fix(driver): use InternalHigh as op result

compio-driver/src/iocp/cp/global.rs

@@ -36,6 +36,10 @@ impl GlobalPort {
     ) -> io::Result<()> {
         self.port.post(res, optr)
     }
+
+    pub fn post_raw<T: ?Sized>(&self, optr: *const Overlapped<T>) -> io::Result<()> {
+        self.port.post_raw(optr)
+    }
 }
 
 impl AsRawHandle for GlobalPort {
@@ -60,7 +64,7 @@ fn iocp_start() -> io::Result<()> {
                 // Any thin pointer is OK because we don't use the type of opcode.
                 let overlapped_ptr: *mut Overlapped<()> = entry.lpOverlapped.cast();
                 let overlapped = unsafe { &*overlapped_ptr };
-                if let Err(e) = syscall!(
+                if let Err(_e) = syscall!(
                     BOOL,
                     PostQueuedCompletionStatus(
                         overlapped.driver as _,
@@ -75,7 +79,7 @@ fn iocp_start() -> io::Result<()> {
                         entry.lpCompletionKey,
                         entry.lpOverlapped,
                         overlapped.driver,
-                        e
+                        _e
                     );
                 }
             }
@@ -138,4 +142,8 @@ impl PortHandle {
     ) -> io::Result<()> {
         self.port.post(res, optr)
     }
+
+    pub fn post_raw<T: ?Sized>(&self, optr: *const Overlapped<T>) -> io::Result<()> {
+        self.port.post_raw(optr)
+    }
 }

compio-driver/src/iocp/cp/mod.rs

@@ -82,20 +82,25 @@ impl CompletionPort {
         res: io::Result<usize>,
         optr: *mut Overlapped<T>,
     ) -> io::Result<()> {
-        if let Err(e) = &res {
-            let code = e.raw_os_error().unwrap_or(ERROR_BAD_COMMAND as _);
-            unsafe { &mut *optr }.base.Internal = ntstatus_from_win32(code) as _;
+        if let Some(overlapped) = unsafe { optr.as_mut() } {
+            match &res {
+                Ok(transferred) => {
+                    overlapped.base.Internal = STATUS_SUCCESS as _;
+                    overlapped.base.InternalHigh = *transferred;
+                }
+                Err(e) => {
+                    let code = e.raw_os_error().unwrap_or(ERROR_BAD_COMMAND as _);
+                    overlapped.base.Internal = ntstatus_from_win32(code) as _;
+                }
+            }
         }
-        // We have to use CompletionKey to transfer the result because it is large
-        // enough. It is OK because we set it to zero when attaching handles to IOCP.
+        self.post_raw(optr)
+    }
+
+    pub fn post_raw<T: ?Sized>(&self, optr: *const Overlapped<T>) -> io::Result<()> {
         syscall!(
             BOOL,
-            PostQueuedCompletionStatus(
-                self.port.as_raw_handle() as _,
-                0,
-                res.unwrap_or_default(),
-                optr.cast()
-            )
+            PostQueuedCompletionStatus(self.port.as_raw_handle() as _, 0, 0, optr.cast())
         )?;
         Ok(())
     }
@@ -143,7 +148,7 @@ impl CompletionPort {
             if let Some(current_driver) = current_driver {
                 if overlapped.driver != current_driver {
                     // Repose the entry to correct port.
-                    if let Err(e) = syscall!(
+                    if let Err(_e) = syscall!(
                         BOOL,
                         PostQueuedCompletionStatus(
                             overlapped.driver as _,
@@ -158,7 +163,7 @@ impl CompletionPort {
                             entry.lpCompletionKey,
                             entry.lpOverlapped,
                             overlapped.driver,
-                            e
+                            _e
                         );
                     }
                 }
@@ -167,11 +172,7 @@ impl CompletionPort {
                 overlapped.base.Internal as NTSTATUS,
                 STATUS_SUCCESS | STATUS_PENDING
             ) {
-                if entry.lpCompletionKey != 0 {
-                    Ok(entry.lpCompletionKey)
-                } else {
-                    Ok(entry.dwNumberOfBytesTransferred as _)
-                }
+                Ok(overlapped.base.InternalHigh)
             } else {
                 let error = unsafe { RtlNtStatusToDosError(overlapped.base.Internal as _) };
                 match error {

compio-driver/src/iocp/cp/multi.rs

@@ -55,4 +55,8 @@ impl PortHandle {
     ) -> io::Result<()> {
         self.port.post(res, optr)
     }
+
+    pub fn post_raw<T: ?Sized>(&self, optr: *const Overlapped<T>) -> io::Result<()> {
+        self.port.post_raw(optr)
+    }
 }

compio-driver/src/iocp/mod.rs

@@ -281,10 +281,7 @@ impl NotifyHandle {
 
     /// Notify the inner driver.
     pub fn notify(&self) -> io::Result<()> {
-        self.port.post(
-            Ok(0),
-            self.overlapped.as_ref() as *const _ as *mut Overlapped<()> as _,
-        )
+        self.port.post_raw(self.overlapped.as_ref())
     }
 }