From: Nicholas Bellinger <n...@linux-iscsi.org>
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.
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 <n...@linux-iscsi.org>
---
drivers/target/iscsi/iscsi_target_core.h | 1 +
drivers/target/iscsi/iscsi_target_nego.c | 209 ++++++++++++++++++++++++++++-
drivers/target/iscsi/iscsi_target_tpg.c | 7 +-
drivers/target/iscsi/iscsi_target_tpg.h | 2 +-
4 files changed, 209 insertions(+), 10 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target_core.h
b/drivers/target/iscsi/iscsi_target_core.h
index 711a028..8a4c32d 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -562,6 +562,7 @@ 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..daebe32 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -377,14 +377,191 @@ 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);
+
+ read_lock_bh(&sk->sk_callback_lock);
+ if (!sk->sk_user_data) {
+ read_unlock_bh(&sk->sk_callback_lock);
+ return;
+ }
+
+ if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {
+ read_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");
+ }
+ read_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);
+ clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags);
+ 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 == 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 +820,11 @@ 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 +841,7 @@ 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 +874,13 @@ 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;
+ login->np = np;
+
login_req = (struct iscsi_login_req *) login->req;
payload_length = ntoh24(login_req->dlength);
@@ -822,7 +1004,7 @@ 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 +1014,16 @@ 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 +1032,12 @@ 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;
}
@@ -896,11 +1083,17 @@ int iscsi_target_start_negotiation(
{
int ret;
+ INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);
+ iscsi_target_set_sock_callbacks(conn);
+
ret = iscsi_target_do_login(conn, login);
- if (ret != 0)
+ if (ret < 0) {
+ 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 c1b1067..6beed70 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);
--
1.7.2.5
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