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/seq_file.h>
38 #include <linux/ratelimit.h>
44 #define PRINTK(x...) do { if (DEBUG) printk(x); } while (0)
47 * Number of guaranteed r1bios in case of extreme VM load:
49 #define NR_RAID1_BIOS 256
52 static void allow_barrier(conf_t
*conf
);
53 static void lower_barrier(conf_t
*conf
);
55 static void * r1bio_pool_alloc(gfp_t gfp_flags
, void *data
)
57 struct pool_info
*pi
= data
;
58 int size
= offsetof(r1bio_t
, bios
[pi
->raid_disks
]);
60 /* allocate a r1bio with room for raid_disks entries in the bios array */
61 return kzalloc(size
, gfp_flags
);
64 static void r1bio_pool_free(void *r1_bio
, void *data
)
69 #define RESYNC_BLOCK_SIZE (64*1024)
70 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
71 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
72 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
73 #define RESYNC_WINDOW (2048*1024)
75 static void * r1buf_pool_alloc(gfp_t gfp_flags
, void *data
)
77 struct pool_info
*pi
= data
;
83 r1_bio
= r1bio_pool_alloc(gfp_flags
, pi
);
88 * Allocate bios : 1 for reading, n-1 for writing
90 for (j
= pi
->raid_disks
; j
-- ; ) {
91 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
94 r1_bio
->bios
[j
] = bio
;
97 * Allocate RESYNC_PAGES data pages and attach them to
99 * If this is a user-requested check/repair, allocate
100 * RESYNC_PAGES for each bio.
102 if (test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
))
107 bio
= r1_bio
->bios
[j
];
108 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
109 page
= alloc_page(gfp_flags
);
113 bio
->bi_io_vec
[i
].bv_page
= page
;
117 /* If not user-requests, copy the page pointers to all bios */
118 if (!test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
)) {
119 for (i
=0; i
<RESYNC_PAGES
; i
++)
120 for (j
=1; j
<pi
->raid_disks
; j
++)
121 r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
=
122 r1_bio
->bios
[0]->bi_io_vec
[i
].bv_page
;
125 r1_bio
->master_bio
= NULL
;
130 for (j
=0 ; j
< pi
->raid_disks
; j
++)
131 for (i
=0; i
< r1_bio
->bios
[j
]->bi_vcnt
; i
++)
132 put_page(r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
135 while ( ++j
< pi
->raid_disks
)
136 bio_put(r1_bio
->bios
[j
]);
137 r1bio_pool_free(r1_bio
, data
);
141 static void r1buf_pool_free(void *__r1_bio
, void *data
)
143 struct pool_info
*pi
= data
;
145 r1bio_t
*r1bio
= __r1_bio
;
147 for (i
= 0; i
< RESYNC_PAGES
; i
++)
148 for (j
= pi
->raid_disks
; j
-- ;) {
150 r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
!=
151 r1bio
->bios
[0]->bi_io_vec
[i
].bv_page
)
152 safe_put_page(r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
154 for (i
=0 ; i
< pi
->raid_disks
; i
++)
155 bio_put(r1bio
->bios
[i
]);
157 r1bio_pool_free(r1bio
, data
);
160 static void put_all_bios(conf_t
*conf
, r1bio_t
*r1_bio
)
164 for (i
= 0; i
< conf
->raid_disks
; i
++) {
165 struct bio
**bio
= r1_bio
->bios
+ i
;
166 if (!BIO_SPECIAL(*bio
))
172 static void free_r1bio(r1bio_t
*r1_bio
)
174 conf_t
*conf
= r1_bio
->mddev
->private;
176 put_all_bios(conf
, r1_bio
);
177 mempool_free(r1_bio
, conf
->r1bio_pool
);
180 static void put_buf(r1bio_t
*r1_bio
)
182 conf_t
*conf
= r1_bio
->mddev
->private;
185 for (i
=0; i
<conf
->raid_disks
; i
++) {
186 struct bio
*bio
= r1_bio
->bios
[i
];
188 rdev_dec_pending(conf
->mirrors
[i
].rdev
, r1_bio
->mddev
);
191 mempool_free(r1_bio
, conf
->r1buf_pool
);
196 static void reschedule_retry(r1bio_t
*r1_bio
)
199 mddev_t
*mddev
= r1_bio
->mddev
;
200 conf_t
*conf
= mddev
->private;
202 spin_lock_irqsave(&conf
->device_lock
, flags
);
203 list_add(&r1_bio
->retry_list
, &conf
->retry_list
);
205 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
207 wake_up(&conf
->wait_barrier
);
208 md_wakeup_thread(mddev
->thread
);
212 * raid_end_bio_io() is called when we have finished servicing a mirrored
213 * operation and are ready to return a success/failure code to the buffer
216 static void call_bio_endio(r1bio_t
*r1_bio
)
218 struct bio
*bio
= r1_bio
->master_bio
;
220 conf_t
*conf
= r1_bio
->mddev
->private;
222 if (bio
->bi_phys_segments
) {
224 spin_lock_irqsave(&conf
->device_lock
, flags
);
225 bio
->bi_phys_segments
--;
226 done
= (bio
->bi_phys_segments
== 0);
227 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
231 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
))
232 clear_bit(BIO_UPTODATE
, &bio
->bi_flags
);
236 * Wake up any possible resync thread that waits for the device
243 static void raid_end_bio_io(r1bio_t
*r1_bio
)
245 struct bio
*bio
= r1_bio
->master_bio
;
247 /* if nobody has done the final endio yet, do it now */
248 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
249 PRINTK(KERN_DEBUG
"raid1: sync end %s on sectors %llu-%llu\n",
250 (bio_data_dir(bio
) == WRITE
) ? "write" : "read",
251 (unsigned long long) bio
->bi_sector
,
252 (unsigned long long) bio
->bi_sector
+
253 (bio
->bi_size
>> 9) - 1);
255 call_bio_endio(r1_bio
);
261 * Update disk head position estimator based on IRQ completion info.
263 static inline void update_head_pos(int disk
, r1bio_t
*r1_bio
)
265 conf_t
*conf
= r1_bio
->mddev
->private;
267 conf
->mirrors
[disk
].head_position
=
268 r1_bio
->sector
+ (r1_bio
->sectors
);
271 static void raid1_end_read_request(struct bio
*bio
, int error
)
273 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
274 r1bio_t
*r1_bio
= bio
->bi_private
;
276 conf_t
*conf
= r1_bio
->mddev
->private;
278 mirror
= r1_bio
->read_disk
;
280 * this branch is our 'one mirror IO has finished' event handler:
282 update_head_pos(mirror
, r1_bio
);
285 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
287 /* If all other devices have failed, we want to return
288 * the error upwards rather than fail the last device.
289 * Here we redefine "uptodate" to mean "Don't want to retry"
292 spin_lock_irqsave(&conf
->device_lock
, flags
);
293 if (r1_bio
->mddev
->degraded
== conf
->raid_disks
||
294 (r1_bio
->mddev
->degraded
== conf
->raid_disks
-1 &&
295 !test_bit(Faulty
, &conf
->mirrors
[mirror
].rdev
->flags
)))
297 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
301 raid_end_bio_io(r1_bio
);
306 char b
[BDEVNAME_SIZE
];
308 KERN_ERR
"md/raid1:%s: %s: "
309 "rescheduling sector %llu\n",
311 bdevname(conf
->mirrors
[mirror
].rdev
->bdev
,
313 (unsigned long long)r1_bio
->sector
);
314 set_bit(R1BIO_ReadError
, &r1_bio
->state
);
315 reschedule_retry(r1_bio
);
318 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
321 static void r1_bio_write_done(r1bio_t
*r1_bio
)
323 if (atomic_dec_and_test(&r1_bio
->remaining
))
325 /* it really is the end of this request */
326 if (test_bit(R1BIO_BehindIO
, &r1_bio
->state
)) {
327 /* free extra copy of the data pages */
328 int i
= r1_bio
->behind_page_count
;
330 safe_put_page(r1_bio
->behind_pages
[i
]);
331 kfree(r1_bio
->behind_pages
);
332 r1_bio
->behind_pages
= NULL
;
334 /* clear the bitmap if all writes complete successfully */
335 bitmap_endwrite(r1_bio
->mddev
->bitmap
, r1_bio
->sector
,
337 !test_bit(R1BIO_Degraded
, &r1_bio
->state
),
338 test_bit(R1BIO_BehindIO
, &r1_bio
->state
));
339 md_write_end(r1_bio
->mddev
);
340 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
))
341 reschedule_retry(r1_bio
);
343 raid_end_bio_io(r1_bio
);
347 static void raid1_end_write_request(struct bio
*bio
, int error
)
349 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
350 r1bio_t
*r1_bio
= bio
->bi_private
;
351 int mirror
, behind
= test_bit(R1BIO_BehindIO
, &r1_bio
->state
);
352 conf_t
*conf
= r1_bio
->mddev
->private;
353 struct bio
*to_put
= NULL
;
356 for (mirror
= 0; mirror
< conf
->raid_disks
; mirror
++)
357 if (r1_bio
->bios
[mirror
] == bio
)
361 * 'one mirror IO has finished' event handler:
363 r1_bio
->bios
[mirror
] = NULL
;
366 md_error(r1_bio
->mddev
, conf
->mirrors
[mirror
].rdev
);
367 /* an I/O failed, we can't clear the bitmap */
368 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
371 * Set R1BIO_Uptodate in our master bio, so that we
372 * will return a good error code for to the higher
373 * levels even if IO on some other mirrored buffer
376 * The 'master' represents the composite IO operation
377 * to user-side. So if something waits for IO, then it
378 * will wait for the 'master' bio.
