On Fri, Oct 6, 2023 at 7:42 PM Ryan Hendrickson
<ryan.hendrickson@xxxxxxxxxxxx> wrote:
>
> At 2023-10-06 19:17+0300, Amir Goldstein <amir73il@xxxxxxxxx> sent:
>
> > On Fri, Oct 6, 2023 at 4:03 PM Sebastian Wick
> > <sebastian.wick@xxxxxxxxxx> wrote:
> >>
> >> It would be nice to have this fixed. A more general question: will you
> >> commit on keeping the escaping stable from now on or do we have to
> >> expect changes at any point in the future?
> >>
> >
> > I prefer that escaping would be handled in userspace, now that the new
> > mount API allows that, so deferring the question to libmount maintainer.
>
> Note that with overlayfs on the new mount API, there are now two levels of
> escaping to consider:
>
> There is the escaping that needs to happen for commas when splitting mount
> parameters; this could be handled in libmount when using the new API.
>
Right.
> And there is the escaping that needs to happen for ':' and '\' when
> parsing the path parameters (':' is only special syntax in lowerdir, but
> the escaping logic seems to apply to upperdir and workdir as well, based
> on my testing). Even using the new API, this is handled in the kernel.
> We'd like to know if this escaping can be considered stable as well, and I
> don't think that's a question for the libmount maintainer.
Agree.
Unlike the comma separated parameters list,
upperdir,workdir,lowerdir are overlayfs specific format.
ovl_unescape() (for upperdir/workdir) unescapes '\' characters.
as does ovl_parse_param_split_lowerdirs().
Not sure why this was needed for upperdir/workdir, but it It has
been this way for a long time.
I see no reason for it to change in the future.
Thanks,
Amir.
