From d381a8010a052813a88e20e089be4a58aad8b40a Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Thu, 15 Aug 2013 13:40:17 -0700 Subject: [PATCH] iscsi-target: Add login negotiation multi-plexing support This patch adds support for login negotiation multi-plexing in iscsi-target code. This involves handling the first login request PDU + payload and login response PDU + payload within __iscsi_target_login_thread() process context, and then changing struct sock->sk_data_ready() so that all subsequent exchanges are handled by workqueue process context, to allow other incoming login requests to be received in parallel by __iscsi_target_login_thread(). Upon login negotiation completion (or failure), ->sk_data_ready() is replaced with the original kernel sockets handler saved in iscsi_conn->orig_data_ready. v3 changes: - Convert iscsi_target_sk_data_ready() lock access to write[lock,unlock]_bh() - Only clear LOGIN_FLAGS_READ_ACTIVE when iscsi_target_do_login() returns zero - Add LOGIN_FLAGS_READY + LOGIN_FLAGS_CLOSED bit checks to iscsi_target_sk_data_ready() - Make INIT_DELAYED_WORK() + iscsi_target_set_sock_callbacks() setup happen earlier by moving from iscsi_target_start_negotiation() into iscsi_target_locate_portal() - Set LOGIN_FLAGS_READY bit in iscsi_target_start_negotiation() after iscsi_target_do_login() returns zero. v2 changes: - Add login_timer in iscsi_target_do_login_rx() to avoid possible endless sleep with MSG_WAITALL for traditional iscsi-target in certain network configurations. - Convert lprintk() -> pr_debug() - Remove forward declarations of iscsi_target_set_sock_callbacks(), iscsi_target_restore_sock_callbacks() and iscsi_target_sk_data_ready() - Make iscsi_target_set_sock_callbacks + iscsi_target_restore_sock_callbacks() static (Fengguang) - Make iscsi_target_do_login_rx() safe for iser-target w/o conn->sock Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target_core.h | 1 + drivers/target/iscsi/iscsi_target_nego.c | 234 +++++++++++++++++++++++++++++-- drivers/target/iscsi/iscsi_target_tpg.c | 7 +- drivers/target/iscsi/iscsi_target_tpg.h | 2 +- 4 files changed, 234 insertions(+), 10 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h index 4622846..43228dc 100644 --- a/drivers/target/iscsi/iscsi_target_core.h +++ b/drivers/target/iscsi/iscsi_target_core.h @@ -564,6 +564,7 @@ struct iscsi_conn { struct timer_list nopin_timer; struct timer_list nopin_response_timer; struct timer_list transport_timer; + struct task_struct *login_kworker; /* Spinlock used for add/deleting cmd's from conn_cmd_list */ spinlock_t cmd_lock; spinlock_t conn_usage_lock; diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c index c4675b4..9defee0f 100644 --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -377,14 +377,207 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log return 0; } +static void iscsi_target_sk_data_ready(struct sock *sk, int count) +{ + struct iscsi_conn *conn = sk->sk_user_data; + bool rc; + + pr_debug("Entering iscsi_target_sk_data_ready: conn: %p\n", conn); + + write_lock_bh(&sk->sk_callback_lock); + if (!sk->sk_user_data) { + write_unlock_bh(&sk->sk_callback_lock); + return; + } + if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) { + write_unlock_bh(&sk->sk_callback_lock); + pr_debug("Got LOGIN_FLAGS_READY=0, conn: %p >>>>\n", conn); + return; + } + if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) { + write_unlock_bh(&sk->sk_callback_lock); + pr_debug("Got LOGIN_FLAGS_CLOSED=1, conn: %p >>>>\n", conn); + return; + } + if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) { + write_unlock_bh(&sk->sk_callback_lock); + pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1, conn: %p >>>>\n", conn); + return; + } + + rc = schedule_delayed_work(&conn->login_work, 0); + if (rc == false) { + pr_debug("iscsi_target_sk_data_ready, schedule_delayed_work" + " got false\n"); + } + write_unlock_bh(&sk->sk_callback_lock); +} + +static void iscsi_target_set_sock_callbacks(struct iscsi_conn *conn) +{ + struct sock *sk; + + if (!conn->sock) + return; + + sk = conn->sock->sk; + pr_debug("Entering iscsi_target_set_sock_callbacks: conn: %p\n", conn); + + write_lock_bh(&sk->sk_callback_lock); + sk->sk_user_data = conn; + conn->orig_data_ready = sk->sk_data_ready; + sk->sk_data_ready = iscsi_target_sk_data_ready; + write_unlock_bh(&sk->sk_callback_lock); +} + +static void iscsi_target_restore_sock_callbacks(struct iscsi_conn *conn) +{ + struct sock *sk; + + if (!conn->sock) + return; + + sk = conn->sock->sk; + pr_debug("Entering iscsi_target_restore_sock_callbacks: conn: %p\n", conn); + + write_lock_bh(&sk->sk_callback_lock); + if (!sk->sk_user_data) { + write_unlock_bh(&sk->sk_callback_lock); + return; + } + sk->sk_user_data = NULL; + sk->sk_data_ready = conn->orig_data_ready; + write_unlock_bh(&sk->sk_callback_lock); +} + +static int iscsi_target_do_login(struct iscsi_conn *, struct iscsi_login *); + +static bool iscsi_target_sk_state_check(struct sock *sk) +{ + if (sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) { + pr_debug("iscsi_target_sk_state_check: TCP_CLOSE_WAIT|TCP_CLOSE," + "returning FALSE\n"); + return false; + } + return true; +} + +static void iscsi_target_login_drop(struct iscsi_conn *conn, struct iscsi_login *login) +{ + struct iscsi_np *np = login->np; + bool zero_tsih = login->zero_tsih; + + iscsi_remove_failed_auth_entry(conn); + iscsi_target_nego_release(conn); + iscsi_target_login_sess_out(conn, np, zero_tsih, true); +} + +static void iscsi_target_login_timeout(unsigned long data) +{ + struct iscsi_conn *conn = (struct iscsi_conn *)data; + + 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 iscsi_conn *conn = container_of(work, + struct iscsi_conn, login_work.work); + 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; + struct timer_list login_timer; + int rc, zero_tsih = login->zero_tsih; + bool state; + + pr_debug("entering iscsi_target_do_login_rx, conn: %p, %s:%d\n", + conn, current->comm, current->pid); + + spin_lock(&tpg->tpg_state_lock); + state = (tpg->tpg_state == TPG_STATE_ACTIVE); + spin_unlock(&tpg->tpg_state_lock); + + if (state == false) { + pr_debug("iscsi_target_do_login_rx: tpg_state != TPG_STATE_ACTIVE\n"); + iscsi_target_restore_sock_callbacks(conn); + iscsi_target_login_drop(conn, login); + iscsit_deaccess_np(np, tpg, tpg_np); + return; + } + + if (conn->sock) { + struct sock *sk = conn->sock->sk; + + read_lock_bh(&sk->sk_callback_lock); + state = iscsi_target_sk_state_check(sk); + read_unlock_bh(&sk->sk_callback_lock); + + if (state == false) { + pr_debug("iscsi_target_do_login_rx, TCP state CLOSE\n"); + iscsi_target_restore_sock_callbacks(conn); + iscsi_target_login_drop(conn, login); + iscsit_deaccess_np(np, tpg, tpg_np); + return; + } + } + + conn->login_kworker = current; + allow_signal(SIGINT); + + init_timer(&login_timer); + login_timer.expires = (get_jiffies_64() + TA_LOGIN_TIMEOUT * HZ); + login_timer.data = (unsigned long)conn; + login_timer.function = iscsi_target_login_timeout; + add_timer(&login_timer); + pr_debug("Starting login_timer for %s/%d\n", current->comm, current->pid); + + rc = conn->conn_transport->iscsit_get_login_rx(conn, login); + del_timer_sync(&login_timer); + flush_signals(current); + conn->login_kworker = NULL; + + if (rc < 0) { + iscsi_target_restore_sock_callbacks(conn); + iscsi_target_login_drop(conn, login); + iscsit_deaccess_np(np, tpg, tpg_np); + return; + } + + pr_debug("iscsi_target_do_login_rx after rx_login_io, %p, %s:%d\n", + conn, current->comm, current->pid); + + rc = iscsi_target_do_login(conn, login); + if (rc < 0) { + iscsi_target_restore_sock_callbacks(conn); + iscsi_target_login_drop(conn, login); + iscsit_deaccess_np(np, tpg, tpg_np); + } else if (!rc) { + if (conn->sock) { + struct sock *sk = conn->sock->sk; + + write_lock_bh(&sk->sk_callback_lock); + clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags); + write_unlock_bh(&sk->sk_callback_lock); + } + } else if (rc == 1) { + iscsi_target_nego_release(conn); + iscsi_post_login_handler(np, conn, zero_tsih); + iscsit_deaccess_np(np, tpg, tpg_np); + } +} + 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) return -1; - if (conn->conn_transport->iscsit_get_login_rx(conn, login) < 0) - return -1; - return 0; } @@ -643,10 +836,11 @@ static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *lo if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) { login->tsih = conn->sess->tsih; login->login_complete = 1; + iscsi_target_restore_sock_callbacks(conn); if (iscsi_target_do_tx_login_io(conn, login) < 0) return -1; - return 0; + return 