lockd: Use xdrgen XDR functions for the NLMv3 FREE_ALL procedure

With all other NLMv3 procedures now converted to xdrgen-generated
XDR functions, the FREE_ALL procedure can be converted as well.
This conversion allows the removal of nlmsvc_retrieve_args(),
a 52-line helper function that was used only by FREE_ALL to
retrieve client information from lockd's internal data
structures.

Replace the NLMPROC_FREE_ALL entry in the nlmsvc_procedures
array with an entry that uses xdrgen-built XDR decoders and
encoders. The procedure handler is updated to use the new
wrapper structure (nlm_notify_wrapper) and call
nlm3svc_lookup_host() directly, eliminating the need for the
now-removed helper function.

Setting pc_argzero to zero is safe because the generated decoder
fills the argp->xdrgen subfields before the procedure runs, so the
zeroing memset performed by the dispatch layer is not needed. The
nlm_notify_wrapper structure has no members beyond the xdrgen
substructure, so no further initialization is required.

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 4ca0eaef29665bc42b2ace5485bc97a26a3fb5b0..ef1ae701b43b3235c77e17499dca93c9fbe78937 100644 (file)
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -100,6 +100,12 @@ struct nlm_shareres_wrapper {
 
 static_assert(offsetof(struct nlm_shareres_wrapper, xdrgen) == 0);
 
+struct nlm_notify_wrapper {
+       struct nlm_notify               xdrgen;
+};
+
+static_assert(offsetof(struct nlm_notify_wrapper, xdrgen) == 0);
+
 static __be32
 nlm_netobj_to_cookie(struct lockd_cookie *cookie, netobj *object)
 {
@@ -240,68 +246,6 @@ static inline __be32 cast_status(__be32 status)
 }
 #endif
 
-/*
- * Obtain client and file from arguments
- */
-static __be32
-nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct lockd_args *argp,
-                       struct nlm_host **hostp, struct nlm_file **filp)
-{
-       struct nlm_host         *host = NULL;
-       struct nlm_file         *file = NULL;
-       struct lockd_lock       *lock = &argp->lock;
-       bool                    is_test = (rqstp->rq_proc == NLMPROC_TEST ||
-                                          rqstp->rq_proc == NLMPROC_TEST_MSG);
-       int                     mode;
-       __be32                  error = 0;
-
-       /* nfsd callbacks must have been installed for this procedure */
-       if (!nlmsvc_ops)
-               return nlm_lck_denied_nolocks;
-
-       /* Obtain host handle */
-       if (!(host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len))
-        || (argp->monitor && nsm_monitor(host) < 0))
-               goto no_locks;
-       *hostp = host;
-
-       /* Obtain file pointer. Not used by FREE_ALL call. */
-       if (filp != NULL) {
-               mode = lock_to_openmode(&lock->fl);
-
-               if (is_test)
-                       mode = O_RDWR;
-
-               error = cast_status(nlm_lookup_file(rqstp, &file, lock, mode));
-               if (error != 0)
-                       goto no_locks;
-               *filp = file;
-
-               /* Set up the missing parts of the file_lock structure */
-               lock->fl.c.flc_flags = FL_POSIX;
-               if (is_test)
-                       lock->fl.c.flc_file = nlmsvc_file_file(file);
-               else
-                       lock->fl.c.flc_file = file->f_file[mode];
-               lock->fl.c.flc_pid = current->tgid;
-               lock->fl.fl_lmops = &nlmsvc_lock_operations;
-               nlmsvc_locks_init_private(&lock->fl, host, (pid_t)lock->svid);
-               if (!lock->fl.c.flc_owner) {
-                       /* lockowner allocation has failed */
-                       nlmsvc_release_host(host);
-                       return nlm_lck_denied_nolocks;
-               }
-       }
-
-       return 0;
-
-no_locks:
-       nlmsvc_release_host(host);
-       if (error)
-               return error;
-       return nlm_lck_denied_nolocks;
-}
-
 /**
  * nlmsvc_proc_null - NULL: Test for presence of service
  * @rqstp: RPC transaction context
@@ -1216,21 +1160,30 @@ static __be32 nlmsvc_proc_nm_lock(struct svc_rqst *rqstp)
        return nlmsvc_do_lock(rqstp, false);
 }
 
-/*
- * FREE_ALL: Release all locks and shares held by client
+/**
+ * nlmsvc_proc_free_all - FREE_ALL: Discard client's lock and share state
+ * @rqstp: RPC transaction context
+ *
+ * Returns:
+ *   %rpc_success:             RPC executed successfully.
+ *
+ * RPC synopsis:
+ *   void NLMPROC_FREE_ALL(nlm_notify) = 23;
  */
-static __be32
-nlmsvc_proc_free_all(struct svc_rqst *rqstp)
+static __be32 nlmsvc_proc_free_all(struct svc_rqst *rqstp)
 {
-       struct lockd_args *argp = rqstp->rq_argp;
+       struct nlm_notify_wrapper *argp = rqstp->rq_argp;
        struct nlm_host *host;
 
-       /* Obtain client */
-       if (nlmsvc_retrieve_args(rqstp, argp, &host, NULL))
-               return rpc_success;
+       host = nlm3svc_lookup_host(rqstp, argp->xdrgen.name, false);
+       if (!host)
+               goto out;
 
        nlmsvc_free_host_resources(host);
+
        nlmsvc_release_host(host);
+
+out:
        return rpc_success;
 }
 
@@ -1476,15 +1429,15 @@ static const struct svc_procedure nlmsvc_procedures[24] = {
                .pc_xdrressize  = NLM3_nlm_res_sz,
                .pc_name        = "NM_LOCK",
        },
-       [NLMPROC_FREE_ALL] = {
-               .pc_func = nlmsvc_proc_free_all,
-               .pc_decode = nlmsvc_decode_notify,
-               .pc_encode = nlmsvc_encode_void,
-               .pc_argsize = sizeof(struct lockd_args),
-               .pc_argzero = sizeof(struct lockd_args),
-               .pc_ressize = sizeof(struct nlm_void),
-               .pc_xdrressize = 0,
-               .pc_name = "FREE_ALL",
+       [NLM_FREE_ALL] = {
+               .pc_func        = nlmsvc_proc_free_all,
+               .pc_decode      = nlm_svc_decode_nlm_notify,
+               .pc_encode      = nlm_svc_encode_void,
+               .pc_argsize     = sizeof(struct nlm_notify_wrapper),
+               .pc_argzero     = 0,
+               .pc_ressize     = 0,
+               .pc_xdrressize  = XDR_void,
+               .pc_name        = "FREE_ALL",
        },
 };
 
@@ -1498,10 +1451,10 @@ union nlmsvc_xdrstore {
        struct nlm_unlockargs_wrapper   unlockargs;
        struct nlm_notifyargs_wrapper   notifyargs;
        struct nlm_shareargs_wrapper    shareargs;
+       struct nlm_notify_wrapper       notify;
        struct nlm_testres_wrapper      testres;
        struct nlm_res_wrapper          res;
        struct nlm_shareres_wrapper     shareres;
-       struct lockd_args               args;
 };
 
 /*