I've looked some more into the __must_check stuff in the driver core,
and tried to fix some functions (especially device_add() is a bit of a
beast; I split off helper functions).
Question: What is considered "good style" concerning symlinks? I would
think I should remove symlinks I created, but most places don't seem to
do this...
--
Cornelia Huck
Linux for zSeries Developer
Tel.: +49-7031-16-4837, Mail: [email protected]
From: Cornelia Huck <[email protected]>
Fix missing checks of return codes for driver model functions called in
the driver core.
Also fix bus_attach_device(), which didn't take into account that
device_attach() may return 0 or 1 on success.
CC: Greg K-H <[email protected]>
Signed-off-by: Cornelia Huck <[email protected]>
base.h | 1
bus.c | 24 +++++++++++-
class.c | 12 ++++--
core.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++-------------
platform.c | 11 ++++-
5 files changed, 133 insertions(+), 30 deletions(-)
diff -Naurp linux-2.6.18-rc1-mm2/drivers/base/base.h linux-2.6.18-rc1-mm2+CH/drivers/base/base.h
--- linux-2.6.18-rc1-mm2/drivers/base/base.h 2006-07-17 17:58:13.000000000 +0200
+++ linux-2.6.18-rc1-mm2+CH/drivers/base/base.h 2006-07-21 13:36:09.000000000 +0200
@@ -17,6 +17,7 @@ extern int attribute_container_init(void
extern int bus_add_device(struct device * dev);
extern int __must_check bus_attach_device(struct device * dev);
+extern void bus_delete_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 -Naurp linux-2.6.18-rc1-mm2/drivers/base/bus.c linux-2.6.18-rc1-mm2+CH/drivers/base/bus.c
--- linux-2.6.18-rc1-mm2/drivers/base/bus.c 2006-07-21 13:49:57.000000000 +0200
+++ linux-2.6.18-rc1-mm2+CH/drivers/base/bus.c 2006-07-21 14:51:20.000000000 +0200
@@ -360,7 +360,7 @@ static void device_remove_attrs(struct b
* bus_add_device - add device to bus
* @dev: device being added
*
- * - Add the device to its bus's list of devices.
+ * - Add attributes.
* - Create link to device's bus.
*/
int bus_add_device(struct device * dev)
@@ -401,13 +401,33 @@ int bus_attach_device(struct device * de
if (bus) {
ret = device_attach(dev);
- if (ret == 0)
+ if (ret >= 0)
klist_add_tail(&dev->knode_bus, &bus->klist_devices);
}
return ret;
}
/**
+ * bus_delete_device - undo bus_add_device
+ * @dev: device being deleted
+ *
+ * - Remove symlink from bus's directory.
+ * - Remove attributes.
+ * - Drop reference taken in bus_add_device().
