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 <trace/events/block.h>
45 #define UNSUPPORTED_MDDEV_FLAGS \
46 ((1L << MD_HAS_JOURNAL) | \
47 (1L << MD_JOURNAL_CLEAN))
50 * Number of guaranteed r1bios in case of extreme VM load:
52 #define NR_RAID1_BIOS 256
54 /* when we get a read error on a read-only array, we redirect to another
55 * device without failing the first device, or trying to over-write to
56 * correct the read error. To keep track of bad blocks on a per-bio
57 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
59 #define IO_BLOCKED ((struct bio *)1)
60 /* When we successfully write to a known bad-block, we need to remove the
61 * bad-block marking which must be done from process context. So we record
62 * the success by setting devs[n].bio to IO_MADE_GOOD
64 #define IO_MADE_GOOD ((struct bio *)2)
66 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
68 /* When there are this many requests queue to be written by
69 * the raid1 thread, we become 'congested' to provide back-pressure
72 static int max_queued_requests = 1024;
74 static void allow_barrier(struct r1conf *conf, sector_t start_next_window,
76 static void lower_barrier(struct r1conf *conf);
78 #define raid1_log(md, fmt, args...) \
79 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
81 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
83 struct pool_info *pi = data;
84 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
86 /* allocate a r1bio with room for raid_disks entries in the bios array */
87 return kzalloc(size, gfp_flags);
90 static void r1bio_pool_free(void *r1_bio, void *data)
95 #define RESYNC_BLOCK_SIZE (64*1024)
96 #define RESYNC_DEPTH 32
97 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
98 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
99 #define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
100 #define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
101 #define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
102 #define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
103 #define NEXT_NORMALIO_DISTANCE (3 * RESYNC_WINDOW_SECTORS)
105 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
107 struct pool_info *pi = data;
108 struct r1bio *r1_bio;
113 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
118 * Allocate bios : 1 for reading, n-1 for writing
120 for (j = pi->raid_disks ; j-- ; ) {
121 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
124 r1_bio->bios[j] = bio;
127 * Allocate RESYNC_PAGES data pages and attach them to
129 * If this is a user-requested check/repair, allocate
130 * RESYNC_PAGES for each bio.
132 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
133 need_pages = pi->raid_disks;
136 for (j = 0; j < need_pages; j++) {
137 bio = r1_bio->bios[j];
138 bio->bi_vcnt = RESYNC_PAGES;
140 if (bio_alloc_pages(bio, gfp_flags))
143 /* If not user-requests, copy the page pointers to all bios */
144 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
145 for (i=0; i<RESYNC_PAGES ; i++)
146 for (j=1; j<pi->raid_disks; j++)
147 r1_bio->bios[j]->bi_io_vec[i].bv_page =
148 r1_bio->bios[0]->bi_io_vec[i].bv_page;
151 r1_bio->master_bio = NULL;
157 bio_free_pages(r1_bio->bios[j]);
160 while (++j < pi->raid_disks)
161 bio_put(r1_bio->bios[j]);
162 r1bio_pool_free(r1_bio, data);
166 static void r1buf_pool_free(void *__r1_bio, void *data)
168 struct pool_info *pi = data;
170 struct r1bio *r1bio = __r1_bio;
172 for (i = 0; i < RESYNC_PAGES; i++)
173 for (j = pi->raid_disks; j-- ;) {
175 r1bio->bios[j]->bi_io_vec[i].bv_page !=
176 r1bio->bios[0]->bi_io_vec[i].bv_page)
177 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
179 for (i=0 ; i < pi->raid_disks; i++)
180 bio_put(r1bio->bios[i]);
182 r1bio_pool_free(r1bio, data);
185 static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
189 for (i = 0; i < conf->raid_disks * 2; i++) {
190 struct bio **bio = r1_bio->bios + i;
191 if (!BIO_SPECIAL(*bio))
197 static void free_r1bio(struct r1bio *r1_bio)
199 struct r1conf *conf = r1_bio->mddev->private;
201 put_all_bios(conf, r1_bio);
202 mempool_free(r1_bio, conf->r1bio_pool);
205 static void put_buf(struct r1bio *r1_bio)
207 struct r1conf *conf = r1_bio->mddev->private;
210 for (i = 0; i < conf->raid_disks * 2; i++) {
211 struct bio *bio = r1_bio->bios[i];
213 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
216 mempool_free(r1_bio, conf->r1buf_pool);
221 static void reschedule_retry(struct r1bio *r1_bio)
224 struct mddev *mddev = r1_bio->mddev;
225 struct r1conf *conf = mddev->private;
227 spin_lock_irqsave(&conf->device_lock, flags);
228 list_add(&r1_bio->retry_list, &conf->retry_list);
230 spin_unlock_irqrestore(&conf->device_lock, flags);
232 wake_up(&conf->wait_barrier);
233 md_wakeup_thread(mddev->thread);
237 * raid_end_bio_io() is called when we have finished servicing a mirrored
238 * operation and are ready to return a success/failure code to the buffer
241 static void call_bio_endio(struct r1bio *r1_bio)
243 struct bio *bio = r1_bio->master_bio;
245 struct r1conf *conf = r1_bio->mddev->private;
246 sector_t start_next_window = r1_bio->start_next_window;
247 sector_t bi_sector = bio->bi_iter.bi_sector;
249 if (bio->bi_phys_segments) {
251 spin_lock_irqsave(&conf->device_lock, flags);
252 bio->bi_phys_segments--;
253 done = (bio->bi_phys_segments == 0);
254 spin_unlock_irqrestore(&conf->device_lock, flags);
256 * make_request() might be waiting for
257 * bi_phys_segments to decrease
259 wake_up(&conf->wait_barrier);
263 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
264 bio->bi_error = -EIO;
269 * Wake up any possible resync thread that waits for the device
272 allow_barrier(conf, start_next_window, bi_sector);
276 static void raid_end_bio_io(struct r1bio *r1_bio)
278 struct bio *bio = r1_bio->master_bio;
280 /* if nobody has done the final endio yet, do it now */
281 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
282 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
283 (bio_data_dir(bio) == WRITE) ? "write" : "read",
284 (unsigned long long) bio->bi_iter.bi_sector,
285 (unsigned long long) bio_end_sector(bio) - 1);
287 call_bio_endio(r1_bio);
293 * Update disk head position estimator based on IRQ completion info.
295 static inline void update_head_pos(int disk, struct r1bio *r1_bio)
297 struct r1conf *conf = r1_bio->mddev->private;
299 conf->mirrors[disk].head_position =
300 r1_bio->sector + (r1_bio->sectors);
304 * Find the disk number which triggered given bio
306 static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
309 struct r1conf *conf = r1_bio->mddev->private;
310 int raid_disks = conf->raid_disks;
312 for (mirror = 0; mirror < raid_disks * 2; mirror++)
313 if (r1_bio->bios[mirror] == bio)
316 BUG_ON(mirror == raid_disks * 2);
317 update_head_pos(mirror, r1_bio);
322 static void raid1_end_read_request(struct bio *bio)
324 int uptodate = !bio->bi_error;
325 struct r1bio *r1_bio = bio->bi_private;
326 struct r1conf *conf = r1_bio->mddev->private;
327 struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
330 * this branch is our 'one mirror IO has finished' event handler:
332 update_head_pos(r1_bio->read_disk, r1_bio);
335 set_bit(R1BIO_Uptodate, &r1_bio->state);
336 else if (test_bit(FailFast, &rdev->flags) &&
337 test_bit(R1BIO_FailFast, &r1_bio->state))
338 /* This was a fail-fast read so we definitely
342 /* If all other devices have failed, we want to return
343 * the error upwards rather than fail the last device.
344 * Here we redefine "uptodate" to mean "Don't want to retry"
347 spin_lock_irqsave(&conf->device_lock, flags);
348 if (r1_bio->mddev->degraded == conf->raid_disks ||
349 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
350 test_bit(In_sync, &rdev->flags)))
352 spin_unlock_irqrestore(&conf->device_lock, flags);
356 raid_end_bio_io(r1_bio);
357 rdev_dec_pending(rdev, conf->mddev);
362 char b[BDEVNAME_SIZE];
363 pr_err_ratelimited("md/raid1:%s: %s: rescheduling sector %llu\n",
365 bdevname(rdev->bdev, b),
366 (unsigned long long)r1_bio->sector);
367 set_bit(R1BIO_ReadError, &r1_bio->state);
368 reschedule_retry(r1_bio);
369 /* don't drop the reference on read_disk yet */
373 static void close_write(struct r1bio *r1_bio)
375 /* it really is the end of this request */
376 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
377 /* free extra copy of the data pages */
378 int i = r1_bio->behind_page_count;
380 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
381 kfree(r1_bio->behind_bvecs);
382 r1_bio->behind_bvecs = NULL;
384 /* clear the bitmap if all writes complete successfully */
385 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
387 !test_bit(R1BIO_Degraded, &r1_bio->state),
388 test_bit(R1BIO_BehindIO, &r1_bio->state));
389 md_write_end(r1_bio->mddev);
392 static void r1_bio_write_done(struct r1bio *r1_bio)
394 if (!atomic_dec_and_test(&r1_bio->remaining))
397 if (test_bit(R1BIO_WriteError, &r1_bio->state))
398 reschedule_retry(r1_bio);
401 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
402 reschedule_retry(r1_bio);
404 raid_end_bio_io(r1_bio);
408 static void raid1_end_write_request(struct bio *bio)
410 struct r1bio *r1_bio = bio->bi_private;
411 int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
412 struct r1conf *conf = r1_bio->mddev->private;
413 struct bio *to_put = NULL;
414 int mirror = find_bio_disk(r1_bio, bio);
415 struct md_rdev *rdev = conf->mirrors[mirror].rdev;
418 discard_error = bio->bi_error && bio_op(bio) == REQ_OP_DISCARD;
421 * 'one mirror IO has finished' event handler:
423 if (bio->bi_error && !discard_error) {
424 set_bit(WriteErrorSeen, &rdev->flags);
425 if (!test_and_set_bit(WantReplacement, &rdev->flags))
426 set_bit(MD_RECOVERY_NEEDED, &
427 conf->mddev->recovery);
429 if (test_bit(FailFast, &rdev->flags) &&
430 (bio->bi_opf & MD_FAILFAST) &&
431 /* We never try FailFast to WriteMostly devices */
432 !test_bit(WriteMostly, &rdev->flags)) {
433 md_error(r1_bio->mddev, rdev);
434 if (!test_bit(Faulty, &rdev->flags))
435 /* This is the only remaining device,
436 * We need to retry the write without
439 set_bit(R1BIO_WriteError, &r1_bio->state);
441 /* Finished with this branch */
442 r1_bio->bios[mirror] = NULL;
446 set_bit(R1BIO_WriteError, &r1_bio->state);
449 * Set R1BIO_Uptodate in our master bio, so that we
450 * will return a good error code for to the higher
451 * levels even if IO on some other mirrored buffer
454 * The 'master' represents the composite IO operation
455 * to user-side. So if something waits for IO, then it
456 * will wait for the 'master' bio.
