[LTP] [PATCH] syscalls/fanotify: Kill the child process before exit

[zhaogongyi]

Hi,

> 
> On Thu, Nov 04, 2021 at 07:37:35PM +0100, Petr Vorel wrote:
> > Hi all,
> >
> > > Before the main process exit abnormally, we need to kill the child
> > > process.
> >
> > Amir, Matthew, could you please have a look?
> 
> If anything, I feel as though stop_children() should probably be called from
> cleanup() as that callback will be invoked if any of the
> SAFE_FANOTIFY_* macros fail anyway, right?

It seems that calling before run_children, we need not cleanup though the SAFE_FANOTIFY_* macros fail.

> 
> I don't feel like there's a need to introduce another helper here to
> explicitly handle the cleanup case, but I could also be wrong.

When we run the testcase simultaneously, and the ulimit of open files is small, the testcase will fail and remain
many while(1) tasks in system, it makes the system very stuck.

Shall we need to cleanup it?

> 
> > > Signed-off-by: Zhao Gongyi <zhaogongyi@huawei.com>
> > > ---
> > >  .../kernel/syscalls/fanotify/fanotify07.c     | 35
> ++++++++++++++++++-
> > >  1 file changed, 34 insertions(+), 1 deletion(-)
> >
> > > diff --git a/testcases/kernel/syscalls/fanotify/fanotify07.c
> > > b/testcases/kernel/syscalls/fanotify/fanotify07.c
> > > index cc56d9019..0a0b4f1e4 100644
> > > --- a/testcases/kernel/syscalls/fanotify/fanotify07.c
> > > +++ b/testcases/kernel/syscalls/fanotify/fanotify07.c
> > > @@ -108,6 +108,39 @@ static int setup_instance(void)
> > >  	return fd;
> > >  }
> >
> > > +static int setup_another_instance(void) {
> > > +	int rval;
> > > +	int fd = fanotify_init(FAN_CLASS_CONTENT, O_RDONLY);
> > > +
> > > +	if (fd == -1) {
> > > +		stop_children();
> > > +		tst_brk(TBROK | TERRNO, "fanotify_init() failed");
> > > +	}
> > > +
> > > +	if (fd < -1) {
> > > +		stop_children();
> > > +		tst_brk(TBROK | TERRNO,
> > > +			"invalid fanotify_init() return %d", fd);
> > > +	}
> > > +
> > > +	rval = fanotify_mark(fd,
> > > +		FAN_MARK_ADD, FAN_ACCESS_PERM, AT_FDCWD, fname);
> > > +
> > > +	if (rval == -1) {
> > > +		stop_children();
> > > +		tst_brk(TBROK | TERRNO, "fanotify_mark() failed");
> > > +	}
> > > +
> > > +	if (rval < -1) {
> > > +		stop_children();
> > > +		tst_brk(TBROK | TERRNO,
> > > +			"invalid fanotify_mark() return %d", rval);
> > > +	}
> > > +
> > > +	return fd;
> > > +}
> > > +
> > >  static void loose_fanotify_events(void)  {
> > >  	int not_responded = 0;
> > > @@ -160,7 +193,7 @@ static void test_fanotify(void)
> > >  	 * Create and destroy another instance. This may hang if
> > >  	 * unanswered fanotify events block notification subsystem.
> > >  	 */
> > > -	newfd = setup_instance();
> > > +	newfd = setup_another_instance();
> >
> > >  	SAFE_CLOSE(newfd);
> 
> /M