From c70bc17083cc73c2b2d32b4fc693fe22c58a863d Mon Sep 17 00:00:00 2001
From: Alberto Massari <alberto.massari@mongodb.com>
Date: Tue, 13 Sep 2022 08:43:13 +0000
Subject: SERVER-63851 Derive ExecutionContext flags from OperationContext

---
 src/mongo/db/commands/find_cmd.cpp           | 4 ----
 src/mongo/db/commands/map_reduce_agg.cpp     | 4 ----
 src/mongo/db/commands/run_aggregate.cpp      | 9 ++-------
 src/mongo/db/pipeline/expression_context.cpp | 9 ++++++---
 src/mongo/db/pipeline/expression_context.h   | 3 ++-
 5 files changed, 10 insertions(+), 19 deletions(-)

(limited to 'src/mongo/db')

diff --git a/src/mongo/db/commands/find_cmd.cpp b/src/mongo/db/commands/find_cmd.cpp
index bf40647a9cf..ba45ad6b615 100644
--- a/src/mongo/db/commands/find_cmd.cpp
+++ b/src/mongo/db/commands/find_cmd.cpp
@@ -142,10 +142,6 @@ boost::intrusive_ptr<ExpressionContext> makeExpressionContext(
         findCommand.getLet(),                    // let
         CurOp::get(opCtx)->dbProfileLevel() > 0  // mayDbProfile
     );
-    if (opCtx->readOnly()) {
-        // Disallow disk use if in read-only mode.
-        expCtx->allowDiskUse = false;
-    }
     expCtx->tempDir = storageGlobalParams.dbpath + "/_tmp";
     expCtx->startExpressionCounters();
 
diff --git a/src/mongo/db/commands/map_reduce_agg.cpp b/src/mongo/db/commands/map_reduce_agg.cpp
index 073e655dcb3..1f31ec3c78f 100644
--- a/src/mongo/db/commands/map_reduce_agg.cpp
+++ b/src/mongo/db/commands/map_reduce_agg.cpp
@@ -107,10 +107,6 @@ auto makeExpressionContext(OperationContext* opCtx,
         boost::none,                             // let
         CurOp::get(opCtx)->dbProfileLevel() > 0  // mayDbProfile
     );
-    if (opCtx->readOnly()) {
-        // Disallow disk use if in read-only mode.
-        expCtx->allowDiskUse = false;
-    }
     expCtx->tempDir = storageGlobalParams.dbpath + "/_tmp";
     return expCtx;
 }
diff --git a/src/mongo/db/commands/run_aggregate.cpp b/src/mongo/db/commands/run_aggregate.cpp
index e61f799620c..4fe8a736ad7 100644
--- a/src/mongo/db/commands/run_aggregate.cpp
+++ b/src/mongo/db/commands/run_aggregate.cpp
@@ -443,15 +443,10 @@ boost::intrusive_ptr<ExpressionContext> makeExpressionContext(
                               MongoProcessInterface::create(opCtx),
                               uassertStatusOK(resolveInvolvedNamespaces(opCtx, request)),
                               uuid,
-                              CurOp::get(opCtx)->dbProfileLevel() > 0);
+                              CurOp::get(opCtx)->dbProfileLevel() > 0,
+                              allowDiskUseByDefault.load());
     expCtx->tempDir = storageGlobalParams.dbpath + "/_tmp";
     expCtx->collationMatchesDefault = collationMatchesDefault;
-    expCtx->forPerShardCursor = request.getPassthroughToShard().has_value();
-    expCtx->allowDiskUse = request.getAllowDiskUse().value_or(allowDiskUseByDefault.load());
-    if (opCtx->readOnly()) {
-        // Disallow disk use if in read-only mode.
-        expCtx->allowDiskUse = false;
-    }
 
     // If the request explicitly specified NOT to use v2 resume tokens for change streams, set this
     // on the expCtx. This can happen if a the request originated from 6.0 mongos, or in test mode.
diff --git a/src/mongo/db/pipeline/expression_context.cpp b/src/mongo/db/pipeline/expression_context.cpp
index b3b433a8c45..9d36a21b888 100644
--- a/src/mongo/db/pipeline/expression_context.cpp
+++ b/src/mongo/db/pipeline/expression_context.cpp
@@ -49,12 +49,13 @@ ExpressionContext::ExpressionContext(OperationContext* opCtx,
                                      std::shared_ptr<MongoProcessInterface> processInterface,
                                      StringMap<ResolvedNamespace> resolvedNamespaces,
                                      boost::optional<UUID> collUUID,
-                                     bool mayDbProfile)
+                                     bool mayDbProfile,
+                                     bool allowDiskUseByDefault)
     : ExpressionContext(opCtx,
                         request.getExplain(),
                         request.getFromMongos(),
                         request.getNeedsMerge(),
-                        request.getAllowDiskUse(),
+                        request.getAllowDiskUse().value_or(allowDiskUseByDefault),
                         request.getBypassDocumentValidation().value_or(false),
                         request.getIsMapReduceCommand(),
                         request.getNamespace(),
@@ -71,6 +72,7 @@ ExpressionContext::ExpressionContext(OperationContext* opCtx,
         // 'jsHeapLimitMB' limit.
         jsHeapLimitMB = boost::none;
     }
+    forPerShardCursor = request.getPassthroughToShard().has_value();
 }
 
 ExpressionContext::ExpressionContext(
@@ -92,7 +94,8 @@ ExpressionContext::ExpressionContext(
     : explain(explain),
       fromMongos(fromMongos),
       needsMerge(needsMerge),
-      allowDiskUse(allowDiskUse),
+      allowDiskUse(allowDiskUse &&
+                   !(opCtx && opCtx->readOnly())),  // Disallow disk use if in read-only mode.
       bypassDocumentValidation(bypassDocumentValidation),
       ns(ns),
       uuid(std::move(collUUID)),
diff --git a/src/mongo/db/pipeline/expression_context.h b/src/mongo/db/pipeline/expression_context.h
index 0d2d87fd361..8629311709a 100644
--- a/src/mongo/db/pipeline/expression_context.h
+++ b/src/mongo/db/pipeline/expression_context.h
@@ -123,7 +123,8 @@ public:
                       std::shared_ptr<MongoProcessInterface> mongoProcessInterface,
                       StringMap<ExpressionContext::ResolvedNamespace> resolvedNamespaces,
                       boost::optional<UUID> collUUID,
-                      bool mayDbProfile = true);
+                      bool mayDbProfile = true,
+                      bool allowDiskUseByDefault = false);
 
     /**
      * Constructs an ExpressionContext to be used for Pipeline parsing and evaluation. This version
-- 
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