From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751849AbZH1Qdm (ORCPT ); Fri, 28 Aug 2009 12:33:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751598AbZH1Qdl (ORCPT ); Fri, 28 Aug 2009 12:33:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47338 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751365AbZH1Qdk (ORCPT ); Fri, 28 Aug 2009 12:33:40 -0400 Message-ID: <4A9806D9.5050409@redhat.com> Date: Fri, 28 Aug 2009 09:33:29 -0700 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Lightning/1.0pre Thunderbird/3.0b3 MIME-Version: 1.0 To: Christoph Hellwig CC: Jamie Lokier , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: adding proper O_SYNC/O_DSYNC, was Re: O_DIRECT and barriers References: <20090821142635.GB30617@infradead.org> <20090821152459.GC6929@shareable.org> <20090821174525.GA28861@infradead.org> <20090822005006.GA22530@shareable.org> <20090824023422.GA775@infradead.org> <20090827143459.GB31453@shareable.org> <20090827171044.GA5427@infradead.org> <4A96C14C.8040105@redhat.com> <20090828154647.GA15808@infradead.org> <4A98008B.6050503@redhat.com> <20090828161745.GA8755@infradead.org> In-Reply-To: <20090828161745.GA8755@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/28/2009 09:17 AM, Christoph Hellwig wrote: > I'll put it on my todo list. Any ABI change like this takes a long time to trickle down. If this is agreed to be the correct approach then adding the O_* definitions earlier is better. Even if it isn't yet implemented. Then, once the kernel side is implemented, programs are ready to use it. I cannot jump the gun and define the flags myself first. > - O_RSYNC basically means we need to commit atime updates before a > read returns, right? No, that's not it. O_RSYNC on its own just means the data is successfully transferred to the calling process (always the case). O_RSYNC|O_DSYNC means that if a read request hits data that is currently in a cache and not yet on the medium, then the write to medium is successful before the read succeeds. O_RSYNC|O_SYNC means the same plus the integrity of file meta information (access time etc). -- ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖ From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulrich Drepper Subject: Re: adding proper O_SYNC/O_DSYNC, was Re: O_DIRECT and barriers Date: Fri, 28 Aug 2009 09:33:29 -0700 Message-ID: <4A9806D9.5050409@redhat.com> References: <20090821142635.GB30617@infradead.org> <20090821152459.GC6929@shareable.org> <20090821174525.GA28861@infradead.org> <20090822005006.GA22530@shareable.org> <20090824023422.GA775@infradead.org> <20090827143459.GB31453@shareable.org> <20090827171044.GA5427@infradead.org> <4A96C14C.8040105@redhat.com> <20090828154647.GA15808@infradead.org> <4A98008B.6050503@redhat.com> <20090828161745.GA8755@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jamie Lokier , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Christoph Hellwig Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47338 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751365AbZH1Qdk (ORCPT ); Fri, 28 Aug 2009 12:33:40 -0400 In-Reply-To: <20090828161745.GA8755@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 08/28/2009 09:17 AM, Christoph Hellwig wrote: > I'll put it on my todo list. Any ABI change like this takes a long time to trickle down. If this is agreed to be the correct approach then adding the O_*=20 definitions earlier is better. Even if it isn't yet implemented. Then= ,=20 once the kernel side is implemented, programs are ready to use it. I=20 cannot jump the gun and define the flags myself first. > - O_RSYNC basically means we need to commit atime updates before a > read returns, right? No, that's not it. O_RSYNC on its own just means the data is successfully transferred to=20 the calling process (always the case). O_RSYNC|O_DSYNC means that if a read request hits data that is currentl= y=20 in a cache and not yet on the medium, then the write to medium is=20 successful before the read succeeds. O_RSYNC|O_SYNC means the same plus the integrity of file meta=20 information (access time etc). --=20 =E2=9E=A7 Ulrich Drepper =E2=9E=A7 Red Hat, Inc. =E2=9E=A7 444 Castro S= t =E2=9E=A7 Mountain View, CA =E2=9D=96 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html