2 * raid1.c : Multiple Devices driver for Linux
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 * RAID-1 management functions.
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
20 * You should have received a copy of the GNU General Public License
21 * (for example /usr/src/linux/COPYING); if not, write to the Free
22 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include <linux/raid/raid1.h>
28 * Number of guaranteed r1bios in case of extreme VM load:
30 #define NR_RAID1_BIOS 256
32 static mdk_personality_t raid1_personality
;
33 static spinlock_t retry_list_lock
= SPIN_LOCK_UNLOCKED
;
34 static LIST_HEAD(retry_list_head
);
36 static void unplug_slaves(mddev_t
*mddev
);
39 static void * r1bio_pool_alloc(int gfp_flags
, void *data
)
41 struct pool_info
*pi
= data
;
43 int size
= offsetof(r1bio_t
, bios
[pi
->raid_disks
]);
45 /* allocate a r1bio with room for raid_disks entries in the bios array */
46 r1_bio
= kmalloc(size
, gfp_flags
);
48 memset(r1_bio
, 0, size
);
50 unplug_slaves(pi
->mddev
);
55 static void r1bio_pool_free(void *r1_bio
, void *data
)
60 #define RESYNC_BLOCK_SIZE (64*1024)
61 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
62 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
63 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
64 #define RESYNC_WINDOW (2048*1024)
66 static void * r1buf_pool_alloc(int gfp_flags
, void *data
)
68 struct pool_info
*pi
= data
;
74 r1_bio
= r1bio_pool_alloc(gfp_flags
, pi
);
76 unplug_slaves(pi
->mddev
);
81 * Allocate bios : 1 for reading, n-1 for writing
83 for (j
= pi
->raid_disks
; j
-- ; ) {
84 bio
= bio_alloc(gfp_flags
, RESYNC_PAGES
);
87 r1_bio
->bios
[j
] = bio
;
90 * Allocate RESYNC_PAGES data pages and attach them to
93 bio
= r1_bio
->bios
[0];
94 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
95 page
= alloc_page(gfp_flags
);
99 bio
->bi_io_vec
[i
].bv_page
= page
;
102 r1_bio
->master_bio
= NULL
;
108 __free_page(bio
->bi_io_vec
[i
-1].bv_page
);
110 while ( ++j
< pi
->raid_disks
)
111 bio_put(r1_bio
->bios
[j
]);
112 r1bio_pool_free(r1_bio
, data
);
116 static void r1buf_pool_free(void *__r1_bio
, void *data
)
118 struct pool_info
*pi
= data
;
120 r1bio_t
*r1bio
= __r1_bio
;
121 struct bio
*bio
= r1bio
->bios
[0];
123 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
124 __free_page(bio
->bi_io_vec
[i
].bv_page
);
125 bio
->bi_io_vec
[i
].bv_page
= NULL
;
127 for (i
=0 ; i
< pi
->raid_disks
; i
++)
128 bio_put(r1bio
->bios
[i
]);
130 r1bio_pool_free(r1bio
, data
);
133 static void put_all_bios(conf_t
*conf
, r1bio_t
*r1_bio
)
137 for (i
= 0; i
< conf
->raid_disks
; i
++) {
138 struct bio
**bio
= r1_bio
->bios
+ i
;
145 static inline void free_r1bio(r1bio_t
*r1_bio
)
149 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
152 * Wake up any possible resync thread that waits for the device
155 spin_lock_irqsave(&conf
->resync_lock
, flags
);
156 if (!--conf
->nr_pending
) {
157 wake_up(&conf
->wait_idle
);
158 wake_up(&conf
->wait_resume
);
160 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
162 put_all_bios(conf
, r1_bio
);
163 mempool_free(r1_bio
, conf
->r1bio_pool
);
166 static inline void put_buf(r1bio_t
*r1_bio
)
168 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
171 mempool_free(r1_bio
, conf
->r1buf_pool
);
173 spin_lock_irqsave(&conf
->resync_lock
, flags
);
177 wake_up(&conf
->wait_resume
);
178 wake_up(&conf
->wait_idle
);
180 if (!--conf
->nr_pending
) {
181 wake_up(&conf
->wait_idle
);
182 wake_up(&conf
->wait_resume
);
184 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
187 static void reschedule_retry(r1bio_t
*r1_bio
)
190 mddev_t
*mddev
= r1_bio
->mddev
;
192 spin_lock_irqsave(&retry_list_lock
, flags
);
193 list_add(&r1_bio
->retry_list
, &retry_list_head
);
194 spin_unlock_irqrestore(&retry_list_lock
, flags
);
196 md_wakeup_thread(mddev
->thread
);
200 * raid_end_bio_io() is called when we have finished servicing a mirrored
201 * operation and are ready to return a success/failure code to the buffer
204 static void raid_end_bio_io(r1bio_t
*r1_bio
)
206 struct bio
*bio
= r1_bio
->master_bio
;
208 bio_endio(bio
, bio
->bi_size
,
209 test_bit(R1BIO_Uptodate
, &r1_bio
->state
) ? 0 : -EIO
);
214 * Update disk head position estimator based on IRQ completion info.
