From ebc05ba7e8600b52a2a0c87a43105143368aca2a Mon Sep 17 00:00:00 2001 From: Sainath Grandhi Date: Fri, 10 Feb 2017 16:03:48 -0800 Subject: tap: Tap character device creation/destroy API This patch provides tap device create/destroy APIs in tap.c. Signed-off-by: Sainath Grandhi Signed-off-by: David S. Miller --- drivers/net/macvtap_main.c | 30 +++++++--------------- drivers/net/tap.c | 62 ++++++++++++++++++++++++++++++++++++++-------- include/linux/if_tap.h | 3 +++ 3 files changed, 63 insertions(+), 32 deletions(-) diff --git a/drivers/net/macvtap_main.c b/drivers/net/macvtap_main.c index 548f339a75bd..215ab7abae89 100644 --- a/drivers/net/macvtap_main.c +++ b/drivers/net/macvtap_main.c @@ -28,7 +28,6 @@ * Variables for dealing with macvtaps device numbers. */ static dev_t macvtap_major; -#define MACVTAP_NUM_DEVS (1U << MINORBITS) static const void *macvtap_net_namespace(struct device *d) { @@ -159,57 +158,46 @@ static struct notifier_block macvtap_notifier_block __read_mostly = { .notifier_call = macvtap_device_event, }; -extern struct file_operations tap_fops; static int macvtap_init(void) { int err; - err = alloc_chrdev_region(&macvtap_major, 0, - MACVTAP_NUM_DEVS, "macvtap"); - if (err) - goto out1; + err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap"); - cdev_init(&macvtap_cdev, &tap_fops); - err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS); if (err) - goto out2; + goto out1; err = class_register(&macvtap_class); if (err) - goto out3; + goto out2; err = register_netdevice_notifier(&macvtap_notifier_block); if (err) - goto out4; + goto out3; err = macvlan_link_register(&macvtap_link_ops); if (err) - goto out5; + goto out4; return 0; -out5: - unregister_netdevice_notifier(&macvtap_notifier_block); out4: - class_unregister(&macvtap_class); + unregister_netdevice_notifier(&macvtap_notifier_block); out3: - cdev_del(&macvtap_cdev); + class_unregister(&macvtap_class); out2: - unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); + tap_destroy_cdev(macvtap_major, &macvtap_cdev); out1: return err; } module_init(macvtap_init); -extern struct idr minor_idr; static void macvtap_exit(void) { rtnl_link_unregister(&macvtap_link_ops); unregister_netdevice_notifier(&macvtap_notifier_block); class_unregister(&macvtap_class); - cdev_del(&macvtap_cdev); - unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); - idr_destroy(&minor_idr); + tap_destroy_cdev(macvtap_major, &macvtap_cdev); } module_exit(macvtap_exit); diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 15ca2d531d05..04ba9782c2f3 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -123,8 +123,12 @@ static struct proto tap_proto = { }; #define TAP_NUM_DEVS (1U << MINORBITS) -static DEFINE_MUTEX(minor_lock); -DEFINE_IDR(minor_idr); +struct major_info { + dev_t major; + struct idr minor_idr; + struct mutex minor_lock; + const char *device_name; +} macvtap_major; #define GOODCOPY_LEN 128 @@ -413,26 +417,26 @@ int tap_get_minor(struct macvlan_dev *vlan) { int retval = -ENOMEM; - mutex_lock(&minor_lock); - retval = idr_alloc(&minor_idr, vlan, 1, TAP_NUM_DEVS, GFP_KERNEL); + mutex_lock(&macvtap_major.minor_lock); + retval = idr_alloc(&macvtap_major.minor_idr, vlan, 1, TAP_NUM_DEVS, GFP_KERNEL); if (retval >= 0) { vlan->minor = retval; } else if (retval == -ENOSPC) { netdev_err(vlan->dev, "Too many tap devices\n"); retval = -EINVAL; } - mutex_unlock(&minor_lock); + mutex_unlock(&macvtap_major.minor_lock); return retval < 0 ? retval : 0; } void tap_free_minor(struct macvlan_dev *vlan) { - mutex_lock(&minor_lock); + mutex_lock(&macvtap_major.minor_lock); if (vlan->minor) { - idr_remove(&minor_idr, vlan->minor); + idr_remove(&macvtap_major.minor_idr, vlan->minor); vlan->minor = 0; } - mutex_unlock(&minor_lock); + mutex_unlock(&macvtap_major.minor_lock); } static struct net_device *dev_get_by_tap_minor(int minor) @@ -440,13 +444,13 @@ static struct net_device *dev_get_by_tap_minor(int minor) struct net_device *dev = NULL; struct macvlan_dev *vlan; - mutex_lock(&minor_lock); - vlan = idr_find(&minor_idr, minor); + mutex_lock(&macvtap_major.minor_lock); + vlan = idr_find(&macvtap_major.minor_idr, minor); if (vlan) { dev = vlan->dev; dev_hold(dev); } - mutex_unlock(&minor_lock); + mutex_unlock(&macvtap_major.minor_lock); return dev; } @@ -1184,3 +1188,39 @@ int tap_queue_resize(struct macvlan_dev *vlan) kfree(arrays); return ret; } + +int tap_create_cdev(struct cdev *tap_cdev, + dev_t *tap_major, const char *device_name) +{ + int err; + + err = alloc_chrdev_region(tap_major, 0, TAP_NUM_DEVS, device_name); + if (err) + goto out1; + + cdev_init(tap_cdev, &tap_fops); + err = cdev_add(tap_cdev, *tap_major, TAP_NUM_DEVS); + if (err) + goto out2; + + macvtap_major.major = MAJOR(*tap_major); + + idr_init(&macvtap_major.minor_idr); + mutex_init(&macvtap_major.minor_lock); + + macvtap_major.device_name = device_name; + + return 0; + +out2: + unregister_chrdev_region(*tap_major, TAP_NUM_DEVS); +out1: + return err; +} + +void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev) +{ + cdev_del(tap_cdev); + unregister_chrdev_region(major, TAP_NUM_DEVS); + idr_destroy(&macvtap_major.minor_idr); +} diff --git a/include/linux/if_tap.h b/include/linux/if_tap.h index 97d27b8ebd55..a2dfd9063a6c 100644 --- a/include/linux/if_tap.h +++ b/include/linux/if_tap.h @@ -19,5 +19,8 @@ void tap_del_queues(struct net_device *dev); int tap_get_minor(struct macvlan_dev *vlan); void tap_free_minor(struct macvlan_dev *vlan); int tap_queue_resize(struct macvlan_dev *vlan); +int tap_create_cdev(struct cdev *tap_cdev, + dev_t *tap_major, const char *device_name); +void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev); #endif /*_LINUX_IF_TAP_H_*/ -- cgit