2 * raid1.c : Multiple Devices driver for Linux
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 * RAID-1 management functions.
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34 #include <linux/slab.h>
35 #include <linux/delay.h>
36 #include <linux/blkdev.h>
37 #include <linux/module.h>
38 #include <linux/seq_file.h>
39 #include <linux/ratelimit.h>
45 * Number of guaranteed r1bios in case of extreme VM load:
47 #define NR_RAID1_BIOS 256
49 /* When there are this many requests queue to be written by
50 * the raid1 thread, we become 'congested' to provide back-pressure
53 static int max_queued_requests
= 1024;
55 static void allow_barrier(struct r1conf
*conf
);
56 static void lower_barrier(struct r1conf
*conf
);
58 static void * r1bio_pool_alloc(gfp_t gfp_flags
, void *data
)
60 struct pool_info
*pi
= data
;
61 int size
= offsetof(struct r1bio
, bios
[pi
->raid_disks
]);
63 /* allocate a r1bio with room for raid_disks entries in the bios array */
64 return kzalloc(size
, gfp_flags
);
67 static void r1bio_pool_free(void *r1_bio
, void *data
)
72 #define RESYNC_BLOCK_SIZE (64*1024)
73 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
74 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
75 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
76 #define RESYNC_WINDOW (2048*1024)
78 static void * r1buf_pool_alloc(gfp_t gfp_flags
, void *data
)
80 struct pool_info
*pi
= data
;
86 r1_bio
= r1bio_pool_alloc(gfp_flags
, pi
);
91 * Allocate bios : 1 for reading, n-1 for writing
93 for (j
= pi
->raid_disks
; j
-- ; ) {
94 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
97 r1_bio
->bios
[j
] = bio
;
100 * Allocate RESYNC_PAGES data pages and attach them to
102 * If this is a user-requested check/repair, allocate
103 * RESYNC_PAGES for each bio.
105 if (test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
))
110 bio
= r1_bio
->bios
[j
];
111 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
112 page
= alloc_page(gfp_flags
);
116 bio
->bi_io_vec
[i
].bv_page
= page
;
120 /* If not user-requests, copy the page pointers to all bios */
121 if (!test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
)) {
122 for (i
=0; i
<RESYNC_PAGES
; i
++)
123 for (j
=1; j
<pi
->raid_disks
; j
++)
124 r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
=
125 r1_bio
->bios
[0]->bi_io_vec
[i
].bv_page
;
128 r1_bio
->master_bio
= NULL
;
133 for (j
=0 ; j
< pi
->raid_disks
; j
++)
134 for (i
=0; i
< r1_bio
->bios
[j
]->bi_vcnt
; i
++)
135 put_page(r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
138 while (++j
< pi
->raid_disks
)
139 bio_put(r1_bio
->bios
[j
]);
140 r1bio_pool_free(r1_bio
, data
);
144 static void r1buf_pool_free(void *__r1_bio
, void *data
)
146 struct pool_info
*pi
= data
;
148 struct r1bio
*r1bio
= __r1_bio
;
150 for (i
= 0; i
< RESYNC_PAGES
; i
++)
151 for (j
= pi
->raid_disks
; j
-- ;) {
153 r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
!=
154 r1bio
->bios
[0]->bi_io_vec
[i
].bv_page
)
155 safe_put_page(r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
157 for (i
=0 ; i
< pi
->raid_disks
; i
++)
158 bio_put(r1bio
->bios
[i
]);
160 r1bio_pool_free(r1bio
, data
);
163 static void put_all_bios(struct r1conf
*conf
, struct r1bio
*r1_bio
)
167 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
168 struct bio
**bio
= r1_bio
->bios
+ i
;
169 if (!BIO_SPECIAL(*bio
))
175 static void free_r1bio(struct r1bio
*r1_bio
)
177 struct r1conf
*conf
= r1_bio
->mddev
->private;
179 put_all_bios(conf
, r1_bio
);
180 mempool_free(r1_bio
, conf
->r1bio_pool
);
183 static void put_buf(struct r1bio
*r1_bio
)
185 struct r1conf
*conf
= r1_bio
->mddev
->private;
188 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
189 struct bio
*bio
= r1_bio
->bios
[i
];
191 rdev_dec_pending(conf
->mirrors
[i
].rdev
, r1_bio
->mddev
);
194 mempool_free(r1_bio
, conf
->r1buf_pool
);
199 static void reschedule_retry(struct r1bio
*r1_bio
)
202 struct mddev
*mddev
= r1_bio
->mddev
;
203 struct r1conf
*conf
= mddev
->private;
205 spin_lock_irqsave(&conf
->device_lock
, flags
);
206 list_add(&r1_bio
->retry_list
, &conf
->retry_list
);
208 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
210 wake_up(&conf
->wait_barrier
);
211 md_wakeup_thread(mddev
->thread
);
215 * raid_end_bio_io() is called when we have finished servicing a mirrored
216 * operation and are ready to return a success/failure code to the buffer
219 static void call_bio_endio(struct r1bio
*r1_bio
)
221 struct bio
*bio
= r1_bio
->master_bio
;
223 struct r1conf
*conf
= r1_bio
->mddev
->private;
225 if (bio
->bi_phys_segments
) {
227 spin_lock_irqsave(&conf
->device_lock
, flags
);
228 bio
->bi_phys_segments
--;
229 done
= (bio
->bi_phys_segments
== 0);
230 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
234 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
))
235 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
239 * Wake up any possible resync thread that waits for the device
246 static void raid_end_bio_io(struct r1bio
*r1_bio
)
248 struct bio
*bio
= r1_bio
->master_bio
;
250 /* if nobody has done the final endio yet, do it now */
251 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
252 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
253 (bio_data_dir(bio
) == WRITE
) ? "write" : "read",
254 (unsigned long long) bio
->bi_sector
,
255 (unsigned long long) bio
->bi_sector
+
256 (bio
->bi_size
>> 9) - 1);
258 call_bio_endio(r1_bio
);
264 * Update disk head position estimator based on IRQ completion info.
266 static inline void update_head_pos(int disk
, struct r1bio
*r1_bio
)
268 struct r1conf
*conf
= r1_bio
->mddev
->private;
270 conf
->mirrors
[disk
].head_position
=
271 r1_bio
->sector
+ (r1_bio
->sectors
);
275 * Find the disk number which triggered given bio
277 static int find_bio_disk(struct r1bio
*r1_bio
, struct bio
*bio
)
280 struct r1conf
*conf
= r1_bio
->mddev
->private;
281 int raid_disks
= conf
->raid_disks
;
283 for (mirror
= 0; mirror
< raid_disks
* 2; mirror
++)
284 if (r1_bio
->bios
[mirror
] == bio
)
287 BUG_ON(mirror
== raid_disks
* 2);
288 update_head_pos(mirror
, r1_bio
);
293 static void raid1_end_read_request(struct bio
*bio
, int error
)
295 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
296 struct r1bio
*r1_bio
= bio
->bi_private
;
298 struct r1conf
*conf
= r1_bio
->mddev
->private;
300 mirror
= r1_bio
->read_disk
;
302 * this branch is our 'one mirror IO has finished' event handler:
304 update_head_pos(mirror
, r1_bio
);
307 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
309 /* If all other devices have failed, we want to return
310 * the error upwards rather than fail the last device.
311 * Here we redefine "uptodate" to mean "Don't want to retry"
314 spin_lock_irqsave(&conf
->device_lock
, flags
);
315 if (r1_bio
->mddev
->degraded
== conf
->raid_disks
||
316 (r1_bio
->mddev
->degraded
== conf
->raid_disks
-1 &&
317 !test_bit(Faulty
, &conf
->mirrors
[mirror
].rdev
->flags
)))
319 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
323 raid_end_bio_io(r1_bio
);
328 char b
[BDEVNAME_SIZE
];
330 KERN_ERR
"md/raid1:%s: %s: "
331 "rescheduling sector %llu\n",
333 bdevname(conf
->mirrors
[mirror
].rdev
->bdev
,
335 (unsigned long long)r1_bio
->sector
);
336 set_bit(R1BIO_ReadError
, &r1_bio
->state
);
337 reschedule_retry(r1_bio
);
340 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
343 static void close_write(struct r1bio
*r1_bio
)
345 /* it really is the end of this request */
346 if (test_bit(R1BIO_BehindIO
, &r1_bio
->state
)) {
347 /* free extra copy of the data pages */
348 int i
= r1_bio
->behind_page_count
;
350 safe_put_page(r1_bio
->behind_bvecs
[i
].bv_page
);
351 kfree(r1_bio
->behind_bvecs
);
352 r1_bio
->behind_bvecs
= NULL
;
354 /* clear the bitmap if all writes complete successfully */
355 bitmap_endwrite(r1_bio
->mddev
->bitmap
, r1_bio
->sector
,
357 !test_bit(R1BIO_Degraded
, &r1_bio
->state
),
358 test_bit(R1BIO_BehindIO
, &r1_bio
->state
));
359 md_write_end(r1_bio
->mddev
);
362 static void r1_bio_write_done(struct r1bio
*r1_bio
)
364 if (!atomic_dec_and_test(&r1_bio
->remaining
))
367 if (test_bit(R1BIO_WriteError
, &r1_bio
->state
))
368 reschedule_retry(r1_bio
);
371 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
))
372 reschedule_retry(r1_bio
);
374 raid_end_bio_io(r1_bio
);
378 static void raid1_end_write_request(struct bio
*bio
, int error
)
380 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
381 struct r1bio
*r1_bio
= bio
->bi_private
;
382 int mirror
, behind
= test_bit(R1BIO_BehindIO
, &r1_bio
->state
);
383 struct r1conf
*conf
= r1_bio
->mddev
->private;
384 struct bio
*to_put
= NULL
;
386 mirror
= find_bio_disk(r1_bio
, bio
);
389 * 'one mirror IO has finished' event handler:
392 set_bit(WriteErrorSeen
,
393 &conf
->mirrors
[mirror
].rdev
->flags
);
394 if (!test_and_set_bit(WantReplacement
,
395 &conf
->mirrors
[mirror
].rdev
->flags
))
396 set_bit(MD_RECOVERY_NEEDED
, &
397 conf
->mddev
->recovery
);
399 set_bit(R1BIO_WriteError
, &r1_bio
->state
);
402 * Set R1BIO_Uptodate in our master bio, so that we
403 * will return a good error code for to the higher
404 * levels even if IO on some other mirrored buffer
407 * The 'master' represents the composite IO operation
408 * to user-side. So if something waits for IO, then it
409 * will wait for the 'master' bio.
