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_event_lock_irq(conf
->wait_barrier
, !conf
->barrier
,
872 spin_unlock_irq(&conf
->resync_lock
);
875 static void allow_barrier(struct r10conf
*conf
)
878 spin_lock_irqsave(&conf
->resync_lock
, flags
);
880 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
881 wake_up(&conf
->wait_barrier
);
884 static void freeze_array(struct r10conf
*conf
)
886 /* stop syncio and normal IO and wait for everything to
888 * We increment barrier and nr_waiting, and then
889 * wait until nr_pending match nr_queued+1
890 * This is called in the context of one normal IO request
891 * that has failed. Thus any sync request that might be pending
892 * will be blocked by nr_pending, and we need to wait for
893 * pending IO requests to complete or be queued for re-try.
894 * Thus the number queued (nr_queued) plus this request (1)
895 * must match the number of pending IOs (nr_pending) before
898 spin_lock_irq(&conf
->resync_lock
);
901 wait_event_lock_irq(conf
->wait_barrier
,
902 conf
->nr_pending
== conf
->nr_queued
+1,
904 flush_pending_writes(conf
));
906 spin_unlock_irq(&conf
->resync_lock
);
909 static void unfreeze_array(struct r10conf
*conf
)
911 /* reverse the effect of the freeze */
912 spin_lock_irq(&conf
->resync_lock
);
915 wake_up(&conf
->wait_barrier
);
916 spin_unlock_irq(&conf
->resync_lock
);
919 static void make_request(struct mddev
*mddev
, struct bio
* bio
)
921 struct r10conf
*conf
= mddev
->private;
922 struct r10bio
*r10_bio
;
923 struct bio
*read_bio
;
925 int chunk_sects
= conf
->chunk_mask
+ 1;
926 const int rw
= bio_data_dir(bio
);
927 const unsigned long do_sync
= (bio
->bi_rw
& REQ_SYNC
);
928 const unsigned long do_fua
= (bio
->bi_rw
& REQ_FUA
);
930 struct md_rdev
*blocked_rdev
;
935 if (unlikely(bio
->bi_rw
& REQ_FLUSH
)) {
936 md_flush_request(mddev
, bio
);
940 /* If this request crosses a chunk boundary, we need to
941 * split it. This will only happen for 1 PAGE (or less) requests.
943 if (unlikely( (bio
->bi_sector
& conf
->chunk_mask
) + (bio
->bi_size
>> 9)
945 conf
->near_copies
< conf
->raid_disks
)) {
947 /* Sanity check -- queue functions should prevent this happening */
948 if (bio
->bi_vcnt
!= 1 ||
951 /* This is a one page bio that upper layers
952 * refuse to split for us, so we need to split it.
955 chunk_sects
- (bio
->bi_sector
& (chunk_sects
- 1)) );
957 /* Each of these 'make_request' calls will call 'wait_barrier'.
958 * If the first succeeds but the second blocks due to the resync
959 * thread raising the barrier, we will deadlock because the
960 * IO to the underlying device will be queued in generic_make_request
961 * and will never complete, so will never reduce nr_pending.
962 * So increment nr_waiting here so no new raise_barriers will
963 * succeed, and so the second wait_barrier cannot block.
965 spin_lock_irq(&conf
->resync_lock
);
967 spin_unlock_irq(&conf
->resync_lock
);
969 make_request(mddev
, &bp
->bio1
);
970 make_request(mddev
, &bp
->bio2
);
972 spin_lock_irq(&conf
->resync_lock
);
974 wake_up(&conf
->wait_barrier
);
975 spin_unlock_irq(&conf
->resync_lock
);
977 bio_pair_release(bp
);
980 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
981 " or bigger than %dk %llu %d\n", mdname(mddev
), chunk_sects
/2,
982 (unsigned long long)bio
->bi_sector
, bio
->bi_size
>> 10);
988 md_write_start(mddev
, bio
);
991 * Register the new request and wait if the reconstruction
992 * thread has put up a bar for new requests.
993 * Continue immediately if no resync is active currently.
997 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
999 r10_bio
->master_bio
= bio
;
1000 r10_bio
->sectors
= bio
->bi_size
>> 9;
1002 r10_bio
->mddev
= mddev
;
1003 r10_bio
->sector
= bio
->bi_sector
;
1006 /* We might need to issue multiple reads to different
1007 * devices if there are bad blocks around, so we keep
1008 * track of the number of reads in bio->bi_phys_segments.
1009 * If this is 0, there is only one r10_bio and no locking
1010 * will be needed when the request completes. If it is
1011 * non-zero, then it is the number of not-completed requests.
1013 bio
->bi_phys_segments
= 0;
1014 clear_bit(BIO_SEG_VALID
, &bio
->bi_flags
);
1018 * read balancing logic:
1020 struct md_rdev
*rdev
;
1024 rdev
= read_balance(conf
, r10_bio
, &max_sectors
);
1026 raid_end_bio_io(r10_bio
);
1029 slot
= r10_bio
->read_slot
;
1031 read_bio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1032 md_trim_bio(read_bio
, r10_bio
->sector
- bio
->bi_sector
,
1035 r10_bio
->devs
[slot
].bio
= read_bio
;
1036 r10_bio
->devs
[slot
].rdev
= rdev
;
1038 read_bio
->bi_sector
= r10_bio
->devs
[slot
].addr
+
1040 read_bio
->bi_bdev
= rdev
->bdev
;
1041 read_bio
->bi_end_io
= raid10_end_read_request
;
1042 read_bio
->bi_rw
= READ
| do_sync
;
1043 read_bio
->bi_private
= r10_bio
;
1045 if (max_sectors
< r10_bio
->sectors
) {
1046 /* Could not read all from this device, so we will
1047 * need another r10_bio.
1049 sectors_handled
= (r10_bio
->sectors
+ max_sectors
1051 r10_bio
->sectors
= max_sectors
;
1052 spin_lock_irq(&conf
->device_lock
);
1053 if (bio
->bi_phys_segments
== 0)
1054 bio
->bi_phys_segments
= 2;
1056 bio
->bi_phys_segments
++;
1057 spin_unlock(&conf
->device_lock
);
1058 /* Cannot call generic_make_request directly
1059 * as that will be queued in __generic_make_request
1060 * and subsequent mempool_alloc might block
1061 * waiting for it. so hand bio over to raid10d.
1063 reschedule_retry(r10_bio
);
1065 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
1067 r10_bio
->master_bio
= bio
;
1068 r10_bio
->sectors
= ((bio
->bi_size
>> 9)
1071 r10_bio
->mddev
= mddev
;
1072 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1075 generic_make_request(read_bio
);
1082 if (conf
->pending_count
>= max_queued_requests
) {
1083 md_wakeup_thread(mddev
->thread
);
1084 wait_event(conf
->wait_barrier
,
1085 conf
->pending_count
< max_queued_requests
);
1087 /* first select target devices under rcu_lock and
1088 * inc refcount on their rdev. Record them by setting
1090 * If there are known/acknowledged bad blocks on any device
1091 * on which we have seen a write error, we want to avoid
1092 * writing to those blocks. This potentially requires several
1093 * writes to write around the bad blocks. Each set of writes
1094 * gets its own r10_bio with a set of bios attached. The number
1095 * of r10_bios is recored in bio->bi_phys_segments just as with
1098 plugged
= mddev_check_plugged(mddev
);
1100 r10_bio
->read_slot
= -1; /* make sure repl_bio gets freed */
1101 raid10_find_phys(conf
, r10_bio
);
1103 blocked_rdev
= NULL
;
1105 max_sectors
= r10_bio
->sectors
;
1107 for (i
= 0; i
< conf
->copies
; i
++) {
1108 int d
= r10_bio
->devs
[i
].devnum
;
1109 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
1110 struct md_rdev
*rrdev
= rcu_dereference(
1111 conf
->mirrors
[d
].replacement
);
1114 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
1115 atomic_inc(&rdev
->nr_pending
);
1116 blocked_rdev
= rdev
;
1119 if (rrdev
&& unlikely(test_bit(Blocked
, &rrdev
->flags
))) {
1120 atomic_inc(&rrdev
->nr_pending
);
1121 blocked_rdev
= rrdev
;
1124 if (rrdev
&& test_bit(Faulty
, &rrdev
->flags
))
1127 r10_bio
->devs
[i
].bio
= NULL
;
1128 r10_bio
->devs
[i
].repl_bio
= NULL
;
1129 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
)) {
1130 set_bit(R10BIO_Degraded
, &r10_bio
->state
);
1133 if (test_bit(WriteErrorSeen
, &rdev
->flags
)) {
1135 sector_t dev_sector
= r10_bio
->devs
[i
].addr
;
1139 is_bad
= is_badblock(rdev
, dev_sector
,
1141 &first_bad
, &bad_sectors
);
1143 /* Mustn't write here until the bad block
1146 atomic_inc(&rdev
->nr_pending
);
1147 set_bit(BlockedBadBlocks
, &rdev
->flags
);
1148 blocked_rdev
= rdev
;
1151 if (is_bad
&& first_bad
<= dev_sector
) {
1152 /* Cannot write here at all */
1153 bad_sectors
-= (dev_sector
- first_bad
);
1154 if (bad_sectors
< max_sectors
)
1155 /* Mustn't write more than bad_sectors
1156 * to other devices yet
1158 max_sectors
= bad_sectors
;
1159 /* We don't set R10BIO_Degraded as that
1160 * only applies if the disk is missing,
1161 * so it might be re-added, and we want to
1162 * know to recover this chunk.
1163 * In this case the device is here, and the
1164 * fact that this chunk is not in-sync is
1165 * recorded in the bad block log.