383 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
385 /* Maybe we can clear some bad blocks. */
386 if (is_badblock(conf
->mirrors
[mirror
].rdev
,
387 r1_bio
->sector
, r1_bio
->sectors
,
388 &first_bad
, &bad_sectors
)) {
389 r1_bio
->bios
[mirror
] = IO_MADE_GOOD
;
390 set_bit(R1BIO_MadeGood
, &r1_bio
->state
);
394 update_head_pos(mirror
, r1_bio
);
397 if (test_bit(WriteMostly
, &conf
->mirrors
[mirror
].rdev
->flags
))
398 atomic_dec(&r1_bio
->behind_remaining
);
401 * In behind mode, we ACK the master bio once the I/O
402 * has safely reached all non-writemostly
403 * disks. Setting the Returned bit ensures that this
404 * gets done only once -- we don't ever want to return
405 * -EIO here, instead we'll wait
407 if (atomic_read(&r1_bio
->behind_remaining
) >= (atomic_read(&r1_bio
->remaining
)-1) &&
408 test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
409 /* Maybe we can return now */
410 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
411 struct bio
*mbio
= r1_bio
->master_bio
;
412 PRINTK(KERN_DEBUG
"raid1: behind end write sectors %llu-%llu\n",
413 (unsigned long long) mbio
->bi_sector
,
414 (unsigned long long) mbio
->bi_sector
+
415 (mbio
->bi_size
>> 9) - 1);
416 call_bio_endio(r1_bio
);
420 if (r1_bio
->bios
[mirror
] == NULL
)
421 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
,
425 * Let's see if all mirrored write operations have finished
428 r1_bio_write_done(r1_bio
);
436 * This routine returns the disk from which the requested read should
437 * be done. There is a per-array 'next expected sequential IO' sector
438 * number - if this matches on the next IO then we use the last disk.
439 * There is also a per-disk 'last know head position' sector that is
440 * maintained from IRQ contexts, both the normal and the resync IO
441 * completion handlers update this position correctly. If there is no
442 * perfect sequential match then we pick the disk whose head is closest.
444 * If there are 2 mirrors in the same 2 devices, performance degrades
445 * because position is mirror, not device based.
447 * The rdev for the device selected will have nr_pending incremented.
449 static int read_balance(conf_t
*conf
, r1bio_t
*r1_bio
, int *max_sectors
)
451 const sector_t this_sector
= r1_bio
->sector
;
453 int best_good_sectors
;
463 * Check if we can balance. We can balance on the whole
464 * device if no resync is going on, or below the resync window.
465 * We take the first readable disk when above the resync window.
468 sectors
= r1_bio
->sectors
;
470 best_dist
= MaxSector
;
471 best_good_sectors
= 0;
473 if (conf
->mddev
->recovery_cp
< MaxSector
&&
474 (this_sector
+ sectors
>= conf
->next_resync
)) {
479 start_disk
= conf
->last_used
;
482 for (i
= 0 ; i
< conf
->raid_disks
; i
++) {
487 int disk
= start_disk
+ i
;
488 if (disk
>= conf
->raid_disks
)
489 disk
-= conf
->raid_disks
;
491 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
492 if (r1_bio
->bios
[disk
] == IO_BLOCKED
494 || test_bit(Faulty
, &rdev
->flags
))
496 if (!test_bit(In_sync
, &rdev
->flags
) &&
497 rdev
->recovery_offset
< this_sector
+ sectors
)
499 if (test_bit(WriteMostly
, &rdev
->flags
)) {
500 /* Don't balance among write-mostly, just
501 * use the first as a last resort */
506 /* This is a reasonable device to use. It might
509 if (is_badblock(rdev
, this_sector
, sectors
,
510 &first_bad
, &bad_sectors
)) {
511 if (best_dist
< MaxSector
)
512 /* already have a better device */
514 if (first_bad
<= this_sector
) {
515 /* cannot read here. If this is the 'primary'
516 * device, then we must not read beyond
517 * bad_sectors from another device..
519 bad_sectors
-= (this_sector
- first_bad
);
520 if (choose_first
&& sectors
> bad_sectors
)
521 sectors
= bad_sectors
;
522 if (best_good_sectors
> sectors
)
523 best_good_sectors
= sectors
;
526 sector_t good_sectors
= first_bad
- this_sector
;
527 if (good_sectors
> best_good_sectors
) {
528 best_good_sectors
= good_sectors
;
536 best_good_sectors
= sectors
;
538 dist
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
540 /* Don't change to another disk for sequential reads */
541 || conf
->next_seq_sect
== this_sector
543 /* If device is idle, use it */
544 || atomic_read(&rdev
->nr_pending
) == 0) {
548 if (dist
< best_dist
) {
554 if (best_disk
>= 0) {
555 rdev
= rcu_dereference(conf
->mirrors
[best_disk
].rdev
);
558 atomic_inc(&rdev
->nr_pending
);
559 if (test_bit(Faulty
, &rdev
->flags
)) {
560 /* cannot risk returning a device that failed
561 * before we inc'ed nr_pending
563 rdev_dec_pending(rdev
, conf
->mddev
);
566 sectors
= best_good_sectors
;
567 conf
->next_seq_sect
= this_sector
+ sectors
;
568 conf
->last_used
= best_disk
;
571 *max_sectors
= sectors
;
576 int md_raid1_congested(mddev_t
*mddev
, int bits
)
578 conf_t
*conf
= mddev
->private;
582 for (i
= 0; i
< mddev
->raid_disks
; i
++) {
583 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
584 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
585 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
589 /* Note the '|| 1' - when read_balance prefers
590 * non-congested targets, it can be removed
592 if ((bits
& (1<<BDI_async_congested
)) || 1)
593 ret
|= bdi_congested(&q
->backing_dev_info
, bits
);
595 ret
&= bdi_congested(&q
->backing_dev_info
, bits
);
601 EXPORT_SYMBOL_GPL(md_raid1_congested
);
603 static int raid1_congested(void *data
, int bits
)
605 mddev_t
*mddev
= data
;
607 return mddev_congested(mddev
, bits
) ||
608 md_raid1_congested(mddev
, bits
);
611 static void flush_pending_writes(conf_t
*conf
)
613 /* Any writes that have been queued but are awaiting
614 * bitmap updates get flushed here.
616 spin_lock_irq(&conf
->device_lock
);
618 if (conf
->pending_bio_list
.head
) {
620 bio
= bio_list_get(&conf
->pending_bio_list
);
621 spin_unlock_irq(&conf
->device_lock
);
622 /* flush any pending bitmap writes to
623 * disk before proceeding w/ I/O */
624 bitmap_unplug(conf
->mddev
->bitmap
);
626 while (bio
) { /* submit pending writes */
627 struct bio
*next
= bio
->bi_next
;
629 generic_make_request(bio
);
633 spin_unlock_irq(&conf
->device_lock
);
637 * Sometimes we need to suspend IO while we do something else,
638 * either some resync/recovery, or reconfigure the array.
639 * To do this we raise a 'barrier'.
640 * The 'barrier' is a counter that can be raised multiple times
641 * to count how many activities are happening which preclude
643 * We can only raise the barrier if there is no pending IO.
644 * i.e. if nr_pending == 0.
645 * We choose only to raise the barrier if no-one is waiting for the
646 * barrier to go down. This means that as soon as an IO request
647 * is ready, no other operations which require a barrier will start
648 * until the IO request has had a chance.
650 * So: regular IO calls 'wait_barrier'. When that returns there
651 * is no backgroup IO happening, It must arrange to call
652 * allow_barrier when it has finished its IO.
653 * backgroup IO calls must call raise_barrier. Once that returns
654 * there is no normal IO happeing. It must arrange to call
655 * lower_barrier when the particular background IO completes.
657 #define RESYNC_DEPTH 32
659 static void raise_barrier(conf_t
*conf
)
661 spin_lock_irq(&conf
->resync_lock
);
663 /* Wait until no block IO is waiting */
664 wait_event_lock_irq(conf
->wait_barrier
, !conf
->nr_waiting
,
665 conf
->resync_lock
, );
667 /* block any new IO from starting */
670 /* Now wait for all pending IO to complete */
671 wait_event_lock_irq(conf
->wait_barrier
,
672 !conf
->nr_pending
&& conf
->barrier
< RESYNC_DEPTH
,
673 conf
->resync_lock
, );
675 spin_unlock_irq(&conf
->resync_lock
);
678 static void lower_barrier(conf_t
*conf
)
681 BUG_ON(conf
->barrier
<= 0);
682 spin_lock_irqsave(&conf
->resync_lock
, flags
);
684 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
685 wake_up(&conf
->wait_barrier
);
688 static void wait_barrier(conf_t
*conf
)
690 spin_lock_irq(&conf
->resync_lock
);
693 wait_event_lock_irq(conf
->wait_barrier
, !conf
->barrier
,
699 spin_unlock_irq(&conf
->resync_lock
);
702 static void allow_barrier(conf_t
*conf
)
705 spin_lock_irqsave(&conf
->resync_lock
, flags
);
707 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
708 wake_up(&conf
->wait_barrier
);
711 static void freeze_array(conf_t
*conf
)
713 /* stop syncio and normal IO and wait for everything to
715 * We increment barrier and nr_waiting, and then
716 * wait until nr_pending match nr_queued+1
717 * This is called in the context of one normal IO request
718 * that has failed. Thus any sync request that might be pending
719 * will be blocked by nr_pending, and we need to wait for
720 * pending IO requests to complete or be queued for re-try.
721 * Thus the number queued (nr_queued) plus this request (1)
722 * must match the number of pending IOs (nr_pending) before
725 spin_lock_irq(&conf
->resync_lock
);
728 wait_event_lock_irq(conf
->wait_barrier
,
729 conf
->nr_pending
== conf
->nr_queued
+1,
731 flush_pending_writes(conf
));
732 spin_unlock_irq(&conf
->resync_lock
);
734 static void unfreeze_array(conf_t
*conf
)
736 /* reverse the effect of the freeze */
737 spin_lock_irq(&conf
->resync_lock
);
740 wake_up(&conf
->wait_barrier
);
741 spin_unlock_irq(&conf
->resync_lock
);
745 /* duplicate the data pages for behind I/O
747 static void alloc_behind_pages(struct bio
*bio
, r1bio_t
*r1_bio
)
750 struct bio_vec
*bvec
;
751 struct page
**pages
= kzalloc(bio
->bi_vcnt
* sizeof(struct page
*),
753 if (unlikely(!pages
))
756 bio_for_each_segment(bvec
, bio
, i
) {
757 pages
[i
] = alloc_page(GFP_NOIO
);
758 if (unlikely(!pages
[i
]))
760 memcpy(kmap(pages
[i
]) + bvec
->bv_offset
,
761 kmap(bvec
->bv_page
) + bvec
->bv_offset
, bvec
->bv_len
);
763 kunmap(bvec
->bv_page
);
765 r1_bio
->behind_pages
= pages
;
766 r1_bio
->behind_page_count
= bio
->bi_vcnt
;
767 set_bit(R1BIO_BehindIO
, &r1_bio
->state
);
771 for (i
= 0; i
< bio
->bi_vcnt
; i
++)
775 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio
->bi_size
);
778 static int make_request(mddev_t
*mddev
, struct bio
* bio
)
780 conf_t
*conf
= mddev
->private;
781 mirror_info_t
*mirror
;
783 struct bio
*read_bio
;
785 struct bitmap
*bitmap
;
787 const int rw
= bio_data_dir(bio
);
788 const unsigned long do_sync
= (bio
->bi_rw
& REQ_SYNC
);
789 const unsigned long do_flush_fua
= (bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
));
790 mdk_rdev_t
*blocked_rdev
;
797 * Register the new request and wait if the reconstruction
798 * thread has put up a bar for new requests.
799 * Continue immediately if no resync is active currently.
802 md_write_start(mddev
, bio
); /* wait on superblock update early */
804 if (bio_data_dir(bio
) == WRITE
&&
805 bio
->bi_sector
+ bio
->bi_size
/512 > mddev
->suspend_lo
&&
806 bio
->bi_sector
< mddev
->suspend_hi
) {
807 /* As the suspend_* range is controlled by
808 * userspace, we want an interruptible
813 flush_signals(current
);
814 prepare_to_wait(&conf
->wait_barrier
,
815 &w
, TASK_INTERRUPTIBLE
);
816 if (bio
->bi_sector
+ bio
->bi_size
/512 <= mddev
->suspend_lo
||
817 bio
->bi_sector
>= mddev
->suspend_hi
)
821 finish_wait(&conf
->wait_barrier
, &w
);
826 bitmap
= mddev
->bitmap
;
829 * make_request() can abort the operation when READA is being
830 * used and no empty request is available.
833 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
835 r1_bio
->master_bio
= bio
;
836 r1_bio
->sectors
= bio
->bi_size
>> 9;
838 r1_bio
->mddev
= mddev
;
839 r1_bio
->sector
= bio
->bi_sector
;
841 /* We might need to issue multiple reads to different
842 * devices if there are bad blocks around, so we keep
843 * track of the number of reads in bio->bi_phys_segments.
844 * If this is 0, there is only one r1_bio and no locking
845 * will be needed when requests complete. If it is
846 * non-zero, then it is the number of not-completed requests.
848 bio
->bi_phys_segments
= 0;
849 clear_bit(BIO_SEG_VALID
, &bio
->bi_flags
);
853 * read balancing logic:
858 rdisk
= read_balance(conf
, r1_bio
, &max_sectors
);
861 /* couldn't find anywhere to read from */
862 raid_end_bio_io(r1_bio
);
865 mirror
= conf
->mirrors
+ rdisk
;
867 if (test_bit(WriteMostly
, &mirror
->rdev
->flags
) &&
869 /* Reading from a write-mostly device must
870 * take care not to over-take any writes
873 wait_event(bitmap
->behind_wait
,
874 atomic_read(&bitmap
->behind_writes
) == 0);
876 r1_bio
->read_disk
= rdisk
;
878 read_bio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
879 md_trim_bio(read_bio
, r1_bio
->sector
- bio
->bi_sector
,
882 r1_bio
->bios
[rdisk
] = read_bio
;
884 read_bio
->bi_sector
= r1_bio
->sector
+ mirror
->rdev
->data_offset
;
885 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
886 read_bio
->bi_end_io
= raid1_end_read_request
;
887 read_bio
->bi_rw
= READ
| do_sync
;
888 read_bio
->bi_private
= r1_bio
;
890 if (max_sectors
< r1_bio
->sectors
) {
891 /* could not read all from this device, so we will
892 * need another r1_bio.
895 sectors_handled
= (r1_bio
->sector
+ max_sectors
897 r1_bio
->sectors
= max_sectors
;
898 spin_lock_irq(&conf
->device_lock
);
899 if (bio
->bi_phys_segments
== 0)
900 bio
->bi_phys_segments
= 2;
902 bio
->bi_phys_segments
++;
903 spin_unlock_irq(&conf
->device_lock
);
904 /* Cannot call generic_make_request directly
905 * as that will be queued in __make_request
906 * and subsequent mempool_alloc might block waiting
907 * for it. So hand bio over to raid1d.
909 reschedule_retry(r1_bio
);
911 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
913 r1_bio
->master_bio
= bio
;
914 r1_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
916 r1_bio
->mddev
= mddev
;
917 r1_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
920 generic_make_request(read_bio
);
927 /* first select target devices under rcu_lock and
928 * inc refcount on their rdev. Record them by setting
930 * If there are known/acknowledged bad blocks on any device on
931 * which we have seen a write error, we want to avoid writing those
933 * This potentially requires several writes to write around
934 * the bad blocks. Each set of writes gets it's own r1bio
935 * with a set of bios attached.
937 plugged
= mddev_check_plugged(mddev
);
939 disks
= conf
->raid_disks
;
943 max_sectors
= r1_bio
->sectors
;
944 for (i
= 0; i
< disks
; i
++) {
945 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
946 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
947 atomic_inc(&rdev
->nr_pending
);
951 r1_bio
->bios
[i
] = NULL
;
952 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
)) {
953 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
957 atomic_inc(&rdev
->nr_pending
);
958 if (test_bit(WriteErrorSeen
, &rdev
->flags
)) {
963 is_bad
= is_badblock(rdev
, r1_bio
->sector
,
965 &first_bad
, &bad_sectors
);
967 /* mustn't write here until the bad block is
969 set_bit(BlockedBadBlocks
, &rdev
->flags
);
973 if (is_bad
&& first_bad
<= r1_bio
->sector
) {
974 /* Cannot write here at all */
975 bad_sectors
-= (r1_bio
->sector
- first_bad
);
976 if (bad_sectors
< max_sectors
)
977 /* mustn't write more than bad_sectors
978 * to other devices yet
980 max_sectors
= bad_sectors
;
981 rdev_dec_pending(rdev
, mddev
);
982 /* We don't set R1BIO_Degraded as that
983 * only applies if the disk is
984 * missing, so it might be re-added,
985 * and we want to know to recover this
987 * In this case the device is here,
988 * and the fact that this chunk is not
989 * in-sync is recorded in the bad
995 int good_sectors
= first_bad
- r1_bio
->sector
;
996 if (good_sectors
< max_sectors
)
997 max_sectors
= good_sectors
;
1000 r1_bio
->bios
[i
] = bio
;
1004 if (unlikely(blocked_rdev
)) {
1005 /* Wait for this device to become unblocked */
1008 for (j
= 0; j
< i
; j
++)
1009 if (r1_bio
->bios
[j
])
1010 rdev_dec_pending(conf
->mirrors
[j
].rdev
, mddev
);
1012 allow_barrier(conf
);
1013 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
1018 if (max_sectors
< r1_bio
->sectors
) {
1019 /* We are splitting this write into multiple parts, so
1020 * we need to prepare for allocating another r1_bio.
