glusterd: Disallow peer with existing volumes to be probed in cluster

Backport of http://review.gluster.org/12864

As of now we do allow peer to get added in the trusted storage pool even if it
has a volume configured. This is definitely not a supported configuration and
can lead to issues as we never claim to support merging clusters. A single node
running a standalone volume can be considered as a cluster.

Change-Id: Id0cf42d6e5f20d6bfdb7ee19d860eee67c7c45be
BUG: 1288963
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-on: http://review.gluster.org/12864
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Kaushal M <kaushal@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-on: http://review.gluster.org/12888

4 files changed, 27 insertions, 4 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-handler.c b/xlators/mgmt/glusterd/src/glusterd-handler.c
index 1296267578a..1e7affd51a1 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handler.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handler.c
@@ -3830,8 +3830,9 @@ set_probe_error_str (int op_ret, int op_errno, char *op_errstr, char *errstr,
         } else {
                 switch (op_errno) {
                         case GF_PROBE_ANOTHER_CLUSTER:
-                                snprintf (errstr, len, "%s is already part of "
-                                          "another cluster", hostname);
+                                snprintf (errstr, len, "%s is either already "
+                                          "part of another cluster or having "
+                                          "volumes configured", hostname);
                                 break;
 
                         case GF_PROBE_VOLUME_CONFLICT:
diff --git a/xlators/mgmt/glusterd/src/glusterd-handshake.c b/xlators/mgmt/glusterd/src/glusterd-handshake.c
index 6579f62da44..d2037fcd579 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handshake.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handshake.c
@@ -991,7 +991,7 @@ out:
 /* Validate if glusterd can serve the management handshake request
  *
  * Requests are allowed if,
- *  - glusterd has no peers, or
+ *  - glusterd has no peers & no volumes, or
  *  - the request came from a known peer
  * A known peer is identified using the following steps
  *  - the dict is checked for a peer uuid, which if present is matched with the
@@ -1011,7 +1011,7 @@ gd_validate_mgmt_hndsk_req (rpcsvc_request_t *req, dict_t *dict)
         this = THIS;
         GF_ASSERT (this);
 
-        if (!glusterd_have_peers ())
+        if (!glusterd_have_peers () && !glusterd_have_volumes ())
                 return _gf_true;
 
         ret = dict_get_str (dict, GD_PEER_ID_KEY, &uuid_str);
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 6fc0dcdc603..98c519751df 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -4543,6 +4543,25 @@ glusterd_all_volumes_with_quota_stopped ()
         return _gf_true;
 }
 
+gf_boolean_t
+glusterd_have_volumes ()
+{
+        xlator_t        *this = NULL;
+        glusterd_conf_t *priv = NULL;
+        gf_boolean_t    volumes_exist = _gf_false;
+
+        this = THIS;
+        GF_VALIDATE_OR_GOTO ("glusterd", (this != NULL), out);
+
+        priv = this->private;
+        GF_VALIDATE_OR_GOTO (this->name, (priv != NULL), out);
+
+
+        volumes_exist = !cds_list_empty (&priv->volumes);
+out:
+        return volumes_exist;
+}
+
 int
 glusterd_volume_count_get (void)
 {
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.h b/xlators/mgmt/glusterd/src/glusterd-utils.h
index e912f64ae23..e6380f596e0 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.h
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.h
@@ -631,6 +631,9 @@ glusterd_check_client_op_version_support (char *volname, uint32_t op_version,
 gf_boolean_t
 glusterd_have_peers ();
 
+gf_boolean_t
+glusterd_have_volumes ();
+
 void
 glusterd_get_rebalance_volfile (glusterd_volinfo_t *volinfo,
                                 char *path, int path_len);