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>
45 #define PRINTK(x...) printk(x)
51 * Number of guaranteed r1bios in case of extreme VM load:
53 #define NR_RAID1_BIOS 256
56 static void allow_barrier(conf_t
*conf
);
57 static void lower_barrier(conf_t
*conf
);
59 static void * r1bio_pool_alloc(gfp_t gfp_flags
, void *data
)
61 struct pool_info
*pi
= data
;
62 int size
= offsetof(r1bio_t
, bios
[pi
->raid_disks
]);
64 /* allocate a r1bio with room for raid_disks entries in the bios array */
65 return kzalloc(size
, gfp_flags
);
68 static void r1bio_pool_free(void *r1_bio
, void *data
)
73 #define RESYNC_BLOCK_SIZE (64*1024)
74 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
75 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
76 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
77 #define RESYNC_WINDOW (2048*1024)
79 static void * r1buf_pool_alloc(gfp_t gfp_flags
, void *data
)
81 struct pool_info
*pi
= data
;
87 r1_bio
= r1bio_pool_alloc(gfp_flags
, pi
);
92 * Allocate bios : 1 for reading, n-1 for writing
94 for (j
= pi
->raid_disks
; j
-- ; ) {
95 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
98 r1_bio
->bios
[j
] = bio
;
101 * Allocate RESYNC_PAGES data pages and attach them to
103 * If this is a user-requested check/repair, allocate
104 * RESYNC_PAGES for each bio.
106 if (test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
))
111 bio
= r1_bio
->bios
[j
];
112 for (i
= 0; i
< RESYNC_PAGES
; i
++) {
113 page
= alloc_page(gfp_flags
);
117 bio
->bi_io_vec
[i
].bv_page
= page
;
121 /* If not user-requests, copy the page pointers to all bios */
122 if (!test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
)) {
123 for (i
=0; i
<RESYNC_PAGES
; i
++)
124 for (j
=1; j
<pi
->raid_disks
; j
++)
125 r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
=
126 r1_bio
->bios
[0]->bi_io_vec
[i
].bv_page
;
129 r1_bio
->master_bio
= NULL
;
134 for (j
=0 ; j
< pi
->raid_disks
; j
++)
135 for (i
=0; i
< r1_bio
->bios
[j
]->bi_vcnt
; i
++)
136 put_page(r1_bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
139 while ( ++j
< pi
->raid_disks
)
140 bio_put(r1_bio
->bios
[j
]);
141 r1bio_pool_free(r1_bio
, data
);
145 static void r1buf_pool_free(void *__r1_bio
, void *data
)
147 struct pool_info
*pi
= data
;
149 r1bio_t
*r1bio
= __r1_bio
;
151 for (i
= 0; i
< RESYNC_PAGES
; i
++)
152 for (j
= pi
->raid_disks
; j
-- ;) {
154 r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
!=
155 r1bio
->bios
[0]->bi_io_vec
[i
].bv_page
)
156 safe_put_page(r1bio
->bios
[j
]->bi_io_vec
[i
].bv_page
);
158 for (i
=0 ; i
< pi
->raid_disks
; i
++)
159 bio_put(r1bio
->bios
[i
]);
161 r1bio_pool_free(r1bio
, data
);
164 static void put_all_bios(conf_t
*conf
, r1bio_t
*r1_bio
)
168 for (i
= 0; i
< conf
->raid_disks
; i
++) {
169 struct bio
**bio
= r1_bio
->bios
+ i
;
170 if (*bio
&& *bio
!= IO_BLOCKED
)
176 static void free_r1bio(r1bio_t
*r1_bio
)
178 conf_t
*conf
= r1_bio
->mddev
->private;
181 * Wake up any possible resync thread that waits for the device
186 put_all_bios(conf
, r1_bio
);
187 mempool_free(r1_bio
, conf
->r1bio_pool
);
190 static void put_buf(r1bio_t
*r1_bio
)
192 conf_t
*conf
= r1_bio
->mddev
->private;
195 for (i
=0; i
<conf
->raid_disks
; i
++) {
196 struct bio
*bio
= r1_bio
->bios
[i
];
198 rdev_dec_pending(conf
->mirrors
[i
].rdev
, r1_bio
->mddev
);
201 mempool_free(r1_bio
, conf
->r1buf_pool
);
206 static void reschedule_retry(r1bio_t
*r1_bio
)
209 mddev_t
*mddev
= r1_bio
->mddev
;
210 conf_t
*conf
= mddev
->private;
212 spin_lock_irqsave(&conf
->device_lock
, flags
);
213 list_add(&r1_bio
->retry_list
, &conf
->retry_list
);
215 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
217 wake_up(&conf
->wait_barrier
);
218 md_wakeup_thread(mddev
->thread
);
222 * raid_end_bio_io() is called when we have finished servicing a mirrored
223 * operation and are ready to return a success/failure code to the buffer
226 static void raid_end_bio_io(r1bio_t
*r1_bio
)
228 struct bio
*bio
= r1_bio
->master_bio
;
230 /* if nobody has done the final endio yet, do it now */
231 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
232 PRINTK(KERN_DEBUG
"raid1: sync end %s on sectors %llu-%llu\n",
233 (bio_data_dir(bio
) == WRITE
) ? "write" : "read",
234 (unsigned long long) bio
->bi_sector
,
235 (unsigned long long) bio
->bi_sector
+
236 (bio
->bi_size
>> 9) - 1);
239 test_bit(R1BIO_Uptodate
, &r1_bio
->state
) ? 0 : -EIO
);
245 * Update disk head position estimator based on IRQ completion info.
247 static inline void update_head_pos(int disk
, r1bio_t
*r1_bio
)
249 conf_t
*conf
= r1_bio
->mddev
->private;
251 conf
->mirrors
[disk
].head_position
=
252 r1_bio
->sector
+ (r1_bio
->sectors
);
255 static void raid1_end_read_request(struct bio
*bio
, int error
)
257 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
258 r1bio_t
*r1_bio
= bio
->bi_private
;
260 conf_t
*conf
= r1_bio
->mddev
->private;
262 mirror
= r1_bio
->read_disk
;
264 * this branch is our 'one mirror IO has finished' event handler:
266 update_head_pos(mirror
, r1_bio
);
269 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
271 /* If all other devices have failed, we want to return
272 * the error upwards rather than fail the last device.
273 * Here we redefine "uptodate" to mean "Don't want to retry"
276 spin_lock_irqsave(&conf
->device_lock
, flags
);
277 if (r1_bio
->mddev
->degraded
== conf
->raid_disks
||
278 (r1_bio
->mddev
->degraded
== conf
->raid_disks
-1 &&
279 !test_bit(Faulty
, &conf
->mirrors
[mirror
].rdev
->flags
)))
281 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
285 raid_end_bio_io(r1_bio
);
290 char b
[BDEVNAME_SIZE
];
292 KERN_ERR
"md/raid1:%s: %s: "
293 "rescheduling sector %llu\n",
295 bdevname(conf
->mirrors
[mirror
].rdev
->bdev
,
297 (unsigned long long)r1_bio
->sector
);
298 reschedule_retry(r1_bio
);
301 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
304 static void r1_bio_write_done(r1bio_t
*r1_bio
)
306 if (atomic_dec_and_test(&r1_bio
->remaining
))
308 /* it really is the end of this request */
309 if (test_bit(R1BIO_BehindIO
, &r1_bio
->state
)) {
310 /* free extra copy of the data pages */
311 int i
= r1_bio
->behind_page_count
;
313 safe_put_page(r1_bio
->behind_pages
[i
]);
314 kfree(r1_bio
->behind_pages
);
315 r1_bio
->behind_pages
= NULL
;
317 /* clear the bitmap if all writes complete successfully */
318 bitmap_endwrite(r1_bio
->mddev
->bitmap
, r1_bio
->sector
,
320 !test_bit(R1BIO_Degraded
, &r1_bio
->state
),
321 test_bit(R1BIO_BehindIO
, &r1_bio
->state
));
322 md_write_end(r1_bio
->mddev
);
323 raid_end_bio_io(r1_bio
);
327 static void raid1_end_write_request(struct bio
*bio
, int error
)
329 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
330 r1bio_t
*r1_bio
= bio
->bi_private
;
331 int mirror
, behind
= test_bit(R1BIO_BehindIO
, &r1_bio
->state
);
332 conf_t
*conf
= r1_bio
->mddev
->private;
333 struct bio
*to_put
= NULL
;
336 for (mirror
= 0; mirror
< conf
->raid_disks
; mirror
++)
337 if (r1_bio
->bios
[mirror
] == bio
)
341 * 'one mirror IO has finished' event handler:
343 r1_bio
->bios
[mirror
] = NULL
;
346 md_error(r1_bio
->mddev
, conf
->mirrors
[mirror
].rdev
);
347 /* an I/O failed, we can't clear the bitmap */
348 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
351 * Set R1BIO_Uptodate in our master bio, so that we
352 * will return a good error code for to the higher
353 * levels even if IO on some other mirrored buffer
356 * The 'master' represents the composite IO operation
357 * to user-side. So if something waits for IO, then it
358 * will wait for the 'master' bio.
360 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
362 update_head_pos(mirror
, r1_bio
);
365 if (test_bit(WriteMostly
, &conf
->mirrors
[mirror
].rdev
->flags
))
366 atomic_dec(&r1_bio
->behind_remaining
);
369 * In behind mode, we ACK the master bio once the I/O
370 * has safely reached all non-writemostly
371 * disks. Setting the Returned bit ensures that this
372 * gets done only once -- we don't ever want to return
373 * -EIO here, instead we'll wait
375 if (atomic_read(&r1_bio
->behind_remaining
) >= (atomic_read(&r1_bio
->remaining
)-1) &&
376 test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
377 /* Maybe we can return now */
378 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
379 struct bio
*mbio
= r1_bio
->master_bio
;
380 PRINTK(KERN_DEBUG
"raid1: behind end write sectors %llu-%llu\n",
381 (unsigned long long) mbio
->bi_sector
,
382 (unsigned long long) mbio
->bi_sector
+
383 (mbio
->bi_size
>> 9) - 1);
388 rdev_dec_pending(conf
->mirrors
[mirror
].rdev
, conf
->mddev
);
391 * Let's see if all mirrored write operations have finished
394 r1_bio_write_done(r1_bio
);
402 * This routine returns the disk from which the requested read should
403 * be done. There is a per-array 'next expected sequential IO' sector
404 * number - if this matches on the next IO then we use the last disk.
405 * There is also a per-disk 'last know head position' sector that is
406 * maintained from IRQ contexts, both the normal and the resync IO
407 * completion handlers update this position correctly. If there is no
408 * perfect sequential match then we pick the disk whose head is closest.
410 * If there are 2 mirrors in the same 2 devices, performance degrades
411 * because position is mirror, not device based.
413 * The rdev for the device selected will have nr_pending incremented.
415 static int read_balance(conf_t
*conf
, r1bio_t
*r1_bio
)
417 const sector_t this_sector
= r1_bio
->sector
;
418 const int sectors
= r1_bio
->sectors
;
428 * Check if we can balance. We can balance on the whole
429 * device if no resync is going on, or below the resync window.
430 * We take the first readable disk when above the resync window.
434 best_dist
= MaxSector
;
435 if (conf
->mddev
->recovery_cp
< MaxSector
&&
436 (this_sector
+ sectors
>= conf
->next_resync
)) {
441 start_disk
= conf
->last_used
;
444 for (i
= 0 ; i
< conf
->raid_disks
; i
++) {
446 int disk
= start_disk
+ i
;
447 if (disk
>= conf
->raid_disks
)
448 disk
-= conf
->raid_disks
;
450 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
451 if (r1_bio
->bios
[disk
] == IO_BLOCKED
453 || test_bit(Faulty
, &rdev
->flags
))
455 if (!test_bit(In_sync
, &rdev
->flags
) &&
456 rdev
->recovery_offset
< this_sector
+ sectors
)
458 if (test_bit(WriteMostly
, &rdev
->flags
)) {
459 /* Don't balance among write-mostly, just
460 * use the first as a last resort */
465 /* This is a reasonable device to use. It might
468 dist
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
470 /* Don't change to another disk for sequential reads */
471 || conf
->next_seq_sect
== this_sector
473 /* If device is idle, use it */
474 || atomic_read(&rdev
->nr_pending
) == 0) {
478 if (dist
< best_dist
) {
484 if (best_disk
>= 0) {
485 rdev
= rcu_dereference(conf
->mirrors
[best_disk
].rdev
);
488 atomic_inc(&rdev
->nr_pending
);
489 if (test_bit(Faulty
, &rdev
->flags
)) {
490 /* cannot risk returning a device that failed
491 * before we inc'ed nr_pending
493 rdev_dec_pending(rdev
, conf
->mddev
);
496 conf
->next_seq_sect
= this_sector
+ sectors
;
497 conf
->last_used
= best_disk
;
504 int md_raid1_congested(mddev_t
*mddev
, int bits
)
506 conf_t
*conf
= mddev
->private;
510 for (i
= 0; i
< mddev
->raid_disks
; i
++) {
511 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
512 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
513 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
517 /* Note the '|| 1' - when read_balance prefers
518 * non-congested targets, it can be removed
520 if ((bits
& (1<<BDI_async_congested
)) || 1)
521 ret
|= bdi_congested(&q
->backing_dev_info
, bits
);
523 ret
&= bdi_congested(&q
->backing_dev_info
, bits
);
529 EXPORT_SYMBOL_GPL(md_raid1_congested
);
531 static int raid1_congested(void *data
, int bits
)
533 mddev_t
*mddev
= data
;
535 return mddev_congested(mddev
, bits
) ||
536 md_raid1_congested(mddev
, bits
);
539 static void flush_pending_writes(conf_t
*conf
)
541 /* Any writes that have been queued but are awaiting
542 * bitmap updates get flushed here.
544 spin_lock_irq(&conf
->device_lock
);
546 if (conf
->pending_bio_list
.head
) {
548 bio
= bio_list_get(&conf
->pending_bio_list
);
549 spin_unlock_irq(&conf
->device_lock
);
550 /* flush any pending bitmap writes to
551 * disk before proceeding w/ I/O */
552 bitmap_unplug(conf
->mddev
->bitmap
);
554 while (bio
) { /* submit pending writes */
555 struct bio
*next
= bio
->bi_next
;
557 generic_make_request(bio
);
561 spin_unlock_irq(&conf
->device_lock
);
565 * Sometimes we need to suspend IO while we do something else,
566 * either some resync/recovery, or reconfigure the array.
567 * To do this we raise a 'barrier'.
568 * The 'barrier' is a counter that can be raised multiple times
569 * to count how many activities are happening which preclude
571 * We can only raise the barrier if there is no pending IO.
572 * i.e. if nr_pending == 0.
573 * We choose only to raise the barrier if no-one is waiting for the
574 * barrier to go down. This means that as soon as an IO request
575 * is ready, no other operations which require a barrier will start
576 * until the IO request has had a chance.
578 * So: regular IO calls 'wait_barrier'. When that returns there
579 * is no backgroup IO happening, It must arrange to call
580 * allow_barrier when it has finished its IO.
581 * backgroup IO calls must call raise_barrier. Once that returns
582 * there is no normal IO happeing. It must arrange to call
583 * lower_barrier when the particular background IO completes.
