The unit load queue can be processed in the middle of setting the
unit's properties, so its load_state would no longer be UNIT_STUB
for the check in bus_unit_set_properties(), which would cause it to
incorrectly return an error.
By default, each iteration of manager_dispatch_sigchld() results in a unit level
sigchld event being invoked. For scope units, this results in a scope_sigchld_event()
which can seemingly stall for workloads that have a large number of PIDs within the
scope. The stall exhibits itself as a SIG_0 being initiated for each u->pids entry
as a result of pid_is_unwaited().
v2:
This patch resolves this condition by only paying to cost of a sigchld in the underlying
scope unit once per sigchld iteration. A new "sigchldgen" member resides within the
Unit struct. The Manager is incremented via the sd event loop, accessed via
sd_event_get_iteration, and the Unit member is set to the same value as the manager each
time that a sigchld event is invoked. If the Manager iteration value and Unit member
match, the sigchld event is not invoked for that iteration.
unit_write_drop_in{,_private}{,_format} are all affected.
We already append a header to the file (and section markers), so those functions
can only be used to write a whole file at once. Including the newline at
the end feels natural.
After this commit newlines will be duplicated. They will be removed in
subsequent commit.
Also, rewrap the "autogenerated" header to fit within 80 columns.
We currently generate log message about unit being started even when
unit was started already and job didn't do anything. This is because job
was requested explicitly and hence became anchor job of the transaction
thus we could not eliminate it. That is fine but, let's not pollute
journal with useless log messages.
$ systemctl start systemd-resolved
$ systemctl start systemd-resolved
$ systemctl start systemd-resolved
Current state:
$ journalctl -u systemd-resolved | grep Started
May 05 15:31:42 rawhide systemd[1]: Started Network Name Resolution.
May 05 15:31:59 rawhide systemd[1]: Started Network Name Resolution.
May 05 15:32:01 rawhide systemd[1]: Started Network Name Resolution.
After patch applied:
$ journalctl -u systemd-resolved | grep Started
May 05 16:42:12 rawhide systemd[1]: Started Network Name Resolution.
Fixes#1723
unit_set_slice() fails with -EBUSY if the unit already has a slice associated
with it. This makes it impossible to override slice through dropin config or
over dbus. There's no reason to disallow slice changes as long as cgroups
aren't realized. Fix it.
Fixes#3240.
Signed-off-by: Tejun Heo <htejun@fb.com>
Reported-by: Davide Cavalca <dcavalca@fb.com>
On the unified hierarchy, blkio controller is renamed to io and the interface
is changed significantly.
* blkio.weight and blkio.weight_device are consolidated into io.weight which
uses the standardized weight range [1, 10000] with 100 as the default value.
* blkio.throttle.{read|write}_{bps|iops}_device are consolidated into io.max.
Expansion of throttling features is being worked on to support
work-conserving absolute limits (io.low and io.high).
* All stats are consolidated into io.stats.
This patchset adds support for the new interface. As the interface has been
revamped and new features are expected to be added, it seems best to treat it
as a separate controller rather than trying to expand the blkio settings
although we might add automatic translation if only blkio settings are
specified.
* io.weight handling is mostly identical to blkio.weight[_device] handling
except that the weight range is different.
* Both read and write bandwidth settings are consolidated into
CGroupIODeviceLimit which describes all limits applicable to the device.
This makes it less painful to add new limits.
* "max" can be used to specify the maximum limit which is equivalent to no
config for max limits and treated as such. If a given CGroupIODeviceLimit
doesn't contain any non-default configs, the config struct is discarded once
the no limit config is applied to cgroup.
* lookup_blkio_device() is renamed to lookup_block_device().
Signed-off-by: Tejun Heo <htejun@fb.com>
And let's make it more accurate: if we have acquire the list of unit drop-ins,
then let's do a full comparison against the old list we already have, and if
things differ in any way, we know we have to reload.
This makes sure we detect changes to drop-in directories in more cases.
This fixes fall-out from 6d10d308c6.
Until that commit, do determine whether a daemon reload was required we compare
the mtime of the main unit file we loaded with the mtime of it on disk for
equality, but for drop-ins we only stored the newest mtime of all of them and
then did a "newer-than" comparison. This was brokeni with the above commit,
when all checks where changed to be for equality.
With this change all checks are now done as "newer-than", fixing the drop-in
mtime case. Strictly speaking this will not detect a number of changes that the
code before above commit detected, but given that the mtime is unlikely to go
backwards, and this is just intended to be a helpful hint anyway, this looks OK
in order to keep things simple.
Fixes: #3123
Let's move the enforcement of the per-unit start limit from unit.c into the
type-specific files again. For unit types that know a concept of "result" codes
this allows us to hook up the start limit condition to it with an explicit
result code. Also, this makes sure that the state checks in clal like
service_start() may be done before the start limit is checked, as the start
limit really should be checked last, right before everything has been verified
to be in order.
The generic start limit logic is left in unit.c, but the invocation of it is
moved into the per-type files, in the various xyz_start() functions, so that
they may place the check at the right location.
Note that this change drops the enforcement entirely from device, slice, target
and scope units, since these unit types generally may not fail activation, or
may only be activated a single time. This is also documented now.
Note that restores the "start-limit-hit" result code that existed before
6bf0f408e4 already in the service code. However,
it's not introduced for all units that have a result code concept.
Fixes#3166.
The concept of merging units exists so that we can create Unit objects for a
number of names early, and then load them only later, possibly merging units
which then turn out to be symlinked to other names. This of course only makes
sense for unit types where multiple names per unit are supported. For all
others, let's refuse the merge operation early.
