From: Eric Sandeen Subject: Re: [PATCH] ext4: add fallocate mode blocking for debugging purposes Date: Tue, 15 Apr 2014 11:15:41 -0500 Message-ID: <534D5B2D.70408@redhat.com> References: <1397420518-29218-1-git-send-email-tytso@mit.edu> <20140413220016.GD8122@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Ext4 Developers List , Namjae Jeon To: =?windows-1252?Q?Luk=E1=9A_Czerner?= , "Theodore Ts'o" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:27502 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750853AbaDOQPp (ORCPT ); Tue, 15 Apr 2014 12:15:45 -0400 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On 4/15/14, 11:02 AM, Luk=E1=9A Czerner wrote: > On Sun, 13 Apr 2014, Theodore Ts'o wrote: >=20 >> Date: Sun, 13 Apr 2014 18:00:16 -0400 >> From: Theodore Ts'o >> To: Ext4 Developers List >> Cc: Namjae Jeon >> Subject: Re: [PATCH] ext4: add fallocate mode blocking for debugging= purposes >> >> On Sun, Apr 13, 2014 at 04:21:58PM -0400, Theodore Ts'o wrote: >>> If a particular fallocate mode is causing test failures, give the >>> tester the ability to block a particular fallocate mode so that the >>> use of a particular fallocate mode will be reported as not supporte= d. >>> >>> For example, if the COLLAPSE_RANGE fallocate mode is causing test >>> failures, this allows us to suppress it so we can more easily test = the >>> rest of the file system code. >> >> Hi Namjae, >> >> One of the reasons this patch set is that after Lukas added >> COLLAPSE_RANGE support into fsx, we've started seeing a number of >> failures which seem to be directly related to COLLAPSE_RANGE. >=20 > Ah, I did mentioned it when I added COLLAPSE_RANGE to the fsx and > fsstress, but I forgot to cc you Namjae, sorry about that. >=20 > But about the patch. It seems a little bit weird to change kernel > for this. The way I am doing it is by changing ltp/fsx.c and > ltp.fsstress.c to disable the particular mode: I tend to agree, better to fix the kernel than to add a knob to turn it off. And fsx changes can happen a lot quicker than kernel changes. [1= ] And if it's really unsafe, and you really want to add a knob, I'd at le= ast default it to off until it's non-corrupting, and add a message that this tunable will go away as soon as it's stable, so you'll have no qualms about quickly deprecating it... -Eric [1] it'd be nifty to make an env. var in xfstests which can globally disable certain fsx operations across all tests which run fsx... -- 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