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 "dm-bio-list.h"
35 #include <linux/raid/raid1.h>
36 #include <linux/raid/bitmap.h>
40 #define PRINTK(x...) printk(x)
46 * Number of guaranteed r1bios in case of extreme VM load:
48 #define NR_RAID1_BIOS 256
51 static void unplug_slaves(mddev_t *mddev);
53 static void allow_barrier(conf_t *conf);
54 static void lower_barrier(conf_t *conf);
56 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
58 struct pool_info *pi = data;
60 int size = offsetof(r1bio_t, bios[pi->raid_disks]);
62 /* allocate a r1bio with room for raid_disks entries in the bios array */
63 r1_bio = kzalloc(size, gfp_flags);
65 unplug_slaves(pi->mddev);
70 static void r1bio_pool_free(void *r1_bio, void *data)
75 #define RESYNC_BLOCK_SIZE (64*1024)
76 //#define RESYNC_BLOCK_SIZE PAGE_SIZE
77 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
78 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
79 #define RESYNC_WINDOW (2048*1024)
81 static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
83 struct pool_info *pi = data;
89 r1_bio = r1bio_pool_alloc(gfp_flags, pi);
91 unplug_slaves(pi->mddev);
96 * Allocate bios : 1 for reading, n-1 for writing
98 for (j = pi->raid_disks ; j-- ; ) {
99 bio = bio_alloc(gfp_flags, RESYNC_PAGES);
102 r1_bio->bios[j] = bio;
105 * Allocate RESYNC_PAGES data pages and attach them to
107 * If this is a user-requested check/repair, allocate
108 * RESYNC_PAGES for each bio.
110 if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
115 bio = r1_bio->bios[j];
116 for (i = 0; i < RESYNC_PAGES; i++) {
117 page = alloc_page(gfp_flags);
121 bio->bi_io_vec[i].bv_page = page;
124 /* If not user-requests, copy the page pointers to all bios */
125 if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
126 for (i=0; i<RESYNC_PAGES ; i++)
127 for (j=1; j<pi->raid_disks; j++)
128 r1_bio->bios[j]->bi_io_vec[i].bv_page =
129 r1_bio->bios[0]->bi_io_vec[i].bv_page;
132 r1_bio->master_bio = NULL;
137 for (i=0; i < RESYNC_PAGES ; i++)
138 for (j=0 ; j < pi->raid_disks; j++)
139 safe_put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
142 while ( ++j < pi->raid_disks )
143 bio_put(r1_bio->bios[j]);
144 r1bio_pool_free(r1_bio, data);
148 static void r1buf_pool_free(void *__r1_bio, void *data)
150 struct pool_info *pi = data;
152 r1bio_t *r1bio = __r1_bio;
154 for (i = 0; i < RESYNC_PAGES; i++)
155 for (j = pi->raid_disks; j-- ;) {
157 r1bio->bios[j]->bi_io_vec[i].bv_page !=
158 r1bio->bios[0]->bi_io_vec[i].bv_page)
159 safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
161 for (i=0 ; i < pi->raid_disks; i++)
162 bio_put(r1bio->bios[i]);
164 r1bio_pool_free(r1bio, data);
167 static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
171 for (i = 0; i < conf->raid_disks; i++) {
172 struct bio **bio = r1_bio->bios + i;
173 if (*bio && *bio != IO_BLOCKED)
179 static inline void free_r1bio(r1bio_t *r1_bio)
181 conf_t *conf = mddev_to_conf(r1_bio->mddev);
184 * Wake up any possible resync thread that waits for the device
189 put_all_bios(conf, r1_bio);
190 mempool_free(r1_bio, conf->r1bio_pool);
193 static inline void put_buf(r1bio_t *r1_bio)
195 conf_t *conf = mddev_to_conf(r1_bio->mddev);
198 for (i=0; i<conf->raid_disks; i++) {
199 struct bio *bio = r1_bio->bios[i];
201 rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
204 mempool_free(r1_bio, conf->r1buf_pool);
209 static void reschedule_retry(r1bio_t *r1_bio)
212 mddev_t *mddev = r1_bio->mddev;
213 conf_t *conf = mddev_to_conf(mddev);
215 spin_lock_irqsave(&conf->device_lock, flags);
216 list_add(&r1_bio->retry_list, &conf->retry_list);
218 spin_unlock_irqrestore(&conf->device_lock, flags);
220 wake_up(&conf->wait_barrier);
221 md_wakeup_thread(mddev->thread);
225 * raid_end_bio_io() is called when we have finished servicing a mirrored
226 * operation and are ready to return a success/failure code to the buffer
229 static void raid_end_bio_io(r1bio_t *r1_bio)
231 struct bio *bio = r1_bio->master_bio;
233 /* if nobody has done the final endio yet, do it now */
234 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
235 PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n",
236 (bio_data_dir(bio) == WRITE) ? "write" : "read",
237 (unsigned long long) bio->bi_sector,
238 (unsigned long long) bio->bi_sector +
239 (bio->bi_size >> 9) - 1);
241 bio_endio(bio, bio->bi_size,
242 test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
248 * Update disk head position estimator based on IRQ completion info.
250 static inline void update_head_pos(int disk, r1bio_t *r1_bio)
252 conf_t *conf = mddev_to_conf(r1_bio->mddev);
254 conf->mirrors[disk].head_position =
255 r1_bio->sector + (r1_bio->sectors);
258 static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
260 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
261 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
263 conf_t *conf = mddev_to_conf(r1_bio->mddev);
268 mirror = r1_bio->read_disk;
270 * this branch is our 'one mirror IO has finished' event handler:
272 update_head_pos(mirror, r1_bio);
274 if (uptodate || conf->working_disks <= 1) {
276 * Set R1BIO_Uptodate in our master bio, so that
277 * we will return a good error code for to the higher
278 * levels even if IO on some other mirrored buffer fails.
280 * The 'master' represents the composite IO operation to
281 * user-side. So if something waits for IO, then it will
282 * wait for the 'master' bio.
