fs/ksmbd/connection.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *   Copyright (C) 2016 Namjae Jeon <namjae.jeon@protocolfreedom.org>
  *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
  */

 #include <linux/mutex.h>
 #include <linux/freezer.h>
 #include <linux/module.h>

 #include "server.h"
 #include "smb_common.h"
 #include "mgmt/ksmbd_ida.h"
 #include "connection.h"
 #include "transport_tcp.h"
 #include "transport_rdma.h"

 static DEFINE_MUTEX(init_lock);

 static struct ksmbd_conn_ops default_conn_ops;

 LIST_HEAD(conn_list);
 DEFINE_RWLOCK(conn_list_lock);

 /**
  * ksmbd_conn_free() - free resources of the connection instance
  *
  * @conn:	connection instance to be cleand up
  *
  * During the thread termination, the corresponding conn instance
  * resources(sock/memory) are released and finally the conn object is freed.
  */
 void ksmbd_conn_free(struct ksmbd_conn *conn)
 {
 	write_lock(&conn_list_lock);
 	list_del(&conn->conns_list);
 	write_unlock(&conn_list_lock);

 	kvfree(conn->request_buf);
 	kfree(conn->preauth_info);
 	kfree(conn);
 }

 /**
  * ksmbd_conn_alloc() - initialize a new connection instance
  *
  * Return:	ksmbd_conn struct on success, otherwise NULL
  */
 struct ksmbd_conn *ksmbd_conn_alloc(void)
 {
 	struct ksmbd_conn *conn;

 	conn = kzalloc(sizeof(struct ksmbd_conn), GFP_KERNEL);
 	if (!conn)
 		return NULL;

 	conn->need_neg = true;
 	conn->status = KSMBD_SESS_NEW;
 	conn->local_nls = load_nls("utf8");
 	if (!conn->local_nls)
 		conn->local_nls = load_nls_default();
 	atomic_set(&conn->req_running, 0);
 	atomic_set(&conn->r_count, 0);
 	conn->total_credits = 1;
 	conn->outstanding_credits = 1;

 	init_waitqueue_head(&conn->req_running_q);
 	INIT_LIST_HEAD(&conn->conns_list);
 	INIT_LIST_HEAD(&conn->sessions);
 	INIT_LIST_HEAD(&conn->requests);
 	INIT_LIST_HEAD(&conn->async_requests);
 	spin_lock_init(&conn->request_lock);
 	spin_lock_init(&conn->credits_lock);
 	ida_init(&conn->async_ida);

 	spin_lock_init(&conn->llist_lock);
 	INIT_LIST_HEAD(&conn->lock_list);

 	write_lock(&conn_list_lock);
 	list_add(&conn->conns_list, &conn_list);
 	write_unlock(&conn_list_lock);
 	return conn;
 }

 bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
 {
 	struct ksmbd_conn *t;
 	bool ret = false;

 	read_lock(&conn_list_lock);
 	list_for_each_entry(t, &conn_list, conns_list) {
 		if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
 			continue;

 		ret = true;
 		break;
 	}
 	read_unlock(&conn_list_lock);
 	return ret;
 }

 void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
 {
 	struct ksmbd_conn *conn = work->conn;
 	struct list_head *requests_queue = NULL;

 	if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
 		requests_queue = &conn->requests;
 		work->syncronous = true;
 	}

 	if (requests_queue) {
 		atomic_inc(&conn->req_running);
 		spin_lock(&conn->request_lock);
 		list_add_tail(&work->request_entry, requests_queue);
 		spin_unlock(&conn->request_lock);
 	}
 }

 int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
 {
 	struct ksmbd_conn *conn = work->conn;
 	int ret = 1;

 	if (list_empty(&work->request_entry) &&
 	    list_empty(&work->async_request_entry))
 		return 0;

 	if (!work->multiRsp)
 		atomic_dec(&conn->req_running);
 	spin_lock(&conn->request_lock);
 	if (!work->multiRsp) {
 		list_del_init(&work->request_entry);
 		if (work->syncronous == false)
 			list_del_init(&work->async_request_entry);
 		ret = 0;
 	}
 	spin_unlock(&conn->request_lock);