461 r1_bio->bios[mirror] = NULL;
464 * Do not set R1BIO_Uptodate if the current device is
465 * rebuilding or Faulty. This is because we cannot use
466 * such device for properly reading the data back (we could
467 * potentially use it, if the current write would have felt
468 * before rdev->recovery_offset, but for simplicity we don't
471 if (test_bit(In_sync, &rdev->flags) &&
472 !test_bit(Faulty, &rdev->flags))
473 set_bit(R1BIO_Uptodate, &r1_bio->state);
475 /* Maybe we can clear some bad blocks. */
476 if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
477 &first_bad, &bad_sectors) && !discard_error) {
478 r1_bio->bios[mirror] = IO_MADE_GOOD;
479 set_bit(R1BIO_MadeGood, &r1_bio->state);
484 if (test_bit(WriteMostly, &rdev->flags))
485 atomic_dec(&r1_bio->behind_remaining);
488 * In behind mode, we ACK the master bio once the I/O
489 * has safely reached all non-writemostly
490 * disks. Setting the Returned bit ensures that this
491 * gets done only once -- we don't ever want to return
492 * -EIO here, instead we'll wait
494 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
495 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
496 /* Maybe we can return now */
497 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
498 struct bio *mbio = r1_bio->master_bio;
499 pr_debug("raid1: behind end write sectors"
501 (unsigned long long) mbio->bi_iter.bi_sector,
502 (unsigned long long) bio_end_sector(mbio) - 1);
503 call_bio_endio(r1_bio);
507 if (r1_bio->bios[mirror] == NULL)
508 rdev_dec_pending(rdev, conf->mddev);
511 * Let's see if all mirrored write operations have finished
514 r1_bio_write_done(r1_bio);
521 * This routine returns the disk from which the requested read should
522 * be done. There is a per-array 'next expected sequential IO' sector
523 * number - if this matches on the next IO then we use the last disk.
524 * There is also a per-disk 'last know head position' sector that is
525 * maintained from IRQ contexts, both the normal and the resync IO
526 * completion handlers update this position correctly. If there is no
527 * perfect sequential match then we pick the disk whose head is closest.
529 * If there are 2 mirrors in the same 2 devices, performance degrades
530 * because position is mirror, not device based.
532 * The rdev for the device selected will have nr_pending incremented.
534 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
536 const sector_t this_sector = r1_bio->sector;
538 int best_good_sectors;
539 int best_disk, best_dist_disk, best_pending_disk;
543 unsigned int min_pending;
544 struct md_rdev *rdev;
546 int choose_next_idle;
550 * Check if we can balance. We can balance on the whole
551 * device if no resync is going on, or below the resync window.
552 * We take the first readable disk when above the resync window.
555 sectors = r1_bio->sectors;
558 best_dist = MaxSector;
559 best_pending_disk = -1;
560 min_pending = UINT_MAX;
561 best_good_sectors = 0;
563 choose_next_idle = 0;
564 clear_bit(R1BIO_FailFast, &r1_bio->state);
566 if ((conf->mddev->recovery_cp < this_sector + sectors) ||
567 (mddev_is_clustered(conf->mddev) &&
568 md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
569 this_sector + sectors)))
574 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
578 unsigned int pending;
581 rdev = rcu_dereference(conf->mirrors[disk].rdev);
582 if (r1_bio->bios[disk] == IO_BLOCKED
584 || test_bit(Faulty, &rdev->flags))
586 if (!test_bit(In_sync, &rdev->flags) &&
587 rdev->recovery_offset < this_sector + sectors)
589 if (test_bit(WriteMostly, &rdev->flags)) {
590 /* Don't balance among write-mostly, just
591 * use the first as a last resort */
592 if (best_dist_disk < 0) {
593 if (is_badblock(rdev, this_sector, sectors,
594 &first_bad, &bad_sectors)) {
595 if (first_bad <= this_sector)
596 /* Cannot use this */
598 best_good_sectors = first_bad - this_sector;
600 best_good_sectors = sectors;
601 best_dist_disk = disk;
602 best_pending_disk = disk;
606 /* This is a reasonable device to use. It might
609 if (is_badblock(rdev, this_sector, sectors,
610 &first_bad, &bad_sectors)) {
611 if (best_dist < MaxSector)
612 /* already have a better device */
614 if (first_bad <= this_sector) {
615 /* cannot read here. If this is the 'primary'
616 * device, then we must not read beyond
617 * bad_sectors from another device..
619 bad_sectors -= (this_sector - first_bad);
620 if (choose_first && sectors > bad_sectors)
621 sectors = bad_sectors;
622 if (best_good_sectors > sectors)
623 best_good_sectors = sectors;
626 sector_t good_sectors = first_bad - this_sector;
627 if (good_sectors > best_good_sectors) {
628 best_good_sectors = good_sectors;
636 best_good_sectors = sectors;
639 /* At least two disks to choose from so failfast is OK */
640 set_bit(R1BIO_FailFast, &r1_bio->state);
642 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
643 has_nonrot_disk |= nonrot;
644 pending = atomic_read(&rdev->nr_pending);
645 dist = abs(this_sector - conf->mirrors[disk].head_position);
650 /* Don't change to another disk for sequential reads */
651 if (conf->mirrors[disk].next_seq_sect == this_sector
653 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
654 struct raid1_info *mirror = &conf->mirrors[disk];
658 * If buffered sequential IO size exceeds optimal
659 * iosize, check if there is idle disk. If yes, choose
660 * the idle disk. read_balance could already choose an
661 * idle disk before noticing it's a sequential IO in
662 * this disk. This doesn't matter because this disk
663 * will idle, next time it will be utilized after the
664 * first disk has IO size exceeds optimal iosize. In
665 * this way, iosize of the first disk will be optimal
666 * iosize at least. iosize of the second disk might be
667 * small, but not a big deal since when the second disk
668 * starts IO, the first disk is likely still busy.
670 if (nonrot && opt_iosize > 0 &&
671 mirror->seq_start != MaxSector &&
672 mirror->next_seq_sect > opt_iosize &&
673 mirror->next_seq_sect - opt_iosize >=
675 choose_next_idle = 1;
681 if (choose_next_idle)
684 if (min_pending > pending) {
685 min_pending = pending;
686 best_pending_disk = disk;
689 if (dist < best_dist) {
691 best_dist_disk = disk;
696 * If all disks are rotational, choose the closest disk. If any disk is
697 * non-rotational, choose the disk with less pending request even the
698 * disk is rotational, which might/might not be optimal for raids with
699 * mixed ratation/non-rotational disks depending on workload.
701 if (best_disk == -1) {
702 if (has_nonrot_disk || min_pending == 0)
703 best_disk = best_pending_disk;
705 best_disk = best_dist_disk;
708 if (best_disk >= 0) {
709 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
712 atomic_inc(&rdev->nr_pending);
713 sectors = best_good_sectors;
715 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
716 conf->mirrors[best_disk].seq_start = this_sector;
718 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
721 *max_sectors = sectors;
726 static int raid1_congested(struct mddev *mddev, int bits)
728 struct r1conf *conf = mddev->private;
731 if ((bits & (1 << WB_async_congested)) &&
732 conf->pending_count >= max_queued_requests)
736 for (i = 0; i < conf->raid_disks * 2; i++) {
737 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
738 if (rdev && !test_bit(Faulty, &rdev->flags)) {
739 struct request_queue *q = bdev_get_queue(rdev->bdev);
743 /* Note the '|| 1' - when read_balance prefers
744 * non-congested targets, it can be removed
746 if ((bits & (1 << WB_async_congested)) || 1)
747 ret |= bdi_congested(q->backing_dev_info, bits);
749 ret &= bdi_congested(q->backing_dev_info, bits);
756 static void flush_pending_writes(struct r1conf *conf)
758 /* Any writes that have been queued but are awaiting
759 * bitmap updates get flushed here.
761 spin_lock_irq(&conf->device_lock);
763 if (conf->pending_bio_list.head) {
765 bio = bio_list_get(&conf->pending_bio_list);
766 conf->pending_count = 0;
767 spin_unlock_irq(&conf->device_lock);
768 /* flush any pending bitmap writes to
769 * disk before proceeding w/ I/O */
770 bitmap_unplug(conf->mddev->bitmap);
771 wake_up(&conf->wait_barrier);
773 while (bio) { /* submit pending writes */
774 struct bio *next = bio->bi_next;
775 struct md_rdev *rdev = (void*)bio->bi_bdev;
777 bio->bi_bdev = rdev->bdev;
778 if (test_bit(Faulty, &rdev->flags)) {
779 bio->bi_error = -EIO;
781 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
782 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
786 generic_make_request(bio);
790 spin_unlock_irq(&conf->device_lock);
794 * Sometimes we need to suspend IO while we do something else,
795 * either some resync/recovery, or reconfigure the array.
796 * To do this we raise a 'barrier'.
797 * The 'barrier' is a counter that can be raised multiple times
798 * to count how many activities are happening which preclude
800 * We can only raise the barrier if there is no pending IO.
801 * i.e. if nr_pending == 0.
802 * We choose only to raise the barrier if no-one is waiting for the
803 * barrier to go down. This means that as soon as an IO request
804 * is ready, no other operations which require a barrier will start
805 * until the IO request has had a chance.
807 * So: regular IO calls 'wait_barrier'. When that returns there
808 * is no backgroup IO happening, It must arrange to call
809 * allow_barrier when it has finished its IO.
810 * backgroup IO calls must call raise_barrier. Once that returns
811 * there is no normal IO happeing. It must arrange to call
812 * lower_barrier when the particular background IO completes.
814 static void raise_barrier(struct r1conf *conf, sector_t sector_nr)
816 spin_lock_irq(&conf->resync_lock);
818 /* Wait until no block IO is waiting */
819 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
822 /* block any new IO from starting */
824 conf->next_resync = sector_nr;
826 /* For these conditions we must wait:
827 * A: while the array is in frozen state
828 * B: while barrier >= RESYNC_DEPTH, meaning resync reach
829 * the max count which allowed.
830 * C: next_resync + RESYNC_SECTORS > start_next_window, meaning
831 * next resync will reach to the window which normal bios are
833 * D: while there are any active requests in the current window.
835 wait_event_lock_irq(conf->wait_barrier,
836 !conf->array_frozen &&
837 conf->barrier < RESYNC_DEPTH &&
838 conf->current_window_requests == 0 &&
839 (conf->start_next_window >=
840 conf->next_resync + RESYNC_SECTORS),
844 spin_unlock_irq(&conf->resync_lock);
847 static void lower_barrier(struct r1conf *conf)
850 BUG_ON(conf->barrier <= 0);
851 spin_lock_irqsave(&conf->resync_lock, flags);
854 spin_unlock_irqrestore(&conf->resync_lock, flags);
855 wake_up(&conf->wait_barrier);
858 static bool need_to_wait_for_sync(struct r1conf *conf, struct bio *bio)
862 if (conf->array_frozen || !bio)
864 else if (conf->barrier && bio_data_dir(bio) == WRITE) {
865 if ((conf->mddev->curr_resync_completed
866 >= bio_end_sector(bio)) ||
867 (conf->start_next_window + NEXT_NORMALIO_DISTANCE
868 <= bio->bi_iter.bi_sector))
877 static sector_t wait_barrier(struct r1conf *conf, struct bio *bio)
881 spin_lock_irq(&conf->resync_lock);
882 if (need_to_wait_for_sync(conf, bio)) {
884 /* Wait for the barrier to drop.
