If I can't write, I want to know.

It's possible that the upload directory doesn't allow write, the
module should be aware of that.  Other reasons may be possible.

modules/exploits/unix/webapp/havalite_upload_exec.rb

@@ -107,6 +107,8 @@ class Metasploit3 < Msf::Exploit::Remote
 			fail_with(Exploit::Failure::Unknown, "#{peer} - Request timed out while uploading")
 		elsif res.code.to_i == 404
 			fail_with(Exploit::Failure::NotFound, "#{peer} - No upload.php found")
+		elsif res.body =~ /"error"\:"abort"/
+			fail_with(Exploit::Failure::Unknown, "#{peer} - Unable to write #{fname}")
 		end
 
 		return fname