1. put the dead val into a macro so that it can be used in other places
2. __lockref_is_dead():
- drop the __ suffix, this is not an internal routine
- drop the spurious cast, the value is already a signed int
- use READ_ONCE to prevent any compile shenanigans
3. provide lockref_is_dead_or_zero()
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260724171422.429284-2-mjguzik@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>