net/smc: receive pending data after RCV_SHUTDOWN (107529e3) · Commits · 戴 / test

smc_rx_recvmsg() first checks if data is available, and then if RCV_SHUTDOWN is set. There is a race when smc_cdc_msg_recv_action() runs in between these 2 checks, receives data and sets RCV_SHUTDOWN. In that case smc_rx_recvmsg() would return from receive without to process the available data. Fix that with a final check for data available if RCV_SHUTDOWN is set. Move the check for data into a function and call it twice. And use the existing helper smc_rx_data_available(). Fixes: ("smc: receive data from RMBE") Reviewed-by:

Ursula Braun <ubraun@linux.ibm.com> Signed-off-by:

Karsten Graul <kgraul@linux.ibm.com> Signed-off-by:

Jakub Kicinski <jakub.kicinski@netronome.com>

net/smc/smc_rx.c

+20 −5

Original line number	Diff line number	Diff line
		@@ -261,6 +261,18 @@ static int smc_rx_recv_urg(struct smc_sock smc, struct msghdr msg, int len,
		return -EAGAIN;
		}

		static bool smc_rx_recvmsg_data_available(struct smc_sock *smc)
		{
		struct smc_connection *conn = &smc->conn;

		if (smc_rx_data_available(conn))
		return true;
		else if (conn->urg_state == SMC_URG_VALID)
		/* we received a single urgent Byte - skip */
		smc_rx_update_cons(smc, 0);
		return false;
		}

		/* smc_rx_recvmsg - receive data from RMBE
		* @msg: copy data to receive buffer
		* @pipe: copy data to pipe if set - indicates splice() call
		@@ -302,15 +314,18 @@ int smc_rx_recvmsg(struct smc_sock smc, struct msghdr msg,
		if (read_done >= target \|\| (pipe && read_done))
		break;

		if (atomic_read(&conn->bytes_to_rcv))
		if (smc_rx_recvmsg_data_available(smc))
		goto copy;
		else if (conn->urg_state == SMC_URG_VALID)
		/* we received a single urgent Byte - skip */
		smc_rx_update_cons(smc, 0);

		if (sk->sk_shutdown & RCV_SHUTDOWN \|\|
		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort)
		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort) {
		/* smc_cdc_msg_recv_action() could have run after
		* above smc_rx_recvmsg_data_available()
		*/
		if (smc_rx_recvmsg_data_available(smc))
		goto copy;
		break;
		}

		if (read_done) {
		if (sk->sk_err \|\|

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