SERVER-29839 Protect from mid-command renames in parseNsOrUUID

17 files changed, 201 insertions, 43 deletions

diff --git a/src/mongo/db/catalog/SConscript b/src/mongo/db/catalog/SConscript
index 5f1f5b2704e..9479faf9f4c 100644
--- a/src/mongo/db/catalog/SConscript
+++ b/src/mongo/db/catalog/SConscript
@@ -125,6 +125,7 @@ env.CppUnitTest(
     LIBDEPS=[
         'database',
         'index_create',
+        '$BUILD_DIR/mongo/db/concurrency/lock_manager',
         '$BUILD_DIR/mongo/db/db_raii',
         '$BUILD_DIR/mongo/db/namespace_string',
         '$BUILD_DIR/mongo/db/op_observer_d',
diff --git a/src/mongo/db/catalog/database_test.cpp b/src/mongo/db/catalog/database_test.cpp
index 4ba521f6b65..35c1127bb64 100644
--- a/src/mongo/db/catalog/database_test.cpp
+++ b/src/mongo/db/catalog/database_test.cpp
@@ -35,6 +35,7 @@
 #include "mongo/db/catalog/index_create.h"
 #include "mongo/db/catalog/uuid_catalog.h"
 #include "mongo/db/client.h"
+#include "mongo/db/concurrency/d_concurrency.h"
 #include "mongo/db/concurrency/write_conflict_exception.h"
 #include "mongo/db/db_raii.h"
 #include "mongo/db/jsobj.h"
@@ -537,4 +538,26 @@ TEST_F(
                       db->makeUniqueCollectionNamespace(_opCtx.get(), model));
     });
 }
+
+TEST_F(DatabaseTest, DBLockCanBePassedToAutoGetDb) {
+    NamespaceString nss("test", "coll");
+    Lock::DBLock lock(_opCtx.get(), nss.db(), MODE_X);
+    {
+        AutoGetDb db(_opCtx.get(), nss.db(), std::move(lock));
+        ASSERT(_opCtx.get()->lockState()->isDbLockedForMode(nss.db(), MODE_X));
+    }
+    // The moved lock should go out of scope here, so the database should no longer be locked.
+    ASSERT_FALSE(_opCtx.get()->lockState()->isDbLockedForMode(nss.db(), MODE_X));
+}
+
+TEST_F(DatabaseTest, DBLockCanBePassedToAutoGetCollectionOrViewForReadCommand) {
+    NamespaceString nss("test", "coll");
+    Lock::DBLock lock(_opCtx.get(), nss.db(), MODE_X);
+    {
+        AutoGetCollectionOrViewForReadCommand coll(_opCtx.get(), nss, std::move(lock));
+        ASSERT(_opCtx.get()->lockState()->isDbLockedForMode(nss.db(), MODE_X));
+    }
+    // The moved lock should go out of scope here, so the database should no longer be locked.
+    ASSERT_FALSE(_opCtx.get()->lockState()->isDbLockedForMode(nss.db(), MODE_X));
+}
 }  // namespace
diff --git a/src/mongo/db/commands/find_cmd.cpp b/src/mongo/db/commands/find_cmd.cpp
index fe1d0940ff9..cbe0ce20d55 100644
--- a/src/mongo/db/commands/find_cmd.cpp
+++ b/src/mongo/db/commands/find_cmd.cpp
@@ -40,6 +40,7 @@
 #include "mongo/db/clientcursor.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/commands/run_aggregate.h"
+#include "mongo/db/concurrency/d_concurrency.h"
 #include "mongo/db/db_raii.h"
 #include "mongo/db/exec/working_set_common.h"
 #include "mongo/db/matcher/extensions_callback_real.h"
@@ -228,14 +229,14 @@ public:
              const std::string& dbname,
              const BSONObj& cmdObj,
              BSONObjBuilder& result) override {
-        const NamespaceString nss(parseNsOrUUID(opCtx, dbname, cmdObj));
-
         // Although it is a command, a find command gets counted as a query.
         globalOpCounters.gotQuery();
 
         // Parse the command BSON to a QueryRequest.
         const bool isExplain = false;
-        auto qrStatus = QueryRequest::makeFromFindCommand(nss, cmdObj, isExplain);
+        // Pass parseNs to makeFromFindCommand in case cmdObj does not have a UUID.
+        auto qrStatus = QueryRequest::makeFromFindCommand(
+            NamespaceString(parseNs(dbname, cmdObj)), cmdObj, isExplain);
         if (!qrStatus.isOK()) {
             return appendCommandStatus(result, qrStatus.getStatus());
         }
@@ -252,6 +253,12 @@ public:
             }
         }
 