1; } break; default: @@ -663,6 +857,7 @@ static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *lo login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT; login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK; } + break; } return 0; @@ -695,10 +890,16 @@ int iscsi_target_locate_portal( char *tmpbuf, *start = NULL, *end = NULL, *key, *value; struct iscsi_session *sess = conn->sess; struct iscsi_tiqn *tiqn; + struct iscsi_tpg_np *tpg_np = NULL; struct iscsi_login_req *login_req; u32 payload_length; int sessiontype = 0, ret = 0; + INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx); + iscsi_target_set_sock_callbacks(conn); + + login->np = np; + login_req = (struct iscsi_login_req *) login->req; payload_length = ntoh24(login_req->dlength); @@ -822,7 +1023,7 @@ get_target: /* * Locate Target Portal Group from Storage Node. */ - conn->tpg = iscsit_get_tpg_from_np(tiqn, np); + conn->tpg = iscsit_get_tpg_from_np(tiqn, np, &tpg_np); if (!conn->tpg) { pr_err("Unable to locate Target Portal Group" " on %s\n", tiqn->tiqn); @@ -832,12 +1033,16 @@ get_target: ret = -1; goto out; } + conn->tpg_np = tpg_np; pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt); /* * Setup crc32c modules from libcrypto */ if (iscsi_login_setup_crypto(conn) < 0) { pr_err("iscsi_login_setup_crypto() failed\n"); + kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put); + iscsit_put_tiqn_for_login(tiqn); + conn->tpg = NULL; ret = -1; goto out; } @@ -846,11 +1051,12 @@ get_target: * process login attempt. */ if (iscsit_access_np(np, conn->tpg) < 0) { + kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put); iscsit_put_tiqn_for_login(tiqn); iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR, ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE); - ret = -1; conn->tpg = NULL; + ret = -1; goto out; } @@ -897,10 +1103,22 @@ int iscsi_target_start_negotiation( int ret; ret = iscsi_target_do_login(conn, login); - if (ret != 0) + if (!ret) { + if (conn->sock) { + struct sock *sk = conn->sock->sk; + + write_lock_bh(&sk->sk_callback_lock); + set_bit(LOGIN_FLAGS_READY, &conn->login_flags); + write_unlock_bh(&sk->sk_callback_lock); + } + } else if (ret < 0) { + cancel_delayed_work_sync(&conn->login_work); + iscsi_target_restore_sock_callbacks(conn); iscsi_remove_failed_auth_entry(conn); + } + if (ret != 0) + iscsi_target_nego_release(conn); - iscsi_target_nego_release(conn); return ret; } diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c index 4bf8913..e070ce2 100644 --- a/drivers/target/iscsi/iscsi_target_tpg.c +++ b/drivers/target/iscsi/iscsi_target_tpg.c @@ -129,7 +129,8 @@ void iscsit_release_discovery_tpg(void) struct iscsi_portal_group *iscsit_get_tpg_from_np( struct iscsi_tiqn *tiqn, - struct iscsi_np *np) + struct iscsi_np *np, + struct iscsi_tpg_np **tpg_np_out) { struct iscsi_portal_group *tpg = NULL; struct iscsi_tpg_np *tpg_np; @@ -147,6 +148,8 @@ struct iscsi_portal_group *iscsit_get_tpg_from_np( spin_lock(&tpg->tpg_np_lock); list_for_each_entry(tpg_np, &tpg->tpg_gnp_list, tpg_np_list) { if (tpg_np->tpg_np == np) { + *tpg_np_out = tpg_np; + kref_get(&tpg_np->tpg_np_kref); spin_unlock(&tpg->tpg_np_lock); spin_unlock(&tiqn->tiqn_tpg_lock); return tpg; @@ -494,6 +497,8 @@ struct iscsi_tpg_np *iscsit_tpg_add_network_portal( INIT_LIST_HEAD(&tpg_np->tpg_np_child_list); INIT_LIST_HEAD(&tpg_np->tpg_np_parent_list); spin_lock_init(&tpg_np->tpg_np_parent_lock); + init_completion(&tpg_np->tpg_np_comp); + kref_init(&tpg_np->tpg_np_kref); tpg_np->tpg_np = np; tpg_np->tpg = tpg; diff --git a/drivers/target/iscsi/iscsi_target_tpg.h b/drivers/target/iscsi/iscsi_target_tpg.h index 60ef4a9..b77693e 100644 --- a/drivers/target/iscsi/iscsi_target_tpg.h +++ b/drivers/target/iscsi/iscsi_target_tpg.h @@ -5,7 +5,7 @@ extern struct iscsi_portal_group *iscsit_alloc_portal_group(struct iscsi_tiqn *, extern int iscsit_load_discovery_tpg(void); extern void iscsit_release_discovery_tpg(void); extern struct iscsi_portal_group *iscsit_get_tpg_from_np(struct iscsi_tiqn *, - struct iscsi_np *); + struct iscsi_np *, struct iscsi_tpg_np **); extern int iscsit_get_tpg(struct iscsi_portal_group *); extern void iscsit_put_tpg(struct iscsi_portal_group *); extern void iscsit_clear_tpg_np_login_threads(struct iscsi_portal_group *, bool); -- 2.7.4