ceph: negotiate authentication protocol; implement AUTH_NONE protocol

When we open a monitor session, we send an initial AUTH message listing
the auth protocols we support, our entity name, and (possibly) a previously
assigned global_id.  The monitor chooses a protocol and responds with an
initial message.

Initially implement AUTH_NONE, a dummy protocol that provides no security,
but works within the new framework.  It generates 'authorizers' that are
used when connecting to (mds, osd) services that simply state our entity
name and global_id.

This is a wire protocol change.

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/rados.h b/fs/ceph/rados.h
index fb23ff9..12bfb2f 100644
--- a/fs/ceph/rados.h
+++ b/fs/ceph/rados.h
@@ -157,7 +157,6 @@
 #define CEPH_OSD_OP_MODE_WR    0x2000
 #define CEPH_OSD_OP_MODE_RMW   0x3000
 #define CEPH_OSD_OP_MODE_SUB   0x4000
-#define CEPH_OSD_OP_MODE_EXEC  0x8000
 
 #define CEPH_OSD_OP_TYPE       0x0f00
 #define CEPH_OSD_OP_TYPE_LOCK  0x0100
@@ -285,6 +284,7 @@
 	CEPH_OSD_FLAG_BALANCE_READS = 256,
 	CEPH_OSD_FLAG_PARALLELEXEC = 512, /* execute op in parallel */
 	CEPH_OSD_FLAG_PGOP = 1024,      /* pg op, no object */
+	CEPH_OSD_FLAG_EXEC = 2048,      /* op may exec */
 };
 
 enum {