lockd: Use xdrgen XDR functions for the NLMv3 UNSHARE procedure

Convert the NLMv3 UNSHARE procedure to use xdrgen-generated XDR
functions nlm_svc_decode_nlm_shareargs and
nlm_svc_encode_nlm_shareres.

The procedure handler is updated to use the wrapper structures
(nlm_shareargs_wrapper and nlm_shareres_wrapper) introduced by
the SHARE conversion patch and accesses arguments through the
argp->xdrgen hierarchy.

The .pc_argzero field is set to zero because the generated
decoder fills argp->xdrgen before the procedure runs, so the
zeroing memset performed by the dispatch layer is no longer
needed.

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 32625ee07c354f1f0cb2861599a822ef8b52c489..de4c15aa725cd12af67d3df61d870adb0a9ba44d 100644 (file)
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -1157,41 +1157,65 @@ out:
                rpc_drop_reply : rpc_success;
 }
 
-/*
- * UNSHARE: Release a DOS share.
+/**
+ * nlmsvc_proc_unshare - UNSHARE: Release a share reservation
+ * @rqstp: RPC transaction context
+ *
+ * Returns:
+ *   %rpc_success:             RPC executed successfully.
+ *   %rpc_drop_reply:          Do not send an RPC reply.
+ *
+ * RPC synopsis:
+ *   nlm_shareres NLM_UNSHARE(nlm_shareargs) = 21;
+ *
+ * Permissible procedure status codes:
+ *   %LCK_GRANTED:             The share reservation was released.
+ *   %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.
+ *
+ * The Linux NLM server implementation also returns:
+ *   %LCK_DENIED_NOLOCKS:      A needed resource could not be allocated.
  */
-static __be32
-nlmsvc_proc_unshare(struct svc_rqst *rqstp)
+static __be32 nlmsvc_proc_unshare(struct svc_rqst *rqstp)
 {
-       struct lockd_args *argp = rqstp->rq_argp;
-       struct lockd_res *resp = rqstp->rq_resp;
-       struct nlm_host *host;
-       struct nlm_file *file;
+       struct nlm_shareargs_wrapper *argp = rqstp->rq_argp;
+       struct nlm_shareres_wrapper *resp = rqstp->rq_resp;
+       struct lockd_lock *lock = &argp->lock;
+       struct nlm_lock xdr_lock = {
+               .fh             = argp->xdrgen.share.fh,
+               .oh             = argp->xdrgen.share.oh,
+               .uppid          = LOCKD_SHARE_SVID,
+       };
+       struct nlm_host *host = NULL;
+       struct nlm_file *file = NULL;
 
-       dprintk("lockd: UNSHARE       called\n");
+       resp->xdrgen.cookie = argp->xdrgen.cookie;
 
-       resp->cookie = argp->cookie;
+       resp->xdrgen.stat = nlm_lck_denied_grace_period;
+       if (locks_in_grace(SVC_NET(rqstp)))
+               goto out;
 
-       /* Don't accept requests during grace period */
-       if (locks_in_grace(SVC_NET(rqstp))) {
-               resp->status = nlm_lck_denied_grace_period;
-               return rpc_success;
-       }
+       resp->xdrgen.stat = nlm_lck_denied_nolocks;
+       host = nlm3svc_lookup_host(rqstp, argp->xdrgen.share.caller_name, false);
+       if (!host)
+               goto out;
 
-       /* 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;
+       resp->xdrgen.stat = nlm3svc_lookup_file(rqstp, host, lock, &file,
+                                               &xdr_lock, F_RDLCK);
+       if (resp->xdrgen.stat)
+               goto out;
 
-       /* Now try to unshare the file */
-       resp->status = cast_status(nlmsvc_unshare_file(host, file,
-                                                      &argp->lock.oh));
+       resp->xdrgen.stat = nlmsvc_unshare_file(host, file, &lock->oh);
 
-       dprintk("lockd: UNSHARE       status %d\n", ntohl(resp->status));
-       nlmsvc_release_lockowner(&argp->lock);
+       nlmsvc_release_lockowner(lock);
+
+out:
+       if (file)
+               nlm_release_file(file);
        nlmsvc_release_host(host);
-       nlm_release_file(file);
-       return rpc_success;
+       return resp->xdrgen.stat == nlm__int__drop_reply ?
+               rpc_drop_reply : rpc_success;
 }
 
 /*
@@ -1448,15 +1472,15 @@ static const struct svc_procedure nlmsvc_procedures[24] = {
                .pc_xdrressize  = NLM3_nlm_shareres_sz,
                .pc_name        = "SHARE",
        },
-       [NLMPROC_UNSHARE] = {
-               .pc_func = nlmsvc_proc_unshare,
-               .pc_decode = nlmsvc_decode_shareargs,
-               .pc_encode = nlmsvc_encode_shareres,
-               .pc_argsize = sizeof(struct lockd_args),
-               .pc_argzero = sizeof(struct lockd_args),
-               .pc_ressize = sizeof(struct lockd_res),
-               .pc_xdrressize = Ck+St+1,
-               .pc_name = "UNSHARE",
+       [NLM_UNSHARE] = {
+               .pc_func        = nlmsvc_proc_unshare,
+               .pc_decode      = nlm_svc_decode_nlm_shareargs,
+               .pc_encode      = nlm_svc_encode_nlm_shareres,
+               .pc_argsize     = sizeof(struct nlm_shareargs_wrapper),
+               .pc_argzero     = 0,
+               .pc_ressize     = sizeof(struct nlm_shareres_wrapper),
+               .pc_xdrressize  = NLM3_nlm_shareres_sz,
+               .pc_name        = "UNSHARE",
        },
        [NLMPROC_NM_LOCK] = {
                .pc_func = nlmsvc_proc_nm_lock,