generic/615: fix loop termination failures

On 6.7-rc2, I've noticed that this test hangs unpredictably because the
stat loop fails to exit.  While the kill $loop_pid command /should/ take
care of it, it clearly isn't.

Set up an additional safety factor by checking for the existence of a
sentinel flag before starting the loop body.  In bash, "[" is a builtin
so the loop should run almost as tightly as it did before.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>
1 file changed