SUNRPC: New xdr_streams XDR encoder API

Now that all client-side XDR encoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC arg *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each encoder function.

Also, all the client-side encoder functions return 0 now, making a
return value superfluous.  Take this opportunity to convert them to
return void instead.

This is a refactoring change.  It should not cause different behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

4 files changed, 54 insertions, 43 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index afe67849269f..651c9da703cb 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -563,8 +563,17 @@ rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 	return cred->cr_ops->crvalidate(task, p);
 }
 
+static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
+				   __be32 *data, void *obj)
+{
+	struct xdr_stream xdr;
+
+	xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
+	encode(rqstp, &xdr, obj);
+}
+
 int
-rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
+rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
 		__be32 *data, void *obj)
 {
 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
@@ -574,7 +583,8 @@ rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
 	if (cred->cr_ops->crwrap_req)
 		return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 	/* By default, we encode the arguments normally. */
-	return encode(rqstp, data, obj);
+	rpcauth_wrap_req_encode(encode, rqstp, data, obj);
+	return 0;
 }
 
 int
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 3835ce35e224..42b46f9a670a 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1231,9 +1231,19 @@ out_bad:
 	return NULL;
 }
 
+static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
+				__be32 *p, void *obj)
+{
+	struct xdr_stream xdr;
+
+	xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
+	encode(rqstp, &xdr, obj);
+}
+
 static inline int
 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
-		kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
+		   kxdreproc_t encode, struct rpc_rqst *rqstp,
+		   __be32 *p, void *obj)
 {
 	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
 	struct xdr_buf	integ_buf;
@@ -1249,9 +1259,7 @@ gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 	*p++ = htonl(rqstp->rq_seqno);
 
-	status = encode(rqstp, p, obj);
-	if (status)
-		return status;
+	gss_wrap_req_encode(encode, rqstp, p, obj);
 
 	if (xdr_buf_subsegment(snd_buf, &integ_buf,
 				offset, snd_buf->len - offset))
@@ -1325,7 +1333,8 @@ out:
 
 static inline int
 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
-		kxdrproc_t encode, struct rpc_rqst *rqstp, __be32 *p, void *obj)
+		  kxdreproc_t encode, struct rpc_rqst *rqstp,
+		  __be32 *p, void *obj)
 {
 	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
 	u32		offset;
@@ -1342,9 +1351,7 @@ gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
 	*p++ = htonl(rqstp->rq_seqno);
 
-	status = encode(rqstp, p, obj);
-	if (status)
-		return status;
+	gss_wrap_req_encode(encode, rqstp, p, obj);
 
 	status = alloc_enc_pages(rqstp);
 	if (status)
@@ -1394,7 +1401,7 @@ gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 
 static int
 gss_wrap_req(struct rpc_task *task,
-	     kxdrproc_t encode, void *rqstp, __be32 *p, void *obj)
+	     kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
 {
 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
@@ -1407,12 +1414,14 @@ gss_wrap_req(struct rpc_task *task,
 		/* The spec seems a little ambiguous here, but I think that not
 		 * wrapping context destruction requests makes the most sense.
 		 */
-		status = encode(rqstp, p, obj);
+		gss_wrap_req_encode(encode, rqstp, p, obj);
+		status = 0;
 		goto out;
 	}
 	switch (gss_cred->gc_service) {
 		case RPC_GSS_SVC_NONE:
-			status = encode(rqstp, p, obj);
+			gss_wrap_req_encode(encode, rqstp, p, obj);
+			status = 0;
 			break;
 		case RPC_GSS_SVC_INTEGRITY:
 			status = gss_wrap_req_integ(cred, ctx, encode,
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 92ce94f5146b..d446a32be667 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1095,7 +1095,7 @@ static void
 rpc_xdr_encode(struct rpc_task *task)
 {
 	struct rpc_rqst	*req = task->tk_rqstp;
-	kxdrproc_t	encode;
+	kxdreproc_t	encode;
 	__be32		*p;
 
 	dprint_status(task);
@@ -1776,9 +1776,8 @@ out_overflow:
 	goto out_garbage;
 }
 
-static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
+static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
 {
-	return 0;
 }
 
 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 43838c72b778..63912a1a2983 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -689,25 +689,21 @@ static void rpcb_getport_done(struct rpc_task *child, void *data)
  * XDR functions for rpcbind
  */
 
-static int rpcb_enc_mapping(struct rpc_rqst *req, __be32 *p,
-			    const struct rpcbind_args *rpcb)
+static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
+			     const struct rpcbind_args *rpcb)
 {
 	struct rpc_task *task = req->rq_task;
-	struct xdr_stream xdr;
+	__be32 *p;
 
 	dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 			task->tk_pid, task->tk_msg.rpc_proc->p_name,
 			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 
-	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
-
-	p = xdr_reserve_space(&xdr, RPCB_mappingargs_sz << 2);
+	p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 	*p++ = cpu_to_be32(rpcb->r_prog);
 	*p++ = cpu_to_be32(rpcb->r_vers);
 	*p++ = cpu_to_be32(rpcb->r_prot);
 	*p   = cpu_to_be32(rpcb->r_port);
-
-	return 0;
 }
 
 static int rpcb_dec_getport(struct rpc_rqst *req, __be32 *p,
@@ -769,27 +765,24 @@ static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 	xdr_encode_opaque(p, string, len);
 }
 
