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;
410 set_bit(R1BIO_Uptodate, &r1_bio->state);
412 /* Maybe we can clear some bad blocks. */
413 if (is_badblock(conf->mirrors[mirror].rdev,
414 r1_bio->sector, r1_bio->sectors,
415 &first_bad, &bad_sectors)) {
416 r1_bio->bios[mirror] = IO_MADE_GOOD;
417 set_bit(R1BIO_MadeGood, &r1_bio->state);
422 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
423 atomic_dec(&r1_bio->behind_remaining);
426 * In behind mode, we ACK the master bio once the I/O
427 * has safely reached all non-writemostly
428 * disks. Setting the Returned bit ensures that this
429 * gets done only once -- we don't ever want to return
430 * -EIO here, instead we'll wait
432 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
433 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
434 /* Maybe we can return now */
435 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
436 struct bio *mbio = r1_bio->master_bio;
437 pr_debug("raid1: behind end write sectors"
439 (unsigned long long) mbio->bi_sector,
440 (unsigned long long) mbio->bi_sector +
441 (mbio->bi_size >> 9) - 1);
442 call_bio_endio(r1_bio);
446 if (r1_bio->bios[mirror] == NULL)
447 rdev_dec_pending(conf->mirrors[mirror].rdev,
451 * Let's see if all mirrored write operations have finished
454 r1_bio_write_done(r1_bio);
462 * This routine returns the disk from which the requested read should
463 * be done. There is a per-array 'next expected sequential IO' sector
464 * number - if this matches on the next IO then we use the last disk.
465 * There is also a per-disk 'last know head position' sector that is
466 * maintained from IRQ contexts, both the normal and the resync IO
467 * completion handlers update this position correctly. If there is no
468 * perfect sequential match then we pick the disk whose head is closest.
470 * If there are 2 mirrors in the same 2 devices, performance degrades
471 * because position is mirror, not device based.
473 * The rdev for the device selected will have nr_pending incremented.
475 static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
477 const sector_t this_sector = r1_bio->sector;
479 int best_good_sectors;
484 struct md_rdev *rdev;
489 * Check if we can balance. We can balance on the whole
490 * device if no resync is going on, or below the resync window.
491 * We take the first readable disk when above the resync window.
494 sectors = r1_bio->sectors;
496 best_dist = MaxSector;
497 best_good_sectors = 0;
499 if (conf->mddev->recovery_cp < MaxSector &&
500 (this_sector + sectors >= conf->next_resync)) {
505 start_disk = conf->last_used;
508 for (i = 0 ; i < conf->raid_disks ; i++) {
513 int disk = start_disk + i;
514 if (disk >= conf->raid_disks)
515 disk -= conf->raid_disks;
517 rdev = rcu_dereference(conf->mirrors[disk].rdev);
518 if (r1_bio->bios[disk] == IO_BLOCKED
520 || test_bit(Faulty, &rdev->flags))
522 if (!test_bit(In_sync, &rdev->flags) &&
523 rdev->recovery_offset < this_sector + sectors)
525 if (test_bit(WriteMostly, &rdev->flags)) {
526 /* Don't balance among write-mostly, just
527 * use the first as a last resort */
529 if (is_badblock(rdev, this_sector, sectors,
530 &first_bad, &bad_sectors)) {
531 if (first_bad < this_sector)
532 /* Cannot use this */
534 best_good_sectors = first_bad - this_sector;
536 best_good_sectors = sectors;
541 /* This is a reasonable device to use. It might
544 if (is_badblock(rdev, this_sector, sectors,
545 &first_bad, &bad_sectors)) {
546 if (best_dist < MaxSector)
547 /* already have a better device */
549 if (first_bad <= this_sector) {
550 /* cannot read here. If this is the 'primary'
551 * device, then we must not read beyond
552 * bad_sectors from another device..
554 bad_sectors -= (this_sector - first_bad);
555 if (choose_first && sectors > bad_sectors)
556 sectors = bad_sectors;
557 if (best_good_sectors > sectors)
558 best_good_sectors = sectors;
561 sector_t good_sectors = first_bad - this_sector;
562 if (good_sectors > best_good_sectors) {
563 best_good_sectors = good_sectors;
571 best_good_sectors = sectors;
573 dist = abs(this_sector - conf->mirrors[disk].head_position);
575 /* Don't change to another disk for sequential reads */
576 || conf->next_seq_sect == this_sector
578 /* If device is idle, use it */
579 || atomic_read(&rdev->nr_pending) == 0) {
583 if (dist < best_dist) {
589 if (best_disk >= 0) {
590 rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
593 atomic_inc(&rdev->nr_pending);
594 if (test_bit(Faulty, &rdev->flags)) {
595 /* cannot risk returning a device that failed
596 * before we inc'ed nr_pending
598 rdev_dec_pending(rdev, conf->mddev);
601 sectors = best_good_sectors;
602 conf->next_seq_sect = this_sector + sectors;
603 conf->last_used = best_disk;
606 *max_sectors = sectors;
611 int md_raid1_congested(struct mddev *mddev, int bits)
613 struct r1conf *conf = mddev->private;
616 if ((bits & (1 << BDI_async_congested)) &&
617 conf->pending_count >= max_queued_requests)
621 for (i = 0; i < mddev->raid_disks; i++) {
622 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
623 if (rdev && !test_bit(Faulty, &rdev->flags)) {
624 struct request_queue *q = bdev_get_queue(rdev->bdev);
628 /* Note the '|| 1' - when read_balance prefers
629 * non-congested targets, it can be removed
631 if ((bits & (1<<BDI_async_congested)) || 1)
632 ret |= bdi_congested(&q->backing_dev_info, bits);
634 ret &= bdi_congested(&q->backing_dev_info, bits);
640 EXPORT_SYMBOL_GPL(md_raid1_congested);
642 static int raid1_congested(void *data, int bits)
644 struct mddev *mddev = data;
646 return mddev_congested(mddev, bits) ||
647 md_raid1_congested(mddev, bits);
650 static void flush_pending_writes(struct r1conf *conf)
652 /* Any writes that have been queued but are awaiting
653 * bitmap updates get flushed here.
655 spin_lock_irq(&conf->device_lock);
657 if (conf->pending_bio_list.head) {
659 bio = bio_list_get(&conf->pending_bio_list);
660 conf->pending_count = 0;
661 spin_unlock_irq(&conf->device_lock);
662 /* flush any pending bitmap writes to
663 * disk before proceeding w/ I/O */
664 bitmap_unplug(conf->mddev->bitmap);
665 wake_up(&conf->wait_barrier);
667 while (bio) { /* submit pending writes */
668 struct bio *next = bio->bi_next;
670 generic_make_request(bio);
674 spin_unlock_irq(&conf->device_lock);
678 * Sometimes we need to suspend IO while we do something else,
679 * either some resync/recovery, or reconfigure the array.
680 * To do this we raise a 'barrier'.
681 * The 'barrier' is a counter that can be raised multiple times
682 * to count how many activities are happening which preclude
684 * We can only raise the barrier if there is no pending IO.
685 * i.e. if nr_pending == 0.
686 * We choose only to raise the barrier if no-one is waiting for the
687 * barrier to go down. This means that as soon as an IO request
688 * is ready, no other operations which require a barrier will start
689 * until the IO request has had a chance.
691 * So: regular IO calls 'wait_barrier'. When that returns there
692 * is no backgroup IO happening, It must arrange to call
693 * allow_barrier when it has finished its IO.
694 * backgroup IO calls must call raise_barrier. Once that returns
695 * there is no normal IO happeing. It must arrange to call
696 * lower_barrier when the particular background IO completes.
