Adding upstream version 256.upstream/256

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1012 insertions, 0 deletions

diff --git a/test/units/TEST-50-DISSECT.sysext.sh b/test/units/TEST-50-DISSECT.sysext.sh
new file mode 100755
index 0000000..3bc8899
--- /dev/null
+++ b/test/units/TEST-50-DISSECT.sysext.sh
@@ -0,0 +1,1012 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+FAKE_ROOTS_DIR="$(mktemp -d --tmpdir="" fake-roots-XXX)"
+FSTYPE=$(stat --file-system --format "%T" /usr)
+
+shopt -s nullglob
+
+# shellcheck disable=SC2317
+at_exit() {
+    set +ex
+
+    local target
+
+    # Note: `cat` here is used intentionally, so we iterate over our own copy of /proc/mounts. Otherwise
+    #       things get very confusing once we start unmounting things, due to changing file offsets.
+    # shellcheck disable=SC2002
+    cat /proc/mounts | while read -r _ target _ _ _ _; do
+        if [[ "$target" =~ ^"$FAKE_ROOTS_DIR" ]]; then
+            umount -Rv "$target"
+        fi
+    done
+
+    rm -rf "${FAKE_ROOTS_DIR}"
+}
+
+trap at_exit EXIT
+
+# Clears the trap command - it needs to be invoked for every test-case subshell
+# so prepending commands with prepend_trap inside the subshell won't preserve
+# the trap commands from outer shell.
+init_trap() {
+    trap - EXIT
+}
+
+prepend_trap() {
+    set +x
+
+    local command=${1}; shift
+    local previous_commands
+
+    previous_commands=$(trap -p EXIT)
+    if [[ -z $previous_commands ]]; then
+        previous_commands=':'
+    else
+        previous_commands=${previous_commands#'trap -- '}
+        previous_commands=${previous_commands%' EXIT'}
+        previous_commands=$(xargs <<<"$previous_commands")
+    fi
+
+    # shellcheck disable=SC2064 # We use double quotes on purpose here.
+    trap "${command}; ${previous_commands}" EXIT
+
+    set -x
+}
+
+prepare_root() {
+    local root=${1:-}
+    local hierarchy=${2:?}
+    local dir
+
+    if [[ -n $root ]] && [[ -d $root ]]; then
+        echo >&2 "Directory $root already exists, possible copy-paste error?"
+        exit 1
+    fi
+
+    local -a leftovers=( "$root/var/lib/extensions/"* "$root/var/lib/extensions.mutable/"* )
+    if [[ ${#leftovers[@]} -gt 0 ]]; then
+        echo >&2 "Leftovers remained, make sure to clean them up in the test case: ${leftovers[*]}"
+        exit 1
+    fi
+
+    for dir in "$hierarchy" "/usr/lib" "/var/lib/extensions/" "/var/lib/extensions.mutable"; do
+        mkdir -p "$root$dir"
+    done
+
+    if [[ -e $root/usr/lib/os-release ]]; then
+        mv "$root/usr/lib/os-release" "$root/usr/lib/os-release.orig"
+    fi
+
+    {
+        echo "ID=testtest"
+        echo "VERSION=1.2.3"
+    } >"$root/usr/lib/os-release"
+
+    prepend_trap "cleanup_os_release ${root@Q}"
+}
+
+cleanup_os_release() {
+    # shellcheck disable=SC2317 # It is not unreachable, used in a trap couple lines above.
+    local root=${1:-}
+
+    # shellcheck disable=SC2317 # It is not unreachable, used in a trap couple lines above.
+    rm -f "$root/usr/lib/os-release"
+    # shellcheck disable=SC2317 # It is not unreachable, used in a trap couple lines above.
+    if [[ -e $root/usr/lib/os-release.orig ]]; then
+        # shellcheck disable=SC2317 # It is not unreachable, used in a trap couple lines above.
