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 "dm-bio-list.h"
35 #include <linux/raid/raid1.h>
36 #include <linux/raid/bitmap.h>
40 #define PRINTK(x...) printk(x)
46 * Number of guaranteed r1bios in case of extreme VM load:
48 #define NR_RAID1_BIOS 256
51 static void unplug_slaves(mddev_t
*mddev
);
53 static void allow_barrier(conf_t
*conf
);
54 static void lower_barrier(conf_t
*conf
);
56 static void * r1bio_pool_alloc(gfp_t gfp_flags
, void *data
)
58 struct pool_info
*pi
= data
;
60 int size
= offsetof(r1bio_t
, bios
[pi
->raid_disks
]);
62 /* allocate a r1bio with room for raid_disks entries in the bios array */
63 r1_bio
= kzalloc(size
, gfp_flags
);
65 unplug_slaves(pi
->mddev
);
70 static void r1bio_pool_free(void *r1_bio
, void *data
)
75 #define RESYNC_BLOCK_SIZE (64*1024)
76 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
77 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
78 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
79 #define RESYNC_WINDOW (2048*1024)
81 static void * r1buf_pool_alloc(gfp_t gfp_flags
, void *data
)
83 struct pool_info
*pi
= data
;
89 r1_bio
= r1bio_pool_alloc(gfp_flags
, pi
);
91 unplug_slaves(pi
->mddev
);
96 * Allocate bios : 1 for reading, n-1 for writing
98 for (j
= pi
->raid_disks
; j
-- ; ) {
99 bio
= bio_alloc(gfp_flags
, RESYNC_PAGES
);
102 r1_bio
->bios
[j
] = bio
;
105 * Allocate RESYNC_PAGES data pages and attach them to
107 * If this is a user-requested check/repair, allocate
108 * RESYNC_PAGES for each bio.
110 if (test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
))
115 bio
= r1_bio
->bios
[j
];
116 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
117 page
= alloc_page(gfp_flags
);
121 bio
->bi_io_vec
[i
].bv_page
= page
;
124 /* If not user-requests, copy the page pointers to all bios */
125 if (!test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
)) {
126 for (i
=0; i
<RESYNC_PAGES
; i
++)
127 for (j
=1; j
<pi
->raid_disks
; j
++)
128 r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
=
129 r1_bio
->bios
[0]->bi_io_vec
[i
].bv_page
;
132 r1_bio
->master_bio
= NULL
;
137 for (i
=0; i
< RESYNC_PAGES
; i
++)
138 for (j
=0 ; j
< pi
->raid_disks
; j
++)
139 safe_put_page(r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
142 while ( ++j
< pi
->raid_disks
)
143 bio_put(r1_bio
->bios
[j
]);
144 r1bio_pool_free(r1_bio
, data
);
148 static void r1buf_pool_free(void *__r1_bio
, void *data
)
150 struct pool_info
*pi
= data
;
152 r1bio_t
*r1bio
= __r1_bio
;
154 for (i
= 0; i
< RESYNC_PAGES
; i
++)
155 for (j
= pi
->raid_disks
; j
-- ;) {
157 r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
!=
158 r1bio
->bios
[0]->bi_io_vec
[i
].bv_page
)
159 safe_put_page(r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
161 for (i
=0 ; i
< pi
->raid_disks
; i
++)
162 bio_put(r1bio
->bios
[i
]);
164 r1bio_pool_free(r1bio
, data
);
167 static void put_all_bios(conf_t
*conf
, r1bio_t
*r1_bio
)
171 for (i
= 0; i
< conf
->raid_disks
; i
++) {
172 struct bio
**bio
= r1_bio
->bios
+ i
;
173 if (*bio
&& *bio
!= IO_BLOCKED
)
179 static void free_r1bio(r1bio_t
*r1_bio
)
181 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
184 * Wake up any possible resync thread that waits for the device
189 put_all_bios(conf
, r1_bio
);
190 mempool_free(r1_bio
, conf
->r1bio_pool
);
193 static void put_buf(r1bio_t
*r1_bio
)
195 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
198 for (i
=0; i
<conf
->raid_disks
; i
++) {
199 struct bio
*bio
= r1_bio
->bios
[i
];
201 rdev_dec_pending(conf
->mirrors
[i
].rdev
, r1_bio
->mddev
);
204 mempool_free(r1_bio
, conf
->r1buf_pool
);
209 static void reschedule_retry(r1bio_t
*r1_bio
)
212 mddev_t
*mddev
= r1_bio
->mddev
;
213 conf_t
*conf
= mddev_to_conf(mddev
);
215 spin_lock_irqsave(&conf
->device_lock
, flags
);
216 list_add(&r1_bio
->retry_list
, &conf
->retry_list
);
218 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
220 wake_up(&conf
->wait_barrier
);
221 md_wakeup_thread(mddev
->thread
);
225 * raid_end_bio_io() is called when we have finished servicing a mirrored
226 * operation and are ready to return a success/failure code to the buffer
229 static void raid_end_bio_io(r1bio_t
*r1_bio
)
231 struct bio
*bio
= r1_bio
->master_bio
;
233 /* if nobody has done the final endio yet, do it now */
234 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
235 PRINTK(KERN_DEBUG
"raid1: sync end %s on sectors %llu-%llu\n",
236 (bio_data_dir(bio
) == WRITE
) ? "write" : "read",
237 (unsigned long long) bio
->bi_sector
,
238 (unsigned long long) bio
->bi_sector
+
239 (bio
->bi_size
>> 9) - 1);
242 test_bit(R1BIO_Uptodate
, &r1_bio
->state
) ? 0 : -EIO
);
248 * Update disk head position estimator based on IRQ completion info.
250 static inline void update_head_pos(int disk
, r1bio_t
*r1_bio
)
252 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
254 conf
->mirrors
[disk
].head_position
=
255 r1_bio
->sector
+ (r1_bio
->sectors
);
258 static void raid1_end_read_request(struct bio
*bio
, int error
)
260 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
261 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
263 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
265 mirror
= r1_bio
->read_disk
;
267 * this branch is our 'one mirror IO has finished' event handler:
269 update_head_pos(mirror
, r1_bio
);
272 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
274 /* If all other devices have failed, we want to return
275 * the error upwards rather than fail the last device.
276 * Here we redefine "uptodate" to mean "Don't want to retry"
279 spin_lock_irqsave(&conf
->device_lock
, flags
);
280 if (r1_bio
->mddev
->degraded
== conf
->raid_disks
||
281 (r1_bio
->mddev
->degraded
== conf
->raid_disks
-1 &&
282 !test_bit(Faulty
, &conf
->mirrors
[mirror
].rdev
->flags
)))
284 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
288 raid_end_bio_io(r1_bio
);
293 char b
[BDEVNAME_SIZE
];
294 if (printk_ratelimit())
295 printk(KERN_ERR
"raid1: %s: rescheduling sector %llu\n",
296 bdevname(conf
->mirrors
[mirror
].rdev
->bdev
,b
), (unsigned long long)r1_bio
->sector
);
297 reschedule_retry(r1_bio
);
300 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
303 static void raid1_end_write_request(struct bio
*bio
, int error
)
305 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
306 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
307 int mirror
, behind
= test_bit(R1BIO_BehindIO
, &r1_bio
->state
);
308 conf_t
*conf
= mddev_to_conf(r1_bio
->mddev
);
309 struct bio
*to_put
= NULL
;
312 for (mirror
= 0; mirror
< conf
->raid_disks
; mirror
++)
313 if (r1_bio
->bios
[mirror
] == bio
)
316 if (error
== -EOPNOTSUPP
&& test_bit(R1BIO_Barrier
, &r1_bio
->state
)) {
317 set_bit(BarriersNotsupp
, &conf
->mirrors
[mirror
].rdev
->flags
);
318 set_bit(R1BIO_BarrierRetry
, &r1_bio
->state
);
319 r1_bio
->mddev
->barriers_work
= 0;
320 /* Don't rdev_dec_pending in this branch - keep it for the retry */
323 * this branch is our 'one mirror IO has finished' event handler:
325 r1_bio
->bios
[mirror
] = NULL
;
328 md_error(r1_bio
->mddev
, conf
->mirrors
[mirror
].rdev
);
329 /* an I/O failed, we can't clear the bitmap */
330 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
333 * Set R1BIO_Uptodate in our master bio, so that
334 * we will return a good error code for to the higher
335 * levels even if IO on some other mirrored buffer fails.
