nfs41: use nfs4_readlink_res

In preparation for nfs41 sequence processing.
Signed-off-by: Andy Admason <andros@netapp.com>
[define nfs4_readlink_res]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4proc.c

@@ -1960,10 +1960,11 @@ static int _nfs4_proc_readlink(struct inode *inode, struct page *page,
 		.pglen    = pglen,
 		.pages    = &page,
 	};
+	struct nfs4_readlink_res res;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READLINK],
 		.rpc_argp = &args,
-		.rpc_resp = NULL,
+		.rpc_resp = &res,
 	};
 
 	return rpc_call_sync(NFS_CLIENT(inode), &msg, 0);

fs/nfs/nfs4xdr.c

@@ -4235,7 +4235,8 @@ static int nfs4_xdr_dec_locku(struct rpc_rqst *rqstp, __be32 *p, struct nfs_lock
 /*
  * Decode READLINK response
  */
-static int nfs4_xdr_dec_readlink(struct rpc_rqst *rqstp, __be32 *p, void *res)
+static int nfs4_xdr_dec_readlink(struct rpc_rqst *rqstp, __be32 *p,
+				 struct nfs4_readlink_res *res)
 {
 	struct xdr_stream xdr;
 	struct compound_hdr hdr;

include/linux/nfs_xdr.h

@@ -754,6 +754,10 @@ struct nfs4_readlink {
 	struct nfs4_sequence_args	seq_args;
 };
 
+struct nfs4_readlink_res {
+	struct nfs4_sequence_res	seq_res;
+};
+
 struct nfs4_rename_arg {
 	const struct nfs_fh *		old_dir;
 	const struct nfs_fh *		new_dir;