For now, it's systemd itself that parses the options string, but as soon
as util-linux' swapon can take the option string directly with -o we
should pass it on unmodified.
We used to make all .swap units either RequiredBy=swap.target or
WantedBy=swap.target. But swap.target should be the "configured swap
units", either through /etc/fstab or non-generated .swap units. It
is surprising when systemd starts treating a swap device that was
possibly temporarily enabled as a hard dependency for other units.
So do not add dependencies with swap.target for units gleaned from
/proc/swaps.
Similarly, we added dependencies for all aliases of the device name,
which clutters up the dependency graph but does not seem to bring any
value, since the status of those following units is consistent with
the main one anyway.
This should be a fix for [1], and it seems the right thing to do
anyway.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1114786
Phenomenon: parameters configured in /etc/fstab for swap units are
ignored. E.g. pri= settings have no effect when systemd starts swap
units. What is even more confusing, .swap units for the name used in
/etc/fstab initially show proper values for Priority=, but after
starting them, they are re-initalized from /proc/swaps and show the -1
value from /proc/swaps.
Change swap units to follow the original configured unit. This way
proper settings are used when starting the swap.
Previous code would only return correct results when discard
was the last option.
While at it, avoid incorrect behaviour for (invalid) 'pri' option
not followed by '=...', and also do not return -1 as the error code.
It is redundant to store 'hash' and 'compare' function pointers in
struct Hashmap separately. The functions always comprise a pair.
Store a single pointer to struct hash_ops instead.
systemd keeps hundreds of hashmaps, so this saves a little bit of
memory.
This way, the list of arguments to that function gets more comprehensive,
and we can get around passing lots of NULL and 0 arguments from socket.c,
swap.c and mount.c.
It also allows for splitting up the code in exec_spawn().
While at it, make ExecContext const in execute.c.
Let's automatically initialize the kill, exec and cgroup contexts of the
various unit types when the object is constructed, instead of
invididually in type-specific code.
Also, when PrivateDevices= is set, set DevicePolicy= to closed.
Previously the returned object of constructor functions where sometimes
returned as last, sometimes as first and sometimes as second parameter.
Let's clean this up a bit. Here are the new rules:
1. The object the new object is derived from is put first, if there is any
2. The object we are creating will be returned in the next arguments
3. This is followed by any additional arguments
Rationale:
For functions that operate on an object we always put that object first.
Constructors should probably not be too different in this regard. Also,
if the additional parameters might want to use varargs which suggests to
put them last.
Note that this new scheme only applies to constructor functions, not to
all other functions. We do give a lot of freedom for those.
Note that this commit only changes the order of the new functions we
added, for old ones we accept the wrong order and leave it like that.
Given that we now have KillMode=mixed where SIGTERM might kill a smaller
set than SIGKILL we need to make sure to always go explicitly throught
the SIGKILL state to get the right end result.
This was introduced in e1770af812 (2012-02-03, swap: replace failure
boolean by result enum).
This just removes unneeded lines of code, no functional change.
Also, introduce a new environment variable named $WATCHDOG_PID which
cotnains the PID of the process that is supposed to send the keep-alive
events. This is similar how $LISTEN_FDS and $LISTEN_PID work together,
and protects against confusing processes further down the process tree
due to inherited environment.
This way, we can avoid executing two /bin/swapon jobs to be dispatched
for the same swap device if it is configured for two different paths.
Previously we were just tracking the device nodes of active swap
devices, which would not allow us to recognize the identity of two swap
devices before they are active.
https://bugs.freedesktop.org/show_bug.cgi?id=69835
This patch converts PID 1 to libsystemd-bus and thus drops the
dependency on libdbus. The only remaining code using libdbus is a test
case that validates our bus marshalling against libdbus' marshalling,
and this dependency can be turned off.
This patch also adds a couple of things to libsystem-bus, that are
necessary to make the port work:
- Synthesizing of "Disconnected" messages when bus connections are
severed.
- Support for attaching multiple vtables for the same interface on the
same path.
This patch also fixes the SetDefaultTarget() and GetDefaultTarget() bus
calls which used an inappropriate signature.
As a side effect we will now generate PropertiesChanged messages which
carry property contents, rather than just invalidation information.
