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-rw-r--r--include/media/dvbdev.h32
1 files changed, 18 insertions, 14 deletions
diff --git a/include/media/dvbdev.h b/include/media/dvbdev.h
index 881ca461b..09279ed00 100644
--- a/include/media/dvbdev.h
+++ b/include/media/dvbdev.h
@@ -126,6 +126,7 @@ struct dvb_adapter {
* struct dvb_device - represents a DVB device node
*
* @list_head: List head with all DVB devices
+ * @ref: reference counter
* @fops: pointer to struct file_operations
* @adapter: pointer to the adapter that holds this device node
* @type: type of the device, as defined by &enum dvb_device_type.
@@ -156,6 +157,7 @@ struct dvb_adapter {
*/
struct dvb_device {
struct list_head list_head;
+ struct kref ref;
const struct file_operations *fops;
struct dvb_adapter *adapter;
enum dvb_device_type type;
@@ -188,6 +190,20 @@ struct dvb_device {
};
/**
+ * dvb_device_get - Increase dvb_device reference
+ *
+ * @dvbdev: pointer to struct dvb_device
+ */
+struct dvb_device *dvb_device_get(struct dvb_device *dvbdev);
+
+/**
+ * dvb_device_put - Decrease dvb_device reference
+ *
+ * @dvbdev: pointer to struct dvb_device
+ */
+void dvb_device_put(struct dvb_device *dvbdev);
+
+/**
* dvb_register_adapter - Registers a new DVB adapter
*
* @adap: pointer to struct dvb_adapter
@@ -231,29 +247,17 @@ int dvb_register_device(struct dvb_adapter *adap,
/**
* dvb_remove_device - Remove a registered DVB device
*
- * This does not free memory. To do that, call dvb_free_device().
+ * This does not free memory. dvb_free_device() will do that when
+ * reference counter is empty
*
* @dvbdev: pointer to struct dvb_device
*/
void dvb_remove_device(struct dvb_device *dvbdev);
-/**
- * dvb_free_device - Free memory occupied by a DVB device.
- *
- * Call dvb_unregister_device() before calling this function.
- *
- * @dvbdev: pointer to struct dvb_device
- */
-void dvb_free_device(struct dvb_device *dvbdev);
/**
* dvb_unregister_device - Unregisters a DVB device
*
- * This is a combination of dvb_remove_device() and dvb_free_device().
- * Using this function is usually a mistake, and is often an indicator
- * for a use-after-free bug (when a userspace process keeps a file
- * handle to a detached device).
- *
* @dvbdev: pointer to struct dvb_device
*/
void dvb_unregister_device(struct dvb_device *dvbdev);