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
6 * RAID-5 management functions.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
13 * You should have received a copy of the GNU General Public License
14 * (for example /usr/src/linux/COPYING); if not, write to the Free
15 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 #include <linux/config.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/raid/raid5.h>
23 #include <linux/highmem.h>
24 #include <linux/bitops.h>
25 #include <asm/atomic.h>
27 #include <linux/raid/bitmap.h>
33 #define NR_STRIPES 256
34 #define STRIPE_SIZE PAGE_SIZE
35 #define STRIPE_SHIFT (PAGE_SHIFT - 9)
36 #define STRIPE_SECTORS (STRIPE_SIZE>>9)
37 #define IO_THRESHOLD 1
39 #define HASH_PAGES_ORDER 0
40 #define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *))
41 #define HASH_MASK (NR_HASH - 1)
43 #define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])
45 /* bio's attached to a stripe+device for I/O are linked together in bi_sector
46 * order without overlap. There may be several bio's per stripe+device, and
47 * a bio could span several devices.
48 * When walking this list for a particular stripe+device, we must never proceed
49 * beyond a bio that extends past this device, as the next bio might no longer
51 * This macro is used to determine the 'next' bio in the list, given the sector
52 * of the current stripe+device
54 #define r5_next_bio(bio, sect) ( ( (bio)->bi_sector + ((bio)->bi_size>>9) < sect + STRIPE_SECTORS) ? (bio)->bi_next : NULL)
56 * The following can be used to debug the driver
59 #define RAID5_PARANOIA 1
60 #if RAID5_PARANOIA && defined(CONFIG_SMP)
61 # define CHECK_DEVLOCK() assert_spin_locked(&conf->device_lock)
63 # define CHECK_DEVLOCK()
66 #define PRINTK(x...) ((void)(RAID5_DEBUG && printk(x)))
72 static void print_raid5_conf (raid5_conf_t
*conf
);
74 static inline void __release_stripe(raid5_conf_t
*conf
, struct stripe_head
*sh
)
76 if (atomic_dec_and_test(&sh
->count
)) {
77 if (!list_empty(&sh
->lru
))
79 if (atomic_read(&conf
->active_stripes
)==0)
81 if (test_bit(STRIPE_HANDLE
, &sh
->state
)) {
82 if (test_bit(STRIPE_DELAYED
, &sh
->state
))
83 list_add_tail(&sh
->lru
, &conf
->delayed_list
);
84 else if (test_bit(STRIPE_BIT_DELAY
, &sh
->state
) &&
85 conf
->seq_write
== sh
->bm_seq
)
86 list_add_tail(&sh
->lru
, &conf
->bitmap_list
);
88 clear_bit(STRIPE_BIT_DELAY
, &sh
->state
);
89 list_add_tail(&sh
->lru
, &conf
->handle_list
);
91 md_wakeup_thread(conf
->mddev
->thread
);
93 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
94 atomic_dec(&conf
->preread_active_stripes
);
95 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
96 md_wakeup_thread(conf
->mddev
->thread
);
98 list_add_tail(&sh
->lru
, &conf
->inactive_list
);
99 atomic_dec(&conf
->active_stripes
);
100 if (!conf
->inactive_blocked
||
101 atomic_read(&conf
->active_stripes
) < (NR_STRIPES
*3/4))
102 wake_up(&conf
->wait_for_stripe
);
106 static void release_stripe(struct stripe_head
*sh
)
108 raid5_conf_t
*conf
= sh
->raid_conf
;
111 spin_lock_irqsave(&conf
->device_lock
, flags
);
112 __release_stripe(conf
, sh
);
113 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
116 static void remove_hash(struct stripe_head
*sh
)
118 PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh
->sector
);
120 if (sh
->hash_pprev
) {
122 sh
->hash_next
->hash_pprev
= sh
->hash_pprev
;
123 *sh
->hash_pprev
= sh
->hash_next
;
124 sh
->hash_pprev
= NULL
;
128 static __inline__
void insert_hash(raid5_conf_t
*conf
, struct stripe_head
*sh
)
130 struct stripe_head
**shp
= &stripe_hash(conf
, sh
->sector
);
132 PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh
->sector
);
135 if ((sh
->hash_next
= *shp
) != NULL
)
136 (*shp
)->hash_pprev
= &sh
->hash_next
;
138 sh
->hash_pprev
= shp
;
142 /* find an idle stripe, make sure it is unhashed, and return it. */
143 static struct stripe_head
*get_free_stripe(raid5_conf_t
*conf
)
145 struct stripe_head
*sh
= NULL
;
146 struct list_head
*first
;
149 if (list_empty(&conf
->inactive_list
))
151 first
= conf
->inactive_list
.next
;
152 sh
= list_entry(first
, struct stripe_head
, lru
);
153 list_del_init(first
);
155 atomic_inc(&conf
->active_stripes
);
160 static void shrink_buffers(struct stripe_head
*sh
, int num
)
165 for (i
=0; i
<num
; i
++) {
169 sh
->dev
[i
].page
= NULL
;
170 page_cache_release(p
);
174 static int grow_buffers(struct stripe_head
*sh
, int num
)
178 for (i
=0; i
<num
; i
++) {
181 if (!(page
= alloc_page(GFP_KERNEL
))) {
184 sh
->dev
[i
].page
= page
;
189 static void raid5_build_block (struct stripe_head
*sh
, int i
);
191 static inline void init_stripe(struct stripe_head
*sh
, sector_t sector
, int pd_idx
)
193 raid5_conf_t
*conf
= sh
->raid_conf
;
194 int disks
= conf
->raid_disks
, i
;
196 if (atomic_read(&sh
->count
) != 0)
198 if (test_bit(STRIPE_HANDLE
, &sh
->state
))
202 PRINTK("init_stripe called, stripe %llu\n",
203 (unsigned long long)sh
->sector
);
211 for (i
=disks
; i
--; ) {
212 struct r5dev
*dev
= &sh
->dev
[i
];
214 if (dev
->toread
|| dev
->towrite
|| dev
->written
||
215 test_bit(R5_LOCKED
, &dev
->flags
)) {
216 printk("sector=%llx i=%d %p %p %p %d\n",
217 (unsigned long long)sh
->sector
, i
, dev
->toread
,
218 dev
->towrite
, dev
->written
,
219 test_bit(R5_LOCKED
, &dev
->flags
));
223 raid5_build_block(sh
, i
);
225 insert_hash(conf
, sh
);
228 static struct stripe_head
*__find_stripe(raid5_conf_t
*conf
, sector_t sector
)
230 struct stripe_head
*sh
;
233 PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector
);
234 for (sh
= stripe_hash(conf
, sector
); sh
; sh
= sh
->hash_next
)
235 if (sh
->sector
== sector
)
237 PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector
);
241 static void unplug_slaves(mddev_t
*mddev
);
242 static void raid5_unplug_device(request_queue_t
*q
);
244 static struct stripe_head
*get_active_stripe(raid5_conf_t
*conf
, sector_t sector
,
245 int pd_idx
, int noblock
)
247 struct stripe_head
*sh
;
249 PRINTK("get_stripe, sector %llu\n", (unsigned long long)sector
);
251 spin_lock_irq(&conf
->device_lock
);
254 wait_event_lock_irq(conf
->wait_for_stripe
,
256 conf
->device_lock
, /* nothing */);
257 sh
= __find_stripe(conf
, sector
);
259 if (!conf
->inactive_blocked
)
260 sh
= get_free_stripe(conf
);
261 if (noblock
&& sh
== NULL
)
264 conf
->inactive_blocked
= 1;
265 wait_event_lock_irq(conf
->wait_for_stripe
,
266 !list_empty(&conf
->inactive_list
) &&
267 (atomic_read(&conf
->active_stripes
) < (NR_STRIPES
*3/4)
268 || !conf
->inactive_blocked
),
270 unplug_slaves(conf
->mddev
);
272 conf
->inactive_blocked
= 0;
274 init_stripe(sh
, sector
, pd_idx
);
276 if (atomic_read(&sh
->count
)) {
277 if (!list_empty(&sh
->lru
))
280 if (!test_bit(STRIPE_HANDLE
, &sh
->state
))
281 atomic_inc(&conf
->active_stripes
);
282 if (list_empty(&sh
->lru
))
284 list_del_init(&sh
->lru
);
287 } while (sh
== NULL
);
290 atomic_inc(&sh
->count
);
292 spin_unlock_irq(&conf
->device_lock
);
296 static int grow_one_stripe(raid5_conf_t
*conf
)
298 struct stripe_head
*sh
;
299 sh
= kmem_cache_alloc(conf
->slab_cache
, GFP_KERNEL
);
302 memset(sh
, 0, sizeof(*sh
) + (conf
->raid_disks
-1)*sizeof(struct r5dev
));
303 sh
->raid_conf
= conf
;
304 spin_lock_init(&sh
->lock
);
306 if (grow_buffers(sh
, conf
->raid_disks
)) {
307 shrink_buffers(sh
, conf
->raid_disks
);
308 kmem_cache_free(conf
->slab_cache
, sh
);
311 /* we just created an active stripe so... */
312 atomic_set(&sh
->count
, 1);
313 atomic_inc(&conf
->active_stripes
);
314 INIT_LIST_HEAD(&sh
->lru
);
319 static int grow_stripes(raid5_conf_t
*conf
, int num
)
322 int devs
= conf
->raid_disks
;
324 sprintf(conf
->cache_name
, "raid5/%s", mdname(conf
->mddev
));
