From patchwork Mon Jan 15 22:50:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 861107 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=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3zL7rd3Gqhz9sNc for ; Tue, 16 Jan 2018 09:51:43 +1100 (AEDT) Received: from localhost ([::1]:41269 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebDbQ-0005H9-7g for incoming@patchwork.ozlabs.org; Mon, 15 Jan 2018 17:51:40 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37497) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebDao-0005Ew-SP for qemu-devel@nongnu.org; Mon, 15 Jan 2018 17:51:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebDan-0004Se-IH for qemu-devel@nongnu.org; Mon, 15 Jan 2018 17:51:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43320) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ebDai-0004M0-Pd; Mon, 15 Jan 2018 17:50:56 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AD41978523; Mon, 15 Jan 2018 22:50:55 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-231.bos.redhat.com [10.18.17.231]) by smtp.corp.redhat.com (Postfix) with ESMTP id F3A5E5D6A6; Mon, 15 Jan 2018 22:50:47 +0000 (UTC) From: John Snow To: qemu-block@nongnu.org Date: Mon, 15 Jan 2018 17:50:47 -0500 Message-Id: <20180115225047.28607-1-jsnow@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Mon, 15 Jan 2018 22:50:55 +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 v2] file-posix: specify expected filetypes 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, John Snow , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" I don't think there's a legitimate reason to open directories as if they were files. This prevents QEMU from opening and attempting to probe a directory inode, which can break in exciting ways. One of those ways is lseek on ext4/xfs, which will return 0x7fffffffffffffff as the file size instead of EISDIR. This can coax QEMU into responding with a confusing "file too big" instead of "Hey, that's not a file". See: https://bugs.launchpad.net/qemu/+bug/1739304/ Signed-off-by: John Snow --- v2: Is something like this what you had in mind, Kevin? I couldn't make the hdev/cdrom checks more specific as I'm not sure which environments expect which, but if you know I can tighten it. block/file-posix.c | 38 +++++++++++++++++++++++++++++--------- 1 file changed, 29 insertions(+), 9 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 36ee89e940..fe06cdb8f8 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -417,7 +417,8 @@ static QemuOptsList raw_runtime_opts = { }; static int raw_open_common(BlockDriverState *bs, QDict *options, - int bdrv_flags, int open_flags, Error **errp) + int bdrv_flags, int open_flags, + bool device, Error **errp) { BDRVRawState *s = bs->opaque; QemuOpts *opts; @@ -556,10 +557,30 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, error_setg_errno(errp, errno, "Could not stat file"); goto fail; } - if (S_ISREG(st.st_mode)) { - s->discard_zeroes = true; - s->has_fallocate = true; + + if (!device) { + if (S_ISBLK(st.st_mode)) { + warn_report("Opening a block device as file using 'file'" + "driver is deprecated"); + } else if (S_ISCHR(st.st_mode)) { + warn_report("Opening a character device as file using the 'file'" + "driver is deprecated"); + } else if (!S_ISREG(st.st_mode)) { + error_setg(errp, "A regular file was expected by the 'file' driver," + "but something else was given"); + goto fail; + } else { + s->discard_zeroes = true; + s->has_fallocate = true; + } + } else { + if (!(S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) { + error_setg(errp, "host_device/host_cdrom driver expects either" + "a character or block device"); + goto fail; + } } + if (S_ISBLK(st.st_mode)) { #ifdef BLKDISCARDZEROES unsigned int arg; @@ -589,7 +610,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, s->needs_alignment = true; } #endif - #ifdef CONFIG_XFS if (platform_test_xfs_fd(s->fd)) { s->is_xfs = true; @@ -611,7 +631,7 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags, BDRVRawState *s = bs->opaque; s->type = FTYPE_FILE; - return raw_open_common(bs, options, flags, 0, errp); + return raw_open_common(bs, options, flags, 0, false, errp); } typedef enum { @@ -2575,7 +2595,7 @@ hdev_open_Mac_error: s->type = FTYPE_FILE; - ret = raw_open_common(bs, options, flags, 0, &local_err); + ret = raw_open_common(bs, options, flags, 0, true, &local_err); if (ret < 0) { error_propagate(errp, local_err); #if defined(__APPLE__) && defined(__MACH__) @@ -2802,7 +2822,7 @@ static int cdrom_open(BlockDriverState *bs, QDict *options, int flags, s->type = FTYPE_CD; /* open will not fail even if no CD is inserted, so add O_NONBLOCK */ - return raw_open_common(bs, options, flags, O_NONBLOCK, errp); + return raw_open_common(bs, options, flags, O_NONBLOCK, true, errp); } static int cdrom_probe_device(const char *filename) @@ -2915,7 +2935,7 @@ static int cdrom_open(BlockDriverState *bs, QDict *options, int flags, s->type = FTYPE_CD; - ret = raw_open_common(bs, options, flags, 0, &local_err); + ret = raw_open_common(bs, options, flags, 0, true, &local_err); if (ret) { error_propagate(errp, local_err); return ret;