414 r1_bio
->bios
[mirror
] = NULL
;
416 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
418 /* Maybe we can clear some bad blocks. */
419 if (is_badblock(conf
->mirrors
[mirror
].rdev
,
420 r1_bio
->sector
, r1_bio
->sectors
,
421 &first_bad
, &bad_sectors
)) {
422 r1_bio
->bios
[mirror
] = IO_MADE_GOOD
;
423 set_bit(R1BIO_MadeGood
, &r1_bio
->state
);
428 if (test_bit(WriteMostly
, &conf
->mirrors
[mirror
].rdev
->flags
))
429 atomic_dec(&r1_bio
->behind_remaining
);
432 * In behind mode, we ACK the master bio once the I/O
433 * has safely reached all non-writemostly
434 * disks. Setting the Returned bit ensures that this
435 * gets done only once -- we don't ever want to return
436 * -EIO here, instead we'll wait
438 if (atomic_read(&r1_bio
->behind_remaining
) >= (atomic_read(&r1_bio
->remaining
)-1) &&
439 test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
440 /* Maybe we can return now */
441 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
442 struct bio
*mbio
= r1_bio
->master_bio
;
443 pr_debug("raid1: behind end write sectors"
445 (unsigned long long) mbio
->bi_sector
,
446 (unsigned long long) mbio
->bi_sector
+
447 (mbio
->bi_size
>> 9) - 1);
448 call_bio_endio(r1_bio
);
452 if (r1_bio
->bios
[mirror
] == NULL
)
453 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
,
457 * Let's see if all mirrored write operations have finished
460 r1_bio_write_done(r1_bio
);
468 * This routine returns the disk from which the requested read should
469 * be done. There is a per-array 'next expected sequential IO' sector
470 * number - if this matches on the next IO then we use the last disk.
471 * There is also a per-disk 'last know head position' sector that is
472 * maintained from IRQ contexts, both the normal and the resync IO
473 * completion handlers update this position correctly. If there is no
474 * perfect sequential match then we pick the disk whose head is closest.
476 * If there are 2 mirrors in the same 2 devices, performance degrades
477 * because position is mirror, not device based.
479 * The rdev for the device selected will have nr_pending incremented.
481 static int read_balance(struct r1conf
*conf
, struct r1bio
*r1_bio
, int *max_sectors
)
483 const sector_t this_sector
= r1_bio
->sector
;
485 int best_good_sectors
;
490 struct md_rdev
*rdev
;
495 * Check if we can balance. We can balance on the whole
496 * device if no resync is going on, or below the resync window.
497 * We take the first readable disk when above the resync window.
500 sectors
= r1_bio
->sectors
;
502 best_dist
= MaxSector
;
503 best_good_sectors
= 0;
505 if (conf
->mddev
->recovery_cp
< MaxSector
&&
506 (this_sector
+ sectors
>= conf
->next_resync
)) {
511 start_disk
= conf
->last_used
;
514 for (i
= 0 ; i
< conf
->raid_disks
* 2 ; i
++) {
519 int disk
= start_disk
+ i
;
520 if (disk
>= conf
->raid_disks
)
521 disk
-= conf
->raid_disks
;
523 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
524 if (r1_bio
->bios
[disk
] == IO_BLOCKED
526 || test_bit(Faulty
, &rdev
->flags
))
528 if (!test_bit(In_sync
, &rdev
->flags
) &&
529 rdev
->recovery_offset
< this_sector
+ sectors
)
531 if (test_bit(WriteMostly
, &rdev
->flags
)) {
532 /* Don't balance among write-mostly, just
533 * use the first as a last resort */
535 if (is_badblock(rdev
, this_sector
, sectors
,
536 &first_bad
, &bad_sectors
)) {
537 if (first_bad
< this_sector
)
538 /* Cannot use this */
540 best_good_sectors
= first_bad
- this_sector
;
542 best_good_sectors
= sectors
;
547 /* This is a reasonable device to use. It might
550 if (is_badblock(rdev
, this_sector
, sectors
,
551 &first_bad
, &bad_sectors
)) {
552 if (best_dist
< MaxSector
)
553 /* already have a better device */
555 if (first_bad
<= this_sector
) {
556 /* cannot read here. If this is the 'primary'
557 * device, then we must not read beyond
558 * bad_sectors from another device..
560 bad_sectors
-= (this_sector
- first_bad
);
561 if (choose_first
&& sectors
> bad_sectors
)
562 sectors
= bad_sectors
;
563 if (best_good_sectors
> sectors
)
564 best_good_sectors
= sectors
;
567 sector_t good_sectors
= first_bad
- this_sector
;
568 if (good_sectors
> best_good_sectors
) {
569 best_good_sectors
= good_sectors
;
577 best_good_sectors
= sectors
;
579 dist
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
581 /* Don't change to another disk for sequential reads */
582 || conf
->next_seq_sect
== this_sector
584 /* If device is idle, use it */
585 || atomic_read(&rdev
->nr_pending
) == 0) {
589 if (dist
< best_dist
) {
595 if (best_disk
>= 0) {
596 rdev
= rcu_dereference(conf
->mirrors
[best_disk
].rdev
);
599 atomic_inc(&rdev
->nr_pending
);
600 if (test_bit(Faulty
, &rdev
->flags
)) {
601 /* cannot risk returning a device that failed
602 * before we inc'ed nr_pending
604 rdev_dec_pending(rdev
, conf
->mddev
);
607 sectors
= best_good_sectors
;
608 conf
->next_seq_sect
= this_sector
+ sectors
;
609 conf
->last_used
= best_disk
;
612 *max_sectors
= sectors
;
617 int md_raid1_congested(struct mddev
*mddev
, int bits
)
619 struct r1conf
*conf
= mddev
->private;
622 if ((bits
& (1 << BDI_async_congested
)) &&
623 conf
->pending_count
>= max_queued_requests
)
627 for (i
= 0; i
< conf
->raid_disks
; i
++) {
628 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
629 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
630 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
634 /* Note the '|| 1' - when read_balance prefers
635 * non-congested targets, it can be removed
637 if ((bits
& (1<<BDI_async_congested
)) || 1)
638 ret
|= bdi_congested(&q
->backing_dev_info
, bits
);
640 ret
&= bdi_congested(&q
->backing_dev_info
, bits
);
646 EXPORT_SYMBOL_GPL(md_raid1_congested
);
648 static int raid1_congested(void *data
, int bits
)
650 struct mddev
*mddev
= data
;
652 return mddev_congested(mddev
, bits
) ||
653 md_raid1_congested(mddev
, bits
);
656 static void flush_pending_writes(struct r1conf
*conf
)
658 /* Any writes that have been queued but are awaiting
659 * bitmap updates get flushed here.
661 spin_lock_irq(&conf
->device_lock
);
663 if (conf
->pending_bio_list
.head
) {
665 bio
= bio_list_get(&conf
->pending_bio_list
);
666 conf
->pending_count
= 0;
667 spin_unlock_irq(&conf
->device_lock
);
668 /* flush any pending bitmap writes to
669 * disk before proceeding w/ I/O */
670 bitmap_unplug(conf
->mddev
->bitmap
);
671 wake_up(&conf
->wait_barrier
);
673 while (bio
) { /* submit pending writes */
674 struct bio
*next
= bio
->bi_next
;
676 generic_make_request(bio
);
680 spin_unlock_irq(&conf
->device_lock
);
684 * Sometimes we need to suspend IO while we do something else,
685 * either some resync/recovery, or reconfigure the array.
686 * To do this we raise a 'barrier'.
687 * The 'barrier' is a counter that can be raised multiple times
688 * to count how many activities are happening which preclude
690 * We can only raise the barrier if there is no pending IO.
691 * i.e. if nr_pending == 0.
692 * We choose only to raise the barrier if no-one is waiting for the
693 * barrier to go down. This means that as soon as an IO request
694 * is ready, no other operations which require a barrier will start
695 * until the IO request has had a chance.
697 * So: regular IO calls 'wait_barrier'. When that returns there
698 * is no backgroup IO happening, It must arrange to call
699 * allow_barrier when it has finished its IO.
700 * backgroup IO calls must call raise_barrier. Once that returns
701 * there is no normal IO happeing. It must arrange to call
702 * lower_barrier when the particular background IO completes.
704 #define RESYNC_DEPTH 32
706 static void raise_barrier(struct r1conf
*conf
)
708 spin_lock_irq(&conf
->resync_lock
);
710 /* Wait until no block IO is waiting */
711 wait_event_lock_irq(conf
->wait_barrier
, !conf
->nr_waiting
,
712 conf
->resync_lock
, );
714 /* block any new IO from starting */
717 /* Now wait for all pending IO to complete */
718 wait_event_lock_irq(conf
->wait_barrier
,
719 !conf
->nr_pending
&& conf
->barrier
< RESYNC_DEPTH
,
720 conf
->resync_lock
, );
722 spin_unlock_irq(&conf
->resync_lock
);
725 static void lower_barrier(struct r1conf
*conf
)
728 BUG_ON(conf
->barrier
<= 0);
729 spin_lock_irqsave(&conf
->resync_lock
, flags
);
731 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
732 wake_up(&conf
->wait_barrier
);
735 static void wait_barrier(struct r1conf
*conf
)
737 spin_lock_irq(&conf
->resync_lock
);
740 wait_event_lock_irq(conf
->wait_barrier
, !conf
->barrier
,
746 spin_unlock_irq(&conf
->resync_lock
);
749 static void allow_barrier(struct r1conf
*conf
)
752 spin_lock_irqsave(&conf
->resync_lock
, flags
);
754 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
755 wake_up(&conf
->wait_barrier
);
758 static void freeze_array(struct r1conf
*conf
)
760 /* stop syncio and normal IO and wait for everything to
762 * We increment barrier and nr_waiting, and then
763 * wait until nr_pending match nr_queued+1
764 * This is called in the context of one normal IO request
765 * that has failed. Thus any sync request that might be pending
766 * will be blocked by nr_pending, and we need to wait for
767 * pending IO requests to complete or be queued for re-try.
