linux/drivers/target/iscsi/iscsi_target_login.c
Maurizio Lombardi 13247018d6 scsi: target: iscsi: Fix hang in the iSCSI login code
If the initiator suddenly stops sending data during a login while keeping
the TCP connection open, the login_work won't be scheduled and will never
release the login semaphore; concurrent login operations will therefore get
stuck and fail.

The bug is due to the inability of the login timeout code to properly
handle this particular case.

Fix the problem by replacing the old per-NP login timer with a new
per-connection timer.

The timer is started when an initiator connects to the target; if it
expires, it sends a SIGINT signal to the thread pointed at by the
conn->login_kworker pointer.

conn->login_kworker is set by calling the iscsit_set_login_timer_kworker()
helper, initially it will point to the np thread; When the login
operation's control is in the process of being passed from the NP-thread to
login_work, the conn->login_worker pointer is set to NULL.  Finally,
login_kworker will be changed to point to the worker thread executing the
login_work job.

If conn->login_kworker is NULL when the timer expires, it means that the
login operation hasn't been completed yet but login_work isn't running, in
this case the timer will mark the login process as failed and will schedule
login_work so the latter will be forced to free the resources it holds.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20230508162219.1731964-2-mlombard@redhat.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-05-22 16:29:39 -04:00

1429 lines
38 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
* This file contains the login functions used by the iSCSI Target driver.
*
* (c) Copyright 2007-2013 Datera, Inc.
*
* Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
*
******************************************************************************/
#include <crypto/hash.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/kthread.h>
#include <linux/sched/signal.h>
#include <linux/idr.h>
#include <linux/tcp.h> /* TCP_NODELAY */
#include <net/ip.h>
#include <net/ipv6.h> /* ipv6_addr_v4mapped() */
#include <scsi/iscsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/iscsi/iscsi_target_core.h>
#include <target/iscsi/iscsi_target_stat.h>
#include "iscsi_target_device.h"
#include "iscsi_target_nego.h"
#include "iscsi_target_erl0.h"
#include "iscsi_target_erl2.h"
#include "iscsi_target_login.h"
#include "iscsi_target_tpg.h"
#include "iscsi_target_util.h"
#include "iscsi_target.h"
#include "iscsi_target_parameters.h"
#include <target/iscsi/iscsi_transport.h>
static struct iscsi_login *iscsi_login_init_conn(struct iscsit_conn *conn)
{
struct iscsi_login *login;
login = kzalloc(sizeof(struct iscsi_login), GFP_KERNEL);
if (!login) {
pr_err("Unable to allocate memory for struct iscsi_login.\n");
return NULL;
}
conn->login = login;
login->conn = conn;
login->first_request = 1;
login->req_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
if (!login->req_buf) {
pr_err("Unable to allocate memory for response buffer.\n");
goto out_login;
}
login->rsp_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
if (!login->rsp_buf) {
pr_err("Unable to allocate memory for request buffer.\n");
goto out_req_buf;
}
conn->conn_login = login;
return login;
out_req_buf:
kfree(login->req_buf);
out_login:
kfree(login);
return NULL;
}
/*
* Used by iscsi_target_nego.c:iscsi_target_locate_portal() to setup
* per struct iscsit_conn libcrypto contexts for crc32c and crc32-intel
*/
int iscsi_login_setup_crypto(struct iscsit_conn *conn)
{
struct crypto_ahash *tfm;
/*
* Setup slicing by CRC32C algorithm for RX and TX libcrypto contexts
* which will default to crc32c_intel.ko for cpu_has_xmm4_2, or fallback
* to software 1x8 byte slicing from crc32c.ko
*/
tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm)) {
pr_err("crypto_alloc_ahash() failed\n");
return -ENOMEM;
}
conn->conn_rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
if (!conn->conn_rx_hash) {
pr_err("ahash_request_alloc() failed for conn_rx_hash\n");
crypto_free_ahash(tfm);
return -ENOMEM;
}
ahash_request_set_callback(conn->conn_rx_hash, 0, NULL, NULL);
conn->conn_tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
if (!conn->conn_tx_hash) {
pr_err("ahash_request_alloc() failed for conn_tx_hash\n");
ahash_request_free(conn->conn_rx_hash);
conn->conn_rx_hash = NULL;
crypto_free_ahash(tfm);
return -ENOMEM;
}
ahash_request_set_callback(conn->conn_tx_hash, 0, NULL, NULL);
return 0;
}
static int iscsi_login_check_initiator_version(
struct iscsit_conn *conn,
u8 version_max,
u8 version_min)
{
if ((version_max != 0x00) || (version_min != 0x00)) {
pr_err("Unsupported iSCSI IETF Pre-RFC Revision,"
" version Min/Max 0x%02x/0x%02x, rejecting login.\n",
version_min, version_max);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_NO_VERSION);
return -1;
}
return 0;
}
int iscsi_check_for_session_reinstatement(struct iscsit_conn *conn)
{
int sessiontype;
struct iscsi_param *initiatorname_param = NULL, *sessiontype_param = NULL;
struct iscsi_portal_group *tpg = conn->tpg;
struct iscsit_session *sess = NULL, *sess_p = NULL;
struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
struct se_session *se_sess, *se_sess_tmp;
initiatorname_param = iscsi_find_param_from_key(
INITIATORNAME, conn->param_list);
sessiontype_param = iscsi_find_param_from_key(
SESSIONTYPE, conn->param_list);
if (!initiatorname_param || !sessiontype_param) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_MISSING_FIELDS);
return -1;
}
sessiontype = (strncmp(sessiontype_param->value, NORMAL, 6)) ? 1 : 0;
spin_lock_bh(&se_tpg->session_lock);
list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
sess_list) {
sess_p = se_sess->fabric_sess_ptr;
spin_lock(&sess_p->conn_lock);
if (atomic_read(&sess_p->session_fall_back_to_erl0) ||
atomic_read(&sess_p->session_logout) ||
atomic_read(&sess_p->session_close) ||
(sess_p->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
spin_unlock(&sess_p->conn_lock);
continue;
}
if (!memcmp(sess_p->isid, conn->sess->isid, 6) &&
(!strcmp(sess_p->sess_ops->InitiatorName,
initiatorname_param->value) &&
(sess_p->sess_ops->SessionType == sessiontype))) {
atomic_set(&sess_p->session_reinstatement, 1);
atomic_set(&sess_p->session_fall_back_to_erl0, 1);
atomic_set(&sess_p->session_close, 1);
spin_unlock(&sess_p->conn_lock);
iscsit_inc_session_usage_count(sess_p);
iscsit_stop_time2retain_timer(sess_p);
sess = sess_p;
break;
}
spin_unlock(&sess_p->conn_lock);
}
spin_unlock_bh(&se_tpg->session_lock);
/*
* If the Time2Retain handler has expired, the session is already gone.
