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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A276EC2BD09 for ; Thu, 27 Jun 2024 11:43:56 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sMnWl-00053z-4M; Thu, 27 Jun 2024 07:42:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sMnWj-00053i-GV for qemu-devel@nongnu.org; Thu, 27 Jun 2024 07:42:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sMnWh-0008Rb-SB for qemu-devel@nongnu.org; Thu, 27 Jun 2024 07:42:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719488572; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9MZEhoDEFKAT7ZtbZ2YdQqCU9vavsYhohaPwjIu37wE=; b=NpSAq3nHN56WujyMg2um8WfAcQqZYCwgTQt7hdxbCruCF6Iqzsf6xjvJWMHfOhD+HxQgqG R084PDvhgaJZGURxhaRvu5RXoJjkcQajuusDUDYW4czQ5mhGTFttfEMhMCaA4ccKhaKdeY 86TUo9kNm7sAE+JPIAcfcXuEE7ey9/E= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-538-wkv_B_EVM7GL5Wmoh9YGJw-1; Thu, 27 Jun 2024 07:42:49 -0400 X-MC-Unique: wkv_B_EVM7GL5Wmoh9YGJw-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 80E161956089; Thu, 27 Jun 2024 11:42:48 +0000 (UTC) Received: from redhat.com (unknown [10.39.192.213]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CD5B219560A3; Thu, 27 Jun 2024 11:42:45 +0000 (UTC) Date: Thu, 27 Jun 2024 13:42:43 +0200 From: Kevin Wolf To: Nir Soffer Cc: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , Stefan Hajnoczi , qemu-devel@nongnu.org, Fam Zheng , qemu-block@nongnu.org, Hanna Reitz Subject: Re: [PATCH v2] Consider discard option when writing zeros Message-ID: References: <20240619174022.1298578-1-nsoffer@redhat.com> <20240624152302.GA2402845@fedora.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.212, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Am 26.06.2024 um 18:27 hat Nir Soffer geschrieben: > On Wed, Jun 26, 2024 at 12:17 PM Daniel P. Berrangé > wrote: > > > On Mon, Jun 24, 2024 at 06:08:26PM +0200, Kevin Wolf wrote: > > > Am 24.06.2024 um 17:23 hat Stefan Hajnoczi geschrieben: > > > > On Wed, Jun 19, 2024 at 08:43:25PM +0300, Nir Soffer wrote: > > > > > Tested using: > > > > > > > > Hi Nir, > > > > This looks like a good candidate for the qemu-iotests test suite. > > Adding > > > > it to the automated tests will protect against future regressions. > > > > > > > > Please add the script and the expected output to > > > > tests/qemu-iotests/test/write-zeroes-unmap and run it using > > > > `(cd build && tests/qemu-iotests/check write-zeroes-unmap)`. > > > > > > > > See the existing test cases in tests/qemu-iotests/ and > > > > tests/qemu-iotests/tests/ for examples. Some are shell scripts and > > > > others are Python. I think shell makes sense for this test case. You > > > > can copy the test framework boilerplate from an existing test case. > > > > > > 'du' can't be used like this in qemu-iotests because it makes > > > assumptions that depend on the filesystem. A test case replicating what > > > Nir did manually would likely fail on XFS with its preallocation. > > > > > > Maybe we could operate on a file exposed by the FUSE export that is > > > backed by qcow2, and then you can use 'qemu-img map' on that qcow2 image > > > to verify the allocation status. Somewhat complicated, but I think it > > > could work. > > > > A simpler option would be to use 'du' but with a fuzzy range test, > > rather than an exact equality test. > > > > For the tests which write 1 MB, check the 'du' usage is "at least 1MB", > > for the tests which expect to unmap blocks, check that the 'du' usage > > is "less than 256kb". This should be within bounds of xfs speculative > > allocation. > > This should work, I'll start with this approach. If we're okay with accepting tests that depend on filesystem behaviour, then 'qemu-img map -f raw --output=json' should be the less risky approach than checking 'du'. Kevin