337 * The 'master' represents the composite IO operation to
338 * user-side. So if something waits for IO, then it will
339 * wait for the 'master' bio.
341 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
343 update_head_pos(mirror
, r1_bio
);
346 if (test_bit(WriteMostly
, &conf
->mirrors
[mirror
].rdev
->flags
))
347 atomic_dec(&r1_bio
->behind_remaining
);
349 /* In behind mode, we ACK the master bio once the I/O has safely
350 * reached all non-writemostly disks. Setting the Returned bit
351 * ensures that this gets done only once -- we don't ever want to
352 * return -EIO here, instead we'll wait */
354 if (atomic_read(&r1_bio
->behind_remaining
) >= (atomic_read(&r1_bio
->remaining
)-1) &&
355 test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
356 /* Maybe we can return now */
357 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
358 struct bio
*mbio
= r1_bio
->master_bio
;
359 PRINTK(KERN_DEBUG
"raid1: behind end write sectors %llu-%llu\n",
360 (unsigned long long) mbio
->bi_sector
,
361 (unsigned long long) mbio
->bi_sector
+
362 (mbio
->bi_size
>> 9) - 1);
367 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
371 * Let's see if all mirrored write operations have finished
374 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
375 if (test_bit(R1BIO_BarrierRetry
, &r1_bio
->state
))
376 reschedule_retry(r1_bio
);
378 /* it really is the end of this request */
379 if (test_bit(R1BIO_BehindIO
, &r1_bio
->state
)) {
380 /* free extra copy of the data pages */
381 int i
= bio
->bi_vcnt
;
383 safe_put_page(bio
->bi_io_vec
[i
].bv_page
);
385 /* clear the bitmap if all writes complete successfully */
386 bitmap_endwrite(r1_bio
->mddev
->bitmap
, r1_bio
->sector
,
388 !test_bit(R1BIO_Degraded
, &r1_bio
->state
),
390 md_write_end(r1_bio
->mddev
);
391 raid_end_bio_io(r1_bio
);
401 * This routine returns the disk from which the requested read should
402 * be done. There is a per-array 'next expected sequential IO' sector
403 * number - if this matches on the next IO then we use the last disk.
404 * There is also a per-disk 'last know head position' sector that is
405 * maintained from IRQ contexts, both the normal and the resync IO
406 * completion handlers update this position correctly. If there is no
407 * perfect sequential match then we pick the disk whose head is closest.
409 * If there are 2 mirrors in the same 2 devices, performance degrades
410 * because position is mirror, not device based.
412 * The rdev for the device selected will have nr_pending incremented.
414 static int read_balance(conf_t
*conf
, r1bio_t
*r1_bio
)
416 const unsigned long this_sector
= r1_bio
->sector
;
417 int new_disk
= conf
->last_used
, disk
= new_disk
;
419 const int sectors
= r1_bio
->sectors
;
420 sector_t new_distance
, current_distance
;
425 * Check if we can balance. We can balance on the whole
426 * device if no resync is going on, or below the resync window.
427 * We take the first readable disk when above the resync window.
430 if (conf
->mddev
->recovery_cp
< MaxSector
&&
431 (this_sector
+ sectors
>= conf
->next_resync
)) {
432 /* Choose the first operation device, for consistancy */
435 for (rdev
= rcu_dereference(conf
->mirrors
[new_disk
].rdev
);
436 r1_bio
->bios
[new_disk
] == IO_BLOCKED
||
437 !rdev
|| !test_bit(In_sync
, &rdev
->flags
)
438 || test_bit(WriteMostly
, &rdev
->flags
);
439 rdev
= rcu_dereference(conf
->mirrors
[++new_disk
].rdev
)) {
441 if (rdev
&& test_bit(In_sync
, &rdev
->flags
) &&
442 r1_bio
->bios
[new_disk
] != IO_BLOCKED
)
443 wonly_disk
= new_disk
;
445 if (new_disk
== conf
->raid_disks
- 1) {
446 new_disk
= wonly_disk
;
454 /* make sure the disk is operational */
455 for (rdev
= rcu_dereference(conf
->mirrors
[new_disk
].rdev
);
456 r1_bio
->bios
[new_disk
] == IO_BLOCKED
||
457 !rdev
|| !test_bit(In_sync
, &rdev
->flags
) ||
458 test_bit(WriteMostly
, &rdev
->flags
);
459 rdev
= rcu_dereference(conf
->mirrors
[new_disk
].rdev
)) {
461 if (rdev
&& test_bit(In_sync
, &rdev
->flags
) &&
462 r1_bio
->bios
[new_disk
] != IO_BLOCKED
)
463 wonly_disk
= new_disk
;
466 new_disk
= conf
->raid_disks
;
468 if (new_disk
== disk
) {
469 new_disk
= wonly_disk
;
478 /* now disk == new_disk == starting point for search */
481 * Don't change to another disk for sequential reads:
483 if (conf
->next_seq_sect
== this_sector
)
485 if (this_sector
== conf
->mirrors
[new_disk
].head_position
)
488 current_distance
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
490 /* Find the disk whose head is closest */
494 disk
= conf
->raid_disks
;
497 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
499 if (!rdev
|| r1_bio
->bios
[disk
] == IO_BLOCKED
||
500 !test_bit(In_sync
, &rdev
->flags
) ||
501 test_bit(WriteMostly
, &rdev
->flags
))
504 if (!atomic_read(&rdev
->nr_pending
)) {
508 new_distance
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
509 if (new_distance
< current_distance
) {
510 current_distance
= new_distance
;
513 } while (disk
!= conf
->last_used
);
519 rdev
= rcu_dereference(conf
->mirrors
[new_disk
].rdev
);
522 atomic_inc(&rdev
->nr_pending
);
523 if (!test_bit(In_sync
, &rdev
->flags
)) {
524 /* cannot risk returning a device that failed
525 * before we inc'ed nr_pending
527 rdev_dec_pending(rdev
, conf
->mddev
);
530 conf
->next_seq_sect
= this_sector
+ sectors
;
531 conf
->last_used
= new_disk
;
538 static void unplug_slaves(mddev_t
*mddev
)
540 conf_t
*conf
= mddev_to_conf(mddev
);
544 for (i
=0; i
<mddev
->raid_disks
; i
++) {
545 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
546 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
) && atomic_read(&rdev
->nr_pending
)) {
547 struct request_queue
*r_queue
= bdev_get_queue(rdev
->bdev
);
549 atomic_inc(&rdev
->nr_pending
);
554 rdev_dec_pending(rdev
, mddev
);
561 static void raid1_unplug(struct request_queue
*q
)
563 mddev_t
*mddev
= q
->queuedata
;
565 unplug_slaves(mddev
);
566 md_wakeup_thread(mddev
->thread
);
569 static int raid1_congested(void *data
, int bits
)
571 mddev_t
*mddev
= data
;
572 conf_t
*conf
= mddev_to_conf(mddev
);
576 for (i
= 0; i
< mddev
->raid_disks
; i
++) {
577 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
578 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
579 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
581 /* Note the '|| 1' - when read_balance prefers
582 * non-congested targets, it can be removed
584 if ((bits
& (1<<BDI_write_congested
)) || 1)
585 ret
|= bdi_congested(&q
->backing_dev_info
, bits
);
587 ret
&= bdi_congested(&q
->backing_dev_info
, bits
);
595 static int flush_pending_writes(conf_t
*conf
)
597 /* Any writes that have been queued but are awaiting
598 * bitmap updates get flushed here.
599 * We return 1 if any requests were actually submitted.
