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-rw-r--r--drivers/md/raid1.c1449
1 files changed, 1449 insertions, 0 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
new file mode 100644
index 00000000000..a389394b52f
--- /dev/null
+++ b/drivers/md/raid1.c
@@ -0,0 +1,1449 @@
+/*
+ * raid1.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
+ *
+ * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
+ *
+ * RAID-1 management functions.
+ *
+ * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
+ *
+ * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
+ * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/raid/raid1.h>
+
+/*
+ * Number of guaranteed r1bios in case of extreme VM load:
+ */
+#define NR_RAID1_BIOS 256
+
+static mdk_personality_t raid1_personality;
+
+static void unplug_slaves(mddev_t *mddev);
+
+
+static void * r1bio_pool_alloc(unsigned int __nocast gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ r1bio_t *r1_bio;
+ int size = offsetof(r1bio_t, bios[pi->raid_disks]);
+
+ /* allocate a r1bio with room for raid_disks entries in the bios array */
+ r1_bio = kmalloc(size, gfp_flags);
+ if (r1_bio)
+ memset(r1_bio, 0, size);
+ else
+ unplug_slaves(pi->mddev);
+
+ return r1_bio;
+}
+
+static void r1bio_pool_free(void *r1_bio, void *data)
+{
+ kfree(r1_bio);
+}
+
+#define RESYNC_BLOCK_SIZE (64*1024)
+//#define RESYNC_BLOCK_SIZE PAGE_SIZE
+#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
+#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
+#define RESYNC_WINDOW (2048*1024)
+
+static void * r1buf_pool_alloc(unsigned int __nocast gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ struct page *page;
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ int i, j;
+
+ r1_bio = r1bio_pool_alloc(gfp_flags, pi);
+ if (!r1_bio) {
+ unplug_slaves(pi->mddev);
+ return NULL;
+ }
+
+ /*
+ * Allocate bios : 1 for reading, n-1 for writing
+ */
+ for (j = pi->raid_disks ; j-- ; ) {
+ bio = bio_alloc(gfp_flags, RESYNC_PAGES);
+ if (!bio)
+ goto out_free_bio;
+ r1_bio->bios[j] = bio;
+ }
+ /*
+ * Allocate RESYNC_PAGES data pages and attach them to
+ * the first bio;
+ */
+ bio = r1_bio->bios[0];
+ for (i = 0; i < RESYNC_PAGES; i++) {
+ page = alloc_page(gfp_flags);
+ if (unlikely(!page))
+ goto out_free_pages;
+
+ bio->bi_io_vec[i].bv_page = page;
+ }
+
+ r1_bio->master_bio = NULL;
+
+ return r1_bio;
+
+out_free_pages:
+ for ( ; i > 0 ; i--)
+ __free_page(bio->bi_io_vec[i-1].bv_page);
+out_free_bio:
+ while ( ++j < pi->raid_disks )
+ bio_put(r1_bio->bios[j]);
+ r1bio_pool_free(r1_bio, data);
+ return NULL;
+}
+
+static void r1buf_pool_free(void *__r1_bio, void *data)
+{
+ struct pool_info *pi = data;
+ int i;
+ r1bio_t *r1bio = __r1_bio;
+ struct bio *bio = r1bio->bios[0];
+
+ for (i = 0; i < RESYNC_PAGES; i++) {
+ __free_page(bio->bi_io_vec[i].bv_page);
+ bio->bi_io_vec[i].bv_page = NULL;
+ }
+ for (i=0 ; i < pi->raid_disks; i++)
+ bio_put(r1bio->bios[i]);
+
+ r1bio_pool_free(r1bio, data);
+}
+
+static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
+{
+ int i;
+
+ for (i = 0; i < conf->raid_disks; i++) {
+ struct bio **bio = r1_bio->bios + i;
+ if (*bio)
+ bio_put(*bio);
+ *bio = NULL;
+ }
+}
+
+static inline void free_r1bio(r1bio_t *r1_bio)
+{
+ unsigned long flags;
+
+ conf_t *conf = mddev_to_conf(r1_bio->mddev);
+
+ /*
+ * Wake up any possible resync thread that waits for the device
+ * to go idle.
+ */
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ if (!--conf->nr_pending) {
+ wake_up(&conf->wait_idle);
+ wake_up(&conf->wait_resume);
+ }
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+
+ put_all_bios(conf, r1_bio);
+ mempool_free(r1_bio, conf->r1bio_pool);
+}
+
+static inline void put_buf(r1bio_t *r1_bio)
+{
+ conf_t *conf = mddev_to_conf(r1_bio->mddev);
+ unsigned long flags;
+
+ mempool_free(r1_bio, conf->r1buf_pool);
+
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ if (!conf->barrier)
+ BUG();
+ --conf->barrier;
+ wake_up(&conf->wait_resume);
+ wake_up(&conf->wait_idle);
+
+ if (!--conf->nr_pending) {
+ wake_up(&conf->wait_idle);
+ wake_up(&conf->wait_resume);
+ }
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+}
+
+static void reschedule_retry(r1bio_t *r1_bio)
+{
+ unsigned long flags;
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev_to_conf(mddev);
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ list_add(&r1_bio->retry_list, &conf->retry_list);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ md_wakeup_thread(mddev->thread);
+}
+
+/*
+ * raid_end_bio_io() is called when we have finished servicing a mirrored
+ * operation and are ready to return a success/failure code to the buffer
+ * cache layer.
