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; 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; 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 int raid_disks = r1_bio->mddev->raid_disks;
282 for (mirror = 0; mirror < raid_disks; mirror++)
283 if (r1_bio->bios[mirror] == bio)
286 BUG_ON(mirror == raid_disks);
287 update_head_pos(mirror, r1_bio);
292 static void raid1_end_read_request(struct bio *bio, int error)
294 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
295 struct r1bio *r1_bio = bio->bi_private;
297 struct r1conf *conf = r1_bio->mddev->private;
299 mirror = r1_bio->read_disk;
301 * this branch is our 'one mirror IO has finished' event handler:
303 update_head_pos(mirror, r1_bio);
306 set_bit(R1BIO_Uptodate, &r1_bio->state);
308 /* If all other devices have failed, we want to return
309 * the error upwards rather than fail the last device.
310 * Here we redefine "uptodate" to mean "Don't want to retry"
313 spin_lock_irqsave(&conf->device_lock, flags);
314 if (r1_bio->mddev->degraded == conf->raid_disks ||
315 (r1_bio->mddev->degraded == conf->raid_disks-1 &&
316 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
318 spin_unlock_irqrestore(&conf->device_lock, flags);
322 raid_end_bio_io(r1_bio);
327 char b[BDEVNAME_SIZE];
329 KERN_ERR "md/raid1:%s: %s: "
330 "rescheduling sector %llu\n",
332 bdevname(conf->mirrors[mirror].rdev->bdev,
334 (unsigned long long)r1_bio->sector);
335 set_bit(R1BIO_ReadError, &r1_bio->state);
336 reschedule_retry(r1_bio);
339 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
342 static void close_write(struct r1bio *r1_bio)
344 /* it really is the end of this request */
345 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
346 /* free extra copy of the data pages */
347 int i = r1_bio->behind_page_count;
349 safe_put_page(r1_bio->behind_bvecs[i].bv_page);
350 kfree(r1_bio->behind_bvecs);
351 r1_bio->behind_bvecs = NULL;
353 /* clear the bitmap if all writes complete successfully */
354 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
356 !test_bit(R1BIO_Degraded, &r1_bio->state),
357 test_bit(R1BIO_BehindIO, &r1_bio->state));
358 md_write_end(r1_bio->mddev);
361 static void r1_bio_write_done(struct r1bio *r1_bio)
363 if (!atomic_dec_and_test(&r1_bio->remaining))
366 if (test_bit(R1BIO_WriteError, &r1_bio->state))
367 reschedule_retry(r1_bio);
370 if (test_bit(R1BIO_MadeGood, &r1_bio->state))
371 reschedule_retry(r1_bio);
373 raid_end_bio_io(r1_bio);
377 static void raid1_end_write_request(struct bio *bio, int error)
379 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
380 struct r1bio *r1_bio = bio->bi_private;
381 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
382 struct r1conf *conf = r1_bio->mddev->private;
383 struct bio *to_put = NULL;
385 mirror = find_bio_disk(r1_bio, bio);
388 * 'one mirror IO has finished' event handler:
391 set_bit(WriteErrorSeen,
392 &conf->mirrors[mirror].rdev->flags);
393 set_bit(R1BIO_WriteError, &r1_bio->state);
396 * Set R1BIO_Uptodate in our master bio, so that we
397 * will return a good error code for to the higher
398 * levels even if IO on some other mirrored buffer
401 * The 'master' represents the composite IO operation
402 * to user-side. So if something waits for IO, then it
403 * will wait for the 'master' bio.
408 r1_bio->bios[mirror] = NULL;
411 * Do not set R1BIO_Uptodate if the current device is
412 * rebuilding or Faulty. This is because we cannot use
413 * such device for properly reading the data back (we could
414 * potentially use it, if the current write would have felt
415 * before rdev->recovery_offset, but for simplicity we don't
418 if (test_bit(In_sync, &conf->mirrors[mirror].rdev->flags) &&
419 !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))
420 set_bit(R1BIO_Uptodate, &r1_bio->state);
422 /* Maybe we can clear some bad blocks. */
423 if (is_badblock(conf->mirrors[mirror].rdev,
424 r1_bio->sector, r1_bio->sectors,
425 &first_bad, &bad_sectors)) {
426 r1_bio->bios[mirror] = IO_MADE_GOOD;
427 set_bit(R1BIO_MadeGood, &r1_bio->state);
432 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
433 atomic_dec(&r1_bio->behind_remaining);
436 * In behind mode, we ACK the master bio once the I/O
437 * has safely reached all non-writemostly
438 * disks. Setting the Returned bit ensures that this
439 * gets done only once -- we don't ever want to return
440 * -EIO here, instead we'll wait
442 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
443 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
444 /* Maybe we can return now */
445 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
446 struct bio *mbio = r1_bio->master_bio;
447 pr_debug("raid1: behind end write sectors"
449 (unsigned long long) mbio->bi_sector,
450 (unsigned long long) mbio->bi_sector +
451 (mbio->bi_size >> 9) - 1);
452 call_bio_endio(r1_bio);
456 if (r1_bio->bios[mirror] == NULL)
457 rdev_dec_pending(conf->mirrors[mirror].rdev,
461 * Let's see if all mirrored write operations have finished
464 r1_bio_write_done(r1_bio);
472 * This routine returns the disk from which the requested read should
473 * be done. There is a per-array 'next expected sequential IO' sector
474 * number - if this matches on the next IO then we use the last disk.
475 * There is also a per-disk 'last know head position' sector that is
476 * maintained from IRQ contexts, both the normal and the resync IO
477 * completion handlers update this position correctly. If there is no
478 * perfect sequential match then we pick the disk whose head is closest.
480 * If there are 2 mirrors in the same 2 devices, performance degrades
481 * because position is mirror, not device based.
483 * The rdev for the device selected will have nr_pending incremented.
485 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
487 const sector_t this_sector = r1_bio->sector;
489 int best_good_sectors;
494 struct md_rdev *rdev;
499 * Check if we can balance. We can balance on the whole
500 * device if no resync is going on, or below the resync window.
501 * We take the first readable disk when above the resync window.
504 sectors = r1_bio->sectors;
506 best_dist = MaxSector;
507 best_good_sectors = 0;
509 if (conf->mddev->recovery_cp < MaxSector &&
510 (this_sector + sectors >= conf->next_resync)) {
515 start_disk = conf->last_used;
518 for (i = 0 ; i < conf->raid_disks ; i++) {
523 int disk = start_disk + i;
524 if (disk >= conf->raid_disks)
525 disk -= conf->raid_disks;
527 rdev = rcu_dereference(conf->mirrors[disk].rdev);
528 if (r1_bio->bios[disk] == IO_BLOCKED
530 || test_bit(Faulty, &rdev->flags))
532 if (!test_bit(In_sync, &rdev->flags) &&
533 rdev->recovery_offset < this_sector + sectors)
535 if (test_bit(WriteMostly, &rdev->flags)) {
536 /* Don't balance among write-mostly, just
537 * use the first as a last resort */
539 if (is_badblock(rdev, this_sector, sectors,
540 &first_bad, &bad_sectors)) {
541 if (first_bad < this_sector)
542 /* Cannot use this */
544 best_good_sectors = first_bad - this_sector;
546 best_good_sectors = sectors;
551 /* This is a reasonable device to use. It might
554 if (is_badblock(rdev, this_sector, sectors,
555 &first_bad, &bad_sectors)) {
556 if (best_dist < MaxSector)
557 /* already have a better device */
559 if (first_bad <= this_sector) {
560 /* cannot read here. If this is the 'primary'
561 * device, then we must not read beyond
562 * bad_sectors from another device..