1170 int good_sectors
= first_bad
- dev_sector
;
1171 if (good_sectors
< max_sectors
)
1172 max_sectors
= good_sectors
;
1175 r10_bio
->devs
[i
].bio
= bio
;
1176 atomic_inc(&rdev
->nr_pending
);
1178 r10_bio
->devs
[i
].repl_bio
= bio
;
1179 atomic_inc(&rrdev
->nr_pending
);
1184 if (unlikely(blocked_rdev
)) {
1185 /* Have to wait for this device to get unblocked, then retry */
1189 for (j
= 0; j
< i
; j
++) {
1190 if (r10_bio
->devs
[j
].bio
) {
1191 d
= r10_bio
->devs
[j
].devnum
;
1192 rdev_dec_pending(conf
->mirrors
[d
].rdev
, mddev
);
1194 if (r10_bio
->devs
[j
].repl_bio
) {
1195 struct md_rdev
*rdev
;
1196 d
= r10_bio
->devs
[j
].devnum
;
1197 rdev
= conf
->mirrors
[d
].replacement
;
1199 /* Race with remove_disk */
1201 rdev
= conf
->mirrors
[d
].rdev
;
1203 rdev_dec_pending(rdev
, mddev
);
1206 allow_barrier(conf
);
1207 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
1212 if (max_sectors
< r10_bio
->sectors
) {
1213 /* We are splitting this into multiple parts, so
1214 * we need to prepare for allocating another r10_bio.
1216 r10_bio
->sectors
= max_sectors
;
1217 spin_lock_irq(&conf
->device_lock
);
1218 if (bio
->bi_phys_segments
== 0)
1219 bio
->bi_phys_segments
= 2;
1221 bio
->bi_phys_segments
++;
1222 spin_unlock_irq(&conf
->device_lock
);
1224 sectors_handled
= r10_bio
->sector
+ max_sectors
- bio
->bi_sector
;
1226 atomic_set(&r10_bio
->remaining
, 1);
1227 bitmap_startwrite(mddev
->bitmap
, r10_bio
->sector
, r10_bio
->sectors
, 0);
1229 for (i
= 0; i
< conf
->copies
; i
++) {
1231 int d
= r10_bio
->devs
[i
].devnum
;
1232 if (!r10_bio
->devs
[i
].bio
)
1235 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1236 md_trim_bio(mbio
, r10_bio
->sector
- bio
->bi_sector
,
1238 r10_bio
->devs
[i
].bio
= mbio
;
1240 mbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
1241 conf
->mirrors
[d
].rdev
->data_offset
);
1242 mbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1243 mbio
->bi_end_io
= raid10_end_write_request
;
1244 mbio
->bi_rw
= WRITE
| do_sync
| do_fua
;
1245 mbio
->bi_private
= r10_bio
;
1247 atomic_inc(&r10_bio
->remaining
);
1248 spin_lock_irqsave(&conf
->device_lock
, flags
);
1249 bio_list_add(&conf
->pending_bio_list
, mbio
);
1250 conf
->pending_count
++;
1251 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1253 if (!r10_bio
->devs
[i
].repl_bio
)
1256 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1257 md_trim_bio(mbio
, r10_bio
->sector
- bio
->bi_sector
,
1259 r10_bio
->devs
[i
].repl_bio
= mbio
;
1261 /* We are actively writing to the original device
1262 * so it cannot disappear, so the replacement cannot
1265 mbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
1266 conf
->mirrors
[d
].replacement
->data_offset
);
1267 mbio
->bi_bdev
= conf
->mirrors
[d
].replacement
->bdev
;
1268 mbio
->bi_end_io
= raid10_end_write_request
;
1269 mbio
->bi_rw
= WRITE
| do_sync
| do_fua
;
1270 mbio
->bi_private
= r10_bio
;
1272 atomic_inc(&r10_bio
->remaining
);
1273 spin_lock_irqsave(&conf
->device_lock
, flags
);
1274 bio_list_add(&conf
->pending_bio_list
, mbio
);
1275 conf
->pending_count
++;
1276 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1279 /* Don't remove the bias on 'remaining' (one_write_done) until
1280 * after checking if we need to go around again.
1283 if (sectors_handled
< (bio
->bi_size
>> 9)) {
1284 one_write_done(r10_bio
);
1285 /* We need another r10_bio. It has already been counted
1286 * in bio->bi_phys_segments.
1288 r10_bio
= mempool_alloc(conf
->r10bio_pool
, GFP_NOIO
);
1290 r10_bio
->master_bio
= bio
;
1291 r10_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
1293 r10_bio
->mddev
= mddev
;
1294 r10_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1298 one_write_done(r10_bio
);
1300 /* In case raid10d snuck in to freeze_array */
1301 wake_up(&conf
->wait_barrier
);
1303 if (do_sync
|| !mddev
->bitmap
|| !plugged
)
1304 md_wakeup_thread(mddev
->thread
);
1307 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
1309 struct r10conf
*conf
= mddev
->private;
1312 if (conf
->near_copies
< conf
->raid_disks
)
1313 seq_printf(seq
, " %dK chunks", mddev
->chunk_sectors
/ 2);
1314 if (conf
->near_copies
> 1)
1315 seq_printf(seq
, " %d near-copies", conf
->near_copies
);
1316 if (conf
->far_copies
> 1) {
1317 if (conf
->far_offset
)
1318 seq_printf(seq
, " %d offset-copies", conf
->far_copies
);
1320 seq_printf(seq
, " %d far-copies", conf
->far_copies
);
1322 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
1323 conf
->raid_disks
- mddev
->degraded
);
1324 for (i
= 0; i
< conf
->raid_disks
; i
++)
1325 seq_printf(seq
, "%s",
1326 conf
->mirrors
[i
].rdev
&&
1327 test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ? "U" : "_");
1328 seq_printf(seq
, "]");
1331 /* check if there are enough drives for
1332 * every block to appear on atleast one.
1333 * Don't consider the device numbered 'ignore'
1334 * as we might be about to remove it.
1336 static int enough(struct r10conf
*conf
, int ignore
)
1341 int n
= conf
->copies
;
1344 if (conf
->mirrors
[first
].rdev
&&
1347 first
= (first
+1) % conf
->raid_disks
;
1351 } while (first
!= 0);
1355 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1357 char b
[BDEVNAME_SIZE
];
1358 struct r10conf
*conf
= mddev
->private;
1361 * If it is not operational, then we have already marked it as dead
1362 * else if it is the last working disks, ignore the error, let the
1363 * next level up know.
1364 * else mark the drive as failed
1366 if (test_bit(In_sync
, &rdev
->flags
)
1367 && !enough(conf
, rdev
->raid_disk
))
1369 * Don't fail the drive, just return an IO error.
1372 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1373 unsigned long flags
;
1374 spin_lock_irqsave(&conf
->device_lock
, flags
);
1376 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1378 * if recovery is running, make sure it aborts.
1380 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1382 set_bit(Blocked
, &rdev
->flags
);
1383 set_bit(Faulty
, &rdev
->flags
);
1384 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1386 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1387 "md/raid10:%s: Operation continuing on %d devices.\n",
1388 mdname(mddev
), bdevname(rdev
->bdev
, b
),
1389 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
1392 static void print_conf(struct r10conf
*conf
)
1395 struct mirror_info
*tmp
;
1397 printk(KERN_DEBUG
"RAID10 conf printout:\n");
1399 printk(KERN_DEBUG
"(!conf)\n");
1402 printk(KERN_DEBUG
" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1405 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1406 char b
[BDEVNAME_SIZE
];
1407 tmp
= conf
->mirrors
+ i
;
1409 printk(KERN_DEBUG
" disk %d, wo:%d, o:%d, dev:%s\n",
1410 i
, !test_bit(In_sync
, &tmp
->rdev
->flags
),
1411 !test_bit(Faulty
, &tmp
->rdev
->flags
),
1412 bdevname(tmp
->rdev
->bdev
,b
));
1416 static void close_sync(struct r10conf
*conf
)
1419 allow_barrier(conf
);
1421 mempool_destroy(conf
->r10buf_pool
);
1422 conf
->r10buf_pool
= NULL
;
1425 static int raid10_spare_active(struct mddev
*mddev
)
1428 struct r10conf
*conf
= mddev
->private;
1429 struct mirror_info
*tmp
;
1431 unsigned long flags
;
1434 * Find all non-in_sync disks within the RAID10 configuration
1435 * and mark them in_sync
1437 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1438 tmp
= conf
->mirrors
+ i
;
1439 if (tmp
->replacement
1440 && tmp
->replacement
->recovery_offset
== MaxSector
1441 && !test_bit(Faulty
, &tmp
->replacement
->flags
)
1442 && !test_and_set_bit(In_sync
, &tmp
->replacement
->flags
)) {
1443 /* Replacement has just become active */
1445 || !test_and_clear_bit(In_sync
, &tmp
->rdev
->flags
))
1448 /* Replaced device not technically faulty,
1449 * but we need to be sure it gets removed
1450 * and never re-added.
