[4/4] iscsi target: check for state change before sending login pdu

Commit Message

Mike Christie Feb. 27, 2017, 3:04 a.m. UTC

Try to shorten the race window where the initiator could drop the connection
while we are performing login operations.

Signed-off-by: Mike Christie <[e-mail]>
---
 drivers/target/iscsi/iscsi_target_login.c | 13 +++++++++++++
 drivers/target/iscsi/iscsi_target_nego.c  |  2 +-
 include/target/iscsi/iscsi_transport.h    |  1 +
 3 files changed, 15 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index d7d406e..dacb773 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -1119,6 +1119,19 @@  int iscsit_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
 int iscsit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
 			u32 length)
 {
+	struct sock *sk = conn->sock->sk;
+	bool state;
+
+	read_lock_bh(&sk->sk_callback_lock);
+	state = iscsi_target_sk_state_check(sk);
+	read_unlock_bh(&sk->sk_callback_lock);
+
+	if (!state) {
+		pr_debug("iscsit_put_login_tx() failed state for conn: %p\n",
+			  conn);
+		return -1;
+	}
+
 	if (iscsi_login_tx_data(conn, login->rsp, login->rsp_buf, length) < 0)
 		return -1;
 
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index 9edac16..b81017f 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -492,7 +492,7 @@  static void iscsi_target_restore_sock_callbacks(struct iscsi_conn *conn)
 
 static int iscsi_target_do_login(struct iscsi_conn *, struct iscsi_login *);
 
-static bool iscsi_target_sk_state_check(struct sock *sk)
+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,"
diff --git a/include/target/iscsi/iscsi_transport.h b/include/target/iscsi/iscsi_transport.h
index b9a76ed..25d8b87 100644
--- a/include/target/iscsi/iscsi_transport.h
+++ b/include/target/iscsi/iscsi_transport.h
@@ -138,6 +138,7 @@  extern void iscsit_add_cmd_to_immediate_queue(struct iscsi_cmd *,
  */
 extern int iscsi_target_check_login_request(struct iscsi_conn *,
 					    struct iscsi_login *);
+extern bool iscsi_target_sk_state_check(struct sock *);
 
 /*
  * From iscsi_target_login.c