[tip:perf/urgent] watchdog: Only disable/enable watchdog if neccessary

[tip-bot for Mandeep Singh Baines <msb@chromium.org>]

Commit-ID:  e04ab2bc41b35c0cb6cdb07c8443f91aa738cf78
Gitweb:     http://git.kernel.org/tip/e04ab2bc41b35c0cb6cdb07c8443f91aa738cf78
Author:     Mandeep Singh Baines <msb@chromium.org>
AuthorDate: Sun, 22 May 2011 22:10:21 -0700
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Mon, 23 May 2011 11:58:58 +0200

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>
---
 kernel/watchdog.c |   20 ++++++++++++--------
 1 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index a06972d..cf0e09f 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,