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>
45 * Number of guaranteed r1bios in case of extreme VM load:
47 #define NR_RAID1_BIOS 256
49 /* when we get a read error on a read-only array, we redirect to another
50 * device without failing the first device, or trying to over-write to
51 * correct the read error. To keep track of bad blocks on a per-bio
52 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
54 #define IO_BLOCKED ((struct bio *)1)
55 /* When we successfully write to a known bad-block, we need to remove the
56 * bad-block marking which must be done from process context. So we record
57 * the success by setting devs[n].bio to IO_MADE_GOOD
59 #define IO_MADE_GOOD ((struct bio *)2)
61 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
63 /* When there are this many requests queue to be written by
64 * the raid1 thread, we become 'congested' to provide back-pressure
67 static int max_queued_requests = 1024;
69 static void allow_barrier(struct r1conf *conf);
70 static void lower_barrier(struct r1conf *conf);
72 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
74 struct pool_info *pi = data;
75 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
77 /* allocate a r1bio with room for raid_disks entries in the bios array */
78 return kzalloc(size, gfp_flags);
81 static void r1bio_pool_free(void *r1_bio, void *data)
86 #define RESYNC_BLOCK_SIZE (64*1024)
87 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
88 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
89 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
90 #define RESYNC_WINDOW (2048*1024)
92 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
94 struct pool_info *pi = data;
99 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
104 * Allocate bios : 1 for reading, n-1 for writing
106 for (j = pi->raid_disks ; j-- ; ) {
107 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
110 r1_bio->bios[j] = bio;
113 * Allocate RESYNC_PAGES data pages and attach them to
115 * If this is a user-requested check/repair, allocate
116 * RESYNC_PAGES for each bio.
118 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
123 bio = r1_bio->bios[j];
124 bio->bi_vcnt = RESYNC_PAGES;
126 if (bio_alloc_pages(bio, gfp_flags))
129 /* If not user-requests, copy the page pointers to all bios */
130 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
131 for (i=0; i<RESYNC_PAGES ; i++)
132 for (j=1; j<pi->raid_disks; j++)
133 r1_bio->bios[j]->bi_io_vec[i].bv_page =
134 r1_bio->bios[0]->bi_io_vec[i].bv_page;
137 r1_bio->master_bio = NULL;
142 while (++j < pi->raid_disks)
143 bio_put(r1_bio->bios[j]);
144 r1bio_pool_free(r1_bio, data);
148 static void r1buf_pool_free(void *__r1_bio, void *data)
150 struct pool_info *pi = data;
152 struct r1bio *r1bio = __r1_bio;
154 for (i = 0; i < RESYNC_PAGES; i++)
155 for (j = pi->raid_disks; j-- ;) {
157 r1bio->bios[j]->bi_io_vec[i].bv_page !=
158 r1bio->bios[0]->bi_io_vec[i].bv_page)
159 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
161 for (i=0 ; i < pi->raid_disks; i++)
162 bio_put(r1bio->bios[i]);
164 r1bio_pool_free(r1bio, data);
167 static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
171 for (i = 0; i < conf->raid_disks * 2; i++) {
172 struct bio **bio = r1_bio->bios + i;
173 if (!BIO_SPECIAL(*bio))
179 static void free_r1bio(struct r1bio *r1_bio)
181 struct r1conf *conf = r1_bio->mddev->private;
183 put_all_bios(conf, r1_bio);
184 mempool_free(r1_bio, conf->r1bio_pool);
187 static void put_buf(struct r1bio *r1_bio)
189 struct r1conf *conf = r1_bio->mddev->private;
192 for (i = 0; i < conf->raid_disks * 2; i++) {
193 struct bio *bio = r1_bio->bios[i];
195 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
198 mempool_free(r1_bio, conf->r1buf_pool);
203 static void reschedule_retry(struct r1bio *r1_bio)
206 struct mddev *mddev = r1_bio->mddev;
207 struct r1conf *conf = mddev->private;
209 spin_lock_irqsave(&conf->device_lock, flags);
210 list_add(&r1_bio->retry_list, &conf->retry_list);
212 spin_unlock_irqrestore(&conf->device_lock, flags);
214 wake_up(&conf->wait_barrier);
215 md_wakeup_thread(mddev->thread);
219 * raid_end_bio_io() is called when we have finished servicing a mirrored
220 * operation and are ready to return a success/failure code to the buffer
223 static void call_bio_endio(struct r1bio *r1_bio)
225 struct bio *bio = r1_bio->master_bio;
227 struct r1conf *conf = r1_bio->mddev->private;
229 if (bio->bi_phys_segments) {
231 spin_lock_irqsave(&conf->device_lock, flags);
232 bio->bi_phys_segments--;
233 done = (bio->bi_phys_segments == 0);
234 spin_unlock_irqrestore(&conf->device_lock, flags);
238 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
239 clear_bit(BIO_UPTODATE, &bio->bi_flags);
243 * Wake up any possible resync thread that waits for the device
250 static void raid_end_bio_io(struct r1bio *r1_bio)
252 struct bio *bio = r1_bio->master_bio;
254 /* if nobody has done the final endio yet, do it now */
255 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
256 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
257 (bio_data_dir(bio) == WRITE) ? "write" : "read",
258 (unsigned long long) bio->bi_sector,
259 (unsigned long long) bio->bi_sector +
260 bio_sectors(bio) - 1);
262 call_bio_endio(r1_bio);
268 * Update disk head position estimator based on IRQ completion info.
270 static inline void update_head_pos(int disk, struct r1bio *r1_bio)
272 struct r1conf *conf = r1_bio->mddev->private;
274 conf->mirrors[disk].head_position =
275 r1_bio->sector + (r1_bio->sectors);
279 * Find the disk number which triggered given bio
281 static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
284 struct r1conf *conf = r1_bio->mddev->private;
285 int raid_disks = conf->raid_disks;
287 for (mirror = 0; mirror < raid_disks * 2; mirror++)
288 if (r1_bio->bios[mirror] == bio)
291 BUG_ON(mirror == raid_disks * 2);
292 update_head_pos(mirror, r1_bio);
297 static void raid1_end_read_request(struct bio *bio, int error)
299 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
300 struct r1bio *r1_bio = bio->bi_private;
302 struct r1conf *conf = r1_bio->mddev->private;
304 mirror = r1_bio->read_disk;
306 * this branch is our 'one mirror IO has finished' event handler:
308 update_head_pos(mirror, r1_bio);
311 set_bit(R1BIO_Uptodate, &r1_bio->state);
313 /* If all other devices have failed, we want to return
314 * the error upwards rather than fail the last device.
315 * Here we redefine "uptodate" to mean "Don't want to retry"
318 spin_lock_irqsave(&conf->device_lock, flags);
319 if (r1_bio->mddev->degraded == conf->raid_disks ||
320 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
321 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
323 spin_unlock_irqrestore(&conf->device_lock, flags);
327 raid_end_bio_io(r1_bio);
328 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
333 char b[BDEVNAME_SIZE];
335 KERN_ERR "md/raid1:%s: %s: "
336 "rescheduling sector %llu\n",
338 bdevname(conf->mirrors[mirror].rdev->bdev,
340 (unsigned long long)r1_bio->sector);
341 set_bit(R1BIO_ReadError, &r1_bio->state);
342 reschedule_retry(r1_bio);
343 /* don't drop the reference on read_disk yet */
347 static void close_write(struct r1bio *r1_bio)
349 /* it really is the end of this request */
350 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
351 /* free extra copy of the data pages */
352 int i = r1_bio->behind_page_count;
354 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
355 kfree(r1_bio->behind_bvecs);
356 r1_bio->behind_bvecs = NULL;
358 /* clear the bitmap if all writes complete successfully */
359 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
361 !test_bit(R1BIO_Degraded, &r1_bio->state),
362 test_bit(R1BIO_BehindIO, &r1_bio->state));
363 md_write_end(r1_bio->mddev);
366 static void r1_bio_write_done(struct r1bio *r1_bio)
368 if (!atomic_dec_and_test(&r1_bio->remaining))
371 if (test_bit(R1BIO_WriteError, &r1_bio->state))
372 reschedule_retry(r1_bio);
375 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
376 reschedule_retry(r1_bio);
378 raid_end_bio_io(r1_bio);
382 static void raid1_end_write_request(struct bio *bio, int error)
384 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
385 struct r1bio *r1_bio = bio->bi_private;
386 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
387 struct r1conf *conf = r1_bio->mddev->private;
388 struct bio *to_put = NULL;
390 mirror = find_bio_disk(r1_bio, bio);
393 * 'one mirror IO has finished' event handler:
396 set_bit(WriteErrorSeen,
397 &conf->mirrors[mirror].rdev->flags);
398 if (!test_and_set_bit(WantReplacement,
399 &conf->mirrors[mirror].rdev->flags))
400 set_bit(MD_RECOVERY_NEEDED, &
401 conf->mddev->recovery);
403 set_bit(R1BIO_WriteError, &r1_bio->state);
406 * Set R1BIO_Uptodate in our master bio, so that we
407 * will return a good error code for to the higher
408 * levels even if IO on some other mirrored buffer
411 * The 'master' represents the composite IO operation
412 * to user-side. So if something waits for IO, then it
413 * will wait for the 'master' bio.
418 r1_bio->bios[mirror] = NULL;
420 set_bit(R1BIO_Uptodate, &r1_bio->state);
422 /* Maybe we can clear some bad blocks. */
423 if (is_badblock(conf->mirrors[mirror].rdev,
424 r1_bio->sector, r1_bio->sectors,
425 &first_bad, &bad_sectors)) {
426 r1_bio->bios[mirror] = IO_MADE_GOOD;
427 set_bit(R1BIO_MadeGood, &r1_bio->state);
432 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
433 atomic_dec(&r1_bio->behind_remaining);
436 * In behind mode, we ACK the master bio once the I/O
437 * has safely reached all non-writemostly
438 * disks. Setting the Returned bit ensures that this
439 * gets done only once -- we don't ever want to return
440 * -EIO here, instead we'll wait
442 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
443 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
444 /* Maybe we can return now */
445 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
446 struct bio *mbio = r1_bio->master_bio;
447 pr_debug("raid1: behind end write sectors"
449 (unsigned long long) mbio->bi_sector,
450 (unsigned long long) mbio->bi_sector +
451 bio_sectors(mbio) - 1);
452 call_bio_endio(r1_bio);
456 if (r1_bio->bios[mirror] == NULL)
457 rdev_dec_pending(conf->mirrors[mirror].rdev,
461 * Let's see if all mirrored write operations have finished
464 r1_bio_write_done(r1_bio);
472 * This routine returns the disk from which the requested read should
473 * be done. There is a per-array 'next expected sequential IO' sector
474 * number - if this matches on the next IO then we use the last disk.
475 * There is also a per-disk 'last know head position' sector that is
476 * maintained from IRQ contexts, both the normal and the resync IO
477 * completion handlers update this position correctly. If there is no
478 * perfect sequential match then we pick the disk whose head is closest.
480 * If there are 2 mirrors in the same 2 devices, performance degrades
481 * because position is mirror, not device based.
483 * The rdev for the device selected will have nr_pending incremented.
485 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
487 const sector_t this_sector = r1_bio->sector;
489 int best_good_sectors;
490 int best_disk, best_dist_disk, best_pending_disk;
494 unsigned int min_pending;
495 struct md_rdev *rdev;
497 int choose_next_idle;
501 * Check if we can balance. We can balance on the whole
502 * device if no resync is going on, or below the resync window.
503 * We take the first readable disk when above the resync window.
506 sectors = r1_bio->sectors;
509 best_dist = MaxSector;
510 best_pending_disk = -1;
511 min_pending = UINT_MAX;
512 best_good_sectors = 0;
514 choose_next_idle = 0;
516 if (conf->mddev->recovery_cp < MaxSector &&
517 (this_sector + sectors >= conf->next_resync))
522 for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
526 unsigned int pending;
529 rdev = rcu_dereference(conf->mirrors[disk].rdev);
530 if (r1_bio->bios[disk] == IO_BLOCKED
532 || test_bit(Unmerged, &rdev->flags)
533 || test_bit(Faulty, &rdev->flags))
535 if (!test_bit(In_sync, &rdev->flags) &&
536 rdev->recovery_offset < this_sector + sectors)
538 if (test_bit(WriteMostly, &rdev->flags)) {
539 /* Don't balance among write-mostly, just
540 * use the first as a last resort */
542 if (is_badblock(rdev, this_sector, sectors,
543 &first_bad, &bad_sectors)) {
544 if (first_bad < this_sector)
545 /* Cannot use this */
547 best_good_sectors = first_bad - this_sector;
549 best_good_sectors = sectors;
554 /* This is a reasonable device to use. It might
557 if (is_badblock(rdev, this_sector, sectors,
558 &first_bad, &bad_sectors)) {
559 if (best_dist < MaxSector)
560 /* already have a better device */
562 if (first_bad <= this_sector) {
563 /* cannot read here. If this is the 'primary'
564 * device, then we must not read beyond
565 * bad_sectors from another device..
567 bad_sectors -= (this_sector - first_bad);
568 if (choose_first && sectors > bad_sectors)
569 sectors = bad_sectors;
570 if (best_good_sectors > sectors)
571 best_good_sectors = sectors;
574 sector_t good_sectors = first_bad - this_sector;
575 if (good_sectors > best_good_sectors) {
576 best_good_sectors = good_sectors;
584 best_good_sectors = sectors;
586 nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev));
587 has_nonrot_disk |= nonrot;
588 pending = atomic_read(&rdev->nr_pending);
589 dist = abs(this_sector - conf->mirrors[disk].head_position);
594 /* Don't change to another disk for sequential reads */
595 if (conf->mirrors[disk].next_seq_sect == this_sector
597 int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
598 struct raid1_info *mirror = &conf->mirrors[disk];
602 * If buffered sequential IO size exceeds optimal
603 * iosize, check if there is idle disk. If yes, choose
604 * the idle disk. read_balance could already choose an
605 * idle disk before noticing it's a sequential IO in
606 * this disk. This doesn't matter because this disk
607 * will idle, next time it will be utilized after the
608 * first disk has IO size exceeds optimal iosize. In
609 * this way, iosize of the first disk will be optimal
610 * iosize at least. iosize of the second disk might be
611 * small, but not a big deal since when the second disk
612 * starts IO, the first disk is likely still busy.
614 if (nonrot && opt_iosize > 0 &&
615 mirror->seq_start != MaxSector &&
616 mirror->next_seq_sect > opt_iosize &&
617 mirror->next_seq_sect - opt_iosize >=
619 choose_next_idle = 1;
624 /* If device is idle, use it */
630 if (choose_next_idle)
633 if (min_pending > pending) {
634 min_pending = pending;
635 best_pending_disk = disk;
638 if (dist < best_dist) {
640 best_dist_disk = disk;
645 * If all disks are rotational, choose the closest disk. If any disk is
646 * non-rotational, choose the disk with less pending request even the
647 * disk is rotational, which might/might not be optimal for raids with
648 * mixed ratation/non-rotational disks depending on workload.
650 if (best_disk == -1) {
652 best_disk = best_pending_disk;
654 best_disk = best_dist_disk;
657 if (best_disk >= 0) {
658 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
661 atomic_inc(&rdev->nr_pending);
662 if (test_bit(Faulty, &rdev->flags)) {
663 /* cannot risk returning a device that failed
664 * before we inc'ed nr_pending
666 rdev_dec_pending(rdev, conf->mddev);
669 sectors = best_good_sectors;
671 if (conf->mirrors[best_disk].next_seq_sect != this_sector)
672 conf->mirrors[best_disk].seq_start = this_sector;
674 conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
677 *max_sectors = sectors;
682 static int raid1_mergeable_bvec(struct request_queue *q,
683 struct bvec_merge_data *bvm,
684 struct bio_vec *biovec)
686 struct mddev *mddev = q->queuedata;
687 struct r1conf *conf = mddev->private;
688 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
689 int max = biovec->bv_len;
691 if (mddev->merge_check_needed) {
694 for (disk = 0; disk < conf->raid_disks * 2; disk++) {
695 struct md_rdev *rdev = rcu_dereference(
696 conf->mirrors[disk].rdev);
697 if (rdev && !test_bit(Faulty, &rdev->flags)) {
698 struct request_queue *q =
699 bdev_get_queue(rdev->bdev);
700 if (q->merge_bvec_fn) {
701 bvm->bi_sector = sector +
703 bvm->bi_bdev = rdev->bdev;
704 max = min(max, q->merge_bvec_fn(
715 int md_raid1_congested(struct mddev *mddev, int bits)
717 struct r1conf *conf = mddev->private;
720 if ((bits & (1 << BDI_async_congested)) &&
721 conf->pending_count >= max_queued_requests)
725 for (i = 0; i < conf->raid_disks * 2; i++) {
726 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
727 if (rdev && !test_bit(Faulty, &rdev->flags)) {
728 struct request_queue *q = bdev_get_queue(rdev->bdev);
732 /* Note the '|| 1' - when read_balance prefers
733 * non-congested targets, it can be removed
735 if ((bits & (1<<BDI_async_congested)) || 1)
736 ret |= bdi_congested(&q->backing_dev_info, bits);
738 ret &= bdi_congested(&q->backing_dev_info, bits);
744 EXPORT_SYMBOL_GPL(md_raid1_congested);
746 static int raid1_congested(void *data, int bits)
748 struct mddev *mddev = data;
750 return mddev_congested(mddev, bits) ||
751 md_raid1_congested(mddev, bits);
754 static void flush_pending_writes(struct r1conf *conf)
756 /* Any writes that have been queued but are awaiting
757 * bitmap updates get flushed here.
759 spin_lock_irq(&conf->device_lock);
761 if (conf->pending_bio_list.head) {
763 bio = bio_list_get(&conf->pending_bio_list);
764 conf->pending_count = 0;
765 spin_unlock_irq(&conf->device_lock);
766 /* flush any pending bitmap writes to
767 * disk before proceeding w/ I/O */
768 bitmap_unplug(conf->mddev->bitmap);
769 wake_up(&conf->wait_barrier);
771 while (bio) { /* submit pending writes */
772 struct bio *next = bio->bi_next;
774 if (unlikely((bio->bi_rw & REQ_DISCARD) &&
775 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
779 generic_make_request(bio);
783 spin_unlock_irq(&conf->device_lock);
787 * Sometimes we need to suspend IO while we do something else,
788 * either some resync/recovery, or reconfigure the array.
789 * To do this we raise a 'barrier'.
790 * The 'barrier' is a counter that can be raised multiple times
791 * to count how many activities are happening which preclude
793 * We can only raise the barrier if there is no pending IO.
794 * i.e. if nr_pending == 0.
795 * We choose only to raise the barrier if no-one is waiting for the
796 * barrier to go down. This means that as soon as an IO request
797 * is ready, no other operations which require a barrier will start
798 * until the IO request has had a chance.
800 * So: regular IO calls 'wait_barrier'. When that returns there
801 * is no backgroup IO happening, It must arrange to call
802 * allow_barrier when it has finished its IO.
