From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phillip Susi Subject: Re: [Bug 70121] Increasing efficiency of full data journaling Date: Fri, 07 Mar 2014 15:41:27 -0500 Message-ID: <531A2EF7.5010005@ubuntu.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit To: bugzilla-daemon@bugzilla.kernel.org, linux-ext4@vger.kernel.org Return-path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120]:40192 "EHLO cdptpa-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751649AbaCGUl2 (ORCPT ); Fri, 7 Mar 2014 15:41:28 -0500 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 3/6/2014 12:28 AM, bugzilla-daemon@bugzilla.kernel.org wrote: >> It does no such thing. > > What does it not? write("foo"); <-- crash write("bar"); Your file now has "foo" and not "bar". The fact that "foo" hit the journal first, and may or may not have hit the final location before the crash doesn't change the fact that you crashed between the two write calls, so "bar" is certainly lost, and if "foo" did hit the disk, then you have a partially written, and thus corrupt file. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTGi73AAoJEI5FoCIzSKrwQq8H/0+giACBP1uYn6fN97yEjGT+ movV5ITpmc6Aq11E2GSF7T60ehTV2Q27PYjxr4YF/fHUfkthBKyISgONwTpXiDUk tYCpMKuAokC5zmhl2UlTwain+Y/By9UnH3DjbAkg7trnGiEcuT6AJXUZh7fYPPXq AKnJNYT+LI8EzPLKRf4DbtL5mPmRsaGDa7zCZ5eVQgtyao1LmaFNTcaojUATpw/n p4cwBHkcauQSs126Z0XryiWXrOpBoYRCwFF42DIlAOd5tSnGyhbE75ul83m5lCC4 BlRrZ6+057RPiYFpmbgTsatatSZBbuGvEwuTICHDJiR8jqmucjarKPg9/wocERA= =PKiE -----END PGP SIGNATURE-----