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 set_bit(R1BIO_WriteError, &r1_bio->state);
397 * Set R1BIO_Uptodate in our master bio, so that we
398 * will return a good error code for to the higher
399 * levels even if IO on some other mirrored buffer
402 * The 'master' represents the composite IO operation
403 * to user-side. So if something waits for IO, then it
404 * will wait for the 'master' bio.
409 r1_bio->bios[mirror] = NULL;
411 set_bit(R1BIO_Uptodate, &r1_bio->state);
413 /* Maybe we can clear some bad blocks. */
414 if (is_badblock(conf->mirrors[mirror].rdev,
415 r1_bio->sector, r1_bio->sectors,
416 &first_bad, &bad_sectors)) {
417 r1_bio->bios[mirror] = IO_MADE_GOOD;
418 set_bit(R1BIO_MadeGood, &r1_bio->state);
423 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
424 atomic_dec(&r1_bio->behind_remaining);
427 * In behind mode, we ACK the master bio once the I/O
428 * has safely reached all non-writemostly
429 * disks. Setting the Returned bit ensures that this
430 * gets done only once -- we don't ever want to return
431 * -EIO here, instead we'll wait
433 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
434 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
435 /* Maybe we can return now */
436 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
437 struct bio *mbio = r1_bio->master_bio;
438 pr_debug("raid1: behind end write sectors"
440 (unsigned long long) mbio->bi_sector,
441 (unsigned long long) mbio->bi_sector +
442 (mbio->bi_size >> 9) - 1);
443 call_bio_endio(r1_bio);
447 if (r1_bio->bios[mirror] == NULL)
448 rdev_dec_pending(conf->mirrors[mirror].rdev,
452 * Let's see if all mirrored write operations have finished
455 r1_bio_write_done(r1_bio);
463 * This routine returns the disk from which the requested read should
464 * be done. There is a per-array 'next expected sequential IO' sector
465 * number - if this matches on the next IO then we use the last disk.
466 * There is also a per-disk 'last know head position' sector that is
467 * maintained from IRQ contexts, both the normal and the resync IO
468 * completion handlers update this position correctly. If there is no
469 * perfect sequential match then we pick the disk whose head is closest.
471 * If there are 2 mirrors in the same 2 devices, performance degrades
472 * because position is mirror, not device based.
474 * The rdev for the device selected will have nr_pending incremented.
476 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
478 const sector_t this_sector = r1_bio->sector;
480 int best_good_sectors;
485 struct md_rdev *rdev;
490 * Check if we can balance. We can balance on the whole
491 * device if no resync is going on, or below the resync window.
492 * We take the first readable disk when above the resync window.
495 sectors = r1_bio->sectors;
497 best_dist = MaxSector;
498 best_good_sectors = 0;
500 if (conf->mddev->recovery_cp < MaxSector &&
501 (this_sector + sectors >= conf->next_resync)) {
506 start_disk = conf->last_used;
509 for (i = 0 ; i < conf->raid_disks * 2 ; i++) {
514 int disk = start_disk + i;
515 if (disk >= conf->raid_disks)
516 disk -= conf->raid_disks;
518 rdev = rcu_dereference(conf->mirrors[disk].rdev);
519 if (r1_bio->bios[disk] == IO_BLOCKED
521 || test_bit(Faulty, &rdev->flags))
523 if (!test_bit(In_sync, &rdev->flags) &&
524 rdev->recovery_offset < this_sector + sectors)
526 if (test_bit(WriteMostly, &rdev->flags)) {
527 /* Don't balance among write-mostly, just
528 * use the first as a last resort */
533 /* This is a reasonable device to use. It might
536 if (is_badblock(rdev, this_sector, sectors,
537 &first_bad, &bad_sectors)) {
538 if (best_dist < MaxSector)
539 /* already have a better device */
541 if (first_bad <= this_sector) {
542 /* cannot read here. If this is the 'primary'
543 * device, then we must not read beyond
544 * bad_sectors from another device..
546 bad_sectors -= (this_sector - first_bad);
547 if (choose_first && sectors > bad_sectors)
548 sectors = bad_sectors;
549 if (best_good_sectors > sectors)
550 best_good_sectors = sectors;
553 sector_t good_sectors = first_bad - this_sector;
554 if (good_sectors > best_good_sectors) {
555 best_good_sectors = good_sectors;
563 best_good_sectors = sectors;
565 dist = abs(this_sector - conf->mirrors[disk].head_position);
567 /* Don't change to another disk for sequential reads */
568 || conf->next_seq_sect == this_sector
570 /* If device is idle, use it */
571 || atomic_read(&rdev->nr_pending) == 0) {
575 if (dist < best_dist) {
581 if (best_disk >= 0) {
582 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
585 atomic_inc(&rdev->nr_pending);
586 if (test_bit(Faulty, &rdev->flags)) {
587 /* cannot risk returning a device that failed
588 * before we inc'ed nr_pending
590 rdev_dec_pending(rdev, conf->mddev);
593 sectors = best_good_sectors;
594 conf->next_seq_sect = this_sector + sectors;
595 conf->last_used = best_disk;
598 *max_sectors = sectors;
603 int md_raid1_congested(struct mddev *mddev, int bits)
605 struct r1conf *conf = mddev->private;
608 if ((bits & (1 << BDI_async_congested)) &&
609 conf->pending_count >= max_queued_requests)
613 for (i = 0; i < conf->raid_disks; i++) {
614 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
615 if (rdev && !test_bit(Faulty, &rdev->flags)) {
616 struct request_queue *q = bdev_get_queue(rdev->bdev);
620 /* Note the '|| 1' - when read_balance prefers
621 * non-congested targets, it can be removed
623 if ((bits & (1<<BDI_async_congested)) || 1)
624 ret |= bdi_congested(&q->backing_dev_info, bits);
626 ret &= bdi_congested(&q->backing_dev_info, bits);
632 EXPORT_SYMBOL_GPL(md_raid1_congested);
634 static int raid1_congested(void *data, int bits)
636 struct mddev *mddev = data;
638 return mddev_congested(mddev, bits) ||
639 md_raid1_congested(mddev, bits);
642 static void flush_pending_writes(struct r1conf *conf)
644 /* Any writes that have been queued but are awaiting
645 * bitmap updates get flushed here.
647 spin_lock_irq(&conf->device_lock);
649 if (conf->pending_bio_list.head) {
651 bio = bio_list_get(&conf->pending_bio_list);
652 conf->pending_count = 0;
653 spin_unlock_irq(&conf->device_lock);
654 /* flush any pending bitmap writes to
655 * disk before proceeding w/ I/O */
656 bitmap_unplug(conf->mddev->bitmap);
657 wake_up(&conf->wait_barrier);
659 while (bio) { /* submit pending writes */
660 struct bio *next = bio->bi_next;
662 generic_make_request(bio);
666 spin_unlock_irq(&conf->device_lock);
670 * Sometimes we need to suspend IO while we do something else,
671 * either some resync/recovery, or reconfigure the array.
672 * To do this we raise a 'barrier'.
673 * The 'barrier' is a counter that can be raised multiple times
674 * to count how many activities are happening which preclude
676 * We can only raise the barrier if there is no pending IO.
677 * i.e. if nr_pending == 0.
678 * We choose only to raise the barrier if no-one is waiting for the
679 * barrier to go down. This means that as soon as an IO request
680 * is ready, no other operations which require a barrier will start
681 * until the IO request has had a chance.
683 * So: regular IO calls 'wait_barrier'. When that returns there
684 * is no backgroup IO happening, It must arrange to call
685 * allow_barrier when it has finished its IO.
686 * backgroup IO calls must call raise_barrier. Once that returns
687 * there is no normal IO happeing. It must arrange to call
688 * lower_barrier when the particular background IO completes.
