crush: use a temporary variable to simplify crush_do_rule

Use a temporary variable here to avoid repeated array lookups and clean up
the code a bit.

This reflects ceph.git commit 6b5be27634ad307b471a5bf0db85c4f5c834885f.

Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/net/ceph/crush/mapper.c b/net/ceph/crush/mapper.c
index 00baad5d3bd..fba9460fe57 100644
--- a/net/ceph/crush/mapper.c
+++ b/net/ceph/crush/mapper.c
@@ -519,14 +519,15 @@ int crush_do_rule(const struct crush_map *map,
         }
 
         for (step = 0; step < rule->len; step++) {
+                struct crush_rule_step *curstep = &rule->steps[step];
+
                 firstn = 0;
-                switch (rule->steps[step].op) {
+                switch (curstep->op) {
                 case CRUSH_RULE_TAKE:
-                        w[0] = rule->steps[step].arg1;
+                        w[0] = curstep->arg1;
 
                         /* find position in force_context/hierarchy */
-                        while (force_pos >= 0 &&
-                               force_context[force_pos] != w[0])
+                        while (force_pos >= 0 && force_context[force_pos] != w[0])
                                 force_pos--;
                         /* and move past it */
                         if (force_pos >= 0)
@@ -538,15 +539,16 @@ int crush_do_rule(const struct crush_map *map,
                 case CRUSH_RULE_CHOOSE_LEAF_FIRSTN:
                 case CRUSH_RULE_CHOOSE_FIRSTN:
                         firstn = 1;
+                        /* fall through */
                 case CRUSH_RULE_CHOOSE_LEAF_INDEP:
                 case CRUSH_RULE_CHOOSE_INDEP:
                         if (wsize == 0)
                                 break;
 
                         recurse_to_leaf =
-                                rule->steps[step].op ==
+                                curstep->op ==
                                  CRUSH_RULE_CHOOSE_LEAF_FIRSTN ||
-                                rule->steps[step].op ==
+                                curstep->op ==
                                 CRUSH_RULE_CHOOSE_LEAF_INDEP;
 
                         /* reset output */
@@ -558,7 +560,7 @@ int crush_do_rule(const struct crush_map *map,
                                  * basically, numrep <= 0 means relative to
                                  * the provided result_max
                                  */
-                                numrep = rule->steps[step].arg1;
+                                numrep = curstep->arg1;
                                 if (numrep <= 0) {
                                         numrep += result_max;
                                         if (numrep <= 0)
@@ -569,7 +571,7 @@ int crush_do_rule(const struct crush_map *map,
                                         /* skip any intermediate types */
                                         while (force_pos &&
                                                force_context[force_pos] < 0 &&
-                                               rule->steps[step].arg2 !=
+                                               curstep->arg2 !=
                                                map->buckets[-1 -
                                                force_context[force_pos]]->type)
                                                 force_pos--;
@@ -583,7 +585,7 @@ int crush_do_rule(const struct crush_map *map,
                                                       map->buckets[-1-w[i]],
                                                       weight,
                                                       x, numrep,
-                                                      rule->steps[step].arg2,
+                                                      curstep->arg2,
                                                       o+osize, j,
                                                       firstn,
                                                       recurse_to_leaf, c+osize);