698 #define RESYNC_DEPTH 32
700 static void raise_barrier(struct r1conf *conf)
702 spin_lock_irq(&conf->resync_lock);
704 /* Wait until no block IO is waiting */
705 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
706 conf->resync_lock, );
708 /* block any new IO from starting */
711 /* Now wait for all pending IO to complete */
712 wait_event_lock_irq(conf->wait_barrier,
713 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
714 conf->resync_lock, );
716 spin_unlock_irq(&conf->resync_lock);
719 static void lower_barrier(struct r1conf *conf)
722 BUG_ON(conf->barrier <= 0);
723 spin_lock_irqsave(&conf->resync_lock, flags);
725 spin_unlock_irqrestore(&conf->resync_lock, flags);
726 wake_up(&conf->wait_barrier);
729 static void wait_barrier(struct r1conf *conf)
731 spin_lock_irq(&conf->resync_lock);
734 /* Wait for the barrier to drop.
735 * However if there are already pending
736 * requests (preventing the barrier from
737 * rising completely), and the
738 * pre-process bio queue isn't empty,
739 * then don't wait, as we need to empty
740 * that queue to get the nr_pending
743 wait_event_lock_irq(conf->wait_barrier,
747 !bio_list_empty(current->bio_list)),
753 spin_unlock_irq(&conf->resync_lock);
756 static void allow_barrier(struct r1conf *conf)
759 spin_lock_irqsave(&conf->resync_lock, flags);
761 spin_unlock_irqrestore(&conf->resync_lock, flags);
762 wake_up(&conf->wait_barrier);
765 static void freeze_array(struct r1conf *conf)
767 /* stop syncio and normal IO and wait for everything to
769 * We increment barrier and nr_waiting, and then
770 * wait until nr_pending match nr_queued+1
771 * This is called in the context of one normal IO request
772 * that has failed. Thus any sync request that might be pending
773 * will be blocked by nr_pending, and we need to wait for
774 * pending IO requests to complete or be queued for re-try.
775 * Thus the number queued (nr_queued) plus this request (1)
776 * must match the number of pending IOs (nr_pending) before
779 spin_lock_irq(&conf->resync_lock);
782 wait_event_lock_irq(conf->wait_barrier,
783 conf->nr_pending == conf->nr_queued+1,
785 flush_pending_writes(conf));
786 spin_unlock_irq(&conf->resync_lock);
788 static void unfreeze_array(struct r1conf *conf)
790 /* reverse the effect of the freeze */
791 spin_lock_irq(&conf->resync_lock);
794 wake_up(&conf->wait_barrier);
795 spin_unlock_irq(&conf->resync_lock);
799 /* duplicate the data pages for behind I/O
801 static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio)
804 struct bio_vec *bvec;
805 struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec),
807 if (unlikely(!bvecs))
810 bio_for_each_segment(bvec, bio, i) {
812 bvecs[i].bv_page = alloc_page(GFP_NOIO);
813 if (unlikely(!bvecs[i].bv_page))
815 memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset,
816 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
817 kunmap(bvecs[i].bv_page);
818 kunmap(bvec->bv_page);
820 r1_bio->behind_bvecs = bvecs;
821 r1_bio->behind_page_count = bio->bi_vcnt;
822 set_bit(R1BIO_BehindIO, &r1_bio->state);
826 for (i = 0; i < bio->bi_vcnt; i++)
827 if (bvecs[i].bv_page)
828 put_page(bvecs[i].bv_page);
830 pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
833 static void make_request(struct mddev *mddev, struct bio * bio)
835 struct r1conf *conf = mddev->private;
836 struct mirror_info *mirror;
837 struct r1bio *r1_bio;
838 struct bio *read_bio;
840 struct bitmap *bitmap;
842 const int rw = bio_data_dir(bio);
843 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
844 const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
845 struct md_rdev *blocked_rdev;
852 * Register the new request and wait if the reconstruction
853 * thread has put up a bar for new requests.
854 * Continue immediately if no resync is active currently.
857 md_write_start(mddev, bio); /* wait on superblock update early */
859 if (bio_data_dir(bio) == WRITE &&
860 bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
861 bio->bi_sector < mddev->suspend_hi) {
862 /* As the suspend_* range is controlled by
863 * userspace, we want an interruptible
868 flush_signals(current);
869 prepare_to_wait(&conf->wait_barrier,
870 &w, TASK_INTERRUPTIBLE);
871 if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
872 bio->bi_sector >= mddev->suspend_hi)
876 finish_wait(&conf->wait_barrier, &w);
881 bitmap = mddev->bitmap;
884 * make_request() can abort the operation when READA is being
885 * used and no empty request is available.
888 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
890 r1_bio->master_bio = bio;
891 r1_bio->sectors = bio->bi_size >> 9;
893 r1_bio->mddev = mddev;
894 r1_bio->sector = bio->bi_sector;
896 /* We might need to issue multiple reads to different
897 * devices if there are bad blocks around, so we keep
898 * track of the number of reads in bio->bi_phys_segments.
899 * If this is 0, there is only one r1_bio and no locking
900 * will be needed when requests complete. If it is
901 * non-zero, then it is the number of not-completed requests.
903 bio->bi_phys_segments = 0;
904 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
908 * read balancing logic:
913 rdisk = read_balance(conf, r1_bio, &max_sectors);
916 /* couldn't find anywhere to read from */
917 raid_end_bio_io(r1_bio);
920 mirror = conf->mirrors + rdisk;
922 if (test_bit(WriteMostly, &mirror->rdev->flags) &&
924 /* Reading from a write-mostly device must
925 * take care not to over-take any writes
928 wait_event(bitmap->behind_wait,
929 atomic_read(&bitmap->behind_writes) == 0);
931 r1_bio->read_disk = rdisk;
933 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
934 md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector,
937 r1_bio->bios[rdisk] = read_bio;
939 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
940 read_bio->bi_bdev = mirror->rdev->bdev;
941 read_bio->bi_end_io = raid1_end_read_request;
942 read_bio->bi_rw = READ | do_sync;
943 read_bio->bi_private = r1_bio;
945 if (max_sectors < r1_bio->sectors) {
946 /* could not read all from this device, so we will
947 * need another r1_bio.
950 sectors_handled = (r1_bio->sector + max_sectors
952 r1_bio->sectors = max_sectors;
953 spin_lock_irq(&conf->device_lock);
954 if (bio->bi_phys_segments == 0)
955 bio->bi_phys_segments = 2;
957 bio->bi_phys_segments++;
958 spin_unlock_irq(&conf->device_lock);
959 /* Cannot call generic_make_request directly
960 * as that will be queued in __make_request
961 * and subsequent mempool_alloc might block waiting
962 * for it. So hand bio over to raid1d.
964 reschedule_retry(r1_bio);
966 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
968 r1_bio->master_bio = bio;
969 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
971 r1_bio->mddev = mddev;
972 r1_bio->sector = bio->bi_sector + sectors_handled;
975 generic_make_request(read_bio);
982 if (conf->pending_count >= max_queued_requests) {
983 md_wakeup_thread(mddev->thread);
984 wait_event(conf->wait_barrier,
985 conf->pending_count < max_queued_requests);
987 /* first select target devices under rcu_lock and
988 * inc refcount on their rdev. Record them by setting
990 * If there are known/acknowledged bad blocks on any device on
991 * which we have seen a write error, we want to avoid writing those
993 * This potentially requires several writes to write around
994 * the bad blocks. Each set of writes gets it's own r1bio
995 * with a set of bios attached.
