NEX-7233 Attempting to destroy ZFS filesystem and create ZFS volume with the same name caused system panic
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Roman Strashkin <roman.strashkin@nexenta.com>
Reviewed by: Alek Pinchuk <alek.pinchuk@nexenta.com>

@@ -2169,10 +2169,14 @@
                         ASSERT(RW_READ_HELD(&ddv->sdev_contents));
                         if (rw_tryupgrade(&ddv->sdev_contents) == 0) {
                                 rw_exit(&ddv->sdev_contents);
                                 rw_enter(&ddv->sdev_contents, RW_WRITER);
                         }
+
+                        if (SDEVTOV(dv)->v_type == VDIR)
+                                (void) sdev_cleandir(dv, NULL, SDEV_ENFORCE);
+
                         sdev_cache_update(ddv, &dv, nm, SDEV_CACHE_DELETE);
                         rw_downgrade(&ddv->sdev_contents);
                         SDEV_RELE(dv);
                         dv = NULL;
                         goto lookup_create_node;