *pd_idx
= stripe
% raid_disks
;
758 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
761 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
768 switch (conf
->algorithm
) {
769 case ALGORITHM_LEFT_ASYMMETRIC
:
770 *pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
771 if (*pd_idx
== raid_disks
-1)
772 (*dd_idx
)++; /* Q D D D P */
773 else if (*dd_idx
>= *pd_idx
)
774 (*dd_idx
) += 2; /* D D P Q D */
776 case ALGORITHM_RIGHT_ASYMMETRIC
:
777 *pd_idx
= stripe
% raid_disks
;
778 if (*pd_idx
== raid_disks
-1)
779 (*dd_idx
)++; /* Q D D D P */
780 else if (*dd_idx
>= *pd_idx
)
781 (*dd_idx
) += 2; /* D D P Q D */
783 case ALGORITHM_LEFT_SYMMETRIC
:
784 *pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
785 *dd_idx
= (*pd_idx
+ 2 + *dd_idx
) % raid_disks
;
787 case ALGORITHM_RIGHT_SYMMETRIC
:
788 *pd_idx
= stripe
% raid_disks
;
789 *dd_idx
= (*pd_idx
+ 2 + *dd_idx
) % raid_disks
;
792 printk (KERN_CRIT
"raid6: unsupported algorithm %d\n",
799 * Finally, compute the new sector number
801 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
806 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
)
808 raid5_conf_t
*conf
= sh
->raid_conf
;
809 int raid_disks
= sh
->disks
;
810 int data_disks
= raid_disks
- conf
->max_degraded
;
811 sector_t new_sector
= sh
->sector
, check
;
812 int sectors_per_chunk
= conf
->chunk_size
>> 9;
815 int chunk_number
, dummy1
, dummy2
, dd_idx
= i
;
819 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
821 BUG_ON(new_sector
!= stripe
);
825 switch(conf
->level
) {
828 switch (conf
->algorithm
) {
829 case ALGORITHM_LEFT_ASYMMETRIC
:
830 case ALGORITHM_RIGHT_ASYMMETRIC
:
834 case ALGORITHM_LEFT_SYMMETRIC
:
835 case ALGORITHM_RIGHT_SYMMETRIC
:
838 i
-= (sh
->pd_idx
+ 1);
841 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
846 if (i
== raid6_next_disk(sh
->pd_idx
, raid_disks
))
847 return 0; /* It is the Q disk */
848 switch (conf
->algorithm
) {
849 case ALGORITHM_LEFT_ASYMMETRIC
:
850 case ALGORITHM_RIGHT_ASYMMETRIC
:
851 if (sh
->pd_idx
== raid_disks
-1)
853 else if (i
> sh
->pd_idx
)
854 i
-= 2; /* D D P Q D */
856 case ALGORITHM_LEFT_SYMMETRIC
:
857 case ALGORITHM_RIGHT_SYMMETRIC
:
858 if (sh
->pd_idx
== raid_disks
-1)
864 i
-= (sh
->pd_idx
+ 2);
868 printk (KERN_CRIT
"raid6: unsupported algorithm %d\n",
874 chunk_number
= stripe
* data_disks
+ i
;
875 r_sector
= (sector_t
)chunk_number
* sectors_per_chunk
+ chunk_offset
;
877 check
= raid5_compute_sector (r_sector
, raid_disks
, data_disks
, &dummy1
, &dummy2
, conf
);
878 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| dummy2
!= sh
->pd_idx
) {
879 printk(KERN_ERR
"compute_blocknr: map not correct\n");
888 * Copy data between a page in the stripe cache, and one or more bion
889 * The page could align with the middle of the bio, or there could be
890 * several bion, each with several bio_vecs, which cover part of the page
891 * Multiple bion are linked together on bi_next. There may be extras
892 * at the end of this list. We ignore them.
894 static void copy_data(int frombio
, struct bio
*bio
,
898 char *pa
= page_address(page
);
903 if (bio
->bi_sector
>= sector
)
904 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
906 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
907 bio_for_each_segment(bvl
, bio
, i
) {
908 int len
= bio_iovec_idx(bio
,i
)->bv_len
;
912 if (page_offset
< 0) {
913 b_offset
= -page_offset
;
914 page_offset
+= b_offset
;
918 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
919 clen
= STRIPE_SIZE
- page_offset
;
923 char *ba
= __bio_kmap_atomic(bio
, i
, KM_USER0
);
925 memcpy(pa
+page_offset
, ba
+b_offset
, clen
);
927 memcpy(ba
+b_offset
, pa
+page_offset
, clen
);
928 __bio_kunmap_atomic(ba
, KM_USER0
);
930 if (clen
< len
) /* hit end of page */
936 #define check_xor() do { \
937 if (count == MAX_XOR_BLOCKS) { \
938 xor_blocks(count, STRIPE_SIZE, dest, ptr);\
944 static void compute_block(struct stripe_head
*sh
, int dd_idx
)
946 int i
, count
, disks
= sh
->disks
;
947 void *ptr
[MAX_XOR_BLOCKS
], *dest
, *p
;
949 PRINTK("compute_block, stripe %llu, idx %d\n",
950 (unsigned long long)sh
->sector
, dd_idx
);
952 dest
= page_address(sh
->dev
[dd_idx
].page
);
953 memset(dest
, 0, STRIPE_SIZE
);
955 for (i
= disks
; i
--; ) {
958 p
= page_address(sh
->dev
[i
].page
);
959 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
962 printk(KERN_ERR
"compute_block() %d, stripe %llu, %d"
963 " not present\n", dd_idx
,
964 (unsigned long long)sh
->sector
, i
);
969 xor_blocks(count
, STRIPE_SIZE
, dest
, ptr
);
970 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
973 static void compute_parity5(struct stripe_head
*sh
, int method
)
975 raid5_conf_t
*conf
= sh
->raid_conf
;
976 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
, count
;
977 void *ptr
[MAX_XOR_BLOCKS
], *dest
;
980 PRINTK("compute_parity5, stripe %llu, method %d\n",
981 (unsigned long long)sh
->sector
, method
);
984 dest
= page_address(sh
->dev
[pd_idx
].page
);
986 case READ_MODIFY_WRITE
:
987 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
));
988 for (i
=disks
; i
-- ;) {
991 if (sh
->dev
[i
].towrite
&&
992 test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
)) {
993 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
994 chosen
= sh
->dev
[i
].towrite
;
995 sh
->dev
[i
].towrite
= NULL
;
997 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
998 wake_up(&conf
->wait_for_overlap
);
1000 BUG_ON(sh
->dev
[i
].written
);
1001 sh
->dev
[i
].written
= chosen
;
1006 case RECONSTRUCT_WRITE
:
1007 memset(dest
, 0, STRIPE_SIZE
);
1008 for (i
= disks
; i
-- ;)
1009 if (i
!=pd_idx
&& sh
->dev
[i
].towrite
) {
1010 chosen
= sh
->dev
[i
].towrite
;
1011 sh
->dev
[i
].towrite
= NULL
;
1013 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1014 wake_up(&conf
->wait_for_overlap
);
1016 BUG_ON(sh
->dev
[i
].written
);
1017 sh
->dev
[i
].written
= chosen
;
1024 xor_blocks(count
, STRIPE_SIZE
, dest
, ptr
);
1028 for (i
= disks
; i
--;)
1029 if (sh
->dev
[i
].written
) {
1030 sector_t sector
= sh
->dev
[i
].sector
;
1031 struct bio
*wbi
= sh
->dev
[i
].written
;
1032 while (wbi
&& wbi
->bi_sector
< sector
+ STRIPE_SECTORS
) {
1033 copy_data(1, wbi
, sh
->dev
[i
].page
, sector
);
1034 wbi
= r5_next_bio(wbi
, sector
);
1037 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1038 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1042 case RECONSTRUCT_WRITE
:
1046 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
1050 case READ_MODIFY_WRITE
:
1051 for (i
= disks
; i
--;)
1052 if (sh
->dev
[i
].written
) {
1053 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
1058 xor_blocks(count
, STRIPE_SIZE
, dest
, ptr
);
1060 if (method
!= CHECK_PARITY
) {
1061 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1062 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1064 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1067 static void compute_parity6(struct stripe_head
*sh
, int method
)
1069 raid6_conf_t
*conf
= sh
->raid_conf
;
1070 int i
, pd_idx
= sh
->pd_idx
, qd_idx
, d0_idx
, disks
= sh
->disks
, count
;
1072 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1075 qd_idx
= raid6_next_disk(pd_idx
, disks
);
1076 d0_idx
= raid6_next_disk(qd_idx
, disks
);
1078 PRINTK("compute_parity, stripe %llu, method %d\n",
1079 (unsigned long long)sh
->sector
, method
);
1082 case READ_MODIFY_WRITE
:
1083 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1084 case RECONSTRUCT_WRITE
:
1085 for (i
= disks
; i
-- ;)
1086 if ( i
!= pd_idx
&& i
!= qd_idx
&& sh
->dev
[i
].towrite
) {
1087 chosen
= sh
->dev
[i
].towrite
;
1088 sh
->dev
[i
].towrite
= NULL
;
1090 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1091 wake_up(&conf
->wait_for_overlap
);
1093 BUG_ON(sh
->dev
[i
].written
);
1094 sh
->dev
[i
].written
= chosen
;
1098 BUG(); /* Not implemented yet */
1101 for (i
= disks
; i
--;)
1102 if (sh
->dev
[i
].written
) {
1103 sector_t sector
= sh
->dev
[i
].sector
;
1104 struct bio
*wbi
= sh
->dev
[i
].written
;
1105 while (wbi
&& wbi
->bi_sector
< sector
+ STRIPE_SECTORS
) {
1106 copy_data(1, wbi
, sh
->dev
[i
].page
, sector
);
1107 wbi
= r5_next_bio(wbi
, sector
);
1110 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1111 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1115 // case RECONSTRUCT_WRITE:
1116 // case CHECK_PARITY:
1117 // case UPDATE_PARITY:
1118 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1119 /* FIX: Is this ordering of drives even remotely optimal? */
1123 ptrs
[count
++] = page_address(sh
->dev
[i
].page
);
1124 if (count
<= disks
-2 && !test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1125 printk("block %d/%d not uptodate on parity calc\n", i
,count
);
1126 i
= raid6_next_disk(i
, disks
);
1127 } while ( i
!= d0_idx
);
1131 raid6_call
.gen_syndrome(disks
, STRIPE_SIZE
, ptrs
);
1134 case RECONSTRUCT_WRITE
:
1135 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1136 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1137 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1138 set_bit(R5_LOCKED
, &sh
->dev
[qd_idx
].flags
);
1141 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1142 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1148 /* Compute one missing block */
1149 static void compute_block_1(struct stripe_head
*sh
, int dd_idx
, int nozero
)
1151 int i
, count
, disks
= sh
->disks
;
1152 void *ptr
[MAX_XOR_BLOCKS
], *dest
, *p
;
1153 int pd_idx
= sh
->pd_idx
;
1154 int qd_idx
= raid6_next_disk(pd_idx
, disks
);
1156 PRINTK("compute_block_1, stripe %llu, idx %d\n",
1157 (unsigned long long)sh
->sector
, dd_idx
);
1159 if ( dd_idx
== qd_idx
) {
1160 /* We're actually computing the Q drive */
1161 compute_parity6(sh
, UPDATE_PARITY
);
1163 dest
= page_address(sh
->dev
[dd_idx
].page
);
1164 if (!nozero
) memset(dest
, 0, STRIPE_SIZE
);
1166 for (i
= disks
; i
--; ) {
1167 if (i
== dd_idx
|| i
== qd_idx
)
1169 p
= page_address(sh
->dev
[i
].page
);
1170 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1173 printk("compute_block() %d, stripe %llu, %d"
1174 " not present\n", dd_idx
,
1175 (unsigned long long)sh
->sector
, i
);
1180 xor_blocks(count
, STRIPE_SIZE
, dest
, ptr
);
1181 if (!nozero
) set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1182 else clear_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1186 /* Compute two missing blocks */
1187 static void compute_block_2(struct stripe_head
*sh
, int dd_idx1
, int dd_idx2
)
1189 int i
, count
, disks
= sh
->disks
;
1190 int pd_idx
= sh
->pd_idx
;
1191 int qd_idx
= raid6_next_disk(pd_idx
, disks
);
1192 int d0_idx
= raid6_next_disk(qd_idx
, disks
);
1195 /* faila and failb are disk numbers relative to d0_idx */
1196 /* pd_idx become disks-2 and qd_idx become disks-1 */
1197 faila
= (dd_idx1
< d0_idx
) ? dd_idx1
+(disks
-d0_idx
) : dd_idx1
-d0_idx
;
1198 failb
= (dd_idx2
< d0_idx
) ? dd_idx2
+(disks
-d0_idx
) : dd_idx2
-d0_idx
;
1200 BUG_ON(faila
== failb
);
1201 if ( failb
< faila
) { int tmp
= faila
; faila
= failb
; failb
= tmp
; }
1203 PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1204 (unsigned long long)sh
->sector
, dd_idx1
, dd_idx2
, faila
, failb
);
1206 if ( failb
== disks
-1 ) {
1207 /* Q disk is one of the missing disks */
1208 if ( faila
== disks
-2 ) {
1209 /* Missing P+Q, just recompute */
1210 compute_parity6(sh
, UPDATE_PARITY
);
1213 /* We're missing D+Q; recompute D from P */
1214 compute_block_1(sh
, (dd_idx1
== qd_idx
) ? dd_idx2
: dd_idx1
, 0);
1215 compute_parity6(sh
, UPDATE_PARITY
); /* Is this necessary? */
1220 /* We're missing D+P or D+D; build pointer table */
1222 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1228 ptrs
[count
++] = page_address(sh
->dev
[i
].page
);
1229 i
= raid6_next_disk(i
, disks
);
1230 if (i
!= dd_idx1
&& i
!= dd_idx2
&&
1231 !test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1232 printk("compute_2 with missing block %d/%d\n", count
, i
);
1233 } while ( i
!= d0_idx
);
1235 if ( failb
== disks
-2 ) {
1236 /* We're missing D+P. */
1237 raid6_datap_recov(disks
, STRIPE_SIZE
, faila
, ptrs
);
1239 /* We're missing D+D. */
1240 raid6_2data_recov(disks
, STRIPE_SIZE
, faila
, failb
, ptrs
);
1243 /* Both the above update both missing blocks */
1244 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx1
].flags
);
1245 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx2
].flags
);
1252 * Each stripe/dev can have one or more bion attached.
