From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24C72C433EF for ; Sat, 5 Feb 2022 02:33:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378993AbiBECdw (ORCPT ); Fri, 4 Feb 2022 21:33:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378981AbiBECdu (ORCPT ); Fri, 4 Feb 2022 21:33:50 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9217C061346 for ; Fri, 4 Feb 2022 18:33:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=+0+OoL26Ayv+ly1T+I4jBBoxGfM4bWwwpHkARxTdN7Q=; b=BEInJHLWnohXin7TqpJzO64xkw 7/CHx3no9lca0WJdohzLxeqvwUf73U1OeUS6jpISpwUJ1ou2HylvoQIicOnn5LqftA/IyIdTmuQSd M8PYDffBPvH5eAbAc6MIZl8Q8mBUofZ4ps8O0EizvwDjkKpaveuKvJHydb+IaiV3Lyl8Zh+0iy6Jf wvJ6MXyyET/CVMY5ar5e8TeXBdPSE9+/mcdB1hBnKGU9QG65i+EgbRKRjviSG9A365VXjlO4b9ST9 OyIjFIMdRauJ4yxbFwhKudnjxuath0vfftMCIgcVqao+C7GaEfV/p818vVQ/tv17Glcc5o4sgSQXz L+GGghjw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nGAtP-005zGw-AU; Sat, 05 Feb 2022 02:33:43 +0000 Date: Fri, 4 Feb 2022 18:33:39 -0800 From: Luis Chamberlain To: Chaitanya Kulkarni , Bart Van Assche Cc: "dwagner@suse.de" , "osandov@fb.com" , "linux-block@vger.kernel.org" , Bart Van Assche Subject: Re: [PATCH] blktests: replace module removal with patient module removal Message-ID: References: <20211116172926.587062-1-mcgrof@kernel.org> <48b1d742-888c-ee14-297e-c63ae3bf37ed@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48b1d742-888c-ee14-297e-c63ae3bf37ed@nvidia.com> Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Jan 26, 2022 at 05:39:13AM +0000, Chaitanya Kulkarni wrote: > On 11/16/21 9:29 AM, Luis Chamberlain wrote: > > A long time ago, in a galaxy far, far away... > > > > I ran into some odd scsi_debug false positives with fstests. This > > prompted me to look into them given these false positives prevents > > me from moving forward with establishing a test baseline with high > > number of cycles. That is, this stupid issue was prevening creating > > high confidence in testing. > > > > I reported it [0] and exchanged some ideas with Doug. However, in > > the end, despite efforts to help things with scsi_debug there were > > still issues lingering which seemed to defy our expectations upstream. > > One of the last hanging fruit issues is and always has been that > > userspace expectations for proper module removal has been broken, > > so in the end I have demonstrated this is a generic issue [1]. > > > > Long ago a WAIT option for module removal was added... that was then > > removed as it was deemed not needed as folks couldn't figure out when > > these races happened. The races are actually pretty easy to trigger, it > > was just never properly documented. A simpe blkdev_open() will easily > > bump a module refcnt, and these days many thing scan do that sort of > > thing. > > > > The proper solution is to implement then a patient module removal > > on kmod and patches have been sent for that and those patches are > > under review. In the meantime we need a work around to open code a > > similar solution for users of old versions of kmod. I sent an open > > coded solution for fstests about since August 19th and has been used > > there for a few months now. Now that that stuff is merged and tested > > in fstests with more exposure, its time to match parity on blktests. > > > > I've tested blktests with this for things which I can run virtually > > for a while now. More wider testig is welcomed. > > > > [0] https://bugzilla.kernel.org/show_bug.cgi?id=212337 > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=214015 > > Signed-off-by: Luis Chamberlain > > --- > > > This looks good to me, I'd wait Bart (CCd here) to review the > srp side. > > Looks good. > > Reviewed-by: Chaitanya Kulkarni Bart, *poke* Luis