[LTP] [PATCH v3] move_mount03: check allow to mount beneath top mount

[Petr Vorel]

> On 20. 03. 24 8:43, Petr Vorel wrote:
> > > On 28. 12. 23 3:55, Wei Gao via ltp wrote:
> > > > +static void cleanup(void)
> > > > +{
> > > > +	if (tst_is_mounted_at_tmpdir(DIRA))
> > > > +		SAFE_UMOUNT(DIRA);
> > > > +
> > > > +	if (tst_is_mounted_at_tmpdir(DIRB))
> > > > +		SAFE_UMOUNT(DIRB);

> > > I believe that DIRB may need to be unmounted twice here. Also please close
> > > fda and fdb here if they're still open.

> > What would do the second mount? move_mount() ?

> > There are SAFE_UMOUNT() in the end of the testing function, that's why usually
> > even these 2 SAFE_UMOUNT() aren't needed (but obviously we need to add them if
> > SAFE_TOUCH() or something quits testing early):

> > move_mount03.c:92: TPASS: move_mount(fda, "", fdb, "", MOVE_MOUNT_BENEATH | MOVE_MOUNT_F_EMPTY_PATH | MOVE_MOUNT_T_EMPTY_PATH) passed
> > move_mount03.c:98: TPASS: access(DIRB "/B", F_OK) passed
> > move_mount03.c:99: TINFO: Umounting /tmp/LTP_movqeTZGu/LTP_DIR_B
> > move_mount03.c:100: TPASS: access(DIRB "/A", F_OK) passed
> > move_mount03.c:102: TINFO: Umounting /tmp/LTP_movqeTZGu/LTP_DIR_B
> > move_mount03.c:103: TINFO: Umounting /tmp/LTP_movqeTZGu/LTP_DIR_A
> > tst_device.c:442: TINFO: No device is mounted at /tmp/LTP_movqeTZGu/LTP_DIR_A
> > tst_device.c:442: TINFO: No device is mounted at /tmp/LTP_movqeTZGu/LTP_DIR_B

> Yes, open_tree() was called with OPEN_TREE_CLONE so after move_mount(), the
> mounts look like this:
> - tmpfs[1] at DIRA
> - tmpfs[1] at DIRB
> - tmpfs[2] at DIRB

> If either SAFE_CLOSE() immediately after move_mount() fails, cleanup() will
> unmount tmpfs[1] from DIRA and tmpfs[2] from DIRB but leave tmpfs[1] mounted
> at DIRB.

@Martin Thanks!
@Wai Please send another version.

Kind regards,
Petr