2 * raid10.c : Multiple Devices driver for Linux
4 * Copyright (C) 2000-2004 Neil Brown
6 * RAID-10 support for md.
8 * Base on code in raid1.c. See raid1.c for further copyright information.
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.
21 #include <linux/slab.h>
22 #include <linux/delay.h>
23 #include <linux/blkdev.h>
24 #include <linux/seq_file.h>
25 #include <linux/ratelimit.h>
32 * RAID10 provides a combination of RAID0 and RAID1 functionality.
33 * The layout of data is defined by
36 * near_copies (stored in low byte of layout)
37 * far_copies (stored in second byte of layout)
38 * far_offset (stored in bit 16 of layout )
40 * The data to be stored is divided into chunks using chunksize.
41 * Each device is divided into far_copies sections.
42 * In each section, chunks are laid out in a style similar to raid0, but
43 * near_copies copies of each chunk is stored (each on a different drive).
44 * The starting device for each section is offset near_copies from the starting
45 * device of the previous section.
46 * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
48 * near_copies and far_copies must be at least one, and their product is at most
51 * If far_offset is true, then the far_copies are handled a bit differently.
52 * The copies are still in different stripes, but instead of be very far apart
53 * on disk, there are adjacent stripes.
57 * Number of guaranteed r10bios in case of extreme VM load:
59 #define NR_RAID10_BIOS 256
61 /* When there are this many requests queue to be written by
62 * the raid10 thread, we become 'congested' to provide back-pressure
65 static int max_queued_requests
= 1024;
67 static void allow_barrier(struct r10conf
*conf
);
68 static void lower_barrier(struct r10conf
*conf
);
70 static void * r10bio_pool_alloc(gfp_t gfp_flags
, void *data
)
72 struct r10conf
*conf
= data
;
73 int size
= offsetof(struct r10bio
, devs
[conf
->copies
]);
75 /* allocate a r10bio with room for raid_disks entries in the bios array */
76 return kzalloc(size
, gfp_flags
);
79 static void r10bio_pool_free(void *r10_bio
, void *data
)
84 /* Maximum size of each resync request */
85 #define RESYNC_BLOCK_SIZE (64*1024)
86 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
87 /* amount of memory to reserve for resync requests */
88 #define RESYNC_WINDOW (1024*1024)
89 /* maximum number of concurrent requests, memory permitting */
90 #define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
93 * When performing a resync, we need to read and compare, so
94 * we need as many pages are there are copies.
95 * When performing a recovery, we need 2 bios, one for read,
96 * one for write (we recover only one drive per r10buf)
99 static void * r10buf_pool_alloc(gfp_t gfp_flags
, void *data
)
101 struct r10conf
*conf
= data
;
103 struct r10bio
*r10_bio
;
108 r10_bio
= r10bio_pool_alloc(gfp_flags
, conf
);
112 if (test_bit(MD_RECOVERY_SYNC
, &conf
->mddev
->recovery
))
113 nalloc
= conf
->copies
; /* resync */
115 nalloc
= 2; /* recovery */
120 for (j
= nalloc
; j
-- ; ) {
121 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
124 r10_bio
->devs
[j
].bio
= bio
;
127 * Allocate RESYNC_PAGES data pages and attach them
130 for (j
= 0 ; j
< nalloc
; j
++) {
131 bio
= r10_bio
->devs
[j
].bio
;
132 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
133 if (j
== 1 && !test_bit(MD_RECOVERY_SYNC
,
134 &conf
->mddev
->recovery
)) {
135 /* we can share bv_page's during recovery */
136 struct bio
*rbio
= r10_bio
->devs
[0].bio
;
137 page
= rbio
->bi_io_vec
[i
].bv_page
;
140 page
= alloc_page(gfp_flags
);
144 bio
->bi_io_vec
[i
].bv_page
= page
;
152 safe_put_page(bio
->bi_io_vec
[i
-1].bv_page
);
154 for (i
= 0; i
< RESYNC_PAGES
; i
++)
155 safe_put_page(r10_bio
->devs
[j
].bio
->bi_io_vec
[i
].bv_page
);
158 while ( ++j
< nalloc
)
159 bio_put(r10_bio
->devs
[j
].bio
);
160 r10bio_pool_free(r10_bio
, conf
);
164 static void r10buf_pool_free(void *__r10_bio
, void *data
)
167 struct r10conf
*conf
= data
;
168 struct r10bio
*r10bio
= __r10_bio
;
171 for (j
=0; j
< conf
->copies
; j
++) {
172 struct bio
*bio
= r10bio
->devs
[j
].bio
;
174 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
175 safe_put_page(bio
->bi_io_vec
[i
].bv_page
);
176 bio
->bi_io_vec
[i
].bv_page
= NULL
;
181 r10bio_pool_free(r10bio
, conf
);
184 static void put_all_bios(struct r10conf
*conf
, struct r10bio
*r10_bio
)
188 for (i
= 0; i
< conf
->copies
; i
++) {
189 struct bio
**bio
= & r10_bio
->devs
[i
].bio
;
190 if (!BIO_SPECIAL(*bio
))
196 static void free_r10bio(struct r10bio
*r10_bio
)
198 struct r10conf
*conf
= r10_bio
->mddev
->private;
200 put_all_bios(conf
, r10_bio
);
201 mempool_free(r10_bio
, conf
->r10bio_pool
);
204 static void put_buf(struct r10bio
*r10_bio
)
206 struct r10conf
*conf
= r10_bio
->mddev
->private;
208 mempool_free(r10_bio
, conf
->r10buf_pool
);
213 static void reschedule_retry(struct r10bio
*r10_bio
)
216 struct mddev
*mddev
= r10_bio
->mddev
;
217 struct r10conf
*conf
= mddev
->private;
219 spin_lock_irqsave(&conf
->device_lock
, flags
);
220 list_add(&r10_bio
->retry_list
, &conf
->retry_list
);
222 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
224 /* wake up frozen array... */
225 wake_up(&conf
->wait_barrier
);
227 md_wakeup_thread(mddev
->thread
);
231 * raid_end_bio_io() is called when we have finished servicing a mirrored
232 * operation and are ready to return a success/failure code to the buffer
235 static void raid_end_bio_io(struct r10bio
*r10_bio
)
237 struct bio
*bio
= r10_bio
->master_bio
;
239 struct r10conf
*conf
= r10_bio
->mddev
->private;
241 if (bio
->bi_phys_segments
) {
243 spin_lock_irqsave(&conf
->device_lock
, flags
);
244 bio
->bi_phys_segments
--;
245 done
= (bio
->bi_phys_segments
== 0);
246 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
249 if (!test_bit(R10BIO_Uptodate
, &r10_bio
->state
))
250 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
254 * Wake up any possible resync thread that waits for the device
259 free_r10bio(r10_bio
);
263 * Update disk head position estimator based on IRQ completion info.
265 static inline void update_head_pos(int slot
, struct r10bio
*r10_bio
)
267 struct r10conf
*conf
= r10_bio
->mddev
->private;
269 conf
->mirrors
[r10_bio
->devs
[slot
].devnum
].head_position
=
270 r10_bio
->devs
[slot
].addr
+ (r10_bio
->sectors
);
274 * Find the disk number which triggered given bio
276 static int find_bio_disk(struct r10conf
*conf
, struct r10bio
*r10_bio
,
277 struct bio
*bio
, int *slotp
)
281 for (slot
= 0; slot
< conf
->copies
; slot
++)
282 if (r10_bio
->devs
[slot
].bio
== bio
)
285 BUG_ON(slot
== conf
->copies
);
286 update_head_pos(slot
, r10_bio
);
290 return r10_bio
->devs
[slot
].devnum
;
293 static void raid10_end_read_request(struct bio
*bio
, int error
)
295 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
296 struct r10bio
*r10_bio
= bio
->bi_private
;
298 struct r10conf
*conf
= r10_bio
->mddev
->private;
301 slot
= r10_bio
->read_slot
;
302 dev
= r10_bio
->devs
[slot
].devnum
;
304 * this branch is our 'one mirror IO has finished' event handler:
306 update_head_pos(slot
, r10_bio
);
310 * Set R10BIO_Uptodate in our master bio, so that
311 * we will return a good error code to the higher
312 * levels even if IO on some other mirrored buffer fails.
314 * The 'master' represents the composite IO operation to
315 * user-side. So if something waits for IO, then it will
316 * wait for the 'master' bio.
318 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
319 raid_end_bio_io(r10_bio
);
320 rdev_dec_pending(conf
->mirrors
[dev
].rdev
, conf
->mddev
);
323 * oops, read error - keep the refcount on the rdev
325 char b
[BDEVNAME_SIZE
];
326 printk_ratelimited(KERN_ERR
327 "md/raid10:%s: %s: rescheduling sector %llu\n",
329 bdevname(conf
->mirrors
[dev
].rdev
->bdev
, b
),
330 (unsigned long long)r10_bio
->sector
);
331 set_bit(R10BIO_ReadError
, &r10_bio
->state
);
332 reschedule_retry(r10_bio
);
336 static void close_write(struct r10bio
*r10_bio
)
338 /* clear the bitmap if all writes complete successfully */
339 bitmap_endwrite(r10_bio
->mddev
->bitmap
, r10_bio
->sector
,
341 !test_bit(R10BIO_Degraded
, &r10_bio
->state
),
343 md_write_end(r10_bio
->mddev
);
346 static void one_write_done(struct r10bio
*r10_bio
)
348 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
349 if (test_bit(R10BIO_WriteError
, &r10_bio
->state
))
350 reschedule_retry(r10_bio
);
352 close_write(r10_bio
);
353 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
))
354 reschedule_retry(r10_bio
);
356 raid_end_bio_io(r10_bio
);
361 static void raid10_end_write_request(struct bio
*bio
, int error
)
363 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
364 struct r10bio
*r10_bio
= bio
->bi_private
;
367 struct r10conf
*conf
= r10_bio
->mddev
->private;
370 dev
= find_bio_disk(conf
, r10_bio
, bio
, &slot
);
373 * this branch is our 'one mirror IO has finished' event handler:
376 set_bit(WriteErrorSeen
, &conf
->mirrors
[dev
].rdev
->flags
);
377 set_bit(R10BIO_WriteError
, &r10_bio
->state
);
381 * Set R10BIO_Uptodate in our master bio, so that
382 * we will return a good error code for to the higher
383 * levels even if IO on some other mirrored buffer fails.
385 * The 'master' represents the composite IO operation to
386 * user-side. So if something waits for IO, then it will
387 * wait for the 'master' bio.
392 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
394 /* Maybe we can clear some bad blocks. */
395 if (is_badblock(conf
->mirrors
[dev
].rdev
,
396 r10_bio
->devs
[slot
].addr
,
398 &first_bad
, &bad_sectors
)) {
400 r10_bio
->devs
[slot
].bio
= IO_MADE_GOOD
;
402 set_bit(R10BIO_MadeGood
, &r10_bio
->state
);
408 * Let's see if all mirrored write operations have finished
411 one_write_done(r10_bio
);
413 rdev_dec_pending(conf
->mirrors
[dev
].rdev
, conf
->mddev
);
418 * RAID10 layout manager
419 * As well as the chunksize and raid_disks count, there are two
420 * parameters: near_copies and far_copies.
421 * near_copies * far_copies must be <= raid_disks.
422 * Normally one of these will be 1.
