From: Benny Halevy Subject: Re: [PATCH 08/31] nfsd41: sanity check client drc maxreqs Date: Thu, 30 Apr 2009 20:34:02 +0300 Message-ID: <49F9E10A.60801@panasas.com> References: <1240938005-23778-1-git-send-email-andros@netapp.com> <1240938005-23778-2-git-send-email-andros@netapp.com> <1240938005-23778-3-git-send-email-andros@netapp.com> <1240938005-23778-4-git-send-email-andros@netapp.com> <1240938005-23778-5-git-send-email-andros@netapp.com> <1240938005-23778-6-git-send-email-andros@netapp.com> <1240938005-23778-7-git-send-email-andros@netapp.com> <1240938005-23778-8-git-send-email-andros@netapp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: bfields@fieldses.org, pnfs@linux-nfs.org, linux-nfs@vger.kernel.org To: andros@netapp.com Return-path: Received: from gw-ca.panasas.com ([209.116.51.66]:6631 "EHLO laguna.int.panasas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933437AbZD3Rfx (ORCPT ); Thu, 30 Apr 2009 13:35:53 -0400 In-Reply-To: <1240938005-23778-8-git-send-email-andros@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Apr. 28, 2009, 19:59 +0300, andros@netapp.com wrote: > From: Andy Adamson > > Ensure the client requested maximum requests are between 1 and > NFSD_MAX_SLOTS_PER_SESSION > > Signed-off-by: Andy Adamson > --- > fs/nfsd/nfs4state.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index e216169..59b601b 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -427,6 +427,11 @@ static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan) > { > int status = 0, np = fchan->maxreqs * NFSD_PAGES_PER_SLOT; > > + if (fchan->maxreqs < 1) > + return nfserr_inval; Is 0 prohibited by the protocol? The server can set it to whatever value it wants, or if we can live with it, it actually provides a nice way to test the server end-cases. Benny > + else if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION) > + fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION; > + > spin_lock(&nfsd_serv->sv_lock); > if (np + nfsd_serv->sv_drc_pages_used > nfsd_serv->sv_drc_max_pages) > np = nfsd_serv->sv_drc_max_pages - nfsd_serv->sv_drc_pages_used;