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 * 2)
521 disk -= conf->raid_disks * 2;
523 rdev = rcu_dereference(conf->mirrors[disk].rdev);
524 if (r1_bio->bios[disk] == IO_BLOCKED
526 || test_bit(Unmerged, &rdev->flags)
527 || test_bit(Faulty, &rdev->flags))
529 if (!test_bit(In_sync, &rdev->flags) &&
530 rdev->recovery_offset < this_sector + sectors)
532 if (test_bit(WriteMostly, &rdev->flags)) {
533 /* Don't balance among write-mostly, just
534 * use the first as a last resort */
536 if (is_badblock(rdev, this_sector, sectors,
537 &first_bad, &bad_sectors)) {
538 if (first_bad < this_sector)
539 /* Cannot use this */
541 best_good_sectors = first_bad - this_sector;
543 best_good_sectors = sectors;
548 /* This is a reasonable device to use. It might
551 if (is_badblock(rdev, this_sector, sectors,
552 &first_bad, &bad_sectors)) {
553 if (best_dist < MaxSector)
554 /* already have a better device */
556 if (first_bad <= this_sector) {
557 /* cannot read here. If this is the 'primary'
558 * device, then we must not read beyond
559 * bad_sectors from another device..
561 bad_sectors -= (this_sector - first_bad);
562 if (choose_first && sectors > bad_sectors)
563 sectors = bad_sectors;
564 if (best_good_sectors > sectors)
565 best_good_sectors = sectors;
568 sector_t good_sectors = first_bad - this_sector;
569 if (good_sectors > best_good_sectors) {
570 best_good_sectors = good_sectors;
578 best_good_sectors = sectors;
580 dist = abs(this_sector - conf->mirrors[disk].head_position);
582 /* Don't change to another disk for sequential reads */
583 || conf->next_seq_sect == this_sector
585 /* If device is idle, use it */
586 || atomic_read(&rdev->nr_pending) == 0) {
590 if (dist < best_dist) {
596 if (best_disk >= 0) {
597 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
600 atomic_inc(&rdev->nr_pending);
601 if (test_bit(Faulty, &rdev->flags)) {
602 /* cannot risk returning a device that failed
603 * before we inc'ed nr_pending
605 rdev_dec_pending(rdev, conf->mddev);
608 sectors = best_good_sectors;
609 conf->next_seq_sect = this_sector + sectors;
610 conf->last_used = best_disk;
613 *max_sectors = sectors;
618 static int raid1_mergeable_bvec(struct request_queue *q,
619 struct bvec_merge_data *bvm,
620 struct bio_vec *biovec)
622 struct mddev *mddev = q->queuedata;
623 struct r1conf *conf = mddev->private;
624 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
625 int max = biovec->bv_len;
627 if (mddev->merge_check_needed) {
630 for (disk = 0; disk < conf->raid_disks * 2; disk++) {
631 struct md_rdev *rdev = rcu_dereference(
632 conf->mirrors[disk].rdev);
633 if (rdev && !test_bit(Faulty, &rdev->flags)) {
634 struct request_queue *q =
635 bdev_get_queue(rdev->bdev);
636 if (q->merge_bvec_fn) {
637 bvm->bi_sector = sector +
639 bvm->bi_bdev = rdev->bdev;
640 max = min(max, q->merge_bvec_fn(
651 int md_raid1_congested(struct mddev *mddev, int bits)
653 struct r1conf *conf = mddev->private;
656 if ((bits & (1 << BDI_async_congested)) &&
657 conf->pending_count >= max_queued_requests)
661 for (i = 0; i < conf->raid_disks * 2; i++) {
662 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
663 if (rdev && !test_bit(Faulty, &rdev->flags)) {
664 struct request_queue *q = bdev_get_queue(rdev->bdev);
668 /* Note the '|| 1' - when read_balance prefers
669 * non-congested targets, it can be removed
671 if ((bits & (1<<BDI_async_congested)) || 1)
672 ret |= bdi_congested(&q->backing_dev_info, bits);
674 ret &= bdi_congested(&q->backing_dev_info, bits);
680 EXPORT_SYMBOL_GPL(md_raid1_congested);
682 static int raid1_congested(void *data, int bits)
684 struct mddev *mddev = data;
686 return mddev_congested(mddev, bits) ||
687 md_raid1_congested(mddev, bits);
690 static void flush_pending_writes(struct r1conf *conf)
692 /* Any writes that have been queued but are awaiting
693 * bitmap updates get flushed here.
695 spin_lock_irq(&conf->device_lock);
697 if (conf->pending_bio_list.head) {
699 bio = bio_list_get(&conf->pending_bio_list);
700 conf->pending_count = 0;
701 spin_unlock_irq(&conf->device_lock);
702 /* flush any pending bitmap writes to
703 * disk before proceeding w/ I/O */
704 bitmap_unplug(conf->mddev->bitmap);
705 wake_up(&conf->wait_barrier);
707 while (bio) { /* submit pending writes */
708 struct bio *next = bio->bi_next;
710 generic_make_request(bio);
714 spin_unlock_irq(&conf->device_lock);
718 * Sometimes we need to suspend IO while we do something else,
719 * either some resync/recovery, or reconfigure the array.
720 * To do this we raise a 'barrier'.
721 * The 'barrier' is a counter that can be raised multiple times
722 * to count how many activities are happening which preclude
724 * We can only raise the barrier if there is no pending IO.
725 * i.e. if nr_pending == 0.
726 * We choose only to raise the barrier if no-one is waiting for the
727 * barrier to go down. This means that as soon as an IO request
728 * is ready, no other operations which require a barrier will start
729 * until the IO request has had a chance.
731 * So: regular IO calls 'wait_barrier'. When that returns there
732 * is no backgroup IO happening, It must arrange to call
733 * allow_barrier when it has finished its IO.
734 * backgroup IO calls must call raise_barrier. Once that returns
735 * there is no normal IO happeing. It must arrange to call
736 * lower_barrier when the particular background IO completes.
738 #define RESYNC_DEPTH 32
740 static void raise_barrier(struct r1conf *conf)
742 spin_lock_irq(&conf->resync_lock);
744 /* Wait until no block IO is waiting */
745 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
746 conf->resync_lock, );
748 /* block any new IO from starting */
751 /* Now wait for all pending IO to complete */
752 wait_event_lock_irq(conf->wait_barrier,
753 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
754 conf->resync_lock, );
756 spin_unlock_irq(&conf->resync_lock);
759 static void lower_barrier(struct r1conf *conf)
762 BUG_ON(conf->barrier <= 0);
763 spin_lock_irqsave(&conf->resync_lock, flags);
765 spin_unlock_irqrestore(&conf->resync_lock, flags);
766 wake_up(&conf->wait_barrier);
769 static void wait_barrier(struct r1conf *conf)
771 spin_lock_irq(&conf->resync_lock);
774 /* Wait for the barrier to drop.
775 * However if there are already pending
776 * requests (preventing the barrier from
777 * rising completely), and the
778 * pre-process bio queue isn't empty,
779 * then don't wait, as we need to empty
780 * that queue to get the nr_pending
783 wait_event_lock_irq(conf->wait_barrier,
787 !bio_list_empty(current->bio_list)),
793 spin_unlock_irq(&conf->resync_lock);
796 static void allow_barrier(struct r1conf *conf)
799 spin_lock_irqsave(&conf->resync_lock, flags);
801 spin_unlock_irqrestore(&conf->resync_lock, flags);
802 wake_up(&conf->wait_barrier);
805 static void freeze_array(struct r1conf *conf)
807 /* stop syncio and normal IO and wait for everything to
809 * We increment barrier and nr_waiting, and then
810 * wait until nr_pending match nr_queued+1
811 * This is called in the context of one normal IO request
812 * that has failed. Thus any sync request that might be pending
813 * will be blocked by nr_pending, and we need to wait for
814 * pending IO requests to complete or be queued for re-try.
