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 static void allow_barrier(conf_t
*conf
);
62 static void lower_barrier(conf_t
*conf
);
64 static void * r10bio_pool_alloc(gfp_t gfp_flags
, void *data
)
67 int size
= offsetof(struct r10bio_s
, devs
[conf
->copies
]);
69 /* allocate a r10bio with room for raid_disks entries in the bios array */
70 return kzalloc(size
, gfp_flags
);
73 static void r10bio_pool_free(void *r10_bio
, void *data
)
78 /* Maximum size of each resync request */
79 #define RESYNC_BLOCK_SIZE (64*1024)
80 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
81 /* amount of memory to reserve for resync requests */
82 #define RESYNC_WINDOW (1024*1024)
83 /* maximum number of concurrent requests, memory permitting */
84 #define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
87 * When performing a resync, we need to read and compare, so
88 * we need as many pages are there are copies.
89 * When performing a recovery, we need 2 bios, one for read,
90 * one for write (we recover only one drive per r10buf)
93 static void * r10buf_pool_alloc(gfp_t gfp_flags
, void *data
)
102 r10_bio
= r10bio_pool_alloc(gfp_flags
, conf
);
106 if (test_bit(MD_RECOVERY_SYNC
, &conf
->mddev
->recovery
))
107 nalloc
= conf
->copies
; /* resync */
109 nalloc
= 2; /* recovery */
114 for (j
= nalloc
; j
-- ; ) {
115 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
118 r10_bio
->devs
[j
].bio
= bio
;
121 * Allocate RESYNC_PAGES data pages and attach them
124 for (j
= 0 ; j
< nalloc
; j
++) {
125 bio
= r10_bio
->devs
[j
].bio
;
126 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
127 if (j
== 1 && !test_bit(MD_RECOVERY_SYNC
,
128 &conf
->mddev
->recovery
)) {
129 /* we can share bv_page's during recovery */
130 struct bio
*rbio
= r10_bio
->devs
[0].bio
;
131 page
= rbio
->bi_io_vec
[i
].bv_page
;
134 page
= alloc_page(gfp_flags
);
138 bio
->bi_io_vec
[i
].bv_page
= page
;
146 safe_put_page(bio
->bi_io_vec
[i
-1].bv_page
);
148 for (i
= 0; i
< RESYNC_PAGES
; i
++)
149 safe_put_page(r10_bio
->devs
[j
].bio
->bi_io_vec
[i
].bv_page
);
152 while ( ++j
< nalloc
)
153 bio_put(r10_bio
->devs
[j
].bio
);
154 r10bio_pool_free(r10_bio
, conf
);
158 static void r10buf_pool_free(void *__r10_bio
, void *data
)
162 r10bio_t
*r10bio
= __r10_bio
;
165 for (j
=0; j
< conf
->copies
; j
++) {
166 struct bio
*bio
= r10bio
->devs
[j
].bio
;
168 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
169 safe_put_page(bio
->bi_io_vec
[i
].bv_page
);
170 bio
->bi_io_vec
[i
].bv_page
= NULL
;
175 r10bio_pool_free(r10bio
, conf
);
178 static void put_all_bios(conf_t
*conf
, r10bio_t
*r10_bio
)
182 for (i
= 0; i
< conf
->copies
; i
++) {
183 struct bio
**bio
= & r10_bio
->devs
[i
].bio
;
184 if (!BIO_SPECIAL(*bio
))
190 static void free_r10bio(r10bio_t
*r10_bio
)
192 conf_t
*conf
= r10_bio
->mddev
->private;
194 put_all_bios(conf
, r10_bio
);
195 mempool_free(r10_bio
, conf
->r10bio_pool
);
198 static void put_buf(r10bio_t
*r10_bio
)
200 conf_t
*conf
= r10_bio
->mddev
->private;
202 mempool_free(r10_bio
, conf
->r10buf_pool
);
207 static void reschedule_retry(r10bio_t
*r10_bio
)
210 mddev_t
*mddev
= r10_bio
->mddev
;
211 conf_t
*conf
= mddev
->private;
213 spin_lock_irqsave(&conf
->device_lock
, flags
);
214 list_add(&r10_bio
->retry_list
, &conf
->retry_list
);
216 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
218 /* wake up frozen array... */
219 wake_up(&conf
->wait_barrier
);
221 md_wakeup_thread(mddev
->thread
);
225 * raid_end_bio_io() is called when we have finished servicing a mirrored
226 * operation and are ready to return a success/failure code to the buffer
229 static void raid_end_bio_io(r10bio_t
*r10_bio
)
231 struct bio
*bio
= r10_bio
->master_bio
;
233 conf_t
*conf
= r10_bio
->mddev
->private;
235 if (bio
->bi_phys_segments
) {
237 spin_lock_irqsave(&conf
->device_lock
, flags
);
238 bio
->bi_phys_segments
--;
239 done
= (bio
->bi_phys_segments
== 0);
240 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
243 if (!test_bit(R10BIO_Uptodate
, &r10_bio
->state
))
244 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
248 * Wake up any possible resync thread that waits for the device
253 free_r10bio(r10_bio
);
257 * Update disk head position estimator based on IRQ completion info.
259 static inline void update_head_pos(int slot
, r10bio_t
*r10_bio
)
261 conf_t
*conf
= r10_bio
->mddev
->private;
263 conf
->mirrors
[r10_bio
->devs
[slot
].devnum
].head_position
=
264 r10_bio
->devs
[slot
].addr
+ (r10_bio
->sectors
);
268 * Find the disk number which triggered given bio
270 static int find_bio_disk(conf_t
*conf
, r10bio_t
*r10_bio
,
271 struct bio
*bio
, int *slotp
)
275 for (slot
= 0; slot
< conf
->copies
; slot
++)
276 if (r10_bio
->devs
[slot
].bio
== bio
)
279 BUG_ON(slot
== conf
->copies
);
280 update_head_pos(slot
, r10_bio
);
284 return r10_bio
->devs
[slot
].devnum
;
287 static void raid10_end_read_request(struct bio
*bio
, int error
)
289 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
290 r10bio_t
*r10_bio
= bio
->bi_private
;
292 conf_t
*conf
= r10_bio
->mddev
->private;
295 slot
= r10_bio
->read_slot
;
296 dev
= r10_bio
->devs
[slot
].devnum
;
298 * this branch is our 'one mirror IO has finished' event handler:
300 update_head_pos(slot
, r10_bio
);
304 * Set R10BIO_Uptodate in our master bio, so that
305 * we will return a good error code to the higher
306 * levels even if IO on some other mirrored buffer fails.
308 * The 'master' represents the composite IO operation to
309 * user-side. So if something waits for IO, then it will
310 * wait for the 'master' bio.
312 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
313 raid_end_bio_io(r10_bio
);
314 rdev_dec_pending(conf
->mirrors
[dev
].rdev
, conf
->mddev
);
317 * oops, read error - keep the refcount on the rdev
319 char b
[BDEVNAME_SIZE
];
320 printk_ratelimited(KERN_ERR
321 "md/raid10:%s: %s: rescheduling sector %llu\n",
323 bdevname(conf
->mirrors
[dev
].rdev
->bdev
, b
),
324 (unsigned long long)r10_bio
->sector
);
325 set_bit(R10BIO_ReadError
, &r10_bio
->state
);
326 reschedule_retry(r10_bio
);
330 static void close_write(r10bio_t
*r10_bio
)
332 /* clear the bitmap if all writes complete successfully */
333 bitmap_endwrite(r10_bio
->mddev
->bitmap
, r10_bio
->sector
,
335 !test_bit(R10BIO_Degraded
, &r10_bio
->state
),
337 md_write_end(r10_bio
->mddev
);
340 static void raid10_end_write_request(struct bio
*bio
, int error
)
342 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
343 r10bio_t
*r10_bio
= bio
->bi_private
;
346 conf_t
*conf
= r10_bio
->mddev
->private;
349 dev
= find_bio_disk(conf
, r10_bio
, bio
, &slot
);
352 * this branch is our 'one mirror IO has finished' event handler:
355 set_bit(WriteErrorSeen
, &conf
->mirrors
[dev
].rdev
->flags
);
356 set_bit(R10BIO_WriteError
, &r10_bio
->state
);
360 * Set R10BIO_Uptodate in our master bio, so that
361 * we will return a good error code for to the higher
362 * levels even if IO on some other mirrored buffer fails.
364 * The 'master' represents the composite IO operation to
365 * user-side. So if something waits for IO, then it will
366 * wait for the 'master' bio.
371 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
373 /* Maybe we can clear some bad blocks. */
374 if (is_badblock(conf
->mirrors
[dev
].rdev
,
375 r10_bio
->devs
[slot
].addr
,
377 &first_bad
, &bad_sectors
)) {
379 r10_bio
->devs
[slot
].bio
= IO_MADE_GOOD
;
381 set_bit(R10BIO_MadeGood
, &r10_bio
->state
);
387 * Let's see if all mirrored write operations have finished
390 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
391 if (test_bit(R10BIO_WriteError
, &r10_bio
->state
))
392 reschedule_retry(r10_bio
);
394 close_write(r10_bio
);
395 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
))
396 reschedule_retry(r10_bio
);
398 raid_end_bio_io(r10_bio
);
402 rdev_dec_pending(conf
->mirrors
[dev
].rdev
, conf
->mddev
);
407 * RAID10 layout manager
408 * As well as the chunksize and raid_disks count, there are two
409 * parameters: near_copies and far_copies.
410 * near_copies * far_copies must be <= raid_disks.
411 * Normally one of these will be 1.
412 * If both are 1, we get raid0.
413 * If near_copies == raid_disks, we get raid1.
415 * Chunks are laid out in raid0 style with near_copies copies of the
416 * first chunk, followed by near_copies copies of the next chunk and
418 * If far_copies > 1, then after 1/far_copies of the array has been assigned
419 * as described above, we start again with a device offset of near_copies.
420 * So we effectively have another copy of the whole array further down all
421 * the drives, but with blocks on different drives.
422 * With this layout, and block is never stored twice on the one device.
424 * raid10_find_phys finds the sector offset of a given virtual sector
425 * on each device that it is on.