1253 * toread/towrite point to the first in a chain.
1254 * The bi_next chain must be in order.
1256 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
1259 raid5_conf_t
*conf
= sh
->raid_conf
;
1262 PRINTK("adding bh b#%llu to stripe s#%llu\n",
1263 (unsigned long long)bi
->bi_sector
,
1264 (unsigned long long)sh
->sector
);
1267 spin_lock(&sh
->lock
);
1268 spin_lock_irq(&conf
->device_lock
);
1270 bip
= &sh
->dev
[dd_idx
].towrite
;
1271 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
1274 bip
= &sh
->dev
[dd_idx
].toread
;
1275 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
1276 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
1278 bip
= & (*bip
)->bi_next
;
1280 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
1283 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
1287 bi
->bi_phys_segments
++;
1288 spin_unlock_irq(&conf
->device_lock
);
1289 spin_unlock(&sh
->lock
);
1291 PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n",
1292 (unsigned long long)bi
->bi_sector
,
1293 (unsigned long long)sh
->sector
, dd_idx
);
1295 if (conf
->mddev
->bitmap
&& firstwrite
) {
1296 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
1298 sh
->bm_seq
= conf
->seq_flush
+1;
1299 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
1303 /* check if page is covered */
1304 sector_t sector
= sh
->dev
[dd_idx
].sector
;
1305 for (bi
=sh
->dev
[dd_idx
].towrite
;
1306 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
1307 bi
&& bi
->bi_sector
<= sector
;
1308 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
1309 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
1310 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
1312 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
1313 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
1318 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
1319 spin_unlock_irq(&conf
->device_lock
);
1320 spin_unlock(&sh
->lock
);
1324 static void end_reshape(raid5_conf_t
*conf
);
1326 static int page_is_zero(struct page
*p
)
1328 char *a
= page_address(p
);
1329 return ((*(u32
*)a
) == 0 &&
1330 memcmp(a
, a
+4, STRIPE_SIZE
-4)==0);
1333 static int stripe_to_pdidx(sector_t stripe
, raid5_conf_t
*conf
, int disks
)
1335 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1337 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
1339 raid5_compute_sector(stripe
* (disks
- conf
->max_degraded
)
1340 *sectors_per_chunk
+ chunk_offset
,
1341 disks
, disks
- conf
->max_degraded
,
1342 &dd_idx
, &pd_idx
, conf
);
1347 handle_requests_to_failed_array(raid5_conf_t
*conf
, struct stripe_head
*sh
,
1348 struct stripe_head_state
*s
, int disks
,
1349 struct bio
**return_bi
)
1352 for (i
= disks
; i
--; ) {
1356 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1359 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
1360 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
1361 /* multiple read failures in one stripe */
1362 md_error(conf
->mddev
, rdev
);
1365 spin_lock_irq(&conf
->device_lock
);
1366 /* fail all writes first */
1367 bi
= sh
->dev
[i
].towrite
;
1368 sh
->dev
[i
].towrite
= NULL
;
1374 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1375 wake_up(&conf
->wait_for_overlap
);
1377 while (bi
&& bi
->bi_sector
<
1378 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1379 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1380 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1381 if (--bi
->bi_phys_segments
== 0) {
1382 md_write_end(conf
->mddev
);
1383 bi
->bi_next
= *return_bi
;
1388 /* and fail all 'written' */
1389 bi
= sh
->dev
[i
].written
;
1390 sh
->dev
[i
].written
= NULL
;
1391 if (bi
) bitmap_end
= 1;
1392 while (bi
&& bi
->bi_sector
<
1393 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1394 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1395 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1396 if (--bi
->bi_phys_segments
== 0) {
1397 md_write_end(conf
->mddev
);
1398 bi
->bi_next
= *return_bi
;
1404 /* fail any reads if this device is non-operational */
1405 if (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
1406 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1407 bi
= sh
->dev
[i
].toread
;
1408 sh
->dev
[i
].toread
= NULL
;
1409 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1410 wake_up(&conf
->wait_for_overlap
);
1411 if (bi
) s
->to_read
--;
1412 while (bi
&& bi
->bi_sector
<
1413 sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1414 struct bio
*nextbi
=
1415 r5_next_bio(bi
, sh
->dev
[i
].sector
);
1416 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1417 if (--bi
->bi_phys_segments
== 0) {
1418 bi
->bi_next
= *return_bi
;
1424 spin_unlock_irq(&conf
->device_lock
);
1426 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
1427 STRIPE_SECTORS
, 0, 0);
1432 static void handle_issuing_new_read_requests5(struct stripe_head
*sh
,
1433 struct stripe_head_state
*s
, int disks
)
1436 for (i
= disks
; i
--; ) {
1437 struct r5dev
*dev
= &sh
->dev
[i
];
1438 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
1439 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1441 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
1442 s
->syncing
|| s
->expanding
||
1443 (s
->failed
&& (sh
->dev
[s
->failed_num
].toread
||
1444 (sh
->dev
[s
->failed_num
].towrite
&&
1445 !test_bit(R5_OVERWRITE
, &sh
->dev
[s
->failed_num
].flags
))
1447 /* we would like to get this block, possibly
1448 * by computing it, but we might not be able to
1450 if (s
->uptodate
== disks
-1) {
1451 PRINTK("Computing block %d\n", i
);
1452 compute_block(sh
, i
);
1454 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
1455 set_bit(R5_LOCKED
, &dev
->flags
);
1456 set_bit(R5_Wantread
, &dev
->flags
);
1458 PRINTK("Reading block %d (sync=%d)\n",
1463 set_bit(STRIPE_HANDLE
, &sh
->state
);
1466 static void handle_issuing_new_read_requests6(struct stripe_head
*sh
,
1467 struct stripe_head_state
*s
, struct r6_state
*r6s
,
1471 for (i
= disks
; i
--; ) {
1472 struct r5dev
*dev
= &sh
->dev
[i
];
1473 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
1474 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1475 (dev
->toread
|| (dev
->towrite
&&
1476 !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
1477 s
->syncing
|| s
->expanding
||
1479 (sh
->dev
[r6s
->failed_num
[0]].toread
||
1482 (sh
->dev
[r6s
->failed_num
[1]].toread
||
1484 /* we would like to get this block, possibly
1485 * by computing it, but we might not be able to
1487 if (s
->uptodate
== disks
-1) {
1488 PRINTK("Computing stripe %llu block %d\n",
1489 (unsigned long long)sh
->sector
, i
);
1490 compute_block_1(sh
, i
, 0);
1492 } else if ( s
->uptodate
== disks
-2 && s
->failed
>= 2 ) {
1493 /* Computing 2-failure is *very* expensive; only
1494 * do it if failed >= 2
1497 for (other
= disks
; other
--; ) {
1500 if (!test_bit(R5_UPTODATE
,
1501 &sh
->dev
[other
].flags
))
1505 PRINTK("Computing stripe %llu blocks %d,%d\n",
1506 (unsigned long long)sh
->sector
,
1508 compute_block_2(sh
, i
, other
);
1510 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
1511 set_bit(R5_LOCKED
, &dev
->flags
);
1512 set_bit(R5_Wantread
, &dev
->flags
);
1514 PRINTK("Reading block %d (sync=%d)\n",
1519 set_bit(STRIPE_HANDLE
, &sh
->state
);
1523 /* handle_completed_write_requests
1524 * any written block on an uptodate or failed drive can be returned.
1525 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
1526 * never LOCKED, so we don't need to test 'failed' directly.
1528 static void handle_completed_write_requests(raid5_conf_t
*conf
,
1529 struct stripe_head
*sh
, int disks
, struct bio
**return_bi
)
1534 for (i
= disks
; i
--; )
1535 if (sh
->dev
[i
].written
) {
1537 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
1538 test_bit(R5_UPTODATE
, &dev
->flags
)) {
1539 /* We can return any write requests */
1540 struct bio
*wbi
, *wbi2
;
1542 PRINTK("Return write for disc %d\n", i
);
1543 spin_lock_irq(&conf
->device_lock
);
1545 dev
->written
= NULL
;
1546 while (wbi
&& wbi
->bi_sector
<
1547 dev
->sector
+ STRIPE_SECTORS
) {
1548 wbi2
= r5_next_bio(wbi
, dev
->sector
);
1549 if (--wbi
->bi_phys_segments
== 0) {
1550 md_write_end(conf
->mddev
);
1551 wbi
->bi_next
= *return_bi
;
1556 if (dev
->towrite
== NULL
)
1558 spin_unlock_irq(&conf
->device_lock
);
1560 bitmap_endwrite(conf
->mddev
->bitmap
,
1563 !test_bit(STRIPE_DEGRADED
, &sh
->state
),
1569 static void handle_issuing_new_write_requests5(raid5_conf_t
*conf
,
1570 struct stripe_head
*sh
, struct stripe_head_state
*s
, int disks
)
1572 int rmw
= 0, rcw
= 0, i
;
1573 for (i
= disks
; i
--; ) {
1574 /* would I have to read this buffer for read_modify_write */
1575 struct r5dev
*dev
= &sh
->dev
[i
];
1576 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
1577 !test_bit(R5_LOCKED
, &dev
->flags
) &&
1578 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
1579 if (test_bit(R5_Insync
, &dev
->flags
))
1582 rmw
+= 2*disks
; /* cannot read it */
1584 /* Would I have to read this buffer for reconstruct_write */
1585 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
1586 !test_bit(R5_LOCKED
, &dev
->flags
) &&
1587 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
1588 if (test_bit(R5_Insync
, &dev
->flags
))
1594 PRINTK("for sector %llu, rmw=%d rcw=%d\n",
1595 (unsigned long long)sh
->sector
, rmw
, rcw
);
1596 set_bit(STRIPE_HANDLE
, &sh
->state
);
1597 if (rmw
< rcw
&& rmw
> 0)
1598 /* prefer read-modify-write, but need to get some data */
1599 for (i
= disks
; i
--; ) {
1600 struct r5dev
*dev
= &sh
->dev
[i
];
1601 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
1602 !test_bit(R5_LOCKED
, &dev
->flags
) &&
1603 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1604 test_bit(R5_Insync
, &dev
->flags
)) {
1606 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
1607 PRINTK("Read_old block "
1608 "%d for r-m-w\n", i
);
1609 set_bit(R5_LOCKED
, &dev
->flags
);
1610 set_bit(R5_Wantread
, &dev
->flags
);
1613 set_bit(STRIPE_DELAYED
, &sh
->state
);
1614 set_bit(STRIPE_HANDLE
, &sh
->state
);
1618 if (rcw
<= rmw
&& rcw
> 0)
1619 /* want reconstruct write, but need to get some data */
1620 for (i
= disks
; i
--; ) {
1621 struct r5dev
*dev
= &sh
->dev
[i
];
1622 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) &&
1624 !test_bit(R5_LOCKED
, &dev
->flags
) &&
1625 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1626 test_bit(R5_Insync
, &dev
->flags
)) {
1628 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
1629 PRINTK("Read_old block "
1630 "%d for Reconstruct\n", i
);
1631 set_bit(R5_LOCKED
, &dev
->flags
);
1632 set_bit(R5_Wantread
, &dev
->flags
);
1635 set_bit(STRIPE_DELAYED
, &sh
->state
);
1636 set_bit(STRIPE_HANDLE
, &sh
->state
);
1640 /* now if nothing is locked, and if we have enough data,
1641 * we can start a write request
1643 if (s
->locked
== 0 && (rcw
== 0 || rmw
== 0) &&
1644 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
1645 PRINTK("Computing parity...\n");
1646 compute_parity5(sh
, rcw
== 0 ?
1647 RECONSTRUCT_WRITE
: READ_MODIFY_WRITE
);
1648 /* now every locked buffer is ready to be written */
1649 for (i
= disks
; i
--; )
1650 if (test_bit(R5_LOCKED
, &sh
->dev
[i
].flags
)) {
1651 PRINTK("Writing block %d\n", i
);
1653 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
1654 if (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
)
1655 || (i
== sh
->pd_idx
&& s
->failed
== 0))
1656 set_bit(STRIPE_INSYNC
, &sh
->state
);
1658 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
1659 atomic_dec(&conf
->preread_active_stripes
);
1660 if (atomic_read(&conf
->preread_active_stripes
) <
1662 md_wakeup_thread(conf
->mddev
->thread
);
1667 static void handle_issuing_new_write_requests6(raid5_conf_t
*conf
,
1668 struct stripe_head
*sh
, struct stripe_head_state
*s
,
1669 struct r6_state
*r6s
, int disks
)
1671 int rcw
= 0, must_compute
= 0, pd_idx
= sh
->pd_idx
, i
;
1672 int qd_idx
= r6s
->qd_idx
;
1673 for (i
= disks
; i
--; ) {
1674 struct r5dev
*dev
= &sh
->dev
[i
];
1675 /* Would I have to read this buffer for reconstruct_write */
1676 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
1677 && i
!= pd_idx
&& i
!= qd_idx
1678 && (!test_bit(R5_LOCKED
, &dev
->flags
)
1680 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
1681 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
1683 PRINTK("raid6: must_compute: "
1684 "disk %d flags=%#lx\n", i
, dev
->flags
);
1689 PRINTK("for sector %llu, rcw=%d, must_compute=%d\n",
1690 (unsigned long long)sh
->sector
, rcw
, must_compute
);
1691 set_bit(STRIPE_HANDLE
, &sh
->state
);
1694 /* want reconstruct write, but need to get some data */
1695 for (i
= disks
; i
--; ) {
1696 struct r5dev
*dev
= &sh
->dev
[i
];
1697 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
1698 && !(s
->failed
== 0 && (i
== pd_idx
|| i
== qd_idx
))
1699 && !test_bit(R5_LOCKED
, &dev
->flags
) &&
1700 !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1701 test_bit(R5_Insync
, &dev
->flags
)) {
1703 test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
1704 PRINTK("Read_old stripe %llu "
1705 "block %d for Reconstruct\n",
1706 (unsigned long long)sh
->sector
, i
);
1707 set_bit(R5_LOCKED
, &dev
->flags
);
1708 set_bit(R5_Wantread
, &dev
->flags
);
1711 PRINTK("Request delayed stripe %llu "
1712 "block %d for Reconstruct\n",
1713 (unsigned long long)sh
->sector
, i
);
1714 set_bit(STRIPE_DELAYED
, &sh
->state
);
1715 set_bit(STRIPE_HANDLE
, &sh
->state
);
1719 /* now if nothing is locked, and if we have enough data, we can start a
1722 if (s
->locked
== 0 && rcw
== 0 &&
1723 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
1724 if (must_compute
> 0) {
1725 /* We have failed blocks and need to compute them */
1726 switch (s
->failed
) {
1730 compute_block_1(sh
, r6s
->failed_num
[0], 0);
1733 compute_block_2(sh
, r6s
->failed_num
[0],
1734 r6s
->failed_num
[1]);
1736 default: /* This request should have been failed? */
1741 PRINTK("Computing parity for stripe %llu\n",
1742 (unsigned long long)sh
->sector
);
1743 compute_parity6(sh
, RECONSTRUCT_WRITE
);
1744 /* now every locked buffer is ready to be written */
1745 for (i
= disks
; i
--; )
1746 if (test_bit(R5_LOCKED
, &sh
->dev
[i
].flags
)) {
1747 PRINTK("Writing stripe %llu block %d\n",
1748 (unsigned long long)sh
->sector
, i
);
1750 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
1752 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
1753 set_bit(STRIPE_INSYNC
, &sh
->state
);
1755 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
1756 atomic_dec(&conf
->preread_active_stripes
);
1757 if (atomic_read(&conf
->preread_active_stripes
) <
1759 md_wakeup_thread(conf
->mddev
->thread
);
1764 static void handle_parity_checks5(raid5_conf_t
*conf
, struct stripe_head
*sh
,
1765 struct stripe_head_state
*s
, int disks
)
1767 set_bit(STRIPE_HANDLE
, &sh
->state
);
1768 if (s
->failed
== 0) {
1769 BUG_ON(s
->uptodate
!= disks
);
1770 compute_parity5(sh
, CHECK_PARITY
);
1772 if (page_is_zero(sh
->dev
[sh
->pd_idx
].page
)) {
1773 /* parity is correct (on disc, not in buffer any more)
1775 set_bit(STRIPE_INSYNC
, &sh
->state
);
1777 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
1778 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
1779 /* don't try to repair!! */
1780 set_bit(STRIPE_INSYNC
, &sh
->state
);
1782 compute_block(sh
, sh
->pd_idx
);
1787 if (!test_bit(STRIPE_INSYNC
, &sh
->state
)) {
1789 /* either failed parity check, or recovery is happening */
1791 s
->failed_num
= sh
->pd_idx
;
1792 dev
= &sh
->dev
[s
->failed_num
];
1793 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
1794 BUG_ON(s
->uptodate
!= disks
);
1796 set_bit(R5_LOCKED
, &dev
->flags
);
1797 set_bit(R5_Wantwrite
, &dev
->flags
);
1798 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
1800 set_bit(STRIPE_INSYNC
, &sh
->state
);
1805 static void handle_parity_checks6(raid5_conf_t
*conf
, struct stripe_head
*sh
,
1806 struct stripe_head_state
*s
,
1807 struct r6_state
*r6s
, struct page
*tmp_page
,
1810 int update_p
= 0, update_q
= 0;
1812 int pd_idx
= sh
->pd_idx
;
1813 int qd_idx
= r6s
->qd_idx
;
1815 set_bit(STRIPE_HANDLE
, &sh
->state
);
1817 BUG_ON(s
->failed
> 2);
1818 BUG_ON(s
->uptodate
< disks
);
1819 /* Want to check and possibly repair P and Q.
1820 * However there could be one 'failed' device, in which
1821 * case we can only check one of them, possibly using the
1822 * other to generate missing data
1825 /* If !tmp_page, we cannot do the calculations,
1826 * but as we have set STRIPE_HANDLE, we will soon be called
1827 * by stripe_handle with a tmp_page - just wait until then.
1830 if (s
->failed
== r6s
->q_failed
) {
1831 /* The only possible failed device holds 'Q', so it
1832 * makes sense to check P (If anything else were failed,
1833 * we would have used P to recreate it).
1835 compute_block_1(sh
, pd_idx
, 1);
1836 if (!page_is_zero(sh
->dev
[pd_idx
].page
)) {
1837 compute_block_1(sh
, pd_idx
, 0);
1841 if (!r6s
->q_failed
&& s
->failed
< 2) {
1842 /* q is not failed, and we didn't use it to generate
1843 * anything, so it makes sense to check it
1845 memcpy(page_address(tmp_page
),
1846 page_address(sh
->dev
[qd_idx
].page
),
1848 compute_parity6(sh
, UPDATE_PARITY
);
1849 if (memcmp(page_address(tmp_page
),
1850 page_address(sh
->dev
[qd_idx
].page
),
1851 STRIPE_SIZE
) != 0) {
1852 clear_bit(STRIPE_INSYNC
, &sh
->state
);
1856 if (update_p
|| update_q
) {
1857 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
1858 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
1859 /* don't try to repair!! */
1860 update_p
= update_q
= 0;
1863 /* now write out any block on a failed drive,
1864 * or P or Q if they need it
1867 if (s
->failed
== 2) {
1868 dev
= &sh
->dev
[r6s
->failed_num
[1]];
1870 set_bit(R5_LOCKED
, &dev
->flags
);
1871 set_bit(R5_Wantwrite
, &dev
->flags
);
1873 if (s
->failed
>= 1) {
1874 dev
= &sh
->dev
[r6s
->failed_num
[0]];
1876 set_bit(R5_LOCKED
, &dev
->flags
);
1877 set_bit(R5_Wantwrite
, &dev
->flags
);
1881 dev
= &sh
->dev
[pd_idx
];
1883 set_bit(R5_LOCKED
, &dev
->flags
);
1884 set_bit(R5_Wantwrite
, &dev
->flags
);
1887 dev
= &sh
->dev
[qd_idx
];
1889 set_bit(R5_LOCKED
, &dev
->flags
);
1890 set_bit(R5_Wantwrite
, &dev
->flags
);
1892 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
1894 set_bit(STRIPE_INSYNC
, &sh
->state
);
1898 static void handle_stripe_expansion(raid5_conf_t
*conf
, struct stripe_head
*sh
,
1899 struct r6_state
*r6s
)
1903 /* We have read all the blocks in this stripe and now we need to
1904 * copy some of them into a target stripe for expand.
1906 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
1907 for (i
= 0; i
< sh
->disks
; i
++)
1908 if (i
!= sh
->pd_idx
&& (r6s
&& i
!= r6s
->qd_idx
)) {
1909 int dd_idx
, pd_idx
, j
;
1910 struct stripe_head
*sh2
;
1912 sector_t bn
= compute_blocknr(sh
, i
);
1913 sector_t s
= raid5_compute_sector(bn
, conf
->raid_disks
,
1915 conf
->max_degraded
, &dd_idx
,
1917 sh2
= get_active_stripe(conf
, s
, conf
->raid_disks
,
1920 /* so far only the early blocks of this stripe
1921 * have been requested. When later blocks
1922 * get requested, we will try again
1925 if (!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
1926 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
1927 /* must have already done this block */
1928 release_stripe(sh2
);
1931 memcpy(page_address(sh2
->dev
[dd_idx
].page
),
1932 page_address(sh
->dev
[i
].page
),
1934 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
1935 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
1936 for (j
= 0; j
< conf
->raid_disks
; j
++)
1937 if (j
!= sh2
->pd_idx
&&
1938 (r6s
&& j
!= r6s
->qd_idx
) &&
1939 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
1941 if (j
== conf
->raid_disks
) {
1942 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
1943 set_bit(STRIPE_HANDLE
, &sh2
->state
);
1945 release_stripe(sh2
);
1950 * handle_stripe - do things to a stripe.
1952 * We lock the stripe and then examine the state of various bits
1953 * to see what needs to be done.
1955 * return some read request which now have data
1956 * return some write requests which are safely on disc
1957 * schedule a read on some buffers
1958 * schedule a write of some buffers
1959 * return confirmation of parity correctness
1961 * Parity calculations are done inside the stripe lock
1962 * buffers are taken off read_list or write_list, and bh_cache buffers
1963 * get BH_Lock set before the stripe lock is released.