*/
if (!sess)
return 0;
pr_debug("%s iSCSI Session SID %u is still active for %s,"
" performing session reinstatement.\n", (sessiontype) ?
"Discovery" : "Normal", sess->sid,
sess->sess_ops->InitiatorName);
spin_lock_bh(&sess->conn_lock);
if (sess->session_state == TARG_SESS_STATE_FAILED) {
spin_unlock_bh(&sess->conn_lock);
iscsit_dec_session_usage_count(sess);
return 0;
}
spin_unlock_bh(&sess->conn_lock);
iscsit_stop_session(sess, 1, 1);
iscsit_dec_session_usage_count(sess);
return 0;
}
static int iscsi_login_set_conn_values(
struct iscsit_session *sess,
struct iscsit_conn *conn,
__be16 cid)
{
int ret;
conn->sess = sess;
conn->cid = be16_to_cpu(cid);
/*
* Generate a random Status sequence number (statsn) for the new
* iSCSI connection.
*/
ret = get_random_bytes_wait(&conn->stat_sn, sizeof(u32));
if (unlikely(ret))
return ret;
mutex_lock(&auth_id_lock);
conn->auth_id = iscsit_global->auth_id++;
mutex_unlock(&auth_id_lock);
return 0;
}
__printf(2, 3) int iscsi_change_param_sprintf(
struct iscsit_conn *conn,
const char *fmt, ...)
{
va_list args;
unsigned char buf[64];
memset(buf, 0, sizeof buf);
va_start(args, fmt);
vsnprintf(buf, sizeof buf, fmt, args);
va_end(args);
if (iscsi_change_param_value(buf, conn->param_list, 0) < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
return -1;
}
return 0;
}
EXPORT_SYMBOL(iscsi_change_param_sprintf);
/*
* This is the leading connection of a new session,
* or session reinstatement.
*/
static int iscsi_login_zero_tsih_s1(
struct iscsit_conn *conn,
unsigned char *buf)
{
struct iscsit_session *sess = NULL;
struct iscsi_login_req *pdu = (struct iscsi_login_req *)buf;
int ret;
sess = kzalloc(sizeof(struct iscsit_session), GFP_KERNEL);
if (!sess) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
pr_err("Could not allocate memory for session\n");
return -ENOMEM;
}
if (iscsi_login_set_conn_values(sess, conn, pdu->cid))
goto free_sess;
sess->init_task_tag = pdu->itt;
memcpy(&sess->isid, pdu->isid, 6);
sess->exp_cmd_sn = be32_to_cpu(pdu->cmdsn);
INIT_LIST_HEAD(&sess->sess_conn_list);
INIT_LIST_HEAD(&sess->sess_ooo_cmdsn_list);
INIT_LIST_HEAD(&sess->cr_active_list);
INIT_LIST_HEAD(&sess->cr_inactive_list);
init_completion(&sess->async_msg_comp);
init_completion(&sess->reinstatement_comp);
init_completion(&sess->session_wait_comp);
init_completion(&sess->session_waiting_on_uc_comp);
mutex_init(&sess->cmdsn_mutex);
spin_lock_init(&sess->conn_lock);
spin_lock_init(&sess->cr_a_lock);
spin_lock_init(&sess->cr_i_lock);
spin_lock_init(&sess->session_usage_lock);
spin_lock_init(&sess->ttt_lock);
timer_setup(&sess->time2retain_timer,
iscsit_handle_time2retain_timeout, 0);
ret = ida_alloc(&sess_ida, GFP_KERNEL);
if (ret < 0) {
pr_err("Session ID allocation failed %d\n", ret);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
goto free_sess;
}
sess->session_index = ret;
sess->creation_time = get_jiffies_64();
/*
* The FFP CmdSN window values will be allocated from the TPG's
* Initiator Node's ACL once the login has been successfully completed.
*/
atomic_set(&sess->max_cmd_sn, be32_to_cpu(pdu->cmdsn));
sess->sess_ops = kzalloc(sizeof(struct iscsi_sess_ops), GFP_KERNEL);
if (!sess->sess_ops) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
pr_err("Unable to allocate memory for"
" struct iscsi_sess_ops.\n");
goto free_id;
}
sess->se_sess = transport_alloc_session(TARGET_PROT_NORMAL);
if (IS_ERR(sess->se_sess)) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
goto free_ops;
}
return 0;
free_ops:
kfree(sess->sess_ops);
free_id:
ida_free(&sess_ida, sess->session_index);
free_sess:
kfree(sess);
conn->sess = NULL;
return -ENOMEM;
}
static int iscsi_login_zero_tsih_s2(
struct iscsit_conn *conn)
{
struct iscsi_node_attrib *na;
struct iscsit_session *sess = conn->sess;
struct iscsi_param *param;
bool iser = false;
sess->tpg = conn->tpg;
/*
* Assign a new TPG Session Handle. Note this is protected with
* struct iscsi_portal_group->np_login_sem from iscsit_access_np().
*/
sess->tsih = ++sess->tpg->ntsih;
if (!sess->tsih)
sess->tsih = ++sess->tpg->ntsih;
/*
* Create the default params from user defined values..
*/
if (iscsi_copy_param_list(&conn->param_list,
conn->tpg->param_list, 1) < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
return -1;
}
if (conn->conn_transport->transport_type == ISCSI_INFINIBAND)
iser = true;
iscsi_set_keys_to_negotiate(conn->param_list, iser);
if (sess->sess_ops->SessionType)
return iscsi_set_keys_irrelevant_for_discovery(
conn->param_list);
na = iscsit_tpg_get_node_attrib(sess);
/*
* If ACL allows non-authorized access in TPG with CHAP,
* then set None to AuthMethod.
*/
param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
if (param && !strstr(param->value, NONE)) {
if (!iscsi_conn_auth_required(conn))
if (iscsi_change_param_sprintf(conn, "AuthMethod=%s",
NONE))
return -1;
}
/*
* Need to send TargetPortalGroupTag back in first login response
* on any iSCSI connection where the Initiator provides TargetName.
* See 5.3.1. Login Phase Start
*
* In our case, we have already located the struct iscsi_tiqn at this point.
*/
if (iscsi_change_param_sprintf(conn, "TargetPortalGroupTag=%hu", sess->tpg->tpgt))
return -1;
/*
* Workaround for Initiators that have broken connection recovery logic.
*
* "We would really like to get rid of this." Linux-iSCSI.org team
*/
if (iscsi_change_param_sprintf(conn, "ErrorRecoveryLevel=%d", na->default_erl))
return -1;
/*
* Set RDMAExtensions=Yes by default for iSER enabled network portals
*/
if (iser) {
struct iscsi_param *param;
unsigned long mrdsl, off;
int rc;
if (iscsi_change_param_sprintf(conn, "RDMAExtensions=Yes"))
return -1;
/*
* Make MaxRecvDataSegmentLength PAGE_SIZE aligned for
* Immediate Data + Unsolicited Data-OUT if necessary..
*/
param = iscsi_find_param_from_key("MaxRecvDataSegmentLength",
conn->param_list);
if (!param) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
return -1;
}
rc = kstrtoul(param->value, 0, &mrdsl);
if (rc < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
return -1;
}
off = mrdsl % PAGE_SIZE;
if (!off)
goto check_prot;
if (mrdsl < PAGE_SIZE)
mrdsl = PAGE_SIZE;
else
mrdsl -= off;
pr_warn("Aligning ISER MaxRecvDataSegmentLength: %lu down"
" to PAGE_SIZE\n", mrdsl);
if (iscsi_change_param_sprintf(conn, "MaxRecvDataSegmentLength=%lu\n", mrdsl))
return -1;
/*
* ISER currently requires that ImmediateData + Unsolicited
* Data be disabled when protection / signature MRs are enabled.
*/
check_prot:
if (sess->se_sess->sup_prot_ops &
(TARGET_PROT_DOUT_STRIP | TARGET_PROT_DOUT_PASS |
TARGET_PROT_DOUT_INSERT)) {
if (iscsi_change_param_sprintf(conn, "ImmediateData=No"))
return -1;
if (iscsi_change_param_sprintf(conn, "InitialR2T=Yes"))
return -1;
pr_debug("Forcing ImmediateData=No + InitialR2T=Yes for"
" T10-PI enabled ISER session\n");
}
}
return 0;
}
static int iscsi_login_non_zero_tsih_s1(
struct iscsit_conn *conn,
unsigned char *buf)
{
struct iscsi_login_req *pdu = (struct iscsi_login_req *)buf;
return iscsi_login_set_conn_values(NULL, conn, pdu->cid);
}
/*
* Add a new connection to an existing session.
*/
static int iscsi_login_non_zero_tsih_s2(
struct iscsit_conn *conn,
unsigned char *buf)
{
struct iscsi_portal_group *tpg = conn->tpg;
struct iscsit_session *sess = NULL, *sess_p = NULL;
struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
struct se_session *se_sess, *se_sess_tmp;
struct iscsi_login_req *pdu = (struct iscsi_login_req *)buf;
bool iser = false;
spin_lock_bh(&se_tpg->session_lock);
list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
sess_list) {
sess_p = (struct iscsit_session *)se_sess->fabric_sess_ptr;
if (atomic_read(&sess_p->session_fall_back_to_erl0) ||
atomic_read(&sess_p->session_logout) ||
atomic_read(&sess_p->session_close) ||
(sess_p->time2retain_timer_flags & ISCSI_TF_EXPIRED))
continue;
if (!memcmp(sess_p->isid, pdu->isid, 6) &&
(sess_p->tsih == be16_to_cpu(pdu->tsih))) {
iscsit_inc_session_usage_count(sess_p);
iscsit_stop_time2retain_timer(sess_p);
sess = sess_p;
break;
}
}
spin_unlock_bh(&se_tpg->session_lock);
/*
* If the Time2Retain handler has expired, the session is already gone.
*/
if (!sess) {
pr_err("Initiator attempting to add a connection to"
" a non-existent session, rejecting iSCSI Login.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_NO_SESSION);
return -1;
}
/*
* Stop the Time2Retain timer if this is a failed session, we restart
* the timer if the login is not successful.
*/
spin_lock_bh(&sess->conn_lock);
if (sess->session_state == TARG_SESS_STATE_FAILED)
atomic_set(&sess->session_continuation, 1);
spin_unlock_bh(&sess->conn_lock);
if (iscsi_login_set_conn_values(sess, conn, pdu->cid) < 0 ||
iscsi_copy_param_list(&conn->param_list,
conn->tpg->param_list, 0) < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
return -1;
}
if (conn->conn_transport->transport_type == ISCSI_INFINIBAND)
iser = true;
iscsi_set_keys_to_negotiate(conn->param_list, iser);
/*
* Need to send TargetPortalGroupTag back in first login response
* on any iSCSI connection where the Initiator provides TargetName.
* See 5.3.1. Login Phase Start
*
* In our case, we have already located the struct iscsi_tiqn at this point.
*/
if (iscsi_change_param_sprintf(conn, "TargetPortalGroupTag=%hu", sess->tpg->tpgt))
return -1;
return 0;
}
int iscsi_login_post_auth_non_zero_tsih(
struct iscsit_conn *conn,
u16 cid,
u32 exp_statsn)
{
struct iscsit_conn *conn_ptr = NULL;
struct iscsi_conn_recovery *cr = NULL;
struct iscsit_session *sess = conn->sess;
/*
* By following item 5 in the login table, if we have found
* an existing ISID and a valid/existing TSIH and an existing
* CID we do connection reinstatement. Currently we dont not
* support it so we send back an non-zero status class to the
* initiator and release the new connection.
*/
conn_ptr = iscsit_get_conn_from_cid_rcfr(sess, cid);
if (conn_ptr) {
pr_err("Connection exists with CID %hu for %s,"
" performing connection reinstatement.\n",
conn_ptr->cid, sess->sess_ops->InitiatorName);
iscsit_connection_reinstatement_rcfr(conn_ptr);
iscsit_dec_conn_usage_count(conn_ptr);
}
/*
* Check for any connection recovery entries containing CID.
* We use the original ExpStatSN sent in the first login request
* to acknowledge commands for the failed connection.
*
* Also note that an explict logout may have already been sent,
* but the response may not be sent due to additional connection
* loss.
*/
if (sess->sess_ops->ErrorRecoveryLevel == 2) {
cr = iscsit_get_inactive_connection_recovery_entry(
sess, cid);
if (cr) {
pr_debug("Performing implicit logout"
" for connection recovery on CID: %hu\n",
conn->cid);
iscsit_discard_cr_cmds_by_expstatsn(cr, exp_statsn);
}
}
/*
* Else we follow item 4 from the login table in that we have
* found an existing ISID and a valid/existing TSIH and a new
* CID we go ahead and continue to add a new connection to the
* session.
*/
pr_debug("Adding CID %hu to existing session for %s.\n",
cid, sess->sess_ops->InitiatorName);
if ((atomic_read(&sess->nconn) + 1) > sess->sess_ops->MaxConnections) {
pr_err("Adding additional connection to this session"
" would exceed MaxConnections %d, login failed.\n",
sess->sess_ops->MaxConnections);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_ISID_ERROR);
return -1;
}
return 0;
}
static void iscsi_post_login_start_timers(struct iscsit_conn *conn)
{
struct iscsit_session *sess = conn->sess;
/*
* FIXME: Unsolicited NopIN support for ISER
*/
if (conn->conn_transport->transport_type == ISCSI_INFINIBAND)
return;
if (!sess->sess_ops->SessionType)
iscsit_start_nopin_timer(conn);
}
int iscsit_start_kthreads(struct iscsit_conn *conn)
{
int ret = 0;
spin_lock(&iscsit_global->ts_bitmap_lock);
conn->bitmap_id = bitmap_find_free_region(iscsit_global->ts_bitmap,
ISCSIT_BITMAP_BITS, get_order(1));
spin_unlock(&iscsit_global->ts_bitmap_lock);
if (conn->bitmap_id < 0) {
pr_err("bitmap_find_free_region() failed for"
" iscsit_start_kthreads()\n");
return -ENOMEM;
}
conn->tx_thread = kthread_run(iscsi_target_tx_thread, conn,
"%s", ISCSI_TX_THREAD_NAME);
if (IS_ERR(conn->tx_thread)) {
pr_err("Unable to start iscsi_target_tx_thread\n");
ret = PTR_ERR(conn->tx_thread);
goto out_bitmap;
}
conn->tx_thread_active = true;
conn->rx_thread = kthread_run(iscsi_target_rx_thread, conn,
"%s", ISCSI_RX_THREAD_NAME);
if (IS_ERR(conn->rx_thread)) {
pr_err("Unable to start iscsi_target_rx_thread\n");
ret = PTR_ERR(conn->rx_thread);
goto out_tx;
}
conn->rx_thread_active = true;
return 0;
out_tx:
send_sig(SIGINT, conn->tx_thread, 1);
kthread_stop(conn->tx_thread);
conn->tx_thread_active = false;
out_bitmap:
spin_lock(&iscsit_global->ts_bitmap_lock);
bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
get_order(1));
spin_unlock(&iscsit_global->ts_bitmap_lock);
return ret;
}
void iscsi_post_login_handler(
struct iscsi_np *np,
struct iscsit_conn *conn,
u8 zero_tsih)
{
int stop_timer = 0;
struct iscsit_session *sess = conn->sess;
struct se_session *se_sess = sess->se_sess;
struct iscsi_portal_group *tpg = sess->tpg;
struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
iscsit_inc_conn_usage_count(conn);
iscsit_collect_login_stats(conn, ISCSI_STATUS_CLS_SUCCESS,
ISCSI_LOGIN_STATUS_ACCEPT);
pr_debug("Moving to TARG_CONN_STATE_LOGGED_IN.\n");
conn->conn_state = TARG_CONN_STATE_LOGGED_IN;
iscsi_set_connection_parameters(conn->conn_ops, conn->param_list);
/*
* SCSI Initiator -> SCSI Target Port Mapping
*/
if (!zero_tsih) {
iscsi_set_session_parameters(sess->sess_ops,
conn->param_list, 0);
iscsi_release_param_list(conn->param_list);
conn->param_list = NULL;
spin_lock_bh(&sess->conn_lock);
atomic_set(&sess->session_continuation, 0);
if (sess->session_state == TARG_SESS_STATE_FAILED) {
pr_debug("Moving to"
" TARG_SESS_STATE_LOGGED_IN.\n");
sess->session_state = TARG_SESS_STATE_LOGGED_IN;
stop_timer = 1;
}
pr_debug("iSCSI Login successful on CID: %hu from %pISpc to"
" %pISpc,%hu\n", conn->cid, &conn->login_sockaddr,
&conn->local_sockaddr, tpg->tpgt);
list_add_tail(&conn->conn_list, &sess->sess_conn_list);
atomic_inc(&sess->nconn);
pr_debug("Incremented iSCSI Connection count to %d"
" from node: %s\n", atomic_read(&sess->nconn),
sess->sess_ops->InitiatorName);
spin_unlock_bh(&sess->conn_lock);
iscsi_post_login_start_timers(conn);
/*
* Determine CPU mask to ensure connection's RX and TX kthreads
* are scheduled on the same CPU.
