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/module.h>
25 #include <linux/seq_file.h>
26 #include <linux/ratelimit.h>
33 * RAID10 provides a combination of RAID0 and RAID1 functionality.
34 * The layout of data is defined by
37 * near_copies (stored in low byte of layout)
38 * far_copies (stored in second byte of layout)
39 * far_offset (stored in bit 16 of layout )
41 * The data to be stored is divided into chunks using chunksize.
42 * Each device is divided into far_copies sections.
43 * In each section, chunks are laid out in a style similar to raid0, but
44 * near_copies copies of each chunk is stored (each on a different drive).
45 * The starting device for each section is offset near_copies from the starting
46 * device of the previous section.
47 * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
49 * near_copies and far_copies must be at least one, and their product is at most
52 * If far_offset is true, then the far_copies are handled a bit differently.
53 * The copies are still in different stripes, but instead of be very far apart
54 * on disk, there are adjacent stripes.
58 * Number of guaranteed r10bios in case of extreme VM load:
60 #define NR_RAID10_BIOS 256
62 /* When there are this many requests queue to be written by
63 * the raid10 thread, we become 'congested' to provide back-pressure
66 static int max_queued_requests
= 1024;
68 static void allow_barrier(struct r10conf
*conf
);
69 static void lower_barrier(struct r10conf
*conf
);
70 static int enough(struct r10conf
*conf
, int ignore
);
72 static void * r10bio_pool_alloc(gfp_t gfp_flags
, void *data
)
74 struct r10conf
*conf
= data
;
75 int size
= offsetof(struct r10bio
, devs
[conf
->copies
]);
77 /* allocate a r10bio with room for raid_disks entries in the
79 return kzalloc(size
, gfp_flags
);
82 static void r10bio_pool_free(void *r10_bio
, void *data
)
87 /* Maximum size of each resync request */
88 #define RESYNC_BLOCK_SIZE (64*1024)
89 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
90 /* amount of memory to reserve for resync requests */
91 #define RESYNC_WINDOW (1024*1024)
92 /* maximum number of concurrent requests, memory permitting */
93 #define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
96 * When performing a resync, we need to read and compare, so
97 * we need as many pages are there are copies.
98 * When performing a recovery, we need 2 bios, one for read,
99 * one for write (we recover only one drive per r10buf)
102 static void * r10buf_pool_alloc(gfp_t gfp_flags
, void *data
)
104 struct r10conf
*conf
= data
;
106 struct r10bio
*r10_bio
;
111 r10_bio
= r10bio_pool_alloc(gfp_flags
, conf
);
115 if (test_bit(MD_RECOVERY_SYNC
, &conf
->mddev
->recovery
))
116 nalloc
= conf
->copies
; /* resync */
118 nalloc
= 2; /* recovery */
123 for (j
= nalloc
; j
-- ; ) {
124 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
127 r10_bio
->devs
[j
].bio
= bio
;
128 if (!conf
->have_replacement
)
130 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
133 r10_bio
->devs
[j
].repl_bio
= bio
;
136 * Allocate RESYNC_PAGES data pages and attach them
139 for (j
= 0 ; j
< nalloc
; j
++) {
140 struct bio
*rbio
= r10_bio
->devs
[j
].repl_bio
;
141 bio
= r10_bio
->devs
[j
].bio
;
142 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
143 if (j
== 1 && !test_bit(MD_RECOVERY_SYNC
,
144 &conf
->mddev
->recovery
)) {
145 /* we can share bv_page's during recovery */
146 struct bio
*rbio
= r10_bio
->devs
[0].bio
;
147 page
= rbio
->bi_io_vec
[i
].bv_page
;
150 page
= alloc_page(gfp_flags
);
154 bio
->bi_io_vec
[i
].bv_page
= page
;
156 rbio
->bi_io_vec
[i
].bv_page
= page
;
164 safe_put_page(bio
->bi_io_vec
[i
-1].bv_page
);
166 for (i
= 0; i
< RESYNC_PAGES
; i
++)
167 safe_put_page(r10_bio
->devs
[j
].bio
->bi_io_vec
[i
].bv_page
);
170 while (++j
< nalloc
) {
171 bio_put(r10_bio
->devs
[j
].bio
);
172 if (r10_bio
->devs
[j
].repl_bio
)
173 bio_put(r10_bio
->devs
[j
].repl_bio
);
175 r10bio_pool_free(r10_bio
, conf
);
179 static void r10buf_pool_free(void *__r10_bio
, void *data
)
182 struct r10conf
*conf
= data
;
183 struct r10bio
*r10bio
= __r10_bio
;
186 for (j
=0; j
< conf
->copies
; j
++) {
187 struct bio
*bio
= r10bio
->devs
[j
].bio
;
189 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
190 safe_put_page(bio
->bi_io_vec
[i
].bv_page
);
191 bio
->bi_io_vec
[i
].bv_page
= NULL
;
195 bio
= r10bio
->devs
[j
].repl_bio
;
199 r10bio_pool_free(r10bio
, conf
);
202 static void put_all_bios(struct r10conf
*conf
, struct r10bio
*r10_bio
)
206 for (i
= 0; i
< conf
->copies
; i
++) {
207 struct bio
**bio
= & r10_bio
->devs
[i
].bio
;
208 if (!BIO_SPECIAL(*bio
))
211 bio
= &r10_bio
->devs
[i
].repl_bio
;
212 if (r10_bio
->read_slot
< 0 && !BIO_SPECIAL(*bio
))
218 static void free_r10bio(struct r10bio
*r10_bio
)
220 struct r10conf
*conf
= r10_bio
->mddev
->private;
222 put_all_bios(conf
, r10_bio
);
223 mempool_free(r10_bio
, conf
->r10bio_pool
);
226 static void put_buf(struct r10bio
*r10_bio
)
228 struct r10conf
*conf
= r10_bio
->mddev
->private;
230 mempool_free(r10_bio
, conf
->r10buf_pool
);
235 static void reschedule_retry(struct r10bio
*r10_bio
)
238 struct mddev
*mddev
= r10_bio
->mddev
;
239 struct r10conf
*conf
= mddev
->private;
241 spin_lock_irqsave(&conf
->device_lock
, flags
);
242 list_add(&r10_bio
->retry_list
, &conf
->retry_list
);
244 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
246 /* wake up frozen array... */
247 wake_up(&conf
->wait_barrier
);
249 md_wakeup_thread(mddev
->thread
);
253 * raid_end_bio_io() is called when we have finished servicing a mirrored
254 * operation and are ready to return a success/failure code to the buffer
257 static void raid_end_bio_io(struct r10bio
*r10_bio
)
259 struct bio
*bio
= r10_bio
->master_bio
;
261 struct r10conf
*conf
= r10_bio
->mddev
->private;
263 if (bio
->bi_phys_segments
) {
265 spin_lock_irqsave(&conf
->device_lock
, flags
);
266 bio
->bi_phys_segments
--;
267 done
= (bio
->bi_phys_segments
== 0);
268 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
271 if (!test_bit(R10BIO_Uptodate
, &r10_bio
->state
))
272 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
276 * Wake up any possible resync thread that waits for the device
281 free_r10bio(r10_bio
);
285 * Update disk head position estimator based on IRQ completion info.
287 static inline void update_head_pos(int slot
, struct r10bio
*r10_bio
)
289 struct r10conf
*conf
= r10_bio
->mddev
->private;
291 conf
->mirrors
[r10_bio
->devs
[slot
].devnum
].head_position
=
292 r10_bio
->devs
[slot
].addr
+ (r10_bio
->sectors
);
296 * Find the disk number which triggered given bio
298 static int find_bio_disk(struct r10conf
*conf
, struct r10bio
*r10_bio
,
299 struct bio
*bio
, int *slotp
, int *replp
)
304 for (slot
= 0; slot
< conf
->copies
; slot
++) {
305 if (r10_bio
->devs
[slot
].bio
== bio
)
307 if (r10_bio
->devs
[slot
].repl_bio
== bio
) {
313 BUG_ON(slot
== conf
->copies
);
314 update_head_pos(slot
, r10_bio
);
320 return r10_bio
->devs
[slot
].devnum
;
323 static void raid10_end_read_request(struct bio
*bio
, int error
)
325 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
326 struct r10bio
*r10_bio
= bio
->bi_private
;
328 struct md_rdev
*rdev
;
329 struct r10conf
*conf
= r10_bio
->mddev
->private;
332 slot
= r10_bio
->read_slot
;
333 dev
= r10_bio
->devs
[slot
].devnum
;
334 rdev
= r10_bio
->devs
[slot
].rdev
;
336 * this branch is our 'one mirror IO has finished' event handler:
338 update_head_pos(slot
, r10_bio
);
342 * Set R10BIO_Uptodate in our master bio, so that
343 * we will return a good error code to the higher
344 * levels even if IO on some other mirrored buffer fails.
346 * The 'master' represents the composite IO operation to
347 * user-side. So if something waits for IO, then it will
348 * wait for the 'master' bio.
350 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
352 /* If all other devices that store this block have
353 * failed, we want to return the error upwards rather
354 * than fail the last device. Here we redefine
355 * "uptodate" to mean "Don't want to retry"
358 spin_lock_irqsave(&conf
->device_lock
, flags
);
359 if (!enough(conf
, rdev
->raid_disk
))
361 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
364 raid_end_bio_io(r10_bio
);
365 rdev_dec_pending(rdev
, conf
->mddev
);
368 * oops, read error - keep the refcount on the rdev
370 char b
[BDEVNAME_SIZE
];
371 printk_ratelimited(KERN_ERR
372 "md/raid10:%s: %s: rescheduling sector %llu\n",
374 bdevname(rdev
->bdev
, b
),
375 (unsigned long long)r10_bio
->sector
);
376 set_bit(R10BIO_ReadError
, &r10_bio
->state
);
377 reschedule_retry(r10_bio
);
381 static void close_write(struct r10bio
*r10_bio
)
383 /* clear the bitmap if all writes complete successfully */
384 bitmap_endwrite(r10_bio
->mddev
->bitmap
, r10_bio
->sector
,
386 !test_bit(R10BIO_Degraded
, &r10_bio
->state
),
388 md_write_end(r10_bio
->mddev
);
391 static void one_write_done(struct r10bio
*r10_bio
)
393 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
394 if (test_bit(R10BIO_WriteError
, &r10_bio
->state
))
395 reschedule_retry(r10_bio
);
397 close_write(r10_bio
);
398 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
))
399 reschedule_retry(r10_bio
);
401 raid_end_bio_io(r10_bio
);
406 static void raid10_end_write_request(struct bio
*bio
, int error
)
408 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
409 struct r10bio
*r10_bio
= bio
->bi_private
;
412 struct r10conf
*conf
= r10_bio
->mddev
->private;
414 struct md_rdev
*rdev
= NULL
;
416 dev
= find_bio_disk(conf
, r10_bio
, bio
, &slot
, &repl
);
419 rdev
= conf
->mirrors
[dev
].replacement
;
423 rdev
= conf
->mirrors
[dev
].rdev
;
426 * this branch is our 'one mirror IO has finished' event handler:
430 /* Never record new bad blocks to replacement,
433 md_error(rdev
->mddev
, rdev
);
435 set_bit(WriteErrorSeen
, &rdev
->flags
);
436 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
437 set_bit(MD_RECOVERY_NEEDED
,
438 &rdev
->mddev
->recovery
);
439 set_bit(R10BIO_WriteError
, &r10_bio
->state
);
444 * Set R10BIO_Uptodate in our master bio, so that
445 * we will return a good error code for to the higher
446 * levels even if IO on some other mirrored buffer fails.
448 * The 'master' represents the composite IO operation to
449 * user-side. So if something waits for IO, then it will
450 * wait for the 'master' bio.
455 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
457 /* Maybe we can clear some bad blocks. */
458 if (is_badblock(rdev
,
459 r10_bio
->devs
[slot
].addr
,
461 &first_bad
, &bad_sectors
)) {
464 r10_bio
->devs
[slot
].repl_bio
= IO_MADE_GOOD
;
466 r10_bio
->devs
[slot
].bio
= IO_MADE_GOOD
;
468 set_bit(R10BIO_MadeGood
, &r10_bio
->state
);
474 * Let's see if all mirrored write operations have finished
477 one_write_done(r10_bio
);
479 rdev_dec_pending(conf
->mirrors
[dev
].rdev
, conf
->mddev
);
483 * RAID10 layout manager
484 * As well as the chunksize and raid_disks count, there are two
485 * parameters: near_copies and far_copies.
486 * near_copies * far_copies must be <= raid_disks.
487 * Normally one of these will be 1.
488 * If both are 1, we get raid0.
489 * If near_copies == raid_disks, we get raid1.
491 * Chunks are laid out in raid0 style with near_copies copies of the
492 * first chunk, followed by near_copies copies of the next chunk and
494 * If far_copies > 1, then after 1/far_copies of the array has been assigned
495 * as described above, we start again with a device offset of near_copies.
496 * So we effectively have another copy of the whole array further down all
497 * the drives, but with blocks on different drives.
498 * With this layout, and block is never stored twice on the one device.
500 * raid10_find_phys finds the sector offset of a given virtual sector
501 * on each device that it is on.
503 * raid10_find_virt does the reverse mapping, from a device and a
504 * sector offset to a virtual address
507 static void raid10_find_phys(struct r10conf
*conf
, struct r10bio
*r10bio
)
517 /* now calculate first sector/dev */
518 chunk
= r10bio
->sector
>> conf
->chunk_shift
;
519 sector
= r10bio
->sector
& conf
->chunk_mask
;
521 chunk
*= conf
->near_copies
;
523 dev
= sector_div(stripe
, conf
->raid_disks
);
524 if (conf
->far_offset
)
525 stripe
*= conf
->far_copies
;
527 sector
+= stripe
<< conf
->chunk_shift
;
529 /* and calculate all the others */
530 for (n
=0; n
< conf
->near_copies
; n
++) {
533 r10bio
->devs
[slot
].addr
= sector
;
534 r10bio
->devs
[slot
].devnum
= d
;
537 for (f
= 1; f
< conf
->far_copies
; f
++) {
538 d
+= conf
->near_copies
;
539 if (d
>= conf
->raid_disks
)
540 d
-= conf
->raid_disks
;
542 r10bio
->devs
[slot
].devnum
= d
;
543 r10bio
->devs
[slot
].addr
= s
;
547 if (dev
>= conf
->raid_disks
) {
549 sector
+= (conf
->chunk_mask
+ 1);
552 BUG_ON(slot
!= conf
->copies
);
555 static sector_t
raid10_find_virt(struct r10conf
*conf
, sector_t sector
, int dev
)
557 sector_t offset
, chunk
, vchunk
;
559 offset
= sector
& conf
->chunk_mask
;
560 if (conf
->far_offset
) {
562 chunk
= sector
>> conf
->chunk_shift
;
563 fc
= sector_div(chunk
, conf
->far_copies
);
564 dev
-= fc
* conf
->near_copies
;
566 dev
+= conf
->raid_disks
;
568 while (sector
>= conf
->stride
) {
569 sector
-= conf
->stride
;
570 if (dev
< conf
->near_copies
)
571 dev
+= conf
->raid_disks
- conf
->near_copies
;
573 dev
-= conf
->near_copies
;
575 chunk
= sector
>> conf
->chunk_shift
;
577 vchunk
= chunk
* conf
->raid_disks
+ dev
;
578 sector_div(vchunk
, conf
->near_copies
);
579 return (vchunk
<< conf
->chunk_shift
) + offset
;
583 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
585 * @bvm: properties of new bio
586 * @biovec: the request that could be merged to it.
588 * Return amount of bytes we can accept at this offset
589 * If near_copies == raid_disk, there are no striping issues,
590 * but in that case, the function isn't called at all.
592 static int raid10_mergeable_bvec(struct request_queue
*q
,
593 struct bvec_merge_data
*bvm
,
594 struct bio_vec
*biovec
)
596 struct mddev
*mddev
= q
->queuedata
;
597 sector_t sector
= bvm
->bi_sector
+ get_start_sect(bvm
->bi_bdev
);
599 unsigned int chunk_sectors
= mddev
->chunk_sectors
;
600 unsigned int bio_sectors
= bvm
->bi_size
>> 9;
602 max
= (chunk_sectors
- ((sector
& (chunk_sectors
- 1)) + bio_sectors
)) << 9;
603 if (max
< 0) max
= 0; /* bio_add cannot handle a negative return */
604 if (max
<= biovec
->bv_len
&& bio_sectors
== 0)
605 return biovec
->bv_len
;
611 * This routine returns the disk from which the requested read should
612 * be done. There is a per-array 'next expected sequential IO' sector
613 * number - if this matches on the next IO then we use the last disk.
614 * There is also a per-disk 'last know head position' sector that is
615 * maintained from IRQ contexts, both the normal and the resync IO
616 * completion handlers update this position correctly. If there is no
617 * perfect sequential match then we pick the disk whose head is closest.
619 * If there are 2 mirrors in the same 2 devices, performance degrades
620 * because position is mirror, not device based.
622 * The rdev for the device selected will have nr_pending incremented.
626 * FIXME: possibly should rethink readbalancing and do it differently
627 * depending on near_copies / far_copies geometry.
629 static struct md_rdev
*read_balance(struct r10conf
*conf
,
630 struct r10bio
*r10_bio
,
633 const sector_t this_sector
= r10_bio
->sector
;
635 int sectors
= r10_bio
->sectors
;
636 int best_good_sectors
;
637 sector_t new_distance
, best_dist
;
638 struct md_rdev
*rdev
, *best_rdev
;
642 raid10_find_phys(conf
, r10_bio
);
645 sectors
= r10_bio
->sectors
;
648 best_dist
= MaxSector
;
649 best_good_sectors
= 0;
652 * Check if we can balance. We can balance on the whole
653 * device if no resync is going on (recovery is ok), or below
654 * the resync window. We take the first readable disk when
655 * above the resync window.
657 if (conf
->mddev
->recovery_cp
< MaxSector
658 && (this_sector
+ sectors
>= conf
->next_resync
))
661 for (slot
= 0; slot
< conf
->copies
; slot
++) {
666 if (r10_bio
->devs
[slot
].bio
== IO_BLOCKED
)
668 disk
= r10_bio
->devs
[slot
].devnum
;
669 rdev
= rcu_dereference(conf
->mirrors
[disk
].replacement
);
670 if (rdev
== NULL
|| test_bit(Faulty
, &rdev
->flags
) ||
671 r10_bio
->devs
[slot
].addr
+ sectors
> rdev
->recovery_offset
)
672 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
675 if (test_bit(Faulty
, &rdev
->flags
))
677 if (!test_bit(In_sync
, &rdev
->flags
) &&
678 r10_bio
->devs
[slot
].addr
+ sectors
> rdev
->recovery_offset
)
681 dev_sector
= r10_bio
->devs
[slot
].addr
;
682 if (is_badblock(rdev
, dev_sector
, sectors
,
683 &first_bad
, &bad_sectors
)) {
684 if (best_dist
< MaxSector
)
685 /* Already have a better slot */
687 if (first_bad
<= dev_sector
) {
688 /* Cannot read here. If this is the
689 * 'primary' device, then we must not read
690 * beyond 'bad_sectors' from another device.
692 bad_sectors
-= (dev_sector
- first_bad
);
693 if (!do_balance
&& sectors
> bad_sectors
)
694 sectors
= bad_sectors
;
695 if (best_good_sectors
> sectors
)
696 best_good_sectors
= sectors
;
698 sector_t good_sectors
=
699 first_bad
- dev_sector
;
700 if (good_sectors
> best_good_sectors
) {
701 best_good_sectors
= good_sectors
;
706 /* Must read from here */
711 best_good_sectors
= sectors
;
716 /* This optimisation is debatable, and completely destroys
717 * sequential read speed for 'far copies' arrays. So only
718 * keep it for 'near' arrays, and review those later.
720 if (conf
->near_copies
> 1 && !atomic_read(&rdev
->nr_pending
))
723 /* for far > 1 always use the lowest address */
724 if (conf
->far_copies
> 1)
725 new_distance
= r10_bio
->devs
[slot
].addr
;
727 new_distance
= abs(r10_bio
->devs
[slot
].addr
-
728 conf
->mirrors
[disk
].head_position
);
729 if (new_distance
< best_dist
) {
730 best_dist
= new_distance
;
735 if (slot
>= conf
->copies
) {
741 atomic_inc(&rdev
->nr_pending
);
742 if (test_bit(Faulty
, &rdev
->flags
)) {
743 /* Cannot risk returning a device that failed
744 * before we inc'ed nr_pending
746 rdev_dec_pending(rdev
, conf
->mddev
);
749 r10_bio
->read_slot
= slot
;
753 *max_sectors
= best_good_sectors
;
758 static int raid10_congested(void *data
, int bits
)
760 struct mddev
*mddev
= data
;
761 struct r10conf
*conf
= mddev
->private;
764 if ((bits
& (1 << BDI_async_congested
)) &&
765 conf
->pending_count
>= max_queued_requests
)
768 if (mddev_congested(mddev
, bits
))
771 for (i
= 0; i
< conf
->raid_disks
&& ret
== 0; i
++) {
772 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
773 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
774 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
776 ret
|= bdi_congested(&q
->backing_dev_info
, bits
);
783 static void flush_pending_writes(struct r10conf
*conf
)
785 /* Any writes that have been queued but are awaiting
786 * bitmap updates get flushed here.
788 spin_lock_irq(&conf
->device_lock
);
790 if (conf
->pending_bio_list
.head
) {
792 bio
= bio_list_get(&conf
->pending_bio_list
);
793 conf
->pending_count
= 0;
794 spin_unlock_irq(&conf
->device_lock
);
795 /* flush any pending bitmap writes to disk
796 * before proceeding w/ I/O */
797 bitmap_unplug(conf
->mddev
->bitmap
);
798 wake_up(&conf
->wait_barrier
);
800 while (bio
) { /* submit pending writes */
801 struct bio
*next
= bio
->bi_next
;
803 generic_make_request(bio
);
807 spin_unlock_irq(&conf
->device_lock
);
811 * Sometimes we need to suspend IO while we do something else,
812 * either some resync/recovery, or reconfigure the array.
813 * To do this we raise a 'barrier'.
814 * The 'barrier' is a counter that can be raised multiple times
815 * to count how many activities are happening which preclude
817 * We can only raise the barrier if there is no pending IO.
818 * i.e. if nr_pending == 0.
819 * We choose only to raise the barrier if no-one is waiting for the
820 * barrier to go down. This means that as soon as an IO request
821 * is ready, no other operations which require a barrier will start
822 * until the IO request has had a chance.
824 * So: regular IO calls 'wait_barrier'. When that returns there
825 * is no backgroup IO happening, It must arrange to call
826 * allow_barrier when it has finished its IO.
827 * backgroup IO calls must call raise_barrier. Once that returns
828 * there is no normal IO happeing. It must arrange to call
829 * lower_barrier when the particular background IO completes.
832 static void raise_barrier(struct r10conf
*conf
, int force
)
834 BUG_ON(force
&& !conf
->barrier
);
835 spin_lock_irq(&conf
->resync_lock
);
837 /* Wait until no block IO is waiting (unless 'force') */
838 wait_event_lock_irq(conf
->wait_barrier
, force
|| !conf
->nr_waiting
,
839 conf
->resync_lock
, );
841 /* block any new IO from starting */
844 /* Now wait for all pending IO to complete */
845 wait_event_lock_irq(conf
->wait_barrier
,
846 !conf
->nr_pending
&& conf
->barrier
< RESYNC_DEPTH
,
847 conf
->resync_lock
, );
849 spin_unlock_irq(&conf
->resync_lock
);
852 static void lower_barrier(struct r10conf
*conf
)
855 spin_lock_irqsave(&conf
->resync_lock
, flags
);
857 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
858 wake_up(&conf
->wait_barrier
);
861 static void wait_barrier(struct r10conf
*conf
)
863 spin_lock_irq(&conf
->resync_lock
);
866 /* Wait for the barrier to drop.
867 * However if there are already pending
868 * requests (preventing the barrier from
869 * rising completely), and the
870 * pre-process bio queue isn't empty,
871 * then don't wait, as we need to empty
872 * that queue to get the nr_pending
875 wait_event_lock_irq(conf
->wait_barrier
,
879 !bio_list_empty(current
->bio_list
)),
885 spin_unlock_irq(&conf
->resync_lock
);
888 static void allow_barrier(struct r10conf
*conf
)
891 spin_lock_irqsave(&conf
->resync_lock
, flags
);
893 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
894 wake_up(&conf
->wait_barrier
);
897 static void freeze_array(struct r10conf
*conf
)
899 /* stop syncio and normal IO and wait for everything to
901 * We increment barrier and nr_waiting, and then
902 * wait until nr_pending match nr_queued+1
903 * This is called in the context of one normal IO request
904 * that has failed. Thus any sync request that might be pending
905 * will be blocked by nr_pending, and we need to wait for
906 * pending IO requests to complete or be queued for re-try.
907 * Thus the number queued (nr_queued) plus this request (1)
908 * must match the number of pending IOs (nr_pending) before
911 spin_lock_irq(&conf
->resync_lock
);
914 wait_event_lock_irq(conf
->wait_barrier
,
915 conf
->nr_pending
== conf
->nr_queued
+1,
917 flush_pending_writes(conf
));
919 spin_unlock_irq(&conf
->resync_lock
);
922 static void unfreeze_array(struct r10conf
*conf
)
924 /* reverse the effect of the freeze */
925 spin_lock_irq(&conf
->resync_lock
);
928 wake_up(&conf
->wait_barrier
);
929 spin_unlock_irq(&conf
->resync_lock
);
932 static void make_request(struct mddev
*mddev
, struct bio
* bio
)
934 struct r10conf
*conf
= mddev
->private;
935 struct r10bio
*r10_bio
;
936 struct bio
*read_bio
;
938 int chunk_sects
= conf
->chunk_mask
+ 1;
939 const int rw
= bio_data_dir(bio
);
940 const unsigned long do_sync
= (bio
->bi_rw
& REQ_SYNC
);
941 const unsigned long do_fua
= (bio
->bi_rw
& REQ_FUA
);
943 struct md_rdev
*blocked_rdev
;
948 if (unlikely(bio
->bi_rw
& REQ_FLUSH
)) {
949 md_flush_request(mddev
, bio
);
953 /* If this request crosses a chunk boundary, we need to
954 * split it. This will only happen for 1 PAGE (or less) requests.
