nvme-fc and nvmet-fc: revise LLDD api for LS reception and LS request

The current LLDD api has:
  nvme-fc: contains api for transport to do LS requests (and aborts of
    them). However, there is no interface for reception of LS's and sending
    responses for them.
  nvmet-fc: contains api for transport to do reception of LS's and sending
    of responses for them. However, there is no interface for doing LS
    requests.

Revise the api's so that both nvme-fc and nvmet-fc can send LS's, as well
as receiving LS's and sending their responses.

Change name of the rcv_ls_req struct to better reflect generic use as
a context to used to send an ls rsp. Specifically:
  nvmefc_tgt_ls_req -> nvmefc_ls_rsp
  nvmefc_tgt_ls_req.nvmet_fc_private -> nvmefc_ls_rsp.nvme_fc_private

Change nvmet_fc_rcv_ls_req() calling sequence to provide handle that
can be used by transport in later LS request sequences for an association.

nvme-fc nvmet_fc nvme_fcloop:
  Revise to adapt to changed names in api header.
  Change calling sequence to nvmet_fc_rcv_ls_req() for hosthandle.
  Add stubs for new interfaces:
    host/fc.c: nvme_fc_rcv_ls_req()
    target/fc.c: nvmet_fc_invalidate_host()

lpfc:
  Revise to adapt code to changed names in api header.
  Change calling sequence to nvmet_fc_rcv_ls_req() for hosthandle.

Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

2 files changed, 67 insertions, 30 deletions

diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index a8ceb7721640..aac7869a70bb 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -28,7 +28,7 @@ struct nvmet_fc_tgtport;
 struct nvmet_fc_tgt_assoc;
 
 struct nvmet_fc_ls_iod {
-	struct nvmefc_tgt_ls_req	*lsreq;
+	struct nvmefc_ls_rsp		*lsrsp;
 	struct nvmefc_tgt_fcp_req	*fcpreq;	/* only if RS */
 
 	struct list_head		ls_list;	/* tgtport->ls_list */
@@ -1146,6 +1146,42 @@ __nvmet_fc_free_assocs(struct nvmet_fc_tgtport *tgtport)
 	spin_unlock_irqrestore(&tgtport->lock, flags);
 }
 
+/**
+ * nvmet_fc_invalidate_host - transport entry point called by an LLDD
+ *                       to remove references to a hosthandle for LS's.
+ *
+ * The nvmet-fc layer ensures that any references to the hosthandle
+ * on the targetport are forgotten (set to NULL).  The LLDD will
+ * typically call this when a login with a remote host port has been
+ * lost, thus LS's for the remote host port are no longer possible.
+ *
+ * If an LS request is outstanding to the targetport/hosthandle (or
+ * issued concurrently with the call to invalidate the host), the
+ * LLDD is responsible for terminating/aborting the LS and completing
+ * the LS request. It is recommended that these terminations/aborts
+ * occur after calling to invalidate the host handle to avoid additional
+ * retries by the nvmet-fc transport. The nvmet-fc transport may
+ * continue to reference host handle while it cleans up outstanding
+ * NVME associations. The nvmet-fc transport will call the
+ * ops->host_release() callback to notify the LLDD that all references
+ * are complete and the related host handle can be recovered.
+ * Note: if there are no references, the callback may be called before
+ * the invalidate host call returns.
+ *
+ * @target_port: pointer to the (registered) target port that a prior
+ *              LS was received on and which supplied the transport the
+ *              hosthandle.
+ * @hosthandle: the handle (pointer) that represents the host port
+ *              that no longer has connectivity and that LS's should
+ *              no longer be directed to.
+ */
+void
+nvmet_fc_invalidate_host(struct nvmet_fc_target_port *target_port,
+			void *hosthandle)
+{
+}
+EXPORT_SYMBOL_GPL(nvmet_fc_invalidate_host);
+
 /*
  * nvmet layer has called to terminate an association
  */
@@ -1371,7 +1407,7 @@ nvmet_fc_ls_create_association(struct nvmet_fc_tgtport *tgtport,
 		dev_err(tgtport->dev,
 			"Create Association LS failed: %s\n",
 			validation_errors[ret]);
-		iod->lsreq->rsplen = nvmet_fc_format_rjt(acc,
+		iod->lsrsp->rsplen = nvmet_fc_format_rjt(acc,
 				NVME_FC_MAX_LS_BUFFER_SIZE, rqst->w0.ls_cmd,
 				FCNVME_RJT_RC_LOGIC,
 				FCNVME_RJT_EXP_NONE, 0);
@@ -1384,7 +1420,7 @@ nvmet_fc_ls_create_association(struct nvmet_fc_tgtport *tgtport,
 