690 #define RESYNC_DEPTH 32
692 static void raise_barrier(struct r1conf *conf)
694 spin_lock_irq(&conf->resync_lock);
696 /* Wait until no block IO is waiting */
697 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
698 conf->resync_lock, );
700 /* block any new IO from starting */
703 /* Now wait for all pending IO to complete */
704 wait_event_lock_irq(conf->wait_barrier,
705 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
706 conf->resync_lock, );
708 spin_unlock_irq(&conf->resync_lock);
711 static void lower_barrier(struct r1conf *conf)
714 BUG_ON(conf->barrier <= 0);
715 spin_lock_irqsave(&conf->resync_lock, flags);
717 spin_unlock_irqrestore(&conf->resync_lock, flags);
718 wake_up(&conf->wait_barrier);
721 static void wait_barrier(struct r1conf *conf)
723 spin_lock_irq(&conf->resync_lock);
726 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
732 spin_unlock_irq(&conf->resync_lock);
735 static void allow_barrier(struct r1conf *conf)
738 spin_lock_irqsave(&conf->resync_lock, flags);
740 spin_unlock_irqrestore(&conf->resync_lock, flags);
741 wake_up(&conf->wait_barrier);
744 static void freeze_array(struct r1conf *conf)
746 /* stop syncio and normal IO and wait for everything to
748 * We increment barrier and nr_waiting, and then
749 * wait until nr_pending match nr_queued+1
750 * This is called in the context of one normal IO request
751 * that has failed. Thus any sync request that might be pending
752 * will be blocked by nr_pending, and we need to wait for
753 * pending IO requests to complete or be queued for re-try.
754 * Thus the number queued (nr_queued) plus this request (1)
755 * must match the number of pending IOs (nr_pending) before
758 spin_lock_irq(&conf->resync_lock);
761 wait_event_lock_irq(conf->wait_barrier,
762 conf->nr_pending == conf->nr_queued+1,
764 flush_pending_writes(conf));
765 spin_unlock_irq(&conf->resync_lock);
767 static void unfreeze_array(struct r1conf *conf)
769 /* reverse the effect of the freeze */
770 spin_lock_irq(&conf->resync_lock);
773 wake_up(&conf->wait_barrier);
774 spin_unlock_irq(&conf->resync_lock);
778 /* duplicate the data pages for behind I/O
780 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
783 struct bio_vec *bvec;
784 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
786 if (unlikely(!bvecs))
789 bio_for_each_segment(bvec, bio, i) {
791 bvecs[i].bv_page = alloc_page(GFP_NOIO);
792 if (unlikely(!bvecs[i].bv_page))
794 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
795 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
796 kunmap(bvecs[i].bv_page);
797 kunmap(bvec->bv_page);
799 r1_bio->behind_bvecs = bvecs;
800 r1_bio->behind_page_count = bio->bi_vcnt;
801 set_bit(R1BIO_BehindIO, &r1_bio->state);
805 for (i = 0; i < bio->bi_vcnt; i++)
806 if (bvecs[i].bv_page)
807 put_page(bvecs[i].bv_page);
809 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
812 static void make_request(struct mddev *mddev, struct bio * bio)
814 struct r1conf *conf = mddev->private;
815 struct mirror_info *mirror;
816 struct r1bio *r1_bio;
817 struct bio *read_bio;
819 struct bitmap *bitmap;
821 const int rw = bio_data_dir(bio);
822 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
823 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
824 struct md_rdev *blocked_rdev;
831 * Register the new request and wait if the reconstruction
832 * thread has put up a bar for new requests.
833 * Continue immediately if no resync is active currently.
836 md_write_start(mddev, bio); /* wait on superblock update early */
838 if (bio_data_dir(bio) == WRITE &&
839 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
840 bio->bi_sector < mddev->suspend_hi) {
841 /* As the suspend_* range is controlled by
842 * userspace, we want an interruptible
847 flush_signals(current);
848 prepare_to_wait(&conf->wait_barrier,
849 &w, TASK_INTERRUPTIBLE);
850 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
851 bio->bi_sector >= mddev->suspend_hi)
855 finish_wait(&conf->wait_barrier, &w);
860 bitmap = mddev->bitmap;
863 * make_request() can abort the operation when READA is being
864 * used and no empty request is available.
867 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
869 r1_bio->master_bio = bio;
870 r1_bio->sectors = bio->bi_size >> 9;
872 r1_bio->mddev = mddev;
873 r1_bio->sector = bio->bi_sector;
875 /* We might need to issue multiple reads to different
876 * devices if there are bad blocks around, so we keep
877 * track of the number of reads in bio->bi_phys_segments.
878 * If this is 0, there is only one r1_bio and no locking
879 * will be needed when requests complete. If it is
880 * non-zero, then it is the number of not-completed requests.
882 bio->bi_phys_segments = 0;
883 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
887 * read balancing logic:
892 rdisk = read_balance(conf, r1_bio, &max_sectors);
895 /* couldn't find anywhere to read from */
896 raid_end_bio_io(r1_bio);
899 mirror = conf->mirrors + rdisk;
901 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
903 /* Reading from a write-mostly device must
904 * take care not to over-take any writes
907 wait_event(bitmap->behind_wait,
908 atomic_read(&bitmap->behind_writes) == 0);
910 r1_bio->read_disk = rdisk;
912 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
913 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
916 r1_bio->bios[rdisk] = read_bio;
918 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
919 read_bio->bi_bdev = mirror->rdev->bdev;
920 read_bio->bi_end_io = raid1_end_read_request;
921 read_bio->bi_rw = READ | do_sync;
922 read_bio->bi_private = r1_bio;
924 if (max_sectors < r1_bio->sectors) {
925 /* could not read all from this device, so we will
926 * need another r1_bio.
929 sectors_handled = (r1_bio->sector + max_sectors
931 r1_bio->sectors = max_sectors;
932 spin_lock_irq(&conf->device_lock);
933 if (bio->bi_phys_segments == 0)
934 bio->bi_phys_segments = 2;
936 bio->bi_phys_segments++;
937 spin_unlock_irq(&conf->device_lock);
938 /* Cannot call generic_make_request directly
939 * as that will be queued in __make_request
940 * and subsequent mempool_alloc might block waiting
941 * for it. So hand bio over to raid1d.
943 reschedule_retry(r1_bio);
945 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
947 r1_bio->master_bio = bio;
948 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
950 r1_bio->mddev = mddev;
951 r1_bio->sector = bio->bi_sector + sectors_handled;
954 generic_make_request(read_bio);
961 if (conf->pending_count >= max_queued_requests) {
962 md_wakeup_thread(mddev->thread);
963 wait_event(conf->wait_barrier,
964 conf->pending_count < max_queued_requests);
966 /* first select target devices under rcu_lock and
967 * inc refcount on their rdev. Record them by setting
969 * If there are known/acknowledged bad blocks on any device on
970 * which we have seen a write error, we want to avoid writing those
972 * This potentially requires several writes to write around
973 * the bad blocks. Each set of writes gets it's own r1bio
974 * with a set of bios attached.