216 static inline void update_head_pos(int disk
, r1bio_t
*r1_bio
)
218 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
220 conf
->mirrors
[disk
].head_position
=
221 r1_bio
->sector
+ (r1_bio
->sectors
);
224 static int raid1_end_read_request(struct bio
*bio
, unsigned int bytes_done
, int error
)
226 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
227 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
229 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
234 mirror
= r1_bio
->read_disk
;
236 * this branch is our 'one mirror IO has finished' event handler:
239 md_error(r1_bio
->mddev
, conf
->mirrors
[mirror
].rdev
);
242 * Set R1BIO_Uptodate in our master bio, so that
243 * we will return a good error code for to the higher
244 * levels even if IO on some other mirrored buffer fails.
246 * The 'master' represents the composite IO operation to
247 * user-side. So if something waits for IO, then it will
248 * wait for the 'master' bio.
250 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
252 update_head_pos(mirror
, r1_bio
);
255 * we have only one bio on the read side
258 raid_end_bio_io(r1_bio
);
263 char b
[BDEVNAME_SIZE
];
264 if (printk_ratelimit())
265 printk(KERN_ERR
"raid1: %s: rescheduling sector %llu\n",
266 bdevname(conf
->mirrors
[mirror
].rdev
->bdev
,b
), (unsigned long long)r1_bio
->sector
);
267 reschedule_retry(r1_bio
);
270 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
274 static int raid1_end_write_request(struct bio
*bio
, unsigned int bytes_done
, int error
)
276 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
277 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
279 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
284 for (mirror
= 0; mirror
< conf
->raid_disks
; mirror
++)
285 if (r1_bio
->bios
[mirror
] == bio
)
289 * this branch is our 'one mirror IO has finished' event handler:
292 md_error(r1_bio
->mddev
, conf
->mirrors
[mirror
].rdev
);
295 * Set R1BIO_Uptodate in our master bio, so that
296 * we will return a good error code for to the higher
297 * levels even if IO on some other mirrored buffer fails.
299 * The 'master' represents the composite IO operation to
300 * user-side. So if something waits for IO, then it will
301 * wait for the 'master' bio.
303 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
305 update_head_pos(mirror
, r1_bio
);
309 * Let's see if all mirrored write operations have finished
312 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
313 md_write_end(r1_bio
->mddev
);
314 raid_end_bio_io(r1_bio
);
317 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
323 * This routine returns the disk from which the requested read should
324 * be done. There is a per-array 'next expected sequential IO' sector
325 * number - if this matches on the next IO then we use the last disk.
326 * There is also a per-disk 'last know head position' sector that is
327 * maintained from IRQ contexts, both the normal and the resync IO
328 * completion handlers update this position correctly. If there is no
329 * perfect sequential match then we pick the disk whose head is closest.
331 * If there are 2 mirrors in the same 2 devices, performance degrades
332 * because position is mirror, not device based.
334 * The rdev for the device selected will have nr_pending incremented.
336 static int read_balance(conf_t
*conf
, r1bio_t
*r1_bio
)
338 const unsigned long this_sector
= r1_bio
->sector
;
339 int new_disk
= conf
->last_used
, disk
= new_disk
;
340 const int sectors
= r1_bio
->sectors
;
341 sector_t new_distance
, current_distance
;
343 spin_lock_irq(&conf
->device_lock
);
345 * Check if it if we can balance. We can balance on the whole
346 * device if no resync is going on, or below the resync window.
347 * We take the first readable disk when above the resync window.