326 sc
= kmem_cache_create(conf
->cache_name
,
327 sizeof(struct stripe_head
)+(devs
-1)*sizeof(struct r5dev
),
331 conf
->slab_cache
= sc
;
333 if (!grow_one_stripe(conf
))
339 static int drop_one_stripe(raid5_conf_t
*conf
)
341 struct stripe_head
*sh
;
343 spin_lock_irq(&conf
->device_lock
);
344 sh
= get_free_stripe(conf
);
345 spin_unlock_irq(&conf
->device_lock
);
348 if (atomic_read(&sh
->count
))
350 shrink_buffers(sh
, conf
->raid_disks
);
351 kmem_cache_free(conf
->slab_cache
, sh
);
352 atomic_dec(&conf
->active_stripes
);
356 static void shrink_stripes(raid5_conf_t
*conf
)
358 while (drop_one_stripe(conf
))
361 kmem_cache_destroy(conf
->slab_cache
);
362 conf
->slab_cache
= NULL
;
365 static int raid5_end_read_request(struct bio
* bi
, unsigned int bytes_done
,
368 struct stripe_head
*sh
= bi
->bi_private
;
369 raid5_conf_t
*conf
= sh
->raid_conf
;
370 int disks
= conf
->raid_disks
, i
;
371 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
376 for (i
=0 ; i
<disks
; i
++)
377 if (bi
== &sh
->dev
[i
].req
)
380 PRINTK("end_read_request %llu/%d, count: %d, uptodate %d.\n",
381 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
392 spin_lock_irqsave(&conf
->device_lock
, flags
);
393 /* we can return a buffer if we bypassed the cache or
394 * if the top buffer is not in highmem. If there are
395 * multiple buffers, leave the extra work to
398 buffer
= sh
->bh_read
[i
];
400 (!PageHighMem(buffer
->b_page
)
401 || buffer
->b_page
== bh
->b_page
)
403 sh
->bh_read
[i
] = buffer
->b_reqnext
;
404 buffer
->b_reqnext
= NULL
;
407 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
408 if (sh
->bh_page
[i
]==bh
->b_page
)
409 set_buffer_uptodate(bh
);
411 if (buffer
->b_page
!= bh
->b_page
)
412 memcpy(buffer
->b_data
, bh
->b_data
, bh
->b_size
);
413 buffer
->b_end_io(buffer
, 1);
416 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
418 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
419 printk("R5: read error corrected!!\n");
420 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
421 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
424 clear_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
425 if (conf
->mddev
->degraded
) {
426 printk("R5: read error not correctable.\n");
427 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
428 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
429 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
430 } else if (test_bit(R5_ReWrite
, &sh
->dev
[i
].flags
)) {
432 printk("R5: read error NOT corrected!!\n");
433 clear_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
434 clear_bit(R5_ReWrite
, &sh
->dev
[i
].flags
);
435 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
437 set_bit(R5_ReadError
, &sh
->dev
[i
].flags
);
439 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
441 /* must restore b_page before unlocking buffer... */
442 if (sh
->bh_page
[i
] != bh
->b_page
) {
443 bh
->b_page
= sh
->bh_page
[i
];
444 bh
->b_data
= page_address(bh
->b_page
);
445 clear_buffer_uptodate(bh
);
448 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
449 set_bit(STRIPE_HANDLE
, &sh
->state
);
454 static int raid5_end_write_request (struct bio
*bi
, unsigned int bytes_done
,
457 struct stripe_head
*sh
= bi
->bi_private
;
458 raid5_conf_t
*conf
= sh
->raid_conf
;
459 int disks
= conf
->raid_disks
, i
;
461 int uptodate
= test_bit(BIO_UPTODATE
, &bi
->bi_flags
);
466 for (i
=0 ; i
<disks
; i
++)
467 if (bi
== &sh
->dev
[i
].req
)
470 PRINTK("end_write_request %llu/%d, count %d, uptodate: %d.\n",
471 (unsigned long long)sh
->sector
, i
, atomic_read(&sh
->count
),
478 spin_lock_irqsave(&conf
->device_lock
, flags
);
480 md_error(conf
->mddev
, conf
->disks
[i
].rdev
);
482 rdev_dec_pending(conf
->disks
[i
].rdev
, conf
->mddev
);
484 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
485 set_bit(STRIPE_HANDLE
, &sh
->state
);
486 __release_stripe(conf
, sh
);
487 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
492 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
);
494 static void raid5_build_block (struct stripe_head
*sh
, int i
)
496 struct r5dev
*dev
= &sh
->dev
[i
];
499 dev
->req
.bi_io_vec
= &dev
->vec
;
501 dev
->req
.bi_max_vecs
++;
502 dev
->vec
.bv_page
= dev
->page
;
503 dev
->vec
.bv_len
= STRIPE_SIZE
;
504 dev
->vec
.bv_offset
= 0;
506 dev
->req
.bi_sector
= sh
->sector
;
507 dev
->req
.bi_private
= sh
;
511 dev
->sector
= compute_blocknr(sh
, i
);
514 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
516 char b
[BDEVNAME_SIZE
];
517 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
518 PRINTK("raid5: error called\n");
523 conf
->working_disks
--;
525 conf
->failed_disks
++;
528 * if recovery was running, make sure it aborts.
530 set_bit(MD_RECOVERY_ERR
, &mddev
->recovery
);
534 "raid5: Disk failure on %s, disabling device."
535 " Operation continuing on %d devices\n",
536 bdevname(rdev
->bdev
,b
), conf
->working_disks
);
541 * Input: a 'big' sector number,
542 * Output: index of the data and parity disk, and the sector # in them.
544 static sector_t
raid5_compute_sector(sector_t r_sector
, unsigned int raid_disks
,
545 unsigned int data_disks
, unsigned int * dd_idx
,
546 unsigned int * pd_idx
, raid5_conf_t
*conf
)
549 unsigned long chunk_number
;
550 unsigned int chunk_offset
;
552 int sectors_per_chunk
= conf
->chunk_size
>> 9;
554 /* First compute the information on this sector */
557 * Compute the chunk number and the sector offset inside the chunk
559 chunk_offset
= sector_div(r_sector
, sectors_per_chunk
);
560 chunk_number
= r_sector
;
561 BUG_ON(r_sector
!= chunk_number
);
564 * Compute the stripe number
566 stripe
= chunk_number
/ data_disks
;
569 * Compute the data disk and parity disk indexes inside the stripe
571 *dd_idx
= chunk_number
% data_disks
;
574 * Select the parity disk based on the user selected algorithm.
576 if (conf
->level
== 4)
577 *pd_idx
= data_disks
;
578 else switch (conf
->algorithm
) {
579 case ALGORITHM_LEFT_ASYMMETRIC
:
580 *pd_idx
= data_disks
- stripe
% raid_disks
;
581 if (*dd_idx
>= *pd_idx
)
584 case ALGORITHM_RIGHT_ASYMMETRIC
:
585 *pd_idx
= stripe
% raid_disks
;
586 if (*dd_idx
>= *pd_idx
)
589 case ALGORITHM_LEFT_SYMMETRIC
:
590 *pd_idx
= data_disks
- stripe
% raid_disks
;
591 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
593 case ALGORITHM_RIGHT_SYMMETRIC
:
594 *pd_idx
= stripe
% raid_disks
;
595 *dd_idx
= (*pd_idx
+ 1 + *dd_idx
) % raid_disks
;
598 printk("raid5: unsupported algorithm %d\n",
603 * Finally, compute the new sector number
605 new_sector
= (sector_t
)stripe
* sectors_per_chunk
+ chunk_offset
;
610 static sector_t
compute_blocknr(struct stripe_head
*sh
, int i
)
612 raid5_conf_t
*conf
= sh
->raid_conf
;
613 int raid_disks
= conf
->raid_disks
, data_disks
= raid_disks
- 1;
614 sector_t new_sector
= sh
->sector
, check
;
615 int sectors_per_chunk
= conf
->chunk_size
>> 9;
618 int chunk_number
, dummy1
, dummy2
, dd_idx
= i
;
621 chunk_offset
= sector_div(new_sector
, sectors_per_chunk
);
623 BUG_ON(new_sector
!= stripe
);
626 switch (conf
->algorithm
) {
627 case ALGORITHM_LEFT_ASYMMETRIC
:
628 case ALGORITHM_RIGHT_ASYMMETRIC
:
632 case ALGORITHM_LEFT_SYMMETRIC
:
633 case ALGORITHM_RIGHT_SYMMETRIC
:
636 i
-= (sh
->pd_idx
+ 1);
639 printk("raid5: unsupported algorithm %d\n",
643 chunk_number
= stripe
* data_disks
+ i
;
644 r_sector
= (sector_t
)chunk_number
* sectors_per_chunk
+ chunk_offset
;
646 check
= raid5_compute_sector (r_sector
, raid_disks
, data_disks
, &dummy1
, &dummy2
, conf
);
647 if (check
!= sh
->sector
|| dummy1
!= dd_idx
|| dummy2
!= sh
->pd_idx
) {
648 printk("compute_blocknr: map not correct\n");
657 * Copy data between a page in the stripe cache, and a bio.
