glusterd: add a cli command to trigger a statedump on a client

With this, we will be able to trigger statedumps on remote Gluster
clients, mainly targetted for applications using libgfapi.

Design:
SIGUSR signal is the most comman way of taking a statedump in Gluster.
But it cannot be used for libgfapi based processes, as the process
loading the library might have already consumed SIGUSR signal. Hence
going by the command way.

One has to issue a Gluster command to initiate a statedump on the
libgfapi based client. The command takes hostname and PID as an
argument. All the glusterds in the cluster, check if they are connected
to the specified hostname, and send an RPC request to all the connected
clients from that hostname (via the mgmt connection).

> URL: http://review.gluster.org/16357
> BUG: 1169302
> Signed-off-by: Poornima G <pgurusid@redhat.com>
> [ndevos: minor fixes and split patch in smaller pieces]
> Reviewed-on-master: https://review.gluster.org/9228
> Reviewed-by: Niels de Vos <ndevos@redhat.com>
> Tested-by: Niels de Vos <ndevos@redhat.com>
> Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
> Reviewed-by: Samikshan Bairagya <samikshan@gmail.com>

BUG: 1418981
Change-Id: Icbe4d2f026b32a2c7d5535e1bfb2cdaaff042e91
Signed-off-by: Shyam <srangana@redhat.com>
Reviewed-on: https://review.gluster.org/16601
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

1 files changed, 67 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd.c b/xlators/mgmt/glusterd/src/glusterd.c
index 18dcf10f2a3..d6f8baff4f2 100644
--- a/xlators/mgmt/glusterd/src/glusterd.c
+++ b/xlators/mgmt/glusterd/src/glusterd.c
@@ -47,6 +47,7 @@
 #include "glusterd-geo-rep.h"
 #include "run.h"
 #include "rpc-clnt-ping.h"
+#include "rpc-common-xdr.h"
 
 #include "syncop.h"
 
@@ -233,6 +234,72 @@ out:
 }
 
 int
+glusterd_client_statedump_submit_req (char *volname, char *target_ip,
+                                      char *pid)
+{
+        gf_statedump             statedump_req      = {0, };
+        glusterd_conf_t         *conf               = NULL;
+        int                      ret                = 0;
+        char                    *end_ptr            = NULL;
+        rpc_transport_t         *trans              = NULL;
+        char                    *ip_addr            = NULL;
+        xlator_t                *this               = NULL;
+        char                     tmp[UNIX_PATH_MAX] = {0, };
+
+        this = THIS;
+        GF_ASSERT (this);
+        conf = this->private;
+        GF_ASSERT (conf);
+
+        if (target_ip == NULL || pid == NULL) {
+                ret = -1;
+                goto out;
+        }
+
+        statedump_req.pid = strtol (pid, &end_ptr, 10);
+
+        gf_msg_debug (this->name, 0, "Performing statedump on volume %s "
+                      "client with pid:%d host:%s", volname, statedump_req.pid,
+                      target_ip);
+
+        pthread_mutex_lock (&conf->xprt_lock);
+        {
+                list_for_each_entry (trans, &conf->xprt_list, list) {
+                        /* check if this connection matches "all" or the
+                         * volname */
+                        if (strncmp (volname, "all", NAME_MAX) &&
+                            strncmp (trans->peerinfo.volname, volname,
+                                     NAME_MAX)) {
+                                /* no match, try next trans */
+                                continue;
+                        }
+
+                        strcpy (tmp, trans->peerinfo.identifier);
+                        ip_addr = strtok (tmp, ":");
+                        if (gf_is_same_address (ip_addr, target_ip)) {
+                                /* Every gluster client would have
+                                 * connected to glusterd(volfile server). This
+                                 * connection is used to send the statedump
+                                 * request rpc to the application.
+                                 */
+                                gf_msg_trace (this->name, 0, "Submitting "
+                                        "statedump rpc request for %s",
+                                        trans->peerinfo.identifier);
+                                rpcsvc_request_submit (conf->rpc, trans,
+                                                       &glusterd_cbk_prog,
+                                                       GF_CBK_STATEDUMP,
+                                                       &statedump_req, this->ctx,
+                                                       (xdrproc_t)xdr_gf_statedump);
+                        }
+                }
+        }
+        pthread_mutex_unlock (&conf->xprt_lock);
+out:
+        return ret;
+
+}
+
+int
 glusterd_fetchspec_notify (xlator_t *this)
 {
         int              ret   = -1;