MacOS SMB clients may behave badly on inode reuse

MacOS SMB clients build vnode cache keyed on "inode" returned via SMB protocol. It obtains this through querying the on-disk ID (MS-FSCC 2.1.9). Default samba behavior when not using the user.DOSATTRIB xattr is to return he inode from stat(2) output. Unfortunately, the MacOS SMB client does not properly handle inode reuse and will generate spurious access denied errors and other issues in this case (further investigation may be warranted regarding HFS+ filesystems and MacOS SMB servers in cases where CNID counter has wrapped around... perhaps server capabilities are altered). For our purposes though, in cases where we aren't using the DOSATTRIB xattr (our default) we will generate a file id from the inode and generation (similar to NFS file handle).