glusterd: clean up portmap on brick disconnect

GlusterD's portmap entry for a brick is cleaned up when a PMAP_SIGNOUT event is
initiated by the brick process at the shutdown. But if the brick process crashes
or gets killed through SIGKILL then this event is not initiated and glusterd
ends up with a stale port. Since GlusterD's portmap traversal happens both ways,
forward for allocation and backward for registry search, there is a possibility
that glusterd might end up running with a stale port for a brick which
eventually will end up with clients to fail to connect to the bricks.

Solution is to clean up the port entry in case the process is down as
part of the brick disconnect event. Although with this the handling
PMAP_SIGNOUT event becomes redundant in most of the cases, but this is
the safeguard method to avoid glusterd getting into the stale port
issues.

> mainline patch : https://review.gluster.org/#/c/18541/

Change-Id: I04c5be6d11e772ee4de16caf56dbb37d5c944303
BUG: 1507747
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
(cherry picked from commit 30e0b86aae00430823f2523c6efa3c4ebbf0a478)

4 files changed, 46 insertions, 11 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-handler.c b/xlators/mgmt/glusterd/src/glusterd-handler.c
index 37ef277f2b7..7f26e9c7d21 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handler.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handler.c
@@ -5980,8 +5980,10 @@ __glusterd_brick_rpc_notify (struct rpc_clnt *rpc, void *mydata,
         glusterd_volinfo_t      *volinfo           = NULL;
         xlator_t                *this              = NULL;
         int                      temp              = 0;
+        int32_t                  pid               = -1;
         glusterd_brickinfo_t    *brickinfo_tmp     = NULL;
         glusterd_brick_proc_t   *brick_proc        = NULL;
+        char                     pidfile[PATH_MAX] = {0};
 
         brickid = mydata;
         if (!brickid)
@@ -6080,6 +6082,29 @@ __glusterd_brick_rpc_notify (struct rpc_clnt *rpc, void *mydata,
                                   "peer=%s;volume=%s;brick=%s",
                                   brickinfo->hostname, volinfo->volname,
                                   brickinfo->path);
+                        /* In case of an abrupt shutdown of a brick PMAP_SIGNOUT
+                         * event is not received by glusterd which can lead to a
+                         * stale port entry in glusterd, so forcibly clean up
+                         * the same if the process is not running
+                         */
+                        GLUSTERD_GET_BRICK_PIDFILE (pidfile, volinfo,
+                                                    brickinfo, conf);
+                        if (!gf_is_service_running (pidfile, &pid)) {
+                                ret = pmap_registry_remove (
+                                                      THIS, brickinfo->port,
+                                                      brickinfo->path,
+                                                      GF_PMAP_PORT_BRICKSERVER,
+                                                      NULL, _gf_true);
+                                if (ret) {
+                                        gf_msg (this->name, GF_LOG_WARNING,
+                                                GD_MSG_PMAP_REGISTRY_REMOVE_FAIL,
+                                                0, "Failed to remove pmap "
+                                                "registry for port %d for "
+                                                "brick %s", brickinfo->port,
+                                                brickinfo->path);
+                                        ret = 0;
+                                }
+                        }
                 }
 
                 if (is_brick_mx_enabled()) {
diff --git a/xlators/mgmt/glusterd/src/glusterd-pmap.c b/xlators/mgmt/glusterd/src/glusterd-pmap.c
index 2a754769c95..1b547e79a5f 100644
--- a/xlators/mgmt/glusterd/src/glusterd-pmap.c
+++ b/xlators/mgmt/glusterd/src/glusterd-pmap.c
@@ -239,7 +239,8 @@ pmap_assign_port (xlator_t *this, int old_port, const char *path)
 
         if (old_port) {
                 ret = pmap_registry_remove (this, 0, path,
-                                            GF_PMAP_PORT_BRICKSERVER, NULL);
+                                            GF_PMAP_PORT_BRICKSERVER, NULL,
+                                            _gf_false);
                 if (ret) {
                         gf_msg (this->name, GF_LOG_WARNING,
                                 GD_MSG_PMAP_REGISTRY_REMOVE_FAIL, 0, "Failed to"
@@ -342,7 +343,8 @@ pmap_registry_extend (xlator_t *this, int port, const char *brickname)
 
