notifier_list_notify() has no return value. This is fine when we just want to invoke side-effects.
Sometimes it's useful for notifiers to produce a return value. This allows notifiers to "veto" an operation and will be used by the block layer before-write notifier.
5dae8e5 notify: add NotiferWithReturn so notifier list can abort
include/qemu/notify.h | 29 +++++++++++++++++++++++++++++
util/notify.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 59 insertions(+)
Upstream: git.qemu.org