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 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 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);
309 struct bio *to_put = NULL;
314 for (mirror = 0; mirror < conf->raid_disks; mirror++)
315 if (r1_bio->bios[mirror] == bio)
318 if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
319 set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
320 set_bit(R1BIO_BarrierRetry, &r1_bio->state);
321 r1_bio->mddev->barriers_work = 0;
322 /* Don't rdev_dec_pending in this branch - keep it for the retry */
325 * this branch is our 'one mirror IO has finished' event handler:
327 r1_bio->bios[mirror] = NULL;
330 md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
331 /* an I/O failed, we can't clear the bitmap */
332 set_bit(R1BIO_Degraded, &r1_bio->state);
335 * Set R1BIO_Uptodate in our master bio, so that
336 * we will return a good error code for to the higher
337 * levels even if IO on some other mirrored buffer fails.
339 * The 'master' represents the composite IO operation to
340 * user-side. So if something waits for IO, then it will
341 * wait for the 'master' bio.
343 set_bit(R1BIO_Uptodate, &r1_bio->state);
345 update_head_pos(mirror, r1_bio);
348 if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
349 atomic_dec(&r1_bio->behind_remaining);
351 /* In behind mode, we ACK the master bio once the I/O has safely
352 * reached all non-writemostly disks. Setting the Returned bit
353 * ensures that this gets done only once -- we don't ever want to
354 * return -EIO here, instead we'll wait */
356 if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
357 test_bit(R1BIO_Uptodate, &r1_bio->state)) {
358 /* Maybe we can return now */
359 if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
360 struct bio *mbio = r1_bio->master_bio;
361 PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
362 (unsigned long long) mbio->bi_sector,
363 (unsigned long long) mbio->bi_sector +
364 (mbio->bi_size >> 9) - 1);
365 bio_endio(mbio, mbio->bi_size, 0);
369 rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
373 * Let's see if all mirrored write operations have finished
376 if (atomic_dec_and_test(&r1_bio->remaining)) {
377 if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
378 reschedule_retry(r1_bio);
381 /* it really is the end of this request */
382 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
383 /* free extra copy of the data pages */
384 int i = bio->bi_vcnt;
386 safe_put_page(bio->bi_io_vec[i].bv_page);
388 /* clear the bitmap if all writes complete successfully */
389 bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
391 !test_bit(R1BIO_Degraded, &r1_bio->state),
393 md_write_end(r1_bio->mddev);
394 raid_end_bio_io(r1_bio);
405 * This routine returns the disk from which the requested read should
406 * be done. There is a per-array 'next expected sequential IO' sector
407 * number - if this matches on the next IO then we use the last disk.
408 * There is also a per-disk 'last know head position' sector that is
409 * maintained from IRQ contexts, both the normal and the resync IO
410 * completion handlers update this position correctly. If there is no
411 * perfect sequential match then we pick the disk whose head is closest.
413 * If there are 2 mirrors in the same 2 devices, performance degrades
414 * because position is mirror, not device based.
416 * The rdev for the device selected will have nr_pending incremented.
418 static int read_balance(conf_t *conf, r1bio_t *r1_bio)
420 const unsigned long this_sector = r1_bio->sector;
421 int new_disk = conf->last_used, disk = new_disk;
423 const int sectors = r1_bio->sectors;
424 sector_t new_distance, current_distance;
429 * Check if we can balance. We can balance on the whole
430 * device if no resync is going on, or below the resync window.
431 * We take the first readable disk when above the resync window.
434 if (conf->mddev->recovery_cp < MaxSector &&
435 (this_sector + sectors >= conf->next_resync)) {
436 /* Choose the first operation device, for consistancy */
439 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
440 r1_bio->bios[new_disk] == IO_BLOCKED ||
441 !rdev || !test_bit(In_sync, &rdev->flags)
442 || test_bit(WriteMostly, &rdev->flags);
443 rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) {
445 if (rdev && test_bit(In_sync, &rdev->flags) &&
446 r1_bio->bios[new_disk] != IO_BLOCKED)
447 wonly_disk = new_disk;
449 if (new_disk == conf->raid_disks - 1) {
450 new_disk = wonly_disk;
458 /* make sure the disk is operational */
459 for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
460 r1_bio->bios[new_disk] == IO_BLOCKED ||
461 !rdev || !test_bit(In_sync, &rdev->flags) ||
462 test_bit(WriteMostly, &rdev->flags);
463 rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) {
465 if (rdev && test_bit(In_sync, &rdev->flags) &&
466 r1_bio->bios[new_disk] != IO_BLOCKED)
467 wonly_disk = new_disk;
470 new_disk = conf->raid_disks;
472 if (new_disk == disk) {
473 new_disk = wonly_disk;
482 /* now disk == new_disk == starting point for search */
485 * Don't change to another disk for sequential reads:
487 if (conf->next_seq_sect == this_sector)
489 if (this_sector == conf->mirrors[new_disk].head_position)
492 current_distance = abs(this_sector - conf->mirrors[disk].head_position);
494 /* Find the disk whose head is closest */
498 disk = conf->raid_disks;
501 rdev = rcu_dereference(conf->mirrors[disk].rdev);
503 if (!rdev || r1_bio->bios[disk] == IO_BLOCKED ||
504 !test_bit(In_sync, &rdev->flags) ||
505 test_bit(WriteMostly, &rdev->flags))