885 * However if there are already pending
886 * requests (preventing the barrier from
887 * rising completely), and the
888 * per-process bio queue isn't empty,
889 * then don't wait, as we need to empty
890 * that queue to allow conf->start_next_window
893 raid1_log(conf->mddev, "wait barrier");
894 wait_event_lock_irq(conf->wait_barrier,
895 !conf->array_frozen &&
897 ((conf->start_next_window <
898 conf->next_resync + RESYNC_SECTORS) &&
900 !bio_list_empty(current->bio_list))),
905 if (bio && bio_data_dir(bio) == WRITE) {
906 if (bio->bi_iter.bi_sector >= conf->next_resync) {
907 if (conf->start_next_window == MaxSector)
908 conf->start_next_window =
910 NEXT_NORMALIO_DISTANCE;
912 if ((conf->start_next_window + NEXT_NORMALIO_DISTANCE)
913 <= bio->bi_iter.bi_sector)
914 conf->next_window_requests++;
916 conf->current_window_requests++;
917 sector = conf->start_next_window;
922 spin_unlock_irq(&conf->resync_lock);
926 static void allow_barrier(struct r1conf *conf, sector_t start_next_window,
931 spin_lock_irqsave(&conf->resync_lock, flags);
933 if (start_next_window) {
934 if (start_next_window == conf->start_next_window) {
935 if (conf->start_next_window + NEXT_NORMALIO_DISTANCE
937 conf->next_window_requests--;
939 conf->current_window_requests--;
941 conf->current_window_requests--;
943 if (!conf->current_window_requests) {
944 if (conf->next_window_requests) {
945 conf->current_window_requests =
946 conf->next_window_requests;
947 conf->next_window_requests = 0;
948 conf->start_next_window +=
949 NEXT_NORMALIO_DISTANCE;
951 conf->start_next_window = MaxSector;
954 spin_unlock_irqrestore(&conf->resync_lock, flags);
955 wake_up(&conf->wait_barrier);
958 static void freeze_array(struct r1conf *conf, int extra)
960 /* stop syncio and normal IO and wait for everything to
962 * We wait until nr_pending match nr_queued+extra
963 * This is called in the context of one normal IO request
964 * that has failed. Thus any sync request that might be pending
965 * will be blocked by nr_pending, and we need to wait for
966 * pending IO requests to complete or be queued for re-try.
967 * Thus the number queued (nr_queued) plus this request (extra)
968 * must match the number of pending IOs (nr_pending) before
971 spin_lock_irq(&conf->resync_lock);
972 conf->array_frozen = 1;
973 raid1_log(conf->mddev, "wait freeze");
974 wait_event_lock_irq_cmd(conf->wait_barrier,
975 conf->nr_pending == conf->nr_queued+extra,
977 flush_pending_writes(conf));
978 spin_unlock_irq(&conf->resync_lock);
980 static void unfreeze_array(struct r1conf *conf)
982 /* reverse the effect of the freeze */
983 spin_lock_irq(&conf->resync_lock);
984 conf->array_frozen = 0;
985 wake_up(&conf->wait_barrier);
986 spin_unlock_irq(&conf->resync_lock);
989 /* duplicate the data pages for behind I/O
991 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
994 struct bio_vec *bvec;
995 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
997 if (unlikely(!bvecs))
1000 bio_for_each_segment_all(bvec, bio, i) {
1002 bvecs[i].bv_page = alloc_page(GFP_NOIO);
1003 if (unlikely(!bvecs[i].bv_page))
1005 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
1006 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
1007 kunmap(bvecs[i].bv_page);
1008 kunmap(bvec->bv_page);
1010 r1_bio->behind_bvecs = bvecs;
1011 r1_bio->behind_page_count = bio->bi_vcnt;
1012 set_bit(R1BIO_BehindIO, &r1_bio->state);
1016 for (i = 0; i < bio->bi_vcnt; i++)
1017 if (bvecs[i].bv_page)
1018 put_page(bvecs[i].bv_page);
1020 pr_debug("%dB behind alloc failed, doing sync I/O\n",
1021 bio->bi_iter.bi_size);
1024 struct raid1_plug_cb {
1025 struct blk_plug_cb cb;
1026 struct bio_list pending;
1030 static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
1032 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
1034 struct mddev *mddev = plug->cb.data;
1035 struct r1conf *conf = mddev->private;
1038 if (from_schedule || current->bio_list) {
1039 spin_lock_irq(&conf->device_lock);
1040 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1041 conf->pending_count += plug->pending_cnt;
1042 spin_unlock_irq(&conf->device_lock);
1043 wake_up(&conf->wait_barrier);
1044 md_wakeup_thread(mddev->thread);
1049 /* we aren't scheduling, so we can do the write-out directly. */
1050 bio = bio_list_get(&plug->pending);
1051 bitmap_unplug(mddev->bitmap);
1052 wake_up(&conf->wait_barrier);
1054 while (bio) { /* submit pending writes */
1055 struct bio *next = bio->bi_next;
1056 struct md_rdev *rdev = (void*)bio->bi_bdev;
1057 bio->bi_next = NULL;
1058 bio->bi_bdev = rdev->bdev;
1059 if (test_bit(Faulty, &rdev->flags)) {
1060 bio->bi_error = -EIO;
1062 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
1063 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
1064 /* Just ignore it */
1067 generic_make_request(bio);
1073 static void raid1_read_request(struct mddev *mddev, struct bio *bio,
1074 struct r1bio *r1_bio)
1076 struct r1conf *conf = mddev->private;
1077 struct raid1_info *mirror;
1078 struct bio *read_bio;
1079 struct bitmap *bitmap = mddev->bitmap;
1080 const int op = bio_op(bio);
1081 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
1082 int sectors_handled;
1086 wait_barrier(conf, bio);
1089 rdisk = read_balance(conf, r1_bio, &max_sectors);
1092 /* couldn't find anywhere to read from */
1093 raid_end_bio_io(r1_bio);
1096 mirror = conf->mirrors + rdisk;
1098 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1101 * Reading from a write-mostly device must take care not to
1102 * over-take any writes that are 'behind'
1104 raid1_log(mddev, "wait behind writes");
1105 wait_event(bitmap->behind_wait,
1106 atomic_read(&bitmap->behind_writes) == 0);
1108 r1_bio->read_disk = rdisk;
1109 r1_bio->start_next_window = 0;
1111 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1112 bio_trim(read_bio, r1_bio->sector - bio->bi_iter.bi_sector,
1115 r1_bio->bios[rdisk] = read_bio;
1117 read_bio->bi_iter.bi_sector = r1_bio->sector +
1118 mirror->rdev->data_offset;
1119 read_bio->bi_bdev = mirror->rdev->bdev;
1120 read_bio->bi_end_io = raid1_end_read_request;
1121 bio_set_op_attrs(read_bio, op, do_sync);
1122 if (test_bit(FailFast, &mirror->rdev->flags) &&
1123 test_bit(R1BIO_FailFast, &r1_bio->state))
1124 read_bio->bi_opf |= MD_FAILFAST;
1125 read_bio->bi_private = r1_bio;
1128 trace_block_bio_remap(bdev_get_queue(read_bio->bi_bdev),
1129 read_bio, disk_devt(mddev->gendisk),
1132 if (max_sectors < r1_bio->sectors) {
1134 * could not read all from this device, so we will need another
1137 sectors_handled = (r1_bio->sector + max_sectors
1138 - bio->bi_iter.bi_sector);
1139 r1_bio->sectors = max_sectors;
1140 spin_lock_irq(&conf->device_lock);
1141 if (bio->bi_phys_segments == 0)
1142 bio->bi_phys_segments = 2;
1144 bio->bi_phys_segments++;
1145 spin_unlock_irq(&conf->device_lock);
1148 * Cannot call generic_make_request directly as that will be
1149 * queued in __make_request and subsequent mempool_alloc might
1150 * block waiting for it. So hand bio over to raid1d.
1152 reschedule_retry(r1_bio);
1154 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1156 r1_bio->master_bio = bio;
1157 r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1159 r1_bio->mddev = mddev;
1160 r1_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
1163 generic_make_request(read_bio);
1166 static void raid1_write_request(struct mddev *mddev, struct bio *bio,
1167 struct r1bio *r1_bio)
1169 struct r1conf *conf = mddev->private;
1171 struct bitmap *bitmap = mddev->bitmap;
1172 unsigned long flags;
1173 struct md_rdev *blocked_rdev;
1174 struct blk_plug_cb *cb;
1175 struct raid1_plug_cb *plug = NULL;
1177 int sectors_handled;
1179 sector_t start_next_window;
1182 * Register the new request and wait if the reconstruction
1183 * thread has put up a bar for new requests.
1184 * Continue immediately if no resync is active currently.
1187 md_write_start(mddev, bio); /* wait on superblock update early */
1189 if ((bio_end_sector(bio) > mddev->suspend_lo &&
1190 bio->bi_iter.bi_sector < mddev->suspend_hi) ||
1191 (mddev_is_clustered(mddev) &&
1192 md_cluster_ops->area_resyncing(mddev, WRITE,
1193 bio->bi_iter.bi_sector, bio_end_sector(bio)))) {
1196 * As the suspend_* range is controlled by userspace, we want
1197 * an interruptible wait.
1201 flush_signals(current);
1202 prepare_to_wait(&conf->wait_barrier,
1203 &w, TASK_INTERRUPTIBLE);
1204 if (bio_end_sector(bio) <= mddev->suspend_lo ||
1205 bio->bi_iter.bi_sector >= mddev->suspend_hi ||
1206 (mddev_is_clustered(mddev) &&
1207 !md_cluster_ops->area_resyncing(mddev, WRITE,
1208 bio->bi_iter.bi_sector,
1209 bio_end_sector(bio))))
1213 finish_wait(&conf->wait_barrier, &w);
1215 start_next_window = wait_barrier(conf, bio);
1217 if (conf->pending_count >= max_queued_requests) {
1218 md_wakeup_thread(mddev->thread);
1219 raid1_log(mddev, "wait queued");
1220 wait_event(conf->wait_barrier,
1221 conf->pending_count < max_queued_requests);
1223 /* first select target devices under rcu_lock and
1224 * inc refcount on their rdev. Record them by setting
1226 * If there are known/acknowledged bad blocks on any device on
1227 * which we have seen a write error, we want to avoid writing those
1229 * This potentially requires several writes to write around
1230 * the bad blocks. Each set of writes gets it's own r1bio
1231 * with a set of bios attached.