815 * Thus the number queued (nr_queued) plus this request (1)
816 * must match the number of pending IOs (nr_pending) before
819 spin_lock_irq(&conf->resync_lock);
822 wait_event_lock_irq(conf->wait_barrier,
823 conf->nr_pending == conf->nr_queued+1,
825 flush_pending_writes(conf));
826 spin_unlock_irq(&conf->resync_lock);
828 static void unfreeze_array(struct r1conf *conf)
830 /* reverse the effect of the freeze */
831 spin_lock_irq(&conf->resync_lock);
834 wake_up(&conf->wait_barrier);
835 spin_unlock_irq(&conf->resync_lock);
839 /* duplicate the data pages for behind I/O
841 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
844 struct bio_vec *bvec;
845 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
847 if (unlikely(!bvecs))
850 bio_for_each_segment(bvec, bio, i) {
852 bvecs[i].bv_page = alloc_page(GFP_NOIO);
853 if (unlikely(!bvecs[i].bv_page))
855 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
856 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
857 kunmap(bvecs[i].bv_page);
858 kunmap(bvec->bv_page);
860 r1_bio->behind_bvecs = bvecs;
861 r1_bio->behind_page_count = bio->bi_vcnt;
862 set_bit(R1BIO_BehindIO, &r1_bio->state);
866 for (i = 0; i < bio->bi_vcnt; i++)
867 if (bvecs[i].bv_page)
868 put_page(bvecs[i].bv_page);
870 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
873 static void make_request(struct mddev *mddev, struct bio * bio)
875 struct r1conf *conf = mddev->private;
876 struct mirror_info *mirror;
877 struct r1bio *r1_bio;
878 struct bio *read_bio;
880 struct bitmap *bitmap;
882 const int rw = bio_data_dir(bio);
883 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
884 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
885 struct md_rdev *blocked_rdev;
891 * Register the new request and wait if the reconstruction
892 * thread has put up a bar for new requests.
893 * Continue immediately if no resync is active currently.
896 md_write_start(mddev, bio); /* wait on superblock update early */
898 if (bio_data_dir(bio) == WRITE &&
899 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
900 bio->bi_sector < mddev->suspend_hi) {
901 /* As the suspend_* range is controlled by
902 * userspace, we want an interruptible
907 flush_signals(current);
908 prepare_to_wait(&conf->wait_barrier,
909 &w, TASK_INTERRUPTIBLE);
910 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
911 bio->bi_sector >= mddev->suspend_hi)
915 finish_wait(&conf->wait_barrier, &w);
920 bitmap = mddev->bitmap;
923 * make_request() can abort the operation when READA is being
924 * used and no empty request is available.
927 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
929 r1_bio->master_bio = bio;
930 r1_bio->sectors = bio->bi_size >> 9;
932 r1_bio->mddev = mddev;
933 r1_bio->sector = bio->bi_sector;
935 /* We might need to issue multiple reads to different
936 * devices if there are bad blocks around, so we keep
937 * track of the number of reads in bio->bi_phys_segments.
938 * If this is 0, there is only one r1_bio and no locking
939 * will be needed when requests complete. If it is
940 * non-zero, then it is the number of not-completed requests.
942 bio->bi_phys_segments = 0;
943 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
947 * read balancing logic:
952 rdisk = read_balance(conf, r1_bio, &max_sectors);
955 /* couldn't find anywhere to read from */
956 raid_end_bio_io(r1_bio);
959 mirror = conf->mirrors + rdisk;
961 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
963 /* Reading from a write-mostly device must
964 * take care not to over-take any writes
967 wait_event(bitmap->behind_wait,
968 atomic_read(&bitmap->behind_writes) == 0);
970 r1_bio->read_disk = rdisk;
972 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
973 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
976 r1_bio->bios[rdisk] = read_bio;
978 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
979 read_bio->bi_bdev = mirror->rdev->bdev;
980 read_bio->bi_end_io = raid1_end_read_request;
981 read_bio->bi_rw = READ | do_sync;
982 read_bio->bi_private = r1_bio;
984 if (max_sectors < r1_bio->sectors) {
985 /* could not read all from this device, so we will
986 * need another r1_bio.
989 sectors_handled = (r1_bio->sector + max_sectors
991 r1_bio->sectors = max_sectors;
992 spin_lock_irq(&conf->device_lock);
993 if (bio->bi_phys_segments == 0)
994 bio->bi_phys_segments = 2;
996 bio->bi_phys_segments++;
997 spin_unlock_irq(&conf->device_lock);
998 /* Cannot call generic_make_request directly
999 * as that will be queued in __make_request
1000 * and subsequent mempool_alloc might block waiting
1001 * for it. So hand bio over to raid1d.
1003 reschedule_retry(r1_bio);
1005 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1007 r1_bio->master_bio = bio;
1008 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1010 r1_bio->mddev = mddev;
1011 r1_bio->sector = bio->bi_sector + sectors_handled;
1014 generic_make_request(read_bio);
1021 if (conf->pending_count >= max_queued_requests) {
1022 md_wakeup_thread(mddev->thread);
1023 wait_event(conf->wait_barrier,
1024 conf->pending_count < max_queued_requests);
1026 /* first select target devices under rcu_lock and
1027 * inc refcount on their rdev. Record them by setting
1029 * If there are known/acknowledged bad blocks on any device on
1030 * which we have seen a write error, we want to avoid writing those
1032 * This potentially requires several writes to write around
1033 * the bad blocks. Each set of writes gets it's own r1bio
1034 * with a set of bios attached.
1037 disks = conf->raid_disks * 2;
1039 blocked_rdev = NULL;
1041 max_sectors = r1_bio->sectors;
1042 for (i = 0; i < disks; i++) {
1043 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1044 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1045 atomic_inc(&rdev->nr_pending);
1046 blocked_rdev = rdev;
1049 r1_bio->bios[i] = NULL;
1050 if (!rdev || test_bit(Faulty, &rdev->flags)
1051 || test_bit(Unmerged, &rdev->flags)) {
1052 if (i < conf->raid_disks)
1053 set_bit(R1BIO_Degraded, &r1_bio->state);
1057 atomic_inc(&rdev->nr_pending);
1058 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1063 is_bad = is_badblock(rdev, r1_bio->sector,
1065 &first_bad, &bad_sectors);
1067 /* mustn't write here until the bad block is
1069 set_bit(BlockedBadBlocks, &rdev->flags);
1070 blocked_rdev = rdev;
1073 if (is_bad && first_bad <= r1_bio->sector) {
1074 /* Cannot write here at all */
1075 bad_sectors -= (r1_bio->sector - first_bad);
1076 if (bad_sectors < max_sectors)
1077 /* mustn't write more than bad_sectors
1078 * to other devices yet
1080 max_sectors = bad_sectors;
1081 rdev_dec_pending(rdev, mddev);
1082 /* We don't set R1BIO_Degraded as that
1083 * only applies if the disk is
1084 * missing, so it might be re-added,
1085 * and we want to know to recover this
1087 * In this case the device is here,
1088 * and the fact that this chunk is not
1089 * in-sync is recorded in the bad
1095 int good_sectors = first_bad - r1_bio->sector;
1096 if (good_sectors < max_sectors)
1097 max_sectors = good_sectors;
1100 r1_bio->bios[i] = bio;
1104 if (unlikely(blocked_rdev)) {
1105 /* Wait for this device to become unblocked */
1108 for (j = 0; j < i; j++)
1109 if (r1_bio->bios[j])
1110 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1112 allow_barrier(conf);
1113 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1118 if (max_sectors < r1_bio->sectors) {
1119 /* We are splitting this write into multiple parts, so
1120 * we need to prepare for allocating another r1_bio.
