fix(tiering): Small test fixes (#6133)

Author: dranikpg

src/server/tiered_storage_test.cc

@@ -13,7 +13,6 @@
 #include "base/flags.h"
 #include "base/logging.h"
 #include "facade/facade_test.h"
-#include "gtest/gtest.h"
 #include "server/engine_shard_set.h"
 #include "server/test_utils.h"
 #include "util/fibers/fibers.h"
@@ -28,6 +27,7 @@ ABSL_DECLARE_FLAG(float, tiered_offload_threshold);
 ABSL_DECLARE_FLAG(float, tiered_upload_threshold);
 ABSL_DECLARE_FLAG(unsigned, tiered_storage_write_depth);
 ABSL_DECLARE_FLAG(bool, tiered_experimental_cooling);
+ABSL_DECLARE_FLAG(uint64_t, registered_buffer_size);
 ABSL_DECLARE_FLAG(bool, tiered_experimental_hash_support);
 
 namespace dfly {
@@ -51,6 +51,12 @@ class TieredStorageTest : public BaseFamilyTest {
       exit(0);
     }
 
+    // Disable registered buffers in half of the runs to use only small heap allocated buffers
+    // to possibly catch out of bounds reads/writes with sanitizers
+    if (absl::InsecureBitGen{}() % 2) {
+      SetFlag(&FLAGS_registered_buffer_size, 0);
+    }
+
     SetFlag(&FLAGS_tiered_storage_write_depth, 15000);
     if (GetFlag(FLAGS_tiered_prefix).empty()) {
       SetFlag(&FLAGS_tiered_prefix, "/tmp/tiered_storage_test");

src/server/tiering/disk_storage.cc

@@ -89,6 +89,8 @@ error_code DiskStorage::Open(string_view path) {
 
   alloc_.AddStorage(0, kInitialSize);
 
+  // TODO(vlad): Even though this is called only once for regular use,
+  // the testing code runs this initializer every time, never unregistering previous buffers
   auto* up = static_cast<UringProactor*>(ProactorBase::me());
   auto registered_buffer_size = absl::GetFlag(FLAGS_registered_buffer_size);
   if (registered_buffer_size > 0) {

src/server/tiering/op_manager_test.cc

@@ -109,10 +109,10 @@ TEST_F(OpManagerTest, SimpleStashesWithReads) {
     }
 
     EXPECT_EQ(GetStats().pending_stash_cnt, 100);
-
-    while (stashed_.size() < 100)
+    while (GetStats().disk_stats.pending_ops > 0)
       util::ThisFiber::SleepFor(1ms);
 
+    EXPECT_EQ(stashed_.size(), 100u);
     EXPECT_EQ(GetStats().disk_stats.allocated_bytes, 100 * kPageSize) << GetStats();
 
     for (unsigned i = 0; i < 100; i++) {