iscsi-target: remove support for obsolete markers

Support for markers is currently broken because of a bug in
iscsi_enforce_integrity_rules(): the "IFMarkInt_Reject" and
"OFMarkInt_Reject" variables are always equal to 1 in
iscsi_enforce_integrity_rules().

Moreover, fixed interval markers keys (IFMarker, OFMarker, IFMarkInt
and OFMarkInt) are obsolete according to iSCSI RFC 7143:

>From http://tools.ietf.org/html/rfc7143#section-13.25:

   13.25.  Obsoleted Keys

   This document obsoletes the following keys defined in [RFC3720]:
   IFMarker, OFMarker, OFMarkInt, and IFMarkInt.  However, iSCSI
   implementations compliant to this document may still receive these
   obsoleted keys -- i.e., in a responder role -- in a text negotiation.

   When an IFMarker or OFMarker key is received, a compliant iSCSI
   implementation SHOULD respond with the constant "Reject" value.  The
   implementation MAY alternatively respond with a "No" value.

   However, the implementation MUST NOT respond with a "NotUnderstood"
   value for either of these keys.

   When an IFMarkInt or OFMarkInt key is received, a compliant iSCSI
   implementation MUST respond with the constant "Reject" value.  The
   implementation MUST NOT respond with a "NotUnderstood" value for
   either of these keys.

This patch disables markers by turning the corresponding parameters to
read-only. The default value of IFMarker and OFMarker remains "No" but
the user cannot change it to "Yes" anymore. The new value of IFMarkInt
and OFMarkInt is "Reject".

(Drop left-over iscsi_get_value_from_number_range + make configfs
 parameters attrs R/W nops - nab)

Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 4 insertions, 16 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 74e6114ff18f..21620c751071 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -2736,11 +2736,7 @@ static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
 	cmd->iov_data_count = iov_count;
 	cmd->tx_size = tx_size;
 
-	/* sendpage is preferred but can't insert markers */
-	if (!conn->conn_ops->IFMarker)
-		ret = iscsit_fe_sendpage_sg(cmd, conn);
-	else
-		ret = iscsit_send_tx_data(cmd, conn, 0);
+	ret = iscsit_fe_sendpage_sg(cmd, conn);
 
 	iscsit_unmap_iovec(cmd);
 
@@ -4072,17 +4068,9 @@ static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
 			" opcode while ERL=0, closing iSCSI connection.\n");
 			return -1;
 		}
-		if (!conn->conn_ops->OFMarker) {
-			pr_err("Unable to recover from unknown"
-			" opcode while OFMarker=No, closing iSCSI"
-				" connection.\n");
-			return -1;
-		}
-		if (iscsit_recover_from_unknown_opcode(conn) < 0) {
-			pr_err("Unable to recover from unknown"
-				" opcode, closing iSCSI connection.\n");
-			return -1;
-		}
+		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
+		       " closing iSCSI connection.\n");
+		ret = -1;
 		break;
 	}