1122 r1_bio->sectors = max_sectors;
1123 spin_lock_irq(&conf->device_lock);
1124 if (bio->bi_phys_segments == 0)
1125 bio->bi_phys_segments = 2;
1127 bio->bi_phys_segments++;
1128 spin_unlock_irq(&conf->device_lock);
1130 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1132 atomic_set(&r1_bio->remaining, 1);
1133 atomic_set(&r1_bio->behind_remaining, 0);
1136 for (i = 0; i < disks; i++) {
1138 if (!r1_bio->bios[i])
1141 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1142 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1146 * Not if there are too many, or cannot
1147 * allocate memory, or a reader on WriteMostly
1148 * is waiting for behind writes to flush */
1150 (atomic_read(&bitmap->behind_writes)
1151 < mddev->bitmap_info.max_write_behind) &&
1152 !waitqueue_active(&bitmap->behind_wait))
1153 alloc_behind_pages(mbio, r1_bio);
1155 bitmap_startwrite(bitmap, r1_bio->sector,
1157 test_bit(R1BIO_BehindIO,
1161 if (r1_bio->behind_bvecs) {
1162 struct bio_vec *bvec;
1165 /* Yes, I really want the '__' version so that
1166 * we clear any unused pointer in the io_vec, rather
1167 * than leave them unchanged. This is important
1168 * because when we come to free the pages, we won't
1169 * know the original bi_idx, so we just free
1172 __bio_for_each_segment(bvec, mbio, j, 0)
1173 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1174 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1175 atomic_inc(&r1_bio->behind_remaining);
1178 r1_bio->bios[i] = mbio;
1180 mbio->bi_sector = (r1_bio->sector +
1181 conf->mirrors[i].rdev->data_offset);
1182 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1183 mbio->bi_end_io = raid1_end_write_request;
1184 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
1185 mbio->bi_private = r1_bio;
1187 atomic_inc(&r1_bio->remaining);
1188 spin_lock_irqsave(&conf->device_lock, flags);
1189 bio_list_add(&conf->pending_bio_list, mbio);
1190 conf->pending_count++;
1191 spin_unlock_irqrestore(&conf->device_lock, flags);
1192 if (!mddev_check_plugged(mddev))
1193 md_wakeup_thread(mddev->thread);
1195 /* Mustn't call r1_bio_write_done before this next test,
1196 * as it could result in the bio being freed.
1198 if (sectors_handled < (bio->bi_size >> 9)) {
1199 r1_bio_write_done(r1_bio);
1200 /* We need another r1_bio. It has already been counted
1201 * in bio->bi_phys_segments
1203 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1204 r1_bio->master_bio = bio;
1205 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1207 r1_bio->mddev = mddev;
1208 r1_bio->sector = bio->bi_sector + sectors_handled;
1212 r1_bio_write_done(r1_bio);
1214 /* In case raid1d snuck in to freeze_array */
1215 wake_up(&conf->wait_barrier);
1218 static void status(struct seq_file *seq, struct mddev *mddev)
1220 struct r1conf *conf = mddev->private;
1223 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1224 conf->raid_disks - mddev->degraded);
1226 for (i = 0; i < conf->raid_disks; i++) {
1227 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1228 seq_printf(seq, "%s",
1229 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1232 seq_printf(seq, "]");
1236 static void error(struct mddev *mddev, struct md_rdev *rdev)
1238 char b[BDEVNAME_SIZE];
1239 struct r1conf *conf = mddev->private;
1242 * If it is not operational, then we have already marked it as dead
1243 * else if it is the last working disks, ignore the error, let the
1244 * next level up know.
1245 * else mark the drive as failed
1247 if (test_bit(In_sync, &rdev->flags)
1248 && (conf->raid_disks - mddev->degraded) == 1) {
1250 * Don't fail the drive, act as though we were just a
1251 * normal single drive.
1252 * However don't try a recovery from this drive as
1253 * it is very likely to fail.
1255 conf->recovery_disabled = mddev->recovery_disabled;
1258 set_bit(Blocked, &rdev->flags);
1259 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1260 unsigned long flags;
1261 spin_lock_irqsave(&conf->device_lock, flags);
1263 set_bit(Faulty, &rdev->flags);
1264 spin_unlock_irqrestore(&conf->device_lock, flags);
1266 * if recovery is running, make sure it aborts.
1268 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1270 set_bit(Faulty, &rdev->flags);
1271 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1273 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1274 "md/raid1:%s: Operation continuing on %d devices.\n",
1275 mdname(mddev), bdevname(rdev->bdev, b),
1276 mdname(mddev), conf->raid_disks - mddev->degraded);
1279 static void print_conf(struct r1conf *conf)
1283 printk(KERN_DEBUG "RAID1 conf printout:\n");
1285 printk(KERN_DEBUG "(!conf)\n");
1288 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1292 for (i = 0; i < conf->raid_disks; i++) {
1293 char b[BDEVNAME_SIZE];
1294 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1296 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1297 i, !test_bit(In_sync, &rdev->flags),
1298 !test_bit(Faulty, &rdev->flags),
1299 bdevname(rdev->bdev,b));
1304 static void close_sync(struct r1conf *conf)
1307 allow_barrier(conf);
1309 mempool_destroy(conf->r1buf_pool);
1310 conf->r1buf_pool = NULL;
1313 static int raid1_spare_active(struct mddev *mddev)
1316 struct r1conf *conf = mddev->private;
1318 unsigned long flags;
1321 * Find all failed disks within the RAID1 configuration
1322 * and mark them readable.
1323 * Called under mddev lock, so rcu protection not needed.
1325 for (i = 0; i < conf->raid_disks; i++) {
1326 struct md_rdev *rdev = conf->mirrors[i].rdev;
1327 struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
1329 && repl->recovery_offset == MaxSector
1330 && !test_bit(Faulty, &repl->flags)
1331 && !test_and_set_bit(In_sync, &repl->flags)) {
1332 /* replacement has just become active */
1334 !test_and_clear_bit(In_sync, &rdev->flags))
1337 /* Replaced device not technically
1338 * faulty, but we need to be sure
1339 * it gets removed and never re-added
1341 set_bit(Faulty, &rdev->flags);
1342 sysfs_notify_dirent_safe(
1347 && !test_bit(Faulty, &rdev->flags)
1348 && !test_and_set_bit(In_sync, &rdev->flags)) {
1350 sysfs_notify_dirent_safe(rdev->sysfs_state);
1353 spin_lock_irqsave(&conf->device_lock, flags);
1354 mddev->degraded -= count;
1355 spin_unlock_irqrestore(&conf->device_lock, flags);
1362 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1364 struct r1conf *conf = mddev->private;
1367 struct mirror_info *p;
1369 int last = conf->raid_disks - 1;
1370 struct request_queue *q = bdev_get_queue(rdev->bdev);
1372 if (mddev->recovery_disabled == conf->recovery_disabled)
1375 if (rdev->raid_disk >= 0)
1376 first = last = rdev->raid_disk;
1378 if (q->merge_bvec_fn) {
1379 set_bit(Unmerged, &rdev->flags);
1380 mddev->merge_check_needed = 1;
1383 for (mirror = first; mirror <= last; mirror++) {
1384 p = conf->mirrors+mirror;
1387 disk_stack_limits(mddev->gendisk, rdev->bdev,
1388 rdev->data_offset << 9);
1390 p->head_position = 0;
1391 rdev->raid_disk = mirror;
1393 /* As all devices are equivalent, we don't need a full recovery
1394 * if this was recently any drive of the array
1396 if (rdev->saved_raid_disk < 0)
1398 rcu_assign_pointer(p->rdev, rdev);
1401 if (test_bit(WantReplacement, &p->rdev->flags) &&
1402 p[conf->raid_disks].rdev == NULL) {
1403 /* Add this device as a replacement */
1404 clear_bit(In_sync, &rdev->flags);
1405 set_bit(Replacement, &rdev->flags);
1406 rdev->raid_disk = mirror;
1409 rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
1413 if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
1414 /* Some requests might not have seen this new
1415 * merge_bvec_fn. We must wait for them to complete
1416 * before merging the device fully.