1022 r1_bio
->sectors
= max_sectors
;
1023 spin_lock_irq(&conf
->device_lock
);
1024 if (bio
->bi_phys_segments
== 0)
1025 bio
->bi_phys_segments
= 2;
1027 bio
->bi_phys_segments
++;
1028 spin_unlock_irq(&conf
->device_lock
);
1030 sectors_handled
= r1_bio
->sector
+ max_sectors
- bio
->bi_sector
;
1032 atomic_set(&r1_bio
->remaining
, 1);
1033 atomic_set(&r1_bio
->behind_remaining
, 0);
1036 for (i
= 0; i
< disks
; i
++) {
1038 if (!r1_bio
->bios
[i
])
1041 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
1042 md_trim_bio(mbio
, r1_bio
->sector
- bio
->bi_sector
, max_sectors
);
1046 * Not if there are too many, or cannot
1047 * allocate memory, or a reader on WriteMostly
1048 * is waiting for behind writes to flush */
1050 (atomic_read(&bitmap
->behind_writes
)
1051 < mddev
->bitmap_info
.max_write_behind
) &&
1052 !waitqueue_active(&bitmap
->behind_wait
))
1053 alloc_behind_pages(mbio
, r1_bio
);
1055 bitmap_startwrite(bitmap
, r1_bio
->sector
,
1057 test_bit(R1BIO_BehindIO
,
1061 if (r1_bio
->behind_pages
) {
1062 struct bio_vec
*bvec
;
1065 /* Yes, I really want the '__' version so that
1066 * we clear any unused pointer in the io_vec, rather
1067 * than leave them unchanged. This is important
1068 * because when we come to free the pages, we won't
1069 * know the original bi_idx, so we just free
1072 __bio_for_each_segment(bvec
, mbio
, j
, 0)
1073 bvec
->bv_page
= r1_bio
->behind_pages
[j
];
1074 if (test_bit(WriteMostly
, &conf
->mirrors
[i
].rdev
->flags
))
1075 atomic_inc(&r1_bio
->behind_remaining
);
1078 r1_bio
->bios
[i
] = mbio
;
1080 mbio
->bi_sector
= (r1_bio
->sector
+
1081 conf
->mirrors
[i
].rdev
->data_offset
);
1082 mbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1083 mbio
->bi_end_io
= raid1_end_write_request
;
1084 mbio
->bi_rw
= WRITE
| do_flush_fua
| do_sync
;
1085 mbio
->bi_private
= r1_bio
;
1087 atomic_inc(&r1_bio
->remaining
);
1088 spin_lock_irqsave(&conf
->device_lock
, flags
);
1089 bio_list_add(&conf
->pending_bio_list
, mbio
);
1090 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1092 r1_bio_write_done(r1_bio
);
1094 /* In case raid1d snuck in to freeze_array */
1095 wake_up(&conf
->wait_barrier
);
1097 if (sectors_handled
< (bio
->bi_size
>> 9)) {
1098 /* We need another r1_bio. It has already been counted
1099 * in bio->bi_phys_segments
1101 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
1102 r1_bio
->master_bio
= bio
;
1103 r1_bio
->sectors
= (bio
->bi_size
>> 9) - sectors_handled
;
1105 r1_bio
->mddev
= mddev
;
1106 r1_bio
->sector
= bio
->bi_sector
+ sectors_handled
;
1110 if (do_sync
|| !bitmap
|| !plugged
)
1111 md_wakeup_thread(mddev
->thread
);
1116 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
1118 conf_t
*conf
= mddev
->private;
1121 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
1122 conf
->raid_disks
- mddev
->degraded
);
1124 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1125 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1126 seq_printf(seq
, "%s",
1127 rdev
&& test_bit(In_sync
, &rdev
->flags
) ? "U" : "_");
1130 seq_printf(seq
, "]");
1134 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1136 char b
[BDEVNAME_SIZE
];
1137 conf_t
*conf
= mddev
->private;
1140 * If it is not operational, then we have already marked it as dead
1141 * else if it is the last working disks, ignore the error, let the
1142 * next level up know.
1143 * else mark the drive as failed
1145 if (test_bit(In_sync
, &rdev
->flags
)
1146 && (conf
->raid_disks
- mddev
->degraded
) == 1) {
1148 * Don't fail the drive, act as though we were just a
1149 * normal single drive.
1150 * However don't try a recovery from this drive as
1151 * it is very likely to fail.
1153 conf
->recovery_disabled
= mddev
->recovery_disabled
;
1156 set_bit(Blocked
, &rdev
->flags
);
1157 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1158 unsigned long flags
;
1159 spin_lock_irqsave(&conf
->device_lock
, flags
);
1161 set_bit(Faulty
, &rdev
->flags
);
1162 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1164 * if recovery is running, make sure it aborts.
1166 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1168 set_bit(Faulty
, &rdev
->flags
);
1169 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1171 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1172 "md/raid1:%s: Operation continuing on %d devices.\n",
1173 mdname(mddev
), bdevname(rdev
->bdev
, b
),
1174 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
1177 static void print_conf(conf_t
*conf
)
1181 printk(KERN_DEBUG
"RAID1 conf printout:\n");
1183 printk(KERN_DEBUG
"(!conf)\n");
1186 printk(KERN_DEBUG
" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1190 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1191 char b
[BDEVNAME_SIZE
];
1192 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1194 printk(KERN_DEBUG
" disk %d, wo:%d, o:%d, dev:%s\n",
1195 i
, !test_bit(In_sync
, &rdev
->flags
),
1196 !test_bit(Faulty
, &rdev
->flags
),
1197 bdevname(rdev
->bdev
,b
));
1202 static void close_sync(conf_t
*conf
)
1205 allow_barrier(conf
);
1207 mempool_destroy(conf
->r1buf_pool
);
1208 conf
->r1buf_pool
= NULL
;
1211 static int raid1_spare_active(mddev_t
*mddev
)
1214 conf_t
*conf
= mddev
->private;
1216 unsigned long flags
;
1219 * Find all failed disks within the RAID1 configuration
1220 * and mark them readable.
1221 * Called under mddev lock, so rcu protection not needed.
1223 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1224 mdk_rdev_t
*rdev
= conf
->mirrors
[i
].rdev
;
1226 && !test_bit(Faulty
, &rdev
->flags
)
1227 && !test_and_set_bit(In_sync
, &rdev
->flags
)) {
1229 sysfs_notify_dirent_safe(rdev
->sysfs_state
);
1232 spin_lock_irqsave(&conf
->device_lock
, flags
);
1233 mddev
->degraded
-= count
;
1234 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1241 static int raid1_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1243 conf_t
*conf
= mddev
->private;
1248 int last
= mddev
->raid_disks
- 1;
1250 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
1253 if (rdev
->raid_disk
>= 0)
1254 first
= last
= rdev
->raid_disk
;
1256 for (mirror
= first
; mirror
<= last
; mirror
++)
1257 if ( !(p
=conf
->mirrors
+mirror
)->rdev
) {
1259 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1260 rdev
->data_offset
<< 9);
1261 /* as we don't honour merge_bvec_fn, we must
1262 * never risk violating it, so limit
1263 * ->max_segments to one lying with a single
1264 * page, as a one page request is never in
1267 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1268 blk_queue_max_segments(mddev
->queue
, 1);
1269 blk_queue_segment_boundary(mddev
->queue
,
1270 PAGE_CACHE_SIZE
- 1);
1273 p
->head_position
= 0;
1274 rdev
->raid_disk
= mirror
;
1276 /* As all devices are equivalent, we don't need a full recovery
1277 * if this was recently any drive of the array
1279 if (rdev
->saved_raid_disk
< 0)
1281 rcu_assign_pointer(p
->rdev
, rdev
);
1284 md_integrity_add_rdev(rdev
, mddev
);
1289 static int raid1_remove_disk(mddev_t
*mddev
, int number
)
1291 conf_t
*conf
= mddev
->private;
1294 mirror_info_t
*p
= conf
->mirrors
+ number
;
1299 if (test_bit(In_sync
, &rdev
->flags
) ||
1300 atomic_read(&rdev
->nr_pending
)) {
1304 /* Only remove non-faulty devices if recovery
1307 if (!test_bit(Faulty
, &rdev
->flags
) &&
1308 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
1309 mddev
->degraded
< conf
->raid_disks
) {
1315 if (atomic_read(&rdev
->nr_pending
)) {
1316 /* lost the race, try later */
1321 err
= md_integrity_register(mddev
);
1330 static void end_sync_read(struct bio
*bio
, int error
)
1332 r1bio_t
*r1_bio
= bio
->bi_private
;
1335 for (i
=r1_bio
->mddev
->raid_disks
; i
--; )
1336 if (r1_bio
->bios
[i
] == bio
)
1339 update_head_pos(i
, r1_bio
);
1341 * we have read a block, now it needs to be re-written,
1342 * or re-read if the read failed.
