From 64bf69ddff7637b7ed7acf9b2a823cc0ee519439 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Tue, 29 Nov 2005 16:16:41 -0800 Subject: [PATCH] [ATM]: deregistration removes device from atm_devs list immediately atm_dev_deregister() removes device from atm_dev list immediately to prevent operations on a phantom device. Decision to free device based only on ->refcnt now. Remove shutdown_atm_dev() use atm_dev_deregister() instead. atm_dev_deregister() also asynchronously releases all vccs related to device. Signed-off-by: Stanislaw Gruszka Signed-off-by: Chas Williams Signed-off-by: David S. Miller --- drivers/atm/atmtcp.c | 20 ++------------------ drivers/usb/atm/usbatm.c | 4 ++-- include/linux/atmdev.h | 14 +++++++------- net/atm/common.c | 30 +++++++++++++++++++++++++++--- net/atm/common.h | 2 ++ net/atm/resources.c | 39 ++++++++++++--------------------------- 6 files changed, 52 insertions(+), 57 deletions(-) diff --git a/drivers/atm/atmtcp.c b/drivers/atm/atmtcp.c index 57f1810fdccd..fc518d85543d 100644 --- a/drivers/atm/atmtcp.c +++ b/drivers/atm/atmtcp.c @@ -246,10 +246,6 @@ static void atmtcp_c_close(struct atm_vcc *vcc) { struct atm_dev *atmtcp_dev; struct atmtcp_dev_data *dev_data; - struct sock *s; - struct hlist_node *node; - struct atm_vcc *walk; - int i; atmtcp_dev = (struct atm_dev *) vcc->dev_data; dev_data = PRIV(atmtcp_dev); @@ -257,20 +253,8 @@ static void atmtcp_c_close(struct atm_vcc *vcc) if (dev_data->persist) return; atmtcp_dev->dev_data = NULL; kfree(dev_data); - shutdown_atm_dev(atmtcp_dev); + atm_dev_deregister(atmtcp_dev); vcc->dev_data = NULL; - read_lock(&vcc_sklist_lock); - for(i = 0; i < VCC_HTABLE_SIZE; ++i) { - struct hlist_head *head = &vcc_hash[i]; - - sk_for_each(s, node, head) { - walk = atm_sk(s); - if (walk->dev != atmtcp_dev) - continue; - wake_up(s->sk_sleep); - } - } - read_unlock(&vcc_sklist_lock); module_put(THIS_MODULE); } @@ -450,7 +434,7 @@ static int atmtcp_remove_persistent(int itf) if (PRIV(dev)->vcc) return 0; kfree(dev_data); atm_dev_put(dev); - shutdown_atm_dev(dev); + atm_dev_deregister(dev); return 0; } diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c index c466739428b2..2e6593e6c1bd 100644 --- a/drivers/usb/atm/usbatm.c +++ b/drivers/usb/atm/usbatm.c @@ -879,7 +879,7 @@ static int usbatm_atm_init(struct usbatm_data *instance) fail: instance->atm_dev = NULL; - shutdown_atm_dev(atm_dev); /* usbatm_atm_dev_close will eventually be called */ + atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */ return ret; } @@ -1164,7 +1164,7 @@ void usbatm_usb_disconnect(struct usb_interface *intf) /* ATM finalize */ if (instance->atm_dev) - shutdown_atm_dev(instance->atm_dev); + atm_dev_deregister(instance->atm_dev); usbatm_put_instance(instance); /* taken in usbatm_usb_probe */ } diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h index 8fadb073c834..b203ea82a0a8 100644 --- a/include/linux/atmdev.h +++ b/include/linux/atmdev.h @@ -274,7 +274,7 @@ enum { enum { - ATM_DF_CLOSE, /* close device when last VCC is closed */ + ATM_DF_REMOVED, /* device was removed from atm_devs list */ }; @@ -415,7 +415,6 @@ struct atm_dev *atm_dev_register(const char *type,const struct atmdev_ops *ops, int number,unsigned long *flags); /* number == -1: pick first available */ struct atm_dev *atm_dev_lookup(int number); void atm_dev_deregister(struct atm_dev *dev); -void shutdown_atm_dev(struct atm_dev *dev); void vcc_insert_socket(struct sock *sk); @@ -457,11 +456,12 @@ static inline void atm_dev_hold(struct atm_dev *dev) static inline void atm_dev_put(struct atm_dev *dev) { - atomic_dec(&dev->refcnt); - - if ((atomic_read(&dev->refcnt) == 