What were you trying to do that didn't work?

When building kdump initramfs against a kernel without erofs kernel module, the dracut erofs module is still included. As a result, the kernel fails to be built. Similarly mkdumprd doesn't includes the dracut squashfs module when squashfs kernel module doesn't exist.

What is the impact of this issue to you?

When bisecting issues involving old kernels that misses erofs kernel module, the kdump initramfs will fail to be booted.

Please provide the package NVR for which the bug is seen:

kdump-utils-1.0.54-1.el10.x86_64

How reproducible is this bug?:

always

Steps to reproduce

1.  Temporarily remove eorfs kernel module, e.g.

   mv /lib/modules/6.12.0-100.el10.x86_64/kernel/fs/erofs/erofs.ko.xz /root
   

2.  kdumpctl rebuild && kdumpctl reload
3.  Trigger kernel panic

Expected results

The kdump initramfs will be booted successfully

Actual results

The kdump initramfs fails to be booted,

mount: /squash/root: unknown filesystem type 'erofs'.
       dmesg(1) may have more information after failed mount system call.
[    1.321901] overlayfs: upper fs does not support RENAME_WHITEOUT.
[    1.323744] overlayfs: failed to set xattr on upper
[    1.324649] overlayfs: ...falling back to uuid=null.
mount: /newroot/squash: mount point does not exist.
       dmesg(1) may have more information after failed mount system call.
switch_root: cannot access /init: No such file or directory
switch_root: failed to execute /init: No such file or directory
[    1.332170] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00007f00