scsi: libfc: Rework PRLI handling

PRLI is only required if the port is acting as an initiator; ports
which support target functionality only do not need to send PRLI.
At the same time the PRLI state is only used if the port initiated
a PRLI transfer; if we received a PRLI request we should _not_
change the state as this would cause our PRLI response to be dropped.
And when we receive a PRLI response we need to check if an image
pair has been established; if not the remote port cannot act as a
target for us and we need to disable target functionality.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/libfc/fc_rport.c b/drivers/scsi/libfc/fc_rport.c
index 426c399..2b8214f 100644 (file)
--- a/drivers/scsi/libfc/fc_rport.c
+++ b/drivers/scsi/libfc/fc_rport.c
@@ -1126,7 +1126,7 @@ static void fc_rport_prli_resp(struct fc_seq *sp, struct fc_frame *fp,
        u32 roles = FC_RPORT_ROLE_UNKNOWN;
        u32 fcp_parm = 0;
        u8 op;
-       u8 resp_code = 0;
+       enum fc_els_spp_resp resp_code;
 
        FC_RPORT_DBG(rdata, "Received a PRLI %s\n", fc_els_resp_type(fp));
 
@@ -1158,8 +1158,8 @@ static void fc_rport_prli_resp(struct fc_seq *sp, struct fc_frame *fp,
                        goto out;
 
                resp_code = (pp->spp.spp_flags & FC_SPP_RESP_MASK);
-               FC_RPORT_DBG(rdata, "PRLI spp_flags = 0x%x\n",
-                            pp->spp.spp_flags);
+               FC_RPORT_DBG(rdata, "PRLI spp_flags = 0x%x spp_type 0x%x\n",
+                            pp->spp.spp_flags, pp->spp.spp_type);
                rdata->spp_type = pp->spp.spp_type;
                if (resp_code != FC_SPP_RESP_ACK) {
                        if (resp_code == FC_SPP_RESP_CONF)
@@ -1177,13 +1177,26 @@ static void fc_rport_prli_resp(struct fc_seq *sp, struct fc_frame *fp,
                if (fcp_parm & FCP_SPPF_CONF_COMPL)
                        rdata->flags |= FC_RP_FLAGS_CONF_REQ;
 
-               prov = fc_passive_prov[FC_TYPE_FCP];
+               /*
+                * Call prli provider if we should act as a target
+                */
+               prov = fc_passive_prov[rdata->spp_type];
                if (prov) {
                        memset(&temp_spp, 0, sizeof(temp_spp));
                        prov->prli(rdata, pp->prli.prli_spp_len,
                                   &pp->spp, &temp_spp);
                }
-
+               /*
+                * Check if the image pair could be established
+                */
+               if (rdata->spp_type != FC_TYPE_FCP ||
+                   resp_code != FC_SPP_RESP_ACK ||
+                   !(pp->spp.spp_flags & FC_SPP_EST_IMG_PAIR)) {
+                       /*
+                        * Nope; we can't use this port as a target.
+                        */
+                       fcp_parm &= ~FCP_SPPF_TARG_FCN;
+               }
                rdata->supported_classes = FC_COS_CLASS3;
                if (fcp_parm & FCP_SPPF_INIT_FCN)
                        roles |= FC_RPORT_ROLE_FCP_INITIATOR;
@@ -1236,6 +1249,15 @@ static void fc_rport_enter_prli(struct fc_rport_priv *rdata)
                return;
        }
 
+       /*
+        * And if the local port does not support the initiator function
+        * there's no need to send a PRLI, either.
+        */
+       if (!(lport->service_params & FCP_SPPF_INIT_FCN)) {
+                   fc_rport_enter_ready(rdata);
+                   return;
+       }
+
        FC_RPORT_DBG(rdata, "Port entered PRLI state from %s state\n",
                     fc_rport_state(rdata));
 
@@ -1926,7 +1948,6 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
        unsigned int len;
        unsigned int plen;
        enum fc_els_spp_resp resp;
-       enum fc_els_spp_resp passive;
        struct fc_seq_els_data rjt_data;
        struct fc4_prov *prov;
 
@@ -1976,15 +1997,21 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
                resp = 0;
 
                if (rspp->spp_type < FC_FC4_PROV_SIZE) {
+                       enum fc_els_spp_resp active = 0, passive = 0;
+
                        prov = fc_active_prov[rspp->spp_type];
                        if (prov)
-                               resp = prov->prli(rdata, plen, rspp, spp);
+                               active = prov->prli(rdata, plen, rspp, spp);
                        prov = fc_passive_prov[rspp->spp_type];
-                       if (prov) {
+                       if (prov)
                                passive = prov->prli(rdata, plen, rspp, spp);
-                               if (!resp || passive == FC_SPP_RESP_ACK)
-                                       resp = passive;
-                       }
+                       if (!active || passive == FC_SPP_RESP_ACK)
+                               resp = passive;
+                       else
+                               resp = active;
+                       FC_RPORT_DBG(rdata, "PRLI rspp type %x "
+                                    "active %x passive %x\n",
+                                    rspp->spp_type, active, passive);
                }
                if (!resp) {
                        if (spp->spp_flags & FC_SPP_EST_IMG_PAIR)
@@ -2005,13 +2032,6 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
        fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
        lport->tt.frame_send(lport, fp);
 
-       switch (rdata->rp_state) {
-       case RPORT_ST_PRLI:
-               fc_rport_enter_ready(rdata);
-               break;
-       default:
-               break;
-       }
        goto drop;
 
 reject_len: