Manual pages: mount.8, umount.8: Clarify that "namespace" means "mount namespace"
There are various references to "namespaces" when it would be
clearer to say "mount namespaces". Also, add references to the
mount_namespaces(7) manual page.
Signed-off-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Manual pages: unshare.1: EXAMPLES: improve persistent mount namespace example
The text describing the persistent mount namespace example
is rather confused. Explain more clearly the purpose of making
the parent directory a bind mount with private propagation.
Also make a few other wording improvements.
Signed-off-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Helge Deller [Wed, 27 May 2020 23:20:58 +0000 (23:20 +0000)]
setarch: fix stderr handling in uname26 tests
A while ago stdout and stderr have been split in these testcases, but
"FATAL: kernel too old" is actually treated as an "okay" output. However
this FATAL ends up on stderr, so when it happens, it is not seen in
the captured stdout.
Fix this by merging stdout/stderr in these cases once again.
Earlier, I patched various pages to consistently use EXAMPLE as a
section heading, rather than EXAMPLES. (At that time, both headings
occurred in util-linux, with roughly equal frequency.)
Since then, I've observed that EXAMPLES is the more common usage
across a large corpus of manual pages. So, in Linux the man-pages
project, I switched to using EXAMPLES also. This patch makes the same
change for util-linux.
Signed-off-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Sami Kerola [Mon, 25 May 2020 07:30:24 +0000 (08:30 +0100)]
more: avoid libmagic telling an empty file is binary
My earlier change that took libmagic in use to identify mime-type of an input
file caused empty files to be marked binary. Before the change empty files
were simply displayed as empty. This change will restore that behavior.
Michael Kerrisk [Sat, 23 May 2020 06:43:25 +0000 (08:43 +0200)]
Manual pages: unshare.1: fix examples, part 3
The time namespaces example had no explanatory text! Add some.
Also, use the "uptime -p" option for output that is more compact
(and perhaps more readable).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk [Sat, 23 May 2020 06:43:24 +0000 (08:43 +0200)]
Manual pages: unshare.1: fix examples, part 2
The explanation of the --kill-child example was quite confused and
also the example shell demo was broken because of quoting issues.
It is not the case that the *children* of 'program' would adopted by
init, but rather that 'program' itself (which would be running as PID
1 inside the namespace and is a child of 'unshare') would be adopted
by init.
Rework the --kill-child example. Add a lot more explanation, and
expand the example shell session to give the reader a much better
picture of what is going on.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk [Sat, 23 May 2020 06:43:23 +0000 (08:43 +0200)]
Manual pages: unshare.1: fix examples, part 1
The examples section of this manual page is rather hard to grok.
First, the arrangement of the text as follows makes life harder
than needed for the reader:
shell demo
explanatory text
It helps the reader if an example *begins* with an explanation of
what is being demonstrated. Therefore, rearrange these examples as:
explanatory text
shell demo
In addition, let's provide a bit more explanation for the first three
examples and expand the second example (user namespaces) a little.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk [Sat, 23 May 2020 06:43:21 +0000 (08:43 +0200)]
Manual pages: nsenter.1: clarify the intro discussion
The intro paragraph talks about entering the namespace of other
processes. That's not quite accurate, since nsenter can be used (via
a bind mount) to enter a namespace that has no member processes. So
rework NAME and the intro paragraph in DESCRIPTION to remove mention
of "processes".
