osd: fix recovery pointer when pulling head before snapid

If recovery wants to pull a snapped object and needs the head first, pull()
does that, but the caller doesn't ++skipped and incorrectly bumps the
recovery pointer, preventing us from going back and re-pulling the snapped
object later.

Return a tristate enum from pull so we can tell what it did and update our
recovery state appropriately.

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

diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index 9d142640ef91787c27d1e329f742f4b3e4584148..b243b579001077c0a46940cc15c510b065d5ba8b 100644 (file)
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -3178,7 +3178,16 @@ void ReplicatedPG::calc_clone_subsets(SnapSet& snapset, const sobject_t& soid,
 
 /** pull - request object from a peer
  */
-bool ReplicatedPG::pull(const sobject_t& soid)
+
+/*
+ * Return values:
+ *  NONE  - didn't pull anything
+ *  YES   - pulled what the caller wanted
+ *  OTHER - needed to pull something else first (_head or _snapdir)
+ */
+enum { PULL_NONE, PULL_OTHER, PULL_YES };
+
+int ReplicatedPG::pull(const sobject_t& soid)
 {
   eversion_t v = missing.missing[soid].need;
 
@@ -3200,7 +3209,7 @@ bool ReplicatedPG::pull(const sobject_t& soid)
          << dendl;
 
   if (fromosd < 0)
-    return false;
+    return PULL_NONE;
 
   map<sobject_t, interval_set<uint64_t> > clone_subsets;
   interval_set<uint64_t> data_subset;
@@ -3214,9 +3223,12 @@ bool ReplicatedPG::pull(const sobject_t& soid)
     if (missing.is_missing(head)) {
       if (pulling.count(head)) {
        dout(10) << " missing but already pulling head " << head << dendl;
-       return false;
+       return PULL_NONE;
       } else {
-       return pull(head);
+       int r = pull(head);
+       if (r != PULL_NONE)
+         return PULL_OTHER;
+       return PULL_NONE;
       }
     }
     head.snap = CEPH_SNAPDIR;
@@ -3225,7 +3237,10 @@ bool ReplicatedPG::pull(const sobject_t& soid)
        dout(10) << " missing but already pulling snapdir " << head << dendl;
        return false;
       } else {
-       return pull(head);
+       int r = pull(head);
+       if (r != PULL_NONE)
+         return PULL_OTHER;
+       return PULL_NONE;
       }
     }
 
@@ -3261,7 +3276,7 @@ bool ReplicatedPG::pull(const sobject_t& soid)
   send_pull_op(soid, v, true, p.data_subset_pulling, fromosd);
   
   start_recovery_op(soid);
-  return true;
+  return PULL_YES;
 }
 
 void ReplicatedPG::send_pull_op(const sobject_t& soid, eversion_t v, bool first,
@@ -4152,10 +4167,19 @@ int ReplicatedPG::recover_primary(int max)
          }
        }
        
-       if (pull(soid)) {
+       int r = pull(soid);
+       switch (r) {
+       case PULL_YES:
          ++started;
-       } else
+         break;
+       case PULL_OTHER:
+         ++started;
+       case PULL_NONE:
          ++skipped;
+         break;
+       default:
+         assert(0);
+       }
        if (started >= max)
          return started;
       }

diff --git a/src/osd/ReplicatedPG.h b/src/osd/ReplicatedPG.h
index 5079f0b8ed2fb958da50f32e7650a439c3f7ad63..884597fee19fc42fc8a69a0668278ba24c350912 100644 (file)
--- a/src/osd/ReplicatedPG.h
+++ b/src/osd/ReplicatedPG.h
@@ -530,7 +530,7 @@ protected:
                    interval_set<uint64_t>& data_subset, 
                    map<sobject_t, interval_set<uint64_t> >& clone_subsets);
 
-  bool pull(const sobject_t& oid);
+  int pull(const sobject_t& oid);
   void send_pull_op(const sobject_t& soid, eversion_t v, bool first, const interval_set<uint64_t>& data_subset, int fromosd);