Linux-Fsdevel Archive on lore.kernel.org
 help / color / Atom feed
From: Kirill Tkhai <ktkhai@virtuozzo.com>
To: viro@zeniv.linux.org.uk, adobriyan@gmail.com,
	davem@davemloft.net, ebiederm@xmission.com,
	akpm@linux-foundation.org, christian.brauner@ubuntu.com,
	areber@redhat.com, serge@hallyn.com,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	ktkhai@virtuozzo.com
Subject: [PATCH 00/23] proc: Introduce /proc/namespaces/ directory to expose namespaces lineary
Date: Thu, 30 Jul 2020 14:59:20 +0300
Message-ID: <159611007271.535980.15362304262237658692.stgit@localhost.localdomain> (raw)

Currently, there is no a way to list or iterate all or subset of namespaces
in the system. Some namespaces are exposed in /proc/[pid]/ns/ directories,
but some also may be as open files, which are not attached to a process.
When a namespace open fd is sent over unix socket and then closed, it is
impossible to know whether the namespace exists or not.

Also, even if namespace is exposed as attached to a process or as open file,
iteration over /proc/*/ns/* or /proc/*/fd/* namespaces is not fast, because
this multiplies at tasks and fds number.

This patchset introduces a new /proc/namespaces/ directory, which exposes
subset of permitted namespaces in linear view:

# ls /proc/namespaces/ -l
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'cgroup:[4026531835]' -> 'cgroup:[4026531835]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'ipc:[4026531839]' -> 'ipc:[4026531839]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'mnt:[4026531840]' -> 'mnt:[4026531840]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'mnt:[4026531861]' -> 'mnt:[4026531861]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'mnt:[4026532133]' -> 'mnt:[4026532133]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'mnt:[4026532134]' -> 'mnt:[4026532134]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'mnt:[4026532135]' -> 'mnt:[4026532135]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'mnt:[4026532136]' -> 'mnt:[4026532136]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'net:[4026531993]' -> 'net:[4026531993]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'pid:[4026531836]' -> 'pid:[4026531836]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'time:[4026531834]' -> 'time:[4026531834]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'user:[4026531837]' -> 'user:[4026531837]'
lrwxrwxrwx 1 root root 0 Jul 29 16:50 'uts:[4026531838]' -> 'uts:[4026531838]'

Namespace ns is exposed, in case of its user_ns is permitted from /proc's pid_ns.
I.e., /proc is related to pid_ns, so in /proc/namespace we show only a ns, which is

	in_userns(pid_ns->user_ns, ns->user_ns).

In case of ns is a user_ns:

	in_userns(pid_ns->user_ns, ns).

The patchset follows this steps:

1)A generic counter in ns_common is introduced instead of separate
  counters for every ns type (net::count, uts_namespace::kref,
  user_namespace::count, etc). Patches [1-8];
2)Patch [9] introduces IDR to link and iterate alive namespaces;
3)Patch [10] is refactoring;
4)Patch [11] actually adds /proc/namespace directory and fs methods;
5)Patches [12-23] make every namespace to use the added methods
  and to appear in /proc/namespace directory.

This may be usefull to write effective debug utils (say, fast build
of networks topology) and checkpoint/restore software.
---

Kirill Tkhai (23):
      ns: Add common refcount into ns_common add use it as counter for net_ns
      uts: Use generic ns_common::count
      ipc: Use generic ns_common::count
      pid: Use generic ns_common::count
      user: Use generic ns_common::count
      mnt: Use generic ns_common::count
      cgroup: Use generic ns_common::count
      time: Use generic ns_common::count
      ns: Introduce ns_idr to be able to iterate all allocated namespaces in the system
      fs: Rename fs/proc/namespaces.c into fs/proc/task_namespaces.c
      fs: Add /proc/namespaces/ directory
      user: Free user_ns one RCU grace period after final counter put
      user: Add user namespaces into ns_idr
      net: Add net namespaces into ns_idr
      pid: Eextract child_reaper check from pidns_for_children_get()
      proc_ns_operations: Add can_get method
      pid: Add pid namespaces into ns_idr
      uts: Free uts namespace one RCU grace period after final counter put
      uts: Add uts namespaces into ns_idr
      ipc: Add ipc namespaces into ns_idr
      mnt: Add mount namespaces into ns_idr
      cgroup: Add cgroup namespaces into ns_idr
      time: Add time namespaces into ns_idr


