[PATCH dlm/next 08/12] kobject: add kset_type_create_and_add() helper

Alexander Aring
2024-08-19T18:38:31Z

Currently there exists the kset_create_and_add() helper that does not
allow to have a different ktype for the created kset kobject. To allow
a different ktype this patch will introduce the function
kset_type_create_and_add() that allows to set a different ktype instead
of using the global default kset_ktype variable.

In my example I need to separate the created kobject inside the kset by
net-namespaces. This patch allows me to do that by providing a user
defined kobj_type structure that implements the necessary namespace
functionality.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
include/linux/kobject.h | 8 ++++--
lib/kobject.c | 59 ++++++++++++++++++++++++++++++-----------
2 files changed, 50 insertions(+), 17 deletions(-)

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index c8219505a79f..7504b7547ed2 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -175,8 +175,12 @@ struct kset {
void kset_init(struct kset *kset);
int __must_check kset_register(struct kset *kset);
void kset_unregister(struct kset *kset);
-struct kset * __must_check kset_create_and_add(const char *name, const struct kset_uevent_ops *u,
- struct kobject *parent_kobj);
+struct kset * __must_check
+kset_type_create_and_add(const char *name, const struct kset_uevent_ops *u,
+ struct kobject *parent_kobj, const struct kobj_type *ktype);
+struct kset * __must_check
+kset_create_and_add(const char *name, const struct kset_uevent_ops *u,
+ struct kobject *parent_kobj);

static inline struct kset *to_kset(struct kobject *kobj)
{
diff --git a/lib/kobject.c b/lib/kobject.c
index 72fa20f405f1..09dd3d4c7f56 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -946,6 +946,7 @@ static const struct kobj_type kset_ktype = {
* @name: the name for the kset
* @uevent_ops: a struct kset_uevent_ops for the kset
* @parent_kobj: the parent kobject of this kset, if any.
+ * @ktype: a struct kobj_type for the kset
*
* This function creates a kset structure dynamically. This structure can
* then be registered with the system and show up in sysfs with a call to
@@ -957,7 +958,8 @@ static const struct kobj_type kset_ktype = {
*/
static struct kset *kset_create(const char *name,
const struct kset_uevent_ops *uevent_ops,
- struct kobject *parent_kobj)
+ struct kobject *parent_kobj,
+ const struct kobj_type *ktype)
{
struct kset *kset;
int retval;
@@ -973,39 +975,38 @@ static struct kset *kset_create(const char *name,
kset->uevent_ops = uevent_ops;
kset->kobj.parent = parent_kobj;

- /*
- * The kobject of this kset will have a type of kset_ktype and belong to
- * no kset itself. That way we can properly free it when it is
- * finished being used.
- */
- kset->kobj.ktype = &kset_ktype;
+ kset->kobj.ktype = ktype;
kset->kobj.kset = NULL;

return kset;
}

/**
- * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs.
+ * kset_type_create_and_add() - Create a struct kset with kobj_type dynamically
+ * and add it to sysfs.
*
* @name: the name for the kset
* @uevent_ops: a struct kset_uevent_ops for the kset
* @parent_kobj: the parent kobject of this kset, if any.
+ * @ktype: a struct kobj_type for the kset
*
- * This function creates a kset structure dynamically and registers it
- * with sysfs. When you are finished with this structure, call
+ * This function creates a kset structure with ktype structure dynamically and
+ * registers it with sysfs. When you are finished with this structure, call
* kset_unregister() and the structure will be dynamically freed when it
- * is no longer being used.
+ * is no longer being used. Works like kset_create_and_add() just with the
+ * possibility to assign kobj_type to the kset.
*
* If the kset was not able to be created, NULL will be returned.
*/
-struct kset *kset_create_and_add(const char *name,
- const struct kset_uevent_ops *uevent_ops,
- struct kobject *parent_kobj)
+struct kset *kset_type_create_and_add(const char *name,
+ const struct kset_uevent_ops *uevent_ops,
+ struct kobject *parent_kobj,
+ const struct kobj_type *ktype)
{
struct kset *kset;
int error;

- kset = kset_create(name, uevent_ops, parent_kobj);
+ kset = kset_create(name, uevent_ops, parent_kobj, ktype);
if (!kset)
return NULL;
error = kset_register(kset);
@@ -1015,6 +1016,34 @@ struct kset *kset_create_and_add(const char *name,
}
return kset;
}
+EXPORT_SYMBOL_GPL(kset_type_create_and_add);
+
+/**
+ * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs.
+ *
+ * @name: the name for the kset
+ * @uevent_ops: a struct kset_uevent_ops for the kset
+ * @parent_kobj: the parent kobject of this kset, if any.
+ *
+ * This function creates a kset structure dynamically and registers it
+ * with sysfs. When you are finished with this structure, call
+ * kset_unregister() and the structure will be dynamically freed when it
+ * is no longer being used.
+ *
+ * If the kset was not able to be created, NULL will be returned.
+ */
+struct kset *kset_create_and_add(const char *name,
+ const struct kset_uevent_ops *uevent_ops,
+ struct kobject *parent_kobj)
+{
+ /*
+ * The kobject of this kset will have a type of kset_ktype and belong to
+ * no kset itself. That way we can properly free it when it is
+ * finished being used.
+ */
+ return kset_type_create_and_add(name, uevent_ops, parent_kobj,
+ &kset_ktype);
+}
EXPORT_SYMBOL_GPL(kset_create_and_add);

--
2.43.0