Re: [PATCH v2] dracut-module-setup.sh: skip installing driver for the loopback interface

[Lichen Liu]

This version of patch looks good to me.

Reviewed-by: Lichen Liu <lichliu(a)redhat.com&gt;


On Fri, Dec 16, 2022 at 9:00 AM Coiby Xu <coxu(a)redhat.com&gt; wrote:
>  Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2151500
>
>  Currently, kdump initrd fails to be built when dumping vmcore to
>  localhost via ssh or nfs,
>
>    kdumpctl[3331]: Cannot get driver information: Operation not supported
>    kdumpctl[1991]: dracut: Failed to get the driver of lo
>    dracut[2020]: Failed to get the driver of lo
>    kdumpctl[1775]: kdump: mkdumprd: failed to make kdump initrd
>    kdumpctl[1775]: kdump: Starting kdump: [FAILED]
>    systemd[1]: kdump.service: Main process exited, code=exited, status=1/FAILURE
>    systemd[1]: kdump.service: Failed with result 'exit-code'.
>    systemd[1]: Failed to start Crash recovery kernel arming.
>    systemd[1]: kdump.service: Consumed 1.710s CPU time.
>
>  This is because the loopback interface is used for transferring vmcore and
>  ethtool can't get the driver of the loopback interface. In fact, once
>  COFNIG_NET is enabled, the loopback device is enabled and there is no driver
>  for the loopback device. So skip installing driver for the loopback device.
>  The loopback interface is implemented in linux/drivers/net/loopback.c
>  and always has the name "lo". So we can safely tell if a network
>  interface is the loopback interface by its name.
>
>  Fixes: a65dde2d ("Reduce kdump memory consumption by only installing needed NIC
> drivers")
>  Reported-by: Martin Pitt <mpitt(a)redhat.com&gt;
>  Reported-by: Rich Megginson <rmeggins(a)redhat.com&gt;
>  Signed-off-by: Coiby Xu <coxu(a)redhat.com&gt;
>  ---
>  v2
>   - distinguish the loopback interface simply by its name
>  ---
>   dracut-module-setup.sh | 2 ++
>   1 file changed, 2 insertions(+)
>
>  diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
>  index 13e99015..aac3d8e5 100755
>  --- a/dracut-module-setup.sh
>  +++ b/dracut-module-setup.sh
>  @@ -387,6 +387,7 @@ kdump_install_nic_driver() {
>       _drivers=()
>
>       for _netif in $1; do
>  +        [[ $_netif != lo ]] || continue
>           _driver=$(_get_nic_driver "$_netif")
>           if [[ -z $_driver ]]; then
>               derror "Failed to get the driver of $_netif"
>  @@ -404,6 +405,7 @@ kdump_install_nic_driver() {
>           _drivers+=("$_driver")
>       done
>
>  +    [[ -n ${_drivers[*]} ]] || return
>       instmods "${_drivers[@]}"
>   }
>
>  --
>  2.38.1
>  _______________________________________________
>  kexec mailing list -- kexec(a)lists.fedoraproject.org
>  To unsubscribe send an email to kexec-leave(a)lists.fedoraproject.org
>  Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
>  List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
>  List Archives:
> https://lists.fedoraproject.org/archives/list/[e-mail]
>  Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue