[SCSI] libiscsi: fix nop response/reply and session cleanup race (26013ad4) · Commits · 戴 / test

If we are responding to a nop from the target by sending our nop, and the session is getting torn down, then iscsi_start_session_recovery could set the conn stop bits while the recv path is sending the nop response and we will hit the bug ons in __iscsi_conn_send_pdu. This has us check the state in __iscsi_conn_send_pdu and fail all incoming mgmt IO if we are not logged in and if the pdu is not login related. It also changes the ordering of the setting of conn stop state bits so they are set after the session state is set (both are set under the session lock). Signed-off-by:

Mike Christie <michaelc@cs.wisc.edu> Signed-off-by:

James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/libiscsi.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -546,6 +546,9 @@ __iscsi_conn_send_pdu(struct iscsi_conn conn, struct iscsi_hdr hdr,
		*/
		task = conn->login_task;
		else {
		if (session->state != ISCSI_STATE_LOGGED_IN)
		return NULL;

		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);

		@@ -2566,8 +2569,6 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
		{
		int old_stop_stage;

		del_timer_sync(&conn->transport_timer);

		mutex_lock(&session->eh_mutex);
		spin_lock_bh(&session->lock);
		if (conn->stop_stage == STOP_CONN_TERM) {
		@@ -2585,13 +2586,17 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
		session->state = ISCSI_STATE_TERMINATE;
		else if (conn->stop_stage != STOP_CONN_RECOVER)
		session->state = ISCSI_STATE_IN_RECOVERY;
		spin_unlock_bh(&session->lock);

		del_timer_sync(&conn->transport_timer);
		iscsi_suspend_tx(conn);

		spin_lock_bh(&session->lock);
		old_stop_stage = conn->stop_stage;
		conn->stop_stage = flag;
		conn->c_stage = ISCSI_CONN_STOPPED;
		spin_unlock_bh(&session->lock);

		iscsi_suspend_tx(conn);
		/*
		* for connection level recovery we should not calculate
		* header digest. conn->hdr_size used for optimization

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