virtio: console: Use cdev_alloc() instead of cdev_init()

This moves to using cdev on the heap instead of it being embedded in the
ports struct. This helps individual refcounting and will allow us to
properly remove cdev structs after hot-unplugs and close operations.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 0c8f2aa3074a589e54a15a86b79abe6aeec9701e..8a9c140d19be8ab58b9bb13de130afab06d3d87d 100644 (file)
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -184,7 +184,7 @@ struct port {
        struct console cons;
 
        /* Each port associates with a separate char device */
-       struct cdev cdev;
+       struct cdev *cdev;
        struct device *dev;
 
        /* A waitqueue for poll() or blocking read operations */
@@ -235,7 +235,7 @@ static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
 
        spin_lock_irqsave(&portdev->ports_lock, flags);
        list_for_each_entry(port, &portdev->ports, list)
-               if (port->cdev.dev == dev)
+               if (port->cdev->dev == dev)
                        goto out;
        port = NULL;
 out:
@@ -1096,14 +1096,20 @@ static int add_port(struct ports_device *portdev, u32 id)
        port->in_vq = portdev->in_vqs[port->id];
        port->out_vq = portdev->out_vqs[port->id];
 
-       cdev_init(&port->cdev, &port_fops);
+       port->cdev = cdev_alloc();
+       if (!port->cdev) {
+               dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
+               err = -ENOMEM;
+               goto free_port;
+       }
+       port->cdev->ops = &port_fops;
 
        devt = MKDEV(portdev->chr_major, id);
-       err = cdev_add(&port->cdev, devt, 1);
+       err = cdev_add(port->cdev, devt, 1);
        if (err < 0) {
                dev_err(&port->portdev->vdev->dev,
                        "Error %d adding cdev for port %u\n", err, id);
-               goto free_port;
+               goto free_cdev;
        }
        port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
                                  devt, port, "vport%up%u",
@@ -1168,7 +1174,7 @@ free_inbufs:
 free_device:
        device_destroy(pdrvdata.class, port->dev->devt);
 free_cdev:
-       cdev_del(&port->cdev);
+       cdev_del(port->cdev);
 free_port:
        kfree(port);
 fail:
@@ -1212,7 +1218,7 @@ static void remove_port(struct port *port)
        }
        sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
        device_destroy(pdrvdata.class, port->dev->devt);
-       cdev_del(&port->cdev);
+       cdev_del(port->cdev);
 
        /* Remove unused data this port might have received. */
        discard_port_data(port);