+        mv "$root/usr/lib/os-release.orig" "$root/usr/lib/os-release"
+    fi
+}
+
+prepare_extension_image() {
+    local root=${1:-}
+    local hierarchy=${2:?}
+    local ext_dir ext_release name
+
+    name="test-extension"
+    ext_dir="$root/var/lib/extensions/$name"
+    ext_release="$ext_dir/usr/lib/extension-release.d/extension-release.$name"
+    mkdir -p "${ext_release%/*}"
+    echo "ID=_any" >"$ext_release"
+    mkdir -p "$ext_dir/$hierarchy"
+    touch "$ext_dir$hierarchy/preexisting-file-in-extension-image"
+
+    prepend_trap "rm -rf ${ext_dir@Q}"
+}
+
+prepare_extension_mutable_dir() {
+    local dir=${1:?}
+
+    mkdir -p "$dir"
+    touch "$dir/preexisting-file-in-extensions-mutable"
+    prepend_trap "rm -rf ${dir@Q}"
+}
+
+make_read_only() {
+    local root=${1:-}
+    local hierarchy=${2:?}
+
+    mount -o bind,ro "$root$hierarchy" "$root$hierarchy"
+    prepend_trap "umount ${root@Q}${hierarchy@Q}"
+}
+
+prepare_hierarchy() {
+    local root=${1:-}
+    local hierarchy=${2:?}
+    local file
+
+    file="$root$hierarchy/preexisting-file-in-hierarchy"
+    touch "$file"
+    prepend_trap "rm -f ${file@Q}"
+}
+
+prepare_read_only_hierarchy() {
+    local root=${1:-}
+    local hierarchy=${2:?}
+
+    prepare_hierarchy "$root" "$hierarchy"
+    make_read_only "$root" "$hierarchy"
+}
+
+move_existing_hierarchy_aside() {
+    local root=${1:-}
+    local hierarchy=${2:?}
+
+    if [[ -z $root ]] && [[ $hierarchy = /usr ]]; then
+        echo >&2 "Hell no, not moving /usr aside"
+        exit 1
+    fi
+
+    local path=$root$hierarchy
+
+    if [[ -e $path ]]; then
+        mv "$path" "$path.orig"
+        prepend_trap "mv ${path@Q}.orig ${path@Q}"
+    fi
+}
+
+# Extra arguments:
+#   -e: check for a preexisting file in extension
+#   -h: check for a preexisting file in hierarchy
+#   -u: check for a preexisting file in upperdir
+extension_verify() {
+    local root=${1:-}
+    local hierarchy=${2:?}
+    local message=${3:?}
+    shift 3
+    # Map each option to a pre-defined file name
+    local -A option_files_map=(
+        [e]="preexisting-file-in-extension-image"
+        [h]="preexisting-file-in-hierarchy"
+        [u]="preexisting-file-in-extensions-mutable"
+    )
+    local -A args=(
+        [e]=0
+        [h]=0
+        [u]=0
+    )
+    local file full_path opt option
+
+    while getopts "ehu" opt; do
+        case "$opt" in
+            e|h|u)
+                args["$opt"]=1
+                ;;
+            *)
+                echo >&2 "Unxexpected option: $opt"
+                exit 1
+        esac
+    done
+
+    for option in "${!option_files_map[@]}"; do
+        file=${option_files_map["$option"]}
+        full_path="$root$hierarchy/$file"
+
+        if [[ ${args["$option"]} -ne 0 ]]; then
+            if [[ ! -f $full_path ]]; then
+                ls -la "$root$hierarchy"
+                echo >&2 "Expected file '$file' to exist under $root$hierarchy $message"
+                exit 1
+            fi
+        else
+            if [[ -f $full_path ]]; then
+                ls -la "$root$hierarchy"
+                echo >&2 "Expected file '$file' to not exist under $root$hierarchy $message"
+                exit 1
+            fi
+        fi
+    done
+}
+
+extension_verify_after_merge() (
+    set +x
+
+    local root=${1:-}
+    local hierarchy=${2:?}
+    shift 2
+
+    extension_verify "$root" "$hierarchy" "after merge" "$@"
+)
+
+extension_verify_after_unmerge() (
+    set +x
+
+    local root=${1:-}
+    local hierarchy=${2:?}
+    shift 2
+
+    extension_verify "$root" "$hierarchy" "after unmerge" "$@"
+)
+
+run_systemd_sysext() {
+    local root=${1:-}
+    shift
+
+    local -a sysext_args
+    sysext_args=()
+
+    if [[ -n $root ]]; then
+        sysext_args+=( "--root=$root" )
+    fi
+    sysext_args+=( "$@" )
+    systemd-sysext "${sysext_args[@]}"
+}
+
+# General systemd-sysext tests
+
+run_sysext_tests() {
+    # The roots_dir variable may be empty - in such case all the tests will run
+    # on /, otherwise they will run on $roots_dir/<SEPARATE_DIR_FOR_TEST>.
+    local roots_dir=${1}; shift
+
+    # Each test runs in a subshell, so we can use traps for cleanups without
+    # clobbering toplevel traps, and we can do skips by invoking "exit 0".