976 plugged = mddev_check_plugged(mddev);
978 disks = conf->raid_disks * 2;
982 max_sectors = r1_bio->sectors;
983 for (i = 0; i < disks; i++) {
984 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
985 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
986 atomic_inc(&rdev->nr_pending);
990 r1_bio->bios[i] = NULL;
991 if (!rdev || test_bit(Faulty, &rdev->flags)) {
992 if (i < conf->raid_disks)
993 set_bit(R1BIO_Degraded, &r1_bio->state);
997 atomic_inc(&rdev->nr_pending);
998 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1003 is_bad = is_badblock(rdev, r1_bio->sector,
1005 &first_bad, &bad_sectors);
1007 /* mustn't write here until the bad block is
1009 set_bit(BlockedBadBlocks, &rdev->flags);
1010 blocked_rdev = rdev;
1013 if (is_bad && first_bad <= r1_bio->sector) {
1014 /* Cannot write here at all */
1015 bad_sectors -= (r1_bio->sector - first_bad);
1016 if (bad_sectors < max_sectors)
1017 /* mustn't write more than bad_sectors
1018 * to other devices yet
1020 max_sectors = bad_sectors;
1021 rdev_dec_pending(rdev, mddev);
1022 /* We don't set R1BIO_Degraded as that
1023 * only applies if the disk is
1024 * missing, so it might be re-added,
1025 * and we want to know to recover this
1027 * In this case the device is here,
1028 * and the fact that this chunk is not
1029 * in-sync is recorded in the bad
1035 int good_sectors = first_bad - r1_bio->sector;
1036 if (good_sectors < max_sectors)
1037 max_sectors = good_sectors;
1040 r1_bio->bios[i] = bio;
1044 if (unlikely(blocked_rdev)) {
1045 /* Wait for this device to become unblocked */
1048 for (j = 0; j < i; j++)
1049 if (r1_bio->bios[j])
1050 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1052 allow_barrier(conf);
1053 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1058 if (max_sectors < r1_bio->sectors) {
1059 /* We are splitting this write into multiple parts, so
1060 * we need to prepare for allocating another r1_bio.
1062 r1_bio->sectors = max_sectors;
1063 spin_lock_irq(&conf->device_lock);
1064 if (bio->bi_phys_segments == 0)
1065 bio->bi_phys_segments = 2;
1067 bio->bi_phys_segments++;
1068 spin_unlock_irq(&conf->device_lock);
1070 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1072 atomic_set(&r1_bio->remaining, 1);
1073 atomic_set(&r1_bio->behind_remaining, 0);
1076 for (i = 0; i < disks; i++) {
1078 if (!r1_bio->bios[i])
1081 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1082 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1086 * Not if there are too many, or cannot
1087 * allocate memory, or a reader on WriteMostly
1088 * is waiting for behind writes to flush */
1090 (atomic_read(&bitmap->behind_writes)
1091 < mddev->bitmap_info.max_write_behind) &&
1092 !waitqueue_active(&bitmap->behind_wait))
1093 alloc_behind_pages(mbio, r1_bio);
1095 bitmap_startwrite(bitmap, r1_bio->sector,
1097 test_bit(R1BIO_BehindIO,
1101 if (r1_bio->behind_bvecs) {
1102 struct bio_vec *bvec;
1105 /* Yes, I really want the '__' version so that
1106 * we clear any unused pointer in the io_vec, rather
1107 * than leave them unchanged. This is important
1108 * because when we come to free the pages, we won't
1109 * know the original bi_idx, so we just free
1112 __bio_for_each_segment(bvec, mbio, j, 0)
1113 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1114 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1115 atomic_inc(&r1_bio->behind_remaining);
1118 r1_bio->bios[i] = mbio;
1120 mbio->bi_sector = (r1_bio->sector +
1121 conf->mirrors[i].rdev->data_offset);
1122 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1123 mbio->bi_end_io = raid1_end_write_request;
1124 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
1125 mbio->bi_private = r1_bio;
1127 atomic_inc(&r1_bio->remaining);
1128 spin_lock_irqsave(&conf->device_lock, flags);
1129 bio_list_add(&conf->pending_bio_list, mbio);
1130 conf->pending_count++;
1131 spin_unlock_irqrestore(&conf->device_lock, flags);
1133 /* Mustn't call r1_bio_write_done before this next test,
1134 * as it could result in the bio being freed.
1136 if (sectors_handled < (bio->bi_size >> 9)) {
1137 r1_bio_write_done(r1_bio);
1138 /* We need another r1_bio. It has already been counted
1139 * in bio->bi_phys_segments
1141 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1142 r1_bio->master_bio = bio;
1143 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1145 r1_bio->mddev = mddev;
1146 r1_bio->sector = bio->bi_sector + sectors_handled;
1150 r1_bio_write_done(r1_bio);
1152 /* In case raid1d snuck in to freeze_array */
1153 wake_up(&conf->wait_barrier);
1155 if (do_sync || !bitmap || !plugged)
1156 md_wakeup_thread(mddev->thread);
1159 static void status(struct seq_file *seq, struct mddev *mddev)
1161 struct r1conf *conf = mddev->private;
1164 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1165 conf->raid_disks - mddev->degraded);
1167 for (i = 0; i < conf->raid_disks; i++) {
1168 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1169 seq_printf(seq, "%s",
1170 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1173 seq_printf(seq, "]");
1177 static void error(struct mddev *mddev, struct md_rdev *rdev)
1179 char b[BDEVNAME_SIZE];
1180 struct r1conf *conf = mddev->private;
1183 * If it is not operational, then we have already marked it as dead
1184 * else if it is the last working disks, ignore the error, let the
1185 * next level up know.
1186 * else mark the drive as failed
1188 if (test_bit(In_sync, &rdev->flags)
1189 && (conf->raid_disks - mddev->degraded) == 1) {
1191 * Don't fail the drive, act as though we were just a
1192 * normal single drive.
1193 * However don't try a recovery from this drive as
1194 * it is very likely to fail.
1196 conf->recovery_disabled = mddev->recovery_disabled;
1199 set_bit(Blocked, &rdev->flags);
1200 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1201 unsigned long flags;
1202 spin_lock_irqsave(&conf->device_lock, flags);
1204 set_bit(Faulty, &rdev->flags);
1205 spin_unlock_irqrestore(&conf->device_lock, flags);
1207 * if recovery is running, make sure it aborts.
1209 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1211 set_bit(Faulty, &rdev->flags);
1212 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1214 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1215 "md/raid1:%s: Operation continuing on %d devices.\n",
1216 mdname(mddev), bdevname(rdev->bdev, b),
1217 mdname(mddev), conf->raid_disks - mddev->degraded);
1220 static void print_conf(struct r1conf *conf)
1224 printk(KERN_DEBUG "RAID1 conf printout:\n");
1226 printk(KERN_DEBUG "(!conf)\n");
1229 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1233 for (i = 0; i < conf->raid_disks; i++) {
1234 char b[BDEVNAME_SIZE];
1235 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1237 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1238 i, !test_bit(In_sync, &rdev->flags),
1239 !test_bit(Faulty, &rdev->flags),
1240 bdevname(rdev->bdev,b));
1245 static void close_sync(struct r1conf *conf)
1248 allow_barrier(conf);
1250 mempool_destroy(conf->r1buf_pool);
1251 conf->r1buf_pool = NULL;
1254 static int raid1_spare_active(struct mddev *mddev)
1257 struct r1conf *conf = mddev->private;
1259 unsigned long flags;
1262 * Find all failed disks within the RAID1 configuration
1263 * and mark them readable.
1264 * Called under mddev lock, so rcu protection not needed.