 fs/mount.h                     |    4 
 fs/namespace.c                 |   14 +
 fs/nsfs.c                      |   78 ++++++++
 fs/proc/Makefile               |    1 
 fs/proc/internal.h             |   18 +-
 fs/proc/namespaces.c           |  382 +++++++++++++++++++++++++++-------------
 fs/proc/root.c                 |   17 ++
 fs/proc/task_namespaces.c      |  183 +++++++++++++++++++
 include/linux/cgroup.h         |    6 -
 include/linux/ipc_namespace.h  |    3 
 include/linux/ns_common.h      |   11 +
 include/linux/pid_namespace.h  |    4 
 include/linux/proc_fs.h        |    1 
 include/linux/proc_ns.h        |   12 +
 include/linux/time_namespace.h |   10 +
 include/linux/user_namespace.h |   10 +
 include/linux/utsname.h        |   10 +
 include/net/net_namespace.h    |   11 -
 init/version.c                 |    2 
 ipc/msgutil.c                  |    2 
 ipc/namespace.c                |   17 +-
 ipc/shm.c                      |    1 
 kernel/cgroup/cgroup.c         |    2 
 kernel/cgroup/namespace.c      |   25 ++-
 kernel/pid.c                   |    2 
 kernel/pid_namespace.c         |   46 +++--
 kernel/time/namespace.c        |   20 +-
 kernel/user.c                  |    2 
 kernel/user_namespace.c        |   23 ++
 kernel/utsname.c               |   23 ++
 net/core/net-sysfs.c           |    6 -
 net/core/net_namespace.c       |   18 +-
 net/ipv4/inet_timewait_sock.c  |    4 
 net/ipv4/tcp_metrics.c         |    2 
 34 files changed, 746 insertions(+), 224 deletions(-)
 create mode 100644 fs/proc/task_namespaces.c

