From: Olaf van der Spek Subject: Re: Atomic non-durable file write API Date: Thu, 23 Dec 2010 16:49:53 +0100 Message-ID: References: <4D0A7278.3080506@gmail.com> <1292710543.17128.14.camel@nayuki> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE To: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:42142 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752799Ab0LWPty convert rfc822-to-8bit (ORCPT ); Thu, 23 Dec 2010 10:49:54 -0500 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Dec 19, 2010 at 5:39 PM, Olaf van der Spek wrote: > On Sat, Dec 18, 2010 at 11:15 PM, Calvin Walton wrote: >> Hmm. I=E2=80=99m doing a little interpretation of what Olaf said her= e; but I >> think you may have misunderstood the question? >> >> He doesn=E2=80=99t care about whether or not the file is securely wr= itten to >> disk (durable); however he doesn=E2=80=99t want to see any partially= written >> files. In other words, something like >> >> =C2=A0 =C2=A0 1. Write to temp file >> =C2=A0 =C2=A0 2. Rename temp file over original file > > Meta data, including file owner, should be preserved. > Ideally, no temp files should be visible either. > >> Where the rename is only committed to disk once the entire contents = of >> the file have been written securely =E2=80=93 whenever that may even= tually >> happen. >> >> He doesn=E2=80=99t want to synchronously wait for the file to be wri= tten, >> because the new data isn=E2=80=99t particularly important. The only = important >> thing is that the file either contains the old or new data after a >> filesystem crash; not incomplete data. So, it=E2=80=99s more of an o= rdering >> problem, I think? (Analogous to putting some sort of barrier between= the >> file write/close and the file rename to maintain ordering.) >> >> Hopefully I=E2=80=99ve interpreted the original question correctly, = because this >> is something I would find interesting as well. > > Yes, you did. Somebody? Olaf -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html