1266 for (i = 0; i < conf->raid_disks; i++) {
1267 struct md_rdev *rdev = conf->mirrors[i].rdev;
1269 && !test_bit(Faulty, &rdev->flags)
1270 && !test_and_set_bit(In_sync, &rdev->flags)) {
1272 sysfs_notify_dirent_safe(rdev->sysfs_state);
1275 spin_lock_irqsave(&conf->device_lock, flags);
1276 mddev->degraded -= count;
1277 spin_unlock_irqrestore(&conf->device_lock, flags);
1284 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1286 struct r1conf *conf = mddev->private;
1289 struct mirror_info *p;
1291 int last = conf->raid_disks - 1;
1293 if (mddev->recovery_disabled == conf->recovery_disabled)
1296 if (rdev->raid_disk >= 0)
1297 first = last = rdev->raid_disk;
1299 for (mirror = first; mirror <= last; mirror++)
1300 if ( !(p=conf->mirrors+mirror)->rdev) {
1302 disk_stack_limits(mddev->gendisk, rdev->bdev,
1303 rdev->data_offset << 9);
1304 /* as we don't honour merge_bvec_fn, we must
1305 * never risk violating it, so limit
1306 * ->max_segments to one lying with a single
1307 * page, as a one page request is never in
1310 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1311 blk_queue_max_segments(mddev->queue, 1);
1312 blk_queue_segment_boundary(mddev->queue,
1313 PAGE_CACHE_SIZE - 1);
1316 p->head_position = 0;
1317 rdev->raid_disk = mirror;
1319 /* As all devices are equivalent, we don't need a full recovery
1320 * if this was recently any drive of the array
1322 if (rdev->saved_raid_disk < 0)
1324 rcu_assign_pointer(p->rdev, rdev);
1327 md_integrity_add_rdev(rdev, mddev);
1332 static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1334 struct r1conf *conf = mddev->private;
1336 int number = rdev->raid_disk;
1337 struct mirror_info *p = conf->mirrors+ number;
1340 if (rdev == p->rdev) {
1341 if (test_bit(In_sync, &rdev->flags) ||
1342 atomic_read(&rdev->nr_pending)) {
1346 /* Only remove non-faulty devices if recovery
1349 if (!test_bit(Faulty, &rdev->flags) &&
1350 mddev->recovery_disabled != conf->recovery_disabled &&
1351 mddev->degraded < conf->raid_disks) {
1357 if (atomic_read(&rdev->nr_pending)) {
1358 /* lost the race, try later */
1363 err = md_integrity_register(mddev);
1372 static void end_sync_read(struct bio *bio, int error)
1374 struct r1bio *r1_bio = bio->bi_private;
1376 update_head_pos(r1_bio->read_disk, r1_bio);
1379 * we have read a block, now it needs to be re-written,
1380 * or re-read if the read failed.
1381 * We don't do much here, just schedule handling by raid1d
1383 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1384 set_bit(R1BIO_Uptodate, &r1_bio->state);
1386 if (atomic_dec_and_test(&r1_bio->remaining))
1387 reschedule_retry(r1_bio);
1390 static void end_sync_write(struct bio *bio, int error)
1392 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1393 struct r1bio *r1_bio = bio->bi_private;
1394 struct mddev *mddev = r1_bio->mddev;
1395 struct r1conf *conf = mddev->private;
1400 mirror = find_bio_disk(r1_bio, bio);
1403 sector_t sync_blocks = 0;
1404 sector_t s = r1_bio->sector;
1405 long sectors_to_go = r1_bio->sectors;
1406 /* make sure these bits doesn't get cleared. */
1408 bitmap_end_sync(mddev->bitmap, s,
1411 sectors_to_go -= sync_blocks;
1412 } while (sectors_to_go > 0);
1413 set_bit(WriteErrorSeen,
1414 &conf->mirrors[mirror].rdev->flags);
1415 set_bit(R1BIO_WriteError, &r1_bio->state);
1416 } else if (is_badblock(conf->mirrors[mirror].rdev,
1419 &first_bad, &bad_sectors) &&
1420 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1423 &first_bad, &bad_sectors)
1425 set_bit(R1BIO_MadeGood, &r1_bio->state);
1427 if (atomic_dec_and_test(&r1_bio->remaining)) {
1428 int s = r1_bio->sectors;
1429 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1430 test_bit(R1BIO_WriteError, &r1_bio->state))
1431 reschedule_retry(r1_bio);
1434 md_done_sync(mddev, s, uptodate);
1439 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1440 int sectors, struct page *page, int rw)
1442 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1446 set_bit(WriteErrorSeen, &rdev->flags);
1447 /* need to record an error - either for the block or the device */
1448 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1449 md_error(rdev->mddev, rdev);
1453 static int fix_sync_read_error(struct r1bio *r1_bio)
1455 /* Try some synchronous reads of other devices to get
1456 * good data, much like with normal read errors. Only
1457 * read into the pages we already have so we don't
1458 * need to re-issue the read request.
1459 * We don't need to freeze the array, because being in an
1460 * active sync request, there is no normal IO, and
1461 * no overlapping syncs.
1462 * We don't need to check is_badblock() again as we
1463 * made sure that anything with a bad block in range
1464 * will have bi_end_io clear.
1466 struct mddev *mddev = r1_bio->mddev;
1467 struct r1conf *conf = mddev->private;
1468 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1469 sector_t sect = r1_bio->sector;
1470 int sectors = r1_bio->sectors;
1475 int d = r1_bio->read_disk;
1477 struct md_rdev *rdev;
1480 if (s > (PAGE_SIZE>>9))
1483 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1484 /* No rcu protection needed here devices
1485 * can only be removed when no resync is
1486 * active, and resync is currently active
1488 rdev = conf->mirrors[d].rdev;
1489 if (sync_page_io(rdev, sect, s<<9,
1490 bio->bi_io_vec[idx].bv_page,
1497 if (d == conf->raid_disks * 2)
1499 } while (!success && d != r1_bio->read_disk);
1502 char b[BDEVNAME_SIZE];
1504 /* Cannot read from anywhere, this block is lost.
1505 * Record a bad block on each device. If that doesn't
1506 * work just disable and interrupt the recovery.
1507 * Don't fail devices as that won't really help.
1509 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1510 " for block %llu\n",
1512 bdevname(bio->bi_bdev, b),
1513 (unsigned long long)r1_bio->sector);
1514 for (d = 0; d < conf->raid_disks * 2; d++) {
1515 rdev = conf->mirrors[d].rdev;
1516 if (!rdev || test_bit(Faulty, &rdev->flags))
1518 if (!rdev_set_badblocks(rdev, sect, s, 0))
1522 conf->recovery_disabled =
1523 mddev->recovery_disabled;
1524 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1525 md_done_sync(mddev, r1_bio->sectors, 0);
1537 /* write it back and re-read */
1538 while (d != r1_bio->read_disk) {
1540 d = conf->raid_disks * 2;
1542 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1544 rdev = conf->mirrors[d].rdev;
1545 if (r1_sync_page_io(rdev, sect, s,
1546 bio->bi_io_vec[idx].bv_page,
1548 r1_bio->bios[d]->bi_end_io = NULL;
1549 rdev_dec_pending(rdev, mddev);
1553 while (d != r1_bio->read_disk) {
1555 d = conf->raid_disks * 2;
1557 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1559 rdev = conf->mirrors[d].rdev;
1560 if (r1_sync_page_io(rdev, sect, s,
1561 bio->bi_io_vec[idx].bv_page,
1563 atomic_add(s, &rdev->corrected_errors);
1569 set_bit(R1BIO_Uptodate, &r1_bio->state);
1570 set_bit(BIO_UPTODATE, &bio->bi_flags);
1574 static int process_checks(struct r1bio *r1_bio)
1576 /* We have read all readable devices. If we haven't
1577 * got the block, then there is no hope left.
1578 * If we have, then we want to do a comparison
1579 * and skip the write if everything is the same.
