• Jiang Yi's avatar
    iscsi-target: Always wait for kthread_should_stop() before kthread exit · c732f308
    Jiang Yi authored
    commit 5e0cf5e6 upstream.
    
    There are three timing problems in the kthread usages of iscsi_target_mod:
    
     - np_thread of struct iscsi_np
     - rx_thread and tx_thread of struct iscsi_conn
    
    In iscsit_close_connection(), it calls
    
     send_sig(SIGINT, conn->tx_thread, 1);
     kthread_stop(conn->tx_thread);
    
    In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive
    SIGINT the kthread will exit without checking the return value of
    kthread_should_stop().
    
    So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...)
    and kthread_stop(...), the kthread_stop() will try to stop an already
    stopped kthread.
    
    This is invalid according to the documentation of kthread_stop().
    
    (Fix -ECONNRESET logout handling in iscsi_target_tx_thread and
     early iscsi_target_rx_thread failure case - nab)
    Signed-off-by: default avatarJiang Yi <jiangyilism@gmail.com>
    Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    c732f308
iscsi_target_login.c 39.5 KB