 	/* format a response */
 
-	iod->lsreq->rsplen = sizeof(*acc);
+	iod->lsrsp->rsplen = sizeof(*acc);
 
 	nvmet_fc_format_rsp_hdr(acc, FCNVME_LS_ACC,
 			fcnvme_lsdesc_len(
@@ -1462,7 +1498,7 @@ nvmet_fc_ls_create_connection(struct nvmet_fc_tgtport *tgtport,
 		dev_err(tgtport->dev,
 			"Create Connection LS failed: %s\n",
 			validation_errors[ret]);
-		iod->lsreq->rsplen = nvmet_fc_format_rjt(acc,
+		iod->lsrsp->rsplen = nvmet_fc_format_rjt(acc,
 				NVME_FC_MAX_LS_BUFFER_SIZE, rqst->w0.ls_cmd,
 				(ret == VERR_NO_ASSOC) ?
 					FCNVME_RJT_RC_INV_ASSOC :
@@ -1477,7 +1513,7 @@ nvmet_fc_ls_create_connection(struct nvmet_fc_tgtport *tgtport,
 
 	/* format a response */
 
-	iod->lsreq->rsplen = sizeof(*acc);
+	iod->lsrsp->rsplen = sizeof(*acc);
 
 	nvmet_fc_format_rsp_hdr(acc, FCNVME_LS_ACC,
 			fcnvme_lsdesc_len(sizeof(struct fcnvme_ls_cr_conn_acc)),
@@ -1542,7 +1578,7 @@ nvmet_fc_ls_disconnect(struct nvmet_fc_tgtport *tgtport,
 		dev_err(tgtport->dev,
 			"Disconnect LS failed: %s\n",
 			validation_errors[ret]);
-		iod->lsreq->rsplen = nvmet_fc_format_rjt(acc,
+		iod->lsrsp->rsplen = nvmet_fc_format_rjt(acc,
 				NVME_FC_MAX_LS_BUFFER_SIZE, rqst->w0.ls_cmd,
 				(ret == VERR_NO_ASSOC) ?
 					FCNVME_RJT_RC_INV_ASSOC :
@@ -1555,7 +1591,7 @@ nvmet_fc_ls_disconnect(struct nvmet_fc_tgtport *tgtport,
 
 	/* format a response */
 
-	iod->lsreq->rsplen = sizeof(*acc);
+	iod->lsrsp->rsplen = sizeof(*acc);
 
 	nvmet_fc_format_rsp_hdr(acc, FCNVME_LS_ACC,
 			fcnvme_lsdesc_len(
@@ -1577,9 +1613,9 @@ static void nvmet_fc_fcp_nvme_cmd_done(struct nvmet_req *nvme_req);
 static const struct nvmet_fabrics_ops nvmet_fc_tgt_fcp_ops;
 
 static void
-nvmet_fc_xmt_ls_rsp_done(struct nvmefc_tgt_ls_req *lsreq)
+nvmet_fc_xmt_ls_rsp_done(struct nvmefc_ls_rsp *lsrsp)
 {
-	struct nvmet_fc_ls_iod *iod = lsreq->nvmet_fc_private;
+	struct nvmet_fc_ls_iod *iod = lsrsp->nvme_fc_private;
 	struct nvmet_fc_tgtport *tgtport = iod->tgtport;
 
 	fc_dma_sync_single_for_cpu(tgtport->dev, iod->rspdma,
@@ -1597,9 +1633,9 @@ nvmet_fc_xmt_ls_rsp(struct nvmet_fc_tgtport *tgtport,
 	fc_dma_sync_single_for_device(tgtport->dev, iod->rspdma,
 				  NVME_FC_MAX_LS_BUFFER_SIZE, DMA_TO_DEVICE);
 
-	ret = tgtport->ops->xmt_ls_rsp(&tgtport->fc_target_port, iod->lsreq);
+	ret = tgtport->ops->xmt_ls_rsp(&tgtport->fc_target_port, iod->lsrsp);
 	if (ret)
-		nvmet_fc_xmt_ls_rsp_done(iod->lsreq);
+		nvmet_fc_xmt_ls_rsp_done(iod->lsrsp);
 }
 
 /*
@@ -1612,12 +1648,12 @@ nvmet_fc_handle_ls_rqst(struct nvmet_fc_tgtport *tgtport,
 	struct fcnvme_ls_rqst_w0 *w0 =
 			(struct fcnvme_ls_rqst_w0 *)iod->rqstbuf;
 
-	iod->lsreq->nvmet_fc_private = iod;
-	iod->lsreq->rspbuf = iod->rspbuf;
-	iod->lsreq->rspdma = iod->rspdma;
-	iod->lsreq->done = nvmet_fc_xmt_ls_rsp_done;
+	iod->lsrsp->nvme_fc_private = iod;
+	iod->lsrsp->rspbuf = iod->rspbuf;
+	iod->lsrsp->rspdma = iod->rspdma;
+	iod->lsrsp->done = nvmet_fc_xmt_ls_rsp_done;
 	/* Be preventative. handlers will later set to valid length */
-	iod->lsreq->rsplen = 0;
+	iod->lsrsp->rsplen = 0;
 
 	iod->assoc = NULL;
 
