2 * raid1.c : Multiple Devices driver for Linux
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
8 * RAID-1 management functions.
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34 #include <linux/slab.h>
35 #include <linux/delay.h>
36 #include <linux/blkdev.h>
37 #include <linux/module.h>
38 #include <linux/seq_file.h>
39 #include <linux/ratelimit.h>
40 #include <linux/sched/signal.h>
42 #include <trace/events/block.h>
48 #define UNSUPPORTED_MDDEV_FLAGS \
49 ((1L << MD_HAS_JOURNAL) | \
50 (1L << MD_JOURNAL_CLEAN) | \
54 * Number of guaranteed r1bios in case of extreme VM load:
56 #define NR_RAID1_BIOS 256
58 /* when we get a read error on a read-only array, we redirect to another
59 * device without failing the first device, or trying to over-write to
60 * correct the read error. To keep track of bad blocks on a per-bio
61 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
63 #define IO_BLOCKED ((struct bio *)1)
64 /* When we successfully write to a known bad-block, we need to remove the
65 * bad-block marking which must be done from process context. So we record
66 * the success by setting devs[n].bio to IO_MADE_GOOD
68 #define IO_MADE_GOOD ((struct bio *)2)
70 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
72 /* When there are this many requests queue to be written by
73 * the raid1 thread, we become 'congested' to provide back-pressure
76 static int max_queued_requests
= 1024;
78 static void allow_barrier(struct r1conf
*conf
, sector_t sector_nr
);
79 static void lower_barrier(struct r1conf
*conf
, sector_t sector_nr
);
81 #define raid1_log(md, fmt, args...) \
82 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
85 * 'strct resync_pages' stores actual pages used for doing the resync
86 * IO, and it is per-bio, so make .bi_private points to it.
88 static inline struct resync_pages
*get_resync_pages(struct bio
*bio
)
90 return bio
->bi_private
;
94 * for resync bio, r1bio pointer can be retrieved from the per-bio
95 * 'struct resync_pages'.
97 static inline struct r1bio
*get_resync_r1bio(struct bio
*bio
)
99 return get_resync_pages(bio
)->raid_bio
;
102 static void * r1bio_pool_alloc(gfp_t gfp_flags
, void *data
)
104 struct pool_info
*pi
= data
;
105 int size
= offsetof(struct r1bio
, bios
[pi
->raid_disks
]);
107 /* allocate a r1bio with room for raid_disks entries in the bios array */
108 return kzalloc(size
, gfp_flags
);
111 static void r1bio_pool_free(void *r1_bio
, void *data
)
116 #define RESYNC_DEPTH 32
117 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
118 #define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
119 #define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
120 #define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
121 #define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
123 static void * r1buf_pool_alloc(gfp_t gfp_flags
, void *data
)
125 struct pool_info
*pi
= data
;
126 struct r1bio
*r1_bio
;
130 struct resync_pages
*rps
;
132 r1_bio
= r1bio_pool_alloc(gfp_flags
, pi
);
136 rps
= kmalloc(sizeof(struct resync_pages
) * pi
->raid_disks
,
142 * Allocate bios : 1 for reading, n-1 for writing
144 for (j
= pi
->raid_disks
; j
-- ; ) {
145 bio
= bio_kmalloc(gfp_flags
, RESYNC_PAGES
);
148 r1_bio
->bios
[j
] = bio
;
151 * Allocate RESYNC_PAGES data pages and attach them to
153 * If this is a user-requested check/repair, allocate
154 * RESYNC_PAGES for each bio.
156 if (test_bit(MD_RECOVERY_REQUESTED
, &pi
->mddev
->recovery
))
157 need_pages
= pi
->raid_disks
;
160 for (j
= 0; j
< pi
->raid_disks
; j
++) {
161 struct resync_pages
*rp
= &rps
[j
];
163 bio
= r1_bio
->bios
[j
];
165 if (j
< need_pages
) {
166 if (resync_alloc_pages(rp
, gfp_flags
))
169 memcpy(rp
, &rps
[0], sizeof(*rp
));
170 resync_get_all_pages(rp
);
174 rp
->raid_bio
= r1_bio
;
175 bio
->bi_private
= rp
;
178 r1_bio
->master_bio
= NULL
;
184 resync_free_pages(&rps
[j
]);
187 while (++j
< pi
->raid_disks
)
188 bio_put(r1_bio
->bios
[j
]);
192 r1bio_pool_free(r1_bio
, data
);
196 static void r1buf_pool_free(void *__r1_bio
, void *data
)
198 struct pool_info
*pi
= data
;
200 struct r1bio
*r1bio
= __r1_bio
;
201 struct resync_pages
*rp
= NULL
;
203 for (i
= pi
->raid_disks
; i
--; ) {
204 rp
= get_resync_pages(r1bio
->bios
[i
]);
205 resync_free_pages(rp
);
206 bio_put(r1bio
->bios
[i
]);
209 /* resync pages array stored in the 1st bio's .bi_private */
212 r1bio_pool_free(r1bio
, data
);
215 static void put_all_bios(struct r1conf
*conf
, struct r1bio
*r1_bio
)
219 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
220 struct bio
**bio
= r1_bio
->bios
+ i
;
221 if (!BIO_SPECIAL(*bio
))
227 static void free_r1bio(struct r1bio
*r1_bio
)
229 struct r1conf
*conf
= r1_bio
->mddev
->private;
231 put_all_bios(conf
, r1_bio
);
232 mempool_free(r1_bio
, conf
->r1bio_pool
);
235 static void put_buf(struct r1bio
*r1_bio
)
237 struct r1conf
*conf
= r1_bio
->mddev
->private;
238 sector_t sect
= r1_bio
->sector
;
241 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
242 struct bio
*bio
= r1_bio
->bios
[i
];
244 rdev_dec_pending(conf
->mirrors
[i
].rdev
, r1_bio
->mddev
);
247 mempool_free(r1_bio
, conf
->r1buf_pool
);
249 lower_barrier(conf
, sect
);
252 static void reschedule_retry(struct r1bio
*r1_bio
)
255 struct mddev
*mddev
= r1_bio
->mddev
;
256 struct r1conf
*conf
= mddev
->private;
259 idx
= sector_to_idx(r1_bio
->sector
);
260 spin_lock_irqsave(&conf
->device_lock
, flags
);
261 list_add(&r1_bio
->retry_list
, &conf
->retry_list
);
262 atomic_inc(&conf
->nr_queued
[idx
]);
263 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
265 wake_up(&conf
->wait_barrier
);
266 md_wakeup_thread(mddev
->thread
);
270 * raid_end_bio_io() is called when we have finished servicing a mirrored
271 * operation and are ready to return a success/failure code to the buffer
274 static void call_bio_endio(struct r1bio
*r1_bio
)
276 struct bio
*bio
= r1_bio
->master_bio
;
277 struct r1conf
*conf
= r1_bio
->mddev
->private;
279 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
))
280 bio
->bi_error
= -EIO
;
284 * Wake up any possible resync thread that waits for the device
287 allow_barrier(conf
, r1_bio
->sector
);
290 static void raid_end_bio_io(struct r1bio
*r1_bio
)
292 struct bio
*bio
= r1_bio
->master_bio
;
294 /* if nobody has done the final endio yet, do it now */
295 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
296 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
297 (bio_data_dir(bio
) == WRITE
) ? "write" : "read",
298 (unsigned long long) bio
->bi_iter
.bi_sector
,
299 (unsigned long long) bio_end_sector(bio
) - 1);
301 call_bio_endio(r1_bio
);
307 * Update disk head position estimator based on IRQ completion info.
309 static inline void update_head_pos(int disk
, struct r1bio
*r1_bio
)
311 struct r1conf
*conf
= r1_bio
->mddev
->private;
313 conf
->mirrors
[disk
].head_position
=
314 r1_bio
->sector
+ (r1_bio
->sectors
);
318 * Find the disk number which triggered given bio
320 static int find_bio_disk(struct r1bio
*r1_bio
, struct bio
*bio
)
323 struct r1conf
*conf
= r1_bio
->mddev
->private;
324 int raid_disks
= conf
->raid_disks
;
326 for (mirror
= 0; mirror
< raid_disks
* 2; mirror
++)
327 if (r1_bio
->bios
[mirror
] == bio
)
330 BUG_ON(mirror
== raid_disks
* 2);
331 update_head_pos(mirror
, r1_bio
);
336 static void raid1_end_read_request(struct bio
*bio
)
338 int uptodate
= !bio
->bi_error
;
339 struct r1bio
*r1_bio
= bio
->bi_private
;
340 struct r1conf
*conf
= r1_bio
->mddev
->private;
341 struct md_rdev
*rdev
= conf
->mirrors
[r1_bio
->read_disk
].rdev
;
344 * this branch is our 'one mirror IO has finished' event handler:
346 update_head_pos(r1_bio
->read_disk
, r1_bio
);
349 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
350 else if (test_bit(FailFast
, &rdev
->flags
) &&
351 test_bit(R1BIO_FailFast
, &r1_bio
->state
))
352 /* This was a fail-fast read so we definitely
356 /* If all other devices have failed, we want to return
357 * the error upwards rather than fail the last device.
358 * Here we redefine "uptodate" to mean "Don't want to retry"
361 spin_lock_irqsave(&conf
->device_lock
, flags
);
362 if (r1_bio
->mddev
->degraded
== conf
->raid_disks
||
363 (r1_bio
->mddev
->degraded
== conf
->raid_disks
-1 &&
364 test_bit(In_sync
, &rdev
->flags
)))
366 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
370 raid_end_bio_io(r1_bio
);
371 rdev_dec_pending(rdev
, conf
->mddev
);
376 char b
[BDEVNAME_SIZE
];
377 pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n",
379 bdevname(rdev
->bdev
, b
),
380 (unsigned long long)r1_bio
->sector
);
381 set_bit(R1BIO_ReadError
, &r1_bio
->state
);
382 reschedule_retry(r1_bio
);
383 /* don't drop the reference on read_disk yet */
387 static void close_write(struct r1bio
*r1_bio
)
389 /* it really is the end of this request */
390 if (test_bit(R1BIO_BehindIO
, &r1_bio
->state
)) {
391 bio_free_pages(r1_bio
->behind_master_bio
);
392 bio_put(r1_bio
->behind_master_bio
);
393 r1_bio
->behind_master_bio
= NULL
;
395 /* clear the bitmap if all writes complete successfully */
396 bitmap_endwrite(r1_bio
->mddev
->bitmap
, r1_bio
->sector
,
398 !test_bit(R1BIO_Degraded
, &r1_bio
->state
),
399 test_bit(R1BIO_BehindIO
, &r1_bio
->state
));
400 md_write_end(r1_bio
->mddev
);
403 static void r1_bio_write_done(struct r1bio
*r1_bio
)
405 if (!atomic_dec_and_test(&r1_bio
->remaining
))
408 if (test_bit(R1BIO_WriteError
, &r1_bio
->state
))
409 reschedule_retry(r1_bio
);
412 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
))
413 reschedule_retry(r1_bio
);
415 raid_end_bio_io(r1_bio
);
419 static void raid1_end_write_request(struct bio
*bio
)
421 struct r1bio
*r1_bio
= bio
->bi_private
;
422 int behind
= test_bit(R1BIO_BehindIO
, &r1_bio
->state
);
423 struct r1conf
*conf
= r1_bio
->mddev
->private;
424 struct bio
*to_put
= NULL
;
425 int mirror
= find_bio_disk(r1_bio
, bio
);
426 struct md_rdev
*rdev
= conf
->mirrors
[mirror
].rdev
;
429 discard_error
= bio
->bi_error
&& bio_op(bio
) == REQ_OP_DISCARD
;
432 * 'one mirror IO has finished' event handler:
434 if (bio
->bi_error
&& !discard_error
) {
435 set_bit(WriteErrorSeen
, &rdev
->flags
);
436 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
437 set_bit(MD_RECOVERY_NEEDED
, &
438 conf
->mddev
->recovery
);
440 if (test_bit(FailFast
, &rdev
->flags
) &&
441 (bio
->bi_opf
& MD_FAILFAST
) &&
442 /* We never try FailFast to WriteMostly devices */
443 !test_bit(WriteMostly
, &rdev
->flags
)) {
444 md_error(r1_bio
->mddev
, rdev
);
445 if (!test_bit(Faulty
, &rdev
->flags
))
446 /* This is the only remaining device,
447 * We need to retry the write without
450 set_bit(R1BIO_WriteError
, &r1_bio
->state
);
452 /* Finished with this branch */
453 r1_bio
->bios
[mirror
] = NULL
;
457 set_bit(R1BIO_WriteError
, &r1_bio
->state
);
460 * Set R1BIO_Uptodate in our master bio, so that we
461 * will return a good error code for to the higher
462 * levels even if IO on some other mirrored buffer
465 * The 'master' represents the composite IO operation
466 * to user-side. So if something waits for IO, then it
467 * will wait for the 'master' bio.