423 * If both are 1, we get raid0.
424 * If near_copies == raid_disks, we get raid1.
426 * Chunks are laid out in raid0 style with near_copies copies of the
427 * first chunk, followed by near_copies copies of the next chunk and
429 * If far_copies > 1, then after 1/far_copies of the array has been assigned
430 * as described above, we start again with a device offset of near_copies.
431 * So we effectively have another copy of the whole array further down all
432 * the drives, but with blocks on different drives.
433 * With this layout, and block is never stored twice on the one device.
435 * raid10_find_phys finds the sector offset of a given virtual sector
436 * on each device that it is on.
438 * raid10_find_virt does the reverse mapping, from a device and a
439 * sector offset to a virtual address
442 static void raid10_find_phys(struct r10conf
*conf
, struct r10bio
*r10bio
)
452 /* now calculate first sector/dev */
453 chunk
= r10bio
->sector
>> conf
->chunk_shift
;
454 sector
= r10bio
->sector
& conf
->chunk_mask
;
456 chunk
*= conf
->near_copies
;
458 dev
= sector_div(stripe
, conf
->raid_disks
);
459 if (conf
->far_offset
)
460 stripe
*= conf
->far_copies
;
462 sector
+= stripe
<< conf
->chunk_shift
;
464 /* and calculate all the others */
465 for (n
=0; n
< conf
->near_copies
; n
++) {
468 r10bio
->devs
[slot
].addr
= sector
;
469 r10bio
->devs
[slot
].devnum
= d
;
472 for (f
= 1; f
< conf
->far_copies
; f
++) {
473 d
+= conf
->near_copies
;
474 if (d
>= conf
->raid_disks
)
475 d
-= conf
->raid_disks
;
477 r10bio
->devs
[slot
].devnum
= d
;
478 r10bio
->devs
[slot
].addr
= s
;
482 if (dev
>= conf
->raid_disks
) {
484 sector
+= (conf
->chunk_mask
+ 1);
487 BUG_ON(slot
!= conf
->copies
);
490 static sector_t
raid10_find_virt(struct r10conf
*conf
, sector_t sector
, int dev
)
492 sector_t offset
, chunk
, vchunk
;
494 offset
= sector
& conf
->chunk_mask
;
495 if (conf
->far_offset
) {
497 chunk
= sector
>> conf
->chunk_shift
;
498 fc
= sector_div(chunk
, conf
->far_copies
);
499 dev
-= fc
* conf
->near_copies
;
501 dev
+= conf
->raid_disks
;
503 while (sector
>= conf
->stride
) {
504 sector
-= conf
->stride
;
505 if (dev
< conf
->near_copies
)
506 dev
+= conf
->raid_disks
- conf
->near_copies
;
508 dev
-= conf
->near_copies
;
510 chunk
= sector
>> conf
->chunk_shift
;
512 vchunk
= chunk
* conf
->raid_disks
+ dev
;
513 sector_div(vchunk
, conf
->near_copies
);
514 return (vchunk
<< conf
->chunk_shift
) + offset
;
518 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
520 * @bvm: properties of new bio
521 * @biovec: the request that could be merged to it.
523 * Return amount of bytes we can accept at this offset
524 * If near_copies == raid_disk, there are no striping issues,
525 * but in that case, the function isn't called at all.
527 static int raid10_mergeable_bvec(struct request_queue
*q
,
528 struct bvec_merge_data
*bvm
,
529 struct bio_vec
*biovec
)
531 struct mddev
*mddev
= q
->queuedata
;
532 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
534 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
535 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
537 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
538 if (max
< 0) max
= 0; /* bio_add cannot handle a negative return */
539 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
540 return biovec
->bv_len
;
546 * This routine returns the disk from which the requested read should
547 * be done. There is a per-array 'next expected sequential IO' sector
548 * number - if this matches on the next IO then we use the last disk.
549 * There is also a per-disk 'last know head position' sector that is
550 * maintained from IRQ contexts, both the normal and the resync IO
551 * completion handlers update this position correctly. If there is no
552 * perfect sequential match then we pick the disk whose head is closest.
554 * If there are 2 mirrors in the same 2 devices, performance degrades
555 * because position is mirror, not device based.
557 * The rdev for the device selected will have nr_pending incremented.
561 * FIXME: possibly should rethink readbalancing and do it differently
562 * depending on near_copies / far_copies geometry.
564 static int read_balance(struct r10conf
*conf
, struct r10bio
*r10_bio
, int *max_sectors
)
566 const sector_t this_sector
= r10_bio
->sector
;
568 int sectors
= r10_bio
->sectors
;
569 int best_good_sectors
;
570 sector_t new_distance
, best_dist
;
571 struct md_rdev
*rdev
;
575 raid10_find_phys(conf
, r10_bio
);
578 sectors
= r10_bio
->sectors
;
580 best_dist
= MaxSector
;
581 best_good_sectors
= 0;
584 * Check if we can balance. We can balance on the whole
585 * device if no resync is going on (recovery is ok), or below
586 * the resync window. We take the first readable disk when
587 * above the resync window.
589 if (conf
->mddev
->recovery_cp
< MaxSector
590 && (this_sector
+ sectors
>= conf
->next_resync
))
593 for (slot
= 0; slot
< conf
->copies
; slot
++) {
598 if (r10_bio
->devs
[slot
].bio
== IO_BLOCKED
)
600 disk
= r10_bio
->devs
[slot
].devnum
;
601 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
604 if (!test_bit(In_sync
, &rdev
->flags
))
607 dev_sector
= r10_bio
->devs
[slot
].addr
;
608 if (is_badblock(rdev
, dev_sector
, sectors
,
609 &first_bad
, &bad_sectors
)) {
610 if (best_dist
< MaxSector
)
611 /* Already have a better slot */
613 if (first_bad
<= dev_sector
) {
614 /* Cannot read here. If this is the
615 * 'primary' device, then we must not read
616 * beyond 'bad_sectors' from another device.
618 bad_sectors
-= (dev_sector
- first_bad
);
619 if (!do_balance
&& sectors
> bad_sectors
)
620 sectors
= bad_sectors
;
621 if (best_good_sectors
> sectors
)
622 best_good_sectors
= sectors
;
624 sector_t good_sectors
=
625 first_bad
- dev_sector
;
626 if (good_sectors
> best_good_sectors
) {
627 best_good_sectors
= good_sectors
;
631 /* Must read from here */
636 best_good_sectors
= sectors
;
641 /* This optimisation is debatable, and completely destroys
642 * sequential read speed for 'far copies' arrays. So only
643 * keep it for 'near' arrays, and review those later.
645 if (conf
->near_copies
> 1 && !atomic_read(&rdev
->nr_pending
))
648 /* for far > 1 always use the lowest address */
649 if (conf
->far_copies
> 1)
650 new_distance
= r10_bio
->devs
[slot
].addr
;
652 new_distance
= abs(r10_bio
->devs
[slot
].addr
-
653 conf
->mirrors
[disk
].head_position
);
654 if (new_distance
< best_dist
) {
655 best_dist
= new_distance
;
659 if (slot
== conf
->copies
)
663 disk
= r10_bio
->devs
[slot
].devnum
;
664 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
667 atomic_inc(&rdev
->nr_pending
);
668 if (test_bit(Faulty
, &rdev
->flags
)) {
669 /* Cannot risk returning a device that failed
670 * before we inc'ed nr_pending
672 rdev_dec_pending(rdev
, conf
->mddev
);
675 r10_bio
->read_slot
= slot
;
679 *max_sectors
= best_good_sectors
;
684 static int raid10_congested(void *data
, int bits
)
686 struct mddev
*mddev
= data
;
687 struct r10conf
*conf
= mddev
->private;
690 if ((bits
& (1 << BDI_async_congested
)) &&
691 conf
->pending_count
>= max_queued_requests
)
694 if (mddev_congested(mddev
, bits
))
697 for (i
= 0; i
< conf
->raid_disks
&& ret
== 0; i
++) {
698 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
699 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
700 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
702 ret
|= bdi_congested(&q
->backing_dev_info
, bits
);
709 static void flush_pending_writes(struct r10conf
*conf
)
711 /* Any writes that have been queued but are awaiting
712 * bitmap updates get flushed here.
714 spin_lock_irq(&conf
->device_lock
);
716 if (conf
->pending_bio_list
.head
) {
718 bio
= bio_list_get(&conf
->pending_bio_list
);
719 conf
->pending_count
= 0;
720 spin_unlock_irq(&conf
->device_lock
);
721 /* flush any pending bitmap writes to disk
722 * before proceeding w/ I/O */
723 bitmap_unplug(conf
->mddev
->bitmap
);
724 wake_up(&conf
->wait_barrier
);
726 while (bio
) { /* submit pending writes */
727 struct bio
*next
= bio
->bi_next
;
729 generic_make_request(bio
);
733 spin_unlock_irq(&conf
->device_lock
);
737 * Sometimes we need to suspend IO while we do something else,
738 * either some resync/recovery, or reconfigure the array.
739 * To do this we raise a 'barrier'.
740 * The 'barrier' is a counter that can be raised multiple times
741 * to count how many activities are happening which preclude
743 * We can only raise the barrier if there is no pending IO.
744 * i.e. if nr_pending == 0.
745 * We choose only to raise the barrier if no-one is waiting for the
746 * barrier to go down. This means that as soon as an IO request
747 * is ready, no other operations which require a barrier will start
748 * until the IO request has had a chance.
750 * So: regular IO calls 'wait_barrier'. When that returns there
751 * is no backgroup IO happening, It must arrange to call
752 * allow_barrier when it has finished its IO.
753 * backgroup IO calls must call raise_barrier. Once that returns
754 * there is no normal IO happeing. It must arrange to call
755 * lower_barrier when the particular background IO completes.
758 static void raise_barrier(struct r10conf
*conf
, int force
)
760 BUG_ON(force
&& !conf
->barrier
);
761 spin_lock_irq(&conf
->resync_lock
);
763 /* Wait until no block IO is waiting (unless 'force') */
764 wait_event_lock_irq(conf
->wait_barrier
, force
|| !conf
->nr_waiting
,
765 conf
->resync_lock
, );
767 /* block any new IO from starting */
770 /* Now wait for all pending IO to complete */
771 wait_event_lock_irq(conf
->wait_barrier
,
772 !conf
->nr_pending
&& conf
->barrier
< RESYNC_DEPTH
,
773 conf
->resync_lock
, );
775 spin_unlock_irq(&conf
->resync_lock
);
778 static void lower_barrier(struct r10conf
*conf
)
781 spin_lock_irqsave(&conf
->resync_lock
, flags
);
783 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
784 wake_up(&conf
->wait_barrier
);
787 static void wait_barrier(struct r10conf
*conf
)
789 spin_lock_irq(&conf
->resync_lock
);
792 wait_event_lock_irq(conf
->wait_barrier
, !conf
->barrier
,
798 spin_unlock_irq(&conf
->resync_lock
);
801 static void allow_barrier(struct r10conf
*conf
)
804 spin_lock_irqsave(&conf
->resync_lock
, flags
);
806 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
807 wake_up(&conf
->wait_barrier
);
810 static void freeze_array(struct r10conf
*conf
)
812 /* stop syncio and normal IO and wait for everything to
814 * We increment barrier and nr_waiting, and then
815 * wait until nr_pending match nr_queued+1
816 * This is called in the context of one normal IO request
817 * that has failed. Thus any sync request that might be pending
818 * will be blocked by nr_pending, and we need to wait for
819 * pending IO requests to complete or be queued for re-try.
820 * Thus the number queued (nr_queued) plus this request (1)
821 * must match the number of pending IOs (nr_pending) before
824 spin_lock_irq(&conf
->resync_lock
);
827 wait_event_lock_irq(conf
->wait_barrier
,
828 conf
->nr_pending
== conf
->nr_queued
+1,
830 flush_pending_writes(conf
));
832 spin_unlock_irq(&conf
->resync_lock
);
835 static void unfreeze_array(struct r10conf
*conf
)
837 /* reverse the effect of the freeze */
838 spin_lock_irq(&conf
->resync_lock
);
841 wake_up(&conf
->wait_barrier
);
842 spin_unlock_irq(&conf
->resync_lock
);
845 static void make_request(struct mddev
*mddev
, struct bio
* bio
)
847 struct r10conf
*conf
= mddev
->private;
848 struct mirror_info
*mirror
;
849 struct r10bio
*r10_bio
;
850 struct bio
*read_bio
;
852 int chunk_sects
= conf
->chunk_mask
+ 1;
853 const int rw
= bio_data_dir(bio
);
854 const unsigned long do_sync
= (bio
->bi_rw
& REQ_SYNC
);
855 const unsigned long do_fua
= (bio
->bi_rw
& REQ_FUA
);
857 struct md_rdev
*blocked_rdev
;
862 if (unlikely(bio
->bi_rw
& REQ_FLUSH
)) {
863 md_flush_request(mddev
, bio
);
867 /* If this request crosses a chunk boundary, we need to
868 * split it. This will only happen for 1 PAGE (or less) requests.
870 if (unlikely( (bio
->bi_sector
& conf
->chunk_mask
) + (bio
->bi_size
>> 9)
872 conf
->near_copies
< conf
->raid_disks
)) {
874 /* Sanity check -- queue functions should prevent this happening */
875 if (bio
->bi_vcnt
!= 1 ||
878 /* This is a one page bio that upper layers
879 * refuse to split for us, so we need to split it.
882 chunk_sects
- (bio
->bi_sector
& (chunk_sects
- 1)) );
884 /* Each of these 'make_request' calls will call 'wait_barrier'.
885 * If the first succeeds but the second blocks due to the resync
886 * thread raising the barrier, we will deadlock because the
887 * IO to the underlying device will be queued in generic_make_request
888 * and will never complete, so will never reduce nr_pending.
889 * So increment nr_waiting here so no new raise_barriers will
890 * succeed, and so the second wait_barrier cannot block.
892 spin_lock_irq(&conf
->resync_lock
);
894 spin_unlock_irq(&conf
->resync_lock
);
896 make_request(mddev
, &bp
->bio1
);
897 make_request(mddev
, &bp
->bio2
);
899 spin_lock_irq(&conf
->resync_lock
);
901 wake_up(&conf
->wait_barrier
);
902 spin_unlock_irq(&conf
->resync_lock
);
904 bio_pair_release(bp
);
907 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
908 " or bigger than %dk %llu %d\n", mdname(mddev
), chunk_sects
/2,
909 (unsigned long long)bio
->bi_sector
, bio
->bi_size
>> 10);
915 md_write_start(mddev
, bio
);
918 * Register the new request and wait if the reconstruction
919 * thread has put up a bar for new requests.
920 * Continue immediately if no resync is active currently.
924 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
926 r10_bio
->master_bio
= bio
;
927 r10_bio
->sectors
= bio
->bi_size
>> 9;
929 r10_bio
->mddev
= mddev
;
930 r10_bio
->sector
= bio
->bi_sector
;
933 /* We might need to issue multiple reads to different
934 * devices if there are bad blocks around, so we keep
935 * track of the number of reads in bio->bi_phys_segments.
936 * If this is 0, there is only one r10_bio and no locking
937 * will be needed when the request completes. If it is
938 * non-zero, then it is the number of not-completed requests.
940 bio
->bi_phys_segments
= 0;
941 clear_bit(BIO_SEG_VALID
, &bio
->bi_flags
);
945 * read balancing logic:
951 disk
= read_balance(conf
, r10_bio
, &max_sectors
);
952 slot
= r10_bio
->read_slot
;
954 raid_end_bio_io(r10_bio
);
957 mirror
= conf
->mirrors
+ disk
;
959 read_bio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
960 md_trim_bio(read_bio
, r10_bio
->sector
- bio
->bi_sector
,
963 r10_bio
->devs
[slot
].bio
= read_bio
;
965 read_bio
->bi_sector
= r10_bio
->devs
[slot
].addr
+
966 mirror
->rdev
->data_offset
;
967 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
968 read_bio
->bi_end_io
= raid10_end_read_request
;
969 read_bio
->bi_rw
= READ
| do_sync
;
970 read_bio
->bi_private
= r10_bio
;
972 if (max_sectors
< r10_bio
->sectors
) {
973 /* Could not read all from this device, so we will
974 * need another r10_bio.
976 sectors_handled
= (r10_bio
->sectors
+ max_sectors
978 r10_bio
->sectors
= max_sectors
;
979 spin_lock_irq(&conf
->device_lock
);
980 if (bio
->bi_phys_segments
== 0)
981 bio
->bi_phys_segments
= 2;
983 bio
->bi_phys_segments
++;
984 spin_unlock(&conf
->device_lock
);
985 /* Cannot call generic_make_request directly
986 * as that will be queued in __generic_make_request
987 * and subsequent mempool_alloc might block
988 * waiting for it. so hand bio over to raid10d.
990 reschedule_retry(r10_bio
);
992 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
994 r10_bio
->master_bio
= bio
;
995 r10_bio
->sectors
= ((bio
->bi_size
>> 9)
998 r10_bio
->mddev
= mddev
;
999 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1002 generic_make_request(read_bio
);
1009 if (conf
->pending_count
>= max_queued_requests
) {
1010 md_wakeup_thread(mddev
->thread
);
1011 wait_event(conf
->wait_barrier
,
1012 conf
->pending_count
< max_queued_requests
);
1014 /* first select target devices under rcu_lock and
1015 * inc refcount on their rdev. Record them by setting
1017 * If there are known/acknowledged bad blocks on any device
1018 * on which we have seen a write error, we want to avoid
1019 * writing to those blocks. This potentially requires several
1020 * writes to write around the bad blocks. Each set of writes
1021 * gets its own r10_bio with a set of bios attached. The number
1022 * of r10_bios is recored in bio->bi_phys_segments just as with
1025 plugged
= mddev_check_plugged(mddev
);
1027 raid10_find_phys(conf
, r10_bio
);
1029 blocked_rdev
= NULL
;
1031 max_sectors
= r10_bio
->sectors
;
1033 for (i
= 0; i
< conf
->copies
; i
++) {
1034 int d
= r10_bio
->devs
[i
].devnum
;
1035 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1036 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
1037 atomic_inc(&rdev
->nr_pending
);
1038 blocked_rdev
= rdev
;
1041 r10_bio
->devs
[i
].bio
= NULL
;
1042 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
)) {
1043 set_bit(R10BIO_Degraded
, &r10_bio
->state
);
1046 if (test_bit(WriteErrorSeen
, &rdev
->flags
)) {
1048 sector_t dev_sector
= r10_bio
->devs
[i
].addr
;
1052 is_bad
= is_badblock(rdev
, dev_sector
,
1054 &first_bad
, &bad_sectors
);
1056 /* Mustn't write here until the bad block
1059 atomic_inc(&rdev
->nr_pending
);
1060 set_bit(BlockedBadBlocks
, &rdev
->flags
);
1061 blocked_rdev
= rdev
;
1064 if (is_bad
&& first_bad
<= dev_sector
) {
1065 /* Cannot write here at all */
1066 bad_sectors
-= (dev_sector
- first_bad
);
1067 if (bad_sectors
< max_sectors
)
1068 /* Mustn't write more than bad_sectors
1069 * to other devices yet
1071 max_sectors
= bad_sectors
;
1072 /* We don't set R10BIO_Degraded as that
1073 * only applies if the disk is missing,
1074 * so it might be re-added, and we want to
1075 * know to recover this chunk.
1076 * In this case the device is here, and the
1077 * fact that this chunk is not in-sync is
1078 * recorded in the bad block log.
1083 int good_sectors
= first_bad
- dev_sector
;
1084 if (good_sectors
< max_sectors
)
1085 max_sectors
= good_sectors
;
1088 r10_bio
->devs
[i
].bio
= bio
;
1089 atomic_inc(&rdev
->nr_pending
);
1093 if (unlikely(blocked_rdev
)) {
1094 /* Have to wait for this device to get unblocked, then retry */
1098 for (j
= 0; j
< i
; j
++)
1099 if (r10_bio
->devs
[j
].bio
) {
1100 d
= r10_bio
->devs
[j
].devnum
;
1101 rdev_dec_pending(conf
->mirrors
[d
].rdev
, mddev
);
1103 allow_barrier(conf
);
1104 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
1109 if (max_sectors
< r10_bio
->sectors
) {
1110 /* We are splitting this into multiple parts, so
1111 * we need to prepare for allocating another r10_bio.
1113 r10_bio
->sectors
= max_sectors
;
1114 spin_lock_irq(&conf
->device_lock
);
1115 if (bio
->bi_phys_segments
== 0)
1116 bio
->bi_phys_segments
= 2;
1118 bio
->bi_phys_segments
++;
1119 spin_unlock_irq(&conf
->device_lock
);
1121 sectors_handled
= r10_bio
->sector
+ max_sectors
- bio
->bi_sector
;
1123 atomic_set(&r10_bio
->remaining
, 1);
1124 bitmap_startwrite(mddev
->bitmap
, r10_bio
->sector
, r10_bio
->sectors
, 0);
1126 for (i
= 0; i
< conf
->copies
; i
++) {
1128 int d
= r10_bio
->devs
[i
].devnum
;
1129 if (!r10_bio
->devs
[i
].bio
)
1132 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1133 md_trim_bio(mbio
, r10_bio
->sector
- bio
->bi_sector
,
1135 r10_bio
->devs
[i
].bio
= mbio
;
1137 mbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
1138 conf
->mirrors
[d
].rdev
->data_offset
);
1139 mbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1140 mbio
->bi_end_io
= raid10_end_write_request
;
1141 mbio
->bi_rw
= WRITE
| do_sync
| do_fua
;
1142 mbio
->bi_private
= r10_bio
;
1144 atomic_inc(&r10_bio
->remaining
);
1145 spin_lock_irqsave(&conf
->device_lock
, flags
);
1146 bio_list_add(&conf
->pending_bio_list
, mbio
);
1147 conf
->pending_count
++;
1148 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1151 /* Don't remove the bias on 'remaining' (one_write_done) until
1152 * after checking if we need to go around again.
1155 if (sectors_handled
< (bio
->bi_size
>> 9)) {
1156 one_write_done(r10_bio
);
1157 /* We need another r10_bio. It has already been counted
1158 * in bio->bi_phys_segments.