1967 static void handle_stripe5(struct stripe_head
*sh
)
1969 raid5_conf_t
*conf
= sh
->raid_conf
;
1970 int disks
= sh
->disks
, i
;
1971 struct bio
*return_bi
= NULL
;
1972 struct stripe_head_state s
;
1975 memset(&s
, 0, sizeof(s
));
1976 PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n",
1977 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
),
1980 spin_lock(&sh
->lock
);
1981 clear_bit(STRIPE_HANDLE
, &sh
->state
);
1982 clear_bit(STRIPE_DELAYED
, &sh
->state
);
1984 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
1985 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
1986 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
1987 /* Now to look around and see what can be done */
1990 for (i
=disks
; i
--; ) {
1992 struct r5dev
*dev
= &sh
->dev
[i
];
1993 clear_bit(R5_Insync
, &dev
->flags
);
1995 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
1996 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
1997 /* maybe we can reply to a read */
1998 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
) {
1999 struct bio
*rbi
, *rbi2
;
2000 PRINTK("Return read for disc %d\n", i
);
2001 spin_lock_irq(&conf
->device_lock
);
2004 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
2005 wake_up(&conf
->wait_for_overlap
);
2006 spin_unlock_irq(&conf
->device_lock
);
2007 while (rbi
&& rbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
2008 copy_data(0, rbi
, dev
->page
, dev
->sector
);
2009 rbi2
= r5_next_bio(rbi
, dev
->sector
);
2010 spin_lock_irq(&conf
->device_lock
);
2011 if (--rbi
->bi_phys_segments
== 0) {
2012 rbi
->bi_next
= return_bi
;
2015 spin_unlock_irq(&conf
->device_lock
);
2020 /* now count some things */
2021 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
2022 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
2028 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
2033 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2034 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
2035 /* The ReadError flag will just be confusing now */
2036 clear_bit(R5_ReadError
, &dev
->flags
);
2037 clear_bit(R5_ReWrite
, &dev
->flags
);
2039 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
2040 || test_bit(R5_ReadError
, &dev
->flags
)) {
2044 set_bit(R5_Insync
, &dev
->flags
);
2047 PRINTK("locked=%d uptodate=%d to_read=%d"
2048 " to_write=%d failed=%d failed_num=%d\n",
2049 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
,
2050 s
.failed
, s
.failed_num
);
2051 /* check if the array has lost two devices and, if so, some requests might
2054 if (s
.failed
> 1 && s
.to_read
+s
.to_write
+s
.written
)
2055 handle_requests_to_failed_array(conf
, sh
, &s
, disks
,
2057 if (s
.failed
> 1 && s
.syncing
) {
2058 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
2059 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2063 /* might be able to return some write requests if the parity block
2064 * is safe, or on a failed drive
2066 dev
= &sh
->dev
[sh
->pd_idx
];
2068 ((test_bit(R5_Insync
, &dev
->flags
) &&
2069 !test_bit(R5_LOCKED
, &dev
->flags
) &&
2070 test_bit(R5_UPTODATE
, &dev
->flags
)) ||
2071 (s
.failed
== 1 && s
.failed_num
== sh
->pd_idx
)))
2072 handle_completed_write_requests(conf
, sh
, disks
, &return_bi
);
2074 /* Now we might consider reading some blocks, either to check/generate
2075 * parity, or to satisfy requests
2076 * or to load a block that is being partially written.
2078 if (s
.to_read
|| s
.non_overwrite
||
2079 (s
.syncing
&& (s
.uptodate
< disks
)) || s
.expanding
)
2080 handle_issuing_new_read_requests5(sh
, &s
, disks
);
2082 /* now to consider writing and what else, if anything should be read */
2084 handle_issuing_new_write_requests5(conf
, sh
, &s
, disks
);
2086 /* maybe we need to check and possibly fix the parity for this stripe
2087 * Any reads will already have been scheduled, so we just see if enough data
2090 if (s
.syncing
&& s
.locked
== 0 &&
2091 !test_bit(STRIPE_INSYNC
, &sh
->state
))
2092 handle_parity_checks5(conf
, sh
, &s
, disks
);
2093 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
2094 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
2095 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2098 /* If the failed drive is just a ReadError, then we might need to progress
2099 * the repair/check process
2101 if (s
.failed
== 1 && !conf
->mddev
->ro
&&
2102 test_bit(R5_ReadError
, &sh
->dev
[s
.failed_num
].flags
)
2103 && !test_bit(R5_LOCKED
, &sh
->dev
[s
.failed_num
].flags
)
2104 && test_bit(R5_UPTODATE
, &sh
->dev
[s
.failed_num
].flags
)
2106 dev
= &sh
->dev
[s
.failed_num
];
2107 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
2108 set_bit(R5_Wantwrite
, &dev
->flags
);
2109 set_bit(R5_ReWrite
, &dev
->flags
);
2110 set_bit(R5_LOCKED
, &dev
->flags
);
2113 /* let's read it back */
2114 set_bit(R5_Wantread
, &dev
->flags
);
2115 set_bit(R5_LOCKED
, &dev
->flags
);
2120 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
2121 /* Need to write out all blocks after computing parity */
2122 sh
->disks
= conf
->raid_disks
;
2123 sh
->pd_idx
= stripe_to_pdidx(sh
->sector
, conf
, conf
->raid_disks
);
2124 compute_parity5(sh
, RECONSTRUCT_WRITE
);
2125 for (i
= conf
->raid_disks
; i
--; ) {
2126 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2128 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
2130 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
2131 } else if (s
.expanded
) {
2132 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2133 atomic_dec(&conf
->reshape_stripes
);
2134 wake_up(&conf
->wait_for_overlap
);
2135 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
2138 if (s
.expanding
&& s
.locked
== 0)
2139 handle_stripe_expansion(conf
, sh
, NULL
);
2141 spin_unlock(&sh
->lock
);
2143 return_io(return_bi
);
2145 for (i
=disks
; i
-- ;) {
2149 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
2151 else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
2156 bi
= &sh
->dev
[i
].req
;
2160 bi
->bi_end_io
= raid5_end_write_request
;
2162 bi
->bi_end_io
= raid5_end_read_request
;
2165 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2166 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
2169 atomic_inc(&rdev
->nr_pending
);
2173 if (s
.syncing
|| s
.expanding
|| s
.expanded
)
2174 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
2176 bi
->bi_bdev
= rdev
->bdev
;
2177 PRINTK("for %llu schedule op %ld on disc %d\n",
2178 (unsigned long long)sh
->sector
, bi
->bi_rw
, i
);
2179 atomic_inc(&sh
->count
);
2180 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
2181 bi
->bi_flags
= 1 << BIO_UPTODATE
;
2183 bi
->bi_max_vecs
= 1;
2185 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
2186 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
2187 bi
->bi_io_vec
[0].bv_offset
= 0;
2188 bi
->bi_size
= STRIPE_SIZE
;
2191 test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
2192 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
2193 generic_make_request(bi
);
2196 set_bit(STRIPE_DEGRADED
, &sh
->state
);
2197 PRINTK("skip op %ld on disc %d for sector %llu\n",
2198 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
2199 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2200 set_bit(STRIPE_HANDLE
, &sh
->state
);
2205 static void handle_stripe6(struct stripe_head
*sh
, struct page
*tmp_page
)
2207 raid6_conf_t
*conf
= sh
->raid_conf
;
2208 int disks
= sh
->disks
;
2209 struct bio
*return_bi
= NULL
;
2210 int i
, pd_idx
= sh
->pd_idx
;
2211 struct stripe_head_state s
;
2212 struct r6_state r6s
;
2213 struct r5dev
*dev
, *pdev
, *qdev
;
2215 r6s
.qd_idx
= raid6_next_disk(pd_idx
, disks
);
2216 PRINTK("handling stripe %llu, state=%#lx cnt=%d, "
2217 "pd_idx=%d, qd_idx=%d\n",
2218 (unsigned long long)sh
->sector
, sh
->state
,
2219 atomic_read(&sh
->count
), pd_idx
, r6s
.qd_idx
);
2220 memset(&s
, 0, sizeof(s
));
2222 spin_lock(&sh
->lock
);
2223 clear_bit(STRIPE_HANDLE
, &sh
->state
);
2224 clear_bit(STRIPE_DELAYED
, &sh
->state
);
2226 s
.syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
2227 s
.expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2228 s
.expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2229 /* Now to look around and see what can be done */
2232 for (i
=disks
; i
--; ) {
2235 clear_bit(R5_Insync
, &dev
->flags
);
2237 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
2238 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
2239 /* maybe we can reply to a read */
2240 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
) {
2241 struct bio
*rbi
, *rbi2
;
2242 PRINTK("Return read for disc %d\n", i
);
2243 spin_lock_irq(&conf
->device_lock
);
2246 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
2247 wake_up(&conf
->wait_for_overlap
);
2248 spin_unlock_irq(&conf
->device_lock
);
2249 while (rbi
&& rbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
2250 copy_data(0, rbi
, dev
->page
, dev
->sector
);
2251 rbi2
= r5_next_bio(rbi
, dev
->sector
);
2252 spin_lock_irq(&conf
->device_lock
);
2253 if (--rbi
->bi_phys_segments
== 0) {
2254 rbi
->bi_next
= return_bi
;
2257 spin_unlock_irq(&conf
->device_lock
);
2262 /* now count some things */
2263 if (test_bit(R5_LOCKED
, &dev
->flags
)) s
.locked
++;
2264 if (test_bit(R5_UPTODATE
, &dev
->flags
)) s
.uptodate
++;
2271 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
2276 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2277 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
2278 /* The ReadError flag will just be confusing now */
2279 clear_bit(R5_ReadError
, &dev
->flags
);
2280 clear_bit(R5_ReWrite
, &dev
->flags
);
2282 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
2283 || test_bit(R5_ReadError
, &dev
->flags
)) {
2285 r6s
.failed_num
[s
.failed
] = i
;
2288 set_bit(R5_Insync
, &dev
->flags
);
2291 PRINTK("locked=%d uptodate=%d to_read=%d"
2292 " to_write=%d failed=%d failed_num=%d,%d\n",
2293 s
.locked
, s
.uptodate
, s
.to_read
, s
.to_write
, s
.failed
,
2294 r6s
.failed_num
[0], r6s
.failed_num
[1]);
2295 /* check if the array has lost >2 devices and, if so, some requests
2296 * might need to be failed
2298 if (s
.failed
> 2 && s
.to_read
+s
.to_write
+s
.written
)
2299 handle_requests_to_failed_array(conf
, sh
, &s
, disks
,
2301 if (s
.failed
> 2 && s
.syncing
) {
2302 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
2303 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2308 * might be able to return some write requests if the parity blocks
2309 * are safe, or on a failed drive
2311 pdev
= &sh
->dev
[pd_idx
];
2312 r6s
.p_failed
= (s
.failed
>= 1 && r6s
.failed_num
[0] == pd_idx
)
2313 || (s
.failed
>= 2 && r6s
.failed_num
[1] == pd_idx
);
2314 qdev
= &sh
->dev
[r6s
.qd_idx
];
2315 r6s
.q_failed
= (s
.failed
>= 1 && r6s
.failed_num
[0] == r6s
.qd_idx
)
2316 || (s
.failed
>= 2 && r6s
.failed_num
[1] == r6s
.qd_idx
);
2319 ( r6s
.p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
2320 && !test_bit(R5_LOCKED
, &pdev
->flags
)
2321 && test_bit(R5_UPTODATE
, &pdev
->flags
)))) &&
2322 ( r6s
.q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
2323 && !test_bit(R5_LOCKED
, &qdev
->flags
)
2324 && test_bit(R5_UPTODATE
, &qdev
->flags
)))))
2325 handle_completed_write_requests(conf
, sh
, disks
, &return_bi
);
2327 /* Now we might consider reading some blocks, either to check/generate
2328 * parity, or to satisfy requests
2329 * or to load a block that is being partially written.
