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iscsi-target: Add login negotiation multi-plexing support

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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>
This commit is contained in:
Nicholas Bellinger 2013-08-15 13:40:17 -07:00
parent a91eb7d9dc
commit d381a8010a
4 changed files with 235 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/target/iscsi/iscsi_target_core.h
View File

@ -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;

236
drivers/target/iscsi/iscsi_target_nego.c
View File

@ -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)
iscsi_remove_failed_auth_entry(conn);
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;
}

7
drivers/target/iscsi/iscsi_target_tpg.c
View File

@ -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;

2
drivers/target/iscsi/iscsi_target_tpg.h
View File

@ -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);