+ */
+static void raid_end_bio_io(r1bio_t *r1_bio)
+{
+ struct bio *bio = r1_bio->master_bio;
+
+ bio_endio(bio, bio->bi_size,
+ test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
+ free_r1bio(r1_bio);
+}
+
+/*
+ * Update disk head position estimator based on IRQ completion info.
+ */
+static inline void update_head_pos(int disk, r1bio_t *r1_bio)
+{
+ conf_t *conf = mddev_to_conf(r1_bio->mddev);
+
+ conf->mirrors[disk].head_position =
+ r1_bio->sector + (r1_bio->sectors);
+}
+
+static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
+ int mirror;
+ conf_t *conf = mddev_to_conf(r1_bio->mddev);
+
+ if (bio->bi_size)
+ return 1;
+
+ mirror = r1_bio->read_disk;
+ /*
+ * this branch is our 'one mirror IO has finished' event handler:
+ */
+ if (!uptodate)
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ else
+ /*
+ * Set R1BIO_Uptodate in our master bio, so that
+ * we will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer fails.
+ *
+ * The 'master' represents the composite IO operation to
+ * user-side. So if something waits for IO, then it will
+ * wait for the 'master' bio.
+ */
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ /*
+ * we have only one bio on the read side
+ */
+ if (uptodate)
+ raid_end_bio_io(r1_bio);
+ else {
+ /*
+ * oops, read error:
+ */
+ char b[BDEVNAME_SIZE];
+ if (printk_ratelimit())
+ printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n",
+ bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
+ reschedule_retry(r1_bio);
+ }
+
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+ return 0;
+}
+
+static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
+ int mirror;
+ conf_t *conf = mddev_to_conf(r1_bio->mddev);
+
+ if (bio->bi_size)
+ return 1;
+
+ for (mirror = 0; mirror < conf->raid_disks; mirror++)
+ if (r1_bio->bios[mirror] == bio)
+ break;
+
+ /*
+ * this branch is our 'one mirror IO has finished' event handler:
+ */
+ if (!uptodate)
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ else
+ /*
+ * Set R1BIO_Uptodate in our master bio, so that
+ * we will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer fails.
+ *
+ * The 'master' represents the composite IO operation to
+ * user-side. So if something waits for IO, then it will
+ * wait for the 'master' bio.
+ */
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ /*
+ *
+ * Let's see if all mirrored write operations have finished
+ * already.
+ */
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ md_write_end(r1_bio->mddev);
+ raid_end_bio_io(r1_bio);
+ }
+
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+ return 0;
+}
+
+
+/*
+ * This routine returns the disk from which the requested read should
+ * be done. There is a per-array 'next expected sequential IO' sector
+ * number - if this matches on the next IO then we use the last disk.
+ * There is also a per-disk 'last know head position' sector that is
+ * maintained from IRQ contexts, both the normal and the resync IO
+ * completion handlers update this position correctly. If there is no
+ * perfect sequential match then we pick the disk whose head is closest.
+ *
+ * If there are 2 mirrors in the same 2 devices, performance degrades
+ * because position is mirror, not device based.
+ *
+ * The rdev for the device selected will have nr_pending incremented.
+ */
+static int read_balance(conf_t *conf, r1bio_t *r1_bio)
+{
+ const unsigned long this_sector = r1_bio->sector;
+ int new_disk = conf->last_used, disk = new_disk;
+ const int sectors = r1_bio->sectors;
+ sector_t new_distance, current_distance;
+ mdk_rdev_t *new_rdev, *rdev;
+
+ rcu_read_lock();
+ /*
+ * Check if it if we can balance. We can balance on the whole
+ * device if no resync is going on, or below the resync window.
+ * We take the first readable disk when above the resync window.
