FROMLIST: locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath

A non-first waiter can potentially spin in the for loop of
rwsem_down_write_slowpath() without sleeping but fail to acquire the
lock even if the rwsem is free if the following sequence happens:

  Non-first waiter       First waiter      Lock holder
  ----------------       ------------      -----------
  Acquire wait_lock
  rwsem_try_write_lock():
    Set handoff bit if RT or
      wait too long
    Set waiter->handoff_set
  Release wait_lock
                         Acquire wait_lock
                         Inherit waiter->handoff_set
                         Release wait_lock
					   Clear owner
                                           Release lock
  if (waiter.handoff_set) {
    rwsem_spin_on_owner(();
    if (OWNER_NULL)
      goto trylock_again;
  }
  trylock_again:
  Acquire wait_lock
  rwsem_try_write_lock():
     if (first->handoff_set && (waiter != first))
     	return false;
  Release wait_lock

It is especially problematic if the non-first waiter is an RT task and
it is running on the same CPU as the first waiter as this can lead to
live lock.

Bug: 252734649

Fixes: d257cc8c ("locking/rwsem: Make handoff bit handling more consistent")
Signed-off-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/lkml/20221012133333.1265281-2-longman@redhat.com/


Signed-off-by: wangting11 <wangting11@xiaomi.com>
Change-Id: I6ac35872e8aae61cb96cd87a365a2d44d66961eb