If the initiator suddenly stops sending data during a login while
keeping the TCP connection open, the sk_data_ready callback won't
schedule the login_work and the latter
will never timeout and release the login semaphore.
All the other login operations will therefore get stuck waiting
for the semaphore to be released.
Add a timer to check if the initiator became unresponsive, this is how it
works:
* The timer is started in iscsi_target_start_negotiation(), before
clearing tre LOGIN_FLAGS_INITIAL_PDU flag.
* If iscsi_target_do_login() returned a non-zero value, this means that
the login operation either failed or didn't require additional PDUs;
in this case the timer is immediately stopped.
* If iscsi_target_do_login() returned zero then the control of
the login operation is passed to login_work that will take over the
responsibility of releasing the login semaphore and stopping the timer.
* If login_work gets stuck, the login timer will expire and
will force the login to fail (by sending a SIGINT to the login kthread
and by closing the socket).
Signed-off-by: Maurizio Lombardi <mlombard@xxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target_login.c | 1 +
drivers/target/iscsi/iscsi_target_nego.c | 56 ++++++++++-------------
drivers/target/iscsi/iscsi_target_util.c | 26 +++++++++++
drivers/target/iscsi/iscsi_target_util.h | 3 ++
include/target/iscsi/iscsi_target_core.h | 1 +
5 files changed, 56 insertions(+), 31 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 27e448c2d066..bb7d5a596266 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -1127,6 +1127,7 @@ static struct iscsit_conn *iscsit_alloc_conn(struct iscsi_np *np)
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;
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index 24040c118e49..f901a7231c48 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -472,12 +472,18 @@ static int iscsi_target_do_login(struct iscsit_conn *, struct iscsi_login *);
static bool __iscsi_target_sk_check_close(struct sock *sk)
{
- if (sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) {
- pr_debug("__iscsi_target_sk_check_close: TCP_CLOSE_WAIT|TCP_CLOSE,"
+ switch (sk->sk_state) {
+ case TCP_FIN_WAIT1:
+ case TCP_FIN_WAIT2:
+ case TCP_CLOSE_WAIT:
+ case TCP_LAST_ACK:
+ case TCP_CLOSE:
+ pr_debug("__iscsi_target_sk_check_close: socket closing,"
"returning TRUE\n");
return true;
+ default:
+ return false;
}
- return false;
}
static bool iscsi_target_sk_check_close(struct iscsit_conn *conn)
@@ -535,25 +541,6 @@ static void iscsi_target_login_drop(struct iscsit_conn *conn, struct iscsi_login
iscsi_target_login_sess_out(conn, zero_tsih, true);
}
-struct conn_timeout {
- struct timer_list timer;
- struct iscsit_conn *conn;
-};
-
-static void iscsi_target_login_timeout(struct timer_list *t)
-{
- struct conn_timeout *timeout = from_timer(timeout, t, timer);
- struct iscsit_conn *conn = timeout->conn;
-
- pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
-
- if (conn->login_kworker) {
- pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
- conn->login_kworker->comm, conn->login_kworker->pid);
- send_sig(SIGINT, conn->login_kworker, 1);
- }
-}
-
static void iscsi_target_do_login_rx(struct work_struct *work)
{
struct iscsit_conn *conn = container_of(work,
@@ -562,7 +549,6 @@ static void iscsi_target_do_login_rx(struct work_struct *work)
struct iscsi_np *np = login->np;
struct iscsi_portal_group *tpg = conn->tpg;
struct iscsi_tpg_np *tpg_np = conn->tpg_np;
- struct conn_timeout timeout;
int rc, zero_tsih = login->zero_tsih;
bool state;
@@ -597,17 +583,13 @@ static void iscsi_target_do_login_rx(struct work_struct *work)
goto err;
}
- conn->login_kworker = current;
allow_signal(SIGINT);
-
- timeout.conn = conn;
- timer_setup_on_stack(&timeout.timer, iscsi_target_login_timeout, 0);
- mod_timer(&timeout.timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
- pr_debug("Starting login timer for %s/%d\n", current->comm, current->pid);
+ iscsit_start_login_timer(conn);
+ conn->login_kworker = current;
rc = conn->conn_transport->iscsit_get_login_rx(conn, login);
- del_timer_sync(&timeout.timer);
- destroy_timer_on_stack(&timeout.timer);
+
+ iscsit_stop_login_timer(conn);
flush_signals(current);
conn->login_kworker = NULL;
@@ -646,6 +628,13 @@ static void iscsi_target_do_login_rx(struct work_struct *work)
if (iscsi_target_sk_check_and_clear(conn,
LOGIN_FLAGS_WRITE_ACTIVE))
goto err;
+
+ /*
+ * Restart the login timer to prevent the
+ * login process from getting stuck if the initiator
+ * stops sending data.
