From 90d96c4f6a44d895f8999da8c4721a04612e6379 Mon Sep 17 00:00:00 2001
From: Kairui Song <kasong@redhat.com>
Date: Tue, 29 Oct 2019 16:29:14 +0800
Subject: [PATCH] 90kernel-modules: don't install any block driver if not
 needed

If hostonly mode is in use, and there isn't any block device included
as hostonly device, then the initramfs won't need any block driver.

Eg. for kdump built image, there could be only one nfs mount point,
or the initramfs may only execute some network operation then reboot.

In such case, skip block driver installation to save space and time.

Signed-off-by: Kairui Song <kasong@redhat.com>
(cherry picked from commit f4ad2e5c8964b6c7b50420299a0096bade6a40bd)

Resolves: #1776659
---
 modules.d/90kernel-modules/module-setup.sh | 32 +++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/modules.d/90kernel-modules/module-setup.sh b/modules.d/90kernel-modules/module-setup.sh
index 3dfceff0..c91ba10c 100755
--- a/modules.d/90kernel-modules/module-setup.sh
+++ b/modules.d/90kernel-modules/module-setup.sh
@@ -2,6 +2,8 @@
 
 # called by dracut
 installkernel() {
+    local _blockfuncs='ahci_platform_get_resources|ata_scsi_ioctl|scsi_add_host|blk_cleanup_queue|register_mtd_blktrans|scsi_esp_register|register_virtio_device|usb_stor_disconnect|mmc_add_host|sdhci_add_host|scsi_add_host_with_dma'
+
     find_kernel_modules_external () {
         local _OLDIFS
         local external_pattern="^/"
@@ -16,11 +18,25 @@ installkernel() {
         done < "$srcmods/modules.dep"
         IFS=$_OLDIFS
     }
-    local _blockfuncs='ahci_platform_get_resources|ata_scsi_ioctl|scsi_add_host|blk_cleanup_queue|register_mtd_blktrans|scsi_esp_register|register_virtio_device|usb_stor_disconnect|mmc_add_host|sdhci_add_host|scsi_add_host_with_dma'
+
+    is_block_dev() {
+        [ -e /sys/dev/block/$1 ] && return 0
+        return 1
+    }
+
+    install_block_modules () {
+        hostonly='' instmods sr_mod sd_mod scsi_dh ata_piix
+        instmods \
+            scsi_dh_rdac scsi_dh_emc scsi_dh_alua \
+            =ide nvme vmd nfit \
+            virtio_blk
+
+        dracut_instmods -o -s "${_blockfuncs}" "=drivers"
+    }
 
     if [[ -z $drivers ]]; then
         hostonly='' instmods \
-            sr_mod sd_mod scsi_dh ata_piix hid_generic unix \
+            hid_generic unix \
             ehci-hcd ehci-pci ehci-platform \
             ohci-hcd ohci-pci \
             uhci-hcd \
@@ -38,10 +54,10 @@ installkernel() {
             ${NULL}
 
         instmods \
-            yenta_socket scsi_dh_rdac scsi_dh_emc scsi_dh_alua \
+            yenta_socket \
             atkbd i8042 usbhid firewire-ohci pcmcia hv-vmbus \
-            virtio virtio_blk virtio_ring virtio_pci virtio_scsi \
-            "=drivers/pcmcia" =ide nvme vmd nfit
+            virtio virtio_ring virtio_pci virtio_scsi \
+            "=drivers/pcmcia"
 
         if [[ "$(uname -m)" == arm* || "$(uname -m)" == aarch64 ]]; then
             # arm/aarch64 specific modules
@@ -72,10 +88,12 @@ installkernel() {
                 ${NULL}
         fi
 
-        dracut_instmods -o -s "${_blockfuncs}" "=drivers"
-
         find_kernel_modules_external | instmods
 
+        if ! [[ $hostonly ]] || for_each_host_dev_and_slaves is_block_dev; then
+            install_block_modules
+        fi
+
         # if not on hostonly mode, install all known filesystems,
         # if the required list is not set via the filesystems variable
         if ! [[ $hostonly ]]; then