1 files changed, 25 insertions, 85 deletions

diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
index 6a4c40766f0f..a88ced93b5e7 100644
--- a/drivers/usb/core/file.c
+++ b/drivers/usb/core/file.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * drivers/usb/core/file.c
  *
@@ -8,17 +9,19 @@
  * (C) Copyright Deti Fliegl 1999 (new USB architecture)
  * (C) Copyright Randy Dunlap 2000
  * (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id,
- 	more docs, etc)
+ *	more docs, etc)
  * (C) Copyright Yggdrasil Computing, Inc. 2000
  *     (usb_device_id matching changes by Adam J. Richter)
  * (C) Copyright Greg Kroah-Hartman 2002-2003
  *
+ * Released under the GPLv2 only.
  */
 
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/rwsem.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/usb.h>
 
 #include "usb.h"
@@ -27,29 +30,21 @@
 static const struct file_operations *usb_minors[MAX_USB_MINORS];
 static DECLARE_RWSEM(minor_rwsem);
 
-static int usb_open(struct inode * inode, struct file * file)
+static int usb_open(struct inode *inode, struct file *file)
 {
-	int minor = iminor(inode);
-	const struct file_operations *c;
 	int err = -ENODEV;
-	const struct file_operations *old_fops, *new_fops = NULL;
+	const struct file_operations *new_fops;
 
 	down_read(&minor_rwsem);
-	c = usb_minors[minor];
+	new_fops = fops_get(usb_minors[iminor(inode)]);
 
-	if (!c || !(new_fops = fops_get(c)))
+	if (!new_fops)
 		goto done;
 
-	old_fops = file->f_op;
-	file->f_op = new_fops;
+	replace_fops(file, new_fops);
 	/* Curiouser and curiouser... NULL ->open() as "no device" ? */
 	if (file->f_op->open)
-		err = file->f_op->open(inode,file);
-	if (err) {
-		fops_put(file->f_op);
-		file->f_op = fops_get(old_fops);
-	}
-	fops_put(old_fops);
+		err = file->f_op->open(inode, file);
  done:
 	up_read(&minor_rwsem);
 	return err;
@@ -61,12 +56,7 @@ static const struct file_operations usb_fops = {
 	.llseek =	noop_llseek,
 };
 
-static struct usb_class {
-	struct kref kref;
-	struct class *class;
-} *usb_class;
-
-static char *usb_devnode(struct device *dev, umode_t *mode)
+static char *usb_devnode(const struct device *dev, umode_t *mode)
 {
 	struct usb_class_driver *drv;
 
@@ -76,49 +66,10 @@ static char *usb_devnode(struct device *dev, umode_t *mode)
 	return drv->devnode(dev, mode);
 }
 
-static int init_usb_class(void)
-{
-	int result = 0;
-
-	if (usb_class != NULL) {
-		kref_get(&usb_class->kref);
-		goto exit;
-	}
-
-	usb_class = kmalloc(sizeof(*usb_class), GFP_KERNEL);
-	if (!usb_class) {
-		result = -ENOMEM;
-		goto exit;
-	}
-
-	kref_init(&usb_class->kref);
-	usb_class->class = class_create(THIS_MODULE, "usbmisc");
-	if (IS_ERR(usb_class->class)) {
-		result = PTR_ERR(usb_class->class);
-		printk(KERN_ERR "class_create failed for usb devices\n");
-		kfree(usb_class);
-		usb_class = NULL;
-		goto exit;
-	}
-	usb_class->class->devnode = usb_devnode;
-
-exit:
-	return result;
-}
-
-static void release_usb_class(struct kref *kref)
-{
-	/* Ok, we cheat as we know we only have one usb_class */
-	class_destroy(usb_class->class);
-	kfree(usb_class);
-	usb_class = NULL;
-}
-
-static void destroy_usb_class(void)
-{
-	if (usb_class)
-		kref_put(&usb_class->kref, release_usb_class);
-}
+const struct class usbmisc_class = {
+	.name		= "usbmisc",
+	.devnode	= usb_devnode,
+};
 
 int usb_major_init(void)
 {
@@ -153,20 +104,19 @@ void usb_major_cleanup(void)
  * usb_deregister_dev() must be called when the driver is done with
  * the minor numbers given out by this function.
  *
- * Returns -EINVAL if something bad happens with trying to register a
+ * Return: -EINVAL if something bad happens with trying to register a
  * device, and 0 on success.
  */
 int usb_register_dev(struct usb_interface *intf,
 		     struct usb_class_driver *class_driver)
 {
-	int retval;
+	int retval = 0;
 	int minor_base = class_driver->minor_base;
 	int minor;
 	char name[20];
-	char *temp;
 
 #ifdef CONFIG_USB_DYNAMIC_MINORS
-	/* 
+	/*
 	 * We don't care what the device tries to start at, we want to start
 	 * at zero to pack the devices into the smallest available space with
 	 * no holes in the minor range.
@@ -179,10 +129,6 @@ int usb_register_dev(struct usb_interface *intf,
 	if (intf->minor >= 0)
 		return -EADDRINUSE;
 
-	retval = init_usb_class();
-	if (retval)
-		return retval;
-
 	dev_dbg(&intf->dev, "looking for a minor, starting at %d\n", minor_base);
 
 	down_write(&minor_rwsem);
@@ -194,27 +140,22 @@ int usb_register_dev(struct usb_interface *intf,
 		intf->minor = minor;
 		break;
 	}
-	up_write(&minor_rwsem);
-	if (intf->minor < 0)
+	if (intf->minor < 0) {
+		up_write(&minor_rwsem);
 		return -EXFULL;
+	}
 
 	/* create a usb class device for this usb interface */
 	snprintf(name, sizeof(name), class_driver->name, minor - minor_base);
-	temp = strrchr(name, '/');
-	if (temp && (temp[1] != '\0'))
-		++temp;
-	else
-		temp = name;
-	intf->usb_dev = device_create(usb_class->class, &intf->dev,
+	intf->usb_dev = device_create(&usbmisc_class, &intf->dev,
 				      MKDEV(USB_MAJOR, minor), class_driver,
-				      "%s", temp);
+				      "%s", kbasename(name));
 	if (IS_ERR(intf->usb_dev)) {
-		down_write(&minor_rwsem);
 		usb_minors[minor] = NULL;
 		intf->minor = -1;
-		up_write(&minor_rwsem);
 		retval = PTR_ERR(intf->usb_dev);
 	}
+	up_write(&minor_rwsem);
 	return retval;
 }
 EXPORT_SYMBOL_GPL(usb_register_dev);
@@ -240,14 +181,13 @@ void usb_deregister_dev(struct usb_interface *intf,
 		return;
 
 	dev_dbg(&intf->dev, "removing %d minor\n", intf->minor);
+	device_destroy(&usbmisc_class, MKDEV(USB_MAJOR, intf->minor));
 
 	down_write(&minor_rwsem);
 	usb_minors[intf->minor] = NULL;
 	up_write(&minor_rwsem);
 
-	device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor));
 	intf->usb_dev = NULL;
 	intf->minor = -1;
-	destroy_usb_class();
 }
 EXPORT_SYMBOL_GPL(usb_deregister_dev);