From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vadim Kochan Subject: [PATCH iproute2 v2] man ip-netns: Notice about loose device when do 'del' Date: Sun, 15 Mar 2015 13:51:42 +0200 Message-ID: <1426420302-13755-1-git-send-email-vadim4j@gmail.com> Cc: develop@kristov.de, Vadim Kochan To: netdev@vger.kernel.org Return-path: Received: from mail-la0-f46.google.com ([209.85.215.46]:33013 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751720AbbCOMDX (ORCPT ); Sun, 15 Mar 2015 08:03:23 -0400 Received: by ladw1 with SMTP id w1so19823232lad.0 for ; Sun, 15 Mar 2015 05:03:21 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Vadim Kochan Signed-off-by: Vadim Kochan --- v2: Fixed wrong 'xargs' command - noticed by Christoph Schulz man/man8/ip-netns.8 | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/man/man8/ip-netns.8 b/man/man8/ip-netns.8 index 28a9544..34c02b6 100644 --- a/man/man8/ip-netns.8 +++ b/man/man8/ip-netns.8 @@ -46,6 +46,9 @@ ip-netns \- process network namespace management A network namespace is logically another copy of the network stack, with its own routes, firewall rules, and network devices. +By default process inherites network namespace from its parent. Initially all +the processes shares the same default network namespace from the init process. + By convention a named network namespace is an object at .BR "/var/run/netns/" NAME that can be opened. The file descriptor resulting from opening @@ -88,14 +91,30 @@ network namespace and assigns NAME. .sp If NAME is present in /var/run/netns it is umounted and the mount point is removed. If this is the last user of the network namespace the -network namespace will be freed, otherwise the network namespace -persists until it has no more users. ip netns delete may fail if -the mount point is in use in another mount namespace. +network namespace will be freed and all physical devices will be moved to the +default one, otherwise the network namespace persists until it has no more +users. ip netns delete may fail if the mount point is in use in another mount +namespace. If .B -all option was specified then all the network namespace names will be removed. +It is possible to "loose" the physical device when it was moved to netns and +then this netns was deleted with a running process: + + $ ip netns add net0 + $ ip link set dev eth0 netns net0 + $ ip netns exec net0 SOME_PROCESS_IN_BACKGROUND + $ ip netns del net0 + +and eth0 will appear in the default netns only after SOME_PROCESS_IN_BACKGROUND +will exit or will be killed. To prevent this the processes running in net0 +should be killed before deleting the netns: + + $ ip netns pids net0 | xargs kill + $ ip netns del net0 + .TP .B ip netns set NAME NETNSID - assign an id to a peer network namespace .sp -- 2.3.1