Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754163AbaKEKmA (ORCPT ); Wed, 5 Nov 2014 05:42:00 -0500 Received: from cn.fujitsu.com ([59.151.112.132]:28234 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753335AbaKEKl6 convert rfc822-to-8bit (ORCPT ); Wed, 5 Nov 2014 05:41:58 -0500 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="42891627" From: Chen Hanxiao To: "Eric W. Biederman" , Serge Hallyn , Oleg Nesterov CC: , , David Howells , Richard Weinberger , Pavel Emelyanov , Vasiliy Kulikov , Mateusz Guzik Subject: [PATCH 0/2v6] ns, procfs: pid conversion between ns and showing pidns hierarchy Date: Wed, 5 Nov 2014 18:41:53 +0800 Message-ID: <1415184115-12022-1-git-send-email-chenhanxiao@cn.fujitsu.com> X-Mailer: git-send-email 1.9.3 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Originating-IP: [10.167.226.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series will expose pid inside containers via procfs. Also show the hierarchy of pid namespcae. Then we could know how pid looks inside a container and their ns relationships. 1. helpful for nested container check/restore >From /proc/PID/ns/pid, we could know whether two pid lived in the same ns. >From this patch, we could know whether two pid had relationship between each other. 2. used for pid translation from container Ex: init_pid_ns ns1 ns2 t1 2 t2 `- 3 1 t3 `- 4 3 t4 `- 5 `- 5 1 t5 `- 6 `- 8 3 It could solve problems like: we see a pid 3 goes wrong in container's log, what is its pid on hosts: a) inside container: # readlink /proc/3/ns/pid pid:[4026532388] b) on host: # cat /proc/pidns_hierarchy 14918 16263 16581 Then we could easily find /proc/16263/ns/pid->4026532388. On host, we knew that reported pid 3 is in level 2, and its parental pid ns is from pid 14918. c) on host, check child of 16263, grep it from status: NSpid: 16268 8 3 We knew that pid 16268 is pid 3 reported by container. v6: fix some get_pid leaks and do some cleanups v5: collect pid by find_ge_pid; use local list inside nslist_proc_show; use get_pid, remove mutex lock. v4: simplify pid collection and some performance optimizamtion fix another race issue. v3: fix a race issue and memory leak issue in pidns_hierarchy; add another two fielsd: NSpgid and NSsid. v2: use a procfs text file instead of dirs under /proc for showing pidns hierarchy; add two new fields: NStgid and NSpid keep fields of Tgid and Pid unchanged for back compatibility. Chen Hanxiao (2): v5 procfs: show hierarchy of pid namespace /proc/PID/status: show all sets of pid according to ns fs/proc/Kconfig | 6 ++ fs/proc/Makefile | 1 + fs/proc/array.c | 17 ++++ fs/proc/pidns_hierarchy.c | 227 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 251 insertions(+) create mode 100644 fs/proc/pidns_hierarchy.c -- 1.9.3 -- 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/