803 * backgroup IO calls must call raise_barrier. Once that returns
804 * there is no normal IO happeing. It must arrange to call
805 * lower_barrier when the particular background IO completes.
807 #define RESYNC_DEPTH 32
809 static void raise_barrier(struct r1conf *conf)
811 spin_lock_irq(&conf->resync_lock);
813 /* Wait until no block IO is waiting */
814 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
817 /* block any new IO from starting */
820 /* Now wait for all pending IO to complete */
821 wait_event_lock_irq(conf->wait_barrier,
822 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
825 spin_unlock_irq(&conf->resync_lock);
828 static void lower_barrier(struct r1conf *conf)
831 BUG_ON(conf->barrier <= 0);
832 spin_lock_irqsave(&conf->resync_lock, flags);
834 spin_unlock_irqrestore(&conf->resync_lock, flags);
835 wake_up(&conf->wait_barrier);
838 static void wait_barrier(struct r1conf *conf)
840 spin_lock_irq(&conf->resync_lock);
843 /* Wait for the barrier to drop.
844 * However if there are already pending
845 * requests (preventing the barrier from
846 * rising completely), and the
847 * pre-process bio queue isn't empty,
848 * then don't wait, as we need to empty
849 * that queue to get the nr_pending
852 wait_event_lock_irq(conf->wait_barrier,
856 !bio_list_empty(current->bio_list)),
861 spin_unlock_irq(&conf->resync_lock);
864 static void allow_barrier(struct r1conf *conf)
867 spin_lock_irqsave(&conf->resync_lock, flags);
869 spin_unlock_irqrestore(&conf->resync_lock, flags);
870 wake_up(&conf->wait_barrier);
873 static void freeze_array(struct r1conf *conf)
875 /* stop syncio and normal IO and wait for everything to
877 * We increment barrier and nr_waiting, and then
878 * wait until nr_pending match nr_queued+1
879 * This is called in the context of one normal IO request
880 * that has failed. Thus any sync request that might be pending
881 * will be blocked by nr_pending, and we need to wait for
882 * pending IO requests to complete or be queued for re-try.
883 * Thus the number queued (nr_queued) plus this request (1)
884 * must match the number of pending IOs (nr_pending) before
887 spin_lock_irq(&conf->resync_lock);
890 wait_event_lock_irq_cmd(conf->wait_barrier,
891 conf->nr_pending == conf->nr_queued+1,
893 flush_pending_writes(conf));
894 spin_unlock_irq(&conf->resync_lock);
896 static void unfreeze_array(struct r1conf *conf)
898 /* reverse the effect of the freeze */
899 spin_lock_irq(&conf->resync_lock);
902 wake_up(&conf->wait_barrier);
903 spin_unlock_irq(&conf->resync_lock);
907 /* duplicate the data pages for behind I/O
909 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
912 struct bio_vec *bvec;
913 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
915 if (unlikely(!bvecs))
918 bio_for_each_segment_all(bvec, bio, i) {
920 bvecs[i].bv_page = alloc_page(GFP_NOIO);
921 if (unlikely(!bvecs[i].bv_page))
923 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
924 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
925 kunmap(bvecs[i].bv_page);
926 kunmap(bvec->bv_page);
928 r1_bio->behind_bvecs = bvecs;
929 r1_bio->behind_page_count = bio->bi_vcnt;
930 set_bit(R1BIO_BehindIO, &r1_bio->state);
934 for (i = 0; i < bio->bi_vcnt; i++)
935 if (bvecs[i].bv_page)
936 put_page(bvecs[i].bv_page);
938 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
941 struct raid1_plug_cb {
942 struct blk_plug_cb cb;
943 struct bio_list pending;
947 static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
949 struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
951 struct mddev *mddev = plug->cb.data;
952 struct r1conf *conf = mddev->private;
955 if (from_schedule || current->bio_list) {
956 spin_lock_irq(&conf->device_lock);
957 bio_list_merge(&conf->pending_bio_list, &plug->pending);
958 conf->pending_count += plug->pending_cnt;
959 spin_unlock_irq(&conf->device_lock);
960 wake_up(&conf->wait_barrier);
961 md_wakeup_thread(mddev->thread);
966 /* we aren't scheduling, so we can do the write-out directly. */
967 bio = bio_list_get(&plug->pending);
968 bitmap_unplug(mddev->bitmap);
969 wake_up(&conf->wait_barrier);
971 while (bio) { /* submit pending writes */
972 struct bio *next = bio->bi_next;
974 if (unlikely((bio->bi_rw & REQ_DISCARD) &&
975 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
979 generic_make_request(bio);
985 static void make_request(struct mddev *mddev, struct bio * bio)
987 struct r1conf *conf = mddev->private;
988 struct raid1_info *mirror;
989 struct r1bio *r1_bio;
990 struct bio *read_bio;
992 struct bitmap *bitmap;
994 const int rw = bio_data_dir(bio);
995 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
996 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
997 const unsigned long do_discard = (bio->bi_rw
998 & (REQ_DISCARD | REQ_SECURE));
999 const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
1000 struct md_rdev *blocked_rdev;
1001 struct blk_plug_cb *cb;
1002 struct raid1_plug_cb *plug = NULL;
1004 int sectors_handled;
1008 * Register the new request and wait if the reconstruction
1009 * thread has put up a bar for new requests.
1010 * Continue immediately if no resync is active currently.
1013 md_write_start(mddev, bio); /* wait on superblock update early */
1015 if (bio_data_dir(bio) == WRITE &&
1016 bio_end_sector(bio) > mddev->suspend_lo &&
1017 bio->bi_sector < mddev->suspend_hi) {
1018 /* As the suspend_* range is controlled by
1019 * userspace, we want an interruptible
1024 flush_signals(current);
1025 prepare_to_wait(&conf->wait_barrier,
1026 &w, TASK_INTERRUPTIBLE);
1027 if (bio_end_sector(bio) <= mddev->suspend_lo ||
1028 bio->bi_sector >= mddev->suspend_hi)
1032 finish_wait(&conf->wait_barrier, &w);
1037 bitmap = mddev->bitmap;
1040 * make_request() can abort the operation when READA is being
1041 * used and no empty request is available.
1044 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1046 r1_bio->master_bio = bio;
1047 r1_bio->sectors = bio_sectors(bio);
1049 r1_bio->mddev = mddev;
1050 r1_bio->sector = bio->bi_sector;
1052 /* We might need to issue multiple reads to different
1053 * devices if there are bad blocks around, so we keep
1054 * track of the number of reads in bio->bi_phys_segments.
1055 * If this is 0, there is only one r1_bio and no locking
1056 * will be needed when requests complete. If it is
1057 * non-zero, then it is the number of not-completed requests.
1059 bio->bi_phys_segments = 0;
1060 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
1064 * read balancing logic:
1069 rdisk = read_balance(conf, r1_bio, &max_sectors);
1072 /* couldn't find anywhere to read from */
1073 raid_end_bio_io(r1_bio);
1076 mirror = conf->mirrors + rdisk;
1078 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
1080 /* Reading from a write-mostly device must
1081 * take care not to over-take any writes
1084 wait_event(bitmap->behind_wait,
1085 atomic_read(&bitmap->behind_writes) == 0);
1087 r1_bio->read_disk = rdisk;
1089 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1090 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
1093 r1_bio->bios[rdisk] = read_bio;
1095 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
1096 read_bio->bi_bdev = mirror->rdev->bdev;
1097 read_bio->bi_end_io = raid1_end_read_request;
1098 read_bio->bi_rw = READ | do_sync;
1099 read_bio->bi_private = r1_bio;
1101 if (max_sectors < r1_bio->sectors) {
1102 /* could not read all from this device, so we will
1103 * need another r1_bio.
1106 sectors_handled = (r1_bio->sector + max_sectors
1108 r1_bio->sectors = max_sectors;
1109 spin_lock_irq(&conf->device_lock);
1110 if (bio->bi_phys_segments == 0)
1111 bio->bi_phys_segments = 2;
1113 bio->bi_phys_segments++;
1114 spin_unlock_irq(&conf->device_lock);
1115 /* Cannot call generic_make_request directly
1116 * as that will be queued in __make_request
1117 * and subsequent mempool_alloc might block waiting
1118 * for it. So hand bio over to raid1d.
1120 reschedule_retry(r1_bio);
1122 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1124 r1_bio->master_bio = bio;
1125 r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1127 r1_bio->mddev = mddev;
1128 r1_bio->sector = bio->bi_sector + sectors_handled;
1131 generic_make_request(read_bio);
1138 if (conf->pending_count >= max_queued_requests) {
1139 md_wakeup_thread(mddev->thread);
1140 wait_event(conf->wait_barrier,
1141 conf->pending_count < max_queued_requests);
1143 /* first select target devices under rcu_lock and
1144 * inc refcount on their rdev. Record them by setting
1146 * If there are known/acknowledged bad blocks on any device on
1147 * which we have seen a write error, we want to avoid writing those
1149 * This potentially requires several writes to write around
1150 * the bad blocks. Each set of writes gets it's own r1bio
1151 * with a set of bios attached.