+ */
+ retry:
+ if (conf->mddev->recovery_cp < MaxSector &&
+ (this_sector + sectors >= conf->next_resync)) {
+ /* Choose the first operation device, for consistancy */
+ new_disk = 0;
+
+ while ((new_rdev=conf->mirrors[new_disk].rdev) == NULL ||
+ !new_rdev->in_sync) {
+ new_disk++;
+ if (new_disk == conf->raid_disks) {
+ new_disk = -1;
+ break;
+ }
+ }
+ goto rb_out;
+ }
+
+
+ /* make sure the disk is operational */
+ while ((new_rdev=conf->mirrors[new_disk].rdev) == NULL ||
+ !new_rdev->in_sync) {
+ if (new_disk <= 0)
+ new_disk = conf->raid_disks;
+ new_disk--;
+ if (new_disk == disk) {
+ new_disk = -1;
+ goto rb_out;
+ }
+ }
+ disk = new_disk;
+ /* now disk == new_disk == starting point for search */
+
+ /*
+ * Don't change to another disk for sequential reads:
+ */
+ if (conf->next_seq_sect == this_sector)
+ goto rb_out;
+ if (this_sector == conf->mirrors[new_disk].head_position)
+ goto rb_out;
+
+ current_distance = abs(this_sector - conf->mirrors[disk].head_position);
+
+ /* Find the disk whose head is closest */
+
+ do {
+ if (disk <= 0)
+ disk = conf->raid_disks;
+ disk--;
+
+ if ((rdev=conf->mirrors[disk].rdev) == NULL ||
+ !rdev->in_sync)
+ continue;
+
+ if (!atomic_read(&rdev->nr_pending)) {
+ new_disk = disk;
+ new_rdev = rdev;
+ break;
+ }
+ new_distance = abs(this_sector - conf->mirrors[disk].head_position);
+ if (new_distance < current_distance) {
+ current_distance = new_distance;
+ new_disk = disk;
+ new_rdev = rdev;
+ }
+ } while (disk != conf->last_used);
+
+rb_out:
+
+
+ if (new_disk >= 0) {
+ conf->next_seq_sect = this_sector + sectors;
+ conf->last_used = new_disk;
+ atomic_inc(&new_rdev->nr_pending);
+ if (!new_rdev->in_sync) {
+ /* cannot risk returning a device that failed
+ * before we inc'ed nr_pending
+ */
+ atomic_dec(&new_rdev->nr_pending);
+ goto retry;
+ }
+ }
+ rcu_read_unlock();
+
+ return new_disk;
+}
+
+static void unplug_slaves(mddev_t *mddev)
+{
+ conf_t *conf = mddev_to_conf(mddev);
+ int i;
+
+ rcu_read_lock();
+ for (i=0; i<mddev->raid_disks; i++) {
+ mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+ if (rdev && !rdev->faulty && atomic_read(&rdev->nr_pending)) {
+ request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
+
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+
+ if (r_queue->unplug_fn)
+ r_queue->unplug_fn(r_queue);
+
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ }
+ }
+ rcu_read_unlock();
+}
+
+static void raid1_unplug(request_queue_t *q)
+{
+ unplug_slaves(q->queuedata);
+}
+
+static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
+ sector_t *error_sector)
+{
+ mddev_t *mddev = q->queuedata;
+ conf_t *conf = mddev_to_conf(mddev);
+ int i, ret = 0;
+
+ rcu_read_lock();
+ for (i=0; i<mddev->raid_disks && ret == 0; i++) {
+ mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+ if (rdev && !rdev->faulty) {
+ struct block_device *bdev = rdev->bdev;
+ request_queue_t *r_queue = bdev_get_queue(bdev);
+
+ if (!r_queue->issue_flush_fn)
+ ret = -EOPNOTSUPP;
+ else {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
+ error_sector);
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ }
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Throttle resync depth, so that we can both get proper overlapping of
+ * requests, but are still able to handle normal requests quickly.
+ */
+#define RESYNC_DEPTH 32
+
+static void device_barrier(conf_t *conf, sector_t sect)
+{
+ spin_lock_irq(&conf->resync_lock);
+ wait_event_lock_irq(conf->wait_idle, !waitqueue_active(&conf->wait_resume),
+ conf->resync_lock, unplug_slaves(conf->mddev));
+
+ if (!conf->barrier++) {
+ wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
+ conf->resync_lock, unplug_slaves(conf->mddev));
+ if (conf->nr_pending)
+ BUG();
+ }
+ wait_event_lock_irq(conf->wait_resume, conf->barrier < RESYNC_DEPTH,
+ conf->resync_lock, unplug_slaves(conf->mddev));
+ conf->next_resync = sect;
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static int make_request(request_queue_t *q, struct bio * bio)
+{
+ mddev_t *mddev = q->queuedata;
+ conf_t *conf = mddev_to_conf(mddev);
+ mirror_info_t *mirror;
+ r1bio_t *r1_bio;
+ struct bio *read_bio;
+ int i, disks;
+ mdk_rdev_t *rdev;
+
+ /*
+ * Register the new request and wait if the reconstruction
+ * thread has put up a bar for new requests.
+ * Continue immediately if no resync is active currently.
+ */
+ spin_lock_irq(&conf->resync_lock);
+ wait_event_lock_irq(conf->wait_resume, !conf->barrier, conf->resync_lock, );
+ conf->nr_pending++;
+ spin_unlock_irq(&conf->resync_lock);
+
+ if (bio_data_dir(bio)==WRITE) {
+ disk_stat_inc(mddev->gendisk, writes);
+ disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bio));
+ } else {
+ disk_stat_inc(mddev->gendisk, reads);
+ disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bio));
+ }
+
+ /*
+ * make_request() can abort the operation when READA is being
+ * used and no empty request is available.
