From 6d48778991e06c9a5886be03be053f2d577f8d7e Mon Sep 17 00:00:00 2001
From: Lukasz Czerniawski <l.czerniawski@icloud.com>
Date: Fri, 2 Aug 2024 17:39:35 +0200
Subject: [PATCH] Fix NtQueryInformationFile and get ChangeTime from single sys
 call

---
 ext/fs/std_fs.rs | 54 +++++++++++++++++-------------------------------
 1 file changed, 19 insertions(+), 35 deletions(-)

diff --git a/ext/fs/std_fs.rs b/ext/fs/std_fs.rs
index 5d12726547..8a031e55de 100644
--- a/ext/fs/std_fs.rs
+++ b/ext/fs/std_fs.rs
@@ -821,35 +821,6 @@ fn stat_extra(
     Ok(info.dwVolumeSerialNumber as u64)
   }
 
-  unsafe fn get_change_time(
-    handle: winapi::shared::ntdef::HANDLE,
-  ) -> std::io::Result<u64> {
-    use winapi::shared::minwindef::FALSE;
-    use winapi::um::fileapi::FILE_BASIC_INFO;
-    use winapi::um::minwinbase::FileBasicInfo;
-    use winapi::um::winbase::GetFileInformationByHandleEx;
-
-    let file_info = {
-      let mut file_info = std::mem::MaybeUninit::<FILE_BASIC_INFO>::zeroed();
-      if GetFileInformationByHandleEx(
-        handle,
-        FileBasicInfo,
-        &mut file_info as *mut _ as *mut _,
-        std::mem::size_of::<FILE_BASIC_INFO>() as u32,
-      ) == FALSE
-      {
-        return Err(std::io::Error::last_os_error());
-      }
-
-      file_info.assume_init()
-    };
-
-    let change_time = file_info.ChangeTime.QuadPart();
-    let unix_time_msec = windows_time_to_unix_time_msec(change_time);
-
-    Ok(unix_time_msec as u64)
-  }
-
   const WINDOWS_TICK: i64 = 10_000; // 100-nanosecond intervals in a millisecond
   const SEC_TO_UNIX_EPOCH: i64 = 11_644_473_600; // Seconds between Windows epoch and Unix epoch
 
@@ -859,23 +830,36 @@ fn stat_extra(
   }
 
   use windows_sys::Wdk::Storage::FileSystem::FILE_ALL_INFORMATION;
+  use windows_sys::Win32::Foundation::NTSTATUS;
 
   unsafe fn query_file_information(
     handle: winapi::shared::ntdef::HANDLE,
-  ) -> std::io::Result<FILE_ALL_INFORMATION> {
+  ) -> Result<FILE_ALL_INFORMATION, NTSTATUS> {
+    use windows_sys::Win32::Foundation::RtlNtStatusToDosError;
+    use windows_sys::Win32::Foundation::ERROR_MORE_DATA;
+    use windows_sys::Win32::System::IO::IO_STATUS_BLOCK;
     use windows_sys::Wdk::Storage::FileSystem::NtQueryInformationFile;
 
     let mut info = std::mem::MaybeUninit::<FILE_ALL_INFORMATION>::zeroed();
+    let mut io_status_block = std::mem::MaybeUninit::<IO_STATUS_BLOCK>::zeroed();
     let status = NtQueryInformationFile(
       handle as _,
-      std::ptr::null_mut(),
+      io_status_block.as_mut_ptr(),
       info.as_mut_ptr() as *mut _,
       std::mem::size_of::<FILE_ALL_INFORMATION>() as _,
       18, /* FileAllInformation */
     );
 
     if status < 0 {
-      return Err(std::io::Error::last_os_error());
+      let converted_status = RtlNtStatusToDosError(status);
+
+      // If error more data is returned, then it means that the buffer is too small to get full filename information
+      // to have that we should retry. However, since we only use BasicInformation and StandardInformation, it is fine to ignore it
+      // since struct is populated with other data anyway.
+
+      if converted_status != ERROR_MORE_DATA {
+        return Err(converted_status as NTSTATUS);
+      }
     }
 
     Ok(info.assume_init())
@@ -900,11 +884,10 @@ fn stat_extra(
 
     let result = get_dev(file_handle);
     fsstat.dev = result?;
-    fsstat.ctime = get_change_time(file_handle).ok();
-
-    CloseHandle(file_handle);
 
     if let Ok(file_info) = query_file_information(file_handle) {
+      fsstat.ctime = Some(windows_time_to_unix_time_msec(&file_info.BasicInformation.ChangeTime) as u64);
+
       if file_info.BasicInformation.FileAttributes
         & winapi::um::winnt::FILE_ATTRIBUTE_REPARSE_POINT
         != 0
@@ -937,6 +920,7 @@ fn stat_extra(
       }
     }
 
+    CloseHandle(file_handle);
     Ok(())
   }
 }