SUNRPC: New xdr_streams XDR decoder API

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

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, 45 insertions, 32 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 651c9da703cb..67e31276682a 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -587,8 +587,18 @@ rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
         return 0;
 }
 
+static int
+rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
+                          __be32 *data, void *obj)
+{
+        struct xdr_stream xdr;
+
+        xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
+        return decode(rqstp, &xdr, obj);
+}
+
 int
-rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
+rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
                 __be32 *data, void *obj)
 {
         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
@@ -599,7 +609,7 @@ rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
                                                    data, obj);
         /* By default, we decode the arguments normally. */
-        return decode(rqstp, data, obj);
+        return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
 }
 
 int
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 42b46f9a670a..45dbf1521b9a 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1503,10 +1503,19 @@ gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
         return 0;
 }
 
+static int
+gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
+                      __be32 *p, void *obj)
+{
+        struct xdr_stream xdr;
+
+        xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
+        return decode(rqstp, &xdr, obj);
+}
 
 static int
 gss_unwrap_resp(struct rpc_task *task,
-                kxdrproc_t decode, void *rqstp, __be32 *p, void *obj)
+                kxdrdproc_t decode, 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,
@@ -1537,7 +1546,7 @@ gss_unwrap_resp(struct rpc_task *task,
         cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
                                                 + (savedlen - head->iov_len);
 out_decode:
-        status = decode(rqstp, p, obj);
+        status = gss_unwrap_req_decode(decode, rqstp, p, obj);
 out:
         gss_put_ctx(ctx);
         dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index d446a32be667..4e8210dcda72 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1535,7 +1535,7 @@ call_decode(struct rpc_task *task)
 {
         struct rpc_clnt *clnt = task->tk_client;
         struct rpc_rqst *req = task->tk_rqstp;
-        kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
+        kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
         __be32          *p;
 
         dprintk("RPC: %5u call_decode (status %d)\n",
@@ -1780,7 +1780,7 @@ static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
 {
 }
 
-static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
+static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
 {
         return 0;
 }
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 63912a1a2983..c652e4cc9fe9 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -706,18 +706,16 @@ static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
         *p   = cpu_to_be32(rpcb->r_port);
 }
 
-static int rpcb_dec_getport(struct rpc_rqst *req, __be32 *p,
+static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
                             struct rpcbind_args *rpcb)
 {
         struct rpc_task *task = req->rq_task;
-        struct xdr_stream xdr;
         unsigned long port;
-
-        xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
+        __be32 *p;
 
         rpcb->r_port = 0;
 
-        p = xdr_inline_decode(&xdr, 4);
+        p = xdr_inline_decode(xdr, 4);
         if (unlikely(p == NULL))
                 return -EIO;
 
@@ -731,20 +729,18 @@ static int rpcb_dec_getport(struct rpc_rqst *req, __be32 *p,
         return 0;
 }
 
-static int rpcb_dec_set(struct rpc_rqst *req, __be32 *p,
+static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
                         unsigned int *boolp)
 {
         struct rpc_task *task = req->rq_task;
-        struct xdr_stream xdr;
-
-        xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
+        __be32 *p;
 
-        p = xdr_inline_decode(&xdr, 4);
+        p = xdr_inline_decode(xdr, 4);
         if (unlikely(p == NULL))
                 return -EIO;
 
         *boolp = 0;
-        if (*p)
+        if (*p != xdr_zero)
                 *boolp = 1;
 
         dprintk("RPC: %5u RPCB_%s call %s\n",
@@ -785,20 +781,18 @@ static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
         encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 }
 
-static int rpcb_dec_getaddr(struct rpc_rqst *req, __be32 *p,
+static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
                             struct rpcbind_args *rpcb)
 {
         struct sockaddr_storage address;
         struct sockaddr *sap = (struct sockaddr *)&address;
         struct rpc_task *task = req->rq_task;
-        struct xdr_stream xdr;
+        __be32 *p;
         u32 len;
 
         rpcb->r_port = 0;
 
-        xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
-
-        p = xdr_inline_decode(&xdr, 4);
+        p = xdr_inline_decode(xdr, 4);
         if (unlikely(p == NULL))
                 goto out_fail;
         len = be32_to_cpup(p);
@@ -816,7 +810,7 @@ static int rpcb_dec_getaddr(struct rpc_rqst *req, __be32 *p,
         if (unlikely(len > RPCBIND_MAXUADDRLEN))
                 goto out_fail;
 
