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,