glusterd, cli: implement gluster system uuid reset command

A commonly faced problem among glusterfs users is: after a fresh
installation of glusterfs in a virtual machine, the VM image is
cloned to make multiple instances of the server. This breaks
glusterd because right after glusterfs installation on the first
boot glusterd would have created the node UUID and this gets
inherited into the clone. The result is wierd behavior at the time
of peer probe where glusterd does not (yet) deal with UUID
collisions in a user friendly way.

To handle it gluster peer reset command is implemented which upon
execution changes the uuid of local glusterd.

Change-Id: If207dd2ad93ab94ef1a3253f409c21c442975f87
BUG: 811493
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.org/3637
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 29 insertions, 11 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd.c b/xlators/mgmt/glusterd/src/glusterd.c
index bd9e6e031fa..c4629c795da 100644
--- a/xlators/mgmt/glusterd/src/glusterd.c
+++ b/xlators/mgmt/glusterd/src/glusterd.c
@@ -43,7 +43,6 @@
 
 #include "glusterd-mountbroker.h"
 
-static uuid_t glusterd_uuid;
 extern struct rpcsvc_program gluster_handshake_prog;
 extern struct rpcsvc_program gluster_pmap_prog;
 extern glusterd_op_info_t opinfo;
@@ -93,28 +92,47 @@ glusterd_uuid_init ()
 
 	ret = glusterd_retrieve_uuid ();
 	if (ret == 0) {
-		uuid_copy (glusterd_uuid, priv->uuid);
 		gf_log (this->name, GF_LOG_INFO,
 			"retrieved UUID: %s", uuid_utoa (priv->uuid));
 		return 0;
 	}
 
-        uuid_generate (glusterd_uuid);
+        ret = glusterd_uuid_generate_save ();
 
-        gf_log (this->name, GF_LOG_INFO, "generated UUID: %s",
-                uuid_utoa (glusterd_uuid));
+        if (ret) {
+                gf_log ("glusterd", GF_LOG_ERROR,
+                          "Unable to generate and save new UUID");
+                return ret;
+        }
+
+        return 0;
+}
+
+int
+glusterd_uuid_generate_save ()
+{
+        int               ret = -1;
+        glusterd_conf_t   *priv = NULL;
+        xlator_t          *this = NULL;
+
+        this = THIS;
+        GF_ASSERT (this);
+        priv = this->private;
+        GF_ASSERT (priv);
 
-        uuid_copy (priv->uuid, glusterd_uuid);
+        uuid_generate (priv->uuid);
+
+        gf_log (this->name, GF_LOG_INFO, "generated UUID: %s",
+                uuid_utoa (priv->uuid));
 
         ret = glusterd_store_global_info (this);
 
-        if (ret) {
+        if (ret)
                 gf_log (this->name, GF_LOG_ERROR,
-                        "Unable to store generated UUID");
-                return ret;
-        }
+                        "Unable to store the generated uuid %s",
+                        uuid_utoa (priv->uuid));
 
-        return 0;
+        return ret;
 }
 
 int