Since systemd 206 the combination of systemd and mkinitcpio
causes, under certain conditions, the rootfs to be double fsck'd.
Symptoms:
```
:: performing fsck on '/dev/sda1'
systemd: clean, 3523/125488 files, 141738/501760 blocks
********************** WARNING **********************
* *
* The root device is not configured to be mounted *
* read-write! It may be fsck'd again later. *
* *
*****************************************************
<snip>
[ OK ] Started File System Check on Root Device
```
This occurs when neither 'ro' or 'rw', or only 'ro' is present
on the kernel command line. The solution is to mount the roofs
as read-write on the kernel command line, so systemd knows to not fsck
it again.
When 'nomodeset' is specified, there's no DRM driver to take over from
efifb. This means no device will be marked as a seat master, so gdm will
never find a sufficiently active seat to start on.
I'm not aware of an especially good way to detect this through a proper
kernel API, so check for the word 'nomodeset' on the command line and
allow fbdev devices to be seat masters if found.
For https://bugzilla.redhat.com/show_bug.cgi?id=1683197.
This also make wait-online optionally take operstate in -i option,
and adds '--operstate' option to wait-online which also takes operstate.
Also, this contains huge refactoring for wait-online.
Previously, 'degraded' state is ambiguous for bonding or bridge master:
1. one or more slave interfaces does not have carrier,
2. no link local address is assigned to the master,
3. combination of the above two.
This makes the above case 1 and 3 are in the new 'degraded-carrier'
state, and makes 'degraded' state as all slaves are active but no
link local address on master.
If e.g., an [Address] section has an invalid setting, then
previously assigned settings in the section is freed, and
only later settings are stored. That may cause partially broken
section stored in Network object.
This makes if an invalid setting is found, then set 'invalid' flag
instead of freeing it. And invalid sections are dropped later by
network_verify().
Previously, the route is added when the .network config is assigned
to a Link. So, if multiple links match the .network file, the route
entry becomes duplicated in the corresponding Network object.
ProtectSystem=strict or ProtectKernelTunable=yes create implicit
read-write mounts, but they are not overridable by TemporaryFileSystem=.
This makes such implicit read-write mounts use the new mount mode.
So, they can be override by TemproraryFileSystem= now.
A typical usecase is that ProtectSystem=strict and ProtectHome=tmpfs.
Fixes#11276.