956 if (unlikely( (bio
->bi_sector
& conf
->chunk_mask
) + (bio
->bi_size
>> 9)
958 conf
->near_copies
< conf
->raid_disks
)) {
960 /* Sanity check -- queue functions should prevent this happening */
961 if (bio
->bi_vcnt
!= 1 ||
964 /* This is a one page bio that upper layers
965 * refuse to split for us, so we need to split it.
968 chunk_sects
- (bio
->bi_sector
& (chunk_sects
- 1)) );
970 /* Each of these 'make_request' calls will call 'wait_barrier'.
971 * If the first succeeds but the second blocks due to the resync
972 * thread raising the barrier, we will deadlock because the
973 * IO to the underlying device will be queued in generic_make_request
974 * and will never complete, so will never reduce nr_pending.
975 * So increment nr_waiting here so no new raise_barriers will
976 * succeed, and so the second wait_barrier cannot block.
978 spin_lock_irq(&conf
->resync_lock
);
980 spin_unlock_irq(&conf
->resync_lock
);
982 make_request(mddev
, &bp
->bio1
);
983 make_request(mddev
, &bp
->bio2
);
985 spin_lock_irq(&conf
->resync_lock
);
987 wake_up(&conf
->wait_barrier
);
988 spin_unlock_irq(&conf
->resync_lock
);
990 bio_pair_release(bp
);
993 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
994 " or bigger than %dk %llu %d\n", mdname(mddev
), chunk_sects
/2,
995 (unsigned long long)bio
->bi_sector
, bio
->bi_size
>> 10);
1001 md_write_start(mddev
, bio
);
1004 * Register the new request and wait if the reconstruction
1005 * thread has put up a bar for new requests.
1006 * Continue immediately if no resync is active currently.
1010 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
1012 r10_bio
->master_bio
= bio
;
1013 r10_bio
->sectors
= bio
->bi_size
>> 9;
1015 r10_bio
->mddev
= mddev
;
1016 r10_bio
->sector
= bio
->bi_sector
;
1019 /* We might need to issue multiple reads to different
1020 * devices if there are bad blocks around, so we keep
1021 * track of the number of reads in bio->bi_phys_segments.
1022 * If this is 0, there is only one r10_bio and no locking
1023 * will be needed when the request completes. If it is
1024 * non-zero, then it is the number of not-completed requests.
1026 bio
->bi_phys_segments
= 0;
1027 clear_bit(BIO_SEG_VALID
, &bio
->bi_flags
);
1031 * read balancing logic:
1033 struct md_rdev
*rdev
;
1037 rdev
= read_balance(conf
, r10_bio
, &max_sectors
);
1039 raid_end_bio_io(r10_bio
);
1042 slot
= r10_bio
->read_slot
;
1044 read_bio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1045 md_trim_bio(read_bio
, r10_bio
->sector
- bio
->bi_sector
,
1048 r10_bio
->devs
[slot
].bio
= read_bio
;
1049 r10_bio
->devs
[slot
].rdev
= rdev
;
1051 read_bio
->bi_sector
= r10_bio
->devs
[slot
].addr
+
1053 read_bio
->bi_bdev
= rdev
->bdev
;
1054 read_bio
->bi_end_io
= raid10_end_read_request
;
1055 read_bio
->bi_rw
= READ
| do_sync
;
1056 read_bio
->bi_private
= r10_bio
;
1058 if (max_sectors
< r10_bio
->sectors
) {
1059 /* Could not read all from this device, so we will
1060 * need another r10_bio.
1062 sectors_handled
= (r10_bio
->sectors
+ max_sectors
1064 r10_bio
->sectors
= max_sectors
;
1065 spin_lock_irq(&conf
->device_lock
);
1066 if (bio
->bi_phys_segments
== 0)
1067 bio
->bi_phys_segments
= 2;
1069 bio
->bi_phys_segments
++;
1070 spin_unlock(&conf
->device_lock
);
1071 /* Cannot call generic_make_request directly
1072 * as that will be queued in __generic_make_request
1073 * and subsequent mempool_alloc might block
1074 * waiting for it. so hand bio over to raid10d.
1076 reschedule_retry(r10_bio
);
1078 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
1080 r10_bio
->master_bio
= bio
;
1081 r10_bio
->sectors
= ((bio
->bi_size
>> 9)
1084 r10_bio
->mddev
= mddev
;
1085 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1088 generic_make_request(read_bio
);
1095 if (conf
->pending_count
>= max_queued_requests
) {
1096 md_wakeup_thread(mddev
->thread
);
1097 wait_event(conf
->wait_barrier
,
1098 conf
->pending_count
< max_queued_requests
);
1100 /* first select target devices under rcu_lock and
1101 * inc refcount on their rdev. Record them by setting
1103 * If there are known/acknowledged bad blocks on any device
1104 * on which we have seen a write error, we want to avoid
1105 * writing to those blocks. This potentially requires several
1106 * writes to write around the bad blocks. Each set of writes
1107 * gets its own r10_bio with a set of bios attached. The number
1108 * of r10_bios is recored in bio->bi_phys_segments just as with
1111 plugged
= mddev_check_plugged(mddev
);
1113 r10_bio
->read_slot
= -1; /* make sure repl_bio gets freed */
1114 raid10_find_phys(conf
, r10_bio
);
1116 blocked_rdev
= NULL
;
1118 max_sectors
= r10_bio
->sectors
;
1120 for (i
= 0; i
< conf
->copies
; i
++) {
1121 int d
= r10_bio
->devs
[i
].devnum
;
1122 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1123 struct md_rdev
*rrdev
= rcu_dereference(
1124 conf
->mirrors
[d
].replacement
);
1127 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
1128 atomic_inc(&rdev
->nr_pending
);
1129 blocked_rdev
= rdev
;
1132 if (rrdev
&& unlikely(test_bit(Blocked
, &rrdev
->flags
))) {
1133 atomic_inc(&rrdev
->nr_pending
);
1134 blocked_rdev
= rrdev
;
1137 if (rrdev
&& test_bit(Faulty
, &rrdev
->flags
))
1140 r10_bio
->devs
[i
].bio
= NULL
;
1141 r10_bio
->devs
[i
].repl_bio
= NULL
;
1142 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
)) {
1143 set_bit(R10BIO_Degraded
, &r10_bio
->state
);
1146 if (test_bit(WriteErrorSeen
, &rdev
->flags
)) {
1148 sector_t dev_sector
= r10_bio
->devs
[i
].addr
;
1152 is_bad
= is_badblock(rdev
, dev_sector
,
1154 &first_bad
, &bad_sectors
);
1156 /* Mustn't write here until the bad block
1159 atomic_inc(&rdev
->nr_pending
);
1160 set_bit(BlockedBadBlocks
, &rdev
->flags
);
1161 blocked_rdev
= rdev
;
1164 if (is_bad
&& first_bad
<= dev_sector
) {
1165 /* Cannot write here at all */
1166 bad_sectors
-= (dev_sector
- first_bad
);
1167 if (bad_sectors
< max_sectors
)
1168 /* Mustn't write more than bad_sectors
1169 * to other devices yet
1171 max_sectors
= bad_sectors
;
1172 /* We don't set R10BIO_Degraded as that
1173 * only applies if the disk is missing,
1174 * so it might be re-added, and we want to
1175 * know to recover this chunk.
1176 * In this case the device is here, and the
1177 * fact that this chunk is not in-sync is
1178 * recorded in the bad block log.
1183 int good_sectors
= first_bad
- dev_sector
;
1184 if (good_sectors
< max_sectors
)
1185 max_sectors
= good_sectors
;
1188 r10_bio
->devs
[i
].bio
= bio
;
1189 atomic_inc(&rdev
->nr_pending
);
1191 r10_bio
->devs
[i
].repl_bio
= bio
;
1192 atomic_inc(&rrdev
->nr_pending
);
1197 if (unlikely(blocked_rdev
)) {
1198 /* Have to wait for this device to get unblocked, then retry */
1202 for (j
= 0; j
< i
; j
++) {
1203 if (r10_bio
->devs
[j
].bio
) {
1204 d
= r10_bio
->devs
[j
].devnum
;
1205 rdev_dec_pending(conf
->mirrors
[d
].rdev
, mddev
);
1207 if (r10_bio
->devs
[j
].repl_bio
) {
1208 struct md_rdev
*rdev
;
1209 d
= r10_bio
->devs
[j
].devnum
;
1210 rdev
= conf
->mirrors
[d
].replacement
;
1212 /* Race with remove_disk */
1214 rdev
= conf
->mirrors
[d
].rdev
;
1216 rdev_dec_pending(rdev
, mddev
);
1219 allow_barrier(conf
);
1220 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
1225 if (max_sectors
< r10_bio
->sectors
) {
1226 /* We are splitting this into multiple parts, so
1227 * we need to prepare for allocating another r10_bio.
1229 r10_bio
->sectors
= max_sectors
;
1230 spin_lock_irq(&conf
->device_lock
);
1231 if (bio
->bi_phys_segments
== 0)
1232 bio
->bi_phys_segments
= 2;
1234 bio
->bi_phys_segments
++;
1235 spin_unlock_irq(&conf
->device_lock
);
1237 sectors_handled
= r10_bio
->sector
+ max_sectors
- bio
->bi_sector
;
1239 atomic_set(&r10_bio
->remaining
, 1);
1240 bitmap_startwrite(mddev
->bitmap
, r10_bio
->sector
, r10_bio
->sectors
, 0);
1242 for (i
= 0; i
< conf
->copies
; i
++) {
1244 int d
= r10_bio
->devs
[i
].devnum
;
1245 if (!r10_bio
->devs
[i
].bio
)
1248 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1249 md_trim_bio(mbio
, r10_bio
->sector
- bio
->bi_sector
,
1251 r10_bio
->devs
[i
].bio
= mbio
;
1253 mbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
1254 conf
->mirrors
[d
].rdev
->data_offset
);
1255 mbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1256 mbio
->bi_end_io
= raid10_end_write_request
;
1257 mbio
->bi_rw
= WRITE
| do_sync
| do_fua
;
1258 mbio
->bi_private
= r10_bio
;
1260 atomic_inc(&r10_bio
->remaining
);
1261 spin_lock_irqsave(&conf
->device_lock
, flags
);
1262 bio_list_add(&conf
->pending_bio_list
, mbio
);
1263 conf
->pending_count
++;
1264 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1266 if (!r10_bio
->devs
[i
].repl_bio
)
1269 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1270 md_trim_bio(mbio
, r10_bio
->sector
- bio
->bi_sector
,
1272 r10_bio
->devs
[i
].repl_bio
= mbio
;
1274 /* We are actively writing to the original device
1275 * so it cannot disappear, so the replacement cannot
1278 mbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
1279 conf
->mirrors
[d
].replacement
->data_offset
);
1280 mbio
->bi_bdev
= conf
->mirrors
[d
].replacement
->bdev
;
1281 mbio
->bi_end_io
= raid10_end_write_request
;
1282 mbio
->bi_rw
= WRITE
| do_sync
| do_fua
;
1283 mbio
->bi_private
= r10_bio
;
1285 atomic_inc(&r10_bio
->remaining
);
1286 spin_lock_irqsave(&conf
->device_lock
, flags
);
1287 bio_list_add(&conf
->pending_bio_list
, mbio
);
1288 conf
->pending_count
++;
1289 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1292 /* Don't remove the bias on 'remaining' (one_write_done) until
1293 * after checking if we need to go around again.
1296 if (sectors_handled
< (bio
->bi_size
>> 9)) {
1297 one_write_done(r10_bio
);
1298 /* We need another r10_bio. It has already been counted
1299 * in bio->bi_phys_segments.
1301 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
1303 r10_bio
->master_bio
= bio
;
1304 r10_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
1306 r10_bio
->mddev
= mddev
;
1307 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1311 one_write_done(r10_bio
);
1313 /* In case raid10d snuck in to freeze_array */
1314 wake_up(&conf
->wait_barrier
);
1316 if (do_sync
|| !mddev
->bitmap
|| !plugged
)
1317 md_wakeup_thread(mddev
->thread
);
1320 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
1322 struct r10conf
*conf
= mddev
->private;
1325 if (conf
->near_copies
< conf
->raid_disks
)
1326 seq_printf(seq
, " %dK chunks", mddev
->chunk_sectors
/ 2);
1327 if (conf
->near_copies
> 1)
1328 seq_printf(seq
, " %d near-copies", conf
->near_copies
);
1329 if (conf
->far_copies
> 1) {
1330 if (conf
->far_offset
)
1331 seq_printf(seq
, " %d offset-copies", conf
->far_copies
);
1333 seq_printf(seq
, " %d far-copies", conf
->far_copies
);
1335 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
1336 conf
->raid_disks
- mddev
->degraded
);
1337 for (i
= 0; i
< conf
->raid_disks
; i
++)
1338 seq_printf(seq
, "%s",
1339 conf
->mirrors
[i
].rdev
&&
1340 test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ? "U" : "_");
1341 seq_printf(seq
, "]");
1344 /* check if there are enough drives for
1345 * every block to appear on atleast one.