1234 disks = conf->raid_disks * 2;
1236 r1_bio->start_next_window = start_next_window;
1237 blocked_rdev = NULL;
1239 max_sectors = r1_bio->sectors;
1240 for (i = 0; i < disks; i++) {
1241 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1242 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1243 atomic_inc(&rdev->nr_pending);
1244 blocked_rdev = rdev;
1247 r1_bio->bios[i] = NULL;
1248 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1249 if (i < conf->raid_disks)
1250 set_bit(R1BIO_Degraded, &r1_bio->state);
1254 atomic_inc(&rdev->nr_pending);
1255 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1260 is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
1261 &first_bad, &bad_sectors);
1263 /* mustn't write here until the bad block is
1265 set_bit(BlockedBadBlocks, &rdev->flags);
1266 blocked_rdev = rdev;
1269 if (is_bad && first_bad <= r1_bio->sector) {
1270 /* Cannot write here at all */
1271 bad_sectors -= (r1_bio->sector - first_bad);
1272 if (bad_sectors < max_sectors)
1273 /* mustn't write more than bad_sectors
1274 * to other devices yet
1276 max_sectors = bad_sectors;
1277 rdev_dec_pending(rdev, mddev);
1278 /* We don't set R1BIO_Degraded as that
1279 * only applies if the disk is
1280 * missing, so it might be re-added,
1281 * and we want to know to recover this
1283 * In this case the device is here,
1284 * and the fact that this chunk is not
1285 * in-sync is recorded in the bad
1291 int good_sectors = first_bad - r1_bio->sector;
1292 if (good_sectors < max_sectors)
1293 max_sectors = good_sectors;
1296 r1_bio->bios[i] = bio;
1300 if (unlikely(blocked_rdev)) {
1301 /* Wait for this device to become unblocked */
1303 sector_t old = start_next_window;
1305 for (j = 0; j < i; j++)
1306 if (r1_bio->bios[j])
1307 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1309 allow_barrier(conf, start_next_window, bio->bi_iter.bi_sector);
1310 raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
1311 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1312 start_next_window = wait_barrier(conf, bio);
1314 * We must make sure the multi r1bios of bio have
1315 * the same value of bi_phys_segments
1317 if (bio->bi_phys_segments && old &&
1318 old != start_next_window)
1319 /* Wait for the former r1bio(s) to complete */
1320 wait_event(conf->wait_barrier,
1321 bio->bi_phys_segments == 1);
1325 if (max_sectors < r1_bio->sectors) {
1326 /* We are splitting this write into multiple parts, so
1327 * we need to prepare for allocating another r1_bio.
1329 r1_bio->sectors = max_sectors;
1330 spin_lock_irq(&conf->device_lock);
1331 if (bio->bi_phys_segments == 0)
1332 bio->bi_phys_segments = 2;
1334 bio->bi_phys_segments++;
1335 spin_unlock_irq(&conf->device_lock);
1337 sectors_handled = r1_bio->sector + max_sectors - bio->bi_iter.bi_sector;
1339 atomic_set(&r1_bio->remaining, 1);
1340 atomic_set(&r1_bio->behind_remaining, 0);
1343 for (i = 0; i < disks; i++) {
1345 if (!r1_bio->bios[i])
1348 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1349 bio_trim(mbio, r1_bio->sector - bio->bi_iter.bi_sector,
1354 * Not if there are too many, or cannot
1355 * allocate memory, or a reader on WriteMostly
1356 * is waiting for behind writes to flush */
1358 (atomic_read(&bitmap->behind_writes)
1359 < mddev->bitmap_info.max_write_behind) &&
1360 !waitqueue_active(&bitmap->behind_wait))
1361 alloc_behind_pages(mbio, r1_bio);
1363 bitmap_startwrite(bitmap, r1_bio->sector,
1365 test_bit(R1BIO_BehindIO,
1369 if (r1_bio->behind_bvecs) {
1370 struct bio_vec *bvec;
1374 * We trimmed the bio, so _all is legit
1376 bio_for_each_segment_all(bvec, mbio, j)
1377 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1378 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1379 atomic_inc(&r1_bio->behind_remaining);
1382 r1_bio->bios[i] = mbio;
1384 mbio->bi_iter.bi_sector = (r1_bio->sector +
1385 conf->mirrors[i].rdev->data_offset);
1386 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1387 mbio->bi_end_io = raid1_end_write_request;
1388 mbio->bi_opf = bio_op(bio) |
1389 (bio->bi_opf & (REQ_SYNC | REQ_PREFLUSH | REQ_FUA));
1390 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags) &&
1391 !test_bit(WriteMostly, &conf->mirrors[i].rdev->flags) &&
1392 conf->raid_disks - mddev->degraded > 1)
1393 mbio->bi_opf |= MD_FAILFAST;
1394 mbio->bi_private = r1_bio;
1396 atomic_inc(&r1_bio->remaining);
1399 trace_block_bio_remap(bdev_get_queue(mbio->bi_bdev),
1400 mbio, disk_devt(mddev->gendisk),
1402 /* flush_pending_writes() needs access to the rdev so...*/
1403 mbio->bi_bdev = (void*)conf->mirrors[i].rdev;
1405 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1407 plug = container_of(cb, struct raid1_plug_cb, cb);
1410 spin_lock_irqsave(&conf->device_lock, flags);
1412 bio_list_add(&plug->pending, mbio);
1413 plug->pending_cnt++;
1415 bio_list_add(&conf->pending_bio_list, mbio);
1416 conf->pending_count++;
1418 spin_unlock_irqrestore(&conf->device_lock, flags);
1420 md_wakeup_thread(mddev->thread);
1422 /* Mustn't call r1_bio_write_done before this next test,
1423 * as it could result in the bio being freed.
1425 if (sectors_handled < bio_sectors(bio)) {
1426 r1_bio_write_done(r1_bio);
1427 /* We need another r1_bio. It has already been counted
1428 * in bio->bi_phys_segments
1430 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1431 r1_bio->master_bio = bio;
1432 r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1434 r1_bio->mddev = mddev;
1435 r1_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
1439 r1_bio_write_done(r1_bio);
1441 /* In case raid1d snuck in to freeze_array */
1442 wake_up(&conf->wait_barrier);
1445 static void raid1_make_request(struct mddev *mddev, struct bio *bio)
1447 struct r1conf *conf = mddev->private;
1448 struct r1bio *r1_bio;
1451 * make_request() can abort the operation when read-ahead is being
1452 * used and no empty request is available.
1455 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1457 r1_bio->master_bio = bio;
1458 r1_bio->sectors = bio_sectors(bio);
1460 r1_bio->mddev = mddev;
1461 r1_bio->sector = bio->bi_iter.bi_sector;
1464 * We might need to issue multiple reads to different devices if there
1465 * are bad blocks around, so we keep track of the number of reads in
1466 * bio->bi_phys_segments. If this is 0, there is only one r1_bio and
1467 * no locking will be needed when requests complete. If it is
1468 * non-zero, then it is the number of not-completed requests.
1470 bio->bi_phys_segments = 0;
1471 bio_clear_flag(bio, BIO_SEG_VALID);
1473 if (bio_data_dir(bio) == READ)
1474 raid1_read_request(mddev, bio, r1_bio);
1476 raid1_write_request(mddev, bio, r1_bio);
1479 static void raid1_status(struct seq_file *seq, struct mddev *mddev)
1481 struct r1conf *conf = mddev->private;
1484 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1485 conf->raid_disks - mddev->degraded);
1487 for (i = 0; i < conf->raid_disks; i++) {
1488 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1489 seq_printf(seq, "%s",
1490 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1493 seq_printf(seq, "]");
1496 static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
1498 char b[BDEVNAME_SIZE];
1499 struct r1conf *conf = mddev->private;
1500 unsigned long flags;
1503 * If it is not operational, then we have already marked it as dead
1504 * else if it is the last working disks, ignore the error, let the
1505 * next level up know.
1506 * else mark the drive as failed
1508 spin_lock_irqsave(&conf->device_lock, flags);
1509 if (test_bit(In_sync, &rdev->flags)
1510 && (conf->raid_disks - mddev->degraded) == 1) {
1512 * Don't fail the drive, act as though we were just a
1513 * normal single drive.
1514 * However don't try a recovery from this drive as
1515 * it is very likely to fail.
1517 conf->recovery_disabled = mddev->recovery_disabled;
1518 spin_unlock_irqrestore(&conf->device_lock, flags);
1521 set_bit(Blocked, &rdev->flags);
1522 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1524 set_bit(Faulty, &rdev->flags);
1526 set_bit(Faulty, &rdev->flags);
1527 spin_unlock_irqrestore(&conf->device_lock, flags);
1529 * if recovery is running, make sure it aborts.
1531 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1532 set_mask_bits(&mddev->sb_flags, 0,
1533 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1534 pr_crit("md/raid1:%s: Disk failure on %s, disabling device.\n"
1535 "md/raid1:%s: Operation continuing on %d devices.\n",
1536 mdname(mddev), bdevname(rdev->bdev, b),
1537 mdname(mddev), conf->raid_disks - mddev->degraded);
1540 static void print_conf(struct r1conf *conf)
1544 pr_debug("RAID1 conf printout:\n");
1546 pr_debug("(!conf)\n");
1549 pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1553 for (i = 0; i < conf->raid_disks; i++) {
1554 char b[BDEVNAME_SIZE];
1555 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1557 pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
1558 i, !test_bit(In_sync, &rdev->flags),
1559 !test_bit(Faulty, &rdev->flags),
1560 bdevname(rdev->bdev,b));
1565 static void close_sync(struct r1conf *conf)
1567 wait_barrier(conf, NULL);
1568 allow_barrier(conf, 0, 0);
1570 mempool_destroy(conf->r1buf_pool);
1571 conf->r1buf_pool = NULL;
1573 spin_lock_irq(&conf->resync_lock);
1574 conf->next_resync = MaxSector - 2 * NEXT_NORMALIO_DISTANCE;
1575 conf->start_next_window = MaxSector;
1576 conf->current_window_requests +=
1577 conf->next_window_requests;
1578 conf->next_window_requests = 0;
1579 spin_unlock_irq(&conf->resync_lock);
1582 static int raid1_spare_active(struct mddev *mddev)
1585 struct r1conf *conf = mddev->private;
1587 unsigned long flags;
1590 * Find all failed disks within the RAID1 configuration
1591 * and mark them readable.
1592 * Called under mddev lock, so rcu protection not needed.
1593 * device_lock used to avoid races with raid1_end_read_request
1594 * which expects 'In_sync' flags and ->degraded to be consistent.
