Ejemplo n.º 1
0
/*
 * Returns:
 * DM_MAPIO_*       : the request has been processed as indicated
 * DM_MAPIO_REQUEUE : the original request needs to be immediately requeued
 * < 0              : the request was completed due to failure
 */
static int map_request(struct dm_rq_target_io *tio)
{
	int r;
	struct dm_target *ti = tio->ti;
	struct mapped_device *md = tio->md;
	struct request *rq = tio->orig;
	struct request *clone = NULL;
	blk_status_t ret;

	r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone);
check_again:
	switch (r) {
	case DM_MAPIO_SUBMITTED:
		/* The target has taken the I/O to submit by itself later */
		break;
	case DM_MAPIO_REMAPPED:
		if (setup_clone(clone, rq, tio, GFP_ATOMIC)) {
			/* -ENOMEM */
			ti->type->release_clone_rq(clone);
			return DM_MAPIO_REQUEUE;
		}

		/* The target has remapped the I/O so dispatch it */
		trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
				     blk_rq_pos(rq));
		ret = dm_dispatch_clone_request(clone, rq);
		if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) {
			blk_rq_unprep_clone(clone);
			tio->ti->type->release_clone_rq(clone);
			tio->clone = NULL;
			if (!rq->q->mq_ops)
				r = DM_MAPIO_DELAY_REQUEUE;
			else
				r = DM_MAPIO_REQUEUE;
			goto check_again;
		}
		break;
	case DM_MAPIO_REQUEUE:
		/* The target wants to requeue the I/O */
		break;
	case DM_MAPIO_DELAY_REQUEUE:
		/* The target wants to requeue the I/O after a delay */
		dm_requeue_original_request(tio, true);
		break;
	case DM_MAPIO_KILL:
		/* The target wants to complete the I/O */
		dm_kill_unmapped_request(rq, BLK_STS_IOERR);
		break;
	default:
		DMWARN("unimplemented target map return value: %d", r);
		BUG();
	}

	return r;
}
Ejemplo n.º 2
0
static void free_rq_clone(struct request *clone)
{
	struct dm_rq_target_io *tio = clone->end_io_data;
	struct mapped_device *md = tio->md;

	blk_rq_unprep_clone(clone);

	if (md->type == DM_TYPE_MQ_REQUEST_BASED)
		/* stacked on blk-mq queue(s) */
		tio->ti->type->release_clone_rq(clone);
	else if (!md->queue->mq_ops)
		/* request_fn queue stacked on request_fn queue(s) */
		free_old_clone_request(md, clone);

	if (!md->queue->mq_ops)
		free_old_rq_tio(tio);
}
Ejemplo n.º 3
0
/*
 * Complete the clone and the original request.
 * Must be called without clone's queue lock held,
 * see end_clone_request() for more details.
 */
static void dm_end_request(struct request *clone, blk_status_t error)
{
	int rw = rq_data_dir(clone);
	struct dm_rq_target_io *tio = clone->end_io_data;
	struct mapped_device *md = tio->md;
	struct request *rq = tio->orig;

	blk_rq_unprep_clone(clone);
	tio->ti->type->release_clone_rq(clone);

	rq_end_stats(md, rq);
	if (!rq->q->mq_ops)
		blk_end_request_all(rq, error);
	else
		blk_mq_end_request(rq, error);
	rq_completed(md, rw, true);
}
Ejemplo n.º 4
0
static void dm_requeue_original_request(struct dm_rq_target_io *tio, bool delay_requeue)
{
	struct mapped_device *md = tio->md;
	struct request *rq = tio->orig;
	int rw = rq_data_dir(rq);

	rq_end_stats(md, rq);
	if (tio->clone) {
		blk_rq_unprep_clone(tio->clone);
		tio->ti->type->release_clone_rq(tio->clone);
	}

	if (!rq->q->mq_ops)
		dm_old_requeue_request(rq);
	else
		dm_mq_delay_requeue_request(rq, delay_requeue ? 100/*ms*/ : 0);

	rq_completed(md, rw, false);
}