Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-vc0-f176.google.com ([209.85.220.176]:50830 "EHLO mail-vc0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755875AbbBIRih (ORCPT ); Mon, 9 Feb 2015 12:38:37 -0500 Received: by mail-vc0-f176.google.com with SMTP id la4so1586663vcb.7 for ; Mon, 09 Feb 2015 09:38:35 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1423501065-14320-1-git-send-email-tigran.mkrtchyan@desy.de> References: <1423501065-14320-1-git-send-email-tigran.mkrtchyan@desy.de> Date: Mon, 9 Feb 2015 12:38:35 -0500 Message-ID: Subject: Re: [PATCH] nfs: do not initialize back channel with DS From: Trond Myklebust To: Tigran Mkrtchyan Cc: Linux NFS Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: Hi Tigran, On Mon, Feb 9, 2015 at 11:57 AM, Tigran Mkrtchyan wrote: > Signed-off-by: Tigran Mkrtchyan > --- > fs/nfs/nfs4proc.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index 2e7c9f7..7f9674d 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -7236,9 +7236,12 @@ static int _nfs4_proc_create_session(struct nfs_client *clp, > .rpc_cred = cred, > }; > int status; > + int flags = SESSION4_PERSIST; > > nfs4_init_channel_attrs(&args); > - args.flags = (SESSION4_PERSIST | SESSION4_BACK_CHAN); > + if (!is_ds_only_client(clp)) > + flags |= SESSION4_BACK_CHAN; > + args.flags = flags; > > status = rpc_call_sync(session->clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT); > trace_nfs4_create_session(clp, status); Why is this useful? If the server doesn't want to create a back channel, then it just clears that flag in the csr_flags field in the reply. Cheers Trond -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@primarydata.com