With #2564 unit start rate limiting was moved from after the condition checks
are to before they are made, in an attempt to fix#2467. This however resulted
in #2684. However, with a previous commit a concept of per socket unit trigger
rate limiting has been added, to fix#2467 more comprehensively, hence the
start limit can be moved after the condition checks again, thus fixing #2684.
Fixes: #2684
This adds a new GetProcesses() bus call to the Unit object which returns an
array consisting of all PIDs, their process names, as well as their full cgroup
paths. This is then used by "systemctl status" to show the per-unit process
tree.
This has the benefit that the client-side no longer needs to access the
cgroupfs directly to show the process tree of a unit. Instead, it now uses this
new API, which means it also works if -H or -M are used correctly, as the
information from the specific host is used, and not the one from the local
system.
Fixes: #2945
There's no point in first determining the drop-in file name path, then
forgetting it again, and then determining it again. Instead, just generated it
once, and then write to ti directly.
With this change the logic for placing transient unit files and drop-ins
generated via "systemctl set-property" is reworked.
The latter are now placed in the newly introduced "control" unit file
directory. The fomer are now placed in the "transient" unit file directory.
Note that the properties originally set when a transient unit was created will
be written to and stay in the transient unit file directory, while later
changes are done via drop-ins.
This is preparation for a later "systemctl revert" addition, where existing
drop-ins are flushed out, but the original transient definition is restored.
The drop-in order we present should actually show what we is in effect, hence
let's not reorder it when writing changes. After all, just sorting
alphabetically is going to break things, as it doesn't respect that /etc breaks
/run breaks /usr...
Previously, transient units were created below the normal runtime directory
/run/systemd/system. With this change they are created in a special transient
directory /run/systemd/transient, which only contains data for transient units.
This clarifies the life-cycle of transient units, and makes clear they are
distinct from user-provided runtime units. In particular, users may now
extend transient units via /run/systemd/system, without systemd interfering
with the life-cycle of these files.
This change also adds code so that when a transient unit exits only the
drop-ins in this new directory are removed, but nothing else.
Fixes: #2139
This replaces the old function call manager_is_reloading_or_reexecuting() which
was used only at very few places. Use the new macro wherever we check whether
we are reloading. This should hopefully make things a bit more readable, given
the nature of Manager:n_reloading being a counter.
Previously, we had two enums ManagerRunningAs and UnitFileScope, that were
mostly identical and converted from one to the other all the time. The latter
had one more value UNIT_FILE_GLOBAL however.
Let's simplify things, and remove ManagerRunningAs and replace it by
UnitFileScope everywhere, thus making the translation unnecessary. Introduce
two new macros MANAGER_IS_SYSTEM() and MANAGER_IS_USER() to simplify checking
if we are running in one or the user context.
* core/unit: extract checking of stat paths into helper function
The same code was repeated three times.
* core: treat masked files as "unchanged"
systemctl prints the "unit file changed on disk" warning
for a masked unit. I think it's better to print nothing in that
case.
When a masked unit is loaded, set mtime as 0. When checking
if a unit with mtime of 0 needs reload, check that the mask
is still in place.
* test-dnssec: fix build without gcrypt
Also reorder the test functions to follow the way they are called
from main().
systemctl prints the "unit file changed on disk" warning
for a masked unit. I think it's better to print nothing in that
case.
When a masked unit is loaded, set mtime as 0. When checking
if a unit with mtime of 0 needs reload, check that the mask
is still in place.
Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands. Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.
Support for net_cls.class_id through the NetClass= configuration directive
has been added in v227 in preparation for a per-unit packet filter mechanism.
However, it turns out the kernel people have decided to deprecate the net_cls
and net_prio controllers in v2. Tejun provides a comprehensive justification
for this in his commit, which has landed during the merge window for kernel
v4.5:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd1060a1d671
As we're aiming for full support for the v2 cgroup hierarchy, we can no
longer support this feature. Userspace tool such as nftables are moving over
to setting rules that are specific to the full cgroup path of a task, which
obsoletes these controllers anyway.
This commit removes support for tweaking details in the net_cls controller,
but keeps the NetClass= directive around for legacy compatibility reasons.
This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section
into the [Unit] section of unit files, and thus support it in all unit types, not just in services.
This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that
repeated start-up failure due to failed conditions is also considered for the start limit logic.
For compatibility the four options may also be configured in the [Service] section still, but we only document them in
their new section [Unit].
This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express
more clearly what it is about, after all it's only triggered through the start limit being hit.
Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike.
Fixes: #2467
This clean-ups timeout handling in PID 1. Specifically, instead of storing 0 in internal timeout variables as
indication for a disabled timeout, use USEC_INFINITY which is in-line with how we do this in the rest of our code
(following the logic that 0 means "no", and USEC_INFINITY means "never").
This also replace all usec_t additions with invocations to usec_add(), so that USEC_INFINITY is properly propagated,
and sd-event considers it has indication for turning off the event source.
This also alters the deserialization of the units to restart timeouts from the time they were originally started from.
Before this patch timeouts would be restarted beginning with the time of the deserialization, which could lead to
artificially prolonged timeouts if a daemon reload took place.
Finally, a new RuntimeMaxSec= setting is introduced for service units, that specifies a maximum runtime after which a
specific service is forcibly terminated. This is useful to put time limits on time-intensive processing jobs.
This also simplifies the various xyz_spawn() calls of the various types in that explicit distruction of the timers is
removed, as that is done anyway by the state change handlers, and a state change is always done when the xyz_spawn()
calls fail.
Fixes: #2249
This adds a new timestamp field to the Unit struct, storing when the last low-level state change took place, and make
sure this is restored after a daemon reload. This new field is useful to allow restarting of per-state timers exactly
where they originally started.
