[PATCH 41/47] drivers/base: check errors

Greg KH
2006-09-26T05:41:29Z

From: Andrew Morton <akpm@osdl.org>

Add lots of return-value checking.

<pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()]
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/base/base.h | 2 -
drivers/base/bus.c | 107 ++++++++++++++++++++++++++++++++----------------
drivers/base/dd.c | 37 ++++++++++++-----
include/linux/device.h | 8 ++--
4 files changed, 104 insertions(+), 50 deletions(-)

diff --git a/drivers/base/base.h b/drivers/base/base.h
index c3b8dc9..d26644a 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -16,7 +16,7 @@ extern int cpu_dev_init(void);
extern int attribute_container_init(void);

extern int bus_add_device(struct device * dev);
-extern void bus_attach_device(struct device * dev);
+extern int bus_attach_device(struct device * dev);
extern void bus_remove_device(struct device * dev);
extern struct bus_type *get_bus(struct bus_type * bus);
extern void put_bus(struct bus_type * bus);
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 4d22a1d..aa685a2 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -371,12 +371,20 @@ int bus_add_device(struct device * dev)
if (bus) {
pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
error = device_add_attrs(bus, dev);
- if (!error) {
- sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "subsystem");
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
- }
+ if (error)
+ goto out;
+ error = sysfs_create_link(&bus->devices.kobj,
+ &dev->kobj, dev->bus_id);
+ if (error)
+ goto out;
+ error = sysfs_create_link(&dev->kobj,
+ &dev->bus->subsys.kset.kobj, "subsystem");
+ if (error)
+ goto out;
+ error = sysfs_create_link(&dev->kobj,
+ &dev->bus->subsys.kset.kobj, "bus");
}
+out:
return error;
}

@@ -386,14 +394,19 @@ int bus_add_device(struct device * dev)
*
* - Try to attach to driver.
*/
-void bus_attach_device(struct device * dev)
+int bus_attach_device(struct device * dev)
{
- struct bus_type * bus = dev->bus;
+ struct bus_type *bus = dev->bus;
+ int ret = 0;

if (bus) {
- device_attach(dev);
- klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ ret = device_attach(dev);
+ if (ret >= 0) {
+ klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ ret = 0;
+ }
}
+ return ret;
}

/**
@@ -455,10 +468,17 @@ #ifdef CONFIG_HOTPLUG
* Thanks to drivers making their tables __devinit, we can't allow manual
* bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
*/
-static void add_bind_files(struct device_driver *drv)
+static int __must_check add_bind_files(struct device_driver *drv)
{
- driver_create_file(drv, &driver_attr_unbind);
- driver_create_file(drv, &driver_attr_bind);
+ int ret;
+
+ ret = driver_create_file(drv, &driver_attr_unbind);
+ if (ret == 0) {
+ ret = driver_create_file(drv, &driver_attr_bind);
+ if (ret)
+ driver_remove_file(drv, &driver_attr_unbind);
+ }
+ return ret;
}

static void remove_bind_files(struct device_driver *drv)
@@ -476,7 +496,7 @@ #endif
* @drv: driver.
*
*/
-int bus_add_driver(struct device_driver * drv)
+int bus_add_driver(struct device_driver *drv)
{
struct bus_type * bus = get_bus(drv->bus);
int error = 0;
@@ -484,27 +504,39 @@ int bus_add_driver(struct device_driver
if (bus) {
pr_debug("bus %s: add driver %s\n", bus->name, drv->name);
error = kobject_set_name(&drv->kobj, "%s", drv->name);
- if (error) {
- put_bus(bus);
- return error;
- }
+ if (error)
+ goto out_put_bus;
drv->kobj.kset = &bus->drivers;
- if ((error = kobject_register(&drv->kobj))) {
- put_bus(bus);
- return error;
- }
+ if ((error = kobject_register(&drv->kobj)))
+ goto out_put_bus;

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

- driver_add_attrs(bus, drv);
- add_bind_files(drv);
+ error = driver_add_attrs(bus, drv);
+ if (error) {
+ /* How the hell do we get out of this pickle? Give up */
+ printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
+ __FUNCTION__, drv->name);
+ }
+ error = add_bind_files(drv);
+ if (error) {
+ /* Ditto */
+ printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
+ __FUNCTION__, drv->name);
+ }
}
return error;
+out_unregister:
+ kobject_unregister(&drv->kobj);
+out_put_bus:
+ put_bus(bus);
+ return error;
}

-
/**
* bus_remove_driver - delete driver from bus's knowledge.
* @drv: driver.
@@ -530,16 +562,21 @@ void bus_remove_driver(struct device_dri

/* Helper for bus_rescan_devices's iter */
-static int bus_rescan_devices_helper(struct device *dev, void *data)
+static int __must_check bus_rescan_devices_helper(struct device *dev,
+ void *data)
{
+ int ret = 0;
+
if (!dev->driver) {
if (dev->parent) /* Needed for USB */
down(&dev->parent->sem);
- device_attach(dev);
+ ret = device_attach(dev);
if (dev->parent)
up(&dev->parent->sem);
+ if (ret > 0)
+ ret = 0;
}
- return 0;
+ return ret < 0 ? ret : 0;
}

