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 there are this many requests queue to be written by
50 * the raid1 thread, we become 'congested' to provide back-pressure
53 static int max_queued_requests = 1024;
55 static void allow_barrier(struct r1conf *conf);
56 static void lower_barrier(struct r1conf *conf);
58 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
60 struct pool_info *pi = data;
61 int size = offsetof(struct r1bio, bios[pi->raid_disks]);
63 /* allocate a r1bio with room for raid_disks entries in the bios array */
64 return kzalloc(size, gfp_flags);
67 static void r1bio_pool_free(void *r1_bio, void *data)
72 #define RESYNC_BLOCK_SIZE (64*1024)
73 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
74 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
75 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
76 #define RESYNC_WINDOW (2048*1024)
78 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
80 struct pool_info *pi = data;
86 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
91 * Allocate bios : 1 for reading, n-1 for writing
93 for (j = pi->raid_disks ; j-- ; ) {
94 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
97 r1_bio->bios[j] = bio;
100 * Allocate RESYNC_PAGES data pages and attach them to
102 * If this is a user-requested check/repair, allocate
103 * RESYNC_PAGES for each bio.
105 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
110 bio = r1_bio->bios[j];
111 for (i = 0; i < RESYNC_PAGES; i++) {
112 page = alloc_page(gfp_flags);
116 bio->bi_io_vec[i].bv_page = page;
120 /* If not user-requests, copy the page pointers to all bios */
121 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
122 for (i=0; i<RESYNC_PAGES ; i++)
123 for (j=1; j<pi->raid_disks; j++)
124 r1_bio->bios[j]->bi_io_vec[i].bv_page =
125 r1_bio->bios[0]->bi_io_vec[i].bv_page;
128 r1_bio->master_bio = NULL;
133 for (j=0 ; j < pi->raid_disks; j++)
134 for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
135 put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
138 while (++j < pi->raid_disks)
139 bio_put(r1_bio->bios[j]);
140 r1bio_pool_free(r1_bio, data);
144 static void r1buf_pool_free(void *__r1_bio, void *data)
146 struct pool_info *pi = data;
148 struct r1bio *r1bio = __r1_bio;
150 for (i = 0; i < RESYNC_PAGES; i++)
151 for (j = pi->raid_disks; j-- ;) {
153 r1bio->bios[j]->bi_io_vec[i].bv_page !=
154 r1bio->bios[0]->bi_io_vec[i].bv_page)
155 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
157 for (i=0 ; i < pi->raid_disks; i++)
158 bio_put(r1bio->bios[i]);
160 r1bio_pool_free(r1bio, data);
163 static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
167 for (i = 0; i < conf->raid_disks * 2; i++) {
168 struct bio **bio = r1_bio->bios + i;
169 if (!BIO_SPECIAL(*bio))
175 static void free_r1bio(struct r1bio *r1_bio)
177 struct r1conf *conf = r1_bio->mddev->private;
179 put_all_bios(conf, r1_bio);
180 mempool_free(r1_bio, conf->r1bio_pool);
183 static void put_buf(struct r1bio *r1_bio)
185 struct r1conf *conf = r1_bio->mddev->private;
188 for (i = 0; i < conf->raid_disks * 2; i++) {
189 struct bio *bio = r1_bio->bios[i];
191 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
194 mempool_free(r1_bio, conf->r1buf_pool);
199 static void reschedule_retry(struct r1bio *r1_bio)
202 struct mddev *mddev = r1_bio->mddev;
203 struct r1conf *conf = mddev->private;
205 spin_lock_irqsave(&conf->device_lock, flags);
206 list_add(&r1_bio->retry_list, &conf->retry_list);
208 spin_unlock_irqrestore(&conf->device_lock, flags);
210 wake_up(&conf->wait_barrier);
211 md_wakeup_thread(mddev->thread);
215 * raid_end_bio_io() is called when we have finished servicing a mirrored
216 * operation and are ready to return a success/failure code to the buffer
219 static void call_bio_endio(struct r1bio *r1_bio)
221 struct bio *bio = r1_bio->master_bio;
223 struct r1conf *conf = r1_bio->mddev->private;
225 if (bio->bi_phys_segments) {
227 spin_lock_irqsave(&conf->device_lock, flags);
228 bio->bi_phys_segments--;
229 done = (bio->bi_phys_segments == 0);
230 spin_unlock_irqrestore(&conf->device_lock, flags);
234 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
235 clear_bit(BIO_UPTODATE, &bio->bi_flags);
239 * Wake up any possible resync thread that waits for the device
246 static void raid_end_bio_io(struct r1bio *r1_bio)
248 struct bio *bio = r1_bio->master_bio;
250 /* if nobody has done the final endio yet, do it now */
251 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
252 pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
253 (bio_data_dir(bio) == WRITE) ? "write" : "read",
254 (unsigned long long) bio->bi_sector,
255 (unsigned long long) bio->bi_sector +
256 (bio->bi_size >> 9) - 1);
258 call_bio_endio(r1_bio);
264 * Update disk head position estimator based on IRQ completion info.
266 static inline void update_head_pos(int disk, struct r1bio *r1_bio)
268 struct r1conf *conf = r1_bio->mddev->private;
270 conf->mirrors[disk].head_position =
271 r1_bio->sector + (r1_bio->sectors);
275 * Find the disk number which triggered given bio
277 static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
280 struct r1conf *conf = r1_bio->mddev->private;
281 int raid_disks = conf->raid_disks;
283 for (mirror = 0; mirror < raid_disks * 2; mirror++)
284 if (r1_bio->bios[mirror] == bio)
287 BUG_ON(mirror == raid_disks * 2);
288 update_head_pos(mirror, r1_bio);
293 static void raid1_end_read_request(struct bio *bio, int error)
295 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
296 struct r1bio *r1_bio = bio->bi_private;
298 struct r1conf *conf = r1_bio->mddev->private;
300 mirror = r1_bio->read_disk;
302 * this branch is our 'one mirror IO has finished' event handler:
304 update_head_pos(mirror, r1_bio);
307 set_bit(R1BIO_Uptodate, &r1_bio->state);
309 /* If all other devices have failed, we want to return
310 * the error upwards rather than fail the last device.
311 * Here we redefine "uptodate" to mean "Don't want to retry"
314 spin_lock_irqsave(&conf->device_lock, flags);
315 if (r1_bio->mddev->degraded == conf->raid_disks ||
316 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
317 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
319 spin_unlock_irqrestore(&conf->device_lock, flags);
323 raid_end_bio_io(r1_bio);
328 char b[BDEVNAME_SIZE];
330 KERN_ERR "md/raid1:%s: %s: "
331 "rescheduling sector %llu\n",
333 bdevname(conf->mirrors[mirror].rdev->bdev,
335 (unsigned long long)r1_bio->sector);
336 set_bit(R1BIO_ReadError, &r1_bio->state);
337 reschedule_retry(r1_bio);
340 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
343 static void close_write(struct r1bio *r1_bio)
345 /* it really is the end of this request */
346 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
347 /* free extra copy of the data pages */
348 int i = r1_bio->behind_page_count;
350 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
351 kfree(r1_bio->behind_bvecs);
352 r1_bio->behind_bvecs = NULL;
354 /* clear the bitmap if all writes complete successfully */
355 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
357 !test_bit(R1BIO_Degraded, &r1_bio->state),
358 test_bit(R1BIO_BehindIO, &r1_bio->state));
359 md_write_end(r1_bio->mddev);
362 static void r1_bio_write_done(struct r1bio *r1_bio)
364 if (!atomic_dec_and_test(&r1_bio->remaining))
367 if (test_bit(R1BIO_WriteError, &r1_bio->state))
368 reschedule_retry(r1_bio);
371 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
372 reschedule_retry(r1_bio);
374 raid_end_bio_io(r1_bio);
378 static void raid1_end_write_request(struct bio *bio, int error)
380 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
381 struct r1bio *r1_bio = bio->bi_private;
382 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
383 struct r1conf *conf = r1_bio->mddev->private;
384 struct bio *to_put = NULL;
386 mirror = find_bio_disk(r1_bio, bio);
389 * 'one mirror IO has finished' event handler:
392 set_bit(WriteErrorSeen,
393 &conf->mirrors[mirror].rdev->flags);
394 if (!test_and_set_bit(WantReplacement,
395 &conf->mirrors[mirror].rdev->flags))
396 set_bit(MD_RECOVERY_NEEDED, &
397 conf->mddev->recovery);
399 set_bit(R1BIO_WriteError, &r1_bio->state);
402 * Set R1BIO_Uptodate in our master bio, so that we
403 * will return a good error code for to the higher
404 * levels even if IO on some other mirrored buffer
407 * The 'master' represents the composite IO operation
408 * to user-side. So if something waits for IO, then it
409 * will wait for the 'master' bio.
