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 4A002C28CF5 for ; Wed, 26 Jan 2022 11:18:30 +0000 (UTC) Received: from localhost ([::1]:48190 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nCgJl-0004Co-AK for qemu-devel@archiver.kernel.org; Wed, 26 Jan 2022 06:18:25 -0500 Received: from eggs.gnu.org ([209.51.188.92]:55558) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nCgHk-0002Ye-0Z for qemu-devel@nongnu.org; Wed, 26 Jan 2022 06:16:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:21263) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nCgHh-0008Vc-6e for qemu-devel@nongnu.org; Wed, 26 Jan 2022 06:16:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643195776; 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=MheVtbodv4JnjFpcoZ94e2zJqt/UtM4s2+SFd/u+bd4=; b=dKWJUkvpeknWLhXyBYMkhly0HUeKJV5XHuSQGVFF0OTntT46uN/Gc22gNhmjb+N/BYzAUW VIMY0QgQAkzmsonYkZInqEuladd9hOztzS/AR8zZBVkY53YyBZK3U4RsG2apeF4t/XQ5xH jIC9x9TbaTB+S+HHJ7MIRpcpZcvJuc0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-588-mKR7jBQBO7GFTHSMlzlQbg-1; Wed, 26 Jan 2022 06:16:12 -0500 X-MC-Unique: mKR7jBQBO7GFTHSMlzlQbg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5E05A814249; Wed, 26 Jan 2022 11:16:11 +0000 (UTC) Received: from localhost (unknown [10.39.195.72]) by smtp.corp.redhat.com (Postfix) with ESMTP id D4CA81059A74; Wed, 26 Jan 2022 11:16:04 +0000 (UTC) Date: Wed, 26 Jan 2022 11:16:03 +0000 From: Stefan Hajnoczi To: Emanuele Giuseppe Esposito Subject: Re: [PATCH 08/12] reopen: add a transaction to drain_end nodes picked in bdrv_reopen_parse_file_or_backing Message-ID: References: <20220118162738.1366281-1-eesposit@redhat.com> <20220118162738.1366281-9-eesposit@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ilvp0HGBT9opExk8" Content-Disposition: inline In-Reply-To: <20220118162738.1366281-9-eesposit@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.155, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=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: , Cc: Kevin Wolf , Fam Zheng , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org, Hanna Reitz , Paolo Bonzini , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --ilvp0HGBT9opExk8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jan 18, 2022 at 11:27:34AM -0500, Emanuele Giuseppe Esposito wrote: > Depending on the options given to reopen_state, > bdrv_reopen_parse_file_or_backing could pick another bs > that could be from another graph, and thus not protected > by subtree_drained_begin called by the callers of this > function. >=20 > We can't simply drain-undrain here, because of transactions. > To simplify the logic, transactions always assume that they > are run under drain, so the various subtree_drain introduced > so far always take care of covering tran_commit(). >=20 > And since we cannot directly do it, as the transaction is > created/committed higher above, we can just add a new > transaction to the list that just executes subtree_drained_end > to match the drained_begin done in this function. >=20 > Signed-off-by: Emanuele Giuseppe Esposito > --- > block.c | 25 ++++++++++++++++++++----- > 1 file changed, 20 insertions(+), 5 deletions(-) >=20 > diff --git a/block.c b/block.c > index fb5bc3077a..fcc44a49a0 100644 > --- a/block.c > +++ b/block.c > @@ -4522,6 +4522,10 @@ int bdrv_reopen_set_read_only(BlockDriverState *bs= , bool read_only, > return bdrv_reopen(bs, opts, true, errp); > } > =20 > +TransactionActionDrv bdrv_drv_subtree_end =3D { > + .clean =3D (void (*)(void *)) bdrv_subtree_drained_end_unlocked, Please don't cast function pointers. If the types don't match please define a wrapper function so the compiler can check the types. --ilvp0HGBT9opExk8 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmHxLXMACgkQnKSrs4Gr c8i3YwgAo9uASWD4lacGzZd43enNW29ykLTW6tG2a0TQTx0M8EjBMpHBYrJZ8eDx 3bPHeEXstY53bBg5otGz5Qm2BXG8LKskGwa6UK5hCg4QjKJ2jF+ca2oq4FO+RZLz E8ZMKnzbnGvpZuBrk47MJZUX0V8gw886+WfnTbRAjZzOxps9OPBJb/bbO11YhvN+ cB5j8WvtuF+PdIThf45BdTCGmUNvI4DTcp9FuNoy352DTVUXKxa48L+zzh3Cj7Xq ewE9W6KXBo7h3JVr0Lih74L7TB80FuR6w2RHVObr8hNf4F7SZaZi+zodtRhsnoVW bVy3fLvp3X9JVVxWkHePbrSUEzcmpA== =gNHb -----END PGP SIGNATURE----- --ilvp0HGBT9opExk8--