658 * There are no alignment or size guarantees between the page or the
659 * bio except that there is some overlap.
660 * All iovecs in the bio must be considered.
662 static void copy_data(int frombio
, struct bio
*bio
,
666 char *pa
= page_address(page
);
671 if (bio
->bi_sector
>= sector
)
672 page_offset
= (signed)(bio
->bi_sector
- sector
) * 512;
674 page_offset
= (signed)(sector
- bio
->bi_sector
) * -512;
675 bio_for_each_segment(bvl
, bio
, i
) {
676 int len
= bio_iovec_idx(bio
,i
)->bv_len
;
680 if (page_offset
< 0) {
681 b_offset
= -page_offset
;
682 page_offset
+= b_offset
;
686 if (len
> 0 && page_offset
+ len
> STRIPE_SIZE
)
687 clen
= STRIPE_SIZE
- page_offset
;
691 char *ba
= __bio_kmap_atomic(bio
, i
, KM_USER0
);
693 memcpy(pa
+page_offset
, ba
+b_offset
, clen
);
695 memcpy(ba
+b_offset
, pa
+page_offset
, clen
);
696 __bio_kunmap_atomic(ba
, KM_USER0
);
698 if (clen
< len
) /* hit end of page */
704 #define check_xor() do { \
705 if (count == MAX_XOR_BLOCKS) { \
706 xor_block(count, STRIPE_SIZE, ptr); \
712 static void compute_block(struct stripe_head
*sh
, int dd_idx
)
714 raid5_conf_t
*conf
= sh
->raid_conf
;
715 int i
, count
, disks
= conf
->raid_disks
;
716 void *ptr
[MAX_XOR_BLOCKS
], *p
;
718 PRINTK("compute_block, stripe %llu, idx %d\n",
719 (unsigned long long)sh
->sector
, dd_idx
);
721 ptr
[0] = page_address(sh
->dev
[dd_idx
].page
);
722 memset(ptr
[0], 0, STRIPE_SIZE
);
724 for (i
= disks
; i
--; ) {
727 p
= page_address(sh
->dev
[i
].page
);
728 if (test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
))
731 printk("compute_block() %d, stripe %llu, %d"
732 " not present\n", dd_idx
,
733 (unsigned long long)sh
->sector
, i
);
738 xor_block(count
, STRIPE_SIZE
, ptr
);
739 set_bit(R5_UPTODATE
, &sh
->dev
[dd_idx
].flags
);
742 static void compute_parity(struct stripe_head
*sh
, int method
)
744 raid5_conf_t
*conf
= sh
->raid_conf
;
745 int i
, pd_idx
= sh
->pd_idx
, disks
= conf
->raid_disks
, count
;
746 void *ptr
[MAX_XOR_BLOCKS
];
749 PRINTK("compute_parity, stripe %llu, method %d\n",
750 (unsigned long long)sh
->sector
, method
);
753 ptr
[0] = page_address(sh
->dev
[pd_idx
].page
);
755 case READ_MODIFY_WRITE
:
756 if (!test_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
))
758 for (i
=disks
; i
-- ;) {
761 if (sh
->dev
[i
].towrite
&&
762 test_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
)) {
763 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
764 chosen
= sh
->dev
[i
].towrite
;
765 sh
->dev
[i
].towrite
= NULL
;
767 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
768 wake_up(&conf
->wait_for_overlap
);
770 if (sh
->dev
[i
].written
) BUG();
771 sh
->dev
[i
].written
= chosen
;
776 case RECONSTRUCT_WRITE
:
777 memset(ptr
[0], 0, STRIPE_SIZE
);
778 for (i
= disks
; i
-- ;)
779 if (i
!=pd_idx
&& sh
->dev
[i
].towrite
) {
780 chosen
= sh
->dev
[i
].towrite
;
781 sh
->dev
[i
].towrite
= NULL
;
783 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
784 wake_up(&conf
->wait_for_overlap
);
786 if (sh
->dev
[i
].written
) BUG();
787 sh
->dev
[i
].written
= chosen
;
794 xor_block(count
, STRIPE_SIZE
, ptr
);
798 for (i
= disks
; i
--;)
799 if (sh
->dev
[i
].written
) {
800 sector_t sector
= sh
->dev
[i
].sector
;
801 struct bio
*wbi
= sh
->dev
[i
].written
;
802 while (wbi
&& wbi
->bi_sector
< sector
+ STRIPE_SECTORS
) {
803 copy_data(1, wbi
, sh
->dev
[i
].page
, sector
);
804 wbi
= r5_next_bio(wbi
, sector
);
807 set_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
808 set_bit(R5_UPTODATE
, &sh
->dev
[i
].flags
);
812 case RECONSTRUCT_WRITE
:
816 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
820 case READ_MODIFY_WRITE
:
821 for (i
= disks
; i
--;)
822 if (sh
->dev
[i
].written
) {
823 ptr
[count
++] = page_address(sh
->dev
[i
].page
);
828 xor_block(count
, STRIPE_SIZE
, ptr
);
830 if (method
!= CHECK_PARITY
) {
831 set_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
832 set_bit(R5_LOCKED
, &sh
->dev
[pd_idx
].flags
);
834 clear_bit(R5_UPTODATE
, &sh
->dev
[pd_idx
].flags
);
838 * Each stripe/dev can have one or more bion attached.
839 * toread/towrite point to the first in a chain.
840 * The bi_next chain must be in order.
842 static int add_stripe_bio(struct stripe_head
*sh
, struct bio
*bi
, int dd_idx
, int forwrite
)
845 raid5_conf_t
*conf
= sh
->raid_conf
;
848 PRINTK("adding bh b#%llu to stripe s#%llu\n",
849 (unsigned long long)bi
->bi_sector
,
850 (unsigned long long)sh
->sector
);
853 spin_lock(&sh
->lock
);
854 spin_lock_irq(&conf
->device_lock
);
856 bip
= &sh
->dev
[dd_idx
].towrite
;
857 if (*bip
== NULL
&& sh
->dev
[dd_idx
].written
== NULL
)
860 bip
= &sh
->dev
[dd_idx
].toread
;
861 while (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
) {
862 if ((*bip
)->bi_sector
+ ((*bip
)->bi_size
>> 9) > bi
->bi_sector
)
864 bip
= & (*bip
)->bi_next
;
866 if (*bip
&& (*bip
)->bi_sector
< bi
->bi_sector
+ ((bi
->bi_size
)>>9))
869 if (*bip
&& bi
->bi_next
&& (*bip
) != bi
->bi_next
)
874 bi
->bi_phys_segments
++;
875 spin_unlock_irq(&conf
->device_lock
);
876 spin_unlock(&sh
->lock
);
878 PRINTK("added bi b#%llu to stripe s#%llu, disk %d.\n",
879 (unsigned long long)bi
->bi_sector
,
880 (unsigned long long)sh
->sector
, dd_idx
);
882 if (conf
->mddev
->bitmap
&& firstwrite
) {
883 sh
->bm_seq
= conf
->seq_write
;
884 bitmap_startwrite(conf
->mddev
->bitmap
, sh
->sector
,
886 set_bit(STRIPE_BIT_DELAY
, &sh
->state
);
890 /* check if page is covered */
891 sector_t sector
= sh
->dev
[dd_idx
].sector
;
892 for (bi
=sh
->dev
[dd_idx
].towrite
;
893 sector
< sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
&&
894 bi
&& bi
->bi_sector
<= sector
;
895 bi
= r5_next_bio(bi
, sh
->dev
[dd_idx
].sector
)) {
896 if (bi
->bi_sector
+ (bi
->bi_size
>>9) >= sector
)
897 sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
899 if (sector
>= sh
->dev
[dd_idx
].sector
+ STRIPE_SECTORS
)
900 set_bit(R5_OVERWRITE
, &sh
->dev
[dd_idx
].flags
);
905 set_bit(R5_Overlap
, &sh
->dev
[dd_idx
].flags
);
906 spin_unlock_irq(&conf
->device_lock
);
907 spin_unlock(&sh
->lock
);
913 * handle_stripe - do things to a stripe.
915 * We lock the stripe and then examine the state of various bits
916 * to see what needs to be done.
918 * return some read request which now have data
919 * return some write requests which are safely on disc
920 * schedule a read on some buffers
921 * schedule a write of some buffers
922 * return confirmation of parity correctness
924 * Parity calculations are done inside the stripe lock
925 * buffers are taken off read_list or write_list, and bh_cache buffers
926 * get BH_Lock set before the stripe lock is released.