768 * Thus the number queued (nr_queued) plus this request (1)
769 * must match the number of pending IOs (nr_pending) before
772 spin_lock_irq(&conf
->resync_lock
);
775 wait_event_lock_irq(conf
->wait_barrier
,
776 conf
->nr_pending
== conf
->nr_queued
+1,
778 flush_pending_writes(conf
));
779 spin_unlock_irq(&conf
->resync_lock
);
781 static void unfreeze_array(struct r1conf
*conf
)
783 /* reverse the effect of the freeze */
784 spin_lock_irq(&conf
->resync_lock
);
787 wake_up(&conf
->wait_barrier
);
788 spin_unlock_irq(&conf
->resync_lock
);
792 /* duplicate the data pages for behind I/O
794 static void alloc_behind_pages(struct bio
*bio
, struct r1bio
*r1_bio
)
797 struct bio_vec
*bvec
;
798 struct bio_vec
*bvecs
= kzalloc(bio
->bi_vcnt
* sizeof(struct bio_vec
),
800 if (unlikely(!bvecs
))
803 bio_for_each_segment(bvec
, bio
, i
) {
805 bvecs
[i
].bv_page
= alloc_page(GFP_NOIO
);
806 if (unlikely(!bvecs
[i
].bv_page
))
808 memcpy(kmap(bvecs
[i
].bv_page
) + bvec
->bv_offset
,
809 kmap(bvec
->bv_page
) + bvec
->bv_offset
, bvec
->bv_len
);
810 kunmap(bvecs
[i
].bv_page
);
811 kunmap(bvec
->bv_page
);
813 r1_bio
->behind_bvecs
= bvecs
;
814 r1_bio
->behind_page_count
= bio
->bi_vcnt
;
815 set_bit(R1BIO_BehindIO
, &r1_bio
->state
);
819 for (i
= 0; i
< bio
->bi_vcnt
; i
++)
820 if (bvecs
[i
].bv_page
)
821 put_page(bvecs
[i
].bv_page
);
823 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio
->bi_size
);
826 static void make_request(struct mddev
*mddev
, struct bio
* bio
)
828 struct r1conf
*conf
= mddev
->private;
829 struct mirror_info
*mirror
;
830 struct r1bio
*r1_bio
;
831 struct bio
*read_bio
;
833 struct bitmap
*bitmap
;
835 const int rw
= bio_data_dir(bio
);
836 const unsigned long do_sync
= (bio
->bi_rw
& REQ_SYNC
);
837 const unsigned long do_flush_fua
= (bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
));
838 struct md_rdev
*blocked_rdev
;
845 * Register the new request and wait if the reconstruction
846 * thread has put up a bar for new requests.
847 * Continue immediately if no resync is active currently.
850 md_write_start(mddev
, bio
); /* wait on superblock update early */
852 if (bio_data_dir(bio
) == WRITE
&&
853 bio
->bi_sector
+ bio
->bi_size
/512 > mddev
->suspend_lo
&&
854 bio
->bi_sector
< mddev
->suspend_hi
) {
855 /* As the suspend_* range is controlled by
856 * userspace, we want an interruptible
861 flush_signals(current
);
862 prepare_to_wait(&conf
->wait_barrier
,
863 &w
, TASK_INTERRUPTIBLE
);
864 if (bio
->bi_sector
+ bio
->bi_size
/512 <= mddev
->suspend_lo
||
865 bio
->bi_sector
>= mddev
->suspend_hi
)
869 finish_wait(&conf
->wait_barrier
, &w
);
874 bitmap
= mddev
->bitmap
;
877 * make_request() can abort the operation when READA is being
878 * used and no empty request is available.
881 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
883 r1_bio
->master_bio
= bio
;
884 r1_bio
->sectors
= bio
->bi_size
>> 9;
886 r1_bio
->mddev
= mddev
;
887 r1_bio
->sector
= bio
->bi_sector
;
889 /* We might need to issue multiple reads to different
890 * devices if there are bad blocks around, so we keep
891 * track of the number of reads in bio->bi_phys_segments.
892 * If this is 0, there is only one r1_bio and no locking
893 * will be needed when requests complete. If it is
894 * non-zero, then it is the number of not-completed requests.
896 bio
->bi_phys_segments
= 0;
897 clear_bit(BIO_SEG_VALID
, &bio
->bi_flags
);
901 * read balancing logic:
906 rdisk
= read_balance(conf
, r1_bio
, &max_sectors
);
909 /* couldn't find anywhere to read from */
910 raid_end_bio_io(r1_bio
);
913 mirror
= conf
->mirrors
+ rdisk
;
915 if (test_bit(WriteMostly
, &mirror
->rdev
->flags
) &&
917 /* Reading from a write-mostly device must
918 * take care not to over-take any writes
921 wait_event(bitmap
->behind_wait
,
922 atomic_read(&bitmap
->behind_writes
) == 0);
924 r1_bio
->read_disk
= rdisk
;
926 read_bio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
927 md_trim_bio(read_bio
, r1_bio
->sector
- bio
->bi_sector
,
930 r1_bio
->bios
[rdisk
] = read_bio
;
932 read_bio
->bi_sector
= r1_bio
->sector
+ mirror
->rdev
->data_offset
;
933 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
934 read_bio
->bi_end_io
= raid1_end_read_request
;
935 read_bio
->bi_rw
= READ
| do_sync
;
936 read_bio
->bi_private
= r1_bio
;
938 if (max_sectors
< r1_bio
->sectors
) {
939 /* could not read all from this device, so we will
940 * need another r1_bio.
943 sectors_handled
= (r1_bio
->sector
+ max_sectors
945 r1_bio
->sectors
= max_sectors
;
946 spin_lock_irq(&conf
->device_lock
);
947 if (bio
->bi_phys_segments
== 0)
948 bio
->bi_phys_segments
= 2;
950 bio
->bi_phys_segments
++;
951 spin_unlock_irq(&conf
->device_lock
);
952 /* Cannot call generic_make_request directly
953 * as that will be queued in __make_request
954 * and subsequent mempool_alloc might block waiting
955 * for it. So hand bio over to raid1d.
957 reschedule_retry(r1_bio
);
959 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
961 r1_bio
->master_bio
= bio
;
962 r1_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
964 r1_bio
->mddev
= mddev
;
965 r1_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
968 generic_make_request(read_bio
);
975 if (conf
->pending_count
>= max_queued_requests
) {
976 md_wakeup_thread(mddev
->thread
);
977 wait_event(conf
->wait_barrier
,
978 conf
->pending_count
< max_queued_requests
);
980 /* first select target devices under rcu_lock and
981 * inc refcount on their rdev. Record them by setting
983 * If there are known/acknowledged bad blocks on any device on
984 * which we have seen a write error, we want to avoid writing those
986 * This potentially requires several writes to write around
987 * the bad blocks. Each set of writes gets it's own r1bio
988 * with a set of bios attached.
990 plugged
= mddev_check_plugged(mddev
);
992 disks
= conf
->raid_disks
* 2;
996 max_sectors
= r1_bio
->sectors
;
997 for (i
= 0; i
< disks
; i
++) {
998 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
999 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
1000 atomic_inc(&rdev
->nr_pending
);
1001 blocked_rdev
= rdev
;
1004 r1_bio
->bios
[i
] = NULL
;
1005 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
)) {
1006 if (i
< conf
->raid_disks
)
1007 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
1011 atomic_inc(&rdev
->nr_pending
);
1012 if (test_bit(WriteErrorSeen
, &rdev
->flags
)) {
1017 is_bad
= is_badblock(rdev
, r1_bio
->sector
,
1019 &first_bad
, &bad_sectors
);
1021 /* mustn't write here until the bad block is
1023 set_bit(BlockedBadBlocks
, &rdev
->flags
);
1024 blocked_rdev
= rdev
;
1027 if (is_bad
&& first_bad
<= r1_bio
->sector
) {
1028 /* Cannot write here at all */
1029 bad_sectors
-= (r1_bio
->sector
- first_bad
);
1030 if (bad_sectors
< max_sectors
)
1031 /* mustn't write more than bad_sectors
1032 * to other devices yet
1034 max_sectors
= bad_sectors
;
1035 rdev_dec_pending(rdev
, mddev
);
1036 /* We don't set R1BIO_Degraded as that
1037 * only applies if the disk is
1038 * missing, so it might be re-added,
1039 * and we want to know to recover this
1041 * In this case the device is here,
1042 * and the fact that this chunk is not
1043 * in-sync is recorded in the bad
1049 int good_sectors
= first_bad
- r1_bio
->sector
;
1050 if (good_sectors
< max_sectors
)
1051 max_sectors
= good_sectors
;
1054 r1_bio
->bios
[i
] = bio
;
1058 if (unlikely(blocked_rdev
)) {
1059 /* Wait for this device to become unblocked */
1062 for (j
= 0; j
< i
; j
++)
1063 if (r1_bio
->bios
[j
])
1064 rdev_dec_pending(conf
->mirrors
[j
].rdev
, mddev
);
1066 allow_barrier(conf
);
1067 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
1072 if (max_sectors
< r1_bio
->sectors
) {
1073 /* We are splitting this write into multiple parts, so
1074 * we need to prepare for allocating another r1_bio.
1076 r1_bio
->sectors
= max_sectors
;
1077 spin_lock_irq(&conf
->device_lock
);
1078 if (bio
->bi_phys_segments
== 0)
1079 bio
->bi_phys_segments
= 2;
1081 bio
->bi_phys_segments
++;
1082 spin_unlock_irq(&conf
->device_lock
);
1084 sectors_handled
= r1_bio
->sector
+ max_sectors
- bio
->bi_sector
;
1086 atomic_set(&r1_bio
->remaining
, 1);
1087 atomic_set(&r1_bio
->behind_remaining
, 0);
1090 for (i
= 0; i
< disks
; i
++) {
1092 if (!r1_bio
->bios
[i
])
1095 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1096 md_trim_bio(mbio
, r1_bio
->sector
- bio
->bi_sector
, max_sectors
);
1100 * Not if there are too many, or cannot
1101 * allocate memory, or a reader on WriteMostly
1102 * is waiting for behind writes to flush */
1104 (atomic_read(&bitmap
->behind_writes
)
1105 < mddev
->bitmap_info
.max_write_behind
) &&
1106 !waitqueue_active(&bitmap
->behind_wait
))
1107 alloc_behind_pages(mbio
, r1_bio
);
1109 bitmap_startwrite(bitmap
, r1_bio
->sector
,
1111 test_bit(R1BIO_BehindIO
,
1115 if (r1_bio
->behind_bvecs
) {
1116 struct bio_vec
*bvec
;
1119 /* Yes, I really want the '__' version so that
1120 * we clear any unused pointer in the io_vec, rather
1121 * than leave them unchanged. This is important
1122 * because when we come to free the pages, we won't
1123 * know the original bi_idx, so we just free
1126 __bio_for_each_segment(bvec
, mbio
, j
, 0)
1127 bvec
->bv_page
= r1_bio
->behind_bvecs
[j
].bv_page
;
1128 if (test_bit(WriteMostly
, &conf
->mirrors
[i
].rdev
->flags
))
1129 atomic_inc(&r1_bio
->behind_remaining
);
1132 r1_bio
->bios
[i
] = mbio
;
1134 mbio
->bi_sector
= (r1_bio
->sector
+
1135 conf
->mirrors
[i
].rdev
->data_offset
);
1136 mbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1137 mbio
->bi_end_io
= raid1_end_write_request
;
1138 mbio
->bi_rw
= WRITE
| do_flush_fua
| do_sync
;
1139 mbio
->bi_private
= r1_bio
;
1141 atomic_inc(&r1_bio
->remaining
);
1142 spin_lock_irqsave(&conf
->device_lock
, flags
);
1143 bio_list_add(&conf
->pending_bio_list
, mbio
);
1144 conf
->pending_count
++;
1145 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1147 /* Mustn't call r1_bio_write_done before this next test,
1148 * as it could result in the bio being freed.
