iscsi_target_sk_data_ready() could be invoked indirectly
by iscsi_target_do_login_rx() from workqueue like following:
iscsi_target_do_login_rx()
iscsi_target_do_login()
iscsi_target_do_tx_login_io()
iscsit_put_login_tx()
iscsi_login_tx_data()
tx_data()
sock_sendmsg_nosec()
tcp_sendmsg()
release_sock()
sk_backlog_rcv()
tcp_v4_do_rcv()
tcp_data_ready()
iscsi_target_sk_data_ready()
At that time LOGIN_FLAGS_READ_ACTIVE is not cleared.
and iscsi_target_sk_data_ready will not read data
from the socket. And some iscsi initiator(i.e. libiscsi)
will wait forever for a reply.
LOGIN_FLAGS_READ_ACTIVE should be cleared early just after
doing the receive and before writing to the socket in
iscsi_target_do_login_rx.
But sad news is that LOGIN_FLAGS_READ_ACTIVE is also used
by sk_state_change to do login cleanup if a socket was closed
at login time. It is supposed to be cleared after the login
pdu is successfully processed and reponsed.
So introduce another flag LOGIN_FLAGS_WRITE_ACTIVE to cover
the transmit part so that sk_state_change could work well
and clear LOGIN_FLAGS_READ_ACTIVE early so that sk_data_ready
could also work.
While at here, use login_flags more efficient.
Signed-off-by: Hou Pu <houpu@xxxxxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target_nego.c | 29 +++++++++++++++++++++++++----
include/target/iscsi/iscsi_target_core.h | 9 +++++----
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index 685d771b51d4..5292b6c51b4e 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -622,6 +622,26 @@ static void iscsi_target_do_login_rx(struct work_struct *work)
if (rc < 0)
goto err;
+ /*
+ * LOGIN_FLAGS_READ_ACTIVE is cleared so that sk_data_ready
+ * could be trigger again after this.
+ *
+ * LOGIN_FLAGS_WRITE_ACTIVE is cleared after we successfully
+ * process a login pdu, so that sk_state_chage could do login
+ * cleanup as needed if the socket is closed. If a delayed work is
+ * ongoing (LOGIN_FLAGS_WRITE_ACTIVE or LOGIN_FLAGS_READ_ACTIVE),
+ * sk_state_change will leave the cleanup to the delayed work or
+ * it will schedule a delayed work to do cleanup.
+ */
+ 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);
+ set_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags);
+ write_unlock_bh(&sk->sk_callback_lock);
+ }
+
pr_debug("iscsi_target_do_login_rx after rx_login_io, %p, %s:%d\n",
conn, current->comm, current->pid);
@@ -629,7 +649,7 @@ static void iscsi_target_do_login_rx(struct work_struct *work)
if (rc < 0) {
goto err;
} else if (!rc) {
- if (iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_READ_ACTIVE))
+ if (iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_WRITE_ACTIVE))
goto err;
} else if (rc == 1) {
iscsi_target_nego_release(conn);
@@ -670,9 +690,10 @@ static void iscsi_target_sk_state_change(struct sock *sk)
state = __iscsi_target_sk_check_close(sk);
pr_debug("__iscsi_target_sk_close_change: state: %d\n", state);
- 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);
+ if (test_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags) ||
+ test_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags)) {
+ pr_debug("Got LOGIN_FLAGS_{READ|WRITE}_ACTIVE=1"
+ "sk_state_change conn: %p\n", conn);
if (state)
set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
write_unlock_bh(&sk->sk_callback_lock);
diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h
index 591cd9e4692c..844bef255e89 100644
--- a/include/target/iscsi/iscsi_target_core.h
+++ b/include/target/iscsi/iscsi_target_core.h
@@ -566,10 +566,11 @@ struct iscsi_conn {
struct socket *sock;
void (*orig_data_ready)(struct sock *);
void (*orig_state_change)(struct sock *);
-#define LOGIN_FLAGS_READ_ACTIVE 1
-#define LOGIN_FLAGS_CLOSED 2
-#define LOGIN_FLAGS_READY 4
-#define LOGIN_FLAGS_INITIAL_PDU 8
+#define LOGIN_FLAGS_READY 0
+#define LOGIN_FLAGS_INITIAL_PDU 1
+#define LOGIN_FLAGS_READ_ACTIVE 2
+#define LOGIN_FLAGS_WRITE_ACTIVE 3
+#define LOGIN_FLAGS_CLOSED 4
unsigned long login_flags;
struct delayed_work login_work;
struct iscsi_login *login;
--
2.11.0
