[SCSI] libfc: Handle discovery failure during ctlr link down

While we wait for GPN_FT response, if the ctlr link goes down, the stack
generates a completion for GPN_FT with error FC_EXCH_CLOSED, and reports a
discovery error. Discovery is not retried in this case, and rightly so.
However, the 'pending' flag stays set, which does not allow subsequent
discovery to succeed as GPN_FT will never be issued. Fix it by clearing the
pending flag when the discovery fails due to GPN_FT failure.

Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/libfc/fc_disc.c

@@ -337,6 +337,13 @@ static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
 			schedule_delayed_work(&disc->disc_work, delay);
 		} else
 			fc_disc_done(disc, DISC_EV_FAILED);
+	} else if (PTR_ERR(fp) == -FC_EX_CLOSED) {
+		/*
+		 * if discovery fails due to lport reset, clear
+		 * pending flag so that subsequent discovery can
+		 * continue
+		 */
+		disc->pending = 0;
 	}
 }