SERVER-37444 Added RequiresCollectionStage and use for COLLSCAN.

This is a pure refactor with no user-facing changes. It is
the first step in making PlanExecutors check their own
validity during yield recovery, rather than requiring the
invalidating actor to issue a kill notification.

4 files changed, 7 insertions, 14 deletions

diff --git a/src/mongo/db/commands/collection_to_capped.cpp b/src/mongo/db/commands/collection_to_capped.cpp
index a7b3530d0e9..816882ad0fb 100644
--- a/src/mongo/db/commands/collection_to_capped.cpp
+++ b/src/mongo/db/commands/collection_to_capped.cpp
@@ -135,9 +135,7 @@ public:
                       str::stream() << "database " << dbname << " not found");
         }
 
-        Status status =
-            cloneCollectionAsCapped(opCtx, db, from.toString(), to.toString(), size, temp);
-        uassertStatusOK(status);
+        cloneCollectionAsCapped(opCtx, db, from.toString(), to.toString(), size, temp);
         return true;
     }
 } cmdCloneCollectionAsCapped;
@@ -180,7 +178,7 @@ public:
             return false;
         }
 
-        uassertStatusOK(convertToCapped(opCtx, nss, size));
+        convertToCapped(opCtx, nss, size);
         return true;
     }
 
diff --git a/src/mongo/db/commands/dbcommands_d.cpp b/src/mongo/db/commands/dbcommands_d.cpp
index 111b693e865..7c715eeacb4 100644
--- a/src/mongo/db/commands/dbcommands_d.cpp
+++ b/src/mongo/db/commands/dbcommands_d.cpp
@@ -315,12 +315,8 @@ public:
                     break;
                 }
 
-                // Have the lock again. See if we were killed.
-                if (!exec->restoreState().isOK()) {
-                    if (!partialOk) {
-                        uasserted(13281, "File deleted during filemd5 command");
-                    }
-                }
+                // Now that we have the lock again, we can restore the PlanExecutor.
+                exec->restoreState();
             }
 
             if (PlanExecutor::DEAD == state || PlanExecutor::FAILURE == state) {
diff --git a/src/mongo/db/commands/getmore_cmd.cpp b/src/mongo/db/commands/getmore_cmd.cpp
index d3484500099..31b465475de 100644
--- a/src/mongo/db/commands/getmore_cmd.cpp
+++ b/src/mongo/db/commands/getmore_cmd.cpp
@@ -411,7 +411,7 @@ public:
 
             PlanExecutor* exec = cursor->getExecutor();
             exec->reattachToOperationContext(opCtx);
-            uassertStatusOK(exec->restoreState());
+            exec->restoreState();
 
             auto planSummary = Explain::getPlanSummary(exec);
             {
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index 7fca7451fb9..9b039f98e96 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -1207,7 +1207,7 @@ void State::finalReduce(OperationContext* opCtx, CurOp* curOp, ProgressMeterHold
             all.push_back(o);
 
             _opCtx->checkForInterrupt();
-            uassertStatusOK(exec->restoreState());
+            exec->restoreState();
         }
 
         uassert(34428,
@@ -1553,8 +1553,7 @@ public:
                         state.reduceAndSpillInMemoryStateIfNeeded();
                         scopedAutoColl.emplace(opCtx, config.nss, MODE_S);
 
-                        auto restoreStatus = exec->restoreState();
-                        uassertStatusOK(restoreStatus);
+                        exec->restoreState();
 
                         reduceTime += t.micros();