1346 * Don't consider the device numbered 'ignore'
1347 * as we might be about to remove it.
1349 static int enough(struct r10conf
*conf
, int ignore
)
1354 int n
= conf
->copies
;
1357 if (conf
->mirrors
[first
].rdev
&&
1360 first
= (first
+1) % conf
->raid_disks
;
1364 } while (first
!= 0);
1368 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1370 char b
[BDEVNAME_SIZE
];
1371 struct r10conf
*conf
= mddev
->private;
1374 * If it is not operational, then we have already marked it as dead
1375 * else if it is the last working disks, ignore the error, let the
1376 * next level up know.
1377 * else mark the drive as failed
1379 if (test_bit(In_sync
, &rdev
->flags
)
1380 && !enough(conf
, rdev
->raid_disk
))
1382 * Don't fail the drive, just return an IO error.
1385 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1386 unsigned long flags
;
1387 spin_lock_irqsave(&conf
->device_lock
, flags
);
1389 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1391 * if recovery is running, make sure it aborts.
1393 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1395 set_bit(Blocked
, &rdev
->flags
);
1396 set_bit(Faulty
, &rdev
->flags
);
1397 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1399 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1400 "md/raid10:%s: Operation continuing on %d devices.\n",
1401 mdname(mddev
), bdevname(rdev
->bdev
, b
),
1402 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
1405 static void print_conf(struct r10conf
*conf
)
1408 struct mirror_info
*tmp
;
1410 printk(KERN_DEBUG
"RAID10 conf printout:\n");
1412 printk(KERN_DEBUG
"(!conf)\n");
1415 printk(KERN_DEBUG
" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1418 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1419 char b
[BDEVNAME_SIZE
];
1420 tmp
= conf
->mirrors
+ i
;
1422 printk(KERN_DEBUG
" disk %d, wo:%d, o:%d, dev:%s\n",
1423 i
, !test_bit(In_sync
, &tmp
->rdev
->flags
),
1424 !test_bit(Faulty
, &tmp
->rdev
->flags
),
1425 bdevname(tmp
->rdev
->bdev
,b
));
1429 static void close_sync(struct r10conf
*conf
)
1432 allow_barrier(conf
);
1434 mempool_destroy(conf
->r10buf_pool
);
1435 conf
->r10buf_pool
= NULL
;
1438 static int raid10_spare_active(struct mddev
*mddev
)
1441 struct r10conf
*conf
= mddev
->private;
1442 struct mirror_info
*tmp
;
1444 unsigned long flags
;
1447 * Find all non-in_sync disks within the RAID10 configuration
1448 * and mark them in_sync
1450 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1451 tmp
= conf
->mirrors
+ i
;
1452 if (tmp
->replacement
1453 && tmp
->replacement
->recovery_offset
== MaxSector
1454 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
1455 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
1456 /* Replacement has just become active */
1458 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
1461 /* Replaced device not technically faulty,
1462 * but we need to be sure it gets removed
1463 * and never re-added.
1465 set_bit(Faulty
, &tmp
->rdev
->flags
);
1466 sysfs_notify_dirent_safe(
1467 tmp
->rdev
->sysfs_state
);
1469 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
1470 } else if (tmp
->rdev
1471 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
1472 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
1474 sysfs_notify_dirent(tmp
->rdev
->sysfs_state
);
1477 spin_lock_irqsave(&conf
->device_lock
, flags
);
1478 mddev
->degraded
-= count
;
1479 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1486 static int raid10_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1488 struct r10conf
*conf
= mddev
->private;
1492 int last
= conf
->raid_disks
- 1;
1494 if (mddev
->recovery_cp
< MaxSector
)
1495 /* only hot-add to in-sync arrays, as recovery is
1496 * very different from resync
1499 if (rdev
->saved_raid_disk
< 0 && !enough(conf
, -1))
1502 if (rdev
->raid_disk
>= 0)
1503 first
= last
= rdev
->raid_disk
;
1505 if (rdev
->saved_raid_disk
>= first
&&
1506 conf
->mirrors
[rdev
->saved_raid_disk
].rdev
== NULL
)
1507 mirror
= rdev
->saved_raid_disk
;
1510 for ( ; mirror
<= last
; mirror
++) {
1511 struct mirror_info
*p
= &conf
->mirrors
[mirror
];
1512 if (p
->recovery_disabled
== mddev
->recovery_disabled
)
1515 if (!test_bit(WantReplacement
, &p
->rdev
->flags
) ||
1516 p
->replacement
!= NULL
)
1518 clear_bit(In_sync
, &rdev
->flags
);
1519 set_bit(Replacement
, &rdev
->flags
);
1520 rdev
->raid_disk
= mirror
;
1522 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1523 rdev
->data_offset
<< 9);
1524 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1525 blk_queue_max_segments(mddev
->queue
, 1);
1526 blk_queue_segment_boundary(mddev
->queue
,
1527 PAGE_CACHE_SIZE
- 1);
1530 rcu_assign_pointer(p
->replacement
, rdev
);
1534 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1535 rdev
->data_offset
<< 9);
1536 /* as we don't honour merge_bvec_fn, we must
1537 * never risk violating it, so limit
1538 * ->max_segments to one lying with a single
1539 * page, as a one page request is never in
1542 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1543 blk_queue_max_segments(mddev
->queue
, 1);
1544 blk_queue_segment_boundary(mddev
->queue
,
1545 PAGE_CACHE_SIZE
- 1);
1548 p
->head_position
= 0;
1549 p
->recovery_disabled
= mddev
->recovery_disabled
- 1;
1550 rdev
->raid_disk
= mirror
;
1552 if (rdev
->saved_raid_disk
!= mirror
)
1554 rcu_assign_pointer(p
->rdev
, rdev
);
1558 md_integrity_add_rdev(rdev
, mddev
);
1563 static int raid10_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1565 struct r10conf
*conf
= mddev
->private;
1567 int number
= rdev
->raid_disk
;
1568 struct md_rdev
**rdevp
;
1569 struct mirror_info
*p
= conf
->mirrors
+ number
;
1572 if (rdev
== p
->rdev
)
1574 else if (rdev
== p
->replacement
)
1575 rdevp
= &p
->replacement
;
1579 if (test_bit(In_sync
, &rdev
->flags
) ||
1580 atomic_read(&rdev
->nr_pending
)) {
1584 /* Only remove faulty devices if recovery
1587 if (!test_bit(Faulty
, &rdev
->flags
) &&
1588 mddev
->recovery_disabled
!= p
->recovery_disabled
&&
1589 (!p
->replacement
|| p
->replacement
== rdev
) &&
1596 if (atomic_read(&rdev
->nr_pending
)) {
1597 /* lost the race, try later */
1601 } else if (p
->replacement
) {
1602 /* We must have just cleared 'rdev' */
1603 p
->rdev
= p
->replacement
;
1604 clear_bit(Replacement
, &p
->replacement
->flags
);
1605 smp_mb(); /* Make sure other CPUs may see both as identical
1606 * but will never see neither -- if they are careful.
1608 p
->replacement
= NULL
;
1609 clear_bit(WantReplacement
, &rdev
->flags
);
1611 /* We might have just remove the Replacement as faulty
1612 * Clear the flag just in case
1614 clear_bit(WantReplacement
, &rdev
->flags
);
1616 err
= md_integrity_register(mddev
);
1625 static void end_sync_read(struct bio
*bio
, int error
)
1627 struct r10bio
*r10_bio
= bio
->bi_private
;
1628 struct r10conf
*conf
= r10_bio
->mddev
->private;
1631 d
= find_bio_disk(conf
, r10_bio
, bio
, NULL
, NULL
);
1633 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1634 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
1636 /* The write handler will notice the lack of
1637 * R10BIO_Uptodate and record any errors etc
1639 atomic_add(r10_bio
->sectors
,
1640 &conf
->mirrors
[d
].rdev
->corrected_errors
);
1642 /* for reconstruct, we always reschedule after a read.
1643 * for resync, only after all reads
1645 rdev_dec_pending(conf
->mirrors
[d
].rdev
, conf
->mddev
);
1646 if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
) ||
1647 atomic_dec_and_test(&r10_bio
->remaining
)) {
1648 /* we have read all the blocks,
1649 * do the comparison in process context in raid10d
1651 reschedule_retry(r10_bio
);
1655 static void end_sync_request(struct r10bio
*r10_bio
)
1657 struct mddev
*mddev
= r10_bio
->mddev
;
1659 while (atomic_dec_and_test(&r10_bio
->remaining
)) {
1660 if (r10_bio
->master_bio
== NULL
) {
1661 /* the primary of several recovery bios */
1662 sector_t s
= r10_bio
->sectors
;
1663 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
1664 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
1665 reschedule_retry(r10_bio
);
1668 md_done_sync(mddev
, s
, 1);
1671 struct r10bio
*r10_bio2
= (struct r10bio
*)r10_bio
->master_bio
;
1672 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
1673 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
1674 reschedule_retry(r10_bio
);
1682 static void end_sync_write(struct bio
*bio
, int error
)
1684 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1685 struct r10bio
*r10_bio
= bio
->bi_private
;
1686 struct mddev
*mddev
= r10_bio
->mddev
;
1687 struct r10conf
*conf
= mddev
->private;
1693 struct md_rdev
*rdev
= NULL
;
1695 d
= find_bio_disk(conf
, r10_bio
, bio
, &slot
, &repl
);
1697 rdev
= conf
->mirrors
[d
].replacement
;
1699 rdev
= conf
->mirrors
[d
].rdev
;
1703 md_error(mddev
, rdev
);
1705 set_bit(WriteErrorSeen
, &rdev
->flags
);
1706 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1707 set_bit(MD_RECOVERY_NEEDED
,
1708 &rdev
->mddev
->recovery
);
1709 set_bit(R10BIO_WriteError
, &r10_bio
->state
);
1711 } else if (is_badblock(rdev
,
1712 r10_bio
->devs
[slot
].addr
,
1714 &first_bad
, &bad_sectors
))
1715 set_bit(R10BIO_MadeGood
, &r10_bio
->state
);
1717 rdev_dec_pending(rdev
, mddev
);
1719 end_sync_request(r10_bio
);
1723 * Note: sync and recover and handled very differently for raid10
1724 * This code is for resync.
1725 * For resync, we read through virtual addresses and read all blocks.
1726 * If there is any error, we schedule a write. The lowest numbered
1727 * drive is authoritative.
1728 * However requests come for physical address, so we need to map.
1729 * For every physical address there are raid_disks/copies virtual addresses,
1730 * which is always are least one, but is not necessarly an integer.
1731 * This means that a physical address can span multiple chunks, so we may
1732 * have to submit multiple io requests for a single sync request.
1735 * We check if all blocks are in-sync and only write to blocks that
1738 static void sync_request_write(struct mddev
*mddev
, struct r10bio
*r10_bio
)
1740 struct r10conf
*conf
= mddev
->private;
1742 struct bio
*tbio
, *fbio
;
1744 atomic_set(&r10_bio
->remaining
, 1);
1746 /* find the first device with a block */
1747 for (i
=0; i
<conf
->copies
; i
++)
1748 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
))
1751 if (i
== conf
->copies
)
1755 fbio
= r10_bio
->devs
[i
].bio
;
1757 /* now find blocks with errors */
1758 for (i
=0 ; i
< conf
->copies
; i
++) {
1760 int vcnt
= r10_bio
->sectors
>> (PAGE_SHIFT
-9);
1762 tbio
= r10_bio
->devs
[i
].bio
;
1764 if (tbio
->bi_end_io
!= end_sync_read
)
1768 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
)) {
1769 /* We know that the bi_io_vec layout is the same for
1770 * both 'first' and 'i', so we just compare them.
1771 * All vec entries are PAGE_SIZE;
1773 for (j
= 0; j
< vcnt
; j
++)
1774 if (memcmp(page_address(fbio
->bi_io_vec
[j
].bv_page
),
1775 page_address(tbio
->bi_io_vec
[j
].bv_page
),
1780 mddev
->resync_mismatches
+= r10_bio
->sectors
;
1781 if (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
))
1782 /* Don't fix anything. */
1785 /* Ok, we need to write this bio, either to correct an
1786 * inconsistency or to correct an unreadable block.
1787 * First we need to fixup bv_offset, bv_len and
1788 * bi_vecs, as the read request might have corrupted these
1790 tbio
->bi_vcnt
= vcnt
;
1791 tbio
->bi_size
= r10_bio
->sectors
<< 9;
1793 tbio
->bi_phys_segments
= 0;
1794 tbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1795 tbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1796 tbio
->bi_next
= NULL
;
1797 tbio
->bi_rw
= WRITE
;
1798 tbio
->bi_private
= r10_bio
;
1799 tbio
->bi_sector
= r10_bio
->devs
[i
].addr
;
1801 for (j
=0; j
< vcnt
; j
++) {
1802 tbio
->bi_io_vec
[j
].bv_offset
= 0;
1803 tbio
->bi_io_vec
[j
].bv_len
= PAGE_SIZE
;
1805 memcpy(page_address(tbio
->bi_io_vec
[j
].bv_page
),
1806 page_address(fbio
->bi_io_vec
[j
].bv_page
),
1809 tbio
->bi_end_io
= end_sync_write
;
1811 d
= r10_bio
->devs
[i
].devnum
;
1812 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1813 atomic_inc(&r10_bio
->remaining
);
1814 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, tbio
->bi_size
>> 9);
1816 tbio
->bi_sector
+= conf
->mirrors
[d
].rdev
->data_offset
;
1817 tbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1818 generic_make_request(tbio
);
1821 /* Now write out to any replacement devices
1824 for (i
= 0; i
< conf
->copies
; i
++) {
1826 int vcnt
= r10_bio
->sectors
>> (PAGE_SHIFT
-9);
1828 tbio
= r10_bio
->devs
[i
].repl_bio
;
1829 if (!tbio
|| !tbio
->bi_end_io
)
1831 if (r10_bio
->devs
[i
].bio
->bi_end_io
!= end_sync_write
1832 && r10_bio
->devs
[i
].bio
!= fbio
)
1833 for (j
= 0; j
< vcnt
; j
++)
1834 memcpy(page_address(tbio
->bi_io_vec
[j
].bv_page
),
1835 page_address(fbio
->bi_io_vec
[j
].bv_page
),
1837 d
= r10_bio
->devs
[i
].devnum
;
1838 atomic_inc(&r10_bio
->remaining
);
1839 md_sync_acct(conf
->mirrors
[d
].replacement
->bdev
,
1840 tbio
->bi_size
>> 9);
1841 generic_make_request(tbio
);
1845 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
1846 md_done_sync(mddev
, r10_bio
->sectors
, 1);
1852 * Now for the recovery code.
1853 * Recovery happens across physical sectors.
1854 * We recover all non-is_sync drives by finding the virtual address of
1855 * each, and then choose a working drive that also has that virt address.
1856 * There is a separate r10_bio for each non-in_sync drive.
1857 * Only the first two slots are in use. The first for reading,
1858 * The second for writing.
1861 static void fix_recovery_read_error(struct r10bio
*r10_bio
)
1863 /* We got a read error during recovery.
1864 * We repeat the read in smaller page-sized sections.
1865 * If a read succeeds, write it to the new device or record
1866 * a bad block if we cannot.
1867 * If a read fails, record a bad block on both old and
1870 struct mddev
*mddev
= r10_bio
->mddev
;
1871 struct r10conf
*conf
= mddev
->private;
1872 struct bio
*bio
= r10_bio
->devs
[0].bio
;
1874 int sectors
= r10_bio
->sectors
;
1876 int dr
= r10_bio
->devs
[0].devnum
;
1877 int dw
= r10_bio
->devs
[1].devnum
;
1881 struct md_rdev
*rdev
;
1885 if (s
> (PAGE_SIZE
>>9))
1888 rdev
= conf
->mirrors
[dr
].rdev
;
1889 addr
= r10_bio
->devs
[0].addr
+ sect
,
1890 ok
= sync_page_io(rdev
,
1893 bio
->bi_io_vec
[idx
].bv_page
,
1896 rdev
= conf
->mirrors
[dw
].rdev
;
1897 addr
= r10_bio
->devs
[1].addr
+ sect
;
1898 ok
= sync_page_io(rdev
,
1901 bio
->bi_io_vec
[idx
].bv_page
,
1904 set_bit(WriteErrorSeen
, &rdev
->flags
);
1905 if (!test_and_set_bit(WantReplacement
,
1907 set_bit(MD_RECOVERY_NEEDED
,
1908 &rdev
->mddev
->recovery
);
1912 /* We don't worry if we cannot set a bad block -
1913 * it really is bad so there is no loss in not
1916 rdev_set_badblocks(rdev
, addr
, s
, 0);
1918 if (rdev
!= conf
->mirrors
[dw
].rdev
) {
1919 /* need bad block on destination too */
1920 struct md_rdev
*rdev2
= conf
->mirrors
[dw
].rdev
;
1921 addr
= r10_bio
->devs
[1].addr
+ sect
;
1922 ok
= rdev_set_badblocks(rdev2
, addr
, s
, 0);
1924 /* just abort the recovery */
1926 "md/raid10:%s: recovery aborted"
1927 " due to read error\n",
1930 conf
->mirrors
[dw
].recovery_disabled
1931 = mddev
->recovery_disabled
;
1932 set_bit(MD_RECOVERY_INTR
,
1945 static void recovery_request_write(struct mddev
*mddev
, struct r10bio
*r10_bio
)
1947 struct r10conf
*conf
= mddev
->private;
1949 struct bio
*wbio
, *wbio2
;
1951 if (!test_bit(R10BIO_Uptodate
, &r10_bio
->state
)) {
1952 fix_recovery_read_error(r10_bio
);
1953 end_sync_request(r10_bio
);
1958 * share the pages with the first bio
1959 * and submit the write request
1961 d
= r10_bio
->devs
[1].devnum
;
1962 wbio
= r10_bio
->devs
[1].bio
;
1963 wbio2
= r10_bio
->devs
[1].repl_bio
;
1964 if (wbio
->bi_end_io
) {
1965 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1966 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, wbio
->bi_size
>> 9);
1967 generic_make_request(wbio
);
1969 if (wbio2
&& wbio2
->bi_end_io
) {
1970 atomic_inc(&conf
->mirrors
[d
].replacement
->nr_pending
);
1971 md_sync_acct(conf
->mirrors
[d
].replacement
->bdev
,
1972 wbio2
->bi_size
>> 9);
1973 generic_make_request(wbio2
);
1979 * Used by fix_read_error() to decay the per rdev read_errors.
1980 * We halve the read error count for every hour that has elapsed
1981 * since the last recorded read error.
1984 static void check_decay_read_errors(struct mddev
*mddev
, struct md_rdev
*rdev
)
1986 struct timespec cur_time_mon
;
1987 unsigned long hours_since_last
;
1988 unsigned int read_errors
= atomic_read(&rdev
->read_errors
);
1990 ktime_get_ts(&cur_time_mon
);
1992 if (rdev
->last_read_error
.tv_sec
== 0 &&
1993 rdev
->last_read_error
.tv_nsec
== 0) {
1994 /* first time we've seen a read error */
1995 rdev
->last_read_error
= cur_time_mon
;
1999 hours_since_last
= (cur_time_mon
.tv_sec
-
2000 rdev
->last_read_error
.tv_sec
) / 3600;
2002 rdev
->last_read_error
= cur_time_mon
;
2005 * if hours_since_last is > the number of bits in read_errors
2006 * just set read errors to 0. We do this to avoid
2007 * overflowing the shift of read_errors by hours_since_last.
2009 if (hours_since_last
>= 8 * sizeof(read_errors
))
2010 atomic_set(&rdev
->read_errors
, 0);
2012 atomic_set(&rdev
->read_errors
, read_errors
>> hours_since_last
);
2015 static int r10_sync_page_io(struct md_rdev
*rdev
, sector_t sector
,
2016 int sectors
, struct page
*page
, int rw
)
2021 if (is_badblock(rdev
, sector
, sectors
, &first_bad
, &bad_sectors
)
2022 && (rw
== READ
|| test_bit(WriteErrorSeen
, &rdev
->flags
)))
2024 if (sync_page_io(rdev
, sector
, sectors
<< 9, page
, rw
, false))
2028 set_bit(WriteErrorSeen
, &rdev
->flags
);
2029 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
2030 set_bit(MD_RECOVERY_NEEDED
,
2031 &rdev
->mddev
->recovery
);
2033 /* need to record an error - either for the block or the device */
2034 if (!rdev_set_badblocks(rdev
, sector
, sectors
, 0))
2035 md_error(rdev
->mddev
, rdev
);
2040 * This is a kernel thread which:
2042 * 1. Retries failed read operations on working mirrors.
2043 * 2. Updates the raid superblock when problems encounter.
2044 * 3. Performs writes following reads for array synchronising.
2047 static void fix_read_error(struct r10conf
*conf
, struct mddev
*mddev
, struct r10bio
*r10_bio
)
2049 int sect
= 0; /* Offset from r10_bio->sector */
2050 int sectors
= r10_bio
->sectors
;
2051 struct md_rdev
*rdev
;
2052 int max_read_errors
= atomic_read(&mddev
->max_corr_read_errors
);
2053 int d
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
2055 /* still own a reference to this rdev, so it cannot
2056 * have been cleared recently.
2058 rdev
= conf
->mirrors
[d
].rdev
;
2060 if (test_bit(Faulty
, &rdev
->flags
))
2061 /* drive has already been failed, just ignore any
2062 more fix_read_error() attempts */
2065 check_decay_read_errors(mddev
, rdev
);
2066 atomic_inc(&rdev
->read_errors
);
2067 if (atomic_read(&rdev
->read_errors
) > max_read_errors
) {
2068 char b
[BDEVNAME_SIZE
];
2069 bdevname(rdev
->bdev
, b
);
2072 "md/raid10:%s: %s: Raid device exceeded "
2073 "read_error threshold [cur %d:max %d]\n",
2075 atomic_read(&rdev
->read_errors
), max_read_errors
);
2077 "md/raid10:%s: %s: Failing raid device\n",
2079 md_error(mddev
, conf
->mirrors
[d
].rdev
);
2080 r10_bio
->devs
[r10_bio
->read_slot
].bio
= IO_BLOCKED
;
2086 int sl
= r10_bio
->read_slot
;
2090 if (s
> (PAGE_SIZE
>>9))
2098 d
= r10_bio
->devs
[sl
].devnum
;
2099 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2101 test_bit(In_sync
, &rdev
->flags
) &&
2102 is_badblock(rdev
, r10_bio
->devs
[sl
].addr
+ sect
, s
,
2103 &first_bad
, &bad_sectors
) == 0) {
2104 atomic_inc(&rdev
->nr_pending
);
2106 success
= sync_page_io(rdev
,
2107 r10_bio
->devs
[sl
].addr
+
2110 conf
->tmppage
, READ
, false);
2111 rdev_dec_pending(rdev
, mddev
);
2117 if (sl
== conf
->copies
)
2119 } while (!success
&& sl
!= r10_bio
->read_slot
);
2123 /* Cannot read from anywhere, just mark the block
2124 * as bad on the first device to discourage future
2127 int dn
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
2128 rdev
= conf
->mirrors
[dn
].rdev
;
2130 if (!rdev_set_badblocks(
2132 r10_bio
->devs
[r10_bio
->read_slot
].addr
2135 md_error(mddev
, rdev
);
2136 r10_bio
->devs
[r10_bio
->read_slot
].bio
2143 /* write it back and re-read */
2145 while (sl
!= r10_bio
->read_slot
) {
2146 char b
[BDEVNAME_SIZE
];
2151 d
= r10_bio
->devs
[sl
].devnum
;
2152 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2154 !test_bit(In_sync
, &rdev
->flags
))
2157 atomic_inc(&rdev
->nr_pending
);
2159 if (r10_sync_page_io(rdev
,
2160 r10_bio
->devs
[sl
].addr
+
2162 s
<<9, conf
->tmppage
, WRITE
)
2164 /* Well, this device is dead */
2166 "md/raid10:%s: read correction "
2168 " (%d sectors at %llu on %s)\n",
2170 (unsigned long long)(
2171 sect
+ rdev
->data_offset
),
2172 bdevname(rdev
->bdev
, b
));
2173 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
2176 bdevname(rdev
->bdev
, b
));
2178 rdev_dec_pending(rdev
, mddev
);
2182 while (sl
!= r10_bio
->read_slot
) {
2183 char b
[BDEVNAME_SIZE
];
2188 d
= r10_bio
->devs
[sl
].devnum
;
2189 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2191 !test_bit(In_sync
, &rdev
->flags
))
2194 atomic_inc(&rdev
->nr_pending
);
2196 switch (r10_sync_page_io(rdev
,
2197 r10_bio
->devs
[sl
].addr
+
2199 s
<<9, conf
->tmppage
,
2202 /* Well, this device is dead */
2204 "md/raid10:%s: unable to read back "
2206 " (%d sectors at %llu on %s)\n",
2208 (unsigned long long)(
2209 sect
+ rdev
->data_offset
),
2210 bdevname(rdev
->bdev
, b
));
2211 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
2214 bdevname(rdev
->bdev
, b
));
2218 "md/raid10:%s: read error corrected"
2219 " (%d sectors at %llu on %s)\n",
2221 (unsigned long long)(
2222 sect
+ rdev
->data_offset
),
2223 bdevname(rdev
->bdev
, b
));
2224 atomic_add(s
, &rdev
->corrected_errors
);
2227 rdev_dec_pending(rdev
, mddev
);
2237 static void bi_complete(struct bio
*bio
, int error
)
2239 complete((struct completion
*)bio
->bi_private
);
2242 static int submit_bio_wait(int rw
, struct bio
*bio
)
2244 struct completion event
;
2247 init_completion(&event
);
2248 bio
->bi_private
= &event
;
2249 bio
->bi_end_io
= bi_complete
;
2250 submit_bio(rw
, bio
);
2251 wait_for_completion(&event
);
2253 return test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2256 static int narrow_write_error(struct r10bio
*r10_bio
, int i
)
2258 struct bio
*bio
= r10_bio
->master_bio
;
2259 struct mddev
*mddev
= r10_bio
->mddev
;
2260 struct r10conf
*conf
= mddev
->private;
2261 struct md_rdev
*rdev
= conf
->mirrors
[r10_bio
->devs
[i
].devnum
].rdev
;
2262 /* bio has the data to be written to slot 'i' where
2263 * we just recently had a write error.
