lkml.org 
[lkml]   [2007]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH -mm 4/5][AIO] - AIO completion signal notification
    On Tue, 23 Jan 2007 21:35:13 -0800 Andrew Morton <akpm@osdl.org> wrote:

    > On Wed, 17 Jan 2007 10:50:18 +0100
    > Sébastien Dugué <sebastien.dugue@bull.net> wrote:
    >
    > > +static long aio_setup_sigevent(struct aio_notify *notify,
    > > + struct sigevent __user *user_event)
    > > +{
    > > + sigevent_t event;
    > > + struct task_struct *target;
    > > +
    > > + if (copy_from_user(&event, user_event, sizeof (event)))
    > > + return -EFAULT;
    > > +
    > > + if (event.sigev_notify == SIGEV_NONE)
    > > + return 0;
    > > +
    > > + notify->notify = event.sigev_notify;
    > > + notify->signo = event.sigev_signo;
    > > + notify->value = event.sigev_value;
    > > +
    > > + read_lock(&tasklist_lock);
    > > + target = good_sigevent(&event);
    > > +
    > > + if (unlikely(!target || (target->flags & PF_EXITING)))
    > > + goto out_unlock;
    > > +
    > > + /*
    > > + * At this point, we know that notify is either SIGEV_SIGNAL or
    > > + * SIGEV_THREAD_ID and the target task is valid. So get a reference
    > > + * on the task, it will be dropped in really_put_req() when
    > > + * we're done with the request.
    > > + */
    > > + get_task_struct(target);
    > > + notify->target = target;
    > > + read_unlock(&tasklist_lock);
    > > +
    > > + /*
    > > + * NOTE: we cannot free the sigqueue in the completion path as
    > > + * the signal may not have been delivered to the target task.
    > > + * Therefore it has to be freed in __sigqueue_free() when the
    > > + * signal is collected if si_code is SI_ASYNCIO.
    > > + */
    > > + notify->sigq = sigqueue_alloc();
    > > +
    > > + if (unlikely(!notify->sigq))
    > > + return -EAGAIN;
    >
    > Did this just leak a ref on the task_struct?
    >

    No, the ref is released in really_put_req() when we dispose of
    the iocb.

    Thanks,

    Sébastien.
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-01-24 13:17    [W:0.030 / U:61.952 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site