--
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>


             reply index

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-30 11:59 Kirill Tkhai [this message]
2020-07-30 11:59 ` [PATCH 01/23] ns: Add common refcount into ns_common add use it as counter for net_ns Kirill Tkhai
2020-07-30 13:35   ` Christian Brauner
2020-07-30 14:07     ` Kirill Tkhai
2020-07-30 15:59       ` Christian Brauner
2020-07-30 14:30   ` Christian Brauner
2020-07-30 14:34     ` Kirill Tkhai
2020-07-30 14:39       ` Christian Brauner
2020-07-30 11:59 ` [PATCH 02/23] uts: Use generic ns_common::count Kirill Tkhai
2020-07-30 14:30   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 03/23] ipc: " Kirill Tkhai
2020-07-30 14:32   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 04/23] pid: " Kirill Tkhai
2020-07-30 14:37   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 05/23] user: " Kirill Tkhai
2020-07-30 14:46   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 06/23] mnt: " Kirill Tkhai
2020-07-30 14:49   ` Christian Brauner
2020-07-30 11:59 ` [PATCH 07/23] cgroup: " Kirill Tkhai
2020-07-30 14:50   ` Christian Brauner
2020-07-30 12:00 ` [PATCH 08/23] time: " Kirill Tkhai
2020-07-30 14:52   ` Christian Brauner
2020-07-30 12:00 ` [PATCH 09/23] ns: Introduce ns_idr to be able to iterate all allocated namespaces in the system Kirill Tkhai
2020-07-30 12:23   ` Matthew Wilcox
2020-07-30 13:32     ` Kirill Tkhai
2020-07-30 13:56       ` Matthew Wilcox
2020-07-30 14:12         ` Kirill Tkhai
2020-07-30 14:15           ` Matthew Wilcox
2020-07-30 14:20             ` Kirill Tkhai
2020-07-30 12:00 ` [PATCH 10/23] fs: Rename fs/proc/namespaces.c into fs/proc/task_namespaces.c Kirill Tkhai
2020-07-30 12:00 ` [PATCH 11/23] fs: Add /proc/namespaces/ directory Kirill Tkhai
2020-07-30 12:18   ` Alexey Dobriyan
2020-07-30 13:22     ` Kirill Tkhai
2020-07-30 13:26   ` Christian Brauner
2020-07-30 14:30     ` Kirill Tkhai
2020-07-30 20:47   ` kernel test robot
2020-07-30 22:20   ` kernel test robot
2020-08-05  8:17   ` kernel test robot
2020-08-05  8:17   ` [RFC PATCH] fs: namespaces_dentry_operations can be static kernel test robot
2020-07-30 12:00 ` [PATCH 12/23] user: Free user_ns one RCU grace period after final counter put Kirill Tkhai
2020-07-30 12:00 ` [PATCH 13/23] user: Add user namespaces into ns_idr Kirill Tkhai
2020-07-30 12:00 ` [PATCH 14/23] net: Add net " Kirill Tkhai
2020-07-30 12:00 ` [PATCH 15/23] pid: Eextract child_reaper check from pidns_for_children_get() Kirill Tkhai
2020-07-30 12:00 ` [PATCH 16/23] proc_ns_operations: Add can_get method Kirill Tkhai
2020-07-30 12:00 ` [PATCH 17/23] pid: Add pid namespaces into ns_idr Kirill Tkhai
2020-07-30 12:00 ` [PATCH 18/23] uts: Free uts namespace one RCU grace period after final counter put Kirill Tkhai
2020-07-30 12:01 ` [PATCH 19/23] uts: Add uts namespaces into ns_idr Kirill Tkhai
2020-07-30 12:01 ` [PATCH 20/23] ipc: Add ipc " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 21/23] mnt: Add mount " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 22/23] cgroup: Add cgroup " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 23/23] time: Add time " Kirill Tkhai
2020-07-30 13:08 ` [PATCH 00/23] proc: Introduce /proc/namespaces/ directory to expose namespaces lineary Christian Brauner
2020-07-30 13:38   ` Christian Brauner
2020-07-30 14:34 ` Eric W. Biederman
2020-07-30 14:42   ` Christian Brauner
2020-07-30 15:01   ` Kirill Tkhai
2020-07-30 22:13     ` Eric W. Biederman
2020-07-31  8:48       ` Pavel Tikhomirov
2020-08-03 10:03       ` Kirill Tkhai
2020-08-03 10:51         ` Alexey Dobriyan
2020-08-06  8:05         ` Andrei Vagin
2020-08-07  8:47           ` Kirill Tkhai
2020-08-10 17:34             ` Andrei Vagin
2020-08-11 10:23               ` Kirill Tkhai
2020-08-12 17:53                 ` Andrei Vagin
2020-08-13  8:12                   ` Kirill Tkhai
2020-08-14  1:16                     ` Andrei Vagin
2020-08-14 15:11                       ` Kirill Tkhai
2020-08-14 19:21                         ` Andrei Vagin
2020-08-17 14:05                           ` Kirill Tkhai
2020-08-17 15:48                             ` Eric W. Biederman
2020-08-17 17:47                               ` Christian Brauner
2020-08-17 18:53                                 ` Eric W. Biederman
2020-08-04  5:43     ` Andrei Vagin
2020-08-04 12:11       ` Pavel Tikhomirov
2020-08-04 14:47       ` Kirill Tkhai

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=159611007271.535980.15362304262237658692.stgit@localhost.localdomain \
    --to=ktkhai@virtuozzo.com \
    --cc=adobriyan@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=areber@redhat.com \
    --cc=christian.brauner@ubuntu.com \
    --cc=davem@davemloft.net \
    --cc=ebiederm@xmission.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=serge@hallyn.com \
    --cc=viro@zeniv.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Fsdevel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-fsdevel/0 linux-fsdevel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-fsdevel linux-fsdevel/ https://lore.kernel.org/linux-fsdevel \
		linux-fsdevel@vger.kernel.org
	public-inbox-index linux-fsdevel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-fsdevel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git