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;
107 static void print_raid5_conf (raid5_conf_t
*conf
);
109 static void __release_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
)
111 if (atomic_dec_and_test(&sh
->count
)) {
112 BUG_ON(!list_empty(&sh
->lru
));
113 BUG_ON(atomic_read(&conf
->active_stripes
)==0);
114 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
115 if (test_bit(STRIPE_DELAYED
, &sh
->state
)) {
116 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
117 blk_plug_device(conf
->mddev
->queue
);
118 } else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
119 sh
->bm_seq
- conf
->seq_write
> 0) {
120 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
121 blk_plug_device(conf
->mddev
->queue
);
123 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
124 list_add_tail(&sh
->lru
, &conf
->handle_list
);
126 md_wakeup_thread(conf
->mddev
->thread
);
128 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
129 atomic_dec(&conf
->preread_active_stripes
);
130 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
131 md_wakeup_thread(conf
->mddev
->thread
);
133 atomic_dec(&conf
->active_stripes
);
134 if (!test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
135 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
136 wake_up(&conf
->wait_for_stripe
);
141 static void release_stripe(struct stripe_head
*sh
)
143 raid5_conf_t
*conf
= sh
->raid_conf
;
146 spin_lock_irqsave(&conf
->device_lock
, flags
);
147 __release_stripe(conf
, sh
);
148 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
151 static inline void remove_hash(struct stripe_head
*sh
)
153 PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh
->sector
);
155 hlist_del_init(&sh
->hash
);
158 static inline void insert_hash(raid5_conf_t
*conf
, struct stripe_head
*sh
)
160 struct hlist_head
*hp
= stripe_hash(conf
, sh
->sector
);
162 PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh
->sector
);
165 hlist_add_head(&sh
->hash
, hp
);
169 /* find an idle stripe, make sure it is unhashed, and return it. */
170 static struct stripe_head
*get_free_stripe(raid5_conf_t
*conf
)
172 struct stripe_head
*sh
= NULL
;
173 struct list_head
*first
;
176 if (list_empty(&conf
->inactive_list
))
178 first
= conf
->inactive_list
.next
;
179 sh
= list_entry(first
, struct stripe_head
, lru
);
180 list_del_init(first
);
182 atomic_inc(&conf
->active_stripes
);
187 static void shrink_buffers(struct stripe_head
*sh
, int num
)
192 for (i
=0; i
<num
; i
++) {
196 sh
->dev
[i
].page
= NULL
;
201 static int grow_buffers(struct stripe_head
*sh
, int num
)
205 for (i
=0; i
<num
; i
++) {
208 if (!(page
= alloc_page(GFP_KERNEL
))) {
211 sh
->dev
[i
].page
= page
;
216 static void raid5_build_block (struct stripe_head
*sh
, int i
);
218 static void init_stripe(struct stripe_head
*sh
, sector_t sector
, int pd_idx
, int disks
)
220 raid5_conf_t
*conf
= sh
->raid_conf
;
223 BUG_ON(atomic_read(&sh
->count
) != 0);
224 BUG_ON(test_bit(STRIPE_HANDLE
, &sh
->state
));
227 PRINTK("init_stripe called, stripe %llu\n",
228 (unsigned long long)sh
->sector
);
238 for (i
= sh
->disks
; i
--; ) {
239 struct r5dev
*dev
= &sh
->dev
[i
];
241 if (dev
->toread
|| dev
->towrite
|| dev
->written
||
242 test_bit(R5_LOCKED
, &dev
->flags
)) {
243 printk("sector=%llx i=%d %p %p %p %d\n",
244 (unsigned long long)sh
->sector
, i
, dev
->toread
,
245 dev
->towrite
, dev
->written
,
246 test_bit(R5_LOCKED
, &dev
->flags
));
250 raid5_build_block(sh
, i
);
252 insert_hash(conf
, sh
);
255 static struct stripe_head
*__find_stripe(raid5_conf_t
*conf
, sector_t sector
, int disks
)
257 struct stripe_head
*sh
;
258 struct hlist_node
*hn
;
261 PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector
);
262 hlist_for_each_entry(sh
, hn
, stripe_hash(conf
, sector
), hash
)
263 if (sh
->sector
== sector
&& sh
->disks
== disks
)
265 PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector
);
269 static void unplug_slaves(mddev_t
*mddev
);
270 static void raid5_unplug_device(request_queue_t
*q
);
272 static struct stripe_head
*get_active_stripe(raid5_conf_t
*conf
, sector_t sector
, int disks
,
273 int pd_idx
, int noblock
)
275 struct stripe_head
*sh
;
277 PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector
);
279 spin_lock_irq(&conf
->device_lock
);
282 wait_event_lock_irq(conf
->wait_for_stripe
,
284 conf
->device_lock
, /* nothing */);
285 sh
= __find_stripe(conf
, sector
, disks
);
287 if (!conf
->inactive_blocked
)
288 sh
= get_free_stripe(conf
);
289 if (noblock
&& sh
== NULL
)
292 conf
->inactive_blocked
= 1;
293 wait_event_lock_irq(conf
->wait_for_stripe
,
294 !list_empty(&conf
->inactive_list
) &&
295 (atomic_read(&conf
->active_stripes
)
296 < (conf
->max_nr_stripes
*3/4)
297 || !conf
->inactive_blocked
),
299 raid5_unplug_device(conf
->mddev
->queue
)
301 conf
->inactive_blocked
= 0;
303 init_stripe(sh
, sector
, pd_idx
, disks
);
305 if (atomic_read(&sh
->count
)) {
306 BUG_ON(!list_empty(&sh
->lru
));
308 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
309 atomic_inc(&conf
->active_stripes
);
310 if (list_empty(&sh
->lru
) &&
311 !test_bit(STRIPE_EXPANDING
, &sh
->state
))
313 list_del_init(&sh
->lru
);
316 } while (sh
== NULL
);
319 atomic_inc(&sh
->count
);
321 spin_unlock_irq(&conf
->device_lock
);
325 static int grow_one_stripe(raid5_conf_t
*conf
)
327 struct stripe_head
*sh
;
328 sh
= kmem_cache_alloc(conf
->slab_cache
, GFP_KERNEL
);
331 memset(sh
, 0, sizeof(*sh
) + (conf
->raid_disks
-1)*sizeof(struct r5dev
));
332 sh
->raid_conf
= conf
;
333 spin_lock_init(&sh
->lock
);
335 if (grow_buffers(sh
, conf
->raid_disks
)) {
336 shrink_buffers(sh
, conf
->raid_disks
);
337 kmem_cache_free(conf
->slab_cache
, sh
);
340 sh
->disks
= conf
->raid_disks
;
341 /* we just created an active stripe so... */
342 atomic_set(&sh
->count
, 1);
343 atomic_inc(&conf
->active_stripes
);
344 INIT_LIST_HEAD(&sh
->lru
);
349 static int grow_stripes(raid5_conf_t
*conf
, int num
)
352 int devs
= conf
->raid_disks
;
354 sprintf(conf
->cache_name
[0], "raid5/%s", mdname(conf
->mddev
));
355 sprintf(conf
->cache_name
[1], "raid5/%s-alt", mdname(conf
->mddev
));
356 conf
->active_name
= 0;
357 sc
= kmem_cache_create(conf
->cache_name
[conf
->active_name
],
358 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
362 conf
->slab_cache
= sc
;
363 conf
->pool_size
= devs
;
365 if (!grow_one_stripe(conf
))
370 #ifdef CONFIG_MD_RAID5_RESHAPE
371 static int resize_stripes(raid5_conf_t
*conf
, int newsize
)
373 /* Make all the stripes able to hold 'newsize' devices.
374 * New slots in each stripe get 'page' set to a new page.
376 * This happens in stages:
377 * 1/ create a new kmem_cache and allocate the required number of
379 * 2/ gather all the old stripe_heads and tranfer the pages across
380 * to the new stripe_heads. This will have the side effect of
381 * freezing the array as once all stripe_heads have been collected,
382 * no IO will be possible. Old stripe heads are freed once their
383 * pages have been transferred over, and the old kmem_cache is
384 * freed when all stripes are done.
385 * 3/ reallocate conf->disks to be suitable bigger. If this fails,
386 * we simple return a failre status - no need to clean anything up.
387 * 4/ allocate new pages for the new slots in the new stripe_heads.
388 * If this fails, we don't bother trying the shrink the
389 * stripe_heads down again, we just leave them as they are.
390 * As each stripe_head is processed the new one is released into
393 * Once step2 is started, we cannot afford to wait for a write,
394 * so we use GFP_NOIO allocations.
396 struct stripe_head
*osh
, *nsh
;
397 LIST_HEAD(newstripes
);
398 struct disk_info
*ndisks
;
403 if (newsize
<= conf
->pool_size
)
404 return 0; /* never bother to shrink */
406 md_allow_write(conf
->mddev
);
409 sc
= kmem_cache_create(conf
->cache_name
[1-conf
->active_name
],
410 sizeof(struct stripe_head
)+(newsize
-1)*sizeof(struct r5dev
),
415 for (i
= conf
->max_nr_stripes
; i
; i
--) {
416 nsh
= kmem_cache_alloc(sc
, GFP_KERNEL
);
420 memset(nsh
, 0, sizeof(*nsh
) + (newsize
-1)*sizeof(struct r5dev
));
422 nsh
->raid_conf
= conf
;
423 spin_lock_init(&nsh
->lock
);
425 list_add(&nsh
->lru
, &newstripes
);
428 /* didn't get enough, give up */
429 while (!list_empty(&newstripes
)) {
430 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
432 kmem_cache_free(sc
, nsh
);
434 kmem_cache_destroy(sc
);
437 /* Step 2 - Must use GFP_NOIO now.
438 * OK, we have enough stripes, start collecting inactive
439 * stripes and copying them over
441 list_for_each_entry(nsh
, &newstripes
, lru
) {
442 spin_lock_irq(&conf
->device_lock
);
443 wait_event_lock_irq(conf
->wait_for_stripe
,
444 !list_empty(&conf
->inactive_list
),
446 unplug_slaves(conf
->mddev
)
448 osh
= get_free_stripe(conf
);
449 spin_unlock_irq(&conf
->device_lock
);
450 atomic_set(&nsh
->count
, 1);
451 for(i
=0; i
<conf
->pool_size
; i
++)
452 nsh
->dev
[i
].page
= osh
->dev
[i
].page
;
453 for( ; i
<newsize
; i
++)
454 nsh
->dev
[i
].page
= NULL
;
455 kmem_cache_free(conf
->slab_cache
, osh
);
457 kmem_cache_destroy(conf
->slab_cache
);
460 * At this point, we are holding all the stripes so the array
461 * is completely stalled, so now is a good time to resize
464 ndisks
= kzalloc(newsize
* sizeof(struct disk_info
), GFP_NOIO
);
466 for (i
=0; i
<conf
->raid_disks
; i
++)
467 ndisks
[i
] = conf
->disks
[i
];
469 conf
->disks
= ndisks
;
473 /* Step 4, return new stripes to service */
474 while(!list_empty(&newstripes
)) {
475 nsh
= list_entry(newstripes
.next
, struct stripe_head
, lru
);
476 list_del_init(&nsh
->lru
);
477 for (i
=conf
->raid_disks
; i
< newsize
; i
++)
478 if (nsh
->dev
[i
].page
== NULL
) {
479 struct page
*p
= alloc_page(GFP_NOIO
);
480 nsh
->dev
[i
].page
= p
;
486 /* critical section pass, GFP_NOIO no longer needed */
488 conf
->slab_cache
= sc
;
489 conf
->active_name
= 1-conf
->active_name
;
490 conf
->pool_size
= newsize
;
495 static int drop_one_stripe(raid5_conf_t
*conf
)
497 struct stripe_head
*sh
;
499 spin_lock_irq(&conf
->device_lock
);
500 sh
= get_free_stripe(conf
);
501 spin_unlock_irq(&conf
->device_lock
);
504 BUG_ON(atomic_read(&sh
->count
));
505 shrink_buffers(sh
, conf
->pool_size
);
506 kmem_cache_free(conf
->slab_cache
, sh
);
507 atomic_dec(&conf
->active_stripes
);
511 static void shrink_stripes(raid5_conf_t
*conf
)
513 while (drop_one_stripe(conf
))
516 if (conf
->slab_cache
)
517 kmem_cache_destroy(conf
->slab_cache
);
518 conf
->slab_cache
= NULL
;
521 static int raid5_end_read_request(struct bio
* bi
, unsigned int bytes_done
,
524 struct stripe_head
*sh
= bi
->bi_private
;
525 raid5_conf_t
*conf
= sh
->raid_conf
;
526 int disks
= sh
->disks
, i
;
527 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
528 char b
[BDEVNAME_SIZE
];
534 for (i
=0 ; i
<disks
; i
++)
535 if (bi
== &sh
->dev
[i
].req
)
538 PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n",
539 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
550 spin_lock_irqsave(&conf
->device_lock
, flags
);
551 /* we can return a buffer if we bypassed the cache or
552 * if the top buffer is not in highmem. If there are
553 * multiple buffers, leave the extra work to
556 buffer
= sh
->bh_read
[i
];
558 (!PageHighMem(buffer
->b_page
)
559 || buffer
->b_page
== bh
->b_page
)
561 sh
->bh_read
[i
] = buffer
->b_reqnext
;
562 buffer
->b_reqnext
= NULL
;
565 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
566 if (sh
->bh_page
[i
]==bh
->b_page
)
567 set_buffer_uptodate(bh
);
569 if (buffer
->b_page
!= bh
->b_page
)
570 memcpy(buffer
->b_data
, bh
->b_data
, bh
->b_size
);
571 buffer
->b_end_io(buffer
, 1);
574 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
576 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
577 rdev
= conf
->disks
[i
].rdev
;
578 printk(KERN_INFO
"raid5:%s: read error corrected (%lu sectors at %llu on %s)\n",
579 mdname(conf
->mddev
), STRIPE_SECTORS
,
580 (unsigned long long)sh
->sector
+ rdev
->data_offset
,
581 bdevname(rdev
->bdev
, b
));
582 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
583 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
585 if (atomic_read(&conf
->disks
[i
].rdev
->read_errors
))
586 atomic_set(&conf
->disks
[i
].rdev
->read_errors
, 0);
588 const char *bdn
= bdevname(conf
->disks
[i
].rdev
->bdev
, b
);
590 rdev
= conf
->disks
[i
].rdev
;
592 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
593 atomic_inc(&rdev
->read_errors
);
594 if (conf
->mddev
->degraded
)
595 printk(KERN_WARNING
"raid5:%s: read error not correctable (sector %llu on %s).\n",
597 (unsigned long long)sh
->sector
+ rdev
->data_offset
,
599 else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
601 printk(KERN_WARNING
"raid5:%s: read error NOT corrected!! (sector %llu on %s).\n",
603 (unsigned long long)sh
->sector
+ rdev
->data_offset
,
605 else if (atomic_read(&rdev
->read_errors
)
606 > conf
->max_nr_stripes
)
608 "raid5:%s: Too many read errors, failing device %s.\n",
609 mdname(conf
->mddev
), bdn
);
613 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
615 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
616 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
617 md_error(conf
->mddev
, rdev
);
620 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
622 /* must restore b_page before unlocking buffer... */
623 if (sh
->bh_page
[i
] != bh
->b_page
) {
624 bh
->b_page
= sh
->bh_page
[i
];
625 bh
->b_data
= page_address(bh
->b_page
);
626 clear_buffer_uptodate(bh
);
629 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
630 set_bit(STRIPE_HANDLE
, &sh
->state
);
635 static int raid5_end_write_request (struct bio
*bi
, unsigned int bytes_done
,
638 struct stripe_head
*sh
= bi
->bi_private
;
639 raid5_conf_t
*conf
= sh
->raid_conf
;
640 int disks
= sh
->disks
, i
;
641 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
646 for (i
=0 ; i
<disks
; i
++)
647 if (bi
== &sh
->dev
[i
].req
)
650 PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n",
651 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
659 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
661 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
663 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
664 set_bit(STRIPE_HANDLE
, &sh
->state
);
670 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
);
672 static void raid5_build_block (struct stripe_head
*sh
, int i
)
674 struct r5dev
*dev
= &sh
->dev
[i
];
677 dev
->req
.bi_io_vec
= &dev
->vec
;
679 dev
->req
.bi_max_vecs
++;
680 dev
->vec
.bv_page
= dev
->page
;
681 dev
->vec
.bv_len
= STRIPE_SIZE
;
682 dev
->vec
.bv_offset
= 0;
684 dev
->req
.bi_sector
= sh
->sector
;
685 dev
->req
.bi_private
= sh
;
688 dev
->sector
= compute_blocknr(sh
, i
);
691 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
693 char b
[BDEVNAME_SIZE
];
694 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
695 PRINTK("raid5: error called\n");
697 if (!test_bit(Faulty
, &rdev
->flags
)) {
698 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
699 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
701 spin_lock_irqsave(&conf
->device_lock
, flags
);
703 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
705 * if recovery was running, make sure it aborts.
707 set_bit(MD_RECOVERY_ERR
, &mddev
->recovery
);
709 set_bit(Faulty
, &rdev
->flags
);
711 "raid5: Disk failure on %s, disabling device."
712 " Operation continuing on %d devices\n",
713 bdevname(rdev
->bdev
,b
), conf
->raid_disks
- mddev
->degraded
);
718 * Input: a 'big' sector number,
719 * Output: index of the data and parity disk, and the sector # in them.
721 static sector_t
raid5_compute_sector(sector_t r_sector
, unsigned int raid_disks
,
722 unsigned int data_disks
, unsigned int * dd_idx
,
723 unsigned int * pd_idx
, raid5_conf_t
*conf
)
726 unsigned long chunk_number
;
727 unsigned int chunk_offset
;
729 int sectors_per_chunk
= conf
->chunk_size
>> 9;
731 /* First compute the information on this sector */
734 * Compute the chunk number and the sector offset inside the chunk
736 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
737 chunk_number
= r_sector
;
738 BUG_ON(r_sector
!= chunk_number
);
741 * Compute the stripe number
743 stripe
= chunk_number
/ data_disks
;
746 * Compute the data disk and parity disk indexes inside the stripe
748 *dd_idx
= chunk_number
% data_disks
;
751 * Select the parity disk based on the user selected algorithm.
753 switch(conf
->level
) {
755 *pd_idx
= data_disks
;
758 switch (conf
->algorithm
) {
759 case ALGORITHM_LEFT_ASYMMETRIC
:
760 *pd_idx
= data_disks
- stripe
% raid_disks
;
761 if (*dd_idx
>= *pd_idx
)
764 case ALGORITHM_RIGHT_ASYMMETRIC
:
765 *pd_idx
= stripe
% raid_disks
;
766 if (*dd_idx
>= *pd_idx
)
769 case ALGORITHM_LEFT_SYMMETRIC
:
770 *pd_idx
= data_disks
- stripe
% raid_disks
;
771 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
773 case ALGORITHM_RIGHT_SYMMETRIC
:
774 *pd_idx
= stripe
% raid_disks
;
775 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
778 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
785 switch (conf
->algorithm
) {
786 case ALGORITHM_LEFT_ASYMMETRIC
:
787 *pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
788 if (*pd_idx
== raid_disks
-1)
789 (*dd_idx
)++; /* Q D D D P */
790 else if (*dd_idx
>= *pd_idx
)
791 (*dd_idx
) += 2; /* D D P Q D */
793 case ALGORITHM_RIGHT_ASYMMETRIC
:
794 *pd_idx
= stripe
% raid_disks
;
795 if (*pd_idx
== raid_disks
-1)
796 (*dd_idx
)++; /* Q D D D P */
797 else if (*dd_idx
>= *pd_idx
)
798 (*dd_idx
) += 2; /* D D P Q D */
800 case ALGORITHM_LEFT_SYMMETRIC
:
801 *pd_idx
= raid_disks
- 1 - (stripe
% raid_disks
);
802 *dd_idx
= (*pd_idx
+ 2 + *dd_idx
) % raid_disks
;
804 case ALGORITHM_RIGHT_SYMMETRIC
:
805 *pd_idx
= stripe
% raid_disks
;
806 *dd_idx
= (*pd_idx
+ 2 + *dd_idx
) % raid_disks
;
809 printk (KERN_CRIT
"raid6: unsupported algorithm %d\n",
816 * Finally, compute the new sector number
818 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
823 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
)
825 raid5_conf_t
*conf
= sh
->raid_conf
;
826 int raid_disks
= sh
->disks
, data_disks
= raid_disks
- 1;
827 sector_t new_sector
= sh
->sector
, check
;
828 int sectors_per_chunk
= conf
->chunk_size
>> 9;
831 int chunk_number
, dummy1
, dummy2
, dd_idx
= i
;
835 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
837 BUG_ON(new_sector
!= stripe
);
841 switch(conf
->level
) {
844 switch (conf
->algorithm
) {
845 case ALGORITHM_LEFT_ASYMMETRIC
:
846 case ALGORITHM_RIGHT_ASYMMETRIC
:
850 case ALGORITHM_LEFT_SYMMETRIC
:
851 case ALGORITHM_RIGHT_SYMMETRIC
:
854 i
-= (sh
->pd_idx
+ 1);
857 printk(KERN_ERR
"raid5: unsupported algorithm %d\n",
862 data_disks
= raid_disks
- 2;
863 if (i
== raid6_next_disk(sh
->pd_idx
, raid_disks
))
864 return 0; /* It is the Q disk */
865 switch (conf
->algorithm
) {
866 case ALGORITHM_LEFT_ASYMMETRIC
:
867 case ALGORITHM_RIGHT_ASYMMETRIC
:
868 if (sh
->pd_idx
== raid_disks
-1)
870 else if (i
> sh
->pd_idx
)
871 i
-= 2; /* D D P Q D */
873 case ALGORITHM_LEFT_SYMMETRIC
:
874 case ALGORITHM_RIGHT_SYMMETRIC
:
875 if (sh
->pd_idx
== raid_disks
-1)
881 i
-= (sh
->pd_idx
+ 2);
885 printk (KERN_CRIT
"raid6: unsupported algorithm %d\n",
891 chunk_number
= stripe
* data_disks
+ i
;
892 r_sector
= (sector_t
)chunk_number
* sectors_per_chunk
+ chunk_offset
;
894 check
= raid5_compute_sector (r_sector
, raid_disks
, data_disks
, &dummy1
, &dummy2
, conf
);
895 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| dummy2
!= sh
->pd_idx
) {
896 printk(KERN_ERR
"compute_blocknr: map not correct\n");
905 * Copy data between a page in the stripe cache, and one or more bion
906 * The page could align with the middle of the bio, or there could be
907 * several bion, each with several bio_vecs, which cover part of the page
908 * Multiple bion are linked together on bi_next. There may be extras
909 * at the end of this list. We ignore them.
911 static void copy_data(int frombio
, struct bio
*bio
,
915 char *pa
= page_address(page
);
920 if (bio
->bi_sector
>= sector
)
921 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
923 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
924 bio_for_each_segment(bvl
, bio
, i
) {
925 int len
= bio_iovec_idx(bio
,i
)->bv_len
;
929 if (page_offset
< 0) {
930 b_offset
= -page_offset
;
931 page_offset
+= b_offset
;
935 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
936 clen
= STRIPE_SIZE
- page_offset
;
940 char *ba
= __bio_kmap_atomic(bio
, i
, KM_USER0
);
942 memcpy(pa
+page_offset
, ba
+b_offset
, clen
);
944 memcpy(ba
+b_offset
, pa
+page_offset
, clen
);
945 __bio_kunmap_atomic(ba
, KM_USER0
);
947 if (clen
< len
) /* hit end of page */
953 #define check_xor() do { \
954 if (count == MAX_XOR_BLOCKS) { \
955 xor_block(count, STRIPE_SIZE, ptr); \
961 static void compute_block(struct stripe_head
*sh
, int dd_idx
)
963 int i
, count
, disks
= sh
->disks
;
964 void *ptr
[MAX_XOR_BLOCKS
], *p
;
966 PRINTK("compute_block, stripe %llu, idx %d\n",
967 (unsigned long long)sh
->sector
, dd_idx
);
969 ptr
[0] = page_address(sh
->dev
[dd_idx
].page
);
970 memset(ptr
[0], 0, STRIPE_SIZE
);
972 for (i
= disks
; i
--; ) {
975 p
= page_address(sh
->dev
[i
].page
);
976 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
979 printk(KERN_ERR
"compute_block() %d, stripe %llu, %d"
980 " not present\n", dd_idx
,
981 (unsigned long long)sh
->sector
, i
);
986 xor_block(count
, STRIPE_SIZE
, ptr
);
987 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
990 static void compute_parity5(struct stripe_head
*sh
, int method
)
992 raid5_conf_t
*conf
= sh
->raid_conf
;
993 int i
, pd_idx
= sh
->pd_idx
, disks
= sh
->disks
, count
;
994 void *ptr
[MAX_XOR_BLOCKS
];
997 PRINTK("compute_parity5, stripe %llu, method %d\n",
998 (unsigned long long)sh
->sector
, method
);
1001 ptr
[0] = page_address(sh
->dev
[pd_idx
].page
);
1003 case READ_MODIFY_WRITE
:
1004 BUG_ON(!test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
));
1005 for (i
=disks
; i
-- ;) {
1008 if (sh
->dev
[i
].towrite
&&
1009 test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
)) {
1010 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
1011 chosen
= sh
->dev
[i
].towrite
;
1012 sh
->dev
[i
].towrite
= NULL
;
1014 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1015 wake_up(&conf
->wait_for_overlap
);
1017 BUG_ON(sh
->dev
[i
].written
);
1018 sh
->dev
[i
].written
= chosen
;
1023 case RECONSTRUCT_WRITE
:
1024 memset(ptr
[0], 0, STRIPE_SIZE
);
1025 for (i
= disks
; i
-- ;)
1026 if (i
!=pd_idx
&& sh
->dev
[i
].towrite
) {
1027 chosen
= sh
->dev
[i
].towrite
;
1028 sh
->dev
[i
].towrite
= NULL
;
1030 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1031 wake_up(&conf
->wait_for_overlap
);
1033 BUG_ON(sh
->dev
[i
].written
);
1034 sh
->dev
[i
].written
= chosen
;
1041 xor_block(count
, STRIPE_SIZE
, ptr
);
1045 for (i
= disks
; i
--;)
1046 if (sh
->dev
[i
].written
) {
1047 sector_t sector
= sh
->dev
[i
].sector
;
1048 struct bio
*wbi
= sh
->dev
[i
].written
;
1049 while (wbi
&& wbi
->bi_sector
< sector
+ STRIPE_SECTORS
) {
1050 copy_data(1, wbi
, sh
->dev
[i
].page
, sector
);
1051 wbi
= r5_next_bio(wbi
, sector
);
1054 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1055 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1059 case RECONSTRUCT_WRITE
:
1063 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
1067 case READ_MODIFY_WRITE
:
1068 for (i
= disks
; i
--;)
1069 if (sh
->dev
[i
].written
) {
1070 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
1075 xor_block(count
, STRIPE_SIZE
, ptr
);
1077 if (method
!= CHECK_PARITY
) {
1078 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1079 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1081 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1084 static void compute_parity6(struct stripe_head
*sh
, int method
)
1086 raid6_conf_t
*conf
= sh
->raid_conf
;
1087 int i
, pd_idx
= sh
->pd_idx
, qd_idx
, d0_idx
, disks
= conf
->raid_disks
, count
;
1089 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1092 qd_idx
= raid6_next_disk(pd_idx
, disks
);
1093 d0_idx
= raid6_next_disk(qd_idx
, disks
);
1095 PRINTK("compute_parity, stripe %llu, method %d\n",
1096 (unsigned long long)sh
->sector
, method
);
1099 case READ_MODIFY_WRITE
:
1100 BUG(); /* READ_MODIFY_WRITE N/A for RAID-6 */
1101 case RECONSTRUCT_WRITE
:
1102 for (i
= disks
; i
-- ;)
1103 if ( i
!= pd_idx
&& i
!= qd_idx
&& sh
->dev
[i
].towrite
) {
1104 chosen
= sh
->dev
[i
].towrite
;
1105 sh
->dev
[i
].towrite
= NULL
;
1107 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1108 wake_up(&conf
->wait_for_overlap
);
1110 BUG_ON(sh
->dev
[i
].written
);
1111 sh
->dev
[i
].written
= chosen
;
1115 BUG(); /* Not implemented yet */
1118 for (i
= disks
; i
--;)
1119 if (sh
->dev
[i
].written
) {
1120 sector_t sector
= sh
->dev
[i
].sector
;
1121 struct bio
*wbi
= sh
->dev
[i
].written
;
1122 while (wbi
&& wbi
->bi_sector
< sector
+ STRIPE_SECTORS
) {
1123 copy_data(1, wbi
, sh
->dev
[i
].page
, sector
);
1124 wbi
= r5_next_bio(wbi
, sector
);
1127 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1128 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
1132 // case RECONSTRUCT_WRITE:
1133 // case CHECK_PARITY:
1134 // case UPDATE_PARITY:
1135 /* Note that unlike RAID-5, the ordering of the disks matters greatly. */
1136 /* FIX: Is this ordering of drives even remotely optimal? */
1140 ptrs
[count
++] = page_address(sh
->dev
[i
].page
);
1141 if (count
<= disks
-2 && !test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1142 printk("block %d/%d not uptodate on parity calc\n", i
,count
);
1143 i
= raid6_next_disk(i
, disks
);
1144 } while ( i
!= d0_idx
);
1148 raid6_call
.gen_syndrome(disks
, STRIPE_SIZE
, ptrs
);
1151 case RECONSTRUCT_WRITE
:
1152 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1153 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1154 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
1155 set_bit(R5_LOCKED
, &sh
->dev
[qd_idx
].flags
);
1158 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
1159 set_bit(R5_UPTODATE
, &sh
->dev
[qd_idx
].flags
);
1165 /* Compute one missing block */
1166 static void compute_block_1(struct stripe_head
*sh
, int dd_idx
, int nozero
)
1168 raid6_conf_t
*conf
= sh
->raid_conf
;
1169 int i
, count
, disks
= conf
->raid_disks
;
1170 void *ptr
[MAX_XOR_BLOCKS
], *p
;
1171 int pd_idx
= sh
->pd_idx
;
1172 int qd_idx
= raid6_next_disk(pd_idx
, disks
);
1174 PRINTK("compute_block_1, stripe %llu, idx %d\n",
1175 (unsigned long long)sh
->sector
, dd_idx
);
1177 if ( dd_idx
== qd_idx
) {
1178 /* We're actually computing the Q drive */
1179 compute_parity6(sh
, UPDATE_PARITY
);
1181 ptr
[0] = page_address(sh
->dev
[dd_idx
].page
);
1182 if (!nozero
) memset(ptr
[0], 0, STRIPE_SIZE
);
1184 for (i
= disks
; i
--; ) {
1185 if (i
== dd_idx
|| i
== qd_idx
)
1187 p
= page_address(sh
->dev
[i
].page
);
1188 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1191 printk("compute_block() %d, stripe %llu, %d"
1192 " not present\n", dd_idx
,
1193 (unsigned long long)sh
