diff --git a/sys/fs/vfs/file.c b/sys/fs/vfs/file.c
index 62f5d55..93dfb95 100644
--- a/sys/fs/vfs/file.c
+++ b/sys/fs/vfs/file.c
@@ -317,6 +317,10 @@
   assert(fd->mp);
   assert(fd->mp->fs);
 
+  kprintf("fd[0x%X]\m", fd);
+  kprintf("fd->mp[0x%X]\m", fd->mp);
+  kprintf("fd->mp->fs[0x%X]\m", fd->mp->fs);
+
   if (fd != 0x0) {
     fd->mp->fs->vfsWrite(fd, ptr, fd->offset, size * nmemb);
     fd->offset += size * nmemb;