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

Alexander Aring
2024-08-14T14:34:51Z

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.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
include/linux/kobject.h | 8 +++++--
lib/kobject.c | 49 +++++++++++++++++++++++++----------------
2 files changed, 36 insertions(+), 21 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..fbae94ea9bb5 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -957,7 +957,8 @@ 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;
@@ -973,17 +974,32 @@ 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;
}

+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, ktype);
+ if (!kset)
+ return NULL;
+ error = kset_register(kset);
+ if (error) {
+ kfree(kset);
+ return NULL;
+ }
+ return kset;
+}
+EXPORT_SYMBOL_GPL(kset_type_create_and_add);
+
/**
* kset_create_and_add() - Create a struct kset dynamically and add it to sysfs.
*
@@ -1002,18 +1018,13 @@ struct kset *kset_create_and_add(const char *name,
const struct kset_uevent_ops *uevent_ops,
struct kobject *parent_kobj)
{
- struct kset *kset;
- int error;
-
- kset = kset_create(name, uevent_ops, parent_kobj);
- if (!kset)
- return NULL;
- error = kset_register(kset);
- if (error) {
- kfree(kset);
- return NULL;
- }
- return kset;
+ /*
+ * 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