->sector
, i
);
1198 xor_block(count
, STRIPE_SIZE
, ptr
);
1199 if (!nozero
) set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1200 else clear_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
1204 /* Compute two missing blocks */
1205 static void compute_block_2(struct stripe_head
*sh
, int dd_idx1
, int dd_idx2
)
1207 raid6_conf_t
*conf
= sh
->raid_conf
;
1208 int i
, count
, disks
= conf
->raid_disks
;
1209 int pd_idx
= sh
->pd_idx
;
1210 int qd_idx
= raid6_next_disk(pd_idx
, disks
);
1211 int d0_idx
= raid6_next_disk(qd_idx
, disks
);
1214 /* faila and failb are disk numbers relative to d0_idx */
1215 /* pd_idx become disks-2 and qd_idx become disks-1 */
1216 faila
= (dd_idx1
< d0_idx
) ? dd_idx1
+(disks
-d0_idx
) : dd_idx1
-d0_idx
;
1217 failb
= (dd_idx2
< d0_idx
) ? dd_idx2
+(disks
-d0_idx
) : dd_idx2
-d0_idx
;
1219 BUG_ON(faila
== failb
);
1220 if ( failb
< faila
) { int tmp
= faila
; faila
= failb
; failb
= tmp
; }
1222 PRINTK("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
1223 (unsigned long long)sh
->sector
, dd_idx1
, dd_idx2
, faila
, failb
);
1225 if ( failb
== disks
-1 ) {
1226 /* Q disk is one of the missing disks */
1227 if ( faila
== disks
-2 ) {
1228 /* Missing P+Q, just recompute */
1229 compute_parity6(sh
, UPDATE_PARITY
);
1232 /* We're missing D+Q; recompute D from P */
1233 compute_block_1(sh
, (dd_idx1
== qd_idx
) ? dd_idx2
: dd_idx1
, 0);
1234 compute_parity6(sh
, UPDATE_PARITY
); /* Is this necessary? */
1239 /* We're missing D+P or D+D; build pointer table */
1241 /**** FIX THIS: This could be very bad if disks is close to 256 ****/
1247 ptrs
[count
++] = page_address(sh
->dev
[i
].page
);
1248 i
= raid6_next_disk(i
, disks
);
1249 if (i
!= dd_idx1
&& i
!= dd_idx2
&&
1250 !test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
1251 printk("compute_2 with missing block %d/%d\n", count
, i
);
1252 } while ( i
!= d0_idx
);
1254 if ( failb
== disks
-2 ) {
1255 /* We're missing D+P. */
1256 raid6_datap_recov(disks
, STRIPE_SIZE
, faila
, ptrs
);
1258 /* We're missing D+D. */
1259 raid6_2data_recov(disks
, STRIPE_SIZE
, faila
, failb
, ptrs
);
1262 /* Both the above update both missing blocks */
1263 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx1
].flags
);
1264 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx2
].flags
);
1271 * Each stripe/dev can have one or more bion attached.
1272 * toread/towrite point to the first in a chain.
1273 * The bi_next chain must be in order.
1275 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
1278 raid5_conf_t
*conf
= sh
->raid_conf
;
1281 PRINTK("adding bh b#%llu to stripe s#%llu\n",
1282 (unsigned long long)bi
->bi_sector
,
1283 (unsigned long long)sh
->sector
);
1286 spin_lock(&sh
->lock
);
1287 spin_lock_irq(&conf
->device_lock
);
1289 bip
= &sh
->dev
[dd_idx
].towrite
;
1290 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
1293 bip
= &sh
->dev
[dd_idx
].toread
;
1294 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
1295 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
1297 bip
= & (*bip
)->bi_next
;
1299 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
1302 BUG_ON(*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
);
1306 bi
->bi_phys_segments
++;
1307 spin_unlock_irq(&conf
->device_lock
);
1308 spin_unlock(&sh
->lock
);
1310 PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n",
1311 (unsigned long long)bi
->bi_sector
,
1312 (unsigned long long)sh
->sector
, dd_idx
);
1314 if (conf
->mddev
->bitmap
&& firstwrite
) {
1315 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
1317 sh
->bm_seq
= conf
->seq_flush
+1;
1318 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
1322 /* check if page is covered */
1323 sector_t sector
= sh
->dev
[dd_idx
].sector
;
1324 for (bi
=sh
->dev
[dd_idx
].towrite
;
1325 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
1326 bi
&& bi
->bi_sector
<= sector
;
1327 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
1328 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
1329 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
1331 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
1332 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
1337 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
1338 spin_unlock_irq(&conf
->device_lock
);
1339 spin_unlock(&sh
->lock
);
1343 static void end_reshape(raid5_conf_t
*conf
);
1345 static int page_is_zero(struct page
*p
)
1347 char *a
= page_address(p
);
1348 return ((*(u32
*)a
) == 0 &&
1349 memcmp(a
, a
+4, STRIPE_SIZE
-4)==0);
1352 static int stripe_to_pdidx(sector_t stripe
, raid5_conf_t
*conf
, int disks
)
1354 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1356 int chunk_offset
= sector_div(stripe
, sectors_per_chunk
);
1358 raid5_compute_sector(stripe
*(disks
-1)*sectors_per_chunk
1359 + chunk_offset
, disks
, disks
-1, &dd_idx
, &pd_idx
, conf
);
1365 * handle_stripe - do things to a stripe.
1367 * We lock the stripe and then examine the state of various bits
1368 * to see what needs to be done.
1370 * return some read request which now have data
1371 * return some write requests which are safely on disc
1372 * schedule a read on some buffers
1373 * schedule a write of some buffers
1374 * return confirmation of parity correctness
1376 * Parity calculations are done inside the stripe lock
1377 * buffers are taken off read_list or write_list, and bh_cache buffers
1378 * get BH_Lock set before the stripe lock is released.
1382 static void handle_stripe5(struct stripe_head
*sh
)
1384 raid5_conf_t
*conf
= sh
->raid_conf
;
1385 int disks
= sh
->disks
;
1386 struct bio
*return_bi
= NULL
;
1389 int syncing
, expanding
, expanded
;
1390 int locked
=0, uptodate
=0, to_read
=0, to_write
=0, failed
=0, written
=0;
1391 int non_overwrite
= 0;
1395 PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n",
1396 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
),
1399 spin_lock(&sh
->lock
);
1400 clear_bit(STRIPE_HANDLE
, &sh
->state
);
1401 clear_bit(STRIPE_DELAYED
, &sh
->state
);
1403 syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
1404 expanding
= test_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
1405 expanded
= test_bit(STRIPE_EXPAND_READY
, &sh
->state
);
1406 /* Now to look around and see what can be done */
1409 for (i
=disks
; i
--; ) {
1412 clear_bit(R5_Insync
, &dev
->flags
);
1414 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
1415 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
1416 /* maybe we can reply to a read */
1417 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
) {
1418 struct bio
*rbi
, *rbi2
;
1419 PRINTK("Return read for disc %d\n", i
);
1420 spin_lock_irq(&conf
->device_lock
);
1423 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1424 wake_up(&conf
->wait_for_overlap
);
1425 spin_unlock_irq(&conf
->device_lock
);
1426 while (rbi
&& rbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
1427 copy_data(0, rbi
, dev
->page
, dev
->sector
);
1428 rbi2
= r5_next_bio(rbi
, dev
->sector
);
1429 spin_lock_irq(&conf
->device_lock
);
1430 if (--rbi
->bi_phys_segments
== 0) {
1431 rbi
->bi_next
= return_bi
;
1434 spin_unlock_irq(&conf
->device_lock
);
1439 /* now count some things */
1440 if (test_bit(R5_LOCKED
, &dev
->flags
)) locked
++;
1441 if (test_bit(R5_UPTODATE
, &dev
->flags
)) uptodate
++;
1444 if (dev
->toread
) to_read
++;
1447 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
1450 if (dev
->written
) written
++;
1451 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
1452 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
1453 /* The ReadError flag will just be confusing now */
1454 clear_bit(R5_ReadError
, &dev
->flags
);
1455 clear_bit(R5_ReWrite
, &dev
->flags
);
1457 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
1458 || test_bit(R5_ReadError
, &dev
->flags
)) {
1462 set_bit(R5_Insync
, &dev
->flags
);
1465 PRINTK("locked=%d uptodate=%d to_read=%d"
1466 " to_write=%d failed=%d failed_num=%d\n",
1467 locked
, uptodate
, to_read
, to_write
, failed
, failed_num
);
1468 /* check if the array has lost two devices and, if so, some requests might
1471 if (failed
> 1 && to_read
+to_write
+written
) {
1472 for (i
=disks
; i
--; ) {
1475 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1478 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
1479 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
1480 /* multiple read failures in one stripe */
1481 md_error(conf
->mddev
, rdev
);
1485 spin_lock_irq(&conf
->device_lock
);
1486 /* fail all writes first */
1487 bi
= sh
->dev
[i
].towrite
;
1488 sh
->dev
[i
].towrite
= NULL
;
1489 if (bi
) { to_write
--; bitmap_end
= 1; }
1491 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1492 wake_up(&conf
->wait_for_overlap
);
1494 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
){
1495 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1496 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1497 if (--bi
->bi_phys_segments
== 0) {
1498 md_write_end(conf
->mddev
);
1499 bi
->bi_next
= return_bi
;
1504 /* and fail all 'written' */
1505 bi
= sh
->dev
[i
].written
;
1506 sh
->dev
[i
].written
= NULL
;
1507 if (bi
) bitmap_end
= 1;
1508 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1509 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1510 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1511 if (--bi
->bi_phys_segments
== 0) {
1512 md_write_end(conf
->mddev
);
1513 bi
->bi_next
= return_bi
;
1519 /* fail any reads if this device is non-operational */
1520 if (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
1521 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1522 bi
= sh
->dev
[i
].toread
;
1523 sh
->dev
[i
].toread
= NULL
;
1524 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1525 wake_up(&conf
->wait_for_overlap
);
1527 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
){
1528 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1529 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1530 if (--bi
->bi_phys_segments
== 0) {
1531 bi
->bi_next
= return_bi
;
1537 spin_unlock_irq(&conf
->device_lock
);
1539 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
1540 STRIPE_SECTORS
, 0, 0);
1543 if (failed
> 1 && syncing
) {
1544 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
1545 clear_bit(STRIPE_SYNCING
, &sh
->state
);
1549 /* might be able to return some write requests if the parity block
1550 * is safe, or on a failed drive
1552 dev
= &sh
->dev
[sh
->pd_idx
];
1554 ( (test_bit(R5_Insync
, &dev
->flags
) && !test_bit(R5_LOCKED
, &dev
->flags
) &&
1555 test_bit(R5_UPTODATE
, &dev
->flags
))
1556 || (failed
== 1 && failed_num
== sh
->pd_idx
))
1558 /* any written block on an uptodate or failed drive can be returned.
1559 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
1560 * never LOCKED, so we don't need to test 'failed' directly.
1562 for (i
=disks
; i
--; )
1563 if (sh
->dev
[i
].written
) {
1565 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
1566 test_bit(R5_UPTODATE
, &dev
->flags
) ) {
1567 /* We can return any write requests */
1568 struct bio
*wbi
, *wbi2
;
1570 PRINTK("Return write for disc %d\n", i
);
1571 spin_lock_irq(&conf
->device_lock
);
1573 dev
->written
= NULL
;
1574 while (wbi
&& wbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
1575 wbi2
= r5_next_bio(wbi
, dev
->sector
);
1576 if (--wbi
->bi_phys_segments
== 0) {
1577 md_write_end(conf
->mddev
);
1578 wbi
->bi_next
= return_bi
;
1583 if (dev
->towrite
== NULL
)
1585 spin_unlock_irq(&conf
->device_lock
);
1587 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
1589 !test_bit(STRIPE_DEGRADED
, &sh
->state
), 0);
1594 /* Now we might consider reading some blocks, either to check/generate
1595 * parity, or to satisfy requests
1596 * or to load a block that is being partially written.
1598 if (to_read
|| non_overwrite
|| (syncing
&& (uptodate
< disks
)) || expanding
) {
1599 for (i
=disks
; i
--;) {
1601 if (!test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1603 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
1606 (failed
&& (sh
->dev
[failed_num
].toread
||
1607 (sh
->dev
[failed_num
].towrite
&& !test_bit(R5_OVERWRITE
, &sh
->dev
[failed_num
].flags
))))
1610 /* we would like to get this block, possibly
1611 * by computing it, but we might not be able to
1613 if (uptodate
== disks
-1) {
1614 PRINTK("Computing block %d\n", i
);
1615 compute_block(sh
, i
);
1617 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
1618 set_bit(R5_LOCKED
, &dev
->flags
);
1619 set_bit(R5_Wantread
, &dev
->flags
);
1621 /* if I am just reading this block and we don't have
1622 a failed drive, or any pending writes then sidestep the cache */
1623 if (sh
->bh_read
[i
] && !sh
->bh_read
[i
]->b_reqnext
&&
1624 ! syncing
&& !failed
&& !to_write
) {
1625 sh
->bh_cache
[i
]->b_page
= sh
->bh_read
[i
]->b_page
;
1626 sh
->bh_cache
[i
]->b_data
= sh
->bh_read
[i
]->b_data
;
1630 PRINTK("Reading block %d (sync=%d)\n",
1635 set_bit(STRIPE_HANDLE
, &sh
->state
);
1638 /* now to consider writing and what else, if anything should be read */
1641 for (i
=disks
; i
--;) {
1642 /* would I have to read this buffer for read_modify_write */
1644 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
1645 (!test_bit(R5_LOCKED
, &dev
->flags
)
1647 || sh
->bh_page
[i
]!=bh
->b_page
1650 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
1651 if (test_bit(R5_Insync
, &dev
->flags
)
1652 /* && !(!mddev->insync && i == sh->pd_idx) */
1655 else rmw
+= 2*disks
; /* cannot read it */
1657 /* Would I have to read this buffer for reconstruct_write */
1658 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
1659 (!test_bit(R5_LOCKED
, &dev
->flags
)
1661 || sh
->bh_page
[i
] != bh
->b_page
1664 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
1665 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
1666 else rcw
+= 2*disks
;
1669 PRINTK("for sector %llu, rmw=%d rcw=%d\n",
1670 (unsigned long long)sh
->sector
, rmw
, rcw
);
1671 set_bit(STRIPE_HANDLE
, &sh
->state
);
1672 if (rmw
< rcw
&& rmw
> 0)
1673 /* prefer read-modify-write, but need to get some data */
1674 for (i
=disks
; i
--;) {
1676 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
1677 !test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1678 test_bit(R5_Insync
, &dev
->flags
)) {
1679 if (test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
1681 PRINTK("Read_old block %d for r-m-w\n", i
);
1682 set_bit(R5_LOCKED
, &dev
->flags
);
1683 set_bit(R5_Wantread
, &dev
->flags
);
1686 set_bit(STRIPE_DELAYED
, &sh
->state
);
1687 set_bit(STRIPE_HANDLE
, &sh
->state
);
1691 if (rcw
<= rmw
&& rcw
> 0)
1692 /* want reconstruct write, but need to get some data */
1693 for (i
=disks
; i
--;) {
1695 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
1696 !test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1697 test_bit(R5_Insync
, &dev
->flags
)) {
1698 if (test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
1700 PRINTK("Read_old block %d for Reconstruct\n", i
);
1701 set_bit(R5_LOCKED
, &dev
->flags
);
1702 set_bit(R5_Wantread
, &dev
->flags
);
1705 set_bit(STRIPE_DELAYED
, &sh
->state
);
1706 set_bit(STRIPE_HANDLE
, &sh
->state
);
1710 /* now if nothing is locked, and if we have enough data, we can start a write request */
1711 if (locked
== 0 && (rcw
== 0 ||rmw
== 0) &&
1712 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
1713 PRINTK("Computing parity...\n");
1714 compute_parity5(sh
, rcw
==0 ? RECONSTRUCT_WRITE
: READ_MODIFY_WRITE
);
1715 /* now every locked buffer is ready to be written */
1717 if (test_bit(R5_LOCKED
, &sh
->dev
[i
].flags
)) {
1718 PRINTK("Writing block %d\n", i
);
1720 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
1721 if (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
)
1722 || (i
==sh
->pd_idx
&& failed
== 0))
1723 set_bit(STRIPE_INSYNC
, &sh
->state
);
1725 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
1726 atomic_dec(&conf
->preread_active_stripes
);
1727 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
1728 md_wakeup_thread(conf
->mddev
->thread
);
1733 /* maybe we need to check and possibly fix the parity for this stripe
1734 * Any reads will already have been scheduled, so we just see if enough data
1737 if (syncing
&& locked
== 0 &&
1738 !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
1739 set_bit(STRIPE_HANDLE
, &sh
->state
);
1741 BUG_ON(uptodate
!= disks
);
1742 compute_parity5(sh
, CHECK_PARITY
);
1744 if (page_is_zero(sh
->dev
[sh
->pd_idx
].page
)) {
1745 /* parity is correct (on disc, not in buffer any more) */
1746 set_bit(STRIPE_INSYNC
, &sh
->state
);
1748 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
1749 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
1750 /* don't try to repair!! */
1751 set_bit(STRIPE_INSYNC
, &sh
->state
);
1753 compute_block(sh
, sh
->pd_idx
);
1758 if (!test_bit(STRIPE_INSYNC
, &sh
->state
)) {
1759 /* either failed parity check, or recovery is happening */
1761 failed_num
= sh
->pd_idx
;
1762 dev
= &sh
->dev
[failed_num
];
1763 BUG_ON(!test_bit(R5_UPTODATE
, &dev
->flags
));
1764 BUG_ON(uptodate
!= disks
);
1766 set_bit(R5_LOCKED
, &dev
->flags
);
1767 set_bit(R5_Wantwrite
, &dev
->flags
);
1768 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
1770 set_bit(STRIPE_INSYNC
, &sh
->state
);
1773 if (syncing
&& locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
1774 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
1775 clear_bit(STRIPE_SYNCING
, &sh
->state
);
1778 /* If the failed drive is just a ReadError, then we might need to progress
1779 * the repair/check process
1781 if (failed
== 1 && ! conf
->mddev
->ro
&&
1782 test_bit(R5_ReadError
, &sh
->dev
[failed_num
].flags
)
1783 && !test_bit(R5_LOCKED
, &sh
->dev
[failed_num
].flags
)
1784 && test_bit(R5_UPTODATE
, &sh
->dev
[failed_num
].flags
)
1786 dev
= &sh
->dev
[failed_num
];
1787 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
1788 set_bit(R5_Wantwrite
, &dev
->flags
);
1789 set_bit(R5_ReWrite
, &dev
->flags
);
1790 set_bit(R5_LOCKED
, &dev
->flags
);
1793 /* let's read it back */
1794 set_bit(R5_Wantread
, &dev
->flags
);
1795 set_bit(R5_LOCKED
, &dev
->flags
);
1800 if (expanded
&& test_bit(STRIPE_EXPANDING
, &sh
->state
)) {
1801 /* Need to write out all blocks after computing parity */
1802 sh
->disks
= conf
->raid_disks
;
1803 sh
->pd_idx
= stripe_to_pdidx(sh
->sector
, conf
, conf
->raid_disks
);
1804 compute_parity5(sh
, RECONSTRUCT_WRITE
);
1805 for (i
= conf
->raid_disks
; i
--;) {
1806 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1808 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
1810 clear_bit(STRIPE_EXPANDING
, &sh
->state
);
1811 } else if (expanded
) {
1812 clear_bit(STRIPE_EXPAND_READY
, &sh
->state
);
1813 atomic_dec(&conf
->reshape_stripes
);
1814 wake_up(&conf
->wait_for_overlap
);
1815 md_done_sync(conf
->mddev
, STRIPE_SECTORS
, 1);
1818 if (expanding
&& locked
== 0) {
1819 /* We have read all the blocks in this stripe and now we need to
1820 * copy some of them into a target stripe for expand.
1822 clear_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
1823 for (i
=0; i
< sh
->disks
; i
++)
1824 if (i
!= sh
->pd_idx
) {
1825 int dd_idx
, pd_idx
, j
;
1826 struct stripe_head
*sh2
;
1828 sector_t bn
= compute_blocknr(sh
, i
);
1829 sector_t s
= raid5_compute_sector(bn
, conf
->raid_disks
,
1831 &dd_idx
, &pd_idx
, conf
);
1832 sh2
= get_active_stripe(conf
, s
, conf
->raid_disks
, pd_idx
, 1);
1834 /* so far only the early blocks of this stripe
1835 * have been requested. When later blocks
1836 * get requested, we will try again
1839 if(!test_bit(STRIPE_EXPANDING
, &sh2
->state
) ||
1840 test_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
)) {
1841 /* must have already done this block */
1842 release_stripe(sh2
);
1845 memcpy(page_address(sh2
->dev
[dd_idx
].page
),
1846 page_address(sh
->dev
[i
].page
),
1848 set_bit(R5_Expanded
, &sh2
->dev
[dd_idx
].flags
);
1849 set_bit(R5_UPTODATE
, &sh2
->dev
[dd_idx
].flags
);
1850 for (j
=0; j
<conf
->raid_disks
; j
++)
1851 if (j
!= sh2
->pd_idx
&&
1852 !test_bit(R5_Expanded
, &sh2
->dev
[j
].flags
))
1854 if (j
== conf
->raid_disks
) {
1855 set_bit(STRIPE_EXPAND_READY
, &sh2
->state
);
1856 set_bit(STRIPE_HANDLE
, &sh2
->state
);
1858 release_stripe(sh2
);
1862 spin_unlock(&sh
->lock
);
1864 while ((bi
=return_bi
)) {
1865 int bytes
= bi
->bi_size
;
1867 return_bi
= bi
->bi_next
;
1870 bi
->bi_end_io(bi
, bytes
, 0);
1872 for (i
=disks
; i
-- ;) {
1876 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
1878 else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
1883 bi
= &sh
->dev
[i
].req
;
1887 bi
->bi_end_io
= raid5_end_write_request
;
1889 bi
->bi_end_io
= raid5_end_read_request
;
1892 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
1893 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
1896 atomic_inc(&rdev
->nr_pending
);
1900 if (syncing
|| expanding
|| expanded
)
1901 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
1903 bi
->bi_bdev
= rdev
->bdev
;
1904 PRINTK("for %llu schedule op %ld on disc %d\n",
1905 (unsigned long long)sh
->sector
, bi
->bi_rw
, i
);
1906 atomic_inc(&sh
->count
);
1907 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
1908 bi
->bi_flags
= 1 << BIO_UPTODATE
;
1910 bi
->bi_max_vecs
= 1;
1912 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
1913 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
1914 bi
->bi_io_vec
[0].bv_offset
= 0;
1915 bi
->bi_size
= STRIPE_SIZE
;
1918 test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
1919 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
1920 generic_make_request(bi
);
1923 set_bit(STRIPE_DEGRADED
, &sh
->state
);
1924 PRINTK("skip op %ld on disc %d for sector %llu\n",
1925 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
1926 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1927 set_bit(STRIPE_HANDLE
, &sh
->state
);
1932 static void handle_stripe6(struct stripe_head
*sh
, struct page
*tmp_page
)
1934 raid6_conf_t
*conf
= sh
->raid_conf
;
1935 int disks
= conf
->raid_disks
;
1936 struct bio
*return_bi
= NULL
;
1940 int locked
=0, uptodate
=0, to_read
=0, to_write
=0, failed
=0, written
=0;
1941 int non_overwrite
= 0;
1942 int failed_num
[2] = {0, 0};
1943 struct r5dev
*dev
, *pdev
, *qdev
;
1944 int pd_idx
= sh
->pd_idx
;
1945 int qd_idx
= raid6_next_disk(pd_idx
, disks
);
1946 int p_failed
, q_failed
;
1948 PRINTK("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d, qd_idx=%d\n",
1949 (unsigned long long)sh
->sector
, sh
->state
, atomic_read(&sh
->count
),
1952 spin_lock(&sh
->lock
);
1953 clear_bit(STRIPE_HANDLE
, &sh
->state
);
1954 clear_bit(STRIPE_DELAYED
, &sh
->state
);
1956 syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
1957 /* Now to look around and see what can be done */
1960 for (i
=disks
; i
--; ) {
1963 clear_bit(R5_Insync
, &dev
->flags
);
1965 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
1966 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
1967 /* maybe we can reply to a read */
1968 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
) {
1969 struct bio
*rbi
, *rbi2
;
1970 PRINTK("Return read for disc %d\n", i
);
1971 spin_lock_irq(&conf
->device_lock
);
1974 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
1975 wake_up(&conf
->wait_for_overlap
);
1976 spin_unlock_irq(&conf
->device_lock
);
1977 while (rbi
&& rbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
1978 copy_data(0, rbi
, dev
->page
, dev
->sector
);
1979 rbi2
= r5_next_bio(rbi
, dev
->sector
);
1980 spin_lock_irq(&conf
->device_lock
);
1981 if (--rbi
->bi_phys_segments
== 0) {
1982 rbi
->bi_next
= return_bi
;
1985 spin_unlock_irq(&conf
->device_lock
);
1990 /* now count some things */
1991 if (test_bit(R5_LOCKED
, &dev
->flags
)) locked
++;
1992 if (test_bit(R5_UPTODATE
, &dev
->flags
)) uptodate
++;
1995 if (dev
->toread
) to_read
++;
1998 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
2001 if (dev
->written
) written
++;
2002 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2003 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)) {
2004 /* The ReadError flag will just be confusing now */
2005 clear_bit(R5_ReadError
, &dev
->flags
);
2006 clear_bit(R5_ReWrite
, &dev
->flags
);
2008 if (!rdev
|| !test_bit(In_sync
, &rdev
->flags
)
2009 || test_bit(R5_ReadError
, &dev
->flags
)) {
2011 failed_num
[failed
] = i
;
2014 set_bit(R5_Insync
, &dev
->flags
);
2017 PRINTK("locked=%d uptodate=%d to_read=%d"
2018 " to_write=%d failed=%d failed_num=%d,%d\n",
2019 locked
, uptodate
, to_read
, to_write
, failed
,
2020 failed_num
[0], failed_num
[1]);
2021 /* check if the array has lost >2 devices and, if so, some requests might
2024 if (failed
> 2 && to_read
+to_write
+written
) {
2025 for (i
=disks
; i
--; ) {
2028 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2031 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2032 if (rdev
&& test_bit(In_sync
, &rdev
->flags
))
2033 /* multiple read failures in one stripe */
2034 md_error(conf
->mddev
, rdev
);
2038 spin_lock_irq(&conf
->device_lock
);
2039 /* fail all writes first */
2040 bi
= sh
->dev
[i
].towrite
;
2041 sh
->dev
[i
].towrite
= NULL
;
2042 if (bi
) { to_write
--; bitmap_end
= 1; }
2044 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2045 wake_up(&conf
->wait_for_overlap
);
2047 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
){
2048 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2049 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2050 if (--bi
->bi_phys_segments
== 0) {
2051 md_write_end(conf
->mddev
);
2052 bi
->bi_next
= return_bi
;
2057 /* and fail all 'written' */
2058 bi
= sh
->dev
[i
].written
;
2059 sh
->dev
[i
].written
= NULL
;
2060 if (bi
) bitmap_end
= 1;
2061 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
2062 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2063 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2064 if (--bi
->bi_phys_segments
== 0) {
2065 md_write_end(conf
->mddev
);
2066 bi
->bi_next
= return_bi
;
2072 /* fail any reads if this device is non-operational */
2073 if (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
2074 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
2075 bi
= sh
->dev
[i
].toread
;
2076 sh
->dev
[i
].toread
= NULL
;
2077 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
2078 wake_up(&conf
->wait_for_overlap
);
2080 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
){
2081 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
2082 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2083 if (--bi
->bi_phys_segments
== 0) {
2084 bi
->bi_next
= return_bi
;
2090 spin_unlock_irq(&conf
->device_lock
);
2092 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2093 STRIPE_SECTORS
, 0, 0);
2096 if (failed
> 2 && syncing
) {
2097 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
2098 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2103 * might be able to return some write requests if the parity blocks
2104 * are safe, or on a failed drive
2106 pdev
= &sh
->dev
[pd_idx
];
2107 p_failed
= (failed
>= 1 && failed_num
[0] == pd_idx
)
2108 || (failed
>= 2 && failed_num
[1] == pd_idx
);
2109 qdev
= &sh
->dev
[qd_idx
];
2110 q_failed
= (failed
>= 1 && failed_num
[0] == qd_idx
)
2111 || (failed
>= 2 && failed_num
[1] == qd_idx
);
2114 ( p_failed
|| ((test_bit(R5_Insync
, &pdev
->flags
)
2115 && !test_bit(R5_LOCKED
, &pdev
->flags
)
2116 && test_bit(R5_UPTODATE
, &pdev
->flags
))) ) &&
2117 ( q_failed
|| ((test_bit(R5_Insync
, &qdev
->flags
)
2118 && !test_bit(R5_LOCKED
, &qdev
->flags
)
2119 && test_bit(R5_UPTODATE
, &qdev
->flags
))) ) ) {
2120 /* any written block on an uptodate or failed drive can be
2121 * returned. Note that if we 'wrote' to a failed drive,
2122 * it will be UPTODATE, but never LOCKED, so we don't need
2123 * to test 'failed' directly.
