[SCSI] iscsi_tcp: Evaluate socket state in data_ready()

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>

1 files changed, 25 insertions, 3 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 518dbd91df85..c7e2ff24ee9e 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -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);