603 spin_lock_irq(&conf
->device_lock
);
605 if (conf
->pending_bio_list
.head
) {
607 bio
= bio_list_get(&conf
->pending_bio_list
);
608 blk_remove_plug(conf
->mddev
->queue
);
609 spin_unlock_irq(&conf
->device_lock
);
610 /* flush any pending bitmap writes to
611 * disk before proceeding w/ I/O */
612 bitmap_unplug(conf
->mddev
->bitmap
);
614 while (bio
) { /* submit pending writes */
615 struct bio
*next
= bio
->bi_next
;
617 generic_make_request(bio
);
622 spin_unlock_irq(&conf
->device_lock
);
627 * Sometimes we need to suspend IO while we do something else,
628 * either some resync/recovery, or reconfigure the array.
629 * To do this we raise a 'barrier'.
630 * The 'barrier' is a counter that can be raised multiple times
631 * to count how many activities are happening which preclude
633 * We can only raise the barrier if there is no pending IO.
634 * i.e. if nr_pending == 0.
635 * We choose only to raise the barrier if no-one is waiting for the
636 * barrier to go down. This means that as soon as an IO request
637 * is ready, no other operations which require a barrier will start
638 * until the IO request has had a chance.
640 * So: regular IO calls 'wait_barrier'. When that returns there
641 * is no backgroup IO happening, It must arrange to call
642 * allow_barrier when it has finished its IO.
643 * backgroup IO calls must call raise_barrier. Once that returns
644 * there is no normal IO happeing. It must arrange to call
645 * lower_barrier when the particular background IO completes.
647 #define RESYNC_DEPTH 32
649 static void raise_barrier(conf_t
*conf
)
651 spin_lock_irq(&conf
->resync_lock
);
653 /* Wait until no block IO is waiting */
654 wait_event_lock_irq(conf
->wait_barrier
, !conf
->nr_waiting
,
656 raid1_unplug(conf
->mddev
->queue
));
658 /* block any new IO from starting */
661 /* No wait for all pending IO to complete */
662 wait_event_lock_irq(conf
->wait_barrier
,
663 !conf
->nr_pending
&& conf
->barrier
< RESYNC_DEPTH
,
665 raid1_unplug(conf
->mddev
->queue
));
667 spin_unlock_irq(&conf
->resync_lock
);
670 static void lower_barrier(conf_t
*conf
)
673 spin_lock_irqsave(&conf
->resync_lock
, flags
);
675 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
676 wake_up(&conf
->wait_barrier
);
679 static void wait_barrier(conf_t
*conf
)
681 spin_lock_irq(&conf
->resync_lock
);
684 wait_event_lock_irq(conf
->wait_barrier
, !conf
->barrier
,
686 raid1_unplug(conf
->mddev
->queue
));
690 spin_unlock_irq(&conf
->resync_lock
);
693 static void allow_barrier(conf_t
*conf
)
696 spin_lock_irqsave(&conf
->resync_lock
, flags
);
698 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
699 wake_up(&conf
->wait_barrier
);
702 static void freeze_array(conf_t
*conf
)
704 /* stop syncio and normal IO and wait for everything to
706 * We increment barrier and nr_waiting, and then
707 * wait until nr_pending match nr_queued+1
708 * This is called in the context of one normal IO request
709 * that has failed. Thus any sync request that might be pending
710 * will be blocked by nr_pending, and we need to wait for
711 * pending IO requests to complete or be queued for re-try.
712 * Thus the number queued (nr_queued) plus this request (1)
713 * must match the number of pending IOs (nr_pending) before
716 spin_lock_irq(&conf
->resync_lock
);
719 wait_event_lock_irq(conf
->wait_barrier
,
720 conf
->nr_pending
== conf
->nr_queued
+1,
722 ({ flush_pending_writes(conf
);
723 raid1_unplug(conf
->mddev
->queue
); }));
724 spin_unlock_irq(&conf
->resync_lock
);
726 static void unfreeze_array(conf_t
*conf
)
728 /* reverse the effect of the freeze */
729 spin_lock_irq(&conf
->resync_lock
);
732 wake_up(&conf
->wait_barrier
);
733 spin_unlock_irq(&conf
->resync_lock
);
737 /* duplicate the data pages for behind I/O */
738 static struct page
**alloc_behind_pages(struct bio
*bio
)
741 struct bio_vec
*bvec
;
742 struct page
**pages
= kzalloc(bio
->bi_vcnt
* sizeof(struct page
*),
744 if (unlikely(!pages
))
747 bio_for_each_segment(bvec
, bio
, i
) {
748 pages
[i
] = alloc_page(GFP_NOIO
);
749 if (unlikely(!pages
[i
]))
751 memcpy(kmap(pages
[i
]) + bvec
->bv_offset
,
752 kmap(bvec
->bv_page
) + bvec
->bv_offset
, bvec
->bv_len
);
754 kunmap(bvec
->bv_page
);
761 for (i
= 0; i
< bio
->bi_vcnt
&& pages
[i
]; i
++)
764 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio
->bi_size
);
768 static int make_request(struct request_queue
*q
, struct bio
* bio
)
770 mddev_t
*mddev
= q
->queuedata
;
771 conf_t
*conf
= mddev_to_conf(mddev
);
772 mirror_info_t
*mirror
;
774 struct bio
*read_bio
;
775 int i
, targets
= 0, disks
;
776 struct bitmap
*bitmap
;
779 struct page
**behind_pages
= NULL
;
780 const int rw
= bio_data_dir(bio
);
781 const int do_sync
= bio_sync(bio
);
782 int cpu
, do_barriers
;
783 mdk_rdev_t
*blocked_rdev
;
786 * Register the new request and wait if the reconstruction
787 * thread has put up a bar for new requests.
788 * Continue immediately if no resync is active currently.
789 * We test barriers_work *after* md_write_start as md_write_start
790 * may cause the first superblock write, and that will check out
794 md_write_start(mddev
, bio
); /* wait on superblock update early */
796 if (unlikely(!mddev
->barriers_work
&& bio_barrier(bio
))) {
799 bio_endio(bio
, -EOPNOTSUPP
);
805 bitmap
= mddev
->bitmap
;
807 cpu
= part_stat_lock();
808 part_stat_inc(cpu
, &mddev
->gendisk
->part0
, ios
[rw
]);
809 part_stat_add(cpu
, &mddev
->gendisk
->part0
, sectors
[rw
],
814 * make_request() can abort the operation when READA is being
815 * used and no empty request is available.
