[multipathd] nr_active inc/dec losts or overzealous

There is some weirdness in the nr_active handling in multipathd, For
instance, whenever you change state to a PATH_DOWN or PATH_SHAKY state,
you decrement the number of active paths, even if you change from
PATH_DOWN to PATH_SHAKY.

This patch attempts to fix the problem.  It slightly changes how some
of the states are handled.

diff --git a/libmultipath/structs_vec.c b/libmultipath/structs_vec.c
index 99cfbf4..a6ca2ca 100644 (file)
--- a/libmultipath/structs_vec.c
+++ b/libmultipath/structs_vec.c
@@ -214,7 +214,7 @@ extern void
 set_no_path_retry(struct multipath *mpp)
 {
        mpp->retry_tick = 0;
-       mpp->nr_active = pathcount(mpp, PATH_UP);
+       mpp->nr_active = pathcount(mpp, PATH_UP) + pathcount(mpp, PATH_GHOST);
        select_no_path_retry(mpp);
 
        switch (mpp->no_path_retry) {

diff --git a/multipathd/main.c b/multipathd/main.c
index 2229991..2550141 100644 (file)
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -282,10 +282,13 @@ update_multipath (struct vectors *vecs, char *mapname)
                                continue;
 
                        if (pp->state != PATH_DOWN) {
+                               int oldstate = pp->state;
                                condlog(2, "%s: mark as failed", pp->dev_t);
                                mpp->stat_path_failures++;
                                pp->state = PATH_DOWN;
-                               update_queue_mode_del_path(mpp);
+                               if (oldstate == PATH_UP ||
+                                   oldstate == PATH_GHOST)
+                                       update_queue_mode_del_path(mpp);
 
                                /*
                                 * if opportune,
@@ -1032,7 +1035,7 @@ exit_daemon (int status)
 }
 
 static void
-fail_path (struct path * pp)
+fail_path (struct path * pp, int del_active)
 {
        if (!pp->mpp)
                return;
@@ -1041,14 +1044,15 @@ fail_path (struct path * pp)
                 pp->dev_t, pp->mpp->alias);
 
        dm_fail_path(pp->mpp->alias, pp->dev_t);
-       update_queue_mode_del_path(pp->mpp);
+       if (del_active)
+               update_queue_mode_del_path(pp->mpp);
 }
 
 /*
  * caller must have locked the path list before calling that function
  */
 static void
-reinstate_path (struct path * pp)
+reinstate_path (struct path * pp, int add_active)
 {
        if (!pp->mpp)
                return;
@@ -1057,7 +1061,8 @@ reinstate_path (struct path * pp)
                condlog(0, "%s: reinstate failed", pp->dev_t);
        else {
                condlog(2, "%s: reinstated", pp->dev_t);
-               update_queue_mode_add_path(pp->mpp);
+               if (add_active)
+                       update_queue_mode_add_path(pp->mpp);
        }
 }
 
@@ -1191,6 +1196,7 @@ checkerloop (void *ap)
                        }
 
                        if (newstate != pp->state) {
+                               int oldstate = pp->state;
                                pp->state = newstate;
                                LOG_MSG(1, checker_message(&pp->checker));
 
@@ -1207,7 +1213,11 @@ checkerloop (void *ap)
                                        /*
                                         * proactively fail path in the DM
                                         */
-                                       fail_path(pp);
+                                       if (oldstate == PATH_UP ||
+                                           oldstate == PATH_GHOST)
+                                               fail_path(pp, 1);
+                                       else
+                                               fail_path(pp, 0);
 
                                        /*
                                         * cancel scheduled failback
@@ -1221,7 +1231,11 @@ checkerloop (void *ap)
                                /*
                                 * reinstate this path
                                 */
-                               reinstate_path(pp);
+                               if (oldstate != PATH_UP &&
+                                   oldstate != PATH_GHOST)
+                                       reinstate_path(pp, 1);
+                               else
+                                       reinstate_path(pp, 0);
 
                                /*
                                 * schedule [defered] failback