Miklos Szeredi <mszeredi@xxxxxxxxxx> writes: > On Wed, Feb 21, 2018 at 9:29 PM, Eric W. Biederman > <ebiederm@xxxxxxxxxxxx> 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. Eric
