mm: remove broken 'kzalloc' mempool

The kzalloc mempool zeros items when they are initially allocated, but
does not rezero used items that are returned to the pool.  Consequently
mempool_alloc()s may return non-zeroed memory.

Since there are/were only two in-tree users for
mempool_create_kzalloc_pool(), and 'fixing' this in a way that will
re-zero used (but not new) items before first use is non-trivial, just
remove it.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mempool.h

@@ -47,22 +47,16 @@ mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
 }
 
 /*
- * 2 mempool_alloc_t's and a mempool_free_t to kmalloc/kzalloc and kfree
- * the amount of memory specified by pool_data
+ * a mempool_alloc_t and a mempool_free_t to kmalloc and kfree the
+ * amount of memory specified by pool_data
  */
 void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
-void *mempool_kzalloc(gfp_t gfp_mask, void *pool_data);
 void mempool_kfree(void *element, void *pool_data);
 static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
 {
 	return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
 			      (void *) size);
 }
-static inline mempool_t *mempool_create_kzalloc_pool(int min_nr, size_t size)
-{
-	return mempool_create(min_nr, mempool_kzalloc, mempool_kfree,
-			      (void *) size);
-}
 
 /*
  * A mempool_alloc_t and mempool_free_t for a simple page allocator that

mm/mempool.c

@@ -308,13 +308,6 @@ void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
 }
 EXPORT_SYMBOL(mempool_kmalloc);
 
-void *mempool_kzalloc(gfp_t gfp_mask, void *pool_data)
-{
-	size_t size = (size_t)pool_data;
-	return kzalloc(size, gfp_mask);
-}
-EXPORT_SYMBOL(mempool_kzalloc);
-
 void mempool_kfree(void *element, void *pool_data)
 {
 	kfree(element);