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk [Sat, 23 May 2020 06:43:20 +0000 (08:43 +0200)]
Manual pages: unshare.1: improve intro paragraphs
The intro paragraphs of this page are rather hard for a newcomer to
grok. The name of the underlying system call (and consequently the
name of the command) are "strange", but let's help the reader by
naming more clearly what unshare(1) does: creating new namespaces. In
addition, clarify and expand the details on making a namespace
persistent using bind mounts.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk [Sat, 23 May 2020 06:43:19 +0000 (08:43 +0200)]
Manual pages: nsenter.1, unshare.1: remove repeated references to clone(2)
Back in commits f85b9777c2965671cd and 894efece9eb894, in the
description of each namespace type, I added repeated cross references
to clone(2). Drop these references. The Section 7 namespaces pages,
which are already noted in the nsenter(1) and unshare(1) manual pages,
provide much more relevant information. Furthermore, pointing the
reader at clone(2) is perhaps a little misleading, since the system
call underlying nsenter(1) is setns(2) and the system call underlying
unshare(1) is unshare(2).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk [Sat, 23 May 2020 06:43:17 +0000 (08:43 +0200)]
Manual pages: nsenter.1, unshare.1: update references to *_namespaces(7) pages
Nowadays, the Linux man-pages project provides separate Section 7
manual pages for each type of namespace. Update the cross references
in nsenter.1 and unshare.1 to reflect this.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Karel Zak [Fri, 22 May 2020 12:39:31 +0000 (14:39 +0200)]
fstrim: add --listed-in <file[:file ..]>
This new option works like --all but it allows to specify multiple
files with filesystems to make fstrim configuration more portable
between distributions. For example:
Karel Zak [Mon, 11 May 2020 11:35:21 +0000 (13:35 +0200)]
hwclock: improve use of settimeofday() portability
The different libc implements TZ deprecation in settimeofday() library
function in the different way. Let's hide these portability issues and
use directly Linux syscall to set timezone.
Addresses: https://github.com/karelzak/util-linux/issues/995 Signed-off-by: Karel Zak <kzak@redhat.com> CC: J William Piggott <elseifthen@gmx.com>
Manual pages: order ENVIRONMENT / FILES / CONFORMING TO consistently
There is value in ensuring that manual page sections use consistently
named sections, as far as possible, and also that sections have a
consistent order within manual pages. This is one of a series of patches
to place manual page sections in a consistent order.
In this patch, we ensure that the ENVIRONMENT, FILES, and CONFORMING TO
sections are always placed toward the end of the page, just above NOTES.
One page is not fixed by this patch: term-utils/agetty.8. This page
is a mess of unusual section names, and probably requires an individual
edit.
Testing that no gross editing mistake (causing accidental loss or addition
of text) was performed as follows:
$ cat $(grep '\.SH' -l $(find . -name '*.[1-9]') |sort) | sort > a
[Apply patch]
$ cat $(grep '\.SH' -l $(find . -name '*.[1-9]') |sort) | sort > b
$ diff a b
$ echo $?
0
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: order NOTES / HISTORY / BUGS / EXAMPLE consistently
There is value in ensuring that manual page sections use consistently
named sections, as far as possible, and also that sections have a
consistent order within manual pages. This is one of a series of patches
to place manual page sections in a consistent order.
In this patch, we ensure that the NOTES, HISTORY, BUGS, and EXAMPLE
sections are always placed near the end of the page, just above
AUTHORS, COPYRIGHT, SEE ALSO, and AVAILABILITY.
One page is not fixed by this patch: term-utils/agetty.8. This page
is a mess of unusual section names, and probably requires an individual
edit.
Testing that no gross editing mistake (causing accidental loss or addition
of text) was performed as follows:
$ cat $(grep '\.SH' -l $(find . -name '*.[1-9]') |sort) | sort > a
[Apply patch]
$ cat $(grep '\.SH' -l $(find . -name '*.[1-9]') |sort) | sort > b
$ diff a b
$ echo $?
0
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: order AUTHORS / COPYRIGHT / SEE ALSO / AVAILABILITY consistently
There is value in ensuring that manual page sections use consistently
named sections, as far as possible, and also that sections have a
consistent order within manual pages. This is one of a series of patches
to place manual page sections in a consistent order.
In this patch, we ensure that the AUTHORS, COPYRIGHT, SEE ALSO, and
AVAILABILITY sections are always placed at the end of the page.
Testing that no gross editing mistake (causing accidental loss or addition
of text) was performed as follows:
$ cat $(grep '\.SH' -l $(find . -name '*.[1-9]') |sort) | sort > a
[Apply patch]
$ cat $(grep '\.SH' -l $(find . -name '*.[1-9]') |sort) | sort > b
$ diff a b
$ echo $?
0
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Karel Zak [Fri, 22 May 2020 08:22:12 +0000 (10:22 +0200)]
agetty: ignore ^C
Danc86 wrote:
With agetty 2.32.1 and earlier, ^C at the login prompt is ignored. I
noticed when upgrading to agetty 2.34, typing ^C now causes agetty to
stop responding for 10 seconds and then it dies (and gets restarted by
system and a new login prompt is printed).
It logs this message:
agetty[46048]: ttyS0: invalid character 0x3 in login name
Previously the !isprint(ascval) condition would have caused control
characters like ^C (\x03) to be discarded, whereas now it falls
through to trying to decode it as part of a UTF-8 sequence, and then
fails.
Fixes: http://github.com/karelzak/util-linux/commit/5de9751997cf490088f62f41fd92be57cf7ceea4
Addresses: https://github.com/karelzak/util-linux/issues/1046 Signed-off-by: Karel Zak <kzak@redhat.com>
Etienne Mollier [Thu, 21 May 2020 15:20:18 +0000 (17:20 +0200)]
bash-completion/umount: shell charaters escape
This patch brings support for automatic dangerous shell characters
escape in umount autocompletion. Due to the very peculiar way for
bash to handle autocompletion routines, proper escaping of the shell
sequences only worked properly inside a function: _umount_point_list,
which will add to the user's namespace at the next umount attempt of
autocompleting mount point.
It also translates calls of gensub to the portable alternatives sub
and gsub, in order to allow the use of various awk implementations
(mawk, Gnu, Busybox, etc), and as such kind of undoes a recent change
to enforce the use of Gnu awk. The whole story landed into the Debian
BTS initially:
The manual pages currently use a multitude of terms--"exit code",
"error code", "return code", "exit code", and so on--when what
is always meant is "exit status" (the POSIX term). This patch fixes
as many of these erroneous terms as I could find.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: Standardize on EXIT STATUS as section title
There is quite some value (in terms of readability and user
expectations) if consistent names are used for the sections
within manual pages. This patch is one of a series to bring
about this consistency.
Currently we have EXIT STATUS (18), EXIT CODES (3), RETURN CODE (7),
RETURN CODES (1), or RETURN VALUE (4 instances in pages that document
commands, rather than functions).
Let's standardize on the EXIT STATUS (which is also what is
suggested in man-pages(7), and is the POSIX terminology).
A subsequent patch will clean up corresponding miswordings in
manual page text.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: Standardize on ENVIRONMENT as section title
There is quite some value (in terms of readability and user
expectations) if consistent names are used for the sections
within manual pages. This patch is one of a series to bring
about this consistency.
But, let's make sure that the section is consistently titled
across pages. Currently we have ENVIRONMENT (many) or ENVIRONMENT
VARIABLES (3). Let's standardize on ENVIRONMENT (which is also
what is suggested in man-pages(7)).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: Standardize on OPTIONS as section title
There is quite some value (in terms of readability and user
expectations) if consistent names are used for the sections
within manual pages. This patch is one of a series to bring
about this consistency.
Currently we have OPTIONS (many) or OPTION (1 page, setpriv(1),
which actually supports multiple options!).
Let's standardize on OPTIONS (which is also what is
suggested in man-pages(7)).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: Standardize on CONFORMING TO as section title
There is quite some value (in terms of readability and user
expectations) if consistent names are used for the sections
within manual pages. This patch is one of a series to bring
about this consistency.
Currently we have STANDARDS (3) or CONFORMING TO (6).