+        // Acquire locks. If the query is on a view, we release our locks and convert the query
+        // request into an aggregation command.
+        Lock::DBLock dbSLock(opCtx, dbname, MODE_IS);
+        const NamespaceString nss(parseNsOrUUID(opCtx, dbname, cmdObj));
+        qr->refreshNSS(opCtx);
+
         // Fill out curop information.
         //
         // We pass negative values for 'ntoreturn' and 'ntoskip' to indicate that these values
@@ -276,9 +283,7 @@ public:
         }
         std::unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
 
-        // Acquire locks. If the query is on a view, we release our locks and convert the query
-        // request into an aggregation command.
-        AutoGetCollectionOrViewForReadCommand ctx(opCtx, nss);
+        AutoGetCollectionOrViewForReadCommand ctx(opCtx, nss, std::move(dbSLock));
         Collection* collection = ctx.getCollection();
         if (ctx.getView()) {
             // Relinquish locks. The aggregation command will re-acquire them.
diff --git a/src/mongo/db/commands/list_indexes.cpp b/src/mongo/db/commands/list_indexes.cpp
index a050e9adfff..74b75cfeffa 100644
--- a/src/mongo/db/commands/list_indexes.cpp
+++ b/src/mongo/db/commands/list_indexes.cpp
@@ -120,6 +120,7 @@ public:
              const string& dbname,
              const BSONObj& cmdObj,
              BSONObjBuilder& result) {
+        Lock::DBLock dbSLock(opCtx, dbname, MODE_IS);
         const NamespaceString ns(parseNsOrUUID(opCtx, dbname, cmdObj));
         const long long defaultBatchSize = std::numeric_limits<long long>::max();
         long long batchSize;
@@ -129,7 +130,7 @@ public:
             return appendCommandStatus(result, parseCursorStatus);
         }
 
-        AutoGetCollectionForReadCommand autoColl(opCtx, ns);
+        AutoGetCollectionForReadCommand autoColl(opCtx, ns, std::move(dbSLock));
         if (!autoColl.getDb()) {
             return appendCommandStatus(
                 result,
diff --git a/src/mongo/db/commands/parallel_collection_scan.cpp b/src/mongo/db/commands/parallel_collection_scan.cpp
index 5fbe37b1132..6b84996369c 100644
--- a/src/mongo/db/commands/parallel_collection_scan.cpp
+++ b/src/mongo/db/commands/parallel_collection_scan.cpp
@@ -89,9 +89,10 @@ public:
                      const string& dbname,
                      const BSONObj& cmdObj,
                      BSONObjBuilder& result) {
+        Lock::DBLock dbSLock(opCtx, dbname, MODE_IS);
         const NamespaceString ns(parseNsOrUUID(opCtx, dbname, cmdObj));
 
-        AutoGetCollectionForReadCommand ctx(opCtx, ns);
+        AutoGetCollectionForReadCommand ctx(opCtx, ns, std::move(dbSLock));
 
         Collection* collection = ctx.getCollection();
         if (!collection)
diff --git a/src/mongo/db/concurrency/d_concurrency.cpp b/src/mongo/db/concurrency/d_concurrency.cpp
index 42e7bb96d7f..d5d9fe1684c 100644
--- a/src/mongo/db/concurrency/d_concurrency.cpp
+++ b/src/mongo/db/concurrency/d_concurrency.cpp
@@ -152,6 +152,15 @@ Lock::GlobalLock::GlobalLock(OperationContext* opCtx,
     _enqueue(lockMode, timeoutMs);
 }
 
+Lock::GlobalLock::GlobalLock(GlobalLock&& otherLock)
+    : _opCtx(otherLock._opCtx),
+      _result(otherLock._result),
+      _pbwm(std::move(otherLock._pbwm)),
+      _isOutermostLock(otherLock._isOutermostLock) {
+    // Mark as moved so the destructor doesn't invalidate the newly-constructed lock.
+    otherLock._result = LOCK_INVALID;
+}
+
 void Lock::GlobalLock::_enqueue(LockMode lockMode, unsigned timeoutMs) {
     if (_opCtx->lockState()->shouldConflictWithSecondaryBatchApplication()) {
         _pbwm.lock(MODE_IS);
@@ -200,8 +209,19 @@ Lock::DBLock::DBLock(OperationContext* opCtx, StringData db, LockMode mode)
     invariant(LOCK_OK == _opCtx->lockState()->lock(_id, _mode));
 }
 
