From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754408Ab0EPS0i (ORCPT ); Sun, 16 May 2010 14:26:38 -0400 Received: from mgw2.diku.dk ([130.225.96.92]:56465 "EHLO mgw2.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752806Ab0EPS0h (ORCPT ); Sun, 16 May 2010 14:26:37 -0400 Date: Sun, 16 May 2010 20:26:31 +0200 (CEST) From: Julia Lawall To: Al Viro Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: ERR_PTR and PTR_ERR In-Reply-To: <20100516173729.GE31073@ZenIV.linux.org.uk> Message-ID: References: <20100516173729.GE31073@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 16 May 2010, Al Viro wrote: > On Sun, May 16, 2010 at 11:05:23AM +0200, Julia Lawall wrote: > > On Sun, 16 May 2010, Julia Lawall wrote: > > > > > I see a number of occurrences of code like the following: > > > > > > if (IS_ERR(alg)) > > > return ERR_PTR(PTR_ERR(alg)); > > > > > > Is there any reason why the second line couldn't just be return alg? > > > > Hmm, never mind. It seems to address a type problem. > > More idiomatic way to deal with that is ERR_CAST(); see e.g. ext2_lookup() for > use case: Thanks. That looks much nicer than ERR_PTR(PTR_ERR(alg)). julia > ... > inode = NULL; > if (ino) { > inode = ext2_iget(dir->i_sb, ino); > if (unlikely(IS_ERR(inode))) { > if (PTR_ERR(inode) == -ESTALE) { > ext2_error(dir->i_sb, __func__, > "deleted inode referenced: %lu", > (unsigned long) ino); > return ERR_PTR(-EIO); > } else { > return ERR_CAST(inode); > } > } > } > return d_splice_alias(inode, dentry); > > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >