Commit fbea4323 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Alex Williamson
Browse files

vfio/mdev: Remove duplicate storage of parent in mdev_device 



mdev_device->type->parent is the same thing.

The struct mdev_device was relying on the kref on the mdev_parent to also
indirectly hold a kref on the mdev_type pointer. Now that the type holds a
kref on the parent we can directly kref the mdev_type and remove this
implicit relationship.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Message-Id: <10-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 18d73124

drivers/vfio/mdev/mdev_core.c

+5 −8
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ static DEFINE_MUTEX(mdev_list_lock); 


struct device *mdev_parent_dev(struct mdev_device *mdev)

{

	return mdev->parent->dev;

	return mdev->type->parent->dev;

}

EXPORT_SYMBOL(mdev_parent_dev);
@@ -58,12 +58,11 @@ void mdev_release_parent(struct kref *kref) 
/* Caller must hold parent unreg_sem read or write lock */

static void mdev_device_remove_common(struct mdev_device *mdev)

{

	struct mdev_parent *parent;

	struct mdev_parent *parent = mdev->type->parent;

	int ret;



	mdev_remove_sysfs_files(mdev);

	device_del(&mdev->dev);

	parent = mdev->parent;

	lockdep_assert_held(&parent->unreg_sem);

	ret = parent->ops->remove(mdev);

	if (ret)
@@ -212,7 +211,7 @@ static void mdev_device_release(struct device *dev) 
	struct mdev_device *mdev = to_mdev_device(dev);



	/* Pairs with the get in mdev_device_create() */

	mdev_put_parent(mdev->parent);

	kobject_put(&mdev->type->kobj);



	mutex_lock(&mdev_list_lock);

	list_del(&mdev->next);
@@ -250,9 +249,8 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid) 
	mdev->dev.release = mdev_device_release;

	mdev->dev.groups = parent->ops->mdev_attr_groups;

	mdev->type = type;

	mdev->parent = parent;

	/* Pairs with the put in mdev_device_release() */

	mdev_get_parent(parent);

	kobject_get(&type->kobj);



	guid_copy(&mdev->uuid, uuid);

	list_add(&mdev->next, &mdev_list);
@@ -300,7 +298,7 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid) 
int mdev_device_remove(struct mdev_device *mdev)

{

	struct mdev_device *tmp;

	struct mdev_parent *parent;

	struct mdev_parent *parent = mdev->type->parent;



	mutex_lock(&mdev_list_lock);

	list_for_each_entry(tmp, &mdev_list, next) {
@@ -321,7 +319,6 @@ int mdev_device_remove(struct mdev_device *mdev) 
	mdev->active = false;

	mutex_unlock(&mdev_list_lock);



	parent = mdev->parent;

	/* Check if parent unregistration has started */

	if (!down_read_trylock(&parent->unreg_sem))

		return -ENODEV;

drivers/vfio/mdev/vfio_mdev.c

+7 −7
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ 
static int vfio_mdev_open(struct vfio_device *core_vdev)

{

	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);

	struct mdev_parent *parent = mdev->parent;

	struct mdev_parent *parent = mdev->type->parent;



	int ret;
@@ -44,7 +44,7 @@ static int vfio_mdev_open(struct vfio_device *core_vdev) 
static void vfio_mdev_release(struct vfio_device *core_vdev)

{

	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);

	struct mdev_parent *parent = mdev->parent;

	struct mdev_parent *parent = mdev->type->parent;



	if (likely(parent->ops->release))

		parent->ops->release(mdev);
@@ -56,7 +56,7 @@ static long vfio_mdev_unlocked_ioctl(struct vfio_device *core_vdev, 
				     unsigned int cmd, unsigned long arg)

{

	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);

	struct mdev_parent *parent = mdev->parent;

	struct mdev_parent *parent = mdev->type->parent;



	if (unlikely(!parent->ops->ioctl))

		return -EINVAL;
@@ -68,7 +68,7 @@ static ssize_t vfio_mdev_read(struct vfio_device *core_vdev, char __user *buf, 
			      size_t count, loff_t *ppos)

{

	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);

	struct mdev_parent *parent = mdev->parent;

	struct mdev_parent *parent = mdev->type->parent;



	if (unlikely(!parent->ops->read))

		return -EINVAL;
@@ -81,7 +81,7 @@ static ssize_t vfio_mdev_write(struct vfio_device *core_vdev, 
			       loff_t *ppos)

{

	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);

	struct mdev_parent *parent = mdev->parent;

	struct mdev_parent *parent = mdev->type->parent;



	if (unlikely(!parent->ops->write))

		return -EINVAL;
@@ -93,7 +93,7 @@ static int vfio_mdev_mmap(struct vfio_device *core_vdev, 
			  struct vm_area_struct *vma)

{

	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);

	struct mdev_parent *parent = mdev->parent;

	struct mdev_parent *parent = mdev->type->parent;



	if (unlikely(!parent->ops->mmap))

		return -EINVAL;
@@ -104,7 +104,7 @@ static int vfio_mdev_mmap(struct vfio_device *core_vdev, 
static void vfio_mdev_request(struct vfio_device *core_vdev, unsigned int count)

{

	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);

	struct mdev_parent *parent = mdev->parent;

	struct mdev_parent *parent = mdev->type->parent;



	if (parent->ops->request)

		parent->ops->request(mdev, count);

include/linux/mdev.h

+0 −1
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ struct mdev_type; 


struct mdev_device {

	struct device dev;

	struct mdev_parent *parent;

	guid_t uuid;

	void *driver_data;

	struct list_head next;