From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file

---
 kernel/drivers/scsi/iscsi_tcp.c |  117 ++++++++++++++++++++++++++++++++++++----------------------
 1 files changed, 73 insertions(+), 44 deletions(-)

diff --git a/kernel/drivers/scsi/iscsi_tcp.c b/kernel/drivers/scsi/iscsi_tcp.c
index 7212e3a..def9fac 100644
--- a/kernel/drivers/scsi/iscsi_tcp.c
+++ b/kernel/drivers/scsi/iscsi_tcp.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * iSCSI Initiator over TCP/IP Data-Path
  *
@@ -6,16 +7,6 @@
  * Copyright (C) 2005 - 2006 Mike Christie
  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
  * maintained by open-iscsi@googlegroups.com
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published
- * by the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  *
  * See the file COPYING included with this distribution for more details.
  *
@@ -44,6 +35,7 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_transport_iscsi.h>
+#include <trace/events/iscsi.h>
 
 #include "iscsi_tcp.h"
 
@@ -72,6 +64,9 @@
 			iscsi_conn_printk(KERN_INFO, _conn,	\
 					     "%s " dbg_fmt,	\
 					     __func__, ##arg);	\
+		iscsi_dbg_trace(trace_iscsi_dbg_sw_tcp,		\
+				&(_conn)->cls_conn->dev,	\
+				"%s " dbg_fmt, __func__, ##arg);\
 	} while (0);
 
 
@@ -522,7 +517,7 @@
 	if (!task->sc)
 		iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count);
 	else {
-		struct scsi_data_buffer *sdb = scsi_out(task->sc);
+		struct scsi_data_buffer *sdb = &task->sc->sdb;
 
 		err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl,
 						  sdb->table.nents, offset,
@@ -563,6 +558,8 @@
 	tcp_conn = conn->dd_data;
 	tcp_sw_conn = tcp_conn->dd_data;
 
+	mutex_init(&tcp_sw_conn->sock_lock);
+
 	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(tfm))
 		goto free_conn;
@@ -597,11 +594,15 @@
 
 static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn)
 {
-	struct iscsi_session *session = conn->session;
 	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
 	struct socket *sock = tcp_sw_conn->sock;
 
+	/*
+	 * The iscsi transport class will make sure we are not called in
+	 * parallel with start, stop, bind and destroys. However, this can be
+	 * called twice if userspace does a stop then a destroy.
+	 */
 	if (!sock)
 		return;
 
@@ -609,9 +610,9 @@
 	iscsi_sw_tcp_conn_restore_callbacks(conn);
 	sock_put(sock->sk);
 
-	spin_lock_bh(&session->frwd_lock);
+	mutex_lock(&tcp_sw_conn->sock_lock);
 	tcp_sw_conn->sock = NULL;
-	spin_unlock_bh(&session->frwd_lock);
+	mutex_unlock(&tcp_sw_conn->sock_lock);
 	sockfd_put(sock);
 }
 
@@ -663,7 +664,6 @@
 		       struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 		       int is_leading)
 {
-	struct iscsi_session *session = cls_session->dd_data;
 	struct iscsi_conn *conn = cls_conn->dd_data;
 	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
@@ -683,10 +683,10 @@
 	if (err)
 		goto free_socket;
 
-	spin_lock_bh(&session->frwd_lock);
+	mutex_lock(&tcp_sw_conn->sock_lock);
 	/* bind iSCSI connection and socket */
 	tcp_sw_conn->sock = sock;
-	spin_unlock_bh(&session->frwd_lock);
+	mutex_unlock(&tcp_sw_conn->sock_lock);
 
 	/* setup Socket parameters */
 	sk = sock->sk;
@@ -721,9 +721,15 @@
 		iscsi_set_param(cls_conn, param, buf, buflen);
 		break;
 	case ISCSI_PARAM_DATADGST_EN:
+		mutex_lock(&tcp_sw_conn->sock_lock);
+		if (!tcp_sw_conn->sock) {
+			mutex_unlock(&tcp_sw_conn->sock_lock);
+			return -ENOTCONN;
+		}
 		iscsi_set_param(cls_conn, param, buf, buflen);
 		tcp_sw_conn->sendpage = conn->datadgst_en ?
 			sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
+		mutex_unlock(&tcp_sw_conn->sock_lock);
 		break;
 	case ISCSI_PARAM_MAX_R2T:
 		return iscsi_tcp_set_max_r2t(conn, buf);
@@ -738,9 +744,10 @@
 				       enum iscsi_param param, char *buf)
 {
 	struct iscsi_conn *conn = cls_conn->dd_data;
-	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
-	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
+	struct iscsi_sw_tcp_conn *tcp_sw_conn;
+	struct iscsi_tcp_conn *tcp_conn;
 	struct sockaddr_in6 addr;
+	struct socket *sock;
 	int rc;
 
