From kay.sievers@vrfy.org Sat Jul 30 16:08:53 2005 Date: Sun, 31 Jul 2005 01:05:53 +0200 From: Kay Sievers To: Greg KH Subject: USB: real nodes instead of usbfs Message-ID: <20050730230553.GA26176@vrfy.org> This patch introduces a /sys/class/usb_device/ class where every connected usb-device will show up: tree /sys/class/usb_device/ /sys/class/usb_device/ |-- usb1.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1 |-- usb2.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2 ... The presence of the "dev" file lets udev create real device nodes. kay@pim:~/src/linux-2.6> tree /dev/bus/usb/ /dev/bus/usb/ |-- 1 | `-- 1 |-- 2 | `-- 1 ... udev rule: SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c" (echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/') This makes libusb pick up the real nodes instead of the mounted usbfs: export USB_DEVFS_PATH=/dev/bus/usb Background: All this makes it possible to manage usb devices with udev instead of the devfs solution. We are currently working on a pam_console/resmgr replacement driven by udev and a pam-helper. It applies ACL's to device nodes, which is required for modern desktop functionalty like "Fast User Switching" or multiple local login support. New patch with its own major. I've succesfully disabled usbfs and use real nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks up the udev managed nodes instead of reading usbfs files. This makes udev to provide symlinks for libusb to pick up: SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c" /sbin/usbdevice: #!/bin/sh echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/' Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/Makefile | 4 +- drivers/usb/core/devio.c | 91 ++++++++++++++++++++++++++++++++++++++++++++-- drivers/usb/core/hub.c | 2 + drivers/usb/core/inode.c | 9 ---- drivers/usb/core/usb.c | 15 ++++++- drivers/usb/core/usb.h | 5 ++ include/linux/usb.h | 2 + 7 files changed, 114 insertions(+), 14 deletions(-) --- gregkh-2.6.orig/drivers/usb/core/Makefile 2005-08-08 16:47:38.000000000 -0700 +++ gregkh-2.6/drivers/usb/core/Makefile 2005-08-08 16:47:39.000000000 -0700 @@ -3,14 +3,14 @@ # usbcore-objs := usb.o hub.o hcd.o urb.o message.o \ - config.o file.o buffer.o sysfs.o + config.o file.o buffer.o sysfs.o devio.o ifeq ($(CONFIG_PCI),y) usbcore-objs += hcd-pci.o endif ifeq ($(CONFIG_USB_DEVICEFS),y) - usbcore-objs += devio.o inode.o devices.o + usbcore-objs += inode.o devices.o endif obj-$(CONFIG_USB) += usbcore.o --- gregkh-2.6.orig/drivers/usb/core/devio.c 2005-08-08 16:47:38.000000000 -0700 +++ gregkh-2.6/drivers/usb/core/devio.c 2005-08-08 16:47:39.000000000 -0700 @@ -43,6 +43,7 @@ #include #include #include +#include #include #include #include @@ -50,6 +51,10 @@ #include "hcd.h" /* for usbcore internals */ #include "usb.h" +#define USB_MAXBUS 64 +#define USB_DEVICE_MAX USB_MAXBUS * 128 +static struct class *usb_device_class; + struct async { struct list_head asynclist; struct dev_state *ps; @@ -487,7 +492,7 @@ */ static int usbdev_open(struct inode *inode, struct file *file) { - struct usb_device *dev; + struct usb_device *dev = NULL; struct dev_state *ps; int ret; @@ -501,11 +506,16 @@ lock_kernel(); ret = -ENOENT; - dev = usb_get_dev(inode->u.generic_ip); + /* check if we are called from a real node or usbfs */ + if (imajor(inode) == USB_DEVICE_MAJOR) + dev = usbdev_lookup_minor(iminor(inode)); + if (!dev) + dev = inode->u.generic_ip; if (!dev) { kfree(ps); goto out; } + usb_get_dev(dev); ret = 0; ps->dev = dev; ps->file = file; @@ -1477,3 +1487,80 @@ .open = usbdev_open, .release = usbdev_release, }; + +struct usb_device *usbdev_lookup_minor(int minor) +{ + struct class_device *class_dev; + struct usb_device *dev = NULL; + + down(&usb_device_class->sem); + list_for_each_entry(class_dev, &usb_device_class->children, node) { + if (class_dev->devt == MKDEV(USB_DEVICE_MAJOR, minor)) { + dev = class_dev->class_data; + break; + } + } + up(&usb_device_class->sem); + + return dev; +}; + +void usbdev_add(struct usb_device *dev) +{ + int minor = ((dev->bus->busnum-1) * 128) + (dev->devnum-1); + + dev->class_dev = class_device_create(usb_device_class, + MKDEV(USB_DEVICE_MAJOR, minor), &dev->dev, + "usbdev%d.