1452 set_bit(Faulty
, &tmp
->rdev
->flags
);
1453 sysfs_notify_dirent_safe(
1454 tmp
->rdev
->sysfs_state
);
1456 sysfs_notify_dirent_safe(tmp
->replacement
->sysfs_state
);
1457 } else if (tmp
->rdev
1458 && !test_bit(Faulty
, &tmp
->rdev
->flags
)
1459 && !test_and_set_bit(In_sync
, &tmp
->rdev
->flags
)) {
1461 sysfs_notify_dirent(tmp
->rdev
->sysfs_state
);
1464 spin_lock_irqsave(&conf
->device_lock
, flags
);
1465 mddev
->degraded
-= count
;
1466 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1473 static int raid10_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1475 struct r10conf
*conf
= mddev
->private;
1479 int last
= conf
->raid_disks
- 1;
1481 if (mddev
->recovery_cp
< MaxSector
)
1482 /* only hot-add to in-sync arrays, as recovery is
1483 * very different from resync
1486 if (!enough(conf
, -1))
1489 if (rdev
->raid_disk
>= 0)
1490 first
= last
= rdev
->raid_disk
;
1492 if (rdev
->saved_raid_disk
>= first
&&
1493 conf
->mirrors
[rdev
->saved_raid_disk
].rdev
== NULL
)
1494 mirror
= rdev
->saved_raid_disk
;
1497 for ( ; mirror
<= last
; mirror
++) {
1498 struct mirror_info
*p
= &conf
->mirrors
[mirror
];
1499 if (p
->recovery_disabled
== mddev
->recovery_disabled
)
1502 if (!test_bit(WantReplacement
, &p
->rdev
->flags
) ||
1503 p
->replacement
!= NULL
)
1505 clear_bit(In_sync
, &rdev
->flags
);
1506 set_bit(Replacement
, &rdev
->flags
);
1507 rdev
->raid_disk
= mirror
;
1509 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1510 rdev
->data_offset
<< 9);
1511 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1512 blk_queue_max_segments(mddev
->queue
, 1);
1513 blk_queue_segment_boundary(mddev
->queue
,
1514 PAGE_CACHE_SIZE
- 1);
1517 rcu_assign_pointer(p
->replacement
, rdev
);
1521 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1522 rdev
->data_offset
<< 9);
1523 /* as we don't honour merge_bvec_fn, we must
1524 * never risk violating it, so limit
1525 * ->max_segments to one lying with a single
1526 * page, as a one page request is never in
1529 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1530 blk_queue_max_segments(mddev
->queue
, 1);
1531 blk_queue_segment_boundary(mddev
->queue
,
1532 PAGE_CACHE_SIZE
- 1);
1535 p
->head_position
= 0;
1536 p
->recovery_disabled
= mddev
->recovery_disabled
- 1;
1537 rdev
->raid_disk
= mirror
;
1539 if (rdev
->saved_raid_disk
!= mirror
)
1541 rcu_assign_pointer(p
->rdev
, rdev
);
1545 md_integrity_add_rdev(rdev
, mddev
);
1550 static int raid10_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1552 struct r10conf
*conf
= mddev
->private;
1554 int number
= rdev
->raid_disk
;
1555 struct md_rdev
**rdevp
;
1556 struct mirror_info
*p
= conf
->mirrors
+ number
;
1559 if (rdev
== p
->rdev
)
1561 else if (rdev
== p
->replacement
)
1562 rdevp
= &p
->replacement
;
1566 if (test_bit(In_sync
, &rdev
->flags
) ||
1567 atomic_read(&rdev
->nr_pending
)) {
1571 /* Only remove faulty devices if recovery
1574 if (!test_bit(Faulty
, &rdev
->flags
) &&
1575 mddev
->recovery_disabled
!= p
->recovery_disabled
&&
1576 (!p
->replacement
|| p
->replacement
== rdev
) &&
1583 if (atomic_read(&rdev
->nr_pending
)) {
1584 /* lost the race, try later */
1588 } else if (p
->replacement
) {
1589 /* We must have just cleared 'rdev' */
1590 p
->rdev
= p
->replacement
;
1591 clear_bit(Replacement
, &p
->replacement
->flags
);
1592 smp_mb(); /* Make sure other CPUs may see both as identical
1593 * but will never see neither -- if they are careful.
1595 p
->replacement
= NULL
;
1596 clear_bit(WantReplacement
, &rdev
->flags
);
1598 /* We might have just remove the Replacement as faulty
1599 * Clear the flag just in case
1601 clear_bit(WantReplacement
, &rdev
->flags
);
1603 err
= md_integrity_register(mddev
);
1612 static void end_sync_read(struct bio
*bio
, int error
)
1614 struct r10bio
*r10_bio
= bio
->bi_private
;
1615 struct r10conf
*conf
= r10_bio
->mddev
->private;
1618 d
= find_bio_disk(conf
, r10_bio
, bio
, NULL
, NULL
);
1620 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1621 set_bit(R10BIO_Uptodate
, &r10_bio
->state
);
1623 /* The write handler will notice the lack of
1624 * R10BIO_Uptodate and record any errors etc
1626 atomic_add(r10_bio
->sectors
,
1627 &conf
->mirrors
[d
].rdev
->corrected_errors
);
1629 /* for reconstruct, we always reschedule after a read.
1630 * for resync, only after all reads
1632 rdev_dec_pending(conf
->mirrors
[d
].rdev
, conf
->mddev
);
1633 if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
) ||
1634 atomic_dec_and_test(&r10_bio
->remaining
)) {
1635 /* we have read all the blocks,
1636 * do the comparison in process context in raid10d
1638 reschedule_retry(r10_bio
);
1642 static void end_sync_request(struct r10bio
*r10_bio
)
1644 struct mddev
*mddev
= r10_bio
->mddev
;
1646 while (atomic_dec_and_test(&r10_bio
->remaining
)) {
1647 if (r10_bio
->master_bio
== NULL
) {
1648 /* the primary of several recovery bios */
1649 sector_t s
= r10_bio
->sectors
;
1650 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
1651 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
1652 reschedule_retry(r10_bio
);
1655 md_done_sync(mddev
, s
, 1);
1658 struct r10bio
*r10_bio2
= (struct r10bio
*)r10_bio
->master_bio
;
1659 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
1660 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
1661 reschedule_retry(r10_bio
);
1669 static void end_sync_write(struct bio
*bio
, int error
)
1671 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1672 struct r10bio
*r10_bio
= bio
->bi_private
;
1673 struct mddev
*mddev
= r10_bio
->mddev
;
1674 struct r10conf
*conf
= mddev
->private;
1680 struct md_rdev
*rdev
= NULL
;
1682 d
= find_bio_disk(conf
, r10_bio
, bio
, &slot
, &repl
);
1684 rdev
= conf
->mirrors
[d
].replacement
;
1687 rdev
= conf
->mirrors
[d
].rdev
;
1692 md_error(mddev
, rdev
);
1694 set_bit(WriteErrorSeen
, &rdev
->flags
);
1695 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1696 set_bit(MD_RECOVERY_NEEDED
,
1697 &rdev
->mddev
->recovery
);
1698 set_bit(R10BIO_WriteError
, &r10_bio
->state
);
1700 } else if (is_badblock(rdev
,
1701 r10_bio
->devs
[slot
].addr
,
1703 &first_bad
, &bad_sectors
))
1704 set_bit(R10BIO_MadeGood
, &r10_bio
->state
);
1706 rdev_dec_pending(rdev
, mddev
);
1708 end_sync_request(r10_bio
);
1712 * Note: sync and recover and handled very differently for raid10
1713 * This code is for resync.
1714 * For resync, we read through virtual addresses and read all blocks.
1715 * If there is any error, we schedule a write. The lowest numbered
1716 * drive is authoritative.
1717 * However requests come for physical address, so we need to map.
1718 * For every physical address there are raid_disks/copies virtual addresses,
1719 * which is always are least one, but is not necessarly an integer.
1720 * This means that a physical address can span multiple chunks, so we may
1721 * have to submit multiple io requests for a single sync request.
1724 * We check if all blocks are in-sync and only write to blocks that
1727 static void sync_request_write(struct mddev
*mddev
, struct r10bio
*r10_bio
)
1729 struct r10conf
*conf
= mddev
->private;
1731 struct bio
*tbio
, *fbio
;
1733 atomic_set(&r10_bio
->remaining
, 1);
1735 /* find the first device with a block */
1736 for (i
=0; i
<conf
->copies
; i
++)
1737 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
))
1740 if (i
== conf
->copies
)
1744 fbio
= r10_bio
->devs
[i
].bio
;
1746 /* now find blocks with errors */
1747 for (i
=0 ; i
< conf
->copies
; i
++) {
1749 int vcnt
= r10_bio
->sectors
>> (PAGE_SHIFT
-9);
1751 tbio
= r10_bio
->devs
[i
].bio
;
1753 if (tbio
->bi_end_io
!= end_sync_read
)
1757 if (test_bit(BIO_UPTODATE
, &r10_bio
->devs
[i
].bio
->bi_flags
)) {
1758 /* We know that the bi_io_vec layout is the same for
1759 * both 'first' and 'i', so we just compare them.
1760 * All vec entries are PAGE_SIZE;
1762 for (j
= 0; j
< vcnt
; j
++)
1763 if (memcmp(page_address(fbio
->bi_io_vec
[j
].bv_page
),
1764 page_address(tbio
->bi_io_vec
[j
].bv_page
),
1769 mddev
->resync_mismatches
+= r10_bio
->sectors
;
1770 if (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
))
1771 /* Don't fix anything. */
1774 /* Ok, we need to write this bio, either to correct an
1775 * inconsistency or to correct an unreadable block.
1776 * First we need to fixup bv_offset, bv_len and
1777 * bi_vecs, as the read request might have corrupted these
1779 tbio
->bi_vcnt
= vcnt
;
1780 tbio
->bi_size
= r10_bio
->sectors
<< 9;
1782 tbio
->bi_phys_segments
= 0;
1783 tbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1784 tbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1785 tbio
->bi_next
= NULL
;
1786 tbio
->bi_rw
= WRITE
;
1787 tbio
->bi_private
= r10_bio
;
1788 tbio
->bi_sector
= r10_bio
->devs
[i
].addr
;
1790 for (j
=0; j
< vcnt
; j
++) {
1791 tbio
->bi_io_vec
[j
].bv_offset
= 0;
1792 tbio
->bi_io_vec
[j
].bv_len
= PAGE_SIZE
;
1794 memcpy(page_address(tbio
->bi_io_vec
[j
].bv_page
),
1795 page_address(fbio
->bi_io_vec
[j
].bv_page
),
1798 tbio
->bi_end_io
= end_sync_write
;
1800 d
= r10_bio
->devs
[i
].devnum
;
1801 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1802 atomic_inc(&r10_bio
->remaining
);
1803 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, tbio
->bi_size
>> 9);
1805 tbio
->bi_sector
+= conf
->mirrors
[d
].rdev
->data_offset
;
1806 tbio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
1807 generic_make_request(tbio
);
1810 /* Now write out to any replacement devices
1813 for (i
= 0; i
< conf
->copies
; i
++) {
1815 int vcnt
= r10_bio
->sectors
>> (PAGE_SHIFT
-9);
1817 tbio
= r10_bio
->devs
[i
].repl_bio
;
1818 if (!tbio
|| !tbio
->bi_end_io
)
1820 if (r10_bio
->devs
[i
].bio
->bi_end_io
!= end_sync_write
1821 && r10_bio
->devs
[i
].bio
!= fbio
)
1822 for (j
= 0; j
< vcnt
; j
++)
1823 memcpy(page_address(tbio
->bi_io_vec
[j
].bv_page
),
1824 page_address(fbio
->bi_io_vec
[j
].bv_page
),
1826 d
= r10_bio
->devs
[i
].devnum
;
1827 atomic_inc(&r10_bio
->remaining
);
1828 md_sync_acct(conf
->mirrors
[d
].replacement
->bdev
,
1829 tbio
->bi_size
>> 9);
1830 generic_make_request(tbio
);
1834 if (atomic_dec_and_test(&r10_bio
->remaining
)) {
1835 md_done_sync(mddev
, r10_bio
->sectors
, 1);
1841 * Now for the recovery code.