414 r1_bio->bios[mirror] = NULL;
416 set_bit(R1BIO_Uptodate, &r1_bio->state);
418 /* Maybe we can clear some bad blocks. */
419 if (is_badblock(conf->mirrors[mirror].rdev,
420 r1_bio->sector, r1_bio->sectors,
421 &first_bad, &bad_sectors)) {
422 r1_bio->bios[mirror] = IO_MADE_GOOD;
423 set_bit(R1BIO_MadeGood, &r1_bio->state);
428 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
429 atomic_dec(&r1_bio->behind_remaining);
432 * In behind mode, we ACK the master bio once the I/O
433 * has safely reached all non-writemostly
434 * disks. Setting the Returned bit ensures that this
435 * gets done only once -- we don't ever want to return
436 * -EIO here, instead we'll wait
438 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
439 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
440 /* Maybe we can return now */
441 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
442 struct bio *mbio = r1_bio->master_bio;
443 pr_debug("raid1: behind end write sectors"
445 (unsigned long long) mbio->bi_sector,
446 (unsigned long long) mbio->bi_sector +
447 (mbio->bi_size >> 9) - 1);
448 call_bio_endio(r1_bio);
452 if (r1_bio->bios[mirror] == NULL)
453 rdev_dec_pending(conf->mirrors[mirror].rdev,
457 * Let's see if all mirrored write operations have finished
460 r1_bio_write_done(r1_bio);
468 * This routine returns the disk from which the requested read should
469 * be done. There is a per-array 'next expected sequential IO' sector
470 * number - if this matches on the next IO then we use the last disk.
471 * There is also a per-disk 'last know head position' sector that is
472 * maintained from IRQ contexts, both the normal and the resync IO
473 * completion handlers update this position correctly. If there is no
474 * perfect sequential match then we pick the disk whose head is closest.
476 * If there are 2 mirrors in the same 2 devices, performance degrades
477 * because position is mirror, not device based.
479 * The rdev for the device selected will have nr_pending incremented.
481 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
483 const sector_t this_sector = r1_bio->sector;
485 int best_good_sectors;
490 struct md_rdev *rdev;
495 * Check if we can balance. We can balance on the whole
496 * device if no resync is going on, or below the resync window.
497 * We take the first readable disk when above the resync window.
500 sectors = r1_bio->sectors;
502 best_dist = MaxSector;
503 best_good_sectors = 0;
505 if (conf->mddev->recovery_cp < MaxSector &&
506 (this_sector + sectors >= conf->next_resync)) {
511 start_disk = conf->last_used;
514 for (i = 0 ; i < conf->raid_disks * 2 ; i++) {
519 int disk = start_disk + i;
520 if (disk >= conf->raid_disks)
521 disk -= conf->raid_disks;
523 rdev = rcu_dereference(conf->mirrors[disk].rdev);
524 if (r1_bio->bios[disk] == IO_BLOCKED
526 || test_bit(Faulty, &rdev->flags))
528 if (!test_bit(In_sync, &rdev->flags) &&
529 rdev->recovery_offset < this_sector + sectors)
531 if (test_bit(WriteMostly, &rdev->flags)) {
532 /* Don't balance among write-mostly, just
533 * use the first as a last resort */
535 if (is_badblock(rdev, this_sector, sectors,
536 &first_bad, &bad_sectors)) {
537 if (first_bad < this_sector)
538 /* Cannot use this */
540 best_good_sectors = first_bad - this_sector;
542 best_good_sectors = sectors;
547 /* This is a reasonable device to use. It might
550 if (is_badblock(rdev, this_sector, sectors,
551 &first_bad, &bad_sectors)) {
552 if (best_dist < MaxSector)
553 /* already have a better device */
555 if (first_bad <= this_sector) {
556 /* cannot read here. If this is the 'primary'
557 * device, then we must not read beyond
558 * bad_sectors from another device..
560 bad_sectors -= (this_sector - first_bad);
561 if (choose_first && sectors > bad_sectors)
562 sectors = bad_sectors;
563 if (best_good_sectors > sectors)
564 best_good_sectors = sectors;
567 sector_t good_sectors = first_bad - this_sector;
568 if (good_sectors > best_good_sectors) {
569 best_good_sectors = good_sectors;
577 best_good_sectors = sectors;
579 dist = abs(this_sector - conf->mirrors[disk].head_position);
581 /* Don't change to another disk for sequential reads */
582 || conf->next_seq_sect == this_sector
584 /* If device is idle, use it */
585 || atomic_read(&rdev->nr_pending) == 0) {
589 if (dist < best_dist) {
595 if (best_disk >= 0) {
596 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
599 atomic_inc(&rdev->nr_pending);
600 if (test_bit(Faulty, &rdev->flags)) {
601 /* cannot risk returning a device that failed
602 * before we inc'ed nr_pending
604 rdev_dec_pending(rdev, conf->mddev);
607 sectors = best_good_sectors;
608 conf->next_seq_sect = this_sector + sectors;
609 conf->last_used = best_disk;
612 *max_sectors = sectors;
617 int md_raid1_congested(struct mddev *mddev, int bits)
619 struct r1conf *conf = mddev->private;
622 if ((bits & (1 << BDI_async_congested)) &&
623 conf->pending_count >= max_queued_requests)
627 for (i = 0; i < conf->raid_disks * 2; i++) {
628 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
629 if (rdev && !test_bit(Faulty, &rdev->flags)) {
630 struct request_queue *q = bdev_get_queue(rdev->bdev);
634 /* Note the '|| 1' - when read_balance prefers
635 * non-congested targets, it can be removed
637 if ((bits & (1<<BDI_async_congested)) || 1)
638 ret |= bdi_congested(&q->backing_dev_info, bits);
640 ret &= bdi_congested(&q->backing_dev_info, bits);
646 EXPORT_SYMBOL_GPL(md_raid1_congested);
648 static int raid1_congested(void *data, int bits)
650 struct mddev *mddev = data;
652 return mddev_congested(mddev, bits) ||
653 md_raid1_congested(mddev, bits);
656 static void flush_pending_writes(struct r1conf *conf)
658 /* Any writes that have been queued but are awaiting
659 * bitmap updates get flushed here.
661 spin_lock_irq(&conf->device_lock);
663 if (conf->pending_bio_list.head) {
665 bio = bio_list_get(&conf->pending_bio_list);
666 conf->pending_count = 0;
667 spin_unlock_irq(&conf->device_lock);
668 /* flush any pending bitmap writes to
669 * disk before proceeding w/ I/O */
670 bitmap_unplug(conf->mddev->bitmap);
671 wake_up(&conf->wait_barrier);
673 while (bio) { /* submit pending writes */
674 struct bio *next = bio->bi_next;
676 generic_make_request(bio);
680 spin_unlock_irq(&conf->device_lock);
684 * Sometimes we need to suspend IO while we do something else,
685 * either some resync/recovery, or reconfigure the array.
686 * To do this we raise a 'barrier'.
687 * The 'barrier' is a counter that can be raised multiple times
688 * to count how many activities are happening which preclude
690 * We can only raise the barrier if there is no pending IO.
691 * i.e. if nr_pending == 0.
692 * We choose only to raise the barrier if no-one is waiting for the
693 * barrier to go down. This means that as soon as an IO request
694 * is ready, no other operations which require a barrier will start
695 * until the IO request has had a chance.
697 * So: regular IO calls 'wait_barrier'. When that returns there
698 * is no backgroup IO happening, It must arrange to call
699 * allow_barrier when it has finished its IO.
700 * backgroup IO calls must call raise_barrier. Once that returns
701 * there is no normal IO happeing. It must arrange to call
702 * lower_barrier when the particular background IO completes.
704 #define RESYNC_DEPTH 32
706 static void raise_barrier(struct r1conf *conf)
708 spin_lock_irq(&conf->resync_lock);
710 /* Wait until no block IO is waiting */
711 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
712 conf->resync_lock, );
714 /* block any new IO from starting */
717 /* Now wait for all pending IO to complete */
718 wait_event_lock_irq(conf->wait_barrier,
719 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
720 conf->resync_lock, );
722 spin_unlock_irq(&conf->resync_lock);
725 static void lower_barrier(struct r1conf *conf)
728 BUG_ON(conf->barrier <= 0);
729 spin_lock_irqsave(&conf->resync_lock, flags);
731 spin_unlock_irqrestore(&conf->resync_lock, flags);
732 wake_up(&conf->wait_barrier);
735 static void wait_barrier(struct r1conf *conf)
737 spin_lock_irq(&conf->resync_lock);
740 /* Wait for the barrier to drop.
741 * However if there are already pending
742 * requests (preventing the barrier from
743 * rising completely), and the
744 * pre-process bio queue isn't empty,
745 * then don't wait, as we need to empty
746 * that queue to get the nr_pending
749 wait_event_lock_irq(conf->wait_barrier,
753 !bio_list_empty(current->bio_list)),
759 spin_unlock_irq(&conf->resync_lock);
762 static void allow_barrier(struct r1conf *conf)
765 spin_lock_irqsave(&conf->resync_lock, flags);
767 spin_unlock_irqrestore(&conf->resync_lock, flags);
768 wake_up(&conf->wait_barrier);
771 static void freeze_array(struct r1conf *conf)
773 /* stop syncio and normal IO and wait for everything to
775 * We increment barrier and nr_waiting, and then
776 * wait until nr_pending match nr_queued+1
777 * This is called in the context of one normal IO request
778 * that has failed. Thus any sync request that might be pending
779 * will be blocked by nr_pending, and we need to wait for
780 * pending IO requests to complete or be queued for re-try.