1343 * We don't do much here, just schedule handling by raid1d
1345 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1346 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1348 if (atomic_dec_and_test(&r1_bio
->remaining
))
1349 reschedule_retry(r1_bio
);
1352 static void end_sync_write(struct bio
*bio
, int error
)
1354 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1355 r1bio_t
*r1_bio
= bio
->bi_private
;
1356 mddev_t
*mddev
= r1_bio
->mddev
;
1357 conf_t
*conf
= mddev
->private;
1363 for (i
= 0; i
< conf
->raid_disks
; i
++)
1364 if (r1_bio
->bios
[i
] == bio
) {
1369 sector_t sync_blocks
= 0;
1370 sector_t s
= r1_bio
->sector
;
1371 long sectors_to_go
= r1_bio
->sectors
;
1372 /* make sure these bits doesn't get cleared. */
1374 bitmap_end_sync(mddev
->bitmap
, s
,
1377 sectors_to_go
-= sync_blocks
;
1378 } while (sectors_to_go
> 0);
1379 md_error(mddev
, conf
->mirrors
[mirror
].rdev
);
1380 } else if (is_badblock(conf
->mirrors
[mirror
].rdev
,
1383 &first_bad
, &bad_sectors
))
1384 set_bit(R1BIO_MadeGood
, &r1_bio
->state
);
1386 update_head_pos(mirror
, r1_bio
);
1388 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1389 int s
= r1_bio
->sectors
;
1390 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
))
1391 reschedule_retry(r1_bio
);
1394 md_done_sync(mddev
, s
, uptodate
);
1399 static int fix_sync_read_error(r1bio_t
*r1_bio
)
1401 /* Try some synchronous reads of other devices to get
1402 * good data, much like with normal read errors. Only
1403 * read into the pages we already have so we don't
1404 * need to re-issue the read request.
1405 * We don't need to freeze the array, because being in an
1406 * active sync request, there is no normal IO, and
1407 * no overlapping syncs.
1408 * We don't need to check is_badblock() again as we
1409 * made sure that anything with a bad block in range
1410 * will have bi_end_io clear.
1412 mddev_t
*mddev
= r1_bio
->mddev
;
1413 conf_t
*conf
= mddev
->private;
1414 struct bio
*bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1415 sector_t sect
= r1_bio
->sector
;
1416 int sectors
= r1_bio
->sectors
;
1421 int d
= r1_bio
->read_disk
;
1426 if (s
> (PAGE_SIZE
>>9))
1429 if (r1_bio
->bios
[d
]->bi_end_io
== end_sync_read
) {
1430 /* No rcu protection needed here devices
1431 * can only be removed when no resync is
1432 * active, and resync is currently active
1434 rdev
= conf
->mirrors
[d
].rdev
;
1435 if (sync_page_io(rdev
, sect
, s
<<9,
1436 bio
->bi_io_vec
[idx
].bv_page
,
1443 if (d
== conf
->raid_disks
)
1445 } while (!success
&& d
!= r1_bio
->read_disk
);
1448 char b
[BDEVNAME_SIZE
];
1449 /* Cannot read from anywhere, array is toast */
1450 md_error(mddev
, conf
->mirrors
[r1_bio
->read_disk
].rdev
);
1451 printk(KERN_ALERT
"md/raid1:%s: %s: unrecoverable I/O read error"
1452 " for block %llu\n",
1454 bdevname(bio
->bi_bdev
, b
),
1455 (unsigned long long)r1_bio
->sector
);
1456 md_done_sync(mddev
, r1_bio
->sectors
, 0);
1462 /* write it back and re-read */
1463 while (d
!= r1_bio
->read_disk
) {
1465 d
= conf
->raid_disks
;
1467 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1469 rdev
= conf
->mirrors
[d
].rdev
;
1470 if (sync_page_io(rdev
, sect
, s
<<9,
1471 bio
->bi_io_vec
[idx
].bv_page
,
1472 WRITE
, false) == 0) {
1473 r1_bio
->bios
[d
]->bi_end_io
= NULL
;
1474 rdev_dec_pending(rdev
, mddev
);
1475 md_error(mddev
, rdev
);
1479 while (d
!= r1_bio
->read_disk
) {
1481 d
= conf
->raid_disks
;
1483 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1485 rdev
= conf
->mirrors
[d
].rdev
;
1486 if (sync_page_io(rdev
, sect
, s
<<9,
1487 bio
->bi_io_vec
[idx
].bv_page
,
1489 md_error(mddev
, rdev
);
1491 atomic_add(s
, &rdev
->corrected_errors
);
1497 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1498 set_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1502 static int process_checks(r1bio_t
*r1_bio
)
1504 /* We have read all readable devices. If we haven't
1505 * got the block, then there is no hope left.
1506 * If we have, then we want to do a comparison
1507 * and skip the write if everything is the same.
1508 * If any blocks failed to read, then we need to
1509 * attempt an over-write
1511 mddev_t
*mddev
= r1_bio
->mddev
;
1512 conf_t
*conf
= mddev
->private;
1516 for (primary
= 0; primary
< conf
->raid_disks
; primary
++)
1517 if (r1_bio
->bios
[primary
]->bi_end_io
== end_sync_read
&&
1518 test_bit(BIO_UPTODATE
, &r1_bio
->bios
[primary
]->bi_flags
)) {
1519 r1_bio
->bios
[primary
]->bi_end_io
= NULL
;
1520 rdev_dec_pending(conf
->mirrors
[primary
].rdev
, mddev
);
1523 r1_bio
->read_disk
= primary
;
1524 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1526 int vcnt
= r1_bio
->sectors
>> (PAGE_SHIFT
- 9);
1527 struct bio
*pbio
= r1_bio
->bios
[primary
];
1528 struct bio
*sbio
= r1_bio
->bios
[i
];
1531 if (r1_bio
->bios
[i
]->bi_end_io
!= end_sync_read
)
1534 if (test_bit(BIO_UPTODATE
, &sbio
->bi_flags
)) {
1535 for (j
= vcnt
; j
-- ; ) {
1537 p
= pbio
->bi_io_vec
[j
].bv_page
;
1538 s
= sbio
->bi_io_vec
[j
].bv_page
;
1539 if (memcmp(page_address(p
),
1547 mddev
->resync_mismatches
+= r1_bio
->sectors
;
1548 if (j
< 0 || (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
)
1549 && test_bit(BIO_UPTODATE
, &sbio
->bi_flags
))) {
1550 /* No need to write to this device. */
1551 sbio
->bi_end_io
= NULL
;
1552 rdev_dec_pending(conf
->mirrors
[i
].rdev
, mddev
);
1555 /* fixup the bio for reuse */
1556 sbio
->bi_vcnt
= vcnt
;
1557 sbio
->bi_size
= r1_bio
->sectors
<< 9;
1559 sbio
->bi_phys_segments
= 0;
1560 sbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1561 sbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1562 sbio
->bi_next
= NULL
;
1563 sbio
->bi_sector
= r1_bio
->sector
+
1564 conf
->mirrors
[i
].rdev
->data_offset
;
1565 sbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1566 size
= sbio
->bi_size
;
1567 for (j
= 0; j
< vcnt
; j
++) {
1569 bi
= &sbio
->bi_io_vec
[j
];
1571 if (size
> PAGE_SIZE
)
1572 bi
->bv_len
= PAGE_SIZE
;
1576 memcpy(page_address(bi
->bv_page
),
1577 page_address(pbio
->bi_io_vec
[j
].bv_page
),
1584 static void sync_request_write(mddev_t
*mddev
, r1bio_t
*r1_bio
)
1586 conf_t
*conf
= mddev
->private;
1588 int disks
= conf
->raid_disks
;
1589 struct bio
*bio
, *wbio
;
1591 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1593 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
))
1594 /* ouch - failed to read all of that. */
1595 if (!fix_sync_read_error(r1_bio
))
1598 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
1599 if (process_checks(r1_bio
) < 0)
1604 atomic_set(&r1_bio
->remaining
, 1);
1605 for (i
= 0; i
< disks
; i
++) {
1606 wbio
= r1_bio
->bios
[i
];
1607 if (wbio
->bi_end_io
== NULL
||
1608 (wbio
->bi_end_io
== end_sync_read
&&
1609 (i
== r1_bio
->read_disk
||
1610 !test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))))
1613 wbio
->bi_rw
= WRITE
;
1614 wbio
->bi_end_io
= end_sync_write
;
1615 atomic_inc(&r1_bio
->remaining
);
1616 md_sync_acct(conf
->mirrors
[i
].rdev
->bdev
, wbio
->bi_size
>> 9);
1618 generic_make_request(wbio
);
1621 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1622 /* if we're here, all write(s) have completed, so clean up */
1623 md_done_sync(mddev
, r1_bio
->sectors
, 1);
1629 * This is a kernel thread which:
1631 * 1. Retries failed read operations on working mirrors.
1632 * 2. Updates the raid superblock when problems encounter.
1633 * 3. Performs writes following reads for array synchronising.