997 plugged = mddev_check_plugged(mddev);
999 disks = conf->raid_disks;
1001 blocked_rdev = NULL;
1003 max_sectors = r1_bio->sectors;
1004 for (i = 0; i < disks; i++) {
1005 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1006 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1007 atomic_inc(&rdev->nr_pending);
1008 blocked_rdev = rdev;
1011 r1_bio->bios[i] = NULL;
1012 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1013 set_bit(R1BIO_Degraded, &r1_bio->state);
1017 atomic_inc(&rdev->nr_pending);
1018 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1023 is_bad = is_badblock(rdev, r1_bio->sector,
1025 &first_bad, &bad_sectors);
1027 /* mustn't write here until the bad block is
1029 set_bit(BlockedBadBlocks, &rdev->flags);
1030 blocked_rdev = rdev;
1033 if (is_bad && first_bad <= r1_bio->sector) {
1034 /* Cannot write here at all */
1035 bad_sectors -= (r1_bio->sector - first_bad);
1036 if (bad_sectors < max_sectors)
1037 /* mustn't write more than bad_sectors
1038 * to other devices yet
1040 max_sectors = bad_sectors;
1041 rdev_dec_pending(rdev, mddev);
1042 /* We don't set R1BIO_Degraded as that
1043 * only applies if the disk is
1044 * missing, so it might be re-added,
1045 * and we want to know to recover this
1047 * In this case the device is here,
1048 * and the fact that this chunk is not
1049 * in-sync is recorded in the bad
1055 int good_sectors = first_bad - r1_bio->sector;
1056 if (good_sectors < max_sectors)
1057 max_sectors = good_sectors;
1060 r1_bio->bios[i] = bio;
1064 if (unlikely(blocked_rdev)) {
1065 /* Wait for this device to become unblocked */
1068 for (j = 0; j < i; j++)
1069 if (r1_bio->bios[j])
1070 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
1072 allow_barrier(conf);
1073 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1078 if (max_sectors < r1_bio->sectors) {
1079 /* We are splitting this write into multiple parts, so
1080 * we need to prepare for allocating another r1_bio.
1082 r1_bio->sectors = max_sectors;
1083 spin_lock_irq(&conf->device_lock);
1084 if (bio->bi_phys_segments == 0)
1085 bio->bi_phys_segments = 2;
1087 bio->bi_phys_segments++;
1088 spin_unlock_irq(&conf->device_lock);
1090 sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
1092 atomic_set(&r1_bio->remaining, 1);
1093 atomic_set(&r1_bio->behind_remaining, 0);
1096 for (i = 0; i < disks; i++) {
1098 if (!r1_bio->bios[i])
1101 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1102 md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
1106 * Not if there are too many, or cannot
1107 * allocate memory, or a reader on WriteMostly
1108 * is waiting for behind writes to flush */
1110 (atomic_read(&bitmap->behind_writes)
1111 < mddev->bitmap_info.max_write_behind) &&
1112 !waitqueue_active(&bitmap->behind_wait))
1113 alloc_behind_pages(mbio, r1_bio);
1115 bitmap_startwrite(bitmap, r1_bio->sector,
1117 test_bit(R1BIO_BehindIO,
1121 if (r1_bio->behind_bvecs) {
1122 struct bio_vec *bvec;
1125 /* Yes, I really want the '__' version so that
1126 * we clear any unused pointer in the io_vec, rather
1127 * than leave them unchanged. This is important
1128 * because when we come to free the pages, we won't
1129 * know the original bi_idx, so we just free
1132 __bio_for_each_segment(bvec, mbio, j, 0)
1133 bvec->bv_page = r1_bio->behind_bvecs[j].bv_page;
1134 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
1135 atomic_inc(&r1_bio->behind_remaining);
1138 r1_bio->bios[i] = mbio;
1140 mbio->bi_sector = (r1_bio->sector +
1141 conf->mirrors[i].rdev->data_offset);
1142 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1143 mbio->bi_end_io = raid1_end_write_request;
1144 mbio->bi_rw = WRITE | do_flush_fua | do_sync;
1145 mbio->bi_private = r1_bio;
1147 atomic_inc(&r1_bio->remaining);
1148 spin_lock_irqsave(&conf->device_lock, flags);
1149 bio_list_add(&conf->pending_bio_list, mbio);
1150 conf->pending_count++;
1151 spin_unlock_irqrestore(&conf->device_lock, flags);
1153 /* Mustn't call r1_bio_write_done before this next test,
1154 * as it could result in the bio being freed.
1156 if (sectors_handled < (bio->bi_size >> 9)) {
1157 r1_bio_write_done(r1_bio);
1158 /* We need another r1_bio. It has already been counted
1159 * in bio->bi_phys_segments
1161 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
1162 r1_bio->master_bio = bio;
1163 r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1165 r1_bio->mddev = mddev;
1166 r1_bio->sector = bio->bi_sector + sectors_handled;
1170 r1_bio_write_done(r1_bio);
1172 /* In case raid1d snuck in to freeze_array */
1173 wake_up(&conf->wait_barrier);
1175 if (do_sync || !bitmap || !plugged)
1176 md_wakeup_thread(mddev->thread);
1179 static void status(struct seq_file *seq, struct mddev *mddev)
1181 struct r1conf *conf = mddev->private;
1184 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1185 conf->raid_disks - mddev->degraded);
1187 for (i = 0; i < conf->raid_disks; i++) {
1188 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1189 seq_printf(seq, "%s",
1190 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1193 seq_printf(seq, "]");
1197 static void error(struct mddev *mddev, struct md_rdev *rdev)
1199 char b[BDEVNAME_SIZE];
1200 struct r1conf *conf = mddev->private;
1203 * If it is not operational, then we have already marked it as dead
1204 * else if it is the last working disks, ignore the error, let the
1205 * next level up know.
1206 * else mark the drive as failed
1208 if (test_bit(In_sync, &rdev->flags)
1209 && (conf->raid_disks - mddev->degraded) == 1) {
1211 * Don't fail the drive, act as though we were just a
1212 * normal single drive.
1213 * However don't try a recovery from this drive as
1214 * it is very likely to fail.
1216 conf->recovery_disabled = mddev->recovery_disabled;
1219 set_bit(Blocked, &rdev->flags);
1220 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1221 unsigned long flags;
1222 spin_lock_irqsave(&conf->device_lock, flags);
1224 set_bit(Faulty, &rdev->flags);
1225 spin_unlock_irqrestore(&conf->device_lock, flags);
1227 * if recovery is running, make sure it aborts.
1229 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1231 set_bit(Faulty, &rdev->flags);
1232 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1234 "md/raid1:%s: Disk failure on %s, disabling device.\n"
1235 "md/raid1:%s: Operation continuing on %d devices.\n",
1236 mdname(mddev), bdevname(rdev->bdev, b),
1237 mdname(mddev), conf->raid_disks - mddev->degraded);
1240 static void print_conf(struct r1conf *conf)
1244 printk(KERN_DEBUG "RAID1 conf printout:\n");
1246 printk(KERN_DEBUG "(!conf)\n");
1249 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1253 for (i = 0; i < conf->raid_disks; i++) {
1254 char b[BDEVNAME_SIZE];
1255 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1257 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1258 i, !test_bit(In_sync, &rdev->flags),
1259 !test_bit(Faulty, &rdev->flags),
1260 bdevname(rdev->bdev,b));
1265 static void close_sync(struct r1conf *conf)
1268 allow_barrier(conf);
1270 mempool_destroy(conf->r1buf_pool);
1271 conf->r1buf_pool = NULL;
1274 static int raid1_spare_active(struct mddev *mddev)
1277 struct r1conf *conf = mddev->private;
1279 unsigned long flags;
1282 * Find all failed disks within the RAID1 configuration
1283 * and mark them readable.
1284 * Called under mddev lock, so rcu protection not needed.
