watchdog: Allow the watchdog to be disabled at runtime

manager_{get|set|override}_watchdog check the validity of the new
timeout or the overridden timeout values using timestamp_is_set which
does not recognize "0" as a valid value. However since f16890f, "0"
indicates a disabled watchdog and so is a value we should be able to
configure in order to disable the watchdog. A value of USEC_INFINITY is
considered a no-op. The behavior should be the same for all watchdog
timeout configurations (runtime, pretimeout, and shutdown).

diff --git a/src/core/manager.c b/src/core/manager.c
index b7af1594497bee989ae0dfd94788b65e61ce7a06..29bb7cca1ab2801b1db5df4af64baf564d5f581b 100644 (file)
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -3419,7 +3419,7 @@ usec_t manager_get_watchdog(Manager *m, WatchdogType t) {
         if (MANAGER_IS_USER(m))
                 return USEC_INFINITY;
 
-        if (timestamp_is_set(m->watchdog_overridden[t]))
+        if (m->watchdog_overridden[t] != USEC_INFINITY)
                 return m->watchdog_overridden[t];
 
         return m->watchdog[t];
@@ -3435,17 +3435,18 @@ void manager_set_watchdog(Manager *m, WatchdogType t, usec_t timeout) {
         if (m->watchdog[t] == timeout)
                 return;
 
-        if (t == WATCHDOG_RUNTIME) {
-                if (!timestamp_is_set(m->watchdog_overridden[WATCHDOG_RUNTIME]))
+        if (m->watchdog_overridden[t] == USEC_INFINITY) {
+                if (t == WATCHDOG_RUNTIME)
                         (void) watchdog_setup(timeout);
-        } else if (t == WATCHDOG_PRETIMEOUT)
-                if (m->watchdog_overridden[WATCHDOG_PRETIMEOUT] == USEC_INFINITY)
+                else if (t == WATCHDOG_PRETIMEOUT)
                         (void) watchdog_setup_pretimeout(timeout);
+        }
 
         m->watchdog[t] = timeout;
 }
 
 void manager_override_watchdog(Manager *m, WatchdogType t, usec_t timeout) {
+        usec_t usec;
 
         assert(m);
 
@@ -3455,12 +3456,11 @@ void manager_override_watchdog(Manager *m, WatchdogType t, usec_t timeout) {
         if (m->watchdog_overridden[t] == timeout)
                 return;
 
-        if (t == WATCHDOG_RUNTIME) {
-                usec_t usec = timestamp_is_set(timeout) ? timeout : m->watchdog[t];
-
+        usec = (timeout == USEC_INFINITY) ? m->watchdog[t] : timeout;
+        if (t == WATCHDOG_RUNTIME)
                 (void) watchdog_setup(usec);
-        } else if (t == WATCHDOG_PRETIMEOUT)
-                (void) watchdog_setup_pretimeout(timeout);
+        else if (t == WATCHDOG_PRETIMEOUT)
+                (void) watchdog_setup_pretimeout(usec);
 
         m->watchdog_overridden[t] = timeout;
 }