2264 * We repeatedly clone the bio and trim down to one block,
2265 * then try the write. Where the write fails we record
2267 * It is conceivable that the bio doesn't exactly align with
2268 * blocks. We must handle this.
2270 * We currently own a reference to the rdev.
2276 int sect_to_write
= r10_bio
->sectors
;
2279 if (rdev
->badblocks
.shift
< 0)
2282 block_sectors
= 1 << rdev
->badblocks
.shift
;
2283 sector
= r10_bio
->sector
;
2284 sectors
= ((r10_bio
->sector
+ block_sectors
)
2285 & ~(sector_t
)(block_sectors
- 1))
2288 while (sect_to_write
) {
2290 if (sectors
> sect_to_write
)
2291 sectors
= sect_to_write
;
2292 /* Write at 'sector' for 'sectors' */
2293 wbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
2294 md_trim_bio(wbio
, sector
- bio
->bi_sector
, sectors
);
2295 wbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
2297 (sector
- r10_bio
->sector
));
2298 wbio
->bi_bdev
= rdev
->bdev
;
2299 if (submit_bio_wait(WRITE
, wbio
) == 0)
2301 ok
= rdev_set_badblocks(rdev
, sector
,
2306 sect_to_write
-= sectors
;
2308 sectors
= block_sectors
;
2313 static void handle_read_error(struct mddev
*mddev
, struct r10bio
*r10_bio
)
2315 int slot
= r10_bio
->read_slot
;
2317 struct r10conf
*conf
= mddev
->private;
2318 struct md_rdev
*rdev
= r10_bio
->devs
[slot
].rdev
;
2319 char b
[BDEVNAME_SIZE
];
2320 unsigned long do_sync
;
2323 /* we got a read error. Maybe the drive is bad. Maybe just
2324 * the block and we can fix it.
2325 * We freeze all other IO, and try reading the block from
2326 * other devices. When we find one, we re-write
2327 * and check it that fixes the read error.
2328 * This is all done synchronously while the array is
2331 bio
= r10_bio
->devs
[slot
].bio
;
2332 bdevname(bio
->bi_bdev
, b
);
2334 r10_bio
->devs
[slot
].bio
= NULL
;
2336 if (mddev
->ro
== 0) {
2338 fix_read_error(conf
, mddev
, r10_bio
);
2339 unfreeze_array(conf
);
2341 r10_bio
->devs
[slot
].bio
= IO_BLOCKED
;
2343 rdev_dec_pending(rdev
, mddev
);
2346 rdev
= read_balance(conf
, r10_bio
, &max_sectors
);
2348 printk(KERN_ALERT
"md/raid10:%s: %s: unrecoverable I/O"
2349 " read error for block %llu\n",
2351 (unsigned long long)r10_bio
->sector
);
2352 raid_end_bio_io(r10_bio
);
2356 do_sync
= (r10_bio
->master_bio
->bi_rw
& REQ_SYNC
);
2357 slot
= r10_bio
->read_slot
;
2360 "md/raid10:%s: %s: redirecting"
2361 "sector %llu to another mirror\n",
2363 bdevname(rdev
->bdev
, b
),
2364 (unsigned long long)r10_bio
->sector
);
2365 bio
= bio_clone_mddev(r10_bio
->master_bio
,
2368 r10_bio
->sector
- bio
->bi_sector
,
2370 r10_bio
->devs
[slot
].bio
= bio
;
2371 r10_bio
->devs
[slot
].rdev
= rdev
;
2372 bio
->bi_sector
= r10_bio
->devs
[slot
].addr
2373 + rdev
->data_offset
;
2374 bio
->bi_bdev
= rdev
->bdev
;
2375 bio
->bi_rw
= READ
| do_sync
;
2376 bio
->bi_private
= r10_bio
;
2377 bio
->bi_end_io
= raid10_end_read_request
;
2378 if (max_sectors
< r10_bio
->sectors
) {
2379 /* Drat - have to split this up more */
2380 struct bio
*mbio
= r10_bio
->master_bio
;
2381 int sectors_handled
=
2382 r10_bio
->sector
+ max_sectors
2384 r10_bio
->sectors
= max_sectors
;
2385 spin_lock_irq(&conf
->device_lock
);
2386 if (mbio
->bi_phys_segments
== 0)
2387 mbio
->bi_phys_segments
= 2;
2389 mbio
->bi_phys_segments
++;
2390 spin_unlock_irq(&conf
->device_lock
);
2391 generic_make_request(bio
);
2393 r10_bio
= mempool_alloc(conf
->r10bio_pool
,
2395 r10_bio
->master_bio
= mbio
;
2396 r10_bio
->sectors
= (mbio
->bi_size
>> 9)
2399 set_bit(R10BIO_ReadError
,
2401 r10_bio
->mddev
= mddev
;
2402 r10_bio
->sector
= mbio
->bi_sector
2407 generic_make_request(bio
);
2410 static void handle_write_completed(struct r10conf
*conf
, struct r10bio
*r10_bio
)
2412 /* Some sort of write request has finished and it
2413 * succeeded in writing where we thought there was a
2414 * bad block. So forget the bad block.
2415 * Or possibly if failed and we need to record
2419 struct md_rdev
*rdev
;
2421 if (test_bit(R10BIO_IsSync
, &r10_bio
->state
) ||
2422 test_bit(R10BIO_IsRecover
, &r10_bio
->state
)) {
2423 for (m
= 0; m
< conf
->copies
; m
++) {
2424 int dev
= r10_bio
->devs
[m
].devnum
;
2425 rdev
= conf
->mirrors
[dev
].rdev
;
2426 if (r10_bio
->devs
[m
].bio
== NULL
)
2428 if (test_bit(BIO_UPTODATE
,
2429 &r10_bio
->devs
[m
].bio
->bi_flags
)) {
2430 rdev_clear_badblocks(
2432 r10_bio
->devs
[m
].addr
,
2435 if (!rdev_set_badblocks(
2437 r10_bio
->devs
[m
].addr
,
2438 r10_bio
->sectors
, 0))
2439 md_error(conf
->mddev
, rdev
);
2441 rdev
= conf
->mirrors
[dev
].replacement
;
2442 if (r10_bio
->devs
[m
].repl_bio
== NULL
)
2444 if (test_bit(BIO_UPTODATE
,
2445 &r10_bio
->devs
[m
].repl_bio
->bi_flags
)) {
2446 rdev_clear_badblocks(
2448 r10_bio
->devs
[m
].addr
,
2451 if (!rdev_set_badblocks(
2453 r10_bio
->devs
[m
].addr
,
2454 r10_bio
->sectors
, 0))
2455 md_error(conf
->mddev
, rdev
);
2460 for (m
= 0; m
< conf
->copies
; m
++) {
2461 int dev
= r10_bio
->devs
[m
].devnum
;
2462 struct bio
*bio
= r10_bio
->devs
[m
].bio
;
2463 rdev
= conf
->mirrors
[dev
].rdev
;
2464 if (bio
== IO_MADE_GOOD
) {
2465 rdev_clear_badblocks(
2467 r10_bio
->devs
[m
].addr
,
2469 rdev_dec_pending(rdev
, conf
->mddev
);
2470 } else if (bio
!= NULL
&&
2471 !test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2472 if (!narrow_write_error(r10_bio
, m
)) {
2473 md_error(conf
->mddev
, rdev
);
2474 set_bit(R10BIO_Degraded
,
2477 rdev_dec_pending(rdev
, conf
->mddev
);
2479 bio
= r10_bio
->devs
[m
].repl_bio
;
2480 rdev
= conf
->mirrors
[dev
].replacement
;
2481 if (rdev
&& bio
== IO_MADE_GOOD
) {
2482 rdev_clear_badblocks(
2484 r10_bio
->devs
[m
].addr
,
2486 rdev_dec_pending(rdev
, conf
->mddev
);
2489 if (test_bit(R10BIO_WriteError
,
2491 close_write(r10_bio
);
2492 raid_end_bio_io(r10_bio
);
2496 static void raid10d(struct mddev
*mddev
)
2498 struct r10bio
*r10_bio
;
2499 unsigned long flags
;
2500 struct r10conf
*conf
= mddev
->private;
2501 struct list_head
*head
= &conf
->retry_list
;
2502 struct blk_plug plug
;
2504 md_check_recovery(mddev
);
2506 blk_start_plug(&plug
);
2509 flush_pending_writes(conf
);
2511 spin_lock_irqsave(&conf
->device_lock
, flags
);
2512 if (list_empty(head
)) {
2513 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2516 r10_bio
= list_entry(head
->prev
, struct r10bio
, retry_list
);
2517 list_del(head
->prev
);
2519 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2521 mddev
= r10_bio
->mddev
;
2522 conf
= mddev
->private;
2523 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
2524 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
2525 handle_write_completed(conf
, r10_bio
);
2526 else if (test_bit(R10BIO_IsSync
, &r10_bio
->state
))
2527 sync_request_write(mddev
, r10_bio
);
2528 else if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
))
2529 recovery_request_write(mddev
, r10_bio
);
2530 else if (test_bit(R10BIO_ReadError
, &r10_bio
->state
))
2531 handle_read_error(mddev
, r10_bio
);
2533 /* just a partial read to be scheduled from a
2536 int slot
= r10_bio
->read_slot
;
2537 generic_make_request(r10_bio
->devs
[slot
].bio
);
2541 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
2542 md_check_recovery(mddev
);
2544 blk_finish_plug(&plug
);
2548 static int init_resync(struct r10conf
*conf
)
2553 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
2554 BUG_ON(conf
->r10buf_pool
);
2555 conf
->have_replacement
= 0;
2556 for (i
= 0; i
< conf
->raid_disks
; i
++)
2557 if (conf
->mirrors
[i
].replacement
)
2558 conf
->have_replacement
= 1;
2559 conf
->r10buf_pool
= mempool_create(buffs
, r10buf_pool_alloc
, r10buf_pool_free
, conf
);
2560 if (!conf
->r10buf_pool
)
2562 conf
->next_resync
= 0;
2567 * perform a "sync" on one "block"
2569 * We need to make sure that no normal I/O request - particularly write
2570 * requests - conflict with active sync requests.
2572 * This is achieved by tracking pending requests and a 'barrier' concept
2573 * that can be installed to exclude normal IO requests.
2575 * Resync and recovery are handled very differently.
2576 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2578 * For resync, we iterate over virtual addresses, read all copies,
2579 * and update if there are differences. If only one copy is live,
2581 * For recovery, we iterate over physical addresses, read a good
2582 * value for each non-in_sync drive, and over-write.
2584 * So, for recovery we may have several outstanding complex requests for a
2585 * given address, one for each out-of-sync device. We model this by allocating
2586 * a number of r10_bio structures, one for each out-of-sync device.
2587 * As we setup these structures, we collect all bio's together into a list
2588 * which we then process collectively to add pages, and then process again
2589 * to pass to generic_make_request.
2591 * The r10_bio structures are linked using a borrowed master_bio pointer.
2592 * This link is counted in ->remaining. When the r10_bio that points to NULL
2593 * has its remaining count decremented to 0, the whole complex operation
2598 static sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
,
2599 int *skipped
, int go_faster
)
2601 struct r10conf
*conf
= mddev
->private;
2602 struct r10bio
*r10_bio
;
2603 struct bio
*biolist
= NULL
, *bio
;
2604 sector_t max_sector
, nr_sectors
;
2607 sector_t sync_blocks
;
2608 sector_t sectors_skipped
= 0;
2609 int chunks_skipped
= 0;
2611 if (!conf
->r10buf_pool
)
2612 if (init_resync(conf
))
2616 max_sector
= mddev
->dev_sectors
;
2617 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2618 max_sector
= mddev
->resync_max_sectors
;
2619 if (sector_nr
>= max_sector
) {
2620 /* If we aborted, we need to abort the
2621 * sync on the 'current' bitmap chucks (there can
2622 * be several when recovering multiple devices).