*/
iscsit_thread_get_cpumask(conn);
conn->conn_rx_reset_cpumask = 1;
conn->conn_tx_reset_cpumask = 1;
/*
* Wakeup the sleeping iscsi_target_rx_thread() now that
* iscsit_conn is in TARG_CONN_STATE_LOGGED_IN state.
*/
complete(&conn->rx_login_comp);
iscsit_dec_conn_usage_count(conn);
if (stop_timer) {
spin_lock_bh(&se_tpg->session_lock);
iscsit_stop_time2retain_timer(sess);
spin_unlock_bh(&se_tpg->session_lock);
}
iscsit_dec_session_usage_count(sess);
return;
}
iscsi_set_session_parameters(sess->sess_ops, conn->param_list, 1);
iscsi_release_param_list(conn->param_list);
conn->param_list = NULL;
iscsit_determine_maxcmdsn(sess);
spin_lock_bh(&se_tpg->session_lock);
__transport_register_session(&sess->tpg->tpg_se_tpg,
se_sess->se_node_acl, se_sess, sess);
pr_debug("Moving to TARG_SESS_STATE_LOGGED_IN.\n");
sess->session_state = TARG_SESS_STATE_LOGGED_IN;
pr_debug("iSCSI Login successful on CID: %hu from %pISpc to %pISpc,%hu\n",
conn->cid, &conn->login_sockaddr, &conn->local_sockaddr,
tpg->tpgt);
spin_lock_bh(&sess->conn_lock);
list_add_tail(&conn->conn_list, &sess->sess_conn_list);
atomic_inc(&sess->nconn);
pr_debug("Incremented iSCSI Connection count to %d from node:"
" %s\n", atomic_read(&sess->nconn),
sess->sess_ops->InitiatorName);
spin_unlock_bh(&sess->conn_lock);
sess->sid = tpg->sid++;
if (!sess->sid)
sess->sid = tpg->sid++;
pr_debug("Established iSCSI session from node: %s\n",
sess->sess_ops->InitiatorName);
tpg->nsessions++;
if (tpg->tpg_tiqn)
tpg->tpg_tiqn->tiqn_nsessions++;
pr_debug("Incremented number of active iSCSI sessions to %u on"
" iSCSI Target Portal Group: %hu\n", tpg->nsessions, tpg->tpgt);
spin_unlock_bh(&se_tpg->session_lock);
iscsi_post_login_start_timers(conn);
/*
* Determine CPU mask to ensure connection's RX and TX kthreads
* are scheduled on the same CPU.
*/
iscsit_thread_get_cpumask(conn);
conn->conn_rx_reset_cpumask = 1;
conn->conn_tx_reset_cpumask = 1;
/*
* Wakeup the sleeping iscsi_target_rx_thread() now that
* iscsit_conn is in TARG_CONN_STATE_LOGGED_IN state.
*/
complete(&conn->rx_login_comp);
iscsit_dec_conn_usage_count(conn);
}
int iscsit_setup_np(
struct iscsi_np *np,
struct sockaddr_storage *sockaddr)
{
struct socket *sock = NULL;
int backlog = ISCSIT_TCP_BACKLOG, ret, len;
switch (np->np_network_transport) {
case ISCSI_TCP:
np->np_ip_proto = IPPROTO_TCP;
np->np_sock_type = SOCK_STREAM;
break;
case ISCSI_SCTP_TCP:
np->np_ip_proto = IPPROTO_SCTP;
np->np_sock_type = SOCK_STREAM;
break;
case ISCSI_SCTP_UDP:
np->np_ip_proto = IPPROTO_SCTP;
np->np_sock_type = SOCK_SEQPACKET;
break;
default:
pr_err("Unsupported network_transport: %d\n",
np->np_network_transport);
return -EINVAL;
}
ret = sock_create(sockaddr->ss_family, np->np_sock_type,
np->np_ip_proto, &sock);
if (ret < 0) {
pr_err("sock_create() failed.\n");
return ret;
}
np->np_socket = sock;
/*
* Setup the np->np_sockaddr from the passed sockaddr setup
* in iscsi_target_configfs.c code..
*/
memcpy(&np->np_sockaddr, sockaddr,
sizeof(struct sockaddr_storage));
if (sockaddr->ss_family == AF_INET6)
len = sizeof(struct sockaddr_in6);
else
len = sizeof(struct sockaddr_in);
/*
* Set SO_REUSEADDR, and disable Nagle Algorithm with TCP_NODELAY.