427 * raid10_find_virt does the reverse mapping, from a device and a
428 * sector offset to a virtual address
431 static void raid10_find_phys(conf_t
*conf
, r10bio_t
*r10bio
)
441 /* now calculate first sector/dev */
442 chunk
= r10bio
->sector
>> conf
->chunk_shift
;
443 sector
= r10bio
->sector
& conf
->chunk_mask
;
445 chunk
*= conf
->near_copies
;
447 dev
= sector_div(stripe
, conf
->raid_disks
);
448 if (conf
->far_offset
)
449 stripe
*= conf
->far_copies
;
451 sector
+= stripe
<< conf
->chunk_shift
;
453 /* and calculate all the others */
454 for (n
=0; n
< conf
->near_copies
; n
++) {
457 r10bio
->devs
[slot
].addr
= sector
;
458 r10bio
->devs
[slot
].devnum
= d
;
461 for (f
= 1; f
< conf
->far_copies
; f
++) {
462 d
+= conf
->near_copies
;
463 if (d
>= conf
->raid_disks
)
464 d
-= conf
->raid_disks
;
466 r10bio
->devs
[slot
].devnum
= d
;
467 r10bio
->devs
[slot
].addr
= s
;
471 if (dev
>= conf
->raid_disks
) {
473 sector
+= (conf
->chunk_mask
+ 1);
476 BUG_ON(slot
!= conf
->copies
);
479 static sector_t
raid10_find_virt(conf_t
*conf
, sector_t sector
, int dev
)
481 sector_t offset
, chunk
, vchunk
;
483 offset
= sector
& conf
->chunk_mask
;
484 if (conf
->far_offset
) {
486 chunk
= sector
>> conf
->chunk_shift
;
487 fc
= sector_div(chunk
, conf
->far_copies
);
488 dev
-= fc
* conf
->near_copies
;
490 dev
+= conf
->raid_disks
;
492 while (sector
>= conf
->stride
) {
493 sector
-= conf
->stride
;
494 if (dev
< conf
->near_copies
)
495 dev
+= conf
->raid_disks
- conf
->near_copies
;
497 dev
-= conf
->near_copies
;
499 chunk
= sector
>> conf
->chunk_shift
;
501 vchunk
= chunk
* conf
->raid_disks
+ dev
;
502 sector_div(vchunk
, conf
->near_copies
);
503 return (vchunk
<< conf
->chunk_shift
) + offset
;
507 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
509 * @bvm: properties of new bio
510 * @biovec: the request that could be merged to it.
512 * Return amount of bytes we can accept at this offset
513 * If near_copies == raid_disk, there are no striping issues,
514 * but in that case, the function isn't called at all.
516 static int raid10_mergeable_bvec(struct request_queue
*q
,
517 struct bvec_merge_data
*bvm
,
518 struct bio_vec
*biovec
)
520 mddev_t
*mddev
= q
->queuedata
;
521 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
523 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
524 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
526 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
527 if (max
< 0) max
= 0; /* bio_add cannot handle a negative return */
528 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
529 return biovec
->bv_len
;
535 * This routine returns the disk from which the requested read should
536 * be done. There is a per-array 'next expected sequential IO' sector
537 * number - if this matches on the next IO then we use the last disk.
538 * There is also a per-disk 'last know head position' sector that is
539 * maintained from IRQ contexts, both the normal and the resync IO
540 * completion handlers update this position correctly. If there is no
541 * perfect sequential match then we pick the disk whose head is closest.
543 * If there are 2 mirrors in the same 2 devices, performance degrades
544 * because position is mirror, not device based.
546 * The rdev for the device selected will have nr_pending incremented.
550 * FIXME: possibly should rethink readbalancing and do it differently
551 * depending on near_copies / far_copies geometry.
553 static int read_balance(conf_t
*conf
, r10bio_t
*r10_bio
, int *max_sectors
)
555 const sector_t this_sector
= r10_bio
->sector
;
557 int sectors
= r10_bio
->sectors
;
558 int best_good_sectors
;
559 sector_t new_distance
, best_dist
;
564 raid10_find_phys(conf
, r10_bio
);
567 sectors
= r10_bio
->sectors
;
569 best_dist
= MaxSector
;
570 best_good_sectors
= 0;
573 * Check if we can balance. We can balance on the whole
574 * device if no resync is going on (recovery is ok), or below
575 * the resync window. We take the first readable disk when
576 * above the resync window.
578 if (conf
->mddev
->recovery_cp
< MaxSector
579 && (this_sector
+ sectors
>= conf
->next_resync
))
582 for (slot
= 0; slot
< conf
->copies
; slot
++) {
587 if (r10_bio
->devs
[slot
].bio
== IO_BLOCKED
)
589 disk
= r10_bio
->devs
[slot
].devnum
;
590 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
593 if (!test_bit(In_sync
, &rdev
->flags
))
596 dev_sector
= r10_bio
->devs
[slot
].addr
;
597 if (is_badblock(rdev
, dev_sector
, sectors
,
598 &first_bad
, &bad_sectors
)) {
599 if (best_dist
< MaxSector
)
600 /* Already have a better slot */
602 if (first_bad
<= dev_sector
) {
603 /* Cannot read here. If this is the
604 * 'primary' device, then we must not read
605 * beyond 'bad_sectors' from another device.
607 bad_sectors
-= (dev_sector
- first_bad
);
608 if (!do_balance
&& sectors
> bad_sectors
)
609 sectors
= bad_sectors
;
610 if (best_good_sectors
> sectors
)
611 best_good_sectors
= sectors
;
613 sector_t good_sectors
=
614 first_bad
- dev_sector
;
615 if (good_sectors
> best_good_sectors
) {
616 best_good_sectors
= good_sectors
;
620 /* Must read from here */
625 best_good_sectors
= sectors
;
630 /* This optimisation is debatable, and completely destroys
631 * sequential read speed for 'far copies' arrays. So only
632 * keep it for 'near' arrays, and review those later.
634 if (conf
->near_copies
> 1 && !atomic_read(&rdev
->nr_pending
))
637 /* for far > 1 always use the lowest address */
638 if (conf
->far_copies
> 1)
639 new_distance
= r10_bio
->devs
[slot
].addr
;
641 new_distance
= abs(r10_bio
->devs
[slot
].addr
-
642 conf
->mirrors
[disk
].head_position
);
643 if (new_distance
< best_dist
) {
644 best_dist
= new_distance
;
648 if (slot
== conf
->copies
)
652 disk
= r10_bio
->devs
[slot
].devnum
;
653 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
656 atomic_inc(&rdev
->nr_pending
);
657 if (test_bit(Faulty
, &rdev
->flags
)) {
658 /* Cannot risk returning a device that failed
659 * before we inc'ed nr_pending
661 rdev_dec_pending(rdev
, conf
->mddev
);
664 r10_bio
->read_slot
= slot
;
668 *max_sectors
= best_good_sectors
;
673 static int raid10_congested(void *data
, int bits
)
675 mddev_t
*mddev
= data
;
676 conf_t
*conf
= mddev
->private;
679 if (mddev_congested(mddev
, bits
))
682 for (i
= 0; i
< conf
->raid_disks
&& ret
== 0; i
++) {
683 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
684 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
685 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
687 ret
|= bdi_congested(&q
->backing_dev_info
, bits
);
694 static void flush_pending_writes(conf_t
*conf
)
696 /* Any writes that have been queued but are awaiting
697 * bitmap updates get flushed here.
699 spin_lock_irq(&conf
->device_lock
);
701 if (conf
->pending_bio_list
.head
) {
703 bio
= bio_list_get(&conf
->pending_bio_list
);
704 spin_unlock_irq(&conf
->device_lock
);
705 /* flush any pending bitmap writes to disk
706 * before proceeding w/ I/O */
707 bitmap_unplug(conf
->mddev
->bitmap
);
709 while (bio
) { /* submit pending writes */
710 struct bio
*next
= bio
->bi_next
;
712 generic_make_request(bio
);
716 spin_unlock_irq(&conf
->device_lock
);
720 * Sometimes we need to suspend IO while we do something else,
721 * either some resync/recovery, or reconfigure the array.
722 * To do this we raise a 'barrier'.
723 * The 'barrier' is a counter that can be raised multiple times
724 * to count how many activities are happening which preclude
726 * We can only raise the barrier if there is no pending IO.
727 * i.e. if nr_pending == 0.
728 * We choose only to raise the barrier if no-one is waiting for the
729 * barrier to go down. This means that as soon as an IO request
730 * is ready, no other operations which require a barrier will start
731 * until the IO request has had a chance.
733 * So: regular IO calls 'wait_barrier'. When that returns there
734 * is no backgroup IO happening, It must arrange to call
735 * allow_barrier when it has finished its IO.
736 * backgroup IO calls must call raise_barrier. Once that returns
737 * there is no normal IO happeing. It must arrange to call
738 * lower_barrier when the particular background IO completes.
741 static void raise_barrier(conf_t
*conf
, int force
)
743 BUG_ON(force
&& !conf
->barrier
);
744 spin_lock_irq(&conf
->resync_lock
);
746 /* Wait until no block IO is waiting (unless 'force') */
747 wait_event_lock_irq(conf
->wait_barrier
, force
|| !conf
->nr_waiting
,
748 conf
->resync_lock
, );
750 /* block any new IO from starting */
753 /* Now wait for all pending IO to complete */
754 wait_event_lock_irq(conf
->wait_barrier
,
755 !conf
->nr_pending
&& conf
->barrier
< RESYNC_DEPTH
,
756 conf
->resync_lock
, );
758 spin_unlock_irq(&conf
->resync_lock
);
761 static void lower_barrier(conf_t
*conf
)
764 spin_lock_irqsave(&conf
->resync_lock
, flags
);
766 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
767 wake_up(&conf
->wait_barrier
);
770 static void wait_barrier(conf_t
*conf
)
772 spin_lock_irq(&conf
->resync_lock
);
775 wait_event_lock_irq(conf
->wait_barrier
, !conf
->barrier
,
781 spin_unlock_irq(&conf
->resync_lock
);
784 static void allow_barrier(conf_t
*conf
)
787 spin_lock_irqsave(&conf
->resync_lock
, flags
);
789 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
790 wake_up(&conf
->wait_barrier
);
793 static void freeze_array(conf_t
*conf
)
795 /* stop syncio and normal IO and wait for everything to
797 * We increment barrier and nr_waiting, and then
798 * wait until nr_pending match nr_queued+1
799 * This is called in the context of one normal IO request
800 * that has failed. Thus any sync request that might be pending
801 * will be blocked by nr_pending, and we need to wait for
802 * pending IO requests to complete or be queued for re-try.
803 * Thus the number queued (nr_queued) plus this request (1)
804 * must match the number of pending IOs (nr_pending) before
807 spin_lock_irq(&conf
->resync_lock
);
810 wait_event_lock_irq(conf
->wait_barrier
,
811 conf
->nr_pending
== conf
->nr_queued
+1,
813 flush_pending_writes(conf
));
815 spin_unlock_irq(&conf
->resync_lock
);
818 static void unfreeze_array(conf_t
*conf
)
820 /* reverse the effect of the freeze */
821 spin_lock_irq(&conf
->resync_lock
);
824 wake_up(&conf
->wait_barrier
);
825 spin_unlock_irq(&conf
->resync_lock
);
828 static int make_request(mddev_t
*mddev
, struct bio
* bio
)
830 conf_t
*conf
= mddev
->private;
831 mirror_info_t
*mirror
;
833 struct bio
*read_bio
;
835 int chunk_sects
= conf
->chunk_mask
+ 1;
836 const int rw
= bio_data_dir(bio
);
837 const unsigned long do_sync
= (bio
->bi_rw
& REQ_SYNC
);
838 const unsigned long do_fua
= (bio
->bi_rw
& REQ_FUA
);
840 mdk_rdev_t
*blocked_rdev
;
845 if (unlikely(bio
->bi_rw
& REQ_FLUSH
)) {
846 md_flush_request(mddev
, bio
);
850 /* If this request crosses a chunk boundary, we need to
851 * split it. This will only happen for 1 PAGE (or less) requests.
853 if (unlikely( (bio
->bi_sector
& conf
->chunk_mask
) + (bio
->bi_size
>> 9)
855 conf
->near_copies
< conf
->raid_disks
)) {
857 /* Sanity check -- queue functions should prevent this happening */
858 if (bio
->bi_vcnt
!= 1 ||
861 /* This is a one page bio that upper layers
862 * refuse to split for us, so we need to split it.
865 chunk_sects
- (bio
->bi_sector
& (chunk_sects
- 1)) );
867 /* Each of these 'make_request' calls will call 'wait_barrier'.
868 * If the first succeeds but the second blocks due to the resync
869 * thread raising the barrier, we will deadlock because the
870 * IO to the underlying device will be queued in generic_make_request
871 * and will never complete, so will never reduce nr_pending.
872 * So increment nr_waiting here so no new raise_barriers will
873 * succeed, and so the second wait_barrier cannot block.
875 spin_lock_irq(&conf
->resync_lock
);
877 spin_unlock_irq(&conf
->resync_lock
);
879 if (make_request(mddev
, &bp
->bio1
))
880 generic_make_request(&bp
->bio1
);
881 if (make_request(mddev
, &bp
->bio2
))
882 generic_make_request(&bp
->bio2
);
884 spin_lock_irq(&conf
->resync_lock
);
886 wake_up(&conf
->wait_barrier
);
887 spin_unlock_irq(&conf
->resync_lock
);
889 bio_pair_release(bp
);
892 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
893 " or bigger than %dk %llu %d\n", mdname(mddev
), chunk_sects
/2,
894 (unsigned long long)bio
->bi_sector
, bio
->bi_size
>> 10);
900 md_write_start(mddev
, bio
);
903 * Register the new request and wait if the reconstruction
904 * thread has put up a bar for new requests.
905 * Continue immediately if no resync is active currently.
909 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
911 r10_bio
->master_bio
= bio
;
912 r10_bio
->sectors
= bio
->bi_size
>> 9;
914 r10_bio
->mddev
= mddev
;
915 r10_bio
->sector
= bio
->bi_sector
;
918 /* We might need to issue multiple reads to different
919 * devices if there are bad blocks around, so we keep
920 * track of the number of reads in bio->bi_phys_segments.
921 * If this is 0, there is only one r10_bio and no locking
922 * will be needed when the request completes. If it is
923 * non-zero, then it is the number of not-completed requests.
925 bio
->bi_phys_segments
= 0;
926 clear_bit(BIO_SEG_VALID
, &bio
->bi_flags
);
930 * read balancing logic:
936 disk
= read_balance(conf
, r10_bio
, &max_sectors
);
937 slot
= r10_bio
->read_slot
;
939 raid_end_bio_io(r10_bio
);
942 mirror
= conf
->mirrors
+ disk
;
944 read_bio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
945 md_trim_bio(read_bio
, r10_bio
->sector
- bio
->bi_sector
,
948 r10_bio
->devs
[slot
].bio
= read_bio
;
950 read_bio
->bi_sector
= r10_bio
->devs
[slot
].addr
+
951 mirror
->rdev
->data_offset
;
952 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
953 read_bio
->bi_end_io
= raid10_end_read_request
;
954 read_bio
->bi_rw
= READ
| do_sync
;
955 read_bio
->bi_private
= r10_bio
;
957 if (max_sectors
< r10_bio
->sectors
) {
958 /* Could not read all from this device, so we will
959 * need another r10_bio.
961 sectors_handled
= (r10_bio
->sectors
+ max_sectors
963 r10_bio
->sectors
= max_sectors
;
964 spin_lock_irq(&conf
->device_lock
);
965 if (bio
->bi_phys_segments
== 0)
966 bio
->bi_phys_segments
= 2;
968 bio
->bi_phys_segments
++;
969 spin_unlock(&conf
->device_lock
);
970 /* Cannot call generic_make_request directly
971 * as that will be queued in __generic_make_request
972 * and subsequent mempool_alloc might block
973 * waiting for it. so hand bio over to raid10d.
975 reschedule_retry(r10_bio
);
977 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
979 r10_bio
->master_bio
= bio
;
980 r10_bio
->sectors
= ((bio
->bi_size
>> 9)
983 r10_bio
->mddev
= mddev
;
984 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
987 generic_make_request(read_bio
);
994 /* first select target devices under rcu_lock and
995 * inc refcount on their rdev. Record them by setting
997 * If there are known/acknowledged bad blocks on any device
998 * on which we have seen a write error, we want to avoid
999 * writing to those blocks. This potentially requires several
1000 * writes to write around the bad blocks. Each set of writes
1001 * gets its own r10_bio with a set of bios attached. The number
1002 * of r10_bios is recored in bio->bi_phys_segments just as with
1005 plugged
= mddev_check_plugged(mddev
);
1007 raid10_find_phys(conf
, r10_bio
);
1009 blocked_rdev
= NULL
;
1011 max_sectors
= r10_bio
->sectors
;
1013 for (i
= 0; i
< conf
->copies
; i
++) {
1014 int d
= r10_bio
->devs
[i
].devnum
;
1015 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1016 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
1017 atomic_inc(&rdev
->nr_pending
);
1018 blocked_rdev
= rdev
;
1021 r10_bio
->devs
[i
].bio
= NULL
;
1022 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
)) {
1023 set_bit(R10BIO_Degraded
, &r10_bio
->state
);
1026 if (test_bit(WriteErrorSeen
, &rdev
->flags
)) {
1028 sector_t dev_sector
= r10_bio
->devs
[i
].addr
;
1032 is_bad
= is_badblock(rdev
, dev_sector
,
1034 &first_bad
, &bad_sectors
);
1036 /* Mustn't write here until the bad block
1039 atomic_inc(&rdev
->nr_pending
);
1040 set_bit(BlockedBadBlocks
, &rdev
->flags
);
1041 blocked_rdev
= rdev
;
1044 if (is_bad
&& first_bad
<= dev_sector
) {
1045 /* Cannot write here at all */
1046 bad_sectors
-= (dev_sector
- first_bad
);
1047 if (bad_sectors
< max_sectors
)
1048 /* Mustn't write more than bad_sectors
1049 * to other devices yet
1051 max_sectors
= bad_sectors
;
1052 /* We don't set R10BIO_Degraded as that
1053 * only applies if the disk is missing,
1054 * so it might be re-added, and we want to
1055 * know to recover this chunk.
1056 * In this case the device is here, and the
1057 * fact that this chunk is not in-sync is
1058 * recorded in the bad block log.
1063 int good_sectors
= first_bad
- dev_sector
;
1064 if (good_sectors
< max_sectors
)
1065 max_sectors
= good_sectors
;
1068 r10_bio
->devs
[i
].bio
= bio
;
1069 atomic_inc(&rdev
->nr_pending
);
1073 if (unlikely(blocked_rdev
)) {
1074 /* Have to wait for this device to get unblocked, then retry */
1078 for (j
= 0; j
< i
; j
++)
1079 if (r10_bio
->devs
[j
].bio
) {
1080 d
= r10_bio
->devs
[j
].devnum
;
1081 rdev_dec_pending(conf
->mirrors
[d
].rdev
, mddev
);
1083 allow_barrier(conf
);
1084 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
1089 if (max_sectors
< r10_bio
->sectors
) {
1090 /* We are splitting this into multiple parts, so
1091 * we need to prepare for allocating another r10_bio.
1093 r10_bio
->sectors
= max_sectors
;
1094 spin_lock_irq(&conf
->device_lock
);
1095 if (bio
->bi_phys_segments
== 0)
1096 bio
->bi_phys_segments
= 2;
1098 bio
->bi_phys_segments
++;
1099 spin_unlock_irq(&conf
->device_lock
);
1101 sectors_handled
= r10_bio
->sector
+ max_sectors
- bio
->bi_sector
;
1103 atomic_set(&r10_bio
->remaining
, 1);
1104 bitmap_startwrite(mddev
->bitmap
, r10_bio
->sector
, r10_bio
->sectors
, 0);
1106 for (i
= 0; i
< conf
->copies
; i
++) {
1108 int d
= r10_bio
->devs
[i
].devnum
;
1109 if (!r10_bio
->devs
[i
].bio
)
1112 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1113 md_trim_bio(mbio
, r10_bio
->sector
- bio
->bi_sector
,
1115 r10_bio
->devs
[i
].bio
= mbio
;
1117 mbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
1118 conf
->mirrors
[d
].rdev
->data_offset
);
1119 mbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1120 mbio
->bi_end_io
= raid10_end_write_request
;
1121 mbio
->bi_rw
= WRITE
| do_sync
| do_fua
;
1122 mbio
->bi_private
= r10_bio
;
1124 atomic_inc(&r10_bio
->remaining
);
1125 spin_lock_irqsave(&conf
->device_lock
, flags
);
1126 bio_list_add(&conf
->pending_bio_list
, mbio
);
1127 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1130 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
1131 /* This matches the end of raid10_end_write_request() */
1132 bitmap_endwrite(r10_bio
->mddev
->bitmap
, r10_bio
->sector
,
1134 !test_bit(R10BIO_Degraded
, &r10_bio
->state
),
1136 md_write_end(mddev
);
1137 raid_end_bio_io(r10_bio
);
1140 /* In case raid10d snuck in to freeze_array */
1141 wake_up(&conf
->wait_barrier
);
1143 if (sectors_handled
< (bio
->bi_size
>> 9)) {
1144 /* We need another r1_bio. It has already been counted
1145 * in bio->bi_phys_segments.
