dm: allow targets to request flushes regardless of underlying device support
Allow targets to override the 'supports flush' calculation.
Set 'flush_supported' if a target needs to receive flushes regardless of
whether or not its underlying devices have support.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 8bdbbfc..bdd65e9 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -212,6 +212,12 @@
char *error;
/*
+ * Set if this target needs to receive flushes regardless of
+ * whether or not its underlying devices have support.
+ */
+ bool flush_supported:1;
+
+ /*
* Set if this target needs to receive discards regardless of
* whether or not its underlying devices have support.
*/