1286 for (i = 0; i < conf->raid_disks; i++) {
1287 struct md_rdev *rdev = conf->mirrors[i].rdev;
1289 && !test_bit(Faulty, &rdev->flags)
1290 && !test_and_set_bit(In_sync, &rdev->flags)) {
1292 sysfs_notify_dirent_safe(rdev->sysfs_state);
1295 spin_lock_irqsave(&conf->device_lock, flags);
1296 mddev->degraded -= count;
1297 spin_unlock_irqrestore(&conf->device_lock, flags);
1304 static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1306 struct r1conf *conf = mddev->private;
1309 struct mirror_info *p;
1311 int last = mddev->raid_disks - 1;
1313 if (mddev->recovery_disabled == conf->recovery_disabled)
1316 if (rdev->raid_disk >= 0)
1317 first = last = rdev->raid_disk;
1319 for (mirror = first; mirror <= last; mirror++)
1320 if ( !(p=conf->mirrors+mirror)->rdev) {
1322 disk_stack_limits(mddev->gendisk, rdev->bdev,
1323 rdev->data_offset << 9);
1324 /* as we don't honour merge_bvec_fn, we must
1325 * never risk violating it, so limit
1326 * ->max_segments to one lying with a single
1327 * page, as a one page request is never in
1330 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1331 blk_queue_max_segments(mddev->queue, 1);
1332 blk_queue_segment_boundary(mddev->queue,
1333 PAGE_CACHE_SIZE - 1);
1336 p->head_position = 0;
1337 rdev->raid_disk = mirror;
1339 /* As all devices are equivalent, we don't need a full recovery
1340 * if this was recently any drive of the array
1342 if (rdev->saved_raid_disk < 0)
1344 rcu_assign_pointer(p->rdev, rdev);
1347 md_integrity_add_rdev(rdev, mddev);
1352 static int raid1_remove_disk(struct mddev *mddev, int number)
1354 struct r1conf *conf = mddev->private;
1356 struct md_rdev *rdev;
1357 struct mirror_info *p = conf->mirrors+ number;
1362 if (test_bit(In_sync, &rdev->flags) ||
1363 atomic_read(&rdev->nr_pending)) {
1367 /* Only remove non-faulty devices if recovery
1370 if (!test_bit(Faulty, &rdev->flags) &&
1371 mddev->recovery_disabled != conf->recovery_disabled &&
1372 mddev->degraded < conf->raid_disks) {
1378 if (atomic_read(&rdev->nr_pending)) {
1379 /* lost the race, try later */
1384 err = md_integrity_register(mddev);
1393 static void end_sync_read(struct bio *bio, int error)
1395 struct r1bio *r1_bio = bio->bi_private;
1397 update_head_pos(r1_bio->read_disk, r1_bio);
1400 * we have read a block, now it needs to be re-written,
1401 * or re-read if the read failed.
1402 * We don't do much here, just schedule handling by raid1d
1404 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1405 set_bit(R1BIO_Uptodate, &r1_bio->state);
1407 if (atomic_dec_and_test(&r1_bio->remaining))
1408 reschedule_retry(r1_bio);
1411 static void end_sync_write(struct bio *bio, int error)
1413 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1414 struct r1bio *r1_bio = bio->bi_private;
1415 struct mddev *mddev = r1_bio->mddev;
1416 struct r1conf *conf = mddev->private;
1421 mirror = find_bio_disk(r1_bio, bio);
1424 sector_t sync_blocks = 0;
1425 sector_t s = r1_bio->sector;
1426 long sectors_to_go = r1_bio->sectors;
1427 /* make sure these bits doesn't get cleared. */
1429 bitmap_end_sync(mddev->bitmap, s,
1432 sectors_to_go -= sync_blocks;
1433 } while (sectors_to_go > 0);
1434 set_bit(WriteErrorSeen,
1435 &conf->mirrors[mirror].rdev->flags);
1436 set_bit(R1BIO_WriteError, &r1_bio->state);
1437 } else if (is_badblock(conf->mirrors[mirror].rdev,
1440 &first_bad, &bad_sectors) &&
1441 !is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
1444 &first_bad, &bad_sectors)
1446 set_bit(R1BIO_MadeGood, &r1_bio->state);
1448 if (atomic_dec_and_test(&r1_bio->remaining)) {
1449 int s = r1_bio->sectors;
1450 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1451 test_bit(R1BIO_WriteError, &r1_bio->state))
1452 reschedule_retry(r1_bio);
1455 md_done_sync(mddev, s, uptodate);
1460 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
1461 int sectors, struct page *page, int rw)
1463 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1467 set_bit(WriteErrorSeen, &rdev->flags);
1468 /* need to record an error - either for the block or the device */
1469 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1470 md_error(rdev->mddev, rdev);
1474 static int fix_sync_read_error(struct r1bio *r1_bio)
1476 /* Try some synchronous reads of other devices to get
1477 * good data, much like with normal read errors. Only
1478 * read into the pages we already have so we don't
1479 * need to re-issue the read request.
1480 * We don't need to freeze the array, because being in an
1481 * active sync request, there is no normal IO, and
1482 * no overlapping syncs.
1483 * We don't need to check is_badblock() again as we
1484 * made sure that anything with a bad block in range
1485 * will have bi_end_io clear.
1487 struct mddev *mddev = r1_bio->mddev;
1488 struct r1conf *conf = mddev->private;
1489 struct bio *bio = r1_bio->bios[r1_bio->read_disk];
1490 sector_t sect = r1_bio->sector;
1491 int sectors = r1_bio->sectors;
1496 int d = r1_bio->read_disk;
1498 struct md_rdev *rdev;
1501 if (s > (PAGE_SIZE>>9))
1504 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1505 /* No rcu protection needed here devices
1506 * can only be removed when no resync is
1507 * active, and resync is currently active
1509 rdev = conf->mirrors[d].rdev;
1510 if (sync_page_io(rdev, sect, s<<9,
1511 bio->bi_io_vec[idx].bv_page,
1518 if (d == conf->raid_disks)
1520 } while (!success && d != r1_bio->read_disk);
1523 char b[BDEVNAME_SIZE];
1525 /* Cannot read from anywhere, this block is lost.
1526 * Record a bad block on each device. If that doesn't
1527 * work just disable and interrupt the recovery.
1528 * Don't fail devices as that won't really help.
1530 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
1531 " for block %llu\n",
1533 bdevname(bio->bi_bdev, b),
1534 (unsigned long long)r1_bio->sector);
1535 for (d = 0; d < conf->raid_disks; d++) {
1536 rdev = conf->mirrors[d].rdev;
1537 if (!rdev || test_bit(Faulty, &rdev->flags))
1539 if (!rdev_set_badblocks(rdev, sect, s, 0))
1543 conf->recovery_disabled =
1544 mddev->recovery_disabled;
1545 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1546 md_done_sync(mddev, r1_bio->sectors, 0);
1558 /* write it back and re-read */
1559 while (d != r1_bio->read_disk) {
1561 d = conf->raid_disks;
1563 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1565 rdev = conf->mirrors[d].rdev;
1566 if (r1_sync_page_io(rdev, sect, s,
1567 bio->bi_io_vec[idx].bv_page,
1569 r1_bio->bios[d]->bi_end_io = NULL;
1570 rdev_dec_pending(rdev, mddev);
1574 while (d != r1_bio->read_disk) {
1576 d = conf->raid_disks;
1578 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1580 rdev = conf->mirrors[d].rdev;
1581 if (r1_sync_page_io(rdev, sect, s,
1582 bio->bi_io_vec[idx].bv_page,
1584 atomic_add(s, &rdev->corrected_errors);
1590 set_bit(R1BIO_Uptodate, &r1_bio->state);
1591 set_bit(BIO_UPTODATE, &bio->bi_flags);
1595 static int process_checks(struct r1bio *r1_bio)
1597 /* We have read all readable devices. If we haven't
1598 * got the block, then there is no hope left.
1599 * If we have, then we want to do a comparison
1600 * and skip the write if everything is the same.