+ *
+ */
+ r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
+
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = bio->bi_size >> 9;
+
+ r1_bio->mddev = mddev;
+ r1_bio->sector = bio->bi_sector;
+
+ r1_bio->state = 0;
+
+ if (bio_data_dir(bio) == READ) {
+ /*
+ * read balancing logic:
+ */
+ int rdisk = read_balance(conf, r1_bio);
+
+ if (rdisk < 0) {
+ /* couldn't find anywhere to read from */
+ raid_end_bio_io(r1_bio);
+ return 0;
+ }
+ mirror = conf->mirrors + rdisk;
+
+ r1_bio->read_disk = rdisk;
+
+ read_bio = bio_clone(bio, GFP_NOIO);
+
+ r1_bio->bios[rdisk] = read_bio;
+
+ read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
+ read_bio->bi_bdev = mirror->rdev->bdev;
+ read_bio->bi_end_io = raid1_end_read_request;
+ read_bio->bi_rw = READ;
+ read_bio->bi_private = r1_bio;
+
+ generic_make_request(read_bio);
+ return 0;
+ }
+
+ /*
+ * WRITE:
+ */
+ /* first select target devices under spinlock and
+ * inc refcount on their rdev. Record them by setting
+ * bios[x] to bio
+ */
+ disks = conf->raid_disks;
+ rcu_read_lock();
+ for (i = 0; i < disks; i++) {
+ if ((rdev=conf->mirrors[i].rdev) != NULL &&
+ !rdev->faulty) {
+ atomic_inc(&rdev->nr_pending);
+ if (rdev->faulty) {
+ atomic_dec(&rdev->nr_pending);
+ r1_bio->bios[i] = NULL;
+ } else
+ r1_bio->bios[i] = bio;
+ } else
+ r1_bio->bios[i] = NULL;
+ }
+ rcu_read_unlock();
+
+ atomic_set(&r1_bio->remaining, 1);
+ md_write_start(mddev);
+ for (i = 0; i < disks; i++) {
+ struct bio *mbio;
+ if (!r1_bio->bios[i])
+ continue;
+
+ mbio = bio_clone(bio, GFP_NOIO);
+ r1_bio->bios[i] = mbio;
+
+ mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
+ mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
+ mbio->bi_end_io = raid1_end_write_request;
+ mbio->bi_rw = WRITE;
+ mbio->bi_private = r1_bio;
+
+ atomic_inc(&r1_bio->remaining);
+ generic_make_request(mbio);
+ }
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ md_write_end(mddev);
+ raid_end_bio_io(r1_bio);
+ }
+
+ return 0;
+}
+
+static void status(struct seq_file *seq, mddev_t *mddev)
+{
+ conf_t *conf = mddev_to_conf(mddev);
+ int i;
+
+ seq_printf(seq, " [%d/%d] [", conf->raid_disks,
+ conf->working_disks);
+ for (i = 0; i < conf->raid_disks; i++)
+ seq_printf(seq, "%s",
+ conf->mirrors[i].rdev &&
+ conf->mirrors[i].rdev->in_sync ? "U" : "_");
+ seq_printf(seq, "]");
+}
+
+
+static void error(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+ char b[BDEVNAME_SIZE];
+ conf_t *conf = mddev_to_conf(mddev);
+
+ /*
+ * If it is not operational, then we have already marked it as dead
+ * else if it is the last working disks, ignore the error, let the
+ * next level up know.
+ * else mark the drive as failed
+ */
+ if (rdev->in_sync
+ && conf->working_disks == 1)
+ /*
+ * Don't fail the drive, act as though we were just a
+ * normal single drive
+ */
+ return;
+ if (rdev->in_sync) {
+ mddev->degraded++;
+ conf->working_disks--;
+ /*
+ * if recovery is running, make sure it aborts.
+ */
+ set_bit(MD_RECOVERY_ERR, &mddev->recovery);
+ }
+ rdev->in_sync = 0;
+ rdev->faulty = 1;
+ mddev->sb_dirty = 1;
+ printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
+ " Operation continuing on %d devices\n",
+ bdevname(rdev->bdev,b), conf->working_disks);
+}
+
+static void print_conf(conf_t *conf)
+{
+ int i;
+ mirror_info_t *tmp;
+
+ printk("RAID1 conf printout:\n");
+ if (!conf) {
+ printk("(!conf)\n");
+ return;
+ }
+ printk(" --- wd:%d rd:%d\n", conf->working_disks,
+ conf->raid_disks);
+
+ for (i = 0; i < conf->raid_disks; i++) {
+ char b[BDEVNAME_SIZE];
+ tmp = conf->mirrors + i;
+ if (tmp->rdev)
+ printk(" disk %d, wo:%d, o:%d, dev:%s\n",
+ i, !tmp->rdev->in_sync, !tmp->rdev->faulty,
+ bdevname(tmp->rdev->bdev,b));
+ }
+}
+
+static void close_sync(conf_t *conf)
+{
+ spin_lock_irq(&conf->resync_lock);
+ wait_event_lock_irq(conf->wait_resume, !conf->barrier,
+ conf->resync_lock, unplug_slaves(conf->mddev));
+ spin_unlock_irq(&conf->resync_lock);
+
+ if (conf->barrier) BUG();
+ if (waitqueue_active(&conf->wait_idle)) BUG();
+
+ mempool_destroy(conf->r1buf_pool);
+ conf->r1buf_pool = NULL;
+}
+
+static int raid1_spare_active(mddev_t *mddev)
+{
+ int i;
+ conf_t *conf = mddev->private;
+ mirror_info_t *tmp;
+
+ /*
+ * Find all failed disks within the RAID1 configuration
+ * and mark them readable
+ */
+ for (i = 0; i < conf->raid_disks; i++) {
+ tmp = conf->mirrors + i;
+ if (tmp->rdev
+ && !tmp->rdev->faulty
+ && !tmp->rdev->in_sync) {
+ conf->working_disks++;
+ mddev->degraded--;
+ tmp->rdev->in_sync = 1;
+ }
+ }
+
+ print_conf(conf);
+ return 0;
+}
+
+
+static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+ conf_t *conf = mddev->private;
+ int found = 0;
+ int mirror;
+ mirror_info_t *p;
+
+ for (mirror=0; mirror < mddev->raid_disks; mirror++)
+ if ( !(p=conf->mirrors+mirror)->rdev) {
+
+ blk_queue_stack_limits(mddev->queue,
+ rdev->bdev->bd_disk->queue);
+ /* as we don't honour merge_bvec_fn, we must never risk
+ * violating it, so limit ->max_sector to one PAGE, as
+ * a one page request is never in violation.
