man: rework UMask= explanation

Mention the JSON user record stuff. Mention pam_umask explicitly.
Mention that UMask= of the per-user user@.service instance can be used
too.

Fixes: #16963
This commit is contained in:
Lennart Poettering 2020-09-14 11:03:59 +02:00 committed by Zbigniew Jędrzejewski-Szmek
parent 2a03b9ed21
commit 60bcb45927
1 changed files with 11 additions and 6 deletions

View File

@ -863,12 +863,17 @@ CapabilityBoundingSet=~CAP_B CAP_C</programlisting>
<listitem><para>Controls the file mode creation mask. Takes an access mode in octal notation. See
<citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry> for
details. Defaults to 0022 for system units. For units of the user service manager the default value
is inherited from the user instance (whose default is inherited from the system service manager, and
thus also is 0022). Hence changing the default value of a user instance, either via
<varname>UMask=</varname> or via a PAM module, will affect the user instance itself and all user
units started by the user instance unless a user unit has specified its own
<varname>UMask=</varname>.</para></listitem>
details. Defaults to 0022 for system units. For user units the default value is inherited from the
per-user service manager (whose default is in turn inherited from the system service manager, and
thus typically also is 0022 — unless overriden by a PAM module). In order to change the per-user mask
for all user services, consider setting the <varname>UMask=</varname> setting of the user's
<filename>user@.service</filename> system service instance. The per-user umask may also be set via
the <varname>umask</varname> field of a user's <ulink url="https://systemd.io/USER_RECORD">JSON User
Record</ulink> (for users managed by
<citerefentry><refentrytitle>systemd-homed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
this field may be controlled via <command>homectl --umask=</command>). It may also be set via a PAM
module, such as <citerefentry
project='man-pages'><refentrytitle>pam_umask</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
</varlistentry>
<varlistentry>