Requested in https://github.com/systemd/systemd/pull/33214#discussion_r1630251308.
Also, reword error messages a bit. When /usr/lib/clock-epoch was introduced,
"build time" stopped being acurate. Just say "epoch" instead.
The same message ID is used in the manager and timesyncd. The event is
essentially equivalent for the user, and it seems reasonable that to search for
both at the same time.
The catalog entry is dropped. It provided almost no additional information above
the message. When the same message ID is now applied to messages from PID1 and
timesyncd, and the clock can be both advanced and rewound, it becomes very hard
to make the catalog entry provide something useful, because catalog entries don't
allow conditionalization.
We would attempt to take the built-in epoch twice. Since
advance_tstamp() is only called from one place, we don't need to do that.
Also, just pass usec_t instead of a pointer to stat buf.
Don't say we set the clock to "recorded timestamp" if we just set it
to the built-in epoch. Also, consistently say "advance" to make it clear
that we'll not attempt to rewind the clock here.
If we're updating on a system with an invalid clock, and we're installing
a newer system version with a higher update, adjust the clock. This
way the invariant that the clock is always later than
max(compile time, timestamp file, other timestamp file) is maintained.
Also, adjust the wording of messages. When /usr/lib/clock-epoch was
introduced, "build time" stopped being acurate. Just say "epoch" instead.
Previously systemd would not use /var/lib/systemd/timesync/clock. This means
that even if /var/ is mounted when systemd is started and the file is
available, we would potentially make one time jump and than another time jump.
From a user's POV, this doesn't seem useful at all.
Also, we would always let /usr/lib/clock-epoch take priority over the built-in
epoch. But there is no guarantee that this file is actually fresh. In
particular, a user may touch /usr/lib/clock-epoch to work around a broken clock
during installation (as recommended in [1]), and then this file will grow stale
over time.
So just load the three timestamps and use the highest one as the epoch.
[1] https://discussion.fedoraproject.org/t/f38-to-f39-40-dnf-system-upgrade-can-fail-on-raspberry-pi/92403
Anything that is part of src/shared becomes part of the shared library, which
is wasteful, because the library is linked into almost all binaries. The
library is also forms a separate link unit, so this prevents the function from
being inlined or such.
Also, move logging into the function. Now that it's not a library function,
there is no reason not to do that.
No functional change yet, just moving stuff around and message format
adjustments.
EPOCH_CLOCK_FILE is also made public for consistency, even though I don't
plan to use it outside of the one location.
Section "Description" didn't actually say what systemd does. And we had a giant
"Concepts" section that actually described units types and other details about
them. So let's move the basic description of functionality to "Description" and
rename the following section to "Units".
The link to the Original Design Document is moved to "See Also", it is of
historical interest mostly at this point.
The only actual change is that when talking about API filesystems, /dev is also
mentioned. (I think /sys+/proc+/dev are the canonical set and should be always
listed on one breath.)
A unit with StandardOutput=journal (the default) will get its stdout/stderr sockets
disconnected when journald stops, as the file descriptors on journald's side are
not preserved (it works on restart, as the FD Store keeps them open during restarts).
Set FileDescriptorStorePreserve=yes so that the journal FD's stay open during a soft
reboot, and applications don't get broken stdout/stderr.
It seems this introduced a regression in the CentOS CI;
14:25:58 FAILED TASKS:14:25:58 -------------
14:25:58 TEST-03-JOBS
14:25:58 TEST-52-HONORFIRSTSHUTDOWN
14:25:58 TEST-63-PATH
Revert for now.
This reverts commit da3c6fc553.
meson does not support changing compilation flags on the fly, when
doing so, the entire build directory has to be cleared explicitly, so
let's add a way to do that by setting WIPE=1.
Let's also allow developers to specify their own meson options via
$MESON_OPTIONS.
If the none format is specified, we don't use the extra trees at all
so let's make the dependencies on the subimages conditional on Format=
not being set to "none".
This speeds up builds when using Format=none.
