Return-Path: Received: from mx2.netapp.com ([216.240.18.37]:27803 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758588Ab0HDU7u convert rfc822-to-8bit (ORCPT ); Wed, 4 Aug 2010 16:59:50 -0400 Subject: Re: Write delegation Content-Type: text/plain; charset=us-ascii From: Andy Adamson In-Reply-To: Date: Wed, 4 Aug 2010 16:59:49 -0400 Cc: linux-nfs@vger.kernel.org Message-Id: <97A00951-577C-4365-AA38-3C6E2D03B372@netapp.com> References: To: Yudong Gao Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Aug 4, 2010, at 3:21 PM, Yudong Gao wrote: > Hi, > > I am not able to find the implementation of directory delegation, > either. Similarly, the callback functions CB_NOTIFY is not > implemented, either. I find that in preprocss_nfs41_op() in > callback_xdr.c, whenever a CB_NOTIFY is encountered, an > NFS4ERR_NOTSUPP is returned directly. CB_NOTIFY is not currently supported on the Linux NFS client. > > Am I missing something? Or they are just not supported in the current version? > > Thanks a lot! > > best, > > Yudong > > On Mon, Aug 2, 2010 at 5:17 PM, Yudong Gao wrote: >> Hi, >> >> I am looking at the delegation implementation in the source code of >> NFS 4.1 in kernel 2.6.32.15. I can find the code for read delegation, >> which is working and can serve the read requests locally. But I can >> never find the code about write delegation, which is supposed to cache >> the write update locally. I try to look at the functions including >> nfs_writepage(s), nfs_file_flush() but none of them checks or uses the >> write delegation. >> >> Is write delegation currently implemented in NFS 4.1? Write delegation is supported but I don't think write behavior changes - writes are still cached and flushed as without a write delegation. The write delegation does prevent open/close and lock/locku from being put on the wire. -->Andy >> >> Thanks! >> >> best, >> >> Yudong >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html