For units which are aliases of other units, reporting preset status as
"enabled" is rather misleading. For example, dbus.service is an alias of
dbus-broker.service. In list-unit-files we'd show both as "enabled". In
particular, systemctl preset ignores aliases, so showing any preset status at
all is always going to be misleading. Let's introduce a new state "alias" and
use that for all aliases.
I was trying to avoid adding a new state, to keep compatibility with previous
behaviour, but for alias unit files it simply doesn't seem very useful to show
any of the existing states. It seems that the clearly showing that those are
aliases for other units will be easiest to understand for users.
When doing list-unit-files with --root, we would re-read the preset
list for every unit. This uses a cache to only do it once. The time
for list-unit-files goes down by about ~30%.
unit_file_query_preset() is also called from src/core/. This patch does not
touch that path, since the saving there are smaller, since preset status is
only read on demand over dbus, and caching would be more complicated.
$ systemctl --no-pager --root /tmp/root2/ cat ctrl-alt-del.target
Failed to resolve symlink /tmp/root2/etc/systemd/system/ctrl-alt-del.target pointing to /usr/lib/systemd/system/reboot.target, ignoring: Channel number out of range
...
Let's be extra careful whenever we return from recvmsg() and see
MSG_CTRUNC set. This generally means we ran into a programming error, as
we didn't size the control buffer large enough. It's an error condition
we should at least log about, or propagate up. Hence do that.
This is particularly important when receiving fds, since for those the
control data can be of any size. In particular on stream sockets that's
nasty, because if we miss an fd because of control data truncation we
cannot recover, we might not even realize that we are one off.
(Also, when failing early, if there's any chance the socket might be
AF_UNIX let's close all received fds, all the time. We got this right
most of the time, but there were a few cases missing. God, UNIX is hard
to use)
Let's define a new, generic bus interface that any daemon can implement
for querying/setting the log level.
We can turn this into something more powerful later on, but for now,
only expose three properties: the log level, log target and the syslog
identifier (with the former two being writable).
This is supposed to be generic, so that it can be implemented by 3rd
party daemons too, eventually.
It's not that I think that "hostname" is vastly superior to "host name". Quite
the opposite — the difference is small, and in some context the two-word version
does fit better. But in the tree, there are ~200 occurrences of the first, and
>1600 of the other, and consistent spelling is more important than any particular
spelling choice.
The watchdog ping is performed for every iteration of manager event
loop. This results in a lot of ioctls on watchdog device driver
especially during boot or if services are aggressively using sd_notify.
Depending on the watchdog device driver this may have performance
impact on embedded systems.
The patch skips sending the watchdog to device driver if the ping is
requested before half of the watchdog timeout.
It's pretty, and it highlights that the pw prompt is kinda special and
needs user input.
We suppress the emoji entirel if there's no emoji support (i.e. this
means we suppress the ASCII replacement), since it carries no additional
information, it is just decoration to highlight a line.
An stdio FILE* stream usually refers to something with a file
descriptor, but that's just "usually". It doesn't have to, when taking
fmemopen() and similar into account. Most of our calls to fileno()
assumed the call couldn't fail. In most cases this was correct, but in
some cases where we didn't know whether we work on files or memory we'd
use the returned fd as if it was unconditionally valid while it wasn't,
and passed it to a multitude of kernel syscalls. Let's fix that, and do
something reasonably smart when encountering this case.
(Running test-fileio with this patch applied will remove tons of ioctl()
calls on -1).
