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, 97 insertions, 25 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 333be2e5c0c..df058330cd0 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -1617,7 +1617,7 @@ glusterd_service_stop (const char *service, char *pidfile, int sig,
                 goto out;
 
         sleep (1);
-        if (gf_is_service_running (pidfile, NULL)) {
+        if (gf_is_service_running (pidfile, &pid)) {
                 ret = kill (pid, SIGKILL);
                 if (ret) {
                         gf_msg (this->name, GF_LOG_ERROR, errno,
@@ -1718,6 +1718,8 @@ glusterd_set_brick_socket_filepath (glusterd_volinfo_t *volinfo,
         xlator_t                *this = NULL;
         glusterd_conf_t         *priv = NULL;
         int                     expected_file_len = 0;
+        char                    export_path[PATH_MAX] = {0,};
+        char                    sock_filepath[PATH_MAX] = {0,};
 
         expected_file_len = strlen (GLUSTERD_SOCK_DIR) + strlen ("/") +
                             MD5_DIGEST_LENGTH*2 + strlen (".socket") + 1;
@@ -1728,18 +1730,10 @@ glusterd_set_brick_socket_filepath (glusterd_volinfo_t *volinfo,
         priv = this->private;
 
         GLUSTERD_GET_VOLUME_DIR (volume_dir, volinfo, priv);
-        if (is_brick_mx_enabled ()) {
-                snprintf (sockpath, len, "%s/run/daemon-%s.socket",
-                          volume_dir, brickinfo->hostname);
-        } else {
-                char                    export_path[PATH_MAX] = {0,};
-                char                    sock_filepath[PATH_MAX] = {0,};
-                GLUSTERD_REMOVE_SLASH_FROM_PATH (brickinfo->path, export_path);
-                snprintf (sock_filepath, PATH_MAX, "%s/run/%s-%s",
-                          volume_dir, brickinfo->hostname, export_path);
-
-                glusterd_set_socket_filepath (sock_filepath, sockpath, len);
-        }
+        GLUSTERD_REMOVE_SLASH_FROM_PATH (brickinfo->path, export_path);
+        snprintf (sock_filepath, PATH_MAX, "%s/run/%s-%s",
+                  volume_dir, brickinfo->hostname, export_path);
+        glusterd_set_socket_filepath (sock_filepath, sockpath, len);
 }
 
 /* connection happens only if it is not aleady connected,
@@ -1833,6 +1827,7 @@ glusterd_volume_start_glusterfs (glusterd_volinfo_t  *volinfo,
         char                    rdma_brick_path[PATH_MAX] = {0,};
         struct rpc_clnt         *rpc = NULL;
         rpc_clnt_connection_t   *conn  = NULL;
+        int                     pid    = -1;
 
         GF_ASSERT (volinfo);
         GF_ASSERT (brickinfo);
@@ -1855,7 +1850,7 @@ glusterd_volume_start_glusterfs (glusterd_volinfo_t  *volinfo,
         }
 
         GLUSTERD_GET_BRICK_PIDFILE (pidfile, volinfo, brickinfo, priv);
-        if (gf_is_service_running (pidfile, NULL)) {
+        if (gf_is_service_running (pidfile, &pid)) {
                 goto connect;
         }
 
@@ -5047,8 +5042,6 @@ attach_brick (xlator_t *this,
 
         GLUSTERD_GET_BRICK_PIDFILE (pidfile1, other_vol, other_brick, conf);
         GLUSTERD_GET_BRICK_PIDFILE (pidfile2, volinfo, brickinfo, conf);
-        (void) sys_unlink (pidfile2);
-        (void) sys_link (pidfile1, pidfile2);
 
         if (volinfo->is_snap_volume) {
                 snprintf (full_id, sizeof(full_id), "/%s/%s/%s.%s.%s",
@@ -5068,6 +5061,10 @@ attach_brick (xlator_t *this,
                                                GLUSTERD_BRICK_ATTACH);
                         rpc_clnt_unref (rpc);
                         if (!ret) {
+                                /* PID file is copied once brick has attached
+                                  successfully
+                                */
+                                glusterd_copy_file (pidfile1, pidfile2);
                                 return 0;
                         }
                 }
@@ -5287,6 +5284,80 @@ find_compatible_brick (glusterd_conf_t *conf,
         return NULL;
 }
 