472 r1_bio
->bios
[mirror
] = NULL
;
475 * Do not set R1BIO_Uptodate if the current device is
476 * rebuilding or Faulty. This is because we cannot use
477 * such device for properly reading the data back (we could
478 * potentially use it, if the current write would have felt
479 * before rdev->recovery_offset, but for simplicity we don't
482 if (test_bit(In_sync
, &rdev
->flags
) &&
483 !test_bit(Faulty
, &rdev
->flags
))
484 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
486 /* Maybe we can clear some bad blocks. */
487 if (is_badblock(rdev
, r1_bio
->sector
, r1_bio
->sectors
,
488 &first_bad
, &bad_sectors
) && !discard_error
) {
489 r1_bio
->bios
[mirror
] = IO_MADE_GOOD
;
490 set_bit(R1BIO_MadeGood
, &r1_bio
->state
);
495 /* we release behind master bio when all write are done */
496 if (r1_bio
->behind_master_bio
== bio
)
499 if (test_bit(WriteMostly
, &rdev
->flags
))
500 atomic_dec(&r1_bio
->behind_remaining
);
503 * In behind mode, we ACK the master bio once the I/O
504 * has safely reached all non-writemostly
505 * disks. Setting the Returned bit ensures that this
506 * gets done only once -- we don't ever want to return
507 * -EIO here, instead we'll wait
509 if (atomic_read(&r1_bio
->behind_remaining
) >= (atomic_read(&r1_bio
->remaining
)-1) &&
510 test_bit(R1BIO_Uptodate
, &r1_bio
->state
)) {
511 /* Maybe we can return now */
512 if (!test_and_set_bit(R1BIO_Returned
, &r1_bio
->state
)) {
513 struct bio
*mbio
= r1_bio
->master_bio
;
514 pr_debug("raid1: behind end write sectors"
516 (unsigned long long) mbio
->bi_iter
.bi_sector
,
517 (unsigned long long) bio_end_sector(mbio
) - 1);
518 call_bio_endio(r1_bio
);
522 if (r1_bio
->bios
[mirror
] == NULL
)
523 rdev_dec_pending(rdev
, conf
->mddev
);
526 * Let's see if all mirrored write operations have finished
529 r1_bio_write_done(r1_bio
);
535 static sector_t
align_to_barrier_unit_end(sector_t start_sector
,
540 WARN_ON(sectors
== 0);
542 * len is the number of sectors from start_sector to end of the
543 * barrier unit which start_sector belongs to.
545 len
= round_up(start_sector
+ 1, BARRIER_UNIT_SECTOR_SIZE
) -
555 * This routine returns the disk from which the requested read should
556 * be done. There is a per-array 'next expected sequential IO' sector
557 * number - if this matches on the next IO then we use the last disk.
558 * There is also a per-disk 'last know head position' sector that is
559 * maintained from IRQ contexts, both the normal and the resync IO
560 * completion handlers update this position correctly. If there is no
561 * perfect sequential match then we pick the disk whose head is closest.
563 * If there are 2 mirrors in the same 2 devices, performance degrades
564 * because position is mirror, not device based.
566 * The rdev for the device selected will have nr_pending incremented.
568 static int read_balance(struct r1conf
*conf
, struct r1bio
*r1_bio
, int *max_sectors
)
570 const sector_t this_sector
= r1_bio
->sector
;
572 int best_good_sectors
;
573 int best_disk
, best_dist_disk
, best_pending_disk
;
577 unsigned int min_pending
;
578 struct md_rdev
*rdev
;
580 int choose_next_idle
;
584 * Check if we can balance. We can balance on the whole
585 * device if no resync is going on, or below the resync window.
586 * We take the first readable disk when above the resync window.
589 sectors
= r1_bio
->sectors
;
592 best_dist
= MaxSector
;
593 best_pending_disk
= -1;
594 min_pending
= UINT_MAX
;
595 best_good_sectors
= 0;
597 choose_next_idle
= 0;
598 clear_bit(R1BIO_FailFast
, &r1_bio
->state
);
600 if ((conf
->mddev
->recovery_cp
< this_sector
+ sectors
) ||
601 (mddev_is_clustered(conf
->mddev
) &&
602 md_cluster_ops
->area_resyncing(conf
->mddev
, READ
, this_sector
,
603 this_sector
+ sectors
)))
608 for (disk
= 0 ; disk
< conf
->raid_disks
* 2 ; disk
++) {
612 unsigned int pending
;
615 rdev
= rcu_dereference(conf
->mirrors
[disk
].rdev
);
616 if (r1_bio
->bios
[disk
] == IO_BLOCKED
618 || test_bit(Faulty
, &rdev
->flags
))
620 if (!test_bit(In_sync
, &rdev
->flags
) &&
621 rdev
->recovery_offset
< this_sector
+ sectors
)
623 if (test_bit(WriteMostly
, &rdev
->flags
)) {
624 /* Don't balance among write-mostly, just
625 * use the first as a last resort */
626 if (best_dist_disk
< 0) {
627 if (is_badblock(rdev
, this_sector
, sectors
,
628 &first_bad
, &bad_sectors
)) {
629 if (first_bad
<= this_sector
)
630 /* Cannot use this */
632 best_good_sectors
= first_bad
- this_sector
;
634 best_good_sectors
= sectors
;
635 best_dist_disk
= disk
;
636 best_pending_disk
= disk
;
640 /* This is a reasonable device to use. It might
643 if (is_badblock(rdev
, this_sector
, sectors
,
644 &first_bad
, &bad_sectors
)) {
645 if (best_dist
< MaxSector
)
646 /* already have a better device */
648 if (first_bad
<= this_sector
) {
649 /* cannot read here. If this is the 'primary'
650 * device, then we must not read beyond
651 * bad_sectors from another device..
653 bad_sectors
-= (this_sector
- first_bad
);
654 if (choose_first
&& sectors
> bad_sectors
)
655 sectors
= bad_sectors
;
656 if (best_good_sectors
> sectors
)
657 best_good_sectors
= sectors
;
660 sector_t good_sectors
= first_bad
- this_sector
;
661 if (good_sectors
> best_good_sectors
) {
662 best_good_sectors
= good_sectors
;
670 best_good_sectors
= sectors
;
673 /* At least two disks to choose from so failfast is OK */
674 set_bit(R1BIO_FailFast
, &r1_bio
->state
);
676 nonrot
= blk_queue_nonrot(bdev_get_queue(rdev
->bdev
));
677 has_nonrot_disk
|= nonrot
;
678 pending
= atomic_read(&rdev
->nr_pending
);
679 dist
= abs(this_sector
- conf
->mirrors
[disk
].head_position
);
684 /* Don't change to another disk for sequential reads */
685 if (conf
->mirrors
[disk
].next_seq_sect
== this_sector
687 int opt_iosize
= bdev_io_opt(rdev
->bdev
) >> 9;
688 struct raid1_info
*mirror
= &conf
->mirrors
[disk
];
692 * If buffered sequential IO size exceeds optimal
693 * iosize, check if there is idle disk. If yes, choose
694 * the idle disk. read_balance could already choose an
695 * idle disk before noticing it's a sequential IO in
696 * this disk. This doesn't matter because this disk
697 * will idle, next time it will be utilized after the
698 * first disk has IO size exceeds optimal iosize. In
699 * this way, iosize of the first disk will be optimal
700 * iosize at least. iosize of the second disk might be
701 * small, but not a big deal since when the second disk
702 * starts IO, the first disk is likely still busy.
704 if (nonrot
&& opt_iosize
> 0 &&
705 mirror
->seq_start
!= MaxSector
&&
706 mirror
->next_seq_sect
> opt_iosize
&&
707 mirror
->next_seq_sect
- opt_iosize
>=
709 choose_next_idle
= 1;
715 if (choose_next_idle
)
718 if (min_pending
> pending
) {
719 min_pending
= pending
;
720 best_pending_disk
= disk
;
723 if (dist
< best_dist
) {
725 best_dist_disk
= disk
;
730 * If all disks are rotational, choose the closest disk. If any disk is
731 * non-rotational, choose the disk with less pending request even the
732 * disk is rotational, which might/might not be optimal for raids with
733 * mixed ratation/non-rotational disks depending on workload.
735 if (best_disk
== -1) {
736 if (has_nonrot_disk
|| min_pending
== 0)
737 best_disk
= best_pending_disk
;
739 best_disk
= best_dist_disk
;
742 if (best_disk
>= 0) {
743 rdev
= rcu_dereference(conf
->mirrors
[best_disk
].rdev
);
746 atomic_inc(&rdev
->nr_pending
);
747 sectors
= best_good_sectors
;
749 if (conf
->mirrors
[best_disk
].next_seq_sect
!= this_sector
)
750 conf
->mirrors
[best_disk
].seq_start
= this_sector
;
752 conf
->mirrors
[best_disk
].next_seq_sect
= this_sector
+ sectors
;
755 *max_sectors
= sectors
;
760 static int raid1_congested(struct mddev
*mddev
, int bits
)
762 struct r1conf
*conf
= mddev
->private;
765 if ((bits
& (1 << WB_async_congested
)) &&
766 conf
->pending_count
>= max_queued_requests
)
770 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
771 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
772 if (rdev
&& !test_bit(Faulty
, &rdev
->flags
)) {
773 struct request_queue
*q
= bdev_get_queue(rdev
->bdev
);
777 /* Note the '|| 1' - when read_balance prefers
778 * non-congested targets, it can be removed
780 if ((bits
& (1 << WB_async_congested
)) || 1)
781 ret
|= bdi_congested(q
->backing_dev_info
, bits
);
783 ret
&= bdi_congested(q
->backing_dev_info
, bits
);
790 static void flush_pending_writes(struct r1conf
*conf
)
792 /* Any writes that have been queued but are awaiting
793 * bitmap updates get flushed here.
795 spin_lock_irq(&conf
->device_lock
);
797 if (conf
->pending_bio_list
.head
) {
799 bio
= bio_list_get(&conf
->pending_bio_list
);
800 conf
->pending_count
= 0;
801 spin_unlock_irq(&conf
->device_lock
);
802 /* flush any pending bitmap writes to
803 * disk before proceeding w/ I/O */
804 bitmap_unplug(conf
->mddev
->bitmap
);
805 wake_up(&conf
->wait_barrier
);
807 while (bio
) { /* submit pending writes */
808 struct bio
*next
= bio
->bi_next
;
809 struct md_rdev
*rdev
= (void*)bio
->bi_bdev
;
811 bio
->bi_bdev
= rdev
->bdev
;
812 if (test_bit(Faulty
, &rdev
->flags
)) {
813 bio
->bi_error
= -EIO
;
815 } else if (unlikely((bio_op(bio
) == REQ_OP_DISCARD
) &&
816 !blk_queue_discard(bdev_get_queue(bio
->bi_bdev
))))
820 generic_make_request(bio
);
824 spin_unlock_irq(&conf
->device_lock
);
828 * Sometimes we need to suspend IO while we do something else,
829 * either some resync/recovery, or reconfigure the array.
830 * To do this we raise a 'barrier'.
831 * The 'barrier' is a counter that can be raised multiple times
832 * to count how many activities are happening which preclude
834 * We can only raise the barrier if there is no pending IO.
835 * i.e. if nr_pending == 0.
836 * We choose only to raise the barrier if no-one is waiting for the
837 * barrier to go down. This means that as soon as an IO request
838 * is ready, no other operations which require a barrier will start
839 * until the IO request has had a chance.
841 * So: regular IO calls 'wait_barrier'. When that returns there
842 * is no backgroup IO happening, It must arrange to call
843 * allow_barrier when it has finished its IO.
844 * backgroup IO calls must call raise_barrier. Once that returns
845 * there is no normal IO happeing. It must arrange to call
846 * lower_barrier when the particular background IO completes.
848 static void raise_barrier(struct r1conf
*conf
, sector_t sector_nr
)
850 int idx
= sector_to_idx(sector_nr
);
852 spin_lock_irq(&conf
->resync_lock
);
854 /* Wait until no block IO is waiting */
855 wait_event_lock_irq(conf
->wait_barrier
,
856 !atomic_read(&conf
->nr_waiting
[idx
]),
859 /* block any new IO from starting */
860 atomic_inc(&conf
->barrier
[idx
]);
862 * In raise_barrier() we firstly increase conf->barrier[idx] then
863 * check conf->nr_pending[idx]. In _wait_barrier() we firstly
864 * increase conf->nr_pending[idx] then check conf->barrier[idx].
865 * A memory barrier here to make sure conf->nr_pending[idx] won't
866 * be fetched before conf->barrier[idx] is increased. Otherwise
867 * there will be a race between raise_barrier() and _wait_barrier().
869 smp_mb__after_atomic();
871 /* For these conditions we must wait:
872 * A: while the array is in frozen state
873 * B: while conf->nr_pending[idx] is not 0, meaning regular I/O
874 * existing in corresponding I/O barrier bucket.
875 * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
876 * max resync count which allowed on current I/O barrier bucket.
878 wait_event_lock_irq(conf
->wait_barrier
,
879 !conf
->array_frozen
&&
880 !atomic_read(&conf
->nr_pending
[idx
]) &&
881 atomic_read(&conf
->barrier
[idx
]) < RESYNC_DEPTH
,
884 atomic_inc(&conf
->nr_pending
[idx
]);
885 spin_unlock_irq(&conf
->resync_lock
);
888 static void lower_barrier(struct r1conf
*conf
, sector_t sector_nr
)
890 int idx
= sector_to_idx(sector_nr
);
892 BUG_ON(atomic_read(&conf
->barrier
[idx
]) <= 0);
894 atomic_dec(&conf
->barrier
[idx
]);
895 atomic_dec(&conf
->nr_pending
[idx
]);
896 wake_up(&conf
->wait_barrier
);
899 static void _wait_barrier(struct r1conf
*conf
, int idx
)
902 * We need to increase conf->nr_pending[idx] very early here,
903 * then raise_barrier() can be blocked when it waits for
904 * conf->nr_pending[idx] to be 0. Then we can avoid holding
905 * conf->resync_lock when there is no barrier raised in same
906 * barrier unit bucket. Also if the array is frozen, I/O
907 * should be blocked until array is unfrozen.
909 atomic_inc(&conf
->nr_pending
[idx
]);
911 * In _wait_barrier() we firstly increase conf->nr_pending[idx], then
912 * check conf->barrier[idx]. In raise_barrier() we firstly increase
913 * conf->barrier[idx], then check conf->nr_pending[idx]. A memory
914 * barrier is necessary here to make sure conf->barrier[idx] won't be
915 * fetched before conf->nr_pending[idx] is increased. Otherwise there
916 * will be a race between _wait_barrier() and raise_barrier().
918 smp_mb__after_atomic();
921 * Don't worry about checking two atomic_t variables at same time
922 * here. If during we check conf->barrier[idx], the array is
923 * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
924 * 0, it is safe to return and make the I/O continue. Because the
925 * array is frozen, all I/O returned here will eventually complete
926 * or be queued, no race will happen. See code comment in
929 if (!READ_ONCE(conf
->array_frozen
) &&
930 !atomic_read(&conf
->barrier
[idx
]))
934 * After holding conf->resync_lock, conf->nr_pending[idx]
935 * should be decreased before waiting for barrier to drop.