930 static void handle_stripe(struct stripe_head
*sh
)
932 raid5_conf_t
*conf
= sh
->raid_conf
;
933 int disks
= conf
->raid_disks
;
934 struct bio
*return_bi
= NULL
;
938 int locked
=0, uptodate
=0, to_read
=0, to_write
=0, failed
=0, written
=0;
939 int non_overwrite
= 0;
943 PRINTK("handling stripe %llu, cnt=%d, pd_idx=%d\n",
944 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
),
947 spin_lock(&sh
->lock
);
948 clear_bit(STRIPE_HANDLE
, &sh
->state
);
949 clear_bit(STRIPE_DELAYED
, &sh
->state
);
951 syncing
= test_bit(STRIPE_SYNCING
, &sh
->state
);
952 /* Now to look around and see what can be done */
954 for (i
=disks
; i
--; ) {
957 clear_bit(R5_Insync
, &dev
->flags
);
958 clear_bit(R5_Syncio
, &dev
->flags
);
960 PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
961 i
, dev
->flags
, dev
->toread
, dev
->towrite
, dev
->written
);
962 /* maybe we can reply to a read */
963 if (test_bit(R5_UPTODATE
, &dev
->flags
) && dev
->toread
) {
964 struct bio
*rbi
, *rbi2
;
965 PRINTK("Return read for disc %d\n", i
);
966 spin_lock_irq(&conf
->device_lock
);
969 if (test_and_clear_bit(R5_Overlap
, &dev
->flags
))
970 wake_up(&conf
->wait_for_overlap
);
971 spin_unlock_irq(&conf
->device_lock
);
972 while (rbi
&& rbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
973 copy_data(0, rbi
, dev
->page
, dev
->sector
);
974 rbi2
= r5_next_bio(rbi
, dev
->sector
);
975 spin_lock_irq(&conf
->device_lock
);
976 if (--rbi
->bi_phys_segments
== 0) {
977 rbi
->bi_next
= return_bi
;
980 spin_unlock_irq(&conf
->device_lock
);
985 /* now count some things */
986 if (test_bit(R5_LOCKED
, &dev
->flags
)) locked
++;
987 if (test_bit(R5_UPTODATE
, &dev
->flags
)) uptodate
++;
990 if (dev
->toread
) to_read
++;
993 if (!test_bit(R5_OVERWRITE
, &dev
->flags
))
996 if (dev
->written
) written
++;
997 rdev
= conf
->disks
[i
].rdev
; /* FIXME, should I be looking rdev */
998 if (!rdev
|| !rdev
->in_sync
) {
999 /* The ReadError flag wil just be confusing now */
1000 clear_bit(R5_ReadError
, &dev
->flags
);
1001 clear_bit(R5_ReWrite
, &dev
->flags
);
1003 if (!rdev
|| !rdev
->in_sync
1004 || test_bit(R5_ReadError
, &dev
->flags
)) {
1008 set_bit(R5_Insync
, &dev
->flags
);
1010 PRINTK("locked=%d uptodate=%d to_read=%d"
1011 " to_write=%d failed=%d failed_num=%d\n",
1012 locked
, uptodate
, to_read
, to_write
, failed
, failed_num
);
1013 /* check if the array has lost two devices and, if so, some requests might
1016 if (failed
> 1 && to_read
+to_write
+written
) {
1017 for (i
=disks
; i
--; ) {
1020 if (test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1021 mdk_rdev_t
*rdev
= conf
->disks
[i
].rdev
;
1022 if (rdev
&& rdev
->in_sync
)
1023 /* multiple read failures in one stripe */
1024 md_error(conf
->mddev
, rdev
);
1027 spin_lock_irq(&conf
->device_lock
);
1028 /* fail all writes first */
1029 bi
= sh
->dev
[i
].towrite
;
1030 sh
->dev
[i
].towrite
= NULL
;
1031 if (bi
) { to_write
--; bitmap_end
= 1; }
1033 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1034 wake_up(&conf
->wait_for_overlap
);
1036 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
){
1037 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1038 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1039 if (--bi
->bi_phys_segments
== 0) {
1040 md_write_end(conf
->mddev
);
1041 bi
->bi_next
= return_bi
;
1046 /* and fail all 'written' */
1047 bi
= sh
->dev
[i
].written
;
1048 sh
->dev
[i
].written
= NULL
;
1049 if (bi
) bitmap_end
= 1;
1050 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
) {
1051 struct bio
*bi2
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1052 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1053 if (--bi
->bi_phys_segments
== 0) {
1054 md_write_end(conf
->mddev
);
1055 bi
->bi_next
= return_bi
;
1061 /* fail any reads if this device is non-operational */
1062 if (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
) ||
1063 test_bit(R5_ReadError
, &sh
->dev
[i
].flags
)) {
1064 bi
= sh
->dev
[i
].toread
;
1065 sh
->dev
[i
].toread
= NULL
;
1066 if (test_and_clear_bit(R5_Overlap
, &sh
->dev
[i
].flags
))
1067 wake_up(&conf
->wait_for_overlap
);
1069 while (bi
&& bi
->bi_sector
< sh
->dev
[i
].sector
+ STRIPE_SECTORS
){
1070 struct bio
*nextbi
= r5_next_bio(bi
, sh
->dev
[i
].sector
);
1071 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1072 if (--bi
->bi_phys_segments
== 0) {
1073 bi
->bi_next
= return_bi
;
1079 spin_unlock_irq(&conf
->device_lock
);
1081 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
1082 STRIPE_SECTORS
, 0, 0);
1085 if (failed
> 1 && syncing
) {
1086 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,0);
1087 clear_bit(STRIPE_SYNCING
, &sh
->state
);
1091 /* might be able to return some write requests if the parity block
1092 * is safe, or on a failed drive
1094 dev
= &sh
->dev
[sh
->pd_idx
];
1096 ( (test_bit(R5_Insync
, &dev
->flags
) && !test_bit(R5_LOCKED
, &dev
->flags
) &&
1097 test_bit(R5_UPTODATE
, &dev
->flags
))
1098 || (failed
== 1 && failed_num
== sh
->pd_idx
))
1100 /* any written block on an uptodate or failed drive can be returned.
1101 * Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
1102 * never LOCKED, so we don't need to test 'failed' directly.
1104 for (i
=disks
; i
--; )
1105 if (sh
->dev
[i
].written
) {
1107 if (!test_bit(R5_LOCKED
, &dev
->flags
) &&
1108 test_bit(R5_UPTODATE
, &dev
->flags
) ) {
1109 /* We can return any write requests */
1110 struct bio
*wbi
, *wbi2
;
1112 PRINTK("Return write for disc %d\n", i
);
1113 spin_lock_irq(&conf
->device_lock
);
1115 dev
->written
= NULL
;
1116 while (wbi
&& wbi
->bi_sector
< dev
->sector
+ STRIPE_SECTORS
) {
1117 wbi2
= r5_next_bio(wbi
, dev
->sector
);
1118 if (--wbi
->bi_phys_segments
== 0) {
1119 md_write_end(conf
->mddev
);
1120 wbi
->bi_next
= return_bi
;
1125 if (dev
->towrite
== NULL
)
1127 spin_unlock_irq(&conf
->device_lock
);
1129 bitmap_endwrite(conf
->mddev
->bitmap
, sh
->sector
,
1131 !test_bit(STRIPE_DEGRADED
, &sh
->state
), 0);
1136 /* Now we might consider reading some blocks, either to check/generate
1137 * parity, or to satisfy requests
1138 * or to load a block that is being partially written.