349 if (conf
->mddev
->recovery_cp
< MaxSector
&&
350 (this_sector
+ sectors
>= conf
->next_resync
)) {
351 /* Choose the first operation device, for consistancy */
354 while (!conf
->mirrors
[new_disk
].rdev
||
355 !conf
->mirrors
[new_disk
].rdev
->in_sync
) {
357 if (new_disk
== conf
->raid_disks
) {
366 /* make sure the disk is operational */
367 while (!conf
->mirrors
[new_disk
].rdev
||
368 !conf
->mirrors
[new_disk
].rdev
->in_sync
) {
370 new_disk
= conf
->raid_disks
;
372 if (new_disk
== disk
) {
378 /* now disk == new_disk == starting point for search */
381 * Don't change to another disk for sequential reads:
383 if (conf
->next_seq_sect
== this_sector
)
385 if (this_sector
== conf
->mirrors
[new_disk
].head_position
)
388 current_distance
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
390 /* Find the disk whose head is closest */
394 disk
= conf
->raid_disks
;
397 if (!conf
->mirrors
[disk
].rdev
||
398 !conf
->mirrors
[disk
].rdev
->in_sync
)
401 if (!atomic_read(&conf
->mirrors
[disk
].rdev
->nr_pending
)) {
405 new_distance
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
406 if (new_distance
< current_distance
) {
407 current_distance
= new_distance
;
410 } while (disk
!= conf
->last_used
);
416 conf
->next_seq_sect
= this_sector
+ sectors
;
417 conf
->last_used
= new_disk
;
418 atomic_inc(&conf
->mirrors
[new_disk
].rdev
->nr_pending
);
420 spin_unlock_irq(&conf
->device_lock
);
425 static void unplug_slaves(mddev_t
*mddev
)
427 conf_t
*conf
= mddev_to_conf(mddev
);
431 spin_lock_irqsave(&conf
->device_lock
, flags
);
432 for (i
=0; i
<mddev
->raid_disks
; i
++) {
433 mdk_rdev_t
*rdev
= conf
->mirrors
[i
].rdev
;
434 if (rdev
&& atomic_read(&rdev
->nr_pending
)) {
435 request_queue_t
*r_queue
= bdev_get_queue(rdev
->bdev
);
437 atomic_inc(&rdev
->nr_pending
);
438 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
440 if (r_queue
->unplug_fn
)
441 r_queue
->unplug_fn(r_queue
);
443 spin_lock_irqsave(&conf
->device_lock
, flags
);
444 atomic_dec(&rdev
->nr_pending
);
447 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
449 static void raid1_unplug(request_queue_t
*q
)
451 unplug_slaves(q
->queuedata
);
454 static int raid1_issue_flush(request_queue_t
*q
, struct gendisk
*disk
,
455 sector_t
*error_sector
)
457 mddev_t
*mddev
= q
->queuedata
;
458 conf_t
*conf
= mddev_to_conf(mddev
);
462 spin_lock_irqsave(&conf
->device_lock
, flags
);
463 for (i
=0; i
<mddev
->raid_disks
; i
++) {
464 mdk_rdev_t
*rdev
= conf
->mirrors
[i
].rdev
;
465 if (rdev
&& !rdev
->faulty
) {
466 struct block_device
*bdev
= rdev
->bdev
;
467 request_queue_t
*r_queue
= bdev_get_queue(bdev
);
469 if (r_queue
->issue_flush_fn
) {
470 ret
= r_queue
->issue_flush_fn(r_queue
, bdev
->bd_disk
, error_sector
);
476 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
481 * Throttle resync depth, so that we can both get proper overlapping of
482 * requests, but are still able to handle normal requests quickly.
484 #define RESYNC_DEPTH 32
486 static void device_barrier(conf_t
*conf
, sector_t sect
)
488 spin_lock_irq(&conf
->resync_lock
);
489 wait_event_lock_irq(conf
->wait_idle
, !waitqueue_active(&conf
->wait_resume
),
490 conf
->resync_lock
, unplug_slaves(conf
->mddev
));
492 if (!conf
->barrier
++) {
493 wait_event_lock_irq(conf
->wait_idle
, !conf
->nr_pending
,
494 conf
->resync_lock
, unplug_slaves(conf
->mddev
));
495 if (conf
->nr_pending
)
498 wait_event_lock_irq(conf
->wait_resume
, conf
->barrier
< RESYNC_DEPTH
,
499 conf
->resync_lock
, unplug_slaves(conf
->mddev
));
500 conf
->next_resync
= sect
;
501 spin_unlock_irq(&conf
->resync_lock
);
504 static int make_request(request_queue_t
*q
, struct bio
* bio
)
506 mddev_t
*mddev
= q
->queuedata
;
507 conf_t
*conf
= mddev_to_conf(mddev
);
508 mirror_info_t
*mirror
;
510 struct bio
*read_bio
;
514 * Register the new request and wait if the reconstruction
515 * thread has put up a bar for new requests.
516 * Continue immediately if no resync is active currently.
518 spin_lock_irq(&conf
->resync_lock
);
519 wait_event_lock_irq(conf
->wait_resume
, !conf
->barrier
, conf
->resync_lock
, );
521 spin_unlock_irq(&conf
->resync_lock
);
523 if (bio_data_dir(bio
)==WRITE
) {
524 disk_stat_inc(mddev
->gendisk
, writes
);
525 disk_stat_add(mddev
->gendisk
, write_sectors
, bio_sectors(bio
));
527 disk_stat_inc(mddev
->gendisk
, reads
);
528 disk_stat_add(mddev
->gendisk
, read_sectors
, bio_sectors(bio
));
532 * make_request() can abort the operation when READA is being
533 * used and no empty request is available.