1636 static void fix_read_error(conf_t
*conf
, int read_disk
,
1637 sector_t sect
, int sectors
)
1639 mddev_t
*mddev
= conf
->mddev
;
1647 if (s
> (PAGE_SIZE
>>9))
1651 /* Note: no rcu protection needed here
1652 * as this is synchronous in the raid1d thread
1653 * which is the thread that might remove
1654 * a device. If raid1d ever becomes multi-threaded....
1659 rdev
= conf
->mirrors
[d
].rdev
;
1661 test_bit(In_sync
, &rdev
->flags
) &&
1662 is_badblock(rdev
, sect
, s
,
1663 &first_bad
, &bad_sectors
) == 0 &&
1664 sync_page_io(rdev
, sect
, s
<<9,
1665 conf
->tmppage
, READ
, false))
1669 if (d
== conf
->raid_disks
)
1672 } while (!success
&& d
!= read_disk
);
1675 /* Cannot read from anywhere -- bye bye array */
1676 md_error(mddev
, conf
->mirrors
[read_disk
].rdev
);
1679 /* write it back and re-read */
1681 while (d
!= read_disk
) {
1683 d
= conf
->raid_disks
;
1685 rdev
= conf
->mirrors
[d
].rdev
;
1687 test_bit(In_sync
, &rdev
->flags
)) {
1688 if (sync_page_io(rdev
, sect
, s
<<9,
1689 conf
->tmppage
, WRITE
, false)
1691 /* Well, this device is dead */
1692 md_error(mddev
, rdev
);
1696 while (d
!= read_disk
) {
1697 char b
[BDEVNAME_SIZE
];
1699 d
= conf
->raid_disks
;
1701 rdev
= conf
->mirrors
[d
].rdev
;
1703 test_bit(In_sync
, &rdev
->flags
)) {
1704 if (sync_page_io(rdev
, sect
, s
<<9,
1705 conf
->tmppage
, READ
, false)
1707 /* Well, this device is dead */
1708 md_error(mddev
, rdev
);
1710 atomic_add(s
, &rdev
->corrected_errors
);
1712 "md/raid1:%s: read error corrected "
1713 "(%d sectors at %llu on %s)\n",
1715 (unsigned long long)(sect
+
1717 bdevname(rdev
->bdev
, b
));
1726 static void raid1d(mddev_t
*mddev
)
1730 unsigned long flags
;
1731 conf_t
*conf
= mddev
->private;
1732 struct list_head
*head
= &conf
->retry_list
;
1734 struct blk_plug plug
;
1736 md_check_recovery(mddev
);
1738 blk_start_plug(&plug
);
1740 char b
[BDEVNAME_SIZE
];
1742 if (atomic_read(&mddev
->plug_cnt
) == 0)
1743 flush_pending_writes(conf
);
1745 spin_lock_irqsave(&conf
->device_lock
, flags
);
1746 if (list_empty(head
)) {
1747 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1750 r1_bio
= list_entry(head
->prev
, r1bio_t
, retry_list
);
1751 list_del(head
->prev
);
1753 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1755 mddev
= r1_bio
->mddev
;
1756 conf
= mddev
->private;
1757 if (test_bit(R1BIO_IsSync
, &r1_bio
->state
)) {
1758 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
)) {
1760 int s
= r1_bio
->sectors
;
1761 for (m
= 0; m
< conf
->raid_disks
; m
++) {
1762 struct bio
*bio
= r1_bio
->bios
[m
];
1763 if (bio
->bi_end_io
!= NULL
&&
1764 test_bit(BIO_UPTODATE
,
1766 rdev
= conf
->mirrors
[m
].rdev
;
1767 rdev_clear_badblocks(
1774 md_done_sync(mddev
, s
, 1);
1776 sync_request_write(mddev
, r1_bio
);
1777 } else if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
)) {
1779 for (m
= 0; m
< conf
->raid_disks
; m
++)
1780 if (r1_bio
->bios
[m
] == IO_MADE_GOOD
) {
1781 rdev
= conf
->mirrors
[m
].rdev
;
1782 rdev_clear_badblocks(
1786 rdev_dec_pending(rdev
, mddev
);
1788 raid_end_bio_io(r1_bio
);
1789 } else if (test_bit(R1BIO_ReadError
, &r1_bio
->state
)) {
1793 clear_bit(R1BIO_ReadError
, &r1_bio
->state
);
1794 /* we got a read error. Maybe the drive is bad. Maybe just
1795 * the block and we can fix it.
1796 * We freeze all other IO, and try reading the block from
1797 * other devices. When we find one, we re-write
1798 * and check it that fixes the read error.
1799 * This is all done synchronously while the array is
1802 if (mddev
->ro
== 0) {
1804 fix_read_error(conf
, r1_bio
->read_disk
,
1807 unfreeze_array(conf
);
1810 conf
->mirrors
[r1_bio
->read_disk
].rdev
);
1812 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1813 bdevname(bio
->bi_bdev
, b
);
1815 disk
= read_balance(conf
, r1_bio
, &max_sectors
);
1817 printk(KERN_ALERT
"md/raid1:%s: %s: unrecoverable I/O"
1818 " read error for block %llu\n",
1820 (unsigned long long)r1_bio
->sector
);
1821 raid_end_bio_io(r1_bio
);
1823 const unsigned long do_sync
= r1_bio
->master_bio
->bi_rw
& REQ_SYNC
;
1825 r1_bio
->bios
[r1_bio
->read_disk
] =
1826 mddev
->ro
? IO_BLOCKED
: NULL
;
1829 r1_bio
->read_disk
= disk
;
1830 bio
= bio_clone_mddev(r1_bio
->master_bio
,
1833 r1_bio
->sector
- bio
->bi_sector
,
1835 r1_bio
->bios
[r1_bio
->read_disk
] = bio
;
1836 rdev
= conf
->mirrors
[disk
].rdev
;
1839 "md/raid1:%s: redirecting sector %llu"
1840 " to other mirror: %s\n",
1842 (unsigned long long)r1_bio
->sector
,
1843 bdevname(rdev
->bdev
, b
));
1844 bio
->bi_sector
= r1_bio
->sector
+ rdev
->data_offset
;
1845 bio
->bi_bdev
= rdev
->bdev
;
1846 bio
->bi_end_io
= raid1_end_read_request
;
1847 bio
->bi_rw
= READ
| do_sync
;
1848 bio
->bi_private
= r1_bio
;
1849 if (max_sectors
< r1_bio
->sectors
) {
1850 /* Drat - have to split this up more */
1851 struct bio
*mbio
= r1_bio
->master_bio
;
1852 int sectors_handled
=
1853 r1_bio
->sector
+ max_sectors
1855 r1_bio
->sectors
= max_sectors
;
1856 spin_lock_irq(&conf
->device_lock
);
1857 if (mbio
->bi_phys_segments
== 0)
1858 mbio
->bi_phys_segments
= 2;
1860 mbio
->bi_phys_segments
++;
1861 spin_unlock_irq(&conf
->device_lock
);
1862 generic_make_request(bio
);
1865 r1_bio
= mempool_alloc(conf
->r1bio_pool
,
1868 r1_bio
->master_bio
= mbio
;
1869 r1_bio
->sectors
= (mbio
->bi_size
>> 9)
1872 set_bit(R1BIO_ReadError
,
1874 r1_bio
->mddev
= mddev
;
1875 r1_bio
->sector
= mbio
->bi_sector
1880 generic_make_request(bio
);
1883 /* just a partial read to be scheduled from separate
1886 generic_make_request(r1_bio
->bios
[r1_bio
->read_disk
]);
1889 if (mddev
->flags
& ~(1<<MD_CHANGE_PENDING
))
1890 md_check_recovery(mddev
);
1892 blk_finish_plug(&plug
);
1896 static int init_resync(conf_t
*conf
)
1900 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
1901 BUG_ON(conf
->r1buf_pool
);
1902 conf
->r1buf_pool
= mempool_create(buffs
, r1buf_pool_alloc
, r1buf_pool_free
,
1904 if (!conf
->r1buf_pool
)
1906 conf
->next_resync
= 0;
1911 * perform a "sync" on one "block"
1913 * We need to make sure that no normal I/O request - particularly write
1914 * requests - conflict with active sync requests.
1916 * This is achieved by tracking pending requests and a 'barrier' concept
1917 * that can be installed to exclude normal IO requests.
1920 static sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
1922 conf_t
*conf
= mddev
->private;
1925 sector_t max_sector
, nr_sectors
;
1929 int write_targets
= 0, read_targets
= 0;
1930 sector_t sync_blocks
;
1931 int still_degraded
= 0;
1932 int good_sectors
= RESYNC_SECTORS
;
1933 int min_bad
= 0; /* number of sectors that are bad in all devices */
1935 if (!conf
->r1buf_pool
)
1936 if (init_resync(conf
))
1939 max_sector
= mddev
->dev_sectors
;
1940 if (sector_nr
>= max_sector
) {
1941 /* If we aborted, we need to abort the
1942 * sync on the 'current' bitmap chunk (there will
1943 * only be one in raid1 resync.
1944 * We can find the current addess in mddev->curr_resync
1946 if (mddev
->curr_resync
< max_sector
) /* aborted */
1947 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
1949 else /* completed sync */
1952 bitmap_close_sync(mddev
->bitmap
);
1957 if (mddev
->bitmap
== NULL
&&
1958 mddev
->recovery_cp
== MaxSector
&&
1959 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
1960 conf
->fullsync
== 0) {
1962 return max_sector
- sector_nr
;
1964 /* before building a request, check if we can skip these blocks..