564 bad_sectors -= (this_sector - first_bad);
565 if (choose_first && sectors > bad_sectors)
566 sectors = bad_sectors;
567 if (best_good_sectors > sectors)
568 best_good_sectors = sectors;
571 sector_t good_sectors = first_bad - this_sector;
572 if (good_sectors > best_good_sectors) {
573 best_good_sectors = good_sectors;
581 best_good_sectors = sectors;
583 dist = abs(this_sector - conf->mirrors[disk].head_position);
585 /* Don't change to another disk for sequential reads */
586 || conf->next_seq_sect == this_sector
588 /* If device is idle, use it */
589 || atomic_read(&rdev->nr_pending) == 0) {
593 if (dist < best_dist) {
599 if (best_disk >= 0) {
600 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
603 atomic_inc(&rdev->nr_pending);
604 if (test_bit(Faulty, &rdev->flags)) {
605 /* cannot risk returning a device that failed
606 * before we inc'ed nr_pending
608 rdev_dec_pending(rdev, conf->mddev);
611 sectors = best_good_sectors;
612 conf->next_seq_sect = this_sector + sectors;
613 conf->last_used = best_disk;
616 *max_sectors = sectors;
621 int md_raid1_congested(struct mddev *mddev, int bits)
623 struct r1conf *conf = mddev->private;
626 if ((bits & (1 << BDI_async_congested)) &&
627 conf->pending_count >= max_queued_requests)
631 for (i = 0; i < mddev->raid_disks; i++) {
632 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
633 if (rdev && !test_bit(Faulty, &rdev->flags)) {
634 struct request_queue *q = bdev_get_queue(rdev->bdev);
638 /* Note the '|| 1' - when read_balance prefers
639 * non-congested targets, it can be removed
641 if ((bits & (1<<BDI_async_congested)) || 1)
642 ret |= bdi_congested(&q->backing_dev_info, bits);
644 ret &= bdi_congested(&q->backing_dev_info, bits);
650 EXPORT_SYMBOL_GPL(md_raid1_congested);
652 static int raid1_congested(void *data, int bits)
654 struct mddev *mddev = data;
656 return mddev_congested(mddev, bits) ||
657 md_raid1_congested(mddev, bits);
660 static void flush_pending_writes(struct r1conf *conf)
662 /* Any writes that have been queued but are awaiting
663 * bitmap updates get flushed here.
665 spin_lock_irq(&conf->device_lock);
667 if (conf->pending_bio_list.head) {
669 bio = bio_list_get(&conf->pending_bio_list);
670 conf->pending_count = 0;
671 spin_unlock_irq(&conf->device_lock);
672 /* flush any pending bitmap writes to
673 * disk before proceeding w/ I/O */
674 bitmap_unplug(conf->mddev->bitmap);
675 wake_up(&conf->wait_barrier);
677 while (bio) { /* submit pending writes */
678 struct bio *next = bio->bi_next;
680 generic_make_request(bio);
684 spin_unlock_irq(&conf->device_lock);
688 * Sometimes we need to suspend IO while we do something else,
689 * either some resync/recovery, or reconfigure the array.
690 * To do this we raise a 'barrier'.
691 * The 'barrier' is a counter that can be raised multiple times
692 * to count how many activities are happening which preclude
694 * We can only raise the barrier if there is no pending IO.
695 * i.e. if nr_pending == 0.
696 * We choose only to raise the barrier if no-one is waiting for the
697 * barrier to go down. This means that as soon as an IO request
698 * is ready, no other operations which require a barrier will start
699 * until the IO request has had a chance.
701 * So: regular IO calls 'wait_barrier'. When that returns there
702 * is no backgroup IO happening, It must arrange to call
703 * allow_barrier when it has finished its IO.
704 * backgroup IO calls must call raise_barrier. Once that returns
705 * there is no normal IO happeing. It must arrange to call
706 * lower_barrier when the particular background IO completes.
708 #define RESYNC_DEPTH 32
710 static void raise_barrier(struct r1conf *conf)
712 spin_lock_irq(&conf->resync_lock);
714 /* Wait until no block IO is waiting */
715 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
716 conf->resync_lock, );
718 /* block any new IO from starting */
721 /* Now wait for all pending IO to complete */
722 wait_event_lock_irq(conf->wait_barrier,
723 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
724 conf->resync_lock, );
726 spin_unlock_irq(&conf->resync_lock);
729 static void lower_barrier(struct r1conf *conf)
732 BUG_ON(conf->barrier <= 0);
733 spin_lock_irqsave(&conf->resync_lock, flags);
735 spin_unlock_irqrestore(&conf->resync_lock, flags);
736 wake_up(&conf->wait_barrier);
739 static void wait_barrier(struct r1conf *conf)
741 spin_lock_irq(&conf->resync_lock);
744 /* Wait for the barrier to drop.
745 * However if there are already pending
746 * requests (preventing the barrier from
747 * rising completely), and the
748 * pre-process bio queue isn't empty,
749 * then don't wait, as we need to empty
750 * that queue to get the nr_pending
753 wait_event_lock_irq(conf->wait_barrier,
757 !bio_list_empty(current->bio_list)),
763 spin_unlock_irq(&conf->resync_lock);
766 static void allow_barrier(struct r1conf *conf)
769 spin_lock_irqsave(&conf->resync_lock, flags);
771 spin_unlock_irqrestore(&conf->resync_lock, flags);
772 wake_up(&conf->wait_barrier);
775 static void freeze_array(struct r1conf *conf)
777 /* stop syncio and normal IO and wait for everything to
779 * We increment barrier and nr_waiting, and then
780 * wait until nr_pending match nr_queued+1
781 * This is called in the context of one normal IO request
782 * that has failed. Thus any sync request that might be pending
783 * will be blocked by nr_pending, and we need to wait for
784 * pending IO requests to complete or be queued for re-try.
785 * Thus the number queued (nr_queued) plus this request (1)
786 * must match the number of pending IOs (nr_pending) before
789 spin_lock_irq(&conf->resync_lock);
792 wait_event_lock_irq(conf->wait_barrier,
793 conf->nr_pending == conf->nr_queued+1,
795 flush_pending_writes(conf));
796 spin_unlock_irq(&conf->resync_lock);
798 static void unfreeze_array(struct r1conf *conf)
800 /* reverse the effect of the freeze */
801 spin_lock_irq(&conf->resync_lock);
804 wake_up(&conf->wait_barrier);
805 spin_unlock_irq(&conf->resync_lock);
809 /* duplicate the data pages for behind I/O
811 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
814 struct bio_vec *bvec;
815 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
817 if (unlikely(!bvecs))
820 bio_for_each_segment(bvec, bio, i) {
822 bvecs[i].bv_page = alloc_page(GFP_NOIO);
823 if (unlikely(!bvecs[i].bv_page))
825 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
826 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
827 kunmap(bvecs[i].bv_page);
828 kunmap(bvec->bv_page);
830 r1_bio->behind_bvecs = bvecs;
831 r1_bio->behind_page_count = bio->bi_vcnt;
832 set_bit(R1BIO_BehindIO, &r1_bio->state);
836 for (i = 0; i < bio->bi_vcnt; i++)
837 if (bvecs[i].bv_page)
838 put_page(bvecs[i].bv_page);
840 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
843 static void make_request(struct mddev *mddev, struct bio * bio)
845 struct r1conf *conf = mddev->private;
846 struct mirror_info *mirror;
847 struct r1bio *r1_bio;
848 struct bio *read_bio;
850 struct bitmap *bitmap;
852 const int rw = bio_data_dir(bio);
853 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
854 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
855 struct md_rdev *blocked_rdev;
862 * Register the new request and wait if the reconstruction
863 * thread has put up a bar for new requests.
864 * Continue immediately if no resync is active currently.
867 md_write_start(mddev, bio); /* wait on superblock update early */
869 if (bio_data_dir(bio) == WRITE &&
870 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
871 bio->bi_sector < mddev->suspend_hi) {
872 /* As the suspend_* range is controlled by
873 * userspace, we want an interruptible
878 flush_signals(current);
879 prepare_to_wait(&conf->wait_barrier,
880 &w, TASK_INTERRUPTIBLE);
881 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
882 bio->bi_sector >= mddev->suspend_hi)
886 finish_wait(&conf->wait_barrier, &w);
891 bitmap = mddev->bitmap;
894 * make_request() can abort the operation when READA is being
895 * used and no empty request is available.
898 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
900 r1_bio->master_bio = bio;
901 r1_bio->sectors = bio->bi_size >> 9;
903 r1_bio->mddev = mddev;
904 r1_bio->sector = bio->bi_sector;
906 /* We might need to issue multiple reads to different
907 * devices if there are bad blocks around, so we keep
908 * track of the number of reads in bio->bi_phys_segments.
