Any thoughts on this fix ? Read-only mode is pretty useless without
it for non-root users.
Daniel
On Mon, Jan 16, 2012 at 06:11:40PM +0000, Daniel P. Berrange wrote:
> From: "Daniel P. Berrange" <berra...@redhat.com>
>
> When 2c74c2cb4bedddbfa67628fbd5f9273b4e0e9903 added support for
> the 'readonly' flag against 9p filesystems, it also made QEMU
> add the O_NOATIME flag as a side-effect.
>
> The O_NOATIME flag, however, may only be set by the file owner,
> or a user with CAP_FOWNER capability. QEMU cannot assume that
> this is the case for filesytems exported to QEMU.
>
> eg, run QEMU as non-root, and attempt to pass the host OS
> filesystem through to the guest OS with readonly enable.
> The result is that the guest OS cannot open any files at
> all.
>
> If O_NOATIME is really required, it should be optionally
> enabled via a separate QEMU command line flag.
>
> * hw/9pfs/virtio-9p.c: Remove O_NOATIME
>
> Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
> ---
> hw/9pfs/virtio-9p.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
>
> diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
> index e6ba6ba..f8e2c07 100644
> --- a/hw/9pfs/virtio-9p.c
> +++ b/hw/9pfs/virtio-9p.c
> @@ -1391,7 +1391,6 @@ static void v9fs_open(void *opaque)
> err = -EROFS;
> goto out;
> }
> - flags |= O_NOATIME;
> }
> err = v9fs_co_open(pdu, fidp, flags);
> if (err < 0) {
> --
> 1.7.7.5
>
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
