blk-mq: Allow requests to never expire

Some types of requests may be started that are not gauranteed to ever
complete. This adds a request flag that a driver can use so mark the
request as such.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 261ccd89e15d..78324a2f0e10 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -619,7 +619,7 @@ void blk_mq_rq_timed_out(struct request *req, bool reserved)
                 break;
         }
 }
-                
+
 static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
                 struct request *rq, void *priv, bool reserved)
 {
@@ -627,6 +627,8 @@ static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
 
         if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
                 return;
+        if (rq->cmd_flags & REQ_NO_TIMEOUT)
+                return;
 
         if (time_after_eq(jiffies, rq->deadline)) {
                 if (!blk_mark_rq_complete(rq))