mds: add comment for subtrees MDCache member

Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>

diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h
index 76e779794a7455d327199ca31835b21734a86e64..ea83169c7e85358494ac886be5bc4448def2a9fb 100644 (file)
--- a/src/mds/MDCache.h
+++ b/src/mds/MDCache.h
@@ -252,7 +252,8 @@ public:
 
   // -- subtrees --
 protected:
-  map<CDir*,set<CDir*> > subtrees;   // nested bounds on subtrees.
+  /* subtree keys and each tree's non-recursive nested subtrees (the "bounds") */
+  map<CDir*,set<CDir*> > subtrees;
   map<CInode*,list<pair<CDir*,CDir*> > > projected_subtree_renames;  // renamed ino -> target dir
   
   // adjust subtree auth specification