[SCSI] libfc: send GPN_ID in reaction to single-port RSCNs.

When an RSCN indicates changes to individual remote ports,
don't blindly log them out and then back in.  Instead, determine
whether they're still in the directory, by doing GPN_ID.

If that is successful, call login, which will send ADISC and reverify,
otherwise, call logoff.  Perhaps we should just delete the rport,
not send LOGO, but it seems safer.

Also, fix a possible issue where if a mix of records in the RSCN
cause us to queue disc_ports for disc_single and then we decide
to do full rediscovery, we leak memory for those disc_ports queued.

So, go through the list of disc_ports even if doing full discovery.
Free the disc_ports in any case.  If any of the disc_single() calls
return error, do a full discovery.

The ability to fill in GPN_ID requests was added to fc_ct_fill().
For this, it needs the FC_ID to be passed in as an arg.
The did parameter for fc_elsct_send() is used for that, since the
actual D_DID will always be 0xfffffc for all CT requests so far.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 14 insertions, 2 deletions

diff --git a/include/scsi/fc_encode.h b/include/scsi/fc_encode.h
index c5ee6bb79e05..27dad703824f 100644
--- a/include/scsi/fc_encode.h
+++ b/include/scsi/fc_encode.h
@@ -32,6 +32,7 @@ struct fc_ct_req {
                 struct fc_ns_gid_ft gid;
                 struct fc_ns_rn_id  rn;
                 struct fc_ns_rft rft;
+                struct fc_ns_fid fid;
         } payload;
 };
 
@@ -94,10 +95,16 @@ static inline struct fc_ct_req *fc_ct_hdr_fill(const struct fc_frame *fp,
 }
 
 /**
- * fc_ct_fill - Fill in a name service request frame
+ * fc_ct_fill() - Fill in a name service request frame
+ * @lport: local port.
+ * @fc_id: FC_ID of non-destination rport for GPN_ID and similar inquiries.
+ * @fp: frame to contain payload.
+ * @op: CT opcode.
+ * @r_ctl: pointer to FC header R_CTL.
+ * @fh_type: pointer to FC-4 type.
  */
 static inline int fc_ct_fill(struct fc_lport *lport,
-                      struct fc_frame *fp,
+                      u32 fc_id, struct fc_frame *fp,
                       unsigned int op, enum fc_rctl *r_ctl,
                       enum fc_fh_type *fh_type)
 {
@@ -109,6 +116,11 @@ static inline int fc_ct_fill(struct fc_lport *lport,
                 ct->payload.gid.fn_fc4_type = FC_TYPE_FCP;
                 break;
 
+        case FC_NS_GPN_ID:
+                ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_fid));
+                hton24(ct->payload.fid.fp_fid, fc_id);
+                break;
+
         case FC_NS_RFT_ID:
                 ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_rft));
                 hton24(ct->payload.rft.fid.fp_fid,