X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=kernel%2Fkmod.c;h=da7fcca279f95123ab167430b7f10db386cdc92f;hb=32f651194a2c437b26ca17b57f1fd0ff6e03d3d2;hp=957a7aab8ebc2b4d1527763c2666298be1dc419c;hpb=a591afc01d9e48affbacb365558a31e53c85af45;p=cascardo%2Flinux.git

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 957a7aab8ebc..da7fcca279f9 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -333,23 +333,74 @@ static atomic_t running_helpers = ATOMIC_INIT(0);
  */
 static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
 
+/*
+ * Used by usermodehelper_read_lock_wait() to wait for usermodehelper_disabled
+ * to become 'false'.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(usermodehelper_disabled_waitq);
+
 /*
  * Time to wait for running_helpers to become zero before the setting of
  * usermodehelper_disabled in usermodehelper_disable() fails
  */
 #define RUNNING_HELPERS_TIMEOUT	(5 * HZ)
 
-void read_lock_usermodehelper(void)
+int usermodehelper_read_trylock(void)
 {
+	int ret = 0;
+
 	down_read(&umhelper_sem);
+	if (usermodehelper_disabled) {
+		up_read(&umhelper_sem);
+		ret = -EAGAIN;
+	}
+	return ret;
 }
-EXPORT_SYMBOL_GPL(read_lock_usermodehelper);
+EXPORT_SYMBOL_GPL(usermodehelper_read_trylock);
 
-void read_unlock_usermodehelper(void)
+long usermodehelper_read_lock_wait(long timeout)
+{
+	DEFINE_WAIT(wait);
+
+	if (timeout < 0)
+		return -EINVAL;
+
+	down_read(&umhelper_sem);
+	for (;;) {
+		prepare_to_wait(&usermodehelper_disabled_waitq, &wait,
+				TASK_UNINTERRUPTIBLE);
+		if (!usermodehelper_disabled)
+			break;
+
+		up_read(&umhelper_sem);
+
+		timeout = schedule_timeout(timeout);
+		if (!timeout)
+			break;
+
+		down_read(&umhelper_sem);
+	}
+	finish_wait(&usermodehelper_disabled_waitq, &wait);
+	return timeout;
+}
+EXPORT_SYMBOL_GPL(usermodehelper_read_lock_wait);
+
+void usermodehelper_read_unlock(void)
 {
 	up_read(&umhelper_sem);
 }
-EXPORT_SYMBOL_GPL(read_unlock_usermodehelper);
+EXPORT_SYMBOL_GPL(usermodehelper_read_unlock);
+
+/**
+ * usermodehelper_enable - allow new helpers to be started again
+ */
+void usermodehelper_enable(void)
+{
+	down_write(&umhelper_sem);
+	usermodehelper_disabled = 0;
+	wake_up(&usermodehelper_disabled_waitq);
+	up_write(&umhelper_sem);
+}
 
 /**
  * usermodehelper_disable - prevent new helpers from being started
@@ -374,31 +425,10 @@ int usermodehelper_disable(void)
 	if (retval)
 		return 0;
 
-	down_write(&umhelper_sem);
-	usermodehelper_disabled = 0;
-	up_write(&umhelper_sem);
+	usermodehelper_enable();
 	return -EAGAIN;
 }
 
-/**
- * usermodehelper_enable - allow new helpers to be started again
- */
-void usermodehelper_enable(void)
-{
-	down_write(&umhelper_sem);
-	usermodehelper_disabled = 0;
-	up_write(&umhelper_sem);
-}
-
-/**
- * usermodehelper_is_disabled - check if new helpers are allowed to be started
- */
-bool usermodehelper_is_disabled(void)
-{
-	return usermodehelper_disabled;
-}
-EXPORT_SYMBOL_GPL(usermodehelper_is_disabled);
-
 static void helper_lock(void)
 {
 	atomic_inc(&running_helpers);