From: Christoph Hellwig <hch@lst.de>
Date: Mon, 11 Jun 2018 17:34:06 +0200
Subject: [PATCH] nvme-fabrics: refactor queue ready check
References: bsc#1098706
Git-commit: 3bc32bb1186ccaf3177cbf29caa6cc14dc510b7b
Patch-mainline: v4.18-rc1

Move the is_connected check to the fibre channel transport, as it has no
meaning for other transports.  To facilitate this split out a new
nvmf_fail_nonready_command helper that is called by the transport when
it is asked to handle a command on a queue that is not ready.

Also avoid a function call for the queue live fast path by inlining
the check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/host/fabrics.c | 59 ++++++++++++++++++---------------------------
 drivers/nvme/host/fabrics.h | 13 ++++++++--
 drivers/nvme/host/fc.c      |  9 +++----
 drivers/nvme/host/rdma.c    |  7 +++---
 drivers/nvme/target/loop.c  |  7 +++---
 5 files changed, 45 insertions(+), 50 deletions(-)

diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index 595040a6ce77..bc4bb162773c 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -536,38 +536,40 @@ static struct nvmf_transport_ops *nvmf_lookup_transport(
 	return NULL;
 }
 
-blk_status_t nvmf_check_if_ready(struct nvme_ctrl *ctrl, struct request *rq,
-		bool queue_live, bool is_connected)
+/*
+ * For something we're not in a state to send to the device the default action
+ * is to busy it and retry it after the controller state is recovered.  However,
+ * anything marked for failfast or nvme multipath is immediately failed.
+ *
+ * Note: commands used to initialize the controller will be marked for failfast.
+ * Note: nvme cli/ioctl commands are marked for failfast.
+ */
+blk_status_t nvmf_fail_nonready_command(struct request *rq)
 {
-	struct nvme_command *cmd = nvme_req(rq)->cmd;
+	if (!blk_noretry_request(rq) && !(rq->cmd_flags & REQ_NVME_MPATH))
+		return BLK_STS_RESOURCE;
+	nvme_req(rq)->status = NVME_SC_ABORT_REQ;
+	return BLK_STS_IOERR;
+}
+EXPORT_SYMBOL_GPL(nvmf_fail_nonready_command);
 
-	if (likely(ctrl->state == NVME_CTRL_LIVE && is_connected))
-		return BLK_STS_OK;
+bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
+		bool queue_live)
+{
+	struct nvme_command *cmd = nvme_req(rq)->cmd;
 
 	switch (ctrl->state) {
 	case NVME_CTRL_NEW:
 	case NVME_CTRL_CONNECTING:
 	case NVME_CTRL_DELETING:
 		/*
-		 * This is the case of starting a new or deleting an association
-		 * but connectivity was lost before it was fully created or torn
-		 * down. We need to error the commands used to initialize the
-		 * controller so the reconnect can go into a retry attempt.  The
-		 * commands should all be marked REQ_FAILFAST_DRIVER, which will
-		 * hit the reject path below. Anything else will be queued while
-		 * the state settles.
-		 */
-		if (!is_connected)
-			break;
-
-		/*
 		 * If queue is live, allow only commands that are internally
 		 * generated pass through.  These are commands on the admin
 		 * queue to initialize the controller. This will reject any
 		 * ioctl admin cmds received while initializing.
 		 */
 		if (queue_live && !(nvme_req(rq)->flags & NVME_REQ_USERCMD))
-			return BLK_STS_OK;
+			return true;
 
 		/*
 		 * If the queue is not live, allow only a connect command.  This
@@ -577,26 +579,13 @@ blk_status_t nvmf_check_if_ready(struct nvme_ctrl *ctrl, struct request *rq,
 		if (!queue_live && blk_rq_is_passthrough(rq) &&
 		     cmd->common.opcode == nvme_fabrics_command &&
 		     cmd->fabrics.fctype == nvme_fabrics_type_connect)
-			return BLK_STS_OK;
-		break;
+			return true;
+		return false;
 	default:
-		break;
+		return false;
 	}
-
-	/*
-	 * Any other new io is something we're not in a state to send to the
-	 * device.  Default action is to busy it and retry it after the
-	 * controller state is recovered. However, anything marked for failfast
-	 * or nvme multipath is immediately failed.  Note: commands used to
-	 * initialize the controller will be marked for failfast.
-	 * Note: nvme cli/ioctl commands are marked for failfast.
-	 */
-	if (!blk_noretry_request(rq) && !(rq->cmd_flags & REQ_NVME_MPATH))
-		return BLK_STS_RESOURCE;
-	nvme_req(rq)->status = NVME_SC_ABORT_REQ;
-	return BLK_STS_IOERR;
 }
-EXPORT_SYMBOL_GPL(nvmf_check_if_ready);
+EXPORT_SYMBOL_GPL(__nvmf_check_ready);
 