1147 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
1149 r10_bio
->master_bio
= bio
;
1150 r10_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
1152 r10_bio
->mddev
= mddev
;
1153 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1158 if (do_sync
|| !mddev
->bitmap
|| !plugged
)
1159 md_wakeup_thread(mddev
->thread
);
1163 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
1165 conf_t
*conf
= mddev
->private;
1168 if (conf
->near_copies
< conf
->raid_disks
)
1169 seq_printf(seq
, " %dK chunks", mddev
->chunk_sectors
/ 2);
1170 if (conf
->near_copies
> 1)
1171 seq_printf(seq
, " %d near-copies", conf
->near_copies
);
1172 if (conf
->far_copies
> 1) {
1173 if (conf
->far_offset
)
1174 seq_printf(seq
, " %d offset-copies", conf
->far_copies
);
1176 seq_printf(seq
, " %d far-copies", conf
->far_copies
);
1178 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
1179 conf
->raid_disks
- mddev
->degraded
);
1180 for (i
= 0; i
< conf
->raid_disks
; i
++)
1181 seq_printf(seq
, "%s",
1182 conf
->mirrors
[i
].rdev
&&
1183 test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ? "U" : "_");
1184 seq_printf(seq
, "]");
1187 /* check if there are enough drives for
1188 * every block to appear on atleast one.
1189 * Don't consider the device numbered 'ignore'
1190 * as we might be about to remove it.
1192 static int enough(conf_t
*conf
, int ignore
)
1197 int n
= conf
->copies
;
1200 if (conf
->mirrors
[first
].rdev
&&
1203 first
= (first
+1) % conf
->raid_disks
;
1207 } while (first
!= 0);
1211 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1213 char b
[BDEVNAME_SIZE
];
1214 conf_t
*conf
= mddev
->private;
1217 * If it is not operational, then we have already marked it as dead
1218 * else if it is the last working disks, ignore the error, let the
1219 * next level up know.
1220 * else mark the drive as failed
1222 if (test_bit(In_sync
, &rdev
->flags
)
1223 && !enough(conf
, rdev
->raid_disk
))
1225 * Don't fail the drive, just return an IO error.
1228 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1229 unsigned long flags
;
1230 spin_lock_irqsave(&conf
->device_lock
, flags
);
1232 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1234 * if recovery is running, make sure it aborts.
1236 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1238 set_bit(Blocked
, &rdev
->flags
);
1239 set_bit(Faulty
, &rdev
->flags
);
1240 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1242 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1243 "md/raid10:%s: Operation continuing on %d devices.\n",
1244 mdname(mddev
), bdevname(rdev
->bdev
, b
),
1245 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
1248 static void print_conf(conf_t
*conf
)
1253 printk(KERN_DEBUG
"RAID10 conf printout:\n");
1255 printk(KERN_DEBUG
"(!conf)\n");
1258 printk(KERN_DEBUG
" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1261 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1262 char b
[BDEVNAME_SIZE
];
1263 tmp
= conf
->mirrors
+ i
;
1265 printk(KERN_DEBUG
" disk %d, wo:%d, o:%d, dev:%s\n",
1266 i
, !test_bit(In_sync
, &tmp
->rdev
->flags
),
1267 !test_bit(Faulty
, &tmp
->rdev
->flags
),
1268 bdevname(tmp
->rdev
->bdev
,b
));
1272 static void close_sync(conf_t
*conf
)
1275 allow_barrier(conf
);
1277 mempool_destroy(conf
->r10buf_pool
);
1278 conf
->r10buf_pool
= NULL
;
1281 static int raid10_spare_active(mddev_t
*mddev
)
1284 conf_t
*conf
= mddev
->private;
1287 unsigned long flags
;
1290 * Find all non-in_sync disks within the RAID10 configuration
1291 * and mark them in_sync
1293 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1294 tmp
= conf
->mirrors
+ i
;
1296 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
1297 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
1299 sysfs_notify_dirent(tmp
->rdev
->sysfs_state
);
1302 spin_lock_irqsave(&conf
->device_lock
, flags
);
1303 mddev
->degraded
-= count
;
1304 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1311 static int raid10_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1313 conf_t
*conf
= mddev
->private;
1317 int last
= conf
->raid_disks
- 1;
1319 if (mddev
->recovery_cp
< MaxSector
)
1320 /* only hot-add to in-sync arrays, as recovery is
1321 * very different from resync
1324 if (!enough(conf
, -1))
1327 if (rdev
->raid_disk
>= 0)
1328 first
= last
= rdev
->raid_disk
;
1330 if (rdev
->saved_raid_disk
>= first
&&
1331 conf
->mirrors
[rdev
->saved_raid_disk
].rdev
== NULL
)
1332 mirror
= rdev
->saved_raid_disk
;
1335 for ( ; mirror
<= last
; mirror
++) {
1336 mirror_info_t
*p
= &conf
->mirrors
[mirror
];
1337 if (p
->recovery_disabled
== mddev
->recovery_disabled
)
1342 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1343 rdev
->data_offset
<< 9);
1344 /* as we don't honour merge_bvec_fn, we must
1345 * never risk violating it, so limit
1346 * ->max_segments to one lying with a single
1347 * page, as a one page request is never in
1350 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1351 blk_queue_max_segments(mddev
->queue
, 1);
1352 blk_queue_segment_boundary(mddev
->queue
,
1353 PAGE_CACHE_SIZE
- 1);
1356 p
->head_position
= 0;
1357 rdev
->raid_disk
= mirror
;
1359 if (rdev
->saved_raid_disk
!= mirror
)
1361 rcu_assign_pointer(p
->rdev
, rdev
);
1365 md_integrity_add_rdev(rdev
, mddev
);
1370 static int raid10_remove_disk(mddev_t
*mddev
, int number
)
1372 conf_t
*conf
= mddev
->private;
1375 mirror_info_t
*p
= conf
->mirrors
+ number
;
1380 if (test_bit(In_sync
, &rdev
->flags
) ||
1381 atomic_read(&rdev
->nr_pending
)) {
1385 /* Only remove faulty devices in recovery
1388 if (!test_bit(Faulty
, &rdev
->flags
) &&
1389 mddev
->recovery_disabled
!= p
->recovery_disabled
&&
1396 if (atomic_read(&rdev
->nr_pending
)) {
1397 /* lost the race, try later */
1402 err
= md_integrity_register(mddev
);
1411 static void end_sync_read(struct bio
*bio
, int error
)
1413 r10bio_t
*r10_bio
= bio
->bi_private
;
1414 conf_t
*conf
= r10_bio
->mddev
->private;
1417 d
= find_bio_disk(conf
, r10_bio
, bio
, NULL
);
1419 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1420 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
1422 atomic_add(r10_bio
->sectors
,
1423 &conf
->mirrors
[d
].rdev
->corrected_errors
);
1424 if (!test_bit(MD_RECOVERY_SYNC
, &conf
->mddev
->recovery
))
1425 md_error(r10_bio
->mddev
,
1426 conf
->mirrors
[d
].rdev
);
1429 /* for reconstruct, we always reschedule after a read.
1430 * for resync, only after all reads
1432 rdev_dec_pending(conf
->mirrors
[d
].rdev
, conf
->mddev
);
1433 if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
) ||
1434 atomic_dec_and_test(&r10_bio
->remaining
)) {
1435 /* we have read all the blocks,
1436 * do the comparison in process context in raid10d
1438 reschedule_retry(r10_bio
);
1442 static void end_sync_write(struct bio
*bio
, int error
)
1444 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1445 r10bio_t
*r10_bio
= bio
->bi_private
;
1446 mddev_t
*mddev
= r10_bio
->mddev
;
1447 conf_t
*conf
= mddev
->private;
1453 d
= find_bio_disk(conf
, r10_bio
, bio
, &slot
);
1456 md_error(mddev
, conf
->mirrors
[d
].rdev
);
1457 else if (is_badblock(conf
->mirrors
[d
].rdev
,
1458 r10_bio
->devs
[slot
].addr
,
1460 &first_bad
, &bad_sectors
))
1461 set_bit(R10BIO_MadeGood
, &r10_bio
->state
);
1463 rdev_dec_pending(conf
->mirrors
[d
].rdev
, mddev
);
1464 while (atomic_dec_and_test(&r10_bio
->remaining
)) {
1465 if (r10_bio
->master_bio
== NULL
) {
1466 /* the primary of several recovery bios */
1467 sector_t s
= r10_bio
->sectors
;
1468 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
))
1469 reschedule_retry(r10_bio
);
1472 md_done_sync(mddev
, s
, 1);
1475 r10bio_t
*r10_bio2
= (r10bio_t
*)r10_bio
->master_bio
;
1476 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
))
1477 reschedule_retry(r10_bio
);
1486 * Note: sync and recover and handled very differently for raid10
1487 * This code is for resync.
1488 * For resync, we read through virtual addresses and read all blocks.
1489 * If there is any error, we schedule a write. The lowest numbered
1490 * drive is authoritative.
1491 * However requests come for physical address, so we need to map.
1492 * For every physical address there are raid_disks/copies virtual addresses,
1493 * which is always are least one, but is not necessarly an integer.
1494 * This means that a physical address can span multiple chunks, so we may
1495 * have to submit multiple io requests for a single sync request.
1498 * We check if all blocks are in-sync and only write to blocks that
1501 static void sync_request_write(mddev_t
*mddev
, r10bio_t
*r10_bio
)
1503 conf_t
*conf
= mddev
->private;
1505 struct bio
*tbio
, *fbio
;
1507 atomic_set(&r10_bio
->remaining
, 1);
1509 /* find the first device with a block */
1510 for (i
=0; i
<conf
->copies
; i
++)
1511 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
))
1514 if (i
== conf
->copies
)
1518 fbio
= r10_bio
->devs
[i
].bio
;
1520 /* now find blocks with errors */
1521 for (i
=0 ; i
< conf
->copies
; i
++) {
1523 int vcnt
= r10_bio
->sectors
>> (PAGE_SHIFT
-9);
1525 tbio
= r10_bio
->devs
[i
].bio
;
1527 if (tbio
->bi_end_io
!= end_sync_read
)
1531 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
)) {
1532 /* We know that the bi_io_vec layout is the same for
1533 * both 'first' and 'i', so we just compare them.
