[PATCH] mm: provide interface for retrieving kmem_cache name

[Knut Omang <knut.omang@oracle.com>]

With the restructuring done in commit 9adeaa226988
("mm, slab: move memcg_cache_params structure to mm/slab.h")

it is no longer possible for code external to mm to access
the name of a kmem_cache as struct kmem_cache has effectively become
opaque. Having access to the cache name is helpful to kernel testing
infrastructure.

Expose a new function kmem_cache_name to mitigate that.

Signed-off-by: Knut Omang <knut.omang@oracle.com>
---
 include/linux/slab.h | 1 +
 mm/slab_common.c     | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 4d2a2fa55ed5..3298c9db6e46 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -702,6 +702,7 @@ static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
 }
 
 unsigned int kmem_cache_size(struct kmem_cache *s);
+const char *kmem_cache_name(struct kmem_cache *s);
 void __init kmem_cache_init_late(void);
 
 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index f9fb27b4c843..269a99dc8214 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -82,6 +82,15 @@ unsigned int kmem_cache_size(struct kmem_cache *s)
 }
 EXPORT_SYMBOL(kmem_cache_size);
 
+/*
+ * Get the name of a slab object
+ */
+const char *kmem_cache_name(struct kmem_cache *s)
+{
+	return s->name;
+}
+EXPORT_SYMBOL(kmem_cache_name);
+
 #ifdef CONFIG_DEBUG_VM
 static int kmem_cache_sanity_check(const char *name, unsigned int size)
 {
-- 
2.20.1