1#!/bin/sh
2# Ensure that df /dev/loop0 errors out if overmounted by another device
3
4# Copyright (C) 2014-2023 Free Software Foundation, Inc.
5
6# This program is free software: you can redistribute it and/or modify
7# it under the terms of the GNU General Public License as published by
8# the Free Software Foundation, either version 3 of the License, or
9# (at your option) any later version.
10
11# This program is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14# GNU General Public License for more details.
15
16# You should have received a copy of the GNU General Public License
17# along with this program.  If not, see <https://www.gnu.org/licenses/>.
18
19. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
20print_ver_ df
21require_root_
22
23cwd=$(pwd)
24cleanup_() { cd /; umount "$cwd/mnt"; umount "$cwd/mnt"; }
25
26skip=0
27
28# Create 2 file systems
29for i in 1 2; do
30  dd if=/dev/zero of=blob$i bs=8192 count=200 > /dev/null 2>&1 \
31                                             || skip=1
32  mkfs -t ext2 -F blob$i \
33    || skip_ "failed to create ext2 file system"
34done
35
36# Mount both at the same place (eclipsing the first)
37mkdir mnt                                    || skip=1
38mount -oloop blob1 mnt                       || skip=1
39eclipsed_dev=$(df --o=source mnt | tail -n1) || skip=1
40mount -oloop blob2 mnt                       || skip=1
41
42test $skip = 1 \
43  && skip_ "insufficient mount/ext2 support"
44
45df . || skip_ "failed to lookup the device for the current dir"
46
47echo "df: cannot access '$eclipsed_dev': over-mounted by another device" > exp
48
49# We should get an error for the eclipsed device and continue
50df $eclipsed_dev . > out 2> err && fail=1
51
52# header and single entry in output
53test $(wc -l < out) = 2 || fail=1
54
55compare exp err || fail=1
56
57test "$fail" = 1 && dump_mount_list_
58
59Exit $fail
60