Fix cdev creation and destruction

2 files changed, 29 insertions, 14 deletions

diff --git a/char.c b/char.c
index b13b08a..4efcb80 100644
--- a/char.c
+++ b/char.c
@@ -37,33 +37,41 @@ int new_doomdev(struct pci_dev *dev)
 {
 	int err = 0;
 	int minor;
-	dev_t devt;
-	struct cdev *doom_cdev;
-	struct device *doomdev;
 	struct doom_data *doom_data;
+	dev_t devt;
+
 	if (next_minor >= DOOMDEV_COUNT) {
 		return -ENOMEM;
 	}
 
-	doom_cdev = cdev_alloc();
-	if (doom_cdev == NULL) {
+	doom_data = kmalloc(sizeof(*doom_data), GFP_KERNEL);
+	if (doom_data == NULL) {
+		err = -ENOMEM;
+		goto error_kmalloc;
+	}
+
+	doom_data->cdev = cdev_alloc();
+	if (doom_data->cdev == NULL) {
 		return -ENOMEM;
 	}
+	cdev_init(doom_data->cdev, &doomdev_fops);
+	ORFAIL(cdev_add(doom_data->cdev, first, 1), error_add);
 
-	doom_cdev->ops = &doomdev_fops;
-	ORFAIL(cdev_add(doom_cdev, first, 1), error_add);
 	minor = next_minor++;
-	doom_data = kmalloc(sizeof(*doom_data), GFP_KERNEL);
-	doom_data->minor = minor;
-	pci_set_drvdata(dev, doom_data);
 	devt = MKDEV(major, minor);
 	ORFAIL_PTR(device_create(doom_class, NULL, devt, NULL,
 				"doom%d", minor),
-			doomdev, error_create);
+			doom_data->device, error_create);
+	
+	pci_set_drvdata(dev, doom_data);
+
+	return 0;
 
 error_create:
-	cdev_del(doom_cdev);
+	cdev_del(doom_data->cdev);
 error_add:
+	kfree(doom_data);
+error_kmalloc:
 	return err;
 }
 
@@ -71,7 +79,8 @@ void destroy_doomdev(struct pci_dev *dev)
 {
 	struct doom_data *data;
 	data = pci_get_drvdata(dev);
-	device_destroy(doom_class, MKDEV(major, data->minor));
+	device_destroy(doom_class, data->device->devt);
+	cdev_del(data->cdev);
 	kfree(data);
 }
 
@@ -87,6 +96,8 @@ int char_init(void)
 		goto error_create;
 	}
 
+	return 0;
+
 error_create:
 	unregister_chrdev_region(first, DOOMDEV_COUNT);
 error_region:
@@ -97,4 +108,5 @@ void char_cleanup(void)
 {
 	unregister_chrdev_region(first, DOOMDEV_COUNT);
 	class_unregister(doom_class);
+	class_destroy(doom_class);
 }
diff --git a/pci.h b/pci.h
index 04c48f2..9e8d07f 100644
--- a/pci.h
+++ b/pci.h
@@ -1,8 +1,11 @@
 #ifndef PCI_H
 #define PCI_H
 
+#include <linux/device.h>
+
 struct doom_data {
-	int minor;
+	struct cdev *cdev;
+	struct device *device;
 };
 
 int pci_init(void);