mm/sl[aou]b: Get rid of __kmem_cache_destroy

What is done there can be done in __kmem_cache_shutdown.

This affects RCU handling somewhat. On rcu free all slab allocators do
not refer to other management structures than the kmem_cache structure.
Therefore these other structures can be freed before the rcu deferred
free to the page allocator occurs.

Reviewed-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

5 files changed, 26 insertions, 36 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 8ca6ec6301fa..de961b48a6a4 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2208,26 +2208,6 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
         }
 }
 
-void __kmem_cache_destroy(struct kmem_cache *cachep)
-{
-        int i;
-        struct kmem_list3 *l3;
-
-        for_each_online_cpu(i)
-            kfree(cachep->array[i]);
-
-        /* NUMA: free the list3 structures */
-        for_each_online_node(i) {
-                l3 = cachep->nodelists[i];
-                if (l3) {
-                        kfree(l3->shared);
-                        free_alien_cache(l3->alien);
-                        kfree(l3);
-                }
-        }
-}
-
-
 /**
  * calculate_slab_order - calculate size (page order) of slabs
  * @cachep: pointer to the cache that is being created
@@ -2364,9 +2344,6 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
  * Cannot be called within a int, but can be interrupted.
  * The @ctor is run when new pages are allocated by the cache.
  *
- * @name must be valid until the cache is destroyed. This implies that
- * the module calling this has to destroy the cache before getting unloaded.
- *
  * The flags are
  *
  * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
@@ -2591,7 +2568,7 @@ __kmem_cache_create (const char *name, size_t size, size_t align,
         cachep->refcount = 1;
 
         if (setup_cpu_cache(cachep, gfp)) {
-                __kmem_cache_destroy(cachep);
+                __kmem_cache_shutdown(cachep);
                 return NULL;
         }
 
@@ -2766,7 +2743,26 @@ EXPORT_SYMBOL(kmem_cache_shrink);
 
 int __kmem_cache_shutdown(struct kmem_cache *cachep)
 {
-        return __cache_shrink(cachep);
+        int i;
+        struct kmem_list3 *l3;
+        int rc = __cache_shrink(cachep);
+
+        if (rc)
+                return rc;
+
+        for_each_online_cpu(i)
+            kfree(cachep->array[i]);
+
+        /* NUMA: free the list3 structures */
+        for_each_online_node(i) {
+                l3 = cachep->nodelists[i];
+                if (l3) {
+                        kfree(l3->shared);
+                        free_alien_cache(l3->alien);
+                        kfree(l3);
+                }
+        }
+        return 0;
 }
 
 /*
diff --git a/mm/slab.h b/mm/slab.h
index 6724aa6f662f..c4f9a361bd18 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -37,6 +37,5 @@ struct kmem_cache *__kmem_cache_create(const char *name, size_t size,
         size_t align, unsigned long flags, void (*ctor)(void *));
 
 int __kmem_cache_shutdown(struct kmem_cache *);
-void __kmem_cache_destroy(struct kmem_cache *);
 
 #endif
diff --git a/mm/slab_common.c b/mm/slab_common.c
index d6deae9108cd..7df814e8fbea 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -153,7 +153,6 @@ void kmem_cache_destroy(struct kmem_cache *s)
                         if (s->flags & SLAB_DESTROY_BY_RCU)
                                 rcu_barrier();
 
-                        __kmem_cache_destroy(s);
                         kmem_cache_free(kmem_cache, s);
                 } else {
                         list_add(&s->list, &slab_caches);
diff --git a/mm/slob.c b/mm/slob.c
index cb4ab9675293..50f605322700 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -538,10 +538,6 @@ struct kmem_cache *__kmem_cache_create(const char *name, size_t size,
         return c;
 }
 
-void __kmem_cache_destroy(struct kmem_cache *c)
-{
-}
-
 void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
 {
         void *b;
diff --git a/mm/slub.c b/mm/slub.c
index 6f932f7a8219..e5e09873f5ec 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3205,12 +3205,12 @@ static inline int kmem_cache_close(struct kmem_cache *s)
 
 int __kmem_cache_shutdown(struct kmem_cache *s)
 {
-        return kmem_cache_close(s);
-}
+        int rc = kmem_cache_close(s);
 
-void __kmem_cache_destroy(struct kmem_cache *s)
-{
-        sysfs_slab_remove(s);
+        if (!rc)
+                sysfs_slab_remove(s);
+
+        return rc;
 }
 
 /********************************************************************