MB-58649: Check Vbucket::isBucketCreation during RangeScanCreate

Fail a create request if the vbucket is in the "create" state so
that the RangeScanCreate won't get system errors if it tries to
open a datafile that has yet to be written/created.

Change-Id: I7640e15cf23f692aaaa56a729012496ff0ce94c1
Reviewed-on: https://review.couchbase.org/c/kv_engine/+/197134
Reviewed-by: Trond Norbye <[email protected]>
Tested-by: Jim Walker <[email protected]>

Author: jimwwalker

engines/ep/src/ep_vb.cc

@@ -1309,7 +1309,11 @@ std::pair<cb::engine_errc, cb::rangescan::Id> EPVBucket::createRangeScan(
             return createRangeScanComplete(std::move(rangeScanCreateToken),
                                            cookie);
         }
+    } else if (isBucketCreation()) {
+        // Scan create is racing with vbucket creation
+        return {cb::engine_errc::temporary_failure, {}};
     } else {
+
         // Create our RangeScanCreateToken, the state will now be Pending
         rangeScanCreateToken = std::make_unique<RangeScanCreateToken>();
         // Place pointer in the cookie so we can get this object back on success

engines/ep/tests/module_tests/range_scan_test.cc

@@ -2015,6 +2015,26 @@ TEST_P(RangeScanTestSimple, limitRangeScans) {
     EXPECT_EQ(0, store->getKVStoreScanTracker().getNumRunningRangeScans());
 }
 
+TEST_P(RangeScanTestSimple, beforeFlush) {
+    Vbid testvb = Vbid(1);
+    setVBucketState(testvb, vbucket_state_active);
+
+    // The vbucket is in "creating" state, i.e. nothing flushed (for couchstore
+    // there is no 1.couch.1 file)
+    EXPECT_EQ(cb::engine_errc::temporary_failure,
+              store->createRangeScan(
+                           *cookie,
+                           std::move(handler),
+                           cb::rangescan::CreateParameters{testvb,
+                                                           CollectionID::Default,
+                                                           {"\0"},
+                                                           {"\xff"},
+                                                           getScanType(),
+                                                           {},
+                                                           {}})
+                      .first);
+}
+
 // A handler which will execute a callback as part of handleStatus
 class MB_54053Handler : public RangeScanDataHandlerIFace {
 public: