[Intel-gfx] [PATCH v15 17/26] vfio: Move device_del() before waiting for the last vfio_device registration refcount

[Yi Liu]

device_del() destroys the vfio-dev/vfioX under the sysfs for vfio_device.
There is no reason to keep it while the device is going to be unregistered.

This movement is also a preparation for adding vfio_device cdev. Kernel
should remove the cdev node of the vfio_device to avoid new registration
refcount increment while the device is going to be unregistered.

Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan at intel.com>
Signed-off-by: Yi Liu <yi.l.liu at intel.com>
---
 drivers/vfio/vfio_main.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 6d45caa1f9a0..294bb5ecfc1c 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -338,6 +338,9 @@ void vfio_unregister_group_dev(struct vfio_device *device)
 	 */
 	vfio_device_group_unregister(device);
 
+	/* Balances device_add in register path */
+	device_del(&device->device);
+
 	vfio_device_put_registration(device);
 	rc = try_wait_for_completion(&device->comp);
 	while (rc <= 0) {
@@ -361,9 +364,6 @@ void vfio_unregister_group_dev(struct vfio_device *device)
 		}
 	}
 
-	/* Balances device_add in register path */
-	device_del(&device->device);
-
 	/* Balances vfio_device_set_group in register path */
 	vfio_device_remove_group(device);
 }
-- 
2.34.1