Let's standardize on the latter (which is also what is
suggested in man-pages(7)).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: Standardize on EXAMPLE as section title
There is quite some value (in terms of readability and user
expectations) if consistent names are used for the sections
within manual pages. This patch is one of a series to bring
about this consistency.
Currently we have EXAMPLE (10) or EXAMPLES (23).
Let's standardize on the EXAMPLE (which is also what is
suggested in man-pages(7)) and used consistently across
a large number of pages in the Linux man-pages project.
(I realize the choice to go EXAMPLE, rather than EXAMPLES,
may be debatable. If necessary, I'd write a patch that instead
goes the other way, but I'd prefer to follow man-pages(7).)
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Manual pages: Standardize on AUTHORS as section title
There is quite some value (in terms of readability and user
expectations) if consistent names are used for the sections
within manual pages. This patch is one of a series to bring
about this consistency.
In the Linux man-pages project, I long ago did away with the
AUTHOR(S) section, but I realize some projects like to keep this.
But, let's make sure that the section is consistently titled
across pages. Currently we have AUTHOR (47) or AUTHORS (41).
Let's standardize on the latter (which is also what is
suggested in man-pages(7)).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Using double quotes in .SH lines containing multiple words is unneeded,
and in any case is not consistently done in the util-linux manual pages,
where double quotes are used in only around half of the cases.
(This usage was long ago elminated in the man-pages project, with
no ill effects reported to date.)
Remove these quotes, so that .SH lines are more uniform, in preparation
for some (more easily) scripted doiscovery of consistency problems in
(and possibly global fixes to) the manual pages.
Other than stripping the double quotes, this patch makes no changes to
the content of the manual pages.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Karel Zak [Tue, 19 May 2020 08:55:20 +0000 (10:55 +0200)]
agetty: extend --issue-file to support multiple paths
The current default behavior is to print the first issue file/dir and
all alternative locations are used as a backup solution only. If something
is found than the rest is ignored. The --issue-file allow to overwrite
this default behavior, but currently it supports only one file/dir.
This patch extend --issue-file to support ':' separated list of paths
and *all* the files (if exist and no empty) in the list are printed.
Karel Zak [Mon, 18 May 2020 12:13:33 +0000 (14:13 +0200)]
libfdisk: (dos) be more robust about max number of partitions
It seems the previous MAXIMUM_PARTS bug fix has not been generic
enough. Let's use the check for all dos_add_partition().
This patch also remove libfdisk attempt to be smart and search for
unused primary partition. If you need more than 60 partition in MBR
than you have a different problem that cannot be solved by libfdisk
...
References: http://github.com/karelzak/util-linux/commit/b80fb30a5b79ce2cc8c7486e1435ec061aa79e2f
Addresses: https://github.com/karelzak/util-linux/issues/1022 Signed-off-by: Karel Zak <kzak@redhat.com>
Karel Zak [Mon, 18 May 2020 09:21:22 +0000 (11:21 +0200)]
Merge branch 'cal_column' of https://github.com/utix/util-linux
* 'cal_column' of https://github.com/utix/util-linux:
cal: Remove todo
cal: Add test, all are checked against ncal
cal: Update man page
cal: Add column mode
cal: Add helper functions for left align
cal: Add weekdays into cal_control
Michael Kerrisk [Sat, 16 May 2020 07:45:11 +0000 (09:45 +0200)]
ipcs.1: ipcs no longer needs read permission on IPC resources
With changes starting around util-linux commit 058e81540fbb0d2b78
that switched from using IPC_STAT to parsing /proc/sysvipc/*,
ipcs now shows all IPC objects rather than just the objects for
which the user has read permission. Update the page to reflect this
fact, and also add a NOTES section describing the historical and
fallback behavior where /proc is not available.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
an-old.tmac: <./sys-utils/mount.8>:2427 (.RE): warning: extra .RE or .RS is missing before it; "an-RS-open" is 0.