285 set_bit(R1BIO_Uptodate, &r1_bio->state);
287 raid_end_bio_io(r1_bio);
292 char b[BDEVNAME_SIZE];
293 if (printk_ratelimit())
294 printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
295 bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
296 reschedule_retry(r1_bio);
299 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
303 static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
305 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
306 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
307 int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
308 conf_t *conf = mddev_to_conf(r1_bio->mddev);
313 for (mirror = 0; mirror < conf->raid_disks; mirror++)
314 if (r1_bio->bios[mirror] == bio)
317 if (error == -ENOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
318 set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
319 set_bit(R1BIO_BarrierRetry, &r1_bio->state);
320 r1_bio->mddev->barriers_work = 0;
323 * this branch is our 'one mirror IO has finished' event handler:
325 r1_bio->bios[mirror] = NULL;
327 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
328 /* an I/O failed, we can't clear the bitmap */
329 set_bit(R1BIO_Degraded, &r1_bio->state);
332 * Set R1BIO_Uptodate in our master bio, so that
333 * we will return a good error code for to the higher
334 * levels even if IO on some other mirrored buffer fails.
336 * The 'master' represents the composite IO operation to
337 * user-side. So if something waits for IO, then it will
338 * wait for the 'master' bio.
340 set_bit(R1BIO_Uptodate, &r1_bio->state);
342 update_head_pos(mirror, r1_bio);
345 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
346 atomic_dec(&r1_bio->behind_remaining);
348 /* In behind mode, we ACK the master bio once the I/O has safely
349 * reached all non-writemostly disks. Setting the Returned bit
350 * ensures that this gets done only once -- we don't ever want to
351 * return -EIO here, instead we'll wait */
353 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
354 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
355 /* Maybe we can return now */
356 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
357 struct bio *mbio = r1_bio->master_bio;
358 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
359 (unsigned long long) mbio->bi_sector,
360 (unsigned long long) mbio->bi_sector +
361 (mbio->bi_size >> 9) - 1);
362 bio_endio(mbio, mbio->bi_size, 0);
369 * Let's see if all mirrored write operations have finished
372 if (atomic_dec_and_test(&r1_bio->remaining)) {
373 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
374 reschedule_retry(r1_bio);
375 /* Don't dec_pending yet, we want to hold
376 * the reference over the retry
380 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
381 /* free extra copy of the data pages */
382 int i = bio->bi_vcnt;
384 safe_put_page(bio->bi_io_vec[i].bv_page);
386 /* clear the bitmap if all writes complete successfully */
387 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
389 !test_bit(R1BIO_Degraded, &r1_bio->state),
391 md_write_end(r1_bio->mddev);
392 raid_end_bio_io(r1_bio);
395 if (r1_bio->bios[mirror]==NULL)
398 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
404 * This routine returns the disk from which the requested read should
405 * be done. There is a per-array 'next expected sequential IO' sector
406 * number - if this matches on the next IO then we use the last disk.
407 * There is also a per-disk 'last know head position' sector that is
408 * maintained from IRQ contexts, both the normal and the resync IO
409 * completion handlers update this position correctly. If there is no
410 * perfect sequential match then we pick the disk whose head is closest.
412 * If there are 2 mirrors in the same 2 devices, performance degrades
413 * because position is mirror, not device based.
415 * The rdev for the device selected will have nr_pending incremented.
417 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
419 const unsigned long this_sector = r1_bio->sector;
420 int new_disk = conf->last_used, disk = new_disk;
422 const int sectors = r1_bio->sectors;
423 sector_t new_distance, current_distance;
428 * Check if we can balance. We can balance on the whole
429 * device if no resync is going on, or below the resync window.
430 * We take the first readable disk when above the resync window.
433 if (conf->mddev->recovery_cp < MaxSector &&
434 (this_sector + sectors >= conf->next_resync)) {
435 /* Choose the first operation device, for consistancy */
438 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
439 r1_bio->bios[new_disk] == IO_BLOCKED ||
440 !rdev || !test_bit(In_sync, &rdev->flags)
441 || test_bit(WriteMostly, &rdev->flags);
442 rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) {
444 if (rdev && test_bit(In_sync, &rdev->flags) &&
445 r1_bio->bios[new_disk] != IO_BLOCKED)
446 wonly_disk = new_disk;
448 if (new_disk == conf->raid_disks - 1) {
449 new_disk = wonly_disk;
457 /* make sure the disk is operational */
458 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
459 r1_bio->bios[new_disk] == IO_BLOCKED ||
460 !rdev || !test_bit(In_sync, &rdev->flags) ||
461 test_bit(WriteMostly, &rdev->flags);
462 rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) {
464 if (rdev && test_bit(In_sync, &rdev->flags) &&
465 r1_bio->bios[new_disk] != IO_BLOCKED)
466 wonly_disk = new_disk;
469 new_disk = conf->raid_disks;
471 if (new_disk == disk) {
472 new_disk = wonly_disk;
481 /* now disk == new_disk == starting point for search */
484 * Don't change to another disk for sequential reads:
486 if (conf->next_seq_sect == this_sector)
488 if (this_sector == conf->mirrors[new_disk].head_position)
491 current_distance = abs(this_sector - conf->mirrors[disk].head_position);
493 /* Find the disk whose head is closest */
497 disk = conf->raid_disks;
500 rdev = rcu_dereference(conf->mirrors[disk].rdev);
502 if (!rdev || r1_bio->bios[disk] == IO_BLOCKED ||
503 !test_bit(In_sync, &rdev->flags) ||
504 test_bit(WriteMostly, &rdev->flags))
507 if (!atomic_read(&rdev->nr_pending)) {
511 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
512 if (new_distance < current_distance) {
513 current_distance = new_distance;
516 } while (disk != conf->last_used);
522 rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
525 atomic_inc(&rdev->nr_pending);
526 if (!test_bit(In_sync, &rdev->flags)) {
527 /* cannot risk returning a device that failed
528 * before we inc'ed nr_pending
530 rdev_dec_pending(rdev, conf->mddev);
533 conf->next_seq_sect = this_sector + sectors;
534 conf->last_used = new_disk;
541 static void unplug_slaves(mddev_t *mddev)
543 conf_t *conf = mddev_to_conf(mddev);
547 for (i=0; i<mddev->raid_disks; i++) {
548 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
549 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
550 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
552 atomic_inc(&rdev->nr_pending);
555 if (r_queue->unplug_fn)
556 r_queue->unplug_fn(r_queue);
558 rdev_dec_pending(rdev, mddev);
565 static void raid1_unplug(request_queue_t *q)
567 mddev_t *mddev = q->queuedata;
569 unplug_slaves(mddev);
570 md_wakeup_thread(mddev->thread);
573 static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
574 sector_t *error_sector)
576 mddev_t *mddev = q->queuedata;
577 conf_t *conf = mddev_to_conf(mddev);
581 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
582 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
583 if (rdev && !test_bit(Faulty, &rdev->flags)) {
584 struct block_device *bdev = rdev->bdev;
585 request_queue_t *r_queue = bdev_get_queue(bdev);
587 if (!r_queue->issue_flush_fn)
590 atomic_inc(&rdev->nr_pending);
592 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
594 rdev_dec_pending(rdev, mddev);
604 * Sometimes we need to suspend IO while we do something else,
605 * either some resync/recovery, or reconfigure the array.