2331 if (s
.to_read
|| s
.non_overwrite
|| (s
.to_write
&& s
.failed
) ||
2332 (s
.syncing
&& (s
.uptodate
< disks
)) || s
.expanding
)
2333 handle_issuing_new_read_requests6(sh
, &s
, &r6s
, disks
);
2335 /* now to consider writing and what else, if anything should be read */
2337 handle_issuing_new_write_requests6(conf
, sh
, &s
, &r6s
, disks
);
2339 /* maybe we need to check and possibly fix the parity for this stripe
2340 * Any reads will already have been scheduled, so we just see if enough
2343 if (s
.syncing
&& s
.locked
== 0 && !test_bit(STRIPE_INSYNC
, &sh
->state
))
2344 handle_parity_checks6(conf
, sh
, &s
, &r6s
, tmp_page
, disks
);
2346 if (s
.syncing
&& s
.locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
2347 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
2348 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2351 /* If the failed drives are just a ReadError, then we might need
2352 * to progress the repair/check process
2354 if (s
.failed
<= 2 && !conf
->mddev
->ro
)
2355 for (i
= 0; i
< s
.failed
; i
++) {
2356 dev
= &sh
->dev
[r6s
.failed_num
[i
]];
2357 if (test_bit(R5_ReadError
, &dev
->flags
)
2358 && !test_bit(R5_LOCKED
, &dev
->flags
)
2359 && test_bit(R5_UPTODATE
, &dev
->flags
)
2361 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
2362 set_bit(R5_Wantwrite
, &dev
->flags
);
2363 set_bit(R5_ReWrite
, &dev
->flags
);
2364 set_bit(R5_LOCKED
, &dev
->flags
);
2366 /* let's read it back */
2367 set_bit(R5_Wantread
, &dev
->flags
);
2368 set_bit(R5_LOCKED
, &dev
->flags
);
2373 if (s
.expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
2374 /* Need to write out all blocks after computing P&Q */
2375 sh
->disks
= conf
->raid_disks
;
2376 sh
->pd_idx
= stripe_to_pdidx(sh
->sector
, conf
,
2378 compute_parity6(sh
, RECONSTRUCT_WRITE
);
2379 for (i
= conf
->raid_disks
; i
-- ; ) {
2380 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2382 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
2384 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
2385 } else if (s
.expanded
) {
2386 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2387 atomic_dec(&conf
->reshape_stripes
);
2388 wake_up(&conf
->wait_for_overlap
);
2389 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
2392 if (s
.expanding
&& s
.locked
== 0)
2393 handle_stripe_expansion(conf
, sh
, &r6s
);
2395 spin_unlock(&sh
->lock
);
2397 return_io(return_bi
);
2399 for (i
=disks
; i
-- ;) {
2403 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
2405 else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
2410 bi
= &sh
->dev
[i
].req
;
2414 bi
->bi_end_io
= raid5_end_write_request
;
2416 bi
->bi_end_io
= raid5_end_read_request
;
2419 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2420 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
2423 atomic_inc(&rdev
->nr_pending
);
2427 if (s
.syncing
|| s
.expanding
|| s
.expanded
)
2428 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
2430 bi
->bi_bdev
= rdev
->bdev
;
2431 PRINTK("for %llu schedule op %ld on disc %d\n",
2432 (unsigned long long)sh
->sector
, bi
->bi_rw
, i
);
2433 atomic_inc(&sh
->count
);
2434 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
2435 bi
->bi_flags
= 1 << BIO_UPTODATE
;
2437 bi
->bi_max_vecs
= 1;
2439 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
2440 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
2441 bi
->bi_io_vec
[0].bv_offset
= 0;
2442 bi
->bi_size
= STRIPE_SIZE
;
2445 test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
2446 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
2447 generic_make_request(bi
);
2450 set_bit(STRIPE_DEGRADED
, &sh
->state
);
2451 PRINTK("skip op %ld on disc %d for sector %llu\n",
2452 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
2453 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2454 set_bit(STRIPE_HANDLE
, &sh
->state
);
2459 static void handle_stripe(struct stripe_head
*sh
, struct page
*tmp_page
)
2461 if (sh
->raid_conf
->level
== 6)
2462 handle_stripe6(sh
, tmp_page
);
2469 static void raid5_activate_delayed(raid5_conf_t
*conf
)
2471 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
2472 while (!list_empty(&conf
->delayed_list
)) {
2473 struct list_head
*l
= conf
->delayed_list
.next
;
2474 struct stripe_head
*sh
;
2475 sh
= list_entry(l
, struct stripe_head
, lru
);
2477 clear_bit(STRIPE_DELAYED
, &sh
->state
);
2478 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
2479 atomic_inc(&conf
->preread_active_stripes
);
2480 list_add_tail(&sh
->lru
, &conf
->handle_list
);
2485 static void activate_bit_delay(raid5_conf_t
*conf
)
2487 /* device_lock is held */
2488 struct list_head head
;
2489 list_add(&head
, &conf
->bitmap_list
);
2490 list_del_init(&conf
->bitmap_list
);
2491 while (!list_empty(&head
)) {
2492 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
2493 list_del_init(&sh
->lru
);
2494 atomic_inc(&sh
->count
);
2495 __release_stripe(conf
, sh
);
2499 static void unplug_slaves(mddev_t
*mddev
)
2501 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2505 for (i
=0; i
<mddev
->raid_disks
; i
++) {
2506 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2507 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) && atomic_read(&rdev
->nr_pending
)) {
2508 request_queue_t
*r_queue
= bdev_get_queue(rdev
->bdev
);
2510 atomic_inc(&rdev
->nr_pending
);
2513 if (r_queue
->unplug_fn
)
2514 r_queue
->unplug_fn(r_queue
);
2516 rdev_dec_pending(rdev
, mddev
);
2523 static void raid5_unplug_device(request_queue_t
*q
)
2525 mddev_t
*mddev
= q
->queuedata
;
2526 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2527 unsigned long flags
;
2529 spin_lock_irqsave(&conf
->device_lock
, flags
);
2531 if (blk_remove_plug(q
)) {
2533 raid5_activate_delayed(conf
);
2535 md_wakeup_thread(mddev
->thread
);
2537 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2539 unplug_slaves(mddev
);
2542 static int raid5_issue_flush(request_queue_t
*q
, struct gendisk
*disk
,
2543 sector_t
*error_sector
)
2545 mddev_t
*mddev
= q
->queuedata
;
2546 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2550 for (i
=0; i
<mddev
->raid_disks
&& ret
== 0; i
++) {
2551 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2552 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
2553 struct block_device
*bdev
= rdev
->bdev
;
2554 request_queue_t
*r_queue
= bdev_get_queue(bdev
);
2556 if (!r_queue
->issue_flush_fn
)
2559 atomic_inc(&rdev
->nr_pending
);
2561 ret
= r_queue
->issue_flush_fn(r_queue
, bdev
->bd_disk
,
2563 rdev_dec_pending(rdev
, mddev
);
2572 static int raid5_congested(void *data
, int bits
)
2574 mddev_t
*mddev
= data
;
2575 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2577 /* No difference between reads and writes. Just check
2578 * how busy the stripe_cache is
2580 if (conf
->inactive_blocked
)
2584 if (list_empty_careful(&conf
->inactive_list
))
2590 /* We want read requests to align with chunks where possible,
2591 * but write requests don't need to.
2593 static int raid5_mergeable_bvec(request_queue_t
*q
, struct bio
*bio
, struct bio_vec
*biovec
)
2595 mddev_t
*mddev
= q
->queuedata
;
2596 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
2598 unsigned int chunk_sectors
= mddev
->chunk_size
>> 9;
2599 unsigned int bio_sectors
= bio
->bi_size
>> 9;
2601 if (bio_data_dir(bio
) == WRITE
)
2602 return biovec
->bv_len
; /* always allow writes to be mergeable */
2604 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
2605 if (max
< 0) max
= 0;
2606 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
2607 return biovec
->bv_len
;
2613 static int in_chunk_boundary(mddev_t
*mddev
, struct bio
*bio
)
2615 sector_t sector
= bio
->bi_sector
+ get_start_sect(bio
->bi_bdev
);
2616 unsigned int chunk_sectors
= mddev
->chunk_size
>> 9;
2617 unsigned int bio_sectors
= bio
->bi_size
>> 9;
2619 return chunk_sectors
>=
2620 ((sector
& (chunk_sectors
- 1)) + bio_sectors
);
2624 * add bio to the retry LIFO ( in O(1) ... we are in interrupt )
2625 * later sampled by raid5d.
2627 static void add_bio_to_retry(struct bio
*bi
,raid5_conf_t
*conf
)
2629 unsigned long flags
;
2631 spin_lock_irqsave(&conf
->device_lock
, flags
);
2633 bi
->bi_next
= conf
->retry_read_aligned_list
;
2634 conf
->retry_read_aligned_list
= bi
;
2636 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2637 md_wakeup_thread(conf
->mddev
->thread
);
2641 static struct bio
*remove_bio_from_retry(raid5_conf_t
*conf
)
2645 bi
= conf
->retry_read_aligned
;
2647 conf
->retry_read_aligned
= NULL
;
2650 bi
= conf
->retry_read_aligned_list
;
2652 conf
->retry_read_aligned_list
= bi
->bi_next
;
2654 bi
->bi_phys_segments
= 1; /* biased count of active stripes */
2655 bi
->bi_hw_segments
= 0; /* count of processed stripes */
2663 * The "raid5_align_endio" should check if the read succeeded and if it
2664 * did, call bio_endio on the original bio (having bio_put the new bio
2666 * If the read failed..
2668 static int raid5_align_endio(struct bio
*bi
, unsigned int bytes
, int error
)
2670 struct bio
* raid_bi
= bi
->bi_private
;
2673 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2680 mddev
= raid_bi
->bi_bdev
->bd_disk
->queue
->queuedata
;
2681 conf
= mddev_to_conf(mddev
);
2682 rdev
= (void*)raid_bi
->bi_next
;
2683 raid_bi
->bi_next
= NULL
;
2685 rdev_dec_pending(rdev
, conf
->mddev
);
2687 if (!error
&& uptodate
) {
2688 bio_endio(raid_bi
, bytes
, 0);
2689 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
2690 wake_up(&conf
->wait_for_stripe
);
2695 PRINTK("raid5_align_endio : io error...handing IO for a retry\n");
2697 add_bio_to_retry(raid_bi
, conf
);
2701 static int bio_fits_rdev(struct bio
*bi
)
2703 request_queue_t
*q
= bdev_get_queue(bi
->bi_bdev
);
2705 if ((bi
->bi_size
>>9) > q
->max_sectors
)
2707 blk_recount_segments(q
, bi
);
2708 if (bi
->bi_phys_segments
> q
->max_phys_segments
||
2709 bi
->bi_hw_segments
> q
->max_hw_segments
)
2712 if (q
->merge_bvec_fn
)
2713 /* it's too hard to apply the merge_bvec_fn at this stage,
2722 static int chunk_aligned_read(request_queue_t
*q
, struct bio
* raid_bio
)
2724 mddev_t
*mddev
= q
->queuedata
;
2725 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2726 const unsigned int raid_disks
= conf
->raid_disks
;
2727 const unsigned int data_disks
= raid_disks
- conf
->max_degraded
;
2728 unsigned int dd_idx
, pd_idx
;
2729 struct bio
* align_bi
;
2732 if (!in_chunk_boundary(mddev
, raid_bio
)) {
2733 PRINTK("chunk_aligned_read : non aligned\n");
2737 * use bio_clone to make a copy of the bio
2739 align_bi
= bio_clone(raid_bio
, GFP_NOIO
);
2743 * set bi_end_io to a new function, and set bi_private to the
2746 align_bi
->bi_end_io
= raid5_align_endio
;
2747 align_bi
->bi_private
= raid_bio
;
2751 align_bi
->bi_sector
= raid5_compute_sector(raid_bio
->bi_sector
,
2759 rdev
= rcu_dereference(conf
->disks
[dd_idx
].rdev
);
2760 if (rdev
&& test_bit(In_sync
, &rdev
->flags
)) {
2761 atomic_inc(&rdev
->nr_pending
);
2763 raid_bio
->bi_next
= (void*)rdev
;
2764 align_bi
->bi_bdev
= rdev
->bdev
;
2765 align_bi
->bi_flags
&= ~(1 << BIO_SEG_VALID
);
2766 align_bi
->bi_sector
+= rdev
->data_offset
;
2768 if (!bio_fits_rdev(align_bi
)) {
2769 /* too big in some way */
2771 rdev_dec_pending(rdev
, mddev
);
2775 spin_lock_irq(&conf
->device_lock
);
2776 wait_event_lock_irq(conf
->wait_for_stripe
,
2778 conf
->device_lock
, /* nothing */);
2779 atomic_inc(&conf
->active_aligned_reads
);
2780 spin_unlock_irq(&conf
->device_lock
);
2782 generic_make_request(align_bi
);
2792 static int make_request(request_queue_t
*q
, struct bio
* bi
)
2794 mddev_t
*mddev
= q
->queuedata
;
2795 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2796 unsigned int dd_idx
, pd_idx
;
2797 sector_t new_sector
;
2798 sector_t logical_sector
, last_sector
;
2799 struct stripe_head
*sh
;
2800 const int rw
= bio_data_dir(bi
);
2803 if (unlikely(bio_barrier(bi
))) {
2804 bio_endio(bi
, bi
->bi_size
, -EOPNOTSUPP
);
2808 md_write_start(mddev
, bi
);
2810 disk_stat_inc(mddev
->gendisk
, ios
[rw
]);
2811 disk_stat_add(mddev
->gendisk
, sectors
[rw
], bio_sectors(bi
));
2814 mddev
->reshape_position
== MaxSector
&&
2815 chunk_aligned_read(q
,bi
))
2818 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
2819 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2821 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
2823 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
2825 int disks
, data_disks
;
2828 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
2829 if (likely(conf
->expand_progress
== MaxSector
))
2830 disks
= conf
->raid_disks
;
2832 /* spinlock is needed as expand_progress may be
2833 * 64bit on a 32bit platform, and so it might be
2834 * possible to see a half-updated value
2835 * Ofcourse expand_progress could change after
2836 * the lock is dropped, so once we get a reference
2837 * to the stripe that we think it is, we will have
2840 spin_lock_irq(&conf
->device_lock
);
2841 disks
= conf
->raid_disks
;
2842 if (logical_sector
>= conf
->expand_progress
)
2843 disks
= conf
->previous_raid_disks
;
2845 if (logical_sector
>= conf
->expand_lo
) {
2846 spin_unlock_irq(&conf
->device_lock
);
2851 spin_unlock_irq(&conf
->device_lock
);
2853 data_disks
= disks
- conf
->max_degraded
;
2855 new_sector
= raid5_compute_sector(logical_sector
, disks
, data_disks
,
2856 &dd_idx
, &pd_idx
, conf
);
2857 PRINTK("raid5: make_request, sector %llu logical %llu\n",
2858 (unsigned long long)new_sector
,
2859 (unsigned long long)logical_sector
);
2861 sh
= get_active_stripe(conf
, new_sector
, disks
, pd_idx
, (bi
->bi_rw
&RWA_MASK
));
2863 if (unlikely(conf
->expand_progress
!= MaxSector
)) {
2864 /* expansion might have moved on while waiting for a
2865 * stripe, so we must do the range check again.
