crush: add SET_CHOOSE_TRIES rule step

Since we can specify the recursive retries in a rule, we may as well also
specify the non-recursive tries too for completeness.

Reflects ceph.git commit d1b97462cffccc871914859eaee562f2786abfd1.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

include/linux/crush/crush.h

@@ -47,7 +47,8 @@ enum {
 	CRUSH_RULE_CHOOSE_LEAF_FIRSTN = 6,
 	CRUSH_RULE_CHOOSE_LEAF_INDEP = 7,
 
-	CRUSH_RULE_SET_CHOOSE_LEAF_TRIES = 9,
+	CRUSH_RULE_SET_CHOOSE_TRIES = 8, /* override choose_total_tries */
+	CRUSH_RULE_SET_CHOOSE_LEAF_TRIES = 9, /* override chooseleaf_descend_once */
 };
 
 /*

net/ceph/crush/mapper.c

@@ -661,6 +661,11 @@ int crush_do_rule(const struct crush_map *map,
 			wsize = 1;
 			break;
 
+		case CRUSH_RULE_SET_CHOOSE_TRIES:
+			if (curstep->arg1 > 0)
+				choose_tries = curstep->arg1;
+			break;
+
 		case CRUSH_RULE_SET_CHOOSE_LEAF_TRIES:
 			if (curstep->arg1 > 0)
 				choose_leaf_tries = curstep->arg1;