glusterd: socketfile & pidfile related fixes for brick multiplexing feature

Problem: While brick-muliplexing is on after restarting glusterd, CLI is
         not showing pid of all brick processes in all volumes.

Solution: While brick-mux is on all local brick process communicated through one
          UNIX socket but as per current code (glusterd_brick_start) it is trying
          to communicate with separate UNIX socket for each volume which is populated
          based on brick-name and vol-name.Because of multiplexing design only one
          UNIX socket is opened so it is throwing poller error and not able to
          fetch correct status of brick process through cli process.
          To resolve the problem write a new function glusterd_set_socket_filepath_for_mux
          that will call by glusterd_brick_start to validate about the existence of socketpath.
          To avoid the continuous EPOLLERR erros in  logs update socket_connect code.

Test:     To reproduce the issue followed below steps
          1) Create two distributed volumes(dist1 and dist2)
          2) Set cluster.brick-multiplex is on
          3) kill glusterd
          4) run command gluster v status
          After apply the patch it shows correct pid for all volumes

> BUG: 1444596
> Change-Id: I5d10af69dea0d0ca19511f43870f34295a54a4d2
> Signed-off-by: Mohit Agrawal <moagrawa@redhat.com>
> Reviewed-on: https://review.gluster.org/17101
> Smoke: Gluster Build System <jenkins@build.gluster.org>
> Reviewed-by: Prashanth Pai <ppai@redhat.com>
> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
> Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
> (cherry picked from commit 21c7f7baccfaf644805e63682e5a7d2a9864a1e6)

Change-Id: I1892c80b9ffa93974f20c92d421660bcf93c4cda
BUG: 1449002
Signed-off-by: Mohit Agrawal <moagrawa@redhat.com>
Reviewed-on: https://review.gluster.org/17210
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-by: Prashanth Pai <ppai@redhat.com>

1 files changed, 27 insertions, 9 deletions

diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index eef1546cc69..cf6f2fc27ed 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -51,6 +51,7 @@
 #include "hashfn.h"
 #include "glusterfs-acl.h"
 #include "events.h"
+#include <sys/types.h>
 
 char *marker_xattrs[] = {"trusted.glusterfs.quota.*",
                          "trusted.glusterfs.*.xtime",
@@ -1841,6 +1842,9 @@ posix_health_check_thread_proc (void *data)
         struct posix_private *priv               = NULL;
         uint32_t              interval           = 0;
         int                   ret                = -1;
+        xlator_t                *top             = NULL;
+        xlator_list_t           **trav_p         = NULL;
+        int                     count            = 0;
 
         this = data;
         priv = this->private;
@@ -1852,7 +1856,6 @@ posix_health_check_thread_proc (void *data)
 
         gf_msg_debug (this->name, 0, "health-check thread started, "
                 "interval = %d seconds", interval);
-
         while (1) {
                 /* aborting sleep() is a request to exit this thread, sleep()
                  * will normally not return when cancelled */
@@ -1889,18 +1892,33 @@ abort:
 
         xlator_notify (this->parents->xlator, GF_EVENT_CHILD_DOWN, this);
 
-        ret = sleep (30);
-        if (ret == 0) {
+        /* Below code is use to ensure if brick multiplexing is enabled if
+           count is more than 1 it means brick mux has enabled
+        */
+        if (this->ctx->active) {
+                top = this->ctx->active->first;
+                for (trav_p = &top->children; *trav_p;
+                                               trav_p = &(*trav_p)->next) {
+                        count++;
+                }
+        }
+
+        if (count == 1) {
                 gf_msg (this->name, GF_LOG_EMERG, 0, P_MSG_HEALTHCHECK_FAILED,
                         "still alive! -> SIGTERM");
-                kill (getpid(), SIGTERM);
-        }
+                ret = sleep (30);
 
-        ret = sleep (30);
-        if (ret == 0) {
+                /* Need to kill the process only while brick mux has not enabled
+                */
+                if (ret == 0)
+                        kill (getpid(), SIGTERM);
+
+                ret = sleep (30);
                 gf_msg (this->name, GF_LOG_EMERG, 0, P_MSG_HEALTHCHECK_FAILED,
-                        "still alive! -> SIGKILL");
-                kill (getpid(), SIGKILL);
+                        "still alive! -> SIGTERM");
+                if (ret == 0)
+                        kill (getpid(), SIGTERM);
+
         }
 
         return NULL;