781 * Thus the number queued (nr_queued) plus this request (1)
782 * must match the number of pending IOs (nr_pending) before
785 spin_lock_irq(&conf->resync_lock);
788 wait_event_lock_irq(conf->wait_barrier,
789 conf->nr_pending == conf->nr_queued+1,
791 flush_pending_writes(conf));
792 spin_unlock_irq(&conf->resync_lock);
794 static void unfreeze_array(struct r1conf *conf)
796 /* reverse the effect of the freeze */
797 spin_lock_irq(&conf->resync_lock);
800 wake_up(&conf->wait_barrier);
801 spin_unlock_irq(&conf->resync_lock);
805 /* duplicate the data pages for behind I/O
807 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
810 struct bio_vec *bvec;
811 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
813 if (unlikely(!bvecs))
816 bio_for_each_segment(bvec, bio, i) {
818 bvecs[i].bv_page = alloc_page(GFP_NOIO);
819 if (unlikely(!bvecs[i].bv_page))
821 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
822 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
823 kunmap(bvecs[i].bv_page);
824 kunmap(bvec->bv_page);
826 r1_bio->behind_bvecs = bvecs;
827 r1_bio->behind_page_count = bio->bi_vcnt;
828 set_bit(R1BIO_BehindIO, &r1_bio->state);
832 for (i = 0; i < bio->bi_vcnt; i++)
833 if (bvecs[i].bv_page)
834 put_page(bvecs[i].bv_page);
836 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
839 static void make_request(struct mddev *mddev, struct bio * bio)
841 struct r1conf *conf = mddev->private;
842 struct mirror_info *mirror;
843 struct r1bio *r1_bio;
844 struct bio *read_bio;
846 struct bitmap *bitmap;
848 const int rw = bio_data_dir(bio);
849 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
850 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
851 struct md_rdev *blocked_rdev;
858 * Register the new request and wait if the reconstruction
859 * thread has put up a bar for new requests.
860 * Continue immediately if no resync is active currently.
863 md_write_start(mddev, bio); /* wait on superblock update early */
865 if (bio_data_dir(bio) == WRITE &&
866 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
867 bio->bi_sector < mddev->suspend_hi) {
868 /* As the suspend_* range is controlled by
869 * userspace, we want an interruptible
874 flush_signals(current);
875 prepare_to_wait(&conf->wait_barrier,
876 &w, TASK_INTERRUPTIBLE);
877 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
878 bio->bi_sector >= mddev->suspend_hi)
882 finish_wait(&conf->wait_barrier, &w);
887 bitmap = mddev->bitmap;
890 * make_request() can abort the operation when READA is being
891 * used and no empty request is available.
894 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
896 r1_bio->master_bio = bio;
897 r1_bio->sectors = bio->bi_size >> 9;
899 r1_bio->mddev = mddev;
900 r1_bio->sector = bio->bi_sector;
902 /* We might need to issue multiple reads to different
903 * devices if there are bad blocks around, so we keep
904 * track of the number of reads in bio->bi_phys_segments.
905 * If this is 0, there is only one r1_bio and no locking
906 * will be needed when requests complete. If it is
907 * non-zero, then it is the number of not-completed requests.
909 bio->bi_phys_segments = 0;
910 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
914 * read balancing logic:
919 rdisk = read_balance(conf, r1_bio, &max_sectors);
922 /* couldn't find anywhere to read from */
923 raid_end_bio_io(r1_bio);
926 mirror = conf->mirrors + rdisk;
928 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
930 /* Reading from a write-mostly device must
931 * take care not to over-take any writes
934 wait_event(bitmap->behind_wait,
935 atomic_read(&bitmap->behind_writes) == 0);
937 r1_bio->read_disk = rdisk;
939 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
940 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
943 r1_bio->bios[rdisk] = read_bio;
945 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
946 read_bio->bi_bdev = mirror->rdev->bdev;
947 read_bio->bi_end_io = raid1_end_read_request;
948 read_bio->bi_rw = READ | do_sync;
949 read_bio->bi_private = r1_bio;
951 if (max_sectors < r1_bio->sectors) {
952 /* could not read all from this device, so we will
953 * need another r1_bio.
956 sectors_handled = (r1_bio->sector + max_sectors
958 r1_bio->sectors = max_sectors;
959 spin_lock_irq(&conf->device_lock);
960 if (bio->bi_phys_segments == 0)
961 bio->bi_phys_segments = 2;
963 bio->bi_phys_segments++;
964 spin_unlock_irq(&conf->device_lock);
965 /* Cannot call generic_make_request directly
966 * as that will be queued in __make_request
967 * and subsequent mempool_alloc might block waiting
968 * for it. So hand bio over to raid1d.
970 reschedule_retry(r1_bio);
972 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
974 r1_bio->master_bio = bio;
975 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
977 r1_bio->mddev = mddev;
978 r1_bio->sector = bio->bi_sector + sectors_handled;
981 generic_make_request(read_bio);
988 if (conf->pending_count >= max_queued_requests) {
989 md_wakeup_thread(mddev->thread);
990 wait_event(conf->wait_barrier,
991 conf->pending_count < max_queued_requests);
993 /* first select target devices under rcu_lock and
994 * inc refcount on their rdev. Record them by setting
996 * If there are known/acknowledged bad blocks on any device on
997 * which we have seen a write error, we want to avoid writing those
999 * This potentially requires several writes to write around
1000 * the bad blocks. Each set of writes gets it's own r1bio
1001 * with a set of bios attached.
1003 plugged = mddev_check_plugged(mddev);
1005 disks = conf->raid_disks * 2;
1007 blocked_rdev = NULL;
1009 max_sectors = r1_bio->sectors;
1010 for (i = 0; i < disks; i++) {
1011 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1012 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1013 atomic_inc(&rdev->nr_pending);
1014 blocked_rdev = rdev;
1017 r1_bio->bios[i] = NULL;
1018 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1019 if (i < conf->raid_disks)
1020 set_bit(R1BIO_Degraded, &r1_bio->state);
1024 atomic_inc(&rdev->nr_pending);
1025 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1030 is_bad = is_badblock(rdev, r1_bio->sector,
1032 &first_bad, &bad_sectors);
1034 /* mustn't write here until the bad block is
1036 set_bit(BlockedBadBlocks, &rdev->flags);
1037 blocked_rdev = rdev;
1040 if (is_bad && first_bad <= r1_bio->sector) {
1041 /* Cannot write here at all */
1042 bad_sectors -= (r1_bio->sector - first_bad);
1043 if (bad_sectors < max_sectors)
1044 /* mustn't write more than bad_sectors
1045 * to other devices yet
1047 max_sectors = bad_sectors;
1048 rdev_dec_pending(rdev, mddev);
1049 /* We don't set R1BIO_Degraded as that
1050 * only applies if the disk is
1051 * missing, so it might be re-added,
1052 * and we want to know to recover this
1054 * In this case the device is here,
1055 * and the fact that this chunk is not
1056 * in-sync is recorded in the bad
1062 int good_sectors = first_bad - r1_bio->sector;
1063 if (good_sectors < max_sectors)
1064 max_sectors = good_sectors;
1067 r1_bio->bios[i] = bio;
1071 if (unlikely(blocked_rdev)) {
1072 /* Wait for this device to become unblocked */
1075 for (j = 0; j < i; j++)
1076 if (r1_bio->bios[j])
1077 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1079 allow_barrier(conf);
1080 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1085 if (max_sectors < r1_bio->sectors) {
1086 /* We are splitting this write into multiple parts, so
1087 * we need to prepare for allocating another r1_bio.
1089 r1_bio->sectors = max_sectors;
1090 spin_lock_irq(&conf->device_lock);
1091 if (bio->bi_phys_segments == 0)
1092 bio->bi_phys_segments = 2;
1094 bio->bi_phys_segments++;
1095 spin_unlock_irq(&conf->device_lock);
1097 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1099 atomic_set(&r1_bio->remaining, 1);
1100 atomic_set(&r1_bio->behind_remaining, 0);
1103 for (i = 0; i < disks; i++) {
1105 if (!r1_bio->bios[i])
1108 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1109 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1113 * Not if there are too many, or cannot
1114 * allocate memory, or a reader on WriteMostly
1115 * is waiting for behind writes to flush */
1117 (atomic_read(&bitmap->behind_writes)
1118 < mddev->bitmap_info.max_write_behind) &&
1119 !waitqueue_active(&bitmap->behind_wait))
1120 alloc_behind_pages(mbio, r1_bio);
1122 bitmap_startwrite(bitmap, r1_bio->sector,
1124 test_bit(R1BIO_BehindIO,
1128 if (r1_bio->behind_bvecs) {
1129 struct bio_vec *bvec;
1132 /* Yes, I really want the '__' version so that
1133 * we clear any unused pointer in the io_vec, rather
1134 * than leave them unchanged. This is important
1135 * because when we come to free the pages, we won't
1136 * know the original bi_idx, so we just free
1139 __bio_for_each_segment(bvec, mbio, j, 0)
1140 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1141 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1142 atomic_inc(&r1_bio->behind_remaining);
1145 r1_bio->bios[i] = mbio;
1147 mbio->bi_sector = (r1_bio->sector +
1148 conf->mirrors[i].rdev->data_offset);
1149 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1150 mbio->bi_end_io = raid1_end_write_request;
1151 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
1152 mbio->bi_private = r1_bio;
1154 atomic_inc(&r1_bio->remaining);
1155 spin_lock_irqsave(&conf->device_lock, flags);
1156 bio_list_add(&conf->pending_bio_list, mbio);
1157 conf->pending_count++;
1158 spin_unlock_irqrestore(&conf->device_lock, flags);
1160 /* Mustn't call r1_bio_write_done before this next test,
1161 * as it could result in the bio being freed.