+ */
+void bus_delete_device(struct device * dev)
+{
+ if (dev->bus) {
+ sysfs_remove_link(&dev->kobj, "subsystem");
+ sysfs_remove_link(&dev->kobj, "bus");
+ sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
+ device_remove_attrs(dev->bus, dev);
+ put_bus(dev->bus);
+ }
+}
+
+
+/**
* bus_remove_device - remove device from bus
* @dev: device to be removed
*
diff -Naurp linux-2.6.18-rc1-mm2/drivers/base/class.c linux-2.6.18-rc1-mm2+CH/drivers/base/class.c
--- linux-2.6.18-rc1-mm2/drivers/base/class.c 2006-07-06 06:09:49.000000000 +0200
+++ linux-2.6.18-rc1-mm2+CH/drivers/base/class.c 2006-07-21 13:43:03.000000000 +0200
@@ -560,7 +560,10 @@ int class_device_add(struct class_device
goto out2;
/* add the needed attributes to this device */
- sysfs_create_link(&class_dev->kobj, &parent_class->subsys.kset.kobj, "subsystem");
+ error = sysfs_create_link(&class_dev->kobj,
+ &parent_class->subsys.kset.kobj, "subsystem");
+ if (error)
+ goto out3;
class_dev->uevent_attr.attr.name = "uevent";
class_dev->uevent_attr.attr.mode = S_IWUSR;
class_dev->uevent_attr.attr.owner = parent_class->owner;
@@ -809,10 +812,13 @@ int class_device_rename(struct class_dev
if (class_dev->dev) {
new_class_name = make_class_name(class_dev->class->name,
&class_dev->kobj);
- sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
- new_class_name);
+ error = sysfs_create_link(&class_dev->dev->kobj,
+ &class_dev->kobj, new_class_name);
+ if (error)
+ goto out;
sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
}
+out:
class_device_put(class_dev);
kfree(old_class_name);
diff -Naurp linux-2.6.18-rc1-mm2/drivers/base/core.c linux-2.6.18-rc1-mm2+CH/drivers/base/core.c
--- linux-2.6.18-rc1-mm2/drivers/base/core.c 2006-07-17 17:58:13.000000000 +0200
+++ linux-2.6.18-rc1-mm2+CH/drivers/base/core.c 2006-07-21 14:51:00.000000000 +0200
@@ -353,6 +353,67 @@ void device_initialize(struct device *de
device_init_wakeup(dev, 0);
}
+static int device_add_class_symlinks(struct device *dev)
+{
+ int error;
+ char *class_name;
+
+ if (!dev->class)
+ return 0;
+ error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
+ "subsystem");
+ if (error)
+ goto out;
+ error = sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
+ dev->bus_id);
+ if (error)
+ goto out_subsys;
+ if (dev->parent) {
+ error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
+ "device");
+ if (error)
+ goto out_busid;
+ class_name = make_class_name(dev->class->name, &dev->kobj);
+ if (IS_ERR(class_name)) {
+ error = PTR_ERR(class_name);
+ goto out_busid;
+ }
+ error = sysfs_create_link(&dev->parent->kobj, &dev->kobj,
+ class_name);
+ kfree(class_name);
+ if (error)
+ goto out_device;
+ }
+ return error;
+out_device:
+ if (dev->parent)
+ sysfs_remove_link(&dev->kobj, "device");
+out_busid:
+ sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id);
+out_subsys:
+ sysfs_remove_link(&dev->kobj, "subsystem");
+out:
+ return error;
+}
+
+static void device_remove_class_symlinks(struct device *dev)
+{
+ char *class_name = NULL;
+
+ if (!dev->class)
+ return;
+ if (dev->parent) {
+ class_name = make_class_name(dev->class->name, &dev->kobj);
+ if (!IS_ERR(class_name)) {
+ sysfs_remove_link(&dev->parent->kobj, class_name);
+ kfree(class_name);
+ }
+ sysfs_remove_link(&dev->kobj, "device");
+ }
+ sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id);
+ sysfs_remove_link(&dev->kobj, "subsystem");
+}
+
/**
* device_add - add device to device hierarchy.
* @dev: device.