606 * To do this we raise a 'barrier'.
607 * The 'barrier' is a counter that can be raised multiple times
608 * to count how many activities are happening which preclude
610 * We can only raise the barrier if there is no pending IO.
611 * i.e. if nr_pending == 0.
612 * We choose only to raise the barrier if no-one is waiting for the
613 * barrier to go down. This means that as soon as an IO request
614 * is ready, no other operations which require a barrier will start
615 * until the IO request has had a chance.
617 * So: regular IO calls 'wait_barrier'. When that returns there
618 * is no backgroup IO happening, It must arrange to call
619 * allow_barrier when it has finished its IO.
620 * backgroup IO calls must call raise_barrier. Once that returns
621 * there is no normal IO happeing. It must arrange to call
622 * lower_barrier when the particular background IO completes.
624 #define RESYNC_DEPTH 32
626 static void raise_barrier(conf_t *conf)
628 spin_lock_irq(&conf->resync_lock);
630 /* Wait until no block IO is waiting */
631 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
633 raid1_unplug(conf->mddev->queue));
635 /* block any new IO from starting */
638 /* No wait for all pending IO to complete */
639 wait_event_lock_irq(conf->wait_barrier,
640 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
642 raid1_unplug(conf->mddev->queue));
644 spin_unlock_irq(&conf->resync_lock);
647 static void lower_barrier(conf_t *conf)
650 spin_lock_irqsave(&conf->resync_lock, flags);
652 spin_unlock_irqrestore(&conf->resync_lock, flags);
653 wake_up(&conf->wait_barrier);
656 static void wait_barrier(conf_t *conf)
658 spin_lock_irq(&conf->resync_lock);
661 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
663 raid1_unplug(conf->mddev->queue));
667 spin_unlock_irq(&conf->resync_lock);
670 static void allow_barrier(conf_t *conf)
673 spin_lock_irqsave(&conf->resync_lock, flags);
675 spin_unlock_irqrestore(&conf->resync_lock, flags);
676 wake_up(&conf->wait_barrier);
679 static void freeze_array(conf_t *conf)
681 /* stop syncio and normal IO and wait for everything to
683 * We increment barrier and nr_waiting, and then
684 * wait until barrier+nr_pending match nr_queued+2
686 spin_lock_irq(&conf->resync_lock);
689 wait_event_lock_irq(conf->wait_barrier,
690 conf->barrier+conf->nr_pending == conf->nr_queued+2,
692 raid1_unplug(conf->mddev->queue));
693 spin_unlock_irq(&conf->resync_lock);
695 static void unfreeze_array(conf_t *conf)
697 /* reverse the effect of the freeze */
698 spin_lock_irq(&conf->resync_lock);
701 wake_up(&conf->wait_barrier);
702 spin_unlock_irq(&conf->resync_lock);
706 /* duplicate the data pages for behind I/O */
707 static struct page **alloc_behind_pages(struct bio *bio)
710 struct bio_vec *bvec;
711 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
713 if (unlikely(!pages))
716 bio_for_each_segment(bvec, bio, i) {
717 pages[i] = alloc_page(GFP_NOIO);
718 if (unlikely(!pages[i]))
720 memcpy(kmap(pages[i]) + bvec->bv_offset,
721 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
723 kunmap(bvec->bv_page);
730 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
733 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
737 static int make_request(request_queue_t *q, struct bio * bio)
739 mddev_t *mddev = q->queuedata;
740 conf_t *conf = mddev_to_conf(mddev);
741 mirror_info_t *mirror;
743 struct bio *read_bio;
744 int i, targets = 0, disks;
746 struct bitmap *bitmap = mddev->bitmap;
749 struct page **behind_pages = NULL;
750 const int rw = bio_data_dir(bio);
753 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
754 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
759 * Register the new request and wait if the reconstruction
760 * thread has put up a bar for new requests.
761 * Continue immediately if no resync is active currently.
763 md_write_start(mddev, bio); /* wait on superblock update early */
767 disk_stat_inc(mddev->gendisk, ios[rw]);
768 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
771 * make_request() can abort the operation when READA is being
772 * used and no empty request is available.
