Re: [Qemu-devel] [Qemu-block] [PATCH v2 7/8] gluster: Support auto-read-only option

[Niels de Vos <ndevos@redhat.com>]

On Fri, Oct 12, 2018 at 12:31:21PM -0500, Eric Blake wrote:
> On 10/12/18 6:55 AM, Kevin Wolf wrote:
> > 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 <kwolf@redhat.com>
> > ---
> >   block/gluster.c | 9 +++++++++
> >   1 file changed, 9 insertions(+)
> > 
> > diff --git a/block/gluster.c b/block/gluster.c
> > index 4fd55a9cc5..68d20c8830 100644
> > --- a/block/gluster.c
> > +++ b/block/gluster.c
> > @@ -849,6 +849,15 @@ static int qemu_gluster_open(BlockDriverState *bs,  QDict *options,
> >       qemu_gluster_parse_flags(bdrv_flags, &open_flags);
> >       s->fd = glfs_open(s->glfs, gconf->path, open_flags);
> > +    if (!s->fd && errno == EACCES) {
> 
> EROFS is not possible as it was for posix file?

EROFS can happen, depending on the configuration of the Gluster volume.
In that case, opening read-only should work fine.

Niels