From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from imap.thunk.org ([74.207.234.97]:40260 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301AbcFKPqA (ORCPT ); Sat, 11 Jun 2016 11:46:00 -0400 Date: Sat, 11 Jun 2016 11:45:55 -0400 From: "Theodore Ts'o" Subject: Re: [PATCH] common: ext4's data=journal mode doesn't support O_DIRECT Message-ID: <20160611154555.GA5489@thunk.org> References: <1465497762-3333-1-git-send-email-tytso@mit.edu> <20160611122026.GT5140@eguan.usersys.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160611122026.GT5140@eguan.usersys.redhat.com> Sender: fstests-owner@vger.kernel.org To: Eryu Guan Cc: fstests@vger.kernel.org List-ID: On Sat, Jun 11, 2016 at 08:20:26PM +0800, Eryu Guan wrote: > > This hunk doesn't apply, there's no detection code for ext4 encryption > in current master. And do we need to filter out ext3 journal mode as > well? Oops, there's another patch this depends upon that I forgot to send out this time around. Let me fix up the spaces and tabs, and probably just combine the two patches. > Just curious, what's the problem running direct I/O tests on journal > mode ext4? ext4 falls back to buffered I/O in this case and I don't see > any test failures caused by it. Perhaps it'd be better to add this > information to commit log too. I'll double check but I think there was at least one dmflaky that failed (or maybe it was just flaky) because the DIO write wasn't really DIO, and if the device went read-only too early, the data write wouldn't make it to the disk, and this caused the test failure. More generally, if a particular file system mode doesn't support Direct I/O, even if it doesn't cause a test failure, it's likely a waste of test resources to run a test which expected that writes be DIO when it really isn't. - Ted