1417 * First we make sure any code which has tested
1418 * our function has submitted the request, then
1419 * we wait for all outstanding requests to complete.
1421 synchronize_sched();
1422 raise_barrier(conf);
1423 lower_barrier(conf);
1424 clear_bit(Unmerged, &rdev->flags);
1426 md_integrity_add_rdev(rdev, mddev);
1431 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1433 struct r1conf *conf = mddev->private;
1435 int number = rdev->raid_disk;
1436 struct mirror_info *p = conf->mirrors+ number;
1438 if (rdev != p->rdev)
1439 p = conf->mirrors + conf->raid_disks + number;
1442 if (rdev == p->rdev) {
1443 if (test_bit(In_sync, &rdev->flags) ||
1444 atomic_read(&rdev->nr_pending)) {
1448 /* Only remove non-faulty devices if recovery
1451 if (!test_bit(Faulty, &rdev->flags) &&
1452 mddev->recovery_disabled != conf->recovery_disabled &&
1453 mddev->degraded < conf->raid_disks) {
1459 if (atomic_read(&rdev->nr_pending)) {
1460 /* lost the race, try later */
1464 } else if (conf->mirrors[conf->raid_disks + number].rdev) {
1465 /* We just removed a device that is being replaced.
1466 * Move down the replacement. We drain all IO before
1467 * doing this to avoid confusion.
1469 struct md_rdev *repl =
1470 conf->mirrors[conf->raid_disks + number].rdev;
1471 raise_barrier(conf);
1472 clear_bit(Replacement, &repl->flags);
1474 conf->mirrors[conf->raid_disks + number].rdev = NULL;
1475 lower_barrier(conf);
1476 clear_bit(WantReplacement, &rdev->flags);
1478 clear_bit(WantReplacement, &rdev->flags);
1479 err = md_integrity_register(mddev);
1488 static void end_sync_read(struct bio *bio, int error)
1490 struct r1bio *r1_bio = bio->bi_private;
1492 update_head_pos(r1_bio->read_disk, r1_bio);
1495 * we have read a block, now it needs to be re-written,
1496 * or re-read if the read failed.
1497 * We don't do much here, just schedule handling by raid1d
1499 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1500 set_bit(R1BIO_Uptodate, &r1_bio->state);
1502 if (atomic_dec_and_test(&r1_bio->remaining))
1503 reschedule_retry(r1_bio);
1506 static void end_sync_write(struct bio *bio, int error)
1508 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1509 struct r1bio *r1_bio = bio->bi_private;
1510 struct mddev *mddev = r1_bio->mddev;
1511 struct r1conf *conf = mddev->private;
1516 mirror = find_bio_disk(r1_bio, bio);
1519 sector_t sync_blocks = 0;
1520 sector_t s = r1_bio->sector;
1521 long sectors_to_go = r1_bio->sectors;
1522 /* make sure these bits doesn't get cleared. */
1524 bitmap_end_sync(mddev->bitmap, s,
1527 sectors_to_go -= sync_blocks;
1528 } while (sectors_to_go > 0);
1529 set_bit(WriteErrorSeen,
1530 &conf->mirrors[mirror].rdev->flags);
1531 if (!test_and_set_bit(WantReplacement,
1532 &conf->mirrors[mirror].rdev->flags))
1533 set_bit(MD_RECOVERY_NEEDED, &
1535 set_bit(R1BIO_WriteError, &r1_bio->state);
1536 } else if (is_badblock(conf->mirrors[mirror].rdev,
1539 &first_bad, &bad_sectors) &&
1540 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1543 &first_bad, &bad_sectors)
1545 set_bit(R1BIO_MadeGood, &r1_bio->state);
1547 if (atomic_dec_and_test(&r1_bio->remaining)) {
1548 int s = r1_bio->sectors;
1549 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1550 test_bit(R1BIO_WriteError, &r1_bio->state))
1551 reschedule_retry(r1_bio);
1554 md_done_sync(mddev, s, uptodate);
1559 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1560 int sectors, struct page *page, int rw)
1562 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1566 set_bit(WriteErrorSeen, &rdev->flags);
1567 if (!test_and_set_bit(WantReplacement,
1569 set_bit(MD_RECOVERY_NEEDED, &
1570 rdev->mddev->recovery);
1572 /* need to record an error - either for the block or the device */
1573 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1574 md_error(rdev->mddev, rdev);
1578 static int fix_sync_read_error(struct r1bio *r1_bio)
1580 /* Try some synchronous reads of other devices to get
1581 * good data, much like with normal read errors. Only
1582 * read into the pages we already have so we don't
1583 * need to re-issue the read request.
1584 * We don't need to freeze the array, because being in an
1585 * active sync request, there is no normal IO, and
1586 * no overlapping syncs.
1587 * We don't need to check is_badblock() again as we
1588 * made sure that anything with a bad block in range
1589 * will have bi_end_io clear.
1591 struct mddev *mddev = r1_bio->mddev;
1592 struct r1conf *conf = mddev->private;
1593 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1594 sector_t sect = r1_bio->sector;
1595 int sectors = r1_bio->sectors;
1600 int d = r1_bio->read_disk;
1602 struct md_rdev *rdev;
1605 if (s > (PAGE_SIZE>>9))
1608 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1609 /* No rcu protection needed here devices
1610 * can only be removed when no resync is
1611 * active, and resync is currently active
1613 rdev = conf->mirrors[d].rdev;
1614 if (sync_page_io(rdev, sect, s<<9,
1615 bio->bi_io_vec[idx].bv_page,
1622 if (d == conf->raid_disks * 2)
1624 } while (!success && d != r1_bio->read_disk);
1627 char b[BDEVNAME_SIZE];
1629 /* Cannot read from anywhere, this block is lost.
1630 * Record a bad block on each device. If that doesn't
1631 * work just disable and interrupt the recovery.
1632 * Don't fail devices as that won't really help.
1634 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1635 " for block %llu\n",
1637 bdevname(bio->bi_bdev, b),
1638 (unsigned long long)r1_bio->sector);
1639 for (d = 0; d < conf->raid_disks * 2; d++) {
1640 rdev = conf->mirrors[d].rdev;
1641 if (!rdev || test_bit(Faulty, &rdev->flags))
1643 if (!rdev_set_badblocks(rdev, sect, s, 0))
1647 conf->recovery_disabled =
1648 mddev->recovery_disabled;
1649 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1650 md_done_sync(mddev, r1_bio->sectors, 0);
1662 /* write it back and re-read */
1663 while (d != r1_bio->read_disk) {
1665 d = conf->raid_disks * 2;
1667 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1669 rdev = conf->mirrors[d].rdev;
1670 if (r1_sync_page_io(rdev, sect, s,
1671 bio->bi_io_vec[idx].bv_page,
1673 r1_bio->bios[d]->bi_end_io = NULL;
1674 rdev_dec_pending(rdev, mddev);
1678 while (d != r1_bio->read_disk) {
1680 d = conf->raid_disks * 2;
1682 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1684 rdev = conf->mirrors[d].rdev;
1685 if (r1_sync_page_io(rdev, sect, s,
1686 bio->bi_io_vec[idx].bv_page,
1688 atomic_add(s, &rdev->corrected_errors);
1694 set_bit(R1BIO_Uptodate, &r1_bio->state);
1695 set_bit(BIO_UPTODATE, &bio->bi_flags);
1699 static int process_checks(struct r1bio *r1_bio)
1701 /* We have read all readable devices. If we haven't
1702 * got the block, then there is no hope left.
1703 * If we have, then we want to do a comparison
1704 * and skip the write if everything is the same.