+/* Below function is use to populate sockpath based on passed pid
+   value as a argument after check the value from proc
+*/
+
+void
+glusterd_get_sock_from_brick_pid (int pid, char *sockpath, size_t len)
+{
+        char fname[128] = {0,};
+        char buf[1024] = {0,};
+        char cmdline[2048] = {0,};
+        xlator_t                *this = NULL;
+        int fd         = -1;
+        int i = 0, j = 0;
+        char   *ptr   = NULL;
+        char   *brptr   = NULL;
+        char tmpsockpath[PATH_MAX] = {0,};
+        size_t blen    = 0;
+
+        this = THIS;
+        GF_ASSERT (this);
+
+        snprintf(fname, sizeof(fname), "/proc/%d/cmdline", pid);
+
+        if (sys_access (fname , R_OK) != 0) {
+                gf_log (this->name, GF_LOG_ERROR,
+                         "brick process %d is not running", pid);
+                return;
+        }
+
+        fd = open(fname, O_RDONLY);
+        if (fd != -1) {
+                blen = (int)sys_read(fd, buf, 1024);
+        } else {
+                gf_log (this->name, GF_LOG_ERROR,
+                         "open failed %s to open a file %s", strerror (errno),
+                                                              fname);
+                return;
+        }
+
+        /* convert cmdline to single string */
+        for (i = 0 , j = 0; i < blen; i++)  {
+                if (buf[i] == '\0')
+                        cmdline[j++] = ' ';
+                else if (buf[i] < 32 || buf[i] > 126) /* remove control char */
+                        continue;
+                else if (buf[i] == '"' || buf[i] == '\\') {
+                        cmdline[j++] = '\\';
+                        cmdline[j++] = buf[i];
+                } else {
+                        cmdline[j++] = buf[i];
+                }
+        }
+        cmdline[j] = '\0';
+        if (fd)
+                sys_close(fd);
+
+        ptr =   strstr(cmdline, "-S ");
+        ptr =   strchr(ptr, '/');
+        brptr = strstr(ptr, "--brick-name");
+        i = 0;
+
+        while (ptr < brptr) {
+                if (*ptr != 32)
+                        tmpsockpath[i++] = *ptr;
+                ptr++;
+        }
+
+        if (tmpsockpath[0]) {
+                strncpy (sockpath, tmpsockpath , i);
+        }
+
+}
+
+
 int
 glusterd_brick_start (glusterd_volinfo_t *volinfo,
                       glusterd_brickinfo_t *brickinfo,
@@ -5298,7 +5369,6 @@ glusterd_brick_start (glusterd_volinfo_t *volinfo,
         glusterd_conf_t         *conf = NULL;
         int32_t                 pid                   = -1;
         char                    pidfile[PATH_MAX]     = {0};
-        FILE                    *fp;
         char                    socketpath[PATH_MAX]  = {0};
         glusterd_volinfo_t      *other_vol;
 
@@ -5352,8 +5422,16 @@ glusterd_brick_start (glusterd_volinfo_t *volinfo,
                          * same port (on another brick) and re-use that.
                          * TBD: re-use RPC connection across bricks
                          */
-                        glusterd_set_brick_socket_filepath (volinfo, brickinfo,
-                                        socketpath, sizeof (socketpath));
+                        if (is_brick_mx_enabled ())
+                                glusterd_get_sock_from_brick_pid (pid, socketpath,
+                                                                  sizeof(socketpath));
+                        else
+                                glusterd_set_brick_socket_filepath (volinfo, brickinfo,
+                                                                    socketpath,
+                                                                    sizeof (socketpath));
+                        gf_log (this->name, GF_LOG_DEBUG,
+                                "Using %s as sockfile for brick %s of volume %s ",
+                                socketpath, brickinfo->path, volinfo->volname);
                         (void) glusterd_brick_connect (volinfo, brickinfo,
                                         socketpath);
                 }
@@ -5392,12 +5470,6 @@ glusterd_brick_start (glusterd_volinfo_t *volinfo,
          *
          * TBD: pray for GlusterD 2 to be ready soon.
          */
-        (void) sys_unlink (pidfile);
-        fp = fopen (pidfile, "w+");
-        if (fp) {
-                (void) fprintf (fp, "0\n");
-                (void) fclose (fp);
-        }
 
         ret = glusterd_volume_start_glusterfs (volinfo, brickinfo, wait);
         if (ret) {