1601 * If any blocks failed to read, then we need to
1602 * attempt an over-write
1604 struct mddev *mddev = r1_bio->mddev;
1605 struct r1conf *conf = mddev->private;
1609 for (primary = 0; primary < conf->raid_disks; primary++)
1610 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1611 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1612 r1_bio->bios[primary]->bi_end_io = NULL;
1613 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1616 r1_bio->read_disk = primary;
1617 for (i = 0; i < conf->raid_disks; i++) {
1619 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1620 struct bio *pbio = r1_bio->bios[primary];
1621 struct bio *sbio = r1_bio->bios[i];
1624 if (r1_bio->bios[i]->bi_end_io != end_sync_read)
1627 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1628 for (j = vcnt; j-- ; ) {
1630 p = pbio->bi_io_vec[j].bv_page;
1631 s = sbio->bi_io_vec[j].bv_page;
1632 if (memcmp(page_address(p),
1640 mddev->resync_mismatches += r1_bio->sectors;
1641 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1642 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1643 /* No need to write to this device. */
1644 sbio->bi_end_io = NULL;
1645 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1648 /* fixup the bio for reuse */
1649 sbio->bi_vcnt = vcnt;
1650 sbio->bi_size = r1_bio->sectors << 9;
1652 sbio->bi_phys_segments = 0;
1653 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1654 sbio->bi_flags |= 1 << BIO_UPTODATE;
1655 sbio->bi_next = NULL;
1656 sbio->bi_sector = r1_bio->sector +
1657 conf->mirrors[i].rdev->data_offset;
1658 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1659 size = sbio->bi_size;
1660 for (j = 0; j < vcnt ; j++) {
1662 bi = &sbio->bi_io_vec[j];
1664 if (size > PAGE_SIZE)
1665 bi->bv_len = PAGE_SIZE;
1669 memcpy(page_address(bi->bv_page),
1670 page_address(pbio->bi_io_vec[j].bv_page),
1677 static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
1679 struct r1conf *conf = mddev->private;
1681 int disks = conf->raid_disks;
1682 struct bio *bio, *wbio;
1684 bio = r1_bio->bios[r1_bio->read_disk];
1686 if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
1687 /* ouch - failed to read all of that. */
1688 if (!fix_sync_read_error(r1_bio))
1691 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1692 if (process_checks(r1_bio) < 0)
1697 atomic_set(&r1_bio->remaining, 1);
1698 for (i = 0; i < disks ; i++) {
1699 wbio = r1_bio->bios[i];
1700 if (wbio->bi_end_io == NULL ||
1701 (wbio->bi_end_io == end_sync_read &&
1702 (i == r1_bio->read_disk ||
1703 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1706 wbio->bi_rw = WRITE;
1707 wbio->bi_end_io = end_sync_write;
1708 atomic_inc(&r1_bio->remaining);
1709 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1711 generic_make_request(wbio);
1714 if (atomic_dec_and_test(&r1_bio->remaining)) {
1715 /* if we're here, all write(s) have completed, so clean up */
1716 int s = r1_bio->sectors;
1717 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
1718 test_bit(R1BIO_WriteError, &r1_bio->state))
1719 reschedule_retry(r1_bio);
1722 md_done_sync(mddev, s, 1);
1728 * This is a kernel thread which:
1730 * 1. Retries failed read operations on working mirrors.
1731 * 2. Updates the raid superblock when problems encounter.
1732 * 3. Performs writes following reads for array synchronising.
1735 static void fix_read_error(struct r1conf *conf, int read_disk,
1736 sector_t sect, int sectors)
1738 struct mddev *mddev = conf->mddev;
1744 struct md_rdev *rdev;
1746 if (s > (PAGE_SIZE>>9))
1750 /* Note: no rcu protection needed here
1751 * as this is synchronous in the raid1d thread
1752 * which is the thread that might remove
1753 * a device. If raid1d ever becomes multi-threaded....
1758 rdev = conf->mirrors[d].rdev;
1760 test_bit(In_sync, &rdev->flags) &&
1761 is_badblock(rdev, sect, s,
1762 &first_bad, &bad_sectors) == 0 &&
1763 sync_page_io(rdev, sect, s<<9,
1764 conf->tmppage, READ, false))
1768 if (d == conf->raid_disks)
1771 } while (!success && d != read_disk);
1774 /* Cannot read from anywhere - mark it bad */
1775 struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
1776 if (!rdev_set_badblocks(rdev, sect, s, 0))
1777 md_error(mddev, rdev);
1780 /* write it back and re-read */
1782 while (d != read_disk) {
1784 d = conf->raid_disks;
1786 rdev = conf->mirrors[d].rdev;
1788 test_bit(In_sync, &rdev->flags))
1789 r1_sync_page_io(rdev, sect, s,
1790 conf->tmppage, WRITE);
1793 while (d != read_disk) {
1794 char b[BDEVNAME_SIZE];
1796 d = conf->raid_disks;
1798 rdev = conf->mirrors[d].rdev;
1800 test_bit(In_sync, &rdev->flags)) {
1801 if (r1_sync_page_io(rdev, sect, s,
1802 conf->tmppage, READ)) {
1803 atomic_add(s, &rdev->corrected_errors);
1805 "md/raid1:%s: read error corrected "
1806 "(%d sectors at %llu on %s)\n",
1808 (unsigned long long)(sect +
1810 bdevname(rdev->bdev, b));
1819 static void bi_complete(struct bio *bio, int error)
1821 complete((struct completion *)bio->bi_private);
1824 static int submit_bio_wait(int rw, struct bio *bio)
1826 struct completion event;
1829 init_completion(&event);
1830 bio->bi_private = &event;
1831 bio->bi_end_io = bi_complete;
1832 submit_bio(rw, bio);
1833 wait_for_completion(&event);
1835 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1838 static int narrow_write_error(struct r1bio *r1_bio, int i)
1840 struct mddev *mddev = r1_bio->mddev;
1841 struct r1conf *conf = mddev->private;
1842 struct md_rdev *rdev = conf->mirrors[i].rdev;
1844 struct bio_vec *vec;
1846 /* bio has the data to be written to device 'i' where
1847 * we just recently had a write error.
1848 * We repeatedly clone the bio and trim down to one block,
1849 * then try the write. Where the write fails we record
1851 * It is conceivable that the bio doesn't exactly align with
1852 * blocks. We must handle this somehow.
1854 * We currently own a reference on the rdev.
1860 int sect_to_write = r1_bio->sectors;
1863 if (rdev->badblocks.shift < 0)
1866 block_sectors = 1 << rdev->badblocks.shift;
1867 sector = r1_bio->sector;
1868 sectors = ((sector + block_sectors)
1869 & ~(sector_t)(block_sectors - 1))
1872 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
1873 vcnt = r1_bio->behind_page_count;
1874 vec = r1_bio->behind_bvecs;
1876 while (vec[idx].bv_page == NULL)
1879 vcnt = r1_bio->master_bio->bi_vcnt;
1880 vec = r1_bio->master_bio->bi_io_vec;
1881 idx = r1_bio->master_bio->bi_idx;
1883 while (sect_to_write) {
1885 if (sectors > sect_to_write)
1886 sectors = sect_to_write;
1887 /* Write at 'sector' for 'sectors'*/
1889 wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
1890 memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
1891 wbio->bi_sector = r1_bio->sector;
1892 wbio->bi_rw = WRITE;
1893 wbio->bi_vcnt = vcnt;
1894 wbio->bi_size = r1_bio->sectors << 9;
1897 md_trim_bio(wbio, sector - r1_bio->sector, sectors);
1898 wbio->bi_sector += rdev->data_offset;
1899 wbio->bi_bdev = rdev->bdev;
1900 if (submit_bio_wait(WRITE, wbio) == 0)
1902 ok = rdev_set_badblocks(rdev, sector,
1907 sect_to_write -= sectors;
1909 sectors = block_sectors;
1914 static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1917 int s = r1_bio->sectors;
1918 for (m = 0; m < conf->raid_disks ; m++) {
1919 struct md_rdev *rdev = conf->mirrors[m].rdev;
1920 struct bio *bio = r1_bio->bios[m];
1921 if (bio->bi_end_io == NULL)
1923 if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1924 test_bit(R1BIO_MadeGood, &r1_bio->state)) {
1925 rdev_clear_badblocks(rdev, r1_bio->sector, s);
1927 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
1928 test_bit(R1BIO_WriteError, &r1_bio->state)) {
1929 if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
1930 md_error(conf->mddev, rdev);
1934 md_done_sync(conf->mddev, s, 1);
1937 static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
1940 for (m = 0; m < conf->raid_disks ; m++)
1941 if (r1_bio->bios[m] == IO_MADE_GOOD) {
1942 struct md_rdev *rdev = conf->mirrors[m].rdev;
1943 rdev_clear_badblocks(rdev,
1946 rdev_dec_pending(rdev, conf->mddev);
1947 } else if (r1_bio->bios[m] != NULL) {
1948 /* This drive got a write error. We need to
1949 * narrow down and record precise write
1952 if (!narrow_write_error(r1_bio, m)) {
1953 md_error(conf->mddev,
1954 conf->mirrors[m].rdev);
1955 /* an I/O failed, we can't clear the bitmap */
1956 set_bit(R1BIO_Degraded, &r1_bio->state);
1958 rdev_dec_pending(conf->mirrors[m].rdev,
1961 if (test_bit(R1BIO_WriteError, &r1_bio->state))
1962 close_write(r1_bio);
1963 raid_end_bio_io(r1_bio);
1966 static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
1970 struct mddev *mddev = conf->mddev;
1972 char b[BDEVNAME_SIZE];
1973 struct md_rdev *rdev;
1975 clear_bit(R1BIO_ReadError, &r1_bio->state);
1976 /* we got a read error. Maybe the drive is bad. Maybe just
1977 * the block and we can fix it.
