watchdog: Only disable/enable watchdog if neccessary

Don't take any action on an unsuccessful write to /proc.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1306127423-3347-2-git-send-email-msb@chromium.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 8 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index a06972d71060..cf0e09f452e7 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -507,15 +507,19 @@ static void watchdog_disable_all_cpus(void)
 int proc_dowatchdog_enabled(struct ctl_table *table, int write,
                      void __user *buffer, size_t *length, loff_t *ppos)
 {
-        proc_dointvec(table, write, buffer, length, ppos);
+        int ret;
 
-        if (write) {
-                if (watchdog_enabled)
-                        watchdog_enable_all_cpus();
-                else
-                        watchdog_disable_all_cpus();
-        }
-        return 0;
+        ret = proc_dointvec(table, write, buffer, length, ppos);
+        if (ret || !write)
+                goto out;
+
+        if (watchdog_enabled)
+                watchdog_enable_all_cpus();
+        else
+                watchdog_disable_all_cpus();
+
+out:
+        return ret;
 }
 
 int proc_dowatchdog_thresh(struct ctl_table *table, int write,