vn_open no longer take proc (now in ndp); new calling convention for namei

lookup converted to new form

lease checks on read and write

add vn_closefile to avoid warnings about void * coersions

increment v_writecount when vn_open is called with intent to write;
decrement v_writecount in vn_close for files open for writing

VOP_OPEN called with vnode locked; vn_open returns vnode locked;
make file flags consistent

missing ABORTOP

add proc pointers to appropriate VOP and vnode operations

expunge user.h, other unneeded headers

more-or-less working with new proc & user structs

add POSIX-style byte-level record locking

update for new VM

fix typos in locking, streamline and fix vn_writechk

new copyright notice

spurious setting of r_val1

do not have to check whether parent directory is NULL

mount structure prefixes go from m_ to mnt_ and M_ to MNT_

vattr_null => VATTR_NULL

new tsleep; rm setjmp's; strings for sleep messages

get rid of unneeded includes

select now passes in file flags (to support FIFO's)

forgot tsleep.h

tsleep

do not unlock vp when trying to modify `.'

read/write locking is now done above the vnode layer