*/
if (np->np_network_transport == ISCSI_TCP)
tcp_sock_set_nodelay(sock->sk);
sock_set_reuseaddr(sock->sk);
ip_sock_set_freebind(sock->sk);
ret = kernel_bind(sock, (struct sockaddr *)&np->np_sockaddr, len);
if (ret < 0) {
pr_err("kernel_bind() failed: %d\n", ret);
goto fail;
}
ret = kernel_listen(sock, backlog);
if (ret != 0) {
pr_err("kernel_listen() failed: %d\n", ret);
goto fail;
}
return 0;
fail:
np->np_socket = NULL;
sock_release(sock);
return ret;
}
int iscsi_target_setup_login_socket(
struct iscsi_np *np,
struct sockaddr_storage *sockaddr)
{
struct iscsit_transport *t;
int rc;
t = iscsit_get_transport(np->np_network_transport);
if (!t)
return -EINVAL;
rc = t->iscsit_setup_np(np, sockaddr);
if (rc < 0) {
iscsit_put_transport(t);
return rc;
}
np->np_transport = t;
np->enabled = true;
return 0;
}
int iscsit_accept_np(struct iscsi_np *np, struct iscsit_conn *conn)
{
struct socket *new_sock, *sock = np->np_socket;
struct sockaddr_in sock_in;
struct sockaddr_in6 sock_in6;
int rc;
rc = kernel_accept(sock, &new_sock, 0);
if (rc < 0)
return rc;
conn->sock = new_sock;
conn->login_family = np->np_sockaddr.ss_family;
if (np->np_sockaddr.ss_family == AF_INET6) {
memset(&sock_in6, 0, sizeof(struct sockaddr_in6));
rc = conn->sock->ops->getname(conn->sock,
(struct sockaddr *)&sock_in6, 1);
if (rc >= 0) {
if (!ipv6_addr_v4mapped(&sock_in6.sin6_addr)) {
memcpy(&conn->login_sockaddr, &sock_in6, sizeof(sock_in6));
} else {
/* Pretend to be an ipv4 socket */
sock_in.sin_family = AF_INET;
sock_in.sin_port = sock_in6.sin6_port;
memcpy(&sock_in.sin_addr, &sock_in6.sin6_addr.s6_addr32[3], 4);
memcpy(&conn->login_sockaddr, &sock_in, sizeof(sock_in));
}
}
rc = conn->sock->ops->getname(conn->sock,
(struct sockaddr *)&sock_in6, 0);
if (rc >= 0) {
if (!ipv6_addr_v4mapped(&sock_in6.sin6_addr)) {
memcpy(&conn->local_sockaddr, &sock_in6, sizeof(sock_in6));
} else {
/* Pretend to be an ipv4 socket */
sock_in.sin_family = AF_INET;
sock_in.sin_port = sock_in6.sin6_port;
memcpy(&sock_in.sin_addr, &sock_in6.sin6_addr.s6_addr32[3], 4);
memcpy(&conn->local_sockaddr, &sock_in, sizeof(sock_in));
}
}
} else {
memset(&sock_in, 0, sizeof(struct sockaddr_in));
rc = conn->sock->ops->getname(conn->sock,
(struct sockaddr *)&sock_in, 1);
if (rc >= 0)
memcpy(&conn->login_sockaddr, &sock_in, sizeof(sock_in));
rc = conn->sock->ops->getname(conn->sock,
(struct sockaddr *)&sock_in, 0);
if (rc >= 0)
memcpy(&conn->local_sockaddr, &sock_in, sizeof(sock_in));
}
return 0;
}
int iscsit_get_login_rx(struct iscsit_conn *conn, struct iscsi_login *login)
{
struct iscsi_login_req *login_req;
u32 padding = 0, payload_length;
if (iscsi_login_rx_data(conn, login->req, ISCSI_HDR_LEN) < 0)
return -1;
login_req = (struct iscsi_login_req *)login->req;
payload_length = ntoh24(login_req->dlength);
padding = ((-payload_length) & 3);
pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
login_req->flags, login_req->itt, login_req->cmdsn,
login_req->exp_statsn, login_req->cid, payload_length);
/*
* Setup the initial iscsi_login values from the leading
* login request PDU.
