Rollup merge of rust-lang#129934 - ChrisDenton:remove-dir-all3, r=Amanieu

Win: Open dir for sync access in remove_dir_all

A small follow up to rust-lang#129800.

We should explicitly open directories for synchronous access. We ultimately use `GetFileInformationByHandleEx` to read directories which should paper over any issues caused by using async directory reads (or else return an error) but it's better to do the right thing in the first place. Note though that `delete` does not read or write any data so it's not necessary there.

Author: workingjubilee

std/src/sys/pal/windows/fs/remove_dir_all.rs

@@ -71,10 +71,12 @@ unsafe fn nt_open_file(
 }
 
 /// Open the file `path` in the directory `parent`, requesting the given `access` rights.
+/// `options` will be OR'd with `FILE_OPEN_REPARSE_POINT`.
 fn open_link_no_reparse(
     parent: &File,
     path: &[u16],
     access: u32,
+    options: u32,
 ) -> Result<Option<File>, WinError> {
     // This is implemented using the lower level `NtOpenFile` function as
     // unfortunately opening a file relative to a parent is not supported by
@@ -96,7 +98,7 @@ fn open_link_no_reparse(
             ..c::OBJECT_ATTRIBUTES::default()
         };
         let share = c::FILE_SHARE_DELETE | c::FILE_SHARE_READ | c::FILE_SHARE_WRITE;
-        let options = c::FILE_OPEN_REPARSE_POINT;
+        let options = c::FILE_OPEN_REPARSE_POINT | options;
         let result = nt_open_file(access, &object, share, options);
 
         // Retry without OBJ_DONT_REPARSE if it's not supported.
@@ -128,13 +130,20 @@ fn open_link_no_reparse(
 }
 
 fn open_dir(parent: &File, name: &[u16]) -> Result<Option<File>, WinError> {
-    open_link_no_reparse(parent, name, c::SYNCHRONIZE | c::FILE_LIST_DIRECTORY)
+    // Open the directory for synchronous directory listing.
+    open_link_no_reparse(
+        parent,
+        name,
+        c::SYNCHRONIZE | c::FILE_LIST_DIRECTORY,
+        // "_IO_NONALERT" means that a synchronous call won't be interrupted.
+        c::FILE_SYNCHRONOUS_IO_NONALERT,
+    )
 }
 
 fn delete(parent: &File, name: &[u16]) -> Result<(), WinError> {
     // Note that the `delete` function consumes the opened file to ensure it's
     // dropped immediately. See module comments for why this is important.
-    match open_link_no_reparse(parent, name, c::SYNCHRONIZE | c::DELETE) {
+    match open_link_no_reparse(parent, name, c::DELETE, 0) {
         Ok(Some(f)) => f.delete(),
         Ok(None) => Ok(()),
         Err(e) => Err(e),