From: Chuck Lever Date: Tue, 12 May 2026 18:13:57 +0000 (-0400) Subject: lockd: Use xdrgen XDR functions for the NLMv3 CANCEL_MSG procedure X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=02a47b6c5c85b28bf4dbf0c6c0ee29e0f735271f;p=thirdparty%2Fkernel%2Flinux.git lockd: Use xdrgen XDR functions for the NLMv3 CANCEL_MSG procedure The CANCEL_MSG procedure is part of NLM's asynchronous lock request flow, where clients send CANCEL_MSG to cancel pending lock requests. This patch continues the xdrgen migration by converting CANCEL_MSG to use generated XDR functions. This patch converts the CANCEL_MSG procedure to use xdrgen functions nlm_svc_decode_nlm_cancargs and nlm_svc_encode_void generated from the NLM version 3 protocol specification. The procedure handler uses xdrgen types through the nlm_cancargs_wrapper structure that bridges between generated code and the legacy lockd_lock representation. 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 lock member of the wrapper is populated explicitly in nlm3svc_lookup_file() rather than relying on zero-initialization. The previous hand-written decoder in svcxdr_decode_cookie() rewrote a zero-length NLM cookie into a four-byte zero cookie, with a comment attributing the substitution to HP-UX clients. The xdrgen-generated netobj decoder performs no such rewrite, so a zero-length request cookie now round-trips unchanged into the CANCEL_RES reply. HP-UX has reached end of support, and CANCEL_MSG is fire-and-forget with no client-side reply matching on the NLM cookie, so the workaround is dropped intentionally here. The NLM async callback mechanism uses client-side functions which continue to take legacy results like struct lockd_res, preventing CANCEL and CANCEL_MSG from sharing code for now. Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c index 17625d43dc373..d055079c94855 100644 --- a/fs/lockd/svcproc.c +++ b/fs/lockd/svcproc.c @@ -478,39 +478,6 @@ nlmsvc_proc_lock(struct svc_rqst *rqstp) return nlmsvc_do_lock(rqstp, true); } -static __be32 -__nlmsvc_proc_cancel(struct svc_rqst *rqstp, struct lockd_res *resp) -{ - struct lockd_args *argp = rqstp->rq_argp; - struct nlm_host *host; - struct nlm_file *file; - struct net *net = SVC_NET(rqstp); - - dprintk("lockd: CANCEL called\n"); - - resp->cookie = argp->cookie; - - /* Don't accept requests during grace period */ - if (locks_in_grace(net)) { - resp->status = nlm_lck_denied_grace_period; - return rpc_success; - } - - /* 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; - - /* Try to cancel request. */ - resp->status = cast_status(nlmsvc_cancel_blocked(net, file, &argp->lock)); - - dprintk("lockd: CANCEL status %d\n", ntohl(resp->status)); - nlmsvc_release_lockowner(&argp->lock); - nlmsvc_release_host(host); - nlm_release_file(file); - return rpc_success; -} - /** * nlmsvc_proc_cancel - CANCEL: Cancel an outstanding blocked lock request * @rqstp: RPC transaction context @@ -900,19 +867,72 @@ static __be32 nlmsvc_proc_lock_msg(struct svc_rqst *rqstp) __nlmsvc_proc_lock_msg); } +static __be32 +__nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp, struct lockd_res *resp) +{ + struct nlm_cancargs_wrapper *argp = rqstp->rq_argp; + unsigned char type = argp->xdrgen.exclusive ? F_WRLCK : F_RDLCK; + struct net *net = SVC_NET(rqstp); + struct nlm_file *file = NULL; + struct nlm_host *host = NULL; + + resp->status = nlm_lck_denied_nolocks; + if (nlm_netobj_to_cookie(&resp->cookie, &argp->xdrgen.cookie)) + goto out; + + resp->status = nlm_lck_denied_grace_period; + if (locks_in_grace(net)) + goto out; + + resp->status = nlm_lck_denied_nolocks; + host = nlm3svc_lookup_host(rqstp, argp->xdrgen.alock.caller_name, false); + if (!host) + goto out; + + resp->status = nlm3svc_lookup_file(rqstp, host, &argp->lock, + &file, &argp->xdrgen.alock, type); + if (resp->status) + goto out; + + resp->status = nlmsvc_cancel_blocked(net, file, &argp->lock); + nlmsvc_release_lockowner(&argp->lock); + +out: + if (file) + nlm_release_file(file); + nlmsvc_release_host(host); + return resp->status == nlm__int__drop_reply ? rpc_drop_reply : rpc_success; +} + +/** + * nlmsvc_proc_cancel_msg - CANCEL_MSG: Cancel an outstanding lock request + * @rqstp: RPC transaction context + * + * Returns: + * %rpc_success: RPC executed successfully. + * %rpc_drop_reply: Do not send an RPC reply. + * %rpc_garbage_args: The request arguments are malformed. + * %rpc_system_err: RPC execution failed. + * + * RPC synopsis: + * void NLMPROC_CANCEL_MSG(nlm_cancargs) = 8; + * + * The response to this request is delivered via the CANCEL_RES procedure. + */ static __be32 nlmsvc_proc_cancel_msg(struct svc_rqst *rqstp) { - struct lockd_args *argp = rqstp->rq_argp; - struct nlm_host *host; + struct nlm_cancargs_wrapper *argp = rqstp->rq_argp; + struct nlm_host *host; - dprintk("lockd: CANCEL_MSG called\n"); + if (argp->xdrgen.cookie.len > NLM_MAXCOOKIELEN) + return rpc_garbage_args; - host = nlmsvc_lookup_host(rqstp, argp->lock.caller, argp->lock.len); + host = nlm3svc_lookup_host(rqstp, argp->xdrgen.alock.caller_name, false); if (!host) return rpc_system_err; return nlmsvc_callback(rqstp, host, NLMPROC_CANCEL_RES, - __nlmsvc_proc_cancel); + __nlmsvc_proc_cancel_msg); } static __be32 nlmsvc_proc_unlock_msg(struct svc_rqst *rqstp) @@ -1188,15 +1208,15 @@ static const struct svc_procedure nlmsvc_procedures[24] = { .pc_xdrressize = XDR_void, .pc_name = "LOCK_MSG", }, - [NLMPROC_CANCEL_MSG] = { - .pc_func = nlmsvc_proc_cancel_msg, - .pc_decode = nlmsvc_decode_cancargs, - .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 = St, - .pc_name = "CANCEL_MSG", + [NLM_CANCEL_MSG] = { + .pc_func = nlmsvc_proc_cancel_msg, + .pc_decode = nlm_svc_decode_nlm_cancargs, + .pc_encode = nlm_svc_encode_void, + .pc_argsize = sizeof(struct nlm_cancargs_wrapper), + .pc_argzero = 0, + .pc_ressize = 0, + .pc_xdrressize = XDR_void, + .pc_name = "CANCEL_MSG", }, [NLMPROC_UNLOCK_MSG] = { .pc_func = nlmsvc_proc_unlock_msg,