1163 if (sectors_handled < (bio->bi_size >> 9)) {
1164 r1_bio_write_done(r1_bio);
1165 /* We need another r1_bio. It has already been counted
1166 * in bio->bi_phys_segments
1168 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1169 r1_bio->master_bio = bio;
1170 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1172 r1_bio->mddev = mddev;
1173 r1_bio->sector = bio->bi_sector + sectors_handled;
1177 r1_bio_write_done(r1_bio);
1179 /* In case raid1d snuck in to freeze_array */
1180 wake_up(&conf->wait_barrier);
1182 if (do_sync || !bitmap || !plugged)
1183 md_wakeup_thread(mddev->thread);
1186 static void status(struct seq_file *seq, struct mddev *mddev)
1188 struct r1conf *conf = mddev->private;
1191 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1192 conf->raid_disks - mddev->degraded);
1194 for (i = 0; i < conf->raid_disks; i++) {
1195 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1196 seq_printf(seq, "%s",
1197 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1200 seq_printf(seq, "]");
1204 static void error(struct mddev *mddev, struct md_rdev *rdev)
1206 char b[BDEVNAME_SIZE];
1207 struct r1conf *conf = mddev->private;
1210 * If it is not operational, then we have already marked it as dead
1211 * else if it is the last working disks, ignore the error, let the
1212 * next level up know.
1213 * else mark the drive as failed
1215 if (test_bit(In_sync, &rdev->flags)
1216 && (conf->raid_disks - mddev->degraded) == 1) {
1218 * Don't fail the drive, act as though we were just a
1219 * normal single drive.
1220 * However don't try a recovery from this drive as
1221 * it is very likely to fail.
1223 conf->recovery_disabled = mddev->recovery_disabled;
1226 set_bit(Blocked, &rdev->flags);
1227 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1228 unsigned long flags;
1229 spin_lock_irqsave(&conf->device_lock, flags);
1231 set_bit(Faulty, &rdev->flags);
1232 spin_unlock_irqrestore(&conf->device_lock, flags);
1234 * if recovery is running, make sure it aborts.
1236 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1238 set_bit(Faulty, &rdev->flags);
1239 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1241 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1242 "md/raid1:%s: Operation continuing on %d devices.\n",
1243 mdname(mddev), bdevname(rdev->bdev, b),
1244 mdname(mddev), conf->raid_disks - mddev->degraded);
1247 static void print_conf(struct r1conf *conf)
1251 printk(KERN_DEBUG "RAID1 conf printout:\n");
1253 printk(KERN_DEBUG "(!conf)\n");
1256 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1260 for (i = 0; i < conf->raid_disks; i++) {
1261 char b[BDEVNAME_SIZE];
1262 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1264 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1265 i, !test_bit(In_sync, &rdev->flags),
1266 !test_bit(Faulty, &rdev->flags),
1267 bdevname(rdev->bdev,b));
1272 static void close_sync(struct r1conf *conf)
1275 allow_barrier(conf);
1277 mempool_destroy(conf->r1buf_pool);
1278 conf->r1buf_pool = NULL;
1281 static int raid1_spare_active(struct mddev *mddev)
1284 struct r1conf *conf = mddev->private;
1286 unsigned long flags;
1289 * Find all failed disks within the RAID1 configuration
1290 * and mark them readable.
1291 * Called under mddev lock, so rcu protection not needed.
1293 for (i = 0; i < conf->raid_disks; i++) {
1294 struct md_rdev *rdev = conf->mirrors[i].rdev;
1295 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1297 && repl->recovery_offset == MaxSector
1298 && !test_bit(Faulty, &repl->flags)
1299 && !test_and_set_bit(In_sync, &repl->flags)) {
1300 /* replacement has just become active */
1302 !test_and_clear_bit(In_sync, &rdev->flags))
1305 /* Replaced device not technically
1306 * faulty, but we need to be sure
1307 * it gets removed and never re-added
1309 set_bit(Faulty, &rdev->flags);
1310 sysfs_notify_dirent_safe(
1315 && !test_bit(Faulty, &rdev->flags)
1316 && !test_and_set_bit(In_sync, &rdev->flags)) {
1318 sysfs_notify_dirent_safe(rdev->sysfs_state);
1321 spin_lock_irqsave(&conf->device_lock, flags);
1322 mddev->degraded -= count;
1323 spin_unlock_irqrestore(&conf->device_lock, flags);
1330 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1332 struct r1conf *conf = mddev->private;
1335 struct mirror_info *p;
1337 int last = conf->raid_disks - 1;
1339 if (mddev->recovery_disabled == conf->recovery_disabled)
1342 if (rdev->raid_disk >= 0)
1343 first = last = rdev->raid_disk;
1345 for (mirror = first; mirror <= last; mirror++) {
1346 p = conf->mirrors+mirror;
1349 disk_stack_limits(mddev->gendisk, rdev->bdev,
1350 rdev->data_offset << 9);
1351 /* as we don't honour merge_bvec_fn, we must
1352 * never risk violating it, so limit
1353 * ->max_segments to one lying with a single
1354 * page, as a one page request is never in
1357 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1358 blk_queue_max_segments(mddev->queue, 1);
1359 blk_queue_segment_boundary(mddev->queue,
1360 PAGE_CACHE_SIZE - 1);
1363 p->head_position = 0;
1364 rdev->raid_disk = mirror;
1366 /* As all devices are equivalent, we don't need a full recovery
1367 * if this was recently any drive of the array
1369 if (rdev->saved_raid_disk < 0)
1371 rcu_assign_pointer(p->rdev, rdev);
1374 if (test_bit(WantReplacement, &p->rdev->flags) &&
1375 p[conf->raid_disks].rdev == NULL) {
1376 /* Add this device as a replacement */
1377 clear_bit(In_sync, &rdev->flags);
1378 set_bit(Replacement, &rdev->flags);
1379 rdev->raid_disk = mirror;
1382 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1386 md_integrity_add_rdev(rdev, mddev);
1391 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1393 struct r1conf *conf = mddev->private;
1395 int number = rdev->raid_disk;
1396 struct mirror_info *p = conf->mirrors+ number;
1398 if (rdev != p->rdev)
1399 p = conf->mirrors + conf->raid_disks + number;
1402 if (rdev == p->rdev) {
1403 if (test_bit(In_sync, &rdev->flags) ||
1404 atomic_read(&rdev->nr_pending)) {
1408 /* Only remove non-faulty devices if recovery
1411 if (!test_bit(Faulty, &rdev->flags) &&
1412 mddev->recovery_disabled != conf->recovery_disabled &&
1413 mddev->degraded < conf->raid_disks) {
1419 if (atomic_read(&rdev->nr_pending)) {
1420 /* lost the race, try later */
1424 } else if (conf->mirrors[conf->raid_disks + number].rdev) {
1425 /* We just removed a device that is being replaced.
1426 * Move down the replacement. We drain all IO before
1427 * doing this to avoid confusion.
1429 struct md_rdev *repl =
1430 conf->mirrors[conf->raid_disks + number].rdev;
1431 raise_barrier(conf);
1432 clear_bit(Replacement, &repl->flags);
1434 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1435 lower_barrier(conf);
1436 clear_bit(WantReplacement, &rdev->flags);
1438 clear_bit(WantReplacement, &rdev->flags);
1439 err = md_integrity_register(mddev);
1448 static void end_sync_read(struct bio *bio, int error)
1450 struct r1bio *r1_bio = bio->bi_private;
1452 update_head_pos(r1_bio->read_disk, r1_bio);
1455 * we have read a block, now it needs to be re-written,
1456 * or re-read if the read failed.