+ */
+ if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
+ mddev->queue->max_sectors > (PAGE_SIZE>>9))
+ blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
+
+ p->head_position = 0;
+ rdev->raid_disk = mirror;
+ found = 1;
+ p->rdev = rdev;
+ break;
+ }
+
+ print_conf(conf);
+ return found;
+}
+
+static int raid1_remove_disk(mddev_t *mddev, int number)
+{
+ conf_t *conf = mddev->private;
+ int err = 0;
+ mdk_rdev_t *rdev;
+ mirror_info_t *p = conf->mirrors+ number;
+
+ print_conf(conf);
+ rdev = p->rdev;
+ if (rdev) {
+ if (rdev->in_sync ||
+ atomic_read(&rdev->nr_pending)) {
+ err = -EBUSY;
+ goto abort;
+ }
+ p->rdev = NULL;
+ synchronize_kernel();
+ if (atomic_read(&rdev->nr_pending)) {
+ /* lost the race, try later */
+ err = -EBUSY;
+ p->rdev = rdev;
+ }
+ }
+abort:
+
+ print_conf(conf);
+ return err;
+}
+
+
+static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
+ conf_t *conf = mddev_to_conf(r1_bio->mddev);
+
+ if (bio->bi_size)
+ return 1;
+
+ if (r1_bio->bios[r1_bio->read_disk] != bio)
+ BUG();
+ update_head_pos(r1_bio->read_disk, r1_bio);
+ /*
+ * we have read a block, now it needs to be re-written,
+ * or re-read if the read failed.
+ * We don't do much here, just schedule handling by raid1d
+ */
+ if (!uptodate)
+ md_error(r1_bio->mddev,
+ conf->mirrors[r1_bio->read_disk].rdev);
+ else
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+ rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
+ reschedule_retry(r1_bio);
+ return 0;
+}
+
+static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev_to_conf(mddev);
+ int i;
+ int mirror=0;
+
+ if (bio->bi_size)
+ return 1;
+
+ for (i = 0; i < conf->raid_disks; i++)
+ if (r1_bio->bios[i] == bio) {
+ mirror = i;
+ break;
+ }
+ if (!uptodate)
+ md_error(mddev, conf->mirrors[mirror].rdev);
+ update_head_pos(mirror, r1_bio);
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ md_done_sync(mddev, r1_bio->sectors, uptodate);
+ put_buf(r1_bio);
+ }
+ rdev_dec_pending(conf->mirrors[mirror].rdev, mddev);
+ return 0;
+}
+
+static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
+{
+ conf_t *conf = mddev_to_conf(mddev);
+ int i;
+ int disks = conf->raid_disks;
+ struct bio *bio, *wbio;
+
+ bio = r1_bio->bios[r1_bio->read_disk];
+
+ /*
+ * schedule writes
+ */
+ if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
+ /*
+ * There is no point trying a read-for-reconstruct as
+ * reconstruct is about to be aborted
+ */
+ char b[BDEVNAME_SIZE];
+ printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
+ " for block %llu\n",
+ bdevname(bio->bi_bdev,b),
+ (unsigned long long)r1_bio->sector);
+ md_done_sync(mddev, r1_bio->sectors, 0);
+ put_buf(r1_bio);
+ return;
+ }
+
+ atomic_set(&r1_bio->remaining, 1);
+ for (i = 0; i < disks ; i++) {
+ wbio = r1_bio->bios[i];
+ if (wbio->bi_end_io != end_sync_write)
+ continue;
+
+ atomic_inc(&conf->mirrors[i].rdev->nr_pending);
+ atomic_inc(&r1_bio->remaining);
+ md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
+ generic_make_request(wbio);
+ }
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ md_done_sync(mddev, r1_bio->sectors, 1);
+ put_buf(r1_bio);
+ }
+}
+
+/*
+ * This is a kernel thread which:
+ *
+ * 1. Retries failed read operations on working mirrors.
+ * 2. Updates the raid superblock when problems encounter.
+ * 3. Performs writes following reads for array syncronising.
