From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751308AbWI1ETk (ORCPT ); Thu, 28 Sep 2006 00:19:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750789AbWI1ETk (ORCPT ); Thu, 28 Sep 2006 00:19:40 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:38358 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1750786AbWI1ETj (ORCPT ); Thu, 28 Sep 2006 00:19:39 -0400 Message-ID: <451B4D58.9070401@garzik.org> Date: Thu, 28 Sep 2006 00:19:36 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.7 (X11/20060913) MIME-Version: 1.0 To: Andrew Morton CC: linux-scsi@vger.kernel.org, Greg KH , LKML , Linus Torvalds Subject: Re: [PATCH] Illustration of warning explosion silliness References: <20060928005830.GA25694@havoc.gtf.org> <20060927183507.5ef244f3.akpm@osdl.org> <451B29FA.7020502@garzik.org> <20060927203417.f07674de.akpm@osdl.org> In-Reply-To: <20060927203417.f07674de.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.3 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > And it's not sufficient to say "gee, I can't think of any reason why this > handler would return an error, so I'll design its callers to assume that". > It is _much_ better to design the callers to assume that callees _can_ > fail, and to stick the `return 0;' into the terminal callee. Because > things can change. huh? You're going off on a tangent. I agree with the above, just like I already agreed that SCSI needs better error checking. You're ignoring the API issue at hand. Let me say it again for the cheap seats: "search" You search a list, and stick a pointer somewhere when found. No hardware touched. No allocations. Real world. There is an example of usage in the kernel today. Yes, SCSI needs better error checking. Yes, device_for_each_child() actors _may_ return errors. No, that doesn't imply device_for_each_child() actors must be FORCED BY DESIGN to return error codes. It's just walking a list. The current implementation and API is fine... save for the "__must_check" marker itself. The actor CAN return an error code via the current API. CAN, not MUST. (using RFC language) Jeff