775 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
777 r1_bio->master_bio = bio;
778 r1_bio->sectors = bio->bi_size >> 9;
780 r1_bio->mddev = mddev;
781 r1_bio->sector = bio->bi_sector;
785 * read balancing logic:
787 int rdisk = read_balance(conf, r1_bio);
790 /* couldn't find anywhere to read from */
791 raid_end_bio_io(r1_bio);
794 mirror = conf->mirrors + rdisk;
796 r1_bio->read_disk = rdisk;
798 read_bio = bio_clone(bio, GFP_NOIO);
800 r1_bio->bios[rdisk] = read_bio;
802 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
803 read_bio->bi_bdev = mirror->rdev->bdev;
804 read_bio->bi_end_io = raid1_end_read_request;
805 read_bio->bi_rw = READ;
806 read_bio->bi_private = r1_bio;
808 generic_make_request(read_bio);
815 /* first select target devices under spinlock and
816 * inc refcount on their rdev. Record them by setting
819 disks = conf->raid_disks;
821 { static int first=1;
822 if (first) printk("First Write sector %llu disks %d\n",
823 (unsigned long long)r1_bio->sector, disks);
828 for (i = 0; i < disks; i++) {
829 if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
830 !test_bit(Faulty, &rdev->flags)) {
831 atomic_inc(&rdev->nr_pending);
832 if (test_bit(Faulty, &rdev->flags)) {
833 rdev_dec_pending(rdev, mddev);
834 r1_bio->bios[i] = NULL;
836 r1_bio->bios[i] = bio;
839 r1_bio->bios[i] = NULL;
843 BUG_ON(targets == 0); /* we never fail the last device */
845 if (targets < conf->raid_disks) {
846 /* array is degraded, we will not clear the bitmap
847 * on I/O completion (see raid1_end_write_request) */
848 set_bit(R1BIO_Degraded, &r1_bio->state);
851 /* do behind I/O ? */
853 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
854 (behind_pages = alloc_behind_pages(bio)) != NULL)
855 set_bit(R1BIO_BehindIO, &r1_bio->state);
857 atomic_set(&r1_bio->remaining, 0);
858 atomic_set(&r1_bio->behind_remaining, 0);
860 do_barriers = bio->bi_rw & BIO_RW_BARRIER;
862 set_bit(R1BIO_Barrier, &r1_bio->state);
865 for (i = 0; i < disks; i++) {
867 if (!r1_bio->bios[i])
870 mbio = bio_clone(bio, GFP_NOIO);
871 r1_bio->bios[i] = mbio;
873 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
874 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
875 mbio->bi_end_io = raid1_end_write_request;
876 mbio->bi_rw = WRITE | do_barriers;
877 mbio->bi_private = r1_bio;
880 struct bio_vec *bvec;
883 /* Yes, I really want the '__' version so that
884 * we clear any unused pointer in the io_vec, rather
885 * than leave them unchanged. This is important
886 * because when we come to free the pages, we won't
887 * know the originial bi_idx, so we just free
890 __bio_for_each_segment(bvec, mbio, j, 0)
891 bvec->bv_page = behind_pages[j];
892 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
893 atomic_inc(&r1_bio->behind_remaining);
896 atomic_inc(&r1_bio->remaining);
898 bio_list_add(&bl, mbio);
900 kfree(behind_pages); /* the behind pages are attached to the bios now */
902 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
903 test_bit(R1BIO_BehindIO, &r1_bio->state));
904 spin_lock_irqsave(&conf->device_lock, flags);
905 bio_list_merge(&conf->pending_bio_list, &bl);
908 blk_plug_device(mddev->queue);
909 spin_unlock_irqrestore(&conf->device_lock, flags);
912 while ((bio = bio_list_pop(&bl)) != NULL)
913 generic_make_request(bio);
919 static void status(struct seq_file *seq, mddev_t *mddev)
921 conf_t *conf = mddev_to_conf(mddev);
924 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
925 conf->working_disks);
926 for (i = 0; i < conf->raid_disks; i++)
927 seq_printf(seq, "%s",
928 conf->mirrors[i].rdev &&
929 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
930 seq_printf(seq, "]");
934 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
936 char b[BDEVNAME_SIZE];
937 conf_t *conf = mddev_to_conf(mddev);
940 * If it is not operational, then we have already marked it as dead
941 * else if it is the last working disks, ignore the error, let the
942 * next level up know.
943 * else mark the drive as failed
945 if (test_bit(In_sync, &rdev->flags)
946 && conf->working_disks == 1)
948 * Don't fail the drive, act as though we were just a
949 * normal single drive
952 if (test_bit(In_sync, &rdev->flags)) {
954 conf->working_disks--;
956 * if recovery is running, make sure it aborts.
958 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
960 clear_bit(In_sync, &rdev->flags);
961 set_bit(Faulty, &rdev->flags);
963 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
964 " Operation continuing on %d devices\n",
965 bdevname(rdev->bdev,b), conf->working_disks);
968 static void print_conf(conf_t *conf)
973 printk("RAID1 conf printout:\n");
978 printk(" --- wd:%d rd:%d\n", conf->working_disks,
981 for (i = 0; i < conf->raid_disks; i++) {
982 char b[BDEVNAME_SIZE];
983 tmp = conf->mirrors + i;
985 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
986 i, !test_bit(In_sync, &tmp->rdev->flags), !test_bit(Faulty, &tmp->rdev->flags),
987 bdevname(tmp->rdev->bdev,b));
991 static void close_sync(conf_t *conf)
996 mempool_destroy(conf->r1buf_pool);
997 conf->r1buf_pool = NULL;
1000 static int raid1_spare_active(mddev_t *mddev)
1003 conf_t *conf = mddev->private;
1007 * Find all failed disks within the RAID1 configuration
1008 * and mark them readable
1010 for (i = 0; i < conf->raid_disks; i++) {
1011 tmp = conf->mirrors + i;
1013 && !test_bit(Faulty, &tmp->rdev->flags)
1014 && !test_bit(In_sync, &tmp->rdev->flags)) {
1015 conf->working_disks++;
1017 set_bit(In_sync, &tmp->rdev->flags);
1026 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1028 conf_t *conf = mddev->private;
1033 for (mirror=0; mirror < mddev->raid_disks; mirror++)
1034 if ( !(p=conf->mirrors+mirror)->rdev) {
1036 blk_queue_stack_limits(mddev->queue,
1037 rdev->bdev->bd_disk->queue);
1038 /* as we don't honour merge_bvec_fn, we must never risk
1039 * violating it, so limit ->max_sector to one PAGE, as
1040 * a one page request is never in violation.
