drm: fixup master code to use krefs

4 files changed, 82 insertions, 57 deletions

diff --git a/linux-core/drmP.h b/linux-core/drmP.h
index 59d44ac2..848fa885 100644
--- a/linux-core/drmP.h
+++ b/linux-core/drmP.h
@@ -670,7 +670,9 @@ struct drm_gem_object {
 
 /* per-master structure */
 struct drm_master {
-	
+
+	struct kref refcount; /* refcount for this master */
+
 	struct list_head head; /**< each minor contains a list of masters */
 	struct drm_minor *minor; /**< link back to minor we are a master for */
 
@@ -1345,12 +1347,13 @@ extern int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 			       struct drm_file *file_priv);
 extern int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 				struct drm_file *file_priv);
-extern struct drm_master *drm_get_master(struct drm_minor *minor);
-extern void drm_put_master(struct drm_master *master);
+struct drm_master *drm_master_create(struct drm_minor *minor);
+extern struct drm_master *drm_master_get(struct drm_master *master);
+extern void drm_master_put(struct drm_master **master);
 extern int drm_get_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
-		     struct drm_driver *driver);
+		       struct drm_driver *driver);
 extern int drm_put_dev(struct drm_device *dev);
-extern int drm_put_minor(struct drm_device *dev, struct drm_minor **p);
+extern int drm_put_minor(struct drm_minor **minor_p);
 extern unsigned int drm_debug; /* 1 to enable debug output */
 
 extern struct class *drm_class;
diff --git a/linux-core/drm_drv.c b/linux-core/drm_drv.c
index c3cc620a..751322db 100644
--- a/linux-core/drm_drv.c
+++ b/linux-core/drm_drv.c
@@ -191,11 +191,6 @@ int drm_lastclose(struct drm_device * dev)
 	drm_drawable_free_all(dev);
 	del_timer(&dev->timer);
 
-	if (dev->primary->master) {
-		drm_put_master(dev->primary->master);
-		dev->primary->master = NULL;
-	}
-	
 	/* Clear AGP information */
 	if (drm_core_has_AGP(dev) && dev->agp) {
 		struct drm_agp_mem *entry, *tempe;
@@ -400,9 +395,10 @@ static void drm_cleanup(struct drm_device * dev)
 	drm_ht_remove(&dev->map_hash);
 	drm_memrange_takedown(&dev->offset_manager);
 
-	drm_put_minor(dev, &dev->primary);
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		drm_put_minor(dev, &dev->control);
+		drm_put_minor(&dev->control);
+
+	drm_put_minor(&dev->primary);
 
 	if (drm_put_dev(dev))
 		DRM_ERROR("Cannot unload module\n");
diff --git a/linux-core/drm_fops.c b/linux-core/drm_fops.c
index 8eb20b47..f45d5e46 100644
--- a/linux-core/drm_fops.c
+++ b/linux-core/drm_fops.c
@@ -260,28 +260,34 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
 	/* if there is no current master make this fd it */
 	mutex_lock(&dev->struct_mutex);
 	if (!priv->minor->master) {
-		priv->minor->master = drm_get_master(priv->minor);
+		/* create a new master */
+		priv->minor->master = drm_master_create(priv->minor);
 		if (!priv->minor->master) {
 			ret = -ENOMEM;
 			goto out_free;
 		}
 
 		priv->is_master = 1;
-		priv->master = priv->minor->master;
+		/* take another reference for the copy in the local file priv */
+		priv->master = drm_master_get(priv->minor->master);
 
 		priv->authenticated = 1;
+
 		mutex_unlock(&dev->struct_mutex);
 		if (dev->driver->master_create) {
 			ret = dev->driver->master_create(dev, priv->master);
 			if (ret) {
-				drm_put_master(priv->minor->master);
-				priv->minor->master = priv->master = NULL;
+				mutex_lock(&dev->struct_mutex);
+				/* drop both references if this fails */
+				drm_master_put(&priv->minor->master);
+				drm_master_put(&priv->master);
 				mutex_unlock(&dev->struct_mutex);
 				goto out_free;
 			}
 		}
 	} else {
-		priv->master = priv->minor->master;
+		/* get a reference to the master */
+		priv->master = drm_master_get(priv->minor->master);
 		mutex_unlock(&dev->struct_mutex);
 	}
 
@@ -453,6 +459,8 @@ int drm_release(struct inode *inode, struct file *filp)
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		drm_fb_release(filp);
 
+	mutex_lock(&dev->struct_mutex);
+
 	if (file_priv->is_master) {
 		struct drm_file *temp;
 		list_for_each_entry(temp, &dev->filelist, lhead) {
@@ -461,18 +469,17 @@ int drm_release(struct inode *inode, struct file *filp)
 				temp->authenticated = 0;
 		}
 
-		if (file_priv->minor->master == file_priv->master)
-			file_priv->minor->master = NULL;
-		drm_put_master(file_priv->master);
+		if (file_priv->minor->master == file_priv->master) {
+			/* drop the reference held my the minor */
+			drm_master_put(&file_priv->minor->master);
+		}
 	}
 
-	file_priv->master = NULL;
+	/* drop the reference held my the file priv */
+	drm_master_put(&file_priv->master);
 	file_priv->is_master = 0;
 