818 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
820 r1_bio
->master_bio
= bio
;
821 r1_bio
->sectors
= bio
->bi_size
>> 9;
823 r1_bio
->mddev
= mddev
;
824 r1_bio
->sector
= bio
->bi_sector
;
828 * read balancing logic:
830 int rdisk
= read_balance(conf
, r1_bio
);
833 /* couldn't find anywhere to read from */
834 raid_end_bio_io(r1_bio
);
837 mirror
= conf
->mirrors
+ rdisk
;
839 r1_bio
->read_disk
= rdisk
;
841 read_bio
= bio_clone(bio
, GFP_NOIO
);
843 r1_bio
->bios
[rdisk
] = read_bio
;
845 read_bio
->bi_sector
= r1_bio
->sector
+ mirror
->rdev
->data_offset
;
846 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
847 read_bio
->bi_end_io
= raid1_end_read_request
;
848 read_bio
->bi_rw
= READ
| do_sync
;
849 read_bio
->bi_private
= r1_bio
;
851 generic_make_request(read_bio
);
858 /* first select target devices under spinlock and
859 * inc refcount on their rdev. Record them by setting
862 disks
= conf
->raid_disks
;
864 { static int first
=1;
865 if (first
) printk("First Write sector %llu disks %d\n",
866 (unsigned long long)r1_bio
->sector
, disks
);
873 for (i
= 0; i
< disks
; i
++) {
874 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
875 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
876 atomic_inc(&rdev
->nr_pending
);
880 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
881 atomic_inc(&rdev
->nr_pending
);
882 if (test_bit(Faulty
, &rdev
->flags
)) {
883 rdev_dec_pending(rdev
, mddev
);
884 r1_bio
->bios
[i
] = NULL
;
886 r1_bio
->bios
[i
] = bio
;
889 r1_bio
->bios
[i
] = NULL
;
893 if (unlikely(blocked_rdev
)) {
894 /* Wait for this device to become unblocked */
897 for (j
= 0; j
< i
; j
++)
899 rdev_dec_pending(conf
->mirrors
[j
].rdev
, mddev
);
902 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
907 BUG_ON(targets
== 0); /* we never fail the last device */
909 if (targets
< conf
->raid_disks
) {
910 /* array is degraded, we will not clear the bitmap
911 * on I/O completion (see raid1_end_write_request) */
912 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
915 /* do behind I/O ? */
917 atomic_read(&bitmap
->behind_writes
) < bitmap
->max_write_behind
&&
918 (behind_pages
= alloc_behind_pages(bio
)) != NULL
)
919 set_bit(R1BIO_BehindIO
, &r1_bio
->state
);
921 atomic_set(&r1_bio
->remaining
, 0);
922 atomic_set(&r1_bio
->behind_remaining
, 0);
924 do_barriers
= bio_barrier(bio
);
926 set_bit(R1BIO_Barrier
, &r1_bio
->state
);
929 for (i
= 0; i
< disks
; i
++) {
931 if (!r1_bio
->bios
[i
])
934 mbio
= bio_clone(bio
, GFP_NOIO
);
935 r1_bio
->bios
[i
] = mbio
;
937 mbio
->bi_sector
= r1_bio
->sector
+ conf
->mirrors
[i
].rdev
->data_offset
;
938 mbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
939 mbio
->bi_end_io
= raid1_end_write_request
;
940 mbio
->bi_rw
= WRITE
| do_barriers
| do_sync
;
941 mbio
->bi_private
= r1_bio
;
944 struct bio_vec
*bvec
;
947 /* Yes, I really want the '__' version so that
948 * we clear any unused pointer in the io_vec, rather
949 * than leave them unchanged. This is important
950 * because when we come to free the pages, we won't
951 * know the originial bi_idx, so we just free
954 __bio_for_each_segment(bvec
, mbio
, j
, 0)
955 bvec
->bv_page
= behind_pages
[j
];
956 if (test_bit(WriteMostly
, &conf
->mirrors
[i
].rdev
->flags
))
957 atomic_inc(&r1_bio
->behind_remaining
);
960 atomic_inc(&r1_bio
->remaining
);
962 bio_list_add(&bl
, mbio
);
964 kfree(behind_pages
); /* the behind pages are attached to the bios now */
966 bitmap_startwrite(bitmap
, bio
->bi_sector
, r1_bio
->sectors
,
967 test_bit(R1BIO_BehindIO
, &r1_bio
->state
));
968 spin_lock_irqsave(&conf
->device_lock
, flags
);
969 bio_list_merge(&conf
->pending_bio_list
, &bl
);
972 blk_plug_device(mddev
->queue
);
973 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
975 /* In case raid1d snuck into freeze_array */
976 wake_up(&conf
->wait_barrier
);
979 md_wakeup_thread(mddev
->thread
);
981 while ((bio
= bio_list_pop(&bl
)) != NULL
)
982 generic_make_request(bio
);
988 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
990 conf_t
*conf
= mddev_to_conf(mddev
);
993 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
994 conf
->raid_disks
- mddev
->degraded
);
996 for (i
= 0; i
< conf
->raid_disks
; i
++) {
997 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
998 seq_printf(seq
, "%s",
999 rdev
&& test_bit(In_sync
, &rdev
->flags
) ? "U" : "_");
1002 seq_printf(seq
, "]");
1006 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1008 char b
[BDEVNAME_SIZE
];
1009 conf_t
*conf
= mddev_to_conf(mddev
);
1012 * If it is not operational, then we have already marked it as dead
1013 * else if it is the last working disks, ignore the error, let the
1014 * next level up know.
1015 * else mark the drive as failed
1017 if (test_bit(In_sync
, &rdev
->flags
)
1018 && (conf
->raid_disks
- mddev
->degraded
) == 1)
1020 * Don't fail the drive, act as though we were just a
1021 * normal single drive
1024 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1025 unsigned long flags
;
1026 spin_lock_irqsave(&conf
->device_lock
, flags
);
1028 set_bit(Faulty
, &rdev
->flags
);
1029 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1031 * if recovery is running, make sure it aborts.
1033 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1035 set_bit(Faulty
, &rdev
->flags
);
1036 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
1037 printk(KERN_ALERT
"raid1: Disk failure on %s, disabling device.\n"
1038 "raid1: Operation continuing on %d devices.\n",
1039 bdevname(rdev
->bdev
,b
), conf
->raid_disks
- mddev
->degraded
);
1042 static void print_conf(conf_t
*conf
)
1046 printk("RAID1 conf printout:\n");
1048 printk("(!conf)\n");
1051 printk(" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1055 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1056 char b
[BDEVNAME_SIZE
];
1057 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1059 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
1060 i
, !test_bit(In_sync
, &rdev
->flags
),
1061 !test_bit(Faulty
, &rdev
->flags
),
1062 bdevname(rdev
->bdev
,b
));
1067 static void close_sync(conf_t
*conf
)
1070 allow_barrier(conf
);
1072 mempool_destroy(conf
->r1buf_pool
);
1073 conf
->r1buf_pool
= NULL
;
1076 static int raid1_spare_active(mddev_t
*mddev
)
1079 conf_t
*conf
= mddev
->private;
1082 * Find all failed disks within the RAID1 configuration
1083 * and mark them readable.
1084 * Called under mddev lock, so rcu protection not needed.
1086 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1087 mdk_rdev_t
*rdev
= conf
->mirrors
[i
].rdev
;
1089 && !test_bit(Faulty
, &rdev
->flags
)
1090 && !test_and_set_bit(In_sync
, &rdev
->flags
)) {
1091 unsigned long flags
;
1092 spin_lock_irqsave(&conf
->device_lock
, flags
);
1094 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1103 static int raid1_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1105 conf_t
*conf
= mddev
->private;
1110 int last
= mddev
->raid_disks
- 1;
1112 if (rdev
->raid_disk
>= 0)
1113 first
= last
= rdev
->raid_disk
;
1115 for (mirror
= first
; mirror
<= last
; mirror
++)
1116 if ( !(p
=conf
->mirrors
+mirror
)->rdev
) {
1118 blk_queue_stack_limits(mddev
->queue
,
1119 rdev
->bdev
->bd_disk
->queue
);
1120 /* as we don't honour merge_bvec_fn, we must never risk
1121 * violating it, so limit ->max_sector to one PAGE, as
1122 * a one page request is never in violation.
1124 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
&&
1125 mddev
->queue
->max_sectors
> (PAGE_SIZE
>>9))
1126 blk_queue_max_sectors(mddev
->queue
, PAGE_SIZE
>>9);
1128 p
->head_position
= 0;
1129 rdev
->raid_disk
= mirror
;
1131 /* As all devices are equivalent, we don't need a full recovery
1132 * if this was recently any drive of the array
1134 if (rdev
->saved_raid_disk
< 0)
1136 rcu_assign_pointer(p
->rdev
, rdev
);
1144 static int raid1_remove_disk(mddev_t
*mddev
, int number
)
1146 conf_t
*conf
= mddev
->private;
1149 mirror_info_t
*p
= conf
->mirrors
+ number
;
1154 if (test_bit(In_sync
, &rdev
->flags
) ||
1155 atomic_read(&rdev
->nr_pending
)) {
1159 /* Only remove non-faulty devices is recovery
1162 if (!test_bit(Faulty
, &rdev
->flags
) &&
1163 mddev
->degraded
< conf
->raid_disks
) {
1169 if (atomic_read(&rdev
->nr_pending
)) {
1170 /* lost the race, try later */
1182 static void end_sync_read(struct bio
*bio
, int error
)
1184 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
1187 for (i
=r1_bio
->mddev
->raid_disks
; i
--; )
1188 if (r1_bio
->bios
[i
] == bio
)
1191 update_head_pos(i
, r1_bio
);
1193 * we have read a block, now it needs to be re-written,
1194 * or re-read if the read failed.
