ceph: include transaction id in ceph_msg_header (protocol change)

Many (most?) message types include a transaction id.  By including it in
the fixed size header, we always have it available even when we are unable
to allocate memory for the (larger, variable sized) message body.  This
will allow us to error out the appropriate request instead of (silently)
dropping the reply.

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/ceph_fs.h b/fs/ceph/ceph_fs.h
index e2fd024..e87dfa6 100644
--- a/fs/ceph/ceph_fs.h
+++ b/fs/ceph/ceph_fs.h
@@ -35,7 +35,7 @@
  * internal cluster protocols separately from the public,
  * client-facing protocol.
  */
-#define CEPH_OSD_PROTOCOL     7 /* cluster internal */
+#define CEPH_OSD_PROTOCOL     8 /* cluster internal */
 #define CEPH_MDS_PROTOCOL     9 /* cluster internal */
 #define CEPH_MON_PROTOCOL     5 /* cluster internal */
 #define CEPH_OSDC_PROTOCOL   22 /* server/client */
@@ -136,7 +136,6 @@
 struct ceph_mon_statfs {
 	struct ceph_mon_request_header monhdr;
 	struct ceph_fsid fsid;
-	__le64 tid;
 } __attribute__ ((packed));
 
 struct ceph_statfs {
@@ -146,7 +145,6 @@
 
 struct ceph_mon_statfs_reply {
 	struct ceph_fsid fsid;
-	__le64 tid;
 	__le64 version;
 	struct ceph_statfs st;
 } __attribute__ ((packed));
@@ -333,7 +331,7 @@
 #define CEPH_MDS_FLAG_WANT_DENTRY   2  /* want dentry in reply */
 
 struct ceph_mds_request_head {
-	__le64 tid, oldest_client_tid;
+	__le64 oldest_client_tid;
 	__le32 mdsmap_epoch;           /* on client */
 	__le32 flags;                  /* CEPH_MDS_FLAG_* */
 	__u8 num_retry, num_fwd;       /* count retry, fwd attempts */
@@ -356,7 +354,6 @@
 
 /* client reply */
 struct ceph_mds_reply_head {
-	__le64 tid;
 	__le32 op;
 	__le32 result;
 	__le32 mdsmap_epoch;
@@ -542,7 +539,6 @@
 	__le32 migrate_seq;
 	__le64 snap_follows;
 	__le32 snap_trace_len;
-	__le64 client_tid;          /* for FLUSH(SNAP) -> FLUSH(SNAP)_ACK */
 
 	/* authlock */
 	__le32 uid, gid, mode;