glusterd/shd: Return null proc if process is not running.

We were ruturning first proc entry even if it is not running.
This was in an assumption that the process could have just
started and not updated the pidfile.

Now we that we have introduced the states for process state,
we can take decision based on that.

Change-Id: Ibfc11c966b0db599a8d6a08d8b975233b2bbfb8c
Fixes: bz#1728766
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>

1 files changed, 40 insertions, 18 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-svc-helper.c b/xlators/mgmt/glusterd/src/glusterd-svc-helper.c
index b98892af61e..cf40a758082 100644
--- a/xlators/mgmt/glusterd/src/glusterd-svc-helper.c
+++ b/xlators/mgmt/glusterd/src/glusterd-svc-helper.c
@@ -396,15 +396,38 @@ out:
     return ret;
 }
 
+gf_boolean_t
+glusterd_is_svcproc_attachable(glusterd_svc_proc_t *svc_proc)
+{
+    int pid = -1;
+    glusterd_svc_t *parent_svc = NULL;
+
+    if (!svc_proc)
+        return _gf_false;
+
+    if (svc_proc->status == GF_SVC_STARTING)
+        return _gf_true;
+
+    if (svc_proc->status == GF_SVC_STARTED ||
+        svc_proc->status == GF_SVC_DISCONNECTED) {
+        parent_svc = cds_list_entry(svc_proc->svcs.next, glusterd_svc_t,
+                                    mux_svc);
+        if (parent_svc && gf_is_service_running(parent_svc->proc.pidfile, &pid))
+            return _gf_true;
+    }
+
+    if (svc_proc->status == GF_SVC_DIED || svc_proc->status == GF_SVC_STOPPING)
+        return _gf_false;
+
+    return _gf_false;
+}
+
 void *
 __gf_find_compatible_svc(gd_node_type daemon)
 {
     glusterd_svc_proc_t *svc_proc = NULL;
-    glusterd_svc_proc_t *return_proc = NULL;
-    glusterd_svc_t *parent_svc = NULL;
     struct cds_list_head *svc_procs = NULL;
     glusterd_conf_t *conf = NULL;
-    int pid = -1;
 
     conf = THIS->private;
     GF_VALIDATE_OR_GOTO("glusterd", conf, out);
@@ -422,15 +445,7 @@ __gf_find_compatible_svc(gd_node_type daemon)
 
     cds_list_for_each_entry(svc_proc, svc_procs, svc_proc_list)
     {
-        parent_svc = cds_list_entry(svc_proc->svcs.next, glusterd_svc_t,
-                                    mux_svc);
-        if (!return_proc)
-            return_proc = svc_proc;
-
-        /* If there is an  already running shd daemons, select it. Otehrwise
-         * select the first one.
-         */
-        if (parent_svc && gf_is_service_running(parent_svc->proc.pidfile, &pid))
+        if (glusterd_is_svcproc_attachable(svc_proc))
             return (void *)svc_proc;
         /*
          * Logic to select one process goes here. Currently there is only one
@@ -438,7 +453,7 @@ __gf_find_compatible_svc(gd_node_type daemon)
          */
     }
 out:
-    return return_proc;
+    return NULL;
 }
 
 glusterd_svc_proc_t *
@@ -455,6 +470,7 @@ glusterd_svcprocess_new()
     CDS_INIT_LIST_HEAD(&new_svcprocess->svc_proc_list);
     CDS_INIT_LIST_HEAD(&new_svcprocess->svcs);
     new_svcprocess->notify = glusterd_muxsvc_common_rpc_notify;
+    new_svcprocess->status = GF_SVC_STARTING;
     return new_svcprocess;
 }
 
@@ -467,6 +483,7 @@ glusterd_shd_svc_mux_init(glusterd_volinfo_t *volinfo, glusterd_svc_t *svc)
     glusterd_conf_t *conf = NULL;
     glusterd_svc_t *parent_svc = NULL;
     int pid = -1;
+    gf_boolean_t stop_daemon = _gf_false;
     char pidfile[PATH_MAX] = {
         0,
     };
@@ -507,9 +524,10 @@ glusterd_shd_svc_mux_init(glusterd_volinfo_t *volinfo, glusterd_svc_t *svc)
 
             if (!mux_proc) {
                 if (pid != -1 && sys_access(pidfile, R_OK) == 0) {
-                    /* stale pid file, stop and unlink it */
-                    glusterd_proc_stop(&svc->proc, SIGTERM, PROC_STOP_FORCE);
-                    glusterd_unlink_file(pidfile);
+                    /* stale pid file, stop and unlink it. This has to be
+                     * done outside the attach_lock.
+                     */
+                    stop_daemon = _gf_true;
                 }
                 mux_proc = __gf_find_compatible_svc(GD_NODE_SHD);
             }
@@ -517,7 +535,6 @@ glusterd_shd_svc_mux_init(glusterd_volinfo_t *volinfo, glusterd_svc_t *svc)
                 /* Take first entry from the process */
                 parent_svc = cds_list_entry(mux_proc->svcs.next, glusterd_svc_t,
                                             mux_svc);
-                glusterd_copy_file(parent_svc->proc.pidfile, svc->proc.pidfile);
                 mux_conn = &parent_svc->conn;
                 if (volinfo)
                     volinfo->shd.attached = _gf_true;
@@ -548,6 +565,10 @@ glusterd_shd_svc_mux_init(glusterd_volinfo_t *volinfo, glusterd_svc_t *svc)
 unlock:
     pthread_mutex_unlock(&conf->attach_lock);
 out:
+    if (stop_daemon) {
+        glusterd_proc_stop(&svc->proc, SIGTERM, PROC_STOP_FORCE);
+        glusterd_unlink_file(pidfile);
+    }
     return ret;
 }
 
@@ -580,7 +601,8 @@ __gf_find_compatible_svc_from_pid(gd_node_type daemon, pid_t pid)
         cds_list_for_each_entry(svc, &svc_proc->svcs, mux_svc)
         {
             if (gf_is_service_running(svc->proc.pidfile, &mux_pid)) {
-                if (mux_pid == pid) {
+                if (mux_pid == pid &&
+                    glusterd_is_svcproc_attachable(svc_proc)) {
                     /*TODO
                      * inefficient loop, but at the moment, there is only
                      * one shd.