[v2] iothread: fix epollfd leak in the process of delIOThread

[Qemu-devel] [PATCH v2] iothread: fix epollfd leak in the process of delIOThread

Posted by Jie Wang 5 years, 11 months ago

From: w00251574 <wangjie88@huawei.com>

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 <wangjie88@huawei.com>
---
 include/block/aio.h | 8 ++++++++
 util/aio-posix.c    | 7 +++++++
 util/aio-win32.c    | 4 ++++
 util/async.c        | 1 +
 4 files changed, 20 insertions(+)

diff --git a/include/block/aio.h b/include/block/aio.h
index a1d6b9e249..ae6f354e6c 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -554,6 +554,14 @@ 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
diff --git a/util/aio-posix.c b/util/aio-posix.c
index d8f0cb4af8..bd81455851 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -713,6 +713,13 @@ void aio_context_setup(AioContext *ctx)
 #endif
 }
 
+void aio_context_destroy(AioContext *ctx)
+{
+#ifdef CONFIG_EPOLL_CREATE1
+    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 a67b00c6ad..e676a8d9b2 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 4dd9d95a9e..03f62787f2 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 = {
-- 
2.15.0.windows.1

Re: [Qemu-devel] [PATCH v2] iothread: fix epollfd leak in the process of delIOThread

Posted by Fam Zheng 5 years, 11 months ago

On Wed, 05/16 14:39, Jie Wang wrote:
> From: w00251574 <wangjie88@huawei.com>
