network-legacy without systemd local live ISO boot

[LaszloGombos]

Describe the bug
I have a problem that booting an ISO in a VM using qemu/kvm, the network is not configured properly. If I add a sleep 1 or udevadm settle before the rd.break=initqueue in 99base/init.sh everything works and eth0 gets an IP address. Without it, I the interface is named ens3 and it does not get an IP. I guess it's a corner case because on real hardware (on two notebooks) I had no problems. But looking at the init.sh code I seems reasonable to add udevadm settle (and not udevsettle) before the main loop.
I use network-legacy and no systemd dracut modules on my iso. But systemd-udevd is available in the initrd.

Distribution used
debian

Dracut version
57

Init system
systemd

[LaszloGombos]

I am able to reproduce a failure - https://github.com/LaszloGombos/dracut/actions/runs/3664855075/jobs/6195536000

Scratch this, this is just a dup of #1901

[LaszloGombos]

CC @Mrfai

[Mrfai]

Here are my logs. The problem is IMO that there's no /lib/dracut/hooks/initqueue/ifup-eth0.sh but only the ifup-lo.sh
I do not use root=/dev/nfs, since I boot from ISO and use the root filesystem from the ISO (it's a squashfs), no nfs. But I still set rd.neednet=1. This is the /proc/cmdline

BOOT_IMAGE=/boot/vmlinuz FAI_FLAGS=menu,verbose,createvt FAI_ACTION=install FAI_CONFIG_SRC=file:///var/lib/fai/config rd.live.image root=live:CDLABEL=FAI_CD rd.neednet ip=dhcp rd.debug

init.log
rdsosreport.txt

[Mrfai]

This only occurs in the dmesg output (I'm not using systemd) during boot when the network is not configured properly:
[ 4.432306] virtio_net virtio0 ens3: renamed from eth0
Therefore I have ens3 with not IP address. When adding the patch (udevadm settle) the I have a eth0 and no rename in dmesg output

[LaszloGombos]

@Mrfai Curious, if you add "net.ifnames=0" to kernel command line does it work (without additional patches) ? Also can you list the full list of dracut modules included ? Are you sure nfs dracut module is not included ?

[Mrfai]

No, it does not help. The network interface is now called eth0 but still does not get an IP address.

[Mrfai]

I've debugged a little bit deeper. This happens when no IP address is assigned and the interface is renamed to ens3.

In 99base/init.sh in the main loop I can see that following files are created in hooks/initqueue
First ifup-lo.sh and 224.sh (IIRC for some nvme devices). In the next iteration ifup-lo.sh is gone but we have ifup-eth0.sh and the file work. And I guess this is why udevsettle exits the loop, without activating eth0.

[LaszloGombos]

Link to debian patch - https://salsa.debian.org/debian/dracut/-/blob/master/debian/patches/udevsettle

[LaszloGombos]

@Mrfai

Also can you list the full list of dracut modules included ?

Perhaps share "dracut --debug -v" output ?

I do not use root=/dev/nfs, since I boot from ISO and use the root filesystem from the ISO (it's a squashfs), no nfs. But I still set rd.neednet=1.

Since this is an unusual need (bring up networking but load the root filesystem from local fs), can you please share a bit more about what you're trying to achieve ? What do you hope to achieve by including the nfs dracut module but not using root=/dev/nfs ?

[Mrfai]

the nfs module is included because I'm using the same initrd (and the root file system) for both booting from network (via root=/dev/nfs) and from an ISO.

[LaszloGombos]

the nfs module is included because I'm using the same initrd (and the root file system) for both booting from network (via root=/dev/nfs) and from an ISO.

@Mrfai Thanks, this use case make sense to me.

When booting from ISO is the ISO on the network or is it on local storage attached the host that you are booting from ?

Why is it important that bring up network for booting from ISO ?

[LaszloGombos]

@Mrfai There is not enough information on this bug to reproduce. If we can not reproduce it, than it would be hard to make progress on this issue.