glusterfsd: Make each multiplexed brick sign in

NOTE: This change will be consumed by brick mux implementation of
glusterd2 only. No corresponsing change in glusterd1 has been made.

When a multiplexed brick process is shutting down, it sends sign out
requests to glusterd for all bricks that it contains. However, sign in
request is only sent for a single brick. Consequently, glusterd has to
use some tricky means to repopulate pmap registry with information of
multiplexed bricks during glusterd restart.

This change makes each multiplexed brick send a sign in request to
glusterd2 which ensures that glusterd2 can easily repopulate pmap
registry with port information.

As a bonus, sign in request will now also contain PID of the brick
sending the request so that glusterd2 can rely on this instead of
having to read/manage brick pidfiles.

Change-Id: I409501515bd9a28ee7a960faca080e97cabe5858
updates: bz#1193929
Signed-off-by: Prashanth Pai <ppai@redhat.com>

1 files changed, 22 insertions, 4 deletions

diff --git a/glusterfsd/src/glusterfsd-mgmt.c b/glusterfsd/src/glusterfsd-mgmt.c
index 54b8215c967..9c9cca2060c 100644
--- a/glusterfsd/src/glusterfsd-mgmt.c
+++ b/glusterfsd/src/glusterfsd-mgmt.c
@@ -2832,6 +2832,8 @@ int
 glusterfs_mgmt_pmap_signin(glusterfs_ctx_t *ctx)
 {
     call_frame_t *frame = NULL;
+    xlator_list_t **trav_p;
+    xlator_t *top;
     pmap_signin_req req = {
         0,
     };
@@ -2861,10 +2863,26 @@ glusterfs_mgmt_pmap_signin(glusterfs_ctx_t *ctx)
         req.brick = cmd_args->brick_name;
 
     req.port = cmd_args->brick_port;
-
-    ret = mgmt_submit_request(&req, frame, ctx, &clnt_pmap_prog, GF_PMAP_SIGNIN,
-                              mgmt_pmap_signin_cbk,
-                              (xdrproc_t)xdr_pmap_signin_req);
+    req.pid = (int)getpid(); /* only glusterd2 consumes this */
+
+    if (ctx->active) {
+        top = ctx->active->first;
+        for (trav_p = &top->children; *trav_p; trav_p = &(*trav_p)->next) {
+            req.brick = (*trav_p)->xlator->name;
+            ret = mgmt_submit_request(&req, frame, ctx, &clnt_pmap_prog,
+                                      GF_PMAP_SIGNIN, mgmt_pmap_signin_cbk,
+                                      (xdrproc_t)xdr_pmap_signin_req);
+            if (ret < 0) {
+                gf_log(THIS->name, GF_LOG_WARNING,
+                       "failed to send sign in request; brick = %s", req.brick);
+            }
+        }
+    } else {
+        ret = mgmt_submit_request(&req, frame, ctx, &clnt_pmap_prog,
+                                  GF_PMAP_SIGNIN, mgmt_pmap_signin_cbk,
+                                  (xdrproc_t)xdr_pmap_signin_req);
+    }
+    /* unfortunately, the caller doesn't care about the returned value */
 
 out:
     if (need_emancipate && ret < 0)