1965 * This call the bitmap_start_sync doesn't actually record anything
1967 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
1968 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
1969 /* We can skip this block, and probably several more */
1974 * If there is non-resync activity waiting for a turn,
1975 * and resync is going fast enough,
1976 * then let it though before starting on this new sync request.
1978 if (!go_faster
&& conf
->nr_waiting
)
1979 msleep_interruptible(1000);
1981 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
1982 r1_bio
= mempool_alloc(conf
->r1buf_pool
, GFP_NOIO
);
1983 raise_barrier(conf
);
1985 conf
->next_resync
= sector_nr
;
1989 * If we get a correctably read error during resync or recovery,
1990 * we might want to read from a different device. So we
1991 * flag all drives that could conceivably be read from for READ,
1992 * and any others (which will be non-In_sync devices) for WRITE.
1993 * If a read fails, we try reading from something else for which READ
1997 r1_bio
->mddev
= mddev
;
1998 r1_bio
->sector
= sector_nr
;
2000 set_bit(R1BIO_IsSync
, &r1_bio
->state
);
2002 for (i
=0; i
< conf
->raid_disks
; i
++) {
2004 bio
= r1_bio
->bios
[i
];
2006 /* take from bio_init */
2007 bio
->bi_next
= NULL
;
2008 bio
->bi_flags
&= ~(BIO_POOL_MASK
-1);
2009 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
2010 bio
->bi_comp_cpu
= -1;
2014 bio
->bi_phys_segments
= 0;
2016 bio
->bi_end_io
= NULL
;
2017 bio
->bi_private
= NULL
;
2019 rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
2021 test_bit(Faulty
, &rdev
->flags
)) {
2023 } else if (!test_bit(In_sync
, &rdev
->flags
)) {
2025 bio
->bi_end_io
= end_sync_write
;
2028 /* may need to read from here */
2029 sector_t first_bad
= MaxSector
;
2032 if (is_badblock(rdev
, sector_nr
, good_sectors
,
2033 &first_bad
, &bad_sectors
)) {
2034 if (first_bad
> sector_nr
)
2035 good_sectors
= first_bad
- sector_nr
;
2037 bad_sectors
-= (sector_nr
- first_bad
);
2039 min_bad
> bad_sectors
)
2040 min_bad
= bad_sectors
;
2043 if (sector_nr
< first_bad
) {
2044 if (test_bit(WriteMostly
, &rdev
->flags
)) {
2052 bio
->bi_end_io
= end_sync_read
;
2056 if (bio
->bi_end_io
) {
2057 atomic_inc(&rdev
->nr_pending
);
2058 bio
->bi_sector
= sector_nr
+ rdev
->data_offset
;
2059 bio
->bi_bdev
= rdev
->bdev
;
2060 bio
->bi_private
= r1_bio
;
2066 r1_bio
->read_disk
= disk
;
2068 if (read_targets
== 0 && min_bad
> 0) {
2069 /* These sectors are bad on all InSync devices, so we
2070 * need to mark them bad on all write targets
2073 for (i
= 0 ; i
< conf
->raid_disks
; i
++)
2074 if (r1_bio
->bios
[i
]->bi_end_io
== end_sync_write
) {
2076 rcu_dereference(conf
->mirrors
[i
].rdev
);
2077 ok
= rdev_set_badblocks(rdev
, sector_nr
,
2081 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
2086 /* Cannot record the badblocks, so need to
2088 * If there are multiple read targets, could just
2089 * fail the really bad ones ???
2091 conf
->recovery_disabled
= mddev
->recovery_disabled
;
2092 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
2098 if (min_bad
> 0 && min_bad
< good_sectors
) {
2099 /* only resync enough to reach the next bad->good
2101 good_sectors
= min_bad
;
2104 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
) && read_targets
> 0)
2105 /* extra read targets are also write targets */
2106 write_targets
+= read_targets
-1;
2108 if (write_targets
== 0 || read_targets
== 0) {
2109 /* There is nowhere to write, so all non-sync
2110 * drives must be failed - so we are finished
2112 sector_t rv
= max_sector
- sector_nr
;
2118 if (max_sector
> mddev
->resync_max
)
2119 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
2120 if (max_sector
> sector_nr
+ good_sectors
)
2121 max_sector
= sector_nr
+ good_sectors
;
2126 int len
= PAGE_SIZE
;
2127 if (sector_nr
+ (len
>>9) > max_sector
)
2128 len
= (max_sector
- sector_nr
) << 9;
2131 if (sync_blocks
== 0) {
2132 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
2133 &sync_blocks
, still_degraded
) &&
2135 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
2137 BUG_ON(sync_blocks
< (PAGE_SIZE
>>9));
2138 if ((len
>> 9) > sync_blocks
)
2139 len
= sync_blocks
<<9;
2142 for (i
=0 ; i
< conf
->raid_disks
; i
++) {
2143 bio
= r1_bio
->bios
[i
];
2144 if (bio
->bi_end_io
) {
2145 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
2146 if (bio_add_page(bio
, page
, len
, 0) == 0) {
2148 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
2151 bio
= r1_bio
->bios
[i
];
2152 if (bio
->bi_end_io
==NULL
)
2154 /* remove last page from this bio */
2156 bio
->bi_size
-= len
;
2157 bio
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
2163 nr_sectors
+= len
>>9;
2164 sector_nr
+= len
>>9;
2165 sync_blocks
-= (len
>>9);
2166 } while (r1_bio
->bios
[disk
]->bi_vcnt
< RESYNC_PAGES
);
2168 r1_bio
->sectors
= nr_sectors
;
2170 /* For a user-requested sync, we read all readable devices and do a
2173 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
2174 atomic_set(&r1_bio
->remaining
, read_targets
);
2175 for (i
=0; i
<conf
->raid_disks
; i
++) {
2176 bio
= r1_bio
->bios
[i
];
2177 if (bio
->bi_end_io
== end_sync_read
) {
2178 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2179 generic_make_request(bio
);
2183 atomic_set(&r1_bio
->remaining
, 1);
2184 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
2185 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2186 generic_make_request(bio
);
2192 static sector_t
raid1_size(mddev_t
*mddev
, sector_t sectors
, int raid_disks
)
2197 return mddev
->dev_sectors
;
2200 static conf_t
*setup_conf(mddev_t
*mddev
)
2204 mirror_info_t
*disk
;
2208 conf
= kzalloc(sizeof(conf_t
), GFP_KERNEL
);
2212 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
2217 conf
->tmppage
= alloc_page(GFP_KERNEL
);
2221 conf
->poolinfo
= kzalloc(sizeof(*conf
->poolinfo
), GFP_KERNEL
);
2222 if (!conf
->poolinfo
)
2224 conf
->poolinfo
->raid_disks
= mddev
->raid_disks
;
2225 conf
->r1bio_pool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
2228 if (!conf
->r1bio_pool
)
2231 conf
->poolinfo
->mddev
= mddev
;
2233 spin_lock_init(&conf
->device_lock
);
2234 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
2235 int disk_idx
= rdev
->raid_disk
;
2236 if (disk_idx
>= mddev
->raid_disks
2239 disk
= conf
->mirrors
+ disk_idx
;
2243 disk
->head_position
= 0;
2245 conf
->raid_disks
= mddev
->raid_disks
;
2246 conf
->mddev
= mddev
;
2247 INIT_LIST_HEAD(&conf
->retry_list
);
2249 spin_lock_init(&conf
->resync_lock
);
2250 init_waitqueue_head(&conf
->wait_barrier
);
2252 bio_list_init(&conf
->pending_bio_list
);
2254 conf
->last_used
= -1;
2255 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2257 disk
= conf
->mirrors
+ i
;
2260 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
2261 disk
->head_position
= 0;
2264 } else if (conf
->last_used
< 0)
2266 * The first working device is used as a
2267 * starting point to read balancing.
2269 conf
->last_used
= i
;
2273 if (conf
->last_used
< 0) {
2274 printk(KERN_ERR
"md/raid1:%s: no operational mirrors\n",
2279 conf
->thread
= md_register_thread(raid1d
, mddev
, NULL
);
2280 if (!conf
->thread
) {
2282 "md/raid1:%s: couldn't allocate thread\n",
2291 if (conf
->r1bio_pool
)
2292 mempool_destroy(conf
->r1bio_pool
);
2293 kfree(conf
->mirrors
);
2294 safe_put_page(conf
->tmppage
);
2295 kfree(conf
->poolinfo
);
2298 return ERR_PTR(err
);
2301 static int run(mddev_t
*mddev
)
2307 if (mddev
->level
!= 1) {
2308 printk(KERN_ERR
"md/raid1:%s: raid level not set to mirroring (%d)\n",
2309 mdname(mddev
), mddev
->level
);
2312 if (mddev
->reshape_position
!= MaxSector
) {
2313 printk(KERN_ERR
"md/raid1:%s: reshape_position set but not supported\n",
2318 * copy the already verified devices into our private RAID1
2319 * bookkeeping area. [whatever we allocate in run(),
2320 * should be freed in stop()]
2322 if (mddev
->private == NULL
)
2323 conf
= setup_conf(mddev
);
2325 conf
= mddev
->private;
2328 return PTR_ERR(conf
);
2330 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
2331 if (!mddev
->gendisk
)
2333 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
2334 rdev
->data_offset
<< 9);
2335 /* as we don't honour merge_bvec_fn, we must never risk
2336 * violating it, so limit ->max_segments to 1 lying within
2337 * a single page, as a one page request is never in violation.
