SUNRPC: Refactor RPC server dispatch method

Currently, svcauth_gss_accept() pre-reserves response buffer space
for the RPC payload length and GSS sequence number before returning
to the dispatcher, which then adds the header's accept_stat field.

The problem is the accept_stat field is supposed to go before the
length and seq_num fields. So svcauth_gss_release() has to relocate
the accept_stat value (see svcauth_gss_prepare_to_wrap()).

To enable these fields to be added to the response buffer in the
correct (final) order, the pointer to the accept_stat has to be made
available to svcauth_gss_accept() so that it can set it before
reserving space for the length and seq_num fields.

As a first step, move the pointer to the location of the accept_stat
field into struct svc_rqst.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 642e394e7a2dfd99d9740eb27bbc1df7595bde5c..0b28a6cf93032886b11bb8f2869bae35716bf3c5 100644 (file)
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -685,15 +685,15 @@ module_exit(exit_nlm);
 /**
  * nlmsvc_dispatch - Process an NLM Request
  * @rqstp: incoming request
- * @statp: pointer to location of accept_stat field in RPC Reply buffer
  *
  * Return values:
  *  %0: Processing complete; do not send a Reply
  *  %1: Processing complete; send Reply in rqstp->rq_res
  */
-static int nlmsvc_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+static int nlmsvc_dispatch(struct svc_rqst *rqstp)
 {
        const struct svc_procedure *procp = rqstp->rq_procinfo;
+       __be32 *statp = rqstp->rq_accept_statp;
 
        if (!procp->pc_decode(rqstp, &rqstp->rq_arg_stream))
                goto out_decode_err;

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index b4c3b71821982e597167bc9191b900a63a2daf78..13b2af55497d43f3dbf9b4a9ad99da5fd1c77be2 100644 (file)
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -980,11 +980,11 @@ out_invalidcred:
 }
 
 static int
-nfs_callback_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+nfs_callback_dispatch(struct svc_rqst *rqstp)
 {
        const struct svc_procedure *procp = rqstp->rq_procinfo;
 
-       *statp = procp->pc_func(rqstp);
+       *rqstp->rq_accept_statp = procp->pc_func(rqstp);
        return 1;
 }
 

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index ef5ee548053b84e5c1249a929e0d2d257e81fbd5..041faa13b852eff9f56dc264dcb2c8400c9894bc 100644 (file)
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -509,7 +509,7 @@ out_trace:
  * nfsd_cache_update - Update an entry in the duplicate reply cache.
  * @rqstp: svc_rqst with a finished Reply
  * @cachetype: which cache to update
- * @statp: Reply's status code
+ * @statp: pointer to Reply's NFS status code, or NULL
  *
  * This is called from nfsd_dispatch when the procedure has been
  * executed and the complete reply is in rqstp->rq_res.

diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index fa0144a742678fd46119dc6c871dba69cd383257..d88498f8b275cf4f7e5fb44c01741a4e7163606e 100644 (file)
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -86,7 +86,7 @@ bool          nfssvc_encode_voidres(struct svc_rqst *rqstp,
  * Function prototypes.
  */
 int            nfsd_svc(int nrservs, struct net *net, const struct cred *cred);
-int            nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp);
+int            nfsd_dispatch(struct svc_rqst *rqstp);
 
 int            nfsd_nrthreads(struct net *);
 int            nfsd_nrpools(struct net *);

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index dfa8ee6c04d5dc40d65ae1aee32b89d4191f7e82..ff10c46b62d3f710d342b96688ea2695eab32e9d 100644 (file)
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -1022,7 +1022,6 @@ out:
 /**
  * nfsd_dispatch - Process an NFS or NFSACL Request
  * @rqstp: incoming request
- * @statp: pointer to location of accept_stat field in RPC Reply buffer
  *
  * This RPC dispatcher integrates the NFS server's duplicate reply cache.
  *
@@ -1030,9 +1029,10 @@ out:
  *  %0: Processing complete; do not send a Reply
  *  %1: Processing complete; send Reply in rqstp->rq_res
  */
-int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+int nfsd_dispatch(struct svc_rqst *rqstp)
 {
        const struct svc_procedure *proc = rqstp->rq_procinfo;
+       __be32 *statp = rqstp->rq_accept_statp;
 
        /*
         * Give the xdr decoder a chance to change this if it wants

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 32eb98e621c338b8bfe31b6febc450c5f3336010..f40a90ca5de69e510f6ff035432db7f8556567c9 100644 (file)
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -251,6 +251,7 @@ struct svc_rqst {
 
        void *                  rq_argp;        /* decoded arguments */
        void *                  rq_resp;        /* xdr'd results */
+       __be32                  *rq_accept_statp;
        void *                  rq_auth_data;   /* flavor-specific data */
        __be32                  rq_auth_stat;   /* authentication status */
        int                     rq_auth_slack;  /* extra space xdr code
@@ -337,7 +338,7 @@ struct svc_deferred_req {
 
 struct svc_process_info {
        union {
-               int  (*dispatch)(struct svc_rqst *, __be32 *);
+               int  (*dispatch)(struct svc_rqst *rqstp);
                struct {
                        unsigned int lovers;
                        unsigned int hivers;
@@ -389,7 +390,7 @@ struct svc_version {
        bool                    vs_need_cong_ctrl;
 
        /* Dispatch function */
-       int                     (*vs_dispatch)(struct svc_rqst *, __be32 *);
+       int                     (*vs_dispatch)(struct svc_rqst *rqstp);
 };
 
 /*

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 167cb928515f387966eb988628c847e3911d7392..16760bc5191fc60057207ea5235da6b6b0714121 100644 (file)
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1232,9 +1232,9 @@ svc_process_common(struct svc_rqst *rqstp)
        const struct svc_procedure *procp = NULL;
        struct svc_serv         *serv = rqstp->rq_server;
        struct svc_process_info process;
-       __be32                  *p, *statp;
        int                     auth_res, rc;
        unsigned int            aoffset;
+       __be32                  *p;
 
        /* Will be turned off by GSS integrity and privacy services */
        set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
@@ -1314,8 +1314,8 @@ svc_process_common(struct svc_rqst *rqstp)
        trace_svc_process(rqstp, progp->pg_name);
 
        aoffset = xdr_stream_pos(xdr);
-       statp = xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT);
-       *statp = rpc_success;
+       rqstp->rq_accept_statp = xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT);
+       *rqstp->rq_accept_statp = rpc_success;
 
        /* un-reserve some of the out-queue now that we have a
         * better idea of reply size
@@ -1324,7 +1324,7 @@ svc_process_common(struct svc_rqst *rqstp)
                svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
 
        /* Call the function that processes the request. */
-       rc = process.dispatch(rqstp, statp);
+       rc = process.dispatch(rqstp);
        if (procp->pc_release)
                procp->pc_release(rqstp);
        if (!rc)
@@ -1332,7 +1332,7 @@ svc_process_common(struct svc_rqst *rqstp)
        if (rqstp->rq_auth_stat != rpc_auth_ok)
                goto err_bad_auth;
 
-       if (*statp != rpc_success)
+       if (*rqstp->rq_accept_statp != rpc_success)
                xdr_truncate_encode(xdr, aoffset);
 
        if (procp->pc_encode == NULL)