936 * Otherwise, we may encounter a race condition because
937 * raise_barrer() might be waiting for conf->nr_pending[idx]
938 * to be 0 at same time.
940 spin_lock_irq(&conf
->resync_lock
);
941 atomic_inc(&conf
->nr_waiting
[idx
]);
942 atomic_dec(&conf
->nr_pending
[idx
]);
944 * In case freeze_array() is waiting for
945 * get_unqueued_pending() == extra
947 wake_up(&conf
->wait_barrier
);
948 /* Wait for the barrier in same barrier unit bucket to drop. */
949 wait_event_lock_irq(conf
->wait_barrier
,
950 !conf
->array_frozen
&&
951 !atomic_read(&conf
->barrier
[idx
]),
953 atomic_inc(&conf
->nr_pending
[idx
]);
954 atomic_dec(&conf
->nr_waiting
[idx
]);
955 spin_unlock_irq(&conf
->resync_lock
);
958 static void wait_read_barrier(struct r1conf
*conf
, sector_t sector_nr
)
960 int idx
= sector_to_idx(sector_nr
);
963 * Very similar to _wait_barrier(). The difference is, for read
964 * I/O we don't need wait for sync I/O, but if the whole array
965 * is frozen, the read I/O still has to wait until the array is
966 * unfrozen. Since there is no ordering requirement with
967 * conf->barrier[idx] here, memory barrier is unnecessary as well.
969 atomic_inc(&conf
->nr_pending
[idx
]);
971 if (!READ_ONCE(conf
->array_frozen
))
974 spin_lock_irq(&conf
->resync_lock
);
975 atomic_inc(&conf
->nr_waiting
[idx
]);
976 atomic_dec(&conf
->nr_pending
[idx
]);
978 * In case freeze_array() is waiting for
979 * get_unqueued_pending() == extra
981 wake_up(&conf
->wait_barrier
);
982 /* Wait for array to be unfrozen */
983 wait_event_lock_irq(conf
->wait_barrier
,
986 atomic_inc(&conf
->nr_pending
[idx
]);
987 atomic_dec(&conf
->nr_waiting
[idx
]);
988 spin_unlock_irq(&conf
->resync_lock
);
991 static void inc_pending(struct r1conf
*conf
, sector_t bi_sector
)
993 /* The current request requires multiple r1_bio, so
994 * we need to increment the pending count, and the corresponding
997 int idx
= sector_to_idx(bi_sector
);
998 atomic_inc(&conf
->nr_pending
[idx
]);
1001 static void wait_barrier(struct r1conf
*conf
, sector_t sector_nr
)
1003 int idx
= sector_to_idx(sector_nr
);
1005 _wait_barrier(conf
, idx
);
1008 static void wait_all_barriers(struct r1conf
*conf
)
1012 for (idx
= 0; idx
< BARRIER_BUCKETS_NR
; idx
++)
1013 _wait_barrier(conf
, idx
);
1016 static void _allow_barrier(struct r1conf
*conf
, int idx
)
1018 atomic_dec(&conf
->nr_pending
[idx
]);
1019 wake_up(&conf
->wait_barrier
);
1022 static void allow_barrier(struct r1conf
*conf
, sector_t sector_nr
)
1024 int idx
= sector_to_idx(sector_nr
);
1026 _allow_barrier(conf
, idx
);
1029 static void allow_all_barriers(struct r1conf
*conf
)
1033 for (idx
= 0; idx
< BARRIER_BUCKETS_NR
; idx
++)
1034 _allow_barrier(conf
, idx
);
1037 /* conf->resync_lock should be held */
1038 static int get_unqueued_pending(struct r1conf
*conf
)
1042 for (ret
= 0, idx
= 0; idx
< BARRIER_BUCKETS_NR
; idx
++)
1043 ret
+= atomic_read(&conf
->nr_pending
[idx
]) -
1044 atomic_read(&conf
->nr_queued
[idx
]);
1049 static void freeze_array(struct r1conf
*conf
, int extra
)
1051 /* Stop sync I/O and normal I/O and wait for everything to
1053 * This is called in two situations:
1054 * 1) management command handlers (reshape, remove disk, quiesce).
1055 * 2) one normal I/O request failed.
1057 * After array_frozen is set to 1, new sync IO will be blocked at
1058 * raise_barrier(), and new normal I/O will blocked at _wait_barrier()
1059 * or wait_read_barrier(). The flying I/Os will either complete or be
1060 * queued. When everything goes quite, there are only queued I/Os left.
1062 * Every flying I/O contributes to a conf->nr_pending[idx], idx is the
1063 * barrier bucket index which this I/O request hits. When all sync and
1064 * normal I/O are queued, sum of all conf->nr_pending[] will match sum
1065 * of all conf->nr_queued[]. But normal I/O failure is an exception,
1066 * in handle_read_error(), we may call freeze_array() before trying to
1067 * fix the read error. In this case, the error read I/O is not queued,
1068 * so get_unqueued_pending() == 1.
1070 * Therefore before this function returns, we need to wait until
1071 * get_unqueued_pendings(conf) gets equal to extra. For
1072 * normal I/O context, extra is 1, in rested situations extra is 0.
1074 spin_lock_irq(&conf
->resync_lock
);
1075 conf
->array_frozen
= 1;
1076 raid1_log(conf
->mddev
, "wait freeze");
1077 wait_event_lock_irq_cmd(
1079 get_unqueued_pending(conf
) == extra
,
1081 flush_pending_writes(conf
));
1082 spin_unlock_irq(&conf
->resync_lock
);
1084 static void unfreeze_array(struct r1conf
*conf
)
1086 /* reverse the effect of the freeze */
1087 spin_lock_irq(&conf
->resync_lock
);
1088 conf
->array_frozen
= 0;
1089 spin_unlock_irq(&conf
->resync_lock
);
1090 wake_up(&conf
->wait_barrier
);
1093 static struct bio
*alloc_behind_master_bio(struct r1bio
*r1_bio
,
1095 int offset
, int size
)
1097 unsigned vcnt
= (size
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1099 struct bio
*behind_bio
= NULL
;
1101 behind_bio
= bio_alloc_mddev(GFP_NOIO
, vcnt
, r1_bio
->mddev
);
1105 /* discard op, we don't support writezero/writesame yet */
1106 if (!bio_has_data(bio
))
1109 while (i
< vcnt
&& size
) {
1111 int len
= min_t(int, PAGE_SIZE
, size
);
1113 page
= alloc_page(GFP_NOIO
);
1114 if (unlikely(!page
))
1117 bio_add_page(behind_bio
, page
, len
, 0);
1123 bio_copy_data_partial(behind_bio
, bio
, offset
,
1124 behind_bio
->bi_iter
.bi_size
);
1126 r1_bio
->behind_master_bio
= behind_bio
;;
1127 set_bit(R1BIO_BehindIO
, &r1_bio
->state
);
1132 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1133 bio
->bi_iter
.bi_size
);
1134 bio_free_pages(behind_bio
);
1139 struct raid1_plug_cb
{
1140 struct blk_plug_cb cb
;
1141 struct bio_list pending
;
1145 static void raid1_unplug(struct blk_plug_cb
*cb
, bool from_schedule
)
1147 struct raid1_plug_cb
*plug
= container_of(cb
, struct raid1_plug_cb
,
1149 struct mddev
*mddev
= plug
->cb
.data
;
1150 struct r1conf
*conf
= mddev
->private;
1153 if (from_schedule
|| current
->bio_list
) {
1154 spin_lock_irq(&conf
->device_lock
);
1155 bio_list_merge(&conf
->pending_bio_list
, &plug
->pending
);
1156 conf
->pending_count
+= plug
->pending_cnt
;
1157 spin_unlock_irq(&conf
->device_lock
);
1158 wake_up(&conf
->wait_barrier
);
1159 md_wakeup_thread(mddev
->thread
);
1164 /* we aren't scheduling, so we can do the write-out directly. */
1165 bio
= bio_list_get(&plug
->pending
);
1166 bitmap_unplug(mddev
->bitmap
);
1167 wake_up(&conf
->wait_barrier
);
1169 while (bio
) { /* submit pending writes */
1170 struct bio
*next
= bio
->bi_next
;
1171 struct md_rdev
*rdev
= (void*)bio
->bi_bdev
;
1172 bio
->bi_next
= NULL
;
1173 bio
->bi_bdev
= rdev
->bdev
;
1174 if (test_bit(Faulty
, &rdev
->flags
)) {
1175 bio
->bi_error
= -EIO
;
1177 } else if (unlikely((bio_op(bio
) == REQ_OP_DISCARD
) &&
1178 !blk_queue_discard(bdev_get_queue(bio
->bi_bdev
))))
1179 /* Just ignore it */
1182 generic_make_request(bio
);
1188 static inline struct r1bio
*
1189 alloc_r1bio(struct mddev
*mddev
, struct bio
*bio
, sector_t sectors_handled
)
1191 struct r1conf
*conf
= mddev
->private;
1192 struct r1bio
*r1_bio
;
1194 r1_bio
= mempool_alloc(conf
->r1bio_pool
, GFP_NOIO
);
1196 r1_bio
->master_bio
= bio
;
1197 r1_bio
->sectors
= bio_sectors(bio
) - sectors_handled
;
1199 r1_bio
->mddev
= mddev
;
1200 r1_bio
->sector
= bio
->bi_iter
.bi_sector
+ sectors_handled
;
1205 static void raid1_read_request(struct mddev
*mddev
, struct bio
*bio
)
1207 struct r1conf
*conf
= mddev
->private;
1208 struct raid1_info
*mirror
;
1209 struct r1bio
*r1_bio
;
1210 struct bio
*read_bio
;
1211 struct bitmap
*bitmap
= mddev
->bitmap
;
1212 const int op
= bio_op(bio
);
1213 const unsigned long do_sync
= (bio
->bi_opf
& REQ_SYNC
);
1214 int sectors_handled
;
1219 * Still need barrier for READ in case that whole
1222 wait_read_barrier(conf
, bio
->bi_iter
.bi_sector
);
1224 r1_bio
= alloc_r1bio(mddev
, bio
, 0);
1227 * make_request() can abort the operation when read-ahead is being
1228 * used and no empty request is available.
1231 rdisk
= read_balance(conf
, r1_bio
, &max_sectors
);
1234 /* couldn't find anywhere to read from */
1235 raid_end_bio_io(r1_bio
);
1238 mirror
= conf
->mirrors
+ rdisk
;
1240 if (test_bit(WriteMostly
, &mirror
->rdev
->flags
) &&
1243 * Reading from a write-mostly device must take care not to
1244 * over-take any writes that are 'behind'
1246 raid1_log(mddev
, "wait behind writes");
1247 wait_event(bitmap
->behind_wait
,
1248 atomic_read(&bitmap
->behind_writes
) == 0);
1250 r1_bio
->read_disk
= rdisk
;
1252 read_bio
= bio_clone_fast(bio
, GFP_NOIO
, mddev
->bio_set
);
1253 bio_trim(read_bio
, r1_bio
->sector
- bio
->bi_iter
.bi_sector
,
1256 r1_bio
->bios
[rdisk
] = read_bio
;
1258 read_bio
->bi_iter
.bi_sector
= r1_bio
->sector
+
1259 mirror
->rdev
->data_offset
;
1260 read_bio
->bi_bdev
= mirror
->rdev
->bdev
;
1261 read_bio
->bi_end_io
= raid1_end_read_request
;
1262 bio_set_op_attrs(read_bio
, op
, do_sync
);
1263 if (test_bit(FailFast
, &mirror
->rdev
->flags
) &&
1264 test_bit(R1BIO_FailFast
, &r1_bio
->state
))
1265 read_bio
->bi_opf
|= MD_FAILFAST
;
1266 read_bio
->bi_private
= r1_bio
;
1269 trace_block_bio_remap(bdev_get_queue(read_bio
->bi_bdev
),
1270 read_bio
, disk_devt(mddev
->gendisk
),
1273 if (max_sectors
< r1_bio
->sectors
) {
1275 * could not read all from this device, so we will need another
1278 sectors_handled
= (r1_bio
->sector
+ max_sectors
1279 - bio
->bi_iter
.bi_sector
);
1280 r1_bio
->sectors
= max_sectors
;
1281 bio_inc_remaining(bio
);
1284 * Cannot call generic_make_request directly as that will be
1285 * queued in __make_request and subsequent mempool_alloc might
1286 * block waiting for it. So hand bio over to raid1d.
1288 reschedule_retry(r1_bio
);
1290 r1_bio
= alloc_r1bio(mddev
, bio
, sectors_handled
);
1293 generic_make_request(read_bio
);
1296 static void raid1_write_request(struct mddev
*mddev
, struct bio
*bio
)
1298 struct r1conf
*conf
= mddev
->private;
1299 struct r1bio
*r1_bio
;
1301 struct bitmap
*bitmap
= mddev
->bitmap
;
1302 unsigned long flags
;
1303 struct md_rdev
*blocked_rdev
;
1304 struct blk_plug_cb
*cb
;
1305 struct raid1_plug_cb
*plug
= NULL
;
1307 int sectors_handled
;
1312 * Register the new request and wait if the reconstruction
1313 * thread has put up a bar for new requests.
1314 * Continue immediately if no resync is active currently.
1317 md_write_start(mddev
, bio
); /* wait on superblock update early */
1319 if ((bio_end_sector(bio
) > mddev
->suspend_lo
&&
1320 bio
->bi_iter
.bi_sector
< mddev
->suspend_hi
) ||
1321 (mddev_is_clustered(mddev
) &&
1322 md_cluster_ops
->area_resyncing(mddev
, WRITE
,
1323 bio
->bi_iter
.bi_sector
, bio_end_sector(bio
)))) {
1326 * As the suspend_* range is controlled by userspace, we want
1327 * an interruptible wait.
