Combining Requires= with Before= doesn't really make sense, since this
means we are requiring something that runs after us, which logically
cannot be fulfilled.
Let's hence downgrade Requires= to Wants= so that the ordering is kept
but no failure propagation implied.
A follow-up for commit a8cb1dc3e0.
Commit a8cb1dc3e0 made sure that initrd-cleanup.service won't be stopped
when initrd-switch-root.target is isolated.
However even with this change, it might happen that initrd-cleanup.service
survives the switch to rootfs (since it has no ordering constraints against
initrd-switch-root.target) and is stopped right after when default.target is
isolated. This led to initrd-cleanup.service entering in failed state as it
happens when oneshot services are stopped.
This patch along with a8cb1dc3e0 should fix issue #4343.
Fixes: #4343
`systemctl isolate initrd-switch-root.target` called by initrd-cleanup.service
kills initrd-cleanup.service itself. Then, initrd-cleanup.service failed and
system goes to emergency shell.
To prevent this problem, this commit adds `Wants=initrd-cleanup.service` to
initrd-switch-root.target.
fixes: #4343.
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.
This will:
* mount all configured filesystems (typically the rootfs on /sysroot)
* reload the configuration to pick up anything from the mounted fs (typically
/sysroot/etc/fstab)
* mount any newly configured filesystems (typically /usr on /sysroot/usr, if
applicable)
* shut-down and clean-up any daemons running in the initramfs (typically udevd)
* switch-root to /sysroot and start the real init
For an example of what files should be included in an initramfs based on this
see
<https://mailman.archlinux.org/pipermail/arch-projects/2013-February/003628.html>.
Cc: Harald Hoyer <harald.hoyer@gmail.com>
Cc: Dave Reisner <d@falconindy.com>
Yu Watanabe