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sysdev: Do not register with sysdev when erroring on add 

When encountering an error while executing the driver's ->add method, we
should cancel registration and unwind what we've regged so far. The low
level ->add methods do return proper error codes but those aren't looked
at in sysdev_driver_register(). Fix that by sharing the unregistering
code.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Borislav Petkov 2011-02-01 17:19:56 +01:00 committed by Greg Kroah-Hartman
parent 1f7da214e2
commit f4203e3032
1 changed files with 44 additions and 17 deletions
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61
drivers/base/sys.c
View File

@ -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