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 5F1FDC02196 for ; Thu, 6 Feb 2025 13:57:51 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tg2NV-0001bk-Ei; Thu, 06 Feb 2025 08:57:13 -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 1tg2NT-0001b5-FD for qemu-devel@nongnu.org; Thu, 06 Feb 2025 08:57:11 -0500 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 1tg2NS-0006G2-1n for qemu-devel@nongnu.org; Thu, 06 Feb 2025 08:57:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738850229; 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=QM55rJnlW0KfBWwmNwRGshhYG2LoNYfdkcXgz4DdSAs=; b=XP+DKL3ONEm0LPiPVn7qvTty++/XCXSvO3sm/N0VY8oHBXmowQFOVF0ulFxitjWHjN8jac 5ecIFFZnIPWCovC6Tm+thnpsSDINpipmb7UQ2yEULJXsuf47ZiJP4KVYdQfM89cfg1ED8H dE5JGfmVCnjLkq5XdGZS39UWOI3A0J8= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-288-KBTNeyb8MpugFP1pizxyxg-1; Thu, 06 Feb 2025 08:57:04 -0500 X-MC-Unique: KBTNeyb8MpugFP1pizxyxg-1 X-Mimecast-MFC-AGG-ID: KBTNeyb8MpugFP1pizxyxg 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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3E767185FBD6; Thu, 6 Feb 2025 13:56:47 +0000 (UTC) Received: from redhat.com (unknown [10.45.225.251]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E09281956052; Thu, 6 Feb 2025 13:56:42 +0000 (UTC) Date: Thu, 6 Feb 2025 14:56:40 +0100 From: Kevin Wolf To: Stefan Hajnoczi Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Paolo Bonzini , Fam Zheng , Vladimir Sementsov-Ogievskiy , Wen Congyang , John Snow , "Michael S. Tsirkin" , Xie Changlong , Hanna Reitz Subject: Re: [PATCH] block: remove unused BLOCK_OP_TYPE_DATAPLANE Message-ID: References: <20250203182529.269066-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250203182529.269066-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_H2=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=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 03.02.2025 um 19:25 hat Stefan Hajnoczi geschrieben: > BLOCK_OP_TYPE_DATAPLANE prevents BlockDriverState from being used by > virtio-blk/virtio-scsi with IOThread. Commit b112a65c52aa ("block: > declare blockjobs and dataplane friends!") eliminated the main reason > for this blocker in 2014. > > Nowadays the block layer supports I/O from multiple AioContexts, so > there is even less reason to block IOThread users. Any legitimate > reasons related to interference would probably also apply to > non-IOThread users. > > The only remaining users are bdrv_op_unblock(BLOCK_OP_TYPE_DATAPLANE) > calls after bdrv_op_block_all(). If we remove BLOCK_OP_TYPE_DATAPLANE > their behavior doesn't change. > > Existing bdrv_op_block_all() callers that don't explicitly unblock > BLOCK_OP_TYPE_DATAPLANE seem to do so simply because no one bothered to > rather than because it is necessary to keep BLOCK_OP_TYPE_DATAPLANE > blocked. > > Signed-off-by: Stefan Hajnoczi Thanks, applied to the block branch. I've actually had pretty much the same patch lying around for.. *checks* five years, but never sent it because I intended it to be part of a more general op blocker removal series. I don't think we actually rely on any of them any more, but proving it was still hard when I tried. One additional part my patch had is removing blk_op_is_blocked() because it's now unused. I'll send this as a separate patch. Kevin