+
+( init_trap
+: "No extension data in /var/lib/extensions.mutable/…, R/O hierarchy, mutability disabled by default, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/simple-read-only-with-read-only-hierarchy"}
+hierarchy=/opt
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+)
+
+
+( init_trap
+: "No extension data in /var/lib/extensions.mutable/…, mutable hierarchy, mutability disabled by default, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/simple-read-only-with-mutable-hierarchy"}
+hierarchy=/opt
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_hierarchy "$fake_root" "$hierarchy"
+touch "$fake_root$hierarchy/should-succeed-on-mutable-fs"
+
+run_systemd_sysext "$fake_root" merge
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+touch "$fake_root$hierarchy/should-succeed-on-mutable-fs-again"
+)
+
+
+( init_trap
+: "No extension data in /var/lib/extensions.mutable/…, no hierarchy either, mutability disabled by default, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/simple-read-only-with-missing-hierarchy"}
+hierarchy=/opt
+
+move_existing_hierarchy_aside "$fake_root" "$hierarchy"
+prepare_root "$fake_root" "$hierarchy"
+rmdir "$fake_root/$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+
+run_systemd_sysext "$fake_root" merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy"
+)
+
+
+( init_trap
+: "No extension data in /var/lib/extensions.mutable/…, empty hierarchy, mutability disabled by default, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/simple-read-only-with-empty-hierarchy"}
+hierarchy=/opt
+
+move_existing_hierarchy_aside "$fake_root" "$hierarchy"
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+make_read_only "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy"
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, mutability disabled by default, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/simple-mutable-with-read-only-hierarchy-disabled"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" merge
+(! touch "$fake_root$hierarchy/should-be-read-only")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, auto-mutability, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/simple-mutable-with-read-only-hierarchy"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=auto merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+test -f "$extension_data_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, missing hierarchy, auto-mutability, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/simple-mutable-with-missing-hierarchy"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+move_existing_hierarchy_aside "$fake_root" "$hierarchy"
+prepare_root "$fake_root" "$hierarchy"
+rmdir "$fake_root/$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+
+run_systemd_sysext "$fake_root" --mutable=auto merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -u
+test -f "$extension_data_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy"
+test -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, empty hierarchy, auto-mutability, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/simple-mutable-with-empty-hierarchy"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+move_existing_hierarchy_aside "$fake_root" "$hierarchy"
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+make_read_only "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=auto merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -u
+test -f "$extension_data_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy"
+test -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… is a symlink to other dir, R/O hierarchy, auto-mutability, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/mutable-symlink-with-read-only-hierarchy"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+extension_real_dir="$fake_root/upperdir"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_real_dir"
+ln -sfTr "$extension_real_dir" "$extension_data_dir"
+prepend_trap "rm -f ${extension_data_dir@Q}"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=auto merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+test -f "$extension_data_dir/now-is-mutable"
+test -f "$extension_real_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test -f "$extension_data_dir/now-is-mutable"
+test -f "$extension_real_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… is a symlink to the hierarchy itself, mutable hierarchy, auto-mutability, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/mutable-self-upper"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+extension_real_dir="$fake_root$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_real_dir"
+ln -sfTr "$extension_real_dir" "$extension_data_dir"
+prepend_trap "rm -f ${extension_data_dir@Q}"
+touch "$fake_root$hierarchy/preexisting-file-in-hierarchy"
+
+run_systemd_sysext "$fake_root" --mutable=auto merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+test -f "$extension_data_dir/now-is-mutable"
+test -f "$extension_real_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h -u
+test -f "$extension_data_dir/now-is-mutable"
+test -f "$extension_real_dir/now-is-mutable"
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… is a symlink to the hierarchy itself, R/O hierarchy, auto-mutability, expected fail"
+fake_root=${roots_dir:+"$roots_dir/failure-self-upper-ro"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+extension_real_dir="$fake_root$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_real_dir"
+ln -sfTr "$extension_real_dir" "$extension_data_dir"
+prepend_trap "rm -f ${extension_data_dir@Q}"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+
+(! run_systemd_sysext "$fake_root" --mutable=auto merge)
