src/patches/suse-2.6.27.39/patches.fixes/iscsi_tcp-Evaluate-socket-state-in-data_ready

   1 From: Hannes Reinecke <hare@suse.de>
   2 Date: Thu, 13 Aug 2009 10:35:43 +0200
   3 Subject: iscsi_tcp: Evaluate socket state in data_ready()
   4 X-Git: 523eeac6703a995d58918aaf321f128f75c13108
   5 References: bnc#472432
   6
   7 The network core will call the state_change() callback
   8 prior to the data_ready() callback, which might cause
   9 us to lose a connection state change.
  10 So we have to evaluate the socket state at the end
  11 of the data_ready() callback, too.
  12
  13 Signed-off-by: Hannes Reinecke <hare@suse.de>
  14 Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
  15 ---
  16  drivers/scsi/iscsi_tcp.c |   27 ++++++++++++++++++++++++---
  17  1 files changed, 24 insertions(+), 3 deletions(-)
  18
  19 diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
  20 index cfcb8ec..b870bfc 100644
  21 --- a/drivers/scsi/iscsi_tcp.c
  22 +++ b/drivers/scsi/iscsi_tcp.c
  23 @@ -1014,6 +1014,24 @@ error:
  24         return 0;
  25  }
  26
  27 +/**
  28 + * iscsi_sw_sk_state_check - check socket state
  29 + * @sk: socket
  30 + *
  31 + * If the socket is in CLOSE or CLOSE_WAIT we should
  32 + * not close the connection if there is still some
  33 + * data pending.
  34 + */
  35 +static inline int iscsi_tcp_state_check(struct sock *sk)
  36 +{
  37 +       if ((sk->sk_state == TCP_CLOSE_WAIT ||
  38 +            sk->sk_state == TCP_CLOSE) &&
  39 +           !atomic_read(&sk->sk_rmem_alloc))
  40 +               return -ECONNRESET;
  41 +
  42 +       return 0;
  43 +}
  44 +
  45  static void
  46  iscsi_tcp_data_ready(struct sock *sk, int flag)
  47  {
  48 @@ -1033,6 +1051,11 @@ iscsi_tcp_data_ready(struct sock *sk, int flag)
  49         rd_desc.count = 1;
  50         tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv);
  51
  52 +       if (iscsi_tcp_state_check(sk) < 0) {
  53 +               debug_tcp("iscsi_tcp_data_ready: TCP_CLOSE|TCP_CLOSE_WAIT\n");
  54 +               iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
  55 +       }
  56 +
  57         read_unlock(&sk->sk_callback_lock);
  58
  59         /* If we had to (atomically) map a highmem page,
  60 @@ -1053,9 +1076,7 @@ iscsi_tcp_state_change(struct sock *sk)
  61         conn = (struct iscsi_conn*)sk->sk_user_data;
  62         session = conn->session;
  63
  64 -       if ((sk->sk_state == TCP_CLOSE_WAIT ||
  65 -            sk->sk_state == TCP_CLOSE) &&
  66 -           !atomic_read(&sk->sk_rmem_alloc)) {
  67 +       if (iscsi_tcp_state_check(sk) < 0) {
  68                 debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
  69                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
  70         }
  71 --
  72 1.6.0.2
  73