[PATCH v1 4/8] NFSD: Clean up nfsd4_encode_layoutget()

[Chuck Lever <cel@xxxxxxxxxx>]

From: Chuck Lever <chuck.lever@xxxxxxxxxx>

De-duplicate the open-coded stateid4 encoder. Adopt the use of the
conventional current XDR encoding helpers. Refactor the encoder to
align with the XDR specification.

Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
 fs/nfsd/nfs4xdr.c |   52 ++++++++++++++++++++++++++++++++++------------------
 fs/nfsd/xdr4.h    |    2 ++
 2 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 24caa1c5613b..13df5b021db6 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4860,32 +4860,48 @@ nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
 	return nfserr_toosmall;
 }
 
+static __be32
+nfsd4_encode_layout4(struct xdr_stream *xdr, const struct nfsd4_layoutget *lgp)
+{
+	const struct nfsd4_layout_ops *ops = nfsd4_layout_ops[lgp->lg_layout_type];
+	__be32 status;
+
+	/* lo_offset */
+	status = nfsd4_encode_offset4(xdr, lgp->lg_seg.offset);
+	if (status != nfs_ok)
+		return status;
+	/* lo_length */
+	status = nfsd4_encode_length4(xdr, lgp->lg_seg.length);
+	if (status != nfs_ok)
+		return status;
+	/* lo_iomode */
+	if (xdr_stream_encode_u32(xdr, lgp->lg_seg.iomode) != XDR_UNIT)
+		return nfserr_resource;
+	/* lo_content */
+	if (xdr_stream_encode_u32(xdr, lgp->lg_layout_type) != XDR_UNIT)
+		return nfserr_resource;
+	return ops->encode_layoutget(xdr, lgp);
+}
+
 static __be32
 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
 		union nfsd4_op_u *u)
 {
 	struct nfsd4_layoutget *lgp = &u->layoutget;
 	struct xdr_stream *xdr = resp->xdr;
-	const struct nfsd4_layout_ops *ops;
-	__be32 *p;
 
-	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
-	if (!p)
+	/* logr_return_on_close */
+	nfserr = nfsd4_encode_bool(xdr, true);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* logr_stateid */
+	nfserr = nfsd4_encode_stateid4(xdr, &lgp->lg_sid);
+	if (nfserr != nfs_ok)
+		return nfserr;
+	/* logr_layout<> */
+	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
 		return nfserr_resource;
-
-	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
-	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
-	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
-				    sizeof(stateid_opaque_t));
-
-	*p++ = cpu_to_be32(1);	/* we always return a single layout */
-	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
-	p = xdr_encode_hyper(p, lgp->lg_seg.length);
-	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
-	*p++ = cpu_to_be32(lgp->lg_layout_type);
-
-	ops = nfsd4_layout_ops[lgp->lg_layout_type];
-	return ops->encode_layoutget(xdr, lgp);
+	return nfsd4_encode_layout4(xdr, lgp);
 }
 
 static __be32
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 43b9c53b7795..1a99db22b25c 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -118,6 +118,8 @@ nfsd4_encode_uint64_t(struct xdr_stream *xdr, u64 val)
 }
 
 #define nfsd4_encode_changeid4(x, v)	nfsd4_encode_uint64_t(x, v)
+#define nfsd4_encode_length4(x, v)	nfsd4_encode_uint64_t(x, v)
+#define nfsd4_encode_offset4(x, v)	nfsd4_encode_uint64_t(x, v)
 
 /**
  * nfsd4_encode_opaque_fixed - Encode a fixed-length XDR opaque type result