1160 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
1162 r10_bio
->master_bio
= bio
;
1163 r10_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
1165 r10_bio
->mddev
= mddev
;
1166 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1170 one_write_done(r10_bio
);
1172 /* In case raid10d snuck in to freeze_array */
1173 wake_up(&conf
->wait_barrier
);
1175 if (do_sync
|| !mddev
->bitmap
|| !plugged
)
1176 md_wakeup_thread(mddev
->thread
);
1179 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
1181 struct r10conf
*conf
= mddev
->private;
1184 if (conf
->near_copies
< conf
->raid_disks
)
1185 seq_printf(seq
, " %dK chunks", mddev
->chunk_sectors
/ 2);
1186 if (conf
->near_copies
> 1)
1187 seq_printf(seq
, " %d near-copies", conf
->near_copies
);
1188 if (conf
->far_copies
> 1) {
1189 if (conf
->far_offset
)
1190 seq_printf(seq
, " %d offset-copies", conf
->far_copies
);
1192 seq_printf(seq
, " %d far-copies", conf
->far_copies
);
1194 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
1195 conf
->raid_disks
- mddev
->degraded
);
1196 for (i
= 0; i
< conf
->raid_disks
; i
++)
1197 seq_printf(seq
, "%s",
1198 conf
->mirrors
[i
].rdev
&&
1199 test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ? "U" : "_");
1200 seq_printf(seq
, "]");
1203 /* check if there are enough drives for
1204 * every block to appear on atleast one.
1205 * Don't consider the device numbered 'ignore'
1206 * as we might be about to remove it.
1208 static int enough(struct r10conf
*conf
, int ignore
)
1213 int n
= conf
->copies
;
1216 if (conf
->mirrors
[first
].rdev
&&
1219 first
= (first
+1) % conf
->raid_disks
;
1223 } while (first
!= 0);
1227 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1229 char b
[BDEVNAME_SIZE
];
1230 struct r10conf
*conf
= mddev
->private;
1233 * If it is not operational, then we have already marked it as dead
1234 * else if it is the last working disks, ignore the error, let the
1235 * next level up know.
1236 * else mark the drive as failed
1238 if (test_bit(In_sync
, &rdev
->flags
)
1239 && !enough(conf
, rdev
->raid_disk
))
1241 * Don't fail the drive, just return an IO error.
1244 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1245 unsigned long flags
;
1246 spin_lock_irqsave(&conf
->device_lock
, flags
);
1248 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1250 * if recovery is running, make sure it aborts.
1252 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1254 set_bit(Blocked
, &rdev
->flags
);
1255 set_bit(Faulty
, &rdev
->flags
);
1256 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1258 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1259 "md/raid10:%s: Operation continuing on %d devices.\n",
1260 mdname(mddev
), bdevname(rdev
->bdev
, b
),
1261 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
1264 static void print_conf(struct r10conf
*conf
)
1267 struct mirror_info
*tmp
;
1269 printk(KERN_DEBUG
"RAID10 conf printout:\n");
1271 printk(KERN_DEBUG
"(!conf)\n");
1274 printk(KERN_DEBUG
" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1277 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1278 char b
[BDEVNAME_SIZE
];
1279 tmp
= conf
->mirrors
+ i
;
1281 printk(KERN_DEBUG
" disk %d, wo:%d, o:%d, dev:%s\n",
1282 i
, !test_bit(In_sync
, &tmp
->rdev
->flags
),
1283 !test_bit(Faulty
, &tmp
->rdev
->flags
),
1284 bdevname(tmp
->rdev
->bdev
,b
));
1288 static void close_sync(struct r10conf
*conf
)
1291 allow_barrier(conf
);
1293 mempool_destroy(conf
->r10buf_pool
);
1294 conf
->r10buf_pool
= NULL
;
1297 static int raid10_spare_active(struct mddev
*mddev
)
1300 struct r10conf
*conf
= mddev
->private;
1301 struct mirror_info
*tmp
;
1303 unsigned long flags
;
1306 * Find all non-in_sync disks within the RAID10 configuration
1307 * and mark them in_sync
1309 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1310 tmp
= conf
->mirrors
+ i
;
1312 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
1313 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
1315 sysfs_notify_dirent(tmp
->rdev
->sysfs_state
);
1318 spin_lock_irqsave(&conf
->device_lock
, flags
);
1319 mddev
->degraded
-= count
;
1320 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1327 static int raid10_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1329 struct r10conf
*conf
= mddev
->private;
1333 int last
= conf
->raid_disks
- 1;
1335 if (mddev
->recovery_cp
< MaxSector
)
1336 /* only hot-add to in-sync arrays, as recovery is
1337 * very different from resync
1340 if (!enough(conf
, -1))
1343 if (rdev
->raid_disk
>= 0)
1344 first
= last
= rdev
->raid_disk
;
1346 if (rdev
->saved_raid_disk
>= first
&&
1347 conf
->mirrors
[rdev
->saved_raid_disk
].rdev
== NULL
)
1348 mirror
= rdev
->saved_raid_disk
;
1351 for ( ; mirror
<= last
; mirror
++) {
1352 struct mirror_info
*p
= &conf
->mirrors
[mirror
];
1353 if (p
->recovery_disabled
== mddev
->recovery_disabled
)
1358 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1359 rdev
->data_offset
<< 9);
1360 /* as we don't honour merge_bvec_fn, we must
1361 * never risk violating it, so limit
1362 * ->max_segments to one lying with a single
1363 * page, as a one page request is never in
1366 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1367 blk_queue_max_segments(mddev
->queue
, 1);
1368 blk_queue_segment_boundary(mddev
->queue
,
1369 PAGE_CACHE_SIZE
- 1);
1372 p
->head_position
= 0;
1373 p
->recovery_disabled
= mddev
->recovery_disabled
- 1;
1374 rdev
->raid_disk
= mirror
;
1376 if (rdev
->saved_raid_disk
!= mirror
)
1378 rcu_assign_pointer(p
->rdev
, rdev
);
1382 md_integrity_add_rdev(rdev
, mddev
);
1387 static int raid10_remove_disk(struct mddev
*mddev
, int number
)
1389 struct r10conf
*conf
= mddev
->private;
1391 struct md_rdev
*rdev
;
1392 struct mirror_info
*p
= conf
->mirrors
+ number
;
1397 if (test_bit(In_sync
, &rdev
->flags
) ||
1398 atomic_read(&rdev
->nr_pending
)) {
1402 /* Only remove faulty devices in recovery
1405 if (!test_bit(Faulty
, &rdev
->flags
) &&
1406 mddev
->recovery_disabled
!= p
->recovery_disabled
&&
1413 if (atomic_read(&rdev
->nr_pending
)) {
1414 /* lost the race, try later */
1419 err
= md_integrity_register(mddev
);
1428 static void end_sync_read(struct bio
*bio
, int error
)
1430 struct r10bio
*r10_bio
= bio
->bi_private
;
1431 struct r10conf
*conf
= r10_bio
->mddev
->private;
1434 d
= find_bio_disk(conf
, r10_bio
, bio
, NULL
);
1436 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1437 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
1439 /* The write handler will notice the lack of
1440 * R10BIO_Uptodate and record any errors etc
1442 atomic_add(r10_bio
->sectors
,
1443 &conf
->mirrors
[d
].rdev
->corrected_errors
);
1445 /* for reconstruct, we always reschedule after a read.
1446 * for resync, only after all reads
1448 rdev_dec_pending(conf
->mirrors
[d
].rdev
, conf
->mddev
);
1449 if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
) ||
1450 atomic_dec_and_test(&r10_bio
->remaining
)) {
1451 /* we have read all the blocks,
1452 * do the comparison in process context in raid10d
1454 reschedule_retry(r10_bio
);
1458 static void end_sync_request(struct r10bio
*r10_bio
)
1460 struct mddev
*mddev
= r10_bio
->mddev
;
1462 while (atomic_dec_and_test(&r10_bio
->remaining
)) {
1463 if (r10_bio
->master_bio
== NULL
) {
1464 /* the primary of several recovery bios */
1465 sector_t s
= r10_bio
->sectors
;
1466 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
1467 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
1468 reschedule_retry(r10_bio
);
1471 md_done_sync(mddev
, s
, 1);
1474 struct r10bio
*r10_bio2
= (struct r10bio
*)r10_bio
->master_bio
;
1475 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
1476 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
1477 reschedule_retry(r10_bio
);
1485 static void end_sync_write(struct bio
*bio
, int error
)
1487 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1488 struct r10bio
*r10_bio
= bio
->bi_private
;
1489 struct mddev
*mddev
= r10_bio
->mddev
;
1490 struct r10conf
*conf
= mddev
->private;
1496 d
= find_bio_disk(conf
, r10_bio
, bio
, &slot
);
1499 set_bit(WriteErrorSeen
, &conf
->mirrors
[d
].rdev
->flags
);
1500 set_bit(R10BIO_WriteError
, &r10_bio
->state
);
1501 } else if (is_badblock(conf
->mirrors
[d
].rdev
,
1502 r10_bio
->devs
[slot
].addr
,
1504 &first_bad
, &bad_sectors
))
1505 set_bit(R10BIO_MadeGood
, &r10_bio
->state
);
1507 rdev_dec_pending(conf
->mirrors
[d
].rdev
, mddev
);
1509 end_sync_request(r10_bio
);
1513 * Note: sync and recover and handled very differently for raid10
1514 * This code is for resync.
1515 * For resync, we read through virtual addresses and read all blocks.
1516 * If there is any error, we schedule a write. The lowest numbered
1517 * drive is authoritative.
1518 * However requests come for physical address, so we need to map.
1519 * For every physical address there are raid_disks/copies virtual addresses,
1520 * which is always are least one, but is not necessarly an integer.
1521 * This means that a physical address can span multiple chunks, so we may
1522 * have to submit multiple io requests for a single sync request.
1525 * We check if all blocks are in-sync and only write to blocks that
1528 static void sync_request_write(struct mddev
*mddev
, struct r10bio
*r10_bio
)
1530 struct r10conf
*conf
= mddev
->private;
1532 struct bio
*tbio
, *fbio
;
1534 atomic_set(&r10_bio
->remaining
, 1);
1536 /* find the first device with a block */
1537 for (i
=0; i
<conf
->copies
; i
++)
1538 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
))
1541 if (i
== conf
->copies
)
1545 fbio
= r10_bio
->devs
[i
].bio
;
1547 /* now find blocks with errors */
1548 for (i
=0 ; i
< conf
->copies
; i
++) {
1550 int vcnt
= r10_bio
->sectors
>> (PAGE_SHIFT
-9);
1552 tbio
= r10_bio
->devs
[i
].bio
;
1554 if (tbio
->bi_end_io
!= end_sync_read
)
1558 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
)) {
1559 /* We know that the bi_io_vec layout is the same for
1560 * both 'first' and 'i', so we just compare them.
1561 * All vec entries are PAGE_SIZE;
1563 for (j
= 0; j
< vcnt
; j
++)
1564 if (memcmp(page_address(fbio
->bi_io_vec
[j
].bv_page
),
1565 page_address(tbio
->bi_io_vec
[j
].bv_page
),
1570 mddev
->resync_mismatches
+= r10_bio
->sectors
;
1571 if (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
))
1572 /* Don't fix anything. */
1575 /* Ok, we need to write this bio, either to correct an
1576 * inconsistency or to correct an unreadable block.