1150 if (sectors_handled
< (bio
->bi_size
>> 9)) {
1151 r1_bio_write_done(r1_bio
);
1152 /* We need another r1_bio. It has already been counted
1153 * in bio->bi_phys_segments
1155 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
1156 r1_bio
->master_bio
= bio
;
1157 r1_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
1159 r1_bio
->mddev
= mddev
;
1160 r1_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1164 r1_bio_write_done(r1_bio
);
1166 /* In case raid1d snuck in to freeze_array */
1167 wake_up(&conf
->wait_barrier
);
1169 if (do_sync
|| !bitmap
|| !plugged
)
1170 md_wakeup_thread(mddev
->thread
);
1173 static void status(struct seq_file
*seq
, struct mddev
*mddev
)
1175 struct r1conf
*conf
= mddev
->private;
1178 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
1179 conf
->raid_disks
- mddev
->degraded
);
1181 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1182 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1183 seq_printf(seq
, "%s",
1184 rdev
&& test_bit(In_sync
, &rdev
->flags
) ? "U" : "_");
1187 seq_printf(seq
, "]");
1191 static void error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1193 char b
[BDEVNAME_SIZE
];
1194 struct r1conf
*conf
= mddev
->private;
1197 * If it is not operational, then we have already marked it as dead
1198 * else if it is the last working disks, ignore the error, let the
1199 * next level up know.
1200 * else mark the drive as failed
1202 if (test_bit(In_sync
, &rdev
->flags
)
1203 && (conf
->raid_disks
- mddev
->degraded
) == 1) {
1205 * Don't fail the drive, act as though we were just a
1206 * normal single drive.
1207 * However don't try a recovery from this drive as
1208 * it is very likely to fail.
1210 conf
->recovery_disabled
= mddev
->recovery_disabled
;
1213 set_bit(Blocked
, &rdev
->flags
);
1214 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1215 unsigned long flags
;
1216 spin_lock_irqsave(&conf
->device_lock
, flags
);
1218 set_bit(Faulty
, &rdev
->flags
);
1219 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1221 * if recovery is running, make sure it aborts.
1223 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1225 set_bit(Faulty
, &rdev
->flags
);
1226 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1228 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1229 "md/raid1:%s: Operation continuing on %d devices.\n",
1230 mdname(mddev
), bdevname(rdev
->bdev
, b
),
1231 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
1234 static void print_conf(struct r1conf
*conf
)
1238 printk(KERN_DEBUG
"RAID1 conf printout:\n");
1240 printk(KERN_DEBUG
"(!conf)\n");
1243 printk(KERN_DEBUG
" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1247 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1248 char b
[BDEVNAME_SIZE
];
1249 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1251 printk(KERN_DEBUG
" disk %d, wo:%d, o:%d, dev:%s\n",
1252 i
, !test_bit(In_sync
, &rdev
->flags
),
1253 !test_bit(Faulty
, &rdev
->flags
),
1254 bdevname(rdev
->bdev
,b
));
1259 static void close_sync(struct r1conf
*conf
)
1262 allow_barrier(conf
);
1264 mempool_destroy(conf
->r1buf_pool
);
1265 conf
->r1buf_pool
= NULL
;
1268 static int raid1_spare_active(struct mddev
*mddev
)
1271 struct r1conf
*conf
= mddev
->private;
1273 unsigned long flags
;
1276 * Find all failed disks within the RAID1 configuration
1277 * and mark them readable.
1278 * Called under mddev lock, so rcu protection not needed.
1280 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1281 struct md_rdev
*rdev
= conf
->mirrors
[i
].rdev
;
1282 struct md_rdev
*repl
= conf
->mirrors
[conf
->raid_disks
+ i
].rdev
;
1284 && repl
->recovery_offset
== MaxSector
1285 && !test_bit(Faulty
, &repl
->flags
)
1286 && !test_and_set_bit(In_sync
, &repl
->flags
)) {
1287 /* replacement has just become active */
1289 !test_and_clear_bit(In_sync
, &rdev
->flags
))
1292 /* Replaced device not technically
1293 * faulty, but we need to be sure
1294 * it gets removed and never re-added
1296 set_bit(Faulty
, &rdev
->flags
);
1297 sysfs_notify_dirent_safe(
1302 && !test_bit(Faulty
, &rdev
->flags
)
1303 && !test_and_set_bit(In_sync
, &rdev
->flags
)) {
1305 sysfs_notify_dirent_safe(rdev
->sysfs_state
);
1308 spin_lock_irqsave(&conf
->device_lock
, flags
);
1309 mddev
->degraded
-= count
;
1310 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1317 static int raid1_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1319 struct r1conf
*conf
= mddev
->private;
1322 struct mirror_info
*p
;
1324 int last
= conf
->raid_disks
- 1;
1326 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
1329 if (rdev
->raid_disk
>= 0)
1330 first
= last
= rdev
->raid_disk
;
1332 for (mirror
= first
; mirror
<= last
; mirror
++) {
1333 p
= conf
->mirrors
+mirror
;
1336 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1337 rdev
->data_offset
<< 9);
1338 /* as we don't honour merge_bvec_fn, we must
1339 * never risk violating it, so limit
1340 * ->max_segments to one lying with a single
1341 * page, as a one page request is never in
1344 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1345 blk_queue_max_segments(mddev
->queue
, 1);
1346 blk_queue_segment_boundary(mddev
->queue
,
1347 PAGE_CACHE_SIZE
- 1);
1350 p
->head_position
= 0;
1351 rdev
->raid_disk
= mirror
;
1353 /* As all devices are equivalent, we don't need a full recovery
1354 * if this was recently any drive of the array
1356 if (rdev
->saved_raid_disk
< 0)
1358 rcu_assign_pointer(p
->rdev
, rdev
);
1361 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
1362 p
[conf
->raid_disks
].rdev
== NULL
) {
1363 /* Add this device as a replacement */
1364 clear_bit(In_sync
, &rdev
->flags
);
1365 set_bit(Replacement
, &rdev
->flags
);
1366 rdev
->raid_disk
= mirror
;
1369 rcu_assign_pointer(p
[conf
->raid_disks
].rdev
, rdev
);
1373 md_integrity_add_rdev(rdev
, mddev
);
1378 static int raid1_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1380 struct r1conf
*conf
= mddev
->private;
1382 int number
= rdev
->raid_disk
;
1383 struct mirror_info
*p
= conf
->mirrors
+ number
;
1385 if (rdev
!= p
->rdev
)
1386 p
= conf
->mirrors
+ conf
->raid_disks
+ number
;
1389 if (rdev
== p
->rdev
) {
1390 if (test_bit(In_sync
, &rdev
->flags
) ||
1391 atomic_read(&rdev
->nr_pending
)) {
1395 /* Only remove non-faulty devices if recovery
1398 if (!test_bit(Faulty
, &rdev
->flags
) &&
1399 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
1400 mddev
->degraded
< conf
->raid_disks
) {
1406 if (atomic_read(&rdev
->nr_pending
)) {
1407 /* lost the race, try later */
1411 } else if (conf
->mirrors
[conf
->raid_disks
+ number
].rdev
) {
1412 /* We just removed a device that is being replaced.
1413 * Move down the replacement. We drain all IO before
1414 * doing this to avoid confusion.
1416 struct md_rdev
*repl
=
1417 conf
->mirrors
[conf
->raid_disks
+ number
].rdev
;
1418 raise_barrier(conf
);
1419 clear_bit(Replacement
, &repl
->flags
);
1421 conf
->mirrors
[conf
->raid_disks
+ number
].rdev
= NULL
;
1422 lower_barrier(conf
);
1423 clear_bit(WantReplacement
, &rdev
->flags
);
1425 clear_bit(WantReplacement
, &rdev
->flags
);
1426 err
= md_integrity_register(mddev
);
1435 static void end_sync_read(struct bio
*bio
, int error
)
1437 struct r1bio
*r1_bio
= bio
->bi_private
;
1439 update_head_pos(r1_bio
->read_disk
, r1_bio
);
1442 * we have read a block, now it needs to be re-written,
1443 * or re-read if the read failed.
1444 * We don't do much here, just schedule handling by raid1d
1446 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1447 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1449 if (atomic_dec_and_test(&r1_bio
->remaining
))
1450 reschedule_retry(r1_bio
);
1453 static void end_sync_write(struct bio
*bio
, int error
)
1455 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1456 struct r1bio
*r1_bio
= bio
->bi_private
;
1457 struct mddev
*mddev
= r1_bio
->mddev
;
1458 struct r1conf
*conf
= mddev
->private;
1463 mirror
= find_bio_disk(r1_bio
, bio
);
1466 sector_t sync_blocks
= 0;
1467 sector_t s
= r1_bio
->sector
;
1468 long sectors_to_go
= r1_bio
->sectors
;
1469 /* make sure these bits doesn't get cleared. */
1471 bitmap_end_sync(mddev
->bitmap
, s
,
1474 sectors_to_go
-= sync_blocks
;
1475 } while (sectors_to_go
> 0);
1476 set_bit(WriteErrorSeen
,
1477 &conf
->mirrors
[mirror
].rdev
->flags
);
1478 if (!test_and_set_bit(WantReplacement
,
1479 &conf
->mirrors
[mirror
].rdev
->flags
))
1480 set_bit(MD_RECOVERY_NEEDED
, &
1482 set_bit(R1BIO_WriteError
, &r1_bio
->state
);
1483 } else if (is_badblock(conf
->mirrors
[mirror
].rdev
,
1486 &first_bad
, &bad_sectors
) &&
1487 !is_badblock(conf
->mirrors
[r1_bio
->read_disk
].rdev
,
1490 &first_bad
, &bad_sectors
)
1492 set_bit(R1BIO_MadeGood
, &r1_bio
->state
);
1494 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1495 int s
= r1_bio
->sectors
;
1496 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
) ||
1497 test_bit(R1BIO_WriteError
, &r1_bio
->state
))
1498 reschedule_retry(r1_bio
);
1501 md_done_sync(mddev
, s
, uptodate
);
1506 static int r1_sync_page_io(struct md_rdev
*rdev
, sector_t sector
,
1507 int sectors
, struct page
*page
, int rw
)
1509 if (sync_page_io(rdev
, sector
, sectors
<< 9, page
, rw
, false))
1513 set_bit(WriteErrorSeen
, &rdev
->flags
);
1514 if (!test_and_set_bit(WantReplacement
,
1516 set_bit(MD_RECOVERY_NEEDED
, &
1517 rdev
->mddev
->recovery
);
1519 /* need to record an error - either for the block or the device */
1520 if (!rdev_set_badblocks(rdev
, sector
, sectors
, 0))
1521 md_error(rdev
->mddev
, rdev
);
1525 static int fix_sync_read_error(struct r1bio
*r1_bio
)
1527 /* Try some synchronous reads of other devices to get
1528 * good data, much like with normal read errors. Only
1529 * read into the pages we already have so we don't
1530 * need to re-issue the read request.