1596 spin_lock_irqsave(&conf->device_lock, flags);
1597 for (i = 0; i < conf->raid_disks; i++) {
1598 struct md_rdev *rdev = conf->mirrors[i].rdev;
1599 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1601 && !test_bit(Candidate, &repl->flags)
1602 && repl->recovery_offset == MaxSector
1603 && !test_bit(Faulty, &repl->flags)
1604 && !test_and_set_bit(In_sync, &repl->flags)) {
1605 /* replacement has just become active */
1607 !test_and_clear_bit(In_sync, &rdev->flags))
1610 /* Replaced device not technically
1611 * faulty, but we need to be sure
1612 * it gets removed and never re-added
1614 set_bit(Faulty, &rdev->flags);
1615 sysfs_notify_dirent_safe(
1620 && rdev->recovery_offset == MaxSector
1621 && !test_bit(Faulty, &rdev->flags)
1622 && !test_and_set_bit(In_sync, &rdev->flags)) {
1624 sysfs_notify_dirent_safe(rdev->sysfs_state);
1627 mddev->degraded -= count;
1628 spin_unlock_irqrestore(&conf->device_lock, flags);
1634 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1636 struct r1conf *conf = mddev->private;
1639 struct raid1_info *p;
1641 int last = conf->raid_disks - 1;
1643 if (mddev->recovery_disabled == conf->recovery_disabled)
1646 if (md_integrity_add_rdev(rdev, mddev))
1649 if (rdev->raid_disk >= 0)
1650 first = last = rdev->raid_disk;
1653 * find the disk ... but prefer rdev->saved_raid_disk
1656 if (rdev->saved_raid_disk >= 0 &&
1657 rdev->saved_raid_disk >= first &&
1658 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1659 first = last = rdev->saved_raid_disk;
1661 for (mirror = first; mirror <= last; mirror++) {
1662 p = conf->mirrors+mirror;
1666 disk_stack_limits(mddev->gendisk, rdev->bdev,
1667 rdev->data_offset << 9);
1669 p->head_position = 0;
1670 rdev->raid_disk = mirror;
1672 /* As all devices are equivalent, we don't need a full recovery
1673 * if this was recently any drive of the array
1675 if (rdev->saved_raid_disk < 0)
1677 rcu_assign_pointer(p->rdev, rdev);
1680 if (test_bit(WantReplacement, &p->rdev->flags) &&
1681 p[conf->raid_disks].rdev == NULL) {
1682 /* Add this device as a replacement */
1683 clear_bit(In_sync, &rdev->flags);
1684 set_bit(Replacement, &rdev->flags);
1685 rdev->raid_disk = mirror;
1688 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1692 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
1693 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
1698 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1700 struct r1conf *conf = mddev->private;
1702 int number = rdev->raid_disk;
1703 struct raid1_info *p = conf->mirrors + number;
1705 if (rdev != p->rdev)
1706 p = conf->mirrors + conf->raid_disks + number;
1709 if (rdev == p->rdev) {
1710 if (test_bit(In_sync, &rdev->flags) ||
1711 atomic_read(&rdev->nr_pending)) {
1715 /* Only remove non-faulty devices if recovery
1718 if (!test_bit(Faulty, &rdev->flags) &&
1719 mddev->recovery_disabled != conf->recovery_disabled &&
1720 mddev->degraded < conf->raid_disks) {
1725 if (!test_bit(RemoveSynchronized, &rdev->flags)) {
1727 if (atomic_read(&rdev->nr_pending)) {
1728 /* lost the race, try later */
1734 if (conf->mirrors[conf->raid_disks + number].rdev) {
1735 /* We just removed a device that is being replaced.
1736 * Move down the replacement. We drain all IO before
1737 * doing this to avoid confusion.
1739 struct md_rdev *repl =
1740 conf->mirrors[conf->raid_disks + number].rdev;
1741 freeze_array(conf, 0);
1742 clear_bit(Replacement, &repl->flags);
1744 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1745 unfreeze_array(conf);
1746 clear_bit(WantReplacement, &rdev->flags);
1748 clear_bit(WantReplacement, &rdev->flags);
1749 err = md_integrity_register(mddev);
1757 static void end_sync_read(struct bio *bio)
1759 struct r1bio *r1_bio = bio->bi_private;
1761 update_head_pos(r1_bio->read_disk, r1_bio);
1764 * we have read a block, now it needs to be re-written,
1765 * or re-read if the read failed.
1766 * We don't do much here, just schedule handling by raid1d
1769 set_bit(R1BIO_Uptodate, &r1_bio->state);
1771 if (atomic_dec_and_test(&r1_bio->remaining))
1772 reschedule_retry(r1_bio);
1775 static void end_sync_write(struct bio *bio)
1777 int uptodate = !bio->bi_error;
1778 struct r1bio *r1_bio = bio->bi_private;
1779 struct mddev *mddev = r1_bio->mddev;
1780 struct r1conf *conf = mddev->private;
1783 struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
1786 sector_t sync_blocks = 0;
1787 sector_t s = r1_bio->sector;
1788 long sectors_to_go = r1_bio->sectors;
1789 /* make sure these bits doesn't get cleared. */
1791 bitmap_end_sync(mddev->bitmap, s,
1794 sectors_to_go -= sync_blocks;
1795 } while (sectors_to_go > 0);
1796 set_bit(WriteErrorSeen, &rdev->flags);
1797 if (!test_and_set_bit(WantReplacement, &rdev->flags))
1798 set_bit(MD_RECOVERY_NEEDED, &
1800 set_bit(R1BIO_WriteError, &r1_bio->state);
1801 } else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
1802 &first_bad, &bad_sectors) &&
1803 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1806 &first_bad, &bad_sectors)
1808 set_bit(R1BIO_MadeGood, &r1_bio->state);
1810 if (atomic_dec_and_test(&r1_bio->remaining)) {
1811 int s = r1_bio->sectors;
1812 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1813 test_bit(R1BIO_WriteError, &r1_bio->state))
1814 reschedule_retry(r1_bio);
1817 md_done_sync(mddev, s, uptodate);
1822 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1823 int sectors, struct page *page, int rw)
1825 if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
1829 set_bit(WriteErrorSeen, &rdev->flags);
1830 if (!test_and_set_bit(WantReplacement,
1832 set_bit(MD_RECOVERY_NEEDED, &
1833 rdev->mddev->recovery);
1835 /* need to record an error - either for the block or the device */
1836 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1837 md_error(rdev->mddev, rdev);
1841 static int fix_sync_read_error(struct r1bio *r1_bio)
1843 /* Try some synchronous reads of other devices to get
1844 * good data, much like with normal read errors. Only
1845 * read into the pages we already have so we don't
1846 * need to re-issue the read request.
1847 * We don't need to freeze the array, because being in an
1848 * active sync request, there is no normal IO, and
1849 * no overlapping syncs.
1850 * We don't need to check is_badblock() again as we
1851 * made sure that anything with a bad block in range
1852 * will have bi_end_io clear.
1854 struct mddev *mddev = r1_bio->mddev;
1855 struct r1conf *conf = mddev->private;
1856 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1857 sector_t sect = r1_bio->sector;
1858 int sectors = r1_bio->sectors;
1860 struct md_rdev *rdev;
1862 rdev = conf->mirrors[r1_bio->read_disk].rdev;
1863 if (test_bit(FailFast, &rdev->flags)) {
1864 /* Don't try recovering from here - just fail it
1865 * ... unless it is the last working device of course */
1866 md_error(mddev, rdev);
1867 if (test_bit(Faulty, &rdev->flags))
1868 /* Don't try to read from here, but make sure
1869 * put_buf does it's thing
1871 bio->bi_end_io = end_sync_write;
1876 int d = r1_bio->read_disk;
1880 if (s > (PAGE_SIZE>>9))
1883 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1884 /* No rcu protection needed here devices
1885 * can only be removed when no resync is
1886 * active, and resync is currently active
1888 rdev = conf->mirrors[d].rdev;
1889 if (sync_page_io(rdev, sect, s<<9,
1890 bio->bi_io_vec[idx].bv_page,
1891 REQ_OP_READ, 0, false)) {
1897 if (d == conf->raid_disks * 2)
1899 } while (!success && d != r1_bio->read_disk);
1902 char b[BDEVNAME_SIZE];
1904 /* Cannot read from anywhere, this block is lost.
1905 * Record a bad block on each device. If that doesn't
1906 * work just disable and interrupt the recovery.
1907 * Don't fail devices as that won't really help.
1909 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
1911 bdevname(bio->bi_bdev, b),
1912 (unsigned long long)r1_bio->sector);
1913 for (d = 0; d < conf->raid_disks * 2; d++) {
1914 rdev = conf->mirrors[d].rdev;
1915 if (!rdev || test_bit(Faulty, &rdev->flags))
1917 if (!rdev_set_badblocks(rdev, sect, s, 0))
1921 conf->recovery_disabled =
1922 mddev->recovery_disabled;
1923 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1924 md_done_sync(mddev, r1_bio->sectors, 0);
1936 /* write it back and re-read */
1937 while (d != r1_bio->read_disk) {
1939 d = conf->raid_disks * 2;
1941 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1943 rdev = conf->mirrors[d].rdev;
1944 if (r1_sync_page_io(rdev, sect, s,
1945 bio->bi_io_vec[idx].bv_page,
1947 r1_bio->bios[d]->bi_end_io = NULL;
1948 rdev_dec_pending(rdev, mddev);
1952 while (d != r1_bio->read_disk) {
1954 d = conf->raid_disks * 2;
1956 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1958 rdev = conf->mirrors[d].rdev;
1959 if (r1_sync_page_io(rdev, sect, s,
1960 bio->bi_io_vec[idx].bv_page,
1962 atomic_add(s, &rdev->corrected_errors);
1968 set_bit(R1BIO_Uptodate, &r1_bio->state);
1973 static void process_checks(struct r1bio *r1_bio)
1975 /* We have read all readable devices. If we haven't
1976 * got the block, then there is no hope left.
1977 * If we have, then we want to do a comparison
1978 * and skip the write if everything is the same.
