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 112CFEE4993 for ; Tue, 22 Aug 2023 19:17:25 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qYWs9-0003Zt-DH; Tue, 22 Aug 2023 15:17:02 -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 1qYWru-0003U0-HM for qemu-devel@nongnu.org; Tue, 22 Aug 2023 15:16:47 -0400 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 1qYWrs-0008TK-E3 for qemu-devel@nongnu.org; Tue, 22 Aug 2023 15:16:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692731803; 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=fMshRVGb68twmz8K5z509ulsc/O+ily7naj9HutWcgA=; b=hcn5eWC3yRxES/jWy8HvtM6zfMkBEbdnknnHUtPBjRSoZgNEC4JvrVZn+5SXIf0YcHX8AD pjTSzB2i4eh6+uA7mJ6ZIYo2HKlVOiVDgo4i13aUn4da/yByTsMVpoX5sB05p7iPK2j6dr xv/vXXG5lwDDVJ3VEsLo+xew1URGn68= Received: from mimecast-mx02.redhat.com (66.187.233.73 [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-426-rzsUIpt4OB6T7NyAAouWxg-1; Tue, 22 Aug 2023 15:16:38 -0400 X-MC-Unique: rzsUIpt4OB6T7NyAAouWxg-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 21F763C0D845; Tue, 22 Aug 2023 19:16:38 +0000 (UTC) Received: from localhost (unknown [10.39.195.69]) by smtp.corp.redhat.com (Postfix) with ESMTP id A9C10492C13; Tue, 22 Aug 2023 19:16:37 +0000 (UTC) Date: Tue, 22 Aug 2023 15:16:36 -0400 From: Stefan Hajnoczi To: Kevin Wolf Cc: qemu-block@nongnu.org, eblake@redhat.com, eesposit@redhat.com, pbonzini@redhat.com, vsementsov@yandex-team.ru, qemu-devel@nongnu.org Subject: Re: [PATCH 10/21] block: Mark bdrv_attach_child_common() GRAPH_WRLOCK Message-ID: <20230822191636.GM727224@fedora> References: <20230817125020.208339-1-kwolf@redhat.com> <20230817125020.208339-11-kwolf@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="iI2gbR7lX4NCGNKG" Content-Disposition: inline In-Reply-To: <20230817125020.208339-11-kwolf@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 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: -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_H4=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org --iI2gbR7lX4NCGNKG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 17, 2023 at 02:50:09PM +0200, Kevin Wolf wrote: > Instead of taking the writer lock internally, require callers to already > hold it when calling bdrv_attach_child_common(). These callers will > typically already hold the graph lock once the locking work is > completed, which means that they can't call functions that take it > internally. >=20 > Note that the transaction callbacks still take the lock internally, so > tran_finalize() must be called without the lock held. This is because > bdrv_append() also calls bdrv_replace_node_noperm(), which currently > requires the transaction callbacks to be called unlocked. In the next > step, both of them can be switched to locked tran_finalize() calls > together. >=20 > Signed-off-by: Kevin Wolf > --- > block.c | 133 +++++++++++++++++++++++++++++++------------------ > block/stream.c | 20 ++++++-- > 2 files changed, 100 insertions(+), 53 deletions(-) Reviewed-by: Stefan Hajnoczi --iI2gbR7lX4NCGNKG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmTlCZQACgkQnKSrs4Gr c8iXHwf/daJpZRefD5T1UcFO3x3rnUrsML/RWJPqFtrJ9M+nbD9aO26Z0nzXpuEs 4fQerad2QQl4jD5PZO7TBKnfoL2TxxuXCiGePf800EduZbRwgkCqy8QIouqDFmbQ Fg4YMzYROuLhTYZZg4zJCj1MjbIBUnWTXCMxprEAmo0e71ho78ml7gIrk7TKrSZm 32gIr8IIfDsfJDS/Rpds61a3SJ/8ho2xvUJDG6SWh55kHIYV7ofzWskrwRjaKdRp tHANxWlQuc0KFF0Qjr4ylbu+GCoHh2GUu5DmYXcYRTRuut/7eK8RqUXN+3jT+rvQ nvJ/b5qMJ/ewCKBnI2IIoOj6q+b8Ag== =arJI -----END PGP SIGNATURE----- --iI2gbR7lX4NCGNKG--