1531 * We don't need to freeze the array, because being in an
1532 * active sync request, there is no normal IO, and
1533 * no overlapping syncs.
1534 * We don't need to check is_badblock() again as we
1535 * made sure that anything with a bad block in range
1536 * will have bi_end_io clear.
1538 struct mddev
*mddev
= r1_bio
->mddev
;
1539 struct r1conf
*conf
= mddev
->private;
1540 struct bio
*bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1541 sector_t sect
= r1_bio
->sector
;
1542 int sectors
= r1_bio
->sectors
;
1547 int d
= r1_bio
->read_disk
;
1549 struct md_rdev
*rdev
;
1552 if (s
> (PAGE_SIZE
>>9))
1555 if (r1_bio
->bios
[d
]->bi_end_io
== end_sync_read
) {
1556 /* No rcu protection needed here devices
1557 * can only be removed when no resync is
1558 * active, and resync is currently active
1560 rdev
= conf
->mirrors
[d
].rdev
;
1561 if (sync_page_io(rdev
, sect
, s
<<9,
1562 bio
->bi_io_vec
[idx
].bv_page
,
1569 if (d
== conf
->raid_disks
* 2)
1571 } while (!success
&& d
!= r1_bio
->read_disk
);
1574 char b
[BDEVNAME_SIZE
];
1576 /* Cannot read from anywhere, this block is lost.
1577 * Record a bad block on each device. If that doesn't
1578 * work just disable and interrupt the recovery.
1579 * Don't fail devices as that won't really help.
1581 printk(KERN_ALERT
"md/raid1:%s: %s: unrecoverable I/O read error"
1582 " for block %llu\n",
1584 bdevname(bio
->bi_bdev
, b
),
1585 (unsigned long long)r1_bio
->sector
);
1586 for (d
= 0; d
< conf
->raid_disks
* 2; d
++) {
1587 rdev
= conf
->mirrors
[d
].rdev
;
1588 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
1590 if (!rdev_set_badblocks(rdev
, sect
, s
, 0))
1594 conf
->recovery_disabled
=
1595 mddev
->recovery_disabled
;
1596 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1597 md_done_sync(mddev
, r1_bio
->sectors
, 0);
1609 /* write it back and re-read */
1610 while (d
!= r1_bio
->read_disk
) {
1612 d
= conf
->raid_disks
* 2;
1614 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1616 rdev
= conf
->mirrors
[d
].rdev
;
1617 if (r1_sync_page_io(rdev
, sect
, s
,
1618 bio
->bi_io_vec
[idx
].bv_page
,
1620 r1_bio
->bios
[d
]->bi_end_io
= NULL
;
1621 rdev_dec_pending(rdev
, mddev
);
1625 while (d
!= r1_bio
->read_disk
) {
1627 d
= conf
->raid_disks
* 2;
1629 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1631 rdev
= conf
->mirrors
[d
].rdev
;
1632 if (r1_sync_page_io(rdev
, sect
, s
,
1633 bio
->bi_io_vec
[idx
].bv_page
,
1635 atomic_add(s
, &rdev
->corrected_errors
);
1641 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1642 set_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1646 static int process_checks(struct r1bio
*r1_bio
)
1648 /* We have read all readable devices. If we haven't
1649 * got the block, then there is no hope left.
1650 * If we have, then we want to do a comparison
1651 * and skip the write if everything is the same.
1652 * If any blocks failed to read, then we need to
1653 * attempt an over-write
1655 struct mddev
*mddev
= r1_bio
->mddev
;
1656 struct r1conf
*conf
= mddev
->private;
1660 for (primary
= 0; primary
< conf
->raid_disks
* 2; primary
++)
1661 if (r1_bio
->bios
[primary
]->bi_end_io
== end_sync_read
&&
1662 test_bit(BIO_UPTODATE
, &r1_bio
->bios
[primary
]->bi_flags
)) {
1663 r1_bio
->bios
[primary
]->bi_end_io
= NULL
;
1664 rdev_dec_pending(conf
->mirrors
[primary
].rdev
, mddev
);
1667 r1_bio
->read_disk
= primary
;
1668 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
1670 int vcnt
= r1_bio
->sectors
>> (PAGE_SHIFT
- 9);
1671 struct bio
*pbio
= r1_bio
->bios
[primary
];
1672 struct bio
*sbio
= r1_bio
->bios
[i
];
1675 if (r1_bio
->bios
[i
]->bi_end_io
!= end_sync_read
)
1678 if (test_bit(BIO_UPTODATE
, &sbio
->bi_flags
)) {
1679 for (j
= vcnt
; j
-- ; ) {
1681 p
= pbio
->bi_io_vec
[j
].bv_page
;
1682 s
= sbio
->bi_io_vec
[j
].bv_page
;
1683 if (memcmp(page_address(p
),
1691 mddev
->resync_mismatches
+= r1_bio
->sectors
;
1692 if (j
< 0 || (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
)
1693 && test_bit(BIO_UPTODATE
, &sbio
->bi_flags
))) {
1694 /* No need to write to this device. */
1695 sbio
->bi_end_io
= NULL
;
1696 rdev_dec_pending(conf
->mirrors
[i
].rdev
, mddev
);
1699 /* fixup the bio for reuse */
1700 sbio
->bi_vcnt
= vcnt
;
1701 sbio
->bi_size
= r1_bio
->sectors
<< 9;
1703 sbio
->bi_phys_segments
= 0;
1704 sbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1705 sbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1706 sbio
->bi_next
= NULL
;
1707 sbio
->bi_sector
= r1_bio
->sector
+
1708 conf
->mirrors
[i
].rdev
->data_offset
;
1709 sbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1710 size
= sbio
->bi_size
;
1711 for (j
= 0; j
< vcnt
; j
++) {
1713 bi
= &sbio
->bi_io_vec
[j
];
1715 if (size
> PAGE_SIZE
)
1716 bi
->bv_len
= PAGE_SIZE
;
1720 memcpy(page_address(bi
->bv_page
),
1721 page_address(pbio
->bi_io_vec
[j
].bv_page
),
1728 static void sync_request_write(struct mddev
*mddev
, struct r1bio
*r1_bio
)
1730 struct r1conf
*conf
= mddev
->private;
1732 int disks
= conf
->raid_disks
* 2;
1733 struct bio
*bio
, *wbio
;
1735 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1737 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
))
1738 /* ouch - failed to read all of that. */
1739 if (!fix_sync_read_error(r1_bio
))
1742 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
1743 if (process_checks(r1_bio
) < 0)
1748 atomic_set(&r1_bio
->remaining
, 1);
1749 for (i
= 0; i
< disks
; i
++) {
1750 wbio
= r1_bio
->bios
[i
];
1751 if (wbio
->bi_end_io
== NULL
||
1752 (wbio
->bi_end_io
== end_sync_read
&&
1753 (i
== r1_bio
->read_disk
||
1754 !test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))))
1757 wbio
->bi_rw
= WRITE
;
1758 wbio
->bi_end_io
= end_sync_write
;
1759 atomic_inc(&r1_bio
->remaining
);
1760 md_sync_acct(conf
->mirrors
[i
].rdev
->bdev
, wbio
->bi_size
>> 9);
1762 generic_make_request(wbio
);
1765 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1766 /* if we're here, all write(s) have completed, so clean up */
1767 md_done_sync(mddev
, r1_bio
->sectors
, 1);
1773 * This is a kernel thread which:
1775 * 1. Retries failed read operations on working mirrors.
1776 * 2. Updates the raid superblock when problems encounter.
1777 * 3. Performs writes following reads for array synchronising.
1780 static void fix_read_error(struct r1conf
*conf
, int read_disk
,
1781 sector_t sect
, int sectors
)
1783 struct mddev
*mddev
= conf
->mddev
;
1789 struct md_rdev
*rdev
;
1791 if (s
> (PAGE_SIZE
>>9))
1795 /* Note: no rcu protection needed here
1796 * as this is synchronous in the raid1d thread
1797 * which is the thread that might remove
1798 * a device. If raid1d ever becomes multi-threaded....
