This changes the fstab-generator to handle mounting of /usr/ a bit
differently than before. Instead of immediately mounting the fs to
/sysroot/usr/ we'll first mount it to /sysusr/usr/ and then add a
separate bind mount that mounts it from /sysusr/usr/ to /sysroot/usr/.
This way we can access /usr independently of the root fs, without for
waiting to be mounted via the /sysusr/ hierarchy. This is useful for
invoking systemd-repart while a root fs doesn't exist yet and for
creating it, with partition data read from the /usr/ hierarchy.
This introduces a new generic target initrd-usr-fs.target that may be
used to generically order services against /sysusr/ to become available.
This reverts commit c7220ca802.
The removal was done as a reaction to the messages from systemd:
initrd-root-fs.target: Requested dependency OnFailure=emergency.target ignored (target units cannot fail).
initrd.target: Requested dependency OnFailure=emergency.target ignored (target units cannot fail).
initrd-root-device.target: Requested dependency OnFailure=emergency.target ignored (target units cannot fail).
initrd-fs.target: Requested dependency OnFailure=emergency.target ignored (target units cannot fail).
local-fs.target: Requested dependency OnFailure=emergency.target ignored (target units cannot fail).
...
But it seems that the messages themselves are wrong, and the units were OK.
See c80a9a33d0, target units can't fail.
I guess we need to figure out some replacement functionality, but at least
let's avoid the warning from systemd for now.
Add a synchronization point so that custom initramfs units can run
after the root device becomes available, before it is fsck'd and
mounted.
This is useful for custom initramfs units that may modify the
root disk partition table, where the root device is not known in
advance (it's dynamically selected by the generators).
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