909 * If this is 0, there is only one r1_bio and no locking
910 * will be needed when requests complete. If it is
911 * non-zero, then it is the number of not-completed requests.
913 bio->bi_phys_segments = 0;
914 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
918 * read balancing logic:
923 rdisk = read_balance(conf, r1_bio, &max_sectors);
926 /* couldn't find anywhere to read from */
927 raid_end_bio_io(r1_bio);
930 mirror = conf->mirrors + rdisk;
932 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
934 /* Reading from a write-mostly device must
935 * take care not to over-take any writes
938 wait_event(bitmap->behind_wait,
939 atomic_read(&bitmap->behind_writes) == 0);
941 r1_bio->read_disk = rdisk;
943 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
944 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
947 r1_bio->bios[rdisk] = read_bio;
949 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
950 read_bio->bi_bdev = mirror->rdev->bdev;
951 read_bio->bi_end_io = raid1_end_read_request;
952 read_bio->bi_rw = READ | do_sync;
953 read_bio->bi_private = r1_bio;
955 if (max_sectors < r1_bio->sectors) {
956 /* could not read all from this device, so we will
957 * need another r1_bio.
960 sectors_handled = (r1_bio->sector + max_sectors
962 r1_bio->sectors = max_sectors;
963 spin_lock_irq(&conf->device_lock);
964 if (bio->bi_phys_segments == 0)
965 bio->bi_phys_segments = 2;
967 bio->bi_phys_segments++;
968 spin_unlock_irq(&conf->device_lock);
969 /* Cannot call generic_make_request directly
970 * as that will be queued in __make_request
971 * and subsequent mempool_alloc might block waiting
972 * for it. So hand bio over to raid1d.
974 reschedule_retry(r1_bio);
976 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
978 r1_bio->master_bio = bio;
979 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
981 r1_bio->mddev = mddev;
982 r1_bio->sector = bio->bi_sector + sectors_handled;
985 generic_make_request(read_bio);
992 if (conf->pending_count >= max_queued_requests) {
993 md_wakeup_thread(mddev->thread);
994 wait_event(conf->wait_barrier,
995 conf->pending_count < max_queued_requests);
997 /* first select target devices under rcu_lock and
998 * inc refcount on their rdev. Record them by setting
1000 * If there are known/acknowledged bad blocks on any device on
1001 * which we have seen a write error, we want to avoid writing those
1003 * This potentially requires several writes to write around
1004 * the bad blocks. Each set of writes gets it's own r1bio
1005 * with a set of bios attached.
1007 plugged = mddev_check_plugged(mddev);
1009 disks = conf->raid_disks;
1011 blocked_rdev = NULL;
1013 max_sectors = r1_bio->sectors;
1014 for (i = 0; i < disks; i++) {
1015 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1016 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1017 atomic_inc(&rdev->nr_pending);
1018 blocked_rdev = rdev;
1021 r1_bio->bios[i] = NULL;
1022 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1023 set_bit(R1BIO_Degraded, &r1_bio->state);
1027 atomic_inc(&rdev->nr_pending);
1028 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1033 is_bad = is_badblock(rdev, r1_bio->sector,
1035 &first_bad, &bad_sectors);
1037 /* mustn't write here until the bad block is
1039 set_bit(BlockedBadBlocks, &rdev->flags);
1040 blocked_rdev = rdev;
1043 if (is_bad && first_bad <= r1_bio->sector) {
1044 /* Cannot write here at all */
1045 bad_sectors -= (r1_bio->sector - first_bad);
1046 if (bad_sectors < max_sectors)
1047 /* mustn't write more than bad_sectors
1048 * to other devices yet
1050 max_sectors = bad_sectors;
1051 rdev_dec_pending(rdev, mddev);
1052 /* We don't set R1BIO_Degraded as that
1053 * only applies if the disk is
1054 * missing, so it might be re-added,
1055 * and we want to know to recover this
1057 * In this case the device is here,
1058 * and the fact that this chunk is not
1059 * in-sync is recorded in the bad
1065 int good_sectors = first_bad - r1_bio->sector;
1066 if (good_sectors < max_sectors)
1067 max_sectors = good_sectors;
1070 r1_bio->bios[i] = bio;
1074 if (unlikely(blocked_rdev)) {
1075 /* Wait for this device to become unblocked */
1078 for (j = 0; j < i; j++)
1079 if (r1_bio->bios[j])
1080 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1082 allow_barrier(conf);
1083 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1088 if (max_sectors < r1_bio->sectors) {
1089 /* We are splitting this write into multiple parts, so
1090 * we need to prepare for allocating another r1_bio.
1092 r1_bio->sectors = max_sectors;
1093 spin_lock_irq(&conf->device_lock);
1094 if (bio->bi_phys_segments == 0)
1095 bio->bi_phys_segments = 2;
1097 bio->bi_phys_segments++;
1098 spin_unlock_irq(&conf->device_lock);
1100 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1102 atomic_set(&r1_bio->remaining, 1);
1103 atomic_set(&r1_bio->behind_remaining, 0);
1106 for (i = 0; i < disks; i++) {
1108 if (!r1_bio->bios[i])
1111 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1112 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1116 * Not if there are too many, or cannot
1117 * allocate memory, or a reader on WriteMostly
1118 * is waiting for behind writes to flush */
1120 (atomic_read(&bitmap->behind_writes)
1121 < mddev->bitmap_info.max_write_behind) &&
1122 !waitqueue_active(&bitmap->behind_wait))
1123 alloc_behind_pages(mbio, r1_bio);
1125 bitmap_startwrite(bitmap, r1_bio->sector,
1127 test_bit(R1BIO_BehindIO,
1131 if (r1_bio->behind_bvecs) {
1132 struct bio_vec *bvec;
1135 /* Yes, I really want the '__' version so that
1136 * we clear any unused pointer in the io_vec, rather
1137 * than leave them unchanged. This is important
1138 * because when we come to free the pages, we won't
1139 * know the original bi_idx, so we just free
1142 bio_for_each_segment_all(bvec, mbio, j)
1143 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1144 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1145 atomic_inc(&r1_bio->behind_remaining);
1148 r1_bio->bios[i] = mbio;
1150 mbio->bi_sector = (r1_bio->sector +
1151 conf->mirrors[i].rdev->data_offset);
1152 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1153 mbio->bi_end_io = raid1_end_write_request;
1154 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
1155 mbio->bi_private = r1_bio;
1157 atomic_inc(&r1_bio->remaining);
1158 spin_lock_irqsave(&conf->device_lock, flags);
1159 bio_list_add(&conf->pending_bio_list, mbio);
1160 conf->pending_count++;
1161 spin_unlock_irqrestore(&conf->device_lock, flags);
1163 /* Mustn't call r1_bio_write_done before this next test,
1164 * as it could result in the bio being freed.
1166 if (sectors_handled < (bio->bi_size >> 9)) {
1167 r1_bio_write_done(r1_bio);
1168 /* We need another r1_bio. It has already been counted
1169 * in bio->bi_phys_segments
1171 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1172 r1_bio->master_bio = bio;
1173 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1175 r1_bio->mddev = mddev;
1176 r1_bio->sector = bio->bi_sector + sectors_handled;
1180 r1_bio_write_done(r1_bio);
1182 /* In case raid1d snuck in to freeze_array */
1183 wake_up(&conf->wait_barrier);
1185 if (do_sync || !bitmap || !plugged)
1186 md_wakeup_thread(mddev->thread);
1189 static void status(struct seq_file *seq, struct mddev *mddev)
1191 struct r1conf *conf = mddev->private;
1194 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1195 conf->raid_disks - mddev->degraded);
1197 for (i = 0; i < conf->raid_disks; i++) {
1198 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1199 seq_printf(seq, "%s",
1200 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1203 seq_printf(seq, "]");
1207 static void error(struct mddev *mddev, struct md_rdev *rdev)
1209 char b[BDEVNAME_SIZE];
1210 struct r1conf *conf = mddev->private;
1213 * If it is not operational, then we have already marked it as dead
1214 * else if it is the last working disks, ignore the error, let the
1215 * next level up know.
