From patchwork Tue Feb 28 12:54:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 9595661 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4D4CB60429 for ; Tue, 28 Feb 2017 13:48:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3BFCB284AD for ; Tue, 28 Feb 2017 13:48:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 30F0C284F1; Tue, 28 Feb 2017 13:48:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D724F284D0 for ; Tue, 28 Feb 2017 13:48:04 +0000 (UTC) Received: from localhost ([::1]:32903 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cii8J-0002eH-Sa for patchwork-qemu-devel@patchwork.kernel.org; Tue, 28 Feb 2017 08:48:03 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43419) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cihJ8-0004Iz-AU for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:55:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cihJ7-0004BG-Hn for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:55:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48756) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cihJ4-00046t-W2; Tue, 28 Feb 2017 07:55:07 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 332B380476; Tue, 28 Feb 2017 12:55:06 +0000 (UTC) Received: from noname.redhat.com (ovpn-116-177.ams2.redhat.com [10.36.116.177]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1SCsXQI029713; Tue, 28 Feb 2017 07:55:04 -0500 From: Kevin Wolf To: qemu-block@nongnu.org Date: Tue, 28 Feb 2017 13:54:01 +0100 Message-Id: <1488286469-9381-17-git-send-email-kwolf@redhat.com> In-Reply-To: <1488286469-9381-1-git-send-email-kwolf@redhat.com> References: <1488286469-9381-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 28 Feb 2017 12:55:06 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 16/44] block: Request real permissions in blk_new_open() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP We can figure out the necessary permissions from the flags that the caller passed. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block/block-backend.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 299948f..03d5495 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -166,17 +166,33 @@ BlockBackend *blk_new_open(const char *filename, const char *reference, { BlockBackend *blk; BlockDriverState *bs; + uint64_t perm; + + /* blk_new_open() is mainly used in .bdrv_create implementations and the + * tools where sharing isn't a concern because the BDS stays private, so we + * just request permission according to the flags. + * + * The exceptions are xen_disk and blockdev_init(); in these cases, the + * caller of blk_new_open() doesn't make use of the permissions, but they + * shouldn't hurt either. We can still share everything here because the + * guest devices will add their own blockers if they can't share. */ + perm = BLK_PERM_CONSISTENT_READ; + if (flags & BDRV_O_RDWR) { + perm |= BLK_PERM_WRITE; + } + if (flags & BDRV_O_RESIZE) { + perm |= BLK_PERM_RESIZE; + } - blk = blk_new(0, BLK_PERM_ALL); + blk = blk_new(perm, BLK_PERM_ALL); bs = bdrv_open(filename, reference, options, flags, errp); if (!bs) { blk_unref(blk); return NULL; } - /* FIXME Use real permissions */ blk->root = bdrv_root_attach_child(bs, "root", &child_root, - 0, BLK_PERM_ALL, blk, &error_abort); + perm, BLK_PERM_ALL, blk, &error_abort); return blk; }