1577 * First we need to fixup bv_offset, bv_len and
1578 * bi_vecs, as the read request might have corrupted these
1580 tbio
->bi_vcnt
= vcnt
;
1581 tbio
->bi_size
= r10_bio
->sectors
<< 9;
1583 tbio
->bi_phys_segments
= 0;
1584 tbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1585 tbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1586 tbio
->bi_next
= NULL
;
1587 tbio
->bi_rw
= WRITE
;
1588 tbio
->bi_private
= r10_bio
;
1589 tbio
->bi_sector
= r10_bio
->devs
[i
].addr
;
1591 for (j
=0; j
< vcnt
; j
++) {
1592 tbio
->bi_io_vec
[j
].bv_offset
= 0;
1593 tbio
->bi_io_vec
[j
].bv_len
= PAGE_SIZE
;
1595 memcpy(page_address(tbio
->bi_io_vec
[j
].bv_page
),
1596 page_address(fbio
->bi_io_vec
[j
].bv_page
),
1599 tbio
->bi_end_io
= end_sync_write
;
1601 d
= r10_bio
->devs
[i
].devnum
;
1602 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1603 atomic_inc(&r10_bio
->remaining
);
1604 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, tbio
->bi_size
>> 9);
1606 tbio
->bi_sector
+= conf
->mirrors
[d
].rdev
->data_offset
;
1607 tbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1608 generic_make_request(tbio
);
1612 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
1613 md_done_sync(mddev
, r10_bio
->sectors
, 1);
1619 * Now for the recovery code.
1620 * Recovery happens across physical sectors.
1621 * We recover all non-is_sync drives by finding the virtual address of
1622 * each, and then choose a working drive that also has that virt address.
1623 * There is a separate r10_bio for each non-in_sync drive.
1624 * Only the first two slots are in use. The first for reading,
1625 * The second for writing.
1628 static void fix_recovery_read_error(struct r10bio
*r10_bio
)
1630 /* We got a read error during recovery.
1631 * We repeat the read in smaller page-sized sections.
1632 * If a read succeeds, write it to the new device or record
1633 * a bad block if we cannot.
1634 * If a read fails, record a bad block on both old and
1637 struct mddev
*mddev
= r10_bio
->mddev
;
1638 struct r10conf
*conf
= mddev
->private;
1639 struct bio
*bio
= r10_bio
->devs
[0].bio
;
1641 int sectors
= r10_bio
->sectors
;
1643 int dr
= r10_bio
->devs
[0].devnum
;
1644 int dw
= r10_bio
->devs
[1].devnum
;
1648 struct md_rdev
*rdev
;
1652 if (s
> (PAGE_SIZE
>>9))
1655 rdev
= conf
->mirrors
[dr
].rdev
;
1656 addr
= r10_bio
->devs
[0].addr
+ sect
,
1657 ok
= sync_page_io(rdev
,
1660 bio
->bi_io_vec
[idx
].bv_page
,
1663 rdev
= conf
->mirrors
[dw
].rdev
;
1664 addr
= r10_bio
->devs
[1].addr
+ sect
;
1665 ok
= sync_page_io(rdev
,
1668 bio
->bi_io_vec
[idx
].bv_page
,
1671 set_bit(WriteErrorSeen
, &rdev
->flags
);
1674 /* We don't worry if we cannot set a bad block -
1675 * it really is bad so there is no loss in not
1678 rdev_set_badblocks(rdev
, addr
, s
, 0);
1680 if (rdev
!= conf
->mirrors
[dw
].rdev
) {
1681 /* need bad block on destination too */
1682 struct md_rdev
*rdev2
= conf
->mirrors
[dw
].rdev
;
1683 addr
= r10_bio
->devs
[1].addr
+ sect
;
1684 ok
= rdev_set_badblocks(rdev2
, addr
, s
, 0);
1686 /* just abort the recovery */
1688 "md/raid10:%s: recovery aborted"
1689 " due to read error\n",
1692 conf
->mirrors
[dw
].recovery_disabled
1693 = mddev
->recovery_disabled
;
1694 set_bit(MD_RECOVERY_INTR
,
1707 static void recovery_request_write(struct mddev
*mddev
, struct r10bio
*r10_bio
)
1709 struct r10conf
*conf
= mddev
->private;
1713 if (!test_bit(R10BIO_Uptodate
, &r10_bio
->state
)) {
1714 fix_recovery_read_error(r10_bio
);
1715 end_sync_request(r10_bio
);
1720 * share the pages with the first bio
1721 * and submit the write request
1723 wbio
= r10_bio
->devs
[1].bio
;
1724 d
= r10_bio
->devs
[1].devnum
;
1726 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1727 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, wbio
->bi_size
>> 9);
1728 generic_make_request(wbio
);
1733 * Used by fix_read_error() to decay the per rdev read_errors.
1734 * We halve the read error count for every hour that has elapsed
1735 * since the last recorded read error.
1738 static void check_decay_read_errors(struct mddev
*mddev
, struct md_rdev
*rdev
)
1740 struct timespec cur_time_mon
;
1741 unsigned long hours_since_last
;
1742 unsigned int read_errors
= atomic_read(&rdev
->read_errors
);
1744 ktime_get_ts(&cur_time_mon
);
1746 if (rdev
->last_read_error
.tv_sec
== 0 &&
1747 rdev
->last_read_error
.tv_nsec
== 0) {
1748 /* first time we've seen a read error */
1749 rdev
->last_read_error
= cur_time_mon
;
1753 hours_since_last
= (cur_time_mon
.tv_sec
-
1754 rdev
->last_read_error
.tv_sec
) / 3600;
1756 rdev
->last_read_error
= cur_time_mon
;
1759 * if hours_since_last is > the number of bits in read_errors
1760 * just set read errors to 0. We do this to avoid
1761 * overflowing the shift of read_errors by hours_since_last.
1763 if (hours_since_last
>= 8 * sizeof(read_errors
))
1764 atomic_set(&rdev
->read_errors
, 0);
1766 atomic_set(&rdev
->read_errors
, read_errors
>> hours_since_last
);
1769 static int r10_sync_page_io(struct md_rdev
*rdev
, sector_t sector
,
1770 int sectors
, struct page
*page
, int rw
)
1775 if (is_badblock(rdev
, sector
, sectors
, &first_bad
, &bad_sectors
)
1776 && (rw
== READ
|| test_bit(WriteErrorSeen
, &rdev
->flags
)))
1778 if (sync_page_io(rdev
, sector
, sectors
<< 9, page
, rw
, false))
1782 set_bit(WriteErrorSeen
, &rdev
->flags
);
1783 /* need to record an error - either for the block or the device */
1784 if (!rdev_set_badblocks(rdev
, sector
, sectors
, 0))
1785 md_error(rdev
->mddev
, rdev
);
1790 * This is a kernel thread which:
1792 * 1. Retries failed read operations on working mirrors.
1793 * 2. Updates the raid superblock when problems encounter.
1794 * 3. Performs writes following reads for array synchronising.
1797 static void fix_read_error(struct r10conf
*conf
, struct mddev
*mddev
, struct r10bio
*r10_bio
)
1799 int sect
= 0; /* Offset from r10_bio->sector */
1800 int sectors
= r10_bio
->sectors
;
1801 struct md_rdev
*rdev
;
1802 int max_read_errors
= atomic_read(&mddev
->max_corr_read_errors
);
1803 int d
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
1805 /* still own a reference to this rdev, so it cannot
1806 * have been cleared recently.
1808 rdev
= conf
->mirrors
[d
].rdev
;
1810 if (test_bit(Faulty
, &rdev
->flags
))
1811 /* drive has already been failed, just ignore any
1812 more fix_read_error() attempts */
1815 check_decay_read_errors(mddev
, rdev
);
1816 atomic_inc(&rdev
->read_errors
);
1817 if (atomic_read(&rdev
->read_errors
) > max_read_errors
) {
1818 char b
[BDEVNAME_SIZE
];
1819 bdevname(rdev
->bdev
, b
);
1822 "md/raid10:%s: %s: Raid device exceeded "
1823 "read_error threshold [cur %d:max %d]\n",
1825 atomic_read(&rdev
->read_errors
), max_read_errors
);
1827 "md/raid10:%s: %s: Failing raid device\n",
1829 md_error(mddev
, conf
->mirrors
[d
].rdev
);
1835 int sl
= r10_bio
->read_slot
;
1839 if (s
> (PAGE_SIZE
>>9))
1847 d
= r10_bio
->devs
[sl
].devnum
;
1848 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1850 test_bit(In_sync
, &rdev
->flags
) &&
1851 is_badblock(rdev
, r10_bio
->devs
[sl
].addr
+ sect
, s
,
1852 &first_bad
, &bad_sectors
) == 0) {
1853 atomic_inc(&rdev
->nr_pending
);
1855 success
= sync_page_io(rdev
,
1856 r10_bio
->devs
[sl
].addr
+
1859 conf
->tmppage
, READ
, false);
1860 rdev_dec_pending(rdev
, mddev
);
1866 if (sl
== conf
->copies
)
1868 } while (!success
&& sl
!= r10_bio
->read_slot
);
1872 /* Cannot read from anywhere, just mark the block
1873 * as bad on the first device to discourage future
1876 int dn
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
1877 rdev
= conf
->mirrors
[dn
].rdev
;
1879 if (!rdev_set_badblocks(
1881 r10_bio
->devs
[r10_bio
->read_slot
].addr
1884 md_error(mddev
, rdev
);
1889 /* write it back and re-read */
1891 while (sl
!= r10_bio
->read_slot
) {
1892 char b
[BDEVNAME_SIZE
];
1897 d
= r10_bio
->devs
[sl
].devnum
;
1898 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1900 !test_bit(In_sync
, &rdev
->flags
))
1903 atomic_inc(&rdev
->nr_pending
);
1905 if (r10_sync_page_io(rdev
,
1906 r10_bio
->devs
[sl
].addr
+
1908 s
<<9, conf
->tmppage
, WRITE
)
1910 /* Well, this device is dead */
1912 "md/raid10:%s: read correction "
1914 " (%d sectors at %llu on %s)\n",
1916 (unsigned long long)(
1917 sect
+ rdev
->data_offset
),
1918 bdevname(rdev
->bdev
, b
));
1919 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
1922 bdevname(rdev
->bdev
, b
));
1924 rdev_dec_pending(rdev
, mddev
);
1928 while (sl
!= r10_bio
->read_slot
) {
1929 char b
[BDEVNAME_SIZE
];
1934 d
= r10_bio
->devs
[sl
].devnum
;
1935 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1937 !test_bit(In_sync
, &rdev
->flags
))
1940 atomic_inc(&rdev
->nr_pending
);
1942 switch (r10_sync_page_io(rdev
,
1943 r10_bio
->devs
[sl
].addr
+
1945 s
<<9, conf
->tmppage
,
1948 /* Well, this device is dead */
1950 "md/raid10:%s: unable to read back "
1952 " (%d sectors at %llu on %s)\n",
1954 (unsigned long long)(
1955 sect
+ rdev
->data_offset
),
1956 bdevname(rdev
->bdev
, b
));
1957 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
1960 bdevname(rdev
->bdev
, b
));
1964 "md/raid10:%s: read error corrected"
1965 " (%d sectors at %llu on %s)\n",
1967 (unsigned long long)(
1968 sect
+ rdev
->data_offset
),
1969 bdevname(rdev
->bdev
, b
));
1970 atomic_add(s
, &rdev
->corrected_errors
);
1973 rdev_dec_pending(rdev
, mddev
);
1983 static void bi_complete(struct bio
*bio
, int error
)
1985 complete((struct completion
*)bio
->bi_private
);
1988 static int submit_bio_wait(int rw
, struct bio
*bio
)
1990 struct completion event
;
1993 init_completion(&event
);
1994 bio
->bi_private
= &event
;
1995 bio
->bi_end_io
= bi_complete
;
1996 submit_bio(rw
, bio
);
1997 wait_for_completion(&event
);
1999 return test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2002 static int narrow_write_error(struct r10bio
*r10_bio
, int i
)
2004 struct bio
*bio
= r10_bio
->master_bio
;
2005 struct mddev
*mddev
= r10_bio
->mddev
;
2006 struct r10conf
*conf
= mddev
->private;
2007 struct md_rdev
*rdev
= conf
->mirrors
[r10_bio
->devs
[i
].devnum
].rdev
;
2008 /* bio has the data to be written to slot 'i' where
2009 * we just recently had a write error.