 	wake_up_all(&conn->req_running_q);
 	return ret;
 }

 static void ksmbd_conn_lock(struct ksmbd_conn *conn)
 {
 	mutex_lock(&conn->srv_mutex);
 }

 static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
 {
 	mutex_unlock(&conn->srv_mutex);
 }

 void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
 {
 	wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
 }

 int ksmbd_conn_write(struct ksmbd_work *work)
 {
 	struct ksmbd_conn *conn = work->conn;
 	size_t len = 0;
 	int sent;
 	struct kvec iov[3];
 	int iov_idx = 0;

 	ksmbd_conn_try_dequeue_request(work);
 	if (!work->response_buf) {
 		pr_err("NULL response header\n");
 		return -EINVAL;
 	}

 	if (work->tr_buf) {
 		iov[iov_idx] = (struct kvec) { work->tr_buf,
 				sizeof(struct smb2_transform_hdr) + 4 };
 		len += iov[iov_idx++].iov_len;
 	}

 	if (work->aux_payload_sz) {
 		iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
 		len += iov[iov_idx++].iov_len;
 		iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
 		len += iov[iov_idx++].iov_len;
 	} else {
 		if (work->tr_buf)
 			iov[iov_idx].iov_len = work->resp_hdr_sz;
 		else
 			iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
 		iov[iov_idx].iov_base = work->response_buf;
 		len += iov[iov_idx++].iov_len;
 	}

 	ksmbd_conn_lock(conn);
 	sent = conn->transport->ops->writev(conn->transport, &iov[0],
 					iov_idx, len,
 					work->need_invalidate_rkey,
 					work->remote_key);
 	ksmbd_conn_unlock(conn);

 	if (sent < 0) {
 		pr_err("Failed to send message: %d\n", sent);
 		return sent;
 	}

 	return 0;
 }

 int ksmbd_conn_rdma_read(struct ksmbd_conn *conn, void *buf,
 			 unsigned int buflen, u32 remote_key, u64 remote_offset,
 			 u32 remote_len)
 {
 	int ret = -EINVAL;

 	if (conn->transport->ops->rdma_read)
 		ret = conn->transport->ops->rdma_read(conn->transport,
 						      buf, buflen,
 						      remote_key, remote_offset,
 						      remote_len);
 	return ret;
 }

 int ksmbd_conn_rdma_write(struct ksmbd_conn *conn, void *buf,
 			  unsigned int buflen, u32 remote_key,
 			  u64 remote_offset, u32 remote_len)
 {
 	int ret = -EINVAL;

 	if (conn->transport->ops->rdma_write)
 		ret = conn->transport->ops->rdma_write(conn->transport,
 						       buf, buflen,
 						       remote_key, remote_offset,
 						       remote_len);
 	return ret;
 }

 bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 {
 	if (!ksmbd_server_running())
 		return false;

 	if (conn->status == KSMBD_SESS_EXITING)
 		return false;

 	if (kthread_should_stop())
 		return false;

 	if (atomic_read(&conn->stats.open_files_count) > 0)
 		return true;

 	/*
 	 * Stop current session if the time that get last request from client
 	 * is bigger than deadtime user configured and opening file count is
 	 * zero.
 	 */
 	if (server_conf.deadtime > 0 &&
 	    time_after(jiffies, conn->last_active + server_conf.deadtime)) {
 		ksmbd_debug(CONN, "No response from client in %lu minutes\n",
 			    server_conf.deadtime / SMB_ECHO_INTERVAL);
 		return false;
 	}
 	return true;
 }