1154 disks = conf->raid_disks * 2;
1156 blocked_rdev = NULL;
1158 max_sectors = r1_bio->sectors;
1159 for (i = 0; i < disks; i++) {
1160 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1161 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1162 atomic_inc(&rdev->nr_pending);
1163 blocked_rdev = rdev;
1166 r1_bio->bios[i] = NULL;
1167 if (!rdev || test_bit(Faulty, &rdev->flags)
1168 || test_bit(Unmerged, &rdev->flags)) {
1169 if (i < conf->raid_disks)
1170 set_bit(R1BIO_Degraded, &r1_bio->state);
1174 atomic_inc(&rdev->nr_pending);
1175 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1180 is_bad = is_badblock(rdev, r1_bio->sector,
1182 &first_bad, &bad_sectors);
1184 /* mustn't write here until the bad block is
1186 set_bit(BlockedBadBlocks, &rdev->flags);
1187 blocked_rdev = rdev;
1190 if (is_bad && first_bad <= r1_bio->sector) {
1191 /* Cannot write here at all */
1192 bad_sectors -= (r1_bio->sector - first_bad);
1193 if (bad_sectors < max_sectors)
1194 /* mustn't write more than bad_sectors
1195 * to other devices yet
1197 max_sectors = bad_sectors;
1198 rdev_dec_pending(rdev, mddev);
1199 /* We don't set R1BIO_Degraded as that
1200 * only applies if the disk is
1201 * missing, so it might be re-added,
1202 * and we want to know to recover this
1204 * In this case the device is here,
1205 * and the fact that this chunk is not
1206 * in-sync is recorded in the bad
1212 int good_sectors = first_bad - r1_bio->sector;
1213 if (good_sectors < max_sectors)
1214 max_sectors = good_sectors;
1217 r1_bio->bios[i] = bio;
1221 if (unlikely(blocked_rdev)) {
1222 /* Wait for this device to become unblocked */
1225 for (j = 0; j < i; j++)
1226 if (r1_bio->bios[j])
1227 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1229 allow_barrier(conf);
1230 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1235 if (max_sectors < r1_bio->sectors) {
1236 /* We are splitting this write into multiple parts, so
1237 * we need to prepare for allocating another r1_bio.
1239 r1_bio->sectors = max_sectors;
1240 spin_lock_irq(&conf->device_lock);
1241 if (bio->bi_phys_segments == 0)
1242 bio->bi_phys_segments = 2;
1244 bio->bi_phys_segments++;
1245 spin_unlock_irq(&conf->device_lock);
1247 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1249 atomic_set(&r1_bio->remaining, 1);
1250 atomic_set(&r1_bio->behind_remaining, 0);
1253 for (i = 0; i < disks; i++) {
1255 if (!r1_bio->bios[i])
1258 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1259 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1263 * Not if there are too many, or cannot
1264 * allocate memory, or a reader on WriteMostly
1265 * is waiting for behind writes to flush */
1267 (atomic_read(&bitmap->behind_writes)
1268 < mddev->bitmap_info.max_write_behind) &&
1269 !waitqueue_active(&bitmap->behind_wait))
1270 alloc_behind_pages(mbio, r1_bio);
1272 bitmap_startwrite(bitmap, r1_bio->sector,
1274 test_bit(R1BIO_BehindIO,
1278 if (r1_bio->behind_bvecs) {
1279 struct bio_vec *bvec;
1283 * We trimmed the bio, so _all is legit
1285 bio_for_each_segment_all(bvec, mbio, j)
1286 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1287 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1288 atomic_inc(&r1_bio->behind_remaining);
1291 r1_bio->bios[i] = mbio;
1293 mbio->bi_sector = (r1_bio->sector +
1294 conf->mirrors[i].rdev->data_offset);
1295 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1296 mbio->bi_end_io = raid1_end_write_request;
1298 WRITE | do_flush_fua | do_sync | do_discard | do_same;
1299 mbio->bi_private = r1_bio;
1301 atomic_inc(&r1_bio->remaining);
1303 cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
1305 plug = container_of(cb, struct raid1_plug_cb, cb);
1308 spin_lock_irqsave(&conf->device_lock, flags);
1310 bio_list_add(&plug->pending, mbio);
1311 plug->pending_cnt++;
1313 bio_list_add(&conf->pending_bio_list, mbio);
1314 conf->pending_count++;
1316 spin_unlock_irqrestore(&conf->device_lock, flags);
1318 md_wakeup_thread(mddev->thread);
1320 /* Mustn't call r1_bio_write_done before this next test,
1321 * as it could result in the bio being freed.
1323 if (sectors_handled < bio_sectors(bio)) {
1324 r1_bio_write_done(r1_bio);
1325 /* We need another r1_bio. It has already been counted
1326 * in bio->bi_phys_segments
1328 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1329 r1_bio->master_bio = bio;
1330 r1_bio->sectors = bio_sectors(bio) - sectors_handled;
1332 r1_bio->mddev = mddev;
1333 r1_bio->sector = bio->bi_sector + sectors_handled;
1337 r1_bio_write_done(r1_bio);
1339 /* In case raid1d snuck in to freeze_array */
1340 wake_up(&conf->wait_barrier);
1343 static void status(struct seq_file *seq, struct mddev *mddev)
1345 struct r1conf *conf = mddev->private;
1348 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1349 conf->raid_disks - mddev->degraded);
1351 for (i = 0; i < conf->raid_disks; i++) {
1352 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1353 seq_printf(seq, "%s",
1354 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1357 seq_printf(seq, "]");
1361 static void error(struct mddev *mddev, struct md_rdev *rdev)
1363 char b[BDEVNAME_SIZE];
1364 struct r1conf *conf = mddev->private;
1367 * If it is not operational, then we have already marked it as dead
1368 * else if it is the last working disks, ignore the error, let the
1369 * next level up know.
1370 * else mark the drive as failed
1372 if (test_bit(In_sync, &rdev->flags)
1373 && (conf->raid_disks - mddev->degraded) == 1) {
1375 * Don't fail the drive, act as though we were just a
1376 * normal single drive.
1377 * However don't try a recovery from this drive as
1378 * it is very likely to fail.
1380 conf->recovery_disabled = mddev->recovery_disabled;
1383 set_bit(Blocked, &rdev->flags);
1384 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1385 unsigned long flags;
1386 spin_lock_irqsave(&conf->device_lock, flags);
1388 set_bit(Faulty, &rdev->flags);
1389 spin_unlock_irqrestore(&conf->device_lock, flags);
1391 * if recovery is running, make sure it aborts.
1393 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1395 set_bit(Faulty, &rdev->flags);
1396 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1398 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1399 "md/raid1:%s: Operation continuing on %d devices.\n",
1400 mdname(mddev), bdevname(rdev->bdev, b),
1401 mdname(mddev), conf->raid_disks - mddev->degraded);
1404 static void print_conf(struct r1conf *conf)
1408 printk(KERN_DEBUG "RAID1 conf printout:\n");
1410 printk(KERN_DEBUG "(!conf)\n");
1413 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1417 for (i = 0; i < conf->raid_disks; i++) {
1418 char b[BDEVNAME_SIZE];
1419 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1421 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1422 i, !test_bit(In_sync, &rdev->flags),
1423 !test_bit(Faulty, &rdev->flags),
1424 bdevname(rdev->bdev,b));
1429 static void close_sync(struct r1conf *conf)
1432 allow_barrier(conf);
1434 mempool_destroy(conf->r1buf_pool);
1435 conf->r1buf_pool = NULL;
1438 static int raid1_spare_active(struct mddev *mddev)
1441 struct r1conf *conf = mddev->private;
1443 unsigned long flags;
1446 * Find all failed disks within the RAID1 configuration
1447 * and mark them readable.
1448 * Called under mddev lock, so rcu protection not needed.
1450 for (i = 0; i < conf->raid_disks; i++) {
1451 struct md_rdev *rdev = conf->mirrors[i].rdev;
1452 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1454 && repl->recovery_offset == MaxSector
1455 && !test_bit(Faulty, &repl->flags)
1456 && !test_and_set_bit(In_sync, &repl->flags)) {
1457 /* replacement has just become active */
1459 !test_and_clear_bit(In_sync, &rdev->flags))
1462 /* Replaced device not technically
1463 * faulty, but we need to be sure
1464 * it gets removed and never re-added
1466 set_bit(Faulty, &rdev->flags);
1467 sysfs_notify_dirent_safe(
1472 && !test_bit(Faulty, &rdev->flags)
1473 && !test_and_set_bit(In_sync, &rdev->flags)) {
1475 sysfs_notify_dirent_safe(rdev->sysfs_state);
1478 spin_lock_irqsave(&conf->device_lock, flags);
1479 mddev->degraded -= count;
1480 spin_unlock_irqrestore(&conf->device_lock, flags);
1487 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1489 struct r1conf *conf = mddev->private;
1492 struct raid1_info *p;
1494 int last = conf->raid_disks - 1;
1495 struct request_queue *q = bdev_get_queue(rdev->bdev);
1497 if (mddev->recovery_disabled == conf->recovery_disabled)
1500 if (rdev->raid_disk >= 0)
1501 first = last = rdev->raid_disk;
1503 if (q->merge_bvec_fn) {
1504 set_bit(Unmerged, &rdev->flags);
1505 mddev->merge_check_needed = 1;
1508 for (mirror = first; mirror <= last; mirror++) {
1509 p = conf->mirrors+mirror;
1512 disk_stack_limits(mddev->gendisk, rdev->bdev,
1513 rdev->data_offset << 9);
1515 p->head_position = 0;
1516 rdev->raid_disk = mirror;
1518 /* As all devices are equivalent, we don't need a full recovery
1519 * if this was recently any drive of the array
1521 if (rdev->saved_raid_disk < 0)
1523 rcu_assign_pointer(p->rdev, rdev);
1526 if (test_bit(WantReplacement, &p->rdev->flags) &&
1527 p[conf->raid_disks].rdev == NULL) {
1528 /* Add this device as a replacement */
1529 clear_bit(In_sync, &rdev->flags);
1530 set_bit(Replacement, &rdev->flags);
1531 rdev->raid_disk = mirror;
1534 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1538 if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
1539 /* Some requests might not have seen this new
1540 * merge_bvec_fn. We must wait for them to complete
1541 * before merging the device fully.
