NFSD: Clean up nfsd4_encode_readlink()

Similar changes to nfsd4_encode_readv(), all bundled into a single
patch.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4xdr.c

@@ -4008,16 +4008,13 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
 static __be32
 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
 {
-	int maxcount;
-	__be32 wire_count;
-	int zero = 0;
+	__be32 *p, *maxcount_p, zero = xdr_zero;
 	struct xdr_stream *xdr = resp->xdr;
 	int length_offset = xdr->buf->len;
-	int status;
-	__be32 *p;
+	int maxcount, status;
 
-	p = xdr_reserve_space(xdr, 4);
-	if (!p)
+	maxcount_p = xdr_reserve_space(xdr, XDR_UNIT);
+	if (!maxcount_p)
 		return nfserr_resource;
 	maxcount = PAGE_SIZE;
 
@@ -4042,14 +4039,11 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd
 		nfserr = nfserrno(status);
 		goto out_err;
 	}
-
-	wire_count = htonl(maxcount);
-	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
-	xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
-	if (maxcount & 3)
-		write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
-						&zero, 4 - (maxcount&3));
-	return 0;
+	*maxcount_p = cpu_to_be32(maxcount);
+	xdr_truncate_encode(xdr, length_offset + 4 + xdr_align_size(maxcount));
+	write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount, &zero,
+			       xdr_pad_size(maxcount));
+	return nfs_ok;
 
 out_err:
 	xdr_truncate_encode(xdr, length_offset);