Hello Sage Weil,
Commit 41ebcc0907c5 ("crush: remove forcefeed functionality") from
May 7, 2012 (linux-next), leads to the following Smatch static
checker warning:
net/ceph/crush/mapper.c:1012 crush_do_rule()
warn: iterator 'j' not incremented
net/ceph/crush/mapper.c
1004 for (i = 0; i < wsize; i++) {
1005 int bno;
1006 numrep = curstep->arg1;
1007 if (numrep <= 0) {
1008 numrep += result_max;
1009 if (numrep <= 0)
1010 continue;
1011 }
--> 1012 j = 0;
^^^^^^
The 2012 commit removed the j++ so now j is always 0.
1013 /* make sure bucket id is valid */
1014 bno = -1 - w[i];
1015 if (bno < 0 || bno >= map->max_buckets) {
1016 /* w[i] is probably CRUSH_ITEM_NONE */
1017 dprintk(" bad w[i] %d\n", w[i]);
1018 continue;
1019 }
1020 if (firstn) {
1021 int recurse_tries;
1022 if (choose_leaf_tries)
1023 recurse_tries =
1024 choose_leaf_tries;
1025 else if (map->chooseleaf_descend_once)
1026 recurse_tries = 1;
1027 else
1028 recurse_tries = choose_tries;
1029 osize += crush_choose_firstn(
1030 map,
1031 cw,
1032 map->buckets[bno],
1033 weight, weight_max,
1034 x, numrep,
1035 curstep->arg2,
1036 o+osize, j,
1037 result_max-osize,
1038 choose_tries,
1039 recurse_tries,
1040 choose_local_retries,
1041 choose_local_fallback_retries,
1042 recurse_to_leaf,
1043 vary_r,
1044 stable,
1045 c+osize,
1046 0,
1047 choose_args);
1048 } else {
1049 out_size = ((numrep < (result_max-osize)) ?
1050 numrep : (result_max-osize));
1051 crush_choose_indep(
1052 map,
1053 cw,
1054 map->buckets[bno],
1055 weight, weight_max,
1056 x, out_size, numrep,
1057 curstep->arg2,
1058 o+osize, j,
1059 choose_tries,
1060 choose_leaf_tries ?
1061 choose_leaf_tries : 1,
1062 recurse_to_leaf,
1063 c+osize,
1064 0,
1065 choose_args);
1066 osize += out_size;
1067 }
1068 }
1069
1070 if (recurse_to_leaf)
1071 /* copy final _leaf_ values to output set */
1072 memcpy(o, c, osize*sizeof(*o));
1073
1074 /* swap o and w arrays */
1075 swap(o, w);
1076 wsize = osize;
1077 break;
1078
1079
1080 case CRUSH_RULE_EMIT:
1081 for (i = 0; i < wsize && result_len < result_max; i++) {
1082 result[result_len] = w[i];
1083 result_len++;
1084 }
1085 wsize = 0;
1086 break;
1087
1088 default:
1089 dprintk(" unknown op %d at step %d\n",
1090 curstep->op, step);
1091 break;
1092 }
1093 }
1094
1095 return result_len;
1096 }
regards,
dan carpenter
