update_watchdog_all_cpus() now passes errors from watchdog_park_threads()
up to functions in the call chain. This allows watchdog_enable_all_cpus()
and proc_watchdog_update() to handle such errors too.
Signed-off-by: Ulrich Obergfell <uober...@redhat.com>
---
kernel/watchdog.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index eb9527c..457113c 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -731,10 +731,17 @@ void lockup_detector_resume(void)
mutex_unlock(&watchdog_proc_mutex);
}
-static void update_watchdog_all_cpus(void)
+static int update_watchdog_all_cpus(void)
{
- watchdog_park_threads();
+ int ret;
+
+ ret = watchdog_park_threads();
+ if (ret)
+ return ret;
+
watchdog_unpark_threads();
+
+ return 0;
}
static int watchdog_enable_all_cpus(void)
@@ -753,9 +760,17 @@ static int watchdog_enable_all_cpus(void)
* Enable/disable the lockup detectors or
* change the sample period 'on the fly'.
*/
- update_watchdog_all_cpus();
+ err = update_watchdog_all_cpus();
+
+ if (err) {
+ watchdog_disable_all_cpus();
+ pr_err("Failed to update lockup detectors, disabled\n");
+ }
}
+ if (err)
+ watchdog_enabled = 0;
+
return err;
}
@@ -851,12 +866,13 @@ static int proc_watchdog_common(int which, struct
ctl_table *table, int write,
} while (cmpxchg(&watchdog_enabled, old, new) != old);
/*
- * Update the run state of the lockup detectors.
- * Restore 'watchdog_enabled' on failure.
+ * Update the run state of the lockup detectors. There is _no_
+ * need to check the value returned by proc_watchdog_update()
+ * and to restore the previous value of 'watchdog_enabled' as
+ * both lockup detectors are disabled if proc_watchdog_update()
+ * returns an error.
*/
err = proc_watchdog_update();
- if (err)
- watchdog_enabled = old;
}
out:
mutex_unlock(&watchdog_proc_mutex);
--
1.7.11.7
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