@@ -1640,7 +1676,7 @@ nvmet_fc_handle_ls_rqst(struct nvmet_fc_tgtport *tgtport,
 		nvmet_fc_ls_disconnect(tgtport, iod);
 		break;
 	default:
-		iod->lsreq->rsplen = nvmet_fc_format_rjt(iod->rspbuf,
+		iod->lsrsp->rsplen = nvmet_fc_format_rjt(iod->rspbuf,
 				NVME_FC_MAX_LS_BUFFER_SIZE, w0->ls_cmd,
 				FCNVME_RJT_RC_INVAL, FCNVME_RJT_EXP_NONE, 0);
 	}
@@ -1674,14 +1710,15 @@ nvmet_fc_handle_ls_rqst_work(struct work_struct *work)
  *
  * @target_port: pointer to the (registered) target port the LS was
  *              received on.
- * @lsreq:      pointer to a lsreq request structure to be used to reference
+ * @lsrsp:      pointer to a lsrsp structure to be used to reference
  *              the exchange corresponding to the LS.
  * @lsreqbuf:   pointer to the buffer containing the LS Request
  * @lsreqbuf_len: length, in bytes, of the received LS request
  */
 int
 nvmet_fc_rcv_ls_req(struct nvmet_fc_target_port *target_port,
-			struct nvmefc_tgt_ls_req *lsreq,
+			void *hosthandle,
+			struct nvmefc_ls_rsp *lsrsp,
 			void *lsreqbuf, u32 lsreqbuf_len)
 {
 	struct nvmet_fc_tgtport *tgtport = targetport_to_tgtport(target_port);
@@ -1699,7 +1736,7 @@ nvmet_fc_rcv_ls_req(struct nvmet_fc_target_port *target_port,
 		return -ENOENT;
 	}
 
-	iod->lsreq = lsreq;
+	iod->lsrsp = lsrsp;
 	iod->fcpreq = NULL;
 	memcpy(iod->rqstbuf, lsreqbuf, lsreqbuf_len);
 	iod->rqstdatalen = lsreqbuf_len;
diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c
index f69ce66e2d44..c11805a155e8 100644
--- a/drivers/nvme/target/fcloop.c
+++ b/drivers/nvme/target/fcloop.c
@@ -228,7 +228,7 @@ struct fcloop_nport {
 
 struct fcloop_lsreq {
 	struct nvmefc_ls_req		*lsreq;
-	struct nvmefc_tgt_ls_req	tgt_ls_req;
+	struct nvmefc_ls_rsp		ls_rsp;
 	int				status;
 	struct list_head		ls_list; /* fcloop_rport->ls_list */
 };
@@ -267,9 +267,9 @@ struct fcloop_ini_fcpreq {
 };
 
 static inline struct fcloop_lsreq *
-tgt_ls_req_to_lsreq(struct nvmefc_tgt_ls_req *tgt_lsreq)
+ls_rsp_to_lsreq(struct nvmefc_ls_rsp *lsrsp)
 {
-	return container_of(tgt_lsreq, struct fcloop_lsreq, tgt_ls_req);
+	return container_of(lsrsp, struct fcloop_lsreq, ls_rsp);
 }
 
 static inline struct fcloop_fcpreq *
@@ -344,7 +344,7 @@ fcloop_ls_req(struct nvme_fc_local_port *localport,
 	}
 
 	tls_req->status = 0;
-	ret = nvmet_fc_rcv_ls_req(rport->targetport, &tls_req->tgt_ls_req,
+	ret = nvmet_fc_rcv_ls_req(rport->targetport, NULL, &tls_req->ls_rsp,
 				 lsreq->rqstaddr, lsreq->rqstlen);
 
 	return ret;
@@ -352,19 +352,19 @@ fcloop_ls_req(struct nvme_fc_local_port *localport,
 
 static int
 fcloop_xmt_ls_rsp(struct nvmet_fc_target_port *targetport,
-			struct nvmefc_tgt_ls_req *tgt_lsreq)
+			struct nvmefc_ls_rsp *lsrsp)
 {
-	struct fcloop_lsreq *tls_req = tgt_ls_req_to_lsreq(tgt_lsreq);
+	struct fcloop_lsreq *tls_req = ls_rsp_to_lsreq(lsrsp);
 	struct nvmefc_ls_req *lsreq = tls_req->lsreq;
 	struct fcloop_tport *tport = targetport->private;
 	struct nvme_fc_remote_port *remoteport = tport->remoteport;
 	struct fcloop_rport *rport;
 
-	memcpy(lsreq->rspaddr, tgt_lsreq->rspbuf,
-		((lsreq->rsplen < tgt_lsreq->rsplen) ?
-				lsreq->rsplen : tgt_lsreq->rsplen));
+	memcpy(lsreq->rspaddr, lsrsp->rspbuf,
+		((lsreq->rsplen < lsrsp->rsplen) ?
+				lsreq->rsplen : lsrsp->rsplen));
 
-	tgt_lsreq->done(tgt_lsreq);
+	lsrsp->done(lsrsp);
 
 	if (remoteport) {
 		rport = remoteport->private;