 /**
  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
  * @p:		connection instance
  *
  * One thread each per connection
  *
  * Return:	0 on success
  */
 int ksmbd_conn_handler_loop(void *p)
 {
 	struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
 	struct ksmbd_transport *t = conn->transport;
 	unsigned int pdu_size;
 	char hdr_buf[4] = {0,};
 	int size;

 	mutex_init(&conn->srv_mutex);
 	__module_get(THIS_MODULE);

 	if (t->ops->prepare && t->ops->prepare(t))
 		goto out;

 	conn->last_active = jiffies;
 	while (ksmbd_conn_alive(conn)) {
 		if (try_to_freeze())
 			continue;

 		kvfree(conn->request_buf);
 		conn->request_buf = NULL;

 		size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
 		if (size != sizeof(hdr_buf))
 			break;

 		pdu_size = get_rfc1002_len(hdr_buf);
 		ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);

 		/*
 		 * Check if pdu size is valid (min : smb header size,
 		 * max : 0x00FFFFFF).
 		 */
 		if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
 		    pdu_size > MAX_STREAM_PROT_LEN) {
 			continue;
 		}

 		/* 4 for rfc1002 length field */
 		size = pdu_size + 4;
 		conn->request_buf = kvmalloc(size, GFP_KERNEL);
 		if (!conn->request_buf)
 			continue;

 		memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
 		if (!ksmbd_smb_request(conn))
 			break;

 		/*
 		 * We already read 4 bytes to find out PDU size, now
 		 * read in PDU
 		 */
 		size = t->ops->read(t, conn->request_buf + 4, pdu_size);
 		if (size < 0) {
 			pr_err("sock_read failed: %d\n", size);
 			break;
 		}

 		if (size != pdu_size) {
 			pr_err("PDU error. Read: %d, Expected: %d\n",
 			       size, pdu_size);
 			continue;
 		}

 		if (!default_conn_ops.process_fn) {
 			pr_err("No connection request callback\n");
 			break;
 		}

 		if (default_conn_ops.process_fn(conn)) {
 			pr_err("Cannot handle request\n");
 			break;
 		}
 	}

 out:
 	/* Wait till all reference dropped to the Server object*/
 	while (atomic_read(&conn->r_count) > 0)
 		schedule_timeout(HZ);

 	unload_nls(conn->local_nls);
 	if (default_conn_ops.terminate_fn)
 		default_conn_ops.terminate_fn(conn);
 	t->ops->disconnect(t);
 	module_put(THIS_MODULE);
 	return 0;
 }

 void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
 {
 	default_conn_ops.process_fn = ops->process_fn;
 	default_conn_ops.terminate_fn = ops->terminate_fn;
 }

 int ksmbd_conn_transport_init(void)
 {
 	int ret;

 	mutex_lock(&init_lock);
 	ret = ksmbd_tcp_init();
 	if (ret) {
 		pr_err("Failed to init TCP subsystem: %d\n", ret);
 		goto out;
 	}

 	ret = ksmbd_rdma_init();
 	if (ret) {
 		pr_err("Failed to init RDMA subsystem: %d\n", ret);
 		goto out;
 	}
 out:
 	mutex_unlock(&init_lock);
 	return ret;
 }

 static void stop_sessions(void)
 {
 	struct ksmbd_conn *conn;
 	struct ksmbd_transport *t;

 again:
 	read_lock(&conn_list_lock);
 	list_for_each_entry(conn, &conn_list, conns_list) {
 		struct task_struct *task;

 		t = conn->transport;
 		task = t->handler;
 		if (task)
 			ksmbd_debug(CONN, "Stop session handler %s/%d\n",
 				    task->comm, task_pid_nr(task));
 		conn->status = KSMBD_SESS_EXITING;
 		if (t->ops->shutdown) {
 			read_unlock(&conn_list_lock);
 			t->ops->shutdown(t);
 			read_lock(&conn_list_lock);
 		}
 	}
 	read_unlock(&conn_list_lock);

 	if (!list_empty(&conn_list)) {
 		schedule_timeout_interruptible(HZ / 10); /* 100ms */
 		goto again;
 	}
 }

 void ksmbd_conn_transport_destroy(void)
 {
 	mutex_lock(&init_lock);
 	ksmbd_tcp_destroy();
 	ksmbd_rdma_destroy();
 	stop_sessions();
 	mutex_unlock(&init_lock);
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2016 Namjae Jeon <namjae.jeon@protocolfreedom.org>
	* Copyright (C) 2018 Samsung Electronics Co., Ltd.
	*/