 int
 pmap_registry_remove (xlator_t *this, int port, const char *brickname,
-                      gf_pmap_port_type_t type, void *xprt)
+                      gf_pmap_port_type_t type, void *xprt,
+                      gf_boolean_t brick_disconnect)
 {
         struct pmap_registry *pmap = NULL;
         int                   p = 0;
@@ -389,11 +391,16 @@ remove:
          * can delete the entire entry.
          */
         if (!pmap->ports[p].xprt) {
-                brick_str = pmap->ports[p].brickname;
-                if (brick_str) {
-                        while (*brick_str != '\0') {
-                                if (*(brick_str++) != ' ') {
-                                        goto out;
+                /* If the signout call is being triggered by brick disconnect
+                 * then clean up all the bricks (in case of brick mux)
+                 */
+                if (!brick_disconnect) {
+                        brick_str = pmap->ports[p].brickname;
+                        if (brick_str) {
+                                while (*brick_str != '\0') {
+                                        if (*(brick_str++) != ' ') {
+                                                goto out;
+                                        }
                                 }
                         }
                 }
@@ -548,14 +555,15 @@ __gluster_pmap_signout (rpcsvc_request_t *req)
                 goto fail;
         }
         rsp.op_ret = pmap_registry_remove (THIS, args.port, args.brick,
-                                           GF_PMAP_PORT_BRICKSERVER, req->trans);
+                                           GF_PMAP_PORT_BRICKSERVER, req->trans,
+                                           _gf_false);
 
         ret = glusterd_get_brickinfo (THIS, args.brick, args.port, &brickinfo);
         if (args.rdma_port) {
                 snprintf(brick_path, PATH_MAX, "%s.rdma", args.brick);
                 rsp.op_ret = pmap_registry_remove (THIS, args.rdma_port,
                                 brick_path, GF_PMAP_PORT_BRICKSERVER,
-                                req->trans);
+                                req->trans, _gf_false);
         }
         /* Update portmap status on brickinfo */
         if (brickinfo)
diff --git a/xlators/mgmt/glusterd/src/glusterd-pmap.h b/xlators/mgmt/glusterd/src/glusterd-pmap.h
index 9965a9577b5..253b4ccc85d 100644
--- a/xlators/mgmt/glusterd/src/glusterd-pmap.h
+++ b/xlators/mgmt/glusterd/src/glusterd-pmap.h
@@ -42,7 +42,8 @@ int pmap_registry_bind (xlator_t *this, int port, const char *brickname,
                         gf_pmap_port_type_t type, void *xprt);
 int pmap_registry_extend (xlator_t *this, int port, const char *brickname);
 int pmap_registry_remove (xlator_t *this, int port, const char *brickname,
-                          gf_pmap_port_type_t type, void *xprt);
+                          gf_pmap_port_type_t type, void *xprt,
+                          gf_boolean_t brick_disconnect);
 int pmap_registry_search (xlator_t *this, const char *brickname,
                           gf_pmap_port_type_t type, gf_boolean_t destroy);
 struct pmap_registry *pmap_registry_get (xlator_t *this);
diff --git a/xlators/mgmt/glusterd/src/glusterd.c b/xlators/mgmt/glusterd/src/glusterd.c
index 4887ff413bf..81a3206d3f8 100644
--- a/xlators/mgmt/glusterd/src/glusterd.c
+++ b/xlators/mgmt/glusterd/src/glusterd.c
@@ -424,7 +424,8 @@ glusterd_rpcsvc_notify (rpcsvc_t *rpc, void *xl, rpcsvc_event_t event,
                 pthread_mutex_lock (&priv->xprt_lock);
                 list_del (&xprt->list);
                 pthread_mutex_unlock (&priv->xprt_lock);
-                pmap_registry_remove (this, 0, NULL, GF_PMAP_PORT_ANY, xprt);
+                pmap_registry_remove (this, 0, NULL, GF_PMAP_PORT_ANY, xprt,
+                                      _gf_false);
                 break;
         }