1842 * Recovery happens across physical sectors.
1843 * We recover all non-is_sync drives by finding the virtual address of
1844 * each, and then choose a working drive that also has that virt address.
1845 * There is a separate r10_bio for each non-in_sync drive.
1846 * Only the first two slots are in use. The first for reading,
1847 * The second for writing.
1850 static void fix_recovery_read_error(struct r10bio
*r10_bio
)
1852 /* We got a read error during recovery.
1853 * We repeat the read in smaller page-sized sections.
1854 * If a read succeeds, write it to the new device or record
1855 * a bad block if we cannot.
1856 * If a read fails, record a bad block on both old and
1859 struct mddev
*mddev
= r10_bio
->mddev
;
1860 struct r10conf
*conf
= mddev
->private;
1861 struct bio
*bio
= r10_bio
->devs
[0].bio
;
1863 int sectors
= r10_bio
->sectors
;
1865 int dr
= r10_bio
->devs
[0].devnum
;
1866 int dw
= r10_bio
->devs
[1].devnum
;
1870 struct md_rdev
*rdev
;
1874 if (s
> (PAGE_SIZE
>>9))
1877 rdev
= conf
->mirrors
[dr
].rdev
;
1878 addr
= r10_bio
->devs
[0].addr
+ sect
,
1879 ok
= sync_page_io(rdev
,
1882 bio
->bi_io_vec
[idx
].bv_page
,
1885 rdev
= conf
->mirrors
[dw
].rdev
;
1886 addr
= r10_bio
->devs
[1].addr
+ sect
;
1887 ok
= sync_page_io(rdev
,
1890 bio
->bi_io_vec
[idx
].bv_page
,
1893 set_bit(WriteErrorSeen
, &rdev
->flags
);
1894 if (!test_and_set_bit(WantReplacement
,
1896 set_bit(MD_RECOVERY_NEEDED
,
1897 &rdev
->mddev
->recovery
);
1901 /* We don't worry if we cannot set a bad block -
1902 * it really is bad so there is no loss in not
1905 rdev_set_badblocks(rdev
, addr
, s
, 0);
1907 if (rdev
!= conf
->mirrors
[dw
].rdev
) {
1908 /* need bad block on destination too */
1909 struct md_rdev
*rdev2
= conf
->mirrors
[dw
].rdev
;
1910 addr
= r10_bio
->devs
[1].addr
+ sect
;
1911 ok
= rdev_set_badblocks(rdev2
, addr
, s
, 0);
1913 /* just abort the recovery */
1915 "md/raid10:%s: recovery aborted"
1916 " due to read error\n",
1919 conf
->mirrors
[dw
].recovery_disabled
1920 = mddev
->recovery_disabled
;
1921 set_bit(MD_RECOVERY_INTR
,
1934 static void recovery_request_write(struct mddev
*mddev
, struct r10bio
*r10_bio
)
1936 struct r10conf
*conf
= mddev
->private;
1938 struct bio
*wbio
, *wbio2
;
1940 if (!test_bit(R10BIO_Uptodate
, &r10_bio
->state
)) {
1941 fix_recovery_read_error(r10_bio
);
1942 end_sync_request(r10_bio
);
1947 * share the pages with the first bio
1948 * and submit the write request
1950 d
= r10_bio
->devs
[1].devnum
;
1951 wbio
= r10_bio
->devs
[1].bio
;
1952 wbio2
= r10_bio
->devs
[1].repl_bio
;
1953 if (wbio
->bi_end_io
) {
1954 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
1955 md_sync_acct(conf
->mirrors
[d
].rdev
->bdev
, wbio
->bi_size
>> 9);
1956 generic_make_request(wbio
);
1958 if (wbio2
&& wbio2
->bi_end_io
) {
1959 atomic_inc(&conf
->mirrors
[d
].replacement
->nr_pending
);
1960 md_sync_acct(conf
->mirrors
[d
].replacement
->bdev
,
1961 wbio2
->bi_size
>> 9);
1962 generic_make_request(wbio2
);
1968 * Used by fix_read_error() to decay the per rdev read_errors.
1969 * We halve the read error count for every hour that has elapsed
1970 * since the last recorded read error.
1973 static void check_decay_read_errors(struct mddev
*mddev
, struct md_rdev
*rdev
)
1975 struct timespec cur_time_mon
;
1976 unsigned long hours_since_last
;
1977 unsigned int read_errors
= atomic_read(&rdev
->read_errors
);
1979 ktime_get_ts(&cur_time_mon
);
1981 if (rdev
->last_read_error
.tv_sec
== 0 &&
1982 rdev
->last_read_error
.tv_nsec
== 0) {
1983 /* first time we've seen a read error */
1984 rdev
->last_read_error
= cur_time_mon
;
1988 hours_since_last
= (cur_time_mon
.tv_sec
-
1989 rdev
->last_read_error
.tv_sec
) / 3600;
1991 rdev
->last_read_error
= cur_time_mon
;
1994 * if hours_since_last is > the number of bits in read_errors
1995 * just set read errors to 0. We do this to avoid
1996 * overflowing the shift of read_errors by hours_since_last.
1998 if (hours_since_last
>= 8 * sizeof(read_errors
))
1999 atomic_set(&rdev
->read_errors
, 0);
2001 atomic_set(&rdev
->read_errors
, read_errors
>> hours_since_last
);
2004 static int r10_sync_page_io(struct md_rdev
*rdev
, sector_t sector
,
2005 int sectors
, struct page
*page
, int rw
)
2010 if (is_badblock(rdev
, sector
, sectors
, &first_bad
, &bad_sectors
)
2011 && (rw
== READ
|| test_bit(WriteErrorSeen
, &rdev
->flags
)))
2013 if (sync_page_io(rdev
, sector
, sectors
<< 9, page
, rw
, false))
2017 set_bit(WriteErrorSeen
, &rdev
->flags
);
2018 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
2019 set_bit(MD_RECOVERY_NEEDED
,
2020 &rdev
->mddev
->recovery
);
2022 /* need to record an error - either for the block or the device */
2023 if (!rdev_set_badblocks(rdev
, sector
, sectors
, 0))
2024 md_error(rdev
->mddev
, rdev
);
2029 * This is a kernel thread which:
2031 * 1. Retries failed read operations on working mirrors.
2032 * 2. Updates the raid superblock when problems encounter.
2033 * 3. Performs writes following reads for array synchronising.
2036 static void fix_read_error(struct r10conf
*conf
, struct mddev
*mddev
, struct r10bio
*r10_bio
)
2038 int sect
= 0; /* Offset from r10_bio->sector */
2039 int sectors
= r10_bio
->sectors
;
2040 struct md_rdev
*rdev
;
2041 int max_read_errors
= atomic_read(&mddev
->max_corr_read_errors
);
2042 int d
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
2044 /* still own a reference to this rdev, so it cannot
2045 * have been cleared recently.
2047 rdev
= conf
->mirrors
[d
].rdev
;
2049 if (test_bit(Faulty
, &rdev
->flags
))
2050 /* drive has already been failed, just ignore any
2051 more fix_read_error() attempts */
2054 check_decay_read_errors(mddev
, rdev
);
2055 atomic_inc(&rdev
->read_errors
);
2056 if (atomic_read(&rdev
->read_errors
) > max_read_errors
) {
2057 char b
[BDEVNAME_SIZE
];
2058 bdevname(rdev
->bdev
, b
);
2061 "md/raid10:%s: %s: Raid device exceeded "
2062 "read_error threshold [cur %d:max %d]\n",
2064 atomic_read(&rdev
->read_errors
), max_read_errors
);
2066 "md/raid10:%s: %s: Failing raid device\n",
2068 md_error(mddev
, conf
->mirrors
[d
].rdev
);
2069 r10_bio
->devs
[r10_bio
->read_slot
].bio
= IO_BLOCKED
;
2075 int sl
= r10_bio
->read_slot
;
2079 if (s
> (PAGE_SIZE
>>9))
2087 d
= r10_bio
->devs
[sl
].devnum
;
2088 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2090 test_bit(In_sync
, &rdev
->flags
) &&
2091 is_badblock(rdev
, r10_bio
->devs
[sl
].addr
+ sect
, s
,
2092 &first_bad
, &bad_sectors
) == 0) {
2093 atomic_inc(&rdev
->nr_pending
);
2095 success
= sync_page_io(rdev
,
2096 r10_bio
->devs
[sl
].addr
+
2099 conf
->tmppage
, READ
, false);
2100 rdev_dec_pending(rdev
, mddev
);
2106 if (sl
== conf
->copies
)
2108 } while (!success
&& sl
!= r10_bio
->read_slot
);
2112 /* Cannot read from anywhere, just mark the block
2113 * as bad on the first device to discourage future
2116 int dn
= r10_bio
->devs
[r10_bio
->read_slot
].devnum
;
2117 rdev
= conf
->mirrors
[dn
].rdev
;
2119 if (!rdev_set_badblocks(
2121 r10_bio
->devs
[r10_bio
->read_slot
].addr
2124 md_error(mddev
, rdev
);
2125 r10_bio
->devs
[r10_bio
->read_slot
].bio
2132 /* write it back and re-read */
2134 while (sl
!= r10_bio
->read_slot
) {
2135 char b
[BDEVNAME_SIZE
];
2140 d
= r10_bio
->devs
[sl
].devnum
;
2141 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2143 !test_bit(In_sync
, &rdev
->flags
))
2146 atomic_inc(&rdev
->nr_pending
);
2148 if (r10_sync_page_io(rdev
,
2149 r10_bio
->devs
[sl
].addr
+
2151 s
<<9, conf
->tmppage
, WRITE
)
2153 /* Well, this device is dead */
2155 "md/raid10:%s: read correction "
2157 " (%d sectors at %llu on %s)\n",
2159 (unsigned long long)(
2160 sect
+ rdev
->data_offset
),
2161 bdevname(rdev
->bdev
, b
));
2162 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
2165 bdevname(rdev
->bdev
, b
));
2167 rdev_dec_pending(rdev
, mddev
);
2171 while (sl
!= r10_bio
->read_slot
) {
2172 char b
[BDEVNAME_SIZE
];
2177 d
= r10_bio
->devs
[sl
].devnum
;
2178 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2180 !test_bit(In_sync
, &rdev
->flags
))
2183 atomic_inc(&rdev
->nr_pending
);
2185 switch (r10_sync_page_io(rdev
,
2186 r10_bio
->devs
[sl
].addr
+
2188 s
<<9, conf
->tmppage
,
2191 /* Well, this device is dead */
2193 "md/raid10:%s: unable to read back "
2195 " (%d sectors at %llu on %s)\n",
2197 (unsigned long long)(
2198 sect
+ rdev
->data_offset
),
2199 bdevname(rdev
->bdev
, b
));
2200 printk(KERN_NOTICE
"md/raid10:%s: %s: failing "
2203 bdevname(rdev
->bdev
, b
));
2207 "md/raid10:%s: read error corrected"
2208 " (%d sectors at %llu on %s)\n",
2210 (unsigned long long)(
2211 sect
+ rdev
->data_offset
),
2212 bdevname(rdev
->bdev
, b
));
2213 atomic_add(s
, &rdev
->corrected_errors
);
2216 rdev_dec_pending(rdev
, mddev
);
2226 static void bi_complete(struct bio
*bio
, int error
)
2228 complete((struct completion
*)bio
->bi_private
);
2231 static int submit_bio_wait(int rw
, struct bio
*bio
)
2233 struct completion event
;
2236 init_completion(&event
);
2237 bio
->bi_private
= &event
;
2238 bio
->bi_end_io
= bi_complete
;
2239 submit_bio(rw
, bio
);
2240 wait_for_completion(&event
);
2242 return test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2245 static int narrow_write_error(struct r10bio
*r10_bio
, int i
)
2247 struct bio
*bio
= r10_bio
->master_bio
;
2248 struct mddev
*mddev
= r10_bio
->mddev
;
2249 struct r10conf
*conf
= mddev
->private;
2250 struct md_rdev
*rdev
= conf
->mirrors
[r10_bio
->devs
[i
].devnum
].rdev
;
2251 /* bio has the data to be written to slot 'i' where
2252 * we just recently had a write error.