1140 if (to_read
|| non_overwrite
|| (syncing
&& (uptodate
< disks
))) {
1141 for (i
=disks
; i
--;) {
1143 if (!test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1145 (dev
->towrite
&& !test_bit(R5_OVERWRITE
, &dev
->flags
)) ||
1147 (failed
&& (sh
->dev
[failed_num
].toread
||
1148 (sh
->dev
[failed_num
].towrite
&& !test_bit(R5_OVERWRITE
, &sh
->dev
[failed_num
].flags
))))
1151 /* we would like to get this block, possibly
1152 * by computing it, but we might not be able to
1154 if (uptodate
== disks
-1) {
1155 PRINTK("Computing block %d\n", i
);
1156 compute_block(sh
, i
);
1158 } else if (test_bit(R5_Insync
, &dev
->flags
)) {
1159 set_bit(R5_LOCKED
, &dev
->flags
);
1160 set_bit(R5_Wantread
, &dev
->flags
);
1162 /* if I am just reading this block and we don't have
1163 a failed drive, or any pending writes then sidestep the cache */
1164 if (sh
->bh_read
[i
] && !sh
->bh_read
[i
]->b_reqnext
&&
1165 ! syncing
&& !failed
&& !to_write
) {
1166 sh
->bh_cache
[i
]->b_page
= sh
->bh_read
[i
]->b_page
;
1167 sh
->bh_cache
[i
]->b_data
= sh
->bh_read
[i
]->b_data
;
1171 PRINTK("Reading block %d (sync=%d)\n",
1174 md_sync_acct(conf
->disks
[i
].rdev
->bdev
,
1179 set_bit(STRIPE_HANDLE
, &sh
->state
);
1182 /* now to consider writing and what else, if anything should be read */
1185 for (i
=disks
; i
--;) {
1186 /* would I have to read this buffer for read_modify_write */
1188 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
1189 (!test_bit(R5_LOCKED
, &dev
->flags
)
1191 || sh
->bh_page
[i
]!=bh
->b_page
1194 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
1195 if (test_bit(R5_Insync
, &dev
->flags
)
1196 /* && !(!mddev->insync && i == sh->pd_idx) */
1199 else rmw
+= 2*disks
; /* cannot read it */
1201 /* Would I have to read this buffer for reconstruct_write */
1202 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
1203 (!test_bit(R5_LOCKED
, &dev
->flags
)
1205 || sh
->bh_page
[i
] != bh
->b_page
1208 !test_bit(R5_UPTODATE
, &dev
->flags
)) {
1209 if (test_bit(R5_Insync
, &dev
->flags
)) rcw
++;
1210 else rcw
+= 2*disks
;
1213 PRINTK("for sector %llu, rmw=%d rcw=%d\n",
1214 (unsigned long long)sh
->sector
, rmw
, rcw
);
1215 set_bit(STRIPE_HANDLE
, &sh
->state
);
1216 if (rmw
< rcw
&& rmw
> 0)
1217 /* prefer read-modify-write, but need to get some data */
1218 for (i
=disks
; i
--;) {
1220 if ((dev
->towrite
|| i
== sh
->pd_idx
) &&
1221 !test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1222 test_bit(R5_Insync
, &dev
->flags
)) {
1223 if (test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
1225 PRINTK("Read_old block %d for r-m-w\n", i
);
1226 set_bit(R5_LOCKED
, &dev
->flags
);
1227 set_bit(R5_Wantread
, &dev
->flags
);
1230 set_bit(STRIPE_DELAYED
, &sh
->state
);
1231 set_bit(STRIPE_HANDLE
, &sh
->state
);
1235 if (rcw
<= rmw
&& rcw
> 0)
1236 /* want reconstruct write, but need to get some data */
1237 for (i
=disks
; i
--;) {
1239 if (!test_bit(R5_OVERWRITE
, &dev
->flags
) && i
!= sh
->pd_idx
&&
1240 !test_bit(R5_LOCKED
, &dev
->flags
) && !test_bit(R5_UPTODATE
, &dev
->flags
) &&
1241 test_bit(R5_Insync
, &dev
->flags
)) {
1242 if (test_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
1244 PRINTK("Read_old block %d for Reconstruct\n", i
);
1245 set_bit(R5_LOCKED
, &dev
->flags
);
1246 set_bit(R5_Wantread
, &dev
->flags
);
1249 set_bit(STRIPE_DELAYED
, &sh
->state
);
1250 set_bit(STRIPE_HANDLE
, &sh
->state
);
1254 /* now if nothing is locked, and if we have enough data, we can start a write request */
1255 if (locked
== 0 && (rcw
== 0 ||rmw
== 0) &&
1256 !test_bit(STRIPE_BIT_DELAY
, &sh
->state
)) {
1257 PRINTK("Computing parity...\n");
1258 compute_parity(sh
, rcw
==0 ? RECONSTRUCT_WRITE
: READ_MODIFY_WRITE
);
1259 /* now every locked buffer is ready to be written */
1261 if (test_bit(R5_LOCKED
, &sh
->dev
[i
].flags
)) {
1262 PRINTK("Writing block %d\n", i
);
1264 set_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
);
1265 if (!test_bit(R5_Insync
, &sh
->dev
[i
].flags
)
1266 || (i
==sh
->pd_idx
&& failed
== 0))
1267 set_bit(STRIPE_INSYNC
, &sh
->state
);
1269 if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
)) {
1270 atomic_dec(&conf
->preread_active_stripes
);
1271 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
)
1272 md_wakeup_thread(conf
->mddev
->thread
);
1277 /* maybe we need to check and possibly fix the parity for this stripe
1278 * Any reads will already have been scheduled, so we just see if enough data
1281 if (syncing
&& locked
== 0 &&
1282 !test_bit(STRIPE_INSYNC
, &sh
->state
) && failed
<= 1) {
1283 set_bit(STRIPE_HANDLE
, &sh
->state
);
1286 if (uptodate
!= disks
)
1288 compute_parity(sh
, CHECK_PARITY
);
1290 pagea
= page_address(sh
->dev
[sh
->pd_idx
].page
);
1291 if ((*(u32
*)pagea
) == 0 &&
1292 !memcmp(pagea
, pagea
+4, STRIPE_SIZE
-4)) {
1293 /* parity is correct (on disc, not in buffer any more) */
1294 set_bit(STRIPE_INSYNC
, &sh
->state
);
1296 conf
->mddev
->resync_mismatches
+= STRIPE_SECTORS
;
1297 if (test_bit(MD_RECOVERY_CHECK
, &conf
->mddev
->recovery
))
1298 /* don't try to repair!! */
1299 set_bit(STRIPE_INSYNC
, &sh
->state
);
1302 if (!test_bit(STRIPE_INSYNC
, &sh
->state
)) {
1304 failed_num
= sh
->pd_idx
;
1305 /* should be able to compute the missing block and write it to spare */
1306 if (!test_bit(R5_UPTODATE
, &sh
->dev
[failed_num
].flags
)) {
1307 if (uptodate
+1 != disks
)
1309 compute_block(sh
, failed_num
);
1312 if (uptodate
!= disks
)
1314 dev
= &sh
->dev
[failed_num
];
1315 set_bit(R5_LOCKED
, &dev
->flags
);
1316 set_bit(R5_Wantwrite
, &dev
->flags
);
1317 clear_bit(STRIPE_DEGRADED
, &sh
->state
);
1319 set_bit(STRIPE_INSYNC
, &sh
->state
);
1320 set_bit(R5_Syncio
, &dev
->flags
);
1323 if (syncing
&& locked
== 0 && test_bit(STRIPE_INSYNC
, &sh
->state
)) {
1324 md_done_sync(conf
->mddev
, STRIPE_SECTORS
,1);
1325 clear_bit(STRIPE_SYNCING
, &sh
->state
);
1328 /* If the failed drive is just a ReadError, then we might need to progress
1329 * the repair/check process
1331 if (failed
== 1 && test_bit(R5_ReadError
, &sh
->dev
[failed_num
].flags
)
1332 && !test_bit(R5_LOCKED
, &sh
->dev
[failed_num
].flags
)
1333 && test_bit(R5_UPTODATE
, &sh
->dev
[failed_num
].flags
)
1335 dev
= &sh
->dev
[failed_num
];
1336 if (!test_bit(R5_ReWrite
, &dev
->flags
)) {
1337 set_bit(R5_Wantwrite
, &dev
->flags
);
1338 set_bit(R5_ReWrite
, &dev
->flags
);
1339 set_bit(R5_LOCKED
, &dev
->flags
);
1341 /* let's read it back */
1342 set_bit(R5_Wantread
, &dev
->flags
);
1343 set_bit(R5_LOCKED
, &dev
->flags
);
1347 spin_unlock(&sh
->lock
);
1349 while ((bi
=return_bi
)) {
1350 int bytes
= bi
->bi_size
;
1352 return_bi
= bi
->bi_next
;
1355 bi
->bi_end_io(bi
, bytes
, 0);
1357 for (i
=disks
; i
-- ;) {
1361 if (test_and_clear_bit(R5_Wantwrite
, &sh
->dev
[i
].flags
))
1363 else if (test_and_clear_bit(R5_Wantread
, &sh
->dev
[i
].flags
))
1368 bi
= &sh
->dev
[i
].req
;
1372 bi
->bi_end_io
= raid5_end_write_request
;
1374 bi
->bi_end_io
= raid5_end_read_request
;
1377 rdev
= conf
->disks
[i
].rdev
;
1378 if (rdev
&& rdev
->faulty
)
1381 atomic_inc(&rdev
->nr_pending
);
1385 if (test_bit(R5_Syncio
, &sh
->dev
[i
].flags
))
1386 md_sync_acct(rdev
->bdev
, STRIPE_SECTORS
);
1388 bi
->bi_bdev
= rdev
->bdev
;
1389 PRINTK("for %llu schedule op %ld on disc %d\n",
1390 (unsigned long long)sh
->sector
, bi
->bi_rw
, i
);
1391 atomic_inc(&sh
->count
);
1392 bi
->bi_sector
= sh
->sector
+ rdev
->data_offset
;
1393 bi
->bi_flags
= 1 << BIO_UPTODATE
;
1395 bi
->bi_max_vecs
= 1;
1397 bi
->bi_io_vec
= &sh
->dev
[i
