Before this the test fails if run in a chroot by a non-root user:
warning: could not become root outside namespace (Operation not permitted)
../sysdeps/unix/sysv/linux/tst-mount.c:36: numeric comparison failure
left: 1 (0x1); from: errno
right: 19 (0x13); from: ENODEV
error: ../sysdeps/unix/sysv/linux/tst-mount.c:39: not true: fd != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:46: not true: r != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:48: not true: r != -1
../sysdeps/unix/sysv/linux/tst-mount.c:52: numeric comparison failure
left: 1 (0x1); from: errno
right: 9 (0x9); from: EBADF
error: ../sysdeps/unix/sysv/linux/tst-mount.c:55: not true: mfd != -1
../sysdeps/unix/sysv/linux/tst-mount.c:58: numeric comparison failure
left: 1 (0x1); from: errno
right: 2 (0x2); from: ENOENT
error: ../sysdeps/unix/sysv/linux/tst-mount.c:61: not true: r != -1
../sysdeps/unix/sysv/linux/tst-mount.c:65: numeric comparison failure
left: 1 (0x1); from: errno
right: 2 (0x2); from: ENOENT
error: ../sysdeps/unix/sysv/linux/tst-mount.c:68: not true: pfd != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:75: not true: fd_tree != -1
../sysdeps/unix/sysv/linux/tst-mount.c:88: numeric comparison failure
left: 1 (0x1); from: errno
right: 38 (0x26); from: ENOSYS
error: 12 test failures
Checking that the test can enter a new mount namespace is more correct
than just checking the return value of support_become_root() as the test
code changes the mount namespace it runs in so running it as root on a
system that does not support mount namespaces should still skip.
Also change the test to remove the unnecessary fork.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It was added on Linux 5.12 (2a1867219c7b27f928e2545782b86daaf9ad50bd)
to allow change the properties of a mount or a mount tree using file
descriptors which the new mount api is based on.
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The new mount API was added on Linux 5.2 with six new syscalls:
fsopen, fsconfig, fsmount, move_mount, fspick, and open_tree.
The new test verifies minimal functionality along with error paths
for specific arguments and their corner cases.
Checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