1978 * We freeze all other IO, and try reading the block from
1979 * other devices. When we find one, we re-write
1980 * and check it that fixes the read error.
1981 * This is all done synchronously while the array is
1984 if (mddev->ro == 0) {
1986 fix_read_error(conf, r1_bio->read_disk,
1987 r1_bio->sector, r1_bio->sectors);
1988 unfreeze_array(conf);
1990 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1992 bio = r1_bio->bios[r1_bio->read_disk];
1993 bdevname(bio->bi_bdev, b);
1995 disk = read_balance(conf, r1_bio, &max_sectors);
1997 printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
1998 " read error for block %llu\n",
1999 mdname(mddev), b, (unsigned long long)r1_bio->sector);
2000 raid_end_bio_io(r1_bio);
2002 const unsigned long do_sync
2003 = r1_bio->master_bio->bi_rw & REQ_SYNC;
2005 r1_bio->bios[r1_bio->read_disk] =
2006 mddev->ro ? IO_BLOCKED : NULL;
2009 r1_bio->read_disk = disk;
2010 bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev);
2011 md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors);
2012 r1_bio->bios[r1_bio->read_disk] = bio;
2013 rdev = conf->mirrors[disk].rdev;
2014 printk_ratelimited(KERN_ERR
2015 "md/raid1:%s: redirecting sector %llu"
2016 " to other mirror: %s\n",
2018 (unsigned long long)r1_bio->sector,
2019 bdevname(rdev->bdev, b));
2020 bio->bi_sector = r1_bio->sector + rdev->data_offset;
2021 bio->bi_bdev = rdev->bdev;
2022 bio->bi_end_io = raid1_end_read_request;
2023 bio->bi_rw = READ | do_sync;
2024 bio->bi_private = r1_bio;
2025 if (max_sectors < r1_bio->sectors) {
2026 /* Drat - have to split this up more */
2027 struct bio *mbio = r1_bio->master_bio;
2028 int sectors_handled = (r1_bio->sector + max_sectors
2030 r1_bio->sectors = max_sectors;
2031 spin_lock_irq(&conf->device_lock);
2032 if (mbio->bi_phys_segments == 0)
2033 mbio->bi_phys_segments = 2;
2035 mbio->bi_phys_segments++;
2036 spin_unlock_irq(&conf->device_lock);
2037 generic_make_request(bio);
2040 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
2042 r1_bio->master_bio = mbio;
2043 r1_bio->sectors = (mbio->bi_size >> 9)
2046 set_bit(R1BIO_ReadError, &r1_bio->state);
2047 r1_bio->mddev = mddev;
2048 r1_bio->sector = mbio->bi_sector + sectors_handled;
2052 generic_make_request(bio);
2056 static void raid1d(struct mddev *mddev)
2058 struct r1bio *r1_bio;
2059 unsigned long flags;
2060 struct r1conf *conf = mddev->private;
2061 struct list_head *head = &conf->retry_list;
2062 struct blk_plug plug;
2064 md_check_recovery(mddev);
2066 blk_start_plug(&plug);
2069 if (atomic_read(&mddev->plug_cnt) == 0)
2070 flush_pending_writes(conf);
2072 spin_lock_irqsave(&conf->device_lock, flags);
2073 if (list_empty(head)) {
2074 spin_unlock_irqrestore(&conf->device_lock, flags);
2077 r1_bio = list_entry(head->prev, struct r1bio, retry_list);
2078 list_del(head->prev);
2080 spin_unlock_irqrestore(&conf->device_lock, flags);
2082 mddev = r1_bio->mddev;
2083 conf = mddev->private;
2084 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
2085 if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2086 test_bit(R1BIO_WriteError, &r1_bio->state))
2087 handle_sync_write_finished(conf, r1_bio);
2089 sync_request_write(mddev, r1_bio);
2090 } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
2091 test_bit(R1BIO_WriteError, &r1_bio->state))
2092 handle_write_finished(conf, r1_bio);
2093 else if (test_bit(R1BIO_ReadError, &r1_bio->state))
2094 handle_read_error(conf, r1_bio);
2096 /* just a partial read to be scheduled from separate
2099 generic_make_request(r1_bio->bios[r1_bio->read_disk]);
2102 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2103 md_check_recovery(mddev);
2105 blk_finish_plug(&plug);
2109 static int init_resync(struct r1conf *conf)
2113 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2114 BUG_ON(conf->r1buf_pool);
2115 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
2117 if (!conf->r1buf_pool)
2119 conf->next_resync = 0;
2124 * perform a "sync" on one "block"
2126 * We need to make sure that no normal I/O request - particularly write
2127 * requests - conflict with active sync requests.
2129 * This is achieved by tracking pending requests and a 'barrier' concept
2130 * that can be installed to exclude normal IO requests.
2133 static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster)
2135 struct r1conf *conf = mddev->private;
2136 struct r1bio *r1_bio;
2138 sector_t max_sector, nr_sectors;
2142 int write_targets = 0, read_targets = 0;
2143 sector_t sync_blocks;
2144 int still_degraded = 0;
2145 int good_sectors = RESYNC_SECTORS;
2146 int min_bad = 0; /* number of sectors that are bad in all devices */
2148 if (!conf->r1buf_pool)
2149 if (init_resync(conf))
2152 max_sector = mddev->dev_sectors;
2153 if (sector_nr >= max_sector) {
2154 /* If we aborted, we need to abort the
2155 * sync on the 'current' bitmap chunk (there will
2156 * only be one in raid1 resync.
2157 * We can find the current addess in mddev->curr_resync
2159 if (mddev->curr_resync < max_sector) /* aborted */
2160 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2162 else /* completed sync */
2165 bitmap_close_sync(mddev->bitmap);
2170 if (mddev->bitmap == NULL &&
2171 mddev->recovery_cp == MaxSector &&
2172 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2173 conf->fullsync == 0) {
2175 return max_sector - sector_nr;
2177 /* before building a request, check if we can skip these blocks..
2178 * This call the bitmap_start_sync doesn't actually record anything
2180 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
2181 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2182 /* We can skip this block, and probably several more */
2187 * If there is non-resync activity waiting for a turn,
2188 * and resync is going fast enough,
2189 * then let it though before starting on this new sync request.