1331 flush_signals(current
);
1332 prepare_to_wait(&conf
->wait_barrier
,
1333 &w
, TASK_INTERRUPTIBLE
);
1334 if (bio_end_sector(bio
) <= mddev
->suspend_lo
||
1335 bio
->bi_iter
.bi_sector
>= mddev
->suspend_hi
||
1336 (mddev_is_clustered(mddev
) &&
1337 !md_cluster_ops
->area_resyncing(mddev
, WRITE
,
1338 bio
->bi_iter
.bi_sector
,
1339 bio_end_sector(bio
))))
1343 finish_wait(&conf
->wait_barrier
, &w
);
1345 wait_barrier(conf
, bio
->bi_iter
.bi_sector
);
1347 r1_bio
= alloc_r1bio(mddev
, bio
, 0);
1349 if (conf
->pending_count
>= max_queued_requests
) {
1350 md_wakeup_thread(mddev
->thread
);
1351 raid1_log(mddev
, "wait queued");
1352 wait_event(conf
->wait_barrier
,
1353 conf
->pending_count
< max_queued_requests
);
1355 /* first select target devices under rcu_lock and
1356 * inc refcount on their rdev. Record them by setting
1358 * If there are known/acknowledged bad blocks on any device on
1359 * which we have seen a write error, we want to avoid writing those
1361 * This potentially requires several writes to write around
1362 * the bad blocks. Each set of writes gets it's own r1bio
1363 * with a set of bios attached.
1366 disks
= conf
->raid_disks
* 2;
1368 blocked_rdev
= NULL
;
1370 max_sectors
= r1_bio
->sectors
;
1371 for (i
= 0; i
< disks
; i
++) {
1372 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1373 if (rdev
&& unlikely(test_bit(Blocked
, &rdev
->flags
))) {
1374 atomic_inc(&rdev
->nr_pending
);
1375 blocked_rdev
= rdev
;
1378 r1_bio
->bios
[i
] = NULL
;
1379 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
)) {
1380 if (i
< conf
->raid_disks
)
1381 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
1385 atomic_inc(&rdev
->nr_pending
);
1386 if (test_bit(WriteErrorSeen
, &rdev
->flags
)) {
1391 is_bad
= is_badblock(rdev
, r1_bio
->sector
, max_sectors
,
1392 &first_bad
, &bad_sectors
);
1394 /* mustn't write here until the bad block is
1396 set_bit(BlockedBadBlocks
, &rdev
->flags
);
1397 blocked_rdev
= rdev
;
1400 if (is_bad
&& first_bad
<= r1_bio
->sector
) {
1401 /* Cannot write here at all */
1402 bad_sectors
-= (r1_bio
->sector
- first_bad
);
1403 if (bad_sectors
< max_sectors
)
1404 /* mustn't write more than bad_sectors
1405 * to other devices yet
1407 max_sectors
= bad_sectors
;
1408 rdev_dec_pending(rdev
, mddev
);
1409 /* We don't set R1BIO_Degraded as that
1410 * only applies if the disk is
1411 * missing, so it might be re-added,
1412 * and we want to know to recover this
1414 * In this case the device is here,
1415 * and the fact that this chunk is not
1416 * in-sync is recorded in the bad
1422 int good_sectors
= first_bad
- r1_bio
->sector
;
1423 if (good_sectors
< max_sectors
)
1424 max_sectors
= good_sectors
;
1427 r1_bio
->bios
[i
] = bio
;
1431 if (unlikely(blocked_rdev
)) {
1432 /* Wait for this device to become unblocked */
1435 for (j
= 0; j
< i
; j
++)
1436 if (r1_bio
->bios
[j
])
1437 rdev_dec_pending(conf
->mirrors
[j
].rdev
, mddev
);
1439 allow_barrier(conf
, bio
->bi_iter
.bi_sector
);
1440 raid1_log(mddev
, "wait rdev %d blocked", blocked_rdev
->raid_disk
);
1441 md_wait_for_blocked_rdev(blocked_rdev
, mddev
);
1442 wait_barrier(conf
, bio
->bi_iter
.bi_sector
);
1446 if (max_sectors
< r1_bio
->sectors
)
1447 r1_bio
->sectors
= max_sectors
;
1449 sectors_handled
= r1_bio
->sector
+ max_sectors
- bio
->bi_iter
.bi_sector
;
1451 atomic_set(&r1_bio
->remaining
, 1);
1452 atomic_set(&r1_bio
->behind_remaining
, 0);
1456 offset
= r1_bio
->sector
- bio
->bi_iter
.bi_sector
;
1457 for (i
= 0; i
< disks
; i
++) {
1458 struct bio
*mbio
= NULL
;
1459 if (!r1_bio
->bios
[i
])
1465 * Not if there are too many, or cannot
1466 * allocate memory, or a reader on WriteMostly
1467 * is waiting for behind writes to flush */
1469 (atomic_read(&bitmap
->behind_writes
)
1470 < mddev
->bitmap_info
.max_write_behind
) &&
1471 !waitqueue_active(&bitmap
->behind_wait
)) {
1472 mbio
= alloc_behind_master_bio(r1_bio
, bio
,
1477 bitmap_startwrite(bitmap
, r1_bio
->sector
,
1479 test_bit(R1BIO_BehindIO
,
1485 if (r1_bio
->behind_master_bio
)
1486 mbio
= bio_clone_fast(r1_bio
->behind_master_bio
,
1490 mbio
= bio_clone_fast(bio
, GFP_NOIO
, mddev
->bio_set
);
1491 bio_trim(mbio
, offset
, max_sectors
);
1495 if (r1_bio
->behind_master_bio
) {
1496 if (test_bit(WriteMostly
, &conf
->mirrors
[i
].rdev
->flags
))
1497 atomic_inc(&r1_bio
->behind_remaining
);
1500 r1_bio
->bios
[i
] = mbio
;
1502 mbio
->bi_iter
.bi_sector
= (r1_bio
->sector
+
1503 conf
->mirrors
[i
].rdev
->data_offset
);
1504 mbio
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
1505 mbio
->bi_end_io
= raid1_end_write_request
;
1506 mbio
->bi_opf
= bio_op(bio
) | (bio
->bi_opf
& (REQ_SYNC
| REQ_FUA
));
1507 if (test_bit(FailFast
, &conf
->mirrors
[i
].rdev
->flags
) &&
1508 !test_bit(WriteMostly
, &conf
->mirrors
[i
].rdev
->flags
) &&
1509 conf
->raid_disks
- mddev
->degraded
> 1)
1510 mbio
->bi_opf
|= MD_FAILFAST
;
1511 mbio
->bi_private
= r1_bio
;
1513 atomic_inc(&r1_bio
->remaining
);
1516 trace_block_bio_remap(bdev_get_queue(mbio
->bi_bdev
),
1517 mbio
, disk_devt(mddev
->gendisk
),
1519 /* flush_pending_writes() needs access to the rdev so...*/
1520 mbio
->bi_bdev
= (void*)conf
->mirrors
[i
].rdev
;
1522 cb
= blk_check_plugged(raid1_unplug
, mddev
, sizeof(*plug
));
1524 plug
= container_of(cb
, struct raid1_plug_cb
, cb
);
1527 spin_lock_irqsave(&conf
->device_lock
, flags
);
1529 bio_list_add(&plug
->pending
, mbio
);
1530 plug
->pending_cnt
++;
1532 bio_list_add(&conf
->pending_bio_list
, mbio
);
1533 conf
->pending_count
++;
1535 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1537 md_wakeup_thread(mddev
->thread
);
1539 /* Mustn't call r1_bio_write_done before this next test,
1540 * as it could result in the bio being freed.
1542 if (sectors_handled
< bio_sectors(bio
)) {
1543 /* We need another r1_bio, which must be counted */
1544 sector_t sect
= bio
->bi_iter
.bi_sector
+ sectors_handled
;
1546 inc_pending(conf
, sect
);
1547 bio_inc_remaining(bio
);
1548 r1_bio_write_done(r1_bio
);
1549 r1_bio
= alloc_r1bio(mddev
, bio
, sectors_handled
);
1553 r1_bio_write_done(r1_bio
);
1555 /* In case raid1d snuck in to freeze_array */
1556 wake_up(&conf
->wait_barrier
);
1559 static void raid1_make_request(struct mddev
*mddev
, struct bio
*bio
)
1564 if (unlikely(bio
->bi_opf
& REQ_PREFLUSH
)) {
1565 md_flush_request(mddev
, bio
);
1569 /* if bio exceeds barrier unit boundary, split it */
1571 sectors
= align_to_barrier_unit_end(
1572 bio
->bi_iter
.bi_sector
, bio_sectors(bio
));
1573 if (sectors
< bio_sectors(bio
)) {
1574 split
= bio_split(bio
, sectors
, GFP_NOIO
, fs_bio_set
);
1575 bio_chain(split
, bio
);
1580 if (bio_data_dir(split
) == READ
) {
1581 raid1_read_request(mddev
, split
);
1584 * If a bio is splitted, the first part of bio will
1585 * pass barrier but the bio is queued in
1586 * current->bio_list (see generic_make_request). If
1587 * there is a raise_barrier() called here, the second
1588 * part of bio can't pass barrier. But since the first
1589 * part bio isn't dispatched to underlaying disks yet,
1590 * the barrier is never released, hence raise_barrier
1591 * will alays wait. We have a deadlock.
1592 * Note, this only happens in read path. For write
1593 * path, the first part of bio is dispatched in a
1594 * schedule() call (because of blk plug) or offloaded
1596 * Quitting from the function immediately can change
1597 * the bio order queued in bio_list and avoid the deadlock.
1600 generic_make_request(bio
);
1604 raid1_write_request(mddev
, split
);
1605 } while (split
!= bio
);
1608 static void raid1_status(struct seq_file
*seq
, struct mddev
*mddev
)
1610 struct r1conf
*conf
= mddev
->private;
1613 seq_printf(seq
, " [%d/%d] [", conf
->raid_disks
,
1614 conf
->raid_disks
- mddev
->degraded
);
1616 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1617 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1618 seq_printf(seq
, "%s",
1619 rdev
&& test_bit(In_sync
, &rdev
->flags
) ? "U" : "_");
1622 seq_printf(seq
, "]");
1625 static void raid1_error(struct mddev
*mddev
, struct md_rdev
*rdev
)
1627 char b
[BDEVNAME_SIZE
];
1628 struct r1conf
*conf
= mddev
->private;
1629 unsigned long flags
;
1632 * If it is not operational, then we have already marked it as dead
1633 * else if it is the last working disks, ignore the error, let the
1634 * next level up know.
1635 * else mark the drive as failed
1637 spin_lock_irqsave(&conf
->device_lock
, flags
);
1638 if (test_bit(In_sync
, &rdev
->flags
)
1639 && (conf
->raid_disks
- mddev
->degraded
) == 1) {
1641 * Don't fail the drive, act as though we were just a
1642 * normal single drive.
1643 * However don't try a recovery from this drive as
1644 * it is very likely to fail.
1646 conf
->recovery_disabled
= mddev
->recovery_disabled
;
1647 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1650 set_bit(Blocked
, &rdev
->flags
);
1651 if (test_and_clear_bit(In_sync
, &rdev
->flags
)) {
1653 set_bit(Faulty
, &rdev
->flags
);
1655 set_bit(Faulty
, &rdev
->flags
);
1656 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1658 * if recovery is running, make sure it aborts.
1660 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
1661 set_mask_bits(&mddev
->sb_flags
, 0,
1662 BIT(MD_SB_CHANGE_DEVS
) | BIT(MD_SB_CHANGE_PENDING
));
1663 pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n"
1664 "md/raid1:%s: Operation continuing on %d devices.\n",
1665 mdname(mddev
), bdevname(rdev
->bdev
, b
),
1666 mdname(mddev
), conf
->raid_disks
- mddev
->degraded
);
1669 static void print_conf(struct r1conf
*conf
)
1673 pr_debug("RAID1 conf printout:\n");
1675 pr_debug("(!conf)\n");
1678 pr_debug(" --- wd:%d rd:%d\n", conf
->raid_disks
- conf
->mddev
->degraded
,
1682 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1683 char b
[BDEVNAME_SIZE
];
1684 struct md_rdev
*rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
1686 pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
1687 i
, !test_bit(In_sync
, &rdev
->flags
),
1688 !test_bit(Faulty
, &rdev
->flags
),
1689 bdevname(rdev
->bdev
,b
));
1694 static void close_sync(struct r1conf
*conf
)
1696 wait_all_barriers(conf
);
1697 allow_all_barriers(conf
);
1699 mempool_destroy(conf
->r1buf_pool
);
1700 conf
->r1buf_pool
= NULL
;
1703 static int raid1_spare_active(struct mddev
*mddev
)
1706 struct r1conf
*conf
= mddev
->private;
1708 unsigned long flags
;
1711 * Find all failed disks within the RAID1 configuration
1712 * and mark them readable.
1713 * Called under mddev lock, so rcu protection not needed.
1714 * device_lock used to avoid races with raid1_end_read_request
1715 * which expects 'In_sync' flags and ->degraded to be consistent.
