Re: NFS client broken in Linus' tip

From: Trond Myklebust
Date: Mon Feb 03 2014 - 15:22:28 EST

On Mon, 2014-02-03 at 10:45 -0500, Trond Myklebust wrote:
> On Feb 3, 2014, at 9:57, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> > On Mon, Feb 03, 2014 at 09:17:30AM -0500, Trond Myklebust wrote:
> >> As I said above, that causes posix_acl_xattr_get() to return the wrong answer (ENODATA instead of EOPNOTSUPP).
> >
> > Is it really the wrong answer? How does userspace care wether this
> > server doesn't support ACLs at all or none is set? The resulting
> > behavior is the same.
> It will certainly cause acl_get_file() to behave differently than previously. Iâve no idea how that will affect applications, though.
> > If there's a good reason to care we might have to go with your patch,
> > but if we can avoid it I'd prefer to keep things simple.
> One alternative is to simply wrap posix_acl_xattr_get() in fs/nfs/nfs3acl.c, and have it check the value of nfs_server_capable(inode, NFS_CAP_ACLS) before returning ENODATA. Thatâs rather ugly too...

FWIW, here is the alternative patch. I've tested it, and it seems to