508 if (!atomic_read(&rdev->nr_pending)) {
512 new_distance = abs(this_sector - conf->mirrors[disk].head_position);
513 if (new_distance < current_distance) {
514 current_distance = new_distance;
517 } while (disk != conf->last_used);
523 rdev = rcu_dereference(conf->mirrors[new_disk].rdev);
526 atomic_inc(&rdev->nr_pending);
527 if (!test_bit(In_sync, &rdev->flags)) {
528 /* cannot risk returning a device that failed
529 * before we inc'ed nr_pending
531 rdev_dec_pending(rdev, conf->mddev);
534 conf->next_seq_sect = this_sector + sectors;
535 conf->last_used = new_disk;
542 static void unplug_slaves(mddev_t *mddev)
544 conf_t *conf = mddev_to_conf(mddev);
548 for (i=0; i<mddev->raid_disks; i++) {
549 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
550 if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
551 request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
553 atomic_inc(&rdev->nr_pending);
556 if (r_queue->unplug_fn)
557 r_queue->unplug_fn(r_queue);
559 rdev_dec_pending(rdev, mddev);
566 static void raid1_unplug(request_queue_t *q)
568 mddev_t *mddev = q->queuedata;
570 unplug_slaves(mddev);
571 md_wakeup_thread(mddev->thread);
574 static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
575 sector_t *error_sector)
577 mddev_t *mddev = q->queuedata;
578 conf_t *conf = mddev_to_conf(mddev);
582 for (i=0; i<mddev->raid_disks && ret == 0; i++) {
583 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
584 if (rdev && !test_bit(Faulty, &rdev->flags)) {
585 struct block_device *bdev = rdev->bdev;
586 request_queue_t *r_queue = bdev_get_queue(bdev);
588 if (!r_queue->issue_flush_fn)
591 atomic_inc(&rdev->nr_pending);
593 ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
595 rdev_dec_pending(rdev, mddev);
605 * Sometimes we need to suspend IO while we do something else,
606 * either some resync/recovery, or reconfigure the array.
607 * To do this we raise a 'barrier'.
608 * The 'barrier' is a counter that can be raised multiple times
609 * to count how many activities are happening which preclude
611 * We can only raise the barrier if there is no pending IO.
612 * i.e. if nr_pending == 0.
613 * We choose only to raise the barrier if no-one is waiting for the
614 * barrier to go down. This means that as soon as an IO request
615 * is ready, no other operations which require a barrier will start
616 * until the IO request has had a chance.
618 * So: regular IO calls 'wait_barrier'. When that returns there
619 * is no backgroup IO happening, It must arrange to call
620 * allow_barrier when it has finished its IO.
621 * backgroup IO calls must call raise_barrier. Once that returns
622 * there is no normal IO happeing. It must arrange to call
623 * lower_barrier when the particular background IO completes.
625 #define RESYNC_DEPTH 32
627 static void raise_barrier(conf_t *conf)
629 spin_lock_irq(&conf->resync_lock);
631 /* Wait until no block IO is waiting */
632 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
634 raid1_unplug(conf->mddev->queue));
636 /* block any new IO from starting */
639 /* No wait for all pending IO to complete */
640 wait_event_lock_irq(conf->wait_barrier,
641 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
643 raid1_unplug(conf->mddev->queue));
645 spin_unlock_irq(&conf->resync_lock);
648 static void lower_barrier(conf_t *conf)
651 spin_lock_irqsave(&conf->resync_lock, flags);
653 spin_unlock_irqrestore(&conf->resync_lock, flags);
654 wake_up(&conf->wait_barrier);
657 static void wait_barrier(conf_t *conf)
659 spin_lock_irq(&conf->resync_lock);
662 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
664 raid1_unplug(conf->mddev->queue));
668 spin_unlock_irq(&conf->resync_lock);
671 static void allow_barrier(conf_t *conf)
674 spin_lock_irqsave(&conf->resync_lock, flags);
676 spin_unlock_irqrestore(&conf->resync_lock, flags);
677 wake_up(&conf->wait_barrier);
680 static void freeze_array(conf_t *conf)
682 /* stop syncio and normal IO and wait for everything to
684 * We increment barrier and nr_waiting, and then
685 * wait until barrier+nr_pending match nr_queued+2
687 spin_lock_irq(&conf->resync_lock);
690 wait_event_lock_irq(conf->wait_barrier,
691 conf->barrier+conf->nr_pending == conf->nr_queued+2,
693 raid1_unplug(conf->mddev->queue));
694 spin_unlock_irq(&conf->resync_lock);
696 static void unfreeze_array(conf_t *conf)
698 /* reverse the effect of the freeze */
699 spin_lock_irq(&conf->resync_lock);
702 wake_up(&conf->wait_barrier);
703 spin_unlock_irq(&conf->resync_lock);
707 /* duplicate the data pages for behind I/O */
708 static struct page **alloc_behind_pages(struct bio *bio)
711 struct bio_vec *bvec;
712 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
714 if (unlikely(!pages))
717 bio_for_each_segment(bvec, bio, i) {
718 pages[i] = alloc_page(GFP_NOIO);
719 if (unlikely(!pages[i]))
721 memcpy(kmap(pages[i]) + bvec->bv_offset,
722 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
724 kunmap(bvec->bv_page);
731 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
734 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
738 static int make_request(request_queue_t *q, struct bio * bio)
740 mddev_t *mddev = q->queuedata;
741 conf_t *conf = mddev_to_conf(mddev);
742 mirror_info_t *mirror;
744 struct bio *read_bio;
745 int i, targets = 0, disks;
747 struct bitmap *bitmap = mddev->bitmap;
750 struct page **behind_pages = NULL;
751 const int rw = bio_data_dir(bio);
755 * Register the new request and wait if the reconstruction
756 * thread has put up a bar for new requests.
757 * Continue immediately if no resync is active currently.