1705 * If any blocks failed to read, then we need to
1706 * attempt an over-write
1708 struct mddev *mddev = r1_bio->mddev;
1709 struct r1conf *conf = mddev->private;
1714 for (primary = 0; primary < conf->raid_disks * 2; primary++)
1715 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1716 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1717 r1_bio->bios[primary]->bi_end_io = NULL;
1718 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1721 r1_bio->read_disk = primary;
1722 vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
1723 for (i = 0; i < conf->raid_disks * 2; i++) {
1725 struct bio *pbio = r1_bio->bios[primary];
1726 struct bio *sbio = r1_bio->bios[i];
1729 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1732 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1733 for (j = vcnt; j-- ; ) {
1735 p = pbio->bi_io_vec[j].bv_page;
1736 s = sbio->bi_io_vec[j].bv_page;
1737 if (memcmp(page_address(p),
1739 sbio->bi_io_vec[j].bv_len))
1745 mddev->resync_mismatches += r1_bio->sectors;
1746 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1747 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1748 /* No need to write to this device. */
1749 sbio->bi_end_io = NULL;
1750 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1753 /* fixup the bio for reuse */
1754 sbio->bi_vcnt = vcnt;
1755 sbio->bi_size = r1_bio->sectors << 9;
1757 sbio->bi_phys_segments = 0;
1758 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1759 sbio->bi_flags |= 1 << BIO_UPTODATE;
1760 sbio->bi_next = NULL;
1761 sbio->bi_sector = r1_bio->sector +
1762 conf->mirrors[i].rdev->data_offset;
1763 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1764 size = sbio->bi_size;
1765 for (j = 0; j < vcnt ; j++) {
1767 bi = &sbio->bi_io_vec[j];
1769 if (size > PAGE_SIZE)
1770 bi->bv_len = PAGE_SIZE;
1774 memcpy(page_address(bi->bv_page),
1775 page_address(pbio->bi_io_vec[j].bv_page),
1782 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1784 struct r1conf *conf = mddev->private;
1786 int disks = conf->raid_disks * 2;
1787 struct bio *bio, *wbio;
1789 bio = r1_bio->bios[r1_bio->read_disk];
1791 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1792 /* ouch - failed to read all of that. */
1793 if (!fix_sync_read_error(r1_bio))
1796 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1797 if (process_checks(r1_bio) < 0)
1802 atomic_set(&r1_bio->remaining, 1);
1803 for (i = 0; i < disks ; i++) {
1804 wbio = r1_bio->bios[i];
1805 if (wbio->bi_end_io == NULL ||
1806 (wbio->bi_end_io == end_sync_read &&
1807 (i == r1_bio->read_disk ||
1808 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1811 wbio->bi_rw = WRITE;
1812 wbio->bi_end_io = end_sync_write;
1813 atomic_inc(&r1_bio->remaining);
1814 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1816 generic_make_request(wbio);
1819 if (atomic_dec_and_test(&r1_bio->remaining)) {
1820 /* if we're here, all write(s) have completed, so clean up */
1821 md_done_sync(mddev, r1_bio->sectors, 1);
1827 * This is a kernel thread which:
1829 * 1. Retries failed read operations on working mirrors.
1830 * 2. Updates the raid superblock when problems encounter.
1831 * 3. Performs writes following reads for array synchronising.
1834 static void fix_read_error(struct r1conf *conf, int read_disk,
1835 sector_t sect, int sectors)
1837 struct mddev *mddev = conf->mddev;
1843 struct md_rdev *rdev;
1845 if (s > (PAGE_SIZE>>9))
1849 /* Note: no rcu protection needed here
1850 * as this is synchronous in the raid1d thread
1851 * which is the thread that might remove
1852 * a device. If raid1d ever becomes multi-threaded....
1857 rdev = conf->mirrors[d].rdev;
1859 (test_bit(In_sync, &rdev->flags) ||
1860 (!test_bit(Faulty, &rdev->flags) &&
1861 rdev->recovery_offset >= sect + s)) &&
1862 is_badblock(rdev, sect, s,
1863 &first_bad, &bad_sectors) == 0 &&
1864 sync_page_io(rdev, sect, s<<9,
1865 conf->tmppage, READ, false))
1869 if (d == conf->raid_disks * 2)
1872 } while (!success && d != read_disk);
1875 /* Cannot read from anywhere - mark it bad */
1876 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
1877 if (!rdev_set_badblocks(rdev, sect, s, 0))
1878 md_error(mddev, rdev);
1881 /* write it back and re-read */
1883 while (d != read_disk) {
1885 d = conf->raid_disks * 2;
1887 rdev = conf->mirrors[d].rdev;
1889 test_bit(In_sync, &rdev->flags))
1890 r1_sync_page_io(rdev, sect, s,
1891 conf->tmppage, WRITE);
1894 while (d != read_disk) {
1895 char b[BDEVNAME_SIZE];
1897 d = conf->raid_disks * 2;
1899 rdev = conf->mirrors[d].rdev;
1901 test_bit(In_sync, &rdev->flags)) {
1902 if (r1_sync_page_io(rdev, sect, s,
1903 conf->tmppage, READ)) {
1904 atomic_add(s, &rdev->corrected_errors);
1906 "md/raid1:%s: read error corrected "
1907 "(%d sectors at %llu on %s)\n",
1909 (unsigned long long)(sect +
1911 bdevname(rdev->bdev, b));
1920 static void bi_complete(struct bio *bio, int error)
1922 complete((struct completion *)bio->bi_private);
1925 static int submit_bio_wait(int rw, struct bio *bio)
1927 struct completion event;
1930 init_completion(&event);
1931 bio->bi_private = &event;
1932 bio->bi_end_io = bi_complete;
1933 submit_bio(rw, bio);
1934 wait_for_completion(&event);
1936 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1939 static int narrow_write_error(struct r1bio *r1_bio, int i)
1941 struct mddev *mddev = r1_bio->mddev;
1942 struct r1conf *conf = mddev->private;
1943 struct md_rdev *rdev = conf->mirrors[i].rdev;
1945 struct bio_vec *vec;
1947 /* bio has the data to be written to device 'i' where
1948 * we just recently had a write error.
1949 * We repeatedly clone the bio and trim down to one block,
1950 * then try the write. Where the write fails we record
1952 * It is conceivable that the bio doesn't exactly align with
1953 * blocks. We must handle this somehow.
1955 * We currently own a reference on the rdev.
1961 int sect_to_write = r1_bio->sectors;
1964 if (rdev->badblocks.shift < 0)
1967 block_sectors = 1 << rdev->badblocks.shift;
1968 sector = r1_bio->sector;
1969 sectors = ((sector + block_sectors)
1970 & ~(sector_t)(block_sectors - 1))
1973 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1974 vcnt = r1_bio->behind_page_count;
1975 vec = r1_bio->behind_bvecs;
1977 while (vec[idx].bv_page == NULL)
1980 vcnt = r1_bio->master_bio->bi_vcnt;
1981 vec = r1_bio->master_bio->bi_io_vec;
1982 idx = r1_bio->master_bio->bi_idx;
1984 while (sect_to_write) {
1986 if (sectors > sect_to_write)
1987 sectors = sect_to_write;
1988 /* Write at 'sector' for 'sectors'*/
1990 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1991 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1992 wbio->bi_sector = r1_bio->sector;
1993 wbio->bi_rw = WRITE;
1994 wbio->bi_vcnt = vcnt;
1995 wbio->bi_size = r1_bio->sectors << 9;
1998 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
1999 wbio->bi_sector += rdev->data_offset;
2000 wbio->bi_bdev = rdev->bdev;
2001 if (submit_bio_wait(WRITE, wbio) == 0)
2003 ok = rdev_set_badblocks(rdev, sector,
2008 sect_to_write -= sectors;
2010 sectors = block_sectors;
2015 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2018 int s = r1_bio->sectors;
2019 for (m = 0; m < conf->raid_disks * 2 ; m++) {
2020 struct md_rdev *rdev = conf->mirrors[m].rdev;
2021 struct bio *bio = r1_bio->bios[m];
2022 if (bio->bi_end_io == NULL)
2024 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2025 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
2026 rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
2028 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
2029 test_bit(R1BIO_WriteError, &r1_bio->state)) {
2030 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
2031 md_error(conf->mddev, rdev);
2035 md_done_sync(conf->mddev, s, 1);
2038 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
2041 for (m = 0; m < conf->raid_disks * 2 ; m++)
2042 if (r1_bio->bios[m] == IO_MADE_GOOD) {
2043 struct md_rdev *rdev = conf->mirrors[m].rdev;
2044 rdev_clear_badblocks(rdev,
2046 r1_bio->sectors, 0);
2047 rdev_dec_pending(rdev, conf->mddev);
2048 } else if (r1_bio->bios[m] != NULL) {
2049 /* This drive got a write error. We need to
2050 * narrow down and record precise write
2053 if (!narrow_write_error(r1_bio, m)) {
2054 md_error(conf->mddev,
2055 conf->mirrors[m].rdev);
2056 /* an I/O failed, we can't clear the bitmap */
2057 set_bit(R1BIO_Degraded, &r1_bio->state);
2059 rdev_dec_pending(conf->mirrors[m].rdev,
2062 if (test_bit(R1BIO_WriteError, &r1_bio->state))
2063 close_write(r1_bio);
2064 raid_end_bio_io(r1_bio);
2067 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
2071 struct mddev *mddev = conf->mddev;
2073 char b[BDEVNAME_SIZE];
2074 struct md_rdev *rdev;
2076 clear_bit(R1BIO_ReadError, &r1_bio->state);
2077 /* we got a read error. Maybe the drive is bad. Maybe just
2078 * the block and we can fix it.
