Use unique StatusCode for IoRing shutdown (handlers for incomplete ops).

src/llfs/ioring_impl.cpp

@@ -121,7 +121,7 @@ IoRingImpl::~IoRingImpl() noexcept
   }
 
   batt::invoke_all_handlers(&this->completions_,  //
-                            StatusOr<i32>{Status{batt::StatusCode::kClosed}});
+                            StatusOr<i32>{::llfs::make_status(StatusCode::kIoRingShutDown)});
 }
 
 //==#==========+==+=+=++=+++++++++++-+-+--+----- --- -- -  -  -   -

src/llfs/ioring_log_flush_op.ipp

@@ -563,7 +563,8 @@ inline bool BasicIoRingLogFlushOp<DriverImpl>::handle_errors(const StatusOr<i32>
       }
       return true;
     }
-    if (!this->quiet_failure_logging) {
+    if (!this->quiet_failure_logging &&
+        result.status() != ::llfs::make_status(StatusCode::kIoRingShutDown)) {
       LLFS_LOG_INFO() << "flush failed: " << result.status();
     } else {
       LLFS_VLOG(1) << "flush failed: " << result.status();

src/llfs/status_code.cpp

@@ -133,6 +133,9 @@ bool initialize_status_codes()
                      "PageCache::put_view failed; page layout id is not registered"),  // 62,
       CODE_WITH_MSG_(StatusCode::kPageCacheSlotNotInitialized,
                      "The page cache slot for this PageId is not initialized"),  // 63,
+      CODE_WITH_MSG_(
+          StatusCode::kIoRingShutDown,
+          "The operation could not be completed because the IoRing was shut down"),  // 64,
   });
   return initialized;
 }

src/llfs/status_code.hpp

@@ -79,6 +79,7 @@ enum struct StatusCode {
   kPageHeaderBadLayoutId = 61,
   kPutViewUnknownLayoutId = 62,
   kPageCacheSlotNotInitialized = 63,
+  kIoRingShutDown = 64,
 };
 
 bool initialize_status_codes();