].vec
;
1398 bi
->bi_io_vec
[0].bv_len
= STRIPE_SIZE
;
1399 bi
->bi_io_vec
[0].bv_offset
= 0;
1400 bi
->bi_size
= STRIPE_SIZE
;
1402 generic_make_request(bi
);
1405 set_bit(STRIPE_DEGRADED
, &sh
->state
);
1406 PRINTK("skip op %ld on disc %d for sector %llu\n",
1407 bi
->bi_rw
, i
, (unsigned long long)sh
->sector
);
1408 clear_bit(R5_LOCKED
, &sh
->dev
[i
].flags
);
1409 set_bit(STRIPE_HANDLE
, &sh
->state
);
1414 static inline void raid5_activate_delayed(raid5_conf_t
*conf
)
1416 if (atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
) {
1417 while (!list_empty(&conf
->delayed_list
)) {
1418 struct list_head
*l
= conf
->delayed_list
.next
;
1419 struct stripe_head
*sh
;
1420 sh
= list_entry(l
, struct stripe_head
, lru
);
1422 clear_bit(STRIPE_DELAYED
, &sh
->state
);
1423 if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE
, &sh
->state
))
1424 atomic_inc(&conf
->preread_active_stripes
);
1425 list_add_tail(&sh
->lru
, &conf
->handle_list
);
1430 static inline void activate_bit_delay(raid5_conf_t
*conf
)
1432 /* device_lock is held */
1433 struct list_head head
;
1434 list_add(&head
, &conf
->bitmap_list
);
1435 list_del_init(&conf
->bitmap_list
);
1436 while (!list_empty(&head
)) {
1437 struct stripe_head
*sh
= list_entry(head
.next
, struct stripe_head
, lru
);
1438 list_del_init(&sh
->lru
);
1439 atomic_inc(&sh
->count
);
1440 __release_stripe(conf
, sh
);
1444 static void unplug_slaves(mddev_t
*mddev
)
1446 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
1450 for (i
=0; i
<mddev
->raid_disks
; i
++) {
1451 mdk_rdev_t
*rdev
= conf
->disks
[i
].rdev
;
1452 if (rdev
&& !rdev
->faulty
&& atomic_read(&rdev
->nr_pending
)) {
1453 request_queue_t
*r_queue
= bdev_get_queue(rdev
->bdev
);
1455 atomic_inc(&rdev
->nr_pending
);
1458 if (r_queue
->unplug_fn
)
1459 r_queue
->unplug_fn(r_queue
);
1461 rdev_dec_pending(rdev
, mddev
);
1468 static void raid5_unplug_device(request_queue_t
*q
)
1470 mddev_t
*mddev
= q
->queuedata
;
1471 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
1472 unsigned long flags
;
1474 spin_lock_irqsave(&conf
->device_lock
, flags
);
1476 if (blk_remove_plug(q
)) {
1478 raid5_activate_delayed(conf
);
1480 md_wakeup_thread(mddev
->thread
);
1482 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1484 unplug_slaves(mddev
);
1487 static int raid5_issue_flush(request_queue_t
*q
, struct gendisk
*disk
,
1488 sector_t
*error_sector
)
1490 mddev_t
*mddev
= q
->queuedata
;
1491 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
1495 for (i
=0; i
<mddev
->raid_disks
&& ret
== 0; i
++) {
1496 mdk_rdev_t
*rdev
= conf
->disks
[i
].rdev
;
1497 if (rdev
&& !rdev
->faulty
) {
1498 struct block_device
*bdev
= rdev
->bdev
;
1499 request_queue_t
*r_queue
= bdev_get_queue(bdev
);
1501 if (!r_queue
->issue_flush_fn
)
1504 atomic_inc(&rdev
->nr_pending
);
1506 ret
= r_queue
->issue_flush_fn(r_queue
, bdev
->bd_disk
,
1508 rdev_dec_pending(rdev
, mddev
);
1517 static inline void raid5_plug_device(raid5_conf_t
*conf
)
1519 spin_lock_irq(&conf
->device_lock
);
1520 blk_plug_device(conf
->mddev
->queue
);
1521 spin_unlock_irq(&conf
->device_lock
);
1524 static int make_request (request_queue_t
*q
, struct bio
* bi
)
1526 mddev_t
*mddev
= q
->queuedata
;
1527 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
1528 const unsigned int raid_disks
= conf
->raid_disks
;
1529 const unsigned int data_disks
= raid_disks
- 1;
1530 unsigned int dd_idx
, pd_idx
;
1531 sector_t new_sector
;
1532 sector_t logical_sector
, last_sector
;
1533 struct stripe_head
*sh
;
1534 const int rw
= bio_data_dir(bi
);
1536 if (unlikely(bio_barrier(bi
))) {
1537 bio_endio(bi
, bi
->bi_size
, -EOPNOTSUPP
);
1541 md_write_start(mddev
, bi
);
1543 disk_stat_inc(mddev
->gendisk
, ios
[rw
]);
1544 disk_stat_add(mddev
->gendisk
, sectors
[rw
], bio_sectors(bi
));
1546 logical_sector
= bi
->bi_sector
& ~((sector_t
)STRIPE_SECTORS
-1);
1547 last_sector
= bi
->bi_sector
+ (bi
->bi_size
>>9);
1549 bi
->bi_phys_segments
= 1; /* over-loaded to count active stripes */
1551 for (;logical_sector
< last_sector
; logical_sector
+= STRIPE_SECTORS
) {
1554 new_sector
= raid5_compute_sector(logical_sector
,
1555 raid_disks
, data_disks
, &dd_idx
, &pd_idx
, conf
);
1557 PRINTK("raid5: make_request, sector %llu logical %llu\n",
1558 (unsigned long long)new_sector
,
1559 (unsigned long long)logical_sector
);
1562 prepare_to_wait(&conf
->wait_for_overlap
, &w
, TASK_UNINTERRUPTIBLE
);
1563 sh
= get_active_stripe(conf
, new_sector
, pd_idx
, (bi
->bi_rw
&RWA_MASK
));
1565 if (!add_stripe_bio(sh
, bi
, dd_idx
, (bi
->bi_rw
&RW_MASK
))) {
1566 /* Add failed due to overlap. Flush everything
1569 raid5_unplug_device(mddev
->queue
);
1574 finish_wait(&conf
->wait_for_overlap
, &w
);
1575 raid5_plug_device(conf
);
1580 /* cannot get stripe for read-ahead, just give-up */
1581 clear_bit(BIO_UPTODATE
, &bi
->bi_flags
);
1582 finish_wait(&conf
->wait_for_overlap
, &w
);
1587 spin_lock_irq(&conf
->device_lock
);
1588 if (--bi
->bi_phys_segments
== 0) {
1589 int bytes
= bi
->bi_size
;
1591 if ( bio_data_dir(bi
) == WRITE
)
1592 md_write_end(mddev
);
1594 bi
->bi_end_io(bi
, bytes
, 0);
1596 spin_unlock_irq(&conf
->device_lock
);
1600 /* FIXME go_faster isn't used */
1601 static sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
1603 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
1604 struct stripe_head
*sh
;
1605 int sectors_per_chunk
= conf
->chunk_size
>> 9;
1607 unsigned long stripe
;
1610 sector_t first_sector
;
1611 int raid_disks
= conf
->raid_disks
;
1612 int data_disks
= raid_disks
-1;
1613 sector_t max_sector
= mddev
->size
<< 1;
1616 if (sector_nr
>= max_sector
) {
1617 /* just being told to finish up .. nothing much to do */
1618 unplug_slaves(mddev
);
1620 if (mddev
->curr_resync
< max_sector
) /* aborted */
1621 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
1623 else /* compelted sync */
1625 bitmap_close_sync(mddev
->bitmap
);
1629 /* if there is 1 or more failed drives and we are trying
1630 * to resync, then assert that we are finished, because there is
1631 * nothing we can do.
1633 if (mddev
->degraded
>= 1 && test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
1634 sector_t rv
= (mddev
->size
<< 1) - sector_nr
;
1638 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
1639 !conf
->fullsync
&& sync_blocks
>= STRIPE_SECTORS
) {
1640 /* we can skip this block, and probably more */
1641 sync_blocks
/= STRIPE_SECTORS
;
1643 return sync_blocks
* STRIPE_SECTORS
; /* keep things rounded to whole stripes */
1647 chunk_offset
= sector_div(x
, sectors_per_chunk
);
1649 BUG_ON(x
!= stripe
);
1651 first_sector
= raid5_compute_sector((sector_t
)stripe
*data_disks
*sectors_per_chunk
1652 + chunk_offset
, raid_disks
, data_disks
, &dd_idx
, &pd_idx
, conf
);
1653 sh
= get_active_stripe(conf
, sector_nr
, pd_idx
, 1);
1655 sh
= get_active_stripe(conf
, sector_nr
, pd_idx
, 0);
1656 /* make sure we don't swamp the stripe cache if someone else
1657 * is trying to get access
1659 schedule_timeout_uninterruptible(1);
1661 bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 0);
1662 spin_lock(&sh
->lock
);
1663 set_bit(STRIPE_SYNCING
, &sh
->state
);
1664 clear_bit(STRIPE_INSYNC
, &sh
->state
);
1665 spin_unlock(&sh
->lock
);
1670 return STRIPE_SECTORS
;
1674 * This is our raid5 kernel thread.
1676 * We scan the hash table for stripes which can be handled now.
1677 * During the scan, completed stripes are saved for us by the interrupt
1678 * handler, so that they will not have to wait for our next wakeup.