 static const match_table_t opt_tokens = {
 	{ NVMF_OPT_TRANSPORT,		"transport=%s"		},
diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
index 0cf0460a5c92..970ed54efc1c 100644
--- a/drivers/nvme/host/fabrics.h
+++ b/drivers/nvme/host/fabrics.h
@@ -159,7 +159,16 @@ void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
 void nvmf_free_options(struct nvmf_ctrl_options *opts);
 int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
 bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
-blk_status_t nvmf_check_if_ready(struct nvme_ctrl *ctrl,
-	struct request *rq, bool queue_live, bool is_connected);
+blk_status_t nvmf_fail_nonready_command(struct request *rq);
+bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
+		bool queue_live);
+
+static inline bool nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
+		bool queue_live)
+{
+	if (likely(ctrl->state == NVME_CTRL_LIVE))
+		return true;
+	return __nvmf_check_ready(ctrl, rq, queue_live);
+}
 
 #endif /* _NVME_FABRICS_H */
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 0cd920784b47..6d4e62025d92 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2276,14 +2276,13 @@ nvme_fc_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct nvme_fc_cmd_iu *cmdiu = &op->cmd_iu;
 	struct nvme_command *sqe = &cmdiu->sqe;
 	enum nvmefc_fcp_datadir	io_dir;
+	bool queue_ready = test_bit(NVME_FC_Q_LIVE, &queue->flags);
 	u32 data_len;
 	blk_status_t ret;
 
-	ret = nvmf_check_if_ready(&queue->ctrl->ctrl, rq,
-		test_bit(NVME_FC_Q_LIVE, &queue->flags),
-		ctrl->rport->remoteport.port_state == FC_OBJSTATE_ONLINE);
-	if (unlikely(ret))
-		return ret;
+	if (ctrl->rport->remoteport.port_state != FC_OBJSTATE_ONLINE ||
+	    !nvmf_check_ready(&queue->ctrl->ctrl, rq, queue_ready))
+		return nvmf_fail_nonready_command(rq);
 
 	ret = nvme_setup_cmd(ns, rq, sqe);
 	if (ret)
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 19fa25dde69a..90b57cff72fe 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1604,15 +1604,14 @@ static blk_status_t nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct nvme_rdma_qe *sqe = &req->sqe;
 	struct nvme_command *c = sqe->data;
 	struct ib_device *dev;
+	bool queue_ready = test_bit(NVME_RDMA_Q_LIVE, &queue->flags);
 	blk_status_t ret;
 	int err;
 
 	WARN_ON_ONCE(rq->tag < 0);
 
-	ret = nvmf_check_if_ready(&queue->ctrl->ctrl, rq,
-		test_bit(NVME_RDMA_Q_LIVE, &queue->flags), true);
-	if (unlikely(ret))
-		return ret;
+	if (!nvmf_check_ready(&queue->ctrl->ctrl, rq, queue_ready))
+		return nvmf_fail_nonready_command(rq);
 
 	dev = queue->device->dev;
 	ib_dma_sync_single_for_cpu(dev, sqe->dma,
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index e10987f87603..d58aa5251165 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -156,12 +156,11 @@ static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct nvme_loop_queue *queue = hctx->driver_data;
 	struct request *req = bd->rq;
 	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
+	bool queue_ready = test_bit(NVME_LOOP_Q_LIVE, &queue->flags);
 	blk_status_t ret;
 
-	ret = nvmf_check_if_ready(&queue->ctrl->ctrl, req,
-		test_bit(NVME_LOOP_Q_LIVE, &queue->flags), true);
-	if (unlikely(ret))
-		return ret;
+	if (!nvmf_check_ready(&queue->ctrl->ctrl, req, queue_ready))
+		return nvmf_fail_nonready_command(req);
 
 	ret = nvme_setup_cmd(ns, req, &iod->cmd);
 	if (ret)
-- 
2.12.3