2010 * We repeatedly clone the bio and trim down to one block,
2011 * then try the write. Where the write fails we record
2013 * It is conceivable that the bio doesn't exactly align with
2014 * blocks. We must handle this.
2016 * We currently own a reference to the rdev.
2022 int sect_to_write
= r10_bio
->sectors
;
2025 if (rdev
->badblocks
.shift
< 0)
2028 block_sectors
= 1 << rdev
->badblocks
.shift
;
2029 sector
= r10_bio
->sector
;
2030 sectors
= ((r10_bio
->sector
+ block_sectors
)
2031 & ~(sector_t
)(block_sectors
- 1))
2034 while (sect_to_write
) {
2036 if (sectors
> sect_to_write
)
2037 sectors
= sect_to_write
;
2038 /* Write at 'sector' for 'sectors' */
2039 wbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
2040 md_trim_bio(wbio
, sector
- bio
->bi_sector
, sectors
);
2041 wbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
2043 (sector
- r10_bio
->sector
));
2044 wbio
->bi_bdev
= rdev
->bdev
;
2045 if (submit_bio_wait(WRITE
, wbio
) == 0)
2047 ok
= rdev_set_badblocks(rdev
, sector
,
2052 sect_to_write
-= sectors
;
2054 sectors
= block_sectors
;
2059 static void handle_read_error(struct mddev
*mddev
, struct r10bio
*r10_bio
)
2061 int slot
= r10_bio
->read_slot
;
2062 int mirror
= r10_bio
->devs
[slot
].devnum
;
2064 struct r10conf
*conf
= mddev
->private;
2065 struct md_rdev
*rdev
;
2066 char b
[BDEVNAME_SIZE
];
2067 unsigned long do_sync
;
2070 /* we got a read error. Maybe the drive is bad. Maybe just
2071 * the block and we can fix it.
2072 * We freeze all other IO, and try reading the block from
2073 * other devices. When we find one, we re-write
2074 * and check it that fixes the read error.
2075 * This is all done synchronously while the array is
2078 if (mddev
->ro
== 0) {
2080 fix_read_error(conf
, mddev
, r10_bio
);
2081 unfreeze_array(conf
);
2083 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, mddev
);
2085 bio
= r10_bio
->devs
[slot
].bio
;
2086 bdevname(bio
->bi_bdev
, b
);
2087 r10_bio
->devs
[slot
].bio
=
2088 mddev
->ro
? IO_BLOCKED
: NULL
;
2090 mirror
= read_balance(conf
, r10_bio
, &max_sectors
);
2092 printk(KERN_ALERT
"md/raid10:%s: %s: unrecoverable I/O"
2093 " read error for block %llu\n",
2095 (unsigned long long)r10_bio
->sector
);
2096 raid_end_bio_io(r10_bio
);
2101 do_sync
= (r10_bio
->master_bio
->bi_rw
& REQ_SYNC
);
2104 slot
= r10_bio
->read_slot
;
2105 rdev
= conf
->mirrors
[mirror
].rdev
;
2108 "md/raid10:%s: %s: redirecting"
2109 "sector %llu to another mirror\n",
2111 bdevname(rdev
->bdev
, b
),
2112 (unsigned long long)r10_bio
->sector
);
2113 bio
= bio_clone_mddev(r10_bio
->master_bio
,
2116 r10_bio
->sector
- bio
->bi_sector
,
2118 r10_bio
->devs
[slot
].bio
= bio
;
2119 bio
->bi_sector
= r10_bio
->devs
[slot
].addr
2120 + rdev
->data_offset
;
2121 bio
->bi_bdev
= rdev
->bdev
;
2122 bio
->bi_rw
= READ
| do_sync
;
2123 bio
->bi_private
= r10_bio
;
2124 bio
->bi_end_io
= raid10_end_read_request
;
2125 if (max_sectors
< r10_bio
->sectors
) {
2126 /* Drat - have to split this up more */
2127 struct bio
*mbio
= r10_bio
->master_bio
;
2128 int sectors_handled
=
2129 r10_bio
->sector
+ max_sectors
2131 r10_bio
->sectors
= max_sectors
;
2132 spin_lock_irq(&conf
->device_lock
);
2133 if (mbio
->bi_phys_segments
== 0)
2134 mbio
->bi_phys_segments
= 2;
2136 mbio
->bi_phys_segments
++;
2137 spin_unlock_irq(&conf
->device_lock
);
2138 generic_make_request(bio
);
2141 r10_bio
= mempool_alloc(conf
->r10bio_pool
,
2143 r10_bio
->master_bio
= mbio
;
2144 r10_bio
->sectors
= (mbio
->bi_size
>> 9)
2147 set_bit(R10BIO_ReadError
,
2149 r10_bio
->mddev
= mddev
;
2150 r10_bio
->sector
= mbio
->bi_sector
2155 generic_make_request(bio
);
2158 static void handle_write_completed(struct r10conf
*conf
, struct r10bio
*r10_bio
)
2160 /* Some sort of write request has finished and it
2161 * succeeded in writing where we thought there was a
2162 * bad block. So forget the bad block.
2163 * Or possibly if failed and we need to record
2167 struct md_rdev
*rdev
;
2169 if (test_bit(R10BIO_IsSync
, &r10_bio
->state
) ||
2170 test_bit(R10BIO_IsRecover
, &r10_bio
->state
)) {
2171 for (m
= 0; m
< conf
->copies
; m
++) {
2172 int dev
= r10_bio
->devs
[m
].devnum
;
2173 rdev
= conf
->mirrors
[dev
].rdev
;
2174 if (r10_bio
->devs
[m
].bio
== NULL
)
2176 if (test_bit(BIO_UPTODATE
,
2177 &r10_bio
->devs
[m
].bio
->bi_flags
)) {
2178 rdev_clear_badblocks(
2180 r10_bio
->devs
[m
].addr
,
2183 if (!rdev_set_badblocks(
2185 r10_bio
->devs
[m
].addr
,
2186 r10_bio
->sectors
, 0))
2187 md_error(conf
->mddev
, rdev
);
2192 for (m
= 0; m
< conf
->copies
; m
++) {
2193 int dev
= r10_bio
->devs
[m
].devnum
;
2194 struct bio
*bio
= r10_bio
->devs
[m
].bio
;
2195 rdev
= conf
->mirrors
[dev
].rdev
;
2196 if (bio
== IO_MADE_GOOD
) {
2197 rdev_clear_badblocks(
2199 r10_bio
->devs
[m
].addr
,
2201 rdev_dec_pending(rdev
, conf
->mddev
);
2202 } else if (bio
!= NULL
&&
2203 !test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2204 if (!narrow_write_error(r10_bio
, m
)) {
2205 md_error(conf
->mddev
, rdev
);
2206 set_bit(R10BIO_Degraded
,
2209 rdev_dec_pending(rdev
, conf
->mddev
);
2212 if (test_bit(R10BIO_WriteError
,
2214 close_write(r10_bio
);
2215 raid_end_bio_io(r10_bio
);
2219 static void raid10d(struct mddev
*mddev
)
2221 struct r10bio
*r10_bio
;
2222 unsigned long flags
;
2223 struct r10conf
*conf
= mddev
->private;
2224 struct list_head
*head
= &conf
->retry_list
;
2225 struct blk_plug plug
;
2227 md_check_recovery(mddev
);
2229 blk_start_plug(&plug
);
2232 flush_pending_writes(conf
);
2234 spin_lock_irqsave(&conf
->device_lock
, flags
);
2235 if (list_empty(head
)) {
2236 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2239 r10_bio
= list_entry(head
->prev
, struct r10bio
, retry_list
);
2240 list_del(head
->prev
);
2242 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2244 mddev
= r10_bio
->mddev
;
2245 conf
= mddev
->private;
2246 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
2247 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
2248 handle_write_completed(conf
, r10_bio
);
2249 else if (test_bit(R10BIO_IsSync
, &r10_bio
->state
))
2250 sync_request_write(mddev
, r10_bio
);
2251 else if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
))
2252 recovery_request_write(mddev
, r10_bio
);
2253 else if (test_bit(R10BIO_ReadError
, &r10_bio
->state
))
2254 handle_read_error(mddev
, r10_bio
);
2256 /* just a partial read to be scheduled from a
2259 int slot
= r10_bio
->read_slot
;
2260 generic_make_request(r10_bio
->devs
[slot
].bio
);
2264 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
2265 md_check_recovery(mddev
);
2267 blk_finish_plug(&plug
);
2271 static int init_resync(struct r10conf
*conf
)
2275 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
2276 BUG_ON(conf
->r10buf_pool
);
2277 conf
->r10buf_pool
= mempool_create(buffs
, r10buf_pool_alloc
, r10buf_pool_free
, conf
);
2278 if (!conf
->r10buf_pool
)
2280 conf
->next_resync
= 0;
2285 * perform a "sync" on one "block"
2287 * We need to make sure that no normal I/O request - particularly write
2288 * requests - conflict with active sync requests.
2290 * This is achieved by tracking pending requests and a 'barrier' concept
2291 * that can be installed to exclude normal IO requests.
2293 * Resync and recovery are handled very differently.
2294 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2296 * For resync, we iterate over virtual addresses, read all copies,
2297 * and update if there are differences. If only one copy is live,
2299 * For recovery, we iterate over physical addresses, read a good
2300 * value for each non-in_sync drive, and over-write.
2302 * So, for recovery we may have several outstanding complex requests for a
2303 * given address, one for each out-of-sync device. We model this by allocating
2304 * a number of r10_bio structures, one for each out-of-sync device.
2305 * As we setup these structures, we collect all bio's together into a list
2306 * which we then process collectively to add pages, and then process again
2307 * to pass to generic_make_request.
2309 * The r10_bio structures are linked using a borrowed master_bio pointer.
2310 * This link is counted in ->remaining. When the r10_bio that points to NULL
2311 * has its remaining count decremented to 0, the whole complex operation
2316 static sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
,
2317 int *skipped
, int go_faster
)
2319 struct r10conf
*conf
= mddev
->private;
2320 struct r10bio
*r10_bio
;
2321 struct bio
*biolist
= NULL
, *bio
;
2322 sector_t max_sector
, nr_sectors
;
2325 sector_t sync_blocks
;
2326 sector_t sectors_skipped
= 0;
2327 int chunks_skipped
= 0;
2329 if (!conf
->r10buf_pool
)
2330 if (init_resync(conf
))
2334 max_sector
= mddev
->dev_sectors
;
2335 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2336 max_sector
= mddev
->resync_max_sectors
;
2337 if (sector_nr
>= max_sector
) {
2338 /* If we aborted, we need to abort the
2339 * sync on the 'current' bitmap chucks (there can
2340 * be several when recovering multiple devices).