2253 * We repeatedly clone the bio and trim down to one block,
2254 * then try the write. Where the write fails we record
2256 * It is conceivable that the bio doesn't exactly align with
2257 * blocks. We must handle this.
2259 * We currently own a reference to the rdev.
2265 int sect_to_write
= r10_bio
->sectors
;
2268 if (rdev
->badblocks
.shift
< 0)
2271 block_sectors
= 1 << rdev
->badblocks
.shift
;
2272 sector
= r10_bio
->sector
;
2273 sectors
= ((r10_bio
->sector
+ block_sectors
)
2274 & ~(sector_t
)(block_sectors
- 1))
2277 while (sect_to_write
) {
2279 if (sectors
> sect_to_write
)
2280 sectors
= sect_to_write
;
2281 /* Write at 'sector' for 'sectors' */
2282 wbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
2283 md_trim_bio(wbio
, sector
- bio
->bi_sector
, sectors
);
2284 wbio
->bi_sector
= (r10_bio
->devs
[i
].addr
+
2286 (sector
- r10_bio
->sector
));
2287 wbio
->bi_bdev
= rdev
->bdev
;
2288 if (submit_bio_wait(WRITE
, wbio
) == 0)
2290 ok
= rdev_set_badblocks(rdev
, sector
,
2295 sect_to_write
-= sectors
;
2297 sectors
= block_sectors
;
2302 static void handle_read_error(struct mddev
*mddev
, struct r10bio
*r10_bio
)
2304 int slot
= r10_bio
->read_slot
;
2306 struct r10conf
*conf
= mddev
->private;
2307 struct md_rdev
*rdev
= r10_bio
->devs
[slot
].rdev
;
2308 char b
[BDEVNAME_SIZE
];
2309 unsigned long do_sync
;
2312 /* we got a read error. Maybe the drive is bad. Maybe just
2313 * the block and we can fix it.
2314 * We freeze all other IO, and try reading the block from
2315 * other devices. When we find one, we re-write
2316 * and check it that fixes the read error.
2317 * This is all done synchronously while the array is
2320 bio
= r10_bio
->devs
[slot
].bio
;
2321 bdevname(bio
->bi_bdev
, b
);
2323 r10_bio
->devs
[slot
].bio
= NULL
;
2325 if (mddev
->ro
== 0) {
2327 fix_read_error(conf
, mddev
, r10_bio
);
2328 unfreeze_array(conf
);
2330 r10_bio
->devs
[slot
].bio
= IO_BLOCKED
;
2332 rdev_dec_pending(rdev
, mddev
);
2335 rdev
= read_balance(conf
, r10_bio
, &max_sectors
);
2337 printk(KERN_ALERT
"md/raid10:%s: %s: unrecoverable I/O"
2338 " read error for block %llu\n",
2340 (unsigned long long)r10_bio
->sector
);
2341 raid_end_bio_io(r10_bio
);
2345 do_sync
= (r10_bio
->master_bio
->bi_rw
& REQ_SYNC
);
2346 slot
= r10_bio
->read_slot
;
2349 "md/raid10:%s: %s: redirecting"
2350 "sector %llu to another mirror\n",
2352 bdevname(rdev
->bdev
, b
),
2353 (unsigned long long)r10_bio
->sector
);
2354 bio
= bio_clone_mddev(r10_bio
->master_bio
,
2357 r10_bio
->sector
- bio
->bi_sector
,
2359 r10_bio
->devs
[slot
].bio
= bio
;
2360 r10_bio
->devs
[slot
].rdev
= rdev
;
2361 bio
->bi_sector
= r10_bio
->devs
[slot
].addr
2362 + rdev
->data_offset
;
2363 bio
->bi_bdev
= rdev
->bdev
;
2364 bio
->bi_rw
= READ
| do_sync
;
2365 bio
->bi_private
= r10_bio
;
2366 bio
->bi_end_io
= raid10_end_read_request
;
2367 if (max_sectors
< r10_bio
->sectors
) {
2368 /* Drat - have to split this up more */
2369 struct bio
*mbio
= r10_bio
->master_bio
;
2370 int sectors_handled
=
2371 r10_bio
->sector
+ max_sectors
2373 r10_bio
->sectors
= max_sectors
;
2374 spin_lock_irq(&conf
->device_lock
);
2375 if (mbio
->bi_phys_segments
== 0)
2376 mbio
->bi_phys_segments
= 2;
2378 mbio
->bi_phys_segments
++;
2379 spin_unlock_irq(&conf
->device_lock
);
2380 generic_make_request(bio
);
2382 r10_bio
= mempool_alloc(conf
->r10bio_pool
,
2384 r10_bio
->master_bio
= mbio
;
2385 r10_bio
->sectors
= (mbio
->bi_size
>> 9)
2388 set_bit(R10BIO_ReadError
,
2390 r10_bio
->mddev
= mddev
;
2391 r10_bio
->sector
= mbio
->bi_sector
2396 generic_make_request(bio
);
2399 static void handle_write_completed(struct r10conf
*conf
, struct r10bio
*r10_bio
)
2401 /* Some sort of write request has finished and it
2402 * succeeded in writing where we thought there was a
2403 * bad block. So forget the bad block.
2404 * Or possibly if failed and we need to record
2408 struct md_rdev
*rdev
;
2410 if (test_bit(R10BIO_IsSync
, &r10_bio
->state
) ||
2411 test_bit(R10BIO_IsRecover
, &r10_bio
->state
)) {
2412 for (m
= 0; m
< conf
->copies
; m
++) {
2413 int dev
= r10_bio
->devs
[m
].devnum
;
2414 rdev
= conf
->mirrors
[dev
].rdev
;
2415 if (r10_bio
->devs
[m
].bio
== NULL
)
2417 if (test_bit(BIO_UPTODATE
,
2418 &r10_bio
->devs
[m
].bio
->bi_flags
)) {
2419 rdev_clear_badblocks(
2421 r10_bio
->devs
[m
].addr
,
2424 if (!rdev_set_badblocks(
2426 r10_bio
->devs
[m
].addr
,
2427 r10_bio
->sectors
, 0))
2428 md_error(conf
->mddev
, rdev
);
2430 rdev
= conf
->mirrors
[dev
].replacement
;
2431 if (r10_bio
->devs
[m
].repl_bio
== NULL
)
2433 if (test_bit(BIO_UPTODATE
,
2434 &r10_bio
->devs
[m
].repl_bio
->bi_flags
)) {
2435 rdev_clear_badblocks(
2437 r10_bio
->devs
[m
].addr
,
2440 if (!rdev_set_badblocks(
2442 r10_bio
->devs
[m
].addr
,
2443 r10_bio
->sectors
, 0))
2444 md_error(conf
->mddev
, rdev
);
2449 for (m
= 0; m
< conf
->copies
; m
++) {
2450 int dev
= r10_bio
->devs
[m
].devnum
;
2451 struct bio
*bio
= r10_bio
->devs
[m
].bio
;
2452 rdev
= conf
->mirrors
[dev
].rdev
;
2453 if (bio
== IO_MADE_GOOD
) {
2454 rdev_clear_badblocks(
2456 r10_bio
->devs
[m
].addr
,
2458 rdev_dec_pending(rdev
, conf
->mddev
);
2459 } else if (bio
!= NULL
&&
2460 !test_bit(BIO_UPTODATE
, &bio
->bi_flags
)) {
2461 if (!narrow_write_error(r10_bio
, m
)) {
2462 md_error(conf
->mddev
, rdev
);
2463 set_bit(R10BIO_Degraded
,
2466 rdev_dec_pending(rdev
, conf
->mddev
);
2468 bio
= r10_bio
->devs
[m
].repl_bio
;
2469 rdev
= conf
->mirrors
[dev
].replacement
;
2470 if (rdev
&& bio
== IO_MADE_GOOD
) {
2471 rdev_clear_badblocks(
2473 r10_bio
->devs
[m
].addr
,
2475 rdev_dec_pending(rdev
, conf
->mddev
);
2478 if (test_bit(R10BIO_WriteError
,
2480 close_write(r10_bio
);
2481 raid_end_bio_io(r10_bio
);
2485 static void raid10d(struct mddev
*mddev
)
2487 struct r10bio
*r10_bio
;
2488 unsigned long flags
;
2489 struct r10conf
*conf
= mddev
->private;
2490 struct list_head
*head
= &conf
->retry_list
;
2491 struct blk_plug plug
;
2493 md_check_recovery(mddev
);
2495 blk_start_plug(&plug
);
2498 flush_pending_writes(conf
);
2500 spin_lock_irqsave(&conf
->device_lock
, flags
);
2501 if (list_empty(head
)) {
2502 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2505 r10_bio
= list_entry(head
->prev
, struct r10bio
, retry_list
);
2506 list_del(head
->prev
);
2508 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2510 mddev
= r10_bio
->mddev
;
2511 conf
= mddev
->private;
2512 if (test_bit(R10BIO_MadeGood
, &r10_bio
->state
) ||
2513 test_bit(R10BIO_WriteError
, &r10_bio
->state
))
2514 handle_write_completed(conf
, r10_bio
);
2515 else if (test_bit(R10BIO_IsSync
, &r10_bio
->state
))
2516 sync_request_write(mddev
, r10_bio
);
2517 else if (test_bit(R10BIO_IsRecover
, &r10_bio
->state
))
2518 recovery_request_write(mddev
, r10_bio
);
2519 else if (test_bit(R10BIO_ReadError
, &r10_bio
->state
))
2520 handle_read_error(mddev
, r10_bio
);
2522 /* just a partial read to be scheduled from a
2525 int slot
= r10_bio
->read_slot
;
2526 generic_make_request(r10_bio
->devs
[slot
].bio
);
2530 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
2531 md_check_recovery(mddev
);
2533 blk_finish_plug(&plug
);
2537 static int init_resync(struct r10conf
*conf
)
2542 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
2543 BUG_ON(conf
->r10buf_pool
);
2544 conf
->have_replacement
= 0;
2545 for (i
= 0; i
< conf
->raid_disks
; i
++)
2546 if (conf
->mirrors
[i
].replacement
)
2547 conf
->have_replacement
= 1;
2548 conf
->r10buf_pool
= mempool_create(buffs
, r10buf_pool_alloc
, r10buf_pool_free
, conf
);
2549 if (!conf
->r10buf_pool
)
2551 conf
->next_resync
= 0;
2556 * perform a "sync" on one "block"
2558 * We need to make sure that no normal I/O request - particularly write
2559 * requests - conflict with active sync requests.