758 * We test barriers_work *after* md_write_start as md_write_start
759 * may cause the first superblock write, and that will check out
763 md_write_start(mddev, bio); /* wait on superblock update early */
765 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
768 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
774 disk_stat_inc(mddev->gendisk, ios[rw]);
775 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
778 * make_request() can abort the operation when READA is being
779 * used and no empty request is available.
782 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
784 r1_bio->master_bio = bio;
785 r1_bio->sectors = bio->bi_size >> 9;
787 r1_bio->mddev = mddev;
788 r1_bio->sector = bio->bi_sector;
792 * read balancing logic:
794 int rdisk = read_balance(conf, r1_bio);
797 /* couldn't find anywhere to read from */
798 raid_end_bio_io(r1_bio);
801 mirror = conf->mirrors + rdisk;
803 r1_bio->read_disk = rdisk;
805 read_bio = bio_clone(bio, GFP_NOIO);
807 r1_bio->bios[rdisk] = read_bio;
809 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
810 read_bio->bi_bdev = mirror->rdev->bdev;
811 read_bio->bi_end_io = raid1_end_read_request;
812 read_bio->bi_rw = READ;
813 read_bio->bi_private = r1_bio;
815 generic_make_request(read_bio);
822 /* first select target devices under spinlock and
823 * inc refcount on their rdev. Record them by setting
826 disks = conf->raid_disks;
828 { static int first=1;
829 if (first) printk("First Write sector %llu disks %d\n",
830 (unsigned long long)r1_bio->sector, disks);
835 for (i = 0; i < disks; i++) {
836 if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
837 !test_bit(Faulty, &rdev->flags)) {
838 atomic_inc(&rdev->nr_pending);
839 if (test_bit(Faulty, &rdev->flags)) {
840 rdev_dec_pending(rdev, mddev);
841 r1_bio->bios[i] = NULL;
843 r1_bio->bios[i] = bio;
846 r1_bio->bios[i] = NULL;
850 BUG_ON(targets == 0); /* we never fail the last device */
852 if (targets < conf->raid_disks) {
853 /* array is degraded, we will not clear the bitmap
854 * on I/O completion (see raid1_end_write_request) */
855 set_bit(R1BIO_Degraded, &r1_bio->state);
858 /* do behind I/O ? */
860 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
861 (behind_pages = alloc_behind_pages(bio)) != NULL)
862 set_bit(R1BIO_BehindIO, &r1_bio->state);
864 atomic_set(&r1_bio->remaining, 0);
865 atomic_set(&r1_bio->behind_remaining, 0);
867 do_barriers = bio_barrier(bio);
869 set_bit(R1BIO_Barrier, &r1_bio->state);
872 for (i = 0; i < disks; i++) {
874 if (!r1_bio->bios[i])
877 mbio = bio_clone(bio, GFP_NOIO);
878 r1_bio->bios[i] = mbio;
880 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
881 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
882 mbio->bi_end_io = raid1_end_write_request;
883 mbio->bi_rw = WRITE | do_barriers;
884 mbio->bi_private = r1_bio;
887 struct bio_vec *bvec;
890 /* Yes, I really want the '__' version so that
891 * we clear any unused pointer in the io_vec, rather
892 * than leave them unchanged. This is important
893 * because when we come to free the pages, we won't
894 * know the originial bi_idx, so we just free
897 __bio_for_each_segment(bvec, mbio, j, 0)
898 bvec->bv_page = behind_pages[j];
899 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
900 atomic_inc(&r1_bio->behind_remaining);
903 atomic_inc(&r1_bio->remaining);
905 bio_list_add(&bl, mbio);
907 kfree(behind_pages); /* the behind pages are attached to the bios now */
909 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
910 test_bit(R1BIO_BehindIO, &r1_bio->state));
911 spin_lock_irqsave(&conf->device_lock, flags);
912 bio_list_merge(&conf->pending_bio_list, &bl);
915 blk_plug_device(mddev->queue);
916 spin_unlock_irqrestore(&conf->device_lock, flags);
919 while ((bio = bio_list_pop(&bl)) != NULL)
920 generic_make_request(bio);
926 static void status(struct seq_file *seq, mddev_t *mddev)
928 conf_t *conf = mddev_to_conf(mddev);
931 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
932 conf->working_disks);
933 for (i = 0; i < conf->raid_disks; i++)
934 seq_printf(seq, "%s",
935 conf->mirrors[i].rdev &&
936 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
937 seq_printf(seq, "]");
941 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
943 char b[BDEVNAME_SIZE];
944 conf_t *conf = mddev_to_conf(mddev);
947 * If it is not operational, then we have already marked it as dead
948 * else if it is the last working disks, ignore the error, let the
949 * next level up know.
950 * else mark the drive as failed
952 if (test_bit(In_sync, &rdev->flags)
953 && conf->working_disks == 1)
955 * Don't fail the drive, act as though we were just a
956 * normal single drive
959 if (test_bit(In_sync, &rdev->flags)) {
961 conf->working_disks--;
963 * if recovery is running, make sure it aborts.