-        p = xdr_inline_decode(&xdr, len);
+        p = xdr_inline_decode(xdr, len);
         if (unlikely(p == NULL))
                 goto out_fail;
         dprintk("RPC: %5u RPCB_%s reply: %s\n", task->tk_pid,
@@ -843,7 +837,7 @@ static struct rpc_procinfo rpcb_procedures2[] = {
         [RPCBPROC_SET] = {
                 .p_proc         = RPCBPROC_SET,
                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
-                .p_decode       = (kxdrproc_t)rpcb_dec_set,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
                 .p_arglen       = RPCB_mappingargs_sz,
                 .p_replen       = RPCB_setres_sz,
                 .p_statidx      = RPCBPROC_SET,
@@ -853,7 +847,7 @@ static struct rpc_procinfo rpcb_procedures2[] = {
         [RPCBPROC_UNSET] = {
                 .p_proc         = RPCBPROC_UNSET,
                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
-                .p_decode       = (kxdrproc_t)rpcb_dec_set,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
                 .p_arglen       = RPCB_mappingargs_sz,
                 .p_replen       = RPCB_setres_sz,
                 .p_statidx      = RPCBPROC_UNSET,
@@ -863,7 +857,7 @@ static struct rpc_procinfo rpcb_procedures2[] = {
         [RPCBPROC_GETPORT] = {
                 .p_proc         = RPCBPROC_GETPORT,
                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
-                .p_decode       = (kxdrproc_t)rpcb_dec_getport,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_getport,
                 .p_arglen       = RPCB_mappingargs_sz,
                 .p_replen       = RPCB_getportres_sz,
                 .p_statidx      = RPCBPROC_GETPORT,
@@ -876,7 +870,7 @@ static struct rpc_procinfo rpcb_procedures3[] = {
         [RPCBPROC_SET] = {
                 .p_proc         = RPCBPROC_SET,
                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
-                .p_decode       = (kxdrproc_t)rpcb_dec_set,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
                 .p_arglen       = RPCB_getaddrargs_sz,
                 .p_replen       = RPCB_setres_sz,
                 .p_statidx      = RPCBPROC_SET,
@@ -886,7 +880,7 @@ static struct rpc_procinfo rpcb_procedures3[] = {
         [RPCBPROC_UNSET] = {
                 .p_proc         = RPCBPROC_UNSET,
                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
-                .p_decode       = (kxdrproc_t)rpcb_dec_set,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
                 .p_arglen       = RPCB_getaddrargs_sz,
                 .p_replen       = RPCB_setres_sz,
                 .p_statidx      = RPCBPROC_UNSET,
@@ -896,7 +890,7 @@ static struct rpc_procinfo rpcb_procedures3[] = {
         [RPCBPROC_GETADDR] = {
                 .p_proc         = RPCBPROC_GETADDR,
                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
-                .p_decode       = (kxdrproc_t)rpcb_dec_getaddr,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
                 .p_arglen       = RPCB_getaddrargs_sz,
                 .p_replen       = RPCB_getaddrres_sz,
                 .p_statidx      = RPCBPROC_GETADDR,
@@ -909,7 +903,7 @@ static struct rpc_procinfo rpcb_procedures4[] = {
         [RPCBPROC_SET] = {
                 .p_proc         = RPCBPROC_SET,
                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
-                .p_decode       = (kxdrproc_t)rpcb_dec_set,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
                 .p_arglen       = RPCB_getaddrargs_sz,
                 .p_replen       = RPCB_setres_sz,
                 .p_statidx      = RPCBPROC_SET,
@@ -919,7 +913,7 @@ static struct rpc_procinfo rpcb_procedures4[] = {
         [RPCBPROC_UNSET] = {
                 .p_proc         = RPCBPROC_UNSET,
                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
-                .p_decode       = (kxdrproc_t)rpcb_dec_set,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
                 .p_arglen       = RPCB_getaddrargs_sz,
                 .p_replen       = RPCB_setres_sz,
                 .p_statidx      = RPCBPROC_UNSET,
@@ -929,7 +923,7 @@ static struct rpc_procinfo rpcb_procedures4[] = {
         [RPCBPROC_GETADDR] = {
                 .p_proc         = RPCBPROC_GETADDR,
                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
-                .p_decode       = (kxdrproc_t)rpcb_dec_getaddr,
+                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
                 .p_arglen       = RPCB_getaddrargs_sz,
                 .p_replen       = RPCB_getaddrres_sz,
                 .p_statidx      = RPCBPROC_GETADDR,