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… is a dangling symlink, auto-mutability, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/read-only-mutable-dangling-symlink"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+ln -sfTr "/should/not/exist/" "$extension_data_dir"
+prepend_trap "rm -f ${extension_data_dir@Q}"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=auto merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… exists but ignored, mutability disabled explicitly, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/disabled"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=no merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… exists but is imported instead, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/imported"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=import merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… does not exist, mutability enabled, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/enabled"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+extension_data_dir_usr="$fake_root/var/lib/extensions.mutable/usr"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+test ! -d "$extension_data_dir"
+
+run_systemd_sysext "$fake_root" --mutable=yes merge
+# systemd-sysext with --mutable=yes creates extensions.mutable directory for
+# the hierarchy, so delete it after the test
+prepend_trap "rm -rf ${extension_data_dir@Q}"
+# systemd-sysext with --mutable=yes creates extensions.mutable directory also
+# for the /usr hierarchy, because the image needs to have
+# /usr/lib/extension-release.d/extension-release.<NAME> file - this causes the
+# /usr hierarchy to also become mutable
+prepend_trap "rm -rf ${extension_data_dir_usr@Q}"
+test -d "$extension_data_dir"
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+test -f "$extension_data_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… does not exist, auto-mutability, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/simple-read-only-explicit"}
+hierarchy=/opt
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=auto merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… does not exist, mutability enabled through env var, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/enabled-env-var"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+extension_data_dir_usr="$fake_root/var/lib/extensions.mutable/usr"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+test ! -d "$extension_data_dir"
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=yes run_systemd_sysext "$fake_root" merge
+# systemd-sysext with --mutable=yes creates extensions.mutable directory for
+# the hierarchy, so delete it after the test
+prepend_trap "rm -rf ${extension_data_dir@Q}"
+# systemd-sysext with --mutable=yes creates extensions.mutable directory also
+# for the /usr hierarchy, because the image needs to have
+# /usr/lib/extension-release.d/extension-release.<NAME> file - this causes the
+# /usr hierarchy to also become mutable
+prepend_trap "rm -rf ${extension_data_dir_usr@Q}"
+test -d "$extension_data_dir"
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+test -f "$extension_data_dir/now-is-mutable"
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=yes run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… does not exist, auto-mutability enabled through env var, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/read-only-auto-env-var"}
+hierarchy=/opt
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=auto run_systemd_sysext "$fake_root" --mutable=auto merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=auto run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, auto-mutability enabled through env var, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/auto-mutable-env-var"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=auto run_systemd_sysext "$fake_root" merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+test -f "$extension_data_dir/now-is-mutable"
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=auto run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, mutability disabled through env var, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/env-var-disabled"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=no run_systemd_sysext "$fake_root" merge
+(! touch "$fake_root$hierarchy/should-be-read-only")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=no run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "/var/lib/extensions.mutable/… exists but is imported through env var, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/imported-env-var"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=import run_systemd_sysext "$fake_root" merge
+(! touch "$fake_root$hierarchy/should-still-fail-on-read-only-fs")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=import run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, mutability enabled through env var but overridden via CLI option, read-only merged"
+fake_root=${roots_dir:+"$roots_dir/env-var-overridden"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=yes run_systemd_sysext "$fake_root" --mutable=no merge
+(! touch "$fake_root$hierarchy/should-be-read-only")
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=yes run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, ephemeral mutability, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/ephemeral"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=ephemeral merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+test ! -f "$extension_data_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test ! -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, ephemeral mutability through env var, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/ephemeral-env-var"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=ephemeral run_systemd_sysext "$fake_root" merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h