2079 * We freeze all other IO, and try reading the block from
2080 * other devices. When we find one, we re-write
2081 * and check it that fixes the read error.
2082 * This is all done synchronously while the array is
2085 if (mddev->ro == 0) {
2087 fix_read_error(conf, r1_bio->read_disk,
2088 r1_bio->sector, r1_bio->sectors);
2089 unfreeze_array(conf);
2091 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2093 bio = r1_bio->bios[r1_bio->read_disk];
2094 bdevname(bio->bi_bdev, b);
2096 disk = read_balance(conf, r1_bio, &max_sectors);
2098 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
2099 " read error for block %llu\n",
2100 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2101 raid_end_bio_io(r1_bio);
2103 const unsigned long do_sync
2104 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2106 r1_bio->bios[r1_bio->read_disk] =
2107 mddev->ro ? IO_BLOCKED : NULL;
2110 r1_bio->read_disk = disk;
2111 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2112 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
2113 r1_bio->bios[r1_bio->read_disk] = bio;
2114 rdev = conf->mirrors[disk].rdev;
2115 printk_ratelimited(KERN_ERR
2116 "md/raid1:%s: redirecting sector %llu"
2117 " to other mirror: %s\n",
2119 (unsigned long long)r1_bio->sector,
2120 bdevname(rdev->bdev, b));
2121 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2122 bio->bi_bdev = rdev->bdev;
2123 bio->bi_end_io = raid1_end_read_request;
2124 bio->bi_rw = READ | do_sync;
2125 bio->bi_private = r1_bio;
2126 if (max_sectors < r1_bio->sectors) {
2127 /* Drat - have to split this up more */
2128 struct bio *mbio = r1_bio->master_bio;
2129 int sectors_handled = (r1_bio->sector + max_sectors
2131 r1_bio->sectors = max_sectors;
2132 spin_lock_irq(&conf->device_lock);
2133 if (mbio->bi_phys_segments == 0)
2134 mbio->bi_phys_segments = 2;
2136 mbio->bi_phys_segments++;
2137 spin_unlock_irq(&conf->device_lock);
2138 generic_make_request(bio);
2141 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2143 r1_bio->master_bio = mbio;
2144 r1_bio->sectors = (mbio->bi_size >> 9)
2147 set_bit(R1BIO_ReadError, &r1_bio->state);
2148 r1_bio->mddev = mddev;
2149 r1_bio->sector = mbio->bi_sector + sectors_handled;
2153 generic_make_request(bio);
2157 static void raid1d(struct mddev *mddev)
2159 struct r1bio *r1_bio;
2160 unsigned long flags;
2161 struct r1conf *conf = mddev->private;
2162 struct list_head *head = &conf->retry_list;
2163 struct blk_plug plug;
2165 md_check_recovery(mddev);
2167 blk_start_plug(&plug);
2170 if (atomic_read(&mddev->plug_cnt) == 0)
2171 flush_pending_writes(conf);
2173 spin_lock_irqsave(&conf->device_lock, flags);
2174 if (list_empty(head)) {
2175 spin_unlock_irqrestore(&conf->device_lock, flags);
2178 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2179 list_del(head->prev);
2181 spin_unlock_irqrestore(&conf->device_lock, flags);
2183 mddev = r1_bio->mddev;
2184 conf = mddev->private;
2185 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2186 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2187 test_bit(R1BIO_WriteError, &r1_bio->state))
2188 handle_sync_write_finished(conf, r1_bio);
2190 sync_request_write(mddev, r1_bio);
2191 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2192 test_bit(R1BIO_WriteError, &r1_bio->state))
2193 handle_write_finished(conf, r1_bio);
2194 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2195 handle_read_error(conf, r1_bio);
2197 /* just a partial read to be scheduled from separate
2200 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2203 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2204 md_check_recovery(mddev);
2206 blk_finish_plug(&plug);
2210 static int init_resync(struct r1conf *conf)
2214 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2215 BUG_ON(conf->r1buf_pool);
2216 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2218 if (!conf->r1buf_pool)
2220 conf->next_resync = 0;
2225 * perform a "sync" on one "block"
2227 * We need to make sure that no normal I/O request - particularly write
2228 * requests - conflict with active sync requests.
2230 * This is achieved by tracking pending requests and a 'barrier' concept
2231 * that can be installed to exclude normal IO requests.
2234 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2236 struct r1conf *conf = mddev->private;
2237 struct r1bio *r1_bio;
2239 sector_t max_sector, nr_sectors;
2243 int write_targets = 0, read_targets = 0;
2244 sector_t sync_blocks;
2245 int still_degraded = 0;
2246 int good_sectors = RESYNC_SECTORS;
2247 int min_bad = 0; /* number of sectors that are bad in all devices */
2249 if (!conf->r1buf_pool)
2250 if (init_resync(conf))
2253 max_sector = mddev->dev_sectors;
2254 if (sector_nr >= max_sector) {
2255 /* If we aborted, we need to abort the
2256 * sync on the 'current' bitmap chunk (there will
2257 * only be one in raid1 resync.
2258 * We can find the current addess in mddev->curr_resync
2260 if (mddev->curr_resync < max_sector) /* aborted */
2261 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2263 else /* completed sync */
2266 bitmap_close_sync(mddev->bitmap);
2271 if (mddev->bitmap == NULL &&
2272 mddev->recovery_cp == MaxSector &&
2273 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2274 conf->fullsync == 0) {
2276 return max_sector - sector_nr;
2278 /* before building a request, check if we can skip these blocks..
2279 * This call the bitmap_start_sync doesn't actually record anything
2281 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2282 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2283 /* We can skip this block, and probably several more */
2288 * If there is non-resync activity waiting for a turn,
2289 * and resync is going fast enough,
2290 * then let it though before starting on this new sync request.
2292 if (!go_faster && conf->nr_waiting)
2293 msleep_interruptible(1000);
2295 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2296 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2297 raise_barrier(conf);
2299 conf->next_resync = sector_nr;
2303 * If we get a correctably read error during resync or recovery,
2304 * we might want to read from a different device. So we
2305 * flag all drives that could conceivably be read from for READ,
2306 * and any others (which will be non-In_sync devices) for WRITE.
