/* * Perform access checking for vnodes obtained from file handles that would * refer to files already opened by a Unix client. You cannot just use * vn_writechk() and VOP_ACCESS() for two reasons. * 1 - You must check for exported rdonly as well as MNT_RDONLY for the write case * 2 - The owner is to be given access irrespective of mode bits for some * operations, so that processes that chmod after opening a file don't * break. I don't like this because it opens a security hole, but since * the nfs server opens a security hole the size of a barn door anyhow, * what the heck. * * The exception to rule 2 is EPERM. If a file is IMMUTABLE, VOP_ACCESS() * will return EPERM instead of EACCES. EPERM is always an error. */