[SCSI] iscsi_tcp: Evaluate socket state in data_ready()
Hannes Reinecke [Thu, 20 Aug 2009 20:10:57 +0000 (15:10 -0500)]
The network core will call the state_change() callback
prior to the data_ready() callback, which might cause
us to lose a connection state change.
So we have to evaluate the socket state at the end
of the data_ready() callback, too.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/iscsi_tcp.c

index 518dbd9..c7e2ff2 100644 (file)
@@ -99,6 +99,24 @@ static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
        return total_consumed;
 }
 
+/**
+ * iscsi_sw_sk_state_check - check socket state
+ * @sk: socket
+ *
+ * If the socket is in CLOSE or CLOSE_WAIT we should
+ * not close the connection if there is still some
+ * data pending.
+ */
+static inline int iscsi_sw_sk_state_check(struct sock *sk)
+{
+       if ((sk->sk_state == TCP_CLOSE_WAIT ||
+            sk->sk_state == TCP_CLOSE) &&
+           !atomic_read(&sk->sk_rmem_alloc))
+               return -ECONNRESET;
+
+       return 0;
+}
+
 static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
 {
        struct iscsi_conn *conn = sk->sk_user_data;
@@ -117,6 +135,12 @@ static void iscsi_sw_tcp_data_ready(struct sock *sk, int flag)
        rd_desc.count = 1;
        tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv);
 
+       if (iscsi_sw_sk_state_check(sk) < 0) {
+               ISCSI_SW_TCP_DBG(conn, "iscsi_tcp_data_ready: "
+                                "TCP_CLOSE|TCP_CLOSE_WAIT\n");
+               iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+       }
+
        read_unlock(&sk->sk_callback_lock);
 
        /* If we had to (atomically) map a highmem page,
@@ -137,9 +161,7 @@ static void iscsi_sw_tcp_state_change(struct sock *sk)
        conn = (struct iscsi_conn*)sk->sk_user_data;
        session = conn->session;
 
-       if ((sk->sk_state == TCP_CLOSE_WAIT ||
-            sk->sk_state == TCP_CLOSE) &&
-           !atomic_read(&sk->sk_rmem_alloc)) {
+       if (iscsi_sw_sk_state_check(sk) < 0) {
                ISCSI_SW_TCP_DBG(conn, "iscsi_tcp_state_change: "
                                 "TCP_CLOSE|TCP_CLOSE_WAIT\n");
                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);