+Lock::DBLock::DBLock(DBLock&& otherLock)
+    : _id(otherLock._id),
+      _opCtx(otherLock._opCtx),
+      _mode(otherLock._mode),
+      _globalLock(std::move(otherLock._globalLock)) {
+    // Mark as moved so the destructor doesn't invalidate the newly-constructed lock.
+    otherLock._mode = MODE_NONE;
+}
+
 Lock::DBLock::~DBLock() {
-    _opCtx->lockState()->unlock(_id);
+    if (_mode != MODE_NONE) {
+        _opCtx->lockState()->unlock(_id);
+    }
 }
 
 void Lock::DBLock::relockWithMode(LockMode newMode) {
diff --git a/src/mongo/db/concurrency/d_concurrency.h b/src/mongo/db/concurrency/d_concurrency.h
index 479dc84fb2a..44be439d539 100644
--- a/src/mongo/db/concurrency/d_concurrency.h
+++ b/src/mongo/db/concurrency/d_concurrency.h
@@ -83,8 +83,17 @@ public:
             lock(mode);
         }
 
+        ResourceLock(ResourceLock&& otherLock)
+            : _rid(otherLock._rid), _locker(otherLock._locker), _result(otherLock._result) {
+            // Mark as moved so the destructor doesn't invalidate the newly-
+            // constructed lock.
+            otherLock._result = LOCK_INVALID;
+        }
+
         ~ResourceLock() {
-            unlock();
+            if (isLocked()) {
+                unlock();
+            }
         }
 
         void lock(LockMode mode);
@@ -174,6 +183,7 @@ public:
         class EnqueueOnly {};
 
         GlobalLock(OperationContext* opCtx, LockMode lockMode, unsigned timeoutMs);
+        GlobalLock(GlobalLock&&);
 
         /**
          * Enqueues lock but does not block on lock acquisition.
@@ -188,10 +198,12 @@ public:
                    EnqueueOnly enqueueOnly);
 
         ~GlobalLock() {
-            if (isLocked() && _isOutermostLock) {
-                _opCtx->recoveryUnit()->abandonSnapshot();
+            if (_result != LOCK_INVALID) {
+                if (isLocked() && _isOutermostLock) {
+                    _opCtx->recoveryUnit()->abandonSnapshot();
+                }
+                _unlock();
             }
-            _unlock();
         }
 
         /**
@@ -268,6 +280,7 @@ public:
     class DBLock {
     public:
         DBLock(OperationContext* opCtx, StringData db, LockMode mode);
+        DBLock(DBLock&&);
         ~DBLock();
 
         /**
diff --git a/src/mongo/db/db_raii.cpp b/src/mongo/db/db_raii.cpp
index bff855fcc5b..018a2591ed3 100644
--- a/src/mongo/db/db_raii.cpp
+++ b/src/mongo/db/db_raii.cpp
@@ -49,13 +49,23 @@ MONGO_FP_DECLARE(setAutoGetCollectionWait);
 AutoGetDb::AutoGetDb(OperationContext* opCtx, StringData ns, LockMode mode)
     : _dbLock(opCtx, ns, mode), _db(dbHolder().get(opCtx, ns)) {}
 
+AutoGetDb::AutoGetDb(OperationContext* opCtx, StringData ns, Lock::DBLock lock)
+    : _dbLock(std::move(lock)), _db(dbHolder().get(opCtx, ns)) {}
+
 AutoGetCollection::AutoGetCollection(OperationContext* opCtx,
                                      const NamespaceString& nss,
                                      LockMode modeDB,
                                      LockMode modeColl,
                                      ViewMode viewMode)
+    : AutoGetCollection(opCtx, nss, modeColl, viewMode, Lock::DBLock(opCtx, nss.db(), modeDB)) {}
+
+AutoGetCollection::AutoGetCollection(OperationContext* opCtx,
+                                     const NamespaceString& nss,
+                                     LockMode modeColl,
+                                     ViewMode viewMode,
+                                     Lock::DBLock lock)
     : _viewMode(viewMode),
-      _autoDb(opCtx, nss.db(), modeDB),
+      _autoDb(opCtx, nss.db(), std::move(lock)),
       _collLock(opCtx->lockState(), nss.ns(), modeColl),
       _coll(_autoDb.getDb() ? _autoDb.getDb()->getCollection(opCtx, nss) : nullptr) {
     Database* db = _autoDb.getDb();
@@ -132,6 +142,15 @@ AutoGetCollectionForRead::AutoGetCollectionForRead(OperationContext* opCtx,
     _ensureMajorityCommittedSnapshotIsValid(nss, opCtx);
 }
 