2339 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
2340 blk_queue_max_segments(mddev
->queue
, 1);
2341 blk_queue_segment_boundary(mddev
->queue
,
2342 PAGE_CACHE_SIZE
- 1);
2346 mddev
->degraded
= 0;
2347 for (i
=0; i
< conf
->raid_disks
; i
++)
2348 if (conf
->mirrors
[i
].rdev
== NULL
||
2349 !test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ||
2350 test_bit(Faulty
, &conf
->mirrors
[i
].rdev
->flags
))
2353 if (conf
->raid_disks
- mddev
->degraded
== 1)
2354 mddev
->recovery_cp
= MaxSector
;
2356 if (mddev
->recovery_cp
!= MaxSector
)
2357 printk(KERN_NOTICE
"md/raid1:%s: not clean"
2358 " -- starting background reconstruction\n",
2361 "md/raid1:%s: active with %d out of %d mirrors\n",
2362 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
2366 * Ok, everything is just fine now
2368 mddev
->thread
= conf
->thread
;
2369 conf
->thread
= NULL
;
2370 mddev
->private = conf
;
2372 md_set_array_sectors(mddev
, raid1_size(mddev
, 0, 0));
2375 mddev
->queue
->backing_dev_info
.congested_fn
= raid1_congested
;
2376 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
2378 return md_integrity_register(mddev
);
2381 static int stop(mddev_t
*mddev
)
2383 conf_t
*conf
= mddev
->private;
2384 struct bitmap
*bitmap
= mddev
->bitmap
;
2386 /* wait for behind writes to complete */
2387 if (bitmap
&& atomic_read(&bitmap
->behind_writes
) > 0) {
2388 printk(KERN_INFO
"md/raid1:%s: behind writes in progress - waiting to stop.\n",
2390 /* need to kick something here to make sure I/O goes? */
2391 wait_event(bitmap
->behind_wait
,
2392 atomic_read(&bitmap
->behind_writes
) == 0);
2395 raise_barrier(conf
);
2396 lower_barrier(conf
);
2398 md_unregister_thread(mddev
->thread
);
2399 mddev
->thread
= NULL
;
2400 if (conf
->r1bio_pool
)
2401 mempool_destroy(conf
->r1bio_pool
);
2402 kfree(conf
->mirrors
);
2403 kfree(conf
->poolinfo
);
2405 mddev
->private = NULL
;
2409 static int raid1_resize(mddev_t
*mddev
, sector_t sectors
)
2411 /* no resync is happening, and there is enough space
2412 * on all devices, so we can resize.
2413 * We need to make sure resync covers any new space.
2414 * If the array is shrinking we should possibly wait until
2415 * any io in the removed space completes, but it hardly seems
2418 md_set_array_sectors(mddev
, raid1_size(mddev
, sectors
, 0));
2419 if (mddev
->array_sectors
> raid1_size(mddev
, sectors
, 0))
2421 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
2422 revalidate_disk(mddev
->gendisk
);
2423 if (sectors
> mddev
->dev_sectors
&&
2424 mddev
->recovery_cp
> mddev
->dev_sectors
) {
2425 mddev
->recovery_cp
= mddev
->dev_sectors
;
2426 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2428 mddev
->dev_sectors
= sectors
;
2429 mddev
->resync_max_sectors
= sectors
;
2433 static int raid1_reshape(mddev_t
*mddev
)
2436 * 1/ resize the r1bio_pool
2437 * 2/ resize conf->mirrors
2439 * We allocate a new r1bio_pool if we can.
2440 * Then raise a device barrier and wait until all IO stops.
2441 * Then resize conf->mirrors and swap in the new r1bio pool.
2443 * At the same time, we "pack" the devices so that all the missing
2444 * devices have the higher raid_disk numbers.
2446 mempool_t
*newpool
, *oldpool
;
2447 struct pool_info
*newpoolinfo
;
2448 mirror_info_t
*newmirrors
;
2449 conf_t
*conf
= mddev
->private;
2450 int cnt
, raid_disks
;
2451 unsigned long flags
;
2454 /* Cannot change chunk_size, layout, or level */
2455 if (mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
||
2456 mddev
->layout
!= mddev
->new_layout
||
2457 mddev
->level
!= mddev
->new_level
) {
2458 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
2459 mddev
->new_layout
= mddev
->layout
;
2460 mddev
->new_level
= mddev
->level
;
2464 err
= md_allow_write(mddev
);
2468 raid_disks
= mddev
->raid_disks
+ mddev
->delta_disks
;
2470 if (raid_disks
< conf
->raid_disks
) {
2472 for (d
= 0; d
< conf
->raid_disks
; d
++)
2473 if (conf
->mirrors
[d
].rdev
)
2475 if (cnt
> raid_disks
)
2479 newpoolinfo
= kmalloc(sizeof(*newpoolinfo
), GFP_KERNEL
);
2482 newpoolinfo
->mddev
= mddev
;
2483 newpoolinfo
->raid_disks
= raid_disks
;
2485 newpool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
2486 r1bio_pool_free
, newpoolinfo
);
2491 newmirrors
= kzalloc(sizeof(struct mirror_info
) * raid_disks
, GFP_KERNEL
);
2494 mempool_destroy(newpool
);
2498 raise_barrier(conf
);
2500 /* ok, everything is stopped */
2501 oldpool
= conf
->r1bio_pool
;
2502 conf
->r1bio_pool
= newpool
;
2504 for (d
= d2
= 0; d
< conf
->raid_disks
; d
++) {
2505 mdk_rdev_t
*rdev
= conf
->mirrors
[d
].rdev
;
2506 if (rdev
&& rdev
->raid_disk
!= d2
) {
2507 sysfs_unlink_rdev(mddev
, rdev
);
2508 rdev
->raid_disk
= d2
;
2509 sysfs_unlink_rdev(mddev
, rdev
);
2510 if (sysfs_link_rdev(mddev
, rdev
))
2512 "md/raid1:%s: cannot register rd%d\n",
2513 mdname(mddev
), rdev
->raid_disk
);
2516 newmirrors
[d2
++].rdev
= rdev
;
2518 kfree(conf
->mirrors
);
2519 conf
->mirrors
= newmirrors
;
2520 kfree(conf
->poolinfo
);
2521 conf
->poolinfo
= newpoolinfo
;
2523 spin_lock_irqsave(&conf
->device_lock
, flags
);
2524 mddev
->degraded
+= (raid_disks
- conf
->raid_disks
);
2525 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2526 conf
->raid_disks
= mddev
->raid_disks
= raid_disks
;
2527 mddev
->delta_disks
= 0;
2529 conf
->last_used
= 0; /* just make sure it is in-range */
2530 lower_barrier(conf
);
2532 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2533 md_wakeup_thread(mddev
->thread
);
2535 mempool_destroy(oldpool
);
2539 static void raid1_quiesce(mddev_t
*mddev
, int state
)
2541 conf_t
*conf
= mddev
->private;
2544 case 2: /* wake for suspend */
2545 wake_up(&conf
->wait_barrier
);
2548 raise_barrier(conf
);
2551 lower_barrier(conf
);
2556 static void *raid1_takeover(mddev_t
*mddev
)
2558 /* raid1 can take over:
2559 * raid5 with 2 devices, any layout or chunk size
2561 if (mddev
->level
== 5 && mddev
->raid_disks
== 2) {
2563 mddev
->new_level
= 1;
2564 mddev
->new_layout
= 0;
2565 mddev
->new_chunk_sectors
= 0;
2566 conf
= setup_conf(mddev
);
2571 return ERR_PTR(-EINVAL
);
2574 static struct mdk_personality raid1_personality
=
2578 .owner
= THIS_MODULE
,
2579 .make_request
= make_request
,
2583 .error_handler
= error
,
2584 .hot_add_disk
= raid1_add_disk
,
2585 .hot_remove_disk
= raid1_remove_disk
,
2586 .spare_active
= raid1_spare_active
,
2587 .sync_request
= sync_request
,
2588 .resize
= raid1_resize
,
2590 .check_reshape
= raid1_reshape
,
2591 .quiesce
= raid1_quiesce
,
2592 .takeover
= raid1_takeover
,
2595 static int __init
raid_init(void)
2597 return register_md_personality(&raid1_personality
);
2600 static void raid_exit(void)
2602 unregister_md_personality(&raid1_personality
);
2605 module_init(raid_init
);
2606 module_exit(raid_exit
);
2607 MODULE_LICENSE("GPL");
2608 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2609 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2610 MODULE_ALIAS("md-raid1");
2611 MODULE_ALIAS("md-level-1");