This patch fixes bz1941106 and bz1941905 which passed empty rd.znet to the kernel command line in the following cases, - The IBM (Z15) KVM guest uses virtio for all devices including network device, so there is no znet device for IBM KVM guest. So we can't assume a s390x machine always has a znet device. - When a bridged network is used, kexec-tools tries to obtain the znet configuration from the ifcfg script of the bridged network rather than from the ifcfg script of znet device.

We can iterate /sys/bus/ccwgroup/devices to tell if there if there is a znet network device. By getting an ifname from znet, we can also avoid mistaking the slave netdev as a znet network device in a bridged network or bonded network.

Note: This patch also assumes there is only one znet device as commit 7148c0a30dfc48221eadf255e8a89619f98a8752 ("add s390x netdev setup") which greatly simplifies the code. According to IBM [1], there could be more than znet devices for a z/VM system and a z/VM system may have a non-znet network device like ConnectX. Since kdump_setup_znet was introduced in 2012 and so far there is no known customer complaint that invalidates this assumption I think it's safe to assume an IBM z/VM system only has one znet device. Besides, there is no z/VM system found on beaker to test the alternative scenarios.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1941905#c13

Signed-off-by: Coiby Xu coxu@redhat.com --- dracut-module-setup.sh | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index a99a0ea..7d9344f 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -460,6 +460,34 @@ kdump_setup_vlan() { fi }

+# find online znet device +# return ifname (_netdev) +# code reaped from the list_configured function of +# https://github.com/hreinecke/s390-tools/blob/master/zconf/znetconf +find_online_znet_device() { + local CCWGROUPBUS_DEVICEDIR="/sys/bus/ccwgroup/devices" + local NETWORK_DEVICES d ifname ONLINE + NETWORK_DEVICES=$(find $CCWGROUPBUS_DEVICEDIR -type l) + for d in $NETWORK_DEVICES + do + read ONLINE < $d/online + if [ $ONLINE -ne 1 ]; then + continue + fi + # determine interface name, if there (only for qeth and if + # device is online) + if [ -f $d/if_name ] + then + read ifname < $d/if_name + elif [ -d $d/net ] + then + ifname=$(ls $d/net/) + fi + [ -n "$ifname" ] && break + done + echo -n "$ifname" +} + # setup s390 znet cmdline # $1: netdev (ifname) # $2: nmcli connection show output @@ -526,6 +554,7 @@ kdump_get_remote_ip() kdump_install_net() { local _destaddr _srcaddr _route _netdev _nm_show_cmd kdumpnic local _static _proto _ip_conf _ip_opts _ifname_opts + local _znet_netdev _nm_show_cmd_znet

_destaddr=$(kdump_get_remote_ip $1) _route=$(kdump_get_ip_route $_destaddr) @@ -535,8 +564,10 @@ kdump_install_net() { _netmac=$(kdump_get_mac_addr $_netdev) kdumpnic=$(kdump_setup_ifname $_netdev)

- if [ "$(uname -m)" = "s390x" ]; then - $(kdump_setup_znet "$_netdev" "$_nm_show_cmd") + _znet_netdev=$(find_online_znet_device) + if [[ -n "$_znet_netdev" ]]; then + _nm_show_cmd_znet=$(get_nmcli_connection_show_cmd_by_ifname "$_znet_netdev") + $(kdump_setup_znet "$_netdev" "$_nm_show_cmd_znet") if [[ $? != 0 ]]; then derror "Failed to set up znet" exit 1