+AutoGetCollectionForRead::AutoGetCollectionForRead(OperationContext* opCtx,
+                                                   const NamespaceString& nss,
+                                                   AutoGetCollection::ViewMode viewMode,
+                                                   Lock::DBLock lock) {
+    _autoColl.emplace(opCtx, nss, MODE_IS, viewMode, std::move(lock));
+
+    // Note: this can yield.
+    _ensureMajorityCommittedSnapshotIsValid(nss, opCtx);
+}
 void AutoGetCollectionForRead::_ensureMajorityCommittedSnapshotIsValid(const NamespaceString& nss,
                                                                        OperationContext* opCtx) {
     while (true) {
@@ -169,9 +188,11 @@ void AutoGetCollectionForRead::_ensureMajorityCommittedSnapshotIsValid(const Nam
 }
 
 AutoGetCollectionForReadCommand::AutoGetCollectionForReadCommand(
-    OperationContext* opCtx, const NamespaceString& nss, AutoGetCollection::ViewMode viewMode) {
-
-    _autoCollForRead.emplace(opCtx, nss, viewMode);
+    OperationContext* opCtx,
+    const NamespaceString& nss,
+    AutoGetCollection::ViewMode viewMode,
+    Lock::DBLock lock) {
+    _autoCollForRead.emplace(opCtx, nss, viewMode, std::move(lock));
     const int doNotChangeProfilingLevel = 0;
     _statsTracker.emplace(opCtx,
                           nss,
@@ -185,6 +206,11 @@ AutoGetCollectionForReadCommand::AutoGetCollectionForReadCommand(
     css->checkShardVersionOrThrow(opCtx);
 }
 
+AutoGetCollectionForReadCommand::AutoGetCollectionForReadCommand(
+    OperationContext* opCtx, const NamespaceString& nss, AutoGetCollection::ViewMode viewMode)
+    : AutoGetCollectionForReadCommand(
+          opCtx, nss, viewMode, Lock::DBLock(opCtx, nss.db(), MODE_IS)) {}
+
 AutoGetCollectionOrViewForReadCommand::AutoGetCollectionOrViewForReadCommand(
     OperationContext* opCtx, const NamespaceString& nss)
     : AutoGetCollectionForReadCommand(opCtx, nss, AutoGetCollection::ViewMode::kViewsPermitted),
@@ -192,6 +218,14 @@ AutoGetCollectionOrViewForReadCommand::AutoGetCollectionOrViewForReadCommand(
                 ? _autoCollForRead->getDb()->getViewCatalog()->lookup(opCtx, nss.ns())
                 : nullptr) {}
 
+AutoGetCollectionOrViewForReadCommand::AutoGetCollectionOrViewForReadCommand(
+    OperationContext* opCtx, const NamespaceString& nss, Lock::DBLock lock)
+    : AutoGetCollectionForReadCommand(
+          opCtx, nss, AutoGetCollection::ViewMode::kViewsPermitted, std::move(lock)),
+      _view(_autoCollForRead->getDb() && !getCollection()
+                ? _autoCollForRead->getDb()->getViewCatalog()->lookup(opCtx, nss.ns())
+                : nullptr) {}
+
 void AutoGetCollectionOrViewForReadCommand::releaseLocksForView() noexcept {
     invariant(_view);
     _view = nullptr;
diff --git a/src/mongo/db/db_raii.h b/src/mongo/db/db_raii.h
index 641b64e7988..7ff6b8f1a1d 100644
--- a/src/mongo/db/db_raii.h
+++ b/src/mongo/db/db_raii.h
@@ -58,6 +58,7 @@ class AutoGetDb {
 
 public:
     AutoGetDb(OperationContext* opCtx, StringData ns, LockMode mode);
+    AutoGetDb(OperationContext* opCtx, StringData ns, Lock::DBLock lock);
 
     Database* getDb() const {
         return _db;
@@ -94,6 +95,11 @@ public:
                       LockMode modeColl)
         : AutoGetCollection(opCtx, nss, modeDB, modeColl, ViewMode::kViewsForbidden) {}
 
+    AutoGetCollection(OperationContext* opCtx,
+                      const NamespaceString& nss,
+                      LockMode modeColl,
+                      ViewMode viewMode,
+                      Lock::DBLock lock);
     /**
      * This constructor is intended for internal use and should not be used outside this file.
      * AutoGetCollectionForReadCommand and AutoGetCollectionOrViewForReadCommand use 'viewMode' to
@@ -272,6 +278,10 @@ public:
                              const NamespaceString& nss,
                              AutoGetCollection::ViewMode viewMode);
 
