ceph: make CRUSH hash function a bucket property

Make the integer hash function a property of the bucket it is used on.  This
allows us to gracefully add support for new hash functions without starting
from scatch.

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 12 insertions, 7 deletions

diff --git a/fs/ceph/crush/hash.h b/fs/ceph/crush/hash.h
index 9ce89f85dc7d..ff48e110e4bb 100644
--- a/fs/ceph/crush/hash.h
+++ b/fs/ceph/crush/hash.h
@@ -1,12 +1,17 @@
 #ifndef _CRUSH_HASH_H
 #define _CRUSH_HASH_H
 
-extern __u32 crush_hash32(__u32 a);
-extern __u32 crush_hash32_2(__u32 a, __u32 b);
-extern __u32 crush_hash32_3(__u32 a, __u32 b, __u32 c);
-extern __u32 crush_hash32_4(__u32 a, __u32 b, __u32 c,
-                            __u32 d);
-extern __u32 crush_hash32_5(__u32 a, __u32 b, __u32 c,
-                            __u32 d, __u32 e);
+#define CRUSH_HASH_RJENKINS1   0
+
+#define CRUSH_HASH_DEFAULT CRUSH_HASH_RJENKINS1
+
+extern const char *crush_hash_name(int type);
+
+extern __u32 crush_hash32(int type, __u32 a);
+extern __u32 crush_hash32_2(int type, __u32 a, __u32 b);
+extern __u32 crush_hash32_3(int type, __u32 a, __u32 b, __u32 c);
+extern __u32 crush_hash32_4(int type, __u32 a, __u32 b, __u32 c, __u32 d);
+extern __u32 crush_hash32_5(int type, __u32 a, __u32 b, __u32 c, __u32 d,
+                            __u32 e);
 
 #endif