diff options
| -rw-r--r-- | drivers/base/sys.c | 61 |
1 files changed, 44 insertions, 17 deletions
diff --git a/drivers/base/sys.c b/drivers/base/sys.c index b094e0d6139f..f6fb54741602 100644 --- a/drivers/base/sys.c +++ b/drivers/base/sys.c @@ -166,6 +166,36 @@ EXPORT_SYMBOL_GPL(sysdev_class_unregister); static DEFINE_MUTEX(sysdev_drivers_lock); +/* + * @dev != NULL means that we're unwinding because some drv->add() + * failed for some reason. You need to grab sysdev_drivers_lock before + * calling this. + */ +static void __sysdev_driver_remove(struct sysdev_class *cls, + struct sysdev_driver *drv, + struct sys_device *from_dev) +{ + struct sys_device *dev = from_dev; + + list_del_init(&drv->entry); + if (!cls) + return; + + if (!drv->remove) + goto kset_put; + + if (dev) + list_for_each_entry_continue_reverse(dev, &cls->kset.list, + kobj.entry) + drv->remove(dev); + else + list_for_each_entry(dev, &cls->kset.list, kobj.entry) + drv->remove(dev); + +kset_put: + kset_put(&cls->kset); +} + /** * sysdev_driver_register - Register auxillary driver * @cls: Device class driver belongs to. @@ -175,9 +205,9 @@ static DEFINE_MUTEX(sysdev_drivers_lock); * called on each operation on devices of that class. The refcount * of @cls is incremented. */ - int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv) { + struct sys_device *dev = NULL; int err = 0; if (!cls) { @@ -198,19 +228,27 @@ int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv) /* If devices of this class already exist, tell the driver */ if (drv->add) { - struct sys_device *dev; - list_for_each_entry(dev, &cls->kset.list, kobj.entry) - drv->add(dev); + list_for_each_entry(dev, &cls->kset.list, kobj.entry) { + err = drv->add(dev); + if (err) + goto unwind; + } } } else { err = -EINVAL; WARN(1, KERN_ERR "%s: invalid device class\n", __func__); } + + goto unlock; + +unwind: + __sysdev_driver_remove(cls, drv, dev); + +unlock: mutex_unlock(&sysdev_drivers_lock); return err; } - /** * sysdev_driver_unregister - Remove an auxillary driver. * @cls: Class driver belongs to. @@ -220,23 +258,12 @@ void sysdev_driver_unregister(struct sysdev_class *cls, struct sysdev_driver *drv) { mutex_lock(&sysdev_drivers_lock); - list_del_init(&drv->entry); - if (cls) { - if (drv->remove) { - struct sys_device *dev; - list_for_each_entry(dev, &cls->kset.list, kobj.entry) - drv->remove(dev); - } - kset_put(&cls->kset); - } + __sysdev_driver_remove(cls, drv, NULL); mutex_unlock(&sysdev_drivers_lock); } - EXPORT_SYMBOL_GPL(sysdev_driver_register); EXPORT_SYMBOL_GPL(sysdev_driver_unregister); - - /** * sysdev_register - add a system device to the tree * @sysdev: device in question |