965 set_bit(MD_RECOVERY_ERR, &mddev->recovery);
967 clear_bit(In_sync, &rdev->flags);
968 set_bit(Faulty, &rdev->flags);
970 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
971 " Operation continuing on %d devices\n",
972 bdevname(rdev->bdev,b), conf->working_disks);
975 static void print_conf(conf_t *conf)
980 printk("RAID1 conf printout:\n");
985 printk(" --- wd:%d rd:%d\n", conf->working_disks,
988 for (i = 0; i < conf->raid_disks; i++) {
989 char b[BDEVNAME_SIZE];
990 tmp = conf->mirrors + i;
992 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
993 i, !test_bit(In_sync, &tmp->rdev->flags), !test_bit(Faulty, &tmp->rdev->flags),
994 bdevname(tmp->rdev->bdev,b));
998 static void close_sync(conf_t *conf)
1001 allow_barrier(conf);
1003 mempool_destroy(conf->r1buf_pool);
1004 conf->r1buf_pool = NULL;
1007 static int raid1_spare_active(mddev_t *mddev)
1010 conf_t *conf = mddev->private;
1014 * Find all failed disks within the RAID1 configuration
1015 * and mark them readable
1017 for (i = 0; i < conf->raid_disks; i++) {
1018 tmp = conf->mirrors + i;
1020 && !test_bit(Faulty, &tmp->rdev->flags)
1021 && !test_bit(In_sync, &tmp->rdev->flags)) {
1022 conf->working_disks++;
1024 set_bit(In_sync, &tmp->rdev->flags);
1033 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1035 conf_t *conf = mddev->private;
1040 for (mirror=0; mirror < mddev->raid_disks; mirror++)
1041 if ( !(p=conf->mirrors+mirror)->rdev) {
1043 blk_queue_stack_limits(mddev->queue,
1044 rdev->bdev->bd_disk->queue);
1045 /* as we don't honour merge_bvec_fn, we must never risk
1046 * violating it, so limit ->max_sector to one PAGE, as
1047 * a one page request is never in violation.
1049 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1050 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1051 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1053 p->head_position = 0;
1054 rdev->raid_disk = mirror;
1056 /* As all devices are equivalent, we don't need a full recovery
1057 * if this was recently any drive of the array
1059 if (rdev->saved_raid_disk < 0)
1061 rcu_assign_pointer(p->rdev, rdev);
1069 static int raid1_remove_disk(mddev_t *mddev, int number)
1071 conf_t *conf = mddev->private;
1074 mirror_info_t *p = conf->mirrors+ number;
1079 if (test_bit(In_sync, &rdev->flags) ||
1080 atomic_read(&rdev->nr_pending)) {
1086 if (atomic_read(&rdev->nr_pending)) {
1087 /* lost the race, try later */
1099 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
1101 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1107 for (i=r1_bio->mddev->raid_disks; i--; )
1108 if (r1_bio->bios[i] == bio)
1111 update_head_pos(i, r1_bio);
1113 * we have read a block, now it needs to be re-written,
1114 * or re-read if the read failed.
1115 * We don't do much here, just schedule handling by raid1d
1117 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1118 set_bit(R1BIO_Uptodate, &r1_bio->state);
1120 if (atomic_dec_and_test(&r1_bio->remaining))
1121 reschedule_retry(r1_bio);
1125 static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
1127 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1128 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1129 mddev_t *mddev = r1_bio->mddev;
1130 conf_t *conf = mddev_to_conf(mddev);
1137 for (i = 0; i < conf->raid_disks; i++)
1138 if (r1_bio->bios[i] == bio) {
1143 int sync_blocks = 0;
1144 sector_t s = r1_bio->sector;
1145 long sectors_to_go = r1_bio->sectors;
1146 /* make sure these bits doesn't get cleared. */
1148 bitmap_end_sync(mddev->bitmap, r1_bio->sector,
1151 sectors_to_go -= sync_blocks;
1152 } while (sectors_to_go > 0);
1153 md_error(mddev, conf->mirrors[mirror].rdev);
1156 update_head_pos(mirror, r1_bio);
1158 if (atomic_dec_and_test(&r1_bio->remaining)) {
1159 md_done_sync(mddev, r1_bio->sectors, uptodate);
1165 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1167 conf_t *conf = mddev_to_conf(mddev);
1169 int disks = conf->raid_disks;
1170 struct bio *bio, *wbio;
1172 bio = r1_bio->bios[r1_bio->read_disk];
1175 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1176 /* We have read all readable devices. If we haven't
1177 * got the block, then there is no hope left.
1178 * If we have, then we want to do a comparison
1179 * and skip the write if everything is the same.
1180 * If any blocks failed to read, then we need to
1181 * attempt an over-write
1184 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1185 for (i=0; i<mddev->raid_disks; i++)
1186 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1187 md_error(mddev, conf->mirrors[i].rdev);
1189 md_done_sync(mddev, r1_bio->sectors, 1);
1193 for (primary=0; primary<mddev->raid_disks; primary++)
1194 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1195 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1196 r1_bio->bios[primary]->bi_end_io = NULL;
1197 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1200 r1_bio->read_disk = primary;
1201 for (i=0; i<mddev->raid_disks; i++)
1202 if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
1203 test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
1205 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1206 struct bio *pbio = r1_bio->bios[primary];
1207 struct bio *sbio = r1_bio->bios[i];
1208 for (j = vcnt; j-- ; )
1209 if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
1210 page_address(sbio->bi_io_vec[j].bv_page),
1214 mddev->resync_mismatches += r1_bio->sectors;
1215 if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
1216 sbio->bi_end_io = NULL;
1217 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1219 /* fixup the bio for reuse */
1220 sbio->bi_vcnt = vcnt;
1221 sbio->bi_size = r1_bio->sectors << 9;
1223 sbio->bi_phys_segments = 0;
1224 sbio->bi_hw_segments = 0;
1225 sbio->bi_hw_front_size = 0;
1226 sbio->bi_hw_back_size = 0;
1227 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1228 sbio->bi_flags |= 1 << BIO_UPTODATE;
1229 sbio->bi_next = NULL;
1230 sbio->bi_sector = r1_bio->sector +
1231 conf->mirrors[i].rdev->data_offset;
1232 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1236 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1237 /* ouch - failed to read all of that.