-	mutex_lock(&dev->struct_mutex);
-
 	list_del(&file_priv->lhead);
-
 	mutex_unlock(&dev->struct_mutex);
 
 	if (dev->driver->postclose)
diff --git a/linux-core/drm_stub.c b/linux-core/drm_stub.c
index 97533d72..4654dca1 100644
--- a/linux-core/drm_stub.c
+++ b/linux-core/drm_stub.c
@@ -88,30 +88,7 @@ again:
 	return new_id;
 }
 
-int drm_setmaster_ioctl(struct drm_device *dev, void *data,
-			struct drm_file *file_priv)
-{
-	if (file_priv->minor->master && file_priv->minor->master != file_priv->master)
-		return -EINVAL;
-
-	if (!file_priv->master)
-		return -EINVAL;
-
-	if (!file_priv->minor->master && file_priv->minor->master != file_priv->master)
-		file_priv->minor->master = file_priv->master;
-	return 0;
-}
-
-int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
-			 struct drm_file *file_priv)
-{
-	if (!file_priv->master)
-		return -EINVAL;
-	file_priv->minor->master = NULL;
-	return 0;
-}
-
-struct drm_master *drm_get_master(struct drm_minor *minor)
+struct drm_master *drm_master_create(struct drm_minor *minor)
 {
 	struct drm_master *master;
 
@@ -119,7 +96,7 @@ struct drm_master *drm_get_master(struct drm_minor *minor)
 	if (!master)
 		return NULL;
 
-//	INIT_LIST_HEAD(&master->filelist);
+	kref_init(&master->refcount);
 	spin_lock_init(&master->lock.spinlock);
 	init_waitqueue_head(&master->lock.lock_queue);
 	drm_ht_create(&master->magiclist, DRM_MAGIC_HASH_ORDER);
@@ -131,8 +108,15 @@ struct drm_master *drm_get_master(struct drm_minor *minor)
 	return master;
 }
 
-void drm_put_master(struct drm_master *master)
+struct drm_master *drm_master_get(struct drm_master *master)
+{
+	kref_get(&master->refcount);
+	return master;
+}
+
+static void drm_master_destroy(struct kref *kref)
 {
+	struct drm_master *master = container_of(kref, struct drm_master, refcount);
 	struct drm_magic_entry *pt, *next;
 	struct drm_device *dev = master->minor->dev;
 
@@ -166,21 +150,56 @@ void drm_put_master(struct drm_master *master)
 	drm_free(master, sizeof(*master), DRM_MEM_DRIVER);
 }
 
+void drm_master_put(struct drm_master **master)
+{
+	kref_put(&(*master)->refcount, drm_master_destroy);
+	*master = NULL;
+}
+
+int drm_setmaster_ioctl(struct drm_device *dev, void *data,
+			struct drm_file *file_priv)
+{
+	if (file_priv->minor->master && file_priv->minor->master != file_priv->master)
+		return -EINVAL;
+
+	if (!file_priv->master)
+		return -EINVAL;
+
+	if (!file_priv->minor->master && file_priv->minor->master != file_priv->master) {
+		mutex_lock(&dev->struct_mutex);
+		file_priv->minor->master = drm_master_get(file_priv->master);
+		mutex_unlock(&dev->struct_mutex);
+	}
+
+	return 0;
+}
+
+int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	if (!file_priv->master)
+		return -EINVAL;
+	mutex_lock(&dev->struct_mutex);
+	drm_master_put(&file_priv->minor->master);
+	mutex_unlock(&dev->struct_mutex);
+	return 0;
+}
+
 static int drm_fill_in_dev(struct drm_device * dev, struct pci_dev *pdev,
 			   const struct pci_device_id *ent,
 			   struct drm_driver *driver)
 {
 	int retcode;
 
+	INIT_LIST_HEAD(&dev->filelist);
 	INIT_LIST_HEAD(&dev->ctxlist);
 	INIT_LIST_HEAD(&dev->vmalist);
 	INIT_LIST_HEAD(&dev->maplist);
-	INIT_LIST_HEAD(&dev->filelist);
 
 	spin_lock_init(&dev->count_lock);
 	spin_lock_init(&dev->drw_lock);
 	spin_lock_init(&dev->tasklet_lock);
-//	spin_lock_init(&dev->lock.spinlock);
+
 	init_timer(&dev->timer);
 	mutex_init(&dev->struct_mutex);
 	mutex_init(&dev->ctxlist_mutex);
@@ -402,10 +421,10 @@ int drm_get_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
 
 	return 0;
 err_g5:
-	drm_put_minor(dev, &dev->primary);
+	drm_put_minor(&dev->primary);
 err_g4:
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
-		drm_put_minor(dev, &dev->control);
+		drm_put_minor(&dev->control);
 err_g3:
 	if (!drm_fb_loaded)
 		pci_disable_device(pdev);
@@ -456,14 +475,14 @@ int drm_put_dev(struct drm_device * dev)
  * last minor released.
  *
  */
-int drm_put_minor(struct drm_device *dev, struct drm_minor **minor_p)
+int drm_put_minor(struct drm_minor **minor_p)
 {
 	struct drm_minor *minor = *minor_p;
 	DRM_DEBUG("release secondary minor %d\n", minor->index);
 
 	if (minor->type == DRM_MINOR_LEGACY) {
-		if (dev->driver->proc_cleanup)
-			dev->driver->proc_cleanup(minor);
+		if (minor->dev->driver->proc_cleanup)
+			minor->dev->driver->proc_cleanup(minor);
 		drm_proc_cleanup(minor, drm_proc_root);
 	}
 	drm_sysfs_device_remove(minor);