Return-Path: Received: from rcsinet10.oracle.com ([148.87.113.121]:40656 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932187Ab0FYQaI (ORCPT ); Fri, 25 Jun 2010 12:30:08 -0400 Message-ID: <4C24D95F.6090301@oracle.com> Date: Fri, 25 Jun 2010 12:29:19 -0400 From: Chuck Lever To: Jeff Layton CC: linux-nfs@vger.kernel.org, trond.myklebust@fys.uio.no, Staubach_Peter@emc.com, bfields@fieldses.org Subject: Re: [PATCH 1/2] sunrpc: split the vs_hidden flag into TCP and UDP variants (try #2) References: <1277480946-23844-1-git-send-email-jlayton@redhat.com> <4C24D057.4090403@oracle.com> <20100625120710.2ead8998@tlielax.poochiereds.net> In-Reply-To: <20100625120710.2ead8998@tlielax.poochiereds.net> Content-Type: text/plain; charset=US-ASCII; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On 06/25/10 12:07 PM, Jeff Layton wrote: > On Fri, 25 Jun 2010 11:50:47 -0400 > Chuck Lever wrote: > >> So this may be a dumb question, but why can't you just change the NFSv4 >> server not to create an RPC listener for UDP? >> > > Unless I'm misunderstanding the code, it's not really structured to do > what you suggest. We don't really create version-specific listeners. We > create listeners for nfsd. We then hook a svc_program to nfsd that has > multiple svc_version structs attached to it. Requests come into nfsd, > it parses them and dispatches them to the appropriate version handlers. > > Now that I think about it though...it may be a little cleaner to create > a nfsd4_dispatch routine that does this check and then calls the generic > nfsd_dispatch. That way we wouldn't penalize NFSv2/3 with this check. I > may respin this patch and do it that way once others have a chance to > comment. Alright, I thought that we had the same issue for NFS/RMDA. Basically we want to allow NFSv3 over RDMA, but we don't want to allow NFSv4 over RDMA (yet). Apparently there's nothing in rpc.nfsd or other parts of user space that allow fine-grained selection of NFSD transports. Maybe we should consider that. Allowing UDP for legacy NFSv2 clients, but accepting only TCP for NFSv3 and NFSv4, is a configuration that might be desirable, for example. >> On 06/25/10 11:49 AM, Jeff Layton wrote: >>> RFC3530 states: >>> >>> Where an NFS version 4 implementation supports operation over the IP >>> network protocol, the supported transports between NFS and IP MUST be >>> among the IETF-approved congestion control transport protocols, which >>> include TCP and SCTP >>> >>> The NFS server currently registers the NFSv4 UDP port with the >>> portmapper, which it really shouldn't do. This patch splits the >>> vs_hidden flag into TCP and UDP variants. A later patch will make >>> the NFS server skip NFSv4+UDP registration with rpcbind. >>> >>> Reported-by: Sachin Prabhu >>> Signed-off-by: Jeff Layton >>> --- >>> fs/nfs/callback_xdr.c | 3 ++- >>> fs/nfsd/nfs2acl.c | 1 - >>> fs/nfsd/nfs3acl.c | 1 - >>> include/linux/sunrpc/svc.h | 5 +++-- >>> net/sunrpc/svc.c | 15 +++++++++++---- >>> 5 files changed, 16 insertions(+), 9 deletions(-) >>> >>> diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c >>> index 05af212..30baf97 100644 >>> --- a/fs/nfs/callback_xdr.c >>> +++ b/fs/nfs/callback_xdr.c >>> @@ -783,7 +783,8 @@ struct svc_version nfs4_callback_version1 = { >>> .vs_proc = nfs4_callback_procedures1, >>> .vs_xdrsize = NFS4_CALLBACK_XDRSIZE, >>> .vs_dispatch = NULL, >>> - .vs_hidden = 1, >>> + .vs_hidden_tcp = true, >>> + .vs_hidden_udp = true, >>> }; >>> >>> struct svc_version nfs4_callback_version4 = { >>> diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c >>> index 6aa5590..ec602b4 100644 >>> --- a/fs/nfsd/nfs2acl.c >>> +++ b/fs/nfsd/nfs2acl.c >>> @@ -352,5 +352,4 @@ struct svc_version nfsd_acl_version2 = { >>> .vs_proc = nfsd_acl_procedures2, >>> .vs_dispatch = nfsd_dispatch, >>> .vs_xdrsize = NFS3_SVC_XDRSIZE, >>> - .vs_hidden = 0, >>> }; >>> diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c >>> index a596e9d..1949a4c 100644 >>> --- a/fs/nfsd/nfs3acl.c >>> +++ b/fs/nfsd/nfs3acl.c >>> @@ -262,6 +262,5 @@ struct svc_version nfsd_acl_version3 = { >>> .vs_proc = nfsd_acl_procedures3, >>> .vs_dispatch = nfsd_dispatch, >>> .vs_xdrsize = NFS3_SVC_XDRSIZE, >>> - .vs_hidden = 0, >>> }; >>> >>> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h >>> index 5a3085b..27ff713 100644 >>> --- a/include/linux/sunrpc/svc.h >>> +++ b/include/linux/sunrpc/svc.h >>> @@ -370,8 +370,9 @@ struct svc_version { >>> struct svc_procedure * vs_proc; /* per-procedure info */ >>> u32 vs_xdrsize; /* xdrsize needed for this version */ >>> >>> - unsigned int vs_hidden : 1; /* Don't register with portmapper. >>> - * Only used for nfsacl so far. */ >>> + /* these flags control whether program is registered with rpcbind */ >>> + bool vs_hidden_tcp; >>> + bool vs_hidden_udp; >>> >>> /* Override dispatch function (e.g. when caching replies). >>> * A return value of 0 means drop the request. >>> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c >>> index d9017d6..487792c 100644 >>> --- a/net/sunrpc/svc.c >>> +++ b/net/sunrpc/svc.c >>> @@ -868,6 +868,7 @@ int svc_register(const struct svc_serv *serv, const int family, >>> struct svc_program *progp; >>> unsigned int i; >>> int error = 0; >>> + bool vs_hidden; >>> >>> BUG_ON(proto == 0&& port == 0); >>> >>> @@ -876,16 +877,20 @@ int svc_register(const struct svc_serv *serv, const int family, >>> if (progp->pg_vers[i] == NULL) >>> continue; >>> >>> + vs_hidden = (proto == IPPROTO_UDP) ? >>> + progp->pg_vers[i]->vs_hidden_udp : >>> + progp->pg_vers[i]->vs_hidden_tcp; >>> + >>> dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n", >>> progp->pg_name, >>> i, >>> - proto == IPPROTO_UDP? "udp" : "tcp", >>> + proto == IPPROTO_UDP ? "udp" : "tcp", >>> port, >>> family, >>> - progp->pg_vers[i]->vs_hidden? >>> + vs_hidden ? >>> " (but not telling portmap)" : ""); >>> >>> - if (progp->pg_vers[i]->vs_hidden) >>> + if (vs_hidden) >>> continue; >>> >>> error = __svc_register(progp->pg_name, progp->pg_prog, >>> @@ -943,7 +948,9 @@ static void svc_unregister(const struct svc_serv *serv) >>> for (i = 0; i< progp->pg_nvers; i++) { >>> if (progp->pg_vers[i] == NULL) >>> continue; >>> - if (progp->pg_vers[i]->vs_hidden) >>> + >>> + if (progp->pg_vers[i]->vs_hidden_tcp&& >>> + progp->pg_vers[i]->vs_hidden_udp) >>> continue; >>> >>> __svc_unregister(progp->pg_prog, i, progp->pg_name); >> > >