1195 * We don't do much here, just schedule handling by raid1d
1197 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1198 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1200 if (atomic_dec_and_test(&r1_bio
->remaining
))
1201 reschedule_retry(r1_bio
);
1204 static void end_sync_write(struct bio
*bio
, int error
)
1206 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1207 r1bio_t
* r1_bio
= (r1bio_t
*)(bio
->bi_private
);
1208 mddev_t
*mddev
= r1_bio
->mddev
;
1209 conf_t
*conf
= mddev_to_conf(mddev
);
1213 for (i
= 0; i
< conf
->raid_disks
; i
++)
1214 if (r1_bio
->bios
[i
] == bio
) {
1219 int sync_blocks
= 0;
1220 sector_t s
= r1_bio
->sector
;
1221 long sectors_to_go
= r1_bio
->sectors
;
1222 /* make sure these bits doesn't get cleared. */
1224 bitmap_end_sync(mddev
->bitmap
, s
,
1227 sectors_to_go
-= sync_blocks
;
1228 } while (sectors_to_go
> 0);
1229 md_error(mddev
, conf
->mirrors
[mirror
].rdev
);
1232 update_head_pos(mirror
, r1_bio
);
1234 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1235 md_done_sync(mddev
, r1_bio
->sectors
, uptodate
);
1240 static void sync_request_write(mddev_t
*mddev
, r1bio_t
*r1_bio
)
1242 conf_t
*conf
= mddev_to_conf(mddev
);
1244 int disks
= conf
->raid_disks
;
1245 struct bio
*bio
, *wbio
;
1247 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1250 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
1251 /* We have read all readable devices. If we haven't
1252 * got the block, then there is no hope left.
1253 * If we have, then we want to do a comparison
1254 * and skip the write if everything is the same.
1255 * If any blocks failed to read, then we need to
1256 * attempt an over-write
1259 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
1260 for (i
=0; i
<mddev
->raid_disks
; i
++)
1261 if (r1_bio
->bios
[i
]->bi_end_io
== end_sync_read
)
1262 md_error(mddev
, conf
->mirrors
[i
].rdev
);
1264 md_done_sync(mddev
, r1_bio
->sectors
, 1);
1268 for (primary
=0; primary
<mddev
->raid_disks
; primary
++)
1269 if (r1_bio
->bios
[primary
]->bi_end_io
== end_sync_read
&&
1270 test_bit(BIO_UPTODATE
, &r1_bio
->bios
[primary
]->bi_flags
)) {
1271 r1_bio
->bios
[primary
]->bi_end_io
= NULL
;
1272 rdev_dec_pending(conf
->mirrors
[primary
].rdev
, mddev
);
1275 r1_bio
->read_disk
= primary
;
1276 for (i
=0; i
<mddev
->raid_disks
; i
++)
1277 if (r1_bio
->bios
[i
]->bi_end_io
== end_sync_read
) {
1279 int vcnt
= r1_bio
->sectors
>> (PAGE_SHIFT
- 9);
1280 struct bio
*pbio
= r1_bio
->bios
[primary
];
1281 struct bio
*sbio
= r1_bio
->bios
[i
];
1283 if (test_bit(BIO_UPTODATE
, &sbio
->bi_flags
)) {
1284 for (j
= vcnt
; j
-- ; ) {
1286 p
= pbio
->bi_io_vec
[j
].bv_page
;
1287 s
= sbio
->bi_io_vec
[j
].bv_page
;
1288 if (memcmp(page_address(p
),
1296 mddev
->resync_mismatches
+= r1_bio
->sectors
;
1297 if (j
< 0 || (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
)
1298 && test_bit(BIO_UPTODATE
, &sbio
->bi_flags
))) {
1299 sbio
->bi_end_io
= NULL
;
1300 rdev_dec_pending(conf
->mirrors
[i
].rdev
, mddev
);
1302 /* fixup the bio for reuse */
1304 sbio
->bi_vcnt
= vcnt
;
1305 sbio
->bi_size
= r1_bio
->sectors
<< 9;
1307 sbio
->bi_phys_segments
= 0;
1308 sbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1309 sbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1310 sbio
->bi_next
= NULL
;
1311 sbio
->bi_sector
= r1_bio
->sector
+
1312 conf
->mirrors
[i
].rdev
->data_offset
;
1313 sbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1314 size
= sbio
->bi_size
;
1315 for (j
= 0; j
< vcnt
; j
++) {
1317 bi
= &sbio
->bi_io_vec
[j
];
1319 if (size
> PAGE_SIZE
)
1320 bi
->bv_len
= PAGE_SIZE
;
1324 memcpy(page_address(bi
->bv_page
),
1325 page_address(pbio
->bi_io_vec
[j
].bv_page
),
1332 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
1333 /* ouch - failed to read all of that.
1334 * Try some synchronous reads of other devices to get
1335 * good data, much like with normal read errors. Only
1336 * read into the pages we already have so we don't
1337 * need to re-issue the read request.
1338 * We don't need to freeze the array, because being in an
1339 * active sync request, there is no normal IO, and
1340 * no overlapping syncs.
1342 sector_t sect
= r1_bio
->sector
;
1343 int sectors
= r1_bio
->sectors
;
1348 int d
= r1_bio
->read_disk
;
1352 if (s
> (PAGE_SIZE
>>9))
1355 if (r1_bio
->bios
[d
]->bi_end_io
== end_sync_read
) {
1356 /* No rcu protection needed here devices
1357 * can only be removed when no resync is
1358 * active, and resync is currently active
1360 rdev
= conf
->mirrors
[d
].rdev
;
1361 if (sync_page_io(rdev
->bdev
,
1362 sect
+ rdev
->data_offset
,
1364 bio
->bi_io_vec
[idx
].bv_page
,
1371 if (d
== conf
->raid_disks
)
1373 } while (!success
&& d
!= r1_bio
->read_disk
);
1377 /* write it back and re-read */
1378 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1379 while (d
!= r1_bio
->read_disk
) {
1381 d
= conf
->raid_disks
;
1383 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1385 rdev
= conf
->mirrors
[d
].rdev
;
1386 atomic_add(s
, &rdev
->corrected_errors
);
1387 if (sync_page_io(rdev
->bdev
,
1388 sect
+ rdev
->data_offset
,
1390 bio
->bi_io_vec
[idx
].bv_page
,
1392 md_error(mddev
, rdev
);
1395 while (d
!= r1_bio
->read_disk
) {
1397 d
= conf
->raid_disks
;
1399 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1401 rdev
= conf
->mirrors
[d
].rdev
;
1402 if (sync_page_io(rdev
->bdev
,
1403 sect
+ rdev
->data_offset
,
1405 bio
->bi_io_vec
[idx
].bv_page
,
1407 md_error(mddev
, rdev
);
1410 char b
[BDEVNAME_SIZE
];
1411 /* Cannot read from anywhere, array is toast */
1412 md_error(mddev
, conf
->mirrors
[r1_bio
->read_disk
].rdev
);
1413 printk(KERN_ALERT
"raid1: %s: unrecoverable I/O read error"
1414 " for block %llu\n",
1415 bdevname(bio
->bi_bdev
,b
),
1416 (unsigned long long)r1_bio
->sector
);
1417 md_done_sync(mddev
, r1_bio
->sectors
, 0);
1430 atomic_set(&r1_bio
->remaining
, 1);
1431 for (i
= 0; i
< disks
; i
++) {
1432 wbio
= r1_bio
->bios
[i
];
1433 if (wbio
->bi_end_io
== NULL
||
1434 (wbio
->bi_end_io
== end_sync_read
&&
1435 (i
== r1_bio
->read_disk
||
1436 !test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))))
1439 wbio
->bi_rw
= WRITE
;
1440 wbio
->bi_end_io
= end_sync_write
;
1441 atomic_inc(&r1_bio
->remaining
);
1442 md_sync_acct(conf
->mirrors
[i
].rdev
->bdev
, wbio
->bi_size
>> 9);
1444 generic_make_request(wbio
);
1447 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1448 /* if we're here, all write(s) have completed, so clean up */
1449 md_done_sync(mddev
, r1_bio
->sectors
, 1);
1455 * This is a kernel thread which:
1457 * 1. Retries failed read operations on working mirrors.