*/
if (login->first_request) {
login_req = (struct iscsi_login_req *)login->req;
login->leading_connection = (!login_req->tsih) ? 1 : 0;
login->current_stage = ISCSI_LOGIN_CURRENT_STAGE(login_req->flags);
login->version_min = login_req->min_version;
login->version_max = login_req->max_version;
memcpy(login->isid, login_req->isid, 6);
login->cmd_sn = be32_to_cpu(login_req->cmdsn);
login->init_task_tag = login_req->itt;
login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
login->cid = be16_to_cpu(login_req->cid);
login->tsih = be16_to_cpu(login_req->tsih);
}
if (iscsi_target_check_login_request(conn, login) < 0)
return -1;
memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
if (iscsi_login_rx_data(conn, login->req_buf,
payload_length + padding) < 0)
return -1;
return 0;
}
int iscsit_put_login_tx(struct iscsit_conn *conn, struct iscsi_login *login,
u32 length)
{
if (iscsi_login_tx_data(conn, login->rsp, login->rsp_buf, length) < 0)
return -1;
return 0;
}
static int
iscsit_conn_set_transport(struct iscsit_conn *conn, struct iscsit_transport *t)
{
int rc;
if (!t->owner) {
conn->conn_transport = t;
return 0;
}
rc = try_module_get(t->owner);
if (!rc) {
pr_err("try_module_get() failed for %s\n", t->name);
return -EINVAL;
}
conn->conn_transport = t;
return 0;
}
static struct iscsit_conn *iscsit_alloc_conn(struct iscsi_np *np)
{
struct iscsit_conn *conn;
conn = kzalloc(sizeof(struct iscsit_conn), GFP_KERNEL);
if (!conn) {
pr_err("Could not allocate memory for new connection\n");
return NULL;
}
pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
conn->conn_state = TARG_CONN_STATE_FREE;
init_waitqueue_head(&conn->queues_wq);
INIT_LIST_HEAD(&conn->conn_list);
INIT_LIST_HEAD(&conn->conn_cmd_list);
INIT_LIST_HEAD(&conn->immed_queue_list);
INIT_LIST_HEAD(&conn->response_queue_list);
init_completion(&conn->conn_post_wait_comp);
init_completion(&conn->conn_wait_comp);
init_completion(&conn->conn_wait_rcfr_comp);
init_completion(&conn->conn_waiting_on_uc_comp);
init_completion(&conn->conn_logout_comp);
init_completion(&conn->rx_half_close_comp);
init_completion(&conn->tx_half_close_comp);
init_completion(&conn->rx_login_comp);
spin_lock_init(&conn->cmd_lock);
spin_lock_init(&conn->conn_usage_lock);
spin_lock_init(&conn->immed_queue_lock);
spin_lock_init(&conn->nopin_timer_lock);
spin_lock_init(&conn->response_queue_lock);
spin_lock_init(&conn->state_lock);
spin_lock_init(&conn->login_worker_lock);
spin_lock_init(&conn->login_timer_lock);
timer_setup(&conn->nopin_response_timer,
iscsit_handle_nopin_response_timeout, 0);
timer_setup(&conn->nopin_timer, iscsit_handle_nopin_timeout, 0);
timer_setup(&conn->login_timer, iscsit_login_timeout, 0);
if (iscsit_conn_set_transport(conn, np->np_transport) < 0)
goto free_conn;
conn->conn_ops = kzalloc(sizeof(struct iscsi_conn_ops), GFP_KERNEL);
if (!conn->conn_ops) {
pr_err("Unable to allocate memory for struct iscsi_conn_ops.\n");
goto put_transport;
}
if (!zalloc_cpumask_var(&conn->conn_cpumask, GFP_KERNEL)) {
pr_err("Unable to allocate conn->conn_cpumask\n");
goto free_conn_ops;
}
if (!zalloc_cpumask_var(&conn->allowed_cpumask, GFP_KERNEL)) {
pr_err("Unable to allocate conn->allowed_cpumask\n");
goto free_conn_cpumask;
}
conn->cmd_cnt = target_alloc_cmd_counter();
if (!conn->cmd_cnt)
goto free_conn_allowed_cpumask;
return conn;
free_conn_allowed_cpumask:
free_cpumask_var(conn->allowed_cpumask);
free_conn_cpumask:
free_cpumask_var(conn->conn_cpumask);
free_conn_ops:
kfree(conn->conn_ops);
put_transport:
iscsit_put_transport(conn->conn_transport);
free_conn:
kfree(conn);
return NULL;
}
void iscsit_free_conn(struct iscsit_conn *conn)
{
target_free_cmd_counter(conn->cmd_cnt);
free_cpumask_var(conn->allowed_cpumask);
free_cpumask_var(conn->conn_cpumask);
kfree(conn->conn_ops);
iscsit_put_transport(conn->conn_transport);
kfree(conn);
}
void iscsi_target_login_sess_out(struct iscsit_conn *conn,
bool zero_tsih, bool new_sess)
{
if (!new_sess)
goto old_sess_out;
pr_err("iSCSI Login negotiation failed.\n");
iscsit_collect_login_stats(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
if (!zero_tsih || !conn->sess)
goto old_sess_out;
transport_free_session(conn->sess->se_sess);
ida_free(&sess_ida, conn->sess->session_index);
kfree(conn->sess->sess_ops);
kfree(conn->sess);
conn->sess = NULL;
old_sess_out:
/*
* If login negotiation fails check if the Time2Retain timer
* needs to be restarted.
*/
if (!zero_tsih && conn->sess) {
spin_lock_bh(&conn->sess->conn_lock);
if (conn->sess->session_state == TARG_SESS_STATE_FAILED) {
struct se_portal_group *se_tpg =
&conn->tpg->tpg_se_tpg;
atomic_set(&conn->sess->session_continuation, 0);
spin_unlock_bh(&conn->sess->conn_lock);
spin_lock_bh(&se_tpg->session_lock);
iscsit_start_time2retain_handler(conn->sess);
spin_unlock_bh(&se_tpg->session_lock);
} else
spin_unlock_bh(&conn->sess->conn_lock);
iscsit_dec_session_usage_count(conn->sess);
}
ahash_request_free(conn->conn_tx_hash);
if (conn->conn_rx_hash) {
struct crypto_ahash *tfm;
tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
ahash_request_free(conn->conn_rx_hash);
crypto_free_ahash(tfm);
}
if (conn->param_list) {
iscsi_release_param_list(conn->param_list);
conn->param_list = NULL;
}
iscsi_target_nego_release(conn);
if (conn->sock) {
sock_release(conn->sock);
conn->sock = NULL;
}
if (conn->conn_transport->iscsit_wait_conn)
conn->conn_transport->iscsit_wait_conn(conn);
if (conn->conn_transport->iscsit_free_conn)
conn->conn_transport->iscsit_free_conn(conn);
iscsit_free_conn(conn);
}
static int __iscsi_target_login_thread(struct iscsi_np *np)
{
u8 *buffer, zero_tsih = 0;
int ret = 0, rc;
struct iscsit_conn *conn = NULL;
struct iscsi_login *login;
struct iscsi_portal_group *tpg = NULL;
struct iscsi_login_req *pdu;
struct iscsi_tpg_np *tpg_np;
bool new_sess = false;
flush_signals(current);
spin_lock_bh(&np->np_thread_lock);
if (atomic_dec_if_positive(&np->np_reset_count) >= 0) {
np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
spin_unlock_bh(&np->np_thread_lock);
complete(&np->np_restart_comp);
return 1;
} else if (np->np_thread_state == ISCSI_NP_THREAD_SHUTDOWN) {
spin_unlock_bh(&np->np_thread_lock);
goto exit;
} else {
np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
}
spin_unlock_bh(&np->np_thread_lock);
conn = iscsit_alloc_conn(np);
if (!conn) {
/* Get another socket */
return 1;
}
rc = np->np_transport->iscsit_accept_np(np, conn);
if (rc == -ENOSYS) {
complete(&np->np_restart_comp);
iscsit_free_conn(conn);
goto exit;
} else if (rc < 0) {
spin_lock_bh(&np->np_thread_lock);
if (atomic_dec_if_positive(&np->np_reset_count) >= 0) {
np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
spin_unlock_bh(&np->np_thread_lock);
complete(&np->np_restart_comp);
iscsit_free_conn(conn);
/* Get another socket */
return 1;
}
spin_unlock_bh(&np->np_thread_lock);
iscsit_free_conn(conn);
return 1;
}
/*
* Perform the remaining iSCSI connection initialization items..
