Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751599Ab3GEWiF (ORCPT ); Fri, 5 Jul 2013 18:38:05 -0400 Received: from mail-bk0-f43.google.com ([209.85.214.43]:46783 "EHLO mail-bk0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750977Ab3GEWiD convert rfc822-to-8bit (ORCPT ); Fri, 5 Jul 2013 18:38:03 -0400 MIME-Version: 1.0 Reply-To: fdmanana@gmail.com In-Reply-To: <20130705204129.GB15943@logfs.org> References: <1370280485-10047-1-git-send-email-joern@logfs.org> <20130705204100.GA15943@logfs.org> <20130705204129.GB15943@logfs.org> Date: Fri, 5 Jul 2013 23:38:01 +0100 Message-ID: Subject: Re: [PATCH 1/2] list: add list_del_each_entry From: Filipe David Manana To: =?UTF-8?Q?J=C3=B6rn_Engel?= Cc: linux-kernel@vger.kernel.org, Chris Mason , "linux-btrfs@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2728 Lines: 78 On Fri, Jul 5, 2013 at 9:41 PM, Jörn Engel wrote: > I have seen a lot of boilerplate code that either follows the pattern of > while (!list_empty(head)) { > pos = list_entry(head->next, struct foo, list); > list_del(pos->list); > ... > } > or some variant thereof. > > With this patch in, people can use > list_del_each_entry(pos, head, list) { > ... > } > > The patch also adds a list_del_each variant, even though I have > only found a single user for that one so far. > > Signed-off-by: Joern Engel > --- > include/linux/list.h | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/include/linux/list.h b/include/linux/list.h > index 6a1f8df..ab39c7d 100644 > --- a/include/linux/list.h > +++ b/include/linux/list.h > @@ -557,6 +557,24 @@ static inline void list_splice_tail_init(struct list_head *list, > #define list_safe_reset_next(pos, n, member) \ > n = list_entry(pos->member.next, typeof(*pos), member) > > +/** > + * list_del_each - removes an entry from the list until it is empty > + * @pos: the &struct list_head to use as a loop cursor. > + * @head: the head of your list. > + */ > +#define list_del_each(pos, head) \ > + while (list_empty(head) ? 0 : (pos = (head)->next, list_del(pos), 1)) > + > +/** > + * list_del_each_entry - removes an entry from the list until it is empty > + * @pos: the type * to use as loop cursor. > + * @head: the head of your list. > + * @member: the name of the list_struct within the struct > + */ > +#define list_del_each_entry(pos, head, member) \ > + while (list_empty(head) && (pos = list_first_entry((head), \ > + typeof(*pos), member), list_del((head)->next), 1)) > + Shouldn't it be while (!list_empty(head) ... ? (not operator addition) thanks > /* > * Double linked lists with a single pointer list head. > * Mostly useful for hash tables where the two pointer list head is > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Filipe David Manana, "Reasonable men adapt themselves to the world. Unreasonable men adapt the world to themselves. That's why all progress depends on unreasonable men." -- 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/