2125 for (i
=disks
; i
--; )
2126 if (sh
->dev
[i
].written
) {
2128 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
2129 test_bit(R5_UPTODATE
, &dev
->flags
) ) {
2130 /* We can return any write requests */
2132 struct bio
*wbi
, *wbi2
;
2133 PRINTK("Return write for stripe %llu disc %d\n",
2134 (unsigned long long)sh
->sector
, i
);
2135 spin_lock_irq(&conf
->device_lock
);
2137 dev
->written
= NULL
;
2138 while (wbi
&& wbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
2139 wbi2
= r5_next_bio(wbi
, dev
->sector
);
2140 if (--wbi
->bi_phys_segments
== 0) {
2141 md_write_end(conf
->mddev
);
2142 wbi
->bi_next
= return_bi
;
2147 if (dev
->towrite
== NULL
)
2149 spin_unlock_irq(&conf
->device_lock
);
2151 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
2153 !test_bit(STRIPE_DEGRADED
, &sh
->state
), 0);
2158 /* Now we might consider reading some blocks, either to check/generate
2159 * parity, or to satisfy requests
2160 * or to load a block that is being partially written.
2162 if (to_read
|| non_overwrite
|| (to_write
&& failed
) || (syncing
&& (uptodate
< disks
))) {
2163 for (i
=disks
; i
--;) {
2165 if (!test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2167 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
2169 (failed
>= 1 && (sh
->dev
[failed_num
[0]].toread
|| to_write
)) ||
2170 (failed
>= 2 && (sh
->dev
[failed_num
[1]].toread
|| to_write
))
2173 /* we would like to get this block, possibly
2174 * by computing it, but we might not be able to
2176 if (uptodate
== disks
-1) {
2177 PRINTK("Computing stripe %llu block %d\n",
2178 (unsigned long long)sh
->sector
, i
);
2179 compute_block_1(sh
, i
, 0);
2181 } else if ( uptodate
== disks
-2 && failed
>= 2 ) {
2182 /* Computing 2-failure is *very* expensive; only do it if failed >= 2 */
2184 for (other
=disks
; other
--;) {
2187 if ( !test_bit(R5_UPTODATE
, &sh
->dev
[other
].flags
) )
2191 PRINTK("Computing stripe %llu blocks %d,%d\n",
2192 (unsigned long long)sh
->sector
, i
, other
);
2193 compute_block_2(sh
, i
, other
);
2195 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
2196 set_bit(R5_LOCKED
, &dev
->flags
);
2197 set_bit(R5_Wantread
, &dev
->flags
);
2199 /* if I am just reading this block and we don't have
2200 a failed drive, or any pending writes then sidestep the cache */
2201 if (sh
->bh_read
[i
] && !sh
->bh_read
[i
]->b_reqnext
&&
2202 ! syncing
&& !failed
&& !to_write
) {
2203 sh
->bh_cache
[i
]->b_page
= sh
->bh_read
[i
]->b_page
;
2204 sh
->bh_cache
[i
]->b_data
= sh
->bh_read
[i
]->b_data
;
2208 PRINTK("Reading block %d (sync=%d)\n",
2213 set_bit(STRIPE_HANDLE
, &sh
->state
);
2216 /* now to consider writing and what else, if anything should be read */
2218 int rcw
=0, must_compute
=0;
2219 for (i
=disks
; i
--;) {
2221 /* Would I have to read this buffer for reconstruct_write */
2222 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
2223 && i
!= pd_idx
&& i
!= qd_idx
2224 && (!test_bit(R5_LOCKED
, &dev
->flags
)
2226 || sh
->bh_page
[i
] != bh
->b_page
2229 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
2230 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
2232 PRINTK("raid6: must_compute: disk %d flags=%#lx\n", i
, dev
->flags
);
2237 PRINTK("for sector %llu, rcw=%d, must_compute=%d\n",
2238 (unsigned long long)sh
->sector
, rcw
, must_compute
);
2239 set_bit(STRIPE_HANDLE
, &sh
->state
);
2242 /* want reconstruct write, but need to get some data */
2243 for (i
=disks
; i
--;) {
2245 if (!test_bit(R5_OVERWRITE
, &dev
->flags
)
2246 && !(failed
== 0 && (i
== pd_idx
|| i
== qd_idx
))
2247 && !test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
2248 test_bit(R5_Insync
, &dev
->flags
)) {
2249 if (test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
2251 PRINTK("Read_old stripe %llu block %d for Reconstruct\n",
2252 (unsigned long long)sh
->sector
, i
);
2253 set_bit(R5_LOCKED
, &dev
->flags
);
2254 set_bit(R5_Wantread
, &dev
->flags
);
2257 PRINTK("Request delayed stripe %llu block %d for Reconstruct\n",
2258 (unsigned long long)sh
->sector
, i
);
2259 set_bit(STRIPE_DELAYED
, &sh
->state
);
2260 set_bit(STRIPE_HANDLE
, &sh
->state
);
2264 /* now if nothing is locked, and if we have enough data, we can start a write request */
2265 if (locked
== 0 && rcw
== 0 &&
2266 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
2267 if ( must_compute
> 0 ) {
2268 /* We have failed blocks and need to compute them */
2271 case 1: compute_block_1(sh
, failed_num
[0], 0); break;
2272 case 2: compute_block_2(sh
, failed_num
[0], failed_num
[1]); break;
2273 default: BUG(); /* This request should have been failed? */
2277 PRINTK("Computing parity for stripe %llu\n", (unsigned long long)sh
->sector
);
2278 compute_parity6(sh
, RECONSTRUCT_WRITE
);
2279 /* now every locked buffer is ready to be written */
2281 if (test_bit(R5_LOCKED
, &sh
->dev
[i
].flags
)) {
2282 PRINTK("Writing stripe %llu block %d\n",
2283 (unsigned long long)sh
->sector
, i
);
2285 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
2287 /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
2288 set_bit(STRIPE_INSYNC
, &sh
->state
);
2290 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
2291 atomic_dec(&conf
->preread_active_stripes
);
2292 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
2293 md_wakeup_thread(conf
->mddev
->thread
);
2298 /* maybe we need to check and possibly fix the parity for this stripe
2299 * Any reads will already have been scheduled, so we just see if enough data
2302 if (syncing
&& locked
== 0 && !test_bit(STRIPE_INSYNC
, &sh
->state
)) {
2303 int update_p
= 0, update_q
= 0;
2306 set_bit(STRIPE_HANDLE
, &sh
->state
);
2309 BUG_ON(uptodate
< disks
);
2310 /* Want to check and possibly repair P and Q.
2311 * However there could be one 'failed' device, in which
2312 * case we can only check one of them, possibly using the
2313 * other to generate missing data
2316 /* If !tmp_page, we cannot do the calculations,
2317 * but as we have set STRIPE_HANDLE, we will soon be called
2318 * by stripe_handle with a tmp_page - just wait until then.
2321 if (failed
== q_failed
) {
2322 /* The only possible failed device holds 'Q', so it makes
2323 * sense to check P (If anything else were failed, we would
2324 * have used P to recreate it).
