On Tuesday 19 September 2006 18:30, Greg KH wrote:
> On Tue, Sep 19, 2006 at 03:06:29PM -0700, David Miller wrote:
> > From: "Rafael J. Wysocki" <[email protected]>
> > Date: Wed, 20 Sep 2006 00:06:52 +0200
> >
> > > I _guess_ the problem is caused by
> > > gregkh-driver-network-class_device-to-device.patch, but I can't verify this,
> > > because the kernel (obviously) doesn't compile if I revert it.
> >
> > Indeed.
> >
> > I thought we threw this patch out because we knew it would cause
> > problems for existing systems? I do remember Greg making an argument
> > as to why we needed the change, but that doesn't make breaking people's
> > systems legitimate in any way.
>
> It's now thrown out, and I think Andrew already had a patch in his tree
> that reverted this.
>
> I'll be bringing it back eventually, but first we are going to work out
> all the kinks by probably putting these changes in the next few SuSE
> alpha releases to see what shakes out in userspace that we need to go
> fix.
>
Greg,
Could you please comment on the patch below which is I believe achieves
the desired result - produces unified sysfs representation of kernel
device tree - without major reshuffle of every kernel subsystem.
--
Dmitry
Driver core: move class_device to /sys/device/... part of the tree
Move sysfs representation of class_device structure from /sys/class/...
to /sys/device/... to provide unified device tree; create symlinks
in /sys/class pointing to /sys/device/... to preserve existing
classification of devices.
Create /sys/device/virtual device which is parent for all class_devices
that do not have real parent device.
Signed-off-by: Dmitry Torokhov <[email protected]>
---
drivers/base/class.c | 154 ++++++++++++++++++++++++---------------------------
1 files changed, 73 insertions(+), 81 deletions(-)
Index: work/drivers/base/class.c
===================================================================
--- work.orig/drivers/base/class.c
+++ work/drivers/base/class.c
@@ -521,60 +521,73 @@ char *make_class_name(const char *name,
return class_name;
}
+static struct device virtual_device = {
+ .bus_id = "virtual",
+};
+
int class_device_add(struct class_device *class_dev)
{
- struct class *parent_class = NULL;
+ struct class *parent_class;
struct class_device *parent_class_dev = NULL;
+ struct device *parent_dev = NULL;
struct class_interface *class_intf;
- char *class_name = NULL;
int error = -EINVAL;
- class_dev = class_device_get(class_dev);
- if (!class_dev)
- return -EINVAL;
-
if (!strlen(class_dev->class_id))
- goto out1;
+ return -EINVAL;
parent_class = class_get(class_dev->class);
if (!parent_class)
- goto out1;
-
- parent_class_dev = class_device_get(class_dev->parent);
+ return -EINVAL;
pr_debug("CLASS: registering class device: ID = '%s'\n",
class_dev->class_id);
+ parent_class_dev = class_device_get(class_dev->parent);
+
+ if (!class_dev->dev)
+ class_dev->dev = &virtual_device;
+ parent_dev = get_device(class_dev->dev);
+
/* first, register with generic layer. */
error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
if (error)
- goto out2;
+ goto err_put_parents;
- if (parent_class_dev)
- class_dev->kobj.parent = &parent_class_dev->kobj;
- else
- class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
+ class_dev->kobj.parent = parent_class_dev ?
+ &parent_class_dev->kobj : &parent_dev->kobj;
error = kobject_add(&class_dev->kobj);
if (error)
- goto out2;
+ goto err_put_parents;
/* 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 err_del_kobject;
+
+ error = sysfs_create_link(&parent_class->subsys.kset.kobj,
+ &class_dev->kobj,
+ class_dev->class_id);
+ if (error)
+ goto err_del_subsys_link;
+
class_dev->uevent_attr.attr.name = "uevent";
class_dev->uevent_attr.attr.mode = S_IWUSR;
class_dev->uevent_attr.attr.owner = parent_class->owner;
class_dev->uevent_attr.store = store_uevent;
error = class_device_create_file(class_dev, &class_dev->uevent_attr);
if (error)
- goto out3;
+ goto err_del_class_link;
if (MAJOR(class_dev->devt)) {
struct class_device_attribute *attr;
attr = kzalloc(sizeof(*attr), GFP_KERNEL);
if (!attr) {
error = -ENOMEM;
- goto out4;
+ goto err_del_uevent_attr;
}
attr->attr.name = "dev";
attr->attr.mode = S_IRUGO;
@@ -583,7 +596,7 @@ int class_device_add(struct class_device
error = class_device_create_file(class_dev, attr);
if (error) {
kfree(attr);
- goto out4;
+ goto err_del_uevent_attr;
}
class_dev->devt_attr = attr;
@@ -591,24 +604,11 @@ int class_device_add(struct class_device
