md: Export and rename find_rdev_nr_rcu

This is required by the clustering module (patches to follow) to
find the device to remove or re-add.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/md.c

@@ -642,7 +642,7 @@ void mddev_unlock(struct mddev *mddev)
 }
 EXPORT_SYMBOL_GPL(mddev_unlock);
 
-static struct md_rdev *find_rdev_nr_rcu(struct mddev *mddev, int nr)
+struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr)
 {
 	struct md_rdev *rdev;
 
@@ -652,6 +652,7 @@ static struct md_rdev *find_rdev_nr_rcu(struct mddev *mddev, int nr)
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(md_find_rdev_nr_rcu);
 
 static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
 {
@@ -2049,11 +2050,11 @@ static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
 		int choice = 0;
 		if (mddev->pers)
 			choice = mddev->raid_disks;
-		while (find_rdev_nr_rcu(mddev, choice))
+		while (md_find_rdev_nr_rcu(mddev, choice))
 			choice++;
 		rdev->desc_nr = choice;
 	} else {
-		if (find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
+		if (md_find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
 			rcu_read_unlock();
 			return -EBUSY;
 		}
@@ -5721,7 +5722,7 @@ static int get_disk_info(struct mddev *mddev, void __user * arg)
 		return -EFAULT;
 
 	rcu_read_lock();
-	rdev = find_rdev_nr_rcu(mddev, info.number);
+	rdev = md_find_rdev_nr_rcu(mddev, info.number);
 	if (rdev) {
 		info.major = MAJOR(rdev->bdev->bd_dev);
 		info.minor = MINOR(rdev->bdev->bd_dev);

drivers/md/md.h

@@ -672,6 +672,7 @@ extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
 extern void md_reload_sb(struct mddev *mddev);
 extern void md_update_sb(struct mddev *mddev, int force);
 extern void md_kick_rdev_from_array(struct md_rdev * rdev);
+struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr);
 static inline int mddev_check_plugged(struct mddev *mddev)
 {
 	return !!blk_check_plugged(md_unplug, mddev,