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driver core: remove fields from struct bus_type
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struct bus_type is static everywhere in the kernel.  This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure.  This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.

Thanks to Kay for the build fixes on this patch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Greg Kroah-Hartman committed Jan 25, 2008
1 parent b249072 commit c6f7e72
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Showing 7 changed files with 104 additions and 70 deletions.
30 changes: 29 additions & 1 deletion drivers/base/base.h
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,34 @@

/* initialisation functions */
/**
* struct bus_type_private - structure to hold the private to the driver core portions of the bus_type structure.
*
* @subsys - the struct kset that defines this bus. This is the main kobject
* @drivers_kset - the list of drivers associated with this bus
* @devices_kset - the list of devices associated with this bus
* @klist_devices - the klist to iterate over the @devices_kset
* @klist_drivers - the klist to iterate over the @drivers_kset
* @bus_notifier - the bus notifier list for anything that cares about things
* on this bus.
* @bus - pointer back to the struct bus_type that this structure is associated
* with.
*
* This structure is the one that is the actual kobject allowing struct
* bus_type to be statically allocated safely. Nothing outside of the driver
* core should ever touch these fields.
*/
struct bus_type_private {
struct kset subsys;
struct kset *drivers_kset;
struct kset *devices_kset;
struct klist klist_devices;
struct klist klist_drivers;
struct blocking_notifier_head bus_notifier;
unsigned int drivers_autoprobe:1;
struct bus_type *bus;
};


/* initialisation functions */
extern int devices_init(void);
extern int buses_init(void);
extern int classes_init(void);
Expand Down
116 changes: 65 additions & 51 deletions drivers/base/bus.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,7 @@
#include "power/power.h"

#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
#define to_bus(obj) container_of(obj, struct bus_type, subsys.kobj)
#define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj)

/*
* sysfs bindings for drivers
Expand All @@ -32,13 +32,17 @@ static int __must_check bus_rescan_devices_helper(struct device *dev,

static struct bus_type *bus_get(struct bus_type *bus)
{
return bus ? container_of(kset_get(&bus->subsys),
struct bus_type, subsys) : NULL;
if (bus) {
kset_get(&bus->p->subsys);
return bus;
}
return NULL;
}

static void bus_put(struct bus_type *bus)
{
kset_put(&bus->subsys);
if (bus)
kset_put(&bus->p->subsys);
}

static ssize_t
Expand Down Expand Up @@ -104,11 +108,11 @@ static ssize_t
bus_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
struct bus_attribute * bus_attr = to_bus_attr(attr);
struct bus_type * bus = to_bus(kobj);
struct bus_type_private *bus_priv = to_bus(kobj);
ssize_t ret = 0;

if (bus_attr->show)
ret = bus_attr->show(bus, buf);
ret = bus_attr->show(bus_priv->bus, buf);
return ret;
}

Expand All @@ -117,11 +121,11 @@ bus_attr_store(struct kobject * kobj, struct attribute * attr,
const char * buf, size_t count)
{
struct bus_attribute * bus_attr = to_bus_attr(attr);
struct bus_type * bus = to_bus(kobj);
struct bus_type_private *bus_priv = to_bus(kobj);
ssize_t ret = 0;

if (bus_attr->store)
ret = bus_attr->store(bus, buf, count);
ret = bus_attr->store(bus_priv->bus, buf, count);
return ret;
}

Expand All @@ -134,7 +138,7 @@ int bus_create_file(struct bus_type * bus, struct bus_attribute * attr)
{
int error;
if (bus_get(bus)) {
error = sysfs_create_file(&bus->subsys.kobj, &attr->attr);
error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
bus_put(bus);
} else
error = -EINVAL;
Expand All @@ -144,7 +148,7 @@ int bus_create_file(struct bus_type * bus, struct bus_attribute * attr)
void bus_remove_file(struct bus_type * bus, struct bus_attribute * attr)
{
if (bus_get(bus)) {
sysfs_remove_file(&bus->subsys.kobj, &attr->attr);
sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
bus_put(bus);
}
}
Expand Down Expand Up @@ -237,16 +241,16 @@ static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);

static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
{
return sprintf(buf, "%d\n", bus->drivers_autoprobe);
return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
}

static ssize_t store_drivers_autoprobe(struct bus_type *bus,
const char *buf, size_t count)
{
if (buf[0] == '0')
bus->drivers_autoprobe = 0;
bus->p->drivers_autoprobe = 0;
else
bus->drivers_autoprobe = 1;
bus->p->drivers_autoprobe = 1;
return count;
}