1542 * First we make sure any code which has tested
1543 * our function has submitted the request, then
1544 * we wait for all outstanding requests to complete.
1546 synchronize_sched();
1547 raise_barrier(conf);
1548 lower_barrier(conf);
1549 clear_bit(Unmerged, &rdev->flags);
1551 md_integrity_add_rdev(rdev, mddev);
1552 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
1553 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
1558 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1560 struct r1conf *conf = mddev->private;
1562 int number = rdev->raid_disk;
1563 struct raid1_info *p = conf->mirrors + number;
1565 if (rdev != p->rdev)
1566 p = conf->mirrors + conf->raid_disks + number;
1569 if (rdev == p->rdev) {
1570 if (test_bit(In_sync, &rdev->flags) ||
1571 atomic_read(&rdev->nr_pending)) {
1575 /* Only remove non-faulty devices if recovery
1578 if (!test_bit(Faulty, &rdev->flags) &&
1579 mddev->recovery_disabled != conf->recovery_disabled &&
1580 mddev->degraded < conf->raid_disks) {
1586 if (atomic_read(&rdev->nr_pending)) {
1587 /* lost the race, try later */
1591 } else if (conf->mirrors[conf->raid_disks + number].rdev) {
1592 /* We just removed a device that is being replaced.
1593 * Move down the replacement. We drain all IO before
1594 * doing this to avoid confusion.
1596 struct md_rdev *repl =
1597 conf->mirrors[conf->raid_disks + number].rdev;
1598 raise_barrier(conf);
1599 clear_bit(Replacement, &repl->flags);
1601 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1602 lower_barrier(conf);
1603 clear_bit(WantReplacement, &rdev->flags);
1605 clear_bit(WantReplacement, &rdev->flags);
1606 err = md_integrity_register(mddev);
1615 static void end_sync_read(struct bio *bio, int error)
1617 struct r1bio *r1_bio = bio->bi_private;
1619 update_head_pos(r1_bio->read_disk, r1_bio);
1622 * we have read a block, now it needs to be re-written,
1623 * or re-read if the read failed.
1624 * We don't do much here, just schedule handling by raid1d
1626 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1627 set_bit(R1BIO_Uptodate, &r1_bio->state);
1629 if (atomic_dec_and_test(&r1_bio->remaining))
1630 reschedule_retry(r1_bio);
1633 static void end_sync_write(struct bio *bio, int error)
1635 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1636 struct r1bio *r1_bio = bio->bi_private;
1637 struct mddev *mddev = r1_bio->mddev;
1638 struct r1conf *conf = mddev->private;
1643 mirror = find_bio_disk(r1_bio, bio);
1646 sector_t sync_blocks = 0;
1647 sector_t s = r1_bio->sector;
1648 long sectors_to_go = r1_bio->sectors;
1649 /* make sure these bits doesn't get cleared. */
1651 bitmap_end_sync(mddev->bitmap, s,
1654 sectors_to_go -= sync_blocks;
1655 } while (sectors_to_go > 0);
1656 set_bit(WriteErrorSeen,
1657 &conf->mirrors[mirror].rdev->flags);
1658 if (!test_and_set_bit(WantReplacement,
1659 &conf->mirrors[mirror].rdev->flags))
1660 set_bit(MD_RECOVERY_NEEDED, &
1662 set_bit(R1BIO_WriteError, &r1_bio->state);
1663 } else if (is_badblock(conf->mirrors[mirror].rdev,
1666 &first_bad, &bad_sectors) &&
1667 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1670 &first_bad, &bad_sectors)
1672 set_bit(R1BIO_MadeGood, &r1_bio->state);
1674 if (atomic_dec_and_test(&r1_bio->remaining)) {
1675 int s = r1_bio->sectors;
1676 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1677 test_bit(R1BIO_WriteError, &r1_bio->state))
1678 reschedule_retry(r1_bio);
1681 md_done_sync(mddev, s, uptodate);
1686 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1687 int sectors, struct page *page, int rw)
1689 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1693 set_bit(WriteErrorSeen, &rdev->flags);
1694 if (!test_and_set_bit(WantReplacement,
1696 set_bit(MD_RECOVERY_NEEDED, &
1697 rdev->mddev->recovery);
1699 /* need to record an error - either for the block or the device */
1700 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1701 md_error(rdev->mddev, rdev);
1705 static int fix_sync_read_error(struct r1bio *r1_bio)
1707 /* Try some synchronous reads of other devices to get
1708 * good data, much like with normal read errors. Only
1709 * read into the pages we already have so we don't
1710 * need to re-issue the read request.
1711 * We don't need to freeze the array, because being in an
1712 * active sync request, there is no normal IO, and
1713 * no overlapping syncs.
1714 * We don't need to check is_badblock() again as we
1715 * made sure that anything with a bad block in range
1716 * will have bi_end_io clear.
1718 struct mddev *mddev = r1_bio->mddev;
1719 struct r1conf *conf = mddev->private;
1720 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1721 sector_t sect = r1_bio->sector;
1722 int sectors = r1_bio->sectors;
1727 int d = r1_bio->read_disk;
1729 struct md_rdev *rdev;
1732 if (s > (PAGE_SIZE>>9))
1735 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1736 /* No rcu protection needed here devices
1737 * can only be removed when no resync is
1738 * active, and resync is currently active
1740 rdev = conf->mirrors[d].rdev;
1741 if (sync_page_io(rdev, sect, s<<9,
1742 bio->bi_io_vec[idx].bv_page,
1749 if (d == conf->raid_disks * 2)
1751 } while (!success && d != r1_bio->read_disk);
1754 char b[BDEVNAME_SIZE];
1756 /* Cannot read from anywhere, this block is lost.
1757 * Record a bad block on each device. If that doesn't
1758 * work just disable and interrupt the recovery.
1759 * Don't fail devices as that won't really help.
1761 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1762 " for block %llu\n",
1764 bdevname(bio->bi_bdev, b),
1765 (unsigned long long)r1_bio->sector);
1766 for (d = 0; d < conf->raid_disks * 2; d++) {
1767 rdev = conf->mirrors[d].rdev;
1768 if (!rdev || test_bit(Faulty, &rdev->flags))
1770 if (!rdev_set_badblocks(rdev, sect, s, 0))
1774 conf->recovery_disabled =
1775 mddev->recovery_disabled;
1776 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1777 md_done_sync(mddev, r1_bio->sectors, 0);
1789 /* write it back and re-read */
1790 while (d != r1_bio->read_disk) {
1792 d = conf->raid_disks * 2;
1794 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1796 rdev = conf->mirrors[d].rdev;
1797 if (r1_sync_page_io(rdev, sect, s,
1798 bio->bi_io_vec[idx].bv_page,
1800 r1_bio->bios[d]->bi_end_io = NULL;
1801 rdev_dec_pending(rdev, mddev);
1805 while (d != r1_bio->read_disk) {
1807 d = conf->raid_disks * 2;
1809 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1811 rdev = conf->mirrors[d].rdev;
1812 if (r1_sync_page_io(rdev, sect, s,
1813 bio->bi_io_vec[idx].bv_page,
1815 atomic_add(s, &rdev->corrected_errors);
1821 set_bit(R1BIO_Uptodate, &r1_bio->state);
1822 set_bit(BIO_UPTODATE, &bio->bi_flags);
1826 static int process_checks(struct r1bio *r1_bio)
1828 /* We have read all readable devices. If we haven't
1829 * got the block, then there is no hope left.
1830 * If we have, then we want to do a comparison
1831 * and skip the write if everything is the same.
1832 * If any blocks failed to read, then we need to
1833 * attempt an over-write
1835 struct mddev *mddev = r1_bio->mddev;
1836 struct r1conf *conf = mddev->private;
1841 for (primary = 0; primary < conf->raid_disks * 2; primary++)
1842 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1843 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1844 r1_bio->bios[primary]->bi_end_io = NULL;
1845 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1848 r1_bio->read_disk = primary;
1849 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
1850 for (i = 0; i < conf->raid_disks * 2; i++) {
1852 struct bio *pbio = r1_bio->bios[primary];
1853 struct bio *sbio = r1_bio->bios[i];
1856 if (sbio->bi_end_io != end_sync_read)
1859 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1860 for (j = vcnt; j-- ; ) {
1862 p = pbio->bi_io_vec[j].bv_page;
1863 s = sbio->bi_io_vec[j].bv_page;
1864 if (memcmp(page_address(p),
1866 sbio->bi_io_vec[j].bv_len))
1872 atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
1873 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1874 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1875 /* No need to write to this device. */
1876 sbio->bi_end_io = NULL;
1877 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1880 /* fixup the bio for reuse */
1882 sbio->bi_vcnt = vcnt;
1883 sbio->bi_size = r1_bio->sectors << 9;
1884 sbio->bi_sector = r1_bio->sector +
1885 conf->mirrors[i].rdev->data_offset;
1886 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1887 sbio->bi_end_io = end_sync_read;
1888 sbio->bi_private = r1_bio;
1890 size = sbio->bi_size;
1891 for (j = 0; j < vcnt ; j++) {
1893 bi = &sbio->bi_io_vec[j];
1895 if (size > PAGE_SIZE)
1896 bi->bv_len = PAGE_SIZE;
1902 bio_copy_data(sbio, pbio);
1907 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1909 struct r1conf *conf = mddev->private;
1911 int disks = conf->raid_disks * 2;
1912 struct bio *bio, *wbio;
1914 bio = r1_bio->bios[r1_bio->read_disk];
1916 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1917 /* ouch - failed to read all of that. */
1918 if (!fix_sync_read_error(r1_bio))
1921 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1922 if (process_checks(r1_bio) < 0)
1927 atomic_set(&r1_bio->remaining, 1);
1928 for (i = 0; i < disks ; i++) {
1929 wbio = r1_bio->bios[i];
1930 if (wbio->bi_end_io == NULL ||
1931 (wbio->bi_end_io == end_sync_read &&
1932 (i == r1_bio->read_disk ||
1933 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1936 wbio->bi_rw = WRITE;
1937 wbio->bi_end_io = end_sync_write;
1938 atomic_inc(&r1_bio->remaining);
1939 md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
1941 generic_make_request(wbio);
1944 if (atomic_dec_and_test(&r1_bio->remaining)) {
1945 /* if we're here, all write(s) have completed, so clean up */
1946 int s = r1_bio->sectors;
1947 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1948 test_bit(R1BIO_WriteError, &r1_bio->state))
1949 reschedule_retry(r1_bio);
1952 md_done_sync(mddev, s, 1);
1958 * This is a kernel thread which:
1960 * 1. Retries failed read operations on working mirrors.