1238 * Try some synchronous reads of other devices to get
1239 * good data, much like with normal read errors. Only
1240 * read into the pages we already have so they we don't
1241 * need to re-issue the read request.
1242 * We don't need to freeze the array, because being in an
1243 * active sync request, there is no normal IO, and
1244 * no overlapping syncs.
1246 sector_t sect = r1_bio->sector;
1247 int sectors = r1_bio->sectors;
1252 int d = r1_bio->read_disk;
1256 if (s > (PAGE_SIZE>>9))
1259 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1260 rdev = conf->mirrors[d].rdev;
1261 if (sync_page_io(rdev->bdev,
1262 sect + rdev->data_offset,
1264 bio->bi_io_vec[idx].bv_page,
1271 if (d == conf->raid_disks)
1273 } while (!success && d != r1_bio->read_disk);
1277 /* write it back and re-read */
1278 set_bit(R1BIO_Uptodate, &r1_bio->state);
1279 while (d != r1_bio->read_disk) {
1281 d = conf->raid_disks;
1283 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1285 rdev = conf->mirrors[d].rdev;
1286 atomic_add(s, &rdev->corrected_errors);
1287 if (sync_page_io(rdev->bdev,
1288 sect + rdev->data_offset,
1290 bio->bi_io_vec[idx].bv_page,
1292 md_error(mddev, rdev);
1295 while (d != r1_bio->read_disk) {
1297 d = conf->raid_disks;
1299 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1301 rdev = conf->mirrors[d].rdev;
1302 if (sync_page_io(rdev->bdev,
1303 sect + rdev->data_offset,
1305 bio->bi_io_vec[idx].bv_page,
1307 md_error(mddev, rdev);
1310 char b[BDEVNAME_SIZE];
1311 /* Cannot read from anywhere, array is toast */
1312 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1313 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1314 " for block %llu\n",
1315 bdevname(bio->bi_bdev,b),
1316 (unsigned long long)r1_bio->sector);
1317 md_done_sync(mddev, r1_bio->sectors, 0);
1330 atomic_set(&r1_bio->remaining, 1);
1331 for (i = 0; i < disks ; i++) {
1332 wbio = r1_bio->bios[i];
1333 if (wbio->bi_end_io == NULL ||
1334 (wbio->bi_end_io == end_sync_read &&
1335 (i == r1_bio->read_disk ||
1336 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1339 wbio->bi_rw = WRITE;
1340 wbio->bi_end_io = end_sync_write;
1341 atomic_inc(&r1_bio->remaining);
1342 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1344 generic_make_request(wbio);
1347 if (atomic_dec_and_test(&r1_bio->remaining)) {
1348 /* if we're here, all write(s) have completed, so clean up */
1349 md_done_sync(mddev, r1_bio->sectors, 1);
1355 * This is a kernel thread which:
1357 * 1. Retries failed read operations on working mirrors.
1358 * 2. Updates the raid superblock when problems encounter.
1359 * 3. Performs writes following reads for array syncronising.
1362 static void raid1d(mddev_t *mddev)
1366 unsigned long flags;
1367 conf_t *conf = mddev_to_conf(mddev);
1368 struct list_head *head = &conf->retry_list;
1372 md_check_recovery(mddev);
1375 char b[BDEVNAME_SIZE];
1376 spin_lock_irqsave(&conf->device_lock, flags);
1378 if (conf->pending_bio_list.head) {
1379 bio = bio_list_get(&conf->pending_bio_list);
1380 blk_remove_plug(mddev->queue);
1381 spin_unlock_irqrestore(&conf->device_lock, flags);
1382 /* flush any pending bitmap writes to disk before proceeding w/ I/O */
1383 if (bitmap_unplug(mddev->bitmap) != 0)
1384 printk("%s: bitmap file write failed!\n", mdname(mddev));
1386 while (bio) { /* submit pending writes */
1387 struct bio *next = bio->bi_next;
1388 bio->bi_next = NULL;
1389 generic_make_request(bio);
1397 if (list_empty(head))
1399 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1400 list_del(head->prev);
1402 spin_unlock_irqrestore(&conf->device_lock, flags);
1404 mddev = r1_bio->mddev;
1405 conf = mddev_to_conf(mddev);
1406 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1407 sync_request_write(mddev, r1_bio);
1409 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1410 /* some requests in the r1bio were BIO_RW_BARRIER
1411 * requests which failed with -EOPNOTSUPP. Hohumm..
1412 * Better resubmit without the barrier.
1413 * We know which devices to resubmit for, because
1414 * all others have had their bios[] entry cleared.
1415 * We already have a nr_pending reference on these rdevs.
1418 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1419 clear_bit(R1BIO_Barrier, &r1_bio->state);
1420 for (i=0; i < conf->raid_disks; i++)
1421 if (r1_bio->bios[i])
1422 atomic_inc(&r1_bio->remaining);
1423 for (i=0; i < conf->raid_disks; i++)
1424 if (r1_bio->bios[i]) {
1425 struct bio_vec *bvec;
1428 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1429 /* copy pages from the failed bio, as
1430 * this might be a write-behind device */
1431 __bio_for_each_segment(bvec, bio, j, 0)
1432 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1433 bio_put(r1_bio->bios[i]);
1434 bio->bi_sector = r1_bio->sector +
1435 conf->mirrors[i].rdev->data_offset;
1436 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1437 bio->bi_end_io = raid1_end_write_request;
1439 bio->bi_private = r1_bio;
1440 r1_bio->bios[i] = bio;
1441 generic_make_request(bio);
1446 /* we got a read error. Maybe the drive is bad. Maybe just
1447 * the block and we can fix it.