	#include <linux/mutex.h>
	#include <linux/freezer.h>
	#include <linux/module.h>

	#include "server.h"
	#include "smb_common.h"
	#include "mgmt/ksmbd_ida.h"
	#include "connection.h"
	#include "transport_tcp.h"
	#include "transport_rdma.h"

	static DEFINE_MUTEX(init_lock);

	static struct ksmbd_conn_ops default_conn_ops;

	LIST_HEAD(conn_list);
	DEFINE_RWLOCK(conn_list_lock);

	/**
	* ksmbd_conn_free() - free resources of the connection instance
	*
	* @conn: connection instance to be cleand up
	*
	* During the thread termination, the corresponding conn instance
	* resources(sock/memory) are released and finally the conn object is freed.
	*/
	void ksmbd_conn_free(struct ksmbd_conn *conn)
	{
	write_lock(&conn_list_lock);
	list_del(&conn->conns_list);
	write_unlock(&conn_list_lock);

	kvfree(conn->request_buf);
	kfree(conn->preauth_info);
	kfree(conn);
	}

	/**
	* ksmbd_conn_alloc() - initialize a new connection instance
	*
	* Return: ksmbd_conn struct on success, otherwise NULL
	*/
	struct ksmbd_conn *ksmbd_conn_alloc(void)
	{
	struct ksmbd_conn *conn;

	conn = kzalloc(sizeof(struct ksmbd_conn), GFP_KERNEL);
	if (!conn)
	return NULL;

	conn->need_neg = true;
	conn->status = KSMBD_SESS_NEW;
	conn->local_nls = load_nls("utf8");
	if (!conn->local_nls)
	conn->local_nls = load_nls_default();
	atomic_set(&conn->req_running, 0);
	atomic_set(&conn->r_count, 0);
	conn->total_credits = 1;
	conn->outstanding_credits = 1;

	init_waitqueue_head(&conn->req_running_q);
	INIT_LIST_HEAD(&conn->conns_list);
	INIT_LIST_HEAD(&conn->sessions);
	INIT_LIST_HEAD(&conn->requests);
	INIT_LIST_HEAD(&conn->async_requests);
	spin_lock_init(&conn->request_lock);
	spin_lock_init(&conn->credits_lock);
	ida_init(&conn->async_ida);

	spin_lock_init(&conn->llist_lock);
	INIT_LIST_HEAD(&conn->lock_list);

	write_lock(&conn_list_lock);
	list_add(&conn->conns_list, &conn_list);
	write_unlock(&conn_list_lock);
	return conn;
	}

	bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
	{
	struct ksmbd_conn *t;
	bool ret = false;

	read_lock(&conn_list_lock);
	list_for_each_entry(t, &conn_list, conns_list) {
	if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
	continue;

	ret = true;
	break;
	}
	read_unlock(&conn_list_lock);
	return ret;
	}

	void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
	{
	struct ksmbd_conn *conn = work->conn;
	struct list_head *requests_queue = NULL;

	if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE) {
	requests_queue = &conn->requests;
	work->syncronous = true;
	}

	if (requests_queue) {
	atomic_inc(&conn->req_running);
	spin_lock(&conn->request_lock);
	list_add_tail(&work->request_entry, requests_queue);
	spin_unlock(&conn->request_lock);
	}
	}

	int ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
	{
	struct ksmbd_conn *conn = work->conn;
	int ret = 1;

	if (list_empty(&work->request_entry) &&
	list_empty(&work->async_request_entry))
	return 0;

	if (!work->multiRsp)
	atomic_dec(&conn->req_running);
	spin_lock(&conn->request_lock);
	if (!work->multiRsp) {
	list_del_init(&work->request_entry);
	if (work->syncronous == false)
	list_del_init(&work->async_request_entry);
	ret = 0;
	}
	spin_unlock(&conn->request_lock);

