From patchwork Thu Jul 27 20:00:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 1813938 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=KjBFYZPP; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RBhrk6BSFz1yYc for ; Fri, 28 Jul 2023 06:17:26 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qP7Am-0000fZ-3i; Thu, 27 Jul 2023 16:01:20 -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 1qP7Ag-0000ez-8l for qemu-devel@nongnu.org; Thu, 27 Jul 2023 16:01:14 -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 1qP7Ae-0002ie-IQ for qemu-devel@nongnu.org; Thu, 27 Jul 2023 16:01:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690488071; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qBxH1iRanqco3HtF82nh9FMyY8AR3YyxU+2pBdaif24=; b=KjBFYZPPaxHjTzAmFduMurtJEC1wSZiJD5Lq+NU8kmWQE/lSaWnqCUHALd9J783y+Qoe+h Q2IyEydltL8DgU2o/V7v7u8nLY75/YngYES6QMaxtadG40mO+rNDit/hqscE+wwC5Q/D9h 4XjjOoAcrPgQGu5XpMac5aWo663byz8= 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-488-f5ICcI7kMFG2uOf07W61wg-1; Thu, 27 Jul 2023 16:01:08 -0400 X-MC-Unique: f5ICcI7kMFG2uOf07W61wg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A9C5938149B8; Thu, 27 Jul 2023 20:01:06 +0000 (UTC) Received: from localhost (unknown [10.39.193.84]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE2C2C57964; Thu, 27 Jul 2023 20:01:05 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Richard Henderson , Hanna Reitz , Stefano Garzarella , Qing Wang , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= Subject: [PULL for-8.1 2/8] block/blkio: do not use open flags in qemu_open() Date: Thu, 27 Jul 2023 16:00:52 -0400 Message-ID: <20230727200058.1071776-3-stefanha@redhat.com> In-Reply-To: <20230727200058.1071776-1-stefanha@redhat.com> References: <20230727200058.1071776-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 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, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Stefano Garzarella qemu_open() in blkio_virtio_blk_common_open() is used to open the character device (e.g. /dev/vhost-vdpa-0 or /dev/vfio/vfio) or in the future eventually the unix socket. In all these cases we cannot open the path in read-only mode, when the `read-only` option of blockdev is on, because the exchange of IOCTL commands for example will fail. In order to open the device read-only, we have to use the `read-only` property of the libblkio driver as we already do in blkio_file_open(). Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for virtio-blk") Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2225439 Reported-by: Qing Wang Signed-off-by: Stefano Garzarella Reviewed-by: Daniel P. Berrangé Message-id: 20230726074807.14041-1-sgarzare@redhat.com Signed-off-by: Stefan Hajnoczi --- block/blkio.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/block/blkio.c b/block/blkio.c index bc1fac48b7..7eb1b94820 100644 --- a/block/blkio.c +++ b/block/blkio.c @@ -686,15 +686,18 @@ static int blkio_virtio_blk_common_open(BlockDriverState *bs, * layer through the "/dev/fdset/N" special path. */ if (fd_supported) { - int open_flags; - - if (flags & BDRV_O_RDWR) { - open_flags = O_RDWR; - } else { - open_flags = O_RDONLY; - } - - fd = qemu_open(path, open_flags, errp); + /* + * `path` can contain the path of a character device + * (e.g. /dev/vhost-vdpa-0 or /dev/vfio/vfio) or a unix socket. + * + * So, we should always open it with O_RDWR flag, also if BDRV_O_RDWR + * is not set in the open flags, because the exchange of IOCTL commands + * for example will fail. + * + * In order to open the device read-only, we are using the `read-only` + * property of the libblkio driver in blkio_file_open(). + */ + fd = qemu_open(path, O_RDWR, errp); if (fd < 0) { return -EINVAL; }