When I work on a linux kernel with samba unix-extensions support compiled in, and the server supports it, I have no way to disable unix-extensions client-side when mounting a share off that server.
"echo 0 > /proc/fs/cifs/LinuxExtensionsEnabled" works for cifs vfs For older smbfs, I don't mind taking a patch forward, but it doesn't seem worth the trouble since the cifs vfs can now replace it for most usage scenarios and probably better to focus on any adding to cifs vfs the few remaining misc features that are only in smbfs.
so it can be closed