2 files changed, 23 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 330addfe9b77..818313e277e7 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4627,6 +4627,7 @@ static int do_md_run(mddev_t *mddev)
 	}
 	set_capacity(mddev->gendisk, mddev->array_sectors);
 	revalidate_disk(mddev->gendisk);
+	mddev->changed = 1;
 	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
 out:
 	return err;
@@ -4715,6 +4716,7 @@ static void md_clean(mddev_t *mddev)
 	mddev->sync_speed_min = mddev->sync_speed_max = 0;
 	mddev->recovery = 0;
 	mddev->in_sync = 0;
+	mddev->changed = 0;
 	mddev->degraded = 0;
 	mddev->safemode = 0;
 	mddev->bitmap_info.offset = 0;
@@ -4830,6 +4832,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
 
 		set_capacity(disk, 0);
 		mutex_unlock(&mddev->open_mutex);
+		mddev->changed = 1;
 		revalidate_disk(disk);
 
 		if (mddev->ro)
@@ -6014,7 +6017,7 @@ static int md_open(struct block_device *bdev, fmode_t mode)
 	atomic_inc(&mddev->openers);
 	mutex_unlock(&mddev->open_mutex);
 
-	check_disk_size_change(mddev->gendisk, bdev);
+	check_disk_change(bdev);
  out:
 	return err;
 }
@@ -6029,6 +6032,21 @@ static int md_release(struct gendisk *disk, fmode_t mode)
 
 	return 0;
 }
+
+static int md_media_changed(struct gendisk *disk)
+{
+	mddev_t *mddev = disk->private_data;
+
+	return mddev->changed;
+}
+
+static int md_revalidate(struct gendisk *disk)
+{
+	mddev_t *mddev = disk->private_data;
+
+	mddev->changed = 0;
+	return 0;
+}
 static const struct block_device_operations md_fops =
 {
 	.owner		= THIS_MODULE,
@@ -6039,6 +6057,8 @@ static const struct block_device_operations md_fops =
 	.compat_ioctl	= md_compat_ioctl,
 #endif
 	.getgeo		= md_getgeo,
+	.media_changed  = md_media_changed,
+	.revalidate_disk= md_revalidate,
 };
 
 static int md_thread(void * arg)
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 7e90b8593b2a..12215d437fcc 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -274,6 +274,8 @@ struct mddev_s
 	atomic_t			active;		/* general refcount */
 	atomic_t			openers;	/* number of active opens */
 
+	int				changed;	/* True if we might need to
+							 * reread partition info */
 	int				degraded;	/* whether md should consider
 							 * adding a spare
 							 */