+
+enum lmv_hash_type {
+ LMV_HASH_TYPE_ALL_CHARS = 1,
+ LMV_HASH_TYPE_FNV_1A_64 = 2,
+};
+
+#define LMV_HASH_NAME_ALL_CHARS "all_char"
+#define LMV_HASH_NAME_FNV_1A_64 "fnv_1a_64"
+
+/**
+ * The FNV-1a hash algorithm is as follows:
+ * hash = FNV_offset_basis
+ * for each octet_of_data to be hashed
+ * hash = hash XOR octet_of_data
+ * hash = hash × FNV_prime
+ * return hash
+ * http://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function#FNV-1a_hash
+ *
+ * http://www.isthe.com/chongo/tech/comp/fnv/index.html#FNV-reference-source
+ * FNV_prime is 2^40 + 2^8 + 0xb3 = 0x100000001b3ULL
+ **/
+#define LUSTRE_FNV_1A_64_PRIME 0x100000001b3ULL
+#define LUSTRE_FNV_1A_64_OFFSET_BIAS 0xcbf29ce484222325ULL
+static inline __u64 lustre_hash_fnv_1a_64(const void *buf, size_t size)
+{
+ __u64 hash = LUSTRE_FNV_1A_64_OFFSET_BIAS;
+ const unsigned char *p = buf;
+ size_t i;
+
+ for (i = 0; i < size; i++) {
+ hash ^= p[i];
+ hash *= LUSTRE_FNV_1A_64_PRIME;
+ }
+
+ return hash;
+}
+