From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Emelyanov Subject: [PATCH][NETNS] Use list_for_each_entry_continue_reverse in setup_net Date: Mon, 17 Sep 2007 15:02:53 +0400 Message-ID: <46EE5EDD.1030005@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Eric W. Biederman" , Linux Netdev List , devel@openvz.org To: David Miller Return-path: Received: from sacred.ru ([62.205.161.221]:47785 "EHLO sacred.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752119AbXIQLFZ (ORCPT ); Mon, 17 Sep 2007 07:05:25 -0400 Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org I proposed introducing a list_for_each_entry_continue_reverse macro to be used in setup_net() when unrolling the failed ->init callback. Here is the macro and some more cleanup in the setup_net() itself to remove one variable from the stack :) Minor, but the code looks nicer. Signed-off-by: Pavel Emelyanov Acked-by: "Eric W. Biederman" --- include/linux/list.h | 14 ++++++++++++++ net/core/net_namespace.c | 8 +++----- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/include/linux/list.h b/include/linux/list.h index f29fc9c..ad9dcb9 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -525,6 +525,20 @@ static inline void list_splice_init_rcu( pos = list_entry(pos->member.next, typeof(*pos), member)) /** + * list_for_each_entry_continue_reverse - iterate backwards from the given point + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + * + * Start to iterate over list of given type backwards, continuing after + * the current position. + */ +#define list_for_each_entry_continue_reverse(pos, head, member) \ + for (pos = list_entry(pos->member.prev, typeof(*pos), member); \ + prefetch(pos->member.prev), &pos->member != (head); \ + pos = list_entry(pos->member.prev, typeof(*pos), member)) + +/** * list_for_each_entry_from - iterate over list of given type from the current point * @pos: the type * to use as a loop cursor. * @head: the head for your list. diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 1fc513c..a9dd261 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -102,7 +102,6 @@ static int setup_net(struct net *net) { /* Must be called with net_mutex held */ struct pernet_operations *ops; - struct list_head *ptr; int error; memset(net, 0, sizeof(struct net)); @@ -110,8 +109,7 @@ static int setup_net(struct net *net) atomic_set(&net->use_count, 0); error = 0; - list_for_each(ptr, &pernet_list) { - ops = list_entry(ptr, struct pernet_operations, list); + list_for_each_entry(ops, &pernet_list, list) { if (ops->init) { error = ops->init(net); if (error < 0) @@ -120,12 +118,12 @@ static int setup_net(struct net *net) } out: return error; + out_undo: /* Walk through the list backwards calling the exit functions * for the pernet modules whose init functions did not fail. */ - for (ptr = ptr->prev; ptr != &pernet_list; ptr = ptr->prev) { - ops = list_entry(ptr, struct pernet_operations, list); + list_for_each_entry_continue_reverse(ops, &pernet_list, list) { if (ops->exit) ops->exit(net); }