+    AutoGetCollectionForRead(OperationContext* opCtx,
+                             const NamespaceString& nss,
+                             AutoGetCollection::ViewMode viewMode,
+                             Lock::DBLock lock);
     Database* getDb() const {
         return _autoColl->getDb();
     }
@@ -309,6 +319,12 @@ public:
         : AutoGetCollectionForReadCommand(
               opCtx, nss, AutoGetCollection::ViewMode::kViewsForbidden) {}
 
+    AutoGetCollectionForReadCommand(OperationContext* opCtx,
+                                    const NamespaceString& nss,
+                                    Lock::DBLock lock)
+        : AutoGetCollectionForReadCommand(
+              opCtx, nss, AutoGetCollection::ViewMode::kViewsForbidden, std::move(lock)) {}
+
     Database* getDb() const {
         return _autoCollForRead->getDb();
     }
@@ -322,6 +338,11 @@ protected:
                                     const NamespaceString& nss,
                                     AutoGetCollection::ViewMode viewMode);
 
+    AutoGetCollectionForReadCommand(OperationContext* opCtx,
+                                    const NamespaceString& nss,
+                                    AutoGetCollection::ViewMode viewMode,
+                                    Lock::DBLock lock);
+
     // '_autoCollForRead' may need to be reset by AutoGetCollectionOrViewForReadCommand, so needs to
     // be a boost::optional.
     boost::optional<AutoGetCollectionForRead> _autoCollForRead;
@@ -343,6 +364,9 @@ class AutoGetCollectionOrViewForReadCommand final : public AutoGetCollectionForR
 
 public:
     AutoGetCollectionOrViewForReadCommand(OperationContext* opCtx, const NamespaceString& nss);
+    AutoGetCollectionOrViewForReadCommand(OperationContext* opCtx,
+                                          const NamespaceString& nss,
+                                          Lock::DBLock lock);
 
     ViewDefinition* getView() const {
         return _view.get();
diff --git a/src/mongo/db/query/SConscript b/src/mongo/db/query/SConscript
index 367b285f454..c57bd8f3016 100644
--- a/src/mongo/db/query/SConscript
+++ b/src/mongo/db/query/SConscript
@@ -246,6 +246,7 @@ env.Library(
     LIBDEPS=[
         "$BUILD_DIR/mongo/base",
         "$BUILD_DIR/mongo/db/repl/read_concern_args",
+        "$BUILD_DIR/mongo/db/catalog/uuid_catalog"
     ],
 )
 
diff --git a/src/mongo/db/query/canonical_query.cpp b/src/mongo/db/query/canonical_query.cpp
index 17d18c6b798..1df80364b65 100644
--- a/src/mongo/db/query/canonical_query.cpp
+++ b/src/mongo/db/query/canonical_query.cpp
@@ -536,7 +536,7 @@ Status CanonicalQuery::isValid(MatchExpression* root, const QueryRequest& parsed
 
 std::string CanonicalQuery::toString() const {
     str::stream ss;
-    ss << "ns=" << _qr->ns();
+    ss << "ns=" << _qr->nss().ns();
 
     if (_qr->getBatchSize()) {
         ss << " batchSize=" << *_qr->getBatchSize();
diff --git a/src/mongo/db/query/query_request.cpp b/src/mongo/db/query/query_request.cpp
index 6e4d0745b2a..00a8915c1c4 100644
--- a/src/mongo/db/query/query_request.cpp
+++ b/src/mongo/db/query/query_request.cpp
@@ -34,6 +34,7 @@
 #include "mongo/base/status_with.h"
 #include "mongo/bson/simple_bsonobj_comparator.h"
 #include "mongo/client/dbclientinterface.h"
+#include "mongo/db/catalog/uuid_catalog.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/dbmessage.h"
 #include "mongo/db/namespace_string.h"
@@ -110,12 +111,21 @@ const char QueryRequest::kFindCommandName[] = "find";
 const char QueryRequest::kShardVersionField[] = "shardVersion";
 
 QueryRequest::QueryRequest(NamespaceString nss) : _nss(std::move(nss)) {}
+QueryRequest::QueryRequest(CollectionUUID uuid) : _uuid(std::move(uuid)) {}
+
+void QueryRequest::refreshNSS(OperationContext* opCtx) {
+    UUIDCatalog& catalog = UUIDCatalog::get(opCtx);
+    if (_uuid) {
+        invariant(catalog.lookupCollectionByUUID(_uuid.get()));
+        _nss = catalog.lookupNSSByUUID(_uuid.get());
+    }
+    invariant(!_nss.isEmpty());
+}
 
