From ab3728508f021757c0ebe2a1285b0c74d220d74c Mon Sep 17 00:00:00 2001
From: Ayush Ranjan <ayushranjan@google.com>
Date: Wed, 16 Feb 2022 19:25:35 -0800
Subject: [PATCH] Add syscall test for rename when an writable FD exists and
 file perms changed.

The gofer server should not attempt to re-open the writable FD on server on
rename. runsc/fsgofer works as expected.

PiperOrigin-RevId: 429197853
---
 test/syscalls/linux/BUILD     |  1 +
 test/syscalls/linux/rename.cc | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index 7f4d64632..88bea0d82 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -2148,6 +2148,7 @@ cc_binary(
         "//test/util:fs_util",
         "@com_google_absl//absl/strings",
         gtest,
+        "//test/util:save_util",
         "//test/util:temp_path",
         "//test/util:test_main",
         "//test/util:test_util",
diff --git a/test/syscalls/linux/rename.cc b/test/syscalls/linux/rename.cc
index 561eed99f..dcbc47a88 100644
--- a/test/syscalls/linux/rename.cc
+++ b/test/syscalls/linux/rename.cc
@@ -23,6 +23,7 @@
 #include "test/util/cleanup.h"
 #include "test/util/file_descriptor.h"
 #include "test/util/fs_util.h"
+#include "test/util/save_util.h"
 #include "test/util/temp_path.h"
 #include "test/util/test_util.h"
 
@@ -87,6 +88,19 @@ TEST(RenameTest, FileToSameDirectory) {
   EXPECT_THAT(Exists(newpath), IsPosixErrorOkAndHolds(true));
 }
 
+TEST(RenameTest, RenameAfterWritableFDAndChmod) {
+  // Restore will require re-opening the writable FD which will fail.
+  const DisableSave ds;
+  const std::string data = "hello world\n";
+  auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  auto wfd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_WRONLY));
+  ASSERT_THAT(chmod(f.path().c_str(), 0444), SyscallSucceeds());
+  std::string const newpath = NewTempAbsPath();
+  ASSERT_THAT(rename(f.path().c_str(), newpath.c_str()), SyscallSucceeds());
+  EXPECT_THAT(WriteFd(wfd.get(), data.c_str(), data.size()),
+              SyscallSucceedsWithValue(data.size()));
+}
+
 TEST(RenameTest, DirectoryToSameDirectory) {
   auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir());
   std::string const newpath = NewTempAbsPath();