+ */
+
+static void raid1d(mddev_t *mddev)
+{
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ unsigned long flags;
+ conf_t *conf = mddev_to_conf(mddev);
+ struct list_head *head = &conf->retry_list;
+ int unplug=0;
+ mdk_rdev_t *rdev;
+
+ md_check_recovery(mddev);
+ md_handle_safemode(mddev);
+
+ for (;;) {
+ char b[BDEVNAME_SIZE];
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (list_empty(head))
+ break;
+ r1_bio = list_entry(head->prev, r1bio_t, retry_list);
+ list_del(head->prev);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ mddev = r1_bio->mddev;
+ conf = mddev_to_conf(mddev);
+ if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
+ sync_request_write(mddev, r1_bio);
+ unplug = 1;
+ } else {
+ int disk;
+ bio = r1_bio->bios[r1_bio->read_disk];
+ if ((disk=read_balance(conf, r1_bio)) == -1) {
+ printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
+ " read error for block %llu\n",
+ bdevname(bio->bi_bdev,b),
+ (unsigned long long)r1_bio->sector);
+ raid_end_bio_io(r1_bio);
+ } else {
+ r1_bio->bios[r1_bio->read_disk] = NULL;
+ r1_bio->read_disk = disk;
+ bio_put(bio);
+ bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
+ r1_bio->bios[r1_bio->read_disk] = bio;
+ rdev = conf->mirrors[disk].rdev;
+ if (printk_ratelimit())
+ printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
+ " another mirror\n",
+ bdevname(rdev->bdev,b),
+ (unsigned long long)r1_bio->sector);
+ bio->bi_sector = r1_bio->sector + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ bio->bi_end_io = raid1_end_read_request;
+ bio->bi_rw = READ;
+ bio->bi_private = r1_bio;
+ unplug = 1;
+ generic_make_request(bio);
+ }
+ }
+ }
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ if (unplug)
+ unplug_slaves(mddev);
+}
+
+
+static int init_resync(conf_t *conf)
+{
+ int buffs;
+
+ buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
+ if (conf->r1buf_pool)
+ BUG();
+ conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
+ conf->poolinfo);
+ if (!conf->r1buf_pool)
+ return -ENOMEM;
+ conf->next_resync = 0;
+ return 0;
+}
+
+/*
+ * perform a "sync" on one "block"
+ *
+ * We need to make sure that no normal I/O request - particularly write
+ * requests - conflict with active sync requests.
+ *
+ * This is achieved by tracking pending requests and a 'barrier' concept
+ * that can be installed to exclude normal IO requests.
+ */
+
+static int sync_request(mddev_t *mddev, sector_t sector_nr, int go_faster)
+{
+ conf_t *conf = mddev_to_conf(mddev);
+ mirror_info_t *mirror;
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ sector_t max_sector, nr_sectors;
+ int disk;
+ int i;
+ int write_targets = 0;
+
+ if (!conf->r1buf_pool)
+ if (init_resync(conf))
+ return -ENOMEM;
+
+ max_sector = mddev->size << 1;
+ if (sector_nr >= max_sector) {
+ close_sync(conf);
+ return 0;
+ }
+
+ /*
+ * If there is non-resync activity waiting for us then
+ * put in a delay to throttle resync.
+ */
+ if (!go_faster && waitqueue_active(&conf->wait_resume))
+ msleep_interruptible(1000);
+ device_barrier(conf, sector_nr + RESYNC_SECTORS);
+
+ /*
+ * If reconstructing, and >1 working disc,
+ * could dedicate one to rebuild and others to
+ * service read requests ..
+ */
+ disk = conf->last_used;
+ /* make sure disk is operational */
+
+ while (conf->mirrors[disk].rdev == NULL ||
+ !conf->mirrors[disk].rdev->in_sync) {
+ if (disk <= 0)
+ disk = conf->raid_disks;
+ disk--;
+ if (disk == conf->last_used)
+ break;
+ }
+ conf->last_used = disk;
+ atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
+
+
+ mirror = conf->mirrors + disk;
+
+ r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
+
+ spin_lock_irq(&conf->resync_lock);
+ conf->nr_pending++;
+ spin_unlock_irq(&conf->resync_lock);
+
+ r1_bio->mddev = mddev;
+ r1_bio->sector = sector_nr;
+ set_bit(R1BIO_IsSync, &r1_bio->state);
+ r1_bio->read_disk = disk;
+
+ for (i=0; i < conf->raid_disks; i++) {
+ bio = r1_bio->bios[i];
+
+ /* take from bio_init */
+ bio->bi_next = NULL;
+ bio->bi_flags |= 1 << BIO_UPTODATE;
+ bio->bi_rw = 0;
+ bio->bi_vcnt = 0;
+ bio->bi_idx = 0;
+ bio->bi_phys_segments = 0;
+ bio->bi_hw_segments = 0;
+ bio->bi_size = 0;
+ bio->bi_end_io = NULL;
+ bio->bi_private = NULL;
+
+ if (i == disk) {
+ bio->bi_rw = READ;
+ bio->bi_end_io = end_sync_read;
