static void discard_buffer(struct buffer_head * bh)
{
- unsigned long b_state, b_state_old;
+ unsigned long b_state;
lock_buffer(bh);
clear_buffer_dirty(bh);
bh->b_bdev = NULL;
- b_state = bh->b_state;
- for (;;) {
- b_state_old = cmpxchg(&bh->b_state, b_state,
- (b_state & ~BUFFER_FLAGS_DISCARD));
- if (b_state_old == b_state)
- break;
- b_state = b_state_old;
- }
+ b_state = READ_ONCE(bh->b_state);
+ do {
+ } while (!try_cmpxchg(&bh->b_state, &b_state,
+ b_state & ~BUFFER_FLAGS_DISCARD));
unlock_buffer(bh);
}