Save/restore simple devices.

We weren't saving simple devices' last allocated inode numbers, which
caused inode number reuse across S/R.

PiperOrigin-RevId: 241414245
Change-Id: I964289978841ef0a57d2fa48daf8eab7633c1284

1 files changed, 33 insertions, 0 deletions

diff --git a/test/syscalls/linux/stat.cc b/test/syscalls/linux/stat.cc
index f96da5706..553fb7e56 100644
--- a/test/syscalls/linux/stat.cc
+++ b/test/syscalls/linux/stat.cc
@@ -429,6 +429,39 @@ TEST_F(StatTest, LstatELOOPPath) {
   ASSERT_THAT(lstat(path.c_str(), &s), SyscallFailsWithErrno(ELOOP));
 }
 
+// Ensure that inode allocation for anonymous devices work correctly across
+// save/restore. In particular, inode numbers should be unique across S/R.
+TEST(SimpleStatTest, AnonDeviceAllocatesUniqueInodesAcrossSaveRestore) {
+  // Use sockets as a convenient way to create inodes on an anonymous device.
+  int fd;
+  ASSERT_THAT(fd = socket(AF_UNIX, SOCK_STREAM, 0), SyscallSucceeds());
+  FileDescriptor fd1(fd);
+  MaybeSave();
+  ASSERT_THAT(fd = socket(AF_UNIX, SOCK_STREAM, 0), SyscallSucceeds());
+  FileDescriptor fd2(fd);
+
+  struct stat st1;
+  struct stat st2;
+  ASSERT_THAT(fstat(fd1.get(), &st1), SyscallSucceeds());
+  ASSERT_THAT(fstat(fd2.get(), &st2), SyscallSucceeds());
+
+  // The two fds should have different inode numbers. Specifically, since fd2
+  // was created later, it should have a higher inode number.
+  EXPECT_GT(st2.st_ino, st1.st_ino);
+
+  // Verify again after another S/R cycle. The inode numbers should remain the
+  // same.
+  MaybeSave();
+
+  struct stat st1_after;
+  struct stat st2_after;
+  ASSERT_THAT(fstat(fd1.get(), &st1_after), SyscallSucceeds());
+  ASSERT_THAT(fstat(fd2.get(), &st2_after), SyscallSucceeds());
+
+  EXPECT_EQ(st1_after.st_ino, st1.st_ino);
+  EXPECT_EQ(st2_after.st_ino, st2.st_ino);
+}
+
 }  // namespace
 
 }  // namespace testing