-static int rpcb_enc_getaddr(struct rpc_rqst *req, __be32 *p,
-			    const struct rpcbind_args *rpcb)
+static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
+			     const struct rpcbind_args *rpcb)
 {
 	struct rpc_task *task = req->rq_task;
-	struct xdr_stream xdr;
+	__be32 *p;
 
 	dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 			task->tk_pid, task->tk_msg.rpc_proc->p_name,
 			rpcb->r_prog, rpcb->r_vers,
 			rpcb->r_netid, rpcb->r_addr);
 
-	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
-
-	p = xdr_reserve_space(&xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
+	p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 	*p++ = cpu_to_be32(rpcb->r_prog);
 	*p = cpu_to_be32(rpcb->r_vers);
 
-	encode_rpcb_string(&xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
-	encode_rpcb_string(&xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
-	encode_rpcb_string(&xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
-	return 0;
+	encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
+	encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
+	encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 }
 
 static int rpcb_dec_getaddr(struct rpc_rqst *req, __be32 *p,
@@ -849,7 +842,7 @@ out_fail:
 static struct rpc_procinfo rpcb_procedures2[] = {
 	[RPCBPROC_SET] = {
 		.p_proc		= RPCBPROC_SET,
-		.p_encode	= (kxdrproc_t)rpcb_enc_mapping,
+		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
 		.p_arglen	= RPCB_mappingargs_sz,
 		.p_replen	= RPCB_setres_sz,
@@ -859,7 +852,7 @@ static struct rpc_procinfo rpcb_procedures2[] = {
 	},
 	[RPCBPROC_UNSET] = {
 		.p_proc		= RPCBPROC_UNSET,
-		.p_encode	= (kxdrproc_t)rpcb_enc_mapping,
+		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
 		.p_arglen	= RPCB_mappingargs_sz,
 		.p_replen	= RPCB_setres_sz,
@@ -869,7 +862,7 @@ static struct rpc_procinfo rpcb_procedures2[] = {
 	},
 	[RPCBPROC_GETPORT] = {
 		.p_proc		= RPCBPROC_GETPORT,
-		.p_encode	= (kxdrproc_t)rpcb_enc_mapping,
+		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 		.p_decode	= (kxdrproc_t)rpcb_dec_getport,
 		.p_arglen	= RPCB_mappingargs_sz,
 		.p_replen	= RPCB_getportres_sz,
@@ -882,7 +875,7 @@ static struct rpc_procinfo rpcb_procedures2[] = {
 static struct rpc_procinfo rpcb_procedures3[] = {
 	[RPCBPROC_SET] = {
 		.p_proc		= RPCBPROC_SET,
-		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
+		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
 		.p_arglen	= RPCB_getaddrargs_sz,
 		.p_replen	= RPCB_setres_sz,
@@ -892,7 +885,7 @@ static struct rpc_procinfo rpcb_procedures3[] = {
 	},
 	[RPCBPROC_UNSET] = {
 		.p_proc		= RPCBPROC_UNSET,
-		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
+		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
 		.p_arglen	= RPCB_getaddrargs_sz,
 		.p_replen	= RPCB_setres_sz,
@@ -902,7 +895,7 @@ static struct rpc_procinfo rpcb_procedures3[] = {
 	},
 	[RPCBPROC_GETADDR] = {
 		.p_proc		= RPCBPROC_GETADDR,
-		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
+		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
 		.p_decode	= (kxdrproc_t)rpcb_dec_getaddr,
 		.p_arglen	= RPCB_getaddrargs_sz,
 		.p_replen	= RPCB_getaddrres_sz,
@@ -915,7 +908,7 @@ static struct rpc_procinfo rpcb_procedures3[] = {
 static struct rpc_procinfo rpcb_procedures4[] = {
 	[RPCBPROC_SET] = {
 		.p_proc		= RPCBPROC_SET,
-		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
+		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
 		.p_arglen	= RPCB_getaddrargs_sz,
 		.p_replen	= RPCB_setres_sz,
@@ -925,7 +918,7 @@ static struct rpc_procinfo rpcb_procedures4[] = {
 	},
 	[RPCBPROC_UNSET] = {
 		.p_proc		= RPCBPROC_UNSET,
-		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
+		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
 		.p_decode	= (kxdrproc_t)rpcb_dec_set,
 		.p_arglen	= RPCB_getaddrargs_sz,
 		.p_replen	= RPCB_setres_sz,
@@ -935,7 +928,7 @@ static struct rpc_procinfo rpcb_procedures4[] = {
 	},
 	[RPCBPROC_GETADDR] = {
 		.p_proc		= RPCBPROC_GETADDR,
-		.p_encode	= (kxdrproc_t)rpcb_enc_getaddr,
+		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
 		.p_decode	= (kxdrproc_t)rpcb_dec_getaddr,
 		.p_arglen	= RPCB_getaddrargs_sz,
 		.p_replen	= RPCB_getaddrres_sz,