585 #define RESYNC_DEPTH 32
587 static void raise_barrier(conf_t
*conf
)
589 spin_lock_irq(&conf
->resync_lock
);
591 /* Wait until no block IO is waiting */
592 wait_event_lock_irq(conf
->wait_barrier
, !conf
->nr_waiting
,
593 conf
->resync_lock
, );
595 /* block any new IO from starting */
598 /* Now wait for all pending IO to complete */
599 wait_event_lock_irq(conf
->wait_barrier
,
600 !conf
->nr_pending
&& conf
->barrier
< RESYNC_DEPTH
,
601 conf
->resync_lock
, );
603 spin_unlock_irq(&conf
->resync_lock
);
606 static void lower_barrier(conf_t
*conf
)
609 BUG_ON(conf
->barrier
<= 0);
610 spin_lock_irqsave(&conf
->resync_lock
, flags
);
612 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
613 wake_up(&conf
->wait_barrier
);
616 static void wait_barrier(conf_t
*conf
)
618 spin_lock_irq(&conf
->resync_lock
);
621 wait_event_lock_irq(conf
->wait_barrier
, !conf
->barrier
,
627 spin_unlock_irq(&conf
->resync_lock
);
630 static void allow_barrier(conf_t
*conf
)
633 spin_lock_irqsave(&conf
->resync_lock
, flags
);
635 spin_unlock_irqrestore(&conf
->resync_lock
, flags
);
636 wake_up(&conf
->wait_barrier
);
639 static void freeze_array(conf_t
*conf
)
641 /* stop syncio and normal IO and wait for everything to
643 * We increment barrier and nr_waiting, and then
644 * wait until nr_pending match nr_queued+1
645 * This is called in the context of one normal IO request
646 * that has failed. Thus any sync request that might be pending
647 * will be blocked by nr_pending, and we need to wait for
648 * pending IO requests to complete or be queued for re-try.
649 * Thus the number queued (nr_queued) plus this request (1)
650 * must match the number of pending IOs (nr_pending) before
653 spin_lock_irq(&conf
->resync_lock
);
656 wait_event_lock_irq(conf
->wait_barrier
,
657 conf
->nr_pending
== conf
->nr_queued
+1,
659 flush_pending_writes(conf
));
660 spin_unlock_irq(&conf
->resync_lock
);
662 static void unfreeze_array(conf_t
*conf
)
664 /* reverse the effect of the freeze */
665 spin_lock_irq(&conf
->resync_lock
);
668 wake_up(&conf
->wait_barrier
);
669 spin_unlock_irq(&conf
->resync_lock
);
673 /* duplicate the data pages for behind I/O
675 static void alloc_behind_pages(struct bio
*bio
, r1bio_t
*r1_bio
)
678 struct bio_vec
*bvec
;
679 struct page
**pages
= kzalloc(bio
->bi_vcnt
* sizeof(struct page
*),
681 if (unlikely(!pages
))
684 bio_for_each_segment(bvec
, bio
, i
) {
685 pages
[i
] = alloc_page(GFP_NOIO
);
686 if (unlikely(!pages
[i
]))
688 memcpy(kmap(pages
[i
]) + bvec
->bv_offset
,
689 kmap(bvec
->bv_page
) + bvec
->bv_offset
, bvec
->bv_len
);
691 kunmap(bvec
->bv_page
);
693 r1_bio
->behind_pages
= pages
;
694 r1_bio
->behind_page_count
= bio
->bi_vcnt
;
695 set_bit(R1BIO_BehindIO
, &r1_bio
->state
);
699 for (i
= 0; i
< bio
->bi_vcnt
; i
++)
703 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio
->bi_size
);
706 static int make_request(mddev_t
*mddev
, struct bio
* bio
)
708 conf_t
*conf
= mddev
->private;
709 mirror_info_t
*mirror
;
711 struct bio
*read_bio
;
712 int i
, targets
= 0, disks
;
713 struct bitmap
*bitmap
;
715 const int rw
= bio_data_dir(bio
);
716 const unsigned long do_sync
= (bio
->bi_rw
& REQ_SYNC
);
717 const unsigned long do_flush_fua
= (bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
));
718 mdk_rdev_t
*blocked_rdev
;
722 * Register the new request and wait if the reconstruction
723 * thread has put up a bar for new requests.
724 * Continue immediately if no resync is active currently.
727 md_write_start(mddev
, bio
); /* wait on superblock update early */
729 if (bio_data_dir(bio
) == WRITE
&&
730 bio
->bi_sector
+ bio
->bi_size
/512 > mddev
->suspend_lo
&&
731 bio
->bi_sector
< mddev
->suspend_hi
) {
732 /* As the suspend_* range is controlled by
733 * userspace, we want an interruptible
738 flush_signals(current
);
739 prepare_to_wait(&conf
->wait_barrier
,
740 &w
, TASK_INTERRUPTIBLE
);
741 if (bio
->bi_sector
+ bio
->bi_size
/512 <= mddev
->suspend_lo
||
742 bio
->bi_sector
>= mddev
->suspend_hi
)
746 finish_wait(&conf
->wait_barrier
, &w
);
751 bitmap
= mddev
->bitmap
;
754 * make_request() can abort the operation when READA is being
755 * used and no empty request is available.
758 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
760 r1_bio
->master_bio
= bio
;
761 r1_bio
->sectors
= bio
->bi_size
>> 9;
763 r1_bio
->mddev
= mddev
;
764 r1_bio
->sector
= bio
->bi_sector
;
768 * read balancing logic:
770 int rdisk
= read_balance(conf
, r1_bio
);
773 /* couldn't find anywhere to read from */
774 raid_end_bio_io(r1_bio
);
777 mirror
= conf
->mirrors
+ rdisk
;
779 if (test_bit(WriteMostly
, &mirror
->rdev
->flags
) &&
781 /* Reading from a write-mostly device must
782 * take care not to over-take any writes
785 wait_event(bitmap
->behind_wait
,
786 atomic_read(&bitmap
->behind_writes
) == 0);
788 r1_bio
->read_disk
= rdisk
;
790 read_bio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
792 r1_bio
->bios
[rdisk
] = read_bio
;
794 read_bio
->bi_sector
= r1_bio
->sector
+ mirror
->rdev
->data_offset
;
795 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
796 read_bio
->bi_end_io
= raid1_end_read_request
;
797 read_bio
->bi_rw
= READ
| do_sync
;
798 read_bio
->bi_private
= r1_bio
;
800 generic_make_request(read_bio
);
807 /* first select target devices under spinlock and
808 * inc refcount on their rdev. Record them by setting
811 plugged
= mddev_check_plugged(mddev
);
813 disks
= conf
->raid_disks
;
817 for (i
= 0; i
< disks
; i
++) {
818 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
819 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
820 atomic_inc(&rdev
->nr_pending
);
824 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
825 atomic_inc(&rdev
->nr_pending
);
826 if (test_bit(Faulty
, &rdev
->flags
)) {
827 rdev_dec_pending(rdev
, mddev
);
828 r1_bio
->bios
[i
] = NULL
;
830 r1_bio
->bios
[i
] = bio
;
834 r1_bio
->bios
[i
] = NULL
;
838 if (unlikely(blocked_rdev
)) {
839 /* Wait for this device to become unblocked */
842 for (j
= 0; j
< i
; j
++)
844 rdev_dec_pending(conf
->mirrors
[j
].rdev
, mddev
);
847 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
852 BUG_ON(targets
== 0); /* we never fail the last device */
854 if (targets
< conf
->raid_disks
) {
855 /* array is degraded, we will not clear the bitmap
856 * on I/O completion (see raid1_end_write_request) */
857 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
861 * Not if there are too many, or cannot allocate memory,
862 * or a reader on WriteMostly is waiting for behind writes
865 (atomic_read(&bitmap
->behind_writes
)
866 < mddev
->bitmap_info
.max_write_behind
) &&
867 !waitqueue_active(&bitmap
->behind_wait
))
868 alloc_behind_pages(bio
, r1_bio
);
870 atomic_set(&r1_bio
->remaining
, 1);
871 atomic_set(&r1_bio
->behind_remaining
, 0);
873 bitmap_startwrite(bitmap
, bio
->bi_sector
, r1_bio
->sectors
,
874 test_bit(R1BIO_BehindIO
, &r1_bio
->state
));
875 for (i
= 0; i
< disks
; i
++) {
877 if (!r1_bio
->bios
[i
])
880 mbio
= bio_clone_mddev(bio
, GFP_NOIO
, mddev
);
881 r1_bio
->bios
[i
] = mbio
;
883 mbio
->bi_sector
= r1_bio
->sector
+ conf
->mirrors
[i
].rdev
->data_offset
;
884 mbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
885 mbio
->bi_end_io
= raid1_end_write_request
;
886 mbio
->bi_rw
= WRITE
| do_flush_fua
| do_sync
;
887 mbio
->bi_private
= r1_bio
;
889 if (r1_bio
->behind_pages
) {
890 struct bio_vec
*bvec
;
893 /* Yes, I really want the '__' version so that
894 * we clear any unused pointer in the io_vec, rather
895 * than leave them unchanged. This is important
896 * because when we come to free the pages, we won't
897 * know the original bi_idx, so we just free
900 __bio_for_each_segment(bvec
, mbio
, j
, 0)
901 bvec
->bv_page
= r1_bio
->behind_pages
[j
];
902 if (test_bit(WriteMostly
, &conf
->mirrors
[i
].rdev
->flags
))
903 atomic_inc(&r1_bio
->behind_remaining
);
906 atomic_inc(&r1_bio
->remaining
);
907 spin_lock_irqsave(&conf
->device_lock
, flags
);
908 bio_list_add(&conf
->pending_bio_list
, mbio
);
909 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
911 r1_bio_write_done(r1_bio
);
913 /* In case raid1d snuck in to freeze_array */
914 wake_up(&conf
->wait_barrier
);
916 if (do_sync
|| !bitmap
|| !plugged
)
917 md_wakeup_thread(mddev
->thread
);
922 static void status(struct seq_file
*seq
, mddev_t
*mddev
)
924 conf_t
*conf
= mddev
->private;
927 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
928 conf
->raid_disks
- mddev
->degraded
);
930 for (i
= 0; i
< conf
->raid_disks
; i
++) {
931 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
932 seq_printf(seq
, "%s",
933 rdev
&& test_bit(In_sync
, &rdev
->flags
) ? "U" : "_");
936 seq_printf(seq
, "]");
940 static void error(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
942 char b
[BDEVNAME_SIZE
];
943 conf_t
*conf
= mddev
->private;
946 * If it is not operational, then we have already marked it as dead
947 * else if it is the last working disks, ignore the error, let the
948 * next level up know.