2326 compute_block_1(sh
, pd_idx
, 1);
2327 if (!page_is_zero(sh
->dev
[pd_idx
].page
)) {
2328 compute_block_1(sh
,pd_idx
,0);
2332 if (!q_failed
&& failed
< 2) {
2333 /* q is not failed, and we didn't use it to generate
2334 * anything, so it makes sense to check it
2336 memcpy(page_address(tmp_page
),
2337 page_address(sh
->dev
[qd_idx
].page
),
2339 compute_parity6(sh
, UPDATE_PARITY
);
2340 if (memcmp(page_address(tmp_page
),
2341 page_address(sh
->dev
[qd_idx
].page
),
2343 clear_bit(STRIPE_INSYNC
, &sh
->state
);
2347 if (update_p
|| update_q
) {
2348 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
2349 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
2350 /* don't try to repair!! */
2351 update_p
= update_q
= 0;
2354 /* now write out any block on a failed drive,
2355 * or P or Q if they need it
2359 dev
= &sh
->dev
[failed_num
[1]];
2361 set_bit(R5_LOCKED
, &dev
->flags
);
2362 set_bit(R5_Wantwrite
, &dev
->flags
);
2365 dev
= &sh
->dev
[failed_num
[0]];
2367 set_bit(R5_LOCKED
, &dev
->flags
);
2368 set_bit(R5_Wantwrite
, &dev
->flags
);
2372 dev
= &sh
->dev
[pd_idx
];
2374 set_bit(R5_LOCKED
, &dev
->flags
);
2375 set_bit(R5_Wantwrite
, &dev
->flags
);
2378 dev
= &sh
->dev
[qd_idx
];
2380 set_bit(R5_LOCKED
, &dev
->flags
);
2381 set_bit(R5_Wantwrite
, &dev
->flags
);
2383 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
2385 set_bit(STRIPE_INSYNC
, &sh
->state
);
2389 if (syncing
&& locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
2390 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
2391 clear_bit(STRIPE_SYNCING
, &sh
->state
);
2394 /* If the failed drives are just a ReadError, then we might need
2395 * to progress the repair/check process
2397 if (failed
<= 2 && ! conf
->mddev
->ro
)
2398 for (i
=0; i
<failed
;i
++) {
2399 dev
= &sh
->dev
[failed_num
[i
]];
2400 if (test_bit(R5_ReadError
, &dev
->flags
)
2401 && !test_bit(R5_LOCKED
, &dev
->flags
)
2402 && test_bit(R5_UPTODATE
, &dev
->flags
)
2404 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
2405 set_bit(R5_Wantwrite
, &dev
->flags
);
2406 set_bit(R5_ReWrite
, &dev
->flags
);
2407 set_bit(R5_LOCKED
, &dev
->flags
);
2409 /* let's read it back */
2410 set_bit(R5_Wantread
, &dev
->flags
);
2411 set_bit(R5_LOCKED
, &dev
->flags
);
2415 spin_unlock(&sh
->lock
);
2417 while ((bi
=return_bi
)) {
2418 int bytes
= bi
->bi_size
;
2420 return_bi
= bi
->bi_next
;
2423 bi
->bi_end_io(bi
, bytes
, 0);
2425 for (i
=disks
; i
-- ;) {
2429 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
2431 else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
2436 bi
= &sh
->dev
[i
].req
;
2440 bi
->bi_end_io
= raid5_end_write_request
;
2442 bi
->bi_end_io
= raid5_end_read_request
;
2445 rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2446 if (rdev
&& test_bit(Faulty
, &rdev
->flags
))
2449 atomic_inc(&rdev
->nr_pending
);
2454 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
2456 bi
->bi_bdev
= rdev
->bdev
;
2457 PRINTK("for %llu schedule op %ld on disc %d\n",
2458 (unsigned long long)sh
->sector
, bi
->bi_rw
, i
);
2459 atomic_inc(&sh
->count
);
2460 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
2461 bi
->bi_flags
= 1 << BIO_UPTODATE
;
2463 bi
->bi_max_vecs
= 1;
2465 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
2466 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
2467 bi
->bi_io_vec
[0].bv_offset
= 0;
2468 bi
->bi_size
= STRIPE_SIZE
;
2471 test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
))
2472 atomic_add(STRIPE_SECTORS
, &rdev
->corrected_errors
);
2473 generic_make_request(bi
);
2476 set_bit(STRIPE_DEGRADED
, &sh
->state
);
2477 PRINTK("skip op %ld on disc %d for sector %llu\n",
2478 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
2479 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
2480 set_bit(STRIPE_HANDLE
, &sh
->state
);
2485 static void handle_stripe(struct stripe_head
*sh
, struct page
*tmp_page
)
2487 if (sh
->raid_conf
->level
== 6)
2488 handle_stripe6(sh
, tmp_page
);
2495 static void raid5_activate_delayed(raid5_conf_t
*conf
)
2497 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
2498 while (!list_empty(&conf
->delayed_list
)) {
2499 struct list_head
*l
= conf
->delayed_list
.next
;
2500 struct stripe_head
*sh
;
2501 sh
= list_entry(l
, struct stripe_head
, lru
);
2503 clear_bit(STRIPE_DELAYED
, &sh
->state
);
2504 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
2505 atomic_inc(&conf
->preread_active_stripes
);
2506 list_add_tail(&sh
->lru
, &conf
->handle_list
);
2511 static void activate_bit_delay(raid5_conf_t
*conf
)
2513 /* device_lock is held */
2514 struct list_head head
;
2515 list_add(&head
, &conf
->bitmap_list
);
2516 list_del_init(&conf
->bitmap_list
);
2517 while (!list_empty(&head
)) {
2518 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
2519 list_del_init(&sh
->lru
);
2520 atomic_inc(&sh
->count
);
2521 __release_stripe(conf
, sh
);
2525 static void unplug_slaves(mddev_t
*mddev
)
2527 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2531 for (i
=0; i
<mddev
->raid_disks
; i
++) {
2532 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2533 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) && atomic_read(&rdev
->nr_pending
)) {
2534 request_queue_t
*r_queue
= bdev_get_queue(rdev
->bdev
);
2536 atomic_inc(&rdev
->nr_pending
);
2539 if (r_queue
->unplug_fn
)
2540 r_queue
->unplug_fn(r_queue
);
2542 rdev_dec_pending(rdev
, mddev
);
2549 static void raid5_unplug_device(request_queue_t
*q
)
2551 mddev_t
*mddev
= q
->queuedata
;
2552 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2553 unsigned long flags
;
2555 spin_lock_irqsave(&conf
->device_lock
, flags
);
2557 if (blk_remove_plug(q
)) {
2559 raid5_activate_delayed(conf
);
2561 md_wakeup_thread(mddev
->thread
);
2563 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2565 unplug_slaves(mddev
);
2568 static int raid5_issue_flush(request_queue_t
*q
, struct gendisk
*disk
,
2569 sector_t
*error_sector
)
2571 mddev_t
*mddev
= q
->queuedata
;
2572 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2576 for (i
=0; i
<mddev
->raid_disks
&& ret
== 0; i
++) {
2577 mdk_rdev_t
*rdev
= rcu_dereference(conf
->disks
[i
].rdev
);
2578 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
2579 struct block_device
*bdev
= rdev
->bdev
;
2580 request_queue_t
*r_queue
= bdev_get_queue(bdev
);
2582 if (!r_queue
->issue_flush_fn
)
2585 atomic_inc(&rdev
->nr_pending
);
2587 ret
= r_queue
->issue_flush_fn(r_queue
, bdev
->bd_disk
,
2589 rdev_dec_pending(rdev
, mddev
);
2598 static int raid5_congested(void *data
, int bits
)
2600 mddev_t
*mddev
= data
;
2601 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2603 /* No difference between reads and writes. Just check
2604 * how busy the stripe_cache is
2606 if (conf
->inactive_blocked
)
2610 if (list_empty_careful(&conf
->inactive_list
))
2616 static int make_request(request_queue_t
*q
, struct bio
* bi
)
2618 mddev_t
*mddev
= q
->queuedata
;
2619 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2620 unsigned int dd_idx
, pd_idx
;
2621 sector_t new_sector
;
2622 sector_t logical_sector
, last_sector
;
2623 struct stripe_head
*sh
;
2624 const int rw
= bio_data_dir(bi
);
2627 if (unlikely(bio_barrier(bi
))) {
2628 bio_endio(bi
, bi
->bi_size
, -EOPNOTSUPP
);
2632 md_write_start(mddev
, bi
);
2634 disk_stat_inc(mddev
->gendisk
, ios
[rw
]);
2635 disk_stat_add(mddev
->gendisk
, sectors
[rw
], bio_sectors(bi
));
2637 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
2638 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
2640 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
2642 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
2644 int disks
, data_disks
;
2647 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
2648 if (likely(conf
->expand_progress
== MaxSector
))
2649 disks
= conf
->raid_disks
;
2651 /* spinlock is needed as expand_progress may be
2652 * 64bit on a 32bit platform, and so it might be
2653 * possible to see a half-updated value
2654 * Ofcourse expand_progress could change after
2655 * the lock is dropped, so once we get a reference
2656 * to the stripe that we think it is, we will have
2659 spin_lock_irq(&conf
->device_lock
);
2660 disks
= conf
->raid_disks
;
2661 if (logical_sector
>= conf
->expand_progress
)
2662 disks
= conf
->previous_raid_disks
;
2664 if (logical_sector
>= conf
->expand_lo
) {
2665 spin_unlock_irq(&conf
->device_lock
);
2670 spin_unlock_irq(&conf
->device_lock
);
2672 data_disks
= disks
- conf
->max_degraded
;
2674 new_sector
= raid5_compute_sector(logical_sector
, disks
, data_disks
,
2675 &dd_idx
, &pd_idx
, conf
);
2676 PRINTK("raid5: make_request, sector %llu logical %llu\n",
2677 (unsigned long long)new_sector
,
2678 (unsigned long long)logical_sector
);
2680 sh
= get_active_stripe(conf
, new_sector
, disks
, pd_idx
, (bi
->bi_rw
&RWA_MASK
));
2682 if (unlikely(conf
->expand_progress
!= MaxSector
)) {
2683 /* expansion might have moved on while waiting for a
2684 * stripe, so we must do the range check again.
2685 * Expansion could still move past after this
2686 * test, but as we are holding a reference to
2687 * 'sh', we know that if that happens,
2688 * STRIPE_EXPANDING will get set and the expansion
2689 * won't proceed until we finish with the stripe.
2692 spin_lock_irq(&conf
->device_lock
);
2693 if (logical_sector
< conf
->expand_progress
&&
2694 disks
== conf
->previous_raid_disks
)
2695 /* mismatch, need to try again */
2697 spin_unlock_irq(&conf
->device_lock
);
2703 /* FIXME what if we get a false positive because these
2704 * are being updated.
2706 if (logical_sector
>= mddev
->suspend_lo
&&
2707 logical_sector
< mddev
->suspend_hi
) {
2713 if (test_bit(STRIPE_EXPANDING
, &sh
->state
) ||
2714 !add_stripe_bio(sh
, bi
, dd_idx
, (bi
->bi_rw
&RW_MASK
))) {
2715 /* Stripe is busy expanding or
2716 * add failed due to overlap. Flush everything
2719 raid5_unplug_device(mddev
->queue
);
2724 finish_wait(&conf
->wait_for_overlap
, &w
);
2725 handle_stripe(sh
, NULL
);
2728 /* cannot get stripe for read-ahead, just give-up */
2729 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
2730 finish_wait(&conf
->wait_for_overlap
, &w
);
2735 spin_lock_irq(&conf
->device_lock
);
2736 remaining
= --bi
->bi_phys_segments
;
2737 spin_unlock_irq(&conf
->device_lock
);
2738 if (remaining
== 0) {
2739 int bytes
= bi
->bi_size
;
2742 md_write_end(mddev
);
2744 bi
->bi_end_io(bi
, bytes
, 0);
2749 static sector_t
reshape_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
)
2751 /* reshaping is quite different to recovery/resync so it is
2752 * handled quite separately ... here.
2754 * On each call to sync_request, we gather one chunk worth of
2755 * destination stripes and flag them as expanding.
2756 * Then we find all the source stripes and request reads.
2757 * As the reads complete, handle_stripe will copy the data
2758 * into the destination stripe and release that stripe.
2760 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
2761 struct stripe_head
*sh
;
2763 sector_t first_sector
, last_sector
;
2768 sector_t writepos
, safepos
, gap
;
2770 if (sector_nr
== 0 &&
2771 conf
->expand_progress
!= 0) {
2772 /* restarting in the middle, skip the initial sectors */
2773 sector_nr
= conf
->expand_progress
;
2774 sector_div(sector_nr
, conf
->raid_disks
-1);
2779 /* we update the metadata when there is more than 3Meg
2780 * in the block range (that is rather arbitrary, should
2781 * probably be time based) or when the data about to be
2782 * copied would over-write the source of the data at
2783 * the front of the range.
2784 * i.e. one new_stripe forward from expand_progress new_maps
2785 * to after where expand_lo old_maps to
2787 writepos
= conf
->expand_progress
+
2788 conf
->chunk_size
/512*(conf
->raid_disks
-1);
2789 sector_div(writepos
, conf
->raid_disks
-1);
2790 safepos
= conf
->expand_lo
;
2791 sector_div(safepos
, conf
->previous_raid_disks
-1);
2792 gap
= conf
->expand_progress
- conf
->expand_lo
;
2794 if (writepos
>= safepos
||
2795 gap
> (conf
->raid_disks
-1)*3000*2 /*3Meg*/) {
2796 /* Cannot proceed until we've updated the superblock... */
2797 wait_event(conf
->wait_for_overlap
,
2798 atomic_read(&conf
->reshape_stripes
)==0);
2799 mddev
->reshape_position
= conf
->expand_progress
;
2800 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
2801 md_wakeup_thread(mddev
->thread
);
2802 wait_event(mddev
->sb_wait
, mddev
->flags
== 0 ||
2803 kthread_should_stop());
2804 spin_lock_irq(&conf
->device_lock
);
2805 conf
->expand_lo
= mddev
->reshape_position
;
2806 spin_unlock_irq(&conf
->device_lock
);
2807 wake_up(&conf
->wait_for_overlap
);
2810 for (i
=0; i
< conf
->chunk_size
/512; i
+= STRIPE_SECTORS
) {
2813 pd_idx
= stripe_to_pdidx(sector_nr
+i
, conf
, conf
->raid_disks
);
2814 sh
= get_active_stripe(conf
, sector_nr
+i
,
2815 conf
->raid_disks
, pd_idx
, 0);
2816 set_bit(STRIPE_EXPANDING
, &sh
->state
);
2817 atomic_inc(&conf
->reshape_stripes
);
2818 /* If any of this stripe is beyond the end of the old
2819 * array, then we need to zero those blocks
2821 for (j
=sh
->disks
; j
--;) {
2823 if (j
== sh
->pd_idx
)
2825 s
= compute_blocknr(sh
, j
);
2826 if (s
< (mddev
->array_size
<<1)) {
2830 memset(page_address(sh
->dev
[j
].page
), 0, STRIPE_SIZE
);
2831 set_bit(R5_Expanded
, &sh
->dev
[j
].flags
);
2832 set_bit(R5_UPTODATE
, &sh
->dev
[j
].flags
);
2835 set_bit(STRIPE_EXPAND_READY
, &sh
->state
);
2836 set_bit(STRIPE_HANDLE
, &sh
->state
);
2840 spin_lock_irq(&conf
->device_lock
);
2841 conf
->expand_progress
= (sector_nr
+ i
)*(conf
->raid_disks
-1);
2842 spin_unlock_irq(&conf
->device_lock
);
2843 /* Ok, those stripe are ready. We can start scheduling
2844 * reads on the source stripes.
2845 * The source stripes are determined by mapping the first and last
2846 * block on the destination stripes.
2848 raid_disks
= conf
->previous_raid_disks
;
2849 data_disks
= raid_disks
- 1;
2851 raid5_compute_sector(sector_nr
*(conf
->raid_disks
-1),
2852 raid_disks
, data_disks
,
2853 &dd_idx
, &pd_idx
, conf
);
2855 raid5_compute_sector((sector_nr
+conf
->chunk_size
/512)
2856 *(conf
->raid_disks
-1) -1,
2857 raid_disks
, data_disks
,
2858 &dd_idx
, &pd_idx
, conf
);
2859 if (last_sector
>= (mddev
->size
<<1))
2860 last_sector
= (mddev
->size
<<1)-1;
2861 while (first_sector
<= last_sector
) {
2862 pd_idx
= stripe_to_pdidx(first_sector
, conf
, conf
->previous_raid_disks
);
2863 sh
= get_active_stripe(conf
, first_sector
,
2864 conf
->previous_raid_disks
, pd_idx
, 0);
2865 set_bit(STRIPE_EXPAND_SOURCE
, &sh
->state
);
2866 set_bit(STRIPE_HANDLE
, &sh
->state
);
2868 first_sector
+= STRIPE_SECTORS
;
2870 return conf
->chunk_size
>>9;
2873 /* FIXME go_faster isn't used */
2874 static inline sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
2876 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
2877 struct stripe_head
*sh
;
2879 int raid_disks
= conf
->raid_disks
;
2880 sector_t max_sector
= mddev
->size
<< 1;
2882 int still_degraded
= 0;
2885 if (sector_nr
>= max_sector
) {
2886 /* just being told to finish up .. nothing much to do */
2887 unplug_slaves(mddev
);
2888 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
)) {
2893 if (mddev
->curr_resync
< max_sector
) /* aborted */
2894 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
2896 else /* completed sync */
2898 bitmap_close_sync(mddev
->bitmap
);
2903 if (test_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
))
2904 return reshape_request(mddev
, sector_nr
, skipped
);
2906 /* if there is too many failed drives and we are trying
2907 * to resync, then assert that we are finished, because there is
2908 * nothing we can do.
