Re: Lots of bugs with current->state = TASK_*INTERRUPTIBLE

[Julia Lawall <julia@diku.dk>]

What about something like the following (drivers/macintosh/adb.c):

        add_wait_queue(&state->wait_queue, &wait);
        current->state = TASK_INTERRUPTIBLE;

	for (;;) {
	        req = state->completed;
                if (req != NULL)
                        state->completed = req->next;
                else if (atomic_read(&state->n_pending) == 0)
                        ret = -EIO;
		if (req != NULL || ret != 0)
			break;

                if (file->f_flags & O_NONBLOCK) {
                        ret = -EAGAIN;
                        break;
		}
                if (signal_pending(current)) {
                        ret = -ERESTARTSYS;
                        break;
                }
                spin_unlock_irqrestore(&state->lock, flags);
                schedule();
        	spin_lock_irqsave(&state->lock, flags);
        }

        current->state = TASK_RUNNING;
        remove_wait_queue(&state->wait_queue, &wait);

There is a call to schedule eventually after the first current->state 
assignment, but it is not right after.

thanks,
julia