Re: [Qemu-devel] [PATCH v4] iothread: fix epollfd leak in the process of delIOThread

[Peter Xu]

On Wed, May 16, 2018 at 07:14:53PM +0800, WangJie (Pluto) wrote:
> Hi, Peter Xu:
>       If call aio_epoll_disable() here, aio_epoll_disable() will return 
> before close ctx->epollfd,
>     Because the ctx->epoll_enabled is false in the moment.
>       In the process of addIOThread, aio_context_setup created epoll without 
> call aio_epoll_try_enable,
>     so ctx->epoll_enabled have no chance to set true.

I see that epoll_available will only be set if epollfd != -1, so it
seems to me to make more sense if we swap the two variables in
aio_epoll_disable(), from current version:

static void aio_epoll_disable(AioContext *ctx)
{
    ctx->epoll_available = false;
    if (!ctx->epoll_enabled) {
        return;
    }
    ctx->epoll_enabled = false;
    close(ctx->epollfd);
}

To:

static void aio_epoll_disable(AioContext *ctx)
{
    ctx->epoll_enabled = false;
    if (!ctx->epoll_available) {
        return;
    }
    ctx->epoll_available = false;
    close(ctx->epollfd);
}

What do you think?  And Fam?

> 
> On 2018/5/16 16:36, Jie Wang wrote:
> > +void aio_context_destroy(AioContext *ctx)
> > +{
> > +#ifdef CONFIG_EPOLL_CREATE1
> > +    if (ctx->epollfd >= 0) {
> > +        close(ctx->epollfd);
> > +    }
> > +#endif
> > +}
> > +
> >  void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
> >                                   int64_t grow, int64_t shrink, Error 
> > **errp)
> 

-- 
Peter Xu