536 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
538 r1_bio
->master_bio
= bio
;
539 r1_bio
->sectors
= bio
->bi_size
>> 9;
541 r1_bio
->mddev
= mddev
;
542 r1_bio
->sector
= bio
->bi_sector
;
546 if (bio_data_dir(bio
) == READ
) {
548 * read balancing logic:
550 int rdisk
= read_balance(conf
, r1_bio
);
553 /* couldn't find anywhere to read from */
554 raid_end_bio_io(r1_bio
);
557 mirror
= conf
->mirrors
+ rdisk
;
559 r1_bio
->read_disk
= rdisk
;
561 read_bio
= bio_clone(bio
, GFP_NOIO
);
563 r1_bio
->bios
[rdisk
] = read_bio
;
565 read_bio
->bi_sector
= r1_bio
->sector
+ mirror
->rdev
->data_offset
;
566 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
567 read_bio
->bi_end_io
= raid1_end_read_request
;
568 read_bio
->bi_rw
= READ
;
569 read_bio
->bi_private
= r1_bio
;
571 generic_make_request(read_bio
);
578 /* first select target devices under spinlock and
579 * inc refcount on their rdev. Record them by setting
582 disks
= conf
->raid_disks
;
583 spin_lock_irq(&conf
->device_lock
);
584 for (i
= 0; i
< disks
; i
++) {
585 if (conf
->mirrors
[i
].rdev
&&
586 !conf
->mirrors
[i
].rdev
->faulty
) {
587 atomic_inc(&conf
->mirrors
[i
].rdev
->nr_pending
);
588 r1_bio
->bios
[i
] = bio
;
590 r1_bio
->bios
[i
] = NULL
;
592 spin_unlock_irq(&conf
->device_lock
);
594 atomic_set(&r1_bio
->remaining
, 1);
595 md_write_start(mddev
);
596 for (i
= 0; i
< disks
; i
++) {
598 if (!r1_bio
->bios
[i
])
601 mbio
= bio_clone(bio
, GFP_NOIO
);
602 r1_bio
->bios
[i
] = mbio
;
604 mbio
->bi_sector
= r1_bio
->sector
+ conf
->mirrors
[i
].rdev
->data_offset
;
605 mbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
606 mbio
->bi_end_io
= raid1_end_write_request
;
608 mbio
->bi_private
= r1_bio
;
610 atomic_inc(&r1_bio
->remaining
);
611 generic_make_request(mbio
);
614 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
616 raid_end_bio_io(r1_bio
);
622 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
624 conf_t
*conf
= mddev_to_conf(mddev
);
627 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
628 conf
->working_disks
);
629 for (i
= 0; i
< conf
->raid_disks
; i
++)
630 seq_printf(seq
, "%s",
631 conf
->mirrors
[i
].rdev
&&
632 conf
->mirrors
[i
].rdev
->in_sync
? "U" : "_");
633 seq_printf(seq
, "]");
637 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
639 char b
[BDEVNAME_SIZE
];
640 conf_t
*conf
= mddev_to_conf(mddev
);
643 * If it is not operational, then we have already marked it as dead
644 * else if it is the last working disks, ignore the error, let the
645 * next level up know.
646 * else mark the drive as failed
649 && conf
->working_disks
== 1)
651 * Don't fail the drive, act as though we were just a
652 * normal single drive
657 conf
->working_disks
--;
659 * if recovery is running, make sure it aborts.
661 set_bit(MD_RECOVERY_ERR
, &mddev
->recovery
);
666 printk(KERN_ALERT
"raid1: Disk failure on %s, disabling device. \n"
667 " Operation continuing on %d devices\n",
668 bdevname(rdev
->bdev
,b
), conf
->working_disks
);
671 static void print_conf(conf_t
*conf
)
676 printk("RAID1 conf printout:\n");
681 printk(" --- wd:%d rd:%d\n", conf
->working_disks
,
684 for (i
= 0; i
< conf
->raid_disks
; i
++) {
685 char b
[BDEVNAME_SIZE
];
686 tmp
= conf
->mirrors
+ i
;
688 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
689 i
, !tmp
->rdev
->in_sync
, !tmp
->rdev
->faulty
,
690 bdevname(tmp
->rdev
->bdev
,b
));
694 static void close_sync(conf_t
*conf
)
696 spin_lock_irq(&conf
->resync_lock
);
697 wait_event_lock_irq(conf
->wait_resume
, !conf
->barrier
,
698 conf
->resync_lock
, unplug_slaves(conf
->mddev
));
699 spin_unlock_irq(&conf
->resync_lock
);
701 if (conf
->barrier
) BUG();
702 if (waitqueue_active(&conf
->wait_idle
)) BUG();
704 mempool_destroy(conf
->r1buf_pool
);
705 conf
->r1buf_pool
= NULL
;
708 static int raid1_spare_active(mddev_t
*mddev
)
711 conf_t
*conf
= mddev
->private;
714 spin_lock_irq(&conf
->device_lock
);
716 * Find all failed disks within the RAID1 configuration
717 * and mark them readable
719 for (i
= 0; i
< conf
->raid_disks
; i
++) {
720 tmp
= conf
->mirrors
+ i
;
722 && !tmp
->rdev
->faulty
723 && !tmp
->rdev
->in_sync
) {
724 conf
->working_disks
++;
726 tmp
->rdev
->in_sync
= 1;
729 spin_unlock_irq(&conf
->device_lock
);
736 static int raid1_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
738 conf_t
*conf
= mddev
->private;
743 spin_lock_irq(&conf
->device_lock
);
744 for (mirror
=0; mirror
< mddev
->raid_disks
; mirror
++)
745 if ( !(p
=conf
->mirrors
+mirror
)->rdev
) {
748 blk_queue_stack_limits(mddev
->queue
,
749 rdev
->bdev
->bd_disk
->queue
);
750 /* as we don't honour merge_bvec_fn, we must never risk
751 * violating it, so limit ->max_sector to one PAGE, as
752 * a one page request is never in violation.
