. Safe I/O, ioctl() and DIAGNOSTICS variants conversion - safe copies,
include grant id in DEV_REVIVE messages.
. Removal of TTY_FLAGS field (and so O_NONBLOCK support).
. Fixed CANCEL behaviour and return code on blocking I/O,
previously handled by O_NONBLOCK
. Totally removed REVIVE replies, previously still possible on
blocking ioctls (REVIVE directly called) and ptys (missing TTY_REVIVE
check), removes deadlock bug with FS
. Removed obsolete *COMPAT options and associated code