1961 * 2. Updates the raid superblock when problems encounter.
1962 * 3. Performs writes following reads for array synchronising.
1965 static void fix_read_error(struct r1conf *conf, int read_disk,
1966 sector_t sect, int sectors)
1968 struct mddev *mddev = conf->mddev;
1974 struct md_rdev *rdev;
1976 if (s > (PAGE_SIZE>>9))
1980 /* Note: no rcu protection needed here
1981 * as this is synchronous in the raid1d thread
1982 * which is the thread that might remove
1983 * a device. If raid1d ever becomes multi-threaded....
1988 rdev = conf->mirrors[d].rdev;
1990 (test_bit(In_sync, &rdev->flags) ||
1991 (!test_bit(Faulty, &rdev->flags) &&
1992 rdev->recovery_offset >= sect + s)) &&
1993 is_badblock(rdev, sect, s,
1994 &first_bad, &bad_sectors) == 0 &&
1995 sync_page_io(rdev, sect, s<<9,
1996 conf->tmppage, READ, false))
2000 if (d == conf->raid_disks * 2)
2003 } while (!success && d != read_disk);
2006 /* Cannot read from anywhere - mark it bad */
2007 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
2008 if (!rdev_set_badblocks(rdev, sect, s, 0))
2009 md_error(mddev, rdev);
2012 /* write it back and re-read */
2014 while (d != read_disk) {
2016 d = conf->raid_disks * 2;
2018 rdev = conf->mirrors[d].rdev;
2020 test_bit(In_sync, &rdev->flags))
2021 r1_sync_page_io(rdev, sect, s,
2022 conf->tmppage, WRITE);
2025 while (d != read_disk) {
2026 char b[BDEVNAME_SIZE];
2028 d = conf->raid_disks * 2;
2030 rdev = conf->mirrors[d].rdev;
2032 test_bit(In_sync, &rdev->flags)) {
2033 if (r1_sync_page_io(rdev, sect, s,
2034 conf->tmppage, READ)) {
2035 atomic_add(s, &rdev->corrected_errors);
2037 "md/raid1:%s: read error corrected "
2038 "(%d sectors at %llu on %s)\n",
2040 (unsigned long long)(sect +
2042 bdevname(rdev->bdev, b));
2051 static int narrow_write_error(struct r1bio *r1_bio, int i)
2053 struct mddev *mddev = r1_bio->mddev;
2054 struct r1conf *conf = mddev->private;
2055 struct md_rdev *rdev = conf->mirrors[i].rdev;
2057 /* bio has the data to be written to device 'i' where
2058 * we just recently had a write error.
2059 * We repeatedly clone the bio and trim down to one block,
2060 * then try the write. Where the write fails we record
2062 * It is conceivable that the bio doesn't exactly align with
2063 * blocks. We must handle this somehow.
2065 * We currently own a reference on the rdev.
2071 int sect_to_write = r1_bio->sectors;
2074 if (rdev->badblocks.shift < 0)
2077 block_sectors = 1 << rdev->badblocks.shift;
2078 sector = r1_bio->sector;
2079 sectors = ((sector + block_sectors)
2080 & ~(sector_t)(block_sectors - 1))
2083 while (sect_to_write) {
2085 if (sectors > sect_to_write)
2086 sectors = sect_to_write;
2087 /* Write at 'sector' for 'sectors'*/
2089 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
2090 unsigned vcnt = r1_bio->behind_page_count;
2091 struct bio_vec *vec = r1_bio->behind_bvecs;
2093 while (!vec->bv_page) {
2098 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
2099 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
2101 wbio->bi_vcnt = vcnt;
2103 wbio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2106 wbio->bi_rw = WRITE;
2107 wbio->bi_sector = r1_bio->sector;
2108 wbio->bi_size = r1_bio->sectors << 9;
2110 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
2111 wbio->bi_sector += rdev->data_offset;
2112 wbio->bi_bdev = rdev->bdev;
2113 if (submit_bio_wait(WRITE, wbio) == 0)
2115 ok = rdev_set_badblocks(rdev, sector,
2120 sect_to_write -= sectors;
2122 sectors = block_sectors;
2127 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2130 int s = r1_bio->sectors;
2131 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2132 struct md_rdev *rdev = conf->mirrors[m].rdev;
2133 struct bio *bio = r1_bio->bios[m];
2134 if (bio->bi_end_io == NULL)
2136 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2137 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2138 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2140 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2141 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2142 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2143 md_error(conf->mddev, rdev);
2147 md_done_sync(conf->mddev, s, 1);
2150 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2153 for (m = 0; m < conf->raid_disks * 2 ; m++)
2154 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2155 struct md_rdev *rdev = conf->mirrors[m].rdev;
2156 rdev_clear_badblocks(rdev,
2158 r1_bio->sectors, 0);
2159 rdev_dec_pending(rdev, conf->mddev);
2160 } else if (r1_bio->bios[m] != NULL) {
2161 /* This drive got a write error. We need to
2162 * narrow down and record precise write
2165 if (!narrow_write_error(r1_bio, m)) {
2166 md_error(conf->mddev,
2167 conf->mirrors[m].rdev);
2168 /* an I/O failed, we can't clear the bitmap */
2169 set_bit(R1BIO_Degraded, &r1_bio->state);
2171 rdev_dec_pending(conf->mirrors[m].rdev,
2174 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2175 close_write(r1_bio);
2176 raid_end_bio_io(r1_bio);
2179 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2183 struct mddev *mddev = conf->mddev;
2185 char b[BDEVNAME_SIZE];
2186 struct md_rdev *rdev;
2188 clear_bit(R1BIO_ReadError, &r1_bio->state);
2189 /* we got a read error. Maybe the drive is bad. Maybe just
2190 * the block and we can fix it.
2191 * We freeze all other IO, and try reading the block from
2192 * other devices. When we find one, we re-write
2193 * and check it that fixes the read error.
2194 * This is all done synchronously while the array is
2197 if (mddev->ro == 0) {
2199 fix_read_error(conf, r1_bio->read_disk,
2200 r1_bio->sector, r1_bio->sectors);
2201 unfreeze_array(conf);
2203 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2204 rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
2206 bio = r1_bio->bios[r1_bio->read_disk];
2207 bdevname(bio->bi_bdev, b);
2209 disk = read_balance(conf, r1_bio, &max_sectors);
2211 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
2212 " read error for block %llu\n",
2213 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2214 raid_end_bio_io(r1_bio);
2216 const unsigned long do_sync
2217 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2219 r1_bio->bios[r1_bio->read_disk] =
2220 mddev->ro ? IO_BLOCKED : NULL;
2223 r1_bio->read_disk = disk;
2224 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2225 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
2226 r1_bio->bios[r1_bio->read_disk] = bio;
2227 rdev = conf->mirrors[disk].rdev;
2228 printk_ratelimited(KERN_ERR
2229 "md/raid1:%s: redirecting sector %llu"
2230 " to other mirror: %s\n",
2232 (unsigned long long)r1_bio->sector,
2233 bdevname(rdev->bdev, b));
2234 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2235 bio->bi_bdev = rdev->bdev;
2236 bio->bi_end_io = raid1_end_read_request;
2237 bio->bi_rw = READ | do_sync;
2238 bio->bi_private = r1_bio;
2239 if (max_sectors < r1_bio->sectors) {
2240 /* Drat - have to split this up more */
2241 struct bio *mbio = r1_bio->master_bio;
2242 int sectors_handled = (r1_bio->sector + max_sectors
2244 r1_bio->sectors = max_sectors;
2245 spin_lock_irq(&conf->device_lock);
2246 if (mbio->bi_phys_segments == 0)
2247 mbio->bi_phys_segments = 2;
2249 mbio->bi_phys_segments++;
2250 spin_unlock_irq(&conf->device_lock);
2251 generic_make_request(bio);
2254 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2256 r1_bio->master_bio = mbio;
2257 r1_bio->sectors = bio_sectors(mbio) - sectors_handled;
2259 set_bit(R1BIO_ReadError, &r1_bio->state);
2260 r1_bio->mddev = mddev;
2261 r1_bio->sector = mbio->bi_sector + sectors_handled;
2265 generic_make_request(bio);
2269 static void raid1d(struct md_thread *thread)
2271 struct mddev *mddev = thread->mddev;
2272 struct r1bio *r1_bio;
2273 unsigned long flags;
2274 struct r1conf *conf = mddev->private;
2275 struct list_head *head = &conf->retry_list;
2276 struct blk_plug plug;
2278 md_check_recovery(mddev);
2280 blk_start_plug(&plug);
2283 flush_pending_writes(conf);
2285 spin_lock_irqsave(&conf->device_lock, flags);
2286 if (list_empty(head)) {
2287 spin_unlock_irqrestore(&conf->device_lock, flags);
2290 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2291 list_del(head->prev);
2293 spin_unlock_irqrestore(&conf->device_lock, flags);
2295 mddev = r1_bio->mddev;
2296 conf = mddev->private;
2297 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2298 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2299 test_bit(R1BIO_WriteError, &r1_bio->state))
2300 handle_sync_write_finished(conf, r1_bio);
2302 sync_request_write(mddev, r1_bio);
2303 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2304 test_bit(R1BIO_WriteError, &r1_bio->state))
2305 handle_write_finished(conf, r1_bio);
2306 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2307 handle_read_error(conf, r1_bio);
2309 /* just a partial read to be scheduled from separate
2312 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2315 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2316 md_check_recovery(mddev);
2318 blk_finish_plug(&plug);
2322 static int init_resync(struct r1conf *conf)
2326 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2327 BUG_ON(conf->r1buf_pool);
2328 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2330 if (!conf->r1buf_pool)
2332 conf->next_resync = 0;
2337 * perform a "sync" on one "block"
2339 * We need to make sure that no normal I/O request - particularly write
2340 * requests - conflict with active sync requests.