2191 if (!go_faster && conf->nr_waiting)
2192 msleep_interruptible(1000);
2194 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2195 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
2196 raise_barrier(conf);
2198 conf->next_resync = sector_nr;
2202 * If we get a correctably read error during resync or recovery,
2203 * we might want to read from a different device. So we
2204 * flag all drives that could conceivably be read from for READ,
2205 * and any others (which will be non-In_sync devices) for WRITE.
2206 * If a read fails, we try reading from something else for which READ
2210 r1_bio->mddev = mddev;
2211 r1_bio->sector = sector_nr;
2213 set_bit(R1BIO_IsSync, &r1_bio->state);
2215 for (i=0; i < conf->raid_disks; i++) {
2216 struct md_rdev *rdev;
2217 bio = r1_bio->bios[i];
2219 /* take from bio_init */
2220 bio->bi_next = NULL;
2221 bio->bi_flags &= ~(BIO_POOL_MASK-1);
2222 bio->bi_flags |= 1 << BIO_UPTODATE;
2226 bio->bi_phys_segments = 0;
2228 bio->bi_end_io = NULL;
2229 bio->bi_private = NULL;
2231 rdev = rcu_dereference(conf->mirrors[i].rdev);
2233 test_bit(Faulty, &rdev->flags)) {
2235 } else if (!test_bit(In_sync, &rdev->flags)) {
2237 bio->bi_end_io = end_sync_write;
2240 /* may need to read from here */
2241 sector_t first_bad = MaxSector;
2244 if (is_badblock(rdev, sector_nr, good_sectors,
2245 &first_bad, &bad_sectors)) {
2246 if (first_bad > sector_nr)
2247 good_sectors = first_bad - sector_nr;
2249 bad_sectors -= (sector_nr - first_bad);
2251 min_bad > bad_sectors)
2252 min_bad = bad_sectors;
2255 if (sector_nr < first_bad) {
2256 if (test_bit(WriteMostly, &rdev->flags)) {
2264 bio->bi_end_io = end_sync_read;
2268 if (bio->bi_end_io) {
2269 atomic_inc(&rdev->nr_pending);
2270 bio->bi_sector = sector_nr + rdev->data_offset;
2271 bio->bi_bdev = rdev->bdev;
2272 bio->bi_private = r1_bio;
2278 r1_bio->read_disk = disk;
2280 if (read_targets == 0 && min_bad > 0) {
2281 /* These sectors are bad on all InSync devices, so we
2282 * need to mark them bad on all write targets
2285 for (i = 0 ; i < conf->raid_disks ; i++)
2286 if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
2287 struct md_rdev *rdev =
2288 rcu_dereference(conf->mirrors[i].rdev);
2289 ok = rdev_set_badblocks(rdev, sector_nr,
2293 set_bit(MD_CHANGE_DEVS, &mddev->flags);
2298 /* Cannot record the badblocks, so need to
2300 * If there are multiple read targets, could just
2301 * fail the really bad ones ???
2303 conf->recovery_disabled = mddev->recovery_disabled;
2304 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
2310 if (min_bad > 0 && min_bad < good_sectors) {
2311 /* only resync enough to reach the next bad->good
2313 good_sectors = min_bad;
2316 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
2317 /* extra read targets are also write targets */
2318 write_targets += read_targets-1;
2320 if (write_targets == 0 || read_targets == 0) {
2321 /* There is nowhere to write, so all non-sync
2322 * drives must be failed - so we are finished
2324 sector_t rv = max_sector - sector_nr;
2330 if (max_sector > mddev->resync_max)
2331 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2332 if (max_sector > sector_nr + good_sectors)
2333 max_sector = sector_nr + good_sectors;
2338 int len = PAGE_SIZE;
2339 if (sector_nr + (len>>9) > max_sector)
2340 len = (max_sector - sector_nr) << 9;
2343 if (sync_blocks == 0) {
2344 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2345 &sync_blocks, still_degraded) &&
2347 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
2349 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
2350 if ((len >> 9) > sync_blocks)
2351 len = sync_blocks<<9;
2354 for (i=0 ; i < conf->raid_disks; i++) {
2355 bio = r1_bio->bios[i];
2356 if (bio->bi_end_io) {
2357 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2358 if (bio_add_page(bio, page, len, 0) == 0) {
2360 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2363 bio = r1_bio->bios[i];
2364 if (bio->bi_end_io==NULL)
2366 /* remove last page from this bio */
2368 bio->bi_size -= len;
2369 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
2375 nr_sectors += len>>9;
2376 sector_nr += len>>9;
2377 sync_blocks -= (len>>9);
2378 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
2380 r1_bio->sectors = nr_sectors;
2382 /* For a user-requested sync, we read all readable devices and do a
2385 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
2386 atomic_set(&r1_bio->remaining, read_targets);
2387 for (i = 0; i < conf->raid_disks && read_targets; i++) {
2388 bio = r1_bio->bios[i];
2389 if (bio->bi_end_io == end_sync_read) {
2391 md_sync_acct(bio->bi_bdev, nr_sectors);
2392 generic_make_request(bio);
2396 atomic_set(&r1_bio->remaining, 1);
2397 bio = r1_bio->bios[r1_bio->read_disk];
2398 md_sync_acct(bio->bi_bdev, nr_sectors);
2399 generic_make_request(bio);
2405 static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
2410 return mddev->dev_sectors;
2413 static struct r1conf *setup_conf(struct mddev *mddev)
2415 struct r1conf *conf;
2417 struct mirror_info *disk;
2418 struct md_rdev *rdev;
2421 conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
2425 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
2430 conf->tmppage = alloc_page(GFP_KERNEL);
2434 conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
2435 if (!conf->poolinfo)
2437 conf->poolinfo->raid_disks = mddev->raid_disks;
2438 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2441 if (!conf->r1bio_pool)
2444 conf->poolinfo->mddev = mddev;
2446 spin_lock_init(&conf->device_lock);
2447 list_for_each_entry(rdev, &mddev->disks, same_set) {
2448 int disk_idx = rdev->raid_disk;
2449 if (disk_idx >= mddev->raid_disks
2452 disk = conf->mirrors + disk_idx;
2456 disk->head_position = 0;
2458 conf->raid_disks = mddev->raid_disks;
2459 conf->mddev = mddev;
2460 INIT_LIST_HEAD(&conf->retry_list);
2462 spin_lock_init(&conf->resync_lock);
2463 init_waitqueue_head(&conf->wait_barrier);
2465 bio_list_init(&conf->pending_bio_list);
2466 conf->pending_count = 0;
2467 conf->recovery_disabled = mddev->recovery_disabled - 1;
2469 conf->last_used = -1;
2470 for (i = 0; i < conf->raid_disks; i++) {
2472 disk = conf->mirrors + i;
2475 !test_bit(In_sync, &disk->rdev->flags)) {
2476 disk->head_position = 0;
2479 } else if (conf->last_used < 0)
2481 * The first working device is used as a
2482 * starting point to read balancing.
2484 conf->last_used = i;
2488 if (conf->last_used < 0) {
2489 printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
2494 conf->thread = md_register_thread(raid1d, mddev, NULL);
2495 if (!conf->thread) {
2497 "md/raid1:%s: couldn't allocate thread\n",
2506 if (conf->r1bio_pool)
2507 mempool_destroy(conf->r1bio_pool);
2508 kfree(conf->mirrors);
2509 safe_put_page(conf->tmppage);
2510 kfree(conf->poolinfo);
2513 return ERR_PTR(err);
2516 static int run(struct mddev *mddev)
2518 struct r1conf *conf;
2520 struct md_rdev *rdev;
2522 if (mddev->level != 1) {
2523 printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
2524 mdname(mddev), mddev->level);
2527 if (mddev->reshape_position != MaxSector) {
2528 printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
2533 * copy the already verified devices into our private RAID1
2534 * bookkeeping area. [whatever we allocate in run(),
2535 * should be freed in stop()]
2537 if (mddev->private == NULL)
2538 conf = setup_conf(mddev);
2540 conf = mddev->private;
2543 return PTR_ERR(conf);
2545 list_for_each_entry(rdev, &mddev->disks, same_set) {
2546 if (!mddev->gendisk)
2548 disk_stack_limits(mddev->gendisk, rdev->bdev,
2549 rdev->data_offset << 9);
2550 /* as we don't honour merge_bvec_fn, we must never risk
2551 * violating it, so limit ->max_segments to 1 lying within
2552 * a single page, as a one page request is never in violation.
