lkml.org 
[lkml]   [2012]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 179/241] RDS: fix rds-ping spinlock recursion
    Date
    3.5.7.2 -stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: "jeff.liu" <jeff.liu@oracle.com>

    commit 5175a5e76bbdf20a614fb47ce7a38f0f39e70226 upstream.

    This is the revised patch for fixing rds-ping spinlock recursion
    according to Venkat's suggestions.

    RDS ping/pong over TCP feature has been broken for years(2.6.39 to
    3.6.0) since we have to set TCP cork and call kernel_sendmsg() between
    ping/pong which both need to lock "struct sock *sk". However, this
    lock has already been hold before rds_tcp_data_ready() callback is
    triggerred. As a result, we always facing spinlock resursion which
    would resulting in system panic.

    Given that RDS ping is only used to test the connectivity and not for
    serious performance measurements, we can queue the pong transmit to
    rds_wq as a delayed response.

    Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
    CC: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
    CC: David S. Miller <davem@davemloft.net>
    CC: James Morris <james.l.morris@oracle.com>
    Signed-off-by: Jie Liu <jeff.liu@oracle.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
    ---
    net/rds/send.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/net/rds/send.c b/net/rds/send.c
    index 96531d4..88eace5 100644
    --- a/net/rds/send.c
    +++ b/net/rds/send.c
    @@ -1122,7 +1122,7 @@ rds_send_pong(struct rds_connection *conn, __be16 dport)
    rds_stats_inc(s_send_pong);

    if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
    - rds_send_xmit(conn);
    + queue_delayed_work(rds_wq, &conn->c_send_w, 0);

    rds_message_put(rm);
    return 0;
    --
    1.7.9.5


    \
     
     \ /
      Last update: 2012-12-13 16:01    [W:4.035 / U:0.452 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site