devicemapper: define the fallback flag

DM_UDEV_DISABLE_LIBRARY_FALLBACK is disabled by most applications today
when using device-mapper, and ensuring that device-mapper is in sync
with udev. This flag instructs devicemapper to not fallback to creating
the device nodes itself. In the case of udev sync not being supported,
devicemapper will attempt to create the devices in a timely manner,
regardless of udev.

Signed-off-by: Vincent Batts <vbatts@redhat.com>

pkg/devicemapper/devmapper_wrapper.go

@@ -86,6 +86,7 @@ const (
 	DmUdevDisableSubsystemRulesFlag = C.DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG
 	DmUdevDisableDiskRulesFlag      = C.DM_UDEV_DISABLE_DISK_RULES_FLAG
 	DmUdevDisableOtherRulesFlag     = C.DM_UDEV_DISABLE_OTHER_RULES_FLAG
+	DmUdevDisableLibraryFallback    = C.DM_UDEV_DISABLE_LIBRARY_FALLBACK
 )
 
 var (