2866 * Expansion could still move past after this
2867 * test, but as we are holding a reference to
2868 * 'sh', we know that if that happens,
2869 * STRIPE_EXPANDING will get set and the expansion
2870 * won't proceed until we finish with the stripe.
2873 spin_lock_irq(&conf
->device_lock
);
2874 if (logical_sector
< conf
->expand_progress
&&
2875 disks
== conf
->previous_raid_disks
)
2876 /* mismatch, need to try again */
2878 spin_unlock_irq(&conf
->device_lock
);
2884 /* FIXME what if we get a false positive because these
2885 * are being updated.
2887 if (logical_sector
>= mddev
->suspend_lo
&&
2888 logical_sector
< mddev
->suspend_hi
) {
2894 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
2895 !add_stripe_bio(sh
, bi
, dd_idx
, (bi
->bi_rw
&RW_MASK
))) {
2896 /* Stripe is busy expanding or
2897 * add failed due to overlap. Flush everything
2900 raid5_unplug_device(mddev
->queue
);
2905 finish_wait(&conf
->wait_for_overlap
, &w
);
2906 handle_stripe(sh
, NULL
);
2909 /* cannot get stripe for read-ahead, just give-up */
2910 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2911 finish_wait(&conf
->wait_for_overlap
, &w
);
2916 spin_lock_irq(&conf
->device_lock
);
2917 remaining
= --bi
->bi_phys_segments
;
2918 spin_unlock_irq(&conf
->device_lock
);
2919 if (remaining
== 0) {
2920 int bytes
= bi
->bi_size
;
2923 md_write_end(mddev
);
2925 bi
->bi_end_io(bi
, bytes
,
2926 test_bit(BIO_UPTODATE
, &bi
->bi_flags
)
2932 static sector_t
reshape_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
)
2934 /* reshaping is quite different to recovery/resync so it is
2935 * handled quite separately ... here.
2937 * On each call to sync_request, we gather one chunk worth of
2938 * destination stripes and flag them as expanding.
2939 * Then we find all the source stripes and request reads.
2940 * As the reads complete, handle_stripe will copy the data
2941 * into the destination stripe and release that stripe.
2943 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
2944 struct stripe_head
*sh
;
2946 sector_t first_sector
, last_sector
;
2947 int raid_disks
= conf
->previous_raid_disks
;
2948 int data_disks
= raid_disks
- conf
->max_degraded
;
2949 int new_data_disks
= conf
->raid_disks
- conf
->max_degraded
;
2952 sector_t writepos
, safepos
, gap
;
2954 if (sector_nr
== 0 &&
2955 conf
->expand_progress
!= 0) {
2956 /* restarting in the middle, skip the initial sectors */
2957 sector_nr
= conf
->expand_progress
;
2958 sector_div(sector_nr
, new_data_disks
);
2963 /* we update the metadata when there is more than 3Meg
2964 * in the block range (that is rather arbitrary, should
2965 * probably be time based) or when the data about to be
2966 * copied would over-write the source of the data at
2967 * the front of the range.
2968 * i.e. one new_stripe forward from expand_progress new_maps
2969 * to after where expand_lo old_maps to
2971 writepos
= conf
->expand_progress
+
2972 conf
->chunk_size
/512*(new_data_disks
);
2973 sector_div(writepos
, new_data_disks
);
2974 safepos
= conf
->expand_lo
;
2975 sector_div(safepos
, data_disks
);
2976 gap
= conf
->expand_progress
- conf
->expand_lo
;
2978 if (writepos
>= safepos
||
2979 gap
> (new_data_disks
)*3000*2 /*3Meg*/) {
2980 /* Cannot proceed until we've updated the superblock... */
2981 wait_event(conf
->wait_for_overlap
,
2982 atomic_read(&conf
->reshape_stripes
)==0);
2983 mddev
->reshape_position
= conf
->expand_progress
;
2984 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
2985 md_wakeup_thread(mddev
->thread
);
2986 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
2987 kthread_should_stop());
2988 spin_lock_irq(&conf
->device_lock
);
2989 conf
->expand_lo
= mddev
->reshape_position
;
2990 spin_unlock_irq(&conf
->device_lock
);
2991 wake_up(&conf
->wait_for_overlap
);
2994 for (i
=0; i
< conf
->chunk_size
/512; i
+= STRIPE_SECTORS
) {
2997 pd_idx
= stripe_to_pdidx(sector_nr
+i
, conf
, conf
->raid_disks
);
2998 sh
= get_active_stripe(conf
, sector_nr
+i
,
2999 conf
->raid_disks
, pd_idx
, 0);
3000 set_bit(STRIPE_EXPANDING
, &sh
->state
);
3001 atomic_inc(&conf
->reshape_stripes
);
3002 /* If any of this stripe is beyond the end of the old
3003 * array, then we need to zero those blocks
3005 for (j
=sh
->disks
; j
--;) {
3007 if (j
== sh
->pd_idx
)
3009 if (conf
->level
== 6 &&
3010 j
== raid6_next_disk(sh
->pd_idx
, sh
->disks
))
3012 s
= compute_blocknr(sh
, j
);
3013 if (s
< (mddev
->array_size
<<1)) {
3017 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
3018 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
3019 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
3022 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
3023 set_bit(STRIPE_HANDLE
, &sh
->state
);
3027 spin_lock_irq(&conf
->device_lock
);
3028 conf
->expand_progress
= (sector_nr
+ i
) * new_data_disks
;
3029 spin_unlock_irq(&conf
->device_lock
);
3030 /* Ok, those stripe are ready. We can start scheduling
3031 * reads on the source stripes.
3032 * The source stripes are determined by mapping the first and last
3033 * block on the destination stripes.
3036 raid5_compute_sector(sector_nr
*(new_data_disks
),
3037 raid_disks
, data_disks
,
3038 &dd_idx
, &pd_idx
, conf
);
3040 raid5_compute_sector((sector_nr
+conf
->chunk_size
/512)
3041 *(new_data_disks
) -1,
3042 raid_disks
, data_disks
,
3043 &dd_idx
, &pd_idx
, conf
);
3044 if (last_sector
>= (mddev
->size
<<1))
3045 last_sector
= (mddev
->size
<<1)-1;
3046 while (first_sector
<= last_sector
) {
3047 pd_idx
= stripe_to_pdidx(first_sector
, conf
,
3048 conf
->previous_raid_disks
);
3049 sh
= get_active_stripe(conf
, first_sector
,
3050 conf
->previous_raid_disks
, pd_idx
, 0);
3051 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
3052 set_bit(STRIPE_HANDLE
, &sh
->state
);
3054 first_sector
+= STRIPE_SECTORS
;
3056 return conf
->chunk_size
>>9;
3059 /* FIXME go_faster isn't used */
3060 static inline sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
3062 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3063 struct stripe_head
*sh
;
3065 int raid_disks
= conf
->raid_disks
;
3066 sector_t max_sector
= mddev
->size
<< 1;
3068 int still_degraded
= 0;
3071 if (sector_nr
>= max_sector
) {
3072 /* just being told to finish up .. nothing much to do */
3073 unplug_slaves(mddev
);
3074 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
3079 if (mddev
->curr_resync
< max_sector
) /* aborted */
3080 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
3082 else /* completed sync */
3084 bitmap_close_sync(mddev
->bitmap
);
3089 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
3090 return reshape_request(mddev
, sector_nr
, skipped
);
3092 /* if there is too many failed drives and we are trying
3093 * to resync, then assert that we are finished, because there is
3094 * nothing we can do.
3096 if (mddev
->degraded
>= conf
->max_degraded
&&
3097 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
3098 sector_t rv
= (mddev
->size
<< 1) - sector_nr
;
3102 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
3103 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
3104 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
3105 /* we can skip this block, and probably more */
3106 sync_blocks
/= STRIPE_SECTORS
;
3108 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
3111 pd_idx
= stripe_to_pdidx(sector_nr
, conf
, raid_disks
);
3112 sh
= get_active_stripe(conf
, sector_nr
, raid_disks
, pd_idx
, 1);
3114 sh
= get_active_stripe(conf
, sector_nr
, raid_disks
, pd_idx
, 0);
3115 /* make sure we don't swamp the stripe cache if someone else
3116 * is trying to get access
3118 schedule_timeout_uninterruptible(1);
3120 /* Need to check if array will still be degraded after recovery/resync
3121 * We don't need to check the 'failed' flag as when that gets set,
3124 for (i
=0; i
<mddev
->raid_disks
; i
++)
3125 if (conf
->disks
[i
].rdev
== NULL
)
3128 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
3130 spin_lock(&sh
->lock
);
3131 set_bit(STRIPE_SYNCING
, &sh
->state
);
3132 clear_bit(STRIPE_INSYNC
, &sh
->state
);
3133 spin_unlock(&sh
->lock
);
3135 handle_stripe(sh
, NULL
);
3138 return STRIPE_SECTORS
;
3141 static int retry_aligned_read(raid5_conf_t
*conf
, struct bio
*raid_bio
)
3143 /* We may not be able to submit a whole bio at once as there
3144 * may not be enough stripe_heads available.
3145 * We cannot pre-allocate enough stripe_heads as we may need
3146 * more than exist in the cache (if we allow ever large chunks).
3147 * So we do one stripe head at a time and record in
3148 * ->bi_hw_segments how many have been done.
3150 * We *know* that this entire raid_bio is in one chunk, so
3151 * it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
3153 struct stripe_head
*sh
;
3155 sector_t sector
, logical_sector
, last_sector
;
3160 logical_sector
= raid_bio
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
3161 sector
= raid5_compute_sector( logical_sector
,
3163 conf
->raid_disks
- conf
->max_degraded
,
3167 last_sector
= raid_bio
->bi_sector
+ (raid_bio
->bi_size
>>9);
3169 for (; logical_sector
< last_sector
;
3170 logical_sector
+= STRIPE_SECTORS
,
3171 sector
+= STRIPE_SECTORS
,
3174 if (scnt
< raid_bio
->bi_hw_segments
)
3175 /* already done this stripe */
3178 sh
= get_active_stripe(conf
, sector
, conf
->raid_disks
, pd_idx
, 1);
3181 /* failed to get a stripe - must wait */
3182 raid_bio
->bi_hw_segments
= scnt
;
3183 conf
->retry_read_aligned
= raid_bio
;
3187 set_bit(R5_ReadError
, &sh
->dev
[dd_idx
].flags
);
3188 if (!add_stripe_bio(sh
, raid_bio
, dd_idx
, 0)) {
3190 raid_bio
->bi_hw_segments
= scnt
;
3191 conf
->retry_read_aligned
= raid_bio
;
3195 handle_stripe(sh
, NULL
);
3199 spin_lock_irq(&conf
->device_lock
);
3200 remaining
= --raid_bio
->bi_phys_segments
;
3201 spin_unlock_irq(&conf
->device_lock
);
3202 if (remaining
== 0) {
3203 int bytes
= raid_bio
->bi_size
;
3205 raid_bio
->bi_size
= 0;
3206 raid_bio
->bi_end_io(raid_bio
, bytes
,
3207 test_bit(BIO_UPTODATE
, &raid_bio
->bi_flags
)
3210 if (atomic_dec_and_test(&conf
->active_aligned_reads
))
3211 wake_up(&conf
->wait_for_stripe
);
3218 * This is our raid5 kernel thread.
3220 * We scan the hash table for stripes which can be handled now.
3221 * During the scan, completed stripes are saved for us by the interrupt
3222 * handler, so that they will not have to wait for our next wakeup.
