block: Reorder struct bio_set

This is prep work for the next patch, which embeds a struct bio_list in
struct bio_set.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>

include/linux/bio.h

@@ -298,39 +298,6 @@ static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
 static inline void bio_disassociate_task(struct bio *bio) { }
 #endif	/* CONFIG_BLK_CGROUP */
 
-/*
- * bio_set is used to allow other portions of the IO system to
- * allocate their own private memory pools for bio and iovec structures.
- * These memory pools in turn all allocate from the bio_slab
- * and the bvec_slabs[].
- */
-#define BIO_POOL_SIZE 2
-#define BIOVEC_NR_POOLS 6
-#define BIOVEC_MAX_IDX	(BIOVEC_NR_POOLS - 1)
-
-struct bio_set {
-	struct kmem_cache *bio_slab;
-	unsigned int front_pad;
-
-	mempool_t *bio_pool;
-#if defined(CONFIG_BLK_DEV_INTEGRITY)
-	mempool_t *bio_integrity_pool;
-#endif
-	mempool_t *bvec_pool;
-};
-
-struct biovec_slab {
-	int nr_vecs;
-	char *name;
-	struct kmem_cache *slab;
-};
-
-/*
- * a small number of entries is fine, not going to be performance critical.
- * basically we just need to survive
- */
-#define BIO_SPLIT_ENTRIES 2
-
 #ifdef CONFIG_HIGHMEM
 /*
  * remember never ever reenable interrupts between a bvec_kmap_irq and
@@ -527,6 +494,39 @@ static inline struct bio *bio_list_get(struct bio_list *bl)
 	return bio;
 }
 
+/*
+ * bio_set is used to allow other portions of the IO system to
+ * allocate their own private memory pools for bio and iovec structures.
+ * These memory pools in turn all allocate from the bio_slab
+ * and the bvec_slabs[].
+ */
+#define BIO_POOL_SIZE 2
+#define BIOVEC_NR_POOLS 6
+#define BIOVEC_MAX_IDX	(BIOVEC_NR_POOLS - 1)
+
+struct bio_set {
+	struct kmem_cache *bio_slab;
+	unsigned int front_pad;
+
+	mempool_t *bio_pool;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	mempool_t *bio_integrity_pool;
+#endif
+	mempool_t *bvec_pool;
+};
+
+struct biovec_slab {
+	int nr_vecs;
+	char *name;
+	struct kmem_cache *slab;
+};
+
+/*
+ * a small number of entries is fine, not going to be performance critical.
+ * basically we just need to survive
+ */
+#define BIO_SPLIT_ENTRIES 2
+
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
 #define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))