1042 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1043 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1044 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1046 p->head_position = 0;
1047 rdev->raid_disk = mirror;
1049 /* As all devices are equivalent, we don't need a full recovery
1050 * if this was recently any drive of the array
1052 if (rdev->saved_raid_disk < 0)
1054 rcu_assign_pointer(p->rdev, rdev);
1062 static int raid1_remove_disk(mddev_t *mddev, int number)
1064 conf_t *conf = mddev->private;
1067 mirror_info_t *p = conf->mirrors+ number;
1072 if (test_bit(In_sync, &rdev->flags) ||
1073 atomic_read(&rdev->nr_pending)) {
1079 if (atomic_read(&rdev->nr_pending)) {
1080 /* lost the race, try later */
1092 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
1094 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1100 for (i=r1_bio->mddev->raid_disks; i--; )
1101 if (r1_bio->bios[i] == bio)
1104 update_head_pos(i, r1_bio);
1106 * we have read a block, now it needs to be re-written,
1107 * or re-read if the read failed.
1108 * We don't do much here, just schedule handling by raid1d
1110 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1111 set_bit(R1BIO_Uptodate, &r1_bio->state);
1113 if (atomic_dec_and_test(&r1_bio->remaining))
1114 reschedule_retry(r1_bio);
1118 static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
1120 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1121 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1122 mddev_t *mddev = r1_bio->mddev;
1123 conf_t *conf = mddev_to_conf(mddev);
1130 for (i = 0; i < conf->raid_disks; i++)
1131 if (r1_bio->bios[i] == bio) {
1136 md_error(mddev, conf->mirrors[mirror].rdev);
1138 update_head_pos(mirror, r1_bio);
1140 if (atomic_dec_and_test(&r1_bio->remaining)) {
1141 md_done_sync(mddev, r1_bio->sectors, uptodate);
1147 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1149 conf_t *conf = mddev_to_conf(mddev);
1151 int disks = conf->raid_disks;
1152 struct bio *bio, *wbio;
1154 bio = r1_bio->bios[r1_bio->read_disk];
1157 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1158 /* We have read all readable devices. If we haven't
1159 * got the block, then there is no hope left.
1160 * If we have, then we want to do a comparison
1161 * and skip the write if everything is the same.
1162 * If any blocks failed to read, then we need to
1163 * attempt an over-write
1166 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1167 for (i=0; i<mddev->raid_disks; i++)
1168 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1169 md_error(mddev, conf->mirrors[i].rdev);
1171 md_done_sync(mddev, r1_bio->sectors, 1);
1175 for (primary=0; primary<mddev->raid_disks; primary++)
1176 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1177 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1178 r1_bio->bios[primary]->bi_end_io = NULL;
1179 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1182 r1_bio->read_disk = primary;
1183 for (i=0; i<mddev->raid_disks; i++)
1184 if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
1185 test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
1187 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1188 struct bio *pbio = r1_bio->bios[primary];
1189 struct bio *sbio = r1_bio->bios[i];
1190 for (j = vcnt; j-- ; )
1191 if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
1192 page_address(sbio->bi_io_vec[j].bv_page),
1196 mddev->resync_mismatches += r1_bio->sectors;
1197 if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
1198 sbio->bi_end_io = NULL;
1199 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1201 /* fixup the bio for reuse */
1202 sbio->bi_vcnt = vcnt;
1203 sbio->bi_size = r1_bio->sectors << 9;
1205 sbio->bi_phys_segments = 0;
1206 sbio->bi_hw_segments = 0;
1207 sbio->bi_hw_front_size = 0;
1208 sbio->bi_hw_back_size = 0;
1209 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1210 sbio->bi_flags |= 1 << BIO_UPTODATE;
1211 sbio->bi_next = NULL;
1212 sbio->bi_sector = r1_bio->sector +
1213 conf->mirrors[i].rdev->data_offset;
1214 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1218 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1219 /* ouch - failed to read all of that.
1220 * Try some synchronous reads of other devices to get
1221 * good data, much like with normal read errors. Only
1222 * read into the pages we already have so they we don't
1223 * need to re-issue the read request.
1224 * We don't need to freeze the array, because being in an
1225 * active sync request, there is no normal IO, and
1226 * no overlapping syncs.
1228 sector_t sect = r1_bio->sector;
1229 int sectors = r1_bio->sectors;
1234 int d = r1_bio->read_disk;
1238 if (s > (PAGE_SIZE>>9))
1241 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1242 rdev = conf->mirrors[d].rdev;
1243 if (sync_page_io(rdev->bdev,
1244 sect + rdev->data_offset,
1246 bio->bi_io_vec[idx].bv_page,
1253 if (d == conf->raid_disks)
1255 } while (!success && d != r1_bio->read_disk);
1259 /* write it back and re-read */
1260 set_bit(R1BIO_Uptodate, &r1_bio->state);
1261 while (d != r1_bio->read_disk) {
1263 d = conf->raid_disks;
1265 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1267 rdev = conf->mirrors[d].rdev;
1268 if (sync_page_io(rdev->bdev,
1269 sect + rdev->data_offset,
1271 bio->bi_io_vec[idx].bv_page,
1273 md_error(mddev, rdev);
1276 while (d != r1_bio->read_disk) {
1278 d = conf->raid_disks;
1280 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1282 rdev = conf->mirrors[d].rdev;
1283 if (sync_page_io(rdev->bdev,
1284 sect + rdev->data_offset,
1286 bio->bi_io_vec[idx].bv_page,
1288 md_error(mddev, rdev);
1291 char b[BDEVNAME_SIZE];
1292 /* Cannot read from anywhere, array is toast */
1293 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1294 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1295 " for block %llu\n",
1296 bdevname(bio->bi_bdev,b),
1297 (unsigned long long)r1_bio->sector);
1298 md_done_sync(mddev, r1_bio->sectors, 0);
1311 atomic_set(&r1_bio->remaining, 1);
1312 for (i = 0; i < disks ; i++) {
1313 wbio = r1_bio->bios[i];
1314 if (wbio->bi_end_io == NULL ||
1315 (wbio->bi_end_io == end_sync_read &&
1316 (i == r1_bio->read_disk ||
1317 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1320 wbio->bi_rw = WRITE;
1321 wbio->bi_end_io = end_sync_write;
1322 atomic_inc(&r1_bio->remaining);
1323 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1325 generic_make_request(wbio);
1328 if (atomic_dec_and_test(&r1_bio->remaining)) {
1329 /* if we're here, all write(s) have completed, so clean up */
1330 md_done_sync(mddev, r1_bio->sectors, 1);
1336 * This is a kernel thread which:
1338 * 1. Retries failed read operations on working mirrors.