1216 * else mark the drive as failed
1218 if (test_bit(In_sync, &rdev->flags)
1219 && (conf->raid_disks - mddev->degraded) == 1) {
1221 * Don't fail the drive, act as though we were just a
1222 * normal single drive.
1223 * However don't try a recovery from this drive as
1224 * it is very likely to fail.
1226 conf->recovery_disabled = mddev->recovery_disabled;
1229 set_bit(Blocked, &rdev->flags);
1230 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1231 unsigned long flags;
1232 spin_lock_irqsave(&conf->device_lock, flags);
1234 set_bit(Faulty, &rdev->flags);
1235 spin_unlock_irqrestore(&conf->device_lock, flags);
1237 * if recovery is running, make sure it aborts.
1239 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1241 set_bit(Faulty, &rdev->flags);
1242 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1244 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1245 "md/raid1:%s: Operation continuing on %d devices.\n",
1246 mdname(mddev), bdevname(rdev->bdev, b),
1247 mdname(mddev), conf->raid_disks - mddev->degraded);
1250 static void print_conf(struct r1conf *conf)
1254 printk(KERN_DEBUG "RAID1 conf printout:\n");
1256 printk(KERN_DEBUG "(!conf)\n");
1259 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1263 for (i = 0; i < conf->raid_disks; i++) {
1264 char b[BDEVNAME_SIZE];
1265 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1267 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1268 i, !test_bit(In_sync, &rdev->flags),
1269 !test_bit(Faulty, &rdev->flags),
1270 bdevname(rdev->bdev,b));
1275 static void close_sync(struct r1conf *conf)
1278 allow_barrier(conf);
1280 mempool_destroy(conf->r1buf_pool);
1281 conf->r1buf_pool = NULL;
1284 static int raid1_spare_active(struct mddev *mddev)
1287 struct r1conf *conf = mddev->private;
1289 unsigned long flags;
1292 * Find all failed disks within the RAID1 configuration
1293 * and mark them readable.
1294 * Called under mddev lock, so rcu protection not needed.
1296 for (i = 0; i < conf->raid_disks; i++) {
1297 struct md_rdev *rdev = conf->mirrors[i].rdev;
1299 && !test_bit(Faulty, &rdev->flags)
1300 && !test_and_set_bit(In_sync, &rdev->flags)) {
1302 sysfs_notify_dirent_safe(rdev->sysfs_state);
1305 spin_lock_irqsave(&conf->device_lock, flags);
1306 mddev->degraded -= count;
1307 spin_unlock_irqrestore(&conf->device_lock, flags);
1314 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1316 struct r1conf *conf = mddev->private;
1319 struct mirror_info *p;
1321 int last = mddev->raid_disks - 1;
1323 if (mddev->recovery_disabled == conf->recovery_disabled)
1326 if (rdev->raid_disk >= 0)
1327 first = last = rdev->raid_disk;
1329 for (mirror = first; mirror <= last; mirror++)
1330 if ( !(p=conf->mirrors+mirror)->rdev) {
1332 disk_stack_limits(mddev->gendisk, rdev->bdev,
1333 rdev->data_offset << 9);
1334 /* as we don't honour merge_bvec_fn, we must
1335 * never risk violating it, so limit
1336 * ->max_segments to one lying with a single
1337 * page, as a one page request is never in
1340 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1341 blk_queue_max_segments(mddev->queue, 1);
1342 blk_queue_segment_boundary(mddev->queue,
1343 PAGE_CACHE_SIZE - 1);
1346 p->head_position = 0;
1347 rdev->raid_disk = mirror;
1349 /* As all devices are equivalent, we don't need a full recovery
1350 * if this was recently any drive of the array
1352 if (rdev->saved_raid_disk < 0)
1354 rcu_assign_pointer(p->rdev, rdev);
1357 md_integrity_add_rdev(rdev, mddev);
1362 static int raid1_remove_disk(struct mddev *mddev, int number)
1364 struct r1conf *conf = mddev->private;
1366 struct md_rdev *rdev;
1367 struct mirror_info *p = conf->mirrors+ number;
1372 if (test_bit(In_sync, &rdev->flags) ||
1373 atomic_read(&rdev->nr_pending)) {
1377 /* Only remove non-faulty devices if recovery
1380 if (!test_bit(Faulty, &rdev->flags) &&
1381 mddev->recovery_disabled != conf->recovery_disabled &&
1382 mddev->degraded < conf->raid_disks) {
1388 if (atomic_read(&rdev->nr_pending)) {
1389 /* lost the race, try later */
1394 err = md_integrity_register(mddev);
1403 static void end_sync_read(struct bio *bio, int error)
1405 struct r1bio *r1_bio = bio->bi_private;
1407 update_head_pos(r1_bio->read_disk, r1_bio);
1410 * we have read a block, now it needs to be re-written,
1411 * or re-read if the read failed.
1412 * We don't do much here, just schedule handling by raid1d
1414 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1415 set_bit(R1BIO_Uptodate, &r1_bio->state);
1417 if (atomic_dec_and_test(&r1_bio->remaining))
1418 reschedule_retry(r1_bio);
1421 static void end_sync_write(struct bio *bio, int error)
1423 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1424 struct r1bio *r1_bio = bio->bi_private;
1425 struct mddev *mddev = r1_bio->mddev;
1426 struct r1conf *conf = mddev->private;
1431 mirror = find_bio_disk(r1_bio, bio);
1434 sector_t sync_blocks = 0;
1435 sector_t s = r1_bio->sector;
1436 long sectors_to_go = r1_bio->sectors;
1437 /* make sure these bits doesn't get cleared. */
1439 bitmap_end_sync(mddev->bitmap, s,
1442 sectors_to_go -= sync_blocks;
1443 } while (sectors_to_go > 0);
1444 set_bit(WriteErrorSeen,
1445 &conf->mirrors[mirror].rdev->flags);
1446 set_bit(R1BIO_WriteError, &r1_bio->state);
1447 } else if (is_badblock(conf->mirrors[mirror].rdev,
1450 &first_bad, &bad_sectors) &&
1451 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1454 &first_bad, &bad_sectors)
1456 set_bit(R1BIO_MadeGood, &r1_bio->state);
1458 if (atomic_dec_and_test(&r1_bio->remaining)) {
1459 int s = r1_bio->sectors;
1460 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1461 test_bit(R1BIO_WriteError, &r1_bio->state))
1462 reschedule_retry(r1_bio);
1465 md_done_sync(mddev, s, uptodate);
1470 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1471 int sectors, struct page *page, int rw)
1473 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1477 set_bit(WriteErrorSeen, &rdev->flags);
1478 /* need to record an error - either for the block or the device */
1479 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1480 md_error(rdev->mddev, rdev);
1484 static int fix_sync_read_error(struct r1bio *r1_bio)
1486 /* Try some synchronous reads of other devices to get
1487 * good data, much like with normal read errors. Only
1488 * read into the pages we already have so we don't
1489 * need to re-issue the read request.
1490 * We don't need to freeze the array, because being in an
1491 * active sync request, there is no normal IO, and
1492 * no overlapping syncs.
1493 * We don't need to check is_badblock() again as we
1494 * made sure that anything with a bad block in range
1495 * will have bi_end_io clear.
1497 struct mddev *mddev = r1_bio->mddev;
1498 struct r1conf *conf = mddev->private;
1499 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1500 sector_t sect = r1_bio->sector;
1501 int sectors = r1_bio->sectors;
1506 int d = r1_bio->read_disk;
1508 struct md_rdev *rdev;
1511 if (s > (PAGE_SIZE>>9))
1514 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1515 /* No rcu protection needed here devices
1516 * can only be removed when no resync is
1517 * active, and resync is currently active
1519 rdev = conf->mirrors[d].rdev;
1520 if (sync_page_io(rdev, sect, s<<9,
1521 bio->bi_io_vec[idx].bv_page,
1528 if (d == conf->raid_disks)
1530 } while (!success && d != r1_bio->read_disk);
1533 char b[BDEVNAME_SIZE];
1535 /* Cannot read from anywhere, this block is lost.
1536 * Record a bad block on each device. If that doesn't
1537 * work just disable and interrupt the recovery.
1538 * Don't fail devices as that won't really help.
