Commit fbd0e2b0 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Alex Williamson
Browse files

vfio/mdev: Reorganize mdev_device_create() 



Once the memory for the struct mdev_device is allocated it should
immediately be device_initialize()'d and filled in so that put_device()
can always be used to undo the allocation.

Place the mdev_get/put_parent() so that they are clearly protecting the
mdev->parent pointer. Move the final put to the release function so that
the lifetime rules are trivial to understand. Update the goto labels to
follow the normal convention.

Remove mdev_device_free() as the release function via device_put() is now
usable in all cases.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Message-Id: <8-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 9a302449

drivers/vfio/mdev/mdev_core.c

+27 −33
Original line number Diff line number Diff line
@@ -71,7 +71,6 @@ static void mdev_device_remove_common(struct mdev_device *mdev) 


	/* Balances with device_initialize() */

	put_device(&mdev->dev);

	mdev_put_parent(parent);

}



static int mdev_device_remove_cb(struct device *dev, void *data)
@@ -208,8 +207,13 @@ void mdev_unregister_device(struct device *dev) 
}

EXPORT_SYMBOL(mdev_unregister_device);



static void mdev_device_free(struct mdev_device *mdev)

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);



	mutex_lock(&mdev_list_lock);

	list_del(&mdev->next);

	mutex_unlock(&mdev_list_lock);
@@ -218,70 +222,61 @@ static void mdev_device_free(struct mdev_device *mdev) 
	kfree(mdev);

}



static void mdev_device_release(struct device *dev)

{

	struct mdev_device *mdev = to_mdev_device(dev);



	mdev_device_free(mdev);

}



int mdev_device_create(struct mdev_type *type, const guid_t *uuid)

{

	int ret;

	struct mdev_device *mdev, *tmp;

	struct mdev_parent *parent = type->parent;



	mdev_get_parent(parent);

	mutex_lock(&mdev_list_lock);



	/* Check for duplicate */

	list_for_each_entry(tmp, &mdev_list, next) {

		if (guid_equal(&tmp->uuid, uuid)) {

			mutex_unlock(&mdev_list_lock);

			ret = -EEXIST;

			goto mdev_fail;

			return -EEXIST;

		}

	}



	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);

	if (!mdev) {

		mutex_unlock(&mdev_list_lock);

		ret = -ENOMEM;

		goto mdev_fail;

		return -ENOMEM;

	}



	device_initialize(&mdev->dev);

	mdev->dev.parent  = parent->dev;

	mdev->dev.bus = &mdev_bus_type;

	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);



	guid_copy(&mdev->uuid, uuid);

	list_add(&mdev->next, &mdev_list);

	mutex_unlock(&mdev_list_lock);



	mdev->parent = parent;

	dev_set_name(&mdev->dev, "%pUl", uuid);



	/* Check if parent unregistration has started */

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

		mdev_device_free(mdev);

		ret = -ENODEV;

		goto mdev_fail;

		goto out_put_device;

	}



	device_initialize(&mdev->dev);

	mdev->dev.parent = parent->dev;

	mdev->dev.bus     = &mdev_bus_type;

	mdev->dev.release = mdev_device_release;

	dev_set_name(&mdev->dev, "%pUl", uuid);

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

	mdev->type = type;



	ret = parent->ops->create(&type->kobj, mdev);

	if (ret)

		goto ops_create_fail;

		goto out_unlock;



	ret = device_add(&mdev->dev);

	if (ret)

		goto add_fail;

		goto out_remove;



	ret = mdev_create_sysfs_files(mdev);

	if (ret)

		goto sysfs_fail;

		goto out_del;



	mdev->active = true;

	dev_dbg(&mdev->dev, "MDEV: created\n");
@@ -289,15 +284,14 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid) 


	return 0;



sysfs_fail:

out_del:

	device_del(&mdev->dev);

add_fail:

out_remove:

	parent->ops->remove(mdev);

ops_create_fail:

out_unlock:

	up_read(&parent->unreg_sem);

out_put_device:

	put_device(&mdev->dev);

mdev_fail:

	mdev_put_parent(parent);

	return ret;

}