From 3085acbec79b3649ac906529778f86a14f330e62 Mon Sep 17 00:00:00 2001
From: Kairui Song <kasong@redhat.com>
Date: Wed, 21 Oct 2020 16:18:07 +0800
Subject: [PATCH] Add a --hostonly-nics option

Currently when network is enabled, dracut will install all network
drivers that are currently loaded, but some time only one NIC is needed
for the initramfs.

So for strict hostonly mode, add a --hostonly-nics option, user can
provide a list of NICs to be enabled, and only needed drivers for
specifed NICs will be installed so save space.

Signed-off-by: Kairui Song <kasong@redhat.com>
(cherry picked from commit 1e92f7285d42fbd3bc01f534f9bd646f6fdd9504)

Cherry-picked from: 1e92f7285d42fbd3bc01f534f9bd646f6fdd9504
Resolves: #1890041

Cherry-picked from: c69961b403c1c83bb4717e1df1470e71cd0245d1
Resolves: #1890041
---
 dracut.sh                                          |  6 ++++++
 modules.d/90kernel-network-modules/module-setup.sh | 18 +++++++++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/dracut.sh b/dracut.sh
index e70dab16..01abe7a4 100755
--- a/dracut.sh
+++ b/dracut.sh
@@ -173,6 +173,8 @@ Creates initial ramdisk images for preloading modules
   --hostonly-i18n       Install only needed keyboard and font files according
                         to the host configuration (default).
   --no-hostonly-i18n    Install all keyboard and font files available.
+  --hostonly-nics [LIST]
+                        Only enable listed NICs in the initramfs.
   --persistent-policy [POLICY]
                         Use [POLICY] to address disks and partitions.
                         POLICY can be any directory name found in /dev/disk.
@@ -400,6 +402,7 @@ rearrange_params()
         --long kernel-image: \
         --long no-hostonly-i18n \
         --long hostonly-i18n \
+        --long hostonly-nics: \
         --long no-machineid \
         -- "$@")
 
@@ -561,6 +564,8 @@ while :; do
                        hostonly_cmdline_l="yes" ;;
         --hostonly-i18n)
                        i18n_install_all_l="no" ;;
+        --hostonly-nics)
+                       hostonly_nics_l+=("$2");           PARMS_TO_STORE+=" '$2'"; shift;;
         --no-hostonly-i18n)
                        i18n_install_all_l="yes" ;;
         --no-hostonly-cmdline)
@@ -720,6 +725,7 @@ unset NPATH
 (( ${#fstab_lines_l[@]} )) && fstab_lines+=( "${fstab_lines_l[@]}" )
 (( ${#install_items_l[@]} )) && install_items+=" ${install_items_l[@]} "
 (( ${#install_optional_items_l[@]} )) && install_optional_items+=" ${install_optional_items_l[@]} "
+(( ${#hostonly_nics_l[@]} )) && hostonly_nics+=" ${hostonly_nics_l[@]} "
 
 # these options override the stuff in the config file
 (( ${#dracutmodules_l[@]} )) && dracutmodules="${dracutmodules_l[@]}"
diff --git a/modules.d/90kernel-network-modules/module-setup.sh b/modules.d/90kernel-network-modules/module-setup.sh
index 600ef112..f36d31f7 100755
--- a/modules.d/90kernel-network-modules/module-setup.sh
+++ b/modules.d/90kernel-network-modules/module-setup.sh
@@ -14,15 +14,27 @@ depends() {
 installkernel() {
     # Include wired net drivers, excluding wireless
     local _arch=$(uname -m)
-    local _net_drivers='eth_type_trans|register_virtio_device|usbnet_open'
+    local _net_symbols='eth_type_trans|register_virtio_device|usbnet_open'
     local _unwanted_drivers='/(wireless|isdn|uwb|net/ethernet|net/phy|net/team)/'
+    local _net_drivers
 
     if [ "$_arch" = "s390" -o "$_arch" = "s390x" ]; then
-        _s390drivers="=drivers/s390/net"
+        dracut_instmods -o -P ".*${_unwanted_drivers}.*" -s "$_net_symbols" "=drivers/s390/net"
     fi
 
-    dracut_instmods -o -P ".*${_unwanted_drivers}.*" -s "$_net_drivers" "=drivers/net" ${_s390drivers:+"$_s390drivers"}
+    if [[ $hostonly_mode == 'strict' ]] && [[ $hostonly_nics ]]; then
+        for _nic in $hostonly_nics; do
+            _net_drivers=$(get_dev_module /sys/class/net/$_nic)
+            if ! [[ $_net_drivers ]]; then
+                derror "--hostonly-nics contains invalid NIC '$_nic'"
+                continue
+            fi
+            hostonly="" instmods $_net_drivers
+        done
+        return 0
+    fi
 
+    dracut_instmods -o -P ".*${_unwanted_drivers}.*" -s "$_net_symbols" "=drivers/net"
     #instmods() will take care of hostonly
     instmods \
         =drivers/net/phy \