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: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index 43228dc786c9..089a0e915da8 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -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;