1457 * We don't do much here, just schedule handling by raid1d
1459 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1460 set_bit(R1BIO_Uptodate, &r1_bio->state);
1462 if (atomic_dec_and_test(&r1_bio->remaining))
1463 reschedule_retry(r1_bio);
1466 static void end_sync_write(struct bio *bio, int error)
1468 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1469 struct r1bio *r1_bio = bio->bi_private;
1470 struct mddev *mddev = r1_bio->mddev;
1471 struct r1conf *conf = mddev->private;
1476 mirror = find_bio_disk(r1_bio, bio);
1479 sector_t sync_blocks = 0;
1480 sector_t s = r1_bio->sector;
1481 long sectors_to_go = r1_bio->sectors;
1482 /* make sure these bits doesn't get cleared. */
1484 bitmap_end_sync(mddev->bitmap, s,
1487 sectors_to_go -= sync_blocks;
1488 } while (sectors_to_go > 0);
1489 set_bit(WriteErrorSeen,
1490 &conf->mirrors[mirror].rdev->flags);
1491 if (!test_and_set_bit(WantReplacement,
1492 &conf->mirrors[mirror].rdev->flags))
1493 set_bit(MD_RECOVERY_NEEDED, &
1495 set_bit(R1BIO_WriteError, &r1_bio->state);
1496 } else if (is_badblock(conf->mirrors[mirror].rdev,
1499 &first_bad, &bad_sectors) &&
1500 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1503 &first_bad, &bad_sectors)
1505 set_bit(R1BIO_MadeGood, &r1_bio->state);
1507 if (atomic_dec_and_test(&r1_bio->remaining)) {
1508 int s = r1_bio->sectors;
1509 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1510 test_bit(R1BIO_WriteError, &r1_bio->state))
1511 reschedule_retry(r1_bio);
1514 md_done_sync(mddev, s, uptodate);
1519 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1520 int sectors, struct page *page, int rw)
1522 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1526 set_bit(WriteErrorSeen, &rdev->flags);
1527 if (!test_and_set_bit(WantReplacement,
1529 set_bit(MD_RECOVERY_NEEDED, &
1530 rdev->mddev->recovery);
1532 /* need to record an error - either for the block or the device */
1533 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1534 md_error(rdev->mddev, rdev);
1538 static int fix_sync_read_error(struct r1bio *r1_bio)
1540 /* Try some synchronous reads of other devices to get
1541 * good data, much like with normal read errors. Only
1542 * read into the pages we already have so we don't
1543 * need to re-issue the read request.
1544 * We don't need to freeze the array, because being in an
1545 * active sync request, there is no normal IO, and
1546 * no overlapping syncs.
1547 * We don't need to check is_badblock() again as we
1548 * made sure that anything with a bad block in range
1549 * will have bi_end_io clear.
1551 struct mddev *mddev = r1_bio->mddev;
1552 struct r1conf *conf = mddev->private;
1553 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1554 sector_t sect = r1_bio->sector;
1555 int sectors = r1_bio->sectors;
1560 int d = r1_bio->read_disk;
1562 struct md_rdev *rdev;
1565 if (s > (PAGE_SIZE>>9))
1568 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1569 /* No rcu protection needed here devices
1570 * can only be removed when no resync is
1571 * active, and resync is currently active
1573 rdev = conf->mirrors[d].rdev;
1574 if (sync_page_io(rdev, sect, s<<9,
1575 bio->bi_io_vec[idx].bv_page,
1582 if (d == conf->raid_disks * 2)
1584 } while (!success && d != r1_bio->read_disk);
1587 char b[BDEVNAME_SIZE];
1589 /* Cannot read from anywhere, this block is lost.
1590 * Record a bad block on each device. If that doesn't
1591 * work just disable and interrupt the recovery.
1592 * Don't fail devices as that won't really help.
1594 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1595 " for block %llu\n",
1597 bdevname(bio->bi_bdev, b),
1598 (unsigned long long)r1_bio->sector);
1599 for (d = 0; d < conf->raid_disks * 2; d++) {
1600 rdev = conf->mirrors[d].rdev;
1601 if (!rdev || test_bit(Faulty, &rdev->flags))
1603 if (!rdev_set_badblocks(rdev, sect, s, 0))
1607 conf->recovery_disabled =
1608 mddev->recovery_disabled;
1609 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1610 md_done_sync(mddev, r1_bio->sectors, 0);
1622 /* write it back and re-read */
1623 while (d != r1_bio->read_disk) {
1625 d = conf->raid_disks * 2;
1627 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1629 rdev = conf->mirrors[d].rdev;
1630 if (r1_sync_page_io(rdev, sect, s,
1631 bio->bi_io_vec[idx].bv_page,
1633 r1_bio->bios[d]->bi_end_io = NULL;
1634 rdev_dec_pending(rdev, mddev);
1638 while (d != r1_bio->read_disk) {
1640 d = conf->raid_disks * 2;
1642 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1644 rdev = conf->mirrors[d].rdev;
1645 if (r1_sync_page_io(rdev, sect, s,
1646 bio->bi_io_vec[idx].bv_page,
1648 atomic_add(s, &rdev->corrected_errors);
1654 set_bit(R1BIO_Uptodate, &r1_bio->state);
1655 set_bit(BIO_UPTODATE, &bio->bi_flags);
1659 static int process_checks(struct r1bio *r1_bio)
1661 /* We have read all readable devices. If we haven't
1662 * got the block, then there is no hope left.
1663 * If we have, then we want to do a comparison
1664 * and skip the write if everything is the same.
1665 * If any blocks failed to read, then we need to
1666 * attempt an over-write
1668 struct mddev *mddev = r1_bio->mddev;
1669 struct r1conf *conf = mddev->private;
1673 for (primary = 0; primary < conf->raid_disks * 2; primary++)
1674 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1675 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1676 r1_bio->bios[primary]->bi_end_io = NULL;
1677 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1680 r1_bio->read_disk = primary;
1681 for (i = 0; i < conf->raid_disks * 2; i++) {
1683 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1684 struct bio *pbio = r1_bio->bios[primary];
1685 struct bio *sbio = r1_bio->bios[i];
1688 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1691 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1692 for (j = vcnt; j-- ; ) {
1694 p = pbio->bi_io_vec[j].bv_page;
1695 s = sbio->bi_io_vec[j].bv_page;
1696 if (memcmp(page_address(p),
1704 mddev->resync_mismatches += r1_bio->sectors;
1705 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1706 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1707 /* No need to write to this device. */
1708 sbio->bi_end_io = NULL;
1709 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1712 /* fixup the bio for reuse */
1713 sbio->bi_vcnt = vcnt;
1714 sbio->bi_size = r1_bio->sectors << 9;
1716 sbio->bi_phys_segments = 0;
1717 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1718 sbio->bi_flags |= 1 << BIO_UPTODATE;
1719 sbio->bi_next = NULL;
1720 sbio->bi_sector = r1_bio->sector +
1721 conf->mirrors[i].rdev->data_offset;
1722 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1723 size = sbio->bi_size;
1724 for (j = 0; j < vcnt ; j++) {
1726 bi = &sbio->bi_io_vec[j];
1728 if (size > PAGE_SIZE)
1729 bi->bv_len = PAGE_SIZE;
1733 memcpy(page_address(bi->bv_page),
1734 page_address(pbio->bi_io_vec[j].bv_page),
1741 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1743 struct r1conf *conf = mddev->private;
1745 int disks = conf->raid_disks * 2;
1746 struct bio *bio, *wbio;
1748 bio = r1_bio->bios[r1_bio->read_disk];
1750 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1751 /* ouch - failed to read all of that. */
1752 if (!fix_sync_read_error(r1_bio))
1755 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1756 if (process_checks(r1_bio) < 0)
1761 atomic_set(&r1_bio->remaining, 1);
1762 for (i = 0; i < disks ; i++) {
1763 wbio = r1_bio->bios[i];
1764 if (wbio->bi_end_io == NULL ||
1765 (wbio->bi_end_io == end_sync_read &&
1766 (i == r1_bio->read_disk ||
1767 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1770 wbio->bi_rw = WRITE;
1771 wbio->bi_end_io = end_sync_write;
1772 atomic_inc(&r1_bio->remaining);
1773 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1775 generic_make_request(wbio);
1778 if (atomic_dec_and_test(&r1_bio->remaining)) {
1779 /* if we're here, all write(s) have completed, so clean up */
1780 md_done_sync(mddev, r1_bio->sectors, 1);
1786 * This is a kernel thread which:
1788 * 1. Retries failed read operations on working mirrors.
1789 * 2. Updates the raid superblock when problems encounter.
1790 * 3. Performs writes following reads for array synchronising.
1793 static void fix_read_error(struct r1conf *conf, int read_disk,
1794 sector_t sect, int sectors)
1796 struct mddev *mddev = conf->mddev;
1802 struct md_rdev *rdev;
1804 if (s > (PAGE_SIZE>>9))
1808 /* Note: no rcu protection needed here
1809 * as this is synchronous in the raid1d thread
1810 * which is the thread that might remove
1811 * a device. If raid1d ever becomes multi-threaded....
