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    Input: evdev - do not report errors form flush() · eb38f3a4
    Takashi Iwai 提交于
    We've got bug reports showing the old systemd-logind (at least
    system-210) aborting unexpectedly, and this turned out to be because
    of an invalid error code from close() call to evdev devices.  close()
    is supposed to return only either EINTR or EBADFD, while the device
    returned ENODEV.  logind was overreacting to it and decided to kill
    itself when an unexpected error code was received.  What a tragedy.
    
    The bad error code comes from flush fops, and actually evdev_flush()
    returns ENODEV when device is disconnected or client's access to it is
    revoked. But in these cases the fact that flush did not actually happen is
    not an error, but rather normal behavior. For non-disconnected devices
    result of flush is also not that interesting as there is no potential of
    data loss and even if it fails application has no way of handling the
    error. Because of that we are better off always returning success from
    evdev_flush().
    
    Also returning EINTR from flush()/close() is discouraged (as it is not
    clear how application should handle this error), so let's stop taking
    evdev->mutex interruptibly.
    
    Bugzilla: http://bugzilla.suse.com/show_bug.cgi?id=939834
    Cc: <stable@vger.kernel.org>
    Signed-off-by: NTakashi Iwai <tiwai@suse.de>
    Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
    eb38f3a4
evdev.c 28.1 KB