1803 rdev
= conf
->mirrors
[d
].rdev
;
1805 test_bit(In_sync
, &rdev
->flags
) &&
1806 is_badblock(rdev
, sect
, s
,
1807 &first_bad
, &bad_sectors
) == 0 &&
1808 sync_page_io(rdev
, sect
, s
<<9,
1809 conf
->tmppage
, READ
, false))
1813 if (d
== conf
->raid_disks
* 2)
1816 } while (!success
&& d
!= read_disk
);
1819 /* Cannot read from anywhere - mark it bad */
1820 struct md_rdev
*rdev
= conf
->mirrors
[read_disk
].rdev
;
1821 if (!rdev_set_badblocks(rdev
, sect
, s
, 0))
1822 md_error(mddev
, rdev
);
1825 /* write it back and re-read */
1827 while (d
!= read_disk
) {
1829 d
= conf
->raid_disks
* 2;
1831 rdev
= conf
->mirrors
[d
].rdev
;
1833 test_bit(In_sync
, &rdev
->flags
))
1834 r1_sync_page_io(rdev
, sect
, s
,
1835 conf
->tmppage
, WRITE
);
1838 while (d
!= read_disk
) {
1839 char b
[BDEVNAME_SIZE
];
1841 d
= conf
->raid_disks
* 2;
1843 rdev
= conf
->mirrors
[d
].rdev
;
1845 test_bit(In_sync
, &rdev
->flags
)) {
1846 if (r1_sync_page_io(rdev
, sect
, s
,
1847 conf
->tmppage
, READ
)) {
1848 atomic_add(s
, &rdev
->corrected_errors
);
1850 "md/raid1:%s: read error corrected "
1851 "(%d sectors at %llu on %s)\n",
1853 (unsigned long long)(sect
+
1855 bdevname(rdev
->bdev
, b
));
1864 static void bi_complete(struct bio
*bio
, int error
)
1866 complete((struct completion
*)bio
->bi_private
);
1869 static int submit_bio_wait(int rw
, struct bio
*bio
)
1871 struct completion event
;
1874 init_completion(&event
);
1875 bio
->bi_private
= &event
;
1876 bio
->bi_end_io
= bi_complete
;
1877 submit_bio(rw
, bio
);
1878 wait_for_completion(&event
);
1880 return test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1883 static int narrow_write_error(struct r1bio
*r1_bio
, int i
)
1885 struct mddev
*mddev
= r1_bio
->mddev
;
1886 struct r1conf
*conf
= mddev
->private;
1887 struct md_rdev
*rdev
= conf
->mirrors
[i
].rdev
;
1889 struct bio_vec
*vec
;
1891 /* bio has the data to be written to device 'i' where
1892 * we just recently had a write error.
1893 * We repeatedly clone the bio and trim down to one block,
1894 * then try the write. Where the write fails we record
1896 * It is conceivable that the bio doesn't exactly align with
1897 * blocks. We must handle this somehow.
1899 * We currently own a reference on the rdev.
1905 int sect_to_write
= r1_bio
->sectors
;
1908 if (rdev
->badblocks
.shift
< 0)
1911 block_sectors
= 1 << rdev
->badblocks
.shift
;
1912 sector
= r1_bio
->sector
;
1913 sectors
= ((sector
+ block_sectors
)
1914 & ~(sector_t
)(block_sectors
- 1))
1917 if (test_bit(R1BIO_BehindIO
, &r1_bio
->state
)) {
1918 vcnt
= r1_bio
->behind_page_count
;
1919 vec
= r1_bio
->behind_bvecs
;
1921 while (vec
[idx
].bv_page
== NULL
)
1924 vcnt
= r1_bio
->master_bio
->bi_vcnt
;
1925 vec
= r1_bio
->master_bio
->bi_io_vec
;
1926 idx
= r1_bio
->master_bio
->bi_idx
;
1928 while (sect_to_write
) {
1930 if (sectors
> sect_to_write
)
1931 sectors
= sect_to_write
;
1932 /* Write at 'sector' for 'sectors'*/
1934 wbio
= bio_alloc_mddev(GFP_NOIO
, vcnt
, mddev
);
1935 memcpy(wbio
->bi_io_vec
, vec
, vcnt
* sizeof(struct bio_vec
));
1936 wbio
->bi_sector
= r1_bio
->sector
;
1937 wbio
->bi_rw
= WRITE
;
1938 wbio
->bi_vcnt
= vcnt
;
1939 wbio
->bi_size
= r1_bio
->sectors
<< 9;
1942 md_trim_bio(wbio
, sector
- r1_bio
->sector
, sectors
);
1943 wbio
->bi_sector
+= rdev
->data_offset
;
1944 wbio
->bi_bdev
= rdev
->bdev
;
1945 if (submit_bio_wait(WRITE
, wbio
) == 0)
1947 ok
= rdev_set_badblocks(rdev
, sector
,
1952 sect_to_write
-= sectors
;
1954 sectors
= block_sectors
;
1959 static void handle_sync_write_finished(struct r1conf
*conf
, struct r1bio
*r1_bio
)
1962 int s
= r1_bio
->sectors
;
1963 for (m
= 0; m
< conf
->raid_disks
* 2 ; m
++) {
1964 struct md_rdev
*rdev
= conf
->mirrors
[m
].rdev
;
1965 struct bio
*bio
= r1_bio
->bios
[m
];
1966 if (bio
->bi_end_io
== NULL
)
1968 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
) &&
1969 test_bit(R1BIO_MadeGood
, &r1_bio
->state
)) {
1970 rdev_clear_badblocks(rdev
, r1_bio
->sector
, s
);
1972 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
) &&
1973 test_bit(R1BIO_WriteError
, &r1_bio
->state
)) {
1974 if (!rdev_set_badblocks(rdev
, r1_bio
->sector
, s
, 0))
1975 md_error(conf
->mddev
, rdev
);
1979 md_done_sync(conf
->mddev
, s
, 1);
1982 static void handle_write_finished(struct r1conf
*conf
, struct r1bio
*r1_bio
)
1985 for (m
= 0; m
< conf
->raid_disks
* 2 ; m
++)
1986 if (r1_bio
->bios
[m
] == IO_MADE_GOOD
) {
1987 struct md_rdev
*rdev
= conf
->mirrors
[m
].rdev
;
1988 rdev_clear_badblocks(rdev
,
1991 rdev_dec_pending(rdev
, conf
->mddev
);
1992 } else if (r1_bio
->bios
[m
] != NULL
) {
1993 /* This drive got a write error. We need to
1994 * narrow down and record precise write
1997 if (!narrow_write_error(r1_bio
, m
)) {
1998 md_error(conf
->mddev
,
1999 conf
->mirrors
[m
].rdev
);
2000 /* an I/O failed, we can't clear the bitmap */
2001 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
2003 rdev_dec_pending(conf
->mirrors
[m
].rdev
,
2006 if (test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2007 close_write(r1_bio
);
2008 raid_end_bio_io(r1_bio
);
2011 static void handle_read_error(struct r1conf
*conf
, struct r1bio
*r1_bio
)
2015 struct mddev
*mddev
= conf
->mddev
;
2017 char b
[BDEVNAME_SIZE
];
2018 struct md_rdev
*rdev
;
2020 clear_bit(R1BIO_ReadError
, &r1_bio
->state
);
2021 /* we got a read error. Maybe the drive is bad. Maybe just
2022 * the block and we can fix it.
2023 * We freeze all other IO, and try reading the block from
2024 * other devices. When we find one, we re-write
2025 * and check it that fixes the read error.
2026 * This is all done synchronously while the array is
2029 if (mddev
->ro
== 0) {
2031 fix_read_error(conf
, r1_bio
->read_disk
,
2032 r1_bio
->sector
, r1_bio
->sectors
);
2033 unfreeze_array(conf
);
2035 md_error(mddev
, conf
->mirrors
[r1_bio
->read_disk
].rdev
);
2037 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
2038 bdevname(bio
->bi_bdev
, b
);
2040 disk
= read_balance(conf
, r1_bio
, &max_sectors
);
2042 printk(KERN_ALERT
"md/raid1:%s: %s: unrecoverable I/O"
2043 " read error for block %llu\n",
2044 mdname(mddev
), b
, (unsigned long long)r1_bio
->sector
);
2045 raid_end_bio_io(r1_bio
);
2047 const unsigned long do_sync
2048 = r1_bio
->master_bio
->bi_rw
& REQ_SYNC
;
2050 r1_bio
->bios
[r1_bio
->read_disk
] =
2051 mddev
->ro
? IO_BLOCKED
: NULL
;
2054 r1_bio
->read_disk
= disk
;
2055 bio
= bio_clone_mddev(r1_bio
->master_bio
, GFP_NOIO
, mddev
);
2056 md_trim_bio(bio
, r1_bio
->sector
- bio
->bi_sector
, max_sectors
);
2057 r1_bio
->bios
[r1_bio
->read_disk
] = bio
;
2058 rdev
= conf
->mirrors
[disk
].rdev
;
2059 printk_ratelimited(KERN_ERR
2060 "md/raid1:%s: redirecting sector %llu"
2061 " to other mirror: %s\n",
2063 (unsigned long long)r1_bio
->sector
,
2064 bdevname(rdev
->bdev
, b
));
2065 bio
->bi_sector
= r1_bio
->sector
+ rdev
->data_offset
;
2066 bio
->bi_bdev
= rdev
->bdev
;
2067 bio
->bi_end_io
= raid1_end_read_request
;
2068 bio
->bi_rw
= READ
| do_sync
;
2069 bio
->bi_private
= r1_bio
;
2070 if (max_sectors
< r1_bio
->sectors
) {
2071 /* Drat - have to split this up more */
2072 struct bio
*mbio
= r1_bio
->master_bio
;
2073 int sectors_handled
= (r1_bio
->sector
+ max_sectors
2075 r1_bio
->sectors
= max_sectors
;
2076 spin_lock_irq(&conf
->device_lock
);
2077 if (mbio
->bi_phys_segments
== 0)
2078 mbio
->bi_phys_segments
= 2;
2080 mbio
->bi_phys_segments
++;
2081 spin_unlock_irq(&conf
->device_lock
);
2082 generic_make_request(bio
);
2085 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
2087 r1_bio
->master_bio
= mbio
;
2088 r1_bio
->sectors
= (mbio
->bi_size
>> 9)
2091 set_bit(R1BIO_ReadError
, &r1_bio
->state
);
2092 r1_bio
->mddev
= mddev
;
2093 r1_bio
->sector
= mbio
->bi_sector
+ sectors_handled
;
2097 generic_make_request(bio
);
2101 static void raid1d(struct mddev
*mddev
)
2103 struct r1bio
*r1_bio
;
2104 unsigned long flags
;
2105 struct r1conf
*conf
= mddev
->private;
2106 struct list_head
*head
= &conf
->retry_list
;
2107 struct blk_plug plug
;
2109 md_check_recovery(mddev
);
2111 blk_start_plug(&plug
);
2114 if (atomic_read(&mddev
->plug_cnt
) == 0)
2115 flush_pending_writes(conf
);
2117 spin_lock_irqsave(&conf
->device_lock
, flags
);
2118 if (list_empty(head
)) {
2119 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2122 r1_bio
= list_entry(head
->prev
, struct r1bio
, retry_list
);
2123 list_del(head
->prev
);
2125 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2127 mddev
= r1_bio
->mddev
;
2128 conf
= mddev
->private;
2129 if (test_bit(R1BIO_IsSync
, &r1_bio
->state
)) {
2130 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
) ||
2131 test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2132 handle_sync_write_finished(conf
, r1_bio
);
2134 sync_request_write(mddev
, r1_bio
);
2135 } else if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
) ||
2136 test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2137 handle_write_finished(conf
, r1_bio
);
2138 else if (test_bit(R1BIO_ReadError
, &r1_bio
->state
))
2139 handle_read_error(conf
, r1_bio
);
2141 /* just a partial read to be scheduled from separate
2144 generic_make_request(r1_bio
->bios
[r1_bio
->read_disk
]);
2147 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
2148 md_check_recovery(mddev
);
2150 blk_finish_plug(&plug
);
2154 static int init_resync(struct r1conf
*conf
)
2158 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
2159 BUG_ON(conf
->r1buf_pool
);
2160 conf
->r1buf_pool
= mempool_create(buffs
, r1buf_pool_alloc
, r1buf_pool_free
,
2162 if (!conf
->r1buf_pool
)
2164 conf
->next_resync
= 0;
2169 * perform a "sync" on one "block"
2171 * We need to make sure that no normal I/O request - particularly write
2172 * requests - conflict with active sync requests.
