From: Sage Weil <sage.weil@dreamhost.com>
Date: Thu, 2 Feb 2012 22:29:59 +0000 (-0800)
Subject: msg: include compat_version in version header
X-Git-Tag: v0.42~45^2~3
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=811e6298ba6afe0f09ebbee05b5b3052ad7c012e;p=ceph.git

msg: include compat_version in version header

header.version is the version we encoded.
header.compat_version is the oldest version of code that can decode it.

If the value is 0, we don't know anything about backward compatibility.

Signed-off-by: Sage Weil <sage.weil@dreamhost.com>
---

diff --git a/src/include/msgr.h b/src/include/msgr.h
index f53c35b37b16..0ac33946c635 100644
--- a/src/include/msgr.h
+++ b/src/include/msgr.h
@@ -156,7 +156,10 @@ struct ceph_msg_header {
 			     receiver: mask against ~PAGE_MASK */
 
 	struct ceph_entity_name src;
-	__le32 reserved;
+
+	/* oldest code we think can decode this.  unknown if zero. */
+	__le16 compat_version;
+	__le16 reserved;
 	__le32 crc;       /* header crc32c */
 } __attribute__ ((packed));