1680 static void raid5d (mddev_t
*mddev
)
1682 struct stripe_head
*sh
;
1683 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
1686 PRINTK("+++ raid5d active\n");
1688 md_check_recovery(mddev
);
1691 spin_lock_irq(&conf
->device_lock
);
1693 struct list_head
*first
;
1695 if (conf
->seq_flush
- conf
->seq_write
> 0) {
1696 int seq
= conf
->seq_flush
;
1697 bitmap_unplug(mddev
->bitmap
);
1698 conf
->seq_write
= seq
;
1699 activate_bit_delay(conf
);
1702 if (list_empty(&conf
->handle_list
) &&
1703 atomic_read(&conf
->preread_active_stripes
) < IO_THRESHOLD
&&
1704 !blk_queue_plugged(mddev
->queue
) &&
1705 !list_empty(&conf
->delayed_list
))
1706 raid5_activate_delayed(conf
);
1708 if (list_empty(&conf
->handle_list
))
1711 first
= conf
->handle_list
.next
;
1712 sh
= list_entry(first
, struct stripe_head
, lru
);
1714 list_del_init(first
);
1715 atomic_inc(&sh
->count
);
1716 if (atomic_read(&sh
->count
)!= 1)
1718 spin_unlock_irq(&conf
->device_lock
);
1724 spin_lock_irq(&conf
->device_lock
);
1726 PRINTK("%d stripes handled\n", handled
);
1728 spin_unlock_irq(&conf
->device_lock
);
1730 unplug_slaves(mddev
);
1732 PRINTK("--- raid5d inactive\n");
1735 struct raid5_sysfs_entry
{
1736 struct attribute attr
;
1737 ssize_t (*show
)(raid5_conf_t
*, char *);
1738 ssize_t (*store
)(raid5_conf_t
*, const char *, ssize_t
);
1742 raid5_show_stripe_cache_size(raid5_conf_t
*conf
, char *page
)
1744 return sprintf(page
, "%d\n", conf
->max_nr_stripes
);
1748 raid5_store_stripe_cache_size(raid5_conf_t
*conf
, const char *page
, ssize_t len
)
1752 if (len
>= PAGE_SIZE
)
1755 new = simple_strtoul(page
, &end
, 10);
1756 if (!*page
|| (*end
&& *end
!= '\n') )
1758 if (new <= 16 || new > 32768)
1760 while (new < conf
->max_nr_stripes
) {
1761 if (drop_one_stripe(conf
))
1762 conf
->max_nr_stripes
--;
1766 while (new > conf
->max_nr_stripes
) {
1767 if (grow_one_stripe(conf
))
1768 conf
->max_nr_stripes
++;
1773 static struct raid5_sysfs_entry raid5_stripecache_size
= {
1774 .attr
= {.name
= "stripe_cache_size", .mode
= S_IRUGO
| S_IWUSR
},
1775 .show
= raid5_show_stripe_cache_size
,
1776 .store
= raid5_store_stripe_cache_size
,
1780 raid5_show_stripe_cache_active(raid5_conf_t
*conf
, char *page
)
1782 return sprintf(page
, "%d\n", atomic_read(&conf
->active_stripes
));
1785 static struct raid5_sysfs_entry raid5_stripecache_active
= {
1786 .attr
= {.name
= "stripe_cache_active", .mode
= S_IRUGO
},
1787 .show
= raid5_show_stripe_cache_active
,
1790 static struct attribute
*raid5_default_attrs
[] = {
1791 &raid5_stripecache_size
.attr
,
1792 &raid5_stripecache_active
.attr
,
1797 raid5_attr_show(struct kobject
*kobj
, struct attribute
*attr
, char *page
)
1799 struct raid5_sysfs_entry
*entry
= container_of(attr
, struct raid5_sysfs_entry
, attr
);
1800 raid5_conf_t
*conf
= container_of(kobj
, raid5_conf_t
, kobj
);
1804 return entry
->show(conf
, page
);
1808 raid5_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
1809 const char *page
, size_t length
)
1811 struct raid5_sysfs_entry
*entry
= container_of(attr
, struct raid5_sysfs_entry
, attr
);
1812 raid5_conf_t
*conf
= container_of(kobj
, raid5_conf_t
, kobj
);
1816 return entry
->store(conf
, page
, length
);
1819 static void raid5_free(struct kobject
*ko
)
1821 raid5_conf_t
*conf
= container_of(ko
, raid5_conf_t
, kobj
);
1826 static struct sysfs_ops raid5_sysfs_ops
= {
1827 .show
= raid5_attr_show
,
1828 .store
= raid5_attr_store
,
1831 static struct kobj_type raid5_ktype
= {
1832 .release
= raid5_free
,
1833 .sysfs_ops
= &raid5_sysfs_ops
,
1834 .default_attrs
= raid5_default_attrs
,
1837 static int run(mddev_t
*mddev
)
1840 int raid_disk
, memory
;
1842 struct disk_info
*disk
;
1843 struct list_head
*tmp
;
1845 if (mddev
->level
!= 5 && mddev
->level
!= 4) {
1846 printk("raid5: %s: raid level not set to 4/5 (%d)\n", mdname(mddev
), mddev
->level
);
1850 mddev
->private = kmalloc (sizeof (raid5_conf_t
)
1851 + mddev
->raid_disks
* sizeof(struct disk_info
),
1853 if ((conf
= mddev
->private) == NULL
)
1855 memset (conf
, 0, sizeof (*conf
) + mddev
->raid_disks
* sizeof(struct disk_info
) );
1856 conf
->mddev
= mddev
;
1858 if ((conf
->stripe_hashtbl
= (struct stripe_head
**) __get_free_pages(GFP_ATOMIC
, HASH_PAGES_ORDER
)) == NULL
)
1860 memset(conf
->stripe_hashtbl
, 0, HASH_PAGES
* PAGE_SIZE
);
1862 spin_lock_init(&conf
->device_lock
);
1863 init_waitqueue_head(&conf
->wait_for_stripe
);
1864 init_waitqueue_head(&conf
->wait_for_overlap
);
1865 INIT_LIST_HEAD(&conf
->handle_list
);
1866 INIT_LIST_HEAD(&conf
->delayed_list
);
1867 INIT_LIST_HEAD(&conf
->bitmap_list
);
1868 INIT_LIST_HEAD(&conf
->inactive_list
);
1869 atomic_set(&conf
->active_stripes
, 0);
1870 atomic_set(&conf
->preread_active_stripes
, 0);
1872 PRINTK("raid5: run(%s) called.\n", mdname(mddev
));
1874 ITERATE_RDEV(mddev
,rdev
,tmp
) {
1875 raid_disk
= rdev
->raid_disk
;
1876 if (raid_disk
>= mddev
->raid_disks
1879 disk
= conf
->disks
+ raid_disk
;
1883 if (rdev
->in_sync
) {
1884 char b
[BDEVNAME_SIZE
];
1885 printk(KERN_INFO
"raid5: device %s operational as raid"
1886 " disk %d\n", bdevname(rdev
->bdev
,b
),
1888 conf
->working_disks
++;
1892 conf
->raid_disks
= mddev
->raid_disks
;
1894 * 0 for a fully functional array, 1 for a degraded array.