949 * else mark the drive as failed
951 if (test_bit(In_sync
, &rdev
->flags
)
952 && (conf
->raid_disks
- mddev
->degraded
) == 1) {
954 * Don't fail the drive, act as though we were just a
955 * normal single drive.
956 * However don't try a recovery from this drive as
957 * it is very likely to fail.
959 mddev
->recovery_disabled
= 1;
962 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
964 spin_lock_irqsave(&conf
->device_lock
, flags
);
966 set_bit(Faulty
, &rdev
->flags
);
967 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
969 * if recovery is running, make sure it aborts.
971 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
973 set_bit(Faulty
, &rdev
->flags
);
974 set_bit(MD_CHANGE_DEVS
, &mddev
->flags
);
976 "md/raid1:%s: Disk failure on %s, disabling device.\n"
977 "md/raid1:%s: Operation continuing on %d devices.\n",
978 mdname(mddev
), bdevname(rdev
->bdev
, b
),
979 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
982 static void print_conf(conf_t
*conf
)
986 printk(KERN_DEBUG
"RAID1 conf printout:\n");
988 printk(KERN_DEBUG
"(!conf)\n");
991 printk(KERN_DEBUG
" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
995 for (i
= 0; i
< conf
->raid_disks
; i
++) {
996 char b
[BDEVNAME_SIZE
];
997 mdk_rdev_t
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
999 printk(KERN_DEBUG
" disk %d, wo:%d, o:%d, dev:%s\n",
1000 i
, !test_bit(In_sync
, &rdev
->flags
),
1001 !test_bit(Faulty
, &rdev
->flags
),
1002 bdevname(rdev
->bdev
,b
));
1007 static void close_sync(conf_t
*conf
)
1010 allow_barrier(conf
);
1012 mempool_destroy(conf
->r1buf_pool
);
1013 conf
->r1buf_pool
= NULL
;
1016 static int raid1_spare_active(mddev_t
*mddev
)
1019 conf_t
*conf
= mddev
->private;
1021 unsigned long flags
;
1024 * Find all failed disks within the RAID1 configuration
1025 * and mark them readable.
1026 * Called under mddev lock, so rcu protection not needed.
1028 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1029 mdk_rdev_t
*rdev
= conf
->mirrors
[i
].rdev
;
1031 && !test_bit(Faulty
, &rdev
->flags
)
1032 && !test_and_set_bit(In_sync
, &rdev
->flags
)) {
1034 sysfs_notify_dirent(rdev
->sysfs_state
);
1037 spin_lock_irqsave(&conf
->device_lock
, flags
);
1038 mddev
->degraded
-= count
;
1039 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1046 static int raid1_add_disk(mddev_t
*mddev
, mdk_rdev_t
*rdev
)
1048 conf_t
*conf
= mddev
->private;
1053 int last
= mddev
->raid_disks
- 1;
1055 if (rdev
->raid_disk
>= 0)
1056 first
= last
= rdev
->raid_disk
;
1058 for (mirror
= first
; mirror
<= last
; mirror
++)
1059 if ( !(p
=conf
->mirrors
+mirror
)->rdev
) {
1061 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1062 rdev
->data_offset
<< 9);
1063 /* as we don't honour merge_bvec_fn, we must
1064 * never risk violating it, so limit
1065 * ->max_segments to one lying with a single
1066 * page, as a one page request is never in
1069 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1070 blk_queue_max_segments(mddev
->queue
, 1);
1071 blk_queue_segment_boundary(mddev
->queue
,
1072 PAGE_CACHE_SIZE
- 1);
1075 p
->head_position
= 0;
1076 rdev
->raid_disk
= mirror
;
1078 /* As all devices are equivalent, we don't need a full recovery
1079 * if this was recently any drive of the array
1081 if (rdev
->saved_raid_disk
< 0)
1083 rcu_assign_pointer(p
->rdev
, rdev
);
1086 md_integrity_add_rdev(rdev
, mddev
);
1091 static int raid1_remove_disk(mddev_t
*mddev
, int number
)
1093 conf_t
*conf
= mddev
->private;
1096 mirror_info_t
*p
= conf
->mirrors
+ number
;
1101 if (test_bit(In_sync
, &rdev
->flags
) ||
1102 atomic_read(&rdev
->nr_pending
)) {
1106 /* Only remove non-faulty devices if recovery
1109 if (!test_bit(Faulty
, &rdev
->flags
) &&
1110 !mddev
->recovery_disabled
&&
1111 mddev
->degraded
< conf
->raid_disks
) {
1117 if (atomic_read(&rdev
->nr_pending
)) {
1118 /* lost the race, try later */
1123 err
= md_integrity_register(mddev
);
1132 static void end_sync_read(struct bio
*bio
, int error
)
1134 r1bio_t
*r1_bio
= bio
->bi_private
;
1137 for (i
=r1_bio
->mddev
->raid_disks
; i
--; )
1138 if (r1_bio
->bios
[i
] == bio
)
1141 update_head_pos(i
, r1_bio
);
1143 * we have read a block, now it needs to be re-written,
1144 * or re-read if the read failed.
1145 * We don't do much here, just schedule handling by raid1d
1147 if (test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
1148 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1150 if (atomic_dec_and_test(&r1_bio
->remaining
))
1151 reschedule_retry(r1_bio
);
1154 static void end_sync_write(struct bio
*bio
, int error
)
1156 int uptodate
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1157 r1bio_t
*r1_bio
= bio
->bi_private
;
1158 mddev_t
*mddev
= r1_bio
->mddev
;
1159 conf_t
*conf
= mddev
->private;
1163 for (i
= 0; i
< conf
->raid_disks
; i
++)
1164 if (r1_bio
->bios
[i
] == bio
) {
1169 sector_t sync_blocks
= 0;
1170 sector_t s
= r1_bio
->sector
;
1171 long sectors_to_go
= r1_bio
->sectors
;
1172 /* make sure these bits doesn't get cleared. */
1174 bitmap_end_sync(mddev
->bitmap
, s
,
1177 sectors_to_go
-= sync_blocks
;
1178 } while (sectors_to_go
> 0);
1179 md_error(mddev
, conf
->mirrors
[mirror
].rdev
);
1182 update_head_pos(mirror
, r1_bio
);
1184 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1185 sector_t s
= r1_bio
->sectors
;
1187 md_done_sync(mddev
, s
, uptodate
);
1191 static int fix_sync_read_error(r1bio_t
*r1_bio
)
1193 /* Try some synchronous reads of other devices to get
1194 * good data, much like with normal read errors. Only
1195 * read into the pages we already have so we don't
1196 * need to re-issue the read request.