%d", dev->bus->busnum, dev->devnum); + + dev->class_dev->class_data = dev; +} + +void usbdev_remove(struct usb_device *dev) +{ + class_device_unregister(dev->class_dev); +} + +static struct cdev usb_device_cdev = { + .kobj = {.name = "usb_device", }, + .owner = THIS_MODULE, +}; + +int __init usbdev_init(void) +{ + int retval; + + retval = register_chrdev_region(MKDEV(USB_DEVICE_MAJOR, 0), + USB_DEVICE_MAX, "usb_device"); + if (retval) { + err("unable to register minors for usb_device"); + goto out; + } + cdev_init(&usb_device_cdev, &usbfs_device_file_operations); + retval = cdev_add(&usb_device_cdev, + MKDEV(USB_DEVICE_MAJOR, 0), USB_DEVICE_MAX); + if (retval) { + err("unable to get usb_device major %d", USB_DEVICE_MAJOR); + unregister_chrdev_region(USB_DEVICE_MAJOR, USB_DEVICE_MAX); + goto out; + } + usb_device_class = class_create(THIS_MODULE, "usb_device"); + if (IS_ERR(usb_device_class)) { + err("unable to register usb_device class"); + retval = PTR_ERR(usb_device_class); + usb_device_class = NULL; + cdev_del(&usb_device_cdev); + unregister_chrdev_region(USB_DEVICE_MAJOR, USB_DEVICE_MAX); + } + +out: + return retval; +} + +void usbdev_cleanup(void) +{ + class_destroy(usb_device_class); + cdev_del(&usb_device_cdev); + unregister_chrdev_region(USB_DEVICE_MAJOR, USB_DEVICE_MAX); +} + --- gregkh-2.6.orig/drivers/usb/core/hub.c 2005-08-08 16:47:38.000000000 -0700 +++ gregkh-2.6/drivers/usb/core/hub.c 2005-08-08 16:47:39.000000000 -0700 @@ -1051,6 +1051,7 @@ dev_dbg (&udev->dev, "unregistering device\n"); release_address(udev); usbfs_remove_device(udev); + usbdev_remove(udev); usb_remove_sysfs_dev_files(udev); /* Avoid races with recursively_mark_NOTATTACHED() */ @@ -1290,6 +1291,7 @@ /* USB device state == configured ... usable */ /* add a /proc/bus/usb entry */ + usbdev_add(udev); usbfs_add_device(udev); return 0; --- gregkh-2.6.orig/drivers/usb/core/inode.c 2005-08-08 16:47:38.000000000 -0700 +++ gregkh-2.6/drivers/usb/core/inode.c 2005-08-08 16:47:39.000000000 -0700 @@ -728,15 +728,9 @@ { int retval; - retval = usb_register(&usbfs_driver); - if (retval) - return retval; - retval = register_filesystem(&usb_fs_type); - if (retval) { - usb_deregister(&usbfs_driver); + if (retval) return retval; - } /* create mount point for usbfs */ usbdir = proc_mkdir("usb", proc_bus); @@ -746,7 +740,6 @@ void usbfs_cleanup(void) { - usb_deregister(&usbfs_driver); unregister_filesystem(&usb_fs_type); if (usbdir) remove_proc_entry("usb", proc_bus); --- gregkh-2.6.orig/drivers/usb/core/usb.c 2005-08-08 16:47:38.000000000 -0700 +++ gregkh-2.6/drivers/usb/core/usb.c 2005-08-08 16:47:39.000000000 -0700 @@ -1478,13 +1478,18 @@ retval = usb_major_init(); if (retval) goto major_init_failed; + retval = usb_register(&usbfs_driver); + if (retval) + goto driver_register_failed; + retval = usbdev_init(); + if (retval) + goto usbdevice_init_failed; retval = usbfs_init(); if (retval) goto fs_init_failed; retval = usb_hub_init(); if (retval) goto hub_init_failed; - retval = driver_register(&usb_generic_driver); if (!retval) goto out; @@ -1493,7 +1498,11 @@ hub_init_failed: usbfs_cleanup(); fs_init_failed: - usb_major_cleanup(); + usbdev_cleanup(); +usbdevice_init_failed: + usb_deregister(&usbfs_driver); +driver_register_failed: + usb_major_cleanup(); major_init_failed: usb_host_cleanup(); host_init_failed: @@ -1514,6 +1523,8 @@ driver_unregister(&usb_generic_driver); usb_major_cleanup(); usbfs_cleanup(); + usb_deregister(&usbfs_driver); + usbdev_cleanup(); usb_hub_cleanup(); usb_host_cleanup(); bus_unregister(&usb_bus_type); --- gregkh-2.6.orig/drivers/usb/core/usb.h 2005-08-08 16:47:38.000000000 -0700 +++ gregkh-2.6/drivers/usb/core/usb.h 2005-08-08 16:47:39.000000000 -0700 @@ -37,6 +37,11 @@ extern struct file_operations usbfs_device_file_operations; extern void usbfs_conn_disc_event(void); +extern int usbdev_init(void); +extern void usbdev_cleanup(void); +extern void usbdev_add(struct usb_device *dev); +extern void usbdev_remove(struct usb_device *dev); +extern struct usb_device *usbdev_lookup_minor(int minor); struct dev_state { struct list_head list; /* state list */ --- gregkh-2.6.orig/include/linux/usb.h 2005-08-08 16:47:38.000000000 -0700 +++ gregkh-2.6/include/linux/usb.h 2005-08-08 16:47:39.000000000 -0700 @@ -5,6 +5,7 @@ #include #define USB_MAJOR 180 +#define USB_DEVICE_MAJOR 189 #ifdef __KERNEL__ @@ -349,6 +350,7 @@ char *manufacturer; char *serial; /* static strings from the device */ struct list_head filelist; + struct class_device *class_dev; struct dentry *usbfs_dentry; /* usbfs dentry entry for the device */ /*