1717 spin_lock_irqsave(&conf
->device_lock
, flags
);
1718 for (i
= 0; i
< conf
->raid_disks
; i
++) {
1719 struct md_rdev
*rdev
= conf
->mirrors
[i
].rdev
;
1720 struct md_rdev
*repl
= conf
->mirrors
[conf
->raid_disks
+ i
].rdev
;
1722 && !test_bit(Candidate
, &repl
->flags
)
1723 && repl
->recovery_offset
== MaxSector
1724 && !test_bit(Faulty
, &repl
->flags
)
1725 && !test_and_set_bit(In_sync
, &repl
->flags
)) {
1726 /* replacement has just become active */
1728 !test_and_clear_bit(In_sync
, &rdev
->flags
))
1731 /* Replaced device not technically
1732 * faulty, but we need to be sure
1733 * it gets removed and never re-added
1735 set_bit(Faulty
, &rdev
->flags
);
1736 sysfs_notify_dirent_safe(
1741 && rdev
->recovery_offset
== MaxSector
1742 && !test_bit(Faulty
, &rdev
->flags
)
1743 && !test_and_set_bit(In_sync
, &rdev
->flags
)) {
1745 sysfs_notify_dirent_safe(rdev
->sysfs_state
);
1748 mddev
->degraded
-= count
;
1749 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
1755 static int raid1_add_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1757 struct r1conf
*conf
= mddev
->private;
1760 struct raid1_info
*p
;
1762 int last
= conf
->raid_disks
- 1;
1764 if (mddev
->recovery_disabled
== conf
->recovery_disabled
)
1767 if (md_integrity_add_rdev(rdev
, mddev
))
1770 if (rdev
->raid_disk
>= 0)
1771 first
= last
= rdev
->raid_disk
;
1774 * find the disk ... but prefer rdev->saved_raid_disk
1777 if (rdev
->saved_raid_disk
>= 0 &&
1778 rdev
->saved_raid_disk
>= first
&&
1779 conf
->mirrors
[rdev
->saved_raid_disk
].rdev
== NULL
)
1780 first
= last
= rdev
->saved_raid_disk
;
1782 for (mirror
= first
; mirror
<= last
; mirror
++) {
1783 p
= conf
->mirrors
+mirror
;
1787 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
1788 rdev
->data_offset
<< 9);
1790 p
->head_position
= 0;
1791 rdev
->raid_disk
= mirror
;
1793 /* As all devices are equivalent, we don't need a full recovery
1794 * if this was recently any drive of the array
1796 if (rdev
->saved_raid_disk
< 0)
1798 rcu_assign_pointer(p
->rdev
, rdev
);
1801 if (test_bit(WantReplacement
, &p
->rdev
->flags
) &&
1802 p
[conf
->raid_disks
].rdev
== NULL
) {
1803 /* Add this device as a replacement */
1804 clear_bit(In_sync
, &rdev
->flags
);
1805 set_bit(Replacement
, &rdev
->flags
);
1806 rdev
->raid_disk
= mirror
;
1809 rcu_assign_pointer(p
[conf
->raid_disks
].rdev
, rdev
);
1813 if (mddev
->queue
&& blk_queue_discard(bdev_get_queue(rdev
->bdev
)))
1814 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
, mddev
->queue
);
1819 static int raid1_remove_disk(struct mddev
*mddev
, struct md_rdev
*rdev
)
1821 struct r1conf
*conf
= mddev
->private;
1823 int number
= rdev
->raid_disk
;
1824 struct raid1_info
*p
= conf
->mirrors
+ number
;
1826 if (rdev
!= p
->rdev
)
1827 p
= conf
->mirrors
+ conf
->raid_disks
+ number
;
1830 if (rdev
== p
->rdev
) {
1831 if (test_bit(In_sync
, &rdev
->flags
) ||
1832 atomic_read(&rdev
->nr_pending
)) {
1836 /* Only remove non-faulty devices if recovery
1839 if (!test_bit(Faulty
, &rdev
->flags
) &&
1840 mddev
->recovery_disabled
!= conf
->recovery_disabled
&&
1841 mddev
->degraded
< conf
->raid_disks
) {
1846 if (!test_bit(RemoveSynchronized
, &rdev
->flags
)) {
1848 if (atomic_read(&rdev
->nr_pending
)) {
1849 /* lost the race, try later */
1855 if (conf
->mirrors
[conf
->raid_disks
+ number
].rdev
) {
1856 /* We just removed a device that is being replaced.
1857 * Move down the replacement. We drain all IO before
1858 * doing this to avoid confusion.
1860 struct md_rdev
*repl
=
1861 conf
->mirrors
[conf
->raid_disks
+ number
].rdev
;
1862 freeze_array(conf
, 0);
1863 clear_bit(Replacement
, &repl
->flags
);
1865 conf
->mirrors
[conf
->raid_disks
+ number
].rdev
= NULL
;
1866 unfreeze_array(conf
);
1867 clear_bit(WantReplacement
, &rdev
->flags
);
1869 clear_bit(WantReplacement
, &rdev
->flags
);
1870 err
= md_integrity_register(mddev
);
1878 static void end_sync_read(struct bio
*bio
)
1880 struct r1bio
*r1_bio
= get_resync_r1bio(bio
);
1882 update_head_pos(r1_bio
->read_disk
, r1_bio
);
1885 * we have read a block, now it needs to be re-written,
1886 * or re-read if the read failed.
1887 * We don't do much here, just schedule handling by raid1d
1890 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
1892 if (atomic_dec_and_test(&r1_bio
->remaining
))
1893 reschedule_retry(r1_bio
);
1896 static void end_sync_write(struct bio
*bio
)
1898 int uptodate
= !bio
->bi_error
;
1899 struct r1bio
*r1_bio
= get_resync_r1bio(bio
);
1900 struct mddev
*mddev
= r1_bio
->mddev
;
1901 struct r1conf
*conf
= mddev
->private;
1904 struct md_rdev
*rdev
= conf
->mirrors
[find_bio_disk(r1_bio
, bio
)].rdev
;
1907 sector_t sync_blocks
= 0;
1908 sector_t s
= r1_bio
->sector
;
1909 long sectors_to_go
= r1_bio
->sectors
;
1910 /* make sure these bits doesn't get cleared. */
1912 bitmap_end_sync(mddev
->bitmap
, s
,
1915 sectors_to_go
-= sync_blocks
;
1916 } while (sectors_to_go
> 0);
1917 set_bit(WriteErrorSeen
, &rdev
->flags
);
1918 if (!test_and_set_bit(WantReplacement
, &rdev
->flags
))
1919 set_bit(MD_RECOVERY_NEEDED
, &
1921 set_bit(R1BIO_WriteError
, &r1_bio
->state
);
1922 } else if (is_badblock(rdev
, r1_bio
->sector
, r1_bio
->sectors
,
1923 &first_bad
, &bad_sectors
) &&
1924 !is_badblock(conf
->mirrors
[r1_bio
->read_disk
].rdev
,
1927 &first_bad
, &bad_sectors
)
1929 set_bit(R1BIO_MadeGood
, &r1_bio
->state
);
1931 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
1932 int s
= r1_bio
->sectors
;
1933 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
) ||
1934 test_bit(R1BIO_WriteError
, &r1_bio
->state
))
1935 reschedule_retry(r1_bio
);
1938 md_done_sync(mddev
, s
, uptodate
);
1943 static int r1_sync_page_io(struct md_rdev
*rdev
, sector_t sector
,
1944 int sectors
, struct page
*page
, int rw
)
1946 if (sync_page_io(rdev
, sector
, sectors
<< 9, page
, rw
, 0, false))
1950 set_bit(WriteErrorSeen
, &rdev
->flags
);
1951 if (!test_and_set_bit(WantReplacement
,
1953 set_bit(MD_RECOVERY_NEEDED
, &
1954 rdev
->mddev
->recovery
);
1956 /* need to record an error - either for the block or the device */
1957 if (!rdev_set_badblocks(rdev
, sector
, sectors
, 0))
1958 md_error(rdev
->mddev
, rdev
);
1962 static int fix_sync_read_error(struct r1bio
*r1_bio
)
1964 /* Try some synchronous reads of other devices to get
1965 * good data, much like with normal read errors. Only
1966 * read into the pages we already have so we don't
1967 * need to re-issue the read request.
1968 * We don't need to freeze the array, because being in an
1969 * active sync request, there is no normal IO, and
1970 * no overlapping syncs.
1971 * We don't need to check is_badblock() again as we
1972 * made sure that anything with a bad block in range
1973 * will have bi_end_io clear.
1975 struct mddev
*mddev
= r1_bio
->mddev
;
1976 struct r1conf
*conf
= mddev
->private;
1977 struct bio
*bio
= r1_bio
->bios
[r1_bio
->read_disk
];
1978 struct page
**pages
= get_resync_pages(bio
)->pages
;
1979 sector_t sect
= r1_bio
->sector
;
1980 int sectors
= r1_bio
->sectors
;
1982 struct md_rdev
*rdev
;
1984 rdev
= conf
->mirrors
[r1_bio
->read_disk
].rdev
;
1985 if (test_bit(FailFast
, &rdev
->flags
)) {
1986 /* Don't try recovering from here - just fail it
1987 * ... unless it is the last working device of course */
1988 md_error(mddev
, rdev
);
1989 if (test_bit(Faulty
, &rdev
->flags
))
1990 /* Don't try to read from here, but make sure
1991 * put_buf does it's thing
1993 bio
->bi_end_io
= end_sync_write
;
1998 int d
= r1_bio
->read_disk
;
2002 if (s
> (PAGE_SIZE
>>9))
2005 if (r1_bio
->bios
[d
]->bi_end_io
== end_sync_read
) {
2006 /* No rcu protection needed here devices
2007 * can only be removed when no resync is
2008 * active, and resync is currently active
2010 rdev
= conf
->mirrors
[d
].rdev
;
2011 if (sync_page_io(rdev
, sect
, s
<<9,
2013 REQ_OP_READ
, 0, false)) {
2019 if (d
== conf
->raid_disks
* 2)
2021 } while (!success
&& d
!= r1_bio
->read_disk
);
2024 char b
[BDEVNAME_SIZE
];
2026 /* Cannot read from anywhere, this block is lost.
2027 * Record a bad block on each device. If that doesn't
2028 * work just disable and interrupt the recovery.
2029 * Don't fail devices as that won't really help.
2031 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
2033 bdevname(bio
->bi_bdev
, b
),
2034 (unsigned long long)r1_bio
->sector
);
2035 for (d
= 0; d
< conf
->raid_disks
* 2; d
++) {
2036 rdev
= conf
->mirrors
[d
].rdev
;
2037 if (!rdev
|| test_bit(Faulty
, &rdev
->flags
))
2039 if (!rdev_set_badblocks(rdev
, sect
, s
, 0))
2043 conf
->recovery_disabled
=
2044 mddev
->recovery_disabled
;
2045 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
2046 md_done_sync(mddev
, r1_bio
->sectors
, 0);
2058 /* write it back and re-read */
2059 while (d
!= r1_bio
->read_disk
) {
2061 d
= conf
->raid_disks
* 2;
2063 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
2065 rdev
= conf
->mirrors
[d
].rdev
;
2066 if (r1_sync_page_io(rdev
, sect
, s
,
2069 r1_bio
->bios
[d
]->bi_end_io
= NULL
;
2070 rdev_dec_pending(rdev
, mddev
);
2074 while (d
!= r1_bio
->read_disk
) {
2076 d
= conf
->raid_disks
* 2;
2078 if (r1_bio
->bios
[d
]->bi_end_io
!= end_sync_read
)
2080 rdev
= conf
->mirrors
[d
].rdev
;
2081 if (r1_sync_page_io(rdev
, sect
, s
,
2084 atomic_add(s
, &rdev
->corrected_errors
);
2090 set_bit(R1BIO_Uptodate
, &r1_bio
->state
);
2095 static void process_checks(struct r1bio
*r1_bio
)
2097 /* We have read all readable devices. If we haven't
2098 * got the block, then there is no hope left.
2099 * If we have, then we want to do a comparison
2100 * and skip the write if everything is the same.
2101 * If any blocks failed to read, then we need to
2102 * attempt an over-write
2104 struct mddev
*mddev
= r1_bio
->mddev
;
2105 struct r1conf
*conf
= mddev
->private;
2110 /* Fix variable parts of all bios */
2111 vcnt
= (r1_bio
->sectors
+ PAGE_SIZE
/ 512 - 1) >> (PAGE_SHIFT
- 9);
2112 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
2117 struct bio
*b
= r1_bio
->bios
[i
];
2118 struct resync_pages
*rp
= get_resync_pages(b
);
2119 if (b
->bi_end_io
!= end_sync_read
)
2121 /* fixup the bio for reuse, but preserve errno */
2122 error
= b
->bi_error
;
2124 b
->bi_error
= error
;
2126 b
->bi_iter
.bi_size
= r1_bio
->sectors
<< 9;
2127 b
->bi_iter
.bi_sector
= r1_bio
->sector
+
2128 conf
->mirrors
[i
].rdev
->data_offset
;
2129 b
->bi_bdev
= conf
->mirrors
[i
].rdev
->bdev
;
2130 b
->bi_end_io
= end_sync_read
;
2131 rp
->raid_bio
= r1_bio
;
2134 size
= b
->bi_iter
.bi_size
;
2135 bio_for_each_segment_all(bi
, b
, j
) {
2137 if (size
> PAGE_SIZE
)
2138 bi
->bv_len
= PAGE_SIZE
;
2144 for (primary
= 0; primary
< conf
->raid_disks
* 2; primary
++)
2145 if (r1_bio
->bios
[primary
]->bi_end_io
== end_sync_read
&&
2146 !r1_bio
->bios
[primary
]->bi_error
) {
2147 r1_bio
->bios
[primary
]->bi_end_io
= NULL
;
2148 rdev_dec_pending(conf
->mirrors
[primary
].rdev
, mddev
);
2151 r1_bio
->read_disk
= primary
;
2152 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
2154 struct bio
*pbio
= r1_bio
->bios
[primary
];
2155 struct bio
*sbio
= r1_bio
->bios
[i
];
2156 int error
= sbio
->bi_error
;
2157 struct page
**ppages
= get_resync_pages(pbio
)->pages
;
2158 struct page
**spages
= get_resync_pages(sbio
)->pages
;
2160 int page_len
[RESYNC_PAGES
] = { 0 };
2162 if (sbio
->bi_end_io
!= end_sync_read
)
2164 /* Now we can 'fixup' the error value */
2167 bio_for_each_segment_all(bi
, sbio
, j
)
2168 page_len
[j
] = bi
->bv_len
;
2171 for (j
= vcnt
; j
-- ; ) {
2172 if (memcmp(page_address(ppages
[j
]),
2173 page_address(spages
[j
]),
2180 atomic64_add(r1_bio
->sectors
, &mddev
->resync_mismatches
);
2181 if (j
< 0 || (test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
)
2183 /* No need to write to this device. */
2184 sbio
->bi_end_io
= NULL
;
2185 rdev_dec_pending(conf
->mirrors
[i
].rdev
, mddev
);
2189 bio_copy_data(sbio
, pbio
);
2193 static void sync_request_write(struct mddev
*mddev
, struct r1bio
*r1_bio
)
2195 struct r1conf
*conf
= mddev
->private;
2197 int disks
= conf
->raid_disks
* 2;
2198 struct bio
*bio
, *wbio
;
2200 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
2202 if (!test_bit(R1BIO_Uptodate
, &r1_bio
->state
))
2203 /* ouch - failed to read all of that. */
2204 if (!fix_sync_read_error(r1_bio
))
2207 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
2208 process_checks(r1_bio
);
2213 atomic_set(&r1_bio
->remaining
, 1);
2214 for (i
= 0; i
< disks
; i
++) {
2215 wbio
= r1_bio
->bios
[i
];
2216 if (wbio
->bi_end_io
== NULL
||
2217 (wbio
->bi_end_io
== end_sync_read
&&
2218 (i
== r1_bio
->read_disk
||
2219 !test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
))))
2222 bio_set_op_attrs(wbio
, REQ_OP_WRITE
, 0);
2223 if (test_bit(FailFast
, &conf
->mirrors
[i
].rdev
->flags
))
2224 wbio
->bi_opf
|= MD_FAILFAST
;
2226 wbio
->bi_end_io
= end_sync_write
;
2227 atomic_inc(&r1_bio
->remaining
);
2228 md_sync_acct(conf
->mirrors
[i
].rdev
->bdev
, bio_sectors(wbio
));
2230 generic_make_request(wbio
);
2233 if (atomic_dec_and_test(&r1_bio
->remaining
)) {
2234 /* if we're here, all write(s) have completed, so clean up */
2235 int s
= r1_bio
->sectors
;
2236 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
) ||
2237 test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2238 reschedule_retry(r1_bio
);
2241 md_done_sync(mddev
, s
, 1);
2247 * This is a kernel thread which:
2249 * 1. Retries failed read operations on working mirrors.
