[SCSI] zfcp: attach and release SAN nameserver port on demand

Changing the zfcp behaviour from always having the nameserver port
open to an on-demand strategy.  This strategy reduces the use of
limited resources like port connections. The patch provides a common
infrastructure which could be used for all WKA ports in future.

Also reduce the number of nameserver lookups by changing the zfcp
behaviour of always querying the nameserver for the corresponding
destination ID of the remote port.  If the destination ID has changed
during the reopen process we will be informed and then trigger a
nameserver query on demand.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index d088d30516f9..c1f69f611e69 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -519,7 +519,7 @@ static const char *zfcp_rec_dbf_ids[] = {
         [75]    = "physical port recovery escalation after failed port "
                   "recovery",
         [76]    = "port recovery escalation after failed unit recovery",
-        [77]    = "recovery opening nameserver port",
+        [77]    = "",
         [78]    = "duplicate request id",
         [79]    = "link down",
         [80]    = "exclusive read-only unit access unsupported",
@@ -829,8 +829,8 @@ void zfcp_rec_dbf_event_action(u8 id2, struct zfcp_erp_action *erp_action)
 void zfcp_san_dbf_event_ct_request(struct zfcp_fsf_req *fsf_req)
 {
         struct zfcp_send_ct *ct = (struct zfcp_send_ct *)fsf_req->data;
-        struct zfcp_port *port = ct->port;
-        struct zfcp_adapter *adapter = port->adapter;
+        struct zfcp_wka_port *wka_port = ct->wka_port;
+        struct zfcp_adapter *adapter = wka_port->adapter;
         struct ct_hdr *hdr = sg_virt(ct->req);
         struct zfcp_san_dbf_record *r = &adapter->san_dbf_buf;
         struct zfcp_san_dbf_record_ct_request *oct = &r->u.ct_req;
@@ -842,7 +842,7 @@ void zfcp_san_dbf_event_ct_request(struct zfcp_fsf_req *fsf_req)
         r->fsf_reqid = (unsigned long)fsf_req;
         r->fsf_seqno = fsf_req->seq_no;
         r->s_id = fc_host_port_id(adapter->scsi_host);
-        r->d_id = port->d_id;
+        r->d_id = wka_port->d_id;
         oct->cmd_req_code = hdr->cmd_rsp_code;
         oct->revision = hdr->revision;
         oct->gs_type = hdr->gs_type;
@@ -863,8 +863,8 @@ void zfcp_san_dbf_event_ct_request(struct zfcp_fsf_req *fsf_req)
 void zfcp_san_dbf_event_ct_response(struct zfcp_fsf_req *fsf_req)
 {
         struct zfcp_send_ct *ct = (struct zfcp_send_ct *)fsf_req->data;
-        struct zfcp_port *port = ct->port;
-        struct zfcp_adapter *adapter = port->adapter;
+        struct zfcp_wka_port *wka_port = ct->wka_port;
+        struct zfcp_adapter *adapter = wka_port->adapter;
         struct ct_hdr *hdr = sg_virt(ct->resp);
         struct zfcp_san_dbf_record *r = &adapter->san_dbf_buf;
         struct zfcp_san_dbf_record_ct_response *rct = &r->u.ct_resp;
@@ -875,7 +875,7 @@ void zfcp_san_dbf_event_ct_response(struct zfcp_fsf_req *fsf_req)
         strncpy(r->tag, "rctc", ZFCP_DBF_TAG_SIZE);
         r->fsf_reqid = (unsigned long)fsf_req;
         r->fsf_seqno = fsf_req->seq_no;
-        r->s_id = port->d_id;
+        r->s_id = wka_port->d_id;
         r->d_id = fc_host_port_id(adapter->scsi_host);
         rct->cmd_rsp_code = hdr->cmd_rsp_code;
         rct->revision = hdr->revision;