/**
@@ -550,9 +587,9 @@ static int bus_rescan_devices_helper(str
* attached and rescan it against existing drivers to see if it matches
* any by calling device_attach() for the unbound devices.
*/
-void bus_rescan_devices(struct bus_type * bus)
+int bus_rescan_devices(struct bus_type * bus)
{
- bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
+ return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
}

/**
@@ -564,7 +601,7 @@ void bus_rescan_devices(struct bus_type
* to use if probing criteria changed during a devices lifetime and
* driver attachment should change accordingly.
*/
-void device_reprobe(struct device *dev)
+int device_reprobe(struct device *dev)
{
if (dev->driver) {
if (dev->parent) /* Needed for USB */
@@ -573,14 +610,14 @@ void device_reprobe(struct device *dev)
if (dev->parent)
up(&dev->parent->sem);
}
-
- bus_rescan_devices_helper(dev, NULL);
+ return bus_rescan_devices_helper(dev, NULL);
}
EXPORT_SYMBOL_GPL(device_reprobe);

-struct bus_type * get_bus(struct bus_type * bus)
+struct bus_type *get_bus(struct bus_type *bus)
{
- return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL;
+ return bus ? container_of(subsys_get(&bus->subsys),
+ struct bus_type, subsys) : NULL;
}

void put_bus(struct bus_type * bus)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 889c711..9f6f11c 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -38,17 +38,29 @@ #define to_drv(node) container_of(node,
*
* This function must be called with @dev->sem held.
*/
-void device_bind_driver(struct device * dev)
+int device_bind_driver(struct device *dev)
{
- if (klist_node_attached(&dev->knode_driver))
- return;
+ int ret;
+
+ if (klist_node_attached(&dev->knode_driver)) {
+ printk(KERN_WARNING "%s: device %s already bound\n",
+ __FUNCTION__, kobject_name(&dev->kobj));
+ return 0;
+ }

pr_debug("bound device '%s' to driver '%s'\n",
dev->bus_id, dev->driver->name);
klist_add_tail(&dev->knode_driver, &dev->driver->klist_devices);
- sysfs_create_link(&dev->driver->kobj, &dev->kobj,
+ ret = sysfs_create_link(&dev->driver->kobj, &dev->kobj,
kobject_name(&dev->kobj));
- sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver");
+ if (ret == 0) {
+ ret = sysfs_create_link(&dev->kobj, &dev->driver->kobj,
+ "driver");
+ if (ret)
+ sysfs_remove_link(&dev->driver->kobj,
+ kobject_name(&dev->kobj));
+ }
+ return ret;
}

/**
@@ -91,7 +103,11 @@ int driver_probe_device(struct device_dr
goto ProbeFailed;
}
}
- device_bind_driver(dev);
+ if (device_bind_driver(dev)) {
+ printk(KERN_ERR "%s: device_bind_driver(%s) failed\n",
+ __FUNCTION__, dev->bus_id);
+ /* How does undo a ->probe? We're screwed. */
+ }
ret = 1;
pr_debug("%s: Bound Device %s to Driver %s\n",
drv->bus->name, dev->bus_id, drv->name);
@@ -139,8 +155,9 @@ int device_attach(struct device * dev)

down(&dev->sem);
if (dev->driver) {
- device_bind_driver(dev);
- ret = 1;
+ ret = device_bind_driver(dev);
+ if (ret == 0)
+ ret = 1;
} else
ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
up(&dev->sem);
@@ -182,9 +199,9 @@ static int __driver_attach(struct device
* returns 0 and the @dev->driver is set, we've found a
* compatible pair.
*/
-void driver_attach(struct device_driver * drv)
+int driver_attach(struct device_driver * drv)
{
- bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
+ return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
}

/**
diff --git a/include/linux/device.h b/include/linux/device.h
index ad4db72..b3da9a8 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -62,7 +62,7 @@ struct bus_type {
extern int __must_check bus_register(struct bus_type * bus);
extern void bus_unregister(struct bus_type * bus);

-extern void bus_rescan_devices(struct bus_type * bus);
+extern int __must_check bus_rescan_devices(struct bus_type * bus);

/* iterator helpers for buses */

@@ -397,11 +397,11 @@ extern int device_rename(struct device *
* Manual binding of a device to driver. See drivers/base/bus.c
* for information on use.
*/
-extern void device_bind_driver(struct device * dev);
+extern int __must_check device_bind_driver(struct device *dev);
extern void device_release_driver(struct device * dev);
extern int __must_check device_attach(struct device * dev);
-extern void driver_attach(struct device_driver * drv);
-extern void device_reprobe(struct device *dev);
+extern int __must_check driver_attach(struct device_driver *drv);
+extern int __must_check device_reprobe(struct device *dev);

/*
* Easy functions for dynamically creating devices on the fly
--
1.4.2.1