2561 * This is achieved by tracking pending requests and a 'barrier' concept
2562 * that can be installed to exclude normal IO requests.
2564 * Resync and recovery are handled very differently.
2565 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2567 * For resync, we iterate over virtual addresses, read all copies,
2568 * and update if there are differences. If only one copy is live,
2570 * For recovery, we iterate over physical addresses, read a good
2571 * value for each non-in_sync drive, and over-write.
2573 * So, for recovery we may have several outstanding complex requests for a
2574 * given address, one for each out-of-sync device. We model this by allocating
2575 * a number of r10_bio structures, one for each out-of-sync device.
2576 * As we setup these structures, we collect all bio's together into a list
2577 * which we then process collectively to add pages, and then process again
2578 * to pass to generic_make_request.
2580 * The r10_bio structures are linked using a borrowed master_bio pointer.
2581 * This link is counted in ->remaining. When the r10_bio that points to NULL
2582 * has its remaining count decremented to 0, the whole complex operation
2587 static sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
,
2588 int *skipped
, int go_faster
)
2590 struct r10conf
*conf
= mddev
->private;
2591 struct r10bio
*r10_bio
;
2592 struct bio
*biolist
= NULL
, *bio
;
2593 sector_t max_sector
, nr_sectors
;
2596 sector_t sync_blocks
;
2597 sector_t sectors_skipped
= 0;
2598 int chunks_skipped
= 0;
2600 if (!conf
->r10buf_pool
)
2601 if (init_resync(conf
))
2605 max_sector
= mddev
->dev_sectors
;
2606 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2607 max_sector
= mddev
->resync_max_sectors
;
2608 if (sector_nr
>= max_sector
) {
2609 /* If we aborted, we need to abort the
2610 * sync on the 'current' bitmap chucks (there can
2611 * be several when recovering multiple devices).
2612 * as we may have started syncing it but not finished.
2613 * We can find the current address in
2614 * mddev->curr_resync, but for recovery,
2615 * we need to convert that to several
2616 * virtual addresses.
2618 if (mddev
->curr_resync
< max_sector
) { /* aborted */
2619 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))
2620 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
2622 else for (i
=0; i
<conf
->raid_disks
; i
++) {
2624 raid10_find_virt(conf
, mddev
->curr_resync
, i
);
2625 bitmap_end_sync(mddev
->bitmap
, sect
,
2629 /* completed sync */
2630 if ((!mddev
->bitmap
|| conf
->fullsync
)
2631 && conf
->have_replacement
2632 && test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
2633 /* Completed a full sync so the replacements
2634 * are now fully recovered.
2636 for (i
= 0; i
< conf
->raid_disks
; i
++)
2637 if (conf
->mirrors
[i
].replacement
)
2638 conf
->mirrors
[i
].replacement
2644 bitmap_close_sync(mddev
->bitmap
);
2647 return sectors_skipped
;
2649 if (chunks_skipped
>= conf
->raid_disks
) {
2650 /* if there has been nothing to do on any drive,
2651 * then there is nothing to do at all..
2654 return (max_sector
- sector_nr
) + sectors_skipped
;
2657 if (max_sector
> mddev
->resync_max
)
2658 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
2660 /* make sure whole request will fit in a chunk - if chunks
2663 if (conf
->near_copies
< conf
->raid_disks
&&
2664 max_sector
> (sector_nr
| conf
->chunk_mask
))
2665 max_sector
= (sector_nr
| conf
->chunk_mask
) + 1;
2667 * If there is non-resync activity waiting for us then
2668 * put in a delay to throttle resync.
2670 if (!go_faster
&& conf
->nr_waiting
)
2671 msleep_interruptible(1000);
2673 /* Again, very different code for resync and recovery.
2674 * Both must result in an r10bio with a list of bios that
2675 * have bi_end_io, bi_sector, bi_bdev set,
2676 * and bi_private set to the r10bio.
2677 * For recovery, we may actually create several r10bios
2678 * with 2 bios in each, that correspond to the bios in the main one.
2679 * In this case, the subordinate r10bios link back through a
2680 * borrowed master_bio pointer, and the counter in the master
2681 * includes a ref from each subordinate.
2683 /* First, we decide what to do and set ->bi_end_io
2684 * To end_sync_read if we want to read, and
2685 * end_sync_write if we will want to write.
2688 max_sync
= RESYNC_PAGES
<< (PAGE_SHIFT
-9);
2689 if (!test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
)) {
2690 /* recovery... the complicated one */
2694 for (i
=0 ; i
<conf
->raid_disks
; i
++) {
2700 struct mirror_info
*mirror
= &conf
->mirrors
[i
];
2702 if ((mirror
->rdev
== NULL
||
2703 test_bit(In_sync
, &mirror
->rdev
->flags
))
2705 (mirror
->replacement
== NULL
||
2707 &mirror
->replacement
->flags
)))
2711 /* want to reconstruct this device */
2713 sect
= raid10_find_virt(conf
, sector_nr
, i
);
2714 /* Unless we are doing a full sync, or a replacement
2715 * we only need to recover the block if it is set in
2718 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2720 if (sync_blocks
< max_sync
)
2721 max_sync
= sync_blocks
;
2723 mirror
->replacement
== NULL
&&
2725 /* yep, skip the sync_blocks here, but don't assume
2726 * that there will never be anything to do here
2728 chunks_skipped
= -1;
2732 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2733 raise_barrier(conf
, rb2
!= NULL
);
2734 atomic_set(&r10_bio
->remaining
, 0);
2736 r10_bio
->master_bio
= (struct bio
*)rb2
;
2738 atomic_inc(&rb2
->remaining
);
2739 r10_bio
->mddev
= mddev
;
2740 set_bit(R10BIO_IsRecover
, &r10_bio
->state
);
2741 r10_bio
->sector
= sect
;
2743 raid10_find_phys(conf
, r10_bio
);
2745 /* Need to check if the array will still be
2748 for (j
=0; j
<conf
->raid_disks
; j
++)
2749 if (conf
->mirrors
[j
].rdev
== NULL
||
2750 test_bit(Faulty
, &conf
->mirrors
[j
].rdev
->flags
)) {
2755 must_sync
= bitmap_start_sync(mddev
->bitmap
, sect
,
2756 &sync_blocks
, still_degraded
);
2759 for (j
=0; j
<conf
->copies
;j
++) {
2761 int d
= r10_bio
->devs
[j
].devnum
;
2762 sector_t from_addr
, to_addr
;
2763 struct md_rdev
*rdev
;
2764 sector_t sector
, first_bad
;
2766 if (!conf
->mirrors
[d
].rdev
||
2767 !test_bit(In_sync
, &conf
->mirrors
[d
].rdev
->flags
))
2769 /* This is where we read from */
2771 rdev
= conf
->mirrors
[d
].rdev
;
2772 sector
= r10_bio
->devs
[j
].addr
;
2774 if (is_badblock(rdev
, sector
, max_sync
,
2775 &first_bad
, &bad_sectors
)) {
2776 if (first_bad
> sector
)
2777 max_sync
= first_bad
- sector
;
2779 bad_sectors
-= (sector
2781 if (max_sync
> bad_sectors
)
2782 max_sync
= bad_sectors
;
2786 bio
= r10_bio
->devs
[0].bio
;
2787 bio
->bi_next
= biolist
;
2789 bio
->bi_private
= r10_bio
;
2790 bio
->bi_end_io
= end_sync_read
;
2792 from_addr
= r10_bio
->devs
[j
].addr
;
2793 bio
->bi_sector
= from_addr
+ rdev
->data_offset
;
2794 bio
->bi_bdev
= rdev
->bdev
;
2795 atomic_inc(&rdev
->nr_pending
);
2796 /* and we write to 'i' (if not in_sync) */
2798 for (k
=0; k
<conf
->copies
; k
++)
2799 if (r10_bio
->devs
[k
].devnum
== i
)
2801 BUG_ON(k
== conf
->copies
);
2802 to_addr
= r10_bio
->devs
[k
].addr
;
2803 r10_bio
->devs
[0].devnum
= d
;
2804 r10_bio
->devs
[0].addr
= from_addr
;
2805 r10_bio
->devs
[1].devnum
= i
;
2806 r10_bio
->devs
[1].addr
= to_addr
;
2808 rdev
= mirror
->rdev
;
2809 if (!test_bit(In_sync
, &rdev
->flags
)) {
2810 bio
= r10_bio
->devs
[1].bio
;
2811 bio
->bi_next
= biolist
;
2813 bio
->bi_private
= r10_bio
;
2814 bio
->bi_end_io
= end_sync_write
;
2816 bio
->bi_sector
= to_addr
2817 + rdev
->data_offset
;
2818 bio
->bi_bdev
= rdev
->bdev
;
2819 atomic_inc(&r10_bio
->remaining
);
2821 r10_bio
->devs
[1].bio
->bi_end_io
= NULL
;
2823 /* and maybe write to replacement */
2824 bio
= r10_bio
->devs
[1].repl_bio
;
2826 bio
->bi_end_io
= NULL
;
2827 rdev
= mirror
->replacement
;
2828 /* Note: if rdev != NULL, then bio
2829 * cannot be NULL as r10buf_pool_alloc will
2830 * have allocated it.
