[PATCH 3.16 177/410] rbd: whitelist RBD_FEATURE_OPERATIONS feature bit

[Ben Hutchings]

3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ilya Dryomov <idryomov@xxxxxxxxx>

commit e573427a440fd67d3f522357d7ac901d59281948 upstream.

This feature bit restricts older clients from performing certain
maintenance operations against an image (e.g. clone, snap create).
krbd does not perform maintenance operations.

Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Reviewed-by: Jason Dillaman <dillaman@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -117,8 +117,11 @@ static int atomic_dec_return_safe(atomic
 
 #define RBD_FEATURE_LAYERING	(1<<0)
 #define RBD_FEATURE_STRIPINGV2	(1<<1)
-#define RBD_FEATURES_ALL \
-	    (RBD_FEATURE_LAYERING | RBD_FEATURE_STRIPINGV2)
+#define RBD_FEATURE_OPERATIONS		(1<<8)
+
+#define RBD_FEATURES_ALL	(RBD_FEATURE_LAYERING |		\
+				 RBD_FEATURE_STRIPINGV2 |	\
+				 RBD_FEATURE_OPERATIONS)
 
 /* Features supported by this (client software) implementation. */