1458 * 2. Updates the raid superblock when problems encounter.
1459 * 3. Performs writes following reads for array syncronising.
1462 static void fix_read_error(conf_t
*conf
, int read_disk
,
1463 sector_t sect
, int sectors
)
1465 mddev_t
*mddev
= conf
->mddev
;
1473 if (s
> (PAGE_SIZE
>>9))
1477 /* Note: no rcu protection needed here
1478 * as this is synchronous in the raid1d thread
1479 * which is the thread that might remove
1480 * a device. If raid1d ever becomes multi-threaded....
1482 rdev
= conf
->mirrors
[d
].rdev
;
1484 test_bit(In_sync
, &rdev
->flags
) &&
1485 sync_page_io(rdev
->bdev
,
1486 sect
+ rdev
->data_offset
,
1488 conf
->tmppage
, READ
))
1492 if (d
== conf
->raid_disks
)
1495 } while (!success
&& d
!= read_disk
);
1498 /* Cannot read from anywhere -- bye bye array */
1499 md_error(mddev
, conf
->mirrors
[read_disk
].rdev
);
1502 /* write it back and re-read */
1504 while (d
!= read_disk
) {
1506 d
= conf
->raid_disks
;
1508 rdev
= conf
->mirrors
[d
].rdev
;
1510 test_bit(In_sync
, &rdev
->flags
)) {
1511 if (sync_page_io(rdev
->bdev
,
1512 sect
+ rdev
->data_offset
,
1513 s
<<9, conf
->tmppage
, WRITE
)
1515 /* Well, this device is dead */
1516 md_error(mddev
, rdev
);
1520 while (d
!= read_disk
) {
1521 char b
[BDEVNAME_SIZE
];
1523 d
= conf
->raid_disks
;
1525 rdev
= conf
->mirrors
[d
].rdev
;
1527 test_bit(In_sync
, &rdev
->flags
)) {
1528 if (sync_page_io(rdev
->bdev
,
1529 sect
+ rdev
->data_offset
,
1530 s
<<9, conf
->tmppage
, READ
)
1532 /* Well, this device is dead */
1533 md_error(mddev
, rdev
);
1535 atomic_add(s
, &rdev
->corrected_errors
);
1537 "raid1:%s: read error corrected "
1538 "(%d sectors at %llu on %s)\n",
1540 (unsigned long long)(sect
+
1542 bdevname(rdev
->bdev
, b
));
1551 static void raid1d(mddev_t
*mddev
)
1555 unsigned long flags
;
1556 conf_t
*conf
= mddev_to_conf(mddev
);
1557 struct list_head
*head
= &conf
->retry_list
;
1561 md_check_recovery(mddev
);
1564 char b
[BDEVNAME_SIZE
];
1566 unplug
+= flush_pending_writes(conf
);
1568 spin_lock_irqsave(&conf
->device_lock
, flags
);
1569 if (list_empty(head
)) {
1570 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1573 r1_bio
= list_entry(head
->prev
, r1bio_t
, retry_list
);
1574 list_del(head
->prev
);
1576 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1578 mddev
= r1_bio
->mddev
;
1579 conf
= mddev_to_conf(mddev
);
1580 if (test_bit(R1BIO_IsSync
, &r1_bio
->state
)) {
1581 sync_request_write(mddev
, r1_bio
);
1583 } else if (test_bit(R1BIO_BarrierRetry
, &r1_bio
->state
)) {
1584 /* some requests in the r1bio were BIO_RW_BARRIER
1585 * requests which failed with -EOPNOTSUPP. Hohumm..
1586 * Better resubmit without the barrier.
1587 * We know which devices to resubmit for, because
1588 * all others have had their bios[] entry cleared.
1589 * We already have a nr_pending reference on these rdevs.
1592 const int do_sync
= bio_sync(r1_bio
->master_bio
);
1593 clear_bit(R1BIO_BarrierRetry
, &r1_bio
->state
);
1594 clear_bit(R1BIO_Barrier
, &r1_bio
->state
);
1595 for (i
=0; i
< conf
->raid_disks
; i
++)
1596 if (r1_bio
->bios
[i
])
1597 atomic_inc(&r1_bio
->remaining
);
1598 for (i
=0; i
< conf
->raid_disks
; i
++)
1599 if (r1_bio
->bios
[i
]) {
1600 struct bio_vec
*bvec
;
1603 bio
= bio_clone(r1_bio
->master_bio
, GFP_NOIO
);
1604 /* copy pages from the failed bio, as
1605 * this might be a write-behind device */
1606 __bio_for_each_segment(bvec
, bio
, j
, 0)
1607 bvec
->bv_page
= bio_iovec_idx(r1_bio
->bios
[i
], j
)->bv_page
;
1608 bio_put(r1_bio
->bios
[i
]);
1609 bio
->bi_sector
= r1_bio
->sector
+
1610 conf
->mirrors
[i
].rdev
->data_offset
;
1611 bio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1612 bio
->bi_end_io
= raid1_end_write_request
;
1613 bio
->bi_rw
= WRITE
| do_sync
;
1614 bio
->bi_private
= r1_bio
;
1615 r1_bio
->bios
[i
] = bio
;
1616 generic_make_request(bio
);
1621 /* we got a read error. Maybe the drive is bad. Maybe just
1622 * the block and we can fix it.
1623 * We freeze all other IO, and try reading the block from
1624 * other devices. When we find one, we re-write
1625 * and check it that fixes the read error.
1626 * This is all done synchronously while the array is
1629 if (mddev
->ro
== 0) {
1631 fix_read_error(conf
, r1_bio
->read_disk
,
1634 unfreeze_array(conf
);
1637 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1638 if ((disk
=read_balance(conf
, r1_bio
)) == -1) {
1639 printk(KERN_ALERT
"raid1: %s: unrecoverable I/O"
1640 " read error for block %llu\n",
1641 bdevname(bio
->bi_bdev
,b
),
1642 (unsigned long long)r1_bio
->sector
);
1643 raid_end_bio_io(r1_bio
);
1645 const int do_sync
= bio_sync(r1_bio
->master_bio
);
1646 r1_bio
->bios
[r1_bio
->read_disk
] =
1647 mddev
->ro
? IO_BLOCKED
: NULL
;
1648 r1_bio
->read_disk
= disk
;
1650 bio
= bio_clone(r1_bio
->master_bio
, GFP_NOIO
);
1651 r1_bio
->bios
[r1_bio
->read_disk
] = bio
;
1652 rdev
= conf
->mirrors
[disk
].rdev
;
1653 if (printk_ratelimit())
1654 printk(KERN_ERR
"raid1: %s: redirecting sector %llu to"
1655 " another mirror\n",
1656 bdevname(rdev
->bdev
,b
),
1657 (unsigned long long)r1_bio
->sector
);
1658 bio
->bi_sector
= r1_bio
->sector
+ rdev
->data_offset
;
1659 bio
->bi_bdev
= rdev
->bdev
;
1660 bio
->bi_end_io
= raid1_end_read_request
;
1661 bio
->bi_rw
= READ
| do_sync
;
1662 bio
->bi_private
= r1_bio
;
1664 generic_make_request(bio
);
1669 unplug_slaves(mddev
);
1673 static int init_resync(conf_t
*conf
)
1677 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
1678 BUG_ON(conf
->r1buf_pool
);
1679 conf
->r1buf_pool
= mempool_create(buffs
, r1buf_pool_alloc
, r1buf_pool_free
,
1681 if (!conf
->r1buf_pool
)
1683 conf
->next_resync
= 0;
1688 * perform a "sync" on one "block"
1690 * We need to make sure that no normal I/O request - particularly write
1691 * requests - conflict with active sync requests.
1693 * This is achieved by tracking pending requests and a 'barrier' concept
1694 * that can be installed to exclude normal IO requests.
