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Commit bb048357 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

iscsi-target: Add sk->sk_state_change to cleanup after TCP failure 



This patch adds a sock->sk_state_change() -> iscsi_target_sk_state_change()
callback in order to handle transient TCP failures during the login process,
where sock->sk_data_ready() -> iscsi_target_sk_data_ready() may not be
called to release connection resources, and relinquish tpg->np_login_lock
via iscsit_deaccess_np()

It performs the sk->sk_state check using iscsi_target_sk_state_check() to
look for TCP_CLOSE_WAIT + TCP_CLOSE, and invokes schedule_delayed_work() ->
iscsi_target_do_cleanup() to perform the remaining cleanup from process
context.

It adds an explicit sk_state_check to iscsi_target_do_login() in order
to determine a state failure when iscsi_target_sk_state_change() may
not be able to proceed before LOGIN_FLAGS_READY=1 is set.

Also use sk->sk_sndtimeo -> sk->sk_rcvtimeo settings during login to
iscsi_target_set_sock_callbacks(), and revert back post login to use
MAX_SCHEDULE_TIMEOUT in iscsi_target_restore_sock_callbacks().

Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent d381a801

drivers/target/iscsi/iscsi_target_core.h

+2 −0
Original line number Diff line number Diff line
@@ -555,11 +555,13 @@ struct iscsi_conn { 
	/* socket used by this connection */

	struct socket		*sock;

	void			(*orig_data_ready)(struct sock *, int);

	void			(*orig_state_change)(struct sock *);

#define LOGIN_FLAGS_READ_ACTIVE		1

#define LOGIN_FLAGS_CLOSED		2

#define LOGIN_FLAGS_READY		4

	unsigned long		login_flags;

	struct delayed_work	login_work;

	struct delayed_work	login_cleanup_work;

	struct iscsi_login	*login;

	struct timer_list	nopin_timer;

	struct timer_list	nopin_response_timer;

drivers/target/iscsi/iscsi_target_nego.c

+101 −0
Original line number Diff line number Diff line
@@ -413,6 +413,8 @@ static void iscsi_target_sk_data_ready(struct sock *sk, int count) 
	write_unlock_bh(&sk->sk_callback_lock);

}



static void iscsi_target_sk_state_change(struct sock *);



static void iscsi_target_set_sock_callbacks(struct iscsi_conn *conn)

{

	struct sock *sk;
@@ -426,8 +428,13 @@ static void iscsi_target_set_sock_callbacks(struct iscsi_conn *conn) 
	write_lock_bh(&sk->sk_callback_lock);

	sk->sk_user_data = conn;

	conn->orig_data_ready = sk->sk_data_ready;

	conn->orig_state_change = sk->sk_state_change;

	sk->sk_data_ready = iscsi_target_sk_data_ready;

	sk->sk_state_change = iscsi_target_sk_state_change;

	write_unlock_bh(&sk->sk_callback_lock);



	sk->sk_sndtimeo = TA_LOGIN_TIMEOUT * HZ;

	sk->sk_rcvtimeo = TA_LOGIN_TIMEOUT * HZ;

}



static void iscsi_target_restore_sock_callbacks(struct iscsi_conn *conn)
@@ -447,7 +454,11 @@ static void iscsi_target_restore_sock_callbacks(struct iscsi_conn *conn) 
	}

	sk->sk_user_data = NULL;

	sk->sk_data_ready = conn->orig_data_ready;

	sk->sk_state_change = conn->orig_state_change;

	write_unlock_bh(&sk->sk_callback_lock);



	sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;

	sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

}



static int iscsi_target_do_login(struct iscsi_conn *, struct iscsi_login *);
@@ -573,6 +584,79 @@ static void iscsi_target_do_login_rx(struct work_struct *work) 
	}

}



static void iscsi_target_do_cleanup(struct work_struct *work)

{

	struct iscsi_conn *conn = container_of(work,

				struct iscsi_conn, login_cleanup_work.work);

	struct sock *sk = conn->sock->sk;

	struct iscsi_login *login = conn->login;

	struct iscsi_np *np = login->np;

	struct iscsi_portal_group *tpg = conn->tpg;

	struct iscsi_tpg_np *tpg_np = conn->tpg_np;



	pr_debug("Entering iscsi_target_do_cleanup\n");



	cancel_delayed_work_sync(&conn->login_work);

	conn->orig_state_change(sk);



	iscsi_target_restore_sock_callbacks(conn);

	iscsi_target_login_drop(conn, login);

	iscsit_deaccess_np(np, tpg, tpg_np);



	pr_debug("iscsi_target_do_cleanup done()\n");

}



static void iscsi_target_sk_state_change(struct sock *sk)

{

	struct iscsi_conn *conn;

	void (*orig_state_change)(struct sock *);

	bool state;



	pr_debug("Entering iscsi_target_sk_state_change\n");



	write_lock_bh(&sk->sk_callback_lock);

	conn = sk->sk_user_data;

	if (!conn) {

		write_unlock_bh(&sk->sk_callback_lock);

		return;

	}

	orig_state_change = conn->orig_state_change;



	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {

		pr_debug("Got LOGIN_FLAGS_READY=0 sk_state_change conn: %p\n",

			 conn);

		write_unlock_bh(&sk->sk_callback_lock);

		orig_state_change(sk);

		return;

	}

	if (test_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {

		pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1 sk_state_change"

			 " conn: %p\n", conn);

		write_unlock_bh(&sk->sk_callback_lock);

		orig_state_change(sk);

		return;

	}

	if (test_and_set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {

		pr_debug("Got LOGIN_FLAGS_CLOSED=1 sk_state_change conn: %p\n",

			 conn);

		write_unlock_bh(&sk->sk_callback_lock);

		orig_state_change(sk);

		return;

	}



	state = iscsi_target_sk_state_check(sk);

	write_unlock_bh(&sk->sk_callback_lock);



	pr_debug("iscsi_target_sk_state_change: state: %d\n", state);



	if (!state) {

		pr_debug("iscsi_target_sk_state_change got failed state\n");

		schedule_delayed_work(&conn->login_cleanup_work, 0);

		return;

	}

	orig_state_change(sk);

}



static int iscsi_target_do_login_io(struct iscsi_conn *conn, struct iscsi_login *login)

{

	if (iscsi_target_do_tx_login_io(conn, login) < 0)
@@ -860,6 +944,21 @@ static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *lo 
		break;

	}



	if (conn->sock) {

		struct sock *sk = conn->sock->sk;

		bool state;



		read_lock_bh(&sk->sk_callback_lock);

		state = iscsi_target_sk_state_check(sk);

		read_unlock_bh(&sk->sk_callback_lock);



		if (!state) {

			pr_debug("iscsi_target_do_login() failed state for"

				 " conn: %p\n", conn);

			return -1;

		}

	}



	return 0;

}
@@ -896,6 +995,7 @@ int iscsi_target_locate_portal( 
	int sessiontype = 0, ret = 0;



	INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);

	INIT_DELAYED_WORK(&conn->login_cleanup_work, iscsi_target_do_cleanup);

	iscsi_target_set_sock_callbacks(conn);



	login->np = np;
@@ -1113,6 +1213,7 @@ int iscsi_target_start_negotiation( 
		}

	} else if (ret < 0) {

		cancel_delayed_work_sync(&conn->login_work);

		cancel_delayed_work_sync(&conn->login_cleanup_work);

		iscsi_target_restore_sock_callbacks(conn);

		iscsi_remove_failed_auth_entry(conn);

	}