sys: FspFsvolSetDispositionInformation: ignore FILE_DISPOSITION_FORCE_IMAGE_SECTION_CHECK flag

src/sys/fileinfo.c

@@ -1513,16 +1513,26 @@ retry:
         if (!NT_SUCCESS(Result))
             goto unlock_exit;
 
-        if (FlagOn(DispositionFlags, FILE_DISPOSITION_FORCE_IMAGE_SECTION_CHECK))
+        /*
-        {
+         * Make sure no process is mapping the file as an image.
-            /* make sure no process is mapping the file as an image */
+         *
+         * NOTE:
+         *     Turns out that NTFS always does this test, even when
+         *     FILE_DISPOSITION_FORCE_IMAGE_SECTION_CHECK has been specified.
+         *     If MmFlushImageSection fails (e.g. an actively running EXE) then
+         *     it only allows the deletion to go through when a secondary hard
+         *     link is being deleted.
+         *
+         *     Since WinFsp does not support hard links, we will go ahead and
+         *     ignore the FILE_DISPOSITION_FORCE_IMAGE_SECTION_CHECK flag and
+         *     always respect the result of MmFlushImageSection.
+         */
         Success = MmFlushImageSection(FileObject->SectionObjectPointer, MmFlushForDelete);
         if (!Success)
         {
             Result = STATUS_CANNOT_DELETE;
             goto unlock_exit;
         }
-        }
 
         if (FlagOn(DispositionFlags, FILE_DISPOSITION_IGNORE_READONLY_ATTRIBUTE))
         {

tst/winfsp-tests/exec-test.c

@@ -200,6 +200,27 @@ static void exec_delete_dotest(ULONG Flags, PWSTR Prefix, ULONG FileInfoTimeout)
     ASSERT(!DeleteFileW(FilePath));
     ASSERT(ERROR_ACCESS_DENIED == GetLastError());
 
+    {
+        MY_FILE_DISPOSITION_INFO_EX DispositionInfo;
+        HANDLE Handle;
+        BOOLEAN Success;
+        Handle = CreateFileW(FilePath,
+            DELETE, FILE_SHARE_DELETE, 0,
+            OPEN_EXISTING, 0, 0);
+        if (INVALID_HANDLE_VALUE != Handle)
+        {
+            DispositionInfo.Disposition = FILE_DISPOSITION_DELETE | FILE_DISPOSITION_POSIX_SEMANTICS;
+            Success = SetFileInformationByHandle(Handle,
+                21/*FileDispositionInfoEx*/, &DispositionInfo, sizeof DispositionInfo);
+            ASSERT(!Success);
+            ASSERT(
+                ERROR_INVALID_PARAMETER == GetLastError() ||
+                ERROR_ACCESS_DENIED == GetLastError());
+            Success = CloseHandle(Handle);
+            ASSERT(Success);
+        }
+    }
+
     WaitHelper(Process, 1000);
 
     ASSERT(DeleteFileW(FilePath));

tst/winfsp-tests/winfsp-tests.h

@@ -154,6 +154,10 @@ typedef struct
 {
     BOOLEAN Disposition;
 } MY_FILE_DISPOSITION_INFO;
+typedef struct
+{
+    UINT32 Disposition;
+} MY_FILE_DISPOSITION_INFO_EX;
 
 void *memfs_start_ex(ULONG Flags, ULONG FileInfoTimeout);
 void *memfs_start(ULONG Flags);