1448 * We freeze all other IO, and try reading the block from
1449 * other devices. When we find one, we re-write
1450 * and check it that fixes the read error.
1451 * This is all done synchronously while the array is
1454 sector_t sect = r1_bio->sector;
1455 int sectors = r1_bio->sectors;
1457 if (mddev->ro == 0) while(sectors) {
1459 int d = r1_bio->read_disk;
1462 if (s > (PAGE_SIZE>>9))
1466 rdev = conf->mirrors[d].rdev;
1468 test_bit(In_sync, &rdev->flags) &&
1469 sync_page_io(rdev->bdev,
1470 sect + rdev->data_offset,
1472 conf->tmppage, READ))
1476 if (d == conf->raid_disks)
1479 } while (!success && d != r1_bio->read_disk);
1482 /* write it back and re-read */
1484 while (d != r1_bio->read_disk) {
1486 d = conf->raid_disks;
1488 rdev = conf->mirrors[d].rdev;
1490 test_bit(In_sync, &rdev->flags)) {
1491 if (sync_page_io(rdev->bdev,
1492 sect + rdev->data_offset,
1493 s<<9, conf->tmppage, WRITE) == 0)
1494 /* Well, this device is dead */
1495 md_error(mddev, rdev);
1499 while (d != r1_bio->read_disk) {
1501 d = conf->raid_disks;
1503 rdev = conf->mirrors[d].rdev;
1505 test_bit(In_sync, &rdev->flags)) {
1506 if (sync_page_io(rdev->bdev,
1507 sect + rdev->data_offset,
1508 s<<9, conf->tmppage, READ) == 0)
1509 /* Well, this device is dead */
1510 md_error(mddev, rdev);
1512 atomic_add(s, &rdev->corrected_errors);
1517 /* Cannot read from anywhere -- bye bye array */
1518 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1525 unfreeze_array(conf);
1527 bio = r1_bio->bios[r1_bio->read_disk];
1528 if ((disk=read_balance(conf, r1_bio)) == -1) {
1529 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1530 " read error for block %llu\n",
1531 bdevname(bio->bi_bdev,b),
1532 (unsigned long long)r1_bio->sector);
1533 raid_end_bio_io(r1_bio);
1535 r1_bio->bios[r1_bio->read_disk] =
1536 mddev->ro ? IO_BLOCKED : NULL;
1537 r1_bio->read_disk = disk;
1539 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1540 r1_bio->bios[r1_bio->read_disk] = bio;
1541 rdev = conf->mirrors[disk].rdev;
1542 if (printk_ratelimit())
1543 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1544 " another mirror\n",
1545 bdevname(rdev->bdev,b),
1546 (unsigned long long)r1_bio->sector);
1547 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1548 bio->bi_bdev = rdev->bdev;
1549 bio->bi_end_io = raid1_end_read_request;
1551 bio->bi_private = r1_bio;
1553 generic_make_request(bio);
1557 spin_unlock_irqrestore(&conf->device_lock, flags);
1559 unplug_slaves(mddev);
1563 static int init_resync(conf_t *conf)
1567 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1568 BUG_ON(conf->r1buf_pool);
1569 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1571 if (!conf->r1buf_pool)
1573 conf->next_resync = 0;
1578 * perform a "sync" on one "block"
1580 * We need to make sure that no normal I/O request - particularly write
1581 * requests - conflict with active sync requests.
1583 * This is achieved by tracking pending requests and a 'barrier' concept
1584 * that can be installed to exclude normal IO requests.
1587 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1589 conf_t *conf = mddev_to_conf(mddev);
1592 sector_t max_sector, nr_sectors;
1596 int write_targets = 0, read_targets = 0;
1598 int still_degraded = 0;
1600 if (!conf->r1buf_pool)
1603 printk("sync start - bitmap %p\n", mddev->bitmap);
1605 if (init_resync(conf))
1609 max_sector = mddev->size << 1;
1610 if (sector_nr >= max_sector) {
1611 /* If we aborted, we need to abort the
1612 * sync on the 'current' bitmap chunk (there will
1613 * only be one in raid1 resync.
1614 * We can find the current addess in mddev->curr_resync
1616 if (mddev->curr_resync < max_sector) /* aborted */
1617 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1619 else /* completed sync */
1622 bitmap_close_sync(mddev->bitmap);
1627 /* before building a request, check if we can skip these blocks..
1628 * This call the bitmap_start_sync doesn't actually record anything
1630 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1631 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1632 /* We can skip this block, and probably several more */
1637 * If there is non-resync activity waiting for a turn,
1638 * and resync is going fast enough,
1639 * then let it though before starting on this new sync request.
1641 if (!go_faster && conf->nr_waiting)
1642 msleep_interruptible(1000);
1644 raise_barrier(conf);
1646 conf->next_resync = sector_nr;
1648 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1651 * If we get a correctably read error during resync or recovery,
1652 * we might want to read from a different device. So we
1653 * flag all drives that could conceivably be read from for READ,
1654 * and any others (which will be non-In_sync devices) for WRITE.
