From 8f3759c04f5e987a97c5d2c73703dc8fedc308b5 Mon Sep 17 00:00:00 2001
From: Chris Frey <cdfrey@foursquare.net>
Date: Sat, 11 Dec 2021 21:42:51 -0500
Subject: [PATCH] Meta: Use fuse2fs if available to avoid root when building
 image

The fuse2fs tool that is part of e2fsprogs-1.46 has a 'fakeroot'
mount option.  This allows a non-root users to modify file ownership
and permissions without actually being root.  This package is
available in Debian bullseye and buster-backports.

If available, the script assumes the user wants to use it.
Otherwise, it falls back to the usual root requirements.

Now that root is not required, the root check in
build-root-filesystem.sh is not necessary.  Since
build-root-filesystem.sh has 'set -e' enabled, removing this check
will not cause a change in functionality.
---
 Meta/build-image-qemu.sh      | 22 +++++++++++++++++-----
 Meta/build-root-filesystem.sh |  4 ----
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/Meta/build-image-qemu.sh b/Meta/build-image-qemu.sh
index 0b29b42707..92ca703f2b 100755
--- a/Meta/build-image-qemu.sh
+++ b/Meta/build-image-qemu.sh
@@ -7,9 +7,15 @@ die() {
     exit 1
 }
 
+USE_FUSE2FS=0
+
 if [ "$(id -u)" != 0 ]; then
-    sudo -E -- "$0" "$@" || die "this script needs to run as root"
-    exit 0
+    if [ -x /usr/sbin/fuse2fs ] && /usr/sbin/fuse2fs --help 2>&1 |grep fakeroot > /dev/null; then
+        USE_FUSE2FS=1
+    else
+        sudo -E -- "$0" "$@" || die "this script needs to run as root"
+        exit 0
+    fi
 else
     : "${SUDO_UID:=0}" "${SUDO_GID:=0}"
 fi
@@ -68,7 +74,7 @@ if [ -f _disk_image ]; then
 
     echo "checking existing image"
     result=0
-    e2fsck -f -y _disk_image || result=$?
+    /usr/sbin/e2fsck -f -y _disk_image || result=$?
     if [ $result -ge 4 ]; then
         rm -f _disk_image
         USE_EXISTING=0
@@ -116,7 +122,9 @@ fi
 printf "mounting filesystem... "
 mkdir -p mnt
 use_genext2fs=0
-if [ "$(uname -s)" = "Darwin" ]; then
+if [ $USE_FUSE2FS -eq 1 ]; then
+    mount_cmd="/usr/sbin/fuse2fs _disk_image mnt/ -o fakeroot,rw"
+elif [ "$(uname -s)" = "Darwin" ]; then
     mount_cmd="fuse-ext2 _disk_image mnt -o rw+,allow_other,uid=501,gid=20"
 elif [ "$(uname -s)" = "OpenBSD" ]; then
     VND=$(vnconfig _disk_image)
@@ -142,7 +150,11 @@ cleanup() {
     if [ -d mnt ]; then
         if [ $use_genext2fs = 0 ] ; then
             printf "unmounting filesystem... "
-            umount mnt || ( sleep 1 && sync && umount mnt )
+            if [ $USE_FUSE2FS -eq 1 ]; then
+                fusermount -u mnt || (sleep 1 && sync && fusermount -u mnt)
+            else
+                umount mnt || ( sleep 1 && sync && umount mnt )
+            fi
             rmdir mnt
         else
             rm -rf mnt
diff --git a/Meta/build-root-filesystem.sh b/Meta/build-root-filesystem.sh
index 14bd84bb8c..8cc8be1112 100755
--- a/Meta/build-root-filesystem.sh
+++ b/Meta/build-root-filesystem.sh
@@ -22,10 +22,6 @@ die() {
     exit 1
 }
 
-if [ "$(id -u)" != 0 ]; then
-    die "this script needs to run as root"
-fi
-
 [ -z "$SERENITY_SOURCE_DIR" ] && die "SERENITY_SOURCE_DIR is not set"
 [ -d "$SERENITY_SOURCE_DIR/Base" ] || die "$SERENITY_SOURCE_DIR/Base doesn't exist"