3224 static void raid5d (mddev_t
*mddev
)
3226 struct stripe_head
*sh
;
3227 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3230 PRINTK("+++ raid5d active\n");
3232 md_check_recovery(mddev
);
3235 spin_lock_irq(&conf
->device_lock
);
3237 struct list_head
*first
;
3240 if (conf
->seq_flush
!= conf
->seq_write
) {
3241 int seq
= conf
->seq_flush
;
3242 spin_unlock_irq(&conf
->device_lock
);
3243 bitmap_unplug(mddev
->bitmap
);
3244 spin_lock_irq(&conf
->device_lock
);
3245 conf
->seq_write
= seq
;
3246 activate_bit_delay(conf
);
3249 if (list_empty(&conf
->handle_list
) &&
3250 atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
&&
3251 !blk_queue_plugged(mddev
->queue
) &&
3252 !list_empty(&conf
->delayed_list
))
3253 raid5_activate_delayed(conf
);
3255 while ((bio
= remove_bio_from_retry(conf
))) {
3257 spin_unlock_irq(&conf
->device_lock
);
3258 ok
= retry_aligned_read(conf
, bio
);
3259 spin_lock_irq(&conf
->device_lock
);
3265 if (list_empty(&conf
->handle_list
))
3268 first
= conf
->handle_list
.next
;
3269 sh
= list_entry(first
, struct stripe_head
, lru
);
3271 list_del_init(first
);
3272 atomic_inc(&sh
->count
);
3273 BUG_ON(atomic_read(&sh
->count
)!= 1);
3274 spin_unlock_irq(&conf
->device_lock
);
3277 handle_stripe(sh
, conf
->spare_page
);
3280 spin_lock_irq(&conf
->device_lock
);
3282 PRINTK("%d stripes handled\n", handled
);
3284 spin_unlock_irq(&conf
->device_lock
);
3286 unplug_slaves(mddev
);
3288 PRINTK("--- raid5d inactive\n");
3292 raid5_show_stripe_cache_size(mddev_t
*mddev
, char *page
)
3294 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3296 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
3302 raid5_store_stripe_cache_size(mddev_t
*mddev
, const char *page
, size_t len
)
3304 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3307 if (len
>= PAGE_SIZE
)
3312 new = simple_strtoul(page
, &end
, 10);
3313 if (!*page
|| (*end
&& *end
!= '\n') )
3315 if (new <= 16 || new > 32768)
3317 while (new < conf
->max_nr_stripes
) {
3318 if (drop_one_stripe(conf
))
3319 conf
->max_nr_stripes
--;
3323 md_allow_write(mddev
);
3324 while (new > conf
->max_nr_stripes
) {
3325 if (grow_one_stripe(conf
))
3326 conf
->max_nr_stripes
++;
3332 static struct md_sysfs_entry
3333 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
3334 raid5_show_stripe_cache_size
,
3335 raid5_store_stripe_cache_size
);
3338 stripe_cache_active_show(mddev_t
*mddev
, char *page
)
3340 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3342 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
3347 static struct md_sysfs_entry
3348 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
3350 static struct attribute
*raid5_attrs
[] = {
3351 &raid5_stripecache_size
.attr
,
3352 &raid5_stripecache_active
.attr
,
3355 static struct attribute_group raid5_attrs_group
= {
3357 .attrs
= raid5_attrs
,
3360 static int run(mddev_t
*mddev
)
3363 int raid_disk
, memory
;
3365 struct disk_info
*disk
;
3366 struct list_head
*tmp
;
3367 int working_disks
= 0;
3369 if (mddev
->level
!= 5 && mddev
->level
!= 4 && mddev
->level
!= 6) {
3370 printk(KERN_ERR
"raid5: %s: raid level not set to 4/5/6 (%d)\n",
3371 mdname(mddev
), mddev
->level
);
3375 if (mddev
->reshape_position
!= MaxSector
) {
3376 /* Check that we can continue the reshape.
3377 * Currently only disks can change, it must
3378 * increase, and we must be past the point where
3379 * a stripe over-writes itself
3381 sector_t here_new
, here_old
;
3383 int max_degraded
= (mddev
->level
== 5 ? 1 : 2);
3385 if (mddev
->new_level
!= mddev
->level
||
3386 mddev
->new_layout
!= mddev
->layout
||
3387 mddev
->new_chunk
!= mddev
->chunk_size
) {
3388 printk(KERN_ERR
"raid5: %s: unsupported reshape "
3389 "required - aborting.\n",
3393 if (mddev
->delta_disks
<= 0) {
3394 printk(KERN_ERR
"raid5: %s: unsupported reshape "
3395 "(reduce disks) required - aborting.\n",
3399 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
3400 /* reshape_position must be on a new-stripe boundary, and one
3401 * further up in new geometry must map after here in old
3404 here_new
= mddev
->reshape_position
;
3405 if (sector_div(here_new
, (mddev
->chunk_size
>>9)*
3406 (mddev
->raid_disks
- max_degraded
))) {
3407 printk(KERN_ERR
"raid5: reshape_position not "
3408 "on a stripe boundary\n");
3411 /* here_new is the stripe we will write to */
3412 here_old
= mddev
->reshape_position
;
3413 sector_div(here_old
, (mddev
->chunk_size
>>9)*
3414 (old_disks
-max_degraded
));
3415 /* here_old is the first stripe that we might need to read
3417 if (here_new
>= here_old
) {
3418 /* Reading from the same stripe as writing to - bad */
3419 printk(KERN_ERR
"raid5: reshape_position too early for "
3420 "auto-recovery - aborting.\n");
3423 printk(KERN_INFO
"raid5: reshape will continue\n");
3424 /* OK, we should be able to continue; */
3428 mddev
->private = kzalloc(sizeof (raid5_conf_t
), GFP_KERNEL
);
3429 if ((conf
= mddev
->private) == NULL
)
3431 if (mddev
->reshape_position
== MaxSector
) {
3432 conf
->previous_raid_disks
= conf
->raid_disks
= mddev
->raid_disks
;
3434 conf
->raid_disks
= mddev
->raid_disks
;
3435 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
3438 conf
->disks
= kzalloc(conf
->raid_disks
* sizeof(struct disk_info
),
3443 conf
->mddev
= mddev
;
3445 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
3448 if (mddev
->level
== 6) {
3449 conf
->spare_page
= alloc_page(GFP_KERNEL
);
3450 if (!conf
->spare_page
)
3453 spin_lock_init(&conf
->device_lock
);
3454 init_waitqueue_head(&conf
->wait_for_stripe
);
3455 init_waitqueue_head(&conf
->wait_for_overlap
);
3456 INIT_LIST_HEAD(&conf
->handle_list
);
3457 INIT_LIST_HEAD(&conf
->delayed_list
);
3458 INIT_LIST_HEAD(&conf
->bitmap_list
);
3459 INIT_LIST_HEAD(&conf
->inactive_list
);
3460 atomic_set(&conf
->active_stripes
, 0);
3461 atomic_set(&conf
->preread_active_stripes
, 0);
3462 atomic_set(&conf
->active_aligned_reads
, 0);
3464 PRINTK("raid5: run(%s) called.\n", mdname(mddev
));
3466 ITERATE_RDEV(mddev
,rdev
,tmp
) {
3467 raid_disk
= rdev
->raid_disk
;
3468 if (raid_disk
>= conf
->raid_disks
3471 disk
= conf
->disks
+ raid_disk
;
3475 if (test_bit(In_sync
, &rdev
->flags
)) {
3476 char b
[BDEVNAME_SIZE
];
3477 printk(KERN_INFO
"raid5: device %s operational as raid"
3478 " disk %d\n", bdevname(rdev
->bdev
,b
),
3485 * 0 for a fully functional array, 1 or 2 for a degraded array.
3487 mddev
->degraded
= conf
->raid_disks
- working_disks
;
3488 conf
->mddev
= mddev
;
3489 conf
->chunk_size
= mddev
->chunk_size
;
3490 conf
->level
= mddev
->level
;
3491 if (conf
->level
== 6)
3492 conf
->max_degraded
= 2;
3494 conf
->max_degraded
= 1;
3495 conf
->algorithm
= mddev
->layout
;
3496 conf
->max_nr_stripes
= NR_STRIPES
;
3497 conf
->expand_progress
= mddev
->reshape_position
;
3499 /* device size must be a multiple of chunk size */
3500 mddev
->size
&= ~(mddev
->chunk_size
/1024 -1);
3501 mddev
->resync_max_sectors
= mddev
->size
<< 1;
3503 if (conf
->level
== 6 && conf
->raid_disks
< 4) {
3504 printk(KERN_ERR
"raid6: not enough configured devices for %s (%d, minimum 4)\n",
3505 mdname(mddev
), conf
->raid_disks
);
3508 if (!conf
->chunk_size
|| conf
->chunk_size
% 4) {
3509 printk(KERN_ERR
"raid5: invalid chunk size %d for %s\n",
3510 conf
->chunk_size
, mdname(mddev
));
3513 if (conf
->algorithm
> ALGORITHM_RIGHT_SYMMETRIC
) {
3515 "raid5: unsupported parity algorithm %d for %s\n",
3516 conf
->algorithm
, mdname(mddev
));
3519 if (mddev
->degraded
> conf
->max_degraded
) {
3520 printk(KERN_ERR
"raid5: not enough operational devices for %s"
3521 " (%d/%d failed)\n",
3522 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
3526 if (mddev
->degraded
> 0 &&
3527 mddev
->recovery_cp
!= MaxSector
) {
3528 if (mddev
->ok_start_degraded
)
3530 "raid5: starting dirty degraded array: %s"
3531 "- data corruption possible.\n",
3535 "raid5: cannot start dirty degraded array for %s\n",
3542 mddev
->thread
= md_register_thread(raid5d
, mddev
, "%s_raid5");
3543 if (!mddev
->thread
) {
3545 "raid5: couldn't allocate thread for %s\n",
3550 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
3551 conf
->raid_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
3552 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
3554 "raid5: couldn't allocate %dkB for buffers\n", memory
);
3555 shrink_stripes(conf
);
3556 md_unregister_thread(mddev
->thread
);
3559 printk(KERN_INFO
"raid5: allocated %dkB for %s\n",
3560 memory
, mdname(mddev
));
3562 if (mddev
->degraded
== 0)
3563 printk("raid5: raid level %d set %s active with %d out of %d"
3564 " devices, algorithm %d\n", conf
->level
, mdname(mddev
),
3565 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
3568 printk(KERN_ALERT
"raid5: raid level %d set %s active with %d"
3569 " out of %d devices, algorithm %d\n", conf
->level
,
3570 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
3571 mddev
->raid_disks
, conf
->algorithm
);
3573 print_raid5_conf(conf
);
3575 if (conf
->expand_progress
!= MaxSector
) {
3576 printk("...ok start reshape thread\n");
3577 conf
->expand_lo
= conf
->expand_progress
;
3578 atomic_set(&conf
->reshape_stripes
, 0);
3579 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
3580 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
3581 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
3582 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
3583 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
3587 /* read-ahead size must cover two whole stripes, which is
3588 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
3591 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
3592 int stripe
= data_disks
*
3593 (mddev
->chunk_size
/ PAGE_SIZE
);
3594 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
3595 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
3598 /* Ok, everything is just fine now */
3599 if (sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
))
3601 "raid5: failed to create sysfs attributes for %s\n",
3604 mddev
->queue
->unplug_fn
= raid5_unplug_device
;
3605 mddev
->queue
->issue_flush_fn
= raid5_issue_flush
;
3606 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
3607 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
3609 mddev
->array_size
= mddev
->size
* (conf
->previous_raid_disks
-
3610 conf
->max_degraded
);
3612 blk_queue_merge_bvec(mddev
->queue
, raid5_mergeable_bvec
);
3617 print_raid5_conf(conf
);
3618 safe_put_page(conf
->spare_page
);
3620 kfree(conf
->stripe_hashtbl
);
3623 mddev
->private = NULL
;
3624 printk(KERN_ALERT
"raid5: failed to run raid set %s\n", mdname(mddev
));
3630 static int stop(mddev_t
*mddev
)
3632 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3634 md_unregister_thread(mddev
->thread
);
3635 mddev
->thread
= NULL
;
3636 shrink_stripes(conf
);
3637 kfree(conf
->stripe_hashtbl
);
3638 mddev
->queue
->backing_dev_info
.congested_fn
= NULL
;
3639 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
3640 sysfs_remove_group(&mddev
->kobj
, &raid5_attrs_group
);
3643 mddev
->private = NULL
;
3648 static void print_sh (struct seq_file
*seq
, struct stripe_head
*sh
)
3652 seq_printf(seq
, "sh %llu, pd_idx %d, state %ld.\n",
3653 (unsigned long long)sh
->sector
, sh
->pd_idx
, sh
->state
);
3654 seq_printf(seq
, "sh %llu, count %d.\n",
3655 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
));
3656 seq_printf(seq
, "sh %llu, ", (unsigned long long)sh
->sector
);
3657 for (i
= 0; i
< sh
->disks
; i
++) {
3658 seq_printf(seq
, "(cache%d: %p %ld) ",
3659 i
, sh
->dev
[i
].page
, sh
->dev
[i
].flags
);
3661 seq_printf(seq
, "\n");
3664 static void printall (struct seq_file
*seq
, raid5_conf_t
*conf
)
3666 struct stripe_head
*sh
;
3667 struct hlist_node
*hn
;
3670 spin_lock_irq(&conf
->device_lock
);
3671 for (i
= 0; i
< NR_HASH
; i
++) {
3672 hlist_for_each_entry(sh
, hn
, &conf
->stripe_hashtbl
[i
], hash
) {
3673 if (sh
->raid_conf
!= conf
)
3678 spin_unlock_irq(&conf
->device_lock
);
3682 static void status (struct seq_file
*seq
, mddev_t
*mddev
)
3684 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3687 seq_printf (seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
, mddev
->chunk_size
>> 10, mddev
->layout
);
3688 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
3689 for (i
= 0; i
< conf
->raid_disks
; i
++)
3690 seq_printf (seq
, "%s",
3691 conf
->disks
[i
].rdev
&&
3692 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
3693 seq_printf (seq
, "]");
3695 seq_printf (seq
, "\n");
3696 printall(seq
, conf
);
3700 static void print_raid5_conf (raid5_conf_t
*conf
)
3703 struct disk_info
*tmp
;
3705 printk("RAID5 conf printout:\n");
3707 printk("(conf==NULL)\n");
3710 printk(" --- rd:%d wd:%d\n", conf
->raid_disks
,
3711 conf
->raid_disks
- conf
->mddev
->degraded
);
3713 for (i
= 0; i
< conf
->raid_disks
; i
++) {
3714 char b
[BDEVNAME_SIZE
];
3715 tmp
= conf
->disks
+ i
;
3717 printk(" disk %d, o:%d, dev:%s\n",
3718 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
3719 bdevname(tmp
->rdev
->bdev
,b
));
3723 static int raid5_spare_active(mddev_t
*mddev
)
3726 raid5_conf_t
*conf
= mddev
->private;
3727 struct disk_info
*tmp
;
3729 for (i
= 0; i
< conf
->raid_disks
; i
++) {
3730 tmp
= conf
->disks
+ i
;
3732 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
3733 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
3734 unsigned long flags
;
3735 spin_lock_irqsave(&conf
->device_lock
, flags
);
3737 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3740 print_raid5_conf(conf
);
3744 static int raid5_remove_disk(mddev_t
*mddev
, int number
)
3746 raid5_conf_t
*conf
= mddev
->private;
3749 struct disk_info
*p
= conf
->disks
+ number
;
3751 print_raid5_conf(conf
);
3754 if (test_bit(In_sync
, &rdev
->flags
) ||
3755 atomic_read(&rdev
->nr_pending
)) {
3761 if (atomic_read(&rdev
->nr_pending
)) {
3762 /* lost the race, try later */
3769 print_raid5_conf(conf
);
3773 static int raid5_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
3775 raid5_conf_t
*conf
= mddev
->private;
3778 struct disk_info
*p
;
3780 if (mddev
->degraded
> conf
->max_degraded
)
3781 /* no point adding a device */
3785 * find the disk ... but prefer rdev->saved_raid_disk
3788 if (rdev
->saved_raid_disk
>= 0 &&
3789 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
3790 disk
= rdev
->saved_raid_disk
;
3793 for ( ; disk
< conf
->raid_disks
; disk
++)
3794 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
3795 clear_bit(In_sync
, &rdev
->flags
);
3796 rdev
->raid_disk
= disk
;
3798 if (rdev
->saved_raid_disk
!= disk
)
3800 rcu_assign_pointer(p
->rdev
, rdev
);
3803 print_raid5_conf(conf
);
3807 static int raid5_resize(mddev_t
*mddev
, sector_t sectors
)
3809 /* no resync is happening, and there is enough space
3810 * on all devices, so we can resize.