2174 * This is achieved by tracking pending requests and a 'barrier' concept
2175 * that can be installed to exclude normal IO requests.
2178 static sector_t
sync_request(struct mddev
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
2180 struct r1conf
*conf
= mddev
->private;
2181 struct r1bio
*r1_bio
;
2183 sector_t max_sector
, nr_sectors
;
2187 int write_targets
= 0, read_targets
= 0;
2188 sector_t sync_blocks
;
2189 int still_degraded
= 0;
2190 int good_sectors
= RESYNC_SECTORS
;
2191 int min_bad
= 0; /* number of sectors that are bad in all devices */
2193 if (!conf
->r1buf_pool
)
2194 if (init_resync(conf
))
2197 max_sector
= mddev
->dev_sectors
;
2198 if (sector_nr
>= max_sector
) {
2199 /* If we aborted, we need to abort the
2200 * sync on the 'current' bitmap chunk (there will
2201 * only be one in raid1 resync.
2202 * We can find the current addess in mddev->curr_resync
2204 if (mddev
->curr_resync
< max_sector
) /* aborted */
2205 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
2207 else /* completed sync */
2210 bitmap_close_sync(mddev
->bitmap
);
2215 if (mddev
->bitmap
== NULL
&&
2216 mddev
->recovery_cp
== MaxSector
&&
2217 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
2218 conf
->fullsync
== 0) {
2220 return max_sector
- sector_nr
;
2222 /* before building a request, check if we can skip these blocks..
2223 * This call the bitmap_start_sync doesn't actually record anything
2225 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
2226 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
2227 /* We can skip this block, and probably several more */
2232 * If there is non-resync activity waiting for a turn,
2233 * and resync is going fast enough,
2234 * then let it though before starting on this new sync request.
2236 if (!go_faster
&& conf
->nr_waiting
)
2237 msleep_interruptible(1000);
2239 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
2240 r1_bio
= mempool_alloc(conf
->r1buf_pool
, GFP_NOIO
);
2241 raise_barrier(conf
);
2243 conf
->next_resync
= sector_nr
;
2247 * If we get a correctably read error during resync or recovery,
2248 * we might want to read from a different device. So we
2249 * flag all drives that could conceivably be read from for READ,
2250 * and any others (which will be non-In_sync devices) for WRITE.
2251 * If a read fails, we try reading from something else for which READ
2255 r1_bio
->mddev
= mddev
;
2256 r1_bio
->sector
= sector_nr
;
2258 set_bit(R1BIO_IsSync
, &r1_bio
->state
);
2260 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
2261 struct md_rdev
*rdev
;
2262 bio
= r1_bio
->bios
[i
];
2264 /* take from bio_init */
2265 bio
->bi_next
= NULL
;
2266 bio
->bi_flags
&= ~(BIO_POOL_MASK
-1);
2267 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
2271 bio
->bi_phys_segments
= 0;
2273 bio
->bi_end_io
= NULL
;
2274 bio
->bi_private
= NULL
;
2276 rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
2278 test_bit(Faulty
, &rdev
->flags
)) {
2279 if (i
< conf
->raid_disks
)
2281 } else if (!test_bit(In_sync
, &rdev
->flags
)) {
2283 bio
->bi_end_io
= end_sync_write
;
2286 /* may need to read from here */
2287 sector_t first_bad
= MaxSector
;
2290 if (is_badblock(rdev
, sector_nr
, good_sectors
,
2291 &first_bad
, &bad_sectors
)) {
2292 if (first_bad
> sector_nr
)
2293 good_sectors
= first_bad
- sector_nr
;
2295 bad_sectors
-= (sector_nr
- first_bad
);
2297 min_bad
> bad_sectors
)
2298 min_bad
= bad_sectors
;
2301 if (sector_nr
< first_bad
) {
2302 if (test_bit(WriteMostly
, &rdev
->flags
)) {
2310 bio
->bi_end_io
= end_sync_read
;
2314 if (bio
->bi_end_io
) {
2315 atomic_inc(&rdev
->nr_pending
);
2316 bio
->bi_sector
= sector_nr
+ rdev
->data_offset
;
2317 bio
->bi_bdev
= rdev
->bdev
;
2318 bio
->bi_private
= r1_bio
;
2324 r1_bio
->read_disk
= disk
;
2326 if (read_targets
== 0 && min_bad
> 0) {
2327 /* These sectors are bad on all InSync devices, so we
2328 * need to mark them bad on all write targets
2331 for (i
= 0 ; i
< conf
->raid_disks
* 2 ; i
++)
2332 if (r1_bio
->bios
[i
]->bi_end_io
== end_sync_write
) {
2333 struct md_rdev
*rdev
=
2334 rcu_dereference(conf
->mirrors
[i
].rdev
);
2335 ok
= rdev_set_badblocks(rdev
, sector_nr
,
2339 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
2344 /* Cannot record the badblocks, so need to
2346 * If there are multiple read targets, could just
2347 * fail the really bad ones ???
2349 conf
->recovery_disabled
= mddev
->recovery_disabled
;
2350 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
2356 if (min_bad
> 0 && min_bad
< good_sectors
) {
2357 /* only resync enough to reach the next bad->good
2359 good_sectors
= min_bad
;
2362 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
) && read_targets
> 0)
2363 /* extra read targets are also write targets */
2364 write_targets
+= read_targets
-1;
2366 if (write_targets
== 0 || read_targets
== 0) {
2367 /* There is nowhere to write, so all non-sync
2368 * drives must be failed - so we are finished
2370 sector_t rv
= max_sector
- sector_nr
;
2376 if (max_sector
> mddev
->resync_max
)
2377 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
2378 if (max_sector
> sector_nr
+ good_sectors
)
2379 max_sector
= sector_nr
+ good_sectors
;
2384 int len
= PAGE_SIZE
;
2385 if (sector_nr
+ (len
>>9) > max_sector
)
2386 len
= (max_sector
- sector_nr
) << 9;
2389 if (sync_blocks
== 0) {
2390 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
2391 &sync_blocks
, still_degraded
) &&
2393 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
2395 BUG_ON(sync_blocks
< (PAGE_SIZE
>>9));
2396 if ((len
>> 9) > sync_blocks
)
2397 len
= sync_blocks
<<9;
2400 for (i
= 0 ; i
< conf
->raid_disks
* 2; i
++) {
2401 bio
= r1_bio
->bios
[i
];
2402 if (bio
->bi_end_io
) {
2403 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
2404 if (bio_add_page(bio
, page
, len
, 0) == 0) {
2406 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
2409 bio
= r1_bio
->bios
[i
];
2410 if (bio
->bi_end_io
==NULL
)
2412 /* remove last page from this bio */
2414 bio
->bi_size
-= len
;
2415 bio
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
2421 nr_sectors
+= len
>>9;
2422 sector_nr
+= len
>>9;
2423 sync_blocks
-= (len
>>9);
2424 } while (r1_bio
->bios
[disk
]->bi_vcnt
< RESYNC_PAGES
);
2426 r1_bio
->sectors
= nr_sectors
;
2428 /* For a user-requested sync, we read all readable devices and do a
2431 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
2432 atomic_set(&r1_bio
->remaining
, read_targets
);
2433 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
2434 bio
= r1_bio
->bios
[i
];
2435 if (bio
->bi_end_io
== end_sync_read
) {
2436 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2437 generic_make_request(bio
);
2441 atomic_set(&r1_bio
->remaining
, 1);
2442 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
2443 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2444 generic_make_request(bio
);
2450 static sector_t
raid1_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
2455 return mddev
->dev_sectors
;
2458 static struct r1conf
*setup_conf(struct mddev
*mddev
)
2460 struct r1conf
*conf
;
2462 struct mirror_info
*disk
;
2463 struct md_rdev
*rdev
;
2466 conf
= kzalloc(sizeof(struct r1conf
), GFP_KERNEL
);
2470 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)
2471 * mddev
->raid_disks
* 2,
2476 conf
->tmppage
= alloc_page(GFP_KERNEL
);
2480 conf
->poolinfo
= kzalloc(sizeof(*conf
->poolinfo
), GFP_KERNEL
);
2481 if (!conf
->poolinfo
)
2483 conf
->poolinfo
->raid_disks
= mddev
->raid_disks
* 2;
2484 conf
->r1bio_pool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
2487 if (!conf
->r1bio_pool
)
2490 conf
->poolinfo
->mddev
= mddev
;
2493 spin_lock_init(&conf
->device_lock
);
2494 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
2495 int disk_idx
= rdev
->raid_disk
;
2496 if (disk_idx
>= mddev
->raid_disks
2499 if (test_bit(Replacement
, &rdev
->flags
))
2500 disk
= conf
->mirrors
+ conf
->raid_disks
+ disk_idx
;
2502 disk
= conf
->mirrors
+ disk_idx
;
2508 disk
->head_position
= 0;
2510 conf
->raid_disks
= mddev
->raid_disks
;
2511 conf
->mddev
= mddev
;
2512 INIT_LIST_HEAD(&conf
->retry_list
);
2514 spin_lock_init(&conf
->resync_lock
);
2515 init_waitqueue_head(&conf
->wait_barrier
);
2517 bio_list_init(&conf
->pending_bio_list
);
2518 conf
->pending_count
= 0;
2519 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
2522 conf
->last_used
= -1;
2523 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
2525 disk
= conf
->mirrors
+ i
;
2527 if (i
< conf
->raid_disks
&&
2528 disk
[conf
->raid_disks
].rdev
) {
2529 /* This slot has a replacement. */
2531 /* No original, just make the replacement
2532 * a recovering spare
2535 disk
[conf
->raid_disks
].rdev
;
2536 disk
[conf
->raid_disks
].rdev
= NULL
;
2537 } else if (!test_bit(In_sync
, &disk
->rdev
->flags
))
2538 /* Original is not in_sync - bad */
2543 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
2544 disk
->head_position
= 0;
2547 } else if (conf
->last_used
< 0)
2549 * The first working device is used as a
2550 * starting point to read balancing.
