dm rq: add DM_MAPIO_DELAY_REQUEUE to delay requeue of blk-mq requests
Otherwise blk-mq will immediately dispatch requests that are requeued
via a BLK_MQ_RQ_QUEUE_BUSY return from blk_mq_ops .queue_rq.
Delayed requeue is implemented using blk_mq_delay_kick_requeue_list()
with a delay of 5 secs. In the context of DM multipath (all paths down)
it doesn't make any sense to requeue more quickly.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 91acfce..ef7962e 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -590,6 +590,7 @@
#define DM_MAPIO_SUBMITTED 0
#define DM_MAPIO_REMAPPED 1
#define DM_MAPIO_REQUEUE DM_ENDIO_REQUEUE
+#define DM_MAPIO_DELAY_REQUEUE 3
#define dm_sector_div64(x, y)( \
{ \