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 D76FFC7EE23 for ; Wed, 1 Mar 2023 20:59:54 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pXTXD-0003YH-KX; Wed, 01 Mar 2023 15:58:47 -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 1pXTXC-0003Uh-5J for qemu-devel@nongnu.org; Wed, 01 Mar 2023 15:58:46 -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 1pXTXA-00041g-Jv for qemu-devel@nongnu.org; Wed, 01 Mar 2023 15:58:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677704324; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9jar66EgWAWpe6Qk8yO0Iso5fl52X8ZjyyQ+aBAGVe0=; b=g8j5hIlRIahdpp5Ji0sJ70ewIhlkq3+qlo31/Wb3MTXTKJ11aX/aZst81UpvMH/a+ORbGy mPJmuDw18THgfd36VeZuxRSf3+hlB3FuRd3aK0AT0lQxYjzvVw9qQDiFjcNvlbPqYCyqTg +6J0Bzkzuoo6GfF1QWZWMtFW/G1IV3s= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-47-b5FlmGpuOb-BSFCwX5_cWw-1; Wed, 01 Mar 2023 15:58:41 -0500 X-MC-Unique: b5FlmGpuOb-BSFCwX5_cWw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 53DBD3811F20; Wed, 1 Mar 2023 20:58:41 +0000 (UTC) Received: from localhost (unknown [10.39.192.234]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC7D62166B26; Wed, 1 Mar 2023 20:58:40 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Fam Zheng , qemu-block@nongnu.org, Emanuele Giuseppe Esposito , Markus Armbruster , Kevin Wolf , Stefan Hajnoczi , "Dr. David Alan Gilbert" , Hanna Reitz Subject: [PATCH 3/6] block: convert bdrv_graph_wrlock() to AIO_WAIT_WHILE_UNLOCKED() Date: Wed, 1 Mar 2023 15:57:58 -0500 Message-Id: <20230301205801.2453491-4-stefanha@redhat.com> In-Reply-To: <20230301205801.2453491-1-stefanha@redhat.com> References: <20230301205801.2453491-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@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, 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 The following conversion is safe and does not change behavior: GLOBAL_STATE_CODE(); ... - AIO_WAIT_WHILE(qemu_get_aio_context(), ...); + AIO_WAIT_WHILE_UNLOCKED(NULL, ...); Since we're in GLOBAL_STATE_CODE(), qemu_get_aio_context() is our home thread's AioContext. Thus AIO_WAIT_WHILE() does not unlock the AioContext: if (ctx_ && in_aio_context_home_thread(ctx_)) { \ while ((cond)) { \ aio_poll(ctx_, true); \ waited_ = true; \ } \ And that means AIO_WAIT_WHILE_UNLOCKED(NULL, ...) can be substituted. Signed-off-by: Stefan Hajnoczi --- block/graph-lock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/graph-lock.c b/block/graph-lock.c index 454c31e691..639526608f 100644 --- a/block/graph-lock.c +++ b/block/graph-lock.c @@ -127,7 +127,7 @@ void bdrv_graph_wrlock(void) * reader lock. */ qatomic_set(&has_writer, 0); - AIO_WAIT_WHILE(qemu_get_aio_context(), reader_count() >= 1); + AIO_WAIT_WHILE_UNLOCKED(NULL, reader_count() >= 1); qatomic_set(&has_writer, 1); /* -- 2.39.2