NFSD: Add nfsd4_encode_fattr4__true()

Add an encoding helper that encodes a single boolean "true" value.
Attributes that always return "true" can use this helper.

In a subsequent patch, this helper will be called from a bitmask
loop, so it is given a standardized synopsis.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4xdr.c

@@ -2948,6 +2948,12 @@ struct nfsd4_fattr_args {
 	bool			contextsupport;
 };
 
+static __be32 nfsd4_encode_fattr4__true(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_bool(xdr, true);
+}
+
 /*
  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
  * ourselves.
@@ -3134,16 +3140,14 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 		p = xdr_encode_hyper(p, args.size);
 	}
 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
-		p = xdr_reserve_space(xdr, 4);
-		if (!p)
-			goto out_resource;
-		*p++ = cpu_to_be32(1);
+		status = nfsd4_encode_fattr4__true(xdr, &args);
+		if (status != nfs_ok)
+			goto out;
 	}
 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
-		p = xdr_reserve_space(xdr, 4);
-		if (!p)
-			goto out_resource;
-		*p++ = cpu_to_be32(1);
+		status = nfsd4_encode_fattr4__true(xdr, &args);
+		if (status != nfs_ok)
+			goto out;
 	}
 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
 		p = xdr_reserve_space(xdr, 4);
@@ -3231,10 +3235,9 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
 	}
 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
-		p = xdr_reserve_space(xdr, 4);
-		if (!p)
-			goto out_resource;
-		*p++ = cpu_to_be32(1);
+		status = nfsd4_encode_fattr4__true(xdr, &args);
+		if (status != nfs_ok)
+			goto out;
 	}
 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
 		p = xdr_reserve_space(xdr, 4);
@@ -3243,16 +3246,14 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 		*p++ = cpu_to_be32(0);
 	}
 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
-		p = xdr_reserve_space(xdr, 4);
-		if (!p)
-			goto out_resource;
-		*p++ = cpu_to_be32(1);
+		status = nfsd4_encode_fattr4__true(xdr, &args);
+		if (status != nfs_ok)
+			goto out;
 	}
 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
-		p = xdr_reserve_space(xdr, 4);
-		if (!p)
-			goto out_resource;
-		*p++ = cpu_to_be32(1);
+		status = nfsd4_encode_fattr4__true(xdr, &args);
+		if (status != nfs_ok)
+			goto out;
 	}
 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
 		p = xdr_reserve_space(xdr, args.fhp->fh_handle.fh_size + 4);
@@ -3291,10 +3292,9 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 			goto out;
 	}
 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
-		p = xdr_reserve_space(xdr, 4);
-		if (!p)
-			goto out_resource;
-		*p++ = cpu_to_be32(1);
+		status = nfsd4_encode_fattr4__true(xdr, &args);
+		if (status != nfs_ok)
+			goto out;
 	}
 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
 		p = xdr_reserve_space(xdr, 8);
@@ -3333,10 +3333,9 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 		*p++ = cpu_to_be32(args.stat.mode & S_IALLUGO);
 	}
 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
-		p = xdr_reserve_space(xdr, 4);
-		if (!p)
-			goto out_resource;
-		*p++ = cpu_to_be32(1);
+		status = nfsd4_encode_fattr4__true(xdr, &args);
+		if (status != nfs_ok)
+			goto out;
 	}
 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
 		p = xdr_reserve_space(xdr, 4);