error = class_device_add_attrs(class_dev);
if (error)
- goto out5;
-
- if (class_dev->dev) {
- class_name = make_class_name(class_dev->class->name,
- &class_dev->kobj);
- error = sysfs_create_link(&class_dev->kobj,
- &class_dev->dev->kobj, "device");
- if (error)
- goto out6;
- error = sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
- class_name);
- if (error)
- goto out7;
- }
+ goto err_del_devt_attr;
error = class_device_add_groups(class_dev);
if (error)
- goto out8;
+ goto err_del_attrs;
kobject_uevent(&class_dev->kobj, KOBJ_ADD);
@@ -621,30 +621,26 @@ int class_device_add(struct class_device
}
up(&parent_class->sem);
- goto out1;
+ return 0;
- out8:
- if (class_dev->dev)
- sysfs_remove_link(&class_dev->kobj, class_name);
- out7:
- if (class_dev->dev)
- sysfs_remove_link(&class_dev->kobj, "device");
- out6:
+ err_del_attrs:
class_device_remove_attrs(class_dev);
- out5:
+ err_del_devt_attr:
if (class_dev->devt_attr)
class_device_remove_file(class_dev, class_dev->devt_attr);
- out4:
+ err_del_uevent_attr:
class_device_remove_file(class_dev, &class_dev->uevent_attr);
- out3:
+ err_del_class_link:
+ sysfs_remove_link(&parent_class->subsys.kset.kobj, class_dev->class_id);
+ err_del_subsys_link:
+ sysfs_remove_link(&class_dev->kobj, "subsystem");
+ err_del_kobject:
kobject_del(&class_dev->kobj);
- out2:
- if(parent_class_dev)
- class_device_put(parent_class_dev);
+ err_put_parents:
+ class_device_put(parent_class_dev);
+ put_device(parent_dev);
class_put(parent_class);
- out1:
- class_device_put(class_dev);
- kfree(class_name);
+
return error;
}
@@ -718,7 +714,8 @@ error:
void class_device_del(struct class_device *class_dev)
{
struct class *parent_class = class_dev->class;
- struct class_device *parent_device = class_dev->parent;
+ struct class_device *parent_class_device = class_dev->parent;
+ struct device *parent_device = class_dev->dev;
struct class_interface *class_intf;
char *class_name = NULL;
@@ -731,12 +728,8 @@ void class_device_del(struct class_devic
up(&parent_class->sem);
}
- if (class_dev->dev) {
- class_name = make_class_name(class_dev->class->name,
- &class_dev->kobj);
- sysfs_remove_link(&class_dev->kobj, "device");
- sysfs_remove_link(&class_dev->dev->kobj, class_name);
- }
+ sysfs_remove_link(&parent_class->subsys.kset.kobj,
+ class_dev->class_id);
sysfs_remove_link(&class_dev->kobj, "subsystem");
class_device_remove_file(class_dev, &class_dev->uevent_attr);
if (class_dev->devt_attr)
@@ -747,7 +740,8 @@ void class_device_del(struct class_devic
kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
kobject_del(&class_dev->kobj);
- class_device_put(parent_device);
+ put_device(parent_device);
+ class_device_put(parent_class_device);
class_put(parent_class);
kfree(class_name);
}
@@ -788,36 +782,30 @@ void class_device_destroy(struct class *
int class_device_rename(struct class_device *class_dev, char *new_name)
{
- int error = 0;
- char *old_class_name = NULL, *new_class_name = NULL;
-
- class_dev = class_device_get(class_dev);
- if (!class_dev)
- return -EINVAL;
+ int error;
+ char *old_name;
pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
new_name);
- if (class_dev->dev)
- old_class_name = make_class_name(class_dev->class->name,
- &class_dev->kobj);
+ old_name = kstrdup(class_dev->class_id, GFP_KERNEL);
+ if (!old_name)
+ return -ENOMEM;
strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
error = kobject_rename(&class_dev->kobj, new_name);
-
- 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);
- sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
+ if (error) {
+ strlcpy(class_dev->class_id, old_name, KOBJ_NAME_LEN);
+ goto out;
}
- class_device_put(class_dev);
- kfree(old_class_name);
- kfree(new_class_name);
+ sysfs_create_link(&class_dev->class->subsys.kset.kobj,
+ &class_dev->kobj, new_name);
+ sysfs_remove_link(&class_dev->class->subsys.kset.kobj, old_name);
+ out:
+ kfree(old_name);
return error;
}
@@ -877,8 +865,6 @@ void class_interface_unregister(struct c
class_put(parent);
}
-
-
int __init classes_init(void)
{
int retval;
@@ -892,6 +878,12 @@ int __init classes_init(void)
subsystem_init(&class_obj_subsys);
if (!class_obj_subsys.kset.subsys)
class_obj_subsys.kset.subsys = &class_obj_subsys;
+
+ retval = device_register(&virtual_device);
+ if (retval)
+ printk(KERN_ERR "Failed to register virtual device, err: %d\n",
+ retval);
+
return 0;
}
-
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