1 files changed, 29 insertions, 0 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 61c15eaf3fb3..49dfb3cb7460 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -333,6 +333,35 @@ extern struct bio *bio_copy_user_iov(struct request_queue *, struct sg_iovec *,
                                      int, int);
 extern int bio_uncopy_user(struct bio *);
 void zero_fill_bio(struct bio *bio);
+extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
+
+/*
+ * 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
+
+struct bio_set {
+        mempool_t *bio_pool;
+        mempool_t *bvec_pools[BIOVEC_NR_POOLS];
+};
+
+struct biovec_slab {
+        int nr_vecs;
+        char *name;
+        struct kmem_cache *slab;
+};
+
+extern struct bio_set *fs_bio_set;
+
+/*
+ * 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
 /*