NFS client broken in Linus' tip

[Trond Myklebust]

On Feb 3, 2014, at 9:57, Christoph Hellwig <hch at infradead.org> 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. I’ve 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. That’s rather ugly too...

--
Trond Myklebust
Linux NFS client maintainer