1339 * 2. Updates the raid superblock when problems encounter.
1340 * 3. Performs writes following reads for array syncronising.
1343 static void raid1d(mddev_t *mddev)
1347 unsigned long flags;
1348 conf_t *conf = mddev_to_conf(mddev);
1349 struct list_head *head = &conf->retry_list;
1353 md_check_recovery(mddev);
1356 char b[BDEVNAME_SIZE];
1357 spin_lock_irqsave(&conf->device_lock, flags);
1359 if (conf->pending_bio_list.head) {
1360 bio = bio_list_get(&conf->pending_bio_list);
1361 blk_remove_plug(mddev->queue);
1362 spin_unlock_irqrestore(&conf->device_lock, flags);
1363 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
1364 if (bitmap_unplug(mddev->bitmap) != 0)
1365 printk("%s: bitmap file write failed!\n", mdname(mddev));
1367 while (bio) { /* submit pending writes */
1368 struct bio *next = bio->bi_next;
1369 bio->bi_next = NULL;
1370 generic_make_request(bio);
1378 if (list_empty(head))
1380 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1381 list_del(head->prev);
1383 spin_unlock_irqrestore(&conf->device_lock, flags);
1385 mddev = r1_bio->mddev;
1386 conf = mddev_to_conf(mddev);
1387 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1388 sync_request_write(mddev, r1_bio);
1390 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1391 /* some requests in the r1bio were BIO_RW_BARRIER
1392 * requests which failed with -ENOTSUPP. Hohumm..
1393 * Better resubmit without the barrier.
1394 * We know which devices to resubmit for, because
1395 * all others have had their bios[] entry cleared.
1398 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1399 clear_bit(R1BIO_Barrier, &r1_bio->state);
1400 for (i=0; i < conf->raid_disks; i++)
1401 if (r1_bio->bios[i]) {
1402 struct bio_vec *bvec;
1405 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1406 /* copy pages from the failed bio, as
1407 * this might be a write-behind device */
1408 __bio_for_each_segment(bvec, bio, j, 0)
1409 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1410 bio_put(r1_bio->bios[i]);
1411 bio->bi_sector = r1_bio->sector +
1412 conf->mirrors[i].rdev->data_offset;
1413 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1414 bio->bi_end_io = raid1_end_write_request;
1416 bio->bi_private = r1_bio;
1417 r1_bio->bios[i] = bio;
1418 generic_make_request(bio);
1423 /* we got a read error. Maybe the drive is bad. Maybe just
1424 * the block and we can fix it.
1425 * We freeze all other IO, and try reading the block from
1426 * other devices. When we find one, we re-write
1427 * and check it that fixes the read error.
1428 * This is all done synchronously while the array is
1431 sector_t sect = r1_bio->sector;
1432 int sectors = r1_bio->sectors;
1434 if (mddev->ro == 0) while(sectors) {
1436 int d = r1_bio->read_disk;
1439 if (s > (PAGE_SIZE>>9))
1443 rdev = conf->mirrors[d].rdev;
1445 test_bit(In_sync, &rdev->flags) &&
1446 sync_page_io(rdev->bdev,
1447 sect + rdev->data_offset,
1449 conf->tmppage, READ))
1453 if (d == conf->raid_disks)
1456 } while (!success && d != r1_bio->read_disk);
1459 /* write it back and re-read */
1461 while (d != r1_bio->read_disk) {
1463 d = conf->raid_disks;
1465 rdev = conf->mirrors[d].rdev;
1467 test_bit(In_sync, &rdev->flags)) {
1468 if (sync_page_io(rdev->bdev,
1469 sect + rdev->data_offset,
1470 s<<9, conf->tmppage, WRITE) == 0)
1471 /* Well, this device is dead */
1472 md_error(mddev, rdev);
1476 while (d != r1_bio->read_disk) {
1478 d = conf->raid_disks;
1480 rdev = conf->mirrors[d].rdev;
1482 test_bit(In_sync, &rdev->flags)) {
1483 if (sync_page_io(rdev->bdev,
1484 sect + rdev->data_offset,
1485 s<<9, conf->tmppage, READ) == 0)
1486 /* Well, this device is dead */
1487 md_error(mddev, rdev);
1491 /* Cannot read from anywhere -- bye bye array */
1492 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1499 unfreeze_array(conf);
1501 bio = r1_bio->bios[r1_bio->read_disk];
1502 if ((disk=read_balance(conf, r1_bio)) == -1) {
1503 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1504 " read error for block %llu\n",
1505 bdevname(bio->bi_bdev,b),
1506 (unsigned long long)r1_bio->sector);
1507 raid_end_bio_io(r1_bio);
1509 r1_bio->bios[r1_bio->read_disk] =
1510 mddev->ro ? IO_BLOCKED : NULL;
1511 r1_bio->read_disk = disk;
1513 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1514 r1_bio->bios[r1_bio->read_disk] = bio;
1515 rdev = conf->mirrors[disk].rdev;
1516 if (printk_ratelimit())
1517 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1518 " another mirror\n",
1519 bdevname(rdev->bdev,b),
1520 (unsigned long long)r1_bio->sector);
1521 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1522 bio->bi_bdev = rdev->bdev;
1523 bio->bi_end_io = raid1_end_read_request;
1525 bio->bi_private = r1_bio;
1527 generic_make_request(bio);
1531 spin_unlock_irqrestore(&conf->device_lock, flags);
1533 unplug_slaves(mddev);
1537 static int init_resync(conf_t *conf)
1541 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1542 if (conf->r1buf_pool)
1544 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1546 if (!conf->r1buf_pool)
1548 conf->next_resync = 0;
1553 * perform a "sync" on one "block"
1555 * We need to make sure that no normal I/O request - particularly write
1556 * requests - conflict with active sync requests.
1558 * This is achieved by tracking pending requests and a 'barrier' concept
1559 * that can be installed to exclude normal IO requests.
