sync_file: get rid of internal reference count.

sync_file uses the reference count of the file, the internal
kref was never getting moved past 1.

We can reintroduce this if we decide we need it later.

[airlied: fix buildbot warnings]
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170413014144.637-2-airlied@gmail.com

drivers/dma-buf/sync_file.c

@@ -41,8 +41,6 @@ static struct sync_file *sync_file_alloc(void)
 	if (IS_ERR(sync_file->file))
 		goto err;
 
-	kref_init(&sync_file->kref);
-
 	init_waitqueue_head(&sync_file->wq);
 
 	INIT_LIST_HEAD(&sync_file->cb.node);
@@ -277,22 +275,15 @@ static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
 
 }
 
-static void sync_file_free(struct kref *kref)
+static int sync_file_release(struct inode *inode, struct file *file)
 {
-	struct sync_file *sync_file = container_of(kref, struct sync_file,
-						     kref);
+	struct sync_file *sync_file = file->private_data;
 
 	if (test_bit(POLL_ENABLED, &sync_file->fence->flags))
 		dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
 	dma_fence_put(sync_file->fence);
 	kfree(sync_file);
-}
-
-static int sync_file_release(struct inode *inode, struct file *file)
-{
-	struct sync_file *sync_file = file->private_data;
 
-	kref_put(&sync_file->kref, sync_file_free);
 	return 0;
 }
 

include/linux/sync_file.h

@@ -14,7 +14,6 @@
 #define _LINUX_SYNC_FILE_H
 
 #include <linux/types.h>
-#include <linux/kref.h>
 #include <linux/ktime.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
@@ -24,7 +23,6 @@
 /**
  * struct sync_file - sync file to export to the userspace
  * @file:		file representing this fence
- * @kref:		reference count on fence.
  * @name:		name of sync_file.  Useful for debugging
  * @sync_file_list:	membership in global file list
  * @wq:			wait queue for fence signaling
@@ -33,7 +31,6 @@
  */
 struct sync_file {
 	struct file		*file;
-	struct kref		kref;
 	char			name[32];
 #ifdef CONFIG_DEBUG_FS
 	struct list_head	sync_file_list;