md: remove ->changed and related code.

We set ->changed to 1 and call check_disk_change at the end
of md_open so that bd_invalidated would be set and thus
partition rescan would happen appropriately.

Now that we call revalidate_disk directly, which sets bd_invalidates,
that indirection is no longer needed and can be removed.

Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/md.c

@@ -4501,7 +4501,6 @@ static int do_md_run(mddev_t * mddev)
 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
 
 	revalidate_disk(mddev->gendisk);
-	mddev->changed = 1;
 	md_new_event(mddev);
 	sysfs_notify_dirent(mddev->sysfs_state);
 	if (mddev->sysfs_action)
@@ -4620,7 +4619,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
 				}
 
 			set_capacity(disk, 0);
-			mddev->changed = 1;
+			revalidate_disk(disk);
 
 			if (mddev->ro)
 				mddev->ro = 0;
@@ -4686,7 +4685,6 @@ out:
 		mddev->sync_speed_min = mddev->sync_speed_max = 0;
 		mddev->recovery = 0;
 		mddev->in_sync = 0;
-		mddev->changed = 0;
 		mddev->degraded = 0;
 		mddev->barriers_work = 0;
 		mddev->safemode = 0;
@@ -5850,7 +5848,6 @@ static int md_open(struct block_device *bdev, fmode_t mode)
 	atomic_inc(&mddev->openers);
 	mutex_unlock(&mddev->open_mutex);
 
-	check_disk_change(bdev);
  out:
 	return err;
 }
@@ -5865,21 +5862,6 @@ 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,
@@ -5890,8 +5872,6 @@ 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)

drivers/md/md.h

@@ -237,7 +237,6 @@ 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
 							 */

drivers/md/raid1.c

@@ -2184,7 +2184,6 @@ static int raid1_resize(mddev_t *mddev, sector_t sectors)
 	if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
 		return -EINVAL;
 	set_capacity(mddev->gendisk, mddev->array_sectors);
-	mddev->changed = 1;
 	revalidate_disk(mddev->gendisk);
 	if (sectors > mddev->dev_sectors &&
 	    mddev->recovery_cp == MaxSector) {

drivers/md/raid5.c

@@ -5335,7 +5335,6 @@ static int raid5_resize(mddev_t *mddev, sector_t sectors)
 	    raid5_size(mddev, sectors, mddev->raid_disks))
 		return -EINVAL;
 	set_capacity(mddev->gendisk, mddev->array_sectors);
-	mddev->changed = 1;
 	revalidate_disk(mddev->gendisk);
 	if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
 		mddev->recovery_cp = mddev->dev_sectors;
@@ -5549,7 +5548,6 @@ static void raid5_finish_reshape(mddev_t *mddev)
 		if (mddev->delta_disks > 0) {
 			md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
 			set_capacity(mddev->gendisk, mddev->array_sectors);
-			mddev->changed = 1;
 			revalidate_disk(mddev->gendisk);
 		} else {
 			int d;