754 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
&&
755 mddev
->queue
->max_sectors
> (PAGE_SIZE
>>9))
756 blk_queue_max_sectors(mddev
->queue
, PAGE_SIZE
>>9);
758 p
->head_position
= 0;
759 rdev
->raid_disk
= mirror
;
763 spin_unlock_irq(&conf
->device_lock
);
769 static int raid1_remove_disk(mddev_t
*mddev
, int number
)
771 conf_t
*conf
= mddev
->private;
773 mirror_info_t
*p
= conf
->mirrors
+ number
;
776 spin_lock_irq(&conf
->device_lock
);
778 if (p
->rdev
->in_sync
||
779 atomic_read(&p
->rdev
->nr_pending
)) {
789 spin_unlock_irq(&conf
->device_lock
);
796 static int end_sync_read(struct bio
*bio
, unsigned int bytes_done
, int error
)
798 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
799 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
800 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
805 if (r1_bio
->bios
[r1_bio
->read_disk
] != bio
)
807 update_head_pos(r1_bio
->read_disk
, r1_bio
);
809 * we have read a block, now it needs to be re-written,
810 * or re-read if the read failed.
811 * We don't do much here, just schedule handling by raid1d
814 md_error(r1_bio
->mddev
,
815 conf
->mirrors
[r1_bio
->read_disk
].rdev
);
817 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
818 rdev_dec_pending(conf
->mirrors
[r1_bio
->read_disk
].rdev
, conf
->mddev
);
819 reschedule_retry(r1_bio
);
823 static int end_sync_write(struct bio
*bio
, unsigned int bytes_done
, int error
)
825 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
826 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
827 mddev_t
*mddev
= r1_bio
->mddev
;
828 conf_t
*conf
= mddev_to_conf(mddev
);
835 for (i
= 0; i
< conf
->raid_disks
; i
++)
836 if (r1_bio
->bios
[i
] == bio
) {
841 md_error(mddev
, conf
->mirrors
[mirror
].rdev
);
842 update_head_pos(mirror
, r1_bio
);
844 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
845 md_done_sync(mddev
, r1_bio
->sectors
, uptodate
);
848 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, mddev
);
852 static void sync_request_write(mddev_t
*mddev
, r1bio_t
*r1_bio
)
854 conf_t
*conf
= mddev_to_conf(mddev
);
856 int disks
= conf
->raid_disks
;
857 struct bio
*bio
, *wbio
;
859 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
864 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
866 * There is no point trying a read-for-reconstruct as
867 * reconstruct is about to be aborted
869 char b
[BDEVNAME_SIZE
];
870 printk(KERN_ALERT
"raid1: %s: unrecoverable I/O read error"
872 bdevname(bio
->bi_bdev
,b
),
873 (unsigned long long)r1_bio
->sector
);
874 md_done_sync(mddev
, r1_bio
->sectors
, 0);
879 atomic_set(&r1_bio
->remaining
, 1);
880 for (i
= 0; i
< disks
; i
++) {
881 wbio
= r1_bio
->bios
[i
];
882 if (wbio
->bi_end_io
!= end_sync_write
)
885 atomic_inc(&conf
->mirrors
[i
].rdev
->nr_pending
);
886 atomic_inc(&r1_bio
->remaining
);
887 md_sync_acct(conf
->mirrors
[i
].rdev
->bdev
, wbio
->bi_size
>> 9);
888 generic_make_request(wbio
);
891 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
892 md_done_sync(mddev
, r1_bio
->sectors
, 1);
898 * This is a kernel thread which:
900 * 1. Retries failed read operations on working mirrors.
901 * 2. Updates the raid superblock when problems encounter.
902 * 3. Performs writes following reads for array syncronising.