+ } else if (conf->mirrors[i].rdev &&
+ !conf->mirrors[i].rdev->faulty &&
+ (!conf->mirrors[i].rdev->in_sync ||
+ sector_nr + RESYNC_SECTORS > mddev->recovery_cp)) {
+ bio->bi_rw = WRITE;
+ bio->bi_end_io = end_sync_write;
+ write_targets ++;
+ } else
+ continue;
+ bio->bi_sector = sector_nr + conf->mirrors[i].rdev->data_offset;
+ bio->bi_bdev = conf->mirrors[i].rdev->bdev;
+ bio->bi_private = r1_bio;
+ }
+ if (write_targets == 0) {
+ /* There is nowhere to write, so all non-sync
+ * drives must be failed - so we are finished
+ */
+ int rv = max_sector - sector_nr;
+ md_done_sync(mddev, rv, 1);
+ put_buf(r1_bio);
+ rdev_dec_pending(conf->mirrors[disk].rdev, mddev);
+ return rv;
+ }
+
+ nr_sectors = 0;
+ do {
+ struct page *page;
+ int len = PAGE_SIZE;
+ if (sector_nr + (len>>9) > max_sector)
+ len = (max_sector - sector_nr) << 9;
+ if (len == 0)
+ break;
+ for (i=0 ; i < conf->raid_disks; i++) {
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io) {
+ page = r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page;
+ if (bio_add_page(bio, page, len, 0) == 0) {
+ /* stop here */
+ r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page = page;
+ while (i > 0) {
+ i--;
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io==NULL) continue;
+ /* remove last page from this bio */
+ bio->bi_vcnt--;
+ bio->bi_size -= len;
+ bio->bi_flags &= ~(1<< BIO_SEG_VALID);
+ }
+ goto bio_full;
+ }
+ }
+ }
+ nr_sectors += len>>9;
+ sector_nr += len>>9;
+ } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
+ bio_full:
+ bio = r1_bio->bios[disk];
+ r1_bio->sectors = nr_sectors;
+
+ md_sync_acct(mirror->rdev->bdev, nr_sectors);
+
+ generic_make_request(bio);
+
+ return nr_sectors;
+}
+
+static int run(mddev_t *mddev)
+{
+ conf_t *conf;
+ int i, j, disk_idx;
+ mirror_info_t *disk;
+ mdk_rdev_t *rdev;
+ struct list_head *tmp;
+
+ if (mddev->level != 1) {
+ printk("raid1: %s: raid level not set to mirroring (%d)\n",
+ mdname(mddev), mddev->level);
+ goto out;
+ }
+ /*
+ * copy the already verified devices into our private RAID1
+ * bookkeeping area. [whatever we allocate in run(),
+ * should be freed in stop()]
+ */
+ conf = kmalloc(sizeof(conf_t), GFP_KERNEL);
+ mddev->private = conf;
+ if (!conf)
+ goto out_no_mem;
+
+ memset(conf, 0, sizeof(*conf));
+ conf->mirrors = kmalloc(sizeof(struct mirror_info)*mddev->raid_disks,
+ GFP_KERNEL);
+ if (!conf->mirrors)
+ goto out_no_mem;
+
+ memset(conf->mirrors, 0, sizeof(struct mirror_info)*mddev->raid_disks);
+
+ conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
+ if (!conf->poolinfo)
+ goto out_no_mem;
+ conf->poolinfo->mddev = mddev;
+ conf->poolinfo->raid_disks = mddev->raid_disks;
+ conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free,
+ conf->poolinfo);
+ if (!conf->r1bio_pool)
+ goto out_no_mem;
+
+ mddev->queue->unplug_fn = raid1_unplug;
+
+ mddev->queue->issue_flush_fn = raid1_issue_flush;
+
+ ITERATE_RDEV(mddev, rdev, tmp) {
+ disk_idx = rdev->raid_disk;
+ if (disk_idx >= mddev->raid_disks
+ || disk_idx < 0)
+ continue;
+ disk = conf->mirrors + disk_idx;
+
+ disk->rdev = rdev;
+
+ blk_queue_stack_limits(mddev->queue,
+ rdev->bdev->bd_disk->queue);
+ /* as we don't honour merge_bvec_fn, we must never risk
+ * violating it, so limit ->max_sector to one PAGE, as
+ * a one page request is never in violation.
+ */
+ if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
+ mddev->queue->max_sectors > (PAGE_SIZE>>9))
+ blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
+
+ disk->head_position = 0;
+ if (!rdev->faulty && rdev->in_sync)
+ conf->working_disks++;
+ }
+ conf->raid_disks = mddev->raid_disks;
+ conf->mddev = mddev;
+ spin_lock_init(&conf->device_lock);
+ INIT_LIST_HEAD(&conf->retry_list);
+ if (conf->working_disks == 1)
+ mddev->recovery_cp = MaxSector;
+
+ spin_lock_init(&conf->resync_lock);
+ init_waitqueue_head(&conf->wait_idle);
+ init_waitqueue_head(&conf->wait_resume);
+
+ if (!conf->working_disks) {
+ printk(KERN_ERR "raid1: no operational mirrors for %s\n",
+ mdname(mddev));
+ goto out_free_conf;
+ }
+
+ mddev->degraded = 0;
+ for (i = 0; i < conf->raid_disks; i++) {
+
+ disk = conf->mirrors + i;
+
+ if (!disk->rdev) {
+ disk->head_position = 0;
+ mddev->degraded++;
+ }
+ }
+
+ /*
+ * find the first working one and use it as a starting point
+ * to read balancing.
