With cgroup v2 the cgroup freezer is implemented as a cgroup
attribute called cgroup.freeze. cgroup can be frozen by writing "1"
to the file and kernel will send us a notification through
"cgroup.events" after the operation is finished and processes in the
cgroup entered quiescent state, i.e. they are not scheduled to
run. Writing "0" to the attribute file does the inverse and process
execution is resumed.
This commit exposes above low-level functionality through systemd's DBus
API. Each unit type must provide specialized implementation for these
methods, otherwise, we return an error. So far only service, scope, and
slice unit types provide the support. It is possible to check if a
given unit has the support using CanFreeze() DBus property.
Note that DBus API has a synchronous behavior and we dispatch the reply
to freeze/thaw requests only after the kernel has notified us that
requested operation was completed.
ubsan complains that we add an offset to a NULL ptr here in some cases.
Which isn't really a bug though, since we only use it as the end
condition for a for loop, but we can still fix it...
Fixes: #15522
Hiding the first column, which may contain bullet circles, with --no-legend
is undocumented and potentially unexpected. On the other hand, not printing
bullet circles with --plain is documented so hiding the column with that
switch is sensible.
The combination "--full --no-legend --no-pager --plain" is appropriate for
automated processing of systemctl output.
Add a simple check on the number of unit files that were found: return
`-ENOENT` when none is found from the function and thus `systemctl`
consequently exits with `1` (`EXIT_FAILURE`) if none were found.
Verification:
```bash
root@image:~# systemctl list-unit-files dbus-nonexistant.service; echo
$?
UNIT FILE STATE VENDOR PRESET
0 unit files listed.
1
root@image:~# systemctl list-unit-files dbus.service; echo $?
UNIT FILE STATE VENDOR PRESET
dbus.service static enabled
1 unit files listed.
0
```
Fixes#15082.
$ sudo ln -svf multi-user.target /run/systemd/generator.early/default.target
'/run/systemd/generator.early/default.target' -> 'multi-user.target'
$ sudo build/systemctl set-default --root=/ sysinit.target
Removed /etc/systemd/system/default.target.
Created symlink /etc/systemd/system/default.target → /usr/lib/systemd/system/sysinit.target.
Note: "multi-user.target" is the default unit (possibly a runtime override).
The output is not super informative, but it should be enough to point the user in
the right direction.
Fixes#3645.
The enum used for column names is integer type while table_set_display() is parsing
arguments on size_t alignment which may result in assert in table_set_display() if
the size between types missmatch. This patch cast the enums to size_t.
It also fixes all other occurences for table_set_display() and
table_set_sort().
Inside format_bytes, we return NULL if the value is UINT64_MAX. This
makes some kind of sense where this has some other semantic meaning than
being a value, but in this case the value is both a.) not the default
(so we definitely want to display it), and b.) means "infinity" (or
"max" in cgroup terminology).
This patch adds a small wrapper around format_bytes that can be used for
these cases, to avoid the following situation:
[root@tangsanjiao ~]# cat /sys/fs/cgroup/workload.slice/memory.low
max
[root@tangsanjiao ~]# systemctl show workload.slice -p MemoryLow
MemoryLow=infinity
[root@tangsanjiao ~]# systemctl status workload.slice | grep low:
Memory: 14.9G (low: (null))
After the patch:
[root@tangsanjiao ~]# systemctl status workload.slice | grep low:
Memory: 15.1G (low: infinity)
Will print a unit and all of its dependencies. Works with cat, status,
list-units, and list-unit-files. This flag can also be used in conjunction
with --reverse, --before, and --after.
We also vastly simplify the list_dependencies_get_dependencies logic.
Instead of using 5 strvs and merging them into one, use one strv and
have the bus append all the map values to it.
Fixes#9273
When processing list of units (either provided manually or as a
wildcard), let's skip units for which we don't have an on-disk
counterpart, but note the -ENOENT error code and propagate it back to
the user.
Fixes: #14082
Follow-up for 0d588deae2.
In that commit the output got moved a 2 chars to the right, hence make
sure to also shift the cgroup tree to the right, so that it gets
properly aligned under the cgroup path again.