1562 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1564 conf_t *conf = mddev_to_conf(mddev);
1567 sector_t max_sector, nr_sectors;
1571 int write_targets = 0, read_targets = 0;
1573 int still_degraded = 0;
1575 if (!conf->r1buf_pool)
1578 printk("sync start - bitmap %p\n", mddev->bitmap);
1580 if (init_resync(conf))
1584 max_sector = mddev->size << 1;
1585 if (sector_nr >= max_sector) {
1586 /* If we aborted, we need to abort the
1587 * sync on the 'current' bitmap chunk (there will
1588 * only be one in raid1 resync.
1589 * We can find the current addess in mddev->curr_resync
1591 if (mddev->curr_resync < max_sector) /* aborted */
1592 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1594 else /* completed sync */
1597 bitmap_close_sync(mddev->bitmap);
1602 /* before building a request, check if we can skip these blocks..
1603 * This call the bitmap_start_sync doesn't actually record anything
1605 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1606 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1607 /* We can skip this block, and probably several more */
1612 * If there is non-resync activity waiting for a turn,
1613 * and resync is going fast enough,
1614 * then let it though before starting on this new sync request.
1616 if (!go_faster && conf->nr_waiting)
1617 msleep_interruptible(1000);
1619 raise_barrier(conf);
1621 conf->next_resync = sector_nr;
1623 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1626 * If we get a correctably read error during resync or recovery,
1627 * we might want to read from a different device. So we
1628 * flag all drives that could conceivably be read from for READ,
1629 * and any others (which will be non-In_sync devices) for WRITE.
1630 * If a read fails, we try reading from something else for which READ
1634 r1_bio->mddev = mddev;
1635 r1_bio->sector = sector_nr;
1637 set_bit(R1BIO_IsSync, &r1_bio->state);
1639 for (i=0; i < conf->raid_disks; i++) {
1641 bio = r1_bio->bios[i];
1643 /* take from bio_init */
1644 bio->bi_next = NULL;
1645 bio->bi_flags |= 1 << BIO_UPTODATE;
1649 bio->bi_phys_segments = 0;
1650 bio->bi_hw_segments = 0;
1652 bio->bi_end_io = NULL;
1653 bio->bi_private = NULL;
1655 rdev = rcu_dereference(conf->mirrors[i].rdev);
1657 test_bit(Faulty, &rdev->flags)) {
1660 } else if (!test_bit(In_sync, &rdev->flags)) {
1662 bio->bi_end_io = end_sync_write;
1665 /* may need to read from here */
1667 bio->bi_end_io = end_sync_read;
1668 if (test_bit(WriteMostly, &rdev->flags)) {
1677 atomic_inc(&rdev->nr_pending);
1678 bio->bi_sector = sector_nr + rdev->data_offset;
1679 bio->bi_bdev = rdev->bdev;
1680 bio->bi_private = r1_bio;
1685 r1_bio->read_disk = disk;
1687 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1688 /* extra read targets are also write targets */
1689 write_targets += read_targets-1;
1691 if (write_targets == 0 || read_targets == 0) {
1692 /* There is nowhere to write, so all non-sync
1693 * drives must be failed - so we are finished
1695 sector_t rv = max_sector - sector_nr;
1705 int len = PAGE_SIZE;
1706 if (sector_nr + (len>>9) > max_sector)
1707 len = (max_sector - sector_nr) << 9;
1710 if (sync_blocks == 0) {
1711 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1712 &sync_blocks, still_degraded) &&
1714 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1716 if (sync_blocks < (PAGE_SIZE>>9))
1718 if (len > (sync_blocks<<9))
1719 len = sync_blocks<<9;
1722 for (i=0 ; i < conf->raid_disks; i++) {
1723 bio = r1_bio->bios[i];
1724 if (bio->bi_end_io) {
1725 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1726 if (bio_add_page(bio, page, len, 0) == 0) {
1728 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1731 bio = r1_bio->bios[i];
1732 if (bio->bi_end_io==NULL)
1734 /* remove last page from this bio */
1736 bio->bi_size -= len;
1737 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1743 nr_sectors += len>>9;
1744 sector_nr += len>>9;
1745 sync_blocks -= (len>>9);
1746 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1748 r1_bio->sectors = nr_sectors;
1750 /* For a user-requested sync, we read all readable devices and do a
1753 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1754 atomic_set(&r1_bio->remaining, read_targets);
1755 for (i=0; i<conf->raid_disks; i++) {
1756 bio = r1_bio->bios[i];
1757 if (bio->bi_end_io == end_sync_read) {
1758 md_sync_acct(conf->mirrors[i].rdev->bdev, nr_sectors);
1759 generic_make_request(bio);
1763 atomic_set(&r1_bio->remaining, 1);
1764 bio = r1_bio->bios[r1_bio->read_disk];
1765 md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev,
1767 generic_make_request(bio);
1774 static int run(mddev_t *mddev)
1778 mirror_info_t *disk;
1780 struct list_head *tmp;
1782 if (mddev->level != 1) {
1783 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1784 mdname(mddev), mddev->level);
1788 * copy the already verified devices into our private RAID1
1789 * bookkeeping area. [whatever we allocate in run(),
1790 * should be freed in stop()]
1792 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1793 mddev->private = conf;
1797 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1802 conf->tmppage = alloc_page(GFP_KERNEL);
1806 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1807 if (!conf->poolinfo)
1809 conf->poolinfo->mddev = mddev;
1810 conf->poolinfo->raid_disks = mddev->raid_disks;
1811 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1814 if (!conf->r1bio_pool)
1817 ITERATE_RDEV(mddev, rdev, tmp) {
1818 disk_idx = rdev->raid_disk;
1819 if (disk_idx >= mddev->raid_disks
1822 disk = conf->mirrors + disk_idx;
1826 blk_queue_stack_limits(mddev->queue,
1827 rdev->bdev->bd_disk->queue);
1828 /* as we don't honour merge_bvec_fn, we must never risk
1829 * violating it, so limit ->max_sector to one PAGE, as
1830 * a one page request is never in violation.
