Much like for the mount units we need fields such as the slice
initialized by the time we activate the swap, hence when the kernel
let's us know about a new swap that appeared we need to initialize the
slice in any Swap object we allocated for that right-away, even if we
can't read the real unit file for the swap device.
For services (and other units) we generally follow the rule that at the
beginning of each cycle, i.e. when the INACTIVE/FAILED state is left for
ACTIVATING/ACTIVE we flush out various state variables. Mount units
handled this differently so far when the unit state change was effected
outside of systemd: in that case these variables would be flushed out
when going back to INACTIVE/FAILED already.
Let's fix that, and flush out this state always during the activating
transition, not during the deactivating transition.
We never know what the changes triggered by mount_set_state() do to the
unit. Let's be safe and copy the device path into our set, so that we
are safe against that.
It doesn't matter what kind of precise failure we had earlier with
loading the unit, let's report that it loaded successfully now, after
all the kernel is an OK source for that, like any other.
Whenever we notice a change on an existing /proc/self/mountinfo line,
let's update the deps generated from it. For that, let's flush out the
old deps generated this way, and add in the new ones.
This takes benefit of the fact that today (unlike a comment this patch
removes says) we can remove deps in a somewhat reasonable way.
Let's set 'from_proc_self_mountinfo' right away, since we know its from
there. This is important so that when the load queue is dispatched (and
thus mount_load() called) this
fact is already known.
In a previous commit we added logic that mount_add_extras() (or more
precisely mount_add_default_dependencies()) adds in dependencies on
remote-fs.target and local-fs.target, hence we can drop this from
mount_setup_new_unit() and let the usual load queue dispatching take
care of this.
Let's initialize two fields with free_and_strdup() rather than directly
with strdup(). The fields should not be initialized so far, but it's
still nicer to be prepared for futzre code changes and always free
what's stored before replacing it.
If we can't process a specific line in /proc/self/mountinfo we should
log about it (which we do), but this should not affect other lines, nor
further processing of mount units. Let's keep these failures local.
Fixes: #10874
We need to make sure that the slice property is initialized whenever
mount_load() is invoked, even if we fail to load things properly off
disk. This is important since we generally don't allow changing the
slice after a unit has been started. But given that we must track the
state of external objects with mount units we must hence initialize the
property no matter what.
This deps are very similar to the -pre deps, hence establish them at the
same place, in particular as they should only be generated if default
deps are on.
This allows us to later on remove similar code that adds in these deps
whenever /proc/self/mountinfo changes.
This adds a helper call for detaching a DnsServer from a DnsStream if
the latter is the "default" stream of the server.
Also, let's unref the stream in dns_stream_stop() rather than
dns_stream_free(): as soon as our stream is disconnected by stopping
there's really no need to keep it as default stream for the server
around.
Since dns_stream_free() calls dns_stream_stop() we can remove it from
the former.
DnsStream and DnsServer have a symbiotic relationship: one DnsStream is
the current "default" stream of the server (and thus reffed by it), but
each stream also refs the server it is connected to. This cyclic
dependency can result in weird situations: when one is
destroyed/unlinked/stopped it needs to unregister itself from the other,
but doing this will trigger unregistration of the other. Hence, let's
make sure we unregister the stream from the server before destroying it,
to break this cycle.
Most likely fixes: #10725
