rfkill: fix double-mutex-locking

rfkill_toggle_radio is called from functions where
rfkill->mutex is already aquired.

Remove the lock from rfkill_toggle_radio() and add it to
the only calling function that calls it without the lock held.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 9 deletions

diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c
index 73d60a307129..4469a7be006c 100644
--- a/net/rfkill/rfkill.c
+++ b/net/rfkill/rfkill.c
@@ -60,11 +60,7 @@ static void rfkill_led_trigger(struct rfkill *rfkill,
 static int rfkill_toggle_radio(struct rfkill *rfkill,
                                 enum rfkill_state state)
 {
-        int retval;
-
-        retval = mutex_lock_interruptible(&rfkill->mutex);
-        if (retval)
-                return retval;
+        int retval = 0;
 
         if (state != rfkill->state) {
                 retval = rfkill->toggle_radio(rfkill->data, state);
@@ -74,7 +70,6 @@ static int rfkill_toggle_radio(struct rfkill *rfkill,
                 }
         }
 
-        mutex_unlock(&rfkill->mutex);
         return retval;
 }
 
@@ -158,12 +153,13 @@ static ssize_t rfkill_state_store(struct device *dev,
         if (!capable(CAP_NET_ADMIN))
                 return -EPERM;
 
+        if (mutex_lock_interruptible(&rfkill->mutex))
+                return -ERESTARTSYS;
         error = rfkill_toggle_radio(rfkill,
                         state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
-        if (error)
-                return error;
+        mutex_unlock(&rfkill->mutex);
 
-        return count;
+        return error ? error : count;
 }
 
 static ssize_t rfkill_claim_show(struct device *dev,