+test ! -f "$extension_data_dir/now-is-mutable"
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=ephemeral run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test ! -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, ephemeral import mutability, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/ephemeral-import"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+run_systemd_sysext "$fake_root" --mutable=ephemeral-import merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+test ! -f "$extension_data_dir/now-is-mutable"
+
+run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test ! -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "Extension data in /var/lib/extensions.mutable/…, R/O hierarchy, ephemeral import mutability through env var, mutable merged"
+fake_root=${roots_dir:+"$roots_dir/ephemeral-import-env-var"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_read_only_hierarchy "$fake_root" "$hierarchy"
+(! touch "$fake_root$hierarchy/should-fail-on-read-only-fs")
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=ephemeral-import run_systemd_sysext "$fake_root" merge
+touch "$fake_root$hierarchy/now-is-mutable"
+extension_verify_after_merge "$fake_root" "$hierarchy" -e -h -u
+test ! -f "$extension_data_dir/now-is-mutable"
+
+SYSTEMD_SYSEXT_MUTABLE_MODE=ephemeral-import run_systemd_sysext "$fake_root" unmerge
+extension_verify_after_unmerge "$fake_root" "$hierarchy" -h
+test ! -f "$extension_data_dir/now-is-mutable"
+test ! -f "$fake_root$hierarchy/now-is-mutable"
+)
+
+
+( init_trap
+: "Extension data pointing to mutable hierarchy, ephemeral import mutability, expected fail"
+fake_root=${roots_dir:+"$roots_dir/ephemeral-import-self"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+extension_real_dir="$fake_root$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_real_dir"
+ln -sfTr "$extension_real_dir" "$extension_data_dir"
+prepend_trap "rm -f ${extension_data_dir@Q}"
+prepare_hierarchy "$fake_root" "$hierarchy"
+touch "$fake_root$hierarchy/should-succeed-on-read-only-fs"
+
+(! run_systemd_sysext "$fake_root" --mutable=ephemeral-import merge)
+)
+
+
+( init_trap
+: "Extension data pointing to mutable hierarchy, import mutability, expected fail"
+fake_root=${roots_dir:+"$roots_dir/import-self"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+extension_real_dir="$fake_root$hierarchy"
+
+[[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_real_dir"
+ln -sfTr "$extension_real_dir" "$extension_data_dir"
+prepend_trap "rm -f ${extension_data_dir@Q}"
+prepare_hierarchy "$fake_root" "$hierarchy"
+touch "$fake_root$hierarchy/should-succeed-on-read-only-fs"
+
+(! run_systemd_sysext "$fake_root" --mutable=import merge)
+)
+
+
+for mutable_mode in no yes ephemeral; do
+    ( init_trap
+    : "Check if merging the hierarchy does not change its permissions, checking with --mutable=${mutable_mode}"
+
+    fake_root=${roots_dir:+"$roots_dir/perm-checks-mutable-$mutable_mode"}
+    hierarchy=/opt
+    extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+    [[ "$FSTYPE" == "fuseblk" ]] && exit 0
+
+    prepare_root "$fake_root" "$hierarchy"
+    prepare_extension_image "$fake_root" "$hierarchy"
+    prepare_extension_mutable_dir "$extension_data_dir"
+    prepare_read_only_hierarchy "${fake_root}" "${hierarchy}"
+
+    full_path="$fake_root$hierarchy"
+    permissions_before_merge=$(stat --format=%A "$full_path")
+
+    run_systemd_sysext "$fake_root" "--mutable=$mutable_mode" merge
+    if [[ $mutable_mode = yes ]]; then
+        # systemd-sysext with --mutable=yes creates extensions.mutable
+        # directory also for the /usr hierarchy, because the image needs to
+        # have /usr/lib/extension-release.d/extension-release.<NAME> file -
+        # this causes the /usr hierarchy to also become mutable
+        extension_data_dir_usr="$fake_root/var/lib/extensions.mutable/usr"
+        prepend_trap "rm -rf ${extension_data_dir_usr@Q}"
+    fi
+
+    permissions_after_merge=$(stat --format=%A "$full_path")
+
+    run_systemd_sysext "$fake_root" unmerge
+
+    permissions_after_unmerge=$(stat --format=%A "$full_path")
+
+    if [[ "$permissions_before_merge" != "$permissions_after_merge" ]]; then
+        echo >&2 "Broken hierarchy permissions after merging with mutable mode ${mutable_mode@Q}, expected ${permissions_before_merge@Q}, got ${permissions_after_merge@Q}"
+        exit 1
+    fi
+
+    if [[ "$permissions_before_merge" != "$permissions_after_unmerge" ]]; then
+        echo >&2 "Broken hierarchy permissions after unmerging with mutable mode ${mutable_mode@Q}, expected ${permissions_before_merge@Q}, got ${permissions_after_unmerge@Q}"
+        exit 1
+    fi
+    )
+done
+
+
+( init_trap
+: "Check if merging fails in case of invalid mutable directory permissions"
+
+fake_root=${roots_dir:+"$roots_dir/mutable-directory-with-invalid-permissions"}
+hierarchy=/opt
+extension_data_dir="$fake_root/var/lib/extensions.mutable$hierarchy"
+
+prepare_root "$fake_root" "$hierarchy"
+prepare_extension_image "$fake_root" "$hierarchy"
+prepare_extension_mutable_dir "$extension_data_dir"
+prepare_hierarchy "$fake_root" "$hierarchy"
+
+old_mode=$(stat --format '%#a' "$fake_root$hierarchy")
+chmod 0755 "$fake_root$hierarchy"
+prepend_trap "chmod ${old_mode@Q} ${fake_root@Q}${hierarchy@Q}"
+chmod 0700 "$extension_data_dir"
+
+(! run_systemd_sysext "$fake_root" --mutable=yes merge)
+)
+
+} # End of run_sysext_tests
+
+
+# For preparing /, we need mutable /usr/. If it is read only, skip running the
+# sysext tests on /.
+if [[ -w /usr ]]; then
+    run_sysext_tests ''
+fi
+run_sysext_tests "$FAKE_ROOTS_DIR"
+
+
+exit 0