summaryrefslogtreecommitdiff
path: root/drivers/target/iscsi/iscsi_target_nego.c
diff options
context:
space:
mode:
authorNicholas Bellinger <nab@linux-iscsi.org>2013-08-16 00:40:17 +0400
committerNicholas Bellinger <nab@linux-iscsi.org>2013-09-10 01:13:31 +0400
commitd381a8010a052813a88e20e089be4a58aad8b40a (patch)
tree89118ae7b5c1bf6fe1be03d4ca6a952fa562d68e /drivers/target/iscsi/iscsi_target_nego.c
parenta91eb7d9dc8e00de9618633dcb62643fd5eee498 (diff)
downloadlinux-d381a8010a052813a88e20e089be4a58aad8b40a.tar.xz
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 <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/iscsi/iscsi_target_nego.c')
-rw-r--r--drivers/target/iscsi/iscsi_target_nego.c234
1 files changed, 226 insertions, 8 deletions
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index c4675b4ceb49..9defee0f0aeb 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;
}