2341 * as we may have started syncing it but not finished.
2342 * We can find the current address in
2343 * mddev->curr_resync, but for recovery,
2344 * we need to convert that to several
2345 * virtual addresses.
2347 if (mddev
->curr_resync
< max_sector
) { /* aborted */
2348 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2349 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
2351 else for (i
=0; i
<conf
->raid_disks
; i
++) {
2353 raid10_find_virt(conf
, mddev
->curr_resync
, i
);
2354 bitmap_end_sync(mddev
->bitmap
, sect
,
2357 } else /* completed sync */
2360 bitmap_close_sync(mddev
->bitmap
);
2363 return sectors_skipped
;
2365 if (chunks_skipped
>= conf
->raid_disks
) {
2366 /* if there has been nothing to do on any drive,
2367 * then there is nothing to do at all..
2370 return (max_sector
- sector_nr
) + sectors_skipped
;
2373 if (max_sector
> mddev
->resync_max
)
2374 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
2376 /* make sure whole request will fit in a chunk - if chunks
2379 if (conf
->near_copies
< conf
->raid_disks
&&
2380 max_sector
> (sector_nr
| conf
->chunk_mask
))
2381 max_sector
= (sector_nr
| conf
->chunk_mask
) + 1;
2383 * If there is non-resync activity waiting for us then
2384 * put in a delay to throttle resync.
2386 if (!go_faster
&& conf
->nr_waiting
)
2387 msleep_interruptible(1000);
2389 /* Again, very different code for resync and recovery.
2390 * Both must result in an r10bio with a list of bios that
2391 * have bi_end_io, bi_sector, bi_bdev set,
2392 * and bi_private set to the r10bio.
2393 * For recovery, we may actually create several r10bios
2394 * with 2 bios in each, that correspond to the bios in the main one.
2395 * In this case, the subordinate r10bios link back through a
2396 * borrowed master_bio pointer, and the counter in the master
2397 * includes a ref from each subordinate.
2399 /* First, we decide what to do and set ->bi_end_io
2400 * To end_sync_read if we want to read, and
2401 * end_sync_write if we will want to write.
2404 max_sync
= RESYNC_PAGES
<< (PAGE_SHIFT
-9);
2405 if (!test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
2406 /* recovery... the complicated one */
2410 for (i
=0 ; i
<conf
->raid_disks
; i
++) {
2417 if (conf
->mirrors
[i
].rdev
== NULL
||
2418 test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
))
2422 /* want to reconstruct this device */
2424 sect
= raid10_find_virt(conf
, sector_nr
, i
);
2425 /* Unless we are doing a full sync, we only need
2426 * to recover the block if it is set in the bitmap
2428 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2430 if (sync_blocks
< max_sync
)
2431 max_sync
= sync_blocks
;
2434 /* yep, skip the sync_blocks here, but don't assume
2435 * that there will never be anything to do here
2437 chunks_skipped
= -1;
2441 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2442 raise_barrier(conf
, rb2
!= NULL
);
2443 atomic_set(&r10_bio
->remaining
, 0);
2445 r10_bio
->master_bio
= (struct bio
*)rb2
;
2447 atomic_inc(&rb2
->remaining
);
2448 r10_bio
->mddev
= mddev
;
2449 set_bit(R10BIO_IsRecover
, &r10_bio
->state
);
2450 r10_bio
->sector
= sect
;
2452 raid10_find_phys(conf
, r10_bio
);
2454 /* Need to check if the array will still be
2457 for (j
=0; j
<conf
->raid_disks
; j
++)
2458 if (conf
->mirrors
[j
].rdev
== NULL
||
2459 test_bit(Faulty
, &conf
->mirrors
[j
].rdev
->flags
)) {
2464 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2465 &sync_blocks
, still_degraded
);
2468 for (j
=0; j
<conf
->copies
;j
++) {
2470 int d
= r10_bio
->devs
[j
].devnum
;
2471 sector_t from_addr
, to_addr
;
2472 struct md_rdev
*rdev
;
2473 sector_t sector
, first_bad
;
2475 if (!conf
->mirrors
[d
].rdev
||
2476 !test_bit(In_sync
, &conf
->mirrors
[d
].rdev
->flags
))
2478 /* This is where we read from */
2480 rdev
= conf
->mirrors
[d
].rdev
;
2481 sector
= r10_bio
->devs
[j
].addr
;
2483 if (is_badblock(rdev
, sector
, max_sync
,
2484 &first_bad
, &bad_sectors
)) {
2485 if (first_bad
> sector
)
2486 max_sync
= first_bad
- sector
;
2488 bad_sectors
-= (sector
2490 if (max_sync
> bad_sectors
)
2491 max_sync
= bad_sectors
;
2495 bio
= r10_bio
->devs
[0].bio
;
2496 bio
->bi_next
= biolist
;
2498 bio
->bi_private
= r10_bio
;
2499 bio
->bi_end_io
= end_sync_read
;
2501 from_addr
= r10_bio
->devs
[j
].addr
;
2502 bio
->bi_sector
= from_addr
+
2503 conf
->mirrors
[d
].rdev
->data_offset
;
2504 bio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
2505 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2506 atomic_inc(&r10_bio
->remaining
);
2507 /* and we write to 'i' */
2509 for (k
=0; k
<conf
->copies
; k
++)
2510 if (r10_bio
->devs
[k
].devnum
== i
)
2512 BUG_ON(k
== conf
->copies
);
2513 bio
= r10_bio
->devs
[1].bio
;
2514 bio
->bi_next
= biolist
;
2516 bio
->bi_private
= r10_bio
;
2517 bio
->bi_end_io
= end_sync_write
;
2519 to_addr
= r10_bio
->devs
[k
].addr
;
2520 bio
->bi_sector
= to_addr
+
2521 conf
->mirrors
[i
].rdev
->data_offset
;
2522 bio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
2524 r10_bio
->devs
[0].devnum
= d
;
2525 r10_bio
->devs
[0].addr
= from_addr
;
2526 r10_bio
->devs
[1].devnum
= i
;
2527 r10_bio
->devs
[1].addr
= to_addr
;
2531 if (j
== conf
->copies
) {
2532 /* Cannot recover, so abort the recovery or
2533 * record a bad block */
2536 atomic_dec(&rb2
->remaining
);
2539 /* problem is that there are bad blocks
2540 * on other device(s)
2543 for (k
= 0; k
< conf
->copies
; k
++)
2544 if (r10_bio
->devs
[k
].devnum
== i
)
2546 if (!rdev_set_badblocks(
2547 conf
->mirrors
[i
].rdev
,
2548 r10_bio
->devs
[k
].addr
,
2553 if (!test_and_set_bit(MD_RECOVERY_INTR
,
2555 printk(KERN_INFO
"md/raid10:%s: insufficient "
2556 "working devices for recovery.\n",
2558 conf
->mirrors
[i
].recovery_disabled
2559 = mddev
->recovery_disabled
;
2564 if (biolist
== NULL
) {
2566 struct r10bio
*rb2
= r10_bio
;
2567 r10_bio
= (struct r10bio
*) rb2
->master_bio
;
2568 rb2
->master_bio
= NULL
;
2574 /* resync. Schedule a read for every block at this virt offset */
2577 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
2579 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
2580 &sync_blocks
, mddev
->degraded
) &&
2581 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
,
2582 &mddev
->recovery
)) {
2583 /* We can skip this block */
2585 return sync_blocks
+ sectors_skipped
;
2587 if (sync_blocks
< max_sync
)
2588 max_sync
= sync_blocks
;
2589 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2591 r10_bio
->mddev
= mddev
;
2592 atomic_set(&r10_bio
->remaining
, 0);
2593 raise_barrier(conf
, 0);
2594 conf
->next_resync
= sector_nr
;
2596 r10_bio
->master_bio
= NULL
;
2597 r10_bio
->sector
= sector_nr
;
2598 set_bit(R10BIO_IsSync
, &r10_bio
->state
);
2599 raid10_find_phys(conf
, r10_bio
);
2600 r10_bio
->sectors
= (sector_nr
| conf
->chunk_mask
) - sector_nr
+1;
2602 for (i
=0; i
<conf
->copies
; i
++) {
2603 int d
= r10_bio
->devs
[i
].devnum
;
2604 sector_t first_bad
, sector
;
2607 bio
= r10_bio
->devs
[i
].bio
;
2608 bio
->bi_end_io
= NULL
;
2609 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2610 if (conf
->mirrors
[d
].rdev
== NULL
||
2611 test_bit(Faulty
, &conf
->mirrors
[d
].rdev
->flags
))
2613 sector
= r10_bio
->devs
[i
].addr
;
2614 if (is_badblock(conf
->mirrors
[d
].rdev
,
2616 &first_bad
, &bad_sectors
)) {
2617 if (first_bad
> sector
)
2618 max_sync
= first_bad
- sector
;
2620 bad_sectors
-= (sector
- first_bad
);
2621 if (max_sync
> bad_sectors
)
2622 max_sync
= max_sync
;
2626 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2627 atomic_inc(&r10_bio
->remaining
);
2628 bio
->bi_next
= biolist
;
2630 bio
->bi_private
= r10_bio
;
2631 bio
->bi_end_io
= end_sync_read
;
2633 bio
->bi_sector
= sector
+
2634 conf
->mirrors
[d
].rdev
->data_offset
;
2635 bio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
2640 for (i
=0; i
<conf
->copies
; i
++) {
2641 int d
= r10_bio
->devs
[i
].devnum
;
2642 if (r10_bio
->devs
[i
].bio
->bi_end_io
)
2643 rdev_dec_pending(conf
->mirrors
[d
].rdev
,
2652 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
2654 bio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
2656 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
2659 bio
->bi_phys_segments
= 0;
2664 if (sector_nr
+ max_sync
< max_sector
)
2665 max_sector
= sector_nr
+ max_sync
;
2668 int len
= PAGE_SIZE
;
2669 if (sector_nr
+ (len
>>9) > max_sector
)
2670 len
= (max_sector
- sector_nr
) << 9;
2673 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
2675 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
2676 if (bio_add_page(bio
, page
, len
, 0))
2680 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
2681 for (bio2
= biolist
;
2682 bio2
&& bio2
!= bio
;
2683 bio2
= bio2
->bi_next
) {
2684 /* remove last page from this bio */
2686 bio2
->bi_size
-= len
;
2687 bio2
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
2691 nr_sectors
+= len
>>9;
2692 sector_nr
+= len
>>9;
2693 } while (biolist
->bi_vcnt
< RESYNC_PAGES
);
2695 r10_bio
->sectors
= nr_sectors
;
2699 biolist
= biolist
->bi_next
;
2701 bio
->bi_next
= NULL
;
2702 r10_bio
= bio
->bi_private
;
2703 r10_bio
->sectors
= nr_sectors
;
2705 if (bio
->bi_end_io
== end_sync_read
) {
2706 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2707 generic_make_request(bio
);
2711 if (sectors_skipped
)
2712 /* pretend they weren't skipped, it makes
2713 * no important difference in this case
2715 md_done_sync(mddev
, sectors_skipped
, 1);
2717 return sectors_skipped
+ nr_sectors
;
2719 /* There is nowhere to write, so all non-sync
2720 * drives must be failed or in resync, all drives
2721 * have a bad block, so try the next chunk...
