*/
#define NOTIFY_STOP (NOTIFY_OK|NOTIFY_STOP_MASK)
+/* Encapsulate (negative) errno value (in particular, NOTIFY_BAD <=> EPERM). */
+static inline int notifier_from_errno(int err)
+{
+ return NOTIFY_STOP_MASK | (NOTIFY_OK - err);
+}
+
+/* Restore (negative) errno value from notify return value. */
+static inline int notifier_to_errno(int ret)
+{
+ ret &= ~NOTIFY_STOP_MASK;
+ return ret > NOTIFY_OK ? NOTIFY_OK - ret : 0;
+}
+
/*
* Declared notifiers so far. I can imagine quite a few more chains
* over time (eg laptop power reset chains, reboot chain (to clean