1) && - test_bit(ATM_DF_CLOSE,&dev->flags)) - shutdown_atm_dev(dev); + if (atomic_dec_and_test(&dev->refcnt)) { + BUG_ON(!test_bit(ATM_DF_REMOVED, &dev->flags)); + if (dev->ops->dev_close) + dev->ops->dev_close(dev); + kfree(dev); + } } diff --git a/net/atm/common.c b/net/atm/common.c index 9e016f404e14..6656b111cc05 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -221,6 +221,29 @@ void vcc_release_async(struct atm_vcc *vcc, int reply) EXPORT_SYMBOL(vcc_release_async); +void atm_dev_release_vccs(struct atm_dev *dev) +{ + int i; + + write_lock_irq(&vcc_sklist_lock); + for (i = 0; i < VCC_HTABLE_SIZE; i++) { + struct hlist_head *head = &vcc_hash[i]; + struct hlist_node *node, *tmp; + struct sock *s; + struct atm_vcc *vcc; + + sk_for_each_safe(s, node, tmp, head) { + vcc = atm_sk(s); + if (vcc->dev == dev) { + vcc_release_async(vcc, -EPIPE); + sk_del_node_init(s); + } + } + } + write_unlock_irq(&vcc_sklist_lock); +} + + static int adjust_tp(struct atm_trafprm *tp,unsigned char aal) { int max_sdu; @@ -332,12 +355,13 @@ static int __vcc_connect(struct atm_vcc *vcc, struct atm_dev *dev, short vpi, return -EINVAL; if (vci > 0 && vci < ATM_NOT_RSV_VCI && !capable(CAP_NET_BIND_SERVICE)) return -EPERM; - error = 0; + error = -ENODEV; if (!try_module_get(dev->ops->owner)) - return -ENODEV; + return error; vcc->dev = dev; write_lock_irq(&vcc_sklist_lock); - if ((error = find_ci(vcc, &vpi, &vci))) { + if (test_bit(ATM_DF_REMOVED, &dev->flags) || + (error = find_ci(vcc, &vpi, &vci))) { write_unlock_irq(&vcc_sklist_lock); goto fail_module_put; } diff --git a/net/atm/common.h b/net/atm/common.h index e49ed41c0e33..4887c317cefe 100644 --- a/net/atm/common.h +++ b/net/atm/common.h @@ -47,4 +47,6 @@ static inline void atm_proc_exit(void) /* SVC */ int svc_change_qos(struct atm_vcc *vcc,struct atm_qos *qos); +void atm_dev_release_vccs(struct atm_dev *dev); + #endif diff --git a/net/atm/resources.c b/net/atm/resources.c index ad533b02b84f..c8c459fcb038 100644 --- a/net/atm/resources.c +++ b/net/atm/resources.c @@ -70,6 +70,7 @@ struct atm_dev *atm_dev_lookup(int number) return dev; } + struct atm_dev *atm_dev_register(const char *type, const struct atmdev_ops *ops, int number, unsigned long *flags) { @@ -123,37 +124,22 @@ struct atm_dev *atm_dev_register(const char *type, const struct atmdev_ops *ops, void atm_dev_deregister(struct atm_dev *dev) { - unsigned long warning_time; - - atm_proc_dev_deregister(dev); - + BUG_ON(test_bit(ATM_DF_REMOVED, &dev->flags)); + set_bit(ATM_DF_REMOVED, &dev->flags); + + /* + * if we remove current device from atm_devs list, new device + * with same number can appear, such we need deregister proc, + * release async all vccs and remove them from vccs list too + */ down(&atm_dev_mutex); list_del(&dev->dev_list); up(&atm_dev_mutex); - warning_time = jiffies; - while (atomic_read(&dev->refcnt) != 1) { - msleep(250); - if ((jiffies - warning_time) > 10 * HZ) { - printk(KERN_EMERG "atm_dev_deregister: waiting for " - "dev %d to become free. Usage count = %d\n", - dev->number, atomic_read(&dev->refcnt)); - warning_time = jiffies; - } - } - - kfree(dev); -} + atm_dev_release_vccs(dev); + atm_proc_dev_deregister(dev); -void shutdown_atm_dev(struct atm_dev *dev) -{ - if (atomic_read(&dev->refcnt) > 1) { - set_bit(ATM_DF_CLOSE, &dev->flags); - return; - } - if (dev->ops->dev_close) - dev->ops->dev_close(dev); - atm_dev_deregister(dev); + atm_dev_put(dev); } @@ -433,4 +419,3 @@ void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos) EXPORT_SYMBOL(atm_dev_register); EXPORT_SYMBOL(atm_dev_deregister); EXPORT_SYMBOL(atm_dev_lookup); -EXPORT_SYMBOL(shutdown_atm_dev); -- 2.20.1