Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755087AbXEDLnD (ORCPT ); Fri, 4 May 2007 07:43:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755097AbXEDLnC (ORCPT ); Fri, 4 May 2007 07:43:02 -0400 Received: from mailer.gwdg.de ([134.76.10.26]:45338 "EHLO mailer.gwdg.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755087AbXEDLnA (ORCPT ); Fri, 4 May 2007 07:43:00 -0400 Date: Fri, 4 May 2007 13:42:09 +0200 (MEST) From: Jan Engelhardt To: "Robert P. J. Day" cc: Andrew Morton , Linux Kernel Mailing List Subject: Re: [PATCH] Rewrite the MAJOR() macro as a call to imajor(). In-Reply-To: Message-ID: References: <20070503231814.e12ad2d7.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Report: Content analysis: 0.0 points, 6.0 required _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1344 Lines: 37 On May 4 2007 04:14, Robert P. J. Day wrote: >> On May 3 2007 23:18, Andrew Morton wrote: >> >> struct inode *i = file->f_mapping->host; >> >> >> >> - return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; >> >> + return i && S_ISBLK(i->i_mode) && imajor(i) == LOOP_MAJOR; >> >> } >> > >> >there's no runtime change, and I count a couple hundred MAJORs in the tree. >> >> Why do we even have imajor() if all it does is calling the MAJOR() >> macro? > > i'm guessing it's to hide the underlying implementation of >extracting the major/minor numbers from an inode, in case that >implementation ever changes, which strikes me as perfectly reasonable. How often has the implementation changed? I think i_rdev has been there for a looong time. But yes, doing the MAJOR => imajor conversion is preferable. Because you don't need the struct declaration for inode then, and may omit to #include . (Other things may need fs.h so it's a bit of a corner case.) > all i was doing was standardizing the small handful of holdouts. Please continue, this was not a rant :) Jan -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/