2623 * as we may have started syncing it but not finished.
2624 * We can find the current address in
2625 * mddev->curr_resync, but for recovery,
2626 * we need to convert that to several
2627 * virtual addresses.
2629 if (mddev
->curr_resync
< max_sector
) { /* aborted */
2630 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2631 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
2633 else for (i
=0; i
<conf
->raid_disks
; i
++) {
2635 raid10_find_virt(conf
, mddev
->curr_resync
, i
);
2636 bitmap_end_sync(mddev
->bitmap
, sect
,
2640 /* completed sync */
2641 if ((!mddev
->bitmap
|| conf
->fullsync
)
2642 && conf
->have_replacement
2643 && test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
2644 /* Completed a full sync so the replacements
2645 * are now fully recovered.
2647 for (i
= 0; i
< conf
->raid_disks
; i
++)
2648 if (conf
->mirrors
[i
].replacement
)
2649 conf
->mirrors
[i
].replacement
2655 bitmap_close_sync(mddev
->bitmap
);
2658 return sectors_skipped
;
2660 if (chunks_skipped
>= conf
->raid_disks
) {
2661 /* if there has been nothing to do on any drive,
2662 * then there is nothing to do at all..
2665 return (max_sector
- sector_nr
) + sectors_skipped
;
2668 if (max_sector
> mddev
->resync_max
)
2669 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
2671 /* make sure whole request will fit in a chunk - if chunks
2674 if (conf
->near_copies
< conf
->raid_disks
&&
2675 max_sector
> (sector_nr
| conf
->chunk_mask
))
2676 max_sector
= (sector_nr
| conf
->chunk_mask
) + 1;
2678 * If there is non-resync activity waiting for us then
2679 * put in a delay to throttle resync.
2681 if (!go_faster
&& conf
->nr_waiting
)
2682 msleep_interruptible(1000);
2684 /* Again, very different code for resync and recovery.
2685 * Both must result in an r10bio with a list of bios that
2686 * have bi_end_io, bi_sector, bi_bdev set,
2687 * and bi_private set to the r10bio.
2688 * For recovery, we may actually create several r10bios
2689 * with 2 bios in each, that correspond to the bios in the main one.
2690 * In this case, the subordinate r10bios link back through a
2691 * borrowed master_bio pointer, and the counter in the master
2692 * includes a ref from each subordinate.
2694 /* First, we decide what to do and set ->bi_end_io
2695 * To end_sync_read if we want to read, and
2696 * end_sync_write if we will want to write.
2699 max_sync
= RESYNC_PAGES
<< (PAGE_SHIFT
-9);
2700 if (!test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
2701 /* recovery... the complicated one */
2705 for (i
=0 ; i
<conf
->raid_disks
; i
++) {
2711 struct mirror_info
*mirror
= &conf
->mirrors
[i
];
2713 if ((mirror
->rdev
== NULL
||
2714 test_bit(In_sync
, &mirror
->rdev
->flags
))
2716 (mirror
->replacement
== NULL
||
2718 &mirror
->replacement
->flags
)))
2722 /* want to reconstruct this device */
2724 sect
= raid10_find_virt(conf
, sector_nr
, i
);
2725 /* Unless we are doing a full sync, or a replacement
2726 * we only need to recover the block if it is set in
2729 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2731 if (sync_blocks
< max_sync
)
2732 max_sync
= sync_blocks
;
2734 mirror
->replacement
== NULL
&&
2736 /* yep, skip the sync_blocks here, but don't assume
2737 * that there will never be anything to do here
2739 chunks_skipped
= -1;
2743 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2744 raise_barrier(conf
, rb2
!= NULL
);
2745 atomic_set(&r10_bio
->remaining
, 0);
2747 r10_bio
->master_bio
= (struct bio
*)rb2
;
2749 atomic_inc(&rb2
->remaining
);
2750 r10_bio
->mddev
= mddev
;
2751 set_bit(R10BIO_IsRecover
, &r10_bio
->state
);
2752 r10_bio
->sector
= sect
;
2754 raid10_find_phys(conf
, r10_bio
);
2756 /* Need to check if the array will still be
2759 for (j
=0; j
<conf
->raid_disks
; j
++)
2760 if (conf
->mirrors
[j
].rdev
== NULL
||
2761 test_bit(Faulty
, &conf
->mirrors
[j
].rdev
->flags
)) {
2766 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2767 &sync_blocks
, still_degraded
);
2770 for (j
=0; j
<conf
->copies
;j
++) {
2772 int d
= r10_bio
->devs
[j
].devnum
;
2773 sector_t from_addr
, to_addr
;
2774 struct md_rdev
*rdev
;
2775 sector_t sector
, first_bad
;
2777 if (!conf
->mirrors
[d
].rdev
||
2778 !test_bit(In_sync
, &conf
->mirrors
[d
].rdev
->flags
))
2780 /* This is where we read from */
2782 rdev
= conf
->mirrors
[d
].rdev
;
2783 sector
= r10_bio
->devs
[j
].addr
;
2785 if (is_badblock(rdev
, sector
, max_sync
,
2786 &first_bad
, &bad_sectors
)) {
2787 if (first_bad
> sector
)
2788 max_sync
= first_bad
- sector
;
2790 bad_sectors
-= (sector
2792 if (max_sync
> bad_sectors
)
2793 max_sync
= bad_sectors
;
2797 bio
= r10_bio
->devs
[0].bio
;
2798 bio
->bi_next
= biolist
;
2800 bio
->bi_private
= r10_bio
;
2801 bio
->bi_end_io
= end_sync_read
;
2803 from_addr
= r10_bio
->devs
[j
].addr
;
2804 bio
->bi_sector
= from_addr
+ rdev
->data_offset
;
2805 bio
->bi_bdev
= rdev
->bdev
;
2806 atomic_inc(&rdev
->nr_pending
);
2807 /* and we write to 'i' (if not in_sync) */
2809 for (k
=0; k
<conf
->copies
; k
++)
2810 if (r10_bio
->devs
[k
].devnum
== i
)
2812 BUG_ON(k
== conf
->copies
);
2813 to_addr
= r10_bio
->devs
[k
].addr
;
2814 r10_bio
->devs
[0].devnum
= d
;
2815 r10_bio
->devs
[0].addr
= from_addr
;
2816 r10_bio
->devs
[1].devnum
= i
;
2817 r10_bio
->devs
[1].addr
= to_addr
;
2819 rdev
= mirror
->rdev
;
2820 if (!test_bit(In_sync
, &rdev
->flags
)) {
2821 bio
= r10_bio
->devs
[1].bio
;
2822 bio
->bi_next
= biolist
;
2824 bio
->bi_private
= r10_bio
;
2825 bio
->bi_end_io
= end_sync_write
;
2827 bio
->bi_sector
= to_addr
2828 + rdev
->data_offset
;
2829 bio
->bi_bdev
= rdev
->bdev
;
2830 atomic_inc(&r10_bio
->remaining
);
2832 r10_bio
->devs
[1].bio
->bi_end_io
= NULL
;
2834 /* and maybe write to replacement */
2835 bio
= r10_bio
->devs
[1].repl_bio
;
2837 bio
->bi_end_io
= NULL
;
2838 rdev
= mirror
->replacement
;
2839 /* Note: if rdev != NULL, then bio
2840 * cannot be NULL as r10buf_pool_alloc will
2841 * have allocated it.
2842 * So the second test here is pointless.
2843 * But it keeps semantic-checkers happy, and
2844 * this comment keeps human reviewers
2847 if (rdev
== NULL
|| bio
== NULL
||
2848 test_bit(Faulty
, &rdev
->flags
))
2850 bio
->bi_next
= biolist
;
2852 bio
->bi_private
= r10_bio
;
2853 bio
->bi_end_io
= end_sync_write
;
2855 bio
->bi_sector
= to_addr
+ rdev
->data_offset
;
2856 bio
->bi_bdev
= rdev
->bdev
;
2857 atomic_inc(&r10_bio
->remaining
);
2860 if (j
== conf
->copies
) {
2861 /* Cannot recover, so abort the recovery or
2862 * record a bad block */
2865 atomic_dec(&rb2
->remaining
);
2868 /* problem is that there are bad blocks
2869 * on other device(s)
2872 for (k
= 0; k
< conf
->copies
; k
++)
2873 if (r10_bio
->devs
[k
].devnum
== i
)
2875 if (!test_bit(In_sync
,
2876 &mirror
->rdev
->flags
)
2877 && !rdev_set_badblocks(
2879 r10_bio
->devs
[k
].addr
,
2882 if (mirror
->replacement
&&
2883 !rdev_set_badblocks(
2884 mirror
->replacement
,
2885 r10_bio
->devs
[k
].addr
,
2890 if (!test_and_set_bit(MD_RECOVERY_INTR
,
2892 printk(KERN_INFO
"md/raid10:%s: insufficient "
2893 "working devices for recovery.\n",
2895 mirror
->recovery_disabled
2896 = mddev
->recovery_disabled
;
2901 if (biolist
== NULL
) {
2903 struct r10bio
*rb2
= r10_bio
;
2904 r10_bio
= (struct r10bio
*) rb2
->master_bio
;
2905 rb2
->master_bio
= NULL
;
2911 /* resync. Schedule a read for every block at this virt offset */
2914 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
2916 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
2917 &sync_blocks
, mddev
->degraded
) &&
2918 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
,
2919 &mddev
->recovery
)) {
2920 /* We can skip this block */
2922 return sync_blocks
+ sectors_skipped
;
2924 if (sync_blocks
< max_sync
)
2925 max_sync
= sync_blocks
;
2926 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2928 r10_bio
->mddev
= mddev
;
2929 atomic_set(&r10_bio
->remaining
, 0);
2930 raise_barrier(conf
, 0);
2931 conf
->next_resync
= sector_nr
;
2933 r10_bio
->master_bio
= NULL
;
2934 r10_bio
->sector
= sector_nr
;
2935 set_bit(R10BIO_IsSync
, &r10_bio
->state
);
2936 raid10_find_phys(conf
, r10_bio
);
2937 r10_bio
->sectors
= (sector_nr
| conf
->chunk_mask
) - sector_nr
+1;
2939 for (i
=0; i
<conf
->copies
; i
++) {
2940 int d
= r10_bio
->devs
[i
].devnum
;
2941 sector_t first_bad
, sector
;
2944 if (r10_bio
->devs
[i
].repl_bio
)
2945 r10_bio
->devs
[i
].repl_bio
->bi_end_io
= NULL
;
2947 bio
= r10_bio
->devs
[i
].bio
;
2948 bio
->bi_end_io
= NULL
;
2949 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2950 if (conf
->mirrors
[d
].rdev
== NULL
||
2951 test_bit(Faulty
, &conf
->mirrors
[d
].rdev
->flags
))
2953 sector
= r10_bio
->devs
[i
].addr
;
2954 if (is_badblock(conf
->mirrors
[d
].rdev
,
2956 &first_bad
, &bad_sectors
)) {
2957 if (first_bad
> sector
)
2958 max_sync
= first_bad
- sector
;
2960 bad_sectors
-= (sector
- first_bad
);
2961 if (max_sync
> bad_sectors
)
2962 max_sync
= max_sync
;
2966 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2967 atomic_inc(&r10_bio
->remaining
);
2968 bio
->bi_next
= biolist
;
2970 bio
->bi_private
= r10_bio
;
2971 bio
->bi_end_io
= end_sync_read
;
2973 bio
->bi_sector
= sector
+
2974 conf
->mirrors
[d
].rdev
->data_offset
;
2975 bio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
2978 if (conf
->mirrors
[d
].replacement
== NULL
||
2980 &conf
->mirrors
[d
].replacement
->flags
))
2983 /* Need to set up for writing to the replacement */
2984 bio
= r10_bio
->devs
[i
].repl_bio
;
2985 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2987 sector
= r10_bio
->devs
[i
].addr
;
2988 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2989 bio
->bi_next
= biolist
;
2991 bio
->bi_private
= r10_bio
;
2992 bio
->bi_end_io
= end_sync_write
;
2994 bio
->bi_sector
= sector
+
2995 conf
->mirrors
[d
].replacement
->data_offset
;
2996 bio
->bi_bdev
= conf
->mirrors
[d
].replacement
->bdev
;
3001 for (i
=0; i
<conf
->copies
; i
++) {
3002 int d
= r10_bio
->devs
[i
].devnum
;
3003 if (r10_bio
->devs
[i
].bio
->bi_end_io
)
3004 rdev_dec_pending(conf
->mirrors
[d
].rdev
,
3006 if (r10_bio
->devs
[i
].repl_bio
&&
3007 r10_bio
->devs
[i
].repl_bio
->bi_end_io
)
3009 conf
->mirrors
[d
].replacement
,
3018 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
3020 bio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
3022 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
3025 bio
->bi_phys_segments
= 0;
3030 if (sector_nr
+ max_sync
< max_sector
)
3031 max_sector
= sector_nr
+ max_sync
;
3034 int len
= PAGE_SIZE
;
3035 if (sector_nr
+ (len
>>9) > max_sector
)
3036 len
= (max_sector
- sector_nr
) << 9;
3039 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
3041 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
3042 if (bio_add_page(bio
, page
, len
, 0))
3046 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
3047 for (bio2
= biolist
;
3048 bio2
&& bio2
!= bio
;
3049 bio2
= bio2
->bi_next
) {
3050 /* remove last page from this bio */
3052 bio2
->bi_size
-= len
;
3053 bio2
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
3057 nr_sectors
+= len
>>9;
3058 sector_nr
+= len
>>9;
3059 } while (biolist
->bi_vcnt
< RESYNC_PAGES
);
3061 r10_bio
->sectors
= nr_sectors
;
3065 biolist
= biolist
->bi_next
;
3067 bio
->bi_next
= NULL
;
3068 r10_bio
= bio
->bi_private
;
3069 r10_bio
->sectors
= nr_sectors
;
3071 if (bio
->bi_end_io
== end_sync_read
) {
3072 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
3073 generic_make_request(bio
);
3077 if (sectors_skipped
)
3078 /* pretend they weren't skipped, it makes
3079 * no important difference in this case
3081 md_done_sync(mddev
, sectors_skipped
, 1);
3083 return sectors_skipped
+ nr_sectors
;
3085 /* There is nowhere to write, so all non-sync
3086 * drives must be failed or in resync, all drives
3087 * have a bad block, so try the next chunk...