2910 if (mddev
->degraded
>= conf
->max_degraded
&&
2911 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
2912 sector_t rv
= (mddev
->size
<< 1) - sector_nr
;
2916 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
2917 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
2918 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
2919 /* we can skip this block, and probably more */
2920 sync_blocks
/= STRIPE_SECTORS
;
2922 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
2925 pd_idx
= stripe_to_pdidx(sector_nr
, conf
, raid_disks
);
2926 sh
= get_active_stripe(conf
, sector_nr
, raid_disks
, pd_idx
, 1);
2928 sh
= get_active_stripe(conf
, sector_nr
, raid_disks
, pd_idx
, 0);
2929 /* make sure we don't swamp the stripe cache if someone else
2930 * is trying to get access
2932 schedule_timeout_uninterruptible(1);
2934 /* Need to check if array will still be degraded after recovery/resync
2935 * We don't need to check the 'failed' flag as when that gets set,
2938 for (i
=0; i
<mddev
->raid_disks
; i
++)
2939 if (conf
->disks
[i
].rdev
== NULL
)
2942 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, still_degraded
);
2944 spin_lock(&sh
->lock
);
2945 set_bit(STRIPE_SYNCING
, &sh
->state
);
2946 clear_bit(STRIPE_INSYNC
, &sh
->state
);
2947 spin_unlock(&sh
->lock
);
2949 handle_stripe(sh
, NULL
);
2952 return STRIPE_SECTORS
;
2956 * This is our raid5 kernel thread.
2958 * We scan the hash table for stripes which can be handled now.
2959 * During the scan, completed stripes are saved for us by the interrupt
2960 * handler, so that they will not have to wait for our next wakeup.
2962 static void raid5d (mddev_t
*mddev
)
2964 struct stripe_head
*sh
;
2965 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2968 PRINTK("+++ raid5d active\n");
2970 md_check_recovery(mddev
);
2973 spin_lock_irq(&conf
->device_lock
);
2975 struct list_head
*first
;
2977 if (conf
->seq_flush
!= conf
->seq_write
) {
2978 int seq
= conf
->seq_flush
;
2979 spin_unlock_irq(&conf
->device_lock
);
2980 bitmap_unplug(mddev
->bitmap
);
2981 spin_lock_irq(&conf
->device_lock
);
2982 conf
->seq_write
= seq
;
2983 activate_bit_delay(conf
);
2986 if (list_empty(&conf
->handle_list
) &&
2987 atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
&&
2988 !blk_queue_plugged(mddev
->queue
) &&
2989 !list_empty(&conf
->delayed_list
))
2990 raid5_activate_delayed(conf
);
2992 if (list_empty(&conf
->handle_list
))
2995 first
= conf
->handle_list
.next
;
2996 sh
= list_entry(first
, struct stripe_head
, lru
);
2998 list_del_init(first
);
2999 atomic_inc(&sh
->count
);
3000 BUG_ON(atomic_read(&sh
->count
)!= 1);
3001 spin_unlock_irq(&conf
->device_lock
);
3004 handle_stripe(sh
, conf
->spare_page
);
3007 spin_lock_irq(&conf
->device_lock
);
3009 PRINTK("%d stripes handled\n", handled
);
3011 spin_unlock_irq(&conf
->device_lock
);
3013 unplug_slaves(mddev
);
3015 PRINTK("--- raid5d inactive\n");
3019 raid5_show_stripe_cache_size(mddev_t
*mddev
, char *page
)
3021 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3023 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
3029 raid5_store_stripe_cache_size(mddev_t
*mddev
, const char *page
, size_t len
)
3031 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3034 if (len
>= PAGE_SIZE
)
3039 new = simple_strtoul(page
, &end
, 10);
3040 if (!*page
|| (*end
&& *end
!= '\n') )
3042 if (new <= 16 || new > 32768)
3044 while (new < conf
->max_nr_stripes
) {
3045 if (drop_one_stripe(conf
))
3046 conf
->max_nr_stripes
--;
3050 md_allow_write(mddev
);
3051 while (new > conf
->max_nr_stripes
) {
3052 if (grow_one_stripe(conf
))
3053 conf
->max_nr_stripes
++;
3059 static struct md_sysfs_entry
3060 raid5_stripecache_size
= __ATTR(stripe_cache_size
, S_IRUGO
| S_IWUSR
,
3061 raid5_show_stripe_cache_size
,
3062 raid5_store_stripe_cache_size
);
3065 stripe_cache_active_show(mddev_t
*mddev
, char *page
)
3067 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3069 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
3074 static struct md_sysfs_entry
3075 raid5_stripecache_active
= __ATTR_RO(stripe_cache_active
);
3077 static struct attribute
*raid5_attrs
[] = {
3078 &raid5_stripecache_size
.attr
,
3079 &raid5_stripecache_active
.attr
,
3082 static struct attribute_group raid5_attrs_group
= {
3084 .attrs
= raid5_attrs
,
3087 static int run(mddev_t
*mddev
)
3090 int raid_disk
, memory
;
3092 struct disk_info
*disk
;
3093 struct list_head
*tmp
;
3094 int working_disks
= 0;
3096 if (mddev
->level
!= 5 && mddev
->level
!= 4 && mddev
->level
!= 6) {
3097 printk(KERN_ERR
"raid5: %s: raid level not set to 4/5/6 (%d)\n",
3098 mdname(mddev
), mddev
->level
);
3102 if (mddev
->reshape_position
!= MaxSector
) {
3103 /* Check that we can continue the reshape.
3104 * Currently only disks can change, it must
3105 * increase, and we must be past the point where
3106 * a stripe over-writes itself
3108 sector_t here_new
, here_old
;
3111 if (mddev
->new_level
!= mddev
->level
||
3112 mddev
->new_layout
!= mddev
->layout
||
3113 mddev
->new_chunk
!= mddev
->chunk_size
) {
3114 printk(KERN_ERR
"raid5: %s: unsupported reshape required - aborting.\n",
3118 if (mddev
->delta_disks
<= 0) {
3119 printk(KERN_ERR
"raid5: %s: unsupported reshape (reduce disks) required - aborting.\n",
3123 old_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
3124 /* reshape_position must be on a new-stripe boundary, and one
3125 * further up in new geometry must map after here in old geometry.
3127 here_new
= mddev
->reshape_position
;
3128 if (sector_div(here_new
, (mddev
->chunk_size
>>9)*(mddev
->raid_disks
-1))) {
3129 printk(KERN_ERR
"raid5: reshape_position not on a stripe boundary\n");
3132 /* here_new is the stripe we will write to */
3133 here_old
= mddev
->reshape_position
;
3134 sector_div(here_old
, (mddev
->chunk_size
>>9)*(old_disks
-1));
3135 /* here_old is the first stripe that we might need to read from */
3136 if (here_new
>= here_old
) {
3137 /* Reading from the same stripe as writing to - bad */
3138 printk(KERN_ERR
"raid5: reshape_position too early for auto-recovery - aborting.\n");
3141 printk(KERN_INFO
"raid5: reshape will continue\n");
3142 /* OK, we should be able to continue; */
3146 mddev
->private = kzalloc(sizeof (raid5_conf_t
), GFP_KERNEL
);
3147 if ((conf
= mddev
->private) == NULL
)
3149 if (mddev
->reshape_position
== MaxSector
) {
3150 conf
->previous_raid_disks
= conf
->raid_disks
= mddev
->raid_disks
;
3152 conf
->raid_disks
= mddev
->raid_disks
;
3153 conf
->previous_raid_disks
= mddev
->raid_disks
- mddev
->delta_disks
;
3156 conf
->disks
= kzalloc(conf
->raid_disks
* sizeof(struct disk_info
),
3161 conf
->mddev
= mddev
;
3163 if ((conf
->stripe_hashtbl
= kzalloc(PAGE_SIZE
, GFP_KERNEL
)) == NULL
)
3166 if (mddev
->level
== 6) {
3167 conf
->spare_page
= alloc_page(GFP_KERNEL
);
3168 if (!conf
->spare_page
)
3171 spin_lock_init(&conf
->device_lock
);
3172 init_waitqueue_head(&conf
->wait_for_stripe
);
3173 init_waitqueue_head(&conf
->wait_for_overlap
);
3174 INIT_LIST_HEAD(&conf
->handle_list
);
3175 INIT_LIST_HEAD(&conf
->delayed_list
);
3176 INIT_LIST_HEAD(&conf
->bitmap_list
);
3177 INIT_LIST_HEAD(&conf
->inactive_list
);
3178 atomic_set(&conf
->active_stripes
, 0);
3179 atomic_set(&conf
->preread_active_stripes
, 0);
3181 PRINTK("raid5: run(%s) called.\n", mdname(mddev
));
3183 ITERATE_RDEV(mddev
,rdev
,tmp
) {
3184 raid_disk
= rdev
->raid_disk
;
3185 if (raid_disk
>= conf
->raid_disks
3188 disk
= conf
->disks
+ raid_disk
;
3192 if (test_bit(In_sync
, &rdev
->flags
)) {
3193 char b
[BDEVNAME_SIZE
];
3194 printk(KERN_INFO
"raid5: device %s operational as raid"
3195 " disk %d\n", bdevname(rdev
->bdev
,b
),
3202 * 0 for a fully functional array, 1 or 2 for a degraded array.
3204 mddev
->degraded
= conf
->raid_disks
- working_disks
;
3205 conf
->mddev
= mddev
;
3206 conf
->chunk_size
= mddev
->chunk_size
;
3207 conf
->level
= mddev
->level
;
3208 if (conf
->level
== 6)
3209 conf
->max_degraded
= 2;
3211 conf
->max_degraded
= 1;
3212 conf
->algorithm
= mddev
->layout
;
3213 conf
->max_nr_stripes
= NR_STRIPES
;
3214 conf
->expand_progress
= mddev
->reshape_position
;
3216 /* device size must be a multiple of chunk size */
3217 mddev
->size
&= ~(mddev
->chunk_size
/1024 -1);
3218 mddev
->resync_max_sectors
= mddev
->size
<< 1;
3220 if (conf
->level
== 6 && conf
->raid_disks
< 4) {
3221 printk(KERN_ERR
"raid6: not enough configured devices for %s (%d, minimum 4)\n",
3222 mdname(mddev
), conf
->raid_disks
);
3225 if (!conf
->chunk_size
|| conf
->chunk_size
% 4) {
3226 printk(KERN_ERR
"raid5: invalid chunk size %d for %s\n",
3227 conf
->chunk_size
, mdname(mddev
));
3230 if (conf
->algorithm
> ALGORITHM_RIGHT_SYMMETRIC
) {
3232 "raid5: unsupported parity algorithm %d for %s\n",
3233 conf
->algorithm
, mdname(mddev
));
3236 if (mddev
->degraded
> conf
->max_degraded
) {
3237 printk(KERN_ERR
"raid5: not enough operational devices for %s"
3238 " (%d/%d failed)\n",
3239 mdname(mddev
), mddev
->degraded
, conf
->raid_disks
);
3243 if (mddev
->degraded
> 0 &&
3244 mddev
->recovery_cp
!= MaxSector
) {
3245 if (mddev
->ok_start_degraded
)
3247 "raid5: starting dirty degraded array: %s"
3248 "- data corruption possible.\n",
3252 "raid5: cannot start dirty degraded array for %s\n",
3259 mddev
->thread
= md_register_thread(raid5d
, mddev
, "%s_raid5");
3260 if (!mddev
->thread
) {
3262 "raid5: couldn't allocate thread for %s\n",
3267 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
3268 conf
->raid_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
3269 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
3271 "raid5: couldn't allocate %dkB for buffers\n", memory
);
3272 shrink_stripes(conf
);
3273 md_unregister_thread(mddev
->thread
);
3276 printk(KERN_INFO
"raid5: allocated %dkB for %s\n",
3277 memory
, mdname(mddev
));
3279 if (mddev
->degraded
== 0)
3280 printk("raid5: raid level %d set %s active with %d out of %d"
3281 " devices, algorithm %d\n", conf
->level
, mdname(mddev
),
3282 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
3285 printk(KERN_ALERT
"raid5: raid level %d set %s active with %d"
3286 " out of %d devices, algorithm %d\n", conf
->level
,
3287 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
3288 mddev
->raid_disks
, conf
->algorithm
);
3290 print_raid5_conf(conf
);
3292 if (conf
->expand_progress
!= MaxSector
) {
3293 printk("...ok start reshape thread\n");
3294 conf
->expand_lo
= conf
->expand_progress
;
3295 atomic_set(&conf
->reshape_stripes
, 0);
3296 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
3297 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
3298 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
3299 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
3300 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
3304 /* read-ahead size must cover two whole stripes, which is
3305 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
3308 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
3309 int stripe
= data_disks
*
3310 (mddev
->chunk_size
/ PAGE_SIZE
);
3311 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
3312 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
3315 /* Ok, everything is just fine now */
3316 sysfs_create_group(&mddev
->kobj
, &raid5_attrs_group
);
3318 mddev
->queue
->unplug_fn
= raid5_unplug_device
;
3319 mddev
->queue
->issue_flush_fn
= raid5_issue_flush
;
3320 mddev
->queue
->backing_dev_info
.congested_fn
= raid5_congested
;
3321 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
3323 mddev
->array_size
= mddev
->size
* (conf
->previous_raid_disks
-
3324 conf
->max_degraded
);
3329 print_raid5_conf(conf
);
3330 safe_put_page(conf
->spare_page
);
3332 kfree(conf
->stripe_hashtbl
);
3335 mddev
->private = NULL
;
3336 printk(KERN_ALERT
"raid5: failed to run raid set %s\n", mdname(mddev
));
3342 static int stop(mddev_t
*mddev
)
3344 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3346 md_unregister_thread(mddev
->thread
);
3347 mddev
->thread
= NULL
;
3348 shrink_stripes(conf
);
3349 kfree(conf
->stripe_hashtbl