2552 conf
->last_used
= i
;
2555 if (conf
->last_used
< 0) {
2556 printk(KERN_ERR
"md/raid1:%s: no operational mirrors\n",
2561 conf
->thread
= md_register_thread(raid1d
, mddev
, NULL
);
2562 if (!conf
->thread
) {
2564 "md/raid1:%s: couldn't allocate thread\n",
2573 if (conf
->r1bio_pool
)
2574 mempool_destroy(conf
->r1bio_pool
);
2575 kfree(conf
->mirrors
);
2576 safe_put_page(conf
->tmppage
);
2577 kfree(conf
->poolinfo
);
2580 return ERR_PTR(err
);
2583 static int run(struct mddev
*mddev
)
2585 struct r1conf
*conf
;
2587 struct md_rdev
*rdev
;
2589 if (mddev
->level
!= 1) {
2590 printk(KERN_ERR
"md/raid1:%s: raid level not set to mirroring (%d)\n",
2591 mdname(mddev
), mddev
->level
);
2594 if (mddev
->reshape_position
!= MaxSector
) {
2595 printk(KERN_ERR
"md/raid1:%s: reshape_position set but not supported\n",
2600 * copy the already verified devices into our private RAID1
2601 * bookkeeping area. [whatever we allocate in run(),
2602 * should be freed in stop()]
2604 if (mddev
->private == NULL
)
2605 conf
= setup_conf(mddev
);
2607 conf
= mddev
->private;
2610 return PTR_ERR(conf
);
2612 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
2613 if (!mddev
->gendisk
)
2615 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
2616 rdev
->data_offset
<< 9);
2617 /* as we don't honour merge_bvec_fn, we must never risk
2618 * violating it, so limit ->max_segments to 1 lying within
2619 * a single page, as a one page request is never in violation.
2621 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
2622 blk_queue_max_segments(mddev
->queue
, 1);
2623 blk_queue_segment_boundary(mddev
->queue
,
2624 PAGE_CACHE_SIZE
- 1);
2628 mddev
->degraded
= 0;
2629 for (i
=0; i
< conf
->raid_disks
; i
++)
2630 if (conf
->mirrors
[i
].rdev
== NULL
||
2631 !test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ||
2632 test_bit(Faulty
, &conf
->mirrors
[i
].rdev
->flags
))
2635 if (conf
->raid_disks
- mddev
->degraded
== 1)
2636 mddev
->recovery_cp
= MaxSector
;
2638 if (mddev
->recovery_cp
!= MaxSector
)
2639 printk(KERN_NOTICE
"md/raid1:%s: not clean"
2640 " -- starting background reconstruction\n",
2643 "md/raid1:%s: active with %d out of %d mirrors\n",
2644 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
2648 * Ok, everything is just fine now
2650 mddev
->thread
= conf
->thread
;
2651 conf
->thread
= NULL
;
2652 mddev
->private = conf
;
2654 md_set_array_sectors(mddev
, raid1_size(mddev
, 0, 0));
2657 mddev
->queue
->backing_dev_info
.congested_fn
= raid1_congested
;
2658 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
2660 return md_integrity_register(mddev
);
2663 static int stop(struct mddev
*mddev
)
2665 struct r1conf
*conf
= mddev
->private;
2666 struct bitmap
*bitmap
= mddev
->bitmap
;
2668 /* wait for behind writes to complete */
2669 if (bitmap
&& atomic_read(&bitmap
->behind_writes
) > 0) {
2670 printk(KERN_INFO
"md/raid1:%s: behind writes in progress - waiting to stop.\n",
2672 /* need to kick something here to make sure I/O goes? */
2673 wait_event(bitmap
->behind_wait
,
2674 atomic_read(&bitmap
->behind_writes
) == 0);
2677 raise_barrier(conf
);
2678 lower_barrier(conf
);
2680 md_unregister_thread(&mddev
->thread
);
2681 if (conf
->r1bio_pool
)
2682 mempool_destroy(conf
->r1bio_pool
);
2683 kfree(conf
->mirrors
);
2684 kfree(conf
->poolinfo
);
2686 mddev
->private = NULL
;
2690 static int raid1_resize(struct mddev
*mddev
, sector_t sectors
)
2692 /* no resync is happening, and there is enough space
2693 * on all devices, so we can resize.
2694 * We need to make sure resync covers any new space.
2695 * If the array is shrinking we should possibly wait until
2696 * any io in the removed space completes, but it hardly seems
2699 md_set_array_sectors(mddev
, raid1_size(mddev
, sectors
, 0));
2700 if (mddev
->array_sectors
> raid1_size(mddev
, sectors
, 0))
2702 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
2703 revalidate_disk(mddev
->gendisk
);
2704 if (sectors
> mddev
->dev_sectors
&&
2705 mddev
->recovery_cp
> mddev
->dev_sectors
) {
2706 mddev
->recovery_cp
= mddev
->dev_sectors
;
2707 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2709 mddev
->dev_sectors
= sectors
;
2710 mddev
->resync_max_sectors
= sectors
;
2714 static int raid1_reshape(struct mddev
*mddev
)
2717 * 1/ resize the r1bio_pool
2718 * 2/ resize conf->mirrors
2720 * We allocate a new r1bio_pool if we can.
2721 * Then raise a device barrier and wait until all IO stops.
2722 * Then resize conf->mirrors and swap in the new r1bio pool.
2724 * At the same time, we "pack" the devices so that all the missing
2725 * devices have the higher raid_disk numbers.
2727 mempool_t
*newpool
, *oldpool
;
2728 struct pool_info
*newpoolinfo
;
2729 struct mirror_info
*newmirrors
;
2730 struct r1conf
*conf
= mddev
->private;
2731 int cnt
, raid_disks
;
2732 unsigned long flags
;
2735 /* Cannot change chunk_size, layout, or level */
2736 if (mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
||
2737 mddev
->layout
!= mddev
->new_layout
||
2738 mddev
->level
!= mddev
->new_level
) {
2739 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
2740 mddev
->new_layout
= mddev
->layout
;
2741 mddev
->new_level
= mddev
->level
;
2745 err
= md_allow_write(mddev
);
2749 raid_disks
= mddev
->raid_disks
+ mddev
->delta_disks
;
2751 if (raid_disks
< conf
->raid_disks
) {
2753 for (d
= 0; d
< conf
->raid_disks
; d
++)
2754 if (conf
->mirrors
[d
].rdev
)
2756 if (cnt
> raid_disks
)
2760 newpoolinfo
= kmalloc(sizeof(*newpoolinfo
), GFP_KERNEL
);
2763 newpoolinfo
->mddev
= mddev
;
2764 newpoolinfo
->raid_disks
= raid_disks
* 2;
2766 newpool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
2767 r1bio_pool_free
, newpoolinfo
);
2772 newmirrors
= kzalloc(sizeof(struct mirror_info
) * raid_disks
* 2,
2776 mempool_destroy(newpool
);
2780 raise_barrier(conf
);
2782 /* ok, everything is stopped */
2783 oldpool
= conf
->r1bio_pool
;
2784 conf
->r1bio_pool
= newpool
;
2786 for (d
= d2
= 0; d
< conf
->raid_disks
; d
++) {
2787 struct md_rdev
*rdev
= conf
->mirrors
[d
].rdev
;
2788 if (rdev
&& rdev
->raid_disk
!= d2
) {
2789 sysfs_unlink_rdev(mddev
, rdev
);
2790 rdev
->raid_disk
= d2
;
2791 sysfs_unlink_rdev(mddev
, rdev
);
2792 if (sysfs_link_rdev(mddev
, rdev
))
2794 "md/raid1:%s: cannot register rd%d\n",
2795 mdname(mddev
), rdev
->raid_disk
);
2798 newmirrors
[d2
++].rdev
= rdev
;
2800 kfree(conf
->mirrors
);
2801 conf
->mirrors
= newmirrors
;
2802 kfree(conf
->poolinfo
);
2803 conf
->poolinfo
= newpoolinfo
;
2805 spin_lock_irqsave(&conf
->device_lock
, flags
);
2806 mddev
->degraded
+= (raid_disks
- conf
->raid_disks
);
2807 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2808 conf
->raid_disks
= mddev
->raid_disks
= raid_disks
;
2809 mddev
->delta_disks
= 0;
2811 conf
->last_used
= 0; /* just make sure it is in-range */
2812 lower_barrier(conf
);
2814 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2815 md_wakeup_thread(mddev
->thread
);
2817 mempool_destroy(oldpool
);
2821 static void raid1_quiesce(struct mddev
*mddev
, int state
)
2823 struct r1conf
*conf
= mddev
->private;
2826 case 2: /* wake for suspend */
2827 wake_up(&conf
->wait_barrier
);
2830 raise_barrier(conf
);
2833 lower_barrier(conf
);
2838 static void *raid1_takeover(struct mddev
*mddev
)
2840 /* raid1 can take over:
2841 * raid5 with 2 devices, any layout or chunk size
2843 if (mddev
->level
== 5 && mddev
->raid_disks
== 2) {
2844 struct r1conf
*conf
;
2845 mddev
->new_level
= 1;
2846 mddev
->new_layout
= 0;
2847 mddev
->new_chunk_sectors
= 0;
2848 conf
= setup_conf(mddev
);
2853 return ERR_PTR(-EINVAL
);
2856 static struct md_personality raid1_personality
=
2860 .owner
= THIS_MODULE
,
2861 .make_request
= make_request
,
2865 .error_handler
= error
,
2866 .hot_add_disk
= raid1_add_disk
,
2867 .hot_remove_disk
= raid1_remove_disk
,
2868 .spare_active
= raid1_spare_active
,
2869 .sync_request
= sync_request
,
2870 .resize
= raid1_resize
,
2872 .check_reshape
= raid1_reshape
,
2873 .quiesce
= raid1_quiesce
,
2874 .takeover
= raid1_takeover
,
2877 static int __init
raid_init(void)
2879 return register_md_personality(&raid1_personality
);
2882 static void raid_exit(void)
2884 unregister_md_personality(&raid1_personality
);
2887 module_init(raid_init
);
2888 module_exit(raid_exit
);
2889 MODULE_LICENSE("GPL");
2890 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2891 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2892 MODULE_ALIAS("md-raid1");
2893 MODULE_ALIAS("md-level-1");
2895 module_param(max_queued_requests
, int, S_IRUGO
|S_IWUSR
);