Fix crash due to MultiGet async IO and direct IO (#10024)

Summary:
MultiGet with async IO is not officially supported with Posix yet. Avoid a crash by using synchronous MultiRead when direct IO is enabled.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10024

Test Plan: Run db_crashtest.py manually

Reviewed By: akankshamahajan15

Differential Revision: D36551053

Pulled By: anand1976

fbshipit-source-id: 72190418fa92dd0397e87825df618b12c9bdecda

db/table_cache.cc

@@ -51,6 +51,7 @@ static void DeleteEntry(const Slice& /*key*/, void* value) {
 #undef WITHOUT_COROUTINES
 #define WITH_COROUTINES
 #include "db/table_cache_sync_and_async.h"
+#undef WITH_COROUTINES
 // clang-format on
 
 namespace ROCKSDB_NAMESPACE {

db/version_set.cc

@@ -82,6 +82,7 @@
 #undef WITHOUT_COROUTINES
 #define WITH_COROUTINES
 #include "db/version_set_sync_and_async.h"
+#undef WITH_COROUTINES
 // clang-format on
 
 namespace ROCKSDB_NAMESPACE {

table/block_based/block_based_table_reader.cc

@@ -96,6 +96,7 @@ CacheAllocationPtr CopyBufferToHeap(MemoryAllocator* allocator, Slice& buf) {
 #undef WITHOUT_COROUTINES
 #define WITH_COROUTINES
 #include "table/block_based/block_based_table_reader_sync_and_async.h"
+#undef WITH_COROUTINES
 // clang-format on
 
 namespace ROCKSDB_NAMESPACE {

table/block_based/block_based_table_reader_sync_and_async.h

@@ -140,12 +140,16 @@ DEFINE_SYNC_AND_ASYNC(void, BlockBasedTable::RetrieveMultipleBlocks)
     IOOptions opts;
     IOStatus s = file->PrepareIOOptions(options, opts);
     if (s.ok()) {
-#if defined(WITHOUT_COROUTINES)
-      s = file->MultiRead(opts, &read_reqs[0], read_reqs.size(), &direct_io_buf,
-                          options.rate_limiter_priority);
-#else   // WITH_COROUTINES
-      co_await batch->context()->reader().MultiReadAsync(
-          file, opts, &read_reqs[0], read_reqs.size(), &direct_io_buf);
+#if defined(WITH_COROUTINES)
+      if (file->use_direct_io()) {
+#endif  // WITH_COROUTINES
+        s = file->MultiRead(opts, &read_reqs[0], read_reqs.size(),
+                            &direct_io_buf, options.rate_limiter_priority);
+#if defined(WITH_COROUTINES)
+      } else {
+        co_await batch->context()->reader().MultiReadAsync(
+            file, opts, &read_reqs[0], read_reqs.size(), &direct_io_buf);
+      }
 #endif  // WITH_COROUTINES
     }
     if (!s.ok()) {