2342 * This is achieved by tracking pending requests and a 'barrier' concept
2343 * that can be installed to exclude normal IO requests.
2346 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2348 struct r1conf *conf = mddev->private;
2349 struct r1bio *r1_bio;
2351 sector_t max_sector, nr_sectors;
2355 int write_targets = 0, read_targets = 0;
2356 sector_t sync_blocks;
2357 int still_degraded = 0;
2358 int good_sectors = RESYNC_SECTORS;
2359 int min_bad = 0; /* number of sectors that are bad in all devices */
2361 if (!conf->r1buf_pool)
2362 if (init_resync(conf))
2365 max_sector = mddev->dev_sectors;
2366 if (sector_nr >= max_sector) {
2367 /* If we aborted, we need to abort the
2368 * sync on the 'current' bitmap chunk (there will
2369 * only be one in raid1 resync.
2370 * We can find the current addess in mddev->curr_resync
2372 if (mddev->curr_resync < max_sector) /* aborted */
2373 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2375 else /* completed sync */
2378 bitmap_close_sync(mddev->bitmap);
2383 if (mddev->bitmap == NULL &&
2384 mddev->recovery_cp == MaxSector &&
2385 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2386 conf->fullsync == 0) {
2388 return max_sector - sector_nr;
2390 /* before building a request, check if we can skip these blocks..
2391 * This call the bitmap_start_sync doesn't actually record anything
2393 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2394 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2395 /* We can skip this block, and probably several more */
2400 * If there is non-resync activity waiting for a turn,
2401 * and resync is going fast enough,
2402 * then let it though before starting on this new sync request.
2404 if (!go_faster && conf->nr_waiting)
2405 msleep_interruptible(1000);
2407 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2408 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2409 raise_barrier(conf);
2411 conf->next_resync = sector_nr;
2415 * If we get a correctably read error during resync or recovery,
2416 * we might want to read from a different device. So we
2417 * flag all drives that could conceivably be read from for READ,
2418 * and any others (which will be non-In_sync devices) for WRITE.
2419 * If a read fails, we try reading from something else for which READ
2423 r1_bio->mddev = mddev;
2424 r1_bio->sector = sector_nr;
2426 set_bit(R1BIO_IsSync, &r1_bio->state);
2428 for (i = 0; i < conf->raid_disks * 2; i++) {
2429 struct md_rdev *rdev;
2430 bio = r1_bio->bios[i];
2433 rdev = rcu_dereference(conf->mirrors[i].rdev);
2435 test_bit(Faulty, &rdev->flags)) {
2436 if (i < conf->raid_disks)
2438 } else if (!test_bit(In_sync, &rdev->flags)) {
2440 bio->bi_end_io = end_sync_write;
2443 /* may need to read from here */
2444 sector_t first_bad = MaxSector;
2447 if (is_badblock(rdev, sector_nr, good_sectors,
2448 &first_bad, &bad_sectors)) {
2449 if (first_bad > sector_nr)
2450 good_sectors = first_bad - sector_nr;
2452 bad_sectors -= (sector_nr - first_bad);
2454 min_bad > bad_sectors)
2455 min_bad = bad_sectors;
2458 if (sector_nr < first_bad) {
2459 if (test_bit(WriteMostly, &rdev->flags)) {
2467 bio->bi_end_io = end_sync_read;
2469 } else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
2470 test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2471 !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
2473 * The device is suitable for reading (InSync),
2474 * but has bad block(s) here. Let's try to correct them,
2475 * if we are doing resync or repair. Otherwise, leave
2476 * this device alone for this sync request.
2479 bio->bi_end_io = end_sync_write;
2483 if (bio->bi_end_io) {
2484 atomic_inc(&rdev->nr_pending);
2485 bio->bi_sector = sector_nr + rdev->data_offset;
2486 bio->bi_bdev = rdev->bdev;
2487 bio->bi_private = r1_bio;
2493 r1_bio->read_disk = disk;
2495 if (read_targets == 0 && min_bad > 0) {
2496 /* These sectors are bad on all InSync devices, so we
2497 * need to mark them bad on all write targets
2500 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2501 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2502 struct md_rdev *rdev = conf->mirrors[i].rdev;
2503 ok = rdev_set_badblocks(rdev, sector_nr,
2507 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2512 /* Cannot record the badblocks, so need to
2514 * If there are multiple read targets, could just
2515 * fail the really bad ones ???
2517 conf->recovery_disabled = mddev->recovery_disabled;
2518 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2524 if (min_bad > 0 && min_bad < good_sectors) {
2525 /* only resync enough to reach the next bad->good
2527 good_sectors = min_bad;
2530 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2531 /* extra read targets are also write targets */
2532 write_targets += read_targets-1;
2534 if (write_targets == 0 || read_targets == 0) {
2535 /* There is nowhere to write, so all non-sync
2536 * drives must be failed - so we are finished
2540 max_sector = sector_nr + min_bad;
2541 rv = max_sector - sector_nr;
2547 if (max_sector > mddev->resync_max)
2548 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2549 if (max_sector > sector_nr + good_sectors)
2550 max_sector = sector_nr + good_sectors;
2555 int len = PAGE_SIZE;
2556 if (sector_nr + (len>>9) > max_sector)
2557 len = (max_sector - sector_nr) << 9;
2560 if (sync_blocks == 0) {
2561 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2562 &sync_blocks, still_degraded) &&
2564 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2566 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2567 if ((len >> 9) > sync_blocks)
2568 len = sync_blocks<<9;
2571 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2572 bio = r1_bio->bios[i];
2573 if (bio->bi_end_io) {
2574 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2575 if (bio_add_page(bio, page, len, 0) == 0) {
2577 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2580 bio = r1_bio->bios[i];
2581 if (bio->bi_end_io==NULL)
2583 /* remove last page from this bio */
2585 bio->bi_size -= len;
2586 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2592 nr_sectors += len>>9;
2593 sector_nr += len>>9;
2594 sync_blocks -= (len>>9);
2595 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2597 r1_bio->sectors = nr_sectors;
2599 /* For a user-requested sync, we read all readable devices and do a
2602 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2603 atomic_set(&r1_bio->remaining, read_targets);
2604 for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
2605 bio = r1_bio->bios[i];
2606 if (bio->bi_end_io == end_sync_read) {
2608 md_sync_acct(bio->bi_bdev, nr_sectors);
2609 generic_make_request(bio);
2613 atomic_set(&r1_bio->remaining, 1);
2614 bio = r1_bio->bios[r1_bio->read_disk];
2615 md_sync_acct(bio->bi_bdev, nr_sectors);
2616 generic_make_request(bio);
2622 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2627 return mddev->dev_sectors;
2630 static struct r1conf *setup_conf(struct mddev *mddev)
2632 struct r1conf *conf;
2634 struct raid1_info *disk;
2635 struct md_rdev *rdev;
2638 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2642 conf->mirrors = kzalloc(sizeof(struct raid1_info)
2643 * mddev->raid_disks * 2,
2648 conf->tmppage = alloc_page(GFP_KERNEL);
2652 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2653 if (!conf->poolinfo)
2655 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2656 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2659 if (!conf->r1bio_pool)
2662 conf->poolinfo->mddev = mddev;
2665 spin_lock_init(&conf->device_lock);
2666 rdev_for_each(rdev, mddev) {
2667 struct request_queue *q;
2668 int disk_idx = rdev->raid_disk;
2669 if (disk_idx >= mddev->raid_disks
2672 if (test_bit(Replacement, &rdev->flags))
2673 disk = conf->mirrors + mddev->raid_disks + disk_idx;
2675 disk = conf->mirrors + disk_idx;
2680 q = bdev_get_queue(rdev->bdev);
2681 if (q->merge_bvec_fn)
2682 mddev->merge_check_needed = 1;
2684 disk->head_position = 0;
2685 disk->seq_start = MaxSector;
2687 conf->raid_disks = mddev->raid_disks;
2688 conf->mddev = mddev;
2689 INIT_LIST_HEAD(&conf->retry_list);
2691 spin_lock_init(&conf->resync_lock);
2692 init_waitqueue_head(&conf->wait_barrier);
2694 bio_list_init(&conf->pending_bio_list);
2695 conf->pending_count = 0;
2696 conf->recovery_disabled = mddev->recovery_disabled - 1;
2699 for (i = 0; i < conf->raid_disks * 2; i++) {
2701 disk = conf->mirrors + i;
2703 if (i < conf->raid_disks &&
2704 disk[conf->raid_disks].rdev) {
2705 /* This slot has a replacement. */
2707 /* No original, just make the replacement