2554 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2555 blk_queue_max_segments(mddev->queue, 1);
2556 blk_queue_segment_boundary(mddev->queue,
2557 PAGE_CACHE_SIZE - 1);
2561 mddev->degraded = 0;
2562 for (i=0; i < conf->raid_disks; i++)
2563 if (conf->mirrors[i].rdev == NULL ||
2564 !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
2565 test_bit(Faulty, &conf->mirrors[i].rdev->flags))
2568 if (conf->raid_disks - mddev->degraded == 1)
2569 mddev->recovery_cp = MaxSector;
2571 if (mddev->recovery_cp != MaxSector)
2572 printk(KERN_NOTICE "md/raid1:%s: not clean"
2573 " -- starting background reconstruction\n",
2576 "md/raid1:%s: active with %d out of %d mirrors\n",
2577 mdname(mddev), mddev->raid_disks - mddev->degraded,
2581 * Ok, everything is just fine now
2583 mddev->thread = conf->thread;
2584 conf->thread = NULL;
2585 mddev->private = conf;
2587 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2590 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2591 mddev->queue->backing_dev_info.congested_data = mddev;
2593 return md_integrity_register(mddev);
2596 static int stop(struct mddev *mddev)
2598 struct r1conf *conf = mddev->private;
2599 struct bitmap *bitmap = mddev->bitmap;
2601 /* wait for behind writes to complete */
2602 if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2603 printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
2605 /* need to kick something here to make sure I/O goes? */
2606 wait_event(bitmap->behind_wait,
2607 atomic_read(&bitmap->behind_writes) == 0);
2610 raise_barrier(conf);
2611 lower_barrier(conf);
2613 md_unregister_thread(&mddev->thread);
2614 if (conf->r1bio_pool)
2615 mempool_destroy(conf->r1bio_pool);
2616 kfree(conf->mirrors);
2617 kfree(conf->poolinfo);
2619 mddev->private = NULL;
2623 static int raid1_resize(struct mddev *mddev, sector_t sectors)
2625 /* no resync is happening, and there is enough space
2626 * on all devices, so we can resize.
2627 * We need to make sure resync covers any new space.
2628 * If the array is shrinking we should possibly wait until
2629 * any io in the removed space completes, but it hardly seems
2632 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2633 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2635 set_capacity(mddev->gendisk, mddev->array_sectors);
2636 revalidate_disk(mddev->gendisk);
2637 if (sectors > mddev->dev_sectors &&
2638 mddev->recovery_cp > mddev->dev_sectors) {
2639 mddev->recovery_cp = mddev->dev_sectors;
2640 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2642 mddev->dev_sectors = sectors;
2643 mddev->resync_max_sectors = sectors;
2647 static int raid1_reshape(struct mddev *mddev)
2650 * 1/ resize the r1bio_pool
2651 * 2/ resize conf->mirrors
2653 * We allocate a new r1bio_pool if we can.
2654 * Then raise a device barrier and wait until all IO stops.
2655 * Then resize conf->mirrors and swap in the new r1bio pool.
2657 * At the same time, we "pack" the devices so that all the missing
2658 * devices have the higher raid_disk numbers.
2660 mempool_t *newpool, *oldpool;
2661 struct pool_info *newpoolinfo;
2662 struct mirror_info *newmirrors;
2663 struct r1conf *conf = mddev->private;
2664 int cnt, raid_disks;
2665 unsigned long flags;
2668 /* Cannot change chunk_size, layout, or level */
2669 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2670 mddev->layout != mddev->new_layout ||
2671 mddev->level != mddev->new_level) {
2672 mddev->new_chunk_sectors = mddev->chunk_sectors;
2673 mddev->new_layout = mddev->layout;
2674 mddev->new_level = mddev->level;
2678 err = md_allow_write(mddev);
2682 raid_disks = mddev->raid_disks + mddev->delta_disks;
2684 if (raid_disks < conf->raid_disks) {
2686 for (d= 0; d < conf->raid_disks; d++)
2687 if (conf->mirrors[d].rdev)
2689 if (cnt > raid_disks)
2693 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2696 newpoolinfo->mddev = mddev;
2697 newpoolinfo->raid_disks = raid_disks;
2699 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2700 r1bio_pool_free, newpoolinfo);
2705 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2708 mempool_destroy(newpool);
2712 raise_barrier(conf);
2714 /* ok, everything is stopped */
2715 oldpool = conf->r1bio_pool;
2716 conf->r1bio_pool = newpool;
2718 for (d = d2 = 0; d < conf->raid_disks; d++) {
2719 struct md_rdev *rdev = conf->mirrors[d].rdev;
2720 if (rdev && rdev->raid_disk != d2) {
2721 sysfs_unlink_rdev(mddev, rdev);
2722 rdev->raid_disk = d2;
2723 sysfs_unlink_rdev(mddev, rdev);
2724 if (sysfs_link_rdev(mddev, rdev))
2726 "md/raid1:%s: cannot register rd%d\n",
2727 mdname(mddev), rdev->raid_disk);
2730 newmirrors[d2++].rdev = rdev;
2732 kfree(conf->mirrors);
2733 conf->mirrors = newmirrors;
2734 kfree(conf->poolinfo);
2735 conf->poolinfo = newpoolinfo;
2737 spin_lock_irqsave(&conf->device_lock, flags);
2738 mddev->degraded += (raid_disks - conf->raid_disks);
2739 spin_unlock_irqrestore(&conf->device_lock, flags);
2740 conf->raid_disks = mddev->raid_disks = raid_disks;
2741 mddev->delta_disks = 0;
2743 conf->last_used = 0; /* just make sure it is in-range */
2744 lower_barrier(conf);
2746 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2747 md_wakeup_thread(mddev->thread);
2749 mempool_destroy(oldpool);
2753 static void raid1_quiesce(struct mddev *mddev, int state)
2755 struct r1conf *conf = mddev->private;
2758 case 2: /* wake for suspend */
2759 wake_up(&conf->wait_barrier);
2762 raise_barrier(conf);
2765 lower_barrier(conf);
2770 static void *raid1_takeover(struct mddev *mddev)
2772 /* raid1 can take over:
2773 * raid5 with 2 devices, any layout or chunk size
2775 if (mddev->level == 5 && mddev->raid_disks == 2) {
2776 struct r1conf *conf;
2777 mddev->new_level = 1;
2778 mddev->new_layout = 0;
2779 mddev->new_chunk_sectors = 0;
2780 conf = setup_conf(mddev);
2785 return ERR_PTR(-EINVAL);
2788 static struct md_personality raid1_personality =
2792 .owner = THIS_MODULE,
2793 .make_request = make_request,
2797 .error_handler = error,
2798 .hot_add_disk = raid1_add_disk,
2799 .hot_remove_disk= raid1_remove_disk,
2800 .spare_active = raid1_spare_active,
2801 .sync_request = sync_request,
2802 .resize = raid1_resize,
2804 .check_reshape = raid1_reshape,
2805 .quiesce = raid1_quiesce,
2806 .takeover = raid1_takeover,
2809 static int __init raid_init(void)
2811 return register_md_personality(&raid1_personality);
2814 static void raid_exit(void)
2816 unregister_md_personality(&raid1_personality);
2819 module_init(raid_init);
2820 module_exit(raid_exit);
2821 MODULE_LICENSE("GPL");
2822 MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
2823 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2824 MODULE_ALIAS("md-raid1");
2825 MODULE_ALIAS("md-level-1");
2827 module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);