1896 mddev
->degraded
= conf
->failed_disks
= conf
->raid_disks
- conf
->working_disks
;
1897 conf
->mddev
= mddev
;
1898 conf
->chunk_size
= mddev
->chunk_size
;
1899 conf
->level
= mddev
->level
;
1900 conf
->algorithm
= mddev
->layout
;
1901 conf
->max_nr_stripes
= NR_STRIPES
;
1903 /* device size must be a multiple of chunk size */
1904 mddev
->size
&= ~(mddev
->chunk_size
/1024 -1);
1905 mddev
->resync_max_sectors
= mddev
->size
<< 1;
1907 if (!conf
->chunk_size
|| conf
->chunk_size
% 4) {
1908 printk(KERN_ERR
"raid5: invalid chunk size %d for %s\n",
1909 conf
->chunk_size
, mdname(mddev
));
1912 if (conf
->algorithm
> ALGORITHM_RIGHT_SYMMETRIC
) {
1914 "raid5: unsupported parity algorithm %d for %s\n",
1915 conf
->algorithm
, mdname(mddev
));
1918 if (mddev
->degraded
> 1) {
1919 printk(KERN_ERR
"raid5: not enough operational devices for %s"
1920 " (%d/%d failed)\n",
1921 mdname(mddev
), conf
->failed_disks
, conf
->raid_disks
);
1925 if (mddev
->degraded
== 1 &&
1926 mddev
->recovery_cp
!= MaxSector
) {
1928 "raid5: cannot start dirty degraded array for %s\n",
1934 mddev
->thread
= md_register_thread(raid5d
, mddev
, "%s_raid5");
1935 if (!mddev
->thread
) {
1937 "raid5: couldn't allocate thread for %s\n",
1942 memory
= conf
->max_nr_stripes
* (sizeof(struct stripe_head
) +
1943 conf
->raid_disks
* ((sizeof(struct bio
) + PAGE_SIZE
))) / 1024;
1944 if (grow_stripes(conf
, conf
->max_nr_stripes
)) {
1946 "raid5: couldn't allocate %dkB for buffers\n", memory
);
1947 shrink_stripes(conf
);
1948 md_unregister_thread(mddev
->thread
);
1951 printk(KERN_INFO
"raid5: allocated %dkB for %s\n",
1952 memory
, mdname(mddev
));
1954 if (mddev
->degraded
== 0)
1955 printk("raid5: raid level %d set %s active with %d out of %d"
1956 " devices, algorithm %d\n", conf
->level
, mdname(mddev
),
1957 mddev
->raid_disks
-mddev
->degraded
, mddev
->raid_disks
,
1960 printk(KERN_ALERT
"raid5: raid level %d set %s active with %d"
1961 " out of %d devices, algorithm %d\n", conf
->level
,
1962 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
1963 mddev
->raid_disks
, conf
->algorithm
);
1965 print_raid5_conf(conf
);
1967 /* read-ahead size must cover two whole stripes, which is
1968 * 2 * (n-1) * chunksize where 'n' is the number of raid devices
1971 int stripe
= (mddev
->raid_disks
-1) * mddev
->chunk_size
1973 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2 * stripe
)
1974 mddev
->queue
->backing_dev_info
.ra_pages
= 2 * stripe
;
1977 /* Ok, everything is just fine now */
1978 conf
->kobj
.parent
= kobject_get(&mddev
->kobj
);
1979 strcpy(conf
->kobj
.name
, "raid5");
1980 conf
->kobj
.ktype
= &raid5_ktype
;
1981 kobject_register(&conf
->kobj
);
1984 mddev
->thread
->timeout
= mddev
->bitmap
->daemon_sleep
* HZ
;
1986 mddev
->queue
->unplug_fn
= raid5_unplug_device
;
1987 mddev
->queue
->issue_flush_fn
= raid5_issue_flush
;
1989 mddev
->array_size
= mddev
->size
* (mddev
->raid_disks
- 1);
1993 print_raid5_conf(conf
);
1994 if (conf
->stripe_hashtbl
)
1995 free_pages((unsigned long) conf
->stripe_hashtbl
,
1999 mddev
->private = NULL
;
2000 printk(KERN_ALERT
"raid5: failed to run raid set %s\n", mdname(mddev
));
2006 static int stop(mddev_t
*mddev
)
2008 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
2010 md_unregister_thread(mddev
->thread
);
2011 mddev
->thread
= NULL
;
2012 shrink_stripes(conf
);
2013 free_pages((unsigned long) conf
->stripe_hashtbl
, HASH_PAGES_ORDER
);
2014 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
2015 kobject_unregister(&conf
->kobj
);
2016 mddev
->private = NULL
;
2021 static void print_sh (struct stripe_head
*sh
)
2025 printk("sh %llu, pd_idx %d, state %ld.\n",
2026 (unsigned long long)sh
->sector
, sh
->pd_idx
, sh
->state
);
2027 printk("sh %llu, count %d.\n",
2028 (unsigned long long)sh
->sector
, atomic_read(&sh
->count
));
2029 printk("sh %llu, ", (unsigned long long)sh
->sector
);
2030 for (i
= 0; i
< sh
->raid_conf
->raid_disks
; i
++) {
2031 printk("(cache%d: %p %ld) ",
2032 i
, sh
->dev
[i
].page
, sh
->dev
[i
].flags
);
2037 static void printall (raid5_conf_t
*conf
)
2039 struct stripe_head
*sh
;
2042 spin_lock_irq(&conf
->device_lock
);
2043 for (i
= 0; i
< NR_HASH
; i
++) {
2044 sh
= conf
->stripe_hashtbl
[i
];
2045 for (; sh
; sh
= sh
->hash_next
) {
2046 if (sh
->raid_conf
!= conf
)
2051 spin_unlock_irq(&conf
->device_lock
);
2055 static void status (struct seq_file
*seq
, mddev_t
*mddev
)
2057 raid5_conf_t
*conf
= (raid5_conf_t
*) mddev
->private;
2060 seq_printf (seq
, " level %d, %dk chunk, algorithm %d", mddev
->level
, mddev
->chunk_size
>> 10, mddev
->layout
);
2061 seq_printf (seq
, " [%d/%d] [", conf
->raid_disks
, conf
->working_disks
);
2062 for (i
= 0; i
< conf
->raid_disks
; i
++)
2063 seq_printf (seq
, "%s",
2064 conf
->disks
[i
].rdev
&&
2065 conf
->disks
[i
].rdev
->in_sync
? "U" : "_");
2066 seq_printf (seq
, "]");
2069 seq_printf (seq, "<"#x":%d>", atomic_read(&conf->x))
2074 static void print_raid5_conf (raid5_conf_t
*conf
)
2077 struct disk_info
*tmp
;
2079 printk("RAID5 conf printout:\n");
2081 printk("(conf==NULL)\n");
2084 printk(" --- rd:%d wd:%d fd:%d\n", conf
->raid_disks
,
2085 conf
->working_disks
, conf
->failed_disks
);
2087 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2088 char b
[BDEVNAME_SIZE
];
2089 tmp
= conf
->disks
+ i
;
2091 printk(" disk %d, o:%d, dev:%s\n",
2092 i
, !tmp
->rdev
->faulty
,
2093 bdevname(tmp
->rdev
->bdev
,b
));
2097 static int raid5_spare_active(mddev_t
*mddev
)
2100 raid5_conf_t
*conf
= mddev
->private;
2101 struct disk_info
*tmp
;
2103 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2104 tmp
= conf
->disks
+ i
;
2106 && !tmp
->rdev
->faulty
2107 && !tmp
->rdev
->in_sync
) {
2109 conf
->failed_disks
--;
2110 conf
->working_disks
++;
2111 tmp
->rdev
->in_sync
= 1;
2114 print_raid5_conf(conf
);
2118 static int raid5_remove_disk(mddev_t
*mddev
, int number
)
2120 raid5_conf_t
*conf
= mddev
->private;
2123 struct disk_info
*p
= conf
->disks
+ number
;
2125 print_raid5_conf(conf
);
2128 if (rdev
->in_sync
||
2129 atomic_read(&rdev
->nr_pending
)) {
2135 if (atomic_read(&rdev
->nr_pending
)) {
2136 /* lost the race, try later */
2143 print_raid5_conf(conf
);
2147 static int raid5_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
2149 raid5_conf_t
*conf
= mddev
->private;
2152 struct disk_info
*p
;
2154 if (mddev
->degraded
> 1)
2155 /* no point adding a device */
2161 for (disk
=0; disk
< mddev
->raid_disks
; disk
++)
2162 if ((p
=conf
->disks
+ disk
)->rdev
== NULL
) {
2164 rdev
->raid_disk
= disk
;
2166 if (rdev
->saved_raid_disk
!= disk
)
2171 print_raid5_conf(conf
);
2175 static int raid5_resize(mddev_t
*mddev
, sector_t sectors
)
2177 /* no resync is happening, and there is enough space
2178 * on all devices, so we can resize.
2179 * We need to make sure resync covers any new space.
2180 * If the array is shrinking we should possibly wait until
2181 * any io in the removed space completes, but it hardly seems
2184 sectors
&= ~((sector_t
)mddev
->chunk_size
/512 - 1);
2185 mddev
->array_size
= (sectors
* (mddev
->raid_disks
-1))>>1;
2186 set_capacity(mddev
->gendisk
, mddev
->array_size
<< 1);
2188 if (sectors
/2 > mddev
->size
&& mddev
->recovery_cp
== MaxSector
) {
2189 mddev
->recovery_cp
= mddev
->size
<< 1;
2190 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2192 mddev
->size
= sectors
/2;
2193 mddev
->resync_max_sectors
= sectors
;
2197 static void raid5_quiesce(mddev_t
*mddev
, int state
)
2199 raid5_conf_t
*conf
= mddev_to_conf(mddev
);
2202 case 1: /* stop all writes */
2203 spin_lock_irq(&conf
->device_lock
);
2205 wait_event_lock_irq(conf
->wait_for_stripe
,
2206 atomic_read(&conf
->active_stripes
) == 0,
2207 conf
->device_lock
, /* nothing */);
2208 spin_unlock_irq(&conf
->device_lock
);
2211 case 0: /* re-enable writes */
2212 spin_lock_irq(&conf
->device_lock
);
2214 wake_up(&conf
->wait_for_stripe
);
2215 spin_unlock_irq(&conf
->device_lock
);
2218 if (mddev
->thread
) {
2220 mddev
->thread
->timeout
= mddev
->bitmap
->daemon_sleep
* HZ
;
2222 mddev
->thread
->timeout
= MAX_SCHEDULE_TIMEOUT
;
2223 md_wakeup_thread(mddev
->thread
);
2226 static mdk_personality_t raid5_personality
=
2229 .owner
= THIS_MODULE
,
2230 .make_request
= make_request
,
2234 .error_handler
= error
,
2235 .hot_add_disk
= raid5_add_disk
,
2236 .hot_remove_disk
= raid5_remove_disk
,
2237 .spare_active
= raid5_spare_active
,
2238 .sync_request
= sync_request
,
2239 .resize
= raid5_resize
,
2240 .quiesce
= raid5_quiesce
,
2243 static int __init
raid5_init (void)
2245 return register_md_personality (RAID5
, &raid5_personality
);
2248 static void raid5_exit (void)
2250 unregister_md_personality (RAID5
);
2253 module_init(raid5_init
);
2254 module_exit(raid5_exit
);
2255 MODULE_LICENSE("GPL");
2256 MODULE_ALIAS("md-personality-4"); /* RAID5 */