MB-41857: Use given ops in openDbForRead

In CouchKVStore::openDbForRead we ignore the ops given and don't pass
them to openSpecificDb. This means we don't track stats at compaction
correctly. Correct this by using the supplied ops.

Change-Id: Ia77e10bc1a7b6c4a479d7c935561590a4713601c
Reviewed-on: http://review.couchbase.org/c/kv_engine/+/137574
Reviewed-by: Jim Walker <[email protected]>
Tested-by: Build Bot <[email protected]>

engines/ep/src/couch-kvstore/couch-kvstore.cc

@@ -2028,7 +2028,8 @@ CouchKVStore::OpenForReadResult CouchKVStore::openDbForRead(
     auto result = openSpecificDB(vbucketId,
                                  fileRev,
                                  handle->getDbHolder(),
-                                 COUCHSTORE_OPEN_FLAG_RDONLY);
+                                 COUCHSTORE_OPEN_FLAG_RDONLY,
+                                 ops);
     if (result != COUCHSTORE_SUCCESS) {
         return {result, std::move(handle)};
     }

engines/ep/tests/module_tests/couch-kvstore_test.cc

@@ -2117,3 +2117,18 @@ TEST_F(CouchstoreTest, CacheLimitBumpedOnOldDbCloseDuringCompaction) {
     EXPECT_TRUE(kvstore->compactDB(lock, ctx));
     EXPECT_EQ(5, CouchKVStoreFileCache::get().getHandle()->capacity());
 }
+
+TEST_F(CouchstoreTest, CompactionUsesCorrectFileOps) {
+    CouchKVStoreFileCache::get().getHandle()->resize(5);
+    CompactionConfig config;
+    auto ctx = std::make_shared<CompactionContext>(config, 0);
+
+    std::mutex mutex;
+    std::unique_lock<std::mutex> lock(mutex);
+    EXPECT_EQ(5, CouchKVStoreFileCache::get().getHandle()->capacity());
+
+    EXPECT_TRUE(kvstore->compactDB(lock, ctx));
+    EXPECT_EQ(5, CouchKVStoreFileCache::get().getHandle()->capacity());
+    auto compactStats = kvstore->getKVStoreStat().fsStatsCompaction;
+    EXPECT_NE(0, compactStats.readCountHisto.getValueCount());
+}