leastpending IO loadbalancing is not displayed properly

While using least pending IO lb policy for the LUN, the
dm_least_pending module is getting loaded and devices
are getting created properly. But multipath
display command does not display the paths for this LUN.

This is due to some explicit parsing for 'round-robin' in
dmparser.c, which has to be updated to accomodate other
load-balancing policies.

References: 444199

Signed-off-by: Hannes Reinecke <hare@suse.de>

diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c
index c2f5af7..bb83c0c 100644 (file)
--- a/libmultipath/dmparser.c
+++ b/libmultipath/dmparser.c
@@ -309,16 +309,20 @@ disassemble_map (vector pathvec, char * params, struct multipath * mpp)
                        pp->pgindex = i + 1;
 
                        for (k = 0; k < num_paths_args; k++)
-                               if (k == 0 && !strncmp(mpp->selector,
-                                                      "round-robin", 11)) {
-                                       p += get_word(p, &word);
-                                       def_minio = atoi(word);
+                               if (k == 0) {
+                                       if (!strncmp(mpp->selector,
+                                                    "round-robin", 11)) {
+                                               p += get_word(p, &word);
+                                               def_minio = atoi(word);
+
+                                               if (mpp->rr_weight == RR_WEIGHT_PRIO
+                                                   && pp->priority > 0)
+                                                       def_minio /= pp->priority;
 
-                                       if (mpp->rr_weight == RR_WEIGHT_PRIO
-                                           && pp->priority > 0)
-                                               def_minio /= pp->priority;
+                                               FREE(word);
+                                       } else
+                                               def_minio = 0;
 
-                                       FREE(word);
                                        if (def_minio != mpp->minio)
                                                mpp->minio = def_minio;
                                }
@@ -347,6 +351,7 @@ disassemble_status (char * params, struct multipath * mpp)
        int num_pg;
        int num_pg_args;
        int num_paths;
+       int def_minio = 0;
        struct path * pp;
        struct pathgroup * pgp;
 
@@ -440,7 +445,7 @@ disassemble_status (char * params, struct multipath * mpp)
                FREE(word);
 
                /*
-                * undef ?
+                * PG Status (discarded, would be '0' anyway)
                 */
                p += get_word(p, NULL);
 
@@ -503,8 +508,17 @@ disassemble_status (char * params, struct multipath * mpp)
                        /*
                         * selector args
                         */
-                       for (k = 0; k < num_pg_args; k++)
-                               p += get_word(p, NULL);
+                       for (k = 0; k < num_pg_args; k++) {
+                               if (!strncmp(mpp->selector,
+                                            "least-pending", 13)) {
+                                       p += get_word(p, &word);
+                                       if (sscanf(word,"%d:*d",
+                                                  &def_minio) == 1 &&
+                                           def_minio != mpp->minio)
+                                                       mpp->minio = def_minio;
+                               } else
+                                       p += get_word(p, NULL);
+                       }
                }
        }
        return 0;