dm bufio: call adjust_total_allocated from __link_buffer and __unlink_buffer

Move the call to adjust_total_allocated() to __link_buffer() and
__unlink_buffer() so that only used buffers are counted.  Reserved
buffers are not.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-bufio.c

@@ -431,8 +431,6 @@ static struct dm_buffer *alloc_buffer(struct dm_bufio_client *c, gfp_t gfp_mask)
 		return NULL;
 	}
 
-	adjust_total_allocated(b->data_mode, (long)c->block_size);
-
 #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
 	b->stack_len = 0;
 #endif
@@ -446,8 +444,6 @@ static void free_buffer(struct dm_buffer *b)
 {
 	struct dm_bufio_client *c = b->c;
 
-	adjust_total_allocated(b->data_mode, -(long)c->block_size);
-
 	free_buffer_data(c, b->data, b->data_mode);
 	kmem_cache_free(c->slab_buffer, b);
 }
@@ -465,6 +461,8 @@ static void __link_buffer(struct dm_buffer *b, sector_t block, int dirty)
 	list_add(&b->lru_list, &c->lru[dirty]);
 	__insert(b->c, b);
 	b->last_accessed = jiffies;
+
+	adjust_total_allocated(b->data_mode, (long)c->block_size);
 }
 
 /*
@@ -479,6 +477,8 @@ static void __unlink_buffer(struct dm_buffer *b)
 	c->n_buffers[b->list_mode]--;
 	__remove(b->c, b);
 	list_del(&b->lru_list);
+
+	adjust_total_allocated(b->data_mode, -(long)c->block_size);
 }
 
 /*