lockd: Use xdrgen XDR functions for the NLMv4 FREE_ALL procedure

With all other NLMv4 procedures now converted to xdrgen-generated
XDR functions, the FREE_ALL procedure can be converted as well.
This conversion allows the removal of nlm4svc_retrieve_args(),
a 79-line helper function that was used only by FREE_ALL to
retrieve client information from lockd's internal data
structures.

Replace the NLMPROC4_FREE_ALL entry in the nlm_procedures4
array with an entry that uses xdrgen-built XDR decoders and
encoders. The procedure handler is updated to use the new
wrapper structure (nlm4_notify_wrapper) and call
nlm4svc_lookup_host() directly, eliminating the need for the
now-removed helper function.

The .pc_argzero field is set to zero because xdrgen decoders
fully initialize all fields in argp->xdrgen, making the early
defensive memset unnecessary. The remaining argp fields that
fall outside the xdrgen structures are cleared explicitly as
needed.

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

diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index 62c90827dfae97b71b2e28f571710af2d9bd4e86..ca0409ea6b2dc86f15be5b501bb4652a184d9ff3 100644 (file)
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -69,6 +69,12 @@ struct nlm4_notifyargs_wrapper {
 
 static_assert(offsetof(struct nlm4_notifyargs_wrapper, xdrgen) == 0);
 
+struct nlm4_notify_wrapper {
+       struct nlm4_notify              xdrgen;
+};
+
+static_assert(offsetof(struct nlm4_notify_wrapper, xdrgen) == 0);
+
 struct nlm4_testres_wrapper {
        struct nlm4_testres             xdrgen;
        struct nlm_lock                 lock;
@@ -191,80 +197,6 @@ nlm4svc_lookup_file(struct svc_rqst *rqstp, struct nlm_host *host,
        return nlm_granted;
 }
 
-/*
- * Obtain client and file from arguments
- */
-static __be32
-nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
-                       struct nlm_host **hostp, struct nlm_file **filp)
-{
-       struct nlm_host         *host = NULL;
-       struct nlm_file         *file = NULL;
-       struct nlm_lock         *lock = &argp->lock;
-       __be32                  error = 0;
-
-       /* nfsd callbacks must have been installed for this procedure */
-       if (!nlmsvc_ops)
-               return nlm_lck_denied_nolocks;
-
-       if (lock->lock_start > OFFSET_MAX ||
-           (lock->lock_len && ((lock->lock_len - 1) > (OFFSET_MAX - lock->lock_start))))
-               return nlm4_fbig;
-
-       /* 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) {
-               int mode = lock_to_openmode(&lock->fl);
-
-               lock->fl.c.flc_flags = FL_POSIX;
-
-               error = nlm_lookup_file(rqstp, &file, lock);
-               if (error)
-                       goto no_locks;
-               *filp = file;
-
-               /* Set up the missing parts of the file_lock structure */
-               lock->fl.c.flc_file = file->f_file[mode];
-               lock->fl.c.flc_pid = current->tgid;
-               lock->fl.fl_start = (loff_t)lock->lock_start;
-               lock->fl.fl_end = lock->lock_len ?
-                                  (loff_t)(lock->lock_start + lock->lock_len - 1) :
-                                  OFFSET_MAX;
-               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);
-       switch (error) {
-       case nlm_granted:
-               return nlm_lck_denied_nolocks;
-       case nlm__int__stale_fh:
-               return nlm4_stale_fh;
-       case nlm__int__failed:
-               return nlm4_failed;
-       default:
-               if (be32_to_cpu(error) >= 30000) {
-                       pr_warn_once("lockd: unhandled internal status %u\n",
-                                    be32_to_cpu(error));
-                       return nlm4_failed;
-               }
-               return error;
-       }
-}
-
 /**
  * nlm4svc_proc_null - NULL: Test for presence of service
  * @rqstp: RPC transaction context
@@ -1191,21 +1123,30 @@ static __be32 nlm4svc_proc_nm_lock(struct svc_rqst *rqstp)
        return nlm4svc_do_lock(rqstp, false);
 }
 
-/*
- * FREE_ALL: Release all locks and shares held by client
+/**
+ * nlm4svc_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 NLMPROC4_FREE_ALL(nlm4_notify) = 23;
  */
-static __be32
-nlm4svc_proc_free_all(struct svc_rqst *rqstp)
+static __be32 nlm4svc_proc_free_all(struct svc_rqst *rqstp)
 {
-       struct nlm_args *argp = rqstp->rq_argp;
+       struct nlm4_notify_wrapper *argp = rqstp->rq_argp;
        struct nlm_host *host;
 
-       /* Obtain client */
-       if (nlm4svc_retrieve_args(rqstp, argp, &host, NULL))
-               return rpc_success;
+       host = nlm4svc_lookup_host(rqstp, argp->xdrgen.name, false);
+       if (!host)
+               goto out;
 
        nlmsvc_free_host_resources(host);
+
        nlmsvc_release_host(host);
+
+out:
        return rpc_success;
 }
 
@@ -1452,15 +1393,15 @@ static const struct svc_procedure nlm4svc_procedures[24] = {
                .pc_xdrressize  = NLM4_nlm4_res_sz,
                .pc_name        = "NM_LOCK",
        },
-       [NLMPROC_FREE_ALL] = {
-               .pc_func = nlm4svc_proc_free_all,
-               .pc_decode = nlm4svc_decode_notify,
-               .pc_encode = nlm4svc_encode_void,
-               .pc_argsize = sizeof(struct nlm_args),
-               .pc_argzero = sizeof(struct nlm_args),
-               .pc_ressize = sizeof(struct nlm_void),
-               .pc_xdrressize = St,
-               .pc_name = "FREE_ALL",
+       [NLMPROC4_FREE_ALL] = {
+               .pc_func        = nlm4svc_proc_free_all,
+               .pc_decode      = nlm4_svc_decode_nlm4_notify,
+               .pc_encode      = nlm4_svc_encode_void,
+               .pc_argsize     = sizeof(struct nlm4_notify_wrapper),
+               .pc_argzero     = 0,
+               .pc_ressize     = 0,
+               .pc_xdrressize  = XDR_void,
+               .pc_name        = "FREE_ALL",
        },
 };
 
@@ -1474,10 +1415,10 @@ union nlm4svc_xdrstore {
        struct nlm4_unlockargs_wrapper  unlockargs;
        struct nlm4_notifyargs_wrapper  notifyargs;
        struct nlm4_shareargs_wrapper   shareargs;
+       struct nlm4_notify_wrapper      notify;
        struct nlm4_testres_wrapper     testres;
        struct nlm4_res_wrapper         res;
        struct nlm4_shareres_wrapper    shareres;
-       struct nlm_args                 args;
 };
 
 static DEFINE_PER_CPU_ALIGNED(unsigned long,