1540 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1541 " for block %llu\n",
1543 bdevname(bio->bi_bdev, b),
1544 (unsigned long long)r1_bio->sector);
1545 for (d = 0; d < conf->raid_disks; d++) {
1546 rdev = conf->mirrors[d].rdev;
1547 if (!rdev || test_bit(Faulty, &rdev->flags))
1549 if (!rdev_set_badblocks(rdev, sect, s, 0))
1553 conf->recovery_disabled =
1554 mddev->recovery_disabled;
1555 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1556 md_done_sync(mddev, r1_bio->sectors, 0);
1568 /* write it back and re-read */
1569 while (d != r1_bio->read_disk) {
1571 d = conf->raid_disks;
1573 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1575 rdev = conf->mirrors[d].rdev;
1576 if (r1_sync_page_io(rdev, sect, s,
1577 bio->bi_io_vec[idx].bv_page,
1579 r1_bio->bios[d]->bi_end_io = NULL;
1580 rdev_dec_pending(rdev, mddev);
1584 while (d != r1_bio->read_disk) {
1586 d = conf->raid_disks;
1588 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1590 rdev = conf->mirrors[d].rdev;
1591 if (r1_sync_page_io(rdev, sect, s,
1592 bio->bi_io_vec[idx].bv_page,
1594 atomic_add(s, &rdev->corrected_errors);
1600 set_bit(R1BIO_Uptodate, &r1_bio->state);
1601 set_bit(BIO_UPTODATE, &bio->bi_flags);
1605 static int process_checks(struct r1bio *r1_bio)
1607 /* We have read all readable devices. If we haven't
1608 * got the block, then there is no hope left.
1609 * If we have, then we want to do a comparison
1610 * and skip the write if everything is the same.
1611 * If any blocks failed to read, then we need to
1612 * attempt an over-write
1614 struct mddev *mddev = r1_bio->mddev;
1615 struct r1conf *conf = mddev->private;
1619 for (primary = 0; primary < conf->raid_disks; primary++)
1620 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1621 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1622 r1_bio->bios[primary]->bi_end_io = NULL;
1623 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1626 r1_bio->read_disk = primary;
1627 for (i = 0; i < conf->raid_disks; i++) {
1629 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1630 struct bio *pbio = r1_bio->bios[primary];
1631 struct bio *sbio = r1_bio->bios[i];
1634 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1637 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1638 for (j = vcnt; j-- ; ) {
1640 p = pbio->bi_io_vec[j].bv_page;
1641 s = sbio->bi_io_vec[j].bv_page;
1642 if (memcmp(page_address(p),
1650 mddev->resync_mismatches += r1_bio->sectors;
1651 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1652 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1653 /* No need to write to this device. */
1654 sbio->bi_end_io = NULL;
1655 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1658 /* fixup the bio for reuse */
1659 sbio->bi_vcnt = vcnt;
1660 sbio->bi_size = r1_bio->sectors << 9;
1662 sbio->bi_phys_segments = 0;
1663 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1664 sbio->bi_flags |= 1 << BIO_UPTODATE;
1665 sbio->bi_next = NULL;
1666 sbio->bi_sector = r1_bio->sector +
1667 conf->mirrors[i].rdev->data_offset;
1668 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1669 size = sbio->bi_size;
1670 for (j = 0; j < vcnt ; j++) {
1672 bi = &sbio->bi_io_vec[j];
1674 if (size > PAGE_SIZE)
1675 bi->bv_len = PAGE_SIZE;
1679 memcpy(page_address(bi->bv_page),
1680 page_address(pbio->bi_io_vec[j].bv_page),
1687 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1689 struct r1conf *conf = mddev->private;
1691 int disks = conf->raid_disks;
1692 struct bio *bio, *wbio;
1694 bio = r1_bio->bios[r1_bio->read_disk];
1696 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1697 /* ouch - failed to read all of that. */
1698 if (!fix_sync_read_error(r1_bio))
1701 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1702 if (process_checks(r1_bio) < 0)
1707 atomic_set(&r1_bio->remaining, 1);
1708 for (i = 0; i < disks ; i++) {
1709 wbio = r1_bio->bios[i];
1710 if (wbio->bi_end_io == NULL ||
1711 (wbio->bi_end_io == end_sync_read &&
1712 (i == r1_bio->read_disk ||
1713 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1716 wbio->bi_rw = WRITE;
1717 wbio->bi_end_io = end_sync_write;
1718 atomic_inc(&r1_bio->remaining);
1719 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1721 generic_make_request(wbio);
1724 if (atomic_dec_and_test(&r1_bio->remaining)) {
1725 /* if we're here, all write(s) have completed, so clean up */
1726 int s = r1_bio->sectors;
1727 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1728 test_bit(R1BIO_WriteError, &r1_bio->state))
1729 reschedule_retry(r1_bio);
1732 md_done_sync(mddev, s, 1);
1738 * This is a kernel thread which:
1740 * 1. Retries failed read operations on working mirrors.
1741 * 2. Updates the raid superblock when problems encounter.
1742 * 3. Performs writes following reads for array synchronising.
1745 static void fix_read_error(struct r1conf *conf, int read_disk,
1746 sector_t sect, int sectors)
1748 struct mddev *mddev = conf->mddev;
1754 struct md_rdev *rdev;
1756 if (s > (PAGE_SIZE>>9))
1760 /* Note: no rcu protection needed here
1761 * as this is synchronous in the raid1d thread
1762 * which is the thread that might remove
1763 * a device. If raid1d ever becomes multi-threaded....
1768 rdev = conf->mirrors[d].rdev;
1770 test_bit(In_sync, &rdev->flags) &&
1771 is_badblock(rdev, sect, s,
1772 &first_bad, &bad_sectors) == 0 &&
1773 sync_page_io(rdev, sect, s<<9,
1774 conf->tmppage, READ, false))
1778 if (d == conf->raid_disks)
1781 } while (!success && d != read_disk);
1784 /* Cannot read from anywhere - mark it bad */
1785 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
1786 if (!rdev_set_badblocks(rdev, sect, s, 0))
1787 md_error(mddev, rdev);
1790 /* write it back and re-read */
1792 while (d != read_disk) {
1794 d = conf->raid_disks;
1796 rdev = conf->mirrors[d].rdev;
1798 test_bit(In_sync, &rdev->flags))
1799 r1_sync_page_io(rdev, sect, s,
1800 conf->tmppage, WRITE);
1803 while (d != read_disk) {
1804 char b[BDEVNAME_SIZE];
1806 d = conf->raid_disks;
1808 rdev = conf->mirrors[d].rdev;
1810 test_bit(In_sync, &rdev->flags)) {
1811 if (r1_sync_page_io(rdev, sect, s,
1812 conf->tmppage, READ)) {
1813 atomic_add(s, &rdev->corrected_errors);
1815 "md/raid1:%s: read error corrected "
1816 "(%d sectors at %llu on %s)\n",
1818 (unsigned long long)(sect +
1820 bdevname(rdev->bdev, b));
1829 static void bi_complete(struct bio *bio, int error)
1831 complete((struct completion *)bio->bi_private);
1834 static int submit_bio_wait(int rw, struct bio *bio)
1836 struct completion event;
1839 init_completion(&event);
1840 bio->bi_private = &event;
1841 bio->bi_end_io = bi_complete;
1842 submit_bio(rw, bio);
1843 wait_for_completion(&event);
1845 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1848 static int narrow_write_error(struct r1bio *r1_bio, int i)
1850 struct mddev *mddev = r1_bio->mddev;
1851 struct r1conf *conf = mddev->private;
1852 struct md_rdev *rdev = conf->mirrors[i].rdev;
1854 struct bio_vec *vec;
1856 /* bio has the data to be written to device 'i' where
1857 * we just recently had a write error.
1858 * We repeatedly clone the bio and trim down to one block,
1859 * then try the write. Where the write fails we record
1861 * It is conceivable that the bio doesn't exactly align with
1862 * blocks. We must handle this somehow.
1864 * We currently own a reference on the rdev.