Previously to automatically create dependencies between mount units we
matched every mount unit agains all others resulting in O(n^2)
complexity. On setups with large amounts of mount units this might make
things slow.
This change replaces the matching code to use a hashtable that is keyed
by a path prefix, and points to a set of units that require that path to
be around. When a new mount unit is installed it is hence sufficient to
simply look up this set of units via its own file system paths to know
which units to order after itself.
This patch also changes all unit types to only create automatic mount
dependencies via the RequiresMountsFor= logic, and this is exposed to
the outside to make things more transparent.
With this change we still have some O(n) complexities in place when
handling mounts, but that's currently unavoidable due to kernel APIs,
and still substantially better than O(n^2) as before.
https://bugs.freedesktop.org/show_bug.cgi?id=69740
Previously we did operations like attach, trim or migrate only on the
controllers that were enabled for a specific unit. With this changes we
will now do them for all supproted controllers, and fall back to all
possible prefix paths if the specified paths do not exist.
This fixes issues if a controller is being disabled for a unit where it
was previously enabled, and makes sure that all processes stay as "far
down" the tree as groups exist.
As we load unit files lazily, we need to make sure something pulls in swap
units that should be started automatically, otherwise the default dependencies
will never be applied.
This partially reinstates code removed in
commit 64347fc2b9.
Also don't order swap devices after swap.target when they are 'nofail'.
There is no need to restrict this to only the 'nofail' case. In the '!nofail'
case the unit is already wanted by swap.target, so this is not a functional change.
Replace the very generic cgroup hookup with a much simpler one. With
this change only the high-level cgroup settings remain, the ability to
set arbitrary cgroup attributes is removed, so is support for adding
units to arbitrary cgroup controllers or setting arbitrary paths for
them (especially paths that are different for the various controllers).
This also introduces a new -.slice root slice, that is the parent of
system.slice and friends. This enables easy admin configuration of
root-level cgrouo properties.
This replaces DeviceDeny= by DevicePolicy=, and implicitly adds in
/dev/null, /dev/zero and friends if DeviceAllow= is used (unless this is
turned off by DevicePolicy=).
In order to prepare for the kernel cgroup rework, let's introduce a new
unit type to systemd, the "slice". Slices can be arranged in a tree and
are useful to partition resources freely and hierarchally by the user.
Each service unit can now be assigned to one of these slices, and later
on login users and machines may too.
Slices translate pretty directly to the cgroup hierarchy, and the
various objects can be assigned to any of the slices in the tree.
I'm assuming that it's fine if a _const_ or _pure_ function
calls assert. It is assumed that the assert won't trigger,
and even if it does, it can only trigger on the first call
with a given set of parameters, and we don't care if the
compiler moves the order of calls.
Before, we would initialize many fields twice: first
by filling the structure with zeros, and then a second
time with the real values. We can let the compiler do
the job for us, avoiding one copy.
A downside of this patch is that text gets slightly
bigger. This is because all zero() calls are effectively
inlined:
$ size build/.libs/systemd
text data bss dec hex filename
before 897737 107300 2560 1007597 f5fed build/.libs/systemd
after 897873 107300 2560 1007733 f6075 build/.libs/systemd
… actually less than 1‰.
A few asserts that the parameter is not null had to be removed. I
don't think this changes much, because first, it is quite unlikely
for the assert to fail, and second, an immediate SEGV is almost as
good as an assert.
All Execs within the service, will get mounted the same
/tmp and /var/tmp directories, if service is configured with
PrivateTmp=yes. Temporary directories are cleaned up by service
itself in addition to systemd-tmpfiles. Directory which is mounted
as inaccessible is created at runtime in /run/systemd.
There are very few differences in the implementations of the kill method in the
unit types that have one. Let's unify them.
This does not yet unify unit_kill() with unit_kill_context().
Starting a swap unit pointing to (What) a symlink (e.g. /dev/mapper/swap
or /dev/disk/by-uuid/...) would have said unit marked active, following
the one using the "actual" device (/dev/{dm-1,sda3}), but that new unit
would be seen as inactive.
Since all requests to stop swap units would follow/redirect to it,
and it is seen inactive, nothing would be done (swapoff never called).
This is because this unit would be treated twice in
swap_process_new_swap, the second call to swap_add_one causing it to
eventually be marked inactive.
Umut Tezduyar Lindskog