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

[WangJie (Pluto)]

Hi, Peter Xu:
        If call aio_epoll_disable() in aio_context_destroy, 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.


On 2018/5/16 16:36, Jie Wang wrote:
> When we call addIOThread, the epollfd created in aio_context_setup,
> but not close it in the process of delIOThread, so the epollfd will leak.
> 
> Signed-off-by: Jie Wang <address@hidden>
> ---
>  include/block/aio.h | 8 ++++++++
>  util/aio-posix.c    | 9 +++++++++
>  util/aio-win32.c    | 4 ++++
>  util/async.c        | 1 +
>  4 files changed, 22 insertions(+)
> 
> diff --git a/include/block/aio.h b/include/block/aio.h
> index a1d6b9e..ae6f354 100644
> --- a/include/block/aio.h
> +++ b/include/block/aio.h
> @@ -555,6 +555,14 @@ static inline bool in_aio_context_home_thread(AioContext 
> *ctx)
>  void aio_context_setup(AioContext *ctx);
>  
>  /**
> + * aio_context_destroy:
> + * @ctx: the aio context
> + *
> + * Destroy the aio context.
> + */
> +void aio_context_destroy(AioContext *ctx);
> +
> +/**
>   * aio_context_set_poll_params:
>   * @ctx: the aio context
>   * @max_ns: how long to busy poll for, in nanoseconds
> diff --git a/util/aio-posix.c b/util/aio-posix.c
> index d8f0cb4..0ade2c7 100644
> --- a/util/aio-posix.c
> +++ b/util/aio-posix.c
> @@ -713,6 +713,15 @@ void aio_context_setup(AioContext *ctx)
>  #endif
>  }
>  
> +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)
>  {
> diff --git a/util/aio-win32.c b/util/aio-win32.c
> index a67b00c..e676a8d 100644
> --- a/util/aio-win32.c
> +++ b/util/aio-win32.c
> @@ -407,6 +407,10 @@ void aio_context_setup(AioContext *ctx)
>  {
>  }
>  
> +void aio_context_destroy(AioContext *ctx)
> +{
> +}
> +
>  void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
>                                   int64_t grow, int64_t shrink, Error **errp)
>  {
> diff --git a/util/async.c b/util/async.c
> index 4dd9d95..03f6278 100644
> --- a/util/async.c
> +++ b/util/async.c
> @@ -298,6 +298,7 @@ aio_ctx_finalize(GSource     *source)
>      qemu_rec_mutex_destroy(&ctx->lock);
>      qemu_lockcnt_destroy(&ctx->list_lock);
>      timerlistgroup_deinit(&ctx->tlg);
> +    aio_context_destroy(ctx);
>  }
>  
>  static GSourceFuncs aio_source_funcs = {
>