target crash / host hang with nvme-all.3 branch of nvme-fabrics

[hch@lst.de ('Christoph Hellwig')]

On Thu, Jun 16, 2016@03:28:06PM -0500, Steve Wise wrote:
> > Just to follow, does Christoph's patch fix the crash?
> 
> It does. 

Unfortunately I think it's still wrong because it will only delete
a single queue per controller.  We'll probably need something
like this instead, which does the same think but also has a retry
loop for additional queues:


diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index b1c6e5b..425b55c 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -1293,19 +1293,20 @@ static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
 
 static void nvmet_rdma_delete_ctrl(struct nvmet_ctrl *ctrl)
 {
-	struct nvmet_rdma_queue *queue, *next;
-	static LIST_HEAD(del_list);
+	struct nvmet_rdma_queue *queue;
 
+restart:
 	mutex_lock(&nvmet_rdma_queue_mutex);
-	list_for_each_entry_safe(queue, next,
-			&nvmet_rdma_queue_list, queue_list) {
-		if (queue->nvme_sq.ctrl->cntlid == ctrl->cntlid)
-			list_move_tail(&queue->queue_list, &del_list);
+	list_for_each_entry(queue, &nvmet_rdma_queue_list, queue_list) {
+		if (queue->nvme_sq.ctrl == ctrl) {
+			list_del_init(&queue->queue_list);
+			mutex_unlock(&nvmet_rdma_queue_mutex);
+
+			__nvmet_rdma_queue_disconnect(queue);
+			goto restart;
+		}
 	}
 	mutex_unlock(&nvmet_rdma_queue_mutex);
-
-	list_for_each_entry_safe(queue, next, &del_list, queue_list)
-		nvmet_rdma_queue_disconnect(queue);
 }
 
 static int nvmet_rdma_add_port(struct nvmet_port *port)