1979 * If any blocks failed to read, then we need to
1980 * attempt an over-write
1982 struct mddev *mddev = r1_bio->mddev;
1983 struct r1conf *conf = mddev->private;
1988 /* Fix variable parts of all bios */
1989 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
1990 for (i = 0; i < conf->raid_disks * 2; i++) {
1994 struct bio *b = r1_bio->bios[i];
1995 if (b->bi_end_io != end_sync_read)
1997 /* fixup the bio for reuse, but preserve errno */
1998 error = b->bi_error;
2000 b->bi_error = error;
2002 b->bi_iter.bi_size = r1_bio->sectors << 9;
2003 b->bi_iter.bi_sector = r1_bio->sector +
2004 conf->mirrors[i].rdev->data_offset;
2005 b->bi_bdev = conf->mirrors[i].rdev->bdev;
2006 b->bi_end_io = end_sync_read;
2007 b->bi_private = r1_bio;
2009 size = b->bi_iter.bi_size;
2010 for (j = 0; j < vcnt ; j++) {
2012 bi = &b->bi_io_vec[j];
2014 if (size > PAGE_SIZE)
2015 bi->bv_len = PAGE_SIZE;
2021 for (primary = 0; primary < conf->raid_disks * 2; primary++)
2022 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
2023 !r1_bio->bios[primary]->bi_error) {
2024 r1_bio->bios[primary]->bi_end_io = NULL;
2025 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
2028 r1_bio->read_disk = primary;
2029 for (i = 0; i < conf->raid_disks * 2; i++) {
2031 struct bio *pbio = r1_bio->bios[primary];
2032 struct bio *sbio = r1_bio->bios[i];
2033 int error = sbio->bi_error;
2035 if (sbio->bi_end_io != end_sync_read)
2037 /* Now we can 'fixup' the error value */
2041 for (j = vcnt; j-- ; ) {
2043 p = pbio->bi_io_vec[j].bv_page;
2044 s = sbio->bi_io_vec[j].bv_page;
2045 if (memcmp(page_address(p),
2047 sbio->bi_io_vec[j].bv_len))
2053 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
2054 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
2056 /* No need to write to this device. */
2057 sbio->bi_end_io = NULL;
2058 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
2062 bio_copy_data(sbio, pbio);
2066 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
2068 struct r1conf *conf = mddev->private;
2070 int disks = conf->raid_disks * 2;
2071 struct bio *bio, *wbio;
2073 bio = r1_bio->bios[r1_bio->read_disk];
2075 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
2076 /* ouch - failed to read all of that. */
2077 if (!fix_sync_read_error(r1_bio))
2080 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2081 process_checks(r1_bio);
2086 atomic_set(&r1_bio->remaining, 1);
2087 for (i = 0; i < disks ; i++) {
2088 wbio = r1_bio->bios[i];
2089 if (wbio->bi_end_io == NULL ||
2090 (wbio->bi_end_io == end_sync_read &&
2091 (i == r1_bio->read_disk ||
2092 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
2095 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2096 if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
2097 wbio->bi_opf |= MD_FAILFAST;
2099 wbio->bi_end_io = end_sync_write;
2100 atomic_inc(&r1_bio->remaining);
2101 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
2103 generic_make_request(wbio);
2106 if (atomic_dec_and_test(&r1_bio->remaining)) {
2107 /* if we're here, all write(s) have completed, so clean up */
2108 int s = r1_bio->sectors;
2109 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2110 test_bit(R1BIO_WriteError, &r1_bio->state))
2111 reschedule_retry(r1_bio);
2114 md_done_sync(mddev, s, 1);
2120 * This is a kernel thread which:
2122 * 1. Retries failed read operations on working mirrors.
2123 * 2. Updates the raid superblock when problems encounter.
2124 * 3. Performs writes following reads for array synchronising.
2127 static void fix_read_error(struct r1conf *conf, int read_disk,
2128 sector_t sect, int sectors)
2130 struct mddev *mddev = conf->mddev;
2136 struct md_rdev *rdev;
2138 if (s > (PAGE_SIZE>>9))
2146 rdev = rcu_dereference(conf->mirrors[d].rdev);
2148 (test_bit(In_sync, &rdev->flags) ||
2149 (!test_bit(Faulty, &rdev->flags) &&
2150 rdev->recovery_offset >= sect + s)) &&
2151 is_badblock(rdev, sect, s,
2152 &first_bad, &bad_sectors) == 0) {
2153 atomic_inc(&rdev->nr_pending);
2155 if (sync_page_io(rdev, sect, s<<9,
2156 conf->tmppage, REQ_OP_READ, 0, false))
2158 rdev_dec_pending(rdev, mddev);
2164 if (d == conf->raid_disks * 2)
2166 } while (!success && d != read_disk);
2169 /* Cannot read from anywhere - mark it bad */
2170 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2171 if (!rdev_set_badblocks(rdev, sect, s, 0))
2172 md_error(mddev, rdev);
2175 /* write it back and re-read */
2177 while (d != read_disk) {
2179 d = conf->raid_disks * 2;
2182 rdev = rcu_dereference(conf->mirrors[d].rdev);
2184 !test_bit(Faulty, &rdev->flags)) {
2185 atomic_inc(&rdev->nr_pending);
2187 r1_sync_page_io(rdev, sect, s,
2188 conf->tmppage, WRITE);
2189 rdev_dec_pending(rdev, mddev);
2194 while (d != read_disk) {
2195 char b[BDEVNAME_SIZE];
2197 d = conf->raid_disks * 2;
2200 rdev = rcu_dereference(conf->mirrors[d].rdev);
2202 !test_bit(Faulty, &rdev->flags)) {
2203 atomic_inc(&rdev->nr_pending);
2205 if (r1_sync_page_io(rdev, sect, s,
2206 conf->tmppage, READ)) {
2207 atomic_add(s, &rdev->corrected_errors);
2208 pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
2210 (unsigned long long)(sect +
2212 bdevname(rdev->bdev, b));
2214 rdev_dec_pending(rdev, mddev);
2223 static int narrow_write_error(struct r1bio *r1_bio, int i)
2225 struct mddev *mddev = r1_bio->mddev;
2226 struct r1conf *conf = mddev->private;
2227 struct md_rdev *rdev = conf->mirrors[i].rdev;
2229 /* bio has the data to be written to device 'i' where
2230 * we just recently had a write error.
2231 * We repeatedly clone the bio and trim down to one block,
2232 * then try the write. Where the write fails we record
2234 * It is conceivable that the bio doesn't exactly align with
2235 * blocks. We must handle this somehow.
2237 * We currently own a reference on the rdev.
2243 int sect_to_write = r1_bio->sectors;
2246 if (rdev->badblocks.shift < 0)
2249 block_sectors = roundup(1 << rdev->badblocks.shift,
2250 bdev_logical_block_size(rdev->bdev) >> 9);
2251 sector = r1_bio->sector;
2252 sectors = ((sector + block_sectors)
2253 & ~(sector_t)(block_sectors - 1))
2256 while (sect_to_write) {
2258 if (sectors > sect_to_write)
2259 sectors = sect_to_write;
2260 /* Write at 'sector' for 'sectors'*/
2262 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2263 unsigned vcnt = r1_bio->behind_page_count;
2264 struct bio_vec *vec = r1_bio->behind_bvecs;
2266 while (!vec->bv_page) {
2271 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
2272 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
2274 wbio->bi_vcnt = vcnt;
2276 wbio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2279 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2280 wbio->bi_iter.bi_sector = r1_bio->sector;
2281 wbio->bi_iter.bi_size = r1_bio->sectors << 9;
2283 bio_trim(wbio, sector - r1_bio->sector, sectors);
2284 wbio->bi_iter.bi_sector += rdev->data_offset;
2285 wbio->bi_bdev = rdev->bdev;
2287 if (submit_bio_wait(wbio) < 0)
2289 ok = rdev_set_badblocks(rdev, sector,
2294 sect_to_write -= sectors;
2296 sectors = block_sectors;
2301 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2304 int s = r1_bio->sectors;
2305 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2306 struct md_rdev *rdev = conf->mirrors[m].rdev;
2307 struct bio *bio = r1_bio->bios[m];
2308 if (bio->bi_end_io == NULL)
2310 if (!bio->bi_error &&
2311 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2312 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2314 if (bio->bi_error &&
2315 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2316 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2317 md_error(conf->mddev, rdev);
2321 md_done_sync(conf->mddev, s, 1);
2324 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2328 for (m = 0; m < conf->raid_disks * 2 ; m++)
2329 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2330 struct md_rdev *rdev = conf->mirrors[m].rdev;
2331 rdev_clear_badblocks(rdev,
2333 r1_bio->sectors, 0);
2334 rdev_dec_pending(rdev, conf->mddev);
2335 } else if (r1_bio->bios[m] != NULL) {
2336 /* This drive got a write error. We need to
2337 * narrow down and record precise write
2341 if (!narrow_write_error(r1_bio, m)) {
2342 md_error(conf->mddev,
2343 conf->mirrors[m].rdev);
2344 /* an I/O failed, we can't clear the bitmap */
2345 set_bit(R1BIO_Degraded, &r1_bio->state);
2347 rdev_dec_pending(conf->mirrors[m].rdev,
2351 spin_lock_irq(&conf->device_lock);
2352 list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
2354 spin_unlock_irq(&conf->device_lock);
2355 md_wakeup_thread(conf->mddev->thread);
2357 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2358 close_write(r1_bio);
2359 raid_end_bio_io(r1_bio);
2363 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2367 struct mddev *mddev = conf->mddev;
2369 char b[BDEVNAME_SIZE];
2370 struct md_rdev *rdev;
2372 sector_t bio_sector;
2374 clear_bit(R1BIO_ReadError, &r1_bio->state);
2375 /* we got a read error. Maybe the drive is bad. Maybe just
2376 * the block and we can fix it.
2377 * We freeze all other IO, and try reading the block from
2378 * other devices. When we find one, we re-write
2379 * and check it that fixes the read error.
