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 716CBCFD31C for ; Mon, 24 Nov 2025 17:46:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vNadi-0005se-Ta; Mon, 24 Nov 2025 12:46:14 -0500 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 1vNadh-0005ru-Fl for qemu-devel@nongnu.org; Mon, 24 Nov 2025 12:46:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vNadd-0004ov-Qy for qemu-devel@nongnu.org; Mon, 24 Nov 2025 12:46:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764006368; 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=BmDKBfVGBF54B/6CW9BfJUfYffvny7jTASdhSiRW2Jc=; b=g7HpVAFu1pw2CgOqMXXLyx6Y+15mzsou3eLuIQu7q7kyNIdIXlFUZ5PqeexQDY8Yh3U1ZA xHBfp8tYWeUE9ruqvtqChl0fJq4NpXS9XJBDbVY0dsKov5BwyNu6++H0dVJXYf2vfs6Qhx 9jEwz3an1vNr6P1p2PyvvrPgVd2wRzc= Received: from mx-prod-mc-03.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-683-qO9GSB6oPdK09byJM-5j1A-1; Mon, 24 Nov 2025 12:46:04 -0500 X-MC-Unique: qO9GSB6oPdK09byJM-5j1A-1 X-Mimecast-MFC-AGG-ID: qO9GSB6oPdK09byJM-5j1A_1764006362 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CAC3C1956048; Mon, 24 Nov 2025 17:46:01 +0000 (UTC) Received: from redhat.com (unknown [10.44.32.81]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 450DB1956056; Mon, 24 Nov 2025 17:45:58 +0000 (UTC) Date: Mon, 24 Nov 2025 18:45:56 +0100 From: Kevin Wolf To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, Jean-Louis Dupond , Vladimir Sementsov-Ogievskiy , Hanna Reitz Subject: Re: [PATCH v2 0/3] block: use pwrite_zeroes_alignment when writing first sector Message-ID: References: <20251007141700.71891-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251007141700.71891-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.075, 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_H2=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable 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 07.10.2025 um 16:16 hat Stefan Hajnoczi geschrieben: > v2: > - Simplify condition to if (!s->needs_alignment) in patch 1 [Vladimir] > > This series fixes a bug I introduced in commit 5634622bcb33 ("file-posix: allow > BLKZEROOUT with -t writeback"). The Linux fallocate(2) and ioctl(BLKZEROOUT) > syscalls require logical block size alignment of the offset and length, even > when the file is opened in buffered I/O mode where read/write operations do not > require alignment. > > The fix is to populate the pwrite_zeroes_alignment block limits field and to > use that limit in create_file_fallback_zero_first_sector(). > > One issue I want to raise is that pwrite_zeroes_alignment is an "optimal > alignment" hint. Hence create_file_fallback_zero_first_sector() had to be > modified to honor the limit explicitly. The block layer doesn't automatically > apply padding in order to align requests. This is different from how QEMU's > block layer pwrite/pread works, where it does automatically apply padding and > read/modify/write as necessary. If you want consistency, please let me know. Thanks, applied to the block branch. Kevin