2250 * 2. Updates the raid superblock when problems encounter.
2251 * 3. Performs writes following reads for array synchronising.
2254 static void fix_read_error(struct r1conf
*conf
, int read_disk
,
2255 sector_t sect
, int sectors
)
2257 struct mddev
*mddev
= conf
->mddev
;
2263 struct md_rdev
*rdev
;
2265 if (s
> (PAGE_SIZE
>>9))
2273 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2275 (test_bit(In_sync
, &rdev
->flags
) ||
2276 (!test_bit(Faulty
, &rdev
->flags
) &&
2277 rdev
->recovery_offset
>= sect
+ s
)) &&
2278 is_badblock(rdev
, sect
, s
,
2279 &first_bad
, &bad_sectors
) == 0) {
2280 atomic_inc(&rdev
->nr_pending
);
2282 if (sync_page_io(rdev
, sect
, s
<<9,
2283 conf
->tmppage
, REQ_OP_READ
, 0, false))
2285 rdev_dec_pending(rdev
, mddev
);
2291 if (d
== conf
->raid_disks
* 2)
2293 } while (!success
&& d
!= read_disk
);
2296 /* Cannot read from anywhere - mark it bad */
2297 struct md_rdev
*rdev
= conf
->mirrors
[read_disk
].rdev
;
2298 if (!rdev_set_badblocks(rdev
, sect
, s
, 0))
2299 md_error(mddev
, rdev
);
2302 /* write it back and re-read */
2304 while (d
!= read_disk
) {
2306 d
= conf
->raid_disks
* 2;
2309 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2311 !test_bit(Faulty
, &rdev
->flags
)) {
2312 atomic_inc(&rdev
->nr_pending
);
2314 r1_sync_page_io(rdev
, sect
, s
,
2315 conf
->tmppage
, WRITE
);
2316 rdev_dec_pending(rdev
, mddev
);
2321 while (d
!= read_disk
) {
2322 char b
[BDEVNAME_SIZE
];
2324 d
= conf
->raid_disks
* 2;
2327 rdev
= rcu_dereference(conf
->mirrors
[d
].rdev
);
2329 !test_bit(Faulty
, &rdev
->flags
)) {
2330 atomic_inc(&rdev
->nr_pending
);
2332 if (r1_sync_page_io(rdev
, sect
, s
,
2333 conf
->tmppage
, READ
)) {
2334 atomic_add(s
, &rdev
->corrected_errors
);
2335 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
2337 (unsigned long long)(sect
+
2339 bdevname(rdev
->bdev
, b
));
2341 rdev_dec_pending(rdev
, mddev
);
2350 static int narrow_write_error(struct r1bio
*r1_bio
, int i
)
2352 struct mddev
*mddev
= r1_bio
->mddev
;
2353 struct r1conf
*conf
= mddev
->private;
2354 struct md_rdev
*rdev
= conf
->mirrors
[i
].rdev
;
2356 /* bio has the data to be written to device 'i' where
2357 * we just recently had a write error.
2358 * We repeatedly clone the bio and trim down to one block,
2359 * then try the write. Where the write fails we record
2361 * It is conceivable that the bio doesn't exactly align with
2362 * blocks. We must handle this somehow.
2364 * We currently own a reference on the rdev.
2370 int sect_to_write
= r1_bio
->sectors
;
2373 if (rdev
->badblocks
.shift
< 0)
2376 block_sectors
= roundup(1 << rdev
->badblocks
.shift
,
2377 bdev_logical_block_size(rdev
->bdev
) >> 9);
2378 sector
= r1_bio
->sector
;
2379 sectors
= ((sector
+ block_sectors
)
2380 & ~(sector_t
)(block_sectors
- 1))
2383 while (sect_to_write
) {
2385 if (sectors
> sect_to_write
)
2386 sectors
= sect_to_write
;
2387 /* Write at 'sector' for 'sectors'*/
2389 if (test_bit(R1BIO_BehindIO
, &r1_bio
->state
)) {
2390 wbio
= bio_clone_fast(r1_bio
->behind_master_bio
,
2393 /* We really need a _all clone */
2394 wbio
->bi_iter
= (struct bvec_iter
){ 0 };
2396 wbio
= bio_clone_fast(r1_bio
->master_bio
, GFP_NOIO
,
2400 bio_set_op_attrs(wbio
, REQ_OP_WRITE
, 0);
2401 wbio
->bi_iter
.bi_sector
= r1_bio
->sector
;
2402 wbio
->bi_iter
.bi_size
= r1_bio
->sectors
<< 9;
2404 bio_trim(wbio
, sector
- r1_bio
->sector
, sectors
);
2405 wbio
->bi_iter
.bi_sector
+= rdev
->data_offset
;
2406 wbio
->bi_bdev
= rdev
->bdev
;
2408 if (submit_bio_wait(wbio
) < 0)
2410 ok
= rdev_set_badblocks(rdev
, sector
,
2415 sect_to_write
-= sectors
;
2417 sectors
= block_sectors
;
2422 static void handle_sync_write_finished(struct r1conf
*conf
, struct r1bio
*r1_bio
)
2425 int s
= r1_bio
->sectors
;
2426 for (m
= 0; m
< conf
->raid_disks
* 2 ; m
++) {
2427 struct md_rdev
*rdev
= conf
->mirrors
[m
].rdev
;
2428 struct bio
*bio
= r1_bio
->bios
[m
];
2429 if (bio
->bi_end_io
== NULL
)
2431 if (!bio
->bi_error
&&
2432 test_bit(R1BIO_MadeGood
, &r1_bio
->state
)) {
2433 rdev_clear_badblocks(rdev
, r1_bio
->sector
, s
, 0);
2435 if (bio
->bi_error
&&
2436 test_bit(R1BIO_WriteError
, &r1_bio
->state
)) {
2437 if (!rdev_set_badblocks(rdev
, r1_bio
->sector
, s
, 0))
2438 md_error(conf
->mddev
, rdev
);
2442 md_done_sync(conf
->mddev
, s
, 1);
2445 static void handle_write_finished(struct r1conf
*conf
, struct r1bio
*r1_bio
)
2450 for (m
= 0; m
< conf
->raid_disks
* 2 ; m
++)
2451 if (r1_bio
->bios
[m
] == IO_MADE_GOOD
) {
2452 struct md_rdev
*rdev
= conf
->mirrors
[m
].rdev
;
2453 rdev_clear_badblocks(rdev
,
2455 r1_bio
->sectors
, 0);
2456 rdev_dec_pending(rdev
, conf
->mddev
);
2457 } else if (r1_bio
->bios
[m
] != NULL
) {
2458 /* This drive got a write error. We need to
2459 * narrow down and record precise write
2463 if (!narrow_write_error(r1_bio
, m
)) {
2464 md_error(conf
->mddev
,
2465 conf
->mirrors
[m
].rdev
);
2466 /* an I/O failed, we can't clear the bitmap */
2467 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
2469 rdev_dec_pending(conf
->mirrors
[m
].rdev
,
2473 spin_lock_irq(&conf
->device_lock
);
2474 list_add(&r1_bio
->retry_list
, &conf
->bio_end_io_list
);
2475 idx
= sector_to_idx(r1_bio
->sector
);
2476 atomic_inc(&conf
->nr_queued
[idx
]);
2477 spin_unlock_irq(&conf
->device_lock
);
2479 * In case freeze_array() is waiting for condition
2480 * get_unqueued_pending() == extra to be true.
2482 wake_up(&conf
->wait_barrier
);
2483 md_wakeup_thread(conf
->mddev
->thread
);
2485 if (test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2486 close_write(r1_bio
);
2487 raid_end_bio_io(r1_bio
);
2491 static void handle_read_error(struct r1conf
*conf
, struct r1bio
*r1_bio
)
2495 struct mddev
*mddev
= conf
->mddev
;
2497 char b
[BDEVNAME_SIZE
];
2498 struct md_rdev
*rdev
;
2500 sector_t bio_sector
;
2502 clear_bit(R1BIO_ReadError
, &r1_bio
->state
);
2503 /* we got a read error. Maybe the drive is bad. Maybe just
2504 * the block and we can fix it.
2505 * We freeze all other IO, and try reading the block from
2506 * other devices. When we find one, we re-write
2507 * and check it that fixes the read error.
2508 * This is all done synchronously while the array is
2512 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
2513 bdevname(bio
->bi_bdev
, b
);
2514 bio_dev
= bio
->bi_bdev
->bd_dev
;
2515 bio_sector
= conf
->mirrors
[r1_bio
->read_disk
].rdev
->data_offset
+ r1_bio
->sector
;
2517 r1_bio
->bios
[r1_bio
->read_disk
] = NULL
;
2519 rdev
= conf
->mirrors
[r1_bio
->read_disk
].rdev
;
2521 && !test_bit(FailFast
, &rdev
->flags
)) {
2522 freeze_array(conf
, 1);
2523 fix_read_error(conf
, r1_bio
->read_disk
,
2524 r1_bio
->sector
, r1_bio
->sectors
);
2525 unfreeze_array(conf
);
2527 r1_bio
->bios
[r1_bio
->read_disk
] = IO_BLOCKED
;
2530 rdev_dec_pending(rdev
, conf
->mddev
);
2533 disk
= read_balance(conf
, r1_bio
, &max_sectors
);
2535 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
2536 mdname(mddev
), b
, (unsigned long long)r1_bio
->sector
);
2537 raid_end_bio_io(r1_bio
);
2539 const unsigned long do_sync
2540 = r1_bio
->master_bio
->bi_opf
& REQ_SYNC
;
2541 r1_bio
->read_disk
= disk
;
2542 bio
= bio_clone_fast(r1_bio
->master_bio
, GFP_NOIO
,
2544 bio_trim(bio
, r1_bio
->sector
- bio
->bi_iter
.bi_sector
,
2546 r1_bio
->bios
[r1_bio
->read_disk
] = bio
;
2547 rdev
= conf
->mirrors
[disk
].rdev
;
2548 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
2550 (unsigned long long)r1_bio
->sector
,
2551 bdevname(rdev
->bdev
, b
));
2552 bio
->bi_iter
.bi_sector
= r1_bio
->sector
+ rdev
->data_offset
;
2553 bio
->bi_bdev
= rdev
->bdev
;
2554 bio
->bi_end_io
= raid1_end_read_request
;
2555 bio_set_op_attrs(bio
, REQ_OP_READ
, do_sync
);
2556 if (test_bit(FailFast
, &rdev
->flags
) &&
2557 test_bit(R1BIO_FailFast
, &r1_bio
->state
))
2558 bio
->bi_opf
|= MD_FAILFAST
;
2559 bio
->bi_private
= r1_bio
;
2560 if (max_sectors
< r1_bio
->sectors
) {
2561 /* Drat - have to split this up more */
2562 struct bio
*mbio
= r1_bio
->master_bio
;
2563 int sectors_handled
= (r1_bio
->sector
+ max_sectors
2564 - mbio
->bi_iter
.bi_sector
);
2565 r1_bio
->sectors
= max_sectors
;
2566 bio_inc_remaining(mbio
);
2567 trace_block_bio_remap(bdev_get_queue(bio
->bi_bdev
),
2568 bio
, bio_dev
, bio_sector
);
2569 generic_make_request(bio
);
2572 r1_bio
= alloc_r1bio(mddev
, mbio
, sectors_handled
);
2573 set_bit(R1BIO_ReadError
, &r1_bio
->state
);
2574 inc_pending(conf
, r1_bio
->sector
);
2578 trace_block_bio_remap(bdev_get_queue(bio
->bi_bdev
),
2579 bio
, bio_dev
, bio_sector
);
2580 generic_make_request(bio
);
2585 static void raid1d(struct md_thread
*thread
)
2587 struct mddev
*mddev
= thread
->mddev
;
2588 struct r1bio
*r1_bio
;
2589 unsigned long flags
;
2590 struct r1conf
*conf
= mddev
->private;
2591 struct list_head
*head
= &conf
->retry_list
;
2592 struct blk_plug plug
;
2595 md_check_recovery(mddev
);
2597 if (!list_empty_careful(&conf
->bio_end_io_list
) &&
2598 !test_bit(MD_SB_CHANGE_PENDING
, &mddev
->sb_flags
)) {
2600 spin_lock_irqsave(&conf
->device_lock
, flags
);
2601 if (!test_bit(MD_SB_CHANGE_PENDING
, &mddev
->sb_flags
))
2602 list_splice_init(&conf
->bio_end_io_list
, &tmp
);
2603 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2604 while (!list_empty(&tmp
)) {
2605 r1_bio
= list_first_entry(&tmp
, struct r1bio
,
2607 list_del(&r1_bio
->retry_list
);
2608 idx
= sector_to_idx(r1_bio
->sector
);
2609 atomic_dec(&conf
->nr_queued
[idx
]);
2610 if (mddev
->degraded
)
2611 set_bit(R1BIO_Degraded
, &r1_bio
->state
);
2612 if (test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2613 close_write(r1_bio
);
2614 raid_end_bio_io(r1_bio
);
2618 blk_start_plug(&plug
);
2621 flush_pending_writes(conf
);
2623 spin_lock_irqsave(&conf
->device_lock
, flags
);
2624 if (list_empty(head
)) {
2625 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2628 r1_bio
= list_entry(head
->prev
, struct r1bio
, retry_list
);
2629 list_del(head
->prev
);
2630 idx
= sector_to_idx(r1_bio
->sector
);
2631 atomic_dec(&conf
->nr_queued
[idx
]);
2632 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
2634 mddev
= r1_bio
->mddev
;
2635 conf
= mddev
->private;
2636 if (test_bit(R1BIO_IsSync
, &r1_bio
->state
)) {
2637 if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
) ||
2638 test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2639 handle_sync_write_finished(conf
, r1_bio
);
2641 sync_request_write(mddev
, r1_bio
);
2642 } else if (test_bit(R1BIO_MadeGood
, &r1_bio
->state
) ||
2643 test_bit(R1BIO_WriteError
, &r1_bio
->state
))
2644 handle_write_finished(conf
, r1_bio
);
2645 else if (test_bit(R1BIO_ReadError
, &r1_bio
->state
))
2646 handle_read_error(conf
, r1_bio
);
2648 /* just a partial read to be scheduled from separate
2651 generic_make_request(r1_bio
->bios
[r1_bio
->read_disk
]);
2654 if (mddev
->sb_flags
& ~(1<<MD_SB_CHANGE_PENDING
))
2655 md_check_recovery(mddev
);
2657 blk_finish_plug(&plug
);
2660 static int init_resync(struct r1conf
*conf
)
2664 buffs
= RESYNC_WINDOW
/ RESYNC_BLOCK_SIZE
;
2665 BUG_ON(conf
->r1buf_pool
);
2666 conf
->r1buf_pool
= mempool_create(buffs
, r1buf_pool_alloc
, r1buf_pool_free
,
2668 if (!conf
->r1buf_pool
)
2674 * perform a "sync" on one "block"
2676 * We need to make sure that no normal I/O request - particularly write
2677 * requests - conflict with active sync requests.