*/
login = iscsi_login_init_conn(conn);
if (!login) {
goto new_sess_out;
}
iscsit_start_login_timer(conn, current);
pr_debug("Moving to TARG_CONN_STATE_XPT_UP.\n");
conn->conn_state = TARG_CONN_STATE_XPT_UP;
/*
* This will process the first login request + payload..
*/
rc = np->np_transport->iscsit_get_login_rx(conn, login);
if (rc == 1)
return 1;
else if (rc < 0)
goto new_sess_out;
buffer = &login->req[0];
pdu = (struct iscsi_login_req *)buffer;
/*
* Used by iscsit_tx_login_rsp() for Login Resonses PDUs
* when Status-Class != 0.
*/
conn->login_itt = pdu->itt;
spin_lock_bh(&np->np_thread_lock);
if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
spin_unlock_bh(&np->np_thread_lock);
pr_err("iSCSI Network Portal on %pISpc currently not"
" active.\n", &np->np_sockaddr);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
goto new_sess_out;
}
spin_unlock_bh(&np->np_thread_lock);
conn->network_transport = np->np_network_transport;
pr_debug("Received iSCSI login request from %pISpc on %s Network"
" Portal %pISpc\n", &conn->login_sockaddr, np->np_transport->name,
&conn->local_sockaddr);
pr_debug("Moving to TARG_CONN_STATE_IN_LOGIN.\n");
conn->conn_state = TARG_CONN_STATE_IN_LOGIN;
if (iscsi_login_check_initiator_version(conn, pdu->max_version,
pdu->min_version) < 0)
goto new_sess_out;
zero_tsih = (pdu->tsih == 0x0000);
if (zero_tsih) {
/*
* This is the leading connection of a new session.
* We wait until after authentication to check for
* session reinstatement.
*/
if (iscsi_login_zero_tsih_s1(conn, buffer) < 0)
goto new_sess_out;
} else {
/*
* Add a new connection to an existing session.
* We check for a non-existant session in
* iscsi_login_non_zero_tsih_s2() below based
* on ISID/TSIH, but wait until after authentication
* to check for connection reinstatement, etc.
*/
if (iscsi_login_non_zero_tsih_s1(conn, buffer) < 0)
goto new_sess_out;
}
/*
* SessionType: Discovery
*
* Locates Default Portal
*
* SessionType: Normal
*
* Locates Target Portal from NP -> Target IQN
*/
rc = iscsi_target_locate_portal(np, conn, login);
if (rc < 0) {
tpg = conn->tpg;
goto new_sess_out;
}
login->zero_tsih = zero_tsih;
if (conn->sess)
conn->sess->se_sess->sup_prot_ops =
conn->conn_transport->iscsit_get_sup_prot_ops(conn);
tpg = conn->tpg;
if (!tpg) {
pr_err("Unable to locate struct iscsit_conn->tpg\n");
goto new_sess_out;
}
if (zero_tsih) {
if (iscsi_login_zero_tsih_s2(conn) < 0)
goto new_sess_out;
} else {
if (iscsi_login_non_zero_tsih_s2(conn, buffer) < 0)
goto old_sess_out;
}
if (conn->conn_transport->iscsit_validate_params) {
ret = conn->conn_transport->iscsit_validate_params(conn);
if (ret < 0) {
if (zero_tsih)
goto new_sess_out;
else
goto old_sess_out;
}
}
ret = iscsi_target_start_negotiation(login, conn);
if (ret < 0)
goto new_sess_out;
if (ret == 1) {
tpg_np = conn->tpg_np;
iscsi_post_login_handler(np, conn, zero_tsih);
iscsit_deaccess_np(np, tpg, tpg_np);
}
tpg = NULL;
tpg_np = NULL;
/* Get another socket */
return 1;
new_sess_out:
new_sess = true;
old_sess_out:
iscsit_stop_login_timer(conn);
tpg_np = conn->tpg_np;
iscsi_target_login_sess_out(conn, zero_tsih, new_sess);
new_sess = false;
if (tpg) {
iscsit_deaccess_np(np, tpg, tpg_np);
tpg = NULL;
tpg_np = NULL;
}
return 1;
exit:
spin_lock_bh(&np->np_thread_lock);
np->np_thread_state = ISCSI_NP_THREAD_EXIT;
spin_unlock_bh(&np->np_thread_lock);
return 0;
}
int iscsi_target_login_thread(void *arg)
{
struct iscsi_np *np = arg;
int ret;
allow_signal(SIGINT);
while (1) {
ret = __iscsi_target_login_thread(np);
/*
* We break and exit here unless another sock_accept() call
* is expected.
*/
if (ret != 1)
break;
}
while (!kthread_should_stop()) {
msleep(100);
}
return 0;
}