2380 * This is all done synchronously while the array is
2384 bio = r1_bio->bios[r1_bio->read_disk];
2385 bdevname(bio->bi_bdev, b);
2386 bio_dev = bio->bi_bdev->bd_dev;
2387 bio_sector = conf->mirrors[r1_bio->read_disk].rdev->data_offset + r1_bio->sector;
2389 r1_bio->bios[r1_bio->read_disk] = NULL;
2391 rdev = conf->mirrors[r1_bio->read_disk].rdev;
2393 && !test_bit(FailFast, &rdev->flags)) {
2394 freeze_array(conf, 1);
2395 fix_read_error(conf, r1_bio->read_disk,
2396 r1_bio->sector, r1_bio->sectors);
2397 unfreeze_array(conf);
2399 r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
2402 rdev_dec_pending(rdev, conf->mddev);
2405 disk = read_balance(conf, r1_bio, &max_sectors);
2407 pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
2408 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2409 raid_end_bio_io(r1_bio);
2411 const unsigned long do_sync
2412 = r1_bio->master_bio->bi_opf & REQ_SYNC;
2413 r1_bio->read_disk = disk;
2414 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2415 bio_trim(bio, r1_bio->sector - bio->bi_iter.bi_sector,
2417 r1_bio->bios[r1_bio->read_disk] = bio;
2418 rdev = conf->mirrors[disk].rdev;
2419 pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
2421 (unsigned long long)r1_bio->sector,
2422 bdevname(rdev->bdev, b));
2423 bio->bi_iter.bi_sector = r1_bio->sector + rdev->data_offset;
2424 bio->bi_bdev = rdev->bdev;
2425 bio->bi_end_io = raid1_end_read_request;
2426 bio_set_op_attrs(bio, REQ_OP_READ, do_sync);
2427 if (test_bit(FailFast, &rdev->flags) &&
2428 test_bit(R1BIO_FailFast, &r1_bio->state))
2429 bio->bi_opf |= MD_FAILFAST;
2430 bio->bi_private = r1_bio;
2431 if (max_sectors < r1_bio->sectors) {
2432 /* Drat - have to split this up more */
2433 struct bio *mbio = r1_bio->master_bio;
2434 int sectors_handled = (r1_bio->sector + max_sectors
2435 - mbio->bi_iter.bi_sector);
2436 r1_bio->sectors = max_sectors;
2437 spin_lock_irq(&conf->device_lock);
2438 if (mbio->bi_phys_segments == 0)
2439 mbio->bi_phys_segments = 2;
2441 mbio->bi_phys_segments++;
2442 spin_unlock_irq(&conf->device_lock);
2443 trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
2444 bio, bio_dev, bio_sector);
2445 generic_make_request(bio);
2448 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2450 r1_bio->master_bio = mbio;
2451 r1_bio->sectors = bio_sectors(mbio) - sectors_handled;
2453 set_bit(R1BIO_ReadError, &r1_bio->state);
2454 r1_bio->mddev = mddev;
2455 r1_bio->sector = mbio->bi_iter.bi_sector +
2460 trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
2461 bio, bio_dev, bio_sector);
2462 generic_make_request(bio);
2467 static void raid1d(struct md_thread *thread)
2469 struct mddev *mddev = thread->mddev;
2470 struct r1bio *r1_bio;
2471 unsigned long flags;
2472 struct r1conf *conf = mddev->private;
2473 struct list_head *head = &conf->retry_list;
2474 struct blk_plug plug;
2476 md_check_recovery(mddev);
2478 if (!list_empty_careful(&conf->bio_end_io_list) &&
2479 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2481 spin_lock_irqsave(&conf->device_lock, flags);
2482 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2483 while (!list_empty(&conf->bio_end_io_list)) {
2484 list_move(conf->bio_end_io_list.prev, &tmp);
2488 spin_unlock_irqrestore(&conf->device_lock, flags);
2489 while (!list_empty(&tmp)) {
2490 r1_bio = list_first_entry(&tmp, struct r1bio,
2492 list_del(&r1_bio->retry_list);
2493 if (mddev->degraded)
2494 set_bit(R1BIO_Degraded, &r1_bio->state);
2495 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2496 close_write(r1_bio);
2497 raid_end_bio_io(r1_bio);
2501 blk_start_plug(&plug);
2504 flush_pending_writes(conf);
2506 spin_lock_irqsave(&conf->device_lock, flags);
2507 if (list_empty(head)) {
2508 spin_unlock_irqrestore(&conf->device_lock, flags);
2511 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2512 list_del(head->prev);
2514 spin_unlock_irqrestore(&conf->device_lock, flags);
2516 mddev = r1_bio->mddev;
2517 conf = mddev->private;
2518 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2519 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2520 test_bit(R1BIO_WriteError, &r1_bio->state))
2521 handle_sync_write_finished(conf, r1_bio);
2523 sync_request_write(mddev, r1_bio);
2524 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2525 test_bit(R1BIO_WriteError, &r1_bio->state))
2526 handle_write_finished(conf, r1_bio);
2527 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2528 handle_read_error(conf, r1_bio);
2530 /* just a partial read to be scheduled from separate
2533 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2536 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2537 md_check_recovery(mddev);
2539 blk_finish_plug(&plug);
2542 static int init_resync(struct r1conf *conf)
2546 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2547 BUG_ON(conf->r1buf_pool);
2548 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2550 if (!conf->r1buf_pool)
2552 conf->next_resync = 0;
2557 * perform a "sync" on one "block"
2559 * We need to make sure that no normal I/O request - particularly write
2560 * requests - conflict with active sync requests.
2562 * This is achieved by tracking pending requests and a 'barrier' concept
2563 * that can be installed to exclude normal IO requests.
2566 static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
2569 struct r1conf *conf = mddev->private;
2570 struct r1bio *r1_bio;
2572 sector_t max_sector, nr_sectors;
2576 int write_targets = 0, read_targets = 0;
2577 sector_t sync_blocks;
2578 int still_degraded = 0;
2579 int good_sectors = RESYNC_SECTORS;
2580 int min_bad = 0; /* number of sectors that are bad in all devices */
2582 if (!conf->r1buf_pool)
2583 if (init_resync(conf))
2586 max_sector = mddev->dev_sectors;
2587 if (sector_nr >= max_sector) {
2588 /* If we aborted, we need to abort the
2589 * sync on the 'current' bitmap chunk (there will
2590 * only be one in raid1 resync.
2591 * We can find the current addess in mddev->curr_resync
2593 if (mddev->curr_resync < max_sector) /* aborted */
2594 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2596 else /* completed sync */
2599 bitmap_close_sync(mddev->bitmap);
2602 if (mddev_is_clustered(mddev)) {
2603 conf->cluster_sync_low = 0;
2604 conf->cluster_sync_high = 0;
2609 if (mddev->bitmap == NULL &&
2610 mddev->recovery_cp == MaxSector &&
2611 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2612 conf->fullsync == 0) {
2614 return max_sector - sector_nr;
2616 /* before building a request, check if we can skip these blocks..
2617 * This call the bitmap_start_sync doesn't actually record anything
2619 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2620 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2621 /* We can skip this block, and probably several more */
2627 * If there is non-resync activity waiting for a turn, then let it
2628 * though before starting on this new sync request.
2630 if (conf->nr_waiting)
2631 schedule_timeout_uninterruptible(1);
2633 /* we are incrementing sector_nr below. To be safe, we check against
2634 * sector_nr + two times RESYNC_SECTORS
2637 bitmap_cond_end_sync(mddev->bitmap, sector_nr,
2638 mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
2639 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2641 raise_barrier(conf, sector_nr);
2645 * If we get a correctably read error during resync or recovery,
2646 * we might want to read from a different device. So we
2647 * flag all drives that could conceivably be read from for READ,
2648 * and any others (which will be non-In_sync devices) for WRITE.
2649 * If a read fails, we try reading from something else for which READ
2653 r1_bio->mddev = mddev;
2654 r1_bio->sector = sector_nr;
2656 set_bit(R1BIO_IsSync, &r1_bio->state);
2658 for (i = 0; i < conf->raid_disks * 2; i++) {
2659 struct md_rdev *rdev;
2660 bio = r1_bio->bios[i];
2663 rdev = rcu_dereference(conf->mirrors[i].rdev);
2665 test_bit(Faulty, &rdev->flags)) {
2666 if (i < conf->raid_disks)
2668 } else if (!test_bit(In_sync, &rdev->flags)) {
2669 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2670 bio->bi_end_io = end_sync_write;
2673 /* may need to read from here */
2674 sector_t first_bad = MaxSector;
2677 if (is_badblock(rdev, sector_nr, good_sectors,
2678 &first_bad, &bad_sectors)) {
2679 if (first_bad > sector_nr)
2680 good_sectors = first_bad - sector_nr;
2682 bad_sectors -= (sector_nr - first_bad);
2684 min_bad > bad_sectors)
2685 min_bad = bad_sectors;
2688 if (sector_nr < first_bad) {
2689 if (test_bit(WriteMostly, &rdev->flags)) {
2696 bio_set_op_attrs(bio, REQ_OP_READ, 0);
2697 bio->bi_end_io = end_sync_read;
2699 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2700 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2701 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2703 * The device is suitable for reading (InSync),
2704 * but has bad block(s) here. Let's try to correct them,
2705 * if we are doing resync or repair. Otherwise, leave
2706 * this device alone for this sync request.
2708 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
2709 bio->bi_end_io = end_sync_write;
2713 if (bio->bi_end_io) {
2714 atomic_inc(&rdev->nr_pending);
2715 bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
2716 bio->bi_bdev = rdev->bdev;
2717 bio->bi_private = r1_bio;
2718 if (test_bit(FailFast, &rdev->flags))
2719 bio->bi_opf |= MD_FAILFAST;
2725 r1_bio->read_disk = disk;
2727 if (read_targets == 0 && min_bad > 0) {
2728 /* These sectors are bad on all InSync devices, so we
2729 * need to mark them bad on all write targets
2732 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2733 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2734 struct md_rdev *rdev = conf->mirrors[i].rdev;
2735 ok = rdev_set_badblocks(rdev, sector_nr,
2739 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
2744 /* Cannot record the badblocks, so need to
2746 * If there are multiple read targets, could just
2747 * fail the really bad ones ???