1534 * All vec entries are PAGE_SIZE;
1536 for (j
= 0; j
< vcnt
; j
++)
1537 if (memcmp(page_address(fbio
->bi_io_vec
[j
].bv_page
),
1538 page_address(tbio
->bi_io_vec
[j
].bv_page
),
1543 mddev
->resync_mismatches
+= r10_bio
->sectors
;
1545 if (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
))
1546 /* Don't fix anything. */
1548 /* Ok, we need to write this bio
1549 * First we need to fixup bv_offset, bv_len and
1550 * bi_vecs, as the read request might have corrupted these
1552 tbio
->bi_vcnt
= vcnt
;
1553 tbio
->bi_size
= r10_bio
->sectors
<< 9;
1555 tbio
->bi_phys_segments
= 0;
1556 tbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1557 tbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1558 tbio
->bi_next
= NULL
;
1559 tbio
->bi_rw
= WRITE
;
1560 tbio
->bi_private
= r10_bio
;
1561 tbio
->bi_sector
= r10_bio
->devs
[i
].addr
;
1563 for (j
=0; j
< vcnt
; j
++) {
1564 tbio
->bi_io_vec
[j
].bv_offset
= 0;
1565 tbio
->bi_io_vec
[j
].bv_len
= PAGE_SIZE
;
1567 memcpy(page_address(tbio
->bi_io_vec
[j
].bv_page
),
1568 page_address(fbio
->bi_io_vec
[j
].bv_page
),
1571 tbio
->bi_end_io
= end_sync_write
;
1573 d
= r10_bio
->devs
[i
].devnum
;
1574 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1575 atomic_inc(&r10_bio
->remaining
);
1576 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, tbio
->bi_size
>> 9);
1578 tbio
->bi_sector
+= conf
->mirrors
[d
].rdev
->data_offset
;
1579 tbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1580 generic_make_request(tbio
);
1584 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
1585 md_done_sync(mddev
, r10_bio
->sectors
, 1);
1591 * Now for the recovery code.
1592 * Recovery happens across physical sectors.
1593 * We recover all non-is_sync drives by finding the virtual address of
1594 * each, and then choose a working drive that also has that virt address.
1595 * There is a separate r10_bio for each non-in_sync drive.
1596 * Only the first two slots are in use. The first for reading,
1597 * The second for writing.
1601 static void recovery_request_write(mddev_t
*mddev
, r10bio_t
*r10_bio
)
1603 conf_t
*conf
= mddev
->private;
1608 * share the pages with the first bio
1609 * and submit the write request
1611 wbio
= r10_bio
->devs
[1].bio
;
1612 d
= r10_bio
->devs
[1].devnum
;
1614 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1615 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, wbio
->bi_size
>> 9);
1616 if (test_bit(R10BIO_Uptodate
, &r10_bio
->state
))
1617 generic_make_request(wbio
);
1620 "md/raid10:%s: recovery aborted due to read error\n",
1622 conf
->mirrors
[d
].recovery_disabled
= mddev
->recovery_disabled
;
1623 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1630 * Used by fix_read_error() to decay the per rdev read_errors.
1631 * We halve the read error count for every hour that has elapsed
1632 * since the last recorded read error.
1635 static void check_decay_read_errors(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1637 struct timespec cur_time_mon
;
1638 unsigned long hours_since_last
;
1639 unsigned int read_errors
= atomic_read(&rdev
->read_errors
);
1641 ktime_get_ts(&cur_time_mon
);
1643 if (rdev
->last_read_error
.tv_sec
== 0 &&
1644 rdev
->last_read_error
.tv_nsec
== 0) {
1645 /* first time we've seen a read error */
1646 rdev
->last_read_error
= cur_time_mon
;
1650 hours_since_last
= (cur_time_mon
.tv_sec
-
1651 rdev
->last_read_error
.tv_sec
) / 3600;
1653 rdev
->last_read_error
= cur_time_mon
;
1656 * if hours_since_last is > the number of bits in read_errors
1657 * just set read errors to 0. We do this to avoid
1658 * overflowing the shift of read_errors by hours_since_last.
1660 if (hours_since_last
>= 8 * sizeof(read_errors
))
1661 atomic_set(&rdev
->read_errors
, 0);
1663 atomic_set(&rdev
->read_errors
, read_errors
>> hours_since_last
);
1667 * This is a kernel thread which:
1669 * 1. Retries failed read operations on working mirrors.
1670 * 2. Updates the raid superblock when problems encounter.
1671 * 3. Performs writes following reads for array synchronising.
1674 static void fix_read_error(conf_t
*conf
, mddev_t
*mddev
, r10bio_t
*r10_bio
)
1676 int sect
= 0; /* Offset from r10_bio->sector */
1677 int sectors
= r10_bio
->sectors
;
1679 int max_read_errors
= atomic_read(&mddev
->max_corr_read_errors
);
1680 int d
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
1682 /* still own a reference to this rdev, so it cannot
1683 * have been cleared recently.
1685 rdev
= conf
->mirrors
[d
].rdev
;
1687 if (test_bit(Faulty
, &rdev
->flags
))
1688 /* drive has already been failed, just ignore any
1689 more fix_read_error() attempts */
1692 check_decay_read_errors(mddev
, rdev
);
1693 atomic_inc(&rdev
->read_errors
);
1694 if (atomic_read(&rdev
->read_errors
) > max_read_errors
) {
1695 char b
[BDEVNAME_SIZE
];
1696 bdevname(rdev
->bdev
, b
);
1699 "md/raid10:%s: %s: Raid device exceeded "
1700 "read_error threshold [cur %d:max %d]\n",
1702 atomic_read(&rdev
->read_errors
), max_read_errors
);
1704 "md/raid10:%s: %s: Failing raid device\n",
1706 md_error(mddev
, conf
->mirrors
[d
].rdev
);
1712 int sl
= r10_bio
->read_slot
;
1716 if (s
> (PAGE_SIZE
>>9))
1724 d
= r10_bio
->devs
[sl
].devnum
;
1725 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1727 test_bit(In_sync
, &rdev
->flags
) &&
1728 is_badblock(rdev
, r10_bio
->devs
[sl
].addr
+ sect
, s
,
1729 &first_bad
, &bad_sectors
) == 0) {
1730 atomic_inc(&rdev
->nr_pending
);
1732 success
= sync_page_io(rdev
,
1733 r10_bio
->devs
[sl
].addr
+
1736 conf
->tmppage
, READ
, false);
1737 rdev_dec_pending(rdev
, mddev
);
1743 if (sl
== conf
->copies
)
1745 } while (!success
&& sl
!= r10_bio
->read_slot
);
1749 /* Cannot read from anywhere -- bye bye array */
1750 int dn
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
1751 md_error(mddev
, conf
->mirrors
[dn
].rdev
);
1756 /* write it back and re-read */
1758 while (sl
!= r10_bio
->read_slot
) {
1759 char b
[BDEVNAME_SIZE
];
1764 d
= r10_bio
->devs
[sl
].devnum
;
1765 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1767 !test_bit(In_sync
, &rdev
->flags
))
1770 atomic_inc(&rdev
->nr_pending
);
1772 if (sync_page_io(rdev
,
1773 r10_bio
->devs
[sl
].addr
+
1775 s
<<9, conf
->tmppage
, WRITE
, false)
1777 /* Well, this device is dead */
1779 "md/raid10:%s: read correction "
1781 " (%d sectors at %llu on %s)\n",
1783 (unsigned long long)(
1784 sect
+ rdev
->data_offset
),
1785 bdevname(rdev
->bdev
, b
));
1786 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
1789 bdevname(rdev
->bdev
, b
));
1790 md_error(mddev
, rdev
);
1792 rdev_dec_pending(rdev
, mddev
);
1796 while (sl
!= r10_bio
->read_slot
) {
1797 char b
[BDEVNAME_SIZE
];
1802 d
= r10_bio
->devs
[sl
].devnum
;
1803 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1805 !test_bit(In_sync
, &rdev
->flags
))
1808 atomic_inc(&rdev
->nr_pending
);
1810 if (sync_page_io(rdev
,
1811 r10_bio
->devs
[sl
].addr
+
1813 s
<<9, conf
->tmppage
,
1814 READ
, false) == 0) {
1815 /* Well, this device is dead */
1817 "md/raid10:%s: unable to read back "
1819 " (%d sectors at %llu on %s)\n",
1821 (unsigned long long)(
1822 sect
+ rdev
->data_offset
),
1823 bdevname(rdev
->bdev
, b
));
1824 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
1827 bdevname(rdev
->bdev
, b
));
1829 md_error(mddev
, rdev
);
1832 "md/raid10:%s: read error corrected"
1833 " (%d sectors at %llu on %s)\n",
1835 (unsigned long long)(
1836 sect
+ rdev
->data_offset
),
1837 bdevname(rdev
->bdev
, b
));
1838 atomic_add(s
, &rdev
->corrected_errors
);
1841 rdev_dec_pending(rdev
, mddev
);
1851 static void bi_complete(struct bio
*bio
, int error
)
1853 complete((struct completion
*)bio
->bi_private
);
1856 static int submit_bio_wait(int rw
, struct bio
*bio
)
1858 struct completion event
;
1861 init_completion(&event
);
1862 bio
->bi_private
= &event
;
1863 bio
->bi_end_io
= bi_complete
;
1864 submit_bio(rw
, bio
);
1865 wait_for_completion(&event
);
1867 return test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1870 static int narrow_write_error(r10bio_t
*r10_bio
, int i
)
1872 struct bio
*bio
= r10_bio
->master_bio
;
1873 mddev_t
*mddev
= r10_bio
->mddev
;
1874 conf_t
*conf
= mddev
->private;
1875 mdk_rdev_t
*rdev
= conf
->mirrors
[r10_bio
->devs
[i
].devnum
].rdev
;
1876 /* bio has the data to be written to slot 'i' where
1877 * we just recently had a write error.
1878 * We repeatedly clone the bio and trim down to one block,
1879 * then try the write. Where the write fails we record
1881 * It is conceivable that the bio doesn't exactly align with
1882 * blocks. We must handle this.
1884 * We currently own a reference to the rdev.
1890 int sect_to_write
= r10_bio
->sectors
;
1893 if (rdev
->badblocks
.shift
< 0)
1896 block_sectors
= 1 << rdev
->badblocks
.shift
;
1897 sector
= r10_bio
->sector
;
1898 sectors
= ((r10_bio
->sector
+ block_sectors
)
1899 & ~(sector_t
)(block_sectors
- 1))
1902 while (sect_to_write
) {
1904 if (sectors
> sect_to_write
)
1905 sectors
= sect_to_write
;
1906 /* Write at 'sector' for 'sectors' */
1907 wbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1908 md_trim_bio(wbio
, sector
- bio
->bi_sector
, sectors
);
1909 wbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
1911 (sector
- r10_bio
->sector
));
1912 wbio
->bi_bdev
= rdev
->bdev
;
1913 if (submit_bio_wait(WRITE
, wbio
) == 0)
1915 ok
= rdev_set_badblocks(rdev
, sector
,
1920 sect_to_write
-= sectors
;
1922 sectors
= block_sectors
;
1927 static void handle_read_error(mddev_t
*mddev
, r10bio_t
*r10_bio
)
1929 int slot
= r10_bio
->read_slot
;
1930 int mirror
= r10_bio
->devs
[slot
].devnum
;
1932 conf_t
*conf
= mddev
->private;
1934 char b
[BDEVNAME_SIZE
];
1935 unsigned long do_sync
;
1938 /* we got a read error. Maybe the drive is bad. Maybe just
1939 * the block and we can fix it.
1940 * We freeze all other IO, and try reading the block from
1941 * other devices. When we find one, we re-write
1942 * and check it that fixes the read error.
1943 * This is all done synchronously while the array is
1946 if (mddev
->ro
== 0) {
1948 fix_read_error(conf
, mddev
, r10_bio
);
1949 unfreeze_array(conf
);
1951 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, mddev
);
1953 bio
= r10_bio
->devs
[slot
].bio
;
1954 bdevname(bio
->bi_bdev
, b
);
1955 r10_bio
->devs
[slot
].bio
=
1956 mddev
->ro
? IO_BLOCKED
: NULL
;
1958 mirror
= read_balance(conf
, r10_bio
, &max_sectors
);
1960 printk(KERN_ALERT
"md/raid10:%s: %s: unrecoverable I/O"
1961 " read error for block %llu\n",
1963 (unsigned long long)r10_bio
->sector
);
1964 raid_end_bio_io(r10_bio
);
1969 do_sync
= (r10_bio
->master_bio
->bi_rw
& REQ_SYNC
);
1972 slot
= r10_bio
->read_slot
;
1973 rdev
= conf
->mirrors
[mirror
].rdev
;
1976 "md/raid10:%s: %s: redirecting"
1977 "sector %llu to another mirror\n",
1979 bdevname(rdev
->bdev
, b
),
1980 (unsigned long long)r10_bio
->sector
);
1981 bio
= bio_clone_mddev(r10_bio
->master_bio
,
1984 r10_bio
->sector
- bio
->bi_sector
,
1986 r10_bio
->devs
[slot
].bio
= bio
;
1987 bio
->bi_sector
= r10_bio
->devs
[slot
].addr
1988 + rdev
->data_offset
;
1989 bio
->bi_bdev
= rdev
->bdev
;
1990 bio
->bi_rw
= READ
| do_sync
;
1991 bio
->bi_private
= r10_bio
;
1992 bio
->bi_end_io
= raid10_end_read_request
;
1993 if (max_sectors
< r10_bio
->sectors
) {
1994 /* Drat - have to split this up more */
1995 struct bio
*mbio
= r10_bio
->master_bio
;
1996 int sectors_handled
=
1997 r10_bio
->sector
+ max_sectors
1999 r10_bio
->sectors
= max_sectors
;
2000 spin_lock_irq(&conf
->device_lock
);
2001 if (mbio
->bi_phys_segments
== 0)
2002 mbio
->bi_phys_segments
= 2;
2004 mbio
->bi_phys_segments
++;
2005 spin_unlock_irq(&conf
->device_lock
);
2006 generic_make_request(bio
);
2009 r10_bio
= mempool_alloc(conf
->r10bio_pool
,
2011 r10_bio
->master_bio
= mbio
;
2012 r10_bio
->sectors
= (mbio
->bi_size
>> 9)
2015 set_bit(R10BIO_ReadError
,
2017 r10_bio
->mddev
= mddev
;
2018 r10_bio
->sector
= mbio
->bi_sector
2023 generic_make_request(bio
);
2026 static void handle_write_completed(conf_t
*conf
, r10bio_t
*r10_bio
)
2028 /* Some sort of write request has finished and it
2029 * succeeded in writing where we thought there was a
2030 * bad block. So forget the bad block.
2035 if (test_bit(R10BIO_IsSync
, &r10_bio
->state
) ||
2036 test_bit(R10BIO_IsRecover
, &r10_bio
->state
)) {
2037 for (m
= 0; m
< conf
->copies
; m
++)
2038 if (r10_bio
->devs
[m
].bio
&&
2039 test_bit(BIO_UPTODATE
,
2040 &r10_bio
->devs
[m
].bio
->bi_flags
)) {
2041 int dev
= r10_bio
->devs
[m
].devnum
;
2042 rdev
= conf
->mirrors
[dev
].rdev
;
2043 rdev_clear_badblocks(
2045 r10_bio
->devs
[m
].addr
,
2050 for (m
= 0; m
< conf
->copies
; m
++) {
2051 int dev
= r10_bio
->devs
[m
].devnum
;
2052 struct bio
*bio
= r10_bio
->devs
[m
].bio
;
2053 rdev
= conf
->mirrors
[dev
].rdev
;
2054 if (bio
== IO_MADE_GOOD
) {
2055 rdev_clear_badblocks(
2057 r10_bio
->devs
[m
].addr
,
2059 rdev_dec_pending(rdev
, conf
->mddev
);
2060 } else if (bio
!= NULL
&&
2061 !test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2062 if (!narrow_write_error(r10_bio
, m
)) {
2063 md_error(conf
->mddev
, rdev
);
2064 set_bit(R10BIO_Degraded
,
2067 rdev_dec_pending(rdev
, conf
->mddev
);
2070 if (test_bit(R10BIO_WriteError
,
2072 close_write(r10_bio
);
2073 raid_end_bio_io(r10_bio
);
2077 static void raid10d(mddev_t
*mddev
)
2080 unsigned long flags
;
2081 conf_t
*conf
= mddev
->private;
2082 struct list_head
*head
= &conf
->retry_list
;
2083 struct blk_plug plug
;
2085 md_check_recovery(mddev
);
2087 blk_start_plug(&plug
);
2090 flush_pending_writes(conf
);
2092 spin_lock_irqsave(&conf
->device_lock
, flags
);
2093 if (list_empty(head
)) {
2094 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2097 r10_bio
= list_entry(head
->prev
, r10bio_t
, retry_list
);
2098 list_del(head
->prev
);
2100 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2102 mddev
= r10_bio
->mddev
;
2103 conf
= mddev
->private;
2104 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
2105 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
2106 handle_write_completed(conf
, r10_bio
);
2107 else if (test_bit(R10BIO_IsSync
, &r10_bio
->state
))
2108 sync_request_write(mddev
, r10_bio
);
2109 else if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
))
2110 recovery_request_write(mddev
, r10_bio
);
2111 else if (test_bit(R10BIO_ReadError
, &r10_bio
->state
))
2112 handle_read_error(mddev
, r10_bio
);
2114 /* just a partial read to be scheduled from a
2117 int slot
= r10_bio
->read_slot
;
2118 generic_make_request(r10_bio
->devs
[slot
].bio
);
2122 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
2123 md_check_recovery(mddev
);
2125 blk_finish_plug(&plug
);
2129 static int init_resync(conf_t
*conf
)
2133 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
2134 BUG_ON(conf
->r10buf_pool
);
2135 conf
->r10buf_pool
= mempool_create(buffs
, r10buf_pool_alloc
, r10buf_pool_free
, conf
);
2136 if (!conf
->r10buf_pool
)
2138 conf
->next_resync
= 0;
2143 * perform a "sync" on one "block"
2145 * We need to make sure that no normal I/O request - particularly write
2146 * requests - conflict with active sync requests.
2148 * This is achieved by tracking pending requests and a 'barrier' concept
2149 * that can be installed to exclude normal IO requests.
2151 * Resync and recovery are handled very differently.
2152 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2154 * For resync, we iterate over virtual addresses, read all copies,
2155 * and update if there are differences. If only one copy is live,
2157 * For recovery, we iterate over physical addresses, read a good
2158 * value for each non-in_sync drive, and over-write.
2160 * So, for recovery we may have several outstanding complex requests for a
2161 * given address, one for each out-of-sync device. We model this by allocating
2162 * a number of r10_bio structures, one for each out-of-sync device.
2163 * As we setup these structures, we collect all bio's together into a list
2164 * which we then process collectively to add pages, and then process again
2165 * to pass to generic_make_request.
2167 * The r10_bio structures are linked using a borrowed master_bio pointer.
2168 * This link is counted in ->remaining. When the r10_bio that points to NULL
2169 * has its remaining count decremented to 0, the whole complex operation
2174 static sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
,
2175 int *skipped
, int go_faster
)
2177 conf_t
*conf
= mddev
->private;
2179 struct bio
*biolist
= NULL
, *bio
;
2180 sector_t max_sector
, nr_sectors
;
2183 sector_t sync_blocks
;
2184 sector_t sectors_skipped
= 0;
2185 int chunks_skipped
= 0;
2187 if (!conf
->r10buf_pool
)
2188 if (init_resync(conf
))
2192 max_sector
= mddev
->dev_sectors
;
2193 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2194 max_sector
= mddev
->resync_max_sectors
;
2195 if (sector_nr
>= max_sector
) {
2196 /* If we aborted, we need to abort the
2197 * sync on the 'current' bitmap chucks (there can
2198 * be several when recovering multiple devices).
2199 * as we may have started syncing it but not finished.
2200 * We can find the current address in
2201 * mddev->curr_resync, but for recovery,
2202 * we need to convert that to several
2203 * virtual addresses.
2205 if (mddev
->curr_resync
< max_sector
) { /* aborted */
2206 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2207 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
2209 else for (i
=0; i
<conf
->raid_disks
; i
++) {
2211 raid10_find_virt(conf
, mddev
->curr_resync
, i
);
2212 bitmap_end_sync(mddev
->bitmap
, sect
,
2215 } else /* completed sync */
2218 bitmap_close_sync(mddev
->bitmap
);
2221 return sectors_skipped
;
2223 if (chunks_skipped
>= conf
->raid_disks
) {
2224 /* if there has been nothing to do on any drive,
2225 * then there is nothing to do at all..
2228 return (max_sector
- sector_nr
) + sectors_skipped
;
2231 if (max_sector
> mddev
->resync_max
)
2232 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
2234 /* make sure whole request will fit in a chunk - if chunks
2237 if (conf
->near_copies
< conf
->raid_disks
&&
2238 max_sector
> (sector_nr
| conf
->chunk_mask
))
2239 max_sector
= (sector_nr
| conf
->chunk_mask
) + 1;
2241 * If there is non-resync activity waiting for us then
2242 * put in a delay to throttle resync.
2244 if (!go_faster
&& conf
->nr_waiting
)
2245 msleep_interruptible(1000);
2247 /* Again, very different code for resync and recovery.
2248 * Both must result in an r10bio with a list of bios that
2249 * have bi_end_io, bi_sector, bi_bdev set,
2250 * and bi_private set to the r10bio.
2251 * For recovery, we may actually create several r10bios
2252 * with 2 bios in each, that correspond to the bios in the main one.
2253 * In this case, the subordinate r10bios link back through a
2254 * borrowed master_bio pointer, and the counter in the master
2255 * includes a ref from each subordinate.
2257 /* First, we decide what to do and set ->bi_end_io
2258 * To end_sync_read if we want to read, and
2259 * end_sync_write if we will want to write.
2262 max_sync
= RESYNC_PAGES
<< (PAGE_SHIFT
-9);
2263 if (!test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
2264 /* recovery... the complicated one */
2268 for (i
=0 ; i
<conf
->raid_disks
; i
++) {
2275 if (conf
->mirrors
[i
].rdev
== NULL
||
2276 test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
))
2280 /* want to reconstruct this device */
2282 sect
= raid10_find_virt(conf
, sector_nr
, i
);
2283 /* Unless we are doing a full sync, we only need
2284 * to recover the block if it is set in the bitmap
2286 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2288 if (sync_blocks
< max_sync
)
2289 max_sync
= sync_blocks
;
2292 /* yep, skip the sync_blocks here, but don't assume
2293 * that there will never be anything to do here
2295 chunks_skipped
= -1;
2299 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2300 raise_barrier(conf
, rb2
!= NULL
);
2301 atomic_set(&r10_bio
->remaining
, 0);
2303 r10_bio
->master_bio
= (struct bio
*)rb2
;
2305 atomic_inc(&rb2
->remaining
);
2306 r10_bio
->mddev
= mddev
;
2307 set_bit(R10BIO_IsRecover
, &r10_bio
->state
);
2308 r10_bio
->sector
= sect
;
2310 raid10_find_phys(conf
, r10_bio
);
2312 /* Need to check if the array will still be
2315 for (j
=0; j
<conf
->raid_disks
; j
++)
2316 if (conf
->mirrors
[j
].rdev
== NULL
||
2317 test_bit(Faulty
, &conf
->mirrors
[j
].rdev
->flags
)) {
2322 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2323 &sync_blocks
, still_degraded
);
2326 for (j
=0; j
<conf
->copies
;j
++) {
2328 int d
= r10_bio
->devs
[j
].devnum
;
2330 sector_t sector
, first_bad
;
2332 if (!conf
->mirrors
[d
].rdev
||
2333 !test_bit(In_sync
, &conf
->mirrors
[d
].rdev
->flags
))
2335 /* This is where we read from */
2337 rdev
= conf
->mirrors
[d
].rdev
;
2338 sector
= r10_bio
->devs
[j
].addr
;
2340 if (is_badblock(rdev
, sector
, max_sync
,
2341 &first_bad
, &bad_sectors
)) {
2342 if (first_bad
> sector
)
2343 max_sync
= first_bad
- sector
;
2345 bad_sectors
-= (sector
2347 if (max_sync
> bad_sectors
)
2348 max_sync
= bad_sectors
;
2352 bio
= r10_bio
->devs
[0].bio
;
2353 bio
->bi_next
= biolist
;
2355 bio
->bi_private
= r10_bio
;
2356 bio
->bi_end_io
= end_sync_read
;
2358 bio
->bi_sector
= r10_bio
->devs
[j
].addr
+
2359 conf
->mirrors
[d
].rdev
->data_offset
;
2360 bio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
2361 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2362 atomic_inc(&r10_bio
->remaining
);
2363 /* and we write to 'i' */
2365 for (k
=0; k
<conf
->copies
; k
++)
2366 if (r10_bio
->devs
[k
].devnum
== i
)
2368 BUG_ON(k
== conf
->copies
);
2369 bio
= r10_bio
->devs
[1].bio
;
2370 bio
->bi_next
= biolist
;
2372 bio
->bi_private
= r10_bio
;
2373 bio
->bi_end_io
= end_sync_write
;
2375 bio
->bi_sector
= r10_bio
->devs
[k
].addr
+
2376 conf
->mirrors
[i
].rdev
->data_offset
;
2377 bio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
2379 r10_bio
->devs
[0].devnum
= d
;
2380 r10_bio
->devs
[1].devnum
= i
;
2384 if (j
== conf
->copies
) {
2385 /* Cannot recover, so abort the recovery or
2386 * record a bad block */
2389 atomic_dec(&rb2
->remaining
);
2392 /* problem is that there are bad blocks
2393 * on other device(s)
2396 for (k
= 0; k
< conf
->copies
; k
++)
2397 if (r10_bio
->devs
[k
].devnum
== i
)
2399 if (!rdev_set_badblocks(
2400 conf
->mirrors
[i
].rdev
,
2401 r10_bio
->devs
[k
].addr
,
2406 if (!test_and_set_bit(MD_RECOVERY_INTR
,
2408 printk(KERN_INFO
"md/raid10:%s: insufficient "
2409 "working devices for recovery.\n",
2411 conf
->mirrors
[i
].recovery_disabled
2412 = mddev
->recovery_disabled
;
2417 if (biolist
== NULL
) {
2419 r10bio_t
*rb2
= r10_bio
;
2420 r10_bio
= (r10bio_t
*) rb2
->master_bio
;
2421 rb2
->master_bio
= NULL
;
2427 /* resync. Schedule a read for every block at this virt offset */
2430 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
2432 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
2433 &sync_blocks
, mddev
->degraded
) &&
2434 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
,
2435 &mddev
->recovery
)) {
2436 /* We can skip this block */
2438 return sync_blocks
+ sectors_skipped
;
2440 if (sync_blocks
< max_sync
)
2441 max_sync
= sync_blocks
;
2442 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2444 r10_bio
->mddev
= mddev
;
2445 atomic_set(&r10_bio
->remaining
, 0);
2446 raise_barrier(conf
, 0);
2447 conf
->next_resync
= sector_nr
;
2449 r10_bio
->master_bio
= NULL
;
2450 r10_bio
->sector
= sector_nr
;
2451 set_bit(R10BIO_IsSync
, &r10_bio
->state
);
2452 raid10_find_phys(conf
, r10_bio
);
2453 r10_bio
->sectors
= (sector_nr
| conf
->chunk_mask
) - sector_nr
+1;
2455 for (i
=0; i
<conf
->copies
; i
++) {
2456 int d
= r10_bio
->devs
[i
].devnum
;
2457 sector_t first_bad
, sector
;
2460 bio
= r10_bio
->devs
[i
].bio
;
2461 bio
->bi_end_io
= NULL
;
2462 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2463 if (conf
->mirrors
[d
].rdev
== NULL
||
2464 test_bit(Faulty
, &conf
->mirrors
[d
].rdev
->flags
))
2466 sector
= r10_bio
->devs
[i
].addr
;
2467 if (is_badblock(conf
->mirrors
[d
].rdev
,
2469 &first_bad
, &bad_sectors
)) {
2470 if (first_bad
> sector
)
2471 max_sync
= first_bad
- sector
;
2473 bad_sectors
-= (sector
- first_bad
);
2474 if (max_sync
> bad_sectors
)
2475 max_sync
= max_sync
;
2479 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2480 atomic_inc(&r10_bio
->remaining
);
2481 bio
->bi_next
= biolist
;
2483 bio
->bi_private
= r10_bio
;
2484 bio
->bi_end_io
= end_sync_read
;
2486 bio
->bi_sector
= sector
+
2487 conf
->mirrors
[d
].rdev
->data_offset
;
2488 bio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
2493 for (i
=0; i
<conf
->copies
; i
++) {
2494 int d
= r10_bio
->devs
[i
].devnum
;
2495 if (r10_bio
->devs
[i
].bio
->bi_end_io
)
2496 rdev_dec_pending(conf
->mirrors
[d
].rdev
,
2505 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
2507 bio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
2509 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
2512 bio
->bi_phys_segments
= 0;
2517 if (sector_nr
+ max_sync
< max_sector
)
2518 max_sector
= sector_nr
+ max_sync
;
2521 int len
= PAGE_SIZE
;
2522 if (sector_nr
+ (len
>>9) > max_sector
)
2523 len
= (max_sector
- sector_nr
) << 9;
2526 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
2528 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
2529 if (bio_add_page(bio
, page
, len
, 0))
2533 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
2534 for (bio2
= biolist
;
2535 bio2
&& bio2
!= bio
;
2536 bio2
= bio2
->bi_next
) {
2537 /* remove last page from this bio */
2539 bio2
->bi_size
-= len
;
2540 bio2
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
2544 nr_sectors
+= len
>>9;
2545 sector_nr
+= len
>>9;
2546 } while (biolist
->bi_vcnt
< RESYNC_PAGES
);
2548 r10_bio
->sectors
= nr_sectors
;
2552 biolist
= biolist
->bi_next
;
2554 bio
->bi_next
= NULL
;
2555 r10_bio
= bio
->bi_private
;
2556 r10_bio
->sectors
= nr_sectors
;
2558 if (bio
->bi_end_io
== end_sync_read
) {
2559 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2560 generic_make_request(bio
);
2564 if (sectors_skipped
)
2565 /* pretend they weren't skipped, it makes
2566 * no important difference in this case
2568 md_done_sync(mddev
, sectors_skipped
, 1);
2570 return sectors_skipped
+ nr_sectors
;
2572 /* There is nowhere to write, so all non-sync
2573 * drives must be failed or in resync, all drives
2574 * have a bad block, so try the next chunk...