2679 * This is achieved by tracking pending requests and a 'barrier' concept
2680 * that can be installed to exclude normal IO requests.
2683 static sector_t
raid1_sync_request(struct mddev
*mddev
, sector_t sector_nr
,
2686 struct r1conf
*conf
= mddev
->private;
2687 struct r1bio
*r1_bio
;
2689 sector_t max_sector
, nr_sectors
;
2693 int write_targets
= 0, read_targets
= 0;
2694 sector_t sync_blocks
;
2695 int still_degraded
= 0;
2696 int good_sectors
= RESYNC_SECTORS
;
2697 int min_bad
= 0; /* number of sectors that are bad in all devices */
2698 int idx
= sector_to_idx(sector_nr
);
2700 if (!conf
->r1buf_pool
)
2701 if (init_resync(conf
))
2704 max_sector
= mddev
->dev_sectors
;
2705 if (sector_nr
>= max_sector
) {
2706 /* If we aborted, we need to abort the
2707 * sync on the 'current' bitmap chunk (there will
2708 * only be one in raid1 resync.
2709 * We can find the current addess in mddev->curr_resync
2711 if (mddev
->curr_resync
< max_sector
) /* aborted */
2712 bitmap_end_sync(mddev
->bitmap
, mddev
->curr_resync
,
2714 else /* completed sync */
2717 bitmap_close_sync(mddev
->bitmap
);
2720 if (mddev_is_clustered(mddev
)) {
2721 conf
->cluster_sync_low
= 0;
2722 conf
->cluster_sync_high
= 0;
2727 if (mddev
->bitmap
== NULL
&&
2728 mddev
->recovery_cp
== MaxSector
&&
2729 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
) &&
2730 conf
->fullsync
== 0) {
2732 return max_sector
- sector_nr
;
2734 /* before building a request, check if we can skip these blocks..
2735 * This call the bitmap_start_sync doesn't actually record anything
2737 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
, &sync_blocks
, 1) &&
2738 !conf
->fullsync
&& !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
2739 /* We can skip this block, and probably several more */
2745 * If there is non-resync activity waiting for a turn, then let it
2746 * though before starting on this new sync request.
2748 if (atomic_read(&conf
->nr_waiting
[idx
]))
2749 schedule_timeout_uninterruptible(1);
2751 /* we are incrementing sector_nr below. To be safe, we check against
2752 * sector_nr + two times RESYNC_SECTORS
2755 bitmap_cond_end_sync(mddev
->bitmap
, sector_nr
,
2756 mddev_is_clustered(mddev
) && (sector_nr
+ 2 * RESYNC_SECTORS
> conf
->cluster_sync_high
));
2757 r1_bio
= mempool_alloc(conf
->r1buf_pool
, GFP_NOIO
);
2759 raise_barrier(conf
, sector_nr
);
2763 * If we get a correctably read error during resync or recovery,
2764 * we might want to read from a different device. So we
2765 * flag all drives that could conceivably be read from for READ,
2766 * and any others (which will be non-In_sync devices) for WRITE.
2767 * If a read fails, we try reading from something else for which READ
2771 r1_bio
->mddev
= mddev
;
2772 r1_bio
->sector
= sector_nr
;
2774 set_bit(R1BIO_IsSync
, &r1_bio
->state
);
2775 /* make sure good_sectors won't go across barrier unit boundary */
2776 good_sectors
= align_to_barrier_unit_end(sector_nr
, good_sectors
);
2778 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
2779 struct md_rdev
*rdev
;
2780 bio
= r1_bio
->bios
[i
];
2782 rdev
= rcu_dereference(conf
->mirrors
[i
].rdev
);
2784 test_bit(Faulty
, &rdev
->flags
)) {
2785 if (i
< conf
->raid_disks
)
2787 } else if (!test_bit(In_sync
, &rdev
->flags
)) {
2788 bio_set_op_attrs(bio
, REQ_OP_WRITE
, 0);
2789 bio
->bi_end_io
= end_sync_write
;
2792 /* may need to read from here */
2793 sector_t first_bad
= MaxSector
;
2796 if (is_badblock(rdev
, sector_nr
, good_sectors
,
2797 &first_bad
, &bad_sectors
)) {
2798 if (first_bad
> sector_nr
)
2799 good_sectors
= first_bad
- sector_nr
;
2801 bad_sectors
-= (sector_nr
- first_bad
);
2803 min_bad
> bad_sectors
)
2804 min_bad
= bad_sectors
;
2807 if (sector_nr
< first_bad
) {
2808 if (test_bit(WriteMostly
, &rdev
->flags
)) {
2815 bio_set_op_attrs(bio
, REQ_OP_READ
, 0);
2816 bio
->bi_end_io
= end_sync_read
;
2818 } else if (!test_bit(WriteErrorSeen
, &rdev
->flags
) &&
2819 test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
) &&
2820 !test_bit(MD_RECOVERY_CHECK
, &mddev
->recovery
)) {
2822 * The device is suitable for reading (InSync),
2823 * but has bad block(s) here. Let's try to correct them,
2824 * if we are doing resync or repair. Otherwise, leave
2825 * this device alone for this sync request.
2827 bio_set_op_attrs(bio
, REQ_OP_WRITE
, 0);
2828 bio
->bi_end_io
= end_sync_write
;
2832 if (bio
->bi_end_io
) {
2833 atomic_inc(&rdev
->nr_pending
);
2834 bio
->bi_iter
.bi_sector
= sector_nr
+ rdev
->data_offset
;
2835 bio
->bi_bdev
= rdev
->bdev
;
2836 if (test_bit(FailFast
, &rdev
->flags
))
2837 bio
->bi_opf
|= MD_FAILFAST
;
2843 r1_bio
->read_disk
= disk
;
2845 if (read_targets
== 0 && min_bad
> 0) {
2846 /* These sectors are bad on all InSync devices, so we
2847 * need to mark them bad on all write targets
2850 for (i
= 0 ; i
< conf
->raid_disks
* 2 ; i
++)
2851 if (r1_bio
->bios
[i
]->bi_end_io
== end_sync_write
) {
2852 struct md_rdev
*rdev
= conf
->mirrors
[i
].rdev
;
2853 ok
= rdev_set_badblocks(rdev
, sector_nr
,
2857 set_bit(MD_SB_CHANGE_DEVS
, &mddev
->sb_flags
);
2862 /* Cannot record the badblocks, so need to
2864 * If there are multiple read targets, could just
2865 * fail the really bad ones ???
2867 conf
->recovery_disabled
= mddev
->recovery_disabled
;
2868 set_bit(MD_RECOVERY_INTR
, &mddev
->recovery
);
2874 if (min_bad
> 0 && min_bad
< good_sectors
) {
2875 /* only resync enough to reach the next bad->good
2877 good_sectors
= min_bad
;
2880 if (test_bit(MD_RECOVERY_SYNC
, &mddev
->recovery
) && read_targets
> 0)
2881 /* extra read targets are also write targets */
2882 write_targets
+= read_targets
-1;
2884 if (write_targets
== 0 || read_targets
== 0) {
2885 /* There is nowhere to write, so all non-sync
2886 * drives must be failed - so we are finished
2890 max_sector
= sector_nr
+ min_bad
;
2891 rv
= max_sector
- sector_nr
;
2897 if (max_sector
> mddev
->resync_max
)
2898 max_sector
= mddev
->resync_max
; /* Don't do IO beyond here */
2899 if (max_sector
> sector_nr
+ good_sectors
)
2900 max_sector
= sector_nr
+ good_sectors
;
2905 int len
= PAGE_SIZE
;
2906 if (sector_nr
+ (len
>>9) > max_sector
)
2907 len
= (max_sector
- sector_nr
) << 9;
2910 if (sync_blocks
== 0) {
2911 if (!bitmap_start_sync(mddev
->bitmap
, sector_nr
,
2912 &sync_blocks
, still_degraded
) &&
2914 !test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
))
2916 if ((len
>> 9) > sync_blocks
)
2917 len
= sync_blocks
<<9;
2920 for (i
= 0 ; i
< conf
->raid_disks
* 2; i
++) {
2921 struct resync_pages
*rp
;
2923 bio
= r1_bio
->bios
[i
];
2924 rp
= get_resync_pages(bio
);
2925 if (bio
->bi_end_io
) {
2926 page
= resync_fetch_page(rp
, rp
->idx
++);
2929 * won't fail because the vec table is big
2930 * enough to hold all these pages
2932 bio_add_page(bio
, page
, len
, 0);
2935 nr_sectors
+= len
>>9;
2936 sector_nr
+= len
>>9;
2937 sync_blocks
-= (len
>>9);
2938 } while (get_resync_pages(r1_bio
->bios
[disk
]->bi_private
)->idx
< RESYNC_PAGES
);
2940 r1_bio
->sectors
= nr_sectors
;
2942 if (mddev_is_clustered(mddev
) &&
2943 conf
->cluster_sync_high
< sector_nr
+ nr_sectors
) {
2944 conf
->cluster_sync_low
= mddev
->curr_resync_completed
;
2945 conf
->cluster_sync_high
= conf
->cluster_sync_low
+ CLUSTER_RESYNC_WINDOW_SECTORS
;
2946 /* Send resync message */
2947 md_cluster_ops
->resync_info_update(mddev
,
2948 conf
->cluster_sync_low
,
2949 conf
->cluster_sync_high
);
2952 /* For a user-requested sync, we read all readable devices and do a
2955 if (test_bit(MD_RECOVERY_REQUESTED
, &mddev
->recovery
)) {
2956 atomic_set(&r1_bio
->remaining
, read_targets
);
2957 for (i
= 0; i
< conf
->raid_disks
* 2 && read_targets
; i
++) {
2958 bio
= r1_bio
->bios
[i
];
2959 if (bio
->bi_end_io
== end_sync_read
) {
2961 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2962 if (read_targets
== 1)
2963 bio
->bi_opf
&= ~MD_FAILFAST
;
2964 generic_make_request(bio
);
2968 atomic_set(&r1_bio
->remaining
, 1);
2969 bio
= r1_bio
->bios
[r1_bio
->read_disk
];
2970 md_sync_acct(bio
->bi_bdev
, nr_sectors
);
2971 if (read_targets
== 1)
2972 bio
->bi_opf
&= ~MD_FAILFAST
;
2973 generic_make_request(bio
);
2979 static sector_t
raid1_size(struct mddev
*mddev
, sector_t sectors
, int raid_disks
)
2984 return mddev
->dev_sectors
;
2987 static struct r1conf
*setup_conf(struct mddev
*mddev
)
2989 struct r1conf
*conf
;
2991 struct raid1_info
*disk
;
2992 struct md_rdev
*rdev
;
2995 conf
= kzalloc(sizeof(struct r1conf
), GFP_KERNEL
);
2999 conf
->nr_pending
= kcalloc(BARRIER_BUCKETS_NR
,
3000 sizeof(atomic_t
), GFP_KERNEL
);
3001 if (!conf
->nr_pending
)
3004 conf
->nr_waiting
= kcalloc(BARRIER_BUCKETS_NR
,
3005 sizeof(atomic_t
), GFP_KERNEL
);
3006 if (!conf
->nr_waiting
)
3009 conf
->nr_queued
= kcalloc(BARRIER_BUCKETS_NR
,
3010 sizeof(atomic_t
), GFP_KERNEL
);
3011 if (!conf
->nr_queued
)
3014 conf
->barrier
= kcalloc(BARRIER_BUCKETS_NR
,
3015 sizeof(atomic_t
), GFP_KERNEL
);
3019 conf
->mirrors
= kzalloc(sizeof(struct raid1_info
)
3020 * mddev
->raid_disks
* 2,
3025 conf
->tmppage
= alloc_page(GFP_KERNEL
);
3029 conf
->poolinfo
= kzalloc(sizeof(*conf
->poolinfo
), GFP_KERNEL
);
3030 if (!conf
->poolinfo
)
3032 conf
->poolinfo
->raid_disks
= mddev
->raid_disks
* 2;
3033 conf
->r1bio_pool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
3036 if (!conf
->r1bio_pool
)
3039 conf
->poolinfo
->mddev
= mddev
;
3042 spin_lock_init(&conf
->device_lock
);
3043 rdev_for_each(rdev
, mddev
) {
3044 struct request_queue
*q
;
3045 int disk_idx
= rdev
->raid_disk
;
3046 if (disk_idx
>= mddev
->raid_disks
