SLUB: Fix sysfs refcounting
If CONFIG_SYSFS is set then free the kmem_cache structure when
sysfs tells us its okay.
Otherwise there is the danger (as pointed out by
Al Viro) that sysfs thinks the kobject still exists after
kmem_cache_destroy() removed it.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: Pekka J Enberg <penberg@cs.helsinki.fi>
diff --git a/mm/slub.c b/mm/slub.c
index 93f5c28..65bf21d 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -247,7 +247,10 @@
static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
{ return 0; }
-static inline void sysfs_slab_remove(struct kmem_cache *s) {}
+static inline void sysfs_slab_remove(struct kmem_cache *s)
+{
+ kfree(s);
+}
#endif
/********************************************************************
@@ -2322,7 +2325,6 @@
if (kmem_cache_close(s))
WARN_ON(1);
sysfs_slab_remove(s);
- kfree(s);
} else
up_write(&slub_lock);
}
@@ -3937,6 +3939,13 @@
return err;
}
+static void kmem_cache_release(struct kobject *kobj)
+{
+ struct kmem_cache *s = to_slab(kobj);
+
+ kfree(s);
+}
+
static struct sysfs_ops slab_sysfs_ops = {
.show = slab_attr_show,
.store = slab_attr_store,
@@ -3944,6 +3953,7 @@
static struct kobj_type slab_ktype = {
.sysfs_ops = &slab_sysfs_ops,
+ .release = kmem_cache_release
};
static int uevent_filter(struct kset *kset, struct kobject *kobj)
@@ -4045,6 +4055,7 @@
{
kobject_uevent(&s->kobj, KOBJ_REMOVE);
kobject_del(&s->kobj);
+ kobject_put(&s->kobj);
}
/*