mm/sl[au]b: use own bulk free function when bulk alloc failed

There is no benefit to call generic bulk free function when
kmem_cache_alloc_bulk() failed. Use own kmem_cache_free_bulk()
instead of generic function.

Note that if kmem_cache_alloc_bulk() fails to allocate first object in
SLUB, size is zero. So allow passing size == 0 to kmem_cache_free_bulk()
like SLAB's.
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

mm/slab.c

@@ -3553,7 +3553,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 	local_irq_enable();
 	cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_);
 	slab_post_alloc_hook(s, objcg, flags, i, p, false);
-	__kmem_cache_free_bulk(s, i, p);
+	kmem_cache_free_bulk(s, i, p);
 	return 0;
 }
 EXPORT_SYMBOL(kmem_cache_alloc_bulk);

mm/slub.c

@@ -3647,7 +3647,7 @@ int build_detached_freelist(struct kmem_cache *s, size_t size,
 /* Note that interrupts must be enabled when calling this function. */
 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
 {
-	if (WARN_ON(!size))
+	if (!size)
 		return;
 
 	do {
@@ -3738,7 +3738,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 error:
 	slub_put_cpu_ptr(s->cpu_slab);
 	slab_post_alloc_hook(s, objcg, flags, i, p, false);
-	__kmem_cache_free_bulk(s, i, p);
+	kmem_cache_free_bulk(s, i, p);
 	return 0;
 }
 EXPORT_SYMBOL(kmem_cache_alloc_bulk);