2 files changed, 14 insertions, 0 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 39ce64432ba6..e1999679a4d5 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -350,6 +350,12 @@ static int attempt_merge(struct request_queue *q, struct request *req,
         if (blk_integrity_rq(req) != blk_integrity_rq(next))
                 return 0;
 
+        /* don't merge requests of different failfast settings */
+        if (blk_failfast_dev(req)       != blk_failfast_dev(next)       ||
+            blk_failfast_transport(req) != blk_failfast_transport(next) ||
+            blk_failfast_driver(req)    != blk_failfast_driver(next))
+                return 0;
+
         /*
          * If we are allowed to merge, then append bio list
          * from next to rq and release next. merge_requests_fn
diff --git a/block/elevator.c b/block/elevator.c
index ca861927ba41..6f2375339a99 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -100,6 +100,14 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio)
         if (bio_integrity(bio) != blk_integrity_rq(rq))
                 return 0;
 
+        /*
+         * Don't merge if failfast settings don't match
+         */
+        if (bio_failfast_dev(bio)       != blk_failfast_dev(rq)         ||
+            bio_failfast_transport(bio) != blk_failfast_transport(rq)   ||
+            bio_failfast_driver(bio)    != blk_failfast_driver(rq))
+                return 0;
+
         if (!elv_iosched_allow_merge(rq, bio))
                 return 0;