Input file is ././sys-utils/unshare.1
<./sys-utils/unshare.1>:176 (macro BR): only 1 argument, but more are expected
<./sys-utils/unshare.1>:181 (macro BR): only 1 argument, but more are expected
<./sys-utils/unshare.1>:240 (macro BR): only 1 argument, but more are expected
<./sys-utils/unshare.1>:246 (macro BR): only 1 argument, but more are expected
Input file is ././term-utils/agetty.8
troff: backtrace: file '<./term-utils/agetty.8>':130
troff: <./term-utils/agetty.8>:130: warning: trailing space
Input file is ././text-utils/more.1
troff: backtrace: file '<./text-utils/more.1>':91
troff: <./text-utils/more.1>:91: warning: macro 'b' not defined
The output from nroff and troff is unchanged, except for the word
"number" in text-utils/more.1, that was missing.
If a user submits a zone management ioctl from user-space, like a zone
reset and a file-system (like zonefs or f2fs) is mounted on the zoned
block device, the zone will get reset and the file-system's cached value
of the zone's write-pointer becomes invalid.
Subsequent writes to this zone from the file-system will result in
unaligned writes and the drive will error out.
Open the block device file in exclusive mode for submitting these ioctls.
If a file-system is mounted the kernel will return -EBUSY and we can't
continue issuing the ioctl.
Reported-by: Coly Li <colyli@suse.de> Cc: Damien Le Moal <Damien.LeMoal@wdc.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Karel Zak <kzak@redhat.com>
Lsblk throws the following error for nvmeNcXnY devices.
lsblk: nvme1c1n1: unknown device name
This is because nvmeNcXnY devices are hidden and do not have
the file /sys/block/<nvmeNcXnY>/dev.
Following patch was added
https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=d51f05bfecb299a830897106460bf395be440c0a
Which made lsblk read from /sys/block/<nvmeNcXnY>/device/dev
which do exist for nvmeNcXnY devices.
After the above patch, the unknown error goes away.
However, another error is encountered in the very next step.
nvme1c1n1: failed to initialize sysfs handler
This is because lsblk looks for /sys/dev/block/242:1
(nvmeNcXnY major:minor) pathname which usually exists for other
block devices but not for the nvmeNcXnY devices as they are hidden.
Below patch does not even print this error for hidden devices
and exits silently.
[kzak@redhat.com: - add prefix to make sysfs_devname_is_hidden()
usable for /sys dumps
- use the function in initialize_device() more early]
Signed-off-by: Ritika Srivastava <ritika.srivastava@oracle.com> Signed-off-by: Karel Zak <kzak@redhat.com>
It seems that directories like /etc/motd.d are already used by PAM or
by another stuff. Let's keep it in admin/distro hands and do not
change the current default.
Karel Zak [Tue, 12 May 2020 12:20:54 +0000 (14:20 +0200)]
login: add support for directories in MOTD_FILE=
The current standard is to use directories to make it easy for
distributions to share resources. This patch also add /etc/motd.d
and /run/motd.d to the default MOTD_FILE=.
Addresses: https://github.com/karelzak/util-linux/issues/10341 Signed-off-by: Karel Zak <kzak@redhat.com>
Sami Kerola [Wed, 6 May 2020 19:19:23 +0000 (20:19 +0100)]
more: make page and arrow up/down to update view
Aim was to introduce page and arrow up/down keys to more(1), but that
also required merging colon_command() and more_key_command() functions.
The more_key_commands enum is pointless from computers point of view.
The command identification performed in read_command() inline with
more_key_command() execution -- but that would be hard for humans, and
source code ought to serve both parties.
Reference: https://github.com/karelzak/util-linux/pull/1003 Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Sami Kerola [Wed, 6 May 2020 19:19:22 +0000 (20:19 +0100)]
more: use libmagic to identify binary files
As the old commend said: 'This code would best be shared with the file(1)
program or, perhaps, more should not try to be so smart'. Now at configure
time one can choose whether more(1) is sharing code with file(1), or not.
