1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8bc46c250ca..c9d233e727f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -378,6 +378,12 @@ struct request_queue {
 
         unsigned int            nr_sorted;
         unsigned int            in_flight[2];
+        /*
+         * Number of active block driver functions for which blk_drain_queue()
+         * must wait. Must be incremented around functions that unlock the
+         * queue_lock internally, e.g. scsi_request_fn().
+         */
+        unsigned int            request_fn_active;
 
         unsigned int            rq_timeout;
         struct timer_list       timeout;