2576 if (sector_nr
+ max_sync
< max_sector
)
2577 max_sector
= sector_nr
+ max_sync
;
2579 sectors_skipped
+= (max_sector
- sector_nr
);
2581 sector_nr
= max_sector
;
2586 raid10_size(mddev_t
*mddev
, sector_t sectors
, int raid_disks
)
2589 conf_t
*conf
= mddev
->private;
2592 raid_disks
= conf
->raid_disks
;
2594 sectors
= conf
->dev_sectors
;
2596 size
= sectors
>> conf
->chunk_shift
;
2597 sector_div(size
, conf
->far_copies
);
2598 size
= size
* raid_disks
;
2599 sector_div(size
, conf
->near_copies
);
2601 return size
<< conf
->chunk_shift
;
2605 static conf_t
*setup_conf(mddev_t
*mddev
)
2607 conf_t
*conf
= NULL
;
2609 sector_t stride
, size
;
2612 if (mddev
->new_chunk_sectors
< (PAGE_SIZE
>> 9) ||
2613 !is_power_of_2(mddev
->new_chunk_sectors
)) {
2614 printk(KERN_ERR
"md/raid10:%s: chunk size must be "
2615 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
2616 mdname(mddev
), PAGE_SIZE
);
2620 nc
= mddev
->new_layout
& 255;
2621 fc
= (mddev
->new_layout
>> 8) & 255;
2622 fo
= mddev
->new_layout
& (1<<16);
2624 if ((nc
*fc
) <2 || (nc
*fc
) > mddev
->raid_disks
||
2625 (mddev
->new_layout
>> 17)) {
2626 printk(KERN_ERR
"md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
2627 mdname(mddev
), mddev
->new_layout
);
2632 conf
= kzalloc(sizeof(conf_t
), GFP_KERNEL
);
2636 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
2641 conf
->tmppage
= alloc_page(GFP_KERNEL
);
2646 conf
->raid_disks
= mddev
->raid_disks
;
2647 conf
->near_copies
= nc
;
2648 conf
->far_copies
= fc
;
2649 conf
->copies
= nc
*fc
;
2650 conf
->far_offset
= fo
;
2651 conf
->chunk_mask
= mddev
->new_chunk_sectors
- 1;
2652 conf
->chunk_shift
= ffz(~mddev
->new_chunk_sectors
);
2654 conf
->r10bio_pool
= mempool_create(NR_RAID10_BIOS
, r10bio_pool_alloc
,
2655 r10bio_pool_free
, conf
);
2656 if (!conf
->r10bio_pool
)
2659 size
= mddev
->dev_sectors
>> conf
->chunk_shift
;
2660 sector_div(size
, fc
);
2661 size
= size
* conf
->raid_disks
;
2662 sector_div(size
, nc
);
2663 /* 'size' is now the number of chunks in the array */
2664 /* calculate "used chunks per device" in 'stride' */
2665 stride
= size
* conf
->copies
;
2667 /* We need to round up when dividing by raid_disks to
2668 * get the stride size.
2670 stride
+= conf
->raid_disks
- 1;
2671 sector_div(stride
, conf
->raid_disks
);
2673 conf
->dev_sectors
= stride
<< conf
->chunk_shift
;
2678 sector_div(stride
, fc
);
2679 conf
->stride
= stride
<< conf
->chunk_shift
;
2682 spin_lock_init(&conf
->device_lock
);
2683 INIT_LIST_HEAD(&conf
->retry_list
);
2685 spin_lock_init(&conf
->resync_lock
);
2686 init_waitqueue_head(&conf
->wait_barrier
);
2688 conf
->thread
= md_register_thread(raid10d
, mddev
, NULL
);
2692 conf
->mddev
= mddev
;
2696 printk(KERN_ERR
"md/raid10:%s: couldn't allocate memory.\n",
2699 if (conf
->r10bio_pool
)
2700 mempool_destroy(conf
->r10bio_pool
);
2701 kfree(conf
->mirrors
);
2702 safe_put_page(conf
->tmppage
);
2705 return ERR_PTR(err
);
2708 static int run(mddev_t
*mddev
)
2711 int i
, disk_idx
, chunk_size
;
2712 mirror_info_t
*disk
;
2717 * copy the already verified devices into our private RAID10
2718 * bookkeeping area. [whatever we allocate in run(),
2719 * should be freed in stop()]
2722 if (mddev
->private == NULL
) {
2723 conf
= setup_conf(mddev
);
2725 return PTR_ERR(conf
);
2726 mddev
->private = conf
;
2728 conf
= mddev
->private;
2732 mddev
->thread
= conf
->thread
;
2733 conf
->thread
= NULL
;
2735 chunk_size
= mddev
->chunk_sectors
<< 9;
2736 blk_queue_io_min(mddev
->queue
, chunk_size
);
2737 if (conf
->raid_disks
% conf
->near_copies
)
2738 blk_queue_io_opt(mddev
->queue
, chunk_size
* conf
->raid_disks
);
2740 blk_queue_io_opt(mddev
->queue
, chunk_size
*
2741 (conf
->raid_disks
/ conf
->near_copies
));
2743 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
2745 disk_idx
= rdev
->raid_disk
;
2746 if (disk_idx
>= conf
->raid_disks
2749 disk
= conf
->mirrors
+ disk_idx
;
2752 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
2753 rdev
->data_offset
<< 9);
2754 /* as we don't honour merge_bvec_fn, we must never risk
2755 * violating it, so limit max_segments to 1 lying
2756 * within a single page.
2758 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
2759 blk_queue_max_segments(mddev
->queue
, 1);
2760 blk_queue_segment_boundary(mddev
->queue
,
2761 PAGE_CACHE_SIZE
- 1);
2764 disk
->head_position
= 0;
2766 /* need to check that every block has at least one working mirror */
2767 if (!enough(conf
, -1)) {
2768 printk(KERN_ERR
"md/raid10:%s: not enough operational mirrors.\n",
2773 mddev
->degraded
= 0;
2774 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2776 disk
= conf
->mirrors
+ i
;
2779 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
2780 disk
->head_position
= 0;
2787 if (mddev
->recovery_cp
!= MaxSector
)
2788 printk(KERN_NOTICE
"md/raid10:%s: not clean"
2789 " -- starting background reconstruction\n",
2792 "md/raid10:%s: active with %d out of %d devices\n",
2793 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
,
2796 * Ok, everything is just fine now
2798 mddev
->dev_sectors
= conf
->dev_sectors
;
2799 size
= raid10_size(mddev
, 0, 0);
2800 md_set_array_sectors(mddev
, size
);
2801 mddev
->resync_max_sectors
= size
;
2803 mddev
->queue
->backing_dev_info
.congested_fn
= raid10_congested
;
2804 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
2806 /* Calculate max read-ahead size.
2807 * We need to readahead at least twice a whole stripe....
2811 int stripe
= conf
->raid_disks
*
2812 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
2813 stripe
/= conf
->near_copies
;
2814 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2* stripe
)
2815 mddev
->queue
->backing_dev_info
.ra_pages
= 2* stripe
;
2818 if (conf
->near_copies
< conf
->raid_disks
)
2819 blk_queue_merge_bvec(mddev
->queue
, raid10_mergeable_bvec
);
2821 if (md_integrity_register(mddev
))
2827 md_unregister_thread(mddev
->thread
);
2828 if (conf
->r10bio_pool
)
2829 mempool_destroy(conf
->r10bio_pool
);
2830 safe_put_page(conf
->tmppage
);
2831 kfree(conf
->mirrors
);
2833 mddev
->private = NULL
;
2838 static int stop(mddev_t
*mddev
)
2840 conf_t
*conf
= mddev
->private;
2842 raise_barrier(conf
, 0);
2843 lower_barrier(conf
);
2845 md_unregister_thread(mddev
->thread
);
2846 mddev
->thread
= NULL
;
2847 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
2848 if (conf
->r10bio_pool
)
2849 mempool_destroy(conf
->r10bio_pool
);
2850 kfree(conf
->mirrors
);
2852 mddev
->private = NULL
;
2856 static void raid10_quiesce(mddev_t
*mddev
, int state
)
2858 conf_t
*conf
= mddev
->private;
2862 raise_barrier(conf
, 0);
2865 lower_barrier(conf
);
2870 static void *raid10_takeover_raid0(mddev_t
*mddev
)
2875 if (mddev
->degraded
> 0) {
2876 printk(KERN_ERR
"md/raid10:%s: Error: degraded raid0!\n",
2878 return ERR_PTR(-EINVAL
);
2881 /* Set new parameters */
2882 mddev
->new_level
= 10;
2883 /* new layout: far_copies = 1, near_copies = 2 */
2884 mddev
->new_layout
= (1<<8) + 2;
2885 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
2886 mddev
->delta_disks
= mddev
->raid_disks
;
2887 mddev
->raid_disks
*= 2;
2888 /* make sure it will be not marked as dirty */
2889 mddev
->recovery_cp
= MaxSector
;
2891 conf
= setup_conf(mddev
);
2892 if (!IS_ERR(conf
)) {
2893 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
2894 if (rdev
->raid_disk
>= 0)
2895 rdev
->new_raid_disk
= rdev
->raid_disk
* 2;
2902 static void *raid10_takeover(mddev_t
*mddev
)
2904 struct raid0_private_data
*raid0_priv
;
2906 /* raid10 can take over:
2907 * raid0 - providing it has only two drives
2909 if (mddev
->level
== 0) {
2910 /* for raid0 takeover only one zone is supported */
2911 raid0_priv
= mddev
->private;
2912 if (raid0_priv
->nr_strip_zones
> 1) {
2913 printk(KERN_ERR
"md/raid10:%s: cannot takeover raid 0"
2914 " with more than one zone.\n",
2916 return ERR_PTR(-EINVAL
);
2918 return raid10_takeover_raid0(mddev
);
2920 return ERR_PTR(-EINVAL
);
2923 static struct mdk_personality raid10_personality
=
2927 .owner
= THIS_MODULE
,
2928 .make_request
= make_request
,
2932 .error_handler
= error
,
2933 .hot_add_disk
= raid10_add_disk
,
2934 .hot_remove_disk
= raid10_remove_disk
,
2935 .spare_active
= raid10_spare_active
,
2936 .sync_request
= sync_request
,
2937 .quiesce
= raid10_quiesce
,
2938 .size
= raid10_size
,
2939 .takeover
= raid10_takeover
,
2942 static int __init
raid_init(void)
2944 return register_md_personality(&raid10_personality
);
2947 static void raid_exit(void)
2949 unregister_md_personality(&raid10_personality
);
2952 module_init(raid_init
);
2953 module_exit(raid_exit
);
2954 MODULE_LICENSE("GPL");
2955 MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
2956 MODULE_ALIAS("md-personality-9"); /* RAID10 */
2957 MODULE_ALIAS("md-raid10");
2958 MODULE_ALIAS("md-level-10");