mm/sl[aou]b: Extract a common function for kmem_cache_destroy

kmem_cache_destroy does basically the same in all allocators.

Extract common code which is easy since we already have common mutex
handling.

Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

1 files changed, 3 insertions, 42 deletions

diff --git a/mm/slab.c b/mm/slab.c
index a6990316849..49a74b349e3 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2206,7 +2206,7 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 	}
 }
 
-static void __kmem_cache_destroy(struct kmem_cache *cachep)
+void __kmem_cache_destroy(struct kmem_cache *cachep)
 {
 	int i;
 	struct kmem_list3 *l3;
@@ -2763,49 +2763,10 @@ int kmem_cache_shrink(struct kmem_cache *cachep)
 }
 EXPORT_SYMBOL(kmem_cache_shrink);
 
-/**
- * kmem_cache_destroy - delete a cache
- * @cachep: the cache to destroy
- *
- * Remove a &struct kmem_cache object from the slab cache.
- *
- * It is expected this function will be called by a module when it is
- * unloaded.  This will remove the cache completely, and avoid a duplicate
- * cache being allocated each time a module is loaded and unloaded, if the
- * module doesn't have persistent in-kernel storage across loads and unloads.
- *
- * The cache must be empty before calling this function.
- *
- * The caller must guarantee that no one will allocate memory from the cache
- * during the kmem_cache_destroy().
- */
-void kmem_cache_destroy(struct kmem_cache *cachep)
+int __kmem_cache_shutdown(struct kmem_cache *cachep)
 {
-	BUG_ON(!cachep || in_interrupt());
-
-	/* Find the cache in the chain of caches. */
-	get_online_cpus();
-	mutex_lock(&slab_mutex);
-	/*
-	 * the chain is never empty, cache_cache is never destroyed
-	 */
-	list_del(&cachep->list);
-	if (__cache_shrink(cachep)) {
-		slab_error(cachep, "Can't free all objects");
-		list_add(&cachep->list, &slab_caches);
-		mutex_unlock(&slab_mutex);
-		put_online_cpus();
-		return;
-	}
-
-	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
-		rcu_barrier();
-
-	__kmem_cache_destroy(cachep);
-	mutex_unlock(&slab_mutex);
-	put_online_cpus();
+	return __cache_shrink(cachep);
 }
-EXPORT_SYMBOL(kmem_cache_destroy);
 
 /*
  * Get the memory for a slab management obj.