 // static
-StatusWith<unique_ptr<QueryRequest>> QueryRequest::makeFromFindCommand(NamespaceString nss,
-                                                                       const BSONObj& cmdObj,
-                                                                       bool isExplain) {
-    auto qr = stdx::make_unique<QueryRequest>(nss);
+StatusWith<unique_ptr<QueryRequest>> QueryRequest::parseFromFindCommand(unique_ptr<QueryRequest> qr,
+                                                                        const BSONObj& cmdObj,
+                                                                        bool isExplain) {
     qr->_explain = isExplain;
 
     // Parse the command BSON by looping through one element at a time.
@@ -385,6 +395,20 @@ StatusWith<unique_ptr<QueryRequest>> QueryRequest::makeFromFindCommand(Namespace
     return std::move(qr);
 }
 
+StatusWith<unique_ptr<QueryRequest>> QueryRequest::makeFromFindCommand(NamespaceString nss,
+                                                                       const BSONObj& cmdObj,
+                                                                       bool isExplain) {
+    BSONElement first = cmdObj.firstElement();
+    if (first.type() == BinData && first.binDataType() == BinDataType::newUUID) {
+        auto uuid = uassertStatusOK(UUID::parse(first));
+        auto qr = stdx::make_unique<QueryRequest>(uuid);
+        return parseFromFindCommand(std::move(qr), cmdObj, isExplain);
+    } else {
+        auto qr = stdx::make_unique<QueryRequest>(nss);
+        return parseFromFindCommand(std::move(qr), cmdObj, isExplain);
+    }
+}
+
 BSONObj QueryRequest::asFindCommand() const {
     BSONObjBuilder bob;
     asFindCommand(&bob);
diff --git a/src/mongo/db/query/query_request.h b/src/mongo/db/query/query_request.h
index 620e50d8804..fa0f269b4b5 100644
--- a/src/mongo/db/query/query_request.h
+++ b/src/mongo/db/query/query_request.h
@@ -31,8 +31,10 @@
 #include <boost/optional.hpp>
 #include <string>
 
+#include "mongo/db/catalog/collection_options.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/namespace_string.h"
+#include "mongo/db/operation_context.h"
 
 namespace mongo {
 
@@ -52,6 +54,8 @@ public:
 
     QueryRequest(NamespaceString nss);
 
+    QueryRequest(CollectionUUID uuid);
+
     /**
      * Returns a non-OK status if any property of the QR has a bad value (e.g. a negative skip
      * value) or if there is a bad combination of options (e.g. awaitData is illegal without
@@ -61,7 +65,8 @@ public:
 
     /**
      * Parses a find command object, 'cmdObj'. Caller must indicate whether or not this lite
-     * parsed query is an explained query or not via 'isExplain'.
+     * parsed query is an explained query or not via 'isExplain'. Accepts a NSS with which
+     * to initialize the QueryRequest if there is no UUID in cmdObj.
      *
      * Returns a heap allocated QueryRequest on success or an error if 'cmdObj' is not well
      * formed.
@@ -71,6 +76,12 @@ public:
                                                                          bool isExplain);
 
     /**
+     * If _uuid exists for this QueryRequest, use it to update the value of _nss via the
+     * UUIDCatalog associated with opCtx.
+     */
+    void refreshNSS(OperationContext* opCtx);
+
+    /**
      * Converts this QR into a find command.
      */
     BSONObj asFindCommand() const;
@@ -131,13 +142,10 @@ public:
     static const std::string metaTextScore;
 
     const NamespaceString& nss() const {
+        invariant(!_nss.isEmpty());
         return _nss;
     }
 
-    const std::string& ns() const {
-        return _nss.ns();
-    }
-
     const BSONObj& getFilter() const {
         return _filter;
     }
@@ -412,6 +420,8 @@ public:
                                                                      int queryOptions);
 
 private:
+    static StatusWith<std::unique_ptr<QueryRequest>> parseFromFindCommand(
+        std::unique_ptr<QueryRequest> qr, const BSONObj& cmdObj, bool isExplain);
     Status init(int ntoskip,
                 int ntoreturn,
                 int queryOptions,
@@ -443,7 +453,8 @@ private:
      */
     void addMetaProjection();
 