1697 static sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
1699 conf_t
*conf
= mddev_to_conf(mddev
);
1702 sector_t max_sector
, nr_sectors
;
1706 int write_targets
= 0, read_targets
= 0;
1708 int still_degraded
= 0;
1710 if (!conf
->r1buf_pool
)
1713 printk("sync start - bitmap %p\n", mddev->bitmap);
1715 if (init_resync(conf
))
1719 max_sector
= mddev
->size
<< 1;
1720 if (sector_nr
>= max_sector
) {
1721 /* If we aborted, we need to abort the
1722 * sync on the 'current' bitmap chunk (there will
1723 * only be one in raid1 resync.
1724 * We can find the current addess in mddev->curr_resync
1726 if (mddev
->curr_resync
< max_sector
) /* aborted */
1727 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
1729 else /* completed sync */
1732 bitmap_close_sync(mddev
->bitmap
);
1737 if (mddev
->bitmap
== NULL
&&
1738 mddev
->recovery_cp
== MaxSector
&&
1739 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
1740 conf
->fullsync
== 0) {
1742 return max_sector
- sector_nr
;
1744 /* before building a request, check if we can skip these blocks..
1745 * This call the bitmap_start_sync doesn't actually record anything
1747 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
1748 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
1749 /* We can skip this block, and probably several more */
1754 * If there is non-resync activity waiting for a turn,
1755 * and resync is going fast enough,
1756 * then let it though before starting on this new sync request.
1758 if (!go_faster
&& conf
->nr_waiting
)
1759 msleep_interruptible(1000);
1761 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
1762 raise_barrier(conf
);
1764 conf
->next_resync
= sector_nr
;
1766 r1_bio
= mempool_alloc(conf
->r1buf_pool
, GFP_NOIO
);
1769 * If we get a correctably read error during resync or recovery,
1770 * we might want to read from a different device. So we
1771 * flag all drives that could conceivably be read from for READ,
1772 * and any others (which will be non-In_sync devices) for WRITE.
1773 * If a read fails, we try reading from something else for which READ
1777 r1_bio
->mddev
= mddev
;
1778 r1_bio
->sector
= sector_nr
;
1780 set_bit(R1BIO_IsSync
, &r1_bio
->state
);
1782 for (i
=0; i
< conf
->raid_disks
; i
++) {
1784 bio
= r1_bio
->bios
[i
];
1786 /* take from bio_init */
1787 bio
->bi_next
= NULL
;
1788 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
1792 bio
->bi_phys_segments
= 0;
1794 bio
->bi_end_io
= NULL
;
1795 bio
->bi_private
= NULL
;
1797 rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1799 test_bit(Faulty
, &rdev
->flags
)) {
1802 } else if (!test_bit(In_sync
, &rdev
->flags
)) {
1804 bio
->bi_end_io
= end_sync_write
;
1807 /* may need to read from here */
1809 bio
->bi_end_io
= end_sync_read
;
1810 if (test_bit(WriteMostly
, &rdev
->flags
)) {
1819 atomic_inc(&rdev
->nr_pending
);
1820 bio
->bi_sector
= sector_nr
+ rdev
->data_offset
;
1821 bio
->bi_bdev
= rdev
->bdev
;
1822 bio
->bi_private
= r1_bio
;
1827 r1_bio
->read_disk
= disk
;
1829 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
) && read_targets
> 0)
1830 /* extra read targets are also write targets */
1831 write_targets
+= read_targets
-1;
1833 if (write_targets
== 0 || read_targets
== 0) {
1834 /* There is nowhere to write, so all non-sync
1835 * drives must be failed - so we are finished
1837 sector_t rv
= max_sector
- sector_nr
;
1843 if (max_sector
> mddev
->resync_max
)
1844 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
1849 int len
= PAGE_SIZE
;
1850 if (sector_nr
+ (len
>>9) > max_sector
)
1851 len
= (max_sector
- sector_nr
) << 9;
1854 if (sync_blocks
== 0) {
1855 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
1856 &sync_blocks
, still_degraded
) &&
1858 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
1860 BUG_ON(sync_blocks
< (PAGE_SIZE
>>9));
1861 if (len
> (sync_blocks
<<9))
1862 len
= sync_blocks
<<9;
1865 for (i
=0 ; i
< conf
->raid_disks
; i
++) {
1866 bio
= r1_bio
->bios
[i
];
1867 if (bio
->bi_end_io
) {
1868 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
1869 if (bio_add_page(bio
, page
, len
, 0) == 0) {
1871 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
1874 bio
= r1_bio
->bios
[i
];
1875 if (bio
->bi_end_io
==NULL
)
1877 /* remove last page from this bio */
1879 bio
->bi_size
-= len
;
1880 bio
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
1886 nr_sectors
+= len
>>9;
1887 sector_nr
+= len
>>9;
1888 sync_blocks
-= (len
>>9);
1889 } while (r1_bio
->bios
[disk
]->bi_vcnt
< RESYNC_PAGES
);
1891 r1_bio
->sectors
= nr_sectors
;
1893 /* For a user-requested sync, we read all readable devices and do a
1896 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
1897 atomic_set(&r1_bio
->remaining
, read_targets
);
1898 for (i
=0; i
<conf
->raid_disks
; i
++) {
1899 bio
= r1_bio
->bios
[i
];
1900 if (bio
->bi_end_io
== end_sync_read
) {
1901 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
1902 generic_make_request(bio
);
1906 atomic_set(&r1_bio
->remaining
, 1);
1907 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1908 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
1909 generic_make_request(bio
);
1915 static int run(mddev_t
*mddev
)
1919 mirror_info_t
*disk
;
1921 struct list_head
*tmp
;
1923 if (mddev
->level
!= 1) {
1924 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1925 mdname(mddev
), mddev
->level
);
1928 if (mddev
->reshape_position
!= MaxSector
) {
1929 printk("raid1: %s: reshape_position set but not supported\n",
1934 * copy the already verified devices into our private RAID1
1935 * bookkeeping area. [whatever we allocate in run(),
1936 * should be freed in stop()]
1938 conf
= kzalloc(sizeof(conf_t
), GFP_KERNEL
);
1939 mddev
->private = conf
;
1943 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
1948 conf
->tmppage
= alloc_page(GFP_KERNEL
);
1952 conf
->poolinfo
= kmalloc(sizeof(*conf
->poolinfo
), GFP_KERNEL
);
1953 if (!conf
->poolinfo
)
1955 conf
->poolinfo
->mddev
= mddev
;
1956 conf
->poolinfo
->raid_disks
= mddev
->raid_disks
;
1957 conf
->r1bio_pool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
1960 if (!conf
->r1bio_pool
)
1963 spin_lock_init(&conf
->device_lock
);
1964 mddev
->queue
->queue_lock
= &conf
->device_lock
;
1966 rdev_for_each(rdev
, tmp
, mddev
) {
1967 disk_idx
= rdev
->raid_disk
;
1968 if (disk_idx
>= mddev
->raid_disks
1971 disk
= conf
->mirrors
+ disk_idx
;
1975 blk_queue_stack_limits(mddev
->queue
,
1976 rdev
->bdev
->bd_disk
->queue
);
1977 /* as we don't honour merge_bvec_fn, we must never risk
1978 * violating it, so limit ->max_sector to one PAGE, as
1979 * a one page request is never in violation.
1981 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
&&
1982 mddev
->queue
->max_sectors
> (PAGE_SIZE
>>9))
1983 blk_queue_max_sectors(mddev
->queue
, PAGE_SIZE
>>9);
1985 disk
->head_position
= 0;
1987 conf
->raid_disks
= mddev
->raid_disks
;
1988 conf
->mddev
= mddev
;
1989 INIT_LIST_HEAD(&conf
->retry_list
);
1991 spin_lock_init(&conf
->resync_lock
);
1992 init_waitqueue_head(&conf
->wait_barrier
);
1994 bio_list_init(&conf
->pending_bio_list
);
1995 bio_list_init(&conf
->flushing_bio_list
);
1998 mddev
->degraded
= 0;
1999 for (i
= 0; i
< conf
->raid_disks
; i
++) {
2001 disk
= conf
->mirrors
+ i
;
2004 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
2005 disk
->head_position
= 0;
2011 if (mddev
->degraded
== conf
->raid_disks
) {
2012 printk(KERN_ERR
"raid1: no operational mirrors for %s\n",
2016 if (conf
->raid_disks
- mddev
->degraded
== 1)
2017 mddev
->recovery_cp
= MaxSector
;
2020 * find the first working one and use it as a starting point
2021 * to read balancing.
2023 for (j
= 0; j
< conf
->raid_disks
&&
2024 (!conf
->mirrors
[j
].rdev
||
2025 !test_bit(In_sync
, &conf
->mirrors
[j
].rdev
->flags
)) ; j
++)
2027 conf
->last_used
= j
;
2030 mddev
->thread
= md_register_thread(raid1d
, mddev
, "%s_raid1");
2031 if (!mddev
->thread
) {
2033 "raid1: couldn't allocate thread for %s\n",
2039 "raid1: raid set %s active with %d out of %d mirrors\n",
2040 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
2043 * Ok, everything is just fine now
2045 mddev
->array_sectors
= mddev
->size
* 2;
2047 mddev
->queue
->unplug_fn
= raid1_unplug
;
2048 mddev
->queue
->backing_dev_info
.congested_fn
= raid1_congested
;
2049 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
2054 printk(KERN_ERR
"raid1: couldn't allocate memory for %s\n",
2059 if (conf
->r1bio_pool
)
2060 mempool_destroy(conf
->r1bio_pool
);
2061 kfree(conf
->mirrors
);
2062 safe_put_page(conf
->tmppage
);
2063 kfree(conf
->poolinfo
);
2065 mddev
->private = NULL
;
2071 static int stop(mddev_t
*mddev
)
2073 conf_t
*conf
= mddev_to_conf(mddev
);
2074 struct bitmap
*bitmap
= mddev
->bitmap
;
2075 int behind_wait
= 0;
2077 /* wait for behind writes to complete */
2078 while (bitmap
&& atomic_read(&bitmap
->behind_writes
) > 0) {
2080 printk(KERN_INFO
"raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev
), behind_wait
);
2081 set_current_state(TASK_UNINTERRUPTIBLE
);
2082 schedule_timeout(HZ
); /* wait a second */
2083 /* need to kick something here to make sure I/O goes? */
2086 md_unregister_thread(mddev
->thread
);
2087 mddev
->thread
= NULL
;
2088 blk_sync_queue(mddev
->queue
); /* the unplug fn references 'conf'*/
2089 if (conf
->r1bio_pool
)
2090 mempool_destroy(conf
->r1bio_pool
);
2091 kfree(conf
->mirrors
);
2092 kfree(conf
->poolinfo
);
2094 mddev
->private = NULL
;
2098 static int raid1_resize(mddev_t
*mddev
, sector_t sectors
)
2100 /* no resync is happening, and there is enough space
2101 * on all devices, so we can resize.
2102 * We need to make sure resync covers any new space.
2103 * If the array is shrinking we should possibly wait until
2104 * any io in the removed space completes, but it hardly seems
2107 mddev
->array_sectors
= sectors
;
2108 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
2110 if (mddev
->array_sectors
/ 2 > mddev
->size
&&
2111 mddev
->recovery_cp
== MaxSector
) {
2112 mddev
->recovery_cp
= mddev
->size
<< 1;
2113 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2115 mddev
->size
= mddev
->array_sectors
/ 2;
2116 mddev
->resync_max_sectors
= sectors
;
2120 static int raid1_reshape(mddev_t
*mddev
)
2123 * 1/ resize the r1bio_pool
2124 * 2/ resize conf->mirrors
2126 * We allocate a new r1bio_pool if we can.
2127 * Then raise a device barrier and wait until all IO stops.
2128 * Then resize conf->mirrors and swap in the new r1bio pool.
2130 * At the same time, we "pack" the devices so that all the missing
2131 * devices have the higher raid_disk numbers.
2133 mempool_t
*newpool
, *oldpool
;
2134 struct pool_info
*newpoolinfo
;
2135 mirror_info_t
*newmirrors
;
2136 conf_t
*conf
= mddev_to_conf(mddev
);
2137 int cnt
, raid_disks
;
2138 unsigned long flags
;
2141 /* Cannot change chunk_size, layout, or level */
2142 if (mddev
->chunk_size
!= mddev
->new_chunk
||
2143 mddev
->layout
!= mddev
->new_layout
||
2144 mddev
->level
!= mddev
->new_level
) {
2145 mddev
->new_chunk
= mddev
->chunk_size
;
2146 mddev
->new_layout
= mddev
->layout
;
2147 mddev
->new_level
= mddev
->level
;
2151 err
= md_allow_write(mddev
);
2155 raid_disks
= mddev
->raid_disks
+ mddev
->delta_disks
;
2157 if (raid_disks
< conf
->raid_disks
) {
2159 for (d
= 0; d
< conf
->raid_disks
; d
++)
2160 if (conf
->mirrors
[d
].rdev
)
2162 if (cnt
> raid_disks
)
2166 newpoolinfo
= kmalloc(sizeof(*newpoolinfo
), GFP_KERNEL
);
2169 newpoolinfo
->mddev
= mddev
;
2170 newpoolinfo
->raid_disks
= raid_disks
;
2172 newpool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
2173 r1bio_pool_free
, newpoolinfo
);
2178 newmirrors
= kzalloc(sizeof(struct mirror_info
) * raid_disks
, GFP_KERNEL
);
2181 mempool_destroy(newpool
);
2185 raise_barrier(conf
);
2187 /* ok, everything is stopped */
2188 oldpool
= conf
->r1bio_pool
;
2189 conf
->r1bio_pool
= newpool
;
2191 for (d
= d2
= 0; d
< conf
->raid_disks
; d
++) {
2192 mdk_rdev_t
*rdev
= conf
->mirrors
[d
].rdev
;
2193 if (rdev
&& rdev
->raid_disk
!= d2
) {
2195 sprintf(nm
, "rd%d", rdev
->raid_disk
);
2196 sysfs_remove_link(&mddev
->kobj
, nm
);
2197 rdev
->raid_disk
= d2
;
2198 sprintf(nm
, "rd%d", rdev
->raid_disk
);
2199 sysfs_remove_link(&mddev
->kobj
, nm
);
2200 if (sysfs_create_link(&mddev
->kobj
,
2203 "md/raid1: cannot register "
2208 newmirrors
[d2
++].rdev
= rdev
;
2210 kfree(conf
->mirrors
);
2211 conf
->mirrors
= newmirrors
;
2212 kfree(conf
->poolinfo
);
2213 conf
->poolinfo
= newpoolinfo
;
2215 spin_lock_irqsave(&conf
->device_lock
, flags
);
2216 mddev
->degraded
+= (raid_disks
- conf
->raid_disks
);
2217 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2218 conf
->raid_disks
= mddev
->raid_disks
= raid_disks
;
2219 mddev
->delta_disks
= 0;
2221 conf
->last_used
= 0; /* just make sure it is in-range */
2222 lower_barrier(conf
);
2224 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2225 md_wakeup_thread(mddev
->thread
);
2227 mempool_destroy(oldpool
);
2231 static void raid1_quiesce(mddev_t
*mddev
, int state
)
2233 conf_t
*conf
= mddev_to_conf(mddev
);
2237 raise_barrier(conf
);
2240 lower_barrier(conf
);
2246 static struct mdk_personality raid1_personality
=
2250 .owner
= THIS_MODULE
,
2251 .make_request
= make_request
,
2255 .error_handler
= error
,
2256 .hot_add_disk
= raid1_add_disk
,
2257 .hot_remove_disk
= raid1_remove_disk
,
2258 .spare_active
= raid1_spare_active
,
2259 .sync_request
= sync_request
,
2260 .resize
= raid1_resize
,
2261 .check_reshape
= raid1_reshape
,
2262 .quiesce
= raid1_quiesce
,
2265 static int __init
raid_init(void)
2267 return register_md_personality(&raid1_personality
);
2270 static void raid_exit(void)
2272 unregister_md_personality(&raid1_personality
);
2275 module_init(raid_init
);
2276 module_exit(raid_exit
);
2277 MODULE_LICENSE("GPL");
2278 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2279 MODULE_ALIAS("md-raid1");
2280 MODULE_ALIAS("md-level-1");