drbd: Refcounting for mdev objects

Preparing removal of drbd_cfg_rwsem

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 240319ce865..8da0e99ee7e 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2052,7 +2052,6 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
 	init_waitqueue_head(&mdev->al_wait);
 	init_waitqueue_head(&mdev->seq_wait);
 
-	/* mdev->tconn->agreed_pro_version gets initialized in drbd_connect() */
 	mdev->write_ordering = WO_bdev_flush;
 	mdev->resync_wenr = LC_FREE;
 	mdev->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
@@ -2272,21 +2271,16 @@ static void drbd_release_all_peer_reqs(struct drbd_conf *mdev)
 }
 
 /* caution. no locking. */
-void drbd_delete_device(struct drbd_conf *mdev)
+void drbd_minor_destroy(struct kref *kref)
 {
+	struct drbd_conf *mdev = container_of(kref, struct drbd_conf, kref);
 	struct drbd_tconn *tconn = mdev->tconn;
 
-	idr_remove(&mdev->tconn->volumes, mdev->vnr);
-	idr_remove(&minors, mdev_to_minor(mdev));
-	synchronize_rcu();
-
 	/* paranoia asserts */
 	D_ASSERT(mdev->open_cnt == 0);
 	D_ASSERT(list_empty(&mdev->tconn->data.work.q));
 	/* end paranoia asserts */
 
-	del_gendisk(mdev->vdisk);
-
 	/* cleanup stuff that may have been allocated during
 	 * device (re-)configuration or state changes */
 
@@ -2320,6 +2314,7 @@ static void drbd_cleanup(void)
 {
 	unsigned int i;
 	struct drbd_conf *mdev;
+	struct drbd_tconn *tconn, *tmp;
 
 	unregister_reboot_notifier(&drbd_notifier);
 
@@ -2337,8 +2332,19 @@ static void drbd_cleanup(void)
 	drbd_genl_unregister();
 
 	down_write(&drbd_cfg_rwsem);
-	idr_for_each_entry(&minors, mdev, i)
-		drbd_delete_device(mdev);
+	idr_for_each_entry(&minors, mdev, i) {
+		idr_remove(&minors, mdev_to_minor(mdev));
+		idr_remove(&mdev->tconn->volumes, mdev->vnr);
+		del_gendisk(mdev->vdisk);
+		synchronize_rcu();
+		kref_put(&mdev->kref, &drbd_minor_destroy);
+	}
+
+	list_for_each_entry_safe(tconn, tmp, &drbd_tconns, all_tconn) {
+		list_del(&tconn->all_tconn);
+		synchronize_rcu();
+		kref_put(&tconn->kref, &conn_destroy);
+	}
 	up_write(&drbd_cfg_rwsem);
 
 	drbd_destroy_mempools();
@@ -2625,6 +2631,7 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor,
 		goto out_idr_remove_vol;
 	}
 	add_disk(disk);
+	kref_init(&mdev->kref); /* one ref for both idrs and the the add_disk */
 
 	/* inherit the connection state */
 	mdev->state.conn = tconn->cstate;