);
3350 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
3351 sysfs_remove_group(&mddev
->kobj
, &raid5_attrs_group
);
3354 mddev
->private = NULL
;
3359 static void print_sh (struct seq_file
*seq
, struct stripe_head
*sh
)
3363 seq_printf(seq
, "sh %llu, pd_idx %d, state %ld.\n",
3364 (unsigned long long)sh
->sector
, sh
->pd_idx
, sh
->state
);
3365 seq_printf(seq
, "sh %llu, count %d.\n",
3366 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
));
3367 seq_printf(seq
, "sh %llu, ", (unsigned long long)sh
->sector
);
3368 for (i
= 0; i
< sh
->disks
; i
++) {
3369 seq_printf(seq
, "(cache%d: %p %ld) ",
3370 i
, sh
->dev
[i
].page
, sh
->dev
[i
].flags
);
3372 seq_printf(seq
, "\n");
3375 static void printall (struct seq_file
*seq
, raid5_conf_t
*conf
)
3377 struct stripe_head
*sh
;
3378 struct hlist_node
*hn
;
3381 spin_lock_irq(&conf
->device_lock
);
3382 for (i
= 0; i
< NR_HASH
; i
++) {
3383 hlist_for_each_entry(sh
, hn
, &conf
->stripe_hashtbl
[i
], hash
) {
3384 if (sh
->raid_conf
!= conf
)
3389 spin_unlock_irq(&conf
->device_lock
);
3393 static void status (struct seq_file
*seq
, mddev_t
*mddev
)
3395 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
3398 seq_printf (seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
, mddev
->chunk_size
>> 10, mddev
->layout
);
3399 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->raid_disks
- mddev
->degraded
);
3400 for (i
= 0; i
< conf
->raid_disks
; i
++)
3401 seq_printf (seq
, "%s",
3402 conf
->disks
[i
].rdev
&&
3403 test_bit(In_sync
, &conf
->disks
[i
].rdev
->flags
) ? "U" : "_");
3404 seq_printf (seq
, "]");
3406 seq_printf (seq
, "\n");
3407 printall(seq
, conf
);
3411 static void print_raid5_conf (raid5_conf_t
*conf
)
3414 struct disk_info
*tmp
;
3416 printk("RAID5 conf printout:\n");
3418 printk("(conf==NULL)\n");
3421 printk(" --- rd:%d wd:%d\n", conf
->raid_disks
,
3422 conf
->raid_disks
- conf
->mddev
->degraded
);
3424 for (i
= 0; i
< conf
->raid_disks
; i
++) {
3425 char b
[BDEVNAME_SIZE
];
3426 tmp
= conf
->disks
+ i
;
3428 printk(" disk %d, o:%d, dev:%s\n",
3429 i
, !test_bit(Faulty
, &tmp
->rdev
->flags
),
3430 bdevname(tmp
->rdev
->bdev
,b
));
3434 static int raid5_spare_active(mddev_t
*mddev
)
3437 raid5_conf_t
*conf
= mddev
->private;
3438 struct disk_info
*tmp
;
3440 for (i
= 0; i
< conf
->raid_disks
; i
++) {
3441 tmp
= conf
->disks
+ i
;
3443 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
3444 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
3445 unsigned long flags
;
3446 spin_lock_irqsave(&conf
->device_lock
, flags
);
3448 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3451 print_raid5_conf(conf
);
3455 static int raid5_remove_disk(mddev_t
*mddev
, int number
)
3457 raid5_conf_t
*conf
= mddev
->private;
3460 struct disk_info
*p
= conf
->disks
+ number
;
3462 print_raid5_conf(conf
);
3465 if (test_bit(In_sync
, &rdev
->flags
) ||
3466 atomic_read(&rdev
->nr_pending
)) {
3472 if (atomic_read(&rdev
->nr_pending
)) {
3473 /* lost the race, try later */
3480 print_raid5_conf(conf
);
3484 static int raid5_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
3486 raid5_conf_t
*conf
= mddev
->private;
3489 struct disk_info
*p
;
3491 if (mddev
->degraded
> conf
->max_degraded
)
3492 /* no point adding a device */
3496 * find the disk ... but prefer rdev->saved_raid_disk
3499 if (rdev
->saved_raid_disk
>= 0 &&
3500 conf
->disks
[rdev
->saved_raid_disk
].rdev
== NULL
)
3501 disk
= rdev
->saved_raid_disk
;
3504 for ( ; disk
< conf
->raid_disks
; disk
++)
3505 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
3506 clear_bit(In_sync
, &rdev
->flags
);
3507 rdev
->raid_disk
= disk
;
3509 if (rdev
->saved_raid_disk
!= disk
)
3511 rcu_assign_pointer(p
->rdev
, rdev
);
3514 print_raid5_conf(conf
);
3518 static int raid5_resize(mddev_t
*mddev
, sector_t sectors
)
3520 /* no resync is happening, and there is enough space
3521 * on all devices, so we can resize.
3522 * We need to make sure resync covers any new space.
3523 * If the array is shrinking we should possibly wait until
3524 * any io in the removed space completes, but it hardly seems
3527 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3529 sectors
&= ~((sector_t
)mddev
->chunk_size
/512 - 1);
3530 mddev
->array_size
= (sectors
* (mddev
->raid_disks
-conf
->max_degraded
))>>1;
3531 set_capacity(mddev
->gendisk
, mddev
->array_size
<< 1);
3533 if (sectors
/2 > mddev
->size
&& mddev
->recovery_cp
== MaxSector
) {
3534 mddev
->recovery_cp
= mddev
->size
<< 1;
3535 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
3537 mddev
->size
= sectors
/2;
3538 mddev
->resync_max_sectors
= sectors
;
3542 #ifdef CONFIG_MD_RAID5_RESHAPE
3543 static int raid5_check_reshape(mddev_t
*mddev
)
3545 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3548 if (mddev
->delta_disks
< 0 ||
3549 mddev
->new_level
!= mddev
->level
)
3550 return -EINVAL
; /* Cannot shrink array or change level yet */
3551 if (mddev
->delta_disks
== 0)
3552 return 0; /* nothing to do */
3554 /* Can only proceed if there are plenty of stripe_heads.
3555 * We need a minimum of one full stripe,, and for sensible progress
3556 * it is best to have about 4 times that.
3557 * If we require 4 times, then the default 256 4K stripe_heads will
3558 * allow for chunk sizes up to 256K, which is probably OK.
3559 * If the chunk size is greater, user-space should request more
3560 * stripe_heads first.
3562 if ((mddev
->chunk_size
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
||
3563 (mddev
->new_chunk
/ STRIPE_SIZE
) * 4 > conf
->max_nr_stripes
) {
3564 printk(KERN_WARNING
"raid5: reshape: not enough stripes. Needed %lu\n",
3565 (mddev
->chunk_size
/ STRIPE_SIZE
)*4);
3569 err
= resize_stripes(conf
, conf
->raid_disks
+ mddev
->delta_disks
);
3573 /* looks like we might be able to manage this */
3577 static int raid5_start_reshape(mddev_t
*mddev
)
3579 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3581 struct list_head
*rtmp
;
3583 int added_devices
= 0;
3584 unsigned long flags
;
3586 if (mddev
->degraded
||
3587 test_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
))
3590 ITERATE_RDEV(mddev
, rdev
, rtmp
)
3591 if (rdev
->raid_disk
< 0 &&
3592 !test_bit(Faulty
, &rdev
->flags
))
3595 if (spares
< mddev
->delta_disks
-1)
3596 /* Not enough devices even to make a degraded array
3601 atomic_set(&conf
->reshape_stripes
, 0);
3602 spin_lock_irq(&conf
->device_lock
);
3603 conf
->previous_raid_disks
= conf
->raid_disks
;
3604 conf
->raid_disks
+= mddev
->delta_disks
;
3605 conf
->expand_progress
= 0;
3606 conf
->expand_lo
= 0;
3607 spin_unlock_irq(&conf
->device_lock
);
3609 /* Add some new drives, as many as will fit.
3610 * We know there are enough to make the newly sized array work.
3612 ITERATE_RDEV(mddev
, rdev
, rtmp
)
3613 if (rdev
->raid_disk
< 0 &&
3614 !test_bit(Faulty
, &rdev
->flags
)) {
3615 if (raid5_add_disk(mddev
, rdev
)) {
3617 set_bit(In_sync
, &rdev
->flags
);
3619 rdev
->recovery_offset
= 0;
3620 sprintf(nm
, "rd%d", rdev
->raid_disk
);
3621 sysfs_create_link(&mddev
->kobj
, &rdev
->kobj
, nm
);
3626 spin_lock_irqsave(&conf
->device_lock
, flags
);
3627 mddev
->degraded
= (conf
->raid_disks
- conf
->previous_raid_disks
) - added_devices
;
3628 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3629 mddev
->raid_disks
= conf
->raid_disks
;
3630 mddev
->reshape_position
= 0;
3631 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
3633 clear_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
);
3634 clear_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
);
3635 set_bit(MD_RECOVERY_RESHAPE
, &mddev
->recovery
);
3636 set_bit(MD_RECOVERY_RUNNING
, &mddev
->recovery
);
3637 mddev
->sync_thread
= md_register_thread(md_do_sync
, mddev
,
3639 if (!mddev
->sync_thread
) {
3640 mddev
->recovery
= 0;
3641 spin_lock_irq(&conf
->device_lock
);
3642 mddev
->raid_disks
= conf
->raid_disks
= conf
->previous_raid_disks
;
3643 conf
->expand_progress
= MaxSector
;
3644 spin_unlock_irq(&conf
->device_lock
);
3647 md_wakeup_thread(mddev
->sync_thread
);
3648 md_new_event(mddev
);
3653 static void end_reshape(raid5_conf_t
*conf
)
3655 struct block_device
*bdev
;
3657 if (!test_bit(MD_RECOVERY_INTR
, &conf
->mddev
->recovery
)) {
3658 conf
->mddev
->array_size
= conf
->mddev
->size
* (conf
->raid_disks
-1);
3659 set_capacity(conf
->mddev
->gendisk
, conf
->mddev
->array_size
<< 1);
3660 conf
->mddev
->changed
= 1;
3662 bdev
= bdget_disk(conf
->mddev
->gendisk
, 0);
3664 mutex_lock(&bdev
->bd_inode
->i_mutex
);
3665 i_size_write(bdev
->bd_inode
, (loff_t
)conf
->mddev
->array_size
<< 10);
3666 mutex_unlock(&bdev
->bd_inode
->i_mutex
);
3669 spin_lock_irq(&conf
->device_lock
);
3670 conf
->expand_progress
= MaxSector
;
3671 spin_unlock_irq(&conf
->device_lock
);
3672 conf
->mddev
->reshape_position
= MaxSector
;
3674 /* read-ahead size must cover two whole stripes, which is
3675 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
3678 int data_disks
= conf
->previous_raid_disks
- conf
->max_degraded
;
3679 int stripe
= data_disks
*
3680 (conf
->mddev
->chunk_size
/ PAGE_SIZE
);
3681 if (conf
->mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
3682 conf
->mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
3687 static void raid5_quiesce(mddev_t
*mddev
, int state
)
3689 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
3692 case 2: /* resume for a suspend */
3693 wake_up(&conf
->wait_for_overlap
);
3696 case 1: /* stop all writes */
3697 spin_lock_irq(&conf
->device_lock
);
3699 wait_event_lock_irq(conf
->wait_for_stripe
,
3700 atomic_read(&conf
->active_stripes
) == 0,
3701 conf
->device_lock
, /* nothing */);
3702 spin_unlock_irq(&conf
->device_lock
);
3705 case 0: /* re-enable writes */
3706 spin_lock_irq(&conf
->device_lock
);
3708 wake_up(&conf
->wait_for_stripe
);
3709 wake_up(&conf
->wait_for_overlap
);
3710 spin_unlock_irq(&conf
->device_lock
);
3715 static struct mdk_personality raid6_personality
=
3719 .owner
= THIS_MODULE
,
3720 .make_request
= make_request
,
3724 .error_handler
= error
,
3725 .hot_add_disk
= raid5_add_disk
,
3726 .hot_remove_disk
= raid5_remove_disk
,
3727 .spare_active
= raid5_spare_active
,
3728 .sync_request
= sync_request
,
3729 .resize
= raid5_resize
,
3730 .quiesce
= raid5_quiesce
,
3732 static struct mdk_personality raid5_personality
=
3736 .owner
= THIS_MODULE
,
3737 .make_request
= make_request
,
3741 .error_handler
= error
,
3742 .hot_add_disk
= raid5_add_disk
,
3743 .hot_remove_disk
= raid5_remove_disk
,
3744 .spare_active
= raid5_spare_active
,
3745 .sync_request
= sync_request
,
3746 .resize
= raid5_resize
,
3747 #ifdef CONFIG_MD_RAID5_RESHAPE
3748 .check_reshape
= raid5_check_reshape
,
3749 .start_reshape
= raid5_start_reshape
,
3751 .quiesce
= raid5_quiesce
,
3754 static struct mdk_personality raid4_personality
=
3758 .owner
= THIS_MODULE
,
3759 .make_request
= make_request
,
3763 .error_handler
= error
,
3764 .hot_add_disk
= raid5_add_disk
,
3765 .hot_remove_disk
= raid5_remove_disk
,
3766 .spare_active
= raid5_spare_active
,
3767 .sync_request
= sync_request
,
3768 .resize
= raid5_resize
,
3769 .quiesce
= raid5_quiesce
,
3772 static int __init
raid5_init(void)
3776 e
= raid6_select_algo();
3779 register_md_personality(&raid6_personality
);
3780 register_md_personality(&raid5_personality
);
3781 register_md_personality(&raid4_personality
);
3785 static void raid5_exit(void)
3787 unregister_md_personality(&raid6_personality
);
3788 unregister_md_personality(&raid5_personality
);
3789 unregister_md_personality(&raid4_personality
);
3792 module_init(raid5_init
);
3793 module_exit(raid5_exit
);
3794 MODULE_LICENSE("GPL");
3795 MODULE_ALIAS("md-personality-4"); /* RAID5 */
3796 MODULE_ALIAS("md-raid5");
3797 MODULE_ALIAS("md-raid4");
3798 MODULE_ALIAS("md-level-5");
3799 MODULE_ALIAS("md-level-4");
3800 MODULE_ALIAS("md-personality-8"); /* RAID6 */
3801 MODULE_ALIAS("md-raid6");
3802 MODULE_ALIAS("md-level-6");
3804 /* This used to be two separate modules, they were: */
3805 MODULE_ALIAS("raid5");
3806 MODULE_ALIAS("raid6");