38e3ea69d4
using VOP_LOOKUP() when VFS_VGET() returns EOPNOTSUPP in the ReaddirPlus RPC. This patch is based upon one by pjd@ for the regular nfs server which has not yet been committed. It is needed when a ZFS volume is exported and ReaddirPlus (which almost always happens for NFSv4) is performed by a client. The patch also simplifies vnode lock handling somewhat. MFC after: 2 weeks