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 DB501C77B7A for ; Thu, 25 May 2023 18:16:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q2FVD-0007mK-By; Thu, 25 May 2023 14:15:55 -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 1q2FVB-0007ju-EZ for qemu-devel@nongnu.org; Thu, 25 May 2023 14:15:53 -0400 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 1q2FVA-0007Q2-2j for qemu-devel@nongnu.org; Thu, 25 May 2023 14:15:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685038550; 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=s6Fmoy2BVoRvJSbd13h45v4mlwROYO/aQn+Jrd8vgZU=; b=eaYvPPlrEUDDsq5aPpZMHn+HqGqLcBwzjBsokcE+MFGaBrVKFBroGFwzOv1YG1hHds66kp fkgqk8AbrGKV6NL1TriSDT7NN1mrxEI6wTHiYe0YEmXTcxE0NPsEa5xkJd4Do266/ursLx vzhG6Ys4+ZT0jjAFm8Zw4nRPlhn3nao= 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-219-zr3tV7sRN5CHp7ObQ4S8nQ-1; Thu, 25 May 2023 14:15:46 -0400 X-MC-Unique: zr3tV7sRN5CHp7ObQ4S8nQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6E2401C07553; Thu, 25 May 2023 18:15:46 +0000 (UTC) Received: from localhost (unknown [10.39.192.5]) by smtp.corp.redhat.com (Postfix) with ESMTP id C5C5F492B0B; Thu, 25 May 2023 18:15:45 +0000 (UTC) Date: Thu, 25 May 2023 14:15:44 -0400 From: Stefan Hajnoczi To: Kevin Wolf Cc: qemu-block@nongnu.org, hreitz@redhat.com, eblake@redhat.com, qemu-devel@nongnu.org Subject: Re: [PATCH 01/12] block-coroutine-wrapper: Take AioContext lock in no_co_wrappers Message-ID: <20230525181544.GC132697@fedora> References: <20230525124713.401149-1-kwolf@redhat.com> <20230525124713.401149-2-kwolf@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="bHgTIdofVBbnfOr3" Content-Disposition: inline In-Reply-To: <20230525124713.401149-2-kwolf@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 --bHgTIdofVBbnfOr3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 25, 2023 at 02:47:02PM +0200, Kevin Wolf wrote: > All of the functions that currently take a BlockDriverState, BdrvChild > or BlockBackend as their first parameter expect the associated > AioContext to be locked when they are called. In the case of > no_co_wrappers, they are called from bottom halves directly in the main > loop, so no other caller can be expected to take the lock for them. This > can result in assertion failures because a lock that isn't taken is > released in nested event loops. >=20 > Looking at the first parameter is already done by co_wrappers to decide > where the coroutine should run, so doing the same in no_co_wrappers is > only consistent. Take the lock in the generated bottom halves to fix the > problem. >=20 > Signed-off-by: Kevin Wolf > --- > include/block/block-common.h | 3 +++ > block/block-backend.c | 7 ++++++- > scripts/block-coroutine-wrapper.py | 25 +++++++++++++++---------- > 3 files changed, 24 insertions(+), 11 deletions(-) Reviewed-by: Stefan Hajnoczi --bHgTIdofVBbnfOr3 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmRvpc8ACgkQnKSrs4Gr c8jkAgf/a2Y8YtdhOfp8GPygpB1ahi1PL2rEtevyItiSTcQgaT57IGXfi3oTwEHl qFlPGSTgQ7WE9rFFeiCWf8Bu3JFdnFV+q9jR9NRZaSMd5t++vvUVgusv0OmHwpZR lbUktutv9hPzngkiviD3TKhVqW1X/2QnPNEFgwJcGbkQpx7sU8tlRBFFQA+vno5E MZ+CN9DML/B3pLfoZMXFwMNrD1jV8dqoKrTKbqhf1WBrgf4D5vFQqJUV1ikmmzB9 695SlpQbP+9bFTGfSegqLpYk0H+eATumgHc8K9wpMFjPEVzaluOeW47RVckpfxcw huFa8m29nRiLREJ6FPB1gjjkmebRNQ== =Na3z -----END PGP SIGNATURE----- --bHgTIdofVBbnfOr3--