1655 * If a read fails, we try reading from something else for which READ
1659 r1_bio->mddev = mddev;
1660 r1_bio->sector = sector_nr;
1662 set_bit(R1BIO_IsSync, &r1_bio->state);
1664 for (i=0; i < conf->raid_disks; i++) {
1666 bio = r1_bio->bios[i];
1668 /* take from bio_init */
1669 bio->bi_next = NULL;
1670 bio->bi_flags |= 1 << BIO_UPTODATE;
1674 bio->bi_phys_segments = 0;
1675 bio->bi_hw_segments = 0;
1677 bio->bi_end_io = NULL;
1678 bio->bi_private = NULL;
1680 rdev = rcu_dereference(conf->mirrors[i].rdev);
1682 test_bit(Faulty, &rdev->flags)) {
1685 } else if (!test_bit(In_sync, &rdev->flags)) {
1687 bio->bi_end_io = end_sync_write;
1690 /* may need to read from here */
1692 bio->bi_end_io = end_sync_read;
1693 if (test_bit(WriteMostly, &rdev->flags)) {
1702 atomic_inc(&rdev->nr_pending);
1703 bio->bi_sector = sector_nr + rdev->data_offset;
1704 bio->bi_bdev = rdev->bdev;
1705 bio->bi_private = r1_bio;
1710 r1_bio->read_disk = disk;
1712 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1713 /* extra read targets are also write targets */
1714 write_targets += read_targets-1;
1716 if (write_targets == 0 || read_targets == 0) {
1717 /* There is nowhere to write, so all non-sync
1718 * drives must be failed - so we are finished
1720 sector_t rv = max_sector - sector_nr;
1730 int len = PAGE_SIZE;
1731 if (sector_nr + (len>>9) > max_sector)
1732 len = (max_sector - sector_nr) << 9;
1735 if (sync_blocks == 0) {
1736 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1737 &sync_blocks, still_degraded) &&
1739 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1741 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
1742 if (len > (sync_blocks<<9))
1743 len = sync_blocks<<9;
1746 for (i=0 ; i < conf->raid_disks; i++) {
1747 bio = r1_bio->bios[i];
1748 if (bio->bi_end_io) {
1749 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1750 if (bio_add_page(bio, page, len, 0) == 0) {
1752 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1755 bio = r1_bio->bios[i];
1756 if (bio->bi_end_io==NULL)
1758 /* remove last page from this bio */
1760 bio->bi_size -= len;
1761 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1767 nr_sectors += len>>9;
1768 sector_nr += len>>9;
1769 sync_blocks -= (len>>9);
1770 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1772 r1_bio->sectors = nr_sectors;
1774 /* For a user-requested sync, we read all readable devices and do a
1777 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1778 atomic_set(&r1_bio->remaining, read_targets);
1779 for (i=0; i<conf->raid_disks; i++) {
1780 bio = r1_bio->bios[i];
1781 if (bio->bi_end_io == end_sync_read) {
1782 md_sync_acct(conf->mirrors[i].rdev->bdev, nr_sectors);
1783 generic_make_request(bio);
1787 atomic_set(&r1_bio->remaining, 1);
1788 bio = r1_bio->bios[r1_bio->read_disk];
1789 md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev,
1791 generic_make_request(bio);
1798 static int run(mddev_t *mddev)
1802 mirror_info_t *disk;
1804 struct list_head *tmp;
1806 if (mddev->level != 1) {
1807 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1808 mdname(mddev), mddev->level);
1811 if (mddev->reshape_position != MaxSector) {
1812 printk("raid1: %s: reshape_position set but not supported\n",
1817 * copy the already verified devices into our private RAID1
1818 * bookkeeping area. [whatever we allocate in run(),
1819 * should be freed in stop()]
1821 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1822 mddev->private = conf;
1826 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1831 conf->tmppage = alloc_page(GFP_KERNEL);
1835 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1836 if (!conf->poolinfo)
1838 conf->poolinfo->mddev = mddev;
1839 conf->poolinfo->raid_disks = mddev->raid_disks;
1840 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1843 if (!conf->r1bio_pool)
1846 ITERATE_RDEV(mddev, rdev, tmp) {
1847 disk_idx = rdev->raid_disk;
1848 if (disk_idx >= mddev->raid_disks
1851 disk = conf->mirrors + disk_idx;
1855 blk_queue_stack_limits(mddev->queue,
1856 rdev->bdev->bd_disk->queue);
1857 /* as we don't honour merge_bvec_fn, we must never risk
1858 * violating it, so limit ->max_sector to one PAGE, as
1859 * a one page request is never in violation.
1861 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1862 mddev->queue->max_sectors > (PAGE_SIZE>>9))
1863 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1865 disk->head_position = 0;
1866 if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags))
1867 conf->working_disks++;
1869 conf->raid_disks = mddev->raid_disks;
1870 conf->mddev = mddev;
1871 spin_lock_init(&conf->device_lock);
1872 INIT_LIST_HEAD(&conf->retry_list);
1873 if (conf->working_disks == 1)
1874 mddev->recovery_cp = MaxSector;
1876 spin_lock_init(&conf->resync_lock);
1877 init_waitqueue_head(&conf->wait_barrier);
1879 bio_list_init(&conf->pending_bio_list);
1880 bio_list_init(&conf->flushing_bio_list);
1882 if (!conf->working_disks) {
1883 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
1888 mddev->degraded = 0;
1889 for (i = 0; i < conf->raid_disks; i++) {
1891 disk = conf->mirrors + i;
1894 disk->head_position = 0;
1900 * find the first working one and use it as a starting point
1901 * to read balancing.