	wake_up_all(&conn->req_running_q);
	return ret;
	}

	static void ksmbd_conn_lock(struct ksmbd_conn *conn)
	{
	mutex_lock(&conn->srv_mutex);
	}

	static void ksmbd_conn_unlock(struct ksmbd_conn *conn)
	{
	mutex_unlock(&conn->srv_mutex);
	}

	void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
	{
	wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
	}

	int ksmbd_conn_write(struct ksmbd_work *work)
	{
	struct ksmbd_conn *conn = work->conn;
	size_t len = 0;
	int sent;
	struct kvec iov[3];
	int iov_idx = 0;

	ksmbd_conn_try_dequeue_request(work);
	if (!work->response_buf) {
	pr_err("NULL response header\n");
	return -EINVAL;
	}

	if (work->tr_buf) {
	iov[iov_idx] = (struct kvec) { work->tr_buf,
	sizeof(struct smb2_transform_hdr) + 4 };
	len += iov[iov_idx++].iov_len;
	}

	if (work->aux_payload_sz) {
	iov[iov_idx] = (struct kvec) { work->response_buf, work->resp_hdr_sz };
	len += iov[iov_idx++].iov_len;
	iov[iov_idx] = (struct kvec) { work->aux_payload_buf, work->aux_payload_sz };
	len += iov[iov_idx++].iov_len;
	} else {
	if (work->tr_buf)
	iov[iov_idx].iov_len = work->resp_hdr_sz;
	else
	iov[iov_idx].iov_len = get_rfc1002_len(work->response_buf) + 4;
	iov[iov_idx].iov_base = work->response_buf;
	len += iov[iov_idx++].iov_len;
	}

	ksmbd_conn_lock(conn);
	sent = conn->transport->ops->writev(conn->transport, &iov[0],
	iov_idx, len,
	work->need_invalidate_rkey,
	work->remote_key);
	ksmbd_conn_unlock(conn);

	if (sent < 0) {
	pr_err("Failed to send message: %d\n", sent);
	return sent;
	}

	return 0;
	}

	int ksmbd_conn_rdma_read(struct ksmbd_conn conn, void buf,
	unsigned int buflen, u32 remote_key, u64 remote_offset,
	u32 remote_len)
	{
	int ret = -EINVAL;

	if (conn->transport->ops->rdma_read)
	ret = conn->transport->ops->rdma_read(conn->transport,
	buf, buflen,
	remote_key, remote_offset,
	remote_len);
	return ret;
	}

	int ksmbd_conn_rdma_write(struct ksmbd_conn conn, void buf,
	unsigned int buflen, u32 remote_key,
	u64 remote_offset, u32 remote_len)
	{
	int ret = -EINVAL;

	if (conn->transport->ops->rdma_write)
	ret = conn->transport->ops->rdma_write(conn->transport,
	buf, buflen,
	remote_key, remote_offset,
	remote_len);
	return ret;
	}

	bool ksmbd_conn_alive(struct ksmbd_conn *conn)
	{
	if (!ksmbd_server_running())
	return false;

	if (conn->status == KSMBD_SESS_EXITING)
	return false;

	if (kthread_should_stop())
	return false;

	if (atomic_read(&conn->stats.open_files_count) > 0)
	return true;

	/*
	* Stop current session if the time that get last request from client
	* is bigger than deadtime user configured and opening file count is
	* zero.
	*/
	if (server_conf.deadtime > 0 &&
	time_after(jiffies, conn->last_active + server_conf.deadtime)) {
	ksmbd_debug(CONN, "No response from client in %lu minutes\n",
	server_conf.deadtime / SMB_ECHO_INTERVAL);
	return false;
	}
	return true;
	}

	/**
	* ksmbd_conn_handler_loop() - session thread to listen on new smb requests
	* @p: connection instance
	*
	* One thread each per connection
	*
	* Return: 0 on success
	*/
	int ksmbd_conn_handler_loop(void *p)
	{
	struct ksmbd_conn conn = (struct ksmbd_conn )p;
	struct ksmbd_transport *t = conn->transport;
	unsigned int pdu_size;
	char hdr_buf[4] = {0,};
	int size;

	mutex_init(&conn->srv_mutex);
	__module_get(THIS_MODULE);

	if (t->ops->prepare && t->ops->prepare(t))
	goto out;

	conn->last_active = jiffies;
	while (ksmbd_conn_alive(conn)) {
	if (try_to_freeze())
	continue;

	kvfree(conn->request_buf);
	conn->request_buf = NULL;

	size = t->ops->read(t, hdr_buf, sizeof(hdr_buf));
	if (size != sizeof(hdr_buf))
	break;

	pdu_size = get_rfc1002_len(hdr_buf);
	ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);

	/*
	* Check if pdu size is valid (min : smb header size,
	* max : 0x00FFFFFF).
	*/
	if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE \|\|
	pdu_size > MAX_STREAM_PROT_LEN) {
	continue;
	}

	/* 4 for rfc1002 length field */
	size = pdu_size + 4;
	conn->request_buf = kvmalloc(size, GFP_KERNEL);
	if (!conn->request_buf)
	continue;

	memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
	if (!ksmbd_smb_request(conn))
	break;

	/*
	* We already read 4 bytes to find out PDU size, now
	* read in PDU
	*/
	size = t->ops->read(t, conn->request_buf + 4, pdu_size);
	if (size < 0) {
	pr_err("sock_read failed: %d\n", size);
	break;
	}

	if (size != pdu_size) {
	pr_err("PDU error. Read: %d, Expected: %d\n",
	size, pdu_size);
	continue;
	}

	if (!default_conn_ops.process_fn) {
	pr_err("No connection request callback\n");
	break;
	}

	if (default_conn_ops.process_fn(conn)) {
	pr_err("Cannot handle request\n");
	break;
	}
	}

	out:
	/* Wait till all reference dropped to the Server object*/
	while (atomic_read(&conn->r_count) > 0)
	schedule_timeout(HZ);

	unload_nls(conn->local_nls);
	if (default_conn_ops.terminate_fn)
	default_conn_ops.terminate_fn(conn);
	t->ops->disconnect(t);
	module_put(THIS_MODULE);
	return 0;
	}

	void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
	{
	default_conn_ops.process_fn = ops->process_fn;
	default_conn_ops.terminate_fn = ops->terminate_fn;
	}

	int ksmbd_conn_transport_init(void)
	{
	int ret;

	mutex_lock(&init_lock);
	ret = ksmbd_tcp_init();
	if (ret) {
	pr_err("Failed to init TCP subsystem: %d\n", ret);
	goto out;
	}

	ret = ksmbd_rdma_init();
	if (ret) {
	pr_err("Failed to init RDMA subsystem: %d\n", ret);
	goto out;
	}
	out:
	mutex_unlock(&init_lock);
	return ret;
	}

	static void stop_sessions(void)
	{
	struct ksmbd_conn *conn;
	struct ksmbd_transport *t;

	again:
	read_lock(&conn_list_lock);
	list_for_each_entry(conn, &conn_list, conns_list) {
	struct task_struct *task;

	t = conn->transport;
	task = t->handler;
	if (task)
	ksmbd_debug(CONN, "Stop session handler %s/%d\n",
	task->comm, task_pid_nr(task));
	conn->status = KSMBD_SESS_EXITING;
	if (t->ops->shutdown) {
	read_unlock(&conn_list_lock);
	t->ops->shutdown(t);
	read_lock(&conn_list_lock);
	}
	}
	read_unlock(&conn_list_lock);

	if (!list_empty(&conn_list)) {
	schedule_timeout_interruptible(HZ / 10); /* 100ms */
	goto again;
	}
	}

	void ksmbd_conn_transport_destroy(void)
	{
	mutex_lock(&init_lock);
	ksmbd_tcp_destroy();
	ksmbd_rdma_destroy();
	stop_sessions();
	mutex_unlock(&init_lock);
	}