Expand Down Expand Up @@ -300,7 +304,7 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start,
if (!bus)
return -EINVAL;

klist_iter_init_node(&bus->klist_devices, &i,
klist_iter_init_node(&bus->p->klist_devices, &i,
(start ? &start->knode_bus : NULL));
while ((dev = next_device(&i)) && !error)
error = fn(dev, data);
Expand Down Expand Up @@ -333,7 +337,7 @@ struct device * bus_find_device(struct bus_type *bus,
if (!bus)
return NULL;

klist_iter_init_node(&bus->klist_devices, &i,
klist_iter_init_node(&bus->p->klist_devices, &i,
(start ? &start->knode_bus : NULL));
while ((dev = next_device(&i)))
if (match(dev, data) && get_device(dev))
Expand Down Expand Up @@ -379,7 +383,7 @@ int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
if (!bus)
return -EINVAL;

klist_iter_init_node(&bus->klist_drivers, &i,
klist_iter_init_node(&bus->p->klist_drivers, &i,
start ? &start->knode_bus : NULL);
while ((drv = next_driver(&i)) && !error)
error = fn(drv, data);
Expand Down Expand Up @@ -420,7 +424,7 @@ static void device_remove_attrs(struct bus_type * bus, struct device * dev)
static int make_deprecated_bus_links(struct device *dev)
{
return sysfs_create_link(&dev->kobj,
&dev->bus->subsys.kobj, "bus");
&dev->bus->p->subsys.kobj, "bus");
}

static void remove_deprecated_bus_links(struct device *dev)
Expand Down Expand Up @@ -449,12 +453,12 @@ int bus_add_device(struct device * dev)
error = device_add_attrs(bus, dev);
if (error)
goto out_put;
error = sysfs_create_link(&bus->devices_kset->kobj,
error = sysfs_create_link(&bus->p->devices_kset->kobj,
&dev->kobj, dev->bus_id);
if (error)
goto out_id;
error = sysfs_create_link(&dev->kobj,
&dev->bus->subsys.kobj, "subsystem");
&dev->bus->p->subsys.kobj, "subsystem");
if (error)
goto out_subsys;
error = make_deprecated_bus_links(dev);
Expand All @@ -466,7 +470,7 @@ int bus_add_device(struct device * dev)
out_deprecated:
sysfs_remove_link(&dev->kobj, "subsystem");
out_subsys:
sysfs_remove_link(&bus->devices_kset->kobj, dev->bus_id);
sysfs_remove_link(&bus->p->devices_kset->kobj, dev->bus_id);
out_id:
device_remove_attrs(bus, dev);
out_put:
Expand All @@ -488,11 +492,11 @@ void bus_attach_device(struct device * dev)

if (bus) {
dev->is_registered = 1;
if (bus->drivers_autoprobe)
if (bus->p->drivers_autoprobe)
ret = device_attach(dev);
WARN_ON(ret < 0);
if (ret >= 0)
klist_add_tail(&dev->knode_bus, &bus->klist_devices);
klist_add_tail(&dev->knode_bus, &bus->p->klist_devices);
else
dev->is_registered = 0;
}
Expand All @@ -512,7 +516,7 @@ void bus_remove_device(struct device * dev)
if (dev->bus) {
sysfs_remove_link(&dev->kobj, "subsystem");
remove_deprecated_bus_links(dev);
sysfs_remove_link(&dev->bus->devices_kset->kobj, dev->bus_id);
sysfs_remove_link(&dev->bus->p->devices_kset->kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
if (dev->is_registered) {
dev->is_registered = 0;
Expand Down Expand Up @@ -638,18 +642,18 @@ int bus_add_driver(struct device_driver *drv)
error = kobject_set_name(&drv->kobj, "%s", drv->name);
if (error)
goto out_put_bus;
drv->kobj.kset = bus->drivers_kset;
drv->kobj.kset = bus->p->drivers_kset;
drv->kobj.ktype = &driver_ktype;
error = kobject_register(&drv->kobj);
if (error)
goto out_put_bus;

if (drv->bus->drivers_autoprobe) {
if (drv->bus->p->drivers_autoprobe) {
error = driver_attach(drv);
if (error)
goto out_unregister;
}
klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
klist_add_tail(&drv->knode_bus, &bus->p->klist_drivers);
module_add_driver(drv->owner, drv);

error = driver_create_file(drv, &driver_attr_uevent);
Expand Down Expand Up @@ -828,7 +832,7 @@ static ssize_t bus_uevent_store(struct bus_type *bus,
enum kobject_action action;

if (kobject_action_type(buf, count, &action) == 0)
kobject_uevent(&bus->subsys.kobj, action);
kobject_uevent(&bus->p->subsys.kobj, action);
return count;
}
static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
Expand All @@ -844,42 +848,50 @@ static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
int bus_register(struct bus_type * bus)
{
int retval;
struct bus_type_private *priv;

priv = kzalloc(sizeof(struct bus_type_private), GFP_KERNEL);
if (!priv)
return -ENOMEM;

priv->bus = bus;
bus->p = priv;

