From 829ed8ef5cca250fac475ad6b0265c792c3af015 Mon Sep 17 00:00:00 2001

From: Kairui Song <kasong@redhat.com>

Date: Wed, 13 Mar 2019 17:36:53 +0800

Subject: [PATCH] squash: also squash systemctl if switch-root is not needed

systemctl need to be accessible on switch-root, but we unmount the

squash image on switch-root, so it will fail. systemctl depends on a lot

of libraries, squash them can save more RAM. So allow modules

(eg. kdump) to tell dracut that switch-root will be intercepted,

then we don't need to take care of that.

Signed-off-by: Kairui Song <kasong@redhat.com>

(cherry picked from commit 3ee0ca5eb74be5d1fbd0e6d643f6fff06234177f)

Resolves: #1691705

---

 dracut-init.sh |  4 ++++

 dracut.sh      | 40 ++++++++++++++++++++++------------------

 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/dracut-init.sh b/dracut-init.sh

index 50d23e2d..b1ac9966 100644

--- a/dracut-init.sh

+++ b/dracut-init.sh

@@ -150,6 +150,10 @@ dracut_module_included() {

     [[ " $mods_to_load $modules_loaded " == *\ $*\ * ]]

 }

+dracut_no_switch_root() {

+    >"$initdir/lib/dracut/no-switch-root"

+}

+

 if ! [[ $DRACUT_INSTALL ]]; then

     DRACUT_INSTALL=$(find_binary dracut-install)

 fi

diff --git a/dracut.sh b/dracut.sh

index 6de88b3e..8144a16e 100755

--- a/dracut.sh

+++ b/dracut.sh

@@ -1772,24 +1772,6 @@ if dracut_module_included "squash"; then

         mv $initdir/$folder $squash_dir/$folder

     done

-    # Reinstall required files for the squash image setup script.

-    # We have moved them inside the squashed image, but they need to be

-    # accessible before mounting the image. Also install systemctl,

-    # it's requires for switch-root, but we will umount the image before switch-root

-    inst_multiple "echo" "sh" "mount" "modprobe" "mkdir" "systemctl"

-    hostonly="" instmods "loop" "squashfs" "overlay"

-

-    for folder in "${squash_candidate[@]}"; do

-        # Remove duplicated files in squashfs image, save some more space

-        [[ ! -d $initdir/$folder/ ]] && continue

-        for file in $(find $initdir/$folder/ -not -type d);

-        do

-            if [[ -e $squash_dir${file#$initdir} ]]; then

-                mv $squash_dir${file#$initdir} $file

-            fi

-        done

-    done

-

     # Move some files out side of the squash image, including:

     # - Files required to boot and mount the squashfs image

     # - Files need to be accessable without mounting the squash image

@@ -1851,6 +1833,28 @@ if dracut_module_included "squash"; then

     ln -s squash/init.sh $initdir/init

     ln -s squash/shutdown.sh $initdir/shutdown

+    # Reinstall required files for the squash image setup script.

+    # We have moved them inside the squashed image, but they need to be

+    # accessible before mounting the image.

+    inst_multiple "echo" "sh" "mount" "modprobe" "mkdir"

+    hostonly="" instmods "loop" "squashfs" "overlay"

+

+    # Only keep systemctl outsite if we need switch root

+    if [[ ! -f "$initdir/lib/dracut/no-switch-root" ]]; then

+      inst "systemctl"

+    fi

+

+    for folder in "${squash_candidate[@]}"; do

+        # Remove duplicated files in squashfs image, save some more space

+        [[ ! -d $initdir/$folder/ ]] && continue

+        for file in $(find $initdir/$folder/ -not -type d);

+        do

+            if [[ -e $squash_dir${file#$initdir} ]]; then

+                mv $squash_dir${file#$initdir} $file

+            fi

+        done

+    done

+

     mksquashfs $squash_dir $squash_img -comp xz -b 64K -Xdict-size 100% &> /dev/null

     if [[ $? != 0 ]]; then