1197 * We don't need to freeze the array, because being in an
1198 * active sync request, there is no normal IO, and
1199 * no overlapping syncs.
1201 mddev_t
*mddev
= r1_bio
->mddev
;
1202 conf_t
*conf
= mddev
->private;
1203 struct bio
*bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1204 sector_t sect
= r1_bio
->sector
;
1205 int sectors
= r1_bio
->sectors
;
1210 int d
= r1_bio
->read_disk
;
1215 if (s
> (PAGE_SIZE
>>9))
1218 if (r1_bio
->bios
[d
]->bi_end_io
== end_sync_read
) {
1219 /* No rcu protection needed here devices
1220 * can only be removed when no resync is
1221 * active, and resync is currently active
1223 rdev
= conf
->mirrors
[d
].rdev
;
1224 if (sync_page_io(rdev
,
1227 bio
->bi_io_vec
[idx
].bv_page
,
1234 if (d
== conf
->raid_disks
)
1236 } while (!success
&& d
!= r1_bio
->read_disk
);
1239 char b
[BDEVNAME_SIZE
];
1240 /* Cannot read from anywhere, array is toast */
1241 md_error(mddev
, conf
->mirrors
[r1_bio
->read_disk
].rdev
);
1242 printk(KERN_ALERT
"md/raid1:%s: %s: unrecoverable I/O read error"
1243 " for block %llu\n",
1245 bdevname(bio
->bi_bdev
, b
),
1246 (unsigned long long)r1_bio
->sector
);
1247 md_done_sync(mddev
, r1_bio
->sectors
, 0);
1253 /* write it back and re-read */
1254 while (d
!= r1_bio
->read_disk
) {
1256 d
= conf
->raid_disks
;
1258 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1260 rdev
= conf
->mirrors
[d
].rdev
;
1261 if (sync_page_io(rdev
,
1264 bio
->bi_io_vec
[idx
].bv_page
,
1265 WRITE
, false) == 0) {
1266 r1_bio
->bios
[d
]->bi_end_io
= NULL
;
1267 rdev_dec_pending(rdev
, mddev
);
1268 md_error(mddev
, rdev
);
1270 atomic_add(s
, &rdev
->corrected_errors
);
1273 while (d
!= r1_bio
->read_disk
) {
1275 d
= conf
->raid_disks
;
1277 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
1279 rdev
= conf
->mirrors
[d
].rdev
;
1280 if (sync_page_io(rdev
,
1283 bio
->bi_io_vec
[idx
].bv_page
,
1285 md_error(mddev
, rdev
);
1291 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1292 set_bit(BIO_UPTODATE
, &bio
->bi_flags
);
1296 static int process_checks(r1bio_t
*r1_bio
)
1298 /* We have read all readable devices. If we haven't
1299 * got the block, then there is no hope left.
1300 * If we have, then we want to do a comparison
1301 * and skip the write if everything is the same.
1302 * If any blocks failed to read, then we need to
1303 * attempt an over-write
1305 mddev_t
*mddev
= r1_bio
->mddev
;
1306 conf_t
*conf
= mddev
->private;
1310 for (primary
= 0; primary
< conf
->raid_disks
; primary
++)
1311 if (r1_bio
->bios
[primary
]->bi_end_io
== end_sync_read
&&
1312 test_bit(BIO_UPTODATE
, &r1_bio
->bios
[primary
]->bi_flags
)) {
1313 r1_bio
->bios
[primary
]->bi_end_io
= NULL
;
1314 rdev_dec_pending(conf
->mirrors
[primary
].rdev
, mddev
);
1317 r1_bio
->read_disk
= primary
;
1318 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1320 int vcnt
= r1_bio
->sectors
>> (PAGE_SHIFT
- 9);
1321 struct bio
*pbio
= r1_bio
->bios
[primary
];
1322 struct bio
*sbio
= r1_bio
->bios
[i
];
1325 if (r1_bio
->bios
[i
]->bi_end_io
!= end_sync_read
)
1328 if (test_bit(BIO_UPTODATE
, &sbio
->bi_flags
)) {
1329 for (j
= vcnt
; j
-- ; ) {
1331 p
= pbio
->bi_io_vec
[j
].bv_page
;
1332 s
= sbio
->bi_io_vec
[j
].bv_page
;
1333 if (memcmp(page_address(p
),
1341 mddev
->resync_mismatches
+= r1_bio
->sectors
;
1342 if (j
< 0 || (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
)
1343 && test_bit(BIO_UPTODATE
, &sbio
->bi_flags
))) {
1344 /* No need to write to this device. */
1345 sbio
->bi_end_io
= NULL
;
1346 rdev_dec_pending(conf
->mirrors
[i
].rdev
, mddev
);
1349 /* fixup the bio for reuse */
1350 sbio
->bi_vcnt
= vcnt
;
1351 sbio
->bi_size
= r1_bio
->sectors
<< 9;
1353 sbio
->bi_phys_segments
= 0;
1354 sbio
->bi_flags
&= ~(BIO_POOL_MASK
- 1);
1355 sbio
->bi_flags
|= 1 << BIO_UPTODATE
;
1356 sbio
->bi_next
= NULL
;
1357 sbio
->bi_sector
= r1_bio
->sector
+
1358 conf
->mirrors
[i
].rdev
->data_offset
;
1359 sbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1360 size
= sbio
->bi_size
;
1361 for (j
= 0; j
< vcnt
; j
++) {
1363 bi
= &sbio
->bi_io_vec
[j
];
1365 if (size
> PAGE_SIZE
)
1366 bi
->bv_len
= PAGE_SIZE
;
1370 memcpy(page_address(bi
->bv_page
),
1371 page_address(pbio
->bi_io_vec
[j
].bv_page
),
1378 static void sync_request_write(mddev_t
*mddev
, r1bio_t
*r1_bio
)
1380 conf_t
*conf
= mddev
->private;
1382 int disks
= conf
->raid_disks
;
1383 struct bio
*bio
, *wbio
;
1385 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1387 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
))
1388 /* ouch - failed to read all of that. */
1389 if (!fix_sync_read_error(r1_bio
))
1392 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
1393 if (process_checks(r1_bio
) < 0)
1398 atomic_set(&r1_bio
->remaining
, 1);
1399 for (i
= 0; i
< disks
; i
++) {
1400 wbio
= r1_bio
->bios
[i
];
1401 if (wbio
->bi_end_io
== NULL
||
1402 (wbio
->bi_end_io
== end_sync_read
&&
1403 (i
== r1_bio
->read_disk
||
1404 !test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))))
1407 wbio
->bi_rw
= WRITE
;
1408 wbio
->bi_end_io
= end_sync_write
;
1409 atomic_inc(&r1_bio
->remaining
);
1410 md_sync_acct(conf
->mirrors
[i
].rdev
->bdev
, wbio
->bi_size
>> 9);
1412 generic_make_request(wbio
);
1415 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1416 /* if we're here, all write(s) have completed, so clean up */
1417 md_done_sync(mddev
, r1_bio
->sectors
, 1);
1423 * This is a kernel thread which:
1425 * 1. Retries failed read operations on working mirrors.
1426 * 2. Updates the raid superblock when problems encounter.
1427 * 3. Performs writes following reads for array syncronising.
