From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756727Ab1HSUlQ (ORCPT ); Fri, 19 Aug 2011 16:41:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:26203 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755633Ab1HSUlM (ORCPT ); Fri, 19 Aug 2011 16:41:12 -0400 Message-ID: <4E4ECA5D.1020907@redhat.com> Date: Fri, 19 Aug 2011 22:41:01 +0200 From: Milan Broz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:5.0) Gecko/20110807 Thunderbird/5.0 MIME-Version: 1.0 To: "Eric W. Biederman" CC: device-mapper development , Linux Kernel Mailing List , Kay Sievers , "David S. Miller" , containers@lists.osdl.org Subject: Re: [dm-devel] clone() with CLONE_NEWNET breaks kobject_uevent_env() References: <4E4CDF44.5080109@redhat.com> <4E4E395B.7070106@redhat.com> <4E4E503B.3050406@redhat.com> In-Reply-To: X-Enigmail-Version: 1.2.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/19/2011 08:39 PM, Eric W. Biederman wrote: > But Kay's suggestion to use netlink_has_listeners() seems like good > idea. IOW if there is no listener, it should skip quietly and not > fail the whole call... > In the case of ESRCH I completely agree. > > We are currently ignoring errors in the semantically more interesting > case when netlink_broadcast does not deliver the packet to one of the > listening netlink sockets. > > How does this patch look? Well, your version still returns -ESRCH, so it is not helping much :-) If you meant to handle it like I fixed in patch below (ignore ESRCH) then I am ok with that approach, patch below fixes the problem we have. Thanks, Milan diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 70af0a7..04b2ed2 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -139,6 +139,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, u64 seq; int i = 0; int retval = 0; + bool delivery_failure; #ifdef CONFIG_NET struct uevent_sock *ue_sk; #endif @@ -251,6 +252,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, if (retval) goto exit; + delivery_failure = false; #if defined(CONFIG_NET) /* send netlink message */ mutex_lock(&uevent_sock_mutex); @@ -281,14 +283,17 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, 0, 1, GFP_KERNEL, kobj_bcast_filter, kobj); - /* ENOBUFS should be handled in userspace */ - if (retval == -ENOBUFS) + if (retval == -ESRCH) retval = 0; + else if (retval) + delivery_failure = true; } else - retval = -ENOMEM; + delivery_failure = true; } mutex_unlock(&uevent_sock_mutex); #endif + if (delivery_failure) + retval = -ENOBUFS; /* call uevent_helper, usually only enabled during early boot */ if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {