[PATCH 12/14] virtio: console: Use cdev_alloc() instead of cdev_init()

Amit Shah
Thu, 02 Sep 2010 12:50:59 -0000

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 at redhat.com>
---
 drivers/char/virtio_console.c |   20 +++++++++++++-------
 1 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index af44332..0c4dc26 100644
--- 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:
@@ -1081,14 +1081,20 @@ 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",
@@ -1153,7 +1159,7 @@ 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:
@@ -1197,7 +1203,7 @@ 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);
--
1.7.2.2