3811 * We need to make sure resync covers any new space.
3812 * If the array is shrinking we should possibly wait until
3813 * any io in the removed space completes, but it hardly seems
3816 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3818 sectors
&= ~((sector_t
)mddev
->chunk_size
/512 - 1);
3819 mddev
->array_size
= (sectors
* (mddev
->raid_disks
-conf
->max_degraded
))>>1;
3820 set_capacity(mddev
->gendisk
, mddev
->array_size
<< 1);
3822 if (sectors
/2 > mddev
->size
&& mddev
->recovery_cp
== MaxSector
) {
3823 mddev
->recovery_cp
= mddev
->size
<< 1;
3824 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
3826 mddev
->size
= sectors
/2;
3827 mddev
->resync_max_sectors
= sectors
;
3831 #ifdef CONFIG_MD_RAID5_RESHAPE
3832 static int raid5_check_reshape(mddev_t
*mddev
)
3834 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3837 if (mddev
->delta_disks
< 0 ||
3838 mddev
->new_level
!= mddev
->level
)
3839 return -EINVAL
; /* Cannot shrink array or change level yet */
3840 if (mddev
->delta_disks
== 0)
3841 return 0; /* nothing to do */
3843 /* Can only proceed if there are plenty of stripe_heads.
3844 * We need a minimum of one full stripe,, and for sensible progress
3845 * it is best to have about 4 times that.
3846 * If we require 4 times, then the default 256 4K stripe_heads will
3847 * allow for chunk sizes up to 256K, which is probably OK.
3848 * If the chunk size is greater, user-space should request more
3849 * stripe_heads first.
3851 if ((mddev
->chunk_size
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
||
3852 (mddev
->new_chunk
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
) {
3853 printk(KERN_WARNING
"raid5: reshape: not enough stripes. Needed %lu\n",
3854 (mddev
->chunk_size
/ STRIPE_SIZE
)*4);
3858 err
= resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
3862 if (mddev
->degraded
> conf
->max_degraded
)
3864 /* looks like we might be able to manage this */
3868 static int raid5_start_reshape(mddev_t
*mddev
)
3870 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3872 struct list_head
*rtmp
;
3874 int added_devices
= 0;
3875 unsigned long flags
;
3877 if (test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
3880 ITERATE_RDEV(mddev
, rdev
, rtmp
)
3881 if (rdev
->raid_disk
< 0 &&
3882 !test_bit(Faulty
, &rdev
->flags
))
3885 if (spares
- mddev
->degraded
< mddev
->delta_disks
- conf
->max_degraded
)
3886 /* Not enough devices even to make a degraded array
3891 atomic_set(&conf
->reshape_stripes
, 0);
3892 spin_lock_irq(&conf
->device_lock
);
3893 conf
->previous_raid_disks
= conf
->raid_disks
;
3894 conf
->raid_disks
+= mddev
->delta_disks
;
3895 conf
->expand_progress
= 0;
3896 conf
->expand_lo
= 0;
3897 spin_unlock_irq(&conf
->device_lock
);
3899 /* Add some new drives, as many as will fit.
3900 * We know there are enough to make the newly sized array work.
3902 ITERATE_RDEV(mddev
, rdev
, rtmp
)
3903 if (rdev
->raid_disk
< 0 &&
3904 !test_bit(Faulty
, &rdev
->flags
)) {
3905 if (raid5_add_disk(mddev
, rdev
)) {
3907 set_bit(In_sync
, &rdev
->flags
);
3909 rdev
->recovery_offset
= 0;
3910 sprintf(nm
, "rd%d", rdev
->raid_disk
);
3911 if (sysfs_create_link(&mddev
->kobj
,
3914 "raid5: failed to create "
3915 " link %s for %s\n",
3921 spin_lock_irqsave(&conf
->device_lock
, flags
);
3922 mddev
->degraded
= (conf
->raid_disks
- conf
->previous_raid_disks
) - added_devices
;
3923 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3924 mddev
->raid_disks
= conf
->raid_disks
;
3925 mddev
->reshape_position
= 0;
3926 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
3928 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
3929 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
3930 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
3931 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
3932 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
3934 if (!mddev
->sync_thread
) {
3935 mddev
->recovery
= 0;
3936 spin_lock_irq(&conf
->device_lock
);
3937 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
3938 conf
->expand_progress
= MaxSector
;
3939 spin_unlock_irq(&conf
->device_lock
);
3942 md_wakeup_thread(mddev
->sync_thread
);
3943 md_new_event(mddev
);
3948 static void end_reshape(raid5_conf_t
*conf
)
3950 struct block_device
*bdev
;
3952 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
3953 conf
->mddev
->array_size
= conf
->mddev
->size
*
3954 (conf
->raid_disks
- conf
->max_degraded
);
3955 set_capacity(conf
->mddev
->gendisk
, conf
->mddev
->array_size
<< 1);
3956 conf
->mddev
->changed
= 1;
3958 bdev
= bdget_disk(conf
->mddev
->gendisk
, 0);
3960 mutex_lock(&bdev
->bd_inode
->i_mutex
);
3961 i_size_write(bdev
->bd_inode
, (loff_t
)conf
->mddev
->array_size
<< 10);
3962 mutex_unlock(&bdev
->bd_inode
->i_mutex
);
3965 spin_lock_irq(&conf
->device_lock
);
3966 conf
->expand_progress
= MaxSector
;
3967 spin_unlock_irq(&conf
->device_lock
);
3968 conf
->mddev
->reshape_position
= MaxSector
;
3970 /* read-ahead size must cover two whole stripes, which is
3971 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
3974 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
3975 int stripe
= data_disks
*
3976 (conf
->mddev
->chunk_size
/ PAGE_SIZE
);
3977 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
3978 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
3983 static void raid5_quiesce(mddev_t
*mddev
, int state
)
3985 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3988 case 2: /* resume for a suspend */
3989 wake_up(&conf
->wait_for_overlap
);
3992 case 1: /* stop all writes */
3993 spin_lock_irq(&conf
->device_lock
);
3995 wait_event_lock_irq(conf
->wait_for_stripe
,
3996 atomic_read(&conf
->active_stripes
) == 0 &&
3997 atomic_read(&conf
->active_aligned_reads
) == 0,
3998 conf
->device_lock
, /* nothing */);
3999 spin_unlock_irq(&conf
->device_lock
);
4002 case 0: /* re-enable writes */
4003 spin_lock_irq(&conf
->device_lock
);
4005 wake_up(&conf
->wait_for_stripe
);
4006 wake_up(&conf
->wait_for_overlap
);
4007 spin_unlock_irq(&conf
->device_lock
);
4012 static struct mdk_personality raid6_personality
=
4016 .owner
= THIS_MODULE
,
4017 .make_request
= make_request
,
4021 .error_handler
= error
,
4022 .hot_add_disk
= raid5_add_disk
,
4023 .hot_remove_disk
= raid5_remove_disk
,
4024 .spare_active
= raid5_spare_active
,
4025 .sync_request
= sync_request
,
4026 .resize
= raid5_resize
,
4027 #ifdef CONFIG_MD_RAID5_RESHAPE
4028 .check_reshape
= raid5_check_reshape
,
4029 .start_reshape
= raid5_start_reshape
,
4031 .quiesce
= raid5_quiesce
,
4033 static struct mdk_personality raid5_personality
=
4037 .owner
= THIS_MODULE
,
4038 .make_request
= make_request
,
4042 .error_handler
= error
,
4043 .hot_add_disk
= raid5_add_disk
,
4044 .hot_remove_disk
= raid5_remove_disk
,
4045 .spare_active
= raid5_spare_active
,
4046 .sync_request
= sync_request
,
4047 .resize
= raid5_resize
,
4048 #ifdef CONFIG_MD_RAID5_RESHAPE
4049 .check_reshape
= raid5_check_reshape
,
4050 .start_reshape
= raid5_start_reshape
,
4052 .quiesce
= raid5_quiesce
,
4055 static struct mdk_personality raid4_personality
=
4059 .owner
= THIS_MODULE
,
4060 .make_request
= make_request
,
4064 .error_handler
= error
,
4065 .hot_add_disk
= raid5_add_disk
,
4066 .hot_remove_disk
= raid5_remove_disk
,
4067 .spare_active
= raid5_spare_active
,
4068 .sync_request
= sync_request
,
4069 .resize
= raid5_resize
,
4070 #ifdef CONFIG_MD_RAID5_RESHAPE
4071 .check_reshape
= raid5_check_reshape
,
4072 .start_reshape
= raid5_start_reshape
,
4074 .quiesce
= raid5_quiesce
,
4077 static int __init
raid5_init(void)
4081 e
= raid6_select_algo();
4084 register_md_personality(&raid6_personality
);
4085 register_md_personality(&raid5_personality
);
4086 register_md_personality(&raid4_personality
);
4090 static void raid5_exit(void)
4092 unregister_md_personality(&raid6_personality
);
4093 unregister_md_personality(&raid5_personality
);
4094 unregister_md_personality(&raid4_personality
);
4097 module_init(raid5_init
);
4098 module_exit(raid5_exit
);
4099 MODULE_LICENSE("GPL");
4100 MODULE_ALIAS("md-personality-4"); /* RAID5 */
4101 MODULE_ALIAS("md-raid5");
4102 MODULE_ALIAS("md-raid4");
4103 MODULE_ALIAS("md-level-5");
4104 MODULE_ALIAS("md-level-4");
4105 MODULE_ALIAS("md-personality-8"); /* RAID6 */
4106 MODULE_ALIAS("md-raid6");
4107 MODULE_ALIAS("md-level-6");
4109 /* This used to be two separate modules, they were: */
4110 MODULE_ALIAS("raid5");
4111 MODULE_ALIAS("raid6");