From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chuck Lever Subject: Re: Correct behavior on O_DIRECT sparse file writes Date: Mon, 15 Oct 2007 11:36:18 -0400 Message-ID: <471388F2.8010605@oracle.com> References: <1192221567.1375.81.camel@think.oraclecorp.com> <20071012140233.ad7b517d.akpm@linux-foundation.org> <871wbzp88o.fsf@mid.deneb.enyo.de> Reply-To: chuck.lever@oracle.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------010204070204000802070609" Cc: Andrew Morton , Chris Mason , linux-fsdevel@vger.kernel.org To: Florian Weimer Return-path: Received: from rgminet01.oracle.com ([148.87.113.118]:12300 "EHLO rgminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751978AbXJOPhu (ORCPT ); Mon, 15 Oct 2007 11:37:50 -0400 In-Reply-To: <871wbzp88o.fsf@mid.deneb.enyo.de> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org This is a multi-part message in MIME format. --------------010204070204000802070609 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Florian Weimer wrote: > * Andrew Morton: > >> I don't think it's a bug. Sure, O_DIRECT is synchronous, but that's >> because it is, err, direct. Not because it provides extra data-integrity >> guarantees. If you want those guarantees, use O_SYNC as well. > > This needs to be prominently documented. Right now, it's far from clear > that you need both O_DIRECT and O_SYNC. It's certainly not a requirement for NFS. O_DIRECT on NFS forces data to the server, which always updates a file's metadata on each write, including indirect blocks. --------------010204070204000802070609 Content-Type: text/x-vcard; charset=utf-8; name="chuck.lever.vcf" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="chuck.lever.vcf" begin:vcard fn:Chuck Lever n:Lever;Chuck org:Oracle Corporation;Corporate Architecture: Linux Projects Group adr:;;1015 Granger Avenue;Ann Arbor;MI;48104;USA title:Principal Member of Staff tel;work:+1 248 614 5091 x-mozilla-html:FALSE version:2.1 end:vcard --------------010204070204000802070609--