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.
This introduces remote-fs-setup.target independently of
remote-fs-pre.target. The former is only for pulling things in, the
latter only for ordering.
The new semantics:
remote-fs-setup.target: is pulled in automatically by all remote mounts.
Shall be used to pull in other units that want to run when at least one
remote mount is set up. Is not ordered against the actual mount units,
in order to allow activation of its dependencies even 'a posteriori',
i.e. when a mount is established outside of systemd and is only picked
up by it.
remote-fs-pre.target: needs to be pulled in automatically by the
implementing service, is otherwise not part of the initial transaction.
This is ordered before all remote mount units.
A service that wants to be pulled in and run before all remote mounts
should hence have:
a) WantedBy=remote-fs-setup.target -- so that it is pulled in
b) Wants=remote-fs-pre.target + Before=remote-fs-pre.target -- so that
it is ordered before the mount point, normally.
First, rename root-fs.target to initrd-root-fs.target to clarify its usage.
Mount units with "x-initrd-rootfs.mount" are now ordered before
initrd-root-fs.target. As we sometimes construct /sysroot mounts in
/etc/fstab in the initrd, we want these to be mounted before the
initrd-root-fs.target is active.
initrd.target can be the default target in the initrd.
(normal startup)
:
:
v
basic.target
|
______________________/|
/ |
| sysroot.mount
| |
| v
| initrd-root-fs.target
| |
| v
| initrd-parse-etc.service
(custom initrd services) |
| v
| (sysroot-usr.mount and
| various mounts marked
| with fstab option
| x-initrd.mount)
| |
| v
| initrd-fs.target
| |
\______________________ |
\|
v
initrd.target
|
v
initrd-cleanup.service
isolates to
initrd-switch-root.target
|
v
______________________/|
/ |
| initrd-udevadm-cleanup-db.service
| |
(custom initrd services) |
| |
\______________________ |
\|
v
initrd-switch-root.target
|
v
initrd-switch-root.service
|
v
switch-root
Instead of using local-fs*.target in the initrd, use root-fs.target for
sysroot.mount and initrd-fs.target for /sysroot/usr and friends.
Using local-fs.target would mean to carry over the activated
local-fs.target to the isolated initrd-switch-root.target and thus in
the real root. Having local-fs.target already active after
deserialization causes ordering problems with the real root services and
targets.
We better isolate to targets for initrd-switch-root.target, which are
only available in the initrd.
We no longer allow early-boot init scripts, however in late boot the
syslog socket and local mounts are established anyway, so let's simplify
our dep graph a bit.
If $syslog doesn't resolve to syslog.target anymore there's no reason to
keep syslog.target around anymore. Let's remove it.
Note that many 3rd party service unit files order themselves after
syslog.target. These will be dangling dependencies now, which should be
unproblematic, however.
Systemd should not introduce any new facilities. Distributions which still
need to support their non-standard/legacy facilities should add them as
patches to their packaging.
The following facilities are no longer recognized:
$x-display-manager
$mail-transfer-agent
$mail-transport-agent
$mail-transfer-agent
$smtp
$null
This target is no longer available:
mail-transfer-agent.target
This was premarily intended to support the LSB facility $httpd which is
only known by Fedora, and a bad idea since it lacks any real-life
usecase.
Similar, drop support for some other old Fedora-specific facilities.
Also, document the rules for introduction of new facilities, to clarify
the situation for the future.
#pragma once has been "un-deprecated" in gcc since 3.3, and is widely supported
in other compilers.
I've been using and maintaining (rebasing) this patch for a while now, as
it annoyed me to see #ifndef fooblahfoo, etc all over the place,
almost arrogant about the annoyance of having to define all these names to
perform a commen but neccicary functionality, when a completely superior
alternative exists.
I havn't sent it till now, cause its kindof a style change, and it is bad
voodoo to mess with style that has been established by more established
editors. So feel free to lambast me as a crazy bafoon.
v2 - preserve externally used headers
The rule is that units that encapsulate our own code are prefixed with
"systemd-". Since the fsck units invoke our own code, hence add the
missing prefix. Since a long long time the fsck units didn't invoke the
naked fsck binaries anymore, and it is unlikely that this well ever
change. On the opposite: the code in systemd-fsck will probably get more
complex over time to handle fsck progress to plymouth forwarding.
Same for quotacheck (but not quotaon!)
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.
Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.
The bits that used to be MIT continue to be MIT.
The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