+ */
+ for (j = 0; j < conf->raid_disks &&
+ (!conf->mirrors[j].rdev ||
+ !conf->mirrors[j].rdev->in_sync) ; j++)
+ /* nothing */;
+ conf->last_used = j;
+
+
+
+ {
+ mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
+ if (!mddev->thread) {
+ printk(KERN_ERR
+ "raid1: couldn't allocate thread for %s\n",
+ mdname(mddev));
+ goto out_free_conf;
+ }
+ }
+ printk(KERN_INFO
+ "raid1: raid set %s active with %d out of %d mirrors\n",
+ mdname(mddev), mddev->raid_disks - mddev->degraded,
+ mddev->raid_disks);
+ /*
+ * Ok, everything is just fine now
+ */
+ mddev->array_size = mddev->size;
+
+ return 0;
+
+out_no_mem:
+ printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
+ mdname(mddev));
+
+out_free_conf:
+ if (conf) {
+ if (conf->r1bio_pool)
+ mempool_destroy(conf->r1bio_pool);
+ if (conf->mirrors)
+ kfree(conf->mirrors);
+ if (conf->poolinfo)
+ kfree(conf->poolinfo);
+ kfree(conf);
+ mddev->private = NULL;
+ }
+out:
+ return -EIO;
+}
+
+static int stop(mddev_t *mddev)
+{
+ conf_t *conf = mddev_to_conf(mddev);
+
+ md_unregister_thread(mddev->thread);
+ mddev->thread = NULL;
+ blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+ if (conf->r1bio_pool)
+ mempool_destroy(conf->r1bio_pool);
+ if (conf->mirrors)
+ kfree(conf->mirrors);
+ if (conf->poolinfo)
+ kfree(conf->poolinfo);
+ kfree(conf);
+ mddev->private = NULL;
+ return 0;
+}
+
+static int raid1_resize(mddev_t *mddev, sector_t sectors)
+{
+ /* no resync is happening, and there is enough space
+ * on all devices, so we can resize.
+ * We need to make sure resync covers any new space.
+ * If the array is shrinking we should possibly wait until
+ * any io in the removed space completes, but it hardly seems
+ * worth it.
+ */
+ mddev->array_size = sectors>>1;
+ set_capacity(mddev->gendisk, mddev->array_size << 1);
+ mddev->changed = 1;
+ if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
+ mddev->recovery_cp = mddev->size << 1;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ }
+ mddev->size = mddev->array_size;
+ return 0;
+}
+
+static int raid1_reshape(mddev_t *mddev, int raid_disks)
+{
+ /* We need to:
+ * 1/ resize the r1bio_pool
+ * 2/ resize conf->mirrors
+ *
+ * We allocate a new r1bio_pool if we can.
+ * Then raise a device barrier and wait until all IO stops.
+ * Then resize conf->mirrors and swap in the new r1bio pool.
+ */
+ mempool_t *newpool, *oldpool;
+ struct pool_info *newpoolinfo;
+ mirror_info_t *newmirrors;
+ conf_t *conf = mddev_to_conf(mddev);
+
+ int d;
+
+ for (d= raid_disks; d < conf->raid_disks; d++)
+ if (conf->mirrors[d].rdev)
+ return -EBUSY;
+
+ newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
+ if (!newpoolinfo)
+ return -ENOMEM;
+ newpoolinfo->mddev = mddev;
+ newpoolinfo->raid_disks = raid_disks;
+
+ newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free, newpoolinfo);
+ if (!newpool) {
+ kfree(newpoolinfo);
+ return -ENOMEM;
+ }
+ newmirrors = kmalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
+ if (!newmirrors) {
+ kfree(newpoolinfo);
+ mempool_destroy(newpool);
+ return -ENOMEM;
+ }
+ memset(newmirrors, 0, sizeof(struct mirror_info)*raid_disks);
+
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier++;
+ wait_event_lock_irq(conf->wait_idle, !conf->nr_pending,
+ conf->resync_lock, unplug_slaves(mddev));
+ spin_unlock_irq(&conf->resync_lock);
+
+ /* ok, everything is stopped */
+ oldpool = conf->r1bio_pool;
+ conf->r1bio_pool = newpool;
+ for (d=0; d < raid_disks && d < conf->raid_disks; d++)
+ newmirrors[d] = conf->mirrors[d];
+ kfree(conf->mirrors);
+ conf->mirrors = newmirrors;
+ kfree(conf->poolinfo);
+ conf->poolinfo = newpoolinfo;
+
+ mddev->degraded += (raid_disks - conf->raid_disks);
+ conf->raid_disks = mddev->raid_disks = raid_disks;
+
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier--;
+ spin_unlock_irq(&conf->resync_lock);
+ wake_up(&conf->wait_resume);
+ wake_up(&conf->wait_idle);
+
+
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
+
+ mempool_destroy(oldpool);
+ return 0;
+}
+
+
+static mdk_personality_t raid1_personality =
+{
+ .name = "raid1",
+ .owner = THIS_MODULE,
+ .make_request = make_request,
+ .run = run,
+ .stop = stop,
+ .status = status,
+ .error_handler = error,
+ .hot_add_disk = raid1_add_disk,
+ .hot_remove_disk= raid1_remove_disk,
+ .spare_active = raid1_spare_active,
+ .sync_request = sync_request,
+ .resize = raid1_resize,
+ .reshape = raid1_reshape,
+};
+
+static int __init raid_init(void)
+{
+ return register_md_personality(RAID1, &raid1_personality);
+}
+
+static void raid_exit(void)
+{
+ unregister_md_personality(RAID1);
+}
+
+module_init(raid_init);
+module_exit(raid_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("md-personality-3"); /* RAID1 */