3049 if (test_bit(Replacement
, &rdev
->flags
))
3050 disk
= conf
->mirrors
+ mddev
->raid_disks
+ disk_idx
;
3052 disk
= conf
->mirrors
+ disk_idx
;
3057 q
= bdev_get_queue(rdev
->bdev
);
3059 disk
->head_position
= 0;
3060 disk
->seq_start
= MaxSector
;
3062 conf
->raid_disks
= mddev
->raid_disks
;
3063 conf
->mddev
= mddev
;
3064 INIT_LIST_HEAD(&conf
->retry_list
);
3065 INIT_LIST_HEAD(&conf
->bio_end_io_list
);
3067 spin_lock_init(&conf
->resync_lock
);
3068 init_waitqueue_head(&conf
->wait_barrier
);
3070 bio_list_init(&conf
->pending_bio_list
);
3071 conf
->pending_count
= 0;
3072 conf
->recovery_disabled
= mddev
->recovery_disabled
- 1;
3075 for (i
= 0; i
< conf
->raid_disks
* 2; i
++) {
3077 disk
= conf
->mirrors
+ i
;
3079 if (i
< conf
->raid_disks
&&
3080 disk
[conf
->raid_disks
].rdev
) {
3081 /* This slot has a replacement. */
3083 /* No original, just make the replacement
3084 * a recovering spare
3087 disk
[conf
->raid_disks
].rdev
;
3088 disk
[conf
->raid_disks
].rdev
= NULL
;
3089 } else if (!test_bit(In_sync
, &disk
->rdev
->flags
))
3090 /* Original is not in_sync - bad */
3095 !test_bit(In_sync
, &disk
->rdev
->flags
)) {
3096 disk
->head_position
= 0;
3098 (disk
->rdev
->saved_raid_disk
< 0))
3104 conf
->thread
= md_register_thread(raid1d
, mddev
, "raid1");
3112 mempool_destroy(conf
->r1bio_pool
);
3113 kfree(conf
->mirrors
);
3114 safe_put_page(conf
->tmppage
);
3115 kfree(conf
->poolinfo
);
3116 kfree(conf
->nr_pending
);
3117 kfree(conf
->nr_waiting
);
3118 kfree(conf
->nr_queued
);
3119 kfree(conf
->barrier
);
3122 return ERR_PTR(err
);
3125 static void raid1_free(struct mddev
*mddev
, void *priv
);
3126 static int raid1_run(struct mddev
*mddev
)
3128 struct r1conf
*conf
;
3130 struct md_rdev
*rdev
;
3132 bool discard_supported
= false;
3134 if (mddev
->level
!= 1) {
3135 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3136 mdname(mddev
), mddev
->level
);
3139 if (mddev
->reshape_position
!= MaxSector
) {
3140 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3145 * copy the already verified devices into our private RAID1
3146 * bookkeeping area. [whatever we allocate in run(),
3147 * should be freed in raid1_free()]
3149 if (mddev
->private == NULL
)
3150 conf
= setup_conf(mddev
);
3152 conf
= mddev
->private;
3155 return PTR_ERR(conf
);
3158 blk_queue_max_write_same_sectors(mddev
->queue
, 0);
3160 rdev_for_each(rdev
, mddev
) {
3161 if (!mddev
->gendisk
)
3163 disk_stack_limits(mddev
->gendisk
, rdev
->bdev
,
3164 rdev
->data_offset
<< 9);
3165 if (blk_queue_discard(bdev_get_queue(rdev
->bdev
)))
3166 discard_supported
= true;
3169 mddev
->degraded
= 0;
3170 for (i
=0; i
< conf
->raid_disks
; i
++)
3171 if (conf
->mirrors
[i
].rdev
== NULL
||
3172 !test_bit(In_sync
, &conf
->mirrors
[i
].rdev
->flags
) ||
3173 test_bit(Faulty
, &conf
->mirrors
[i
].rdev
->flags
))
3176 if (conf
->raid_disks
- mddev
->degraded
== 1)
3177 mddev
->recovery_cp
= MaxSector
;
3179 if (mddev
->recovery_cp
!= MaxSector
)
3180 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3182 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3183 mdname(mddev
), mddev
->raid_disks
- mddev
->degraded
,
3187 * Ok, everything is just fine now
3189 mddev
->thread
= conf
->thread
;
3190 conf
->thread
= NULL
;
3191 mddev
->private = conf
;
3192 set_bit(MD_FAILFAST_SUPPORTED
, &mddev
->flags
);
3194 md_set_array_sectors(mddev
, raid1_size(mddev
, 0, 0));
3197 if (discard_supported
)
3198 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
,
3201 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD
,
3205 ret
= md_integrity_register(mddev
);
3207 md_unregister_thread(&mddev
->thread
);
3208 raid1_free(mddev
, conf
);
3213 static void raid1_free(struct mddev
*mddev
, void *priv
)
3215 struct r1conf
*conf
= priv
;
3217 mempool_destroy(conf
->r1bio_pool
);
3218 kfree(conf
->mirrors
);
3219 safe_put_page(conf
->tmppage
);
3220 kfree(conf
->poolinfo
);
3221 kfree(conf
->nr_pending
);
3222 kfree(conf
->nr_waiting
);
3223 kfree(conf
->nr_queued
);
3224 kfree(conf
->barrier
);
3228 static int raid1_resize(struct mddev
*mddev
, sector_t sectors
)
3230 /* no resync is happening, and there is enough space
3231 * on all devices, so we can resize.
3232 * We need to make sure resync covers any new space.
3233 * If the array is shrinking we should possibly wait until
3234 * any io in the removed space completes, but it hardly seems
3237 sector_t newsize
= raid1_size(mddev
, sectors
, 0);
3238 if (mddev
->external_size
&&
3239 mddev
->array_sectors
> newsize
)
3241 if (mddev
->bitmap
) {
3242 int ret
= bitmap_resize(mddev
->bitmap
, newsize
, 0, 0);
3246 md_set_array_sectors(mddev
, newsize
);
3247 if (sectors
> mddev
->dev_sectors
&&
3248 mddev
->recovery_cp
> mddev
->dev_sectors
) {
3249 mddev
->recovery_cp
= mddev
->dev_sectors
;
3250 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
3252 mddev
->dev_sectors
= sectors
;
3253 mddev
->resync_max_sectors
= sectors
;
3257 static int raid1_reshape(struct mddev
*mddev
)
3260 * 1/ resize the r1bio_pool
3261 * 2/ resize conf->mirrors
3263 * We allocate a new r1bio_pool if we can.
3264 * Then raise a device barrier and wait until all IO stops.
3265 * Then resize conf->mirrors and swap in the new r1bio pool.
3267 * At the same time, we "pack" the devices so that all the missing
3268 * devices have the higher raid_disk numbers.
3270 mempool_t
*newpool
, *oldpool
;
3271 struct pool_info
*newpoolinfo
;
3272 struct raid1_info
*newmirrors
;
3273 struct r1conf
*conf
= mddev
->private;
3274 int cnt
, raid_disks
;
3275 unsigned long flags
;
3278 /* Cannot change chunk_size, layout, or level */
3279 if (mddev
->chunk_sectors
!= mddev
->new_chunk_sectors
||
3280 mddev
->layout
!= mddev
->new_layout
||
3281 mddev
->level
!= mddev
->new_level
) {
3282 mddev
->new_chunk_sectors
= mddev
->chunk_sectors
;
3283 mddev
->new_layout
= mddev
->layout
;
3284 mddev
->new_level
= mddev
->level
;
3288 if (!mddev_is_clustered(mddev
)) {
3289 err
= md_allow_write(mddev
);
3294 raid_disks
= mddev
->raid_disks
+ mddev
->delta_disks
;
3296 if (raid_disks
< conf
->raid_disks
) {
3298 for (d
= 0; d
< conf
->raid_disks
; d
++)
3299 if (conf
->mirrors
[d
].rdev
)
3301 if (cnt
> raid_disks
)
3305 newpoolinfo
= kmalloc(sizeof(*newpoolinfo
), GFP_KERNEL
);
3308 newpoolinfo
->mddev
= mddev
;
3309 newpoolinfo
->raid_disks
= raid_disks
* 2;
3311 newpool
= mempool_create(NR_RAID1_BIOS
, r1bio_pool_alloc
,
3312 r1bio_pool_free
, newpoolinfo
);
3317 newmirrors
= kzalloc(sizeof(struct raid1_info
) * raid_disks
* 2,
3321 mempool_destroy(newpool
);
3325 freeze_array(conf
, 0);
3327 /* ok, everything is stopped */
3328 oldpool
= conf
->r1bio_pool
;
3329 conf
->r1bio_pool
= newpool
;
3331 for (d
= d2
= 0; d
< conf
->raid_disks
; d
++) {
3332 struct md_rdev
*rdev
= conf
->mirrors
[d
].rdev
;
3333 if (rdev
&& rdev
->raid_disk
!= d2
) {
3334 sysfs_unlink_rdev(mddev
, rdev
);
3335 rdev
->raid_disk
= d2
;
3336 sysfs_unlink_rdev(mddev
, rdev
);
3337 if (sysfs_link_rdev(mddev
, rdev
))
3338 pr_warn("md/raid1:%s: cannot register rd%d\n",
3339 mdname(mddev
), rdev
->raid_disk
);
3342 newmirrors
[d2
++].rdev
= rdev
;
3344 kfree(conf
->mirrors
);
3345 conf
->mirrors
= newmirrors
;
3346 kfree(conf
->poolinfo
);
3347 conf
->poolinfo
= newpoolinfo
;
3349 spin_lock_irqsave(&conf
->device_lock
, flags
);
3350 mddev
->degraded
+= (raid_disks
- conf
->raid_disks
);
3351 spin_unlock_irqrestore(&conf
->device_lock
, flags
);
3352 conf
->raid_disks
= mddev
->raid_disks
= raid_disks
;
3353 mddev
->delta_disks
= 0;
3355 unfreeze_array(conf
);
3357 set_bit(MD_RECOVERY_RECOVER
, &mddev
->recovery
);
3358 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
3359 md_wakeup_thread(mddev
->thread
);
3361 mempool_destroy(oldpool
);
3365 static void raid1_quiesce(struct mddev
*mddev
, int state
)
3367 struct r1conf
*conf
= mddev
->private;
3370 case 2: /* wake for suspend */
3371 wake_up(&conf
->wait_barrier
);
3374 freeze_array(conf
, 0);
3377 unfreeze_array(conf
);
3382 static void *raid1_takeover(struct mddev
*mddev
)
3384 /* raid1 can take over:
3385 * raid5 with 2 devices, any layout or chunk size
3387 if (mddev
->level
== 5 && mddev
->raid_disks
== 2) {
3388 struct r1conf
*conf
;
3389 mddev
->new_level
= 1;
3390 mddev
->new_layout
= 0;
3391 mddev
->new_chunk_sectors
= 0;
3392 conf
= setup_conf(mddev
);
3393 if (!IS_ERR(conf
)) {
3394 /* Array must appear to be quiesced */
3395 conf
->array_frozen
= 1;
3396 mddev_clear_unsupported_flags(mddev
,
3397 UNSUPPORTED_MDDEV_FLAGS
);
3401 return ERR_PTR(-EINVAL
);
3404 static struct md_personality raid1_personality
=
3408 .owner
= THIS_MODULE
,
3409 .make_request
= raid1_make_request
,
3412 .status
= raid1_status
,
3413 .error_handler
= raid1_error
,
3414 .hot_add_disk
= raid1_add_disk
,
3415 .hot_remove_disk
= raid1_remove_disk
,
3416 .spare_active
= raid1_spare_active
,
3417 .sync_request
= raid1_sync_request
,
3418 .resize
= raid1_resize
,
3420 .check_reshape
= raid1_reshape
,
3421 .quiesce
= raid1_quiesce
,
3422 .takeover
= raid1_takeover
,
3423 .congested
= raid1_congested
,
3426 static int __init
raid_init(void)
3428 return register_md_personality(&raid1_personality
);
3431 static void raid_exit(void)
3433 unregister_md_personality(&raid1_personality
);
3436 module_init(raid_init
);
3437 module_exit(raid_exit
);
3438 MODULE_LICENSE("GPL");
3439 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3440 MODULE_ALIAS("md-personality-3"); /* RAID1 */
3441 MODULE_ALIAS("md-raid1");
3442 MODULE_ALIAS("md-level-1");
3444 module_param(max_queued_requests
, int, S_IRUGO
|S_IWUSR
);