Inside blk_mq_queue_tag_busy_iter() we already grabbed request's
refcount before calling ->fn(), so needn't to grab it one more time
in blk_mq_check_expired().
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq.c | 25 +++++++------------------
1 file changed, 7 insertions(+), 18 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index d2725f94491d..4d3457d2957f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -917,6 +917,10 @@ void blk_mq_put_rq_ref(struct request *rq)
__blk_mq_free_request(rq);
}
+/*
+ * This request won't be re-allocated because its refcount is held when
+ * calling this callback.
+ */
static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
struct request *rq, void *priv, bool reserved)
{
@@ -930,27 +934,12 @@ static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
return true;
/*
- * We have reason to believe the request may be expired. Take a
- * reference on the request to lock this request lifetime into its
- * currently allocated context to prevent it from being reallocated in
- * the event the completion by-passes this timeout handler.
- *
- * If the reference was already released, then the driver beat the
- * timeout handler to posting a natural completion.
- */
- if (!refcount_inc_not_zero(&rq->ref))
- return true;
-
- /*
- * The request is now locked and cannot be reallocated underneath the
- * timeout handler's processing. Re-verify this exact request is truly
- * expired; if it is not expired, then the request was completed and
- * reallocated as a new request.
+ * Re-verify this exact request is truly expired; if it is not expired,
+ * then the request was completed and reallocated as a new request
+ * after returning from blk_mq_check_expired().
*/
if (blk_mq_req_expired(rq, next))
blk_mq_rq_timed_out(rq, reserved);
-
- blk_mq_put_rq_ref(rq);
return true;
}
--
2.31.1
