From 0007914f1dc1e84d26901ada2b3aa046f1de0cae Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Tue, 1 Jun 2010 11:35:27 +0000
Subject: [PATCH] Make RX data digest failures handling more smart

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@1731 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 iscsi-scst/kernel/digest.c  |  3 ++-
 iscsi-scst/kernel/iscsi.c   |  6 ++----
 iscsi-scst/kernel/iscsi.h   |  4 ++++
 iscsi-scst/kernel/nthread.c | 16 ++++++++++------
 4 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/iscsi-scst/kernel/digest.c b/iscsi-scst/kernel/digest.c
index 7d6da1d23..f9d338e91 100644
--- a/iscsi-scst/kernel/digest.c
+++ b/iscsi-scst/kernel/digest.c
@@ -188,7 +188,8 @@ int digest_rx_data(struct iscsi_cmnd *cmnd)
 		cmnd->conn->rpadding);
 
 	if (unlikely(crc != cmnd->ddigest)) {
-		PRINT_ERROR("%s", "RX data digest failed");
+		TRACE(TRACE_MINOR|TRACE_MGMT_DEBUG, "%s", "RX data digest "
+			"failed");
 		TRACE_MGMT_DBG("Calculated crc %x, ddigest %x, offset %d", crc,
 			cmnd->ddigest, offset);
 		iscsi_dump_pdu(&cmnd->pdu);
diff --git a/iscsi-scst/kernel/iscsi.c b/iscsi-scst/kernel/iscsi.c
index a6b96f4d4..2d9d557ad 100644
--- a/iscsi-scst/kernel/iscsi.c
+++ b/iscsi-scst/kernel/iscsi.c
@@ -69,8 +69,6 @@ static void cmnd_remove_data_wait_hash(struct iscsi_cmnd *cmnd);
 static void iscsi_send_task_mgmt_resp(struct iscsi_cmnd *req, int status);
 static void iscsi_check_send_delayed_tm_resp(struct iscsi_session *sess);
 static void req_cmnd_release(struct iscsi_cmnd *req);
-static int iscsi_preliminary_complete(struct iscsi_cmnd *req,
-	struct iscsi_cmnd *orig_req, bool get_data);
 static int cmnd_insert_data_wait_hash(struct iscsi_cmnd *cmnd);
 static void __cmnd_abort(struct iscsi_cmnd *cmnd);
 static void iscsi_set_resid(struct iscsi_cmnd *rsp, bool bufflen_set);
@@ -943,7 +941,7 @@ out:
 	return res;
 }
 
-static int set_scst_preliminary_status_rsp(struct iscsi_cmnd *req,
+int set_scst_preliminary_status_rsp(struct iscsi_cmnd *req,
 	bool get_data, int key, int asc, int ascq)
 {
 	int res = 0;
@@ -1334,7 +1332,7 @@ static void iscsi_set_resid(struct iscsi_cmnd *rsp, bool bufflen_set)
 	return;
 }
 
-static int iscsi_preliminary_complete(struct iscsi_cmnd *req,
+int iscsi_preliminary_complete(struct iscsi_cmnd *req,
 	struct iscsi_cmnd *orig_req, bool get_data)
 {
 	int res = 0;
diff --git a/iscsi-scst/kernel/iscsi.h b/iscsi-scst/kernel/iscsi.h
index 7c3ed3401..3cb20c4da 100644
--- a/iscsi-scst/kernel/iscsi.h
+++ b/iscsi-scst/kernel/iscsi.h
@@ -487,6 +487,10 @@ extern void conn_abort(struct iscsi_conn *conn);
 extern void iscsi_restart_cmnd(struct iscsi_cmnd *cmnd);
 extern void iscsi_fail_data_waiting_cmnd(struct iscsi_cmnd *cmnd);
 extern void iscsi_send_nop_in(struct iscsi_conn *conn);
+extern int iscsi_preliminary_complete(struct iscsi_cmnd *req,
+	struct iscsi_cmnd *orig_req, bool get_data);
+extern int set_scst_preliminary_status_rsp(struct iscsi_cmnd *req,
+	bool get_data, int key, int asc, int ascq);
 
 /* conn.c */
 extern struct iscsi_conn *conn_lookup(struct iscsi_session *, u16);
diff --git a/iscsi-scst/kernel/nthread.c b/iscsi-scst/kernel/nthread.c
index b1b4e2c80..e94718bef 100644
--- a/iscsi-scst/kernel/nthread.c
+++ b/iscsi-scst/kernel/nthread.c
@@ -776,8 +776,13 @@ static int iscsi_rx_check_ddigest(struct iscsi_conn *conn)
 			cmnd->ddigest_checked = 1;
 			res = digest_rx_data(cmnd);
 			if (unlikely(res != 0)) {
-				mark_conn_closed(conn);
-				goto out;
+				if (unlikely(cmnd->scst_cmd == NULL)) {
+					/* Just drop it */
+					iscsi_preliminary_complete(cmnd, cmnd, false);
+				} else
+					set_scst_preliminary_status_rsp(cmnd, false,
+						SCST_LOAD_SENSE(iscsi_sense_crc_error));
+				res = 0;
 			}
 		} else if (cmnd_opcode(cmnd) == ISCSI_OP_SCSI_CMD) {
 			cmd_add_on_rx_ddigest_list(cmnd, cmnd);
@@ -786,19 +791,18 @@ static int iscsi_rx_check_ddigest(struct iscsi_conn *conn)
 			/*
 			 * We could get here only for Nop-Out. ISCSI RFC
 			 * doesn't specify how to deal with digest errors in
-			 * this case. Is closing connection correct?
+			 * this case. Let's just drop the command.
 			 */
 			TRACE_DBG("cmnd %p, opcode %x: checking NOP RX "
 				"ddigest", cmnd, cmnd_opcode(cmnd));
 			res = digest_rx_data(cmnd);
 			if (unlikely(res != 0)) {
-				mark_conn_closed(conn);
-				goto out;
+				iscsi_preliminary_complete(cmnd, cmnd, false);
+				res = 0;
 			}
 		}
 	}
 
-out:
 	return res;
 }