Re: [PATCHv2 3/3] nvme-pci: fix queue_rqs list splitting

[Christoph Hellwig <hch@lst.de>]

> +			rq_list_move(rqlist, &requeue_list, req, prev, next);
> +
> +			req = prev;
> +			if (!req)
> +				continue;

Shouldn't this be a break?

> +			*rqlist = next;
> +			prev = NULL;
> +		} else
> +			prev = req;
> +	}

I wonder if a restart label here would be a little cleaner, something
like:


diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 992ee314e91ba..29b433fd12bdd 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -999,9 +999,11 @@ static bool nvme_prep_rq_batch(struct nvme_queue *nvmeq, struct request *req)
 
 static void nvme_queue_rqs(struct request **rqlist)
 {
-	struct request *req, *next, *prev = NULL;
+	struct request *req, *next, *prev;
 	struct request *requeue_list = NULL;
 
+restart:
+	prev = NULL;
 	rq_list_for_each_safe(rqlist, req, next) {
 		struct nvme_queue *nvmeq = req->mq_hctx->driver_data;
 
@@ -1009,9 +1011,9 @@ static void nvme_queue_rqs(struct request **rqlist)
 			/* detach 'req' and add to remainder list */
 			rq_list_move(rqlist, &requeue_list, req, prev, next);
 
+			if (!prev)
+				break;
 			req = prev;
-			if (!req)
-				continue;
 		}
 
 		if (!next || req->mq_hctx != next->mq_hctx) {
@@ -1019,9 +1021,9 @@ static void nvme_queue_rqs(struct request **rqlist)
 			req->rq_next = NULL;
 			nvme_submit_cmds(nvmeq, rqlist);
 			*rqlist = next;
-			prev = NULL;
-		} else
-			prev = req;
+			goto restart;
+		}
+		prev = req;
 	}
 
 	*rqlist = requeue_list;