1870 int sect_to_write = r1_bio->sectors;
1873 if (rdev->badblocks.shift < 0)
1876 block_sectors = 1 << rdev->badblocks.shift;
1877 sector = r1_bio->sector;
1878 sectors = ((sector + block_sectors)
1879 & ~(sector_t)(block_sectors - 1))
1882 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1883 vcnt = r1_bio->behind_page_count;
1884 vec = r1_bio->behind_bvecs;
1886 while (vec[idx].bv_page == NULL)
1889 vcnt = r1_bio->master_bio->bi_vcnt;
1890 vec = r1_bio->master_bio->bi_io_vec;
1891 idx = r1_bio->master_bio->bi_idx;
1893 while (sect_to_write) {
1895 if (sectors > sect_to_write)
1896 sectors = sect_to_write;
1897 /* Write at 'sector' for 'sectors'*/
1899 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1900 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1901 wbio->bi_sector = r1_bio->sector;
1902 wbio->bi_rw = WRITE;
1903 wbio->bi_vcnt = vcnt;
1904 wbio->bi_size = r1_bio->sectors << 9;
1907 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
1908 wbio->bi_sector += rdev->data_offset;
1909 wbio->bi_bdev = rdev->bdev;
1910 if (submit_bio_wait(WRITE, wbio) == 0)
1912 ok = rdev_set_badblocks(rdev, sector,
1917 sect_to_write -= sectors;
1919 sectors = block_sectors;
1924 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1927 int s = r1_bio->sectors;
1928 for (m = 0; m < conf->raid_disks ; m++) {
1929 struct md_rdev *rdev = conf->mirrors[m].rdev;
1930 struct bio *bio = r1_bio->bios[m];
1931 if (bio->bi_end_io == NULL)
1933 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1934 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
1935 rdev_clear_badblocks(rdev, r1_bio->sector, s);
1937 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1938 test_bit(R1BIO_WriteError, &r1_bio->state)) {
1939 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
1940 md_error(conf->mddev, rdev);
1944 md_done_sync(conf->mddev, s, 1);
1947 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1950 for (m = 0; m < conf->raid_disks ; m++)
1951 if (r1_bio->bios[m] == IO_MADE_GOOD) {
1952 struct md_rdev *rdev = conf->mirrors[m].rdev;
1953 rdev_clear_badblocks(rdev,
1956 rdev_dec_pending(rdev, conf->mddev);
1957 } else if (r1_bio->bios[m] != NULL) {
1958 /* This drive got a write error. We need to
1959 * narrow down and record precise write
1962 if (!narrow_write_error(r1_bio, m)) {
1963 md_error(conf->mddev,
1964 conf->mirrors[m].rdev);
1965 /* an I/O failed, we can't clear the bitmap */
1966 set_bit(R1BIO_Degraded, &r1_bio->state);
1968 rdev_dec_pending(conf->mirrors[m].rdev,
1971 if (test_bit(R1BIO_WriteError, &r1_bio->state))
1972 close_write(r1_bio);
1973 raid_end_bio_io(r1_bio);
1976 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
1980 struct mddev *mddev = conf->mddev;
1982 char b[BDEVNAME_SIZE];
1983 struct md_rdev *rdev;
1985 clear_bit(R1BIO_ReadError, &r1_bio->state);
1986 /* we got a read error. Maybe the drive is bad. Maybe just
1987 * the block and we can fix it.
1988 * We freeze all other IO, and try reading the block from
1989 * other devices. When we find one, we re-write
1990 * and check it that fixes the read error.
1991 * This is all done synchronously while the array is
1994 if (mddev->ro == 0) {
1996 fix_read_error(conf, r1_bio->read_disk,
1997 r1_bio->sector, r1_bio->sectors);
1998 unfreeze_array(conf);
2000 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
2002 bio = r1_bio->bios[r1_bio->read_disk];
2003 bdevname(bio->bi_bdev, b);
2005 disk = read_balance(conf, r1_bio, &max_sectors);
2007 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
2008 " read error for block %llu\n",
2009 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2010 raid_end_bio_io(r1_bio);
2012 const unsigned long do_sync
2013 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2015 r1_bio->bios[r1_bio->read_disk] =
2016 mddev->ro ? IO_BLOCKED : NULL;
2019 r1_bio->read_disk = disk;
2020 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2021 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
2022 r1_bio->bios[r1_bio->read_disk] = bio;
2023 rdev = conf->mirrors[disk].rdev;
2024 printk_ratelimited(KERN_ERR
2025 "md/raid1:%s: redirecting sector %llu"
2026 " to other mirror: %s\n",
2028 (unsigned long long)r1_bio->sector,
2029 bdevname(rdev->bdev, b));
2030 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2031 bio->bi_bdev = rdev->bdev;
2032 bio->bi_end_io = raid1_end_read_request;
2033 bio->bi_rw = READ | do_sync;
2034 bio->bi_private = r1_bio;
2035 if (max_sectors < r1_bio->sectors) {
2036 /* Drat - have to split this up more */
2037 struct bio *mbio = r1_bio->master_bio;
2038 int sectors_handled = (r1_bio->sector + max_sectors
2040 r1_bio->sectors = max_sectors;
2041 spin_lock_irq(&conf->device_lock);
2042 if (mbio->bi_phys_segments == 0)
2043 mbio->bi_phys_segments = 2;
2045 mbio->bi_phys_segments++;
2046 spin_unlock_irq(&conf->device_lock);
2047 generic_make_request(bio);
2050 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2052 r1_bio->master_bio = mbio;
2053 r1_bio->sectors = (mbio->bi_size >> 9)
2056 set_bit(R1BIO_ReadError, &r1_bio->state);
2057 r1_bio->mddev = mddev;
2058 r1_bio->sector = mbio->bi_sector + sectors_handled;
2062 generic_make_request(bio);
2066 static void raid1d(struct mddev *mddev)
2068 struct r1bio *r1_bio;
2069 unsigned long flags;
2070 struct r1conf *conf = mddev->private;
2071 struct list_head *head = &conf->retry_list;
2072 struct blk_plug plug;
2074 md_check_recovery(mddev);
2076 blk_start_plug(&plug);
2079 if (atomic_read(&mddev->plug_cnt) == 0)
2080 flush_pending_writes(conf);
2082 spin_lock_irqsave(&conf->device_lock, flags);
2083 if (list_empty(head)) {
2084 spin_unlock_irqrestore(&conf->device_lock, flags);
2087 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2088 list_del(head->prev);
2090 spin_unlock_irqrestore(&conf->device_lock, flags);
2092 mddev = r1_bio->mddev;
2093 conf = mddev->private;
2094 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2095 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2096 test_bit(R1BIO_WriteError, &r1_bio->state))
2097 handle_sync_write_finished(conf, r1_bio);
2099 sync_request_write(mddev, r1_bio);
2100 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2101 test_bit(R1BIO_WriteError, &r1_bio->state))
2102 handle_write_finished(conf, r1_bio);
2103 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2104 handle_read_error(conf, r1_bio);
2106 /* just a partial read to be scheduled from separate
2109 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2112 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2113 md_check_recovery(mddev);
2115 blk_finish_plug(&plug);
2119 static int init_resync(struct r1conf *conf)
2123 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2124 BUG_ON(conf->r1buf_pool);
2125 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2127 if (!conf->r1buf_pool)
2129 conf->next_resync = 0;
2134 * perform a "sync" on one "block"
2136 * We need to make sure that no normal I/O request - particularly write
2137 * requests - conflict with active sync requests.
2139 * This is achieved by tracking pending requests and a 'barrier' concept
2140 * that can be installed to exclude normal IO requests.
2143 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2145 struct r1conf *conf = mddev->private;
2146 struct r1bio *r1_bio;
2148 sector_t max_sector, nr_sectors;
2152 int write_targets = 0, read_targets = 0;
2153 sector_t sync_blocks;
2154 int still_degraded = 0;
2155 int good_sectors = RESYNC_SECTORS;
2156 int min_bad = 0; /* number of sectors that are bad in all devices */
2158 if (!conf->r1buf_pool)
2159 if (init_resync(conf))
2162 max_sector = mddev->dev_sectors;
2163 if (sector_nr >= max_sector) {
2164 /* If we aborted, we need to abort the
2165 * sync on the 'current' bitmap chunk (there will
2166 * only be one in raid1 resync.