2749 conf->recovery_disabled = mddev->recovery_disabled;
2750 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2756 if (min_bad > 0 && min_bad < good_sectors) {
2757 /* only resync enough to reach the next bad->good
2759 good_sectors = min_bad;
2762 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2763 /* extra read targets are also write targets */
2764 write_targets += read_targets-1;
2766 if (write_targets == 0 || read_targets == 0) {
2767 /* There is nowhere to write, so all non-sync
2768 * drives must be failed - so we are finished
2772 max_sector = sector_nr + min_bad;
2773 rv = max_sector - sector_nr;
2779 if (max_sector > mddev->resync_max)
2780 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2781 if (max_sector > sector_nr + good_sectors)
2782 max_sector = sector_nr + good_sectors;
2787 int len = PAGE_SIZE;
2788 if (sector_nr + (len>>9) > max_sector)
2789 len = (max_sector - sector_nr) << 9;
2792 if (sync_blocks == 0) {
2793 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2794 &sync_blocks, still_degraded) &&
2796 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2798 if ((len >> 9) > sync_blocks)
2799 len = sync_blocks<<9;
2802 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2803 bio = r1_bio->bios[i];
2804 if (bio->bi_end_io) {
2805 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2806 if (bio_add_page(bio, page, len, 0) == 0) {
2808 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2811 bio = r1_bio->bios[i];
2812 if (bio->bi_end_io==NULL)
2814 /* remove last page from this bio */
2816 bio->bi_iter.bi_size -= len;
2817 bio_clear_flag(bio, BIO_SEG_VALID);
2823 nr_sectors += len>>9;
2824 sector_nr += len>>9;
2825 sync_blocks -= (len>>9);
2826 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2828 r1_bio->sectors = nr_sectors;
2830 if (mddev_is_clustered(mddev) &&
2831 conf->cluster_sync_high < sector_nr + nr_sectors) {
2832 conf->cluster_sync_low = mddev->curr_resync_completed;
2833 conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
2834 /* Send resync message */
2835 md_cluster_ops->resync_info_update(mddev,
2836 conf->cluster_sync_low,
2837 conf->cluster_sync_high);
2840 /* For a user-requested sync, we read all readable devices and do a
2843 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2844 atomic_set(&r1_bio->remaining, read_targets);
2845 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2846 bio = r1_bio->bios[i];
2847 if (bio->bi_end_io == end_sync_read) {
2849 md_sync_acct(bio->bi_bdev, nr_sectors);
2850 if (read_targets == 1)
2851 bio->bi_opf &= ~MD_FAILFAST;
2852 generic_make_request(bio);
2856 atomic_set(&r1_bio->remaining, 1);
2857 bio = r1_bio->bios[r1_bio->read_disk];
2858 md_sync_acct(bio->bi_bdev, nr_sectors);
2859 if (read_targets == 1)
2860 bio->bi_opf &= ~MD_FAILFAST;
2861 generic_make_request(bio);
2867 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2872 return mddev->dev_sectors;
2875 static struct r1conf *setup_conf(struct mddev *mddev)
2877 struct r1conf *conf;
2879 struct raid1_info *disk;
2880 struct md_rdev *rdev;
2883 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2887 conf->mirrors = kzalloc(sizeof(struct raid1_info)
2888 * mddev->raid_disks * 2,
2893 conf->tmppage = alloc_page(GFP_KERNEL);
2897 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2898 if (!conf->poolinfo)
2900 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2901 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2904 if (!conf->r1bio_pool)
2907 conf->poolinfo->mddev = mddev;
2910 spin_lock_init(&conf->device_lock);
2911 rdev_for_each(rdev, mddev) {
2912 struct request_queue *q;
2913 int disk_idx = rdev->raid_disk;
2914 if (disk_idx >= mddev->raid_disks
2917 if (test_bit(Replacement, &rdev->flags))
2918 disk = conf->mirrors + mddev->raid_disks + disk_idx;
2920 disk = conf->mirrors + disk_idx;
2925 q = bdev_get_queue(rdev->bdev);
2927 disk->head_position = 0;
2928 disk->seq_start = MaxSector;
2930 conf->raid_disks = mddev->raid_disks;
2931 conf->mddev = mddev;
2932 INIT_LIST_HEAD(&conf->retry_list);
2933 INIT_LIST_HEAD(&conf->bio_end_io_list);
2935 spin_lock_init(&conf->resync_lock);
2936 init_waitqueue_head(&conf->wait_barrier);
2938 bio_list_init(&conf->pending_bio_list);
2939 conf->pending_count = 0;
2940 conf->recovery_disabled = mddev->recovery_disabled - 1;
2942 conf->start_next_window = MaxSector;
2943 conf->current_window_requests = conf->next_window_requests = 0;
2946 for (i = 0; i < conf->raid_disks * 2; i++) {
2948 disk = conf->mirrors + i;
2950 if (i < conf->raid_disks &&
2951 disk[conf->raid_disks].rdev) {
2952 /* This slot has a replacement. */
2954 /* No original, just make the replacement
2955 * a recovering spare
2958 disk[conf->raid_disks].rdev;
2959 disk[conf->raid_disks].rdev = NULL;
2960 } else if (!test_bit(In_sync, &disk->rdev->flags))
2961 /* Original is not in_sync - bad */
2966 !test_bit(In_sync, &disk->rdev->flags)) {
2967 disk->head_position = 0;
2969 (disk->rdev->saved_raid_disk < 0))
2975 conf->thread = md_register_thread(raid1d, mddev, "raid1");
2983 mempool_destroy(conf->r1bio_pool);
2984 kfree(conf->mirrors);
2985 safe_put_page(conf->tmppage);
2986 kfree(conf->poolinfo);
2989 return ERR_PTR(err);
2992 static void raid1_free(struct mddev *mddev, void *priv);
2993 static int raid1_run(struct mddev *mddev)
2995 struct r1conf *conf;
2997 struct md_rdev *rdev;
2999 bool discard_supported = false;
3001 if (mddev->level != 1) {
3002 pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
3003 mdname(mddev), mddev->level);
3006 if (mddev->reshape_position != MaxSector) {
3007 pr_warn("md/raid1:%s: reshape_position set but not supported\n",
3012 * copy the already verified devices into our private RAID1
3013 * bookkeeping area. [whatever we allocate in run(),
3014 * should be freed in raid1_free()]
3016 if (mddev->private == NULL)
3017 conf = setup_conf(mddev);
3019 conf = mddev->private;
3022 return PTR_ERR(conf);
3025 blk_queue_max_write_same_sectors(mddev->queue, 0);
3027 rdev_for_each(rdev, mddev) {
3028 if (!mddev->gendisk)
3030 disk_stack_limits(mddev->gendisk, rdev->bdev,
3031 rdev->data_offset << 9);
3032 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
3033 discard_supported = true;
3036 mddev->degraded = 0;
3037 for (i=0; i < conf->raid_disks; i++)
3038 if (conf->mirrors[i].rdev == NULL ||
3039 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
3040 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
3043 if (conf->raid_disks - mddev->degraded == 1)
3044 mddev->recovery_cp = MaxSector;
3046 if (mddev->recovery_cp != MaxSector)
3047 pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
3049 pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
3050 mdname(mddev), mddev->raid_disks - mddev->degraded,
3054 * Ok, everything is just fine now
3056 mddev->thread = conf->thread;
3057 conf->thread = NULL;
3058 mddev->private = conf;
3059 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3061 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
3064 if (discard_supported)
3065 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
3068 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
3072 ret = md_integrity_register(mddev);
3074 md_unregister_thread(&mddev->thread);
3075 raid1_free(mddev, conf);
3080 static void raid1_free(struct mddev *mddev, void *priv)
3082 struct r1conf *conf = priv;
3084 mempool_destroy(conf->r1bio_pool);
3085 kfree(conf->mirrors);
3086 safe_put_page(conf->tmppage);
3087 kfree(conf->poolinfo);
3091 static int raid1_resize(struct mddev *mddev, sector_t sectors)
3093 /* no resync is happening, and there is enough space
3094 * on all devices, so we can resize.
3095 * We need to make sure resync covers any new space.
3096 * If the array is shrinking we should possibly wait until
3097 * any io in the removed space completes, but it hardly seems
3100 sector_t newsize = raid1_size(mddev, sectors, 0);
3101 if (mddev->external_size &&
3102 mddev->array_sectors > newsize)
3104 if (mddev->bitmap) {
3105 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
3109 md_set_array_sectors(mddev, newsize);
3110 set_capacity(mddev->gendisk, mddev->array_sectors);
3111 revalidate_disk(mddev->gendisk);
3112 if (sectors > mddev->dev_sectors &&
3113 mddev->recovery_cp > mddev->dev_sectors) {
3114 mddev->recovery_cp = mddev->dev_sectors;
3115 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3117 mddev->dev_sectors = sectors;
3118 mddev->resync_max_sectors = sectors;
3122 static int raid1_reshape(struct mddev *mddev)
3125 * 1/ resize the r1bio_pool
3126 * 2/ resize conf->mirrors
3128 * We allocate a new r1bio_pool if we can.
3129 * Then raise a device barrier and wait until all IO stops.
3130 * Then resize conf->mirrors and swap in the new r1bio pool.
3132 * At the same time, we "pack" the devices so that all the missing
3133 * devices have the higher raid_disk numbers.
3135 mempool_t *newpool, *oldpool;
3136 struct pool_info *newpoolinfo;
3137 struct raid1_info *newmirrors;
3138 struct r1conf *conf = mddev->private;
3139 int cnt, raid_disks;
3140 unsigned long flags;
3143 /* Cannot change chunk_size, layout, or level */
3144 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
3145 mddev->layout != mddev->new_layout ||
3146 mddev->level != mddev->new_level) {
3147 mddev->new_chunk_sectors = mddev->chunk_sectors;
3148 mddev->new_layout = mddev->layout;
3149 mddev->new_level = mddev->level;
3153 if (!mddev_is_clustered(mddev)) {
3154 err = md_allow_write(mddev);
3159 raid_disks = mddev->raid_disks + mddev->delta_disks;
3161 if (raid_disks < conf->raid_disks) {
3163 for (d= 0; d < conf->raid_disks; d++)
3164 if (conf->mirrors[d].rdev)
3166 if (cnt > raid_disks)
3170 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
3173 newpoolinfo->mddev = mddev;
3174 newpoolinfo->raid_disks = raid_disks * 2;
3176 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
3177 r1bio_pool_free, newpoolinfo);
3182 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2,
3186 mempool_destroy(newpool);
3190 freeze_array(conf, 0);
3192 /* ok, everything is stopped */
3193 oldpool = conf->r1bio_pool;
3194 conf->r1bio_pool = newpool;
3196 for (d = d2 = 0; d < conf->raid_disks; d++) {
3197 struct md_rdev *rdev = conf->mirrors[d].rdev;
3198 if (rdev && rdev->raid_disk != d2) {
3199 sysfs_unlink_rdev(mddev, rdev);
3200 rdev->raid_disk = d2;
3201 sysfs_unlink_rdev(mddev, rdev);
3202 if (sysfs_link_rdev(mddev, rdev))
3203 pr_warn("md/raid1:%s: cannot register rd%d\n",
3204 mdname(mddev), rdev->raid_disk);
3207 newmirrors[d2++].rdev = rdev;
3209 kfree(conf->mirrors);
3210 conf->mirrors = newmirrors;
3211 kfree(conf->poolinfo);
3212 conf->poolinfo = newpoolinfo;
3214 spin_lock_irqsave(&conf->device_lock, flags);
3215 mddev->degraded += (raid_disks - conf->raid_disks);
3216 spin_unlock_irqrestore(&conf->device_lock, flags);
3217 conf->raid_disks = mddev->raid_disks = raid_disks;
3218 mddev->delta_disks = 0;
3220 unfreeze_array(conf);
3222 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3223 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3224 md_wakeup_thread(mddev->thread);
3226 mempool_destroy(oldpool);
3230 static void raid1_quiesce(struct mddev *mddev, int state)
3232 struct r1conf *conf = mddev->private;
3235 case 2: /* wake for suspend */
3236 wake_up(&conf->wait_barrier);
3239 freeze_array(conf, 0);
3242 unfreeze_array(conf);
3247 static void *raid1_takeover(struct mddev *mddev)
3249 /* raid1 can take over:
3250 * raid5 with 2 devices, any layout or chunk size
3252 if (mddev->level == 5 && mddev->raid_disks == 2) {
3253 struct r1conf *conf;
3254 mddev->new_level = 1;
3255 mddev->new_layout = 0;
3256 mddev->new_chunk_sectors = 0;
3257 conf = setup_conf(mddev);
3258 if (!IS_ERR(conf)) {
3259 /* Array must appear to be quiesced */
3260 conf->array_frozen = 1;
3261 mddev_clear_unsupported_flags(mddev,
3262 UNSUPPORTED_MDDEV_FLAGS);
3266 return ERR_PTR(-EINVAL);
3269 static struct md_personality raid1_personality =
3273 .owner = THIS_MODULE,
3274 .make_request = raid1_make_request,
3277 .status = raid1_status,
3278 .error_handler = raid1_error,
3279 .hot_add_disk = raid1_add_disk,
3280 .hot_remove_disk= raid1_remove_disk,
3281 .spare_active = raid1_spare_active,
3282 .sync_request = raid1_sync_request,
3283 .resize = raid1_resize,
3285 .check_reshape = raid1_reshape,
3286 .quiesce = raid1_quiesce,
3287 .takeover = raid1_takeover,
3288 .congested = raid1_congested,
3291 static int __init raid_init(void)
3293 return register_md_personality(&raid1_personality);
3296 static void raid_exit(void)
3298 unregister_md_personality(&raid1_personality);
3301 module_init(raid_init);
3302 module_exit(raid_exit);
3303 MODULE_LICENSE("GPL");
3304 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3305 MODULE_ALIAS("md-personality-3"); /* RAID1 */
3306 MODULE_ALIAS("md-raid1");
3307 MODULE_ALIAS("md-level-1");
3309 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);