1580 * If any blocks failed to read, then we need to
1581 * attempt an over-write
1583 struct mddev *mddev = r1_bio->mddev;
1584 struct r1conf *conf = mddev->private;
1588 for (primary = 0; primary < conf->raid_disks * 2; primary++)
1589 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1590 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1591 r1_bio->bios[primary]->bi_end_io = NULL;
1592 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1595 r1_bio->read_disk = primary;
1596 for (i = 0; i < conf->raid_disks * 2; i++) {
1598 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1599 struct bio *pbio = r1_bio->bios[primary];
1600 struct bio *sbio = r1_bio->bios[i];
1603 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1606 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1607 for (j = vcnt; j-- ; ) {
1609 p = pbio->bi_io_vec[j].bv_page;
1610 s = sbio->bi_io_vec[j].bv_page;
1611 if (memcmp(page_address(p),
1619 mddev->resync_mismatches += r1_bio->sectors;
1620 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1621 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1622 /* No need to write to this device. */
1623 sbio->bi_end_io = NULL;
1624 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1627 /* fixup the bio for reuse */
1628 sbio->bi_vcnt = vcnt;
1629 sbio->bi_size = r1_bio->sectors << 9;
1631 sbio->bi_phys_segments = 0;
1632 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1633 sbio->bi_flags |= 1 << BIO_UPTODATE;
1634 sbio->bi_next = NULL;
1635 sbio->bi_sector = r1_bio->sector +
1636 conf->mirrors[i].rdev->data_offset;
1637 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1638 size = sbio->bi_size;
1639 for (j = 0; j < vcnt ; j++) {
1641 bi = &sbio->bi_io_vec[j];
1643 if (size > PAGE_SIZE)
1644 bi->bv_len = PAGE_SIZE;
1648 memcpy(page_address(bi->bv_page),
1649 page_address(pbio->bi_io_vec[j].bv_page),
1656 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1658 struct r1conf *conf = mddev->private;
1660 int disks = conf->raid_disks * 2;
1661 struct bio *bio, *wbio;
1663 bio = r1_bio->bios[r1_bio->read_disk];
1665 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1666 /* ouch - failed to read all of that. */
1667 if (!fix_sync_read_error(r1_bio))
1670 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1671 if (process_checks(r1_bio) < 0)
1676 atomic_set(&r1_bio->remaining, 1);
1677 for (i = 0; i < disks ; i++) {
1678 wbio = r1_bio->bios[i];
1679 if (wbio->bi_end_io == NULL ||
1680 (wbio->bi_end_io == end_sync_read &&
1681 (i == r1_bio->read_disk ||
1682 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1685 wbio->bi_rw = WRITE;
1686 wbio->bi_end_io = end_sync_write;
1687 atomic_inc(&r1_bio->remaining);
1688 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1690 generic_make_request(wbio);
1693 if (atomic_dec_and_test(&r1_bio->remaining)) {
1694 /* if we're here, all write(s) have completed, so clean up */
1695 md_done_sync(mddev, r1_bio->sectors, 1);
1701 * This is a kernel thread which:
1703 * 1. Retries failed read operations on working mirrors.
1704 * 2. Updates the raid superblock when problems encounter.
1705 * 3. Performs writes following reads for array synchronising.
1708 static void fix_read_error(struct r1conf *conf, int read_disk,
1709 sector_t sect, int sectors)
1711 struct mddev *mddev = conf->mddev;
1717 struct md_rdev *rdev;
1719 if (s > (PAGE_SIZE>>9))
1723 /* Note: no rcu protection needed here
1724 * as this is synchronous in the raid1d thread
1725 * which is the thread that might remove
1726 * a device. If raid1d ever becomes multi-threaded....
1731 rdev = conf->mirrors[d].rdev;
1733 test_bit(In_sync, &rdev->flags) &&
1734 is_badblock(rdev, sect, s,
1735 &first_bad, &bad_sectors) == 0 &&
1736 sync_page_io(rdev, sect, s<<9,
1737 conf->tmppage, READ, false))
1741 if (d == conf->raid_disks * 2)
1744 } while (!success && d != read_disk);
1747 /* Cannot read from anywhere - mark it bad */
1748 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
1749 if (!rdev_set_badblocks(rdev, sect, s, 0))
1750 md_error(mddev, rdev);
1753 /* write it back and re-read */
1755 while (d != read_disk) {
1757 d = conf->raid_disks * 2;
1759 rdev = conf->mirrors[d].rdev;
1761 test_bit(In_sync, &rdev->flags))
1762 r1_sync_page_io(rdev, sect, s,
1763 conf->tmppage, WRITE);
1766 while (d != read_disk) {
1767 char b[BDEVNAME_SIZE];
1769 d = conf->raid_disks * 2;
1771 rdev = conf->mirrors[d].rdev;
1773 test_bit(In_sync, &rdev->flags)) {
1774 if (r1_sync_page_io(rdev, sect, s,
1775 conf->tmppage, READ)) {
1776 atomic_add(s, &rdev->corrected_errors);
1778 "md/raid1:%s: read error corrected "
1779 "(%d sectors at %llu on %s)\n",
1781 (unsigned long long)(sect +
1783 bdevname(rdev->bdev, b));
1792 static void bi_complete(struct bio *bio, int error)
1794 complete((struct completion *)bio->bi_private);
1797 static int submit_bio_wait(int rw, struct bio *bio)
1799 struct completion event;
1802 init_completion(&event);
1803 bio->bi_private = &event;
1804 bio->bi_end_io = bi_complete;
1805 submit_bio(rw, bio);
1806 wait_for_completion(&event);
1808 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1811 static int narrow_write_error(struct r1bio *r1_bio, int i)
1813 struct mddev *mddev = r1_bio->mddev;
1814 struct r1conf *conf = mddev->private;
1815 struct md_rdev *rdev = conf->mirrors[i].rdev;
1817 struct bio_vec *vec;
1819 /* bio has the data to be written to device 'i' where
1820 * we just recently had a write error.
1821 * We repeatedly clone the bio and trim down to one block,
1822 * then try the write. Where the write fails we record
1824 * It is conceivable that the bio doesn't exactly align with
1825 * blocks. We must handle this somehow.
1827 * We currently own a reference on the rdev.
1833 int sect_to_write = r1_bio->sectors;
1836 if (rdev->badblocks.shift < 0)
1839 block_sectors = 1 << rdev->badblocks.shift;
1840 sector = r1_bio->sector;
1841 sectors = ((sector + block_sectors)
1842 & ~(sector_t)(block_sectors - 1))
1845 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1846 vcnt = r1_bio->behind_page_count;
1847 vec = r1_bio->behind_bvecs;
1849 while (vec[idx].bv_page == NULL)
1852 vcnt = r1_bio->master_bio->bi_vcnt;
1853 vec = r1_bio->master_bio->bi_io_vec;
1854 idx = r1_bio->master_bio->bi_idx;
1856 while (sect_to_write) {
1858 if (sectors > sect_to_write)
1859 sectors = sect_to_write;
1860 /* Write at 'sector' for 'sectors'*/
1862 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1863 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1864 wbio->bi_sector = r1_bio->sector;
1865 wbio->bi_rw = WRITE;
1866 wbio->bi_vcnt = vcnt;
1867 wbio->bi_size = r1_bio->sectors << 9;
1870 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
1871 wbio->bi_sector += rdev->data_offset;
1872 wbio->bi_bdev = rdev->bdev;
1873 if (submit_bio_wait(WRITE, wbio) == 0)
1875 ok = rdev_set_badblocks(rdev, sector,
1880 sect_to_write -= sectors;
1882 sectors = block_sectors;
1887 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1890 int s = r1_bio->sectors;
1891 for (m = 0; m < conf->raid_disks * 2 ; m++) {
1892 struct md_rdev *rdev = conf->mirrors[m].rdev;
1893 struct bio *bio = r1_bio->bios[m];
1894 if (bio->bi_end_io == NULL)
1896 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1897 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
1898 rdev_clear_badblocks(rdev, r1_bio->sector, s);
1900 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1901 test_bit(R1BIO_WriteError, &r1_bio->state)) {
1902 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
1903 md_error(conf->mddev, rdev);
1907 md_done_sync(conf->mddev, s, 1);
1910 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1913 for (m = 0; m < conf->raid_disks * 2 ; m++)
1914 if (r1_bio->bios[m] == IO_MADE_GOOD) {
1915 struct md_rdev *rdev = conf->mirrors[m].rdev;
1916 rdev_clear_badblocks(rdev,
1919 rdev_dec_pending(rdev, conf->mddev);
1920 } else if (r1_bio->bios[m] != NULL) {
1921 /* This drive got a write error. We need to
1922 * narrow down and record precise write
1925 if (!narrow_write_error(r1_bio, m)) {
1926 md_error(conf->mddev,
1927 conf->mirrors[m].rdev);
1928 /* an I/O failed, we can't clear the bitmap */
1929 set_bit(R1BIO_Degraded, &r1_bio->state);
1931 rdev_dec_pending(conf->mirrors[m].rdev,
1934 if (test_bit(R1BIO_WriteError, &r1_bio->state))
1935 close_write(r1_bio);
1936 raid_end_bio_io(r1_bio);
1939 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
1943 struct mddev *mddev = conf->mddev;
1945 char b[BDEVNAME_SIZE];
1946 struct md_rdev *rdev;
1948 clear_bit(R1BIO_ReadError, &r1_bio->state);
1949 /* we got a read error. Maybe the drive is bad. Maybe just
1950 * the block and we can fix it.
