From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35241) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecfhF-0004im-Ft for qemu-devel@nongnu.org; Fri, 19 Jan 2018 18:03:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecfhE-0005kt-HX for qemu-devel@nongnu.org; Fri, 19 Jan 2018 18:03:41 -0500 References: <20180119224735.12169-1-jsnow@redhat.com> From: Eric Blake Message-ID: <086ccaa6-eefb-47e4-a865-78075ddd827d@redhat.com> Date: Fri, 19 Jan 2018 17:03:27 -0600 MIME-Version: 1.0 In-Reply-To: <20180119224735.12169-1-jsnow@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="JUxs1XHKRbnw390AsGQIE632ohLwY4pv0" Subject: Re: [Qemu-devel] [PATCH v4] file-posix: specify expected filetypes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: John Snow , qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --JUxs1XHKRbnw390AsGQIE632ohLwY4pv0 From: Eric Blake To: John Snow , qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org Message-ID: <086ccaa6-eefb-47e4-a865-78075ddd827d@redhat.com> Subject: Re: [Qemu-devel] [PATCH v4] file-posix: specify expected filetypes References: <20180119224735.12169-1-jsnow@redhat.com> In-Reply-To: <20180119224735.12169-1-jsnow@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 01/19/2018 04:47 PM, John Snow wrote: > Adjust each caller of raw_open_common to specify if they are expecting > host and character devices or not. Tighten expectations of file types u= pon > open in the common code and refuse types that are not expected. >=20 > This has two effects: >=20 > (1) Character and block devices are now considered deprecated for the > 'file' driver, which expects only S_IFREG, and > (2) no file-posix driver (file, host_cdrom, or host_device) can open > directories now. >=20 > 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 prob= e > 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". >=20 > See: https://bugs.launchpad.net/qemu/+bug/1739304/ > Signed-off-by: John Snow > --- Reviewed-by: Eric Blake --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org --JUxs1XHKRbnw390AsGQIE632ohLwY4pv0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlpieUEACgkQp6FrSiUn Q2pPGAf/cqoeP6HxOpRFRL/fSx39wf+gTVDiP9z7fDiCgr472wTX3l0RDoYLFcTZ Y03JW61JXOQ6gWbaPyB3SspHHkg6r5ahaGzT5pMXDnFxMjWMKAwLCtz4hwZVh15e IyCUS/yuppi5xSGoXnxSb+JMqSILXVCPzd+iOhyWv0XzRuXJ/OMZyS4V7pUSEXxL ZgcCSAeICj9rCv/eiR/K6lMFVZS8wU/XOtMHdMjZrJFrQLc5vkL05ILk73f4Dpqr Kn3YZC6jc2XazcWVYQ476l6HOLOAdqVrdk4M9qTJ3LUkTZpCSPdlZZGDbEP8lEut NFzuGGGxlLTT1nbflyorfpG8E/LtwA== =tZaf -----END PGP SIGNATURE----- --JUxs1XHKRbnw390AsGQIE632ohLwY4pv0--