+ */
+ iscsit_start_login_timer(conn);
} else if (rc == 1) {
cancel_delayed_work(&conn->login_work);
iscsi_target_nego_release(conn);
@@ -657,6 +646,7 @@ static void iscsi_target_do_login_rx(struct work_struct *work)
err:
iscsi_target_restore_sock_callbacks(conn);
cancel_delayed_work(&conn->login_work);
+ iscsit_stop_login_timer(conn);
iscsi_target_login_drop(conn, login);
iscsit_deaccess_np(np, tpg, tpg_np);
}
@@ -1358,6 +1348,9 @@ int iscsi_target_start_negotiation(
set_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
write_unlock_bh(&sk->sk_callback_lock);
}
+
+ iscsit_start_login_timer(conn);
+
/*
* If iscsi_target_do_login returns zero to signal more PDU
* exchanges are required to complete the login, go ahead and
@@ -1377,6 +1370,7 @@ int iscsi_target_start_negotiation(
}
if (ret != 0) {
cancel_delayed_work_sync(&conn->login_work);
+ iscsit_stop_login_timer(conn);
iscsi_target_nego_release(conn);
}
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 26dc8ed3045b..414e883c5a0d 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -1040,6 +1040,32 @@ void iscsit_stop_nopin_timer(struct iscsit_conn *conn)
spin_unlock_bh(&conn->nopin_timer_lock);
}
+void iscsit_login_timeout(struct timer_list *t)
+{
+ struct iscsit_conn *conn = from_timer(conn, t, login_timer);
+
+ pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
+
+ if (conn->login_kworker) {
+ pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
+ conn->login_kworker->comm, conn->login_kworker->pid);
+ send_sig(SIGINT, conn->login_kworker, 1);
+ }
+ kernel_sock_shutdown(conn->sock, SHUT_RDWR);
+}
+
+void iscsit_start_login_timer(struct iscsit_conn *conn)
+{
+ pr_debug("Login timer started\n");
+ mod_timer(&conn->login_timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
+}
+
+void iscsit_stop_login_timer(struct iscsit_conn *conn)
+{
+ pr_debug("Login timer stopped\n");
+ timer_delete_sync(&conn->login_timer);
+}
+
int iscsit_send_tx_data(
struct iscsit_cmd *cmd,
struct iscsit_conn *conn,
diff --git a/drivers/target/iscsi/iscsi_target_util.h b/drivers/target/iscsi/iscsi_target_util.h
index 33ea799a0850..b3ffb7b204a8 100644
--- a/drivers/target/iscsi/iscsi_target_util.h
+++ b/drivers/target/iscsi/iscsi_target_util.h
@@ -56,6 +56,9 @@ extern void iscsit_handle_nopin_timeout(struct timer_list *t);
extern void __iscsit_start_nopin_timer(struct iscsit_conn *);
extern void iscsit_start_nopin_timer(struct iscsit_conn *);
extern void iscsit_stop_nopin_timer(struct iscsit_conn *);
+extern void iscsit_login_timeout(struct timer_list *t);
+extern void iscsit_start_login_timer(struct iscsit_conn *);
+extern void iscsit_stop_login_timer(struct iscsit_conn *);
extern int iscsit_send_tx_data(struct iscsit_cmd *, struct iscsit_conn *, int);
extern int iscsit_fe_sendpage_sg(struct iscsit_cmd *, struct iscsit_conn *);
extern int iscsit_tx_login_rsp(struct iscsit_conn *, u8, u8);
diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h
index 94d06ddfd80a..c52022a4e93a 100644
--- a/include/target/iscsi/iscsi_target_core.h
+++ b/include/target/iscsi/iscsi_target_core.h
@@ -568,6 +568,7 @@ struct iscsit_conn {
struct timer_list nopin_timer;
struct timer_list nopin_response_timer;
struct timer_list transport_timer;
+ struct timer_list login_timer;
struct task_struct *login_kworker;
/* Spinlock used for add/deleting cmd's from conn_cmd_list */
spinlock_t cmd_lock;
--
2.31.1
