lockd: Use xdrgen XDR functions for the NLMv3 NM_LOCK procedure

Now that nlmsvc_do_lock() has been introduced to handle both
monitored and non-monitored lock requests, the NLMv3 NM_LOCK
procedure can be converted to use xdrgen-generated XDR
functions. This conversion allows the removal of
__nlmsvc_proc_lock(), a helper function that was previously
shared between the LOCK and NM_LOCK procedures.

Replace the NLMPROC_NM_LOCK entry in the nlmsvc_procedures
array with an entry that uses xdrgen-built XDR decoders and
encoders. The procedure handler is reduced to a thin wrapper
around nlmsvc_do_lock() with the monitored flag set to false.

The pc_argzero=0 choice was justified for the LOCK conversion
and applies unchanged here, since both procedures share the
same nlm_lockargs_wrapper layout and decoder.

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

diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index de4c15aa725cd12af67d3df61d870adb0a9ba44d..4ca0eaef29665bc42b2ace5485bc97a26a3fb5b0 100644 (file)
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -392,38 +392,6 @@ out:
                rpc_drop_reply : rpc_success;
 }
 
-static __be32
-__nlmsvc_proc_lock(struct svc_rqst *rqstp, struct lockd_res *resp)
-{
-       struct lockd_args *argp = rqstp->rq_argp;
-       struct nlm_host *host;
-       struct nlm_file *file;
-       __be32 rc = rpc_success;
-
-       dprintk("lockd: LOCK          called\n");
-
-       resp->cookie = argp->cookie;
-
-       /* Obtain client and file */
-       if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
-               return resp->status == nlm__int__drop_reply ?
-                       rpc_drop_reply : rpc_success;
-
-       /* Now try to lock the file */
-       resp->status = cast_status(nlmsvc_lock(rqstp, file, host, &argp->lock,
-                                              argp->block, &argp->cookie,
-                                              argp->reclaim));
-       if (resp->status == nlm__int__drop_reply)
-               rc = rpc_drop_reply;
-       else
-               dprintk("lockd: LOCK         status %d\n", ntohl(resp->status));
-
-       nlmsvc_release_lockowner(&argp->lock);
-       nlmsvc_release_host(host);
-       nlm_release_file(file);
-       return rc;
-}
-
 static __be32
 nlmsvc_do_lock(struct svc_rqst *rqstp, bool monitored)
 {
@@ -1218,18 +1186,34 @@ out:
                rpc_drop_reply : rpc_success;
 }
 
-/*
- * NM_LOCK: Create an unmonitored lock
+/**
+ * nlmsvc_proc_nm_lock - NM_LOCK: Establish a non-monitored lock
+ * @rqstp: RPC transaction context
+ *
+ * Returns:
+ *   %rpc_success:             RPC executed successfully.
+ *   %rpc_drop_reply:          Do not send an RPC reply.
+ *
+ * RPC synopsis:
+ *   nlm_res NLM_NM_LOCK(nlm_lockargs) = 22;
+ *
+ * Permissible procedure status codes:
+ *   %LCK_GRANTED:             The requested lock was granted.
+ *   %LCK_DENIED:              The requested lock conflicted with existing
+ *                             lock reservations for the file.
+ *   %LCK_DENIED_NOLOCKS:      The server could not allocate the resources
+ *                             needed to process the request.
+ *   %LCK_BLOCKED:             The blocking request cannot be granted
+ *                             immediately. The server will send an
+ *                             NLM_GRANTED callback to the client when
+ *                             the lock can be granted.
+ *   %LCK_DENIED_GRACE_PERIOD: The server has recently restarted and is
+ *                             re-establishing existing locks, and is not
+ *                             yet ready to accept normal service requests.
  */
-static __be32
-nlmsvc_proc_nm_lock(struct svc_rqst *rqstp)
+static __be32 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp)
 {
-       struct lockd_args *argp = rqstp->rq_argp;
-
-       dprintk("lockd: NM_LOCK       called\n");
-
-       argp->monitor = 0;              /* just clean the monitor flag */
-       return __nlmsvc_proc_lock(rqstp, rqstp->rq_resp);
+       return nlmsvc_do_lock(rqstp, false);
 }
 
 /*
@@ -1482,15 +1466,15 @@ static const struct svc_procedure nlmsvc_procedures[24] = {
                .pc_xdrressize  = NLM3_nlm_shareres_sz,
                .pc_name        = "UNSHARE",
        },
-       [NLMPROC_NM_LOCK] = {
-               .pc_func = nlmsvc_proc_nm_lock,
-               .pc_decode = nlmsvc_decode_lockargs,
-               .pc_encode = nlmsvc_encode_res,
-               .pc_argsize = sizeof(struct lockd_args),
-               .pc_argzero = sizeof(struct lockd_args),
-               .pc_ressize = sizeof(struct lockd_res),
-               .pc_xdrressize = Ck+St,
-               .pc_name = "NM_LOCK",
+       [NLM_NM_LOCK] = {
+               .pc_func        = nlmsvc_proc_nm_lock,
+               .pc_decode      = nlm_svc_decode_nlm_lockargs,
+               .pc_encode      = nlm_svc_encode_nlm_res,
+               .pc_argsize     = sizeof(struct nlm_lockargs_wrapper),
+               .pc_argzero     = 0,
+               .pc_ressize     = sizeof(struct nlm_res_wrapper),
+               .pc_xdrressize  = NLM3_nlm_res_sz,
+               .pc_name        = "NM_LOCK",
        },
        [NLMPROC_FREE_ALL] = {
                .pc_func = nlmsvc_proc_free_all,