2167 * We can find the current addess in mddev->curr_resync
2169 if (mddev->curr_resync < max_sector) /* aborted */
2170 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2172 else /* completed sync */
2175 bitmap_close_sync(mddev->bitmap);
2180 if (mddev->bitmap == NULL &&
2181 mddev->recovery_cp == MaxSector &&
2182 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2183 conf->fullsync == 0) {
2185 return max_sector - sector_nr;
2187 /* before building a request, check if we can skip these blocks..
2188 * This call the bitmap_start_sync doesn't actually record anything
2190 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2191 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2192 /* We can skip this block, and probably several more */
2197 * If there is non-resync activity waiting for a turn,
2198 * and resync is going fast enough,
2199 * then let it though before starting on this new sync request.
2201 if (!go_faster && conf->nr_waiting)
2202 msleep_interruptible(1000);
2204 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2205 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2206 raise_barrier(conf);
2208 conf->next_resync = sector_nr;
2212 * If we get a correctably read error during resync or recovery,
2213 * we might want to read from a different device. So we
2214 * flag all drives that could conceivably be read from for READ,
2215 * and any others (which will be non-In_sync devices) for WRITE.
2216 * If a read fails, we try reading from something else for which READ
2220 r1_bio->mddev = mddev;
2221 r1_bio->sector = sector_nr;
2223 set_bit(R1BIO_IsSync, &r1_bio->state);
2225 for (i=0; i < conf->raid_disks; i++) {
2226 struct md_rdev *rdev;
2227 bio = r1_bio->bios[i];
2229 /* take from bio_init */
2230 bio->bi_next = NULL;
2231 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2232 bio->bi_flags |= 1 << BIO_UPTODATE;
2236 bio->bi_phys_segments = 0;
2238 bio->bi_end_io = NULL;
2239 bio->bi_private = NULL;
2241 rdev = rcu_dereference(conf->mirrors[i].rdev);
2243 test_bit(Faulty, &rdev->flags)) {
2245 } else if (!test_bit(In_sync, &rdev->flags)) {
2247 bio->bi_end_io = end_sync_write;
2250 /* may need to read from here */
2251 sector_t first_bad = MaxSector;
2254 if (is_badblock(rdev, sector_nr, good_sectors,
2255 &first_bad, &bad_sectors)) {
2256 if (first_bad > sector_nr)
2257 good_sectors = first_bad - sector_nr;
2259 bad_sectors -= (sector_nr - first_bad);
2261 min_bad > bad_sectors)
2262 min_bad = bad_sectors;
2265 if (sector_nr < first_bad) {
2266 if (test_bit(WriteMostly, &rdev->flags)) {
2274 bio->bi_end_io = end_sync_read;
2278 if (bio->bi_end_io) {
2279 atomic_inc(&rdev->nr_pending);
2280 bio->bi_sector = sector_nr + rdev->data_offset;
2281 bio->bi_bdev = rdev->bdev;
2282 bio->bi_private = r1_bio;
2288 r1_bio->read_disk = disk;
2290 if (read_targets == 0 && min_bad > 0) {
2291 /* These sectors are bad on all InSync devices, so we
2292 * need to mark them bad on all write targets
2295 for (i = 0 ; i < conf->raid_disks ; i++)
2296 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2297 struct md_rdev *rdev =
2298 rcu_dereference(conf->mirrors[i].rdev);
2299 ok = rdev_set_badblocks(rdev, sector_nr,
2303 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2308 /* Cannot record the badblocks, so need to
2310 * If there are multiple read targets, could just
2311 * fail the really bad ones ???
2313 conf->recovery_disabled = mddev->recovery_disabled;
2314 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2320 if (min_bad > 0 && min_bad < good_sectors) {
2321 /* only resync enough to reach the next bad->good
2323 good_sectors = min_bad;
2326 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2327 /* extra read targets are also write targets */
2328 write_targets += read_targets-1;
2330 if (write_targets == 0 || read_targets == 0) {
2331 /* There is nowhere to write, so all non-sync
2332 * drives must be failed - so we are finished
2336 max_sector = sector_nr + min_bad;
2337 rv = max_sector - sector_nr;
2343 if (max_sector > mddev->resync_max)
2344 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2345 if (max_sector > sector_nr + good_sectors)
2346 max_sector = sector_nr + good_sectors;
2351 int len = PAGE_SIZE;
2352 if (sector_nr + (len>>9) > max_sector)
2353 len = (max_sector - sector_nr) << 9;
2356 if (sync_blocks == 0) {
2357 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2358 &sync_blocks, still_degraded) &&
2360 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2362 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2363 if ((len >> 9) > sync_blocks)
2364 len = sync_blocks<<9;
2367 for (i=0 ; i < conf->raid_disks; i++) {
2368 bio = r1_bio->bios[i];
2369 if (bio->bi_end_io) {
2370 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2371 if (bio_add_page(bio, page, len, 0) == 0) {
2373 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2376 bio = r1_bio->bios[i];
2377 if (bio->bi_end_io==NULL)
2379 /* remove last page from this bio */
2381 bio->bi_size -= len;
2382 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2388 nr_sectors += len>>9;
2389 sector_nr += len>>9;
2390 sync_blocks -= (len>>9);
2391 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2393 r1_bio->sectors = nr_sectors;
2395 /* For a user-requested sync, we read all readable devices and do a
2398 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2399 atomic_set(&r1_bio->remaining, read_targets);
2400 for (i = 0; i < conf->raid_disks && read_targets; i++) {
2401 bio = r1_bio->bios[i];
2402 if (bio->bi_end_io == end_sync_read) {
2404 md_sync_acct(bio->bi_bdev, nr_sectors);
2405 generic_make_request(bio);
2409 atomic_set(&r1_bio->remaining, 1);
2410 bio = r1_bio->bios[r1_bio->read_disk];
2411 md_sync_acct(bio->bi_bdev, nr_sectors);
2412 generic_make_request(bio);
2418 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2423 return mddev->dev_sectors;
2426 static struct r1conf *setup_conf(struct mddev *mddev)
2428 struct r1conf *conf;
2430 struct mirror_info *disk;
2431 struct md_rdev *rdev;
2434 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2438 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
2443 conf->tmppage = alloc_page(GFP_KERNEL);
2447 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2448 if (!conf->poolinfo)
2450 conf->poolinfo->raid_disks = mddev->raid_disks;
2451 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2454 if (!conf->r1bio_pool)
2457 conf->poolinfo->mddev = mddev;
2459 spin_lock_init(&conf->device_lock);
2460 list_for_each_entry(rdev, &mddev->disks, same_set) {
2461 int disk_idx = rdev->raid_disk;
2462 if (disk_idx >= mddev->raid_disks
2465 disk = conf->mirrors + disk_idx;
2469 disk->head_position = 0;
2471 conf->raid_disks = mddev->raid_disks;
2472 conf->mddev = mddev;
2473 INIT_LIST_HEAD(&conf->retry_list);
2475 spin_lock_init(&conf->resync_lock);
2476 init_waitqueue_head(&conf->wait_barrier);
2478 bio_list_init(&conf->pending_bio_list);
2479 conf->pending_count = 0;
2480 conf->recovery_disabled = mddev->recovery_disabled - 1;
2482 conf->last_used = -1;
2483 for (i = 0; i < conf->raid_disks; i++) {
2485 disk = conf->mirrors + i;
2488 !test_bit(In_sync, &disk->rdev->flags)) {
2489 disk->head_position = 0;
2492 } else if (conf->last_used < 0)
2494 * The first working device is used as a
2495 * starting point to read balancing.
