Patch "zfcp: fix D_ID field with actual value on tracing SAN responses" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

zfcp: fix D_ID field with actual value on tracing SAN responses

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
zfcp-fix-d_id-field-with-actual-value-on-tracing-san-responses.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Steffen Maier <[email protected]>
Date: Wed, 10 Aug 2016 18:30:51 +0200
Subject: zfcp: fix D_ID field with actual value on tracing SAN responses

From: Steffen Maier <[email protected]>

commit 771bf03537ddfa4a4dde62ef9dfbc82e4f77ab20 upstream.

With commit 2c55b750a884b86dea8b4cc5f15e1484cc47a25c ("[SCSI] zfcp: Redesign of the debug tracing for SAN records.") we lost the N_Port-ID where an ELS response comes from. With commit 7c7dc196814b9e1d5cc254dc579a5fa78ae524f7 ("[SCSI] zfcp: Simplify handling of ct and els requests") we lost the N_Port-ID where a CT response comes from. It's especially useful if the request SAN trace record with D_ID was already lost due to trace buffer wrap.

GS uses an open WKA port handle and ELS just a D_ID, and only for ELS we could get D_ID from QTCB bottom via zfcp_fsf_req. To cover both cases, add a new field to zfcp_fsf_ct_els and fill it in on request to use in SAN response trace. Strictly speaking the D_ID on SAN response is the FC frame's S_ID. We don't need a field for the other end which is always us.

---
 drivers/s390/scsi/zfcp_dbf.c |    2 +-
 drivers/s390/scsi/zfcp_fsf.c |    2 ++
 drivers/s390/scsi/zfcp_fsf.h |    4 +++-
 3 files changed, 6 insertions(+), 2 deletions(-)

@@ -407,7 +407,7 @@ void zfcp_dbf_san_res(char *tag, struct
 
 	length = (u16)(ct_els->resp->length + FC_CT_HDR_LEN);
 	zfcp_dbf_san(tag, dbf, sg_virt(ct_els->resp), ZFCP_DBF_SAN_RES, length,
-		     fsf->req_id, 0);
+		     fsf->req_id, ct_els->d_id);
 }
 
 /**

@@ -1079,6 +1079,7 @@ int zfcp_fsf_send_ct(struct zfcp_fc_wka_
 
 	req->handler = zfcp_fsf_send_ct_handler;
 	req->qtcb->header.port_handle = wka_port->handle;
+	ct->d_id = wka_port->d_id;
 	req->data = ct;
 
 	zfcp_dbf_san_req("fssct_1", req, wka_port->d_id);

@@ -1175,6 +1176,7 @@ int zfcp_fsf_send_els(struct zfcp_adapte
 
 	hton24(req->qtcb->bottom.support.d_id, d_id);
 	req->handler = zfcp_fsf_send_els_handler;
+	els->d_id = d_id;
 	req->data = els;
 
 	zfcp_dbf_san_req("fssels1", req, d_id);

@@ -3,7 +3,7 @@
  *
  * Interface to the FSF support functions.
  *
- * Copyright IBM Corp. 2002, 2010
+ * Copyright IBM Corp. 2002, 2015
  */
 
 #ifndef FSF_H

@@ -436,6 +436,7 @@ struct zfcp_blk_drv_data {
  * @handler_data: data passed to handler function
  * @port: Optional pointer to port for zfcp internal ELS (only test link ADISC)
  * @status: used to pass error status to calling function
+ * @d_id: Destination ID of either open WKA port for CT or of D_ID for ELS
  */
 struct zfcp_fsf_ct_els {
 	struct scatterlist *req;

@@ -444,6 +445,7 @@ struct zfcp_fsf_ct_els {
 	void *handler_data;
 	struct zfcp_port *port;
 	int status;
+	u32 d_id;
 };
 
 #endif				/* FSF_H */

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/zfcp-fix-els-gs-request-response-length-for-hardware-data-router.patch queue-4.4/zfcp-trace-on-request-for-open-and-close-of-wka-port.patch queue-4.4/zfcp-close-window-with-unblocked-rport-during-rport-gone.patch queue-4.4/zfcp-retain-trace-level-for-scsi-and-hba-fsf-response-records.patch queue-4.4/zfcp-restore-dont-use-0-to-indicate-invalid-lun-in-rec-trace.patch queue-4.4/zfcp-fix-fc_host-port_type-with-npiv.patch queue-4.4/zfcp-fix-d_id-field-with-actual-value-on-tracing-san-responses.patch queue-4.4/zfcp-fix-payload-trace-length-for-san-request-response.patch queue-4.4/scsi-zfcp-spin_lock_irqsave-is-not-nestable.patch queue-4.4/zfcp-restore-tracing-of-handle-for-port-and-lun-with-hba-records.patch queue-4.4/zfcp-trace-full-payload-of-all-san-records-req-resp-iels.patch