2723 if (sector_nr
+ max_sync
< max_sector
)
2724 max_sector
= sector_nr
+ max_sync
;
2726 sectors_skipped
+= (max_sector
- sector_nr
);
2728 sector_nr
= max_sector
;
2733 raid10_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
2736 struct r10conf
*conf
= mddev
->private;
2739 raid_disks
= conf
->raid_disks
;
2741 sectors
= conf
->dev_sectors
;
2743 size
= sectors
>> conf
->chunk_shift
;
2744 sector_div(size
, conf
->far_copies
);
2745 size
= size
* raid_disks
;
2746 sector_div(size
, conf
->near_copies
);
2748 return size
<< conf
->chunk_shift
;
2752 static struct r10conf
*setup_conf(struct mddev
*mddev
)
2754 struct r10conf
*conf
= NULL
;
2756 sector_t stride
, size
;
2759 if (mddev
->new_chunk_sectors
< (PAGE_SIZE
>> 9) ||
2760 !is_power_of_2(mddev
->new_chunk_sectors
)) {
2761 printk(KERN_ERR
"md/raid10:%s: chunk size must be "
2762 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
2763 mdname(mddev
), PAGE_SIZE
);
2767 nc
= mddev
->new_layout
& 255;
2768 fc
= (mddev
->new_layout
>> 8) & 255;
2769 fo
= mddev
->new_layout
& (1<<16);
2771 if ((nc
*fc
) <2 || (nc
*fc
) > mddev
->raid_disks
||
2772 (mddev
->new_layout
>> 17)) {
2773 printk(KERN_ERR
"md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
2774 mdname(mddev
), mddev
->new_layout
);
2779 conf
= kzalloc(sizeof(struct r10conf
), GFP_KERNEL
);
2783 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
2788 conf
->tmppage
= alloc_page(GFP_KERNEL
);
2793 conf
->raid_disks
= mddev
->raid_disks
;
2794 conf
->near_copies
= nc
;
2795 conf
->far_copies
= fc
;
2796 conf
->copies
= nc
*fc
;
2797 conf
->far_offset
= fo
;
2798 conf
->chunk_mask
= mddev
->new_chunk_sectors
- 1;
2799 conf
->chunk_shift
= ffz(~mddev
->new_chunk_sectors
);
2801 conf
->r10bio_pool
= mempool_create(NR_RAID10_BIOS
, r10bio_pool_alloc
,
2802 r10bio_pool_free
, conf
);
2803 if (!conf
->r10bio_pool
)
2806 size
= mddev
->dev_sectors
>> conf
->chunk_shift
;
2807 sector_div(size
, fc
);
2808 size
= size
* conf
->raid_disks
;
2809 sector_div(size
, nc
);
2810 /* 'size' is now the number of chunks in the array */
2811 /* calculate "used chunks per device" in 'stride' */
2812 stride
= size
* conf
->copies
;
2814 /* We need to round up when dividing by raid_disks to
2815 * get the stride size.
2817 stride
+= conf
->raid_disks
- 1;
2818 sector_div(stride
, conf
->raid_disks
);
2820 conf
->dev_sectors
= stride
<< conf
->chunk_shift
;
2825 sector_div(stride
, fc
);
2826 conf
->stride
= stride
<< conf
->chunk_shift
;
2829 spin_lock_init(&conf
->device_lock
);
2830 INIT_LIST_HEAD(&conf
->retry_list
);
2832 spin_lock_init(&conf
->resync_lock
);
2833 init_waitqueue_head(&conf
->wait_barrier
);
2835 conf
->thread
= md_register_thread(raid10d
, mddev
, NULL
);
2839 conf
->mddev
= mddev
;
2843 printk(KERN_ERR
"md/raid10:%s: couldn't allocate memory.\n",
2846 if (conf
->r10bio_pool
)
2847 mempool_destroy(conf
->r10bio_pool
);
2848 kfree(conf
->mirrors
);
2849 safe_put_page(conf
->tmppage
);
2852 return ERR_PTR(err
);
2855 static int run(struct mddev
*mddev
)
2857 struct r10conf
*conf
;
2858 int i
, disk_idx
, chunk_size
;
2859 struct mirror_info
*disk
;
2860 struct md_rdev
*rdev
;
2864 * copy the already verified devices into our private RAID10
2865 * bookkeeping area. [whatever we allocate in run(),
2866 * should be freed in stop()]
2869 if (mddev
->private == NULL
) {
2870 conf
= setup_conf(mddev
);
2872 return PTR_ERR(conf
);
2873 mddev
->private = conf
;
2875 conf
= mddev
->private;
2879 mddev
->thread
= conf
->thread
;
2880 conf
->thread
= NULL
;
2882 chunk_size
= mddev
->chunk_sectors
<< 9;
2883 blk_queue_io_min(mddev
->queue
, chunk_size
);
2884 if (conf
->raid_disks
% conf
->near_copies
)
2885 blk_queue_io_opt(mddev
->queue
, chunk_size
* conf
->raid_disks
);
2887 blk_queue_io_opt(mddev
->queue
, chunk_size
*
2888 (conf
->raid_disks
/ conf
->near_copies
));
2890 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
2892 disk_idx
= rdev
->raid_disk
;
2893 if (disk_idx
>= conf
->raid_disks
2896 disk
= conf
->mirrors
+ disk_idx
;
2899 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
2900 rdev
->data_offset
<< 9);
2901 /* as we don't honour merge_bvec_fn, we must never risk
2902 * violating it, so limit max_segments to 1 lying
2903 * within a single page.
2905 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
2906 blk_queue_max_segments(mddev
->queue
, 1);
2907 blk_queue_segment_boundary(mddev
->queue
,
2908 PAGE_CACHE_SIZE
- 1);
2911 disk
->head_position
= 0;
2913 /* need to check that every block has at least one working mirror */
2914 if (!enough(conf
, -1)) {
2915 printk(KERN_ERR
"md/raid10:%s: not enough operational mirrors.\n",
2920 mddev
->degraded
= 0;
2921 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2923 disk
= conf
->mirrors
+ i
;
2926 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
2927 disk
->head_position
= 0;
2932 disk
->recovery_disabled
= mddev
->recovery_disabled
- 1;
2935 if (mddev
->recovery_cp
!= MaxSector
)
2936 printk(KERN_NOTICE
"md/raid10:%s: not clean"
2937 " -- starting background reconstruction\n",
2940 "md/raid10:%s: active with %d out of %d devices\n",
2941 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
,
2944 * Ok, everything is just fine now
2946 mddev
->dev_sectors
= conf
->dev_sectors
;
2947 size
= raid10_size(mddev
, 0, 0);
2948 md_set_array_sectors(mddev
, size
);
2949 mddev
->resync_max_sectors
= size
;
2951 mddev
->queue
->backing_dev_info
.congested_fn
= raid10_congested
;
2952 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
2954 /* Calculate max read-ahead size.
2955 * We need to readahead at least twice a whole stripe....
2959 int stripe
= conf
->raid_disks
*
2960 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
2961 stripe
/= conf
->near_copies
;
2962 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2* stripe
)
2963 mddev
->queue
->backing_dev_info
.ra_pages
= 2* stripe
;
2966 if (conf
->near_copies
< conf
->raid_disks
)
2967 blk_queue_merge_bvec(mddev
->queue
, raid10_mergeable_bvec
);
2969 if (md_integrity_register(mddev
))
2975 md_unregister_thread(&mddev
->thread
);
2976 if (conf
->r10bio_pool
)
2977 mempool_destroy(conf
->r10bio_pool
);
2978 safe_put_page(conf
->tmppage
);
2979 kfree(conf
->mirrors
);
2981 mddev
->private = NULL
;
2986 static int stop(struct mddev
*mddev
)
2988 struct r10conf
*conf
= mddev
->private;
2990 raise_barrier(conf
, 0);
2991 lower_barrier(conf
);
2993 md_unregister_thread(&mddev
->thread
);
2994 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
2995 if (conf
->r10bio_pool
)
2996 mempool_destroy(conf
->r10bio_pool
);
2997 kfree(conf
->mirrors
);
2999 mddev
->private = NULL
;
3003 static void raid10_quiesce(struct mddev
*mddev
, int state
)
3005 struct r10conf
*conf
= mddev
->private;
3009 raise_barrier(conf
, 0);
3012 lower_barrier(conf
);
3017 static void *raid10_takeover_raid0(struct mddev
*mddev
)
3019 struct md_rdev
*rdev
;
3020 struct r10conf
*conf
;
3022 if (mddev
->degraded
> 0) {
3023 printk(KERN_ERR
"md/raid10:%s: Error: degraded raid0!\n",
3025 return ERR_PTR(-EINVAL
);
3028 /* Set new parameters */
3029 mddev
->new_level
= 10;
3030 /* new layout: far_copies = 1, near_copies = 2 */
3031 mddev
->new_layout
= (1<<8) + 2;
3032 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
3033 mddev
->delta_disks
= mddev
->raid_disks
;
3034 mddev
->raid_disks
*= 2;
3035 /* make sure it will be not marked as dirty */
3036 mddev
->recovery_cp
= MaxSector
;
3038 conf
= setup_conf(mddev
);
3039 if (!IS_ERR(conf
)) {
3040 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
3041 if (rdev
->raid_disk
>= 0)
3042 rdev
->new_raid_disk
= rdev
->raid_disk
* 2;
3049 static void *raid10_takeover(struct mddev
*mddev
)
3051 struct r0conf
*raid0_conf
;
3053 /* raid10 can take over:
3054 * raid0 - providing it has only two drives
3056 if (mddev
->level
== 0) {
3057 /* for raid0 takeover only one zone is supported */
3058 raid0_conf
= mddev
->private;
3059 if (raid0_conf
->nr_strip_zones
> 1) {
3060 printk(KERN_ERR
"md/raid10:%s: cannot takeover raid 0"
3061 " with more than one zone.\n",
3063 return ERR_PTR(-EINVAL
);
3065 return raid10_takeover_raid0(mddev
);
3067 return ERR_PTR(-EINVAL
);
3070 static struct md_personality raid10_personality
=
3074 .owner
= THIS_MODULE
,
3075 .make_request
= make_request
,
3079 .error_handler
= error
,
3080 .hot_add_disk
= raid10_add_disk
,
3081 .hot_remove_disk
= raid10_remove_disk
,
3082 .spare_active
= raid10_spare_active
,
3083 .sync_request
= sync_request
,
3084 .quiesce
= raid10_quiesce
,
3085 .size
= raid10_size
,
3086 .takeover
= raid10_takeover
,
3089 static int __init
raid_init(void)
3091 return register_md_personality(&raid10_personality
);
3094 static void raid_exit(void)
3096 unregister_md_personality(&raid10_personality
);
3099 module_init(raid_init
);
3100 module_exit(raid_exit
);
3101 MODULE_LICENSE("GPL");
3102 MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
3103 MODULE_ALIAS("md-personality-9"); /* RAID10 */
3104 MODULE_ALIAS("md-raid10");
3105 MODULE_ALIAS("md-level-10");
3107 module_param(max_queued_requests
, int, S_IRUGO
|S_IWUSR
);