The kernel has a special wchan called `lbolt', which is triggered each
second. It doesn't seem to be used a lot and it seems pretty redundant,
because we can specify a timeout value to the *sleep() routines. In an
attempt to eventually remove lbolt, make the NFS/RPC code use a timeout
of `hz' when trying to reconnect.
Only the TTY code (not MPSAFE TTY) and the VFS syncer seem to use lbolt
now.
Reviewed by: attilio, jhb
Approved by: philip (mentor), alfred, dfr
remove unused pid field of file context struct
map nfs4 error codes to errnos
eliminate redundant code from nfs4_request
use zero stateid on setattr that doesn't set file size
use same clientid on all mounts until reboot
invalidate dirty bufs in nfs4_close, to play it safe
open file for writing if truncating and it's not already open
Approved by: alfred
