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 lists1p.gnu.org (lists1p.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 DCBAEC79FB6 for ; Wed, 9 Sep 2026 18:38:12 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x4NB8-0005hd-NP; Wed, 09 Sep 2026 14:37:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x4NB6-0005go-Hl for qemu-devel@nongnu.org; Wed, 09 Sep 2026 14:37:48 -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 1x4NB4-0006o0-Ka for qemu-devel@nongnu.org; Wed, 09 Sep 2026 14:37:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1788979065; 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: in-reply-to:in-reply-to:references:references; bh=9A3kljZKbAJVVSHuP0SY1V6egf60EnbMBEcag7VsMHY=; b=FqkPlUwPTMV03AxRhxQE1J/OaMDeWy8zQFPzBGnQbWANGugPUPGjqbI0ZTgDY1Mq/LVjR4 0pvG4RHvpsVTZ9y+iJcFNydtlxeIRmC516LV1w/oYUTbyDo5Ig57H26j4lslx4jhwBTGon EjuvV9Bm8DrzZ7KKgBryUrt85Gl+F5s= Received: from mx-prod-mc-05.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-270-RIOC-G9rNN-bcd2bmsZIhg-1; Wed, 09 Sep 2026 14:37:41 -0400 X-MC-Unique: RIOC-G9rNN-bcd2bmsZIhg-1 X-Mimecast-MFC-AGG-ID: RIOC-G9rNN-bcd2bmsZIhg_1788979058 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3D1D61954B19; Wed, 9 Sep 2026 18:37:38 +0000 (UTC) Received: from localhost (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 854D218004D4; Wed, 9 Sep 2026 18:37:37 +0000 (UTC) Date: Wed, 9 Sep 2026 14:37:36 -0400 From: Stefan Hajnoczi To: Niklas Cassel Cc: Kevin Wolf , Fam Zheng , Hanna Reitz , Sam Li , Damien Le Moal , qemu-block@nongnu.org, qemu-devel@nongnu.org Subject: Re: [PATCH v4 07/12] block: reject zone appends that are not a multiple of the sector size Message-ID: <20260909183736.GF20134@fedora> References: <20260907110748.1868714-1-cassel@kernel.org> <20260907110748.1868714-8-cassel@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="p0rRWq7IGw9g1sIY" Content-Disposition: inline In-Reply-To: <20260907110748.1868714-8-cassel@kernel.org> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development 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 --p0rRWq7IGw9g1sIY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Sep 07, 2026 at 01:07:42PM +0200, Niklas Cassel wrote: > Zone write pointers are tracked and reported in units of > BDRV_SECTOR_SIZE, so an append whose data size is not a multiple of it > would leave a write pointer that cannot be represented, neither in a > BlockZoneDescriptor nor in the virtio and NVMe zone reports derived from > one. >=20 > Nothing states that invariant. file-posix, the only driver that carries > out an append itself, does enforce it, but only as a side effect of > checking each iovec against BlockLimits.write_granularity, which is never > smaller than the sector size. That conflates two constraints: the sector > granularity holds for every driver, whereas write_granularity describes a > coarser requirement of the medium below a driver, and only a driver that > has such a medium should express it. >=20 > Check the invariant once in bdrv_co_zone_append(), so that it no longer > rests on a driver that happens to have a granularity of its own to > report. >=20 > This is a lower bound, not the alignment that a guest has to observe. The > block layer cannot know that one, because it also depends on the logical > block size the device is configured with, which is a property of the > frontend. The alignment that applies to a guest is the larger of the two, > and it is the frontend that reports it, that validates requests against > it, and that has to refuse a device whose write pointers do not satisfy > it. >=20 > Reviewed-by: Damien Le Moal > Signed-off-by: Niklas Cassel > --- > block/io.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) Reviewed-by: Stefan Hajnoczi --p0rRWq7IGw9g1sIY Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmqhp3AACgkQnKSrs4Gr c8iEwAgAq3YyUtC2FyTIq2t1+ec7EaspVKkbBt/J55D9CXrXbFSjSTafkzjcUe0h KAAuktgZJJJp9rvYvc2HeWOFq8vsfl6jfIwfJl/E7VqIJe//+1R/06rV+XT9fcw4 lnyBnsUKZNydNTHB93Cy479Mwh/tJ21P6hOyHl8qn+xfLgIE1QPhdRhqwvoECfXf ZGtBdQ15Uk+HAVifbQD3rNwa+T3dt6cYNp3jk6D9U2e7ZleZRkWd5NyAeS4IQpoh 7vLv5U4jt7FqeLthnZarbYanI8HaLrZt9XYOZW4CwQ4aFEghTs9/4W5xv5r7hH7x 4T6wXDJdiVKXbEaYWxis0Mvf+XrpvA== =VtWn -----END PGP SIGNATURE----- --p0rRWq7IGw9g1sIY--