SERVER-30357 Allow users to run the validate cmd with {background:true}

2 files changed, 22 insertions, 10 deletions

diff --git a/src/mongo/db/catalog/collection_validation.cpp b/src/mongo/db/catalog/collection_validation.cpp
index 40c1a3e567e..e1a08a705c0 100644
--- a/src/mongo/db/catalog/collection_validation.cpp
+++ b/src/mongo/db/catalog/collection_validation.cpp
@@ -390,6 +390,12 @@ Status validate(OperationContext* opCtx,
     invariant(!opCtx->lockState()->isLocked());
     invariant(!(background && (level == kValidateFull)));
 
+    if (background) {
+        // Force a checkpoint to ensure background validation has a checkpoint on which to run.
+        // TODO (SERVER-43134): to sort out how to do this properly.
+        opCtx->recoveryUnit()->waitUntilUnjournaledWritesDurable(opCtx);
+    }
+
     AutoGetDb autoDB(opCtx, nss.db(), MODE_IX);
     boost::optional<Lock::CollectionLock> collLock;
     if (background) {
@@ -510,6 +516,7 @@ Status validate(OperationContext* opCtx,
         if (MONGO_FAIL_POINT(pauseCollectionValidationWithLock)) {
             invariant(opCtx->lockState()->isCollectionLockedForMode(collection->ns(), MODE_IX));
             _validationIsPausedForTest.store(true);
+            log() << "Failpoint 'pauseCollectionValidationWithLock' activated.";
             MONGO_FAIL_POINT_PAUSE_WHILE_SET(pauseCollectionValidationWithLock);
             _validationIsPausedForTest.store(false);
         }
diff --git a/src/mongo/db/commands/validate.cpp b/src/mongo/db/commands/validate.cpp
index 8fd9e900e74..43c5fcae3b0 100644
--- a/src/mongo/db/commands/validate.cpp
+++ b/src/mongo/db/commands/validate.cpp
@@ -116,25 +116,30 @@ public:
 
         const NamespaceString nss(CommandHelpers::parseNsCollectionRequired(dbname, cmdObj));
 
-        const bool full = cmdObj["full"].trueValue();
-
-        ValidateCmdLevel level = kValidateNormal;
-        if (full) {
-            level = kValidateFull;
-        }
-
-        // TODO (SERVER-30357): Add support for background validation.
-        const bool background = false;
+        const bool background = cmdObj["background"].trueValue();
 
         // Background validation requires the storage engine to support checkpoints because it
         // performs the validation on a checkpoint using checkpoint cursors.
         if (background && !opCtx->getServiceContext()->getStorageEngine()->supportsCheckpoints()) {
-            uasserted(ErrorCodes::CommandFailed,
+            uasserted(ErrorCodes::CommandNotSupported,
                       str::stream() << "Running validate on collection " << nss
                                     << " with { background: true } is not supported on the "
                                     << storageGlobalParams.engine << " storage engine");
         }
 
+        const bool full = cmdObj["full"].trueValue();
+
+        if (background && full) {
+            uasserted(ErrorCodes::CommandNotSupported,
+                      str::stream() << "Running the validate command with both { background: true }"
+                                    << " and { full: true } is not supported.");
+        }
+
+        ValidateCmdLevel level = kValidateNormal;
+        if (full) {
+            level = kValidateFull;
+        }
+
         if (!serverGlobalParams.quiet.load()) {
             LOG(0) << "CMD: validate " << nss.ns();
         }