From bb048357dad6d604520c91586334c9c230366a14 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Thu, 5 Sep 2013 14:54:04 -0700 Subject: [PATCH] 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 --- drivers/target/iscsi/iscsi_target_core.h | 2 + drivers/target/iscsi/iscsi_target_nego.c | 101 +++++++++++++++++++++++++++++++ 2 files changed, 103 insertions(+) diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h index 43228dc..089a0e9 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; diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c index 9defee0f..9d0c910 100644 --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -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); } -- 2.7.4