osd: warn if reencoding and OSDMap with fewer features than the mon

It is very dangerous to reencode and OSDMap with fewer features than the
mon intended as we may be introducing a different variation of the same
OSDMap epoch into the wild.  Add a build warning here as well as this is
a potentially serious problem.

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

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 322cf5c0f6b2d2fcc6e667d27f70a791a2bd2905..ade5b99468c970d6713d165df0f778b0364cf7fb 100644 (file)
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -6191,6 +6191,11 @@ void OSD::handle_osd_map(MOSDMap *m)
       if (o->test_flag(CEPH_OSDMAP_FULL))
        last_marked_full = e;
 
+#warning FIXME: we are unsafely encoding a new full OSDMap
+      if (inc.encode_features & ~CEPH_FEATURES_ALL)
+       derr << "WARNING: encoding full OSDMap with fewer features than the mon"
+            << dendl;
+
       bufferlist fbl;
       o->encode(fbl);