2831 * So the second test here is pointless.
2832 * But it keeps semantic-checkers happy, and
2833 * this comment keeps human reviewers
2836 if (rdev
== NULL
|| bio
== NULL
||
2837 test_bit(Faulty
, &rdev
->flags
))
2839 bio
->bi_next
= biolist
;
2841 bio
->bi_private
= r10_bio
;
2842 bio
->bi_end_io
= end_sync_write
;
2844 bio
->bi_sector
= to_addr
+ rdev
->data_offset
;
2845 bio
->bi_bdev
= rdev
->bdev
;
2846 atomic_inc(&r10_bio
->remaining
);
2849 if (j
== conf
->copies
) {
2850 /* Cannot recover, so abort the recovery or
2851 * record a bad block */
2854 atomic_dec(&rb2
->remaining
);
2857 /* problem is that there are bad blocks
2858 * on other device(s)
2861 for (k
= 0; k
< conf
->copies
; k
++)
2862 if (r10_bio
->devs
[k
].devnum
== i
)
2864 if (!test_bit(In_sync
,
2865 &mirror
->rdev
->flags
)
2866 && !rdev_set_badblocks(
2868 r10_bio
->devs
[k
].addr
,
2871 if (mirror
->replacement
&&
2872 !rdev_set_badblocks(
2873 mirror
->replacement
,
2874 r10_bio
->devs
[k
].addr
,
2879 if (!test_and_set_bit(MD_RECOVERY_INTR
,
2881 printk(KERN_INFO
"md/raid10:%s: insufficient "
2882 "working devices for recovery.\n",
2884 mirror
->recovery_disabled
2885 = mddev
->recovery_disabled
;
2890 if (biolist
== NULL
) {
2892 struct r10bio
*rb2
= r10_bio
;
2893 r10_bio
= (struct r10bio
*) rb2
->master_bio
;
2894 rb2
->master_bio
= NULL
;
2900 /* resync. Schedule a read for every block at this virt offset */
2903 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
2905 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
2906 &sync_blocks
, mddev
->degraded
) &&
2907 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
,
2908 &mddev
->recovery
)) {
2909 /* We can skip this block */
2911 return sync_blocks
+ sectors_skipped
;
2913 if (sync_blocks
< max_sync
)
2914 max_sync
= sync_blocks
;
2915 r10_bio
= mempool_alloc(conf
->r10buf_pool
, GFP_NOIO
);
2917 r10_bio
->mddev
= mddev
;
2918 atomic_set(&r10_bio
->remaining
, 0);
2919 raise_barrier(conf
, 0);
2920 conf
->next_resync
= sector_nr
;
2922 r10_bio
->master_bio
= NULL
;
2923 r10_bio
->sector
= sector_nr
;
2924 set_bit(R10BIO_IsSync
, &r10_bio
->state
);
2925 raid10_find_phys(conf
, r10_bio
);
2926 r10_bio
->sectors
= (sector_nr
| conf
->chunk_mask
) - sector_nr
+1;
2928 for (i
=0; i
<conf
->copies
; i
++) {
2929 int d
= r10_bio
->devs
[i
].devnum
;
2930 sector_t first_bad
, sector
;
2933 if (r10_bio
->devs
[i
].repl_bio
)
2934 r10_bio
->devs
[i
].repl_bio
->bi_end_io
= NULL
;
2936 bio
= r10_bio
->devs
[i
].bio
;
2937 bio
->bi_end_io
= NULL
;
2938 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2939 if (conf
->mirrors
[d
].rdev
== NULL
||
2940 test_bit(Faulty
, &conf
->mirrors
[d
].rdev
->flags
))
2942 sector
= r10_bio
->devs
[i
].addr
;
2943 if (is_badblock(conf
->mirrors
[d
].rdev
,
2945 &first_bad
, &bad_sectors
)) {
2946 if (first_bad
> sector
)
2947 max_sync
= first_bad
- sector
;
2949 bad_sectors
-= (sector
- first_bad
);
2950 if (max_sync
> bad_sectors
)
2951 max_sync
= max_sync
;
2955 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2956 atomic_inc(&r10_bio
->remaining
);
2957 bio
->bi_next
= biolist
;
2959 bio
->bi_private
= r10_bio
;
2960 bio
->bi_end_io
= end_sync_read
;
2962 bio
->bi_sector
= sector
+
2963 conf
->mirrors
[d
].rdev
->data_offset
;
2964 bio
->bi_bdev
= conf
->mirrors
[d
].rdev
->bdev
;
2967 if (conf
->mirrors
[d
].replacement
== NULL
||
2969 &conf
->mirrors
[d
].replacement
->flags
))
2972 /* Need to set up for writing to the replacement */
2973 bio
= r10_bio
->devs
[i
].repl_bio
;
2974 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
2976 sector
= r10_bio
->devs
[i
].addr
;
2977 atomic_inc(&conf
->mirrors
[d
].rdev
->nr_pending
);
2978 bio
->bi_next
= biolist
;
2980 bio
->bi_private
= r10_bio
;
2981 bio
->bi_end_io
= end_sync_write
;
2983 bio
->bi_sector
= sector
+
2984 conf
->mirrors
[d
].replacement
->data_offset
;
2985 bio
->bi_bdev
= conf
->mirrors
[d
].replacement
->bdev
;
2990 for (i
=0; i
<conf
->copies
; i
++) {
2991 int d
= r10_bio
->devs
[i
].devnum
;
2992 if (r10_bio
->devs
[i
].bio
->bi_end_io
)
2993 rdev_dec_pending(conf
->mirrors
[d
].rdev
,
2995 if (r10_bio
->devs
[i
].repl_bio
&&
2996 r10_bio
->devs
[i
].repl_bio
->bi_end_io
)
2998 conf
->mirrors
[d
].replacement
,
3007 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
3009 bio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
3011 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
3014 bio
->bi_phys_segments
= 0;
3019 if (sector_nr
+ max_sync
< max_sector
)
3020 max_sector
= sector_nr
+ max_sync
;
3023 int len
= PAGE_SIZE
;
3024 if (sector_nr
+ (len
>>9) > max_sector
)
3025 len
= (max_sector
- sector_nr
) << 9;
3028 for (bio
= biolist
; bio
; bio
=bio
->bi_next
) {
3030 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
3031 if (bio_add_page(bio
, page
, len
, 0))
3035 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
3036 for (bio2
= biolist
;
3037 bio2
&& bio2
!= bio
;
3038 bio2
= bio2
->bi_next
) {
3039 /* remove last page from this bio */
3041 bio2
->bi_size
-= len
;
3042 bio2
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
3046 nr_sectors
+= len
>>9;
3047 sector_nr
+= len
>>9;
3048 } while (biolist
->bi_vcnt
< RESYNC_PAGES
);
3050 r10_bio
->sectors
= nr_sectors
;
3054 biolist
= biolist
->bi_next
;
3056 bio
->bi_next
= NULL
;
3057 r10_bio
= bio
->bi_private
;
3058 r10_bio
->sectors
= nr_sectors
;
3060 if (bio
->bi_end_io
== end_sync_read
) {
3061 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
3062 generic_make_request(bio
);
3066 if (sectors_skipped
)
3067 /* pretend they weren't skipped, it makes
3068 * no important difference in this case
3070 md_done_sync(mddev
, sectors_skipped
, 1);
3072 return sectors_skipped
+ nr_sectors
;
3074 /* There is nowhere to write, so all non-sync
3075 * drives must be failed or in resync, all drives
3076 * have a bad block, so try the next chunk...
3078 if (sector_nr
+ max_sync
< max_sector
)
3079 max_sector
= sector_nr
+ max_sync
;
3081 sectors_skipped
+= (max_sector
- sector_nr
);
3083 sector_nr
= max_sector
;
3088 raid10_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
3091 struct r10conf
*conf
= mddev
->private;
3094 raid_disks
= conf
->raid_disks
;
3096 sectors
= conf
->dev_sectors
;
3098 size
= sectors
>> conf
->chunk_shift
;
3099 sector_div(size
, conf
->far_copies
);
3100 size
= size
* raid_disks
;
3101 sector_div(size
, conf
->near_copies
);
3103 return size
<< conf
->chunk_shift
;
3107 static struct r10conf
*setup_conf(struct mddev
*mddev
)
3109 struct r10conf
*conf
= NULL
;
3111 sector_t stride
, size
;
3114 if (mddev
->new_chunk_sectors
< (PAGE_SIZE
>> 9) ||
3115 !is_power_of_2(mddev
->new_chunk_sectors
)) {
3116 printk(KERN_ERR
"md/raid10:%s: chunk size must be "
3117 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
3118 mdname(mddev
), PAGE_SIZE
);
3122 nc
= mddev
->new_layout
& 255;
3123 fc
= (mddev
->new_layout
>> 8) & 255;
3124 fo
= mddev
->new_layout
& (1<<16);
3126 if ((nc
*fc
) <2 || (nc
*fc
) > mddev
->raid_disks
||
3127 (mddev
->new_layout
>> 17)) {
3128 printk(KERN_ERR
"md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
3129 mdname(mddev
), mddev
->new_layout
);
3134 conf
= kzalloc(sizeof(struct r10conf
), GFP_KERNEL
);
3138 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
3143 conf
->tmppage
= alloc_page(GFP_KERNEL
);
3148 conf
->raid_disks
= mddev
->raid_disks
;
3149 conf
->near_copies
= nc
;
3150 conf
->far_copies
= fc
;
3151 conf
->copies
= nc
*fc
;
3152 conf
->far_offset
= fo
;
3153 conf
->chunk_mask
= mddev
->new_chunk_sectors
- 1;
3154 conf
->chunk_shift
= ffz(~mddev
->new_chunk_sectors
);
3156 conf
->r10bio_pool
= mempool_create(NR_RAID10_BIOS
, r10bio_pool_alloc
,
3157 r10bio_pool_free
, conf
);
3158 if (!conf
->r10bio_pool
)
3161 size
= mddev
->dev_sectors
>> conf
->chunk_shift
;
3162 sector_div(size
, fc
);
3163 size
= size
* conf
->raid_disks
;
3164 sector_div(size
, nc
);
3165 /* 'size' is now the number of chunks in the array */
3166 /* calculate "used chunks per device" in 'stride' */
3167 stride
= size
* conf
->copies
;
3169 /* We need to round up when dividing by raid_disks to
3170 * get the stride size.