2708 * a recovering spare
2711 disk[conf->raid_disks].rdev;
2712 disk[conf->raid_disks].rdev = NULL;
2713 } else if (!test_bit(In_sync, &disk->rdev->flags))
2714 /* Original is not in_sync - bad */
2719 !test_bit(In_sync, &disk->rdev->flags)) {
2720 disk->head_position = 0;
2722 (disk->rdev->saved_raid_disk < 0))
2728 conf->thread = md_register_thread(raid1d, mddev, "raid1");
2729 if (!conf->thread) {
2731 "md/raid1:%s: couldn't allocate thread\n",
2740 if (conf->r1bio_pool)
2741 mempool_destroy(conf->r1bio_pool);
2742 kfree(conf->mirrors);
2743 safe_put_page(conf->tmppage);
2744 kfree(conf->poolinfo);
2747 return ERR_PTR(err);
2750 static int stop(struct mddev *mddev);
2751 static int run(struct mddev *mddev)
2753 struct r1conf *conf;
2755 struct md_rdev *rdev;
2757 bool discard_supported = false;
2759 if (mddev->level != 1) {
2760 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2761 mdname(mddev), mddev->level);
2764 if (mddev->reshape_position != MaxSector) {
2765 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2770 * copy the already verified devices into our private RAID1
2771 * bookkeeping area. [whatever we allocate in run(),
2772 * should be freed in stop()]
2774 if (mddev->private == NULL)
2775 conf = setup_conf(mddev);
2777 conf = mddev->private;
2780 return PTR_ERR(conf);
2783 blk_queue_max_write_same_sectors(mddev->queue,
2784 mddev->chunk_sectors);
2785 rdev_for_each(rdev, mddev) {
2786 if (!mddev->gendisk)
2788 disk_stack_limits(mddev->gendisk, rdev->bdev,
2789 rdev->data_offset << 9);
2790 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
2791 discard_supported = true;
2794 mddev->degraded = 0;
2795 for (i=0; i < conf->raid_disks; i++)
2796 if (conf->mirrors[i].rdev == NULL ||
2797 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2798 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2801 if (conf->raid_disks - mddev->degraded == 1)
2802 mddev->recovery_cp = MaxSector;
2804 if (mddev->recovery_cp != MaxSector)
2805 printk(KERN_NOTICE "md/raid1:%s: not clean"
2806 " -- starting background reconstruction\n",
2809 "md/raid1:%s: active with %d out of %d mirrors\n",
2810 mdname(mddev), mddev->raid_disks - mddev->degraded,
2814 * Ok, everything is just fine now
2816 mddev->thread = conf->thread;
2817 conf->thread = NULL;
2818 mddev->private = conf;
2820 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2823 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2824 mddev->queue->backing_dev_info.congested_data = mddev;
2825 blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
2827 if (discard_supported)
2828 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
2831 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
2835 ret = md_integrity_register(mddev);
2841 static int stop(struct mddev *mddev)
2843 struct r1conf *conf = mddev->private;
2844 struct bitmap *bitmap = mddev->bitmap;
2846 /* wait for behind writes to complete */
2847 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2848 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2850 /* need to kick something here to make sure I/O goes? */
2851 wait_event(bitmap->behind_wait,
2852 atomic_read(&bitmap->behind_writes) == 0);
2855 raise_barrier(conf);
2856 lower_barrier(conf);
2858 md_unregister_thread(&mddev->thread);
2859 if (conf->r1bio_pool)
2860 mempool_destroy(conf->r1bio_pool);
2861 kfree(conf->mirrors);
2862 safe_put_page(conf->tmppage);
2863 kfree(conf->poolinfo);
2865 mddev->private = NULL;
2869 static int raid1_resize(struct mddev *mddev, sector_t sectors)
2871 /* no resync is happening, and there is enough space
2872 * on all devices, so we can resize.
2873 * We need to make sure resync covers any new space.
2874 * If the array is shrinking we should possibly wait until
2875 * any io in the removed space completes, but it hardly seems
2878 sector_t newsize = raid1_size(mddev, sectors, 0);
2879 if (mddev->external_size &&
2880 mddev->array_sectors > newsize)
2882 if (mddev->bitmap) {
2883 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
2887 md_set_array_sectors(mddev, newsize);
2888 set_capacity(mddev->gendisk, mddev->array_sectors);
2889 revalidate_disk(mddev->gendisk);
2890 if (sectors > mddev->dev_sectors &&
2891 mddev->recovery_cp > mddev->dev_sectors) {
2892 mddev->recovery_cp = mddev->dev_sectors;
2893 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2895 mddev->dev_sectors = sectors;
2896 mddev->resync_max_sectors = sectors;
2900 static int raid1_reshape(struct mddev *mddev)
2903 * 1/ resize the r1bio_pool
2904 * 2/ resize conf->mirrors
2906 * We allocate a new r1bio_pool if we can.
2907 * Then raise a device barrier and wait until all IO stops.
2908 * Then resize conf->mirrors and swap in the new r1bio pool.
2910 * At the same time, we "pack" the devices so that all the missing
2911 * devices have the higher raid_disk numbers.
2913 mempool_t *newpool, *oldpool;
2914 struct pool_info *newpoolinfo;
2915 struct raid1_info *newmirrors;
2916 struct r1conf *conf = mddev->private;
2917 int cnt, raid_disks;
2918 unsigned long flags;
2921 /* Cannot change chunk_size, layout, or level */
2922 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2923 mddev->layout != mddev->new_layout ||
2924 mddev->level != mddev->new_level) {
2925 mddev->new_chunk_sectors = mddev->chunk_sectors;
2926 mddev->new_layout = mddev->layout;
2927 mddev->new_level = mddev->level;
2931 err = md_allow_write(mddev);
2935 raid_disks = mddev->raid_disks + mddev->delta_disks;
2937 if (raid_disks < conf->raid_disks) {
2939 for (d= 0; d < conf->raid_disks; d++)
2940 if (conf->mirrors[d].rdev)
2942 if (cnt > raid_disks)
2946 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2949 newpoolinfo->mddev = mddev;
2950 newpoolinfo->raid_disks = raid_disks * 2;
2952 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2953 r1bio_pool_free, newpoolinfo);
2958 newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2,
2962 mempool_destroy(newpool);
2966 raise_barrier(conf);
2968 /* ok, everything is stopped */
2969 oldpool = conf->r1bio_pool;
2970 conf->r1bio_pool = newpool;
2972 for (d = d2 = 0; d < conf->raid_disks; d++) {
2973 struct md_rdev *rdev = conf->mirrors[d].rdev;
2974 if (rdev && rdev->raid_disk != d2) {
2975 sysfs_unlink_rdev(mddev, rdev);
2976 rdev->raid_disk = d2;
2977 sysfs_unlink_rdev(mddev, rdev);
2978 if (sysfs_link_rdev(mddev, rdev))
2980 "md/raid1:%s: cannot register rd%d\n",
2981 mdname(mddev), rdev->raid_disk);
2984 newmirrors[d2++].rdev = rdev;
2986 kfree(conf->mirrors);
2987 conf->mirrors = newmirrors;
2988 kfree(conf->poolinfo);
2989 conf->poolinfo = newpoolinfo;
2991 spin_lock_irqsave(&conf->device_lock, flags);
2992 mddev->degraded += (raid_disks - conf->raid_disks);
2993 spin_unlock_irqrestore(&conf->device_lock, flags);
2994 conf->raid_disks = mddev->raid_disks = raid_disks;
2995 mddev->delta_disks = 0;
2997 lower_barrier(conf);
2999 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3000 md_wakeup_thread(mddev->thread);
3002 mempool_destroy(oldpool);
3006 static void raid1_quiesce(struct mddev *mddev, int state)
3008 struct r1conf *conf = mddev->private;
3011 case 2: /* wake for suspend */
3012 wake_up(&conf->wait_barrier);
3015 raise_barrier(conf);
3018 lower_barrier(conf);
3023 static void *raid1_takeover(struct mddev *mddev)
3025 /* raid1 can take over:
3026 * raid5 with 2 devices, any layout or chunk size
3028 if (mddev->level == 5 && mddev->raid_disks == 2) {
3029 struct r1conf *conf;
3030 mddev->new_level = 1;
3031 mddev->new_layout = 0;
3032 mddev->new_chunk_sectors = 0;
3033 conf = setup_conf(mddev);
3038 return ERR_PTR(-EINVAL);
3041 static struct md_personality raid1_personality =
3045 .owner = THIS_MODULE,
3046 .make_request = make_request,
3050 .error_handler = error,
3051 .hot_add_disk = raid1_add_disk,
3052 .hot_remove_disk= raid1_remove_disk,
3053 .spare_active = raid1_spare_active,
3054 .sync_request = sync_request,
3055 .resize = raid1_resize,
3057 .check_reshape = raid1_reshape,
3058 .quiesce = raid1_quiesce,
3059 .takeover = raid1_takeover,
3062 static int __init raid_init(void)
3064 return register_md_personality(&raid1_personality);
3067 static void raid_exit(void)
3069 unregister_md_personality(&raid1_personality);
3072 module_init(raid_init);
3073 module_exit(raid_exit);
3074 MODULE_LICENSE("GPL");
3075 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
3076 MODULE_ALIAS("md-personality-3"); /* RAID1 */
3077 MODULE_ALIAS("md-raid1");
3078 MODULE_ALIAS("md-level-1");
3080 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);