Miklos Szeredi <mszer...@redhat.com> writes:
> On Wed, Feb 21, 2018 at 9:29 PM, Eric W. Biederman
> <ebied...@xmission.com> wrote:
>> Ensure the translation happens by failing to read or write
>> posix acls when the filesystem has not indicated it supports
>> posix acls.
> For the first iteration this is fine, but we could convert the raw
> xattrs as well, if we later want to, right?
I will say maybe. This is tricky. The code would not be too hard,
and the function to do the work posix_acl_fix_xattr_userns already
exists in fs/posix_acl.c
I don't actually expect that to work longterm. I expect the direction
the kernel internals are moving is that all filesystems that implement
posix acls will be expected to implement .get_acl and .set_acl.
I would have to reread the old thread that got us to this point with
posix acls before I could really understand the backwards compatible
fuse use case, and I would have to reread the rest of the acl processing
in the kernel before I could recall exactly what makes sense.
If there was an obvious way to whitelist xattrs that fuse can support
for user namespaces I think I would go for that. Just to avoid future
problems with future xattrs.