Move the explanation of options three columns to the right: then almost
all options fit and we do not need to break lines so often.
When a multi-line explanation precedes a section break, i.e. there is a
half-line on the right side, do not use an empty space. This saves a line,
and actually looks visually better because the text is still clearly
separated, but we don't get the big vertical white space.
This copies the commands log-level and log-target (to query and set the current
settings) from systemd-analyze to systemctl, essentially reverting
a65615ca5d. Controllling the log level settings
of the manager is basic functionality, that should be available even if
systemd-analyze (which is more of an analysis tool) is not installed. This is
like dmesg and journalctl, which should be available even if a debugger and
more advanced tools to analyze the kernel are not available. (Note that dmesg
is used to control the log level too, not just to browse the kernel logs.)
I chose to copy&paste the methods from analyze.c to the new location. There
isn't enough code to share, because acquire_bus() in both places has a
different signature despite the same name, so the only part that is common
is the invocation of sd_bus_set_property().
This cleans up and unifies the outut of --help texts a bit:
1. Highlight the human friendly description string, not the command
line via ANSI sequences. Previously both this description string and
the brief command line summary was marked with the same ANSI
highlight sequence, but given we auto-page to less and less does not
honour multi-line highlights only the command line summary was
affectively highlighted. Rationale: for highlighting the description
instead of the command line: the command line summary is relatively
boring, and mostly the same for out tools, the description on the
other hand is pregnant, important and captions the whole thing and
hence deserves highlighting.
2. Always suffix "Options" with ":" in the help text
3. Rename "Flags" → "Options" in one case
4. Move commands to the top in a few cases
5. add coloring to many more help pages
6. Unify on COMMAND instead of {COMMAND} in the command line summary.
Some tools did it one way, others the other way. I am not sure what
precisely {} is supposed to mean, that uppercasing doesn't, hence
let's simplify and stick to the {}-less syntax
And minor other tweaks.
This makes the ask-password agent handling more alike the polkit agent
handling again, and introduces ask_password_agent_open_if_enabled() that
works just like the already existing polkit_agent_open_if_enabled().
For all units that aren't timers, if it is activated by another unit,
add the triggering unit under the "TriggeredBy:" header. If a unit can
trigger other units, print the units it triggers other the "Triggers:"
header.
See https://bugzilla.redhat.com/show_bug.cgi?id=1763488: when we say that
'foo@*.service' is not a valid unit name, this is not clear enough. Let's
include the name of the operation that does not support globbing in the
error message:
$ build/systemctl enable 'foo@*.service'
Glob pattern passed to enable, but globs are not supported for this.
Invalid unit name "foo@*.service" escaped as "foo@\x2a.service".
...
chase_symlinks() would return negative on error, and either a non-negative status
or a non-negative fd when CHASE_OPEN was given. This made the interface quite
complicated, because dependning on the flags used, we would get two different
"types" of return object. Coverity was always confused by this, and flagged
every use of chase_symlinks() without CHASE_OPEN as a resource leak (because it
would this that an fd is returned). This patch uses a saparate output parameter,
so there is no confusion.
(I think it is OK to have functions which return either an error or an fd. It's
only returning *either* an fd or a non-fd that is confusing.)
For executables which take a verb, we should list the verbs first, and
then options which modify those verbs second. The general layout of
the man page is from general description to specific details, usually
Overview, Commands, Options, Return Value, Examples, References.
Introduce support for configuring cpus and mems for processes using
cgroup v2 CPUSET controller. This allows users to limit which cpus
and memory NUMA nodes can be used by processes to better utilize
system resources.
The cgroup v2 interfaces to control it are cpuset.cpus and cpuset.mems
where the requested configuration is written. However, it doesn't mean
that the requested configuration will be actually used as parent cgroup
may limit the cpus or mems as well. In order to reflect the real
configuration cgroup v2 provides read-only files cpuset.cpus.effective
and cpuset.mems.effective which are exported to users as well.
The "Ex" variant was originally only added for ExecStartXYZ= but it makes
sense to have feature parity for the rest of the exec command properties
as well (e.g. ExecReload=, ExecStop=, etc).