vmwatchdog: BKL pushdown

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/s390/char/vmwatchdog.c b/drivers/s390/char/vmwatchdog.c
index 19f8389291b62c3f13b76eafde98ae03f1677666..ee80e936d5145e142bf0baa9d7519168b8c2a5c2 100644 (file)
--- a/drivers/s390/char/vmwatchdog.c
+++ b/drivers/s390/char/vmwatchdog.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/watchdog.h>
+#include <linux/smp_lock.h>
 
 #include <asm/ebcdic.h>
 #include <asm/io.h>
@@ -131,11 +132,15 @@ static int __init vmwdt_probe(void)
 static int vmwdt_open(struct inode *i, struct file *f)
 {
        int ret;
-       if (test_and_set_bit(0, &vmwdt_is_open))
+       lock_kernel();
+       if (test_and_set_bit(0, &vmwdt_is_open)) {
+               unlock_kernel();
                return -EBUSY;
+       }
        ret = vmwdt_keepalive();
        if (ret)
                clear_bit(0, &vmwdt_is_open);
+       unlock_kernel();
        return ret ? ret : nonseekable_open(i, f);
 }