Except for DM_MAPIO_REQUEUE, map_request() handles other dispatch exception already, so return BLK_STS_* from map_request() directly.
Another change is that if dm_dispatch_clone_request() returns BLK_STS_DEV_RESOURCE from underlying queue, this status is returned to blk-mq too, since underlying queue's RESTART can handle dm-rq's RESTART in this case. Cc: Mike Snitzer <[email protected]> Cc: Laurence Oberman <[email protected]> Cc: Bart Van Assche <[email protected]> Signed-off-by: Ming Lei <[email protected]> --- drivers/md/dm-rq.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index 1408e6664c16..830e1ccfbb44 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -482,9 +482,10 @@ static void init_tio(struct dm_rq_target_io *tio, struct request *rq, /* * 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 + * BLK_STS_OK : the request has been processed aready, no need to + * ask block layer to handle it any more + * BLK_STS_RESOURCE : the original request needs to be immediately requeued + * BLK_STS_DEV_RESOURCE : same with BLK_STS_RESOURCE, but blk-mq need this info */ static int map_request(struct dm_rq_target_io *tio) { @@ -493,7 +494,7 @@ static int map_request(struct dm_rq_target_io *tio) struct mapped_device *md = tio->md; struct request *rq = tio->orig; struct request *clone = NULL; - blk_status_t ret; + blk_status_t ret, result = BLK_STS_OK; r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone); check_again: @@ -513,15 +514,16 @@ static int map_request(struct dm_rq_target_io *tio) blk_rq_pos(rq)); ret = dm_dispatch_clone_request(tio, clone, rq); if (dispatch_busy(ret)) { - if (!rq->q->mq_ops) + if (!rq->q->mq_ops) { r = DM_MAPIO_DELAY_REQUEUE; - else - r = DM_MAPIO_REQUEUE; - goto check_again; + goto check_again; + } + result = ret; } break; case DM_MAPIO_REQUEUE: /* The target wants to requeue the I/O */ + result = BLK_STS_RESOURCE; break; case DM_MAPIO_DELAY_REQUEUE: /* The target wants to requeue the I/O after a delay */ @@ -536,7 +538,7 @@ static int map_request(struct dm_rq_target_io *tio) BUG(); } - return r; + return result; } static void dm_start_request(struct mapped_device *md, struct request *orig) @@ -599,7 +601,7 @@ static void map_tio_request(struct kthread_work *work) { struct dm_rq_target_io *tio = container_of(work, struct dm_rq_target_io, work); - if (map_request(tio) == DM_MAPIO_REQUEUE) + if (dispatch_busy(map_request(tio))) dm_requeue_original_request(tio, false); } @@ -754,6 +756,7 @@ static blk_status_t dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx, struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq); struct mapped_device *md = tio->md; struct dm_target *ti = md->immutable_target; + blk_status_t ret; if (unlikely(!ti)) { int srcu_idx; @@ -777,14 +780,15 @@ static blk_status_t dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx, tio->ti = ti; /* Direct call is fine since .queue_rq allows allocations */ - if (map_request(tio) == DM_MAPIO_REQUEUE) { + ret = map_request(tio); + if (dispatch_busy(ret)) { /* Undo dm_start_request() before requeuing */ rq_end_stats(md, rq); rq_completed(md, rq_data_dir(rq), false); - return BLK_STS_RESOURCE; + return ret; } - return BLK_STS_OK; + return ret; } static const struct blk_mq_ops dm_mq_ops = { -- 2.9.5