2307 * If a read fails, we try reading from something else for which READ
2311 r1_bio->mddev = mddev;
2312 r1_bio->sector = sector_nr;
2314 set_bit(R1BIO_IsSync, &r1_bio->state);
2316 for (i = 0; i < conf->raid_disks * 2; i++) {
2317 struct md_rdev *rdev;
2318 bio = r1_bio->bios[i];
2320 /* take from bio_init */
2321 bio->bi_next = NULL;
2322 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2323 bio->bi_flags |= 1 << BIO_UPTODATE;
2327 bio->bi_phys_segments = 0;
2329 bio->bi_end_io = NULL;
2330 bio->bi_private = NULL;
2332 rdev = rcu_dereference(conf->mirrors[i].rdev);
2334 test_bit(Faulty, &rdev->flags)) {
2335 if (i < conf->raid_disks)
2337 } else if (!test_bit(In_sync, &rdev->flags)) {
2339 bio->bi_end_io = end_sync_write;
2342 /* may need to read from here */
2343 sector_t first_bad = MaxSector;
2346 if (is_badblock(rdev, sector_nr, good_sectors,
2347 &first_bad, &bad_sectors)) {
2348 if (first_bad > sector_nr)
2349 good_sectors = first_bad - sector_nr;
2351 bad_sectors -= (sector_nr - first_bad);
2353 min_bad > bad_sectors)
2354 min_bad = bad_sectors;
2357 if (sector_nr < first_bad) {
2358 if (test_bit(WriteMostly, &rdev->flags)) {
2366 bio->bi_end_io = end_sync_read;
2370 if (bio->bi_end_io) {
2371 atomic_inc(&rdev->nr_pending);
2372 bio->bi_sector = sector_nr + rdev->data_offset;
2373 bio->bi_bdev = rdev->bdev;
2374 bio->bi_private = r1_bio;
2380 r1_bio->read_disk = disk;
2382 if (read_targets == 0 && min_bad > 0) {
2383 /* These sectors are bad on all InSync devices, so we
2384 * need to mark them bad on all write targets
2387 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2388 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2389 struct md_rdev *rdev = conf->mirrors[i].rdev;
2390 ok = rdev_set_badblocks(rdev, sector_nr,
2394 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2399 /* Cannot record the badblocks, so need to
2401 * If there are multiple read targets, could just
2402 * fail the really bad ones ???
2404 conf->recovery_disabled = mddev->recovery_disabled;
2405 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2411 if (min_bad > 0 && min_bad < good_sectors) {
2412 /* only resync enough to reach the next bad->good
2414 good_sectors = min_bad;
2417 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2418 /* extra read targets are also write targets */
2419 write_targets += read_targets-1;
2421 if (write_targets == 0 || read_targets == 0) {
2422 /* There is nowhere to write, so all non-sync
2423 * drives must be failed - so we are finished
2425 sector_t rv = max_sector - sector_nr;
2431 if (max_sector > mddev->resync_max)
2432 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2433 if (max_sector > sector_nr + good_sectors)
2434 max_sector = sector_nr + good_sectors;
2439 int len = PAGE_SIZE;
2440 if (sector_nr + (len>>9) > max_sector)
2441 len = (max_sector - sector_nr) << 9;
2444 if (sync_blocks == 0) {
2445 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2446 &sync_blocks, still_degraded) &&
2448 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2450 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2451 if ((len >> 9) > sync_blocks)
2452 len = sync_blocks<<9;
2455 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2456 bio = r1_bio->bios[i];
2457 if (bio->bi_end_io) {
2458 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2459 if (bio_add_page(bio, page, len, 0) == 0) {
2461 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2464 bio = r1_bio->bios[i];
2465 if (bio->bi_end_io==NULL)
2467 /* remove last page from this bio */
2469 bio->bi_size -= len;
2470 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2476 nr_sectors += len>>9;
2477 sector_nr += len>>9;
2478 sync_blocks -= (len>>9);
2479 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2481 r1_bio->sectors = nr_sectors;
2483 /* For a user-requested sync, we read all readable devices and do a
2486 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2487 atomic_set(&r1_bio->remaining, read_targets);
2488 for (i = 0; i < conf->raid_disks * 2; i++) {
2489 bio = r1_bio->bios[i];
2490 if (bio->bi_end_io == end_sync_read) {
2491 md_sync_acct(bio->bi_bdev, nr_sectors);
2492 generic_make_request(bio);
2496 atomic_set(&r1_bio->remaining, 1);
2497 bio = r1_bio->bios[r1_bio->read_disk];
2498 md_sync_acct(bio->bi_bdev, nr_sectors);
2499 generic_make_request(bio);
2505 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2510 return mddev->dev_sectors;
2513 static struct r1conf *setup_conf(struct mddev *mddev)
2515 struct r1conf *conf;
2517 struct mirror_info *disk;
2518 struct md_rdev *rdev;
2521 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2525 conf->mirrors = kzalloc(sizeof(struct mirror_info)
2526 * mddev->raid_disks * 2,
2531 conf->tmppage = alloc_page(GFP_KERNEL);
2535 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2536 if (!conf->poolinfo)
2538 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2539 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2542 if (!conf->r1bio_pool)
2545 conf->poolinfo->mddev = mddev;
2548 spin_lock_init(&conf->device_lock);
2549 rdev_for_each(rdev, mddev) {
2550 struct request_queue *q;
2551 int disk_idx = rdev->raid_disk;
2552 if (disk_idx >= mddev->raid_disks
2555 if (test_bit(Replacement, &rdev->flags))
2556 disk = conf->mirrors + conf->raid_disks + disk_idx;
2558 disk = conf->mirrors + disk_idx;
2563 q = bdev_get_queue(rdev->bdev);
2564 if (q->merge_bvec_fn)
2565 mddev->merge_check_needed = 1;
2567 disk->head_position = 0;
2569 conf->raid_disks = mddev->raid_disks;
2570 conf->mddev = mddev;
2571 INIT_LIST_HEAD(&conf->retry_list);
2573 spin_lock_init(&conf->resync_lock);
2574 init_waitqueue_head(&conf->wait_barrier);
2576 bio_list_init(&conf->pending_bio_list);
2577 conf->pending_count = 0;
2578 conf->recovery_disabled = mddev->recovery_disabled - 1;
2581 conf->last_used = -1;
2582 for (i = 0; i < conf->raid_disks * 2; i++) {
2584 disk = conf->mirrors + i;
2586 if (i < conf->raid_disks &&
2587 disk[conf->raid_disks].rdev) {
2588 /* This slot has a replacement. */
2590 /* No original, just make the replacement
2591 * a recovering spare
2594 disk[conf->raid_disks].rdev;
2595 disk[conf->raid_disks].rdev = NULL;
2596 } else if (!test_bit(In_sync, &disk->rdev->flags))
2597 /* Original is not in_sync - bad */
2602 !test_bit(In_sync, &disk->rdev->flags)) {
2603 disk->head_position = 0;
2605 (disk->rdev->saved_raid_disk < 0))
2607 } else if (conf->last_used < 0)
2609 * The first working device is used as a
2610 * starting point to read balancing.