905 static void raid1d(mddev_t
*mddev
)
907 struct list_head
*head
= &retry_list_head
;
911 conf_t
*conf
= mddev_to_conf(mddev
);
915 md_check_recovery(mddev
);
916 md_handle_safemode(mddev
);
919 char b
[BDEVNAME_SIZE
];
920 spin_lock_irqsave(&retry_list_lock
, flags
);
921 if (list_empty(head
))
923 r1_bio
= list_entry(head
->prev
, r1bio_t
, retry_list
);
924 list_del(head
->prev
);
925 spin_unlock_irqrestore(&retry_list_lock
, flags
);
927 mddev
= r1_bio
->mddev
;
928 conf
= mddev_to_conf(mddev
);
929 if (test_bit(R1BIO_IsSync
, &r1_bio
->state
)) {
930 sync_request_write(mddev
, r1_bio
);
934 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
935 if ((disk
=read_balance(conf
, r1_bio
)) == -1) {
936 printk(KERN_ALERT
"raid1: %s: unrecoverable I/O"
937 " read error for block %llu\n",
938 bdevname(bio
->bi_bdev
,b
),
939 (unsigned long long)r1_bio
->sector
);
940 raid_end_bio_io(r1_bio
);
942 r1_bio
->bios
[r1_bio
->read_disk
] = NULL
;
943 r1_bio
->read_disk
= disk
;
944 r1_bio
->bios
[r1_bio
->read_disk
] = bio
;
945 rdev
= conf
->mirrors
[disk
].rdev
;
946 if (printk_ratelimit())
947 printk(KERN_ERR
"raid1: %s: redirecting sector %llu to"
949 bdevname(rdev
->bdev
,b
),
950 (unsigned long long)r1_bio
->sector
);
951 bio
->bi_bdev
= rdev
->bdev
;
952 bio
->bi_sector
= r1_bio
->sector
+ rdev
->data_offset
;
955 generic_make_request(bio
);
959 spin_unlock_irqrestore(&retry_list_lock
, flags
);
961 unplug_slaves(mddev
);
965 static int init_resync(conf_t
*conf
)
969 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
970 if (conf
->r1buf_pool
)
972 conf
->r1buf_pool
= mempool_create(buffs
, r1buf_pool_alloc
, r1buf_pool_free
,
974 if (!conf
->r1buf_pool
)
976 conf
->next_resync
= 0;
981 * perform a "sync" on one "block"
983 * We need to make sure that no normal I/O request - particularly write
984 * requests - conflict with active sync requests.
986 * This is achieved by tracking pending requests and a 'barrier' concept
987 * that can be installed to exclude normal IO requests.
990 static int sync_request(mddev_t
*mddev
, sector_t sector_nr
, int go_faster
)
992 conf_t
*conf
= mddev_to_conf(mddev
);
993 mirror_info_t
*mirror
;
996 sector_t max_sector
, nr_sectors
;
999 int write_targets
= 0;
1001 if (!conf
->r1buf_pool
)
1002 if (init_resync(conf
))
1005 max_sector
= mddev
->size
<< 1;
1006 if (sector_nr
>= max_sector
) {
1012 * If there is non-resync activity waiting for us then
1013 * put in a delay to throttle resync.
1015 if (!go_faster
&& waitqueue_active(&conf
->wait_resume
))
1016 schedule_timeout(HZ
);
1017 device_barrier(conf
, sector_nr
+ RESYNC_SECTORS
);
1020 * If reconstructing, and >1 working disc,
1021 * could dedicate one to rebuild and others to
1022 * service read requests ..
1024 disk
= conf
->last_used
;
1025 /* make sure disk is operational */
1026 spin_lock_irq(&conf
->device_lock
);
1027 while (conf
->mirrors
[disk
].rdev
== NULL
||
1028 !conf
->mirrors
[disk
].rdev
->in_sync
) {
1030 disk
= conf
->raid_disks
;
1032 if (disk
== conf
->last_used
)
1035 conf
->last_used
= disk
;
1036 atomic_inc(&conf
->mirrors
[disk
].rdev
->nr_pending
);
1037 spin_unlock_irq(&conf
->device_lock
);
1039 mirror
= conf
->mirrors
+ disk
;
1041 r1_bio
= mempool_alloc(conf
->r1buf_pool
, GFP_NOIO
);
1043 spin_lock_irq(&conf
->resync_lock
);
1045 spin_unlock_irq(&conf
->resync_lock
);
1047 r1_bio
->mddev
= mddev
;
1048 r1_bio
->sector
= sector_nr
;
1049 set_bit(R1BIO_IsSync
, &r1_bio
->state
);
1050 r1_bio
->read_disk
= disk
;
1052 for (i
=0; i
< conf
->raid_disks
; i
++) {
1053 bio
= r1_bio
->bios
[i
];
1055 /* take from bio_init */
1056 bio
->bi_next
= NULL
;
1057 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
1061 bio
->bi_phys_segments
= 0;
1062 bio
->bi_hw_segments
= 0;
1064 bio
->bi_end_io
= NULL
;
1065 bio
->bi_private
= NULL
;
1069 bio
->bi_end_io
= end_sync_read
;
1070 } else if (conf
->mirrors
[i
].rdev
&&
1071 !conf
->mirrors
[i
].rdev
->faulty
