[PATCH 06/10] vfio: Move device open/close code to be helpfers

[Yi Liu <yi.l.liu@xxxxxxxxx>]

This makes vfio_device_open/close() to be the top level helpers for device
open and close. It handles the open_count, and vfio_device_first_open()
vfio_device_last_close() do the container/iommufd use/unuse and the device
open.

Current vfio_device_open() handles the device open and the device file
open which is group specific. After this change, the group specific code
is in the vfio_device_open_file() which would be moved to separate group
source code in future.

Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
 drivers/vfio/vfio_main.c | 46 +++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 4f2d32d4a3d0..964d44a35624 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -828,20 +828,41 @@ static void vfio_device_last_close(struct vfio_device *device)
 	module_put(device->dev->driver->owner);
 }
 
-static struct file *vfio_device_open(struct vfio_device *device)
+static int vfio_device_open(struct vfio_device *device)
 {
-	struct file *filep;
-	int ret;
+	int ret = 0;
 
 	mutex_lock(&device->dev_set->lock);
 	device->open_count++;
 	if (device->open_count == 1) {
 		ret = vfio_device_first_open(device);
 		if (ret)
-			goto err_unlock;
+			device->open_count--;
 	}
 	mutex_unlock(&device->dev_set->lock);
 
+	return ret;
+}
+
+static void vfio_device_close(struct vfio_device *device)
+{
+	mutex_lock(&device->dev_set->lock);
+	vfio_assert_device_open(device);
+	if (device->open_count == 1)
+		vfio_device_last_close(device);
+	device->open_count--;
+	mutex_unlock(&device->dev_set->lock);
+}
+
+static struct file *vfio_device_open_file(struct vfio_device *device)
+{
+	struct file *filep;
+	int ret;
+
+	ret = vfio_device_open(device);
+	if (ret)
+		goto err_out;
+
 	/*
 	 * We can't use anon_inode_getfd() because we need to modify
 	 * the f_mode flags directly to allow more than just ioctls
@@ -870,12 +891,8 @@ static struct file *vfio_device_open(struct vfio_device *device)
 	return filep;
 
 err_close_device:
-	mutex_lock(&device->dev_set->lock);
-	if (device->open_count == 1)
-		vfio_device_last_close(device);
-err_unlock:
-	device->open_count--;
-	mutex_unlock(&device->dev_set->lock);
+	vfio_device_close(device);
+err_out:
 	return ERR_PTR(ret);
 }
 
@@ -903,7 +920,7 @@ static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
 		goto err_put_device;
 	}
 
-	filep = vfio_device_open(device);
+	filep = vfio_device_open_file(device);
 	if (IS_ERR(filep)) {
 		ret = PTR_ERR(filep);
 		goto err_put_fdno;
@@ -1086,12 +1103,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
 {
 	struct vfio_device *device = filep->private_data;
 
-	mutex_lock(&device->dev_set->lock);
-	vfio_assert_device_open(device);
-	if (device->open_count == 1)
-		vfio_device_last_close(device);
-	device->open_count--;
-	mutex_unlock(&device->dev_set->lock);
+	vfio_device_close(device);
 
 	vfio_device_put_registration(device);
 
-- 
2.34.1