2497 conf->last_used = i;
2501 if (conf->last_used < 0) {
2502 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2507 conf->thread = md_register_thread(raid1d, mddev, NULL);
2508 if (!conf->thread) {
2510 "md/raid1:%s: couldn't allocate thread\n",
2519 if (conf->r1bio_pool)
2520 mempool_destroy(conf->r1bio_pool);
2521 kfree(conf->mirrors);
2522 safe_put_page(conf->tmppage);
2523 kfree(conf->poolinfo);
2526 return ERR_PTR(err);
2529 static int run(struct mddev *mddev)
2531 struct r1conf *conf;
2533 struct md_rdev *rdev;
2535 if (mddev->level != 1) {
2536 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2537 mdname(mddev), mddev->level);
2540 if (mddev->reshape_position != MaxSector) {
2541 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2546 * copy the already verified devices into our private RAID1
2547 * bookkeeping area. [whatever we allocate in run(),
2548 * should be freed in stop()]
2550 if (mddev->private == NULL)
2551 conf = setup_conf(mddev);
2553 conf = mddev->private;
2556 return PTR_ERR(conf);
2558 list_for_each_entry(rdev, &mddev->disks, same_set) {
2559 if (!mddev->gendisk)
2561 disk_stack_limits(mddev->gendisk, rdev->bdev,
2562 rdev->data_offset << 9);
2563 /* as we don't honour merge_bvec_fn, we must never risk
2564 * violating it, so limit ->max_segments to 1 lying within
2565 * a single page, as a one page request is never in violation.
2567 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2568 blk_queue_max_segments(mddev->queue, 1);
2569 blk_queue_segment_boundary(mddev->queue,
2570 PAGE_CACHE_SIZE - 1);
2574 mddev->degraded = 0;
2575 for (i=0; i < conf->raid_disks; i++)
2576 if (conf->mirrors[i].rdev == NULL ||
2577 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2578 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2581 if (conf->raid_disks - mddev->degraded == 1)
2582 mddev->recovery_cp = MaxSector;
2584 if (mddev->recovery_cp != MaxSector)
2585 printk(KERN_NOTICE "md/raid1:%s: not clean"
2586 " -- starting background reconstruction\n",
2589 "md/raid1:%s: active with %d out of %d mirrors\n",
2590 mdname(mddev), mddev->raid_disks - mddev->degraded,
2594 * Ok, everything is just fine now
2596 mddev->thread = conf->thread;
2597 conf->thread = NULL;
2598 mddev->private = conf;
2600 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2603 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2604 mddev->queue->backing_dev_info.congested_data = mddev;
2606 return md_integrity_register(mddev);
2609 static int stop(struct mddev *mddev)
2611 struct r1conf *conf = mddev->private;
2612 struct bitmap *bitmap = mddev->bitmap;
2614 /* wait for behind writes to complete */
2615 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2616 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2618 /* need to kick something here to make sure I/O goes? */
2619 wait_event(bitmap->behind_wait,
2620 atomic_read(&bitmap->behind_writes) == 0);
2623 raise_barrier(conf);
2624 lower_barrier(conf);
2626 md_unregister_thread(&mddev->thread);
2627 if (conf->r1bio_pool)
2628 mempool_destroy(conf->r1bio_pool);
2629 kfree(conf->mirrors);
2630 kfree(conf->poolinfo);
2632 mddev->private = NULL;
2636 static int raid1_resize(struct mddev *mddev, sector_t sectors)
2638 /* no resync is happening, and there is enough space
2639 * on all devices, so we can resize.
2640 * We need to make sure resync covers any new space.
2641 * If the array is shrinking we should possibly wait until
2642 * any io in the removed space completes, but it hardly seems
2645 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2646 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2648 set_capacity(mddev->gendisk, mddev->array_sectors);
2649 revalidate_disk(mddev->gendisk);
2650 if (sectors > mddev->dev_sectors &&
2651 mddev->recovery_cp > mddev->dev_sectors) {
2652 mddev->recovery_cp = mddev->dev_sectors;
2653 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2655 mddev->dev_sectors = sectors;
2656 mddev->resync_max_sectors = sectors;
2660 static int raid1_reshape(struct mddev *mddev)
2663 * 1/ resize the r1bio_pool
2664 * 2/ resize conf->mirrors
2666 * We allocate a new r1bio_pool if we can.
2667 * Then raise a device barrier and wait until all IO stops.
2668 * Then resize conf->mirrors and swap in the new r1bio pool.
2670 * At the same time, we "pack" the devices so that all the missing
2671 * devices have the higher raid_disk numbers.
2673 mempool_t *newpool, *oldpool;
2674 struct pool_info *newpoolinfo;
2675 struct mirror_info *newmirrors;
2676 struct r1conf *conf = mddev->private;
2677 int cnt, raid_disks;
2678 unsigned long flags;
2681 /* Cannot change chunk_size, layout, or level */
2682 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2683 mddev->layout != mddev->new_layout ||
2684 mddev->level != mddev->new_level) {
2685 mddev->new_chunk_sectors = mddev->chunk_sectors;
2686 mddev->new_layout = mddev->layout;
2687 mddev->new_level = mddev->level;
2691 err = md_allow_write(mddev);
2695 raid_disks = mddev->raid_disks + mddev->delta_disks;
2697 if (raid_disks < conf->raid_disks) {
2699 for (d= 0; d < conf->raid_disks; d++)
2700 if (conf->mirrors[d].rdev)
2702 if (cnt > raid_disks)
2706 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2709 newpoolinfo->mddev = mddev;
2710 newpoolinfo->raid_disks = raid_disks;
2712 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2713 r1bio_pool_free, newpoolinfo);
2718 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2721 mempool_destroy(newpool);
2725 raise_barrier(conf);
2727 /* ok, everything is stopped */
2728 oldpool = conf->r1bio_pool;
2729 conf->r1bio_pool = newpool;
2731 for (d = d2 = 0; d < conf->raid_disks; d++) {
2732 struct md_rdev *rdev = conf->mirrors[d].rdev;
2733 if (rdev && rdev->raid_disk != d2) {
2734 sysfs_unlink_rdev(mddev, rdev);
2735 rdev->raid_disk = d2;
2736 sysfs_unlink_rdev(mddev, rdev);
2737 if (sysfs_link_rdev(mddev, rdev))
2739 "md/raid1:%s: cannot register rd%d\n",
2740 mdname(mddev), rdev->raid_disk);
2743 newmirrors[d2++].rdev = rdev;
2745 kfree(conf->mirrors);
2746 conf->mirrors = newmirrors;
2747 kfree(conf->poolinfo);
2748 conf->poolinfo = newpoolinfo;
2750 spin_lock_irqsave(&conf->device_lock, flags);
2751 mddev->degraded += (raid_disks - conf->raid_disks);
2752 spin_unlock_irqrestore(&conf->device_lock, flags);
2753 conf->raid_disks = mddev->raid_disks = raid_disks;
2754 mddev->delta_disks = 0;
2756 conf->last_used = 0; /* just make sure it is in-range */
2757 lower_barrier(conf);
2759 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2760 md_wakeup_thread(mddev->thread);
2762 mempool_destroy(oldpool);
2766 static void raid1_quiesce(struct mddev *mddev, int state)
2768 struct r1conf *conf = mddev->private;
2771 case 2: /* wake for suspend */
2772 wake_up(&conf->wait_barrier);
2775 raise_barrier(conf);
2778 lower_barrier(conf);
2783 static void *raid1_takeover(struct mddev *mddev)
2785 /* raid1 can take over:
2786 * raid5 with 2 devices, any layout or chunk size
2788 if (mddev->level == 5 && mddev->raid_disks == 2) {
2789 struct r1conf *conf;
2790 mddev->new_level = 1;
2791 mddev->new_layout = 0;
2792 mddev->new_chunk_sectors = 0;
2793 conf = setup_conf(mddev);
2798 return ERR_PTR(-EINVAL);
2801 static struct md_personality raid1_personality =
2805 .owner = THIS_MODULE,
2806 .make_request = make_request,
2810 .error_handler = error,
2811 .hot_add_disk = raid1_add_disk,
2812 .hot_remove_disk= raid1_remove_disk,
2813 .spare_active = raid1_spare_active,
2814 .sync_request = sync_request,
2815 .resize = raid1_resize,
2817 .check_reshape = raid1_reshape,
2818 .quiesce = raid1_quiesce,
2819 .takeover = raid1_takeover,
2822 static int __init raid_init(void)
2824 return register_md_personality(&raid1_personality);
2827 static void raid_exit(void)
2829 unregister_md_personality(&raid1_personality);
2832 module_init(raid_init);
2833 module_exit(raid_exit);
2834 MODULE_LICENSE("GPL");
2835 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2836 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2837 MODULE_ALIAS("md-raid1");
2838 MODULE_ALIAS("md-level-1");
2840 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);