NFS: EXCHANGE_ID should save the server major and minor ID

Save the server major and minor ID results from EXCHANGE_ID, as they
are needed for detecting server trunking.

Signed-off-by: Chuck Lever <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/client.c

···
 		nfs_idmap_delete(clp);
 
 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
+	kfree(clp->cl_serverowner);
 	kfree(clp->cl_serverscope);
 	kfree(clp->cl_implid);
 }

fs/nfs/nfs4proc.c

···
 				clp->cl_rpcclient->cl_nodename,
 				clp->cl_rpcclient->cl_auth->au_flavor);
 
+	res.server_owner = kzalloc(sizeof(struct nfs41_server_owner),
+					GFP_KERNEL);
+	if (unlikely(res.server_owner == NULL)) {
+		status = -ENOMEM;
+		goto out;
+	}
+
 	res.server_scope = kzalloc(sizeof(struct nfs41_server_scope),
 					GFP_KERNEL);
 	if (unlikely(res.server_scope == NULL)) {
 		status = -ENOMEM;
-		goto out;
+		goto out_server_owner;
 	}
 
 	res.impl_id = kzalloc(sizeof(struct nfs41_impl_id), GFP_KERNEL);
···
 	status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
 	if (status == 0)
 		status = nfs4_check_cl_exchange_flags(clp->cl_exchange_flags);
+
+	if (status == 0) {
+		kfree(clp->cl_serverowner);
+		clp->cl_serverowner = res.server_owner;
+		res.server_owner = NULL;
+	}
 
 	if (status == 0) {
 		/* use the most recent implementation id */
···
 		}
 	}
 
+out_server_owner:
+	kfree(res.server_owner);
 out_server_scope:
 	kfree(res.server_scope);
 out:

fs/nfs/nfs4xdr.c

···
 	if (dummy != SP4_NONE)
 		return -EIO;
 
-	/* Throw away minor_id */
+	/* server_owner4.so_minor_id */
 	p = xdr_inline_decode(xdr, 8);
 	if (unlikely(!p))
 		goto out_overflow;
+	p = xdr_decode_hyper(p, &res->server_owner->minor_id);
 
-	/* Throw away Major id */
+	/* server_owner4.so_major_id */
 	status = decode_opaque_inline(xdr, &dummy, &dummy_str);
 	if (unlikely(status))
 		return status;
-
-	/* Save server_scope */
-	status = decode_opaque_inline(xdr, &dummy, &dummy_str);
-	if (unlikely(status))
-		return status;
-
 	if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
 		return -EIO;
+	memcpy(res->server_owner->major_id, dummy_str, dummy);
+	res->server_owner->major_id_sz = dummy;
 
+	/* server_scope4 */
+	status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+	if (unlikely(status))
+		return status;
+	if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
+		return -EIO;
 	memcpy(res->server_scope->server_scope, dummy_str, dummy);
 	res->server_scope->server_scope_sz = dummy;
 

include/linux/nfs_fs_sb.h

···
 	/* The flags used for obtaining the clientid during EXCHANGE_ID */
 	u32			cl_exchange_flags;
 	struct nfs4_session	*cl_session;	/* shared session */
+	struct nfs41_server_owner *cl_serverowner;
 	struct nfs41_server_scope *cl_serverscope;
 	struct nfs41_impl_id	*cl_implid;
 #endif /* CONFIG_NFS_V4 */

include/linux/nfs_xdr.h

···
 	u32				flags;
 };
 
-struct server_owner {
+struct nfs41_server_owner {
 	uint64_t			minor_id;
 	uint32_t			major_id_sz;
 	char				major_id[NFS4_OPAQUE_LIMIT];
···
 struct nfs41_exchange_id_res {
 	struct nfs_client		*client;
 	u32				flags;
+	struct nfs41_server_owner	*server_owner;
 	struct nfs41_server_scope	*server_scope;
 	struct nfs41_impl_id		*impl_id;
 };