1430 static void fix_read_error(conf_t
*conf
, int read_disk
,
1431 sector_t sect
, int sectors
)
1433 mddev_t
*mddev
= conf
->mddev
;
1441 if (s
> (PAGE_SIZE
>>9))
1445 /* Note: no rcu protection needed here
1446 * as this is synchronous in the raid1d thread
1447 * which is the thread that might remove
1448 * a device. If raid1d ever becomes multi-threaded....
1450 rdev
= conf
->mirrors
[d
].rdev
;
1452 test_bit(In_sync
, &rdev
->flags
) &&
1453 sync_page_io(rdev
, sect
, s
<<9,
1454 conf
->tmppage
, READ
, false))
1458 if (d
== conf
->raid_disks
)
1461 } while (!success
&& d
!= read_disk
);
1464 /* Cannot read from anywhere -- bye bye array */
1465 md_error(mddev
, conf
->mirrors
[read_disk
].rdev
);
1468 /* write it back and re-read */
1470 while (d
!= read_disk
) {
1472 d
= conf
->raid_disks
;
1474 rdev
= conf
->mirrors
[d
].rdev
;
1476 test_bit(In_sync
, &rdev
->flags
)) {
1477 if (sync_page_io(rdev
, sect
, s
<<9,
1478 conf
->tmppage
, WRITE
, false)
1480 /* Well, this device is dead */
1481 md_error(mddev
, rdev
);
1485 while (d
!= read_disk
) {
1486 char b
[BDEVNAME_SIZE
];
1488 d
= conf
->raid_disks
;
1490 rdev
= conf
->mirrors
[d
].rdev
;
1492 test_bit(In_sync
, &rdev
->flags
)) {
1493 if (sync_page_io(rdev
, sect
, s
<<9,
1494 conf
->tmppage
, READ
, false)
1496 /* Well, this device is dead */
1497 md_error(mddev
, rdev
);
1499 atomic_add(s
, &rdev
->corrected_errors
);
1501 "md/raid1:%s: read error corrected "
1502 "(%d sectors at %llu on %s)\n",
1504 (unsigned long long)(sect
+
1506 bdevname(rdev
->bdev
, b
));
1515 static void raid1d(mddev_t
*mddev
)
1519 unsigned long flags
;
1520 conf_t
*conf
= mddev
->private;
1521 struct list_head
*head
= &conf
->retry_list
;
1523 struct blk_plug plug
;
1525 md_check_recovery(mddev
);
1527 blk_start_plug(&plug
);
1529 char b
[BDEVNAME_SIZE
];
1531 if (atomic_read(&mddev
->plug_cnt
) == 0)
1532 flush_pending_writes(conf
);
1534 spin_lock_irqsave(&conf
->device_lock
, flags
);
1535 if (list_empty(head
)) {
1536 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1539 r1_bio
= list_entry(head
->prev
, r1bio_t
, retry_list
);
1540 list_del(head
->prev
);
1542 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1544 mddev
= r1_bio
->mddev
;
1545 conf
= mddev
->private;
1546 if (test_bit(R1BIO_IsSync
, &r1_bio
->state
))
1547 sync_request_write(mddev
, r1_bio
);
1551 /* we got a read error. Maybe the drive is bad. Maybe just
1552 * the block and we can fix it.
1553 * We freeze all other IO, and try reading the block from
1554 * other devices. When we find one, we re-write
1555 * and check it that fixes the read error.
1556 * This is all done synchronously while the array is
1559 if (mddev
->ro
== 0) {
1561 fix_read_error(conf
, r1_bio
->read_disk
,
1564 unfreeze_array(conf
);
1567 conf
->mirrors
[r1_bio
->read_disk
].rdev
);
1569 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1570 if ((disk
=read_balance(conf
, r1_bio
)) == -1) {
1571 printk(KERN_ALERT
"md/raid1:%s: %s: unrecoverable I/O"
1572 " read error for block %llu\n",
1574 bdevname(bio
->bi_bdev
,b
),
1575 (unsigned long long)r1_bio
->sector
);
1576 raid_end_bio_io(r1_bio
);
1578 const unsigned long do_sync
= r1_bio
->master_bio
->bi_rw
& REQ_SYNC
;
1579 r1_bio
->bios
[r1_bio
->read_disk
] =
1580 mddev
->ro
? IO_BLOCKED
: NULL
;
1581 r1_bio
->read_disk
= disk
;
1583 bio
= bio_clone_mddev(r1_bio
->master_bio
,
1585 r1_bio
->bios
[r1_bio
->read_disk
] = bio
;
1586 rdev
= conf
->mirrors
[disk
].rdev
;
1589 "md/raid1:%s: redirecting sector %llu"
1590 " to other mirror: %s\n",
1592 (unsigned long long)r1_bio
->sector
,
1593 bdevname(rdev
->bdev
, b
));
1594 bio
->bi_sector
= r1_bio
->sector
+ rdev
->data_offset
;
1595 bio
->bi_bdev
= rdev
->bdev
;
1596 bio
->bi_end_io
= raid1_end_read_request
;
1597 bio
->bi_rw
= READ
| do_sync
;
1598 bio
->bi_private
= r1_bio
;
1599 generic_make_request(bio
);
1604 blk_finish_plug(&plug
);
1608 static int init_resync(conf_t
*conf
)
1612 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
1613 BUG_ON(conf
->r1buf_pool
);
1614 conf
->r1buf_pool
= mempool_create(buffs
, r1buf_pool_alloc
, r1buf_pool_free
,
1616 if (!conf
->r1buf_pool
)
1618 conf
->next_resync
= 0;
1623 * perform a "sync" on one "block"
1625 * We need to make sure that no normal I/O request - particularly write
1626 * requests - conflict with active sync requests.
1628 * This is achieved by tracking pending requests and a 'barrier' concept
1629 * that can be installed to exclude normal IO requests.
1632 static sector_t
sync_request(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
)
1634 conf_t
*conf
= mddev
->private;
1637 sector_t max_sector
, nr_sectors
;
1641 int write_targets
= 0, read_targets
= 0;
1642 sector_t sync_blocks
;
1643 int still_degraded
= 0;
1645 if (!conf
->r1buf_pool
)
1646 if (init_resync(conf
))
1649 max_sector
= mddev
->dev_sectors
;
1650 if (sector_nr
>= max_sector
) {
1651 /* If we aborted, we need to abort the
1652 * sync on the 'current' bitmap chunk (there will
1653 * only be one in raid1 resync.
1654 * We can find the current addess in mddev->curr_resync
1656 if (mddev
->curr_resync
< max_sector
) /* aborted */
1657 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
1659 else /* completed sync */
1662 bitmap_close_sync(mddev
->bitmap
);
1667 if (mddev
->bitmap
== NULL
&&
1668 mddev
->recovery_cp
== MaxSector
&&
1669 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
1670 conf
->fullsync
== 0) {
1672 return max_sector
- sector_nr
;
1674 /* before building a request, check if we can skip these blocks..
1675 * This call the bitmap_start_sync doesn't actually record anything
1677 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
1678 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
1679 /* We can skip this block, and probably several more */
1684 * If there is non-resync activity waiting for a turn,
1685 * and resync is going fast enough,
1686 * then let it though before starting on this new sync request.
1688 if (!go_faster
&& conf
->nr_waiting
)
1689 msleep_interruptible(1000);
1691 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
);
1692 r1_bio
= mempool_alloc(conf
->r1buf_pool
, GFP_NOIO
);
1693 raise_barrier(conf
);
1695 conf
->next_resync
= sector_nr
;
1699 * If we get a correctably read error during resync or recovery,
1700 * we might want to read from a different device. So we
1701 * flag all drives that could conceivably be read from for READ,
1702 * and any others (which will be non-In_sync devices) for WRITE.
