glusterd: Use client-op-versions during "volume set"

The supported op-versions of the client and the name of the requested volume,
are saved during server_getspec(). These are used during the staging of volume
set. If the option being set is not supported by any of the clients which
currently have the volume mounted, then set will fail.

Change-Id: I4e6b60b274d5200508762dc0204cfa848a6c0aa4
BUG: 907311
Signed-off-by: Kaushal M <kaushal@redhat.com>
Reviewed-on: http://review.gluster.org/4424
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>

2 files changed, 59 insertions, 2 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-handshake.c b/xlators/mgmt/glusterd/src/glusterd-handshake.c
index 5b3299d54..8b9647026 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handshake.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handshake.c
@@ -127,8 +127,8 @@ server_getspec (rpcsvc_request_t *req)
         dict_t               *dict                   = NULL;
         xlator_t             *this                   = NULL;
         glusterd_conf_t      *conf                   = NULL;
-        int                   client_min_op_version  = 0;
-        int                   client_max_op_version  = 0;
+        int                   client_min_op_version  = 1;       // OP-VERSIONs start at 1
+        int                   client_max_op_version  = 1;
 
         this = THIS;
         GF_ASSERT (this);
@@ -199,10 +199,22 @@ server_getspec (rpcsvc_request_t *req)
                                 req->trans->peerinfo.identifier);
                         goto fail;
                 }
+
         }
 
+        // Store the op-versions supported by the client
+        req->trans->peerinfo.max_op_version = client_max_op_version;
+        req->trans->peerinfo.min_op_version = client_min_op_version;
+
         volume = args.key;
 
+        // Store the name of volume  being mounted
+        if (volume[0] == '/')
+                strncpy (req->trans->peerinfo.volname, &volume[1],
+                         strlen(&volume[1]));
+        else
+                strncpy (req->trans->peerinfo.volname, volume, strlen(volume));
+
         trans = req->trans;
         ret = rpcsvc_transport_peername (trans, (char *)&addrstr,
                                          sizeof (addrstr));
diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index ea2aa0e21..26e61b4f6 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -339,6 +339,44 @@ out:
 }
 
 static int
+glusterd_check_client_op_version_support (char *volname, uint32_t op_version,
+                                          char **op_errstr)
+{
+        int                     ret = 0;
+        xlator_t                *this = NULL;
+        glusterd_conf_t         *priv = NULL;
+        rpc_transport_t         *xprt = NULL;
+
+        this = THIS;
+        GF_ASSERT(this);
+        priv = this->private;
+        GF_ASSERT(priv);
+
+        pthread_mutex_lock (&priv->xprt_lock);
+        list_for_each_entry (xprt, &priv->xprt_list, list) {
+                if ((!strcmp(volname, xprt->peerinfo.volname)) &&
+                    ((op_version > xprt->peerinfo.max_op_version) ||
+                     (op_version < xprt->peerinfo.min_op_version))) {
+                        ret = -1;
+                        break;
+                }
+        }
+        pthread_mutex_unlock (&priv->xprt_lock);
+
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "One or more clients "
+                        "don't support the required op-version");
+                ret = gf_asprintf (op_errstr, "One or more connected clients "
+                                   "cannot support the feature being set. "
+                                   "These clients need to be upgraded or "
+                                   "disconnected before running this command"
+                                   " again");
+                return -1;
+        }
+        return 0;
+}
+
+static int
 glusterd_op_stage_set_volume (dict_t *dict, char **op_errstr)
 {
         int                             ret                     = -1;
@@ -622,6 +660,13 @@ glusterd_op_stage_set_volume (dict_t *dict, char **op_errstr)
                 }
         }
 
+        // Check if all the connected clients support the new op-version
+        ret = glusterd_check_client_op_version_support (volname,
+                                                        local_new_op_version,
+                                                        op_errstr);
+        if (ret)
+                goto out;
+
         if (origin_glusterd) {
                 ret = dict_set_uint32 (dict, "new-op-version",
                                        local_new_op_version);