2612 conf->last_used = i;
2615 if (conf->last_used < 0) {
2616 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2621 conf->thread = md_register_thread(raid1d, mddev, "raid1");
2622 if (!conf->thread) {
2624 "md/raid1:%s: couldn't allocate thread\n",
2633 if (conf->r1bio_pool)
2634 mempool_destroy(conf->r1bio_pool);
2635 kfree(conf->mirrors);
2636 safe_put_page(conf->tmppage);
2637 kfree(conf->poolinfo);
2640 return ERR_PTR(err);
2643 static int stop(struct mddev *mddev);
2644 static int run(struct mddev *mddev)
2646 struct r1conf *conf;
2648 struct md_rdev *rdev;
2651 if (mddev->level != 1) {
2652 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2653 mdname(mddev), mddev->level);
2656 if (mddev->reshape_position != MaxSector) {
2657 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2662 * copy the already verified devices into our private RAID1
2663 * bookkeeping area. [whatever we allocate in run(),
2664 * should be freed in stop()]
2666 if (mddev->private == NULL)
2667 conf = setup_conf(mddev);
2669 conf = mddev->private;
2672 return PTR_ERR(conf);
2674 rdev_for_each(rdev, mddev) {
2675 if (!mddev->gendisk)
2677 disk_stack_limits(mddev->gendisk, rdev->bdev,
2678 rdev->data_offset << 9);
2681 mddev->degraded = 0;
2682 for (i=0; i < conf->raid_disks; i++)
2683 if (conf->mirrors[i].rdev == NULL ||
2684 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2685 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2688 if (conf->raid_disks - mddev->degraded == 1)
2689 mddev->recovery_cp = MaxSector;
2691 if (mddev->recovery_cp != MaxSector)
2692 printk(KERN_NOTICE "md/raid1:%s: not clean"
2693 " -- starting background reconstruction\n",
2696 "md/raid1:%s: active with %d out of %d mirrors\n",
2697 mdname(mddev), mddev->raid_disks - mddev->degraded,
2701 * Ok, everything is just fine now
2703 mddev->thread = conf->thread;
2704 conf->thread = NULL;
2705 mddev->private = conf;
2707 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2710 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2711 mddev->queue->backing_dev_info.congested_data = mddev;
2712 blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
2715 ret = md_integrity_register(mddev);
2721 static int stop(struct mddev *mddev)
2723 struct r1conf *conf = mddev->private;
2724 struct bitmap *bitmap = mddev->bitmap;
2726 /* wait for behind writes to complete */
2727 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2728 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2730 /* need to kick something here to make sure I/O goes? */
2731 wait_event(bitmap->behind_wait,
2732 atomic_read(&bitmap->behind_writes) == 0);
2735 raise_barrier(conf);
2736 lower_barrier(conf);
2738 md_unregister_thread(&mddev->thread);
2739 if (conf->r1bio_pool)
2740 mempool_destroy(conf->r1bio_pool);
2741 kfree(conf->mirrors);
2742 kfree(conf->poolinfo);
2744 mddev->private = NULL;
2748 static int raid1_resize(struct mddev *mddev, sector_t sectors)
2750 /* no resync is happening, and there is enough space
2751 * on all devices, so we can resize.
2752 * We need to make sure resync covers any new space.
2753 * If the array is shrinking we should possibly wait until
2754 * any io in the removed space completes, but it hardly seems
2757 sector_t newsize = raid1_size(mddev, sectors, 0);
2758 if (mddev->external_size &&
2759 mddev->array_sectors > newsize)
2761 if (mddev->bitmap) {
2762 int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0);
2766 md_set_array_sectors(mddev, newsize);
2767 set_capacity(mddev->gendisk, mddev->array_sectors);
2768 revalidate_disk(mddev->gendisk);
2769 if (sectors > mddev->dev_sectors &&
2770 mddev->recovery_cp > mddev->dev_sectors) {
2771 mddev->recovery_cp = mddev->dev_sectors;
2772 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2774 mddev->dev_sectors = sectors;
2775 mddev->resync_max_sectors = sectors;
2779 static int raid1_reshape(struct mddev *mddev)
2782 * 1/ resize the r1bio_pool
2783 * 2/ resize conf->mirrors
2785 * We allocate a new r1bio_pool if we can.
2786 * Then raise a device barrier and wait until all IO stops.
2787 * Then resize conf->mirrors and swap in the new r1bio pool.
2789 * At the same time, we "pack" the devices so that all the missing
2790 * devices have the higher raid_disk numbers.
2792 mempool_t *newpool, *oldpool;
2793 struct pool_info *newpoolinfo;
2794 struct mirror_info *newmirrors;
2795 struct r1conf *conf = mddev->private;
2796 int cnt, raid_disks;
2797 unsigned long flags;
2800 /* Cannot change chunk_size, layout, or level */
2801 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2802 mddev->layout != mddev->new_layout ||
2803 mddev->level != mddev->new_level) {
2804 mddev->new_chunk_sectors = mddev->chunk_sectors;
2805 mddev->new_layout = mddev->layout;
2806 mddev->new_level = mddev->level;
2810 err = md_allow_write(mddev);
2814 raid_disks = mddev->raid_disks + mddev->delta_disks;
2816 if (raid_disks < conf->raid_disks) {
2818 for (d= 0; d < conf->raid_disks; d++)
2819 if (conf->mirrors[d].rdev)
2821 if (cnt > raid_disks)
2825 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2828 newpoolinfo->mddev = mddev;
2829 newpoolinfo->raid_disks = raid_disks * 2;
2831 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2832 r1bio_pool_free, newpoolinfo);
2837 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks * 2,
2841 mempool_destroy(newpool);
2845 raise_barrier(conf);
2847 /* ok, everything is stopped */
2848 oldpool = conf->r1bio_pool;
2849 conf->r1bio_pool = newpool;
2851 for (d = d2 = 0; d < conf->raid_disks; d++) {
2852 struct md_rdev *rdev = conf->mirrors[d].rdev;
2853 if (rdev && rdev->raid_disk != d2) {
2854 sysfs_unlink_rdev(mddev, rdev);
2855 rdev->raid_disk = d2;
2856 sysfs_unlink_rdev(mddev, rdev);
2857 if (sysfs_link_rdev(mddev, rdev))
2859 "md/raid1:%s: cannot register rd%d\n",
2860 mdname(mddev), rdev->raid_disk);
2863 newmirrors[d2++].rdev = rdev;
2865 kfree(conf->mirrors);
2866 conf->mirrors = newmirrors;
2867 kfree(conf->poolinfo);
2868 conf->poolinfo = newpoolinfo;
2870 spin_lock_irqsave(&conf->device_lock, flags);
2871 mddev->degraded += (raid_disks - conf->raid_disks);
2872 spin_unlock_irqrestore(&conf->device_lock, flags);
2873 conf->raid_disks = mddev->raid_disks = raid_disks;
2874 mddev->delta_disks = 0;
2876 conf->last_used = 0; /* just make sure it is in-range */
2877 lower_barrier(conf);
2879 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2880 md_wakeup_thread(mddev->thread);
2882 mempool_destroy(oldpool);
2886 static void raid1_quiesce(struct mddev *mddev, int state)
2888 struct r1conf *conf = mddev->private;
2891 case 2: /* wake for suspend */
2892 wake_up(&conf->wait_barrier);
2895 raise_barrier(conf);
2898 lower_barrier(conf);
2903 static void *raid1_takeover(struct mddev *mddev)
2905 /* raid1 can take over:
2906 * raid5 with 2 devices, any layout or chunk size
2908 if (mddev->level == 5 && mddev->raid_disks == 2) {
2909 struct r1conf *conf;
2910 mddev->new_level = 1;
2911 mddev->new_layout = 0;
2912 mddev->new_chunk_sectors = 0;
2913 conf = setup_conf(mddev);
2918 return ERR_PTR(-EINVAL);
2921 static struct md_personality raid1_personality =
2925 .owner = THIS_MODULE,
2926 .make_request = make_request,
2930 .error_handler = error,
2931 .hot_add_disk = raid1_add_disk,
2932 .hot_remove_disk= raid1_remove_disk,
2933 .spare_active = raid1_spare_active,
2934 .sync_request = sync_request,
2935 .resize = raid1_resize,
2937 .check_reshape = raid1_reshape,
2938 .quiesce = raid1_quiesce,
2939 .takeover = raid1_takeover,
2942 static int __init raid_init(void)
2944 return register_md_personality(&raid1_personality);
2947 static void raid_exit(void)
2949 unregister_md_personality(&raid1_personality);
2952 module_init(raid_init);
2953 module_exit(raid_exit);
2954 MODULE_LICENSE("GPL");
2955 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2956 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2957 MODULE_ALIAS("md-raid1");
2958 MODULE_ALIAS("md-level-1");
2960 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);