1903 for (j = 0; j < conf->raid_disks &&
1904 (!conf->mirrors[j].rdev ||
1905 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
1907 conf->last_used = j;
1910 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
1911 if (!mddev->thread) {
1913 "raid1: couldn't allocate thread for %s\n",
1919 "raid1: raid set %s active with %d out of %d mirrors\n",
1920 mdname(mddev), mddev->raid_disks - mddev->degraded,
1923 * Ok, everything is just fine now
1925 mddev->array_size = mddev->size;
1927 mddev->queue->unplug_fn = raid1_unplug;
1928 mddev->queue->issue_flush_fn = raid1_issue_flush;
1933 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
1938 if (conf->r1bio_pool)
1939 mempool_destroy(conf->r1bio_pool);
1940 kfree(conf->mirrors);
1941 safe_put_page(conf->tmppage);
1942 kfree(conf->poolinfo);
1944 mddev->private = NULL;
1950 static int stop(mddev_t *mddev)
1952 conf_t *conf = mddev_to_conf(mddev);
1953 struct bitmap *bitmap = mddev->bitmap;
1954 int behind_wait = 0;
1956 /* wait for behind writes to complete */
1957 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
1959 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
1960 set_current_state(TASK_UNINTERRUPTIBLE);
1961 schedule_timeout(HZ); /* wait a second */
1962 /* need to kick something here to make sure I/O goes? */
1965 md_unregister_thread(mddev->thread);
1966 mddev->thread = NULL;
1967 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
1968 if (conf->r1bio_pool)
1969 mempool_destroy(conf->r1bio_pool);
1970 kfree(conf->mirrors);
1971 kfree(conf->poolinfo);
1973 mddev->private = NULL;
1977 static int raid1_resize(mddev_t *mddev, sector_t sectors)
1979 /* no resync is happening, and there is enough space
1980 * on all devices, so we can resize.
1981 * We need to make sure resync covers any new space.
1982 * If the array is shrinking we should possibly wait until
1983 * any io in the removed space completes, but it hardly seems
1986 mddev->array_size = sectors>>1;
1987 set_capacity(mddev->gendisk, mddev->array_size << 1);
1989 if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
1990 mddev->recovery_cp = mddev->size << 1;
1991 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1993 mddev->size = mddev->array_size;
1994 mddev->resync_max_sectors = sectors;
1998 static int raid1_reshape(mddev_t *mddev)
2001 * 1/ resize the r1bio_pool
2002 * 2/ resize conf->mirrors
2004 * We allocate a new r1bio_pool if we can.
2005 * Then raise a device barrier and wait until all IO stops.
2006 * Then resize conf->mirrors and swap in the new r1bio pool.
2008 * At the same time, we "pack" the devices so that all the missing
2009 * devices have the higher raid_disk numbers.
2011 mempool_t *newpool, *oldpool;
2012 struct pool_info *newpoolinfo;
2013 mirror_info_t *newmirrors;
2014 conf_t *conf = mddev_to_conf(mddev);
2015 int cnt, raid_disks;
2019 /* Cannot change chunk_size, layout, or level */
2020 if (mddev->chunk_size != mddev->new_chunk ||
2021 mddev->layout != mddev->new_layout ||
2022 mddev->level != mddev->new_level) {
2023 mddev->new_chunk = mddev->chunk_size;
2024 mddev->new_layout = mddev->layout;
2025 mddev->new_level = mddev->level;
2029 raid_disks = mddev->raid_disks + mddev->delta_disks;
2031 if (raid_disks < conf->raid_disks) {
2033 for (d= 0; d < conf->raid_disks; d++)
2034 if (conf->mirrors[d].rdev)
2036 if (cnt > raid_disks)
2040 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2043 newpoolinfo->mddev = mddev;
2044 newpoolinfo->raid_disks = raid_disks;
2046 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2047 r1bio_pool_free, newpoolinfo);
2052 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2055 mempool_destroy(newpool);
2059 raise_barrier(conf);
2061 /* ok, everything is stopped */
2062 oldpool = conf->r1bio_pool;
2063 conf->r1bio_pool = newpool;
2065 for (d=d2=0; d < conf->raid_disks; d++)
2066 if (conf->mirrors[d].rdev) {
2067 conf->mirrors[d].rdev->raid_disk = d2;
2068 newmirrors[d2++].rdev = conf->mirrors[d].rdev;
2070 kfree(conf->mirrors);
2071 conf->mirrors = newmirrors;
2072 kfree(conf->poolinfo);
2073 conf->poolinfo = newpoolinfo;
2075 mddev->degraded += (raid_disks - conf->raid_disks);
2076 conf->raid_disks = mddev->raid_disks = raid_disks;
2077 mddev->delta_disks = 0;
2079 conf->last_used = 0; /* just make sure it is in-range */
2080 lower_barrier(conf);
2082 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2083 md_wakeup_thread(mddev->thread);
2085 mempool_destroy(oldpool);
2089 static void raid1_quiesce(mddev_t *mddev, int state)
2091 conf_t *conf = mddev_to_conf(mddev);
2095 raise_barrier(conf);
2098 lower_barrier(conf);
2104 static struct mdk_personality raid1_personality =
2108 .owner = THIS_MODULE,
2109 .make_request = make_request,
2113 .error_handler = error,
2114 .hot_add_disk = raid1_add_disk,
2115 .hot_remove_disk= raid1_remove_disk,
2116 .spare_active = raid1_spare_active,
2117 .sync_request = sync_request,
2118 .resize = raid1_resize,
2119 .check_reshape = raid1_reshape,
2120 .quiesce = raid1_quiesce,
2123 static int __init raid_init(void)
2125 return register_md_personality(&raid1_personality);
2128 static void raid_exit(void)
2130 unregister_md_personality(&raid1_personality);
2133 module_init(raid_init);
2134 module_exit(raid_exit);
2135 MODULE_LICENSE("GPL");
2136 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2137 MODULE_ALIAS("md-raid1");
2138 MODULE_ALIAS("md-level-1");