1816 rdev = conf->mirrors[d].rdev;
1818 test_bit(In_sync, &rdev->flags) &&
1819 is_badblock(rdev, sect, s,
1820 &first_bad, &bad_sectors) == 0 &&
1821 sync_page_io(rdev, sect, s<<9,
1822 conf->tmppage, READ, false))
1826 if (d == conf->raid_disks * 2)
1829 } while (!success && d != read_disk);
1832 /* Cannot read from anywhere - mark it bad */
1833 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
1834 if (!rdev_set_badblocks(rdev, sect, s, 0))
1835 md_error(mddev, rdev);
1838 /* write it back and re-read */
1840 while (d != read_disk) {
1842 d = conf->raid_disks * 2;
1844 rdev = conf->mirrors[d].rdev;
1846 test_bit(In_sync, &rdev->flags))
1847 r1_sync_page_io(rdev, sect, s,
1848 conf->tmppage, WRITE);
1851 while (d != read_disk) {
1852 char b[BDEVNAME_SIZE];
1854 d = conf->raid_disks * 2;
1856 rdev = conf->mirrors[d].rdev;
1858 test_bit(In_sync, &rdev->flags)) {
1859 if (r1_sync_page_io(rdev, sect, s,
1860 conf->tmppage, READ)) {
1861 atomic_add(s, &rdev->corrected_errors);
1863 "md/raid1:%s: read error corrected "
1864 "(%d sectors at %llu on %s)\n",
1866 (unsigned long long)(sect +
1868 bdevname(rdev->bdev, b));
1877 static void bi_complete(struct bio *bio, int error)
1879 complete((struct completion *)bio->bi_private);
1882 static int submit_bio_wait(int rw, struct bio *bio)
1884 struct completion event;
1887 init_completion(&event);
1888 bio->bi_private = &event;
1889 bio->bi_end_io = bi_complete;
1890 submit_bio(rw, bio);
1891 wait_for_completion(&event);
1893 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1896 static int narrow_write_error(struct r1bio *r1_bio, int i)
1898 struct mddev *mddev = r1_bio->mddev;
1899 struct r1conf *conf = mddev->private;
1900 struct md_rdev *rdev = conf->mirrors[i].rdev;
1902 struct bio_vec *vec;
1904 /* bio has the data to be written to device 'i' where
1905 * we just recently had a write error.
1906 * We repeatedly clone the bio and trim down to one block,
1907 * then try the write. Where the write fails we record
1909 * It is conceivable that the bio doesn't exactly align with
1910 * blocks. We must handle this somehow.
1912 * We currently own a reference on the rdev.
1918 int sect_to_write = r1_bio->sectors;
1921 if (rdev->badblocks.shift < 0)
1924 block_sectors = 1 << rdev->badblocks.shift;
1925 sector = r1_bio->sector;
1926 sectors = ((sector + block_sectors)
1927 & ~(sector_t)(block_sectors - 1))
1930 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1931 vcnt = r1_bio->behind_page_count;
1932 vec = r1_bio->behind_bvecs;
1934 while (vec[idx].bv_page == NULL)
1937 vcnt = r1_bio->master_bio->bi_vcnt;
1938 vec = r1_bio->master_bio->bi_io_vec;
1939 idx = r1_bio->master_bio->bi_idx;
1941 while (sect_to_write) {
1943 if (sectors > sect_to_write)
1944 sectors = sect_to_write;
1945 /* Write at 'sector' for 'sectors'*/
1947 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1948 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1949 wbio->bi_sector = r1_bio->sector;
1950 wbio->bi_rw = WRITE;
1951 wbio->bi_vcnt = vcnt;
1952 wbio->bi_size = r1_bio->sectors << 9;
1955 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
1956 wbio->bi_sector += rdev->data_offset;
1957 wbio->bi_bdev = rdev->bdev;
1958 if (submit_bio_wait(WRITE, wbio) == 0)
1960 ok = rdev_set_badblocks(rdev, sector,
1965 sect_to_write -= sectors;
1967 sectors = block_sectors;
1972 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1975 int s = r1_bio->sectors;
1976 for (m = 0; m < conf->raid_disks * 2 ; m++) {
1977 struct md_rdev *rdev = conf->mirrors[m].rdev;
1978 struct bio *bio = r1_bio->bios[m];
1979 if (bio->bi_end_io == NULL)
1981 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1982 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
1983 rdev_clear_badblocks(rdev, r1_bio->sector, s);
1985 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1986 test_bit(R1BIO_WriteError, &r1_bio->state)) {
1987 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
1988 md_error(conf->mddev, rdev);
1992 md_done_sync(conf->mddev, s, 1);
1995 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1998 for (m = 0; m < conf->raid_disks * 2 ; m++)
1999 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2000 struct md_rdev *rdev = conf->mirrors[m].rdev;
2001 rdev_clear_badblocks(rdev,
2004 rdev_dec_pending(rdev, conf->mddev);
2005 } else if (r1_bio->bios[m] != NULL) {
2006 /* This drive got a write error. We need to
2007 * narrow down and record precise write
2010 if (!narrow_write_error(r1_bio, m)) {
2011 md_error(conf->mddev,
2012 conf->mirrors[m].rdev);
2013 /* an I/O failed, we can't clear the bitmap */
2014 set_bit(R1BIO_Degraded, &r1_bio->state);
2016 rdev_dec_pending(conf->mirrors[m].rdev,
2019 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2020 close_write(r1_bio);
2021 raid_end_bio_io(r1_bio);
2024 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2028 struct mddev *mddev = conf->mddev;
2030 char b[BDEVNAME_SIZE];
2031 struct md_rdev *rdev;
2033 clear_bit(R1BIO_ReadError, &r1_bio->state);
2034 /* we got a read error. Maybe the drive is bad. Maybe just
2035 * the block and we can fix it.
2036 * We freeze all other IO, and try reading the block from
2037 * other devices. When we find one, we re-write
2038 * and check it that fixes the read error.
2039 * This is all done synchronously while the array is
2042 if (mddev->ro == 0) {
2044 fix_read_error(conf, r1_bio->read_disk,
2045 r1_bio->sector, r1_bio->sectors);
2046 unfreeze_array(conf);
2048 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2050 bio = r1_bio->bios[r1_bio->read_disk];
2051 bdevname(bio->bi_bdev, b);
2053 disk = read_balance(conf, r1_bio, &max_sectors);
2055 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
2056 " read error for block %llu\n",
2057 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2058 raid_end_bio_io(r1_bio);
2060 const unsigned long do_sync
2061 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2063 r1_bio->bios[r1_bio->read_disk] =
2064 mddev->ro ? IO_BLOCKED : NULL;
2067 r1_bio->read_disk = disk;
2068 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2069 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
2070 r1_bio->bios[r1_bio->read_disk] = bio;
2071 rdev = conf->mirrors[disk].rdev;
2072 printk_ratelimited(KERN_ERR
2073 "md/raid1:%s: redirecting sector %llu"
2074 " to other mirror: %s\n",
2076 (unsigned long long)r1_bio->sector,
2077 bdevname(rdev->bdev, b));
2078 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2079 bio->bi_bdev = rdev->bdev;
2080 bio->bi_end_io = raid1_end_read_request;
2081 bio->bi_rw = READ | do_sync;
2082 bio->bi_private = r1_bio;
2083 if (max_sectors < r1_bio->sectors) {
2084 /* Drat - have to split this up more */
2085 struct bio *mbio = r1_bio->master_bio;
2086 int sectors_handled = (r1_bio->sector + max_sectors
2088 r1_bio->sectors = max_sectors;
2089 spin_lock_irq(&conf->device_lock);
2090 if (mbio->bi_phys_segments == 0)
2091 mbio->bi_phys_segments = 2;
2093 mbio->bi_phys_segments++;
2094 spin_unlock_irq(&conf->device_lock);
2095 generic_make_request(bio);
2098 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2100 r1_bio->master_bio = mbio;
2101 r1_bio->sectors = (mbio->bi_size >> 9)
2104 set_bit(R1BIO_ReadError, &r1_bio->state);
2105 r1_bio->mddev = mddev;
2106 r1_bio->sector = mbio->bi_sector + sectors_handled;
2110 generic_make_request(bio);
2114 static void raid1d(struct mddev *mddev)
2116 struct r1bio *r1_bio;
2117 unsigned long flags;
2118 struct r1conf *conf = mddev->private;
2119 struct list_head *head = &conf->retry_list;
2120 struct blk_plug plug;
2122 md_check_recovery(mddev);
2124 blk_start_plug(&plug);
2127 if (atomic_read(&mddev->plug_cnt) == 0)
2128 flush_pending_writes(conf);
2130 spin_lock_irqsave(&conf->device_lock, flags);
2131 if (list_empty(head)) {
2132 spin_unlock_irqrestore(&conf->device_lock, flags);
2135 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2136 list_del(head->prev);
2138 spin_unlock_irqrestore(&conf->device_lock, flags);
2140 mddev = r1_bio->mddev;
2141 conf = mddev->private;
2142 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2143 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2144 test_bit(R1BIO_WriteError, &r1_bio->state))
2145 handle_sync_write_finished(conf, r1_bio);
2147 sync_request_write(mddev, r1_bio);
2148 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2149 test_bit(R1BIO_WriteError, &r1_bio->state))
2150 handle_write_finished(conf, r1_bio);
2151 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2152 handle_read_error(conf, r1_bio);
2154 /* just a partial read to be scheduled from separate
2157 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2160 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2161 md_check_recovery(mddev);
2163 blk_finish_plug(&plug);
2167 static int init_resync(struct r1conf *conf)
2171 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2172 BUG_ON(conf->r1buf_pool);
2173 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2175 if (!conf->r1buf_pool)
2177 conf->next_resync = 0;
2182 * perform a "sync" on one "block"
2184 * We need to make sure that no normal I/O request - particularly write
2185 * requests - conflict with active sync requests.