1832 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1833 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1834 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1836 disk->head_position = 0;
1837 if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags))
1838 conf->working_disks++;
1840 conf->raid_disks = mddev->raid_disks;
1841 conf->mddev = mddev;
1842 spin_lock_init(&conf->device_lock);
1843 INIT_LIST_HEAD(&conf->retry_list);
1844 if (conf->working_disks == 1)
1845 mddev->recovery_cp = MaxSector;
1847 spin_lock_init(&conf->resync_lock);
1848 init_waitqueue_head(&conf->wait_barrier);
1850 bio_list_init(&conf->pending_bio_list);
1851 bio_list_init(&conf->flushing_bio_list);
1853 if (!conf->working_disks) {
1854 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
1859 mddev->degraded = 0;
1860 for (i = 0; i < conf->raid_disks; i++) {
1862 disk = conf->mirrors + i;
1865 disk->head_position = 0;
1871 * find the first working one and use it as a starting point
1872 * to read balancing.
1874 for (j = 0; j < conf->raid_disks &&
1875 (!conf->mirrors[j].rdev ||
1876 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
1878 conf->last_used = j;
1881 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
1882 if (!mddev->thread) {
1884 "raid1: couldn't allocate thread for %s\n",
1890 "raid1: raid set %s active with %d out of %d mirrors\n",
1891 mdname(mddev), mddev->raid_disks - mddev->degraded,
1894 * Ok, everything is just fine now
1896 mddev->array_size = mddev->size;
1898 mddev->queue->unplug_fn = raid1_unplug;
1899 mddev->queue->issue_flush_fn = raid1_issue_flush;
1904 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
1909 if (conf->r1bio_pool)
1910 mempool_destroy(conf->r1bio_pool);
1911 kfree(conf->mirrors);
1912 safe_put_page(conf->tmppage);
1913 kfree(conf->poolinfo);
1915 mddev->private = NULL;
1921 static int stop(mddev_t *mddev)
1923 conf_t *conf = mddev_to_conf(mddev);
1924 struct bitmap *bitmap = mddev->bitmap;
1925 int behind_wait = 0;
1927 /* wait for behind writes to complete */
1928 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1930 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
1931 set_current_state(TASK_UNINTERRUPTIBLE);
1932 schedule_timeout(HZ); /* wait a second */
1933 /* need to kick something here to make sure I/O goes? */
1936 md_unregister_thread(mddev->thread);
1937 mddev->thread = NULL;
1938 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
1939 if (conf->r1bio_pool)
1940 mempool_destroy(conf->r1bio_pool);
1941 kfree(conf->mirrors);
1942 kfree(conf->poolinfo);
1944 mddev->private = NULL;
1948 static int raid1_resize(mddev_t *mddev, sector_t sectors)
1950 /* no resync is happening, and there is enough space
1951 * on all devices, so we can resize.
1952 * We need to make sure resync covers any new space.
1953 * If the array is shrinking we should possibly wait until
1954 * any io in the removed space completes, but it hardly seems
1957 mddev->array_size = sectors>>1;
1958 set_capacity(mddev->gendisk, mddev->array_size << 1);
1960 if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
1961 mddev->recovery_cp = mddev->size << 1;
1962 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1964 mddev->size = mddev->array_size;
1965 mddev->resync_max_sectors = sectors;
1969 static int raid1_reshape(mddev_t *mddev, int raid_disks)
1972 * 1/ resize the r1bio_pool
1973 * 2/ resize conf->mirrors
1975 * We allocate a new r1bio_pool if we can.
1976 * Then raise a device barrier and wait until all IO stops.
1977 * Then resize conf->mirrors and swap in the new r1bio pool.
1979 * At the same time, we "pack" the devices so that all the missing
1980 * devices have the higher raid_disk numbers.
1982 mempool_t *newpool, *oldpool;
1983 struct pool_info *newpoolinfo;
1984 mirror_info_t *newmirrors;
1985 conf_t *conf = mddev_to_conf(mddev);
1990 if (raid_disks < conf->raid_disks) {
1992 for (d= 0; d < conf->raid_disks; d++)
1993 if (conf->mirrors[d].rdev)
1995 if (cnt > raid_disks)
1999 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2002 newpoolinfo->mddev = mddev;
2003 newpoolinfo->raid_disks = raid_disks;
2005 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2006 r1bio_pool_free, newpoolinfo);
2011 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2014 mempool_destroy(newpool);
2018 raise_barrier(conf);
2020 /* ok, everything is stopped */
2021 oldpool = conf->r1bio_pool;
2022 conf->r1bio_pool = newpool;
2024 for (d=d2=0; d < conf->raid_disks; d++)
2025 if (conf->mirrors[d].rdev) {
2026 conf->mirrors[d].rdev->raid_disk = d2;
2027 newmirrors[d2++].rdev = conf->mirrors[d].rdev;
2029 kfree(conf->mirrors);
2030 conf->mirrors = newmirrors;
2031 kfree(conf->poolinfo);
2032 conf->poolinfo = newpoolinfo;
2034 mddev->degraded += (raid_disks - conf->raid_disks);
2035 conf->raid_disks = mddev->raid_disks = raid_disks;
2037 conf->last_used = 0; /* just make sure it is in-range */
2038 lower_barrier(conf);
2040 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2041 md_wakeup_thread(mddev->thread);
2043 mempool_destroy(oldpool);
2047 static void raid1_quiesce(mddev_t *mddev, int state)
2049 conf_t *conf = mddev_to_conf(mddev);
2053 raise_barrier(conf);
2056 lower_barrier(conf);
2062 static struct mdk_personality raid1_personality =
2066 .owner = THIS_MODULE,
2067 .make_request = make_request,
2071 .error_handler = error,
2072 .hot_add_disk = raid1_add_disk,
2073 .hot_remove_disk= raid1_remove_disk,
2074 .spare_active = raid1_spare_active,
2075 .sync_request = sync_request,
2076 .resize = raid1_resize,
2077 .reshape = raid1_reshape,
2078 .quiesce = raid1_quiesce,
2081 static int __init raid_init(void)
2083 return register_md_personality(&raid1_personality);
2086 static void raid_exit(void)
2088 unregister_md_personality(&raid1_personality);
2091 module_init(raid_init);
2092 module_exit(raid_exit);
2093 MODULE_LICENSE("GPL");
2094 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2095 MODULE_ALIAS("md-raid1");
2096 MODULE_ALIAS("md-level-1");