blk-mq: add might_sleep check to blk_mq_get_driver_tag()
If the caller passes in wait=true, it has to be able to block
for a driver tag. We just had a bug where flush insertion
would block on tag allocation, while we had preempt disabled.
Ensure that we catch cases like that earlier next time.
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b6dc9ba..fa7d86f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -864,6 +864,8 @@ bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
.flags = wait ? 0 : BLK_MQ_REQ_NOWAIT,
};
+ might_sleep_if(wait);
+
if (rq->tag != -1)
goto done;