2187 * This is achieved by tracking pending requests and a 'barrier' concept
2188 * that can be installed to exclude normal IO requests.
2191 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2193 struct r1conf *conf = mddev->private;
2194 struct r1bio *r1_bio;
2196 sector_t max_sector, nr_sectors;
2200 int write_targets = 0, read_targets = 0;
2201 sector_t sync_blocks;
2202 int still_degraded = 0;
2203 int good_sectors = RESYNC_SECTORS;
2204 int min_bad = 0; /* number of sectors that are bad in all devices */
2206 if (!conf->r1buf_pool)
2207 if (init_resync(conf))
2210 max_sector = mddev->dev_sectors;
2211 if (sector_nr >= max_sector) {
2212 /* If we aborted, we need to abort the
2213 * sync on the 'current' bitmap chunk (there will
2214 * only be one in raid1 resync.
2215 * We can find the current addess in mddev->curr_resync
2217 if (mddev->curr_resync < max_sector) /* aborted */
2218 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2220 else /* completed sync */
2223 bitmap_close_sync(mddev->bitmap);
2228 if (mddev->bitmap == NULL &&
2229 mddev->recovery_cp == MaxSector &&
2230 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2231 conf->fullsync == 0) {
2233 return max_sector - sector_nr;
2235 /* before building a request, check if we can skip these blocks..
2236 * This call the bitmap_start_sync doesn't actually record anything
2238 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2239 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2240 /* We can skip this block, and probably several more */
2245 * If there is non-resync activity waiting for a turn,
2246 * and resync is going fast enough,
2247 * then let it though before starting on this new sync request.
2249 if (!go_faster && conf->nr_waiting)
2250 msleep_interruptible(1000);
2252 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2253 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2254 raise_barrier(conf);
2256 conf->next_resync = sector_nr;
2260 * If we get a correctably read error during resync or recovery,
2261 * we might want to read from a different device. So we
2262 * flag all drives that could conceivably be read from for READ,
2263 * and any others (which will be non-In_sync devices) for WRITE.
2264 * If a read fails, we try reading from something else for which READ
2268 r1_bio->mddev = mddev;
2269 r1_bio->sector = sector_nr;
2271 set_bit(R1BIO_IsSync, &r1_bio->state);
2273 for (i = 0; i < conf->raid_disks * 2; i++) {
2274 struct md_rdev *rdev;
2275 bio = r1_bio->bios[i];
2277 /* take from bio_init */
2278 bio->bi_next = NULL;
2279 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2280 bio->bi_flags |= 1 << BIO_UPTODATE;
2284 bio->bi_phys_segments = 0;
2286 bio->bi_end_io = NULL;
2287 bio->bi_private = NULL;
2289 rdev = rcu_dereference(conf->mirrors[i].rdev);
2291 test_bit(Faulty, &rdev->flags)) {
2292 if (i < conf->raid_disks)
2294 } else if (!test_bit(In_sync, &rdev->flags)) {
2296 bio->bi_end_io = end_sync_write;
2299 /* may need to read from here */
2300 sector_t first_bad = MaxSector;
2303 if (is_badblock(rdev, sector_nr, good_sectors,
2304 &first_bad, &bad_sectors)) {
2305 if (first_bad > sector_nr)
2306 good_sectors = first_bad - sector_nr;
2308 bad_sectors -= (sector_nr - first_bad);
2310 min_bad > bad_sectors)
2311 min_bad = bad_sectors;
2314 if (sector_nr < first_bad) {
2315 if (test_bit(WriteMostly, &rdev->flags)) {
2323 bio->bi_end_io = end_sync_read;
2327 if (bio->bi_end_io) {
2328 atomic_inc(&rdev->nr_pending);
2329 bio->bi_sector = sector_nr + rdev->data_offset;
2330 bio->bi_bdev = rdev->bdev;
2331 bio->bi_private = r1_bio;
2337 r1_bio->read_disk = disk;
2339 if (read_targets == 0 && min_bad > 0) {
2340 /* These sectors are bad on all InSync devices, so we
2341 * need to mark them bad on all write targets
2344 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2345 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2346 struct md_rdev *rdev =
2347 rcu_dereference(conf->mirrors[i].rdev);
2348 ok = rdev_set_badblocks(rdev, sector_nr,
2352 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2357 /* Cannot record the badblocks, so need to
2359 * If there are multiple read targets, could just
2360 * fail the really bad ones ???
2362 conf->recovery_disabled = mddev->recovery_disabled;
2363 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2369 if (min_bad > 0 && min_bad < good_sectors) {
2370 /* only resync enough to reach the next bad->good
2372 good_sectors = min_bad;
2375 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2376 /* extra read targets are also write targets */
2377 write_targets += read_targets-1;
2379 if (write_targets == 0 || read_targets == 0) {
2380 /* There is nowhere to write, so all non-sync
2381 * drives must be failed - so we are finished
2383 sector_t rv = max_sector - sector_nr;
2389 if (max_sector > mddev->resync_max)
2390 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2391 if (max_sector > sector_nr + good_sectors)
2392 max_sector = sector_nr + good_sectors;
2397 int len = PAGE_SIZE;
2398 if (sector_nr + (len>>9) > max_sector)
2399 len = (max_sector - sector_nr) << 9;
2402 if (sync_blocks == 0) {
2403 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2404 &sync_blocks, still_degraded) &&
2406 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2408 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2409 if ((len >> 9) > sync_blocks)
2410 len = sync_blocks<<9;
2413 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2414 bio = r1_bio->bios[i];
2415 if (bio->bi_end_io) {
2416 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2417 if (bio_add_page(bio, page, len, 0) == 0) {
2419 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2422 bio = r1_bio->bios[i];
2423 if (bio->bi_end_io==NULL)
2425 /* remove last page from this bio */
2427 bio->bi_size -= len;
2428 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2434 nr_sectors += len>>9;
2435 sector_nr += len>>9;
2436 sync_blocks -= (len>>9);
2437 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2439 r1_bio->sectors = nr_sectors;
2441 /* For a user-requested sync, we read all readable devices and do a
2444 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2445 atomic_set(&r1_bio->remaining, read_targets);
2446 for (i = 0; i < conf->raid_disks * 2; i++) {
2447 bio = r1_bio->bios[i];
2448 if (bio->bi_end_io == end_sync_read) {
2449 md_sync_acct(bio->bi_bdev, nr_sectors);
2450 generic_make_request(bio);
2454 atomic_set(&r1_bio->remaining, 1);
2455 bio = r1_bio->bios[r1_bio->read_disk];
2456 md_sync_acct(bio->bi_bdev, nr_sectors);
2457 generic_make_request(bio);
2463 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2468 return mddev->dev_sectors;
2471 static struct r1conf *setup_conf(struct mddev *mddev)
2473 struct r1conf *conf;
2475 struct mirror_info *disk;
2476 struct md_rdev *rdev;
2479 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2483 conf->mirrors = kzalloc(sizeof(struct mirror_info)
2484 * mddev->raid_disks * 2,
2489 conf->tmppage = alloc_page(GFP_KERNEL);
2493 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2494 if (!conf->poolinfo)
2496 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2497 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2500 if (!conf->r1bio_pool)
2503 conf->poolinfo->mddev = mddev;
2506 spin_lock_init(&conf->device_lock);
2507 list_for_each_entry(rdev, &mddev->disks, same_set) {
2508 int disk_idx = rdev->raid_disk;
2509 if (disk_idx >= mddev->raid_disks
2512 if (test_bit(Replacement, &rdev->flags))
2513 disk = conf->mirrors + conf->raid_disks + disk_idx;
2515 disk = conf->mirrors + disk_idx;
2521 disk->head_position = 0;
2523 conf->raid_disks = mddev->raid_disks;
2524 conf->mddev = mddev;
2525 INIT_LIST_HEAD(&conf->retry_list);
2527 spin_lock_init(&conf->resync_lock);
2528 init_waitqueue_head(&conf->wait_barrier);
2530 bio_list_init(&conf->pending_bio_list);
2531 conf->pending_count = 0;
2532 conf->recovery_disabled = mddev->recovery_disabled - 1;
2535 conf->last_used = -1;
2536 for (i = 0; i < conf->raid_disks * 2; i++) {
2538 disk = conf->mirrors + i;
2540 if (i < conf->raid_disks &&
2541 disk[conf->raid_disks].rdev) {
2542 /* This slot has a replacement. */
2544 /* No original, just make the replacement
2545 * a recovering spare
2548 disk[conf->raid_disks].rdev;
2549 disk[conf->raid_disks].rdev = NULL;
2550 } else if (!test_bit(In_sync, &disk->rdev->flags))
2551 /* Original is not in_sync - bad */
2556 !test_bit(In_sync, &disk->rdev->flags)) {
2557 disk->head_position = 0;
2560 } else if (conf->last_used < 0)
2562 * The first working device is used as a
2563 * starting point to read balancing.