1703 * If a read fails, we try reading from something else for which READ
1707 r1_bio
->mddev
= mddev
;
1708 r1_bio
->sector
= sector_nr
;
1710 set_bit(R1BIO_IsSync
, &r1_bio
->state
);
1712 for (i
=0; i
< conf
->raid_disks
; i
++) {
1714 bio
= r1_bio
->bios
[i
];
1716 /* take from bio_init */
1717 bio
->bi_next
= NULL
;
1718 bio
->bi_flags
&= ~(BIO_POOL_MASK
-1);
1719 bio
->bi_flags
|= 1 << BIO_UPTODATE
;
1720 bio
->bi_comp_cpu
= -1;
1724 bio
->bi_phys_segments
= 0;
1726 bio
->bi_end_io
= NULL
;
1727 bio
->bi_private
= NULL
;
1729 rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1731 test_bit(Faulty
, &rdev
->flags
)) {
1734 } else if (!test_bit(In_sync
, &rdev
->flags
)) {
1736 bio
->bi_end_io
= end_sync_write
;
1739 /* may need to read from here */
1741 bio
->bi_end_io
= end_sync_read
;
1742 if (test_bit(WriteMostly
, &rdev
->flags
)) {
1751 atomic_inc(&rdev
->nr_pending
);
1752 bio
->bi_sector
= sector_nr
+ rdev
->data_offset
;
1753 bio
->bi_bdev
= rdev
->bdev
;
1754 bio
->bi_private
= r1_bio
;
1759 r1_bio
->read_disk
= disk
;
1761 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
) && read_targets
> 0)
1762 /* extra read targets are also write targets */
1763 write_targets
+= read_targets
-1;
1765 if (write_targets
== 0 || read_targets
== 0) {
1766 /* There is nowhere to write, so all non-sync
1767 * drives must be failed - so we are finished
1769 sector_t rv
= max_sector
- sector_nr
;
1775 if (max_sector
> mddev
->resync_max
)
1776 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
1781 int len
= PAGE_SIZE
;
1782 if (sector_nr
+ (len
>>9) > max_sector
)
1783 len
= (max_sector
- sector_nr
) << 9;
1786 if (sync_blocks
== 0) {
1787 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
1788 &sync_blocks
, still_degraded
) &&
1790 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
1792 BUG_ON(sync_blocks
< (PAGE_SIZE
>>9));
1793 if ((len
>> 9) > sync_blocks
)
1794 len
= sync_blocks
<<9;
1797 for (i
=0 ; i
< conf
->raid_disks
; i
++) {
1798 bio
= r1_bio
->bios
[i
];
1799 if (bio
->bi_end_io
) {
1800 page
= bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
;
1801 if (bio_add_page(bio
, page
, len
, 0) == 0) {
1803 bio
->bi_io_vec
[bio
->bi_vcnt
].bv_page
= page
;
1806 bio
= r1_bio
->bios
[i
];
1807 if (bio
->bi_end_io
==NULL
)
1809 /* remove last page from this bio */
1811 bio
->bi_size
-= len
;
1812 bio
->bi_flags
&= ~(1<< BIO_SEG_VALID
);
1818 nr_sectors
+= len
>>9;
1819 sector_nr
+= len
>>9;
1820 sync_blocks
-= (len
>>9);
1821 } while (r1_bio
->bios
[disk
]->bi_vcnt
< RESYNC_PAGES
);
1823 r1_bio
->sectors
= nr_sectors
;
1825 /* For a user-requested sync, we read all readable devices and do a
1828 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
1829 atomic_set(&r1_bio
->remaining
, read_targets
);
1830 for (i
=0; i
<conf
->raid_disks
; i
++) {
1831 bio
= r1_bio
->bios
[i
];
1832 if (bio
->bi_end_io
== end_sync_read
) {
1833 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
1834 generic_make_request(bio
);
1838 atomic_set(&r1_bio
->remaining
, 1);
1839 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1840 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
1841 generic_make_request(bio
);
1847 static sector_t
raid1_size(mddev_t
*mddev
, sector_t sectors
, int raid_disks
)
1852 return mddev
->dev_sectors
;
1855 static conf_t
*setup_conf(mddev_t
*mddev
)
1859 mirror_info_t
*disk
;
1863 conf
= kzalloc(sizeof(conf_t
), GFP_KERNEL
);
1867 conf
->mirrors
= kzalloc(sizeof(struct mirror_info
)*mddev
->raid_disks
,
1872 conf
->tmppage
= alloc_page(GFP_KERNEL
);
1876 conf
->poolinfo
= kzalloc(sizeof(*conf
->poolinfo
), GFP_KERNEL
);
1877 if (!conf
->poolinfo
)
1879 conf
->poolinfo
->raid_disks
= mddev
->raid_disks
;
1880 conf
->r1bio_pool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
1883 if (!conf
->r1bio_pool
)
1886 conf
->poolinfo
->mddev
= mddev
;
1888 spin_lock_init(&conf
->device_lock
);
1889 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
1890 int disk_idx
= rdev
->raid_disk
;
1891 if (disk_idx
>= mddev
->raid_disks
1894 disk
= conf
->mirrors
+ disk_idx
;
1898 disk
->head_position
= 0;
1900 conf
->raid_disks
= mddev
->raid_disks
;
1901 conf
->mddev
= mddev
;
1902 INIT_LIST_HEAD(&conf
->retry_list
);
1904 spin_lock_init(&conf
->resync_lock
);
1905 init_waitqueue_head(&conf
->wait_barrier
);
1907 bio_list_init(&conf
->pending_bio_list
);
1909 conf
->last_used
= -1;
1910 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1912 disk
= conf
->mirrors
+ i
;
1915 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
1916 disk
->head_position
= 0;
1919 } else if (conf
->last_used
< 0)
1921 * The first working device is used as a
1922 * starting point to read balancing.
1924 conf
->last_used
= i
;
1928 if (conf
->last_used
< 0) {
1929 printk(KERN_ERR
"md/raid1:%s: no operational mirrors\n",
1934 conf
->thread
= md_register_thread(raid1d
, mddev
, NULL
);
1935 if (!conf
->thread
) {
1937 "md/raid1:%s: couldn't allocate thread\n",
1946 if (conf
->r1bio_pool
)
1947 mempool_destroy(conf
->r1bio_pool
);
1948 kfree(conf
->mirrors
);
1949 safe_put_page(conf
->tmppage
);
1950 kfree(conf
->poolinfo
);
1953 return ERR_PTR(err
);
1956 static int run(mddev_t
*mddev
)
1962 if (mddev
->level
!= 1) {
1963 printk(KERN_ERR
"md/raid1:%s: raid level not set to mirroring (%d)\n",
1964 mdname(mddev
), mddev
->level
);
1967 if (mddev
->reshape_position
!= MaxSector
) {
1968 printk(KERN_ERR
"md/raid1:%s: reshape_position set but not supported\n",
1973 * copy the already verified devices into our private RAID1
1974 * bookkeeping area. [whatever we allocate in run(),
1975 * should be freed in stop()]
1977 if (mddev
->private == NULL
)
1978 conf
= setup_conf(mddev
);
1980 conf
= mddev
->private;
1983 return PTR_ERR(conf
);
1985 list_for_each_entry(rdev
, &mddev
->disks
, same_set
) {
1986 if (!mddev
->gendisk
)
1988 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1989 rdev
->data_offset
<< 9);
1990 /* as we don't honour merge_bvec_fn, we must never risk
1991 * violating it, so limit ->max_segments to 1 lying within
1992 * a single page, as a one page request is never in violation.