3089 if (sector_nr
+ max_sync
< max_sector
)
3090 max_sector
= sector_nr
+ max_sync
;
3092 sectors_skipped
+= (max_sector
- sector_nr
);
3094 sector_nr
= max_sector
;
3099 raid10_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
3102 struct r10conf
*conf
= mddev
->private;
3105 raid_disks
= conf
->raid_disks
;
3107 sectors
= conf
->dev_sectors
;
3109 size
= sectors
>> conf
->chunk_shift
;
3110 sector_div(size
, conf
->far_copies
);
3111 size
= size
* raid_disks
;
3112 sector_div(size
, conf
->near_copies
);
3114 return size
<< conf
->chunk_shift
;
3118 static struct r10conf
*setup_conf(struct mddev
*mddev
)
3120 struct r10conf
*conf
= NULL
;
3122 sector_t stride
, size
;
3125 if (mddev
->new_chunk_sectors
< (PAGE_SIZE
>> 9) ||
3126 !is_power_of_2(mddev
->new_chunk_sectors
)) {
3127 printk(KERN_ERR
"md/raid10:%s: chunk size must be "
3128 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
3129 mdname(mddev
), PAGE_SIZE
);
3133 nc
= mddev
->new_layout
& 255;
3134 fc
= (mddev
->new_layout
>> 8) & 255;
3135 fo
= mddev
->new_layout
& (1<<16);
3137 if ((nc
*fc
) <2 || (nc
*fc
) > mddev
->raid_disks
||
3138 (mddev
->new_layout
>> 17)) {
3139 printk(KERN_ERR
"md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
3140 mdname(mddev
), mddev
->new_layout
);
3145 conf
= kzalloc(sizeof(struct r10conf
), GFP_KERNEL
);
3149 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
3154 conf
->tmppage
= alloc_page(GFP_KERNEL
);
3159 conf
->raid_disks
= mddev
->raid_disks
;
3160 conf
->near_copies
= nc
;
3161 conf
->far_copies
= fc
;
3162 conf
->copies
= nc
*fc
;
3163 conf
->far_offset
= fo
;
3164 conf
->chunk_mask
= mddev
->new_chunk_sectors
- 1;
3165 conf
->chunk_shift
= ffz(~mddev
->new_chunk_sectors
);
3167 conf
->r10bio_pool
= mempool_create(NR_RAID10_BIOS
, r10bio_pool_alloc
,
3168 r10bio_pool_free
, conf
);
3169 if (!conf
->r10bio_pool
)
3172 size
= mddev
->dev_sectors
>> conf
->chunk_shift
;
3173 sector_div(size
, fc
);
3174 size
= size
* conf
->raid_disks
;
3175 sector_div(size
, nc
);
3176 /* 'size' is now the number of chunks in the array */
3177 /* calculate "used chunks per device" in 'stride' */
3178 stride
= size
* conf
->copies
;
3180 /* We need to round up when dividing by raid_disks to
3181 * get the stride size.
3183 stride
+= conf
->raid_disks
- 1;
3184 sector_div(stride
, conf
->raid_disks
);
3186 conf
->dev_sectors
= stride
<< conf
->chunk_shift
;
3191 sector_div(stride
, fc
);
3192 conf
->stride
= stride
<< conf
->chunk_shift
;
3195 spin_lock_init(&conf
->device_lock
);
3196 INIT_LIST_HEAD(&conf
->retry_list
);
3198 spin_lock_init(&conf
->resync_lock
);
3199 init_waitqueue_head(&conf
->wait_barrier
);
3201 conf
->thread
= md_register_thread(raid10d
, mddev
, NULL
);
3205 conf
->mddev
= mddev
;
3209 printk(KERN_ERR
"md/raid10:%s: couldn't allocate memory.\n",
3212 if (conf
->r10bio_pool
)
3213 mempool_destroy(conf
->r10bio_pool
);
3214 kfree(conf
->mirrors
);
3215 safe_put_page(conf
->tmppage
);
3218 return ERR_PTR(err
);
3221 static int run(struct mddev
*mddev
)
3223 struct r10conf
*conf
;
3224 int i
, disk_idx
, chunk_size
;
3225 struct mirror_info
*disk
;
3226 struct md_rdev
*rdev
;
3230 * copy the already verified devices into our private RAID10
3231 * bookkeeping area. [whatever we allocate in run(),
3232 * should be freed in stop()]
3235 if (mddev
->private == NULL
) {
3236 conf
= setup_conf(mddev
);
3238 return PTR_ERR(conf
);
3239 mddev
->private = conf
;
3241 conf
= mddev
->private;
3245 mddev
->thread
= conf
->thread
;
3246 conf
->thread
= NULL
;
3248 chunk_size
= mddev
->chunk_sectors
<< 9;
3249 blk_queue_io_min(mddev
->queue
, chunk_size
);
3250 if (conf
->raid_disks
% conf
->near_copies
)
3251 blk_queue_io_opt(mddev
->queue
, chunk_size
* conf
->raid_disks
);
3253 blk_queue_io_opt(mddev
->queue
, chunk_size
*
3254 (conf
->raid_disks
/ conf
->near_copies
));
3256 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
3258 disk_idx
= rdev
->raid_disk
;
3259 if (disk_idx
>= conf
->raid_disks
3262 disk
= conf
->mirrors
+ disk_idx
;
3264 if (test_bit(Replacement
, &rdev
->flags
)) {
3265 if (disk
->replacement
)
3267 disk
->replacement
= rdev
;
3274 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
3275 rdev
->data_offset
<< 9);
3276 /* as we don't honour merge_bvec_fn, we must never risk
3277 * violating it, so limit max_segments to 1 lying
3278 * within a single page.
3280 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
3281 blk_queue_max_segments(mddev
->queue
, 1);
3282 blk_queue_segment_boundary(mddev
->queue
,
3283 PAGE_CACHE_SIZE
- 1);
3286 disk
->head_position
= 0;
3288 /* need to check that every block has at least one working mirror */
3289 if (!enough(conf
, -1)) {
3290 printk(KERN_ERR
"md/raid10:%s: not enough operational mirrors.\n",
3295 mddev
->degraded
= 0;
3296 for (i
= 0; i
< conf
->raid_disks
; i
++) {
3298 disk
= conf
->mirrors
+ i
;
3300 if (!disk
->rdev
&& disk
->replacement
) {
3301 /* The replacement is all we have - use it */
3302 disk
->rdev
= disk
->replacement
;
3303 disk
->replacement
= NULL
;
3304 clear_bit(Replacement
, &disk
->rdev
->flags
);
3308 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
3309 disk
->head_position
= 0;
3314 disk
->recovery_disabled
= mddev
->recovery_disabled
- 1;
3317 if (mddev
->recovery_cp
!= MaxSector
)
3318 printk(KERN_NOTICE
"md/raid10:%s: not clean"
3319 " -- starting background reconstruction\n",
3322 "md/raid10:%s: active with %d out of %d devices\n",
3323 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
,
3326 * Ok, everything is just fine now
3328 mddev
->dev_sectors
= conf
->dev_sectors
;
3329 size
= raid10_size(mddev
, 0, 0);
3330 md_set_array_sectors(mddev
, size
);
3331 mddev
->resync_max_sectors
= size
;
3333 mddev
->queue
->backing_dev_info
.congested_fn
= raid10_congested
;
3334 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
3336 /* Calculate max read-ahead size.
3337 * We need to readahead at least twice a whole stripe....
3341 int stripe
= conf
->raid_disks
*
3342 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
3343 stripe
/= conf
->near_copies
;
3344 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2* stripe
)
3345 mddev
->queue
->backing_dev_info
.ra_pages
= 2* stripe
;
3348 if (conf
->near_copies
< conf
->raid_disks
)
3349 blk_queue_merge_bvec(mddev
->queue
, raid10_mergeable_bvec
);
3351 if (md_integrity_register(mddev
))
3357 md_unregister_thread(&mddev
->thread
);
3358 if (conf
->r10bio_pool
)
3359 mempool_destroy(conf
->r10bio_pool
);
3360 safe_put_page(conf
->tmppage
);
3361 kfree(conf
->mirrors
);
3363 mddev
->private = NULL
;
3368 static int stop(struct mddev
*mddev
)
3370 struct r10conf
*conf
= mddev
->private;
3372 raise_barrier(conf
, 0);
3373 lower_barrier(conf
);
3375 md_unregister_thread(&mddev
->thread
);
3376 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
3377 if (conf
->r10bio_pool
)
3378 mempool_destroy(conf
->r10bio_pool
);
3379 kfree(conf
->mirrors
);
3381 mddev
->private = NULL
;
3385 static void raid10_quiesce(struct mddev
*mddev
, int state
)
3387 struct r10conf
*conf
= mddev
->private;
3391 raise_barrier(conf
, 0);
3394 lower_barrier(conf
);
3399 static void *raid10_takeover_raid0(struct mddev
*mddev
)
3401 struct md_rdev
*rdev
;
3402 struct r10conf
*conf
;
3404 if (mddev
->degraded
> 0) {
3405 printk(KERN_ERR
"md/raid10:%s: Error: degraded raid0!\n",
3407 return ERR_PTR(-EINVAL
);
3410 /* Set new parameters */
3411 mddev
->new_level
= 10;
3412 /* new layout: far_copies = 1, near_copies = 2 */
3413 mddev
->new_layout
= (1<<8) + 2;
3414 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
3415 mddev
->delta_disks
= mddev
->raid_disks
;
3416 mddev
->raid_disks
*= 2;
3417 /* make sure it will be not marked as dirty */
3418 mddev
->recovery_cp
= MaxSector
;
3420 conf
= setup_conf(mddev
);
3421 if (!IS_ERR(conf
)) {
3422 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
3423 if (rdev
->raid_disk
>= 0)
3424 rdev
->new_raid_disk
= rdev
->raid_disk
* 2;
3431 static void *raid10_takeover(struct mddev
*mddev
)
3433 struct r0conf
*raid0_conf
;
3435 /* raid10 can take over:
3436 * raid0 - providing it has only two drives
3438 if (mddev
->level
== 0) {
3439 /* for raid0 takeover only one zone is supported */
3440 raid0_conf
= mddev
->private;
3441 if (raid0_conf
->nr_strip_zones
> 1) {
3442 printk(KERN_ERR
"md/raid10:%s: cannot takeover raid 0"
3443 " with more than one zone.\n",
3445 return ERR_PTR(-EINVAL
);
3447 return raid10_takeover_raid0(mddev
);
3449 return ERR_PTR(-EINVAL
);
3452 static struct md_personality raid10_personality
=
3456 .owner
= THIS_MODULE
,
3457 .make_request
= make_request
,
3461 .error_handler
= error
,
3462 .hot_add_disk
= raid10_add_disk
,
3463 .hot_remove_disk
= raid10_remove_disk
,
3464 .spare_active
= raid10_spare_active
,
3465 .sync_request
= sync_request
,
3466 .quiesce
= raid10_quiesce
,
3467 .size
= raid10_size
,
3468 .takeover
= raid10_takeover
,
3471 static int __init
raid_init(void)
3473 return register_md_personality(&raid10_personality
);
3476 static void raid_exit(void)
3478 unregister_md_personality(&raid10_personality
);
3481 module_init(raid_init
);
3482 module_exit(raid_exit
);
3483 MODULE_LICENSE("GPL");
3484 MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
3485 MODULE_ALIAS("md-personality-9"); /* RAID10 */
3486 MODULE_ALIAS("md-raid10");
3487 MODULE_ALIAS("md-level-10");
3489 module_param(max_queued_requests
, int, S_IRUGO
|S_IWUSR
);