2565 conf->last_used = i;
2568 if (conf->last_used < 0) {
2569 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2574 conf->thread = md_register_thread(raid1d, mddev, NULL);
2575 if (!conf->thread) {
2577 "md/raid1:%s: couldn't allocate thread\n",
2586 if (conf->r1bio_pool)
2587 mempool_destroy(conf->r1bio_pool);
2588 kfree(conf->mirrors);
2589 safe_put_page(conf->tmppage);
2590 kfree(conf->poolinfo);
2593 return ERR_PTR(err);
2596 static int run(struct mddev *mddev)
2598 struct r1conf *conf;
2600 struct md_rdev *rdev;
2602 if (mddev->level != 1) {
2603 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2604 mdname(mddev), mddev->level);
2607 if (mddev->reshape_position != MaxSector) {
2608 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2613 * copy the already verified devices into our private RAID1
2614 * bookkeeping area. [whatever we allocate in run(),
2615 * should be freed in stop()]
2617 if (mddev->private == NULL)
2618 conf = setup_conf(mddev);
2620 conf = mddev->private;
2623 return PTR_ERR(conf);
2625 list_for_each_entry(rdev, &mddev->disks, same_set) {
2626 if (!mddev->gendisk)
2628 disk_stack_limits(mddev->gendisk, rdev->bdev,
2629 rdev->data_offset << 9);
2630 /* as we don't honour merge_bvec_fn, we must never risk
2631 * violating it, so limit ->max_segments to 1 lying within
2632 * a single page, as a one page request is never in violation.
2634 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2635 blk_queue_max_segments(mddev->queue, 1);
2636 blk_queue_segment_boundary(mddev->queue,
2637 PAGE_CACHE_SIZE - 1);
2641 mddev->degraded = 0;
2642 for (i=0; i < conf->raid_disks; i++)
2643 if (conf->mirrors[i].rdev == NULL ||
2644 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2645 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2648 if (conf->raid_disks - mddev->degraded == 1)
2649 mddev->recovery_cp = MaxSector;
2651 if (mddev->recovery_cp != MaxSector)
2652 printk(KERN_NOTICE "md/raid1:%s: not clean"
2653 " -- starting background reconstruction\n",
2656 "md/raid1:%s: active with %d out of %d mirrors\n",
2657 mdname(mddev), mddev->raid_disks - mddev->degraded,
2661 * Ok, everything is just fine now
2663 mddev->thread = conf->thread;
2664 conf->thread = NULL;
2665 mddev->private = conf;
2667 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2670 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2671 mddev->queue->backing_dev_info.congested_data = mddev;
2673 return md_integrity_register(mddev);
2676 static int stop(struct mddev *mddev)
2678 struct r1conf *conf = mddev->private;
2679 struct bitmap *bitmap = mddev->bitmap;
2681 /* wait for behind writes to complete */
2682 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2683 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2685 /* need to kick something here to make sure I/O goes? */
2686 wait_event(bitmap->behind_wait,
2687 atomic_read(&bitmap->behind_writes) == 0);
2690 raise_barrier(conf);
2691 lower_barrier(conf);
2693 md_unregister_thread(&mddev->thread);
2694 if (conf->r1bio_pool)
2695 mempool_destroy(conf->r1bio_pool);
2696 kfree(conf->mirrors);
2697 kfree(conf->poolinfo);
2699 mddev->private = NULL;
2703 static int raid1_resize(struct mddev *mddev, sector_t sectors)
2705 /* no resync is happening, and there is enough space
2706 * on all devices, so we can resize.
2707 * We need to make sure resync covers any new space.
2708 * If the array is shrinking we should possibly wait until
2709 * any io in the removed space completes, but it hardly seems
2712 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2713 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2715 set_capacity(mddev->gendisk, mddev->array_sectors);
2716 revalidate_disk(mddev->gendisk);
2717 if (sectors > mddev->dev_sectors &&
2718 mddev->recovery_cp > mddev->dev_sectors) {
2719 mddev->recovery_cp = mddev->dev_sectors;
2720 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2722 mddev->dev_sectors = sectors;
2723 mddev->resync_max_sectors = sectors;
2727 static int raid1_reshape(struct mddev *mddev)
2730 * 1/ resize the r1bio_pool
2731 * 2/ resize conf->mirrors
2733 * We allocate a new r1bio_pool if we can.
2734 * Then raise a device barrier and wait until all IO stops.
2735 * Then resize conf->mirrors and swap in the new r1bio pool.
2737 * At the same time, we "pack" the devices so that all the missing
2738 * devices have the higher raid_disk numbers.
2740 mempool_t *newpool, *oldpool;
2741 struct pool_info *newpoolinfo;
2742 struct mirror_info *newmirrors;
2743 struct r1conf *conf = mddev->private;
2744 int cnt, raid_disks;
2745 unsigned long flags;
2748 /* Cannot change chunk_size, layout, or level */
2749 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2750 mddev->layout != mddev->new_layout ||
2751 mddev->level != mddev->new_level) {
2752 mddev->new_chunk_sectors = mddev->chunk_sectors;
2753 mddev->new_layout = mddev->layout;
2754 mddev->new_level = mddev->level;
2758 err = md_allow_write(mddev);
2762 raid_disks = mddev->raid_disks + mddev->delta_disks;
2764 if (raid_disks < conf->raid_disks) {
2766 for (d= 0; d < conf->raid_disks; d++)
2767 if (conf->mirrors[d].rdev)
2769 if (cnt > raid_disks)
2773 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2776 newpoolinfo->mddev = mddev;
2777 newpoolinfo->raid_disks = raid_disks * 2;
2779 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2780 r1bio_pool_free, newpoolinfo);
2785 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks * 2,
2789 mempool_destroy(newpool);
2793 raise_barrier(conf);
2795 /* ok, everything is stopped */
2796 oldpool = conf->r1bio_pool;
2797 conf->r1bio_pool = newpool;
2799 for (d = d2 = 0; d < conf->raid_disks; d++) {
2800 struct md_rdev *rdev = conf->mirrors[d].rdev;
2801 if (rdev && rdev->raid_disk != d2) {
2802 sysfs_unlink_rdev(mddev, rdev);
2803 rdev->raid_disk = d2;
2804 sysfs_unlink_rdev(mddev, rdev);
2805 if (sysfs_link_rdev(mddev, rdev))
2807 "md/raid1:%s: cannot register rd%d\n",
2808 mdname(mddev), rdev->raid_disk);
2811 newmirrors[d2++].rdev = rdev;
2813 kfree(conf->mirrors);
2814 conf->mirrors = newmirrors;
2815 kfree(conf->poolinfo);
2816 conf->poolinfo = newpoolinfo;
2818 spin_lock_irqsave(&conf->device_lock, flags);
2819 mddev->degraded += (raid_disks - conf->raid_disks);
2820 spin_unlock_irqrestore(&conf->device_lock, flags);
2821 conf->raid_disks = mddev->raid_disks = raid_disks;
2822 mddev->delta_disks = 0;
2824 conf->last_used = 0; /* just make sure it is in-range */
2825 lower_barrier(conf);
2827 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2828 md_wakeup_thread(mddev->thread);
2830 mempool_destroy(oldpool);
2834 static void raid1_quiesce(struct mddev *mddev, int state)
2836 struct r1conf *conf = mddev->private;
2839 case 2: /* wake for suspend */
2840 wake_up(&conf->wait_barrier);
2843 raise_barrier(conf);
2846 lower_barrier(conf);
2851 static void *raid1_takeover(struct mddev *mddev)
2853 /* raid1 can take over:
2854 * raid5 with 2 devices, any layout or chunk size
2856 if (mddev->level == 5 && mddev->raid_disks == 2) {
2857 struct r1conf *conf;
2858 mddev->new_level = 1;
2859 mddev->new_layout = 0;
2860 mddev->new_chunk_sectors = 0;
2861 conf = setup_conf(mddev);
2866 return ERR_PTR(-EINVAL);
2869 static struct md_personality raid1_personality =
2873 .owner = THIS_MODULE,
2874 .make_request = make_request,
2878 .error_handler = error,
2879 .hot_add_disk = raid1_add_disk,
2880 .hot_remove_disk= raid1_remove_disk,
2881 .spare_active = raid1_spare_active,
2882 .sync_request = sync_request,
2883 .resize = raid1_resize,
2885 .check_reshape = raid1_reshape,
2886 .quiesce = raid1_quiesce,
2887 .takeover = raid1_takeover,
2890 static int __init raid_init(void)
2892 return register_md_personality(&raid1_personality);
2895 static void raid_exit(void)
2897 unregister_md_personality(&raid1_personality);
2900 module_init(raid_init);
2901 module_exit(raid_exit);
2902 MODULE_LICENSE("GPL");
2903 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2904 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2905 MODULE_ALIAS("md-raid1");
2906 MODULE_ALIAS("md-level-1");
2908 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);