BLOCKING_INIT_NOTIFIER_HEAD(&bus->bus_notifier);
BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);

retval = kobject_set_name(&bus->subsys.kobj, "%s", bus->name);
retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
if (retval)
goto out;

bus->subsys.kobj.kset = bus_kset;
bus->subsys.kobj.ktype = &bus_ktype;
priv->subsys.kobj.kset = bus_kset;
priv->subsys.kobj.ktype = &bus_ktype;
priv->drivers_autoprobe = 1;

retval = kset_register(&bus->subsys);
retval = kset_register(&priv->subsys);
if (retval)
goto out;

retval = bus_create_file(bus, &bus_attr_uevent);
if (retval)
goto bus_uevent_fail;

bus->devices_kset = kset_create_and_add("devices", NULL,
&bus->subsys.kobj);
if (!bus->devices_kset) {
priv->devices_kset = kset_create_and_add("devices", NULL,
&priv->subsys.kobj);
if (!priv->devices_kset) {
retval = -ENOMEM;
goto bus_devices_fail;
}

bus->drivers_kset = kset_create_and_add("drivers", NULL,
&bus->subsys.kobj);
if (!bus->drivers_kset) {
priv->drivers_kset = kset_create_and_add("drivers", NULL,
&priv->subsys.kobj);
if (!priv->drivers_kset) {
retval = -ENOMEM;
goto bus_drivers_fail;
}

klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put);
klist_init(&bus->klist_drivers, NULL, NULL);
klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
klist_init(&priv->klist_drivers, NULL, NULL);

bus->drivers_autoprobe = 1;
retval = add_probe_files(bus);
if (retval)
goto bus_probe_files_fail;
Expand All @@ -894,13 +906,14 @@ int bus_register(struct bus_type * bus)
bus_attrs_fail:
remove_probe_files(bus);
bus_probe_files_fail:
kset_unregister(bus->drivers_kset);
kset_unregister(bus->p->drivers_kset);
bus_drivers_fail:
kset_unregister(bus->devices_kset);
kset_unregister(bus->p->devices_kset);
bus_devices_fail:
bus_remove_file(bus, &bus_attr_uevent);
bus_uevent_fail:
kset_unregister(&bus->subsys);
kset_unregister(&bus->p->subsys);
kfree(bus->p);
out:
return retval;
}
Expand All @@ -917,33 +930,34 @@ void bus_unregister(struct bus_type * bus)
pr_debug("bus %s: unregistering\n", bus->name);
bus_remove_attrs(bus);
remove_probe_files(bus);
kset_unregister(bus->drivers_kset);
kset_unregister(bus->devices_kset);
kset_unregister(bus->p->drivers_kset);
kset_unregister(bus->p->devices_kset);
bus_remove_file(bus, &bus_attr_uevent);
kset_unregister(&bus->subsys);
kset_unregister(&bus->p->subsys);
kfree(bus->p);
}

int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
{
return blocking_notifier_chain_register(&bus->bus_notifier, nb);
return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
}
EXPORT_SYMBOL_GPL(bus_register_notifier);

int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&bus->bus_notifier, nb);
return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
}
EXPORT_SYMBOL_GPL(bus_unregister_notifier);

struct kset *bus_get_kset(struct bus_type *bus)
{
return &bus->subsys;
return &bus->p->subsys;
}
EXPORT_SYMBOL_GPL(bus_get_kset);

struct klist *bus_get_device_klist(struct bus_type *bus)
{
return &bus->klist_devices;
return &bus->p->klist_devices;
}
EXPORT_SYMBOL_GPL(bus_get_device_klist);

Expand Down
6 changes: 3 additions & 3 deletions drivers/base/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -769,7 +769,7 @@ int device_add(struct device *dev)

/* notify clients of device entry (new way) */
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->bus_notifier,
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_ADD_DEVICE, dev);

error = device_create_file(dev, &uevent_attr);
Expand Down Expand Up @@ -820,7 +820,7 @@ int device_add(struct device *dev)
dpm_sysfs_remove(dev);
PMError:
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->bus_notifier,
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
device_remove_attrs(dev);
AttrsError:
Expand Down Expand Up @@ -999,7 +999,7 @@ void device_del(struct device * dev)
if (platform_notify_remove)
platform_notify_remove(dev);
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->bus_notifier,
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
kobject_del(&dev->kobj);
Expand Down
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