1994 if (rdev
->bdev
->bd_disk
->queue
->merge_bvec_fn
) {
1995 blk_queue_max_segments(mddev
->queue
, 1);
1996 blk_queue_segment_boundary(mddev
->queue
,
1997 PAGE_CACHE_SIZE
- 1);
2001 mddev
->degraded
= 0;
2002 for (i
=0; i
< conf
->raid_disks
; i
++)
2003 if (conf
->mirrors
[i
].rdev
== NULL
||
2004 !test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ||
2005 test_bit(Faulty
, &conf
->mirrors
[i
].rdev
->flags
))
2008 if (conf
->raid_disks
- mddev
->degraded
== 1)
2009 mddev
->recovery_cp
= MaxSector
;
2011 if (mddev
->recovery_cp
!= MaxSector
)
2012 printk(KERN_NOTICE
"md/raid1:%s: not clean"
2013 " -- starting background reconstruction\n",
2016 "md/raid1:%s: active with %d out of %d mirrors\n",
2017 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
2021 * Ok, everything is just fine now
2023 mddev
->thread
= conf
->thread
;
2024 conf
->thread
= NULL
;
2025 mddev
->private = conf
;
2027 md_set_array_sectors(mddev
, raid1_size(mddev
, 0, 0));
2030 mddev
->queue
->backing_dev_info
.congested_fn
= raid1_congested
;
2031 mddev
->queue
->backing_dev_info
.congested_data
= mddev
;
2033 return md_integrity_register(mddev
);
2036 static int stop(mddev_t
*mddev
)
2038 conf_t
*conf
= mddev
->private;
2039 struct bitmap
*bitmap
= mddev
->bitmap
;
2041 /* wait for behind writes to complete */
2042 if (bitmap
&& atomic_read(&bitmap
->behind_writes
) > 0) {
2043 printk(KERN_INFO
"md/raid1:%s: behind writes in progress - waiting to stop.\n",
2045 /* need to kick something here to make sure I/O goes? */
2046 wait_event(bitmap
->behind_wait
,
2047 atomic_read(&bitmap
->behind_writes
) == 0);
2050 raise_barrier(conf
);
2051 lower_barrier(conf
);
2053 md_unregister_thread(mddev
->thread
);
2054 mddev
->thread
= NULL
;
2055 if (conf
->r1bio_pool
)
2056 mempool_destroy(conf
->r1bio_pool
);
2057 kfree(conf
->mirrors
);
2058 kfree(conf
->poolinfo
);
2060 mddev
->private = NULL
;
2064 static int raid1_resize(mddev_t
*mddev
, sector_t sectors
)
2066 /* no resync is happening, and there is enough space
2067 * on all devices, so we can resize.
2068 * We need to make sure resync covers any new space.
2069 * If the array is shrinking we should possibly wait until
2070 * any io in the removed space completes, but it hardly seems
2073 md_set_array_sectors(mddev
, raid1_size(mddev
, sectors
, 0));
2074 if (mddev
->array_sectors
> raid1_size(mddev
, sectors
, 0))
2076 set_capacity(mddev
->gendisk
, mddev
->array_sectors
);
2077 revalidate_disk(mddev
->gendisk
);
2078 if (sectors
> mddev
->dev_sectors
&&
2079 mddev
->recovery_cp
> mddev
->dev_sectors
) {
2080 mddev
->recovery_cp
= mddev
->dev_sectors
;
2081 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2083 mddev
->dev_sectors
= sectors
;
2084 mddev
->resync_max_sectors
= sectors
;
2088 static int raid1_reshape(mddev_t
*mddev
)
2091 * 1/ resize the r1bio_pool
2092 * 2/ resize conf->mirrors
2094 * We allocate a new r1bio_pool if we can.
2095 * Then raise a device barrier and wait until all IO stops.
2096 * Then resize conf->mirrors and swap in the new r1bio pool.
2098 * At the same time, we "pack" the devices so that all the missing
2099 * devices have the higher raid_disk numbers.
2101 mempool_t
*newpool
, *oldpool
;
2102 struct pool_info
*newpoolinfo
;
2103 mirror_info_t
*newmirrors
;
2104 conf_t
*conf
= mddev
->private;
2105 int cnt
, raid_disks
;
2106 unsigned long flags
;
2109 /* Cannot change chunk_size, layout, or level */
2110 if (mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
||
2111 mddev
->layout
!= mddev
->new_layout
||
2112 mddev
->level
!= mddev
->new_level
) {
2113 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
2114 mddev
->new_layout
= mddev
->layout
;
2115 mddev
->new_level
= mddev
->level
;
2119 err
= md_allow_write(mddev
);
2123 raid_disks
= mddev
->raid_disks
+ mddev
->delta_disks
;
2125 if (raid_disks
< conf
->raid_disks
) {
2127 for (d
= 0; d
< conf
->raid_disks
; d
++)
2128 if (conf
->mirrors
[d
].rdev
)
2130 if (cnt
> raid_disks
)
2134 newpoolinfo
= kmalloc(sizeof(*newpoolinfo
), GFP_KERNEL
);
2137 newpoolinfo
->mddev
= mddev
;
2138 newpoolinfo
->raid_disks
= raid_disks
;
2140 newpool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
2141 r1bio_pool_free
, newpoolinfo
);
2146 newmirrors
= kzalloc(sizeof(struct mirror_info
) * raid_disks
, GFP_KERNEL
);
2149 mempool_destroy(newpool
);
2153 raise_barrier(conf
);
2155 /* ok, everything is stopped */
2156 oldpool
= conf
->r1bio_pool
;
2157 conf
->r1bio_pool
= newpool
;
2159 for (d
= d2
= 0; d
< conf
->raid_disks
; d
++) {
2160 mdk_rdev_t
*rdev
= conf
->mirrors
[d
].rdev
;
2161 if (rdev
&& rdev
->raid_disk
!= d2
) {
2163 sprintf(nm
, "rd%d", rdev
->raid_disk
);
2164 sysfs_remove_link(&mddev
->kobj
, nm
);
2165 rdev
->raid_disk
= d2
;
2166 sprintf(nm
, "rd%d", rdev
->raid_disk
);
2167 sysfs_remove_link(&mddev
->kobj
, nm
);
2168 if (sysfs_create_link(&mddev
->kobj
,
2171 "md/raid1:%s: cannot register "
2176 newmirrors
[d2
++].rdev
= rdev
;
2178 kfree(conf
->mirrors
);
2179 conf
->mirrors
= newmirrors
;
2180 kfree(conf
->poolinfo
);
2181 conf
->poolinfo
= newpoolinfo
;
2183 spin_lock_irqsave(&conf
->device_lock
, flags
);
2184 mddev
->degraded
+= (raid_disks
- conf
->raid_disks
);
2185 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2186 conf
->raid_disks
= mddev
->raid_disks
= raid_disks
;
2187 mddev
->delta_disks
= 0;
2189 conf
->last_used
= 0; /* just make sure it is in-range */
2190 lower_barrier(conf
);
2192 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
2193 md_wakeup_thread(mddev
->thread
);
2195 mempool_destroy(oldpool
);
2199 static void raid1_quiesce(mddev_t
*mddev
, int state
)
2201 conf_t
*conf
= mddev
->private;
2204 case 2: /* wake for suspend */
2205 wake_up(&conf
->wait_barrier
);
2208 raise_barrier(conf
);
2211 lower_barrier(conf
);
2216 static void *raid1_takeover(mddev_t
*mddev
)
2218 /* raid1 can take over:
2219 * raid5 with 2 devices, any layout or chunk size
2221 if (mddev
->level
== 5 && mddev
->raid_disks
== 2) {
2223 mddev
->new_level
= 1;
2224 mddev
->new_layout
= 0;
2225 mddev
->new_chunk_sectors
= 0;
2226 conf
= setup_conf(mddev
);
2231 return ERR_PTR(-EINVAL
);
2234 static struct mdk_personality raid1_personality
=
2238 .owner
= THIS_MODULE
,
2239 .make_request
= make_request
,
2243 .error_handler
= error
,
2244 .hot_add_disk
= raid1_add_disk
,
2245 .hot_remove_disk
= raid1_remove_disk
,
2246 .spare_active
= raid1_spare_active
,
2247 .sync_request
= sync_request
,
2248 .resize
= raid1_resize
,
2250 .check_reshape
= raid1_reshape
,
2251 .quiesce
= raid1_quiesce
,
2252 .takeover
= raid1_takeover
,
2255 static int __init
raid_init(void)
2257 return register_md_personality(&raid1_personality
);
2260 static void raid_exit(void)
2262 unregister_md_personality(&raid1_personality
);
2265 module_init(raid_init
);
2266 module_exit(raid_exit
);
2267 MODULE_LICENSE("GPL");
2268 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2269 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2270 MODULE_ALIAS("md-raid1");
2271 MODULE_ALIAS("md-level-1");