-    const NamespaceString _nss;
+    NamespaceString _nss;
+    OptionalCollectionUUID _uuid;
 
     BSONObj _filter;
     BSONObj _proj;
diff --git a/src/mongo/s/balancer_configuration_test.cpp b/src/mongo/s/balancer_configuration_test.cpp
index 834d3d12157..da21e716f18 100644
--- a/src/mongo/s/balancer_configuration_test.cpp
+++ b/src/mongo/s/balancer_configuration_test.cpp
@@ -74,7 +74,7 @@ protected:
 
             auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-            ASSERT_EQ(query->ns(), "config.settings");
+            ASSERT_EQ(query->nss().ns(), "config.settings");
             ASSERT_BSONOBJ_EQ(query->getFilter(), BSON("_id" << key));
 
             checkReadConcern(request.cmdObj, Timestamp(0, 0), repl::OpTime::kUninitializedTerm);
diff --git a/src/mongo/s/catalog/sharding_catalog_test.cpp b/src/mongo/s/catalog/sharding_catalog_test.cpp
index 425e08473b2..de9aee82029 100644
--- a/src/mongo/s/catalog/sharding_catalog_test.cpp
+++ b/src/mongo/s/catalog/sharding_catalog_test.cpp
@@ -110,7 +110,7 @@ TEST_F(ShardingCatalogClientTest, GetCollectionExisting) {
             auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
             // Ensure the query is correct
-            ASSERT_EQ(query->ns(), CollectionType::ConfigNS);
+            ASSERT_EQ(query->nss().ns(), CollectionType::ConfigNS);
             ASSERT_BSONOBJ_EQ(query->getFilter(),
                               BSON(CollectionType::fullNs(expectedColl.getNs().ns())));
             ASSERT_BSONOBJ_EQ(query->getSort(), BSONObj());
@@ -174,7 +174,7 @@ TEST_F(ShardingCatalogClientTest, GetDatabaseExisting) {
 
         auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-        ASSERT_EQ(query->ns(), DatabaseType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), DatabaseType::ConfigNS);
         ASSERT_BSONOBJ_EQ(query->getFilter(), BSON(DatabaseType::name(expectedDb.getName())));
         ASSERT_BSONOBJ_EQ(query->getSort(), BSONObj());
         ASSERT(!query->getLimit());
@@ -294,7 +294,7 @@ TEST_F(ShardingCatalogClientTest, GetAllShardsValid) {
 
         auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-        ASSERT_EQ(query->ns(), ShardType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), ShardType::ConfigNS);
         ASSERT_BSONOBJ_EQ(query->getFilter(), BSONObj());
         ASSERT_BSONOBJ_EQ(query->getSort(), BSONObj());
         ASSERT_FALSE(query->getLimit().is_initialized());
@@ -392,7 +392,7 @@ TEST_F(ShardingCatalogClientTest, GetChunksForNSWithSortAndLimit) {
 
             auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-            ASSERT_EQ(query->ns(), ChunkType::ConfigNS);
+            ASSERT_EQ(query->nss().ns(), ChunkType::ConfigNS);
             ASSERT_BSONOBJ_EQ(query->getFilter(), chunksQuery);
             ASSERT_BSONOBJ_EQ(query->getSort(), BSON(ChunkType::lastmod() << -1));
             ASSERT_EQ(query->getLimit().get(), 1);
@@ -446,7 +446,7 @@ TEST_F(ShardingCatalogClientTest, GetChunksForNSNoSortNoLimit) {
 
         auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-        ASSERT_EQ(query->ns(), ChunkType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), ChunkType::ConfigNS);
         ASSERT_BSONOBJ_EQ(query->getFilter(), chunksQuery);
         ASSERT_BSONOBJ_EQ(query->getSort(), BSONObj());
         ASSERT_FALSE(query->getLimit().is_initialized());
@@ -808,7 +808,7 @@ TEST_F(ShardingCatalogClientTest, GetCollectionsValidResultsNoDb) {
 
             auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-            ASSERT_EQ(query->ns(), CollectionType::ConfigNS);
+            ASSERT_EQ(query->nss().ns(), CollectionType::ConfigNS);
             ASSERT_BSONOBJ_EQ(query->getFilter(), BSONObj());
             ASSERT_BSONOBJ_EQ(query->getSort(), BSONObj());
 
