From patchwork Fri Oct 12 11:55:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 983024 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42Wmjd2ZYyz9s47 for ; Fri, 12 Oct 2018 23:04:53 +1100 (AEDT) Received: from localhost ([::1]:39808 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAwBX-0005jU-05 for incoming@patchwork.ozlabs.org; Fri, 12 Oct 2018 08:04:51 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38063) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAw2z-0007gG-AT for qemu-devel@nongnu.org; Fri, 12 Oct 2018 07:56:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAw2y-0005zt-FJ for qemu-devel@nongnu.org; Fri, 12 Oct 2018 07:56:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42744) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gAw2t-0005mS-0E; Fri, 12 Oct 2018 07:55:55 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DBA0630820C0; Fri, 12 Oct 2018 11:55:53 +0000 (UTC) Received: from dhcp-200-186.str.redhat.com (dhcp-200-186.str.redhat.com [10.33.200.186]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8EEC36F102; Fri, 12 Oct 2018 11:55:52 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 12 Oct 2018 13:55:29 +0200 Message-Id: <20181012115532.12645-6-kwolf@redhat.com> In-Reply-To: <20181012115532.12645-1-kwolf@redhat.com> References: <20181012115532.12645-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Fri, 12 Oct 2018 11:55:53 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 5/8] file-posix: Support auto-read-only option 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, pkrempa@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" If read-only=off, but auto-read-only=on is given, open the file read-write if we have the permissions, but instead of erroring out for read-only files, just degrade to read-only. Signed-off-by: Kevin Wolf --- block/file-posix.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/block/file-posix.c b/block/file-posix.c index 2da3a76355..eead3f2df3 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -527,6 +527,19 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->fd = -1; fd = qemu_open(filename, s->open_flags, 0644); + + if (fd < 0 && (errno == EACCES || errno == EROFS)) { + /* Try to degrade to read-only, but if it doesn't work, still use the + * normal error message. */ + ret = bdrv_apply_auto_read_only(bs, NULL, NULL); + if (ret == 0) { + bdrv_flags &= ~BDRV_O_RDWR; + raw_parse_flags(bdrv_flags, &s->open_flags); + assert(!(s->open_flags & O_CREAT)); + fd = qemu_open(filename, s->open_flags); + } + } + if (fd < 0) { ret = -errno; error_setg_errno(errp, errno, "Could not open '%s'", filename);