Commit 6093e348 authored by Parav Pandit's avatar Parav Pandit Committed by Alex Williamson
Browse files

vfio/mdev: Fix aborting mdev child device removal if one fails 



device_for_each_child() stops executing callback function for remaining
child devices, if callback hits an error.
Each child mdev device is independent of each other.
While unregistering parent device, mdev core must remove all child mdev
devices.
Therefore, mdev_device_remove_cb() always returns success so that
device_for_each_child doesn't abort if one child removal hits error.

While at it, improve remove and unregister functions for below simplicity.

There isn't need to pass forced flag pointer during mdev parent
removal which invokes mdev_device_remove(). So simplify the flow.

mdev_device_remove() is called from two paths.
1. mdev_unregister_driver()
     mdev_device_remove_cb()
       mdev_device_remove()
2. remove_store()
     mdev_device_remove()

Fixes: 7b96953b ("vfio: Mediated device Core driver")
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: default avatarParav Pandit <parav@mellanox.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent a6d6f4f1

drivers/vfio/mdev/mdev_core.c

+4 −6
Original line number Diff line number Diff line
@@ -149,10 +149,10 @@ static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove) 


static int mdev_device_remove_cb(struct device *dev, void *data)

{

	if (!dev_is_mdev(dev))

		return 0;

	if (dev_is_mdev(dev))

		mdev_device_remove(dev, true);



	return mdev_device_remove(dev, data ? *(bool *)data : true);

	return 0;

}



/*
@@ -240,7 +240,6 @@ EXPORT_SYMBOL(mdev_register_device); 
void mdev_unregister_device(struct device *dev)

{

	struct mdev_parent *parent;

	bool force_remove = true;



	mutex_lock(&parent_list_lock);

	parent = __find_parent_device(dev);
@@ -254,8 +253,7 @@ void mdev_unregister_device(struct device *dev) 
	list_del(&parent->next);

	class_compat_remove_link(mdev_bus_compat_class, dev, NULL);



	device_for_each_child(dev, (void *)&force_remove,

			      mdev_device_remove_cb);

	device_for_each_child(dev, NULL, mdev_device_remove_cb);



	parent_remove_sysfs_files(parent);