From: Eric Sandeen Subject: Re: [PATCH RFC] Insure direct IO writes do not use the page cache Date: Wed, 29 Jul 2009 14:48:11 -0500 Message-ID: <4A70A77B.6080006@redhat.com> References: <6601abe90907281728h22be79fenc68a16b578e28a91@mail.gmail.com> <6601abe90907290910x7cf1122cwac689d1f106326d3@mail.gmail.com> <4A708451.4060908@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: ext4 development To: Curt Wohlgemuth Return-path: Received: from mx2.redhat.com ([66.187.237.31]:49261 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752764AbZG2TsO (ORCPT ); Wed, 29 Jul 2009 15:48:14 -0400 In-Reply-To: <4A708451.4060908@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Eric Sandeen wrote: ... > Also, IIRC xfs does the conversion to written (vs. unwritten) extents in > an IO completion handler, just FWIW. After talking w/ Jeff Moyer, realized that w/o using the io completion, there's a race with AIO. Userspace will get notified that the write is done before the extents get flipped to initialized .... -Eric