@@ -866,7 +866,7 @@ TEST_F(ShardingCatalogClientTest, GetCollectionsValidResultsWithDb) {
 
         auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-        ASSERT_EQ(query->ns(), CollectionType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), CollectionType::ConfigNS);
         {
             BSONObjBuilder b;
             b.appendRegex(CollectionType::fullNs(), "^test\\.");
@@ -915,7 +915,7 @@ TEST_F(ShardingCatalogClientTest, GetCollectionsInvalidCollectionType) {
 
         auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-        ASSERT_EQ(query->ns(), CollectionType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), CollectionType::ConfigNS);
         {
             BSONObjBuilder b;
             b.appendRegex(CollectionType::fullNs(), "^test\\.");
@@ -962,7 +962,7 @@ TEST_F(ShardingCatalogClientTest, GetDatabasesForShardValid) {
 
         auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-        ASSERT_EQ(query->ns(), DatabaseType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), DatabaseType::ConfigNS);
         ASSERT_BSONOBJ_EQ(query->getFilter(),
                           BSON(DatabaseType::primary(dbt1.getPrimary().toString())));
         ASSERT_BSONOBJ_EQ(query->getSort(), BSONObj());
@@ -1038,7 +1038,7 @@ TEST_F(ShardingCatalogClientTest, GetTagsForCollection) {
 
         auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-        ASSERT_EQ(query->ns(), TagsType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), TagsType::ConfigNS);
         ASSERT_BSONOBJ_EQ(query->getFilter(), BSON(TagsType::ns("TestDB.TestColl")));
         ASSERT_BSONOBJ_EQ(query->getSort(), BSON(TagsType::min() << 1));
 
@@ -1664,7 +1664,7 @@ TEST_F(ShardingCatalogClientTest, GetNewKeys) {
             fromjson("{purpose: 'none',"
                      "expiresAt: {$gt: {$timestamp: {t: 1234, i: 5678}}}}"));
 
-        ASSERT_EQ(KeysCollectionDocument::ConfigNS, query->ns());
+        ASSERT_EQ(KeysCollectionDocument::ConfigNS, query->nss().ns());
         ASSERT_BSONOBJ_EQ(expectedQuery, query->getFilter());
         ASSERT_BSONOBJ_EQ(BSON("expiresAt" << 1), query->getSort());
         ASSERT_FALSE(query->getLimit().is_initialized());
@@ -1717,7 +1717,7 @@ TEST_F(ShardingCatalogClientTest, GetNewKeysWithEmptyCollection) {
             fromjson("{purpose: 'none',"
                      "expiresAt: {$gt: {$timestamp: {t: 1234, i: 5678}}}}"));
 
-        ASSERT_EQ(KeysCollectionDocument::ConfigNS, query->ns());
+        ASSERT_EQ(KeysCollectionDocument::ConfigNS, query->nss().ns());
         ASSERT_BSONOBJ_EQ(expectedQuery, query->getFilter());
         ASSERT_BSONOBJ_EQ(BSON("expiresAt" << 1), query->getSort());
         ASSERT_FALSE(query->getLimit().is_initialized());
diff --git a/src/mongo/s/cluster_identity_loader_test.cpp b/src/mongo/s/cluster_identity_loader_test.cpp
index 24b77c5d8eb..213fec88d7e 100644
--- a/src/mongo/s/cluster_identity_loader_test.cpp
+++ b/src/mongo/s/cluster_identity_loader_test.cpp
@@ -83,7 +83,7 @@ public:
 
             auto query = assertGet(QueryRequest::makeFromFindCommand(nss, request.cmdObj, false));
 
-            ASSERT_EQ(query->ns(), "config.version");
+            ASSERT_EQ(query->nss().ns(), "config.version");
             ASSERT_BSONOBJ_EQ(query->getFilter(), BSONObj());
             ASSERT_FALSE(query->getLimit().is_initialized());
 
diff --git a/src/mongo/s/sharding_test_fixture.cpp b/src/mongo/s/sharding_test_fixture.cpp
index aad4203cde3..9f4583f485a 100644
--- a/src/mongo/s/sharding_test_fixture.cpp
+++ b/src/mongo/s/sharding_test_fixture.cpp
@@ -308,7 +308,7 @@ void ShardingTestFixture::expectGetShards(const std::vector<ShardType>& shards)
         ASSERT_OK(queryResult.getStatus());
 
         const auto& query = queryResult.getValue();
-        ASSERT_EQ(query->ns(), ShardType::ConfigNS);
+        ASSERT_EQ(query->nss().ns(), ShardType::ConfigNS);
 
         ASSERT_BSONOBJ_EQ(query->getFilter(), BSONObj());
         ASSERT_BSONOBJ_EQ(query->getSort(), BSONObj());