 	switch(param) {
@@ -748,17 +755,36 @@
 	case ISCSI_PARAM_CONN_ADDRESS:
 	case ISCSI_PARAM_LOCAL_PORT:
 		spin_lock_bh(&conn->session->frwd_lock);
-		if (!tcp_sw_conn || !tcp_sw_conn->sock) {
+		if (!conn->session->leadconn) {
 			spin_unlock_bh(&conn->session->frwd_lock);
 			return -ENOTCONN;
 		}
+		/*
+		 * The conn has been setup and bound, so just grab a ref
+		 * incase a destroy runs while we are in the net layer.
+		 */
+		iscsi_get_conn(conn->cls_conn);
+		spin_unlock_bh(&conn->session->frwd_lock);
+
+		tcp_conn = conn->dd_data;
+		tcp_sw_conn = tcp_conn->dd_data;
+
+		mutex_lock(&tcp_sw_conn->sock_lock);
+		sock = tcp_sw_conn->sock;
+		if (!sock) {
+			rc = -ENOTCONN;
+			goto sock_unlock;
+		}
+
 		if (param == ISCSI_PARAM_LOCAL_PORT)
-			rc = kernel_getsockname(tcp_sw_conn->sock,
+			rc = kernel_getsockname(sock,
 						(struct sockaddr *)&addr);
 		else
-			rc = kernel_getpeername(tcp_sw_conn->sock,
+			rc = kernel_getpeername(sock,
 						(struct sockaddr *)&addr);
-		spin_unlock_bh(&conn->session->frwd_lock);
+sock_unlock:
+		mutex_unlock(&tcp_sw_conn->sock_lock);
+		iscsi_put_conn(conn->cls_conn);
 		if (rc < 0)
 			return rc;
 
@@ -775,15 +801,17 @@
 				       enum iscsi_host_param param, char *buf)
 {
 	struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
-	struct iscsi_session *session = tcp_sw_host->session;
+	struct iscsi_session *session;
 	struct iscsi_conn *conn;
 	struct iscsi_tcp_conn *tcp_conn;
 	struct iscsi_sw_tcp_conn *tcp_sw_conn;
 	struct sockaddr_in6 addr;
+	struct socket *sock;
 	int rc;
 
 	switch (param) {
 	case ISCSI_HOST_PARAM_IPADDRESS:
+		session = tcp_sw_host->session;
 		if (!session)
 			return -ENOTCONN;
 
@@ -794,16 +822,22 @@
 			return -ENOTCONN;
 		}
 		tcp_conn = conn->dd_data;
-
 		tcp_sw_conn = tcp_conn->dd_data;
-		if (!tcp_sw_conn->sock) {
-			spin_unlock_bh(&session->frwd_lock);
-			return -ENOTCONN;
-		}
-
-		rc = kernel_getsockname(tcp_sw_conn->sock,
-					(struct sockaddr *)&addr);
+		/*
+		 * The conn has been setup and bound, so just grab a ref
+		 * incase a destroy runs while we are in the net layer.
+		 */
+		iscsi_get_conn(conn->cls_conn);
 		spin_unlock_bh(&session->frwd_lock);
+
+		mutex_lock(&tcp_sw_conn->sock_lock);
+		sock = tcp_sw_conn->sock;
+		if (!sock)
+			rc = -ENOTCONN;
+		else
+			rc = kernel_getsockname(sock, (struct sockaddr *)&addr);
+		mutex_unlock(&tcp_sw_conn->sock_lock);
+		iscsi_put_conn(conn->cls_conn);
 		if (rc < 0)
 			return rc;
 
@@ -872,12 +906,14 @@
 	if (!cls_session)
 		goto remove_host;
 	session = cls_session->dd_data;
-	tcp_sw_host = iscsi_host_priv(shost);
-	tcp_sw_host->session = session;
 
 	shost->can_queue = session->scsi_cmds_max;
 	if (iscsi_tcp_r2tpool_alloc(session))
 		goto remove_session;
+
+	/* We are now fully setup so expose the session to sysfs. */
+	tcp_sw_host = iscsi_host_priv(shost);
+	tcp_sw_host->session = session;
 	return cls_session;
 
 remove_session:
@@ -960,12 +996,6 @@
 	return 0;
 }
 
-static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev)
-{
-	blk_queue_flag_set(QUEUE_FLAG_BIDI, sdev->request_queue);
-	return 0;
-}
-
 static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
 {
 	struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host);
@@ -973,8 +1003,8 @@
 	struct iscsi_conn *conn = session->leadconn;
 
 	if (conn->datadgst_en)
-		sdev->request_queue->backing_dev_info->capabilities
-			|= BDI_CAP_STABLE_WRITES;
+		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES,
+				   sdev->request_queue);
 	blk_queue_dma_alignment(sdev->request_queue, 0);
 	return 0;
 }
@@ -992,8 +1022,7 @@
 	.eh_abort_handler       = iscsi_eh_abort,
 	.eh_device_reset_handler= iscsi_eh_device_reset,
 	.eh_target_reset_handler = iscsi_eh_recover_target,
-	.use_clustering         = DISABLE_CLUSTERING,
-	.slave_alloc            = iscsi_sw_tcp_slave_alloc,
+	.dma_boundary		= PAGE_SIZE - 1,
 	.slave_configure        = iscsi_sw_tcp_slave_configure,
 	.target_alloc		= iscsi_target_alloc,
 	.proc_name		= "iscsi_tcp",

--
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