Addresses: http://bugs.debian.org/139205 Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Wolfram Sang [Mon, 11 May 2020 16:10:48 +0000 (18:10 +0200)]
sfdisk: avoid unneeded empty lines with '--list-free'
Similar to commit 4a52959d1 ("(s)fdisk: avoid unneeded empty lines with
'--list'"), there were also two superfluous empty lines when /dev/sr0
didn't contain a medium. Refactor the '--list-free' code the same way as
in the mentioned commit.
Wolfram Sang [Wed, 6 May 2020 10:39:21 +0000 (12:39 +0200)]
(s)fdisk: avoid unneeded empty lines with '--list'
On my system, I got two superfluous empty lines because /dev/sr0 didn't
contain a medium. Refactor the code to handle the seperator within
print_device_pt() and print it only when assigning the device worked.
This unifies handling between print_all_devices_pt and (s)fdisk because
the latter did not consider the return code for the seperator while the
former did. Also, it saves some lines of code.
Addresses: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=814184 (first part) Signed-off-by: Wolfram Sang <wsa@kernel.org>
libblkid: add dax capability detection in topology probing
The dax (direct access) blockdev capability is exposed via sysfs, add it
to the list of topology values to be obtained while probing.
Expose blkid_topology_get_dax() symbol that programs can link against
for querying the capability.
Reorder the idinfos array to give precedence to the sysfs over ioctl so
that the dax probe has a chance to be executed, as there is no ioctl
interface for it.
Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
Mark Hindley [Tue, 5 May 2020 19:28:55 +0000 (21:28 +0200)]
tests: Fix for misc/fallocate test build failure.
This was already a known possible failure case. However, in the migration to a
clearer separation of stdout and stderr in the testsuite, the logfile used to
detect the failure was not updated.
Karel Zak [Mon, 4 May 2020 10:27:42 +0000 (12:27 +0200)]
agetty: save the original speed on --keep-baud
agetty cycling through the baud rates specified on command line
(triggered by BREAK). Unfortunately, the original baud rate (probably
the best one) is tried only first time on --keep-baud.
Addresses: https://github.com/karelzak/util-linux/issues/1025 Signed-off-by: Karel Zak <kzak@redhat.com>
Sven Wiltink [Fri, 1 May 2020 14:35:40 +0000 (16:35 +0200)]
lsblk: Fall back to ID_SERIAL
In some cases ID_SERIAL_SHORT isn't provided by libudev, but ID_SERIAL
is. An example of this are virtio devices. See the output of udevadm
info:
P: /devices/pci0000:00/0000:00:06.0/virtio2/block/vdb
N: vdb
S: disk/by-id/virtio-08491434ee711d3420e9
S: disk/by-path/pci-0000:00:06.0
S: disk/by-path/virtio-pci-0000:00:06.0
E: DEVLINKS=/dev/disk/by-id/virtio-08491434ee711d3420e9 /dev/disk/by-path/pci-0000:00:06.0 /dev/disk/by-path/virtio-pci-0000:00:06.0
E: DEVNAME=/dev/vdb
E: DEVPATH=/devices/pci0000:00/0000:00:06.0/virtio2/block/vdb
E: DEVTYPE=disk
E: ID_PATH=pci-0000:00:06.0
E: ID_PATH_TAG=pci-0000_00_06_0
E: ID_SERIAL=08491434ee711d3420e9
E: MAJOR=252
E: MINOR=16
E: SUBSYSTEM=block
E: TAGS=:systemd:
E: USEC_INITIALIZED=1403804
[kzak@redhat.com: - add ID_SERIAL also to get_properties_by_file()]
After unshare(...) is called, /proc/self/ns/pid does not change.
Instead, only /proc/self/ns/pid_for_children is affected. So bind-mounting
/proc/self/ns/pid results in the original namespace getting bind-mounted.
Fix this by instead bind-mounting ns/pid_for_children.