&&
1072 (!conf
->mirrors
[i
].rdev
->in_sync
||
1073 sector_nr
+ RESYNC_SECTORS
> mddev
->recovery_cp
)) {
1075 bio
->bi_end_io
= end_sync_write
;
1079 bio
->bi_sector
= sector_nr
+ conf
->mirrors
[i
].rdev
->data_offset
;
1080 bio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1081 bio
->bi_private
= r1_bio
;
1083 if (write_targets
== 0) {
1084 /* There is nowhere to write, so all non-sync
1085 * drives must be failed - so we are finished
1087 int rv
= max_sector
- sector_nr
;
1088 md_done_sync(mddev
, rv
, 1);
1090 atomic_dec(&conf
->mirrors
[disk
].rdev
->nr_pending
);
1097 int len
= PAGE_SIZE
;
1098 if (sector_nr
+ (len
>>9) > max_sector
)
1099 len
= (max_sector
- sector_nr
) << 9;
1102 for (i
=0 ; i
< conf
->raid_disks
; i
++) {
1103 bio
= r1_bio
->bios
[i
];
1104 if (bio
->bi_end_io
) {
1105 page
= r1_bio
->bios
[0]->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
1106 if (bio_add_page(bio
, page
, len
, 0) == 0) {
1108 r1_bio
->bios
[0]->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
1111 bio
= r1_bio
->bios
[i
];
1112 if (bio
->bi_end_io
==NULL
) continue;
1113 /* remove last page from this bio */
1115 bio
->bi_size
-= len
;
1116 bio
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
1122 nr_sectors
+= len
>>9;
1123 sector_nr
+= len
>>9;
1124 } while (r1_bio
->bios
[disk
]->bi_vcnt
< RESYNC_PAGES
);
1126 bio
= r1_bio
->bios
[disk
];
1127 r1_bio
->sectors
= nr_sectors
;
1129 md_sync_acct(mirror
->rdev
->bdev
, nr_sectors
);
1131 generic_make_request(bio
);
1136 static int run(mddev_t
*mddev
)
1140 mirror_info_t
*disk
;
1142 struct list_head
*tmp
;
1144 if (mddev
->level
!= 1) {
1145 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1146 mdname(mddev
), mddev
->level
);
1150 * copy the already verified devices into our private RAID1
1151 * bookkeeping area. [whatever we allocate in run(),
1152 * should be freed in stop()]
1154 conf
= kmalloc(sizeof(conf_t
), GFP_KERNEL
);
1155 mddev
->private = conf
;
1159 memset(conf
, 0, sizeof(*conf
));
1160 conf
->mirrors
= kmalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
1165 memset(conf
->mirrors
, 0, sizeof(struct mirror_info
)*mddev
->raid_disks
);
1167 conf
->poolinfo
= kmalloc(sizeof(*conf
->poolinfo
), GFP_KERNEL
);
1168 if (!conf
->poolinfo
)
1170 conf
->poolinfo
->mddev
= mddev
;
1171 conf
->poolinfo
->raid_disks
= mddev
->raid_disks
;
1172 conf
->r1bio_pool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
1175 if (!conf
->r1bio_pool
)
1178 mddev
->queue
->unplug_fn
= raid1_unplug
;
1180 mddev
->queue
->issue_flush_fn
= raid1_issue_flush
;
1182 ITERATE_RDEV(mddev
, rdev
, tmp
) {
1183 disk_idx
= rdev
->raid_disk
;
1184 if (disk_idx
>= mddev
->raid_disks
1187 disk
= conf
->mirrors
+ disk_idx
;
1191 blk_queue_stack_limits(mddev
->queue
,
1192 rdev
->bdev
->bd_disk
->queue
);
1193 /* as we don't honour merge_bvec_fn, we must never risk
1194 * violating it, so limit ->max_sector to one PAGE, as
1195 * a one page request is never in violation.
1197 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
&&
1198 mddev
->queue
->max_sectors
> (PAGE_SIZE
>>9))
1199 blk_queue_max_sectors(mddev
->queue
, PAGE_SIZE
>>9);
1201 disk
->head_position
= 0;
1202 if (!rdev
->faulty
&& rdev
->in_sync
)
1203 conf
->working_disks
++;
1205 conf
->raid_disks
= mddev
->raid_disks
;
1206 conf
->mddev
= mddev
;
1207 conf
->device_lock
= SPIN_LOCK_UNLOCKED
;
1208 if (conf
->working_disks
== 1)
1209 mddev
->recovery_cp
= MaxSector
;
1211 conf
->resync_lock
= SPIN_LOCK_UNLOCKED
;
1212 init_waitqueue_head(&conf
->wait_idle
);
1213 init_waitqueue_head(&conf
->wait_resume
);
1215 if (!conf
->working_disks
) {
1216 printk(KERN_ERR
"raid1: no operational mirrors for %s\n",
1221 mddev
->degraded
= 0;
1222 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1224 disk
= conf
->mirrors
+ i
;
1227 disk
->head_position
= 0;
1233 * find the first working one and use it as a starting point
1234 * to read balancing.
1236 for (j
= 0; j
< conf
->raid_disks
&&
1237 (!conf
->mirrors
[j
].rdev
||
1238 !conf
->mirrors
[j
].rdev
->in_sync
) ; j
++)
1240 conf
->last_used
= j
;
1245 mddev
->thread
= md_register_thread(raid1d
, mddev
, "%s_raid1");
1246 if (!mddev
->thread
) {
1248 "raid1: couldn't allocate thread for %s\n",
1254 "raid1: raid set %s active with %d out of %d mirrors\n",
1255 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
1258 * Ok, everything is just fine now
1260 mddev
->array_size
= mddev
->size
;
1265 printk(KERN_ERR
"raid1: couldn't allocate memory for %s\n",
1270 if (conf
->r1bio_pool
)
1271 mempool_destroy(conf
->r1bio_pool
);
1273 kfree(conf
->mirrors
);
1275 kfree(conf
->poolinfo
);
1277 mddev
->private = NULL
;
1283 static int stop(mddev_t
*mddev
)
1285 conf_t
*conf
= mddev_to_conf(mddev
);
1287 md_unregister_thread(mddev
->thread
);
1288 mddev
->thread
= NULL
;
1289 if (conf
->r1bio_pool
)
1290 mempool_destroy(conf
->r1bio_pool
);
1292 kfree(conf
->mirrors
);
1294 kfree(conf
->poolinfo
);
1296 mddev
->private = NULL
;
1300 static int raid1_resize(mddev_t
*mddev
, sector_t sectors
)
1302 /* no resync is happening, and there is enough space
1303 * on all devices, so we can resize.
1304 * We need to make sure resync covers any new space.
1305 * If the array is shrinking we should possibly wait until
1306 * any io in the removed space completes, but it hardly seems
1309 mddev
->array_size
= sectors
>>1;
1310 set_capacity(mddev
->gendisk
, mddev
->array_size
<< 1);
1312 if (mddev
->array_size
> mddev
->size
&& mddev
->recovery_cp
== MaxSector
) {
1313 mddev
->recovery_cp
= mddev
->size
<< 1;
1314 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
1316 mddev
->size
= mddev
->array_size
;
1320 static int raid1_reshape(mddev_t
*mddev
, int raid_disks
)
1323 * 1/ resize the r1bio_pool
1324 * 2/ resize conf->mirrors
1326 * We allocate a new r1bio_pool if we can.
1327 * Then raise a device barrier and wait until all IO stops.
1328 * Then resize conf->mirrors and swap in the new r1bio pool.
1330 mempool_t
*newpool
, *oldpool
;
1331 struct pool_info
*newpoolinfo
;
1332 mirror_info_t
*newmirrors
;
1333 conf_t
*conf
= mddev_to_conf(mddev
);
1337 for (d
= raid_disks
; d
< conf
->raid_disks
; d
++)
1338 if (conf
->mirrors
[d
].rdev
)
1341 newpoolinfo
= kmalloc(sizeof(newpoolinfo
), GFP_KERNEL
);
1344 newpoolinfo
->mddev
= mddev
;
1345 newpoolinfo
->raid_disks
= raid_disks
;
1347 newpool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
1348 r1bio_pool_free
, newpoolinfo
);
1353 newmirrors
= kmalloc(sizeof(struct mirror_info
) * raid_disks
, GFP_KERNEL
);
1356 mempool_destroy(newpool
);
1359 memset(newmirrors
, 0, sizeof(struct mirror_info
)*raid_disks
);
1361 spin_lock_irq(&conf
->resync_lock
);
1363 wait_event_lock_irq(conf
->wait_idle
, !conf
->nr_pending
,
1364 conf
->resync_lock
, unplug_slaves(mddev
));
1365 spin_unlock_irq(&conf
->resync_lock
);
1367 /* ok, everything is stopped */
1368 oldpool
= conf
->r1bio_pool
;
1369 conf
->r1bio_pool
= newpool
;
1370 for (d
=0; d
< raid_disks
&& d
< conf
->raid_disks
; d
++)
1371 newmirrors
[d
] = conf
->mirrors
[d
];
1372 kfree(conf
->mirrors
);
1373 conf
->mirrors
= newmirrors
;
1374 kfree(conf
->poolinfo
);
1375 conf
->poolinfo
= newpoolinfo
;
1377 mddev
->degraded
+= (raid_disks
- conf
->raid_disks
);
1378 conf
->raid_disks
= mddev
->raid_disks
= raid_disks
;
1380 spin_lock_irq(&conf
->resync_lock
);
1382 spin_unlock_irq(&conf
->resync_lock
);
1383 wake_up(&conf
->wait_resume
);
1384 wake_up(&conf
->wait_idle
);
1387 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
1388 md_wakeup_thread(mddev
->thread
);
1390 mempool_destroy(oldpool
);
1395 static mdk_personality_t raid1_personality
=
1398 .owner
= THIS_MODULE
,
1399 .make_request
= make_request
,
1403 .error_handler
= error
,
1404 .hot_add_disk
= raid1_add_disk
,
1405 .hot_remove_disk
= raid1_remove_disk
,
1406 .spare_active
= raid1_spare_active
,
1407 .sync_request
= sync_request
,
1408 .resize
= raid1_resize
,
1409 .reshape
= raid1_reshape
,
1412 static int __init
raid_init(void)
1414 return register_md_personality(RAID1
, &raid1_personality
);
1417 static void raid_exit(void)
1419 unregister_md_personality(RAID1
);
1422 module_init(raid_init
);
1423 module_exit(raid_exit
);
1424 MODULE_LICENSE("GPL");
1425 MODULE_ALIAS("md-personality-3"); /* RAID1 */