3172 stride
+= conf
->raid_disks
- 1;
3173 sector_div(stride
, conf
->raid_disks
);
3175 conf
->dev_sectors
= stride
<< conf
->chunk_shift
;
3180 sector_div(stride
, fc
);
3181 conf
->stride
= stride
<< conf
->chunk_shift
;
3184 spin_lock_init(&conf
->device_lock
);
3185 INIT_LIST_HEAD(&conf
->retry_list
);
3187 spin_lock_init(&conf
->resync_lock
);
3188 init_waitqueue_head(&conf
->wait_barrier
);
3190 conf
->thread
= md_register_thread(raid10d
, mddev
, NULL
);
3194 conf
->mddev
= mddev
;
3198 printk(KERN_ERR
"md/raid10:%s: couldn't allocate memory.\n",
3201 if (conf
->r10bio_pool
)
3202 mempool_destroy(conf
->r10bio_pool
);
3203 kfree(conf
->mirrors
);
3204 safe_put_page(conf
->tmppage
);
3207 return ERR_PTR(err
);
3210 static int run(struct mddev
*mddev
)
3212 struct r10conf
*conf
;
3213 int i
, disk_idx
, chunk_size
;
3214 struct mirror_info
*disk
;
3215 struct md_rdev
*rdev
;
3219 * copy the already verified devices into our private RAID10
3220 * bookkeeping area. [whatever we allocate in run(),
3221 * should be freed in stop()]
3224 if (mddev
->private == NULL
) {
3225 conf
= setup_conf(mddev
);
3227 return PTR_ERR(conf
);
3228 mddev
->private = conf
;
3230 conf
= mddev
->private;
3234 mddev
->thread
= conf
->thread
;
3235 conf
->thread
= NULL
;
3237 chunk_size
= mddev
->chunk_sectors
<< 9;
3238 blk_queue_io_min(mddev
->queue
, chunk_size
);
3239 if (conf
->raid_disks
% conf
->near_copies
)
3240 blk_queue_io_opt(mddev
->queue
, chunk_size
* conf
->raid_disks
);
3242 blk_queue_io_opt(mddev
->queue
, chunk_size
*
3243 (conf
->raid_disks
/ conf
->near_copies
));
3245 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
3247 disk_idx
= rdev
->raid_disk
;
3248 if (disk_idx
>= conf
->raid_disks
3251 disk
= conf
->mirrors
+ disk_idx
;
3253 if (test_bit(Replacement
, &rdev
->flags
)) {
3254 if (disk
->replacement
)
3256 disk
->replacement
= rdev
;
3263 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
3264 rdev
->data_offset
<< 9);
3265 /* as we don't honour merge_bvec_fn, we must never risk
3266 * violating it, so limit max_segments to 1 lying
3267 * within a single page.
3269 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
3270 blk_queue_max_segments(mddev
->queue
, 1);
3271 blk_queue_segment_boundary(mddev
->queue
,
3272 PAGE_CACHE_SIZE
- 1);
3275 disk
->head_position
= 0;
3277 /* need to check that every block has at least one working mirror */
3278 if (!enough(conf
, -1)) {
3279 printk(KERN_ERR
"md/raid10:%s: not enough operational mirrors.\n",
3284 mddev
->degraded
= 0;
3285 for (i
= 0; i
< conf
->raid_disks
; i
++) {
3287 disk
= conf
->mirrors
+ i
;
3289 if (!disk
->rdev
&& disk
->replacement
) {
3290 /* The replacement is all we have - use it */
3291 disk
->rdev
= disk
->replacement
;
3292 disk
->replacement
= NULL
;
3293 clear_bit(Replacement
, &disk
->rdev
->flags
);
3297 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
3298 disk
->head_position
= 0;
3303 disk
->recovery_disabled
= mddev
->recovery_disabled
- 1;
3306 if (mddev
->recovery_cp
!= MaxSector
)
3307 printk(KERN_NOTICE
"md/raid10:%s: not clean"
3308 " -- starting background reconstruction\n",
3311 "md/raid10:%s: active with %d out of %d devices\n",
3312 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
,
3315 * Ok, everything is just fine now
3317 mddev
->dev_sectors
= conf
->dev_sectors
;
3318 size
= raid10_size(mddev
, 0, 0);
3319 md_set_array_sectors(mddev
, size
);
3320 mddev
->resync_max_sectors
= size
;
3322 mddev
->queue
->backing_dev_info
.congested_fn
= raid10_congested
;
3323 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
3325 /* Calculate max read-ahead size.
3326 * We need to readahead at least twice a whole stripe....
3330 int stripe
= conf
->raid_disks
*
3331 ((mddev
->chunk_sectors
<< 9) / PAGE_SIZE
);
3332 stripe
/= conf
->near_copies
;
3333 if (mddev
->queue
->backing_dev_info
.ra_pages
< 2* stripe
)
3334 mddev
->queue
->backing_dev_info
.ra_pages
= 2* stripe
;
3337 if (conf
->near_copies
< conf
->raid_disks
)
3338 blk_queue_merge_bvec(mddev
->queue
, raid10_mergeable_bvec
);
3340 if (md_integrity_register(mddev
))
3346 md_unregister_thread(&mddev
->thread
);
3347 if (conf
->r10bio_pool
)
3348 mempool_destroy(conf
->r10bio_pool
);
3349 safe_put_page(conf
->tmppage
);
3350 kfree(conf
->mirrors
);
3352 mddev
->private = NULL
;
3357 static int stop(struct mddev
*mddev
)
3359 struct r10conf
*conf
= mddev
->private;
3361 raise_barrier(conf
, 0);
3362 lower_barrier(conf
);
3364 md_unregister_thread(&mddev
->thread
);
3365 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
3366 if (conf
->r10bio_pool
)
3367 mempool_destroy(conf
->r10bio_pool
);
3368 kfree(conf
->mirrors
);
3370 mddev
->private = NULL
;
3374 static void raid10_quiesce(struct mddev
*mddev
, int state
)
3376 struct r10conf
*conf
= mddev
->private;
3380 raise_barrier(conf
, 0);
3383 lower_barrier(conf
);
3388 static void *raid10_takeover_raid0(struct mddev
*mddev
)
3390 struct md_rdev
*rdev
;
3391 struct r10conf
*conf
;
3393 if (mddev
->degraded
> 0) {
3394 printk(KERN_ERR
"md/raid10:%s: Error: degraded raid0!\n",
3396 return ERR_PTR(-EINVAL
);
3399 /* Set new parameters */
3400 mddev
->new_level
= 10;
3401 /* new layout: far_copies = 1, near_copies = 2 */
3402 mddev
->new_layout
= (1<<8) + 2;
3403 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
3404 mddev
->delta_disks
= mddev
->raid_disks
;
3405 mddev
->raid_disks
*= 2;
3406 /* make sure it will be not marked as dirty */
3407 mddev
->recovery_cp
= MaxSector
;
3409 conf
= setup_conf(mddev
);
3410 if (!IS_ERR(conf
)) {
3411 list_for_each_entry(rdev
, &mddev
->disks
, same_set
)
3412 if (rdev
->raid_disk
>= 0)
3413 rdev
->new_raid_disk
= rdev
->raid_disk
* 2;
3420 static void *raid10_takeover(struct mddev
*mddev
)
3422 struct r0conf
*raid0_conf
;
3424 /* raid10 can take over:
3425 * raid0 - providing it has only two drives
3427 if (mddev
->level
== 0) {
3428 /* for raid0 takeover only one zone is supported */
3429 raid0_conf
= mddev
->private;
3430 if (raid0_conf
->nr_strip_zones
> 1) {
3431 printk(KERN_ERR
"md/raid10:%s: cannot takeover raid 0"
3432 " with more than one zone.\n",
3434 return ERR_PTR(-EINVAL
);
3436 return raid10_takeover_raid0(mddev
);
3438 return ERR_PTR(-EINVAL
);
3441 static struct md_personality raid10_personality
=
3445 .owner
= THIS_MODULE
,
3446 .make_request
= make_request
,
3450 .error_handler
= error
,
3451 .hot_add_disk
= raid10_add_disk
,
3452 .hot_remove_disk
= raid10_remove_disk
,
3453 .spare_active
= raid10_spare_active
,
3454 .sync_request
= sync_request
,
3455 .quiesce
= raid10_quiesce
,
3456 .size
= raid10_size
,
3457 .takeover
= raid10_takeover
,
3460 static int __init
raid_init(void)
3462 return register_md_personality(&raid10_personality
);
3465 static void raid_exit(void)
3467 unregister_md_personality(&raid10_personality
);
3470 module_init(raid_init
);
3471 module_exit(raid_exit
);
3472 MODULE_LICENSE("GPL");
3473 MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
3474 MODULE_ALIAS("md-personality-9"); /* RAID10 */
3475 MODULE_ALIAS("md-raid10");
3476 MODULE_ALIAS("md-level-10");
3478 module_param(max_queued_requests
, int, S_IRUGO
|S_IWUSR
);