1951 * We freeze all other IO, and try reading the block from
1952 * other devices. When we find one, we re-write
1953 * and check it that fixes the read error.
1954 * This is all done synchronously while the array is
1957 if (mddev->ro == 0) {
1959 fix_read_error(conf, r1_bio->read_disk,
1960 r1_bio->sector, r1_bio->sectors);
1961 unfreeze_array(conf);
1963 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1965 bio = r1_bio->bios[r1_bio->read_disk];
1966 bdevname(bio->bi_bdev, b);
1968 disk = read_balance(conf, r1_bio, &max_sectors);
1970 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
1971 " read error for block %llu\n",
1972 mdname(mddev), b, (unsigned long long)r1_bio->sector);
1973 raid_end_bio_io(r1_bio);
1975 const unsigned long do_sync
1976 = r1_bio->master_bio->bi_rw & REQ_SYNC;
1978 r1_bio->bios[r1_bio->read_disk] =
1979 mddev->ro ? IO_BLOCKED : NULL;
1982 r1_bio->read_disk = disk;
1983 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
1984 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
1985 r1_bio->bios[r1_bio->read_disk] = bio;
1986 rdev = conf->mirrors[disk].rdev;
1987 printk_ratelimited(KERN_ERR
1988 "md/raid1:%s: redirecting sector %llu"
1989 " to other mirror: %s\n",
1991 (unsigned long long)r1_bio->sector,
1992 bdevname(rdev->bdev, b));
1993 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1994 bio->bi_bdev = rdev->bdev;
1995 bio->bi_end_io = raid1_end_read_request;
1996 bio->bi_rw = READ | do_sync;
1997 bio->bi_private = r1_bio;
1998 if (max_sectors < r1_bio->sectors) {
1999 /* Drat - have to split this up more */
2000 struct bio *mbio = r1_bio->master_bio;
2001 int sectors_handled = (r1_bio->sector + max_sectors
2003 r1_bio->sectors = max_sectors;
2004 spin_lock_irq(&conf->device_lock);
2005 if (mbio->bi_phys_segments == 0)
2006 mbio->bi_phys_segments = 2;
2008 mbio->bi_phys_segments++;
2009 spin_unlock_irq(&conf->device_lock);
2010 generic_make_request(bio);
2013 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2015 r1_bio->master_bio = mbio;
2016 r1_bio->sectors = (mbio->bi_size >> 9)
2019 set_bit(R1BIO_ReadError, &r1_bio->state);
2020 r1_bio->mddev = mddev;
2021 r1_bio->sector = mbio->bi_sector + sectors_handled;
2025 generic_make_request(bio);
2029 static void raid1d(struct mddev *mddev)
2031 struct r1bio *r1_bio;
2032 unsigned long flags;
2033 struct r1conf *conf = mddev->private;
2034 struct list_head *head = &conf->retry_list;
2035 struct blk_plug plug;
2037 md_check_recovery(mddev);
2039 blk_start_plug(&plug);
2042 if (atomic_read(&mddev->plug_cnt) == 0)
2043 flush_pending_writes(conf);
2045 spin_lock_irqsave(&conf->device_lock, flags);
2046 if (list_empty(head)) {
2047 spin_unlock_irqrestore(&conf->device_lock, flags);
2050 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2051 list_del(head->prev);
2053 spin_unlock_irqrestore(&conf->device_lock, flags);
2055 mddev = r1_bio->mddev;
2056 conf = mddev->private;
2057 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2058 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2059 test_bit(R1BIO_WriteError, &r1_bio->state))
2060 handle_sync_write_finished(conf, r1_bio);
2062 sync_request_write(mddev, r1_bio);
2063 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2064 test_bit(R1BIO_WriteError, &r1_bio->state))
2065 handle_write_finished(conf, r1_bio);
2066 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2067 handle_read_error(conf, r1_bio);
2069 /* just a partial read to be scheduled from separate
2072 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2075 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2076 md_check_recovery(mddev);
2078 blk_finish_plug(&plug);
2082 static int init_resync(struct r1conf *conf)
2086 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2087 BUG_ON(conf->r1buf_pool);
2088 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2090 if (!conf->r1buf_pool)
2092 conf->next_resync = 0;
2097 * perform a "sync" on one "block"
2099 * We need to make sure that no normal I/O request - particularly write
2100 * requests - conflict with active sync requests.
2102 * This is achieved by tracking pending requests and a 'barrier' concept
2103 * that can be installed to exclude normal IO requests.
2106 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2108 struct r1conf *conf = mddev->private;
2109 struct r1bio *r1_bio;
2111 sector_t max_sector, nr_sectors;
2115 int write_targets = 0, read_targets = 0;
2116 sector_t sync_blocks;
2117 int still_degraded = 0;
2118 int good_sectors = RESYNC_SECTORS;
2119 int min_bad = 0; /* number of sectors that are bad in all devices */
2121 if (!conf->r1buf_pool)
2122 if (init_resync(conf))
2125 max_sector = mddev->dev_sectors;
2126 if (sector_nr >= max_sector) {
2127 /* If we aborted, we need to abort the
2128 * sync on the 'current' bitmap chunk (there will
2129 * only be one in raid1 resync.
2130 * We can find the current addess in mddev->curr_resync
2132 if (mddev->curr_resync < max_sector) /* aborted */
2133 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2135 else /* completed sync */
2138 bitmap_close_sync(mddev->bitmap);
2143 if (mddev->bitmap == NULL &&
2144 mddev->recovery_cp == MaxSector &&
2145 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2146 conf->fullsync == 0) {
2148 return max_sector - sector_nr;
2150 /* before building a request, check if we can skip these blocks..
2151 * This call the bitmap_start_sync doesn't actually record anything
2153 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2154 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2155 /* We can skip this block, and probably several more */
2160 * If there is non-resync activity waiting for a turn,
2161 * and resync is going fast enough,
2162 * then let it though before starting on this new sync request.
2164 if (!go_faster && conf->nr_waiting)
2165 msleep_interruptible(1000);
2167 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2168 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2169 raise_barrier(conf);
2171 conf->next_resync = sector_nr;
2175 * If we get a correctably read error during resync or recovery,
2176 * we might want to read from a different device. So we
2177 * flag all drives that could conceivably be read from for READ,
2178 * and any others (which will be non-In_sync devices) for WRITE.