@@ -367,7 +428,6 @@ void device_initialize(struct device *de
int device_add(struct device *dev)
{
struct device *parent = NULL;
- char *class_name = NULL;
int error = -EINVAL;
dev = get_device(dev);
@@ -395,14 +455,16 @@ int device_add(struct device *dev)
if (dev->driver)
dev->uevent_attr.attr.owner = dev->driver->owner;
dev->uevent_attr.store = store_uevent;
- device_create_file(dev, &dev->uevent_attr);
+ error = device_create_file(dev, &dev->uevent_attr);
+ if (error)
+ goto attrError;
if (MAJOR(dev->devt)) {
struct device_attribute *attr;
attr = kzalloc(sizeof(*attr), GFP_KERNEL);
if (!attr) {
error = -ENOMEM;
- goto PMError;
+ goto ueventattrError;
}
attr->attr.name = "dev";
attr->attr.mode = S_IRUGO;
@@ -412,24 +474,13 @@ int device_add(struct device *dev)
error = device_create_file(dev, attr);
if (error) {
kfree(attr);
- goto attrError;
+ goto ueventattrError;
}
-
dev->devt_attr = attr;
}
- if (dev->class) {
- sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
- "subsystem");
- sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
- dev->bus_id);
- if (parent) {
- sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device");
- class_name = make_class_name(dev->class->name, &dev->kobj);
- sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name);
- }
- }
-
+ if ((error = device_add_class_symlinks(dev)))
+ goto SymlinkError;
if ((error = device_add_attrs(dev)))
goto AttrsError;
if ((error = device_add_groups(dev)))
@@ -439,7 +490,12 @@ int device_add(struct device *dev)
if ((error = bus_add_device(dev)))
goto BusError;
kobject_uevent(&dev->kobj, KOBJ_ADD);
- bus_attach_device(dev);
+ if ((error = bus_attach_device(dev))) {
+ if (error < 0)
+ goto attachError;
+ else
+ error = 0;
+ }
if (parent)
klist_add_tail(&dev->knode_parent, &parent->klist_children);
@@ -450,9 +506,10 @@ int device_add(struct device *dev)
up(&dev->class->sem);
}
Done:
- kfree(class_name);
put_device(dev);
return error;
+ attachError:
+ bus_delete_device(dev);
BusError:
device_pm_remove(dev);
PMError:
@@ -460,10 +517,14 @@ int device_add(struct device *dev)
GroupError:
device_remove_attrs(dev);
AttrsError:
+ device_remove_class_symlinks(dev);
+ SymlinkError:
if (dev->devt_attr) {
device_remove_file(dev, dev->devt_attr);
kfree(dev->devt_attr);
}
+ ueventattrError:
+ device_remove_file(dev, &dev->uevent_attr);
attrError:
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
kobject_del(&dev->kobj);
@@ -769,17 +830,25 @@ int device_rename(struct device *dev, ch
if (old_class_name) {
new_class_name = make_class_name(dev->class->name, &dev->kobj);
if (new_class_name) {
- sysfs_create_link(&dev->parent->kobj, &dev->kobj,
- new_class_name);
+ error = sysfs_create_link(&dev->parent->kobj,
+ &dev->kobj, new_class_name);
+ if (error)
+ goto out;
sysfs_remove_link(&dev->parent->kobj, old_class_name);
}
}
if (dev->class) {
sysfs_remove_link(&dev->class->subsys.kset.kobj,
old_symlink_name);
- sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
- dev->bus_id);
+ error = sysfs_create_link(&dev->class->subsys.kset.kobj,
+ &dev->kobj, dev->bus_id);
+ if (error) {
+ /* Uh... how to unravel this if restoring can fail? */
+ printk(KERN_ERR"%s: sysfs_create_symlink(%s) failed\n",
+ __FUNCTION__, dev->bus_id);
+ }
}
+out:
put_device(dev);
kfree(old_class_name);
diff -Naurp linux-2.6.18-rc1-mm2/drivers/base/platform.c linux-2.6.18-rc1-mm2+CH/drivers/base/platform.c
--- linux-2.6.18-rc1-mm2/drivers/base/platform.c 2006-07-06 06:09:49.000000000 +0200
+++ linux-2.6.18-rc1-mm2+CH/drivers/base/platform.c 2006-07-21 14:04:45.000000000 +0200
@@ -537,8 +537,15 @@ EXPORT_SYMBOL_GPL(platform_bus_type);
int __init platform_bus_init(void)
{
- device_register(&platform_bus);
- return bus_register(&platform_bus_type);
+ int error;
+
+ error = device_register(&platform_bus);
+ if (error)
+ return error;
+ error = bus_register(&platform_bus_type);
+ if (error)
+ device_unregister(&platform_bus);
+ return error;
}
#ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
-
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