From mboxrd@z Thu Jan 1 00:00:00 1970 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 From: Kevin Wolf 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 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v2 5/8] file-posix: Support auto-read-only option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, eblake@redhat.com, pkrempa@redhat.com, qemu-devel@nongnu.org If read-only=3Doff, but auto-read-only=3Don 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, QDi= ct *options, =20 s->fd =3D -1; fd =3D qemu_open(filename, s->open_flags, 0644); + + if (fd < 0 && (errno =3D=3D EACCES || errno =3D=3D EROFS)) { + /* Try to degrade to read-only, but if it doesn't work, still us= e the + * normal error message. */ + ret =3D bdrv_apply_auto_read_only(bs, NULL, NULL); + if (ret =3D=3D 0) { + bdrv_flags &=3D ~BDRV_O_RDWR; + raw_parse_flags(bdrv_flags, &s->open_flags); + assert(!(s->open_flags & O_CREAT)); + fd =3D qemu_open(filename, s->open_flags); + } + } + if (fd < 0) { ret =3D -errno; error_setg_errno(errp, errno, "Could not open '%s'", filename); --=20 2.19.1