2179 * If a read fails, we try reading from something else for which READ
2183 r1_bio->mddev = mddev;
2184 r1_bio->sector = sector_nr;
2186 set_bit(R1BIO_IsSync, &r1_bio->state);
2188 for (i = 0; i < conf->raid_disks * 2; i++) {
2189 struct md_rdev *rdev;
2190 bio = r1_bio->bios[i];
2192 /* take from bio_init */
2193 bio->bi_next = NULL;
2194 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2195 bio->bi_flags |= 1 << BIO_UPTODATE;
2199 bio->bi_phys_segments = 0;
2201 bio->bi_end_io = NULL;
2202 bio->bi_private = NULL;
2204 rdev = rcu_dereference(conf->mirrors[i].rdev);
2206 test_bit(Faulty, &rdev->flags)) {
2207 if (i < conf->raid_disks)
2209 } else if (!test_bit(In_sync, &rdev->flags)) {
2211 bio->bi_end_io = end_sync_write;
2214 /* may need to read from here */
2215 sector_t first_bad = MaxSector;
2218 if (is_badblock(rdev, sector_nr, good_sectors,
2219 &first_bad, &bad_sectors)) {
2220 if (first_bad > sector_nr)
2221 good_sectors = first_bad - sector_nr;
2223 bad_sectors -= (sector_nr - first_bad);
2225 min_bad > bad_sectors)
2226 min_bad = bad_sectors;
2229 if (sector_nr < first_bad) {
2230 if (test_bit(WriteMostly, &rdev->flags)) {
2238 bio->bi_end_io = end_sync_read;
2242 if (bio->bi_end_io) {
2243 atomic_inc(&rdev->nr_pending);
2244 bio->bi_sector = sector_nr + rdev->data_offset;
2245 bio->bi_bdev = rdev->bdev;
2246 bio->bi_private = r1_bio;
2252 r1_bio->read_disk = disk;
2254 if (read_targets == 0 && min_bad > 0) {
2255 /* These sectors are bad on all InSync devices, so we
2256 * need to mark them bad on all write targets
2259 for (i = 0 ; i < conf->raid_disks * 2 ; i++)
2260 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2261 struct md_rdev *rdev =
2262 rcu_dereference(conf->mirrors[i].rdev);
2263 ok = rdev_set_badblocks(rdev, sector_nr,
2267 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2272 /* Cannot record the badblocks, so need to
2274 * If there are multiple read targets, could just
2275 * fail the really bad ones ???
2277 conf->recovery_disabled = mddev->recovery_disabled;
2278 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2284 if (min_bad > 0 && min_bad < good_sectors) {
2285 /* only resync enough to reach the next bad->good
2287 good_sectors = min_bad;
2290 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2291 /* extra read targets are also write targets */
2292 write_targets += read_targets-1;
2294 if (write_targets == 0 || read_targets == 0) {
2295 /* There is nowhere to write, so all non-sync
2296 * drives must be failed - so we are finished
2298 sector_t rv = max_sector - sector_nr;
2304 if (max_sector > mddev->resync_max)
2305 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2306 if (max_sector > sector_nr + good_sectors)
2307 max_sector = sector_nr + good_sectors;
2312 int len = PAGE_SIZE;
2313 if (sector_nr + (len>>9) > max_sector)
2314 len = (max_sector - sector_nr) << 9;
2317 if (sync_blocks == 0) {
2318 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2319 &sync_blocks, still_degraded) &&
2321 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2323 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2324 if ((len >> 9) > sync_blocks)
2325 len = sync_blocks<<9;
2328 for (i = 0 ; i < conf->raid_disks * 2; i++) {
2329 bio = r1_bio->bios[i];
2330 if (bio->bi_end_io) {
2331 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2332 if (bio_add_page(bio, page, len, 0) == 0) {
2334 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2337 bio = r1_bio->bios[i];
2338 if (bio->bi_end_io==NULL)
2340 /* remove last page from this bio */
2342 bio->bi_size -= len;
2343 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2349 nr_sectors += len>>9;
2350 sector_nr += len>>9;
2351 sync_blocks -= (len>>9);
2352 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2354 r1_bio->sectors = nr_sectors;
2356 /* For a user-requested sync, we read all readable devices and do a
2359 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2360 atomic_set(&r1_bio->remaining, read_targets);
2361 for (i = 0; i < conf->raid_disks * 2; i++) {
2362 bio = r1_bio->bios[i];
2363 if (bio->bi_end_io == end_sync_read) {
2364 md_sync_acct(bio->bi_bdev, nr_sectors);
2365 generic_make_request(bio);
2369 atomic_set(&r1_bio->remaining, 1);
2370 bio = r1_bio->bios[r1_bio->read_disk];
2371 md_sync_acct(bio->bi_bdev, nr_sectors);
2372 generic_make_request(bio);
2378 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2383 return mddev->dev_sectors;
2386 static struct r1conf *setup_conf(struct mddev *mddev)
2388 struct r1conf *conf;
2390 struct mirror_info *disk;
2391 struct md_rdev *rdev;
2394 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2398 conf->mirrors = kzalloc(sizeof(struct mirror_info)
2399 * mddev->raid_disks * 2,
2404 conf->tmppage = alloc_page(GFP_KERNEL);
2408 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2409 if (!conf->poolinfo)
2411 conf->poolinfo->raid_disks = mddev->raid_disks * 2;
2412 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2415 if (!conf->r1bio_pool)
2418 conf->poolinfo->mddev = mddev;
2420 spin_lock_init(&conf->device_lock);
2421 list_for_each_entry(rdev, &mddev->disks, same_set) {
2422 int disk_idx = rdev->raid_disk;
2423 if (disk_idx >= mddev->raid_disks
2426 disk = conf->mirrors + disk_idx;
2430 disk->head_position = 0;
2432 conf->raid_disks = mddev->raid_disks;
2433 conf->mddev = mddev;
2434 INIT_LIST_HEAD(&conf->retry_list);
2436 spin_lock_init(&conf->resync_lock);
2437 init_waitqueue_head(&conf->wait_barrier);
2439 bio_list_init(&conf->pending_bio_list);
2440 conf->pending_count = 0;
2441 conf->recovery_disabled = mddev->recovery_disabled - 1;
2443 conf->last_used = -1;
2444 for (i = 0; i < conf->raid_disks * 2; i++) {
2446 disk = conf->mirrors + i;
2449 !test_bit(In_sync, &disk->rdev->flags)) {
2450 disk->head_position = 0;
2453 } else if (conf->last_used < 0)
2455 * The first working device is used as a
2456 * starting point to read balancing.
2458 conf->last_used = i;
2462 if (conf->last_used < 0) {
2463 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2468 conf->thread = md_register_thread(raid1d, mddev, NULL);
2469 if (!conf->thread) {
2471 "md/raid1:%s: couldn't allocate thread\n",
2480 if (conf->r1bio_pool)
2481 mempool_destroy(conf->r1bio_pool);
2482 kfree(conf->mirrors);
2483 safe_put_page(conf->tmppage);
2484 kfree(conf->poolinfo);
2487 return ERR_PTR(err);
2490 static int run(struct mddev *mddev)
2492 struct r1conf *conf;
2494 struct md_rdev *rdev;
2496 if (mddev->level != 1) {
2497 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2498 mdname(mddev), mddev->level);
2501 if (mddev->reshape_position != MaxSector) {
2502 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2507 * copy the already verified devices into our private RAID1
2508 * bookkeeping area. [whatever we allocate in run(),
2509 * should be freed in stop()]
2511 if (mddev->private == NULL)
2512 conf = setup_conf(mddev);
2514 conf = mddev->private;
2517 return PTR_ERR(conf);
2519 list_for_each_entry(rdev, &mddev->disks, same_set) {
2520 if (!mddev->gendisk)
2522 disk_stack_limits(mddev->gendisk, rdev->bdev,
2523 rdev->data_offset << 9);
2524 /* as we don't honour merge_bvec_fn, we must never risk
2525 * violating it, so limit ->max_segments to 1 lying within
2526 * a single page, as a one page request is never in violation.
2528 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2529 blk_queue_max_segments(mddev->queue, 1);
2530 blk_queue_segment_boundary(mddev->queue,
2531 PAGE_CACHE_SIZE - 1);
2535 mddev->degraded = 0;
2536 for (i=0; i < conf->raid_disks; i++)
2537 if (conf->mirrors[i].rdev == NULL ||
2538 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2539 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2542 if (conf->raid_disks - mddev->degraded == 1)
2543 mddev->recovery_cp = MaxSector;
2545 if (mddev->recovery_cp != MaxSector)
2546 printk(KERN_NOTICE "md/raid1:%s: not clean"
2547 " -- starting background reconstruction\n",
2550 "md/raid1:%s: active with %d out of %d mirrors\n",
2551 mdname(mddev), mddev->raid_disks - mddev->degraded,
2555 * Ok, everything is just fine now
2557 mddev->thread = conf->thread;
2558 conf->thread = NULL;
2559 mddev->private = conf;
2561 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2564 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2565 mddev->queue->backing_dev_info.congested_data = mddev;
2567 return md_integrity_register(mddev);
2570 static int stop(struct mddev *mddev)
2572 struct r1conf *conf = mddev->private;
2573 struct bitmap *bitmap = mddev->bitmap;
2575 /* wait for behind writes to complete */
2576 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2577 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2579 /* need to kick something here to make sure I/O goes? */
2580 wait_event(bitmap->behind_wait,
2581 atomic_read(&bitmap->behind_writes) == 0);
2584 raise_barrier(conf);
2585 lower_barrier(conf);
2587 md_unregister_thread(&mddev->thread);
2588 if (conf->r1bio_pool)
2589 mempool_destroy(conf->r1bio_pool);
2590 kfree(conf->mirrors);
2591 kfree(conf->poolinfo);
2593 mddev->private = NULL;
2597 static int raid1_resize(struct mddev *mddev, sector_t sectors)
2599 /* no resync is happening, and there is enough space
2600 * on all devices, so we can resize.
2601 * We need to make sure resync covers any new space.
2602 * If the array is shrinking we should possibly wait until
2603 * any io in the removed space completes, but it hardly seems
2606 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2607 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2609 set_capacity(mddev->gendisk, mddev->array_sectors);
2610 revalidate_disk(mddev->gendisk);
2611 if (sectors > mddev->dev_sectors &&
2612 mddev->recovery_cp > mddev->dev_sectors) {
2613 mddev->recovery_cp = mddev->dev_sectors;
2614 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2616 mddev->dev_sectors = sectors;
2617 mddev->resync_max_sectors = sectors;
2621 static int raid1_reshape(struct mddev *mddev)
2624 * 1/ resize the r1bio_pool
2625 * 2/ resize conf->mirrors
2627 * We allocate a new r1bio_pool if we can.
2628 * Then raise a device barrier and wait until all IO stops.
2629 * Then resize conf->mirrors and swap in the new r1bio pool.
2631 * At the same time, we "pack" the devices so that all the missing
2632 * devices have the higher raid_disk numbers.
2634 mempool_t *newpool, *oldpool;
2635 struct pool_info *newpoolinfo;
2636 struct mirror_info *newmirrors;
2637 struct r1conf *conf = mddev->private;
2638 int cnt, raid_disks;
2639 unsigned long flags;
2642 /* Cannot change chunk_size, layout, or level */
2643 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2644 mddev->layout != mddev->new_layout ||
2645 mddev->level != mddev->new_level) {
2646 mddev->new_chunk_sectors = mddev->chunk_sectors;
2647 mddev->new_layout = mddev->layout;
2648 mddev->new_level = mddev->level;
2652 err = md_allow_write(mddev);
2656 raid_disks = mddev->raid_disks + mddev->delta_disks;
2658 if (raid_disks < conf->raid_disks) {
2660 for (d= 0; d < conf->raid_disks; d++)
2661 if (conf->mirrors[d].rdev)
2663 if (cnt > raid_disks)
2667 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2670 newpoolinfo->mddev = mddev;
2671 newpoolinfo->raid_disks = raid_disks * 2;
2673 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2674 r1bio_pool_free, newpoolinfo);
2679 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks * 2,
2683 mempool_destroy(newpool);
2687 raise_barrier(conf);
2689 /* ok, everything is stopped */
2690 oldpool = conf->r1bio_pool;
2691 conf->r1bio_pool = newpool;
2693 for (d = d2 = 0; d < conf->raid_disks; d++) {
2694 struct md_rdev *rdev = conf->mirrors[d].rdev;
2695 if (rdev && rdev->raid_disk != d2) {
2696 sysfs_unlink_rdev(mddev, rdev);
2697 rdev->raid_disk = d2;
2698 sysfs_unlink_rdev(mddev, rdev);
2699 if (sysfs_link_rdev(mddev, rdev))
2701 "md/raid1:%s: cannot register rd%d\n",
2702 mdname(mddev), rdev->raid_disk);
2705 newmirrors[d2++].rdev = rdev;
2707 kfree(conf->mirrors);
2708 conf->mirrors = newmirrors;
2709 kfree(conf->poolinfo);
2710 conf->poolinfo = newpoolinfo;
2712 spin_lock_irqsave(&conf->device_lock, flags);
2713 mddev->degraded += (raid_disks - conf->raid_disks);
2714 spin_unlock_irqrestore(&conf->device_lock, flags);
2715 conf->raid_disks = mddev->raid_disks = raid_disks;
2716 mddev->delta_disks = 0;
2718 conf->last_used = 0; /* just make sure it is in-range */
2719 lower_barrier(conf);
2721 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2722 md_wakeup_thread(mddev->thread);
2724 mempool_destroy(oldpool);
2728 static void raid1_quiesce(struct mddev *mddev, int state)
2730 struct r1conf *conf = mddev->private;
2733 case 2: /* wake for suspend */
2734 wake_up(&conf->wait_barrier);
2737 raise_barrier(conf);
2740 lower_barrier(conf);
2745 static void *raid1_takeover(struct mddev *mddev)
2747 /* raid1 can take over:
2748 * raid5 with 2 devices, any layout or chunk size
2750 if (mddev->level == 5 && mddev->raid_disks == 2) {
2751 struct r1conf *conf;
2752 mddev->new_level = 1;
2753 mddev->new_layout = 0;
2754 mddev->new_chunk_sectors = 0;
2755 conf = setup_conf(mddev);
2760 return ERR_PTR(-EINVAL);
2763 static struct md_personality raid1_personality =
2767 .owner = THIS_MODULE,
2768 .make_request = make_request,
2772 .error_handler = error,
2773 .hot_add_disk = raid1_add_disk,
2774 .hot_remove_disk= raid1_remove_disk,
2775 .spare_active = raid1_spare_active,
2776 .sync_request = sync_request,
2777 .resize = raid1_resize,
2779 .check_reshape = raid1_reshape,
2780 .quiesce = raid1_quiesce,
2781 .takeover = raid1_takeover,
2784 static int __init raid_init(void)
2786 return register_md_personality(&raid1_personality);
2789 static void raid_exit(void)
2791 unregister_md_personality(&raid1_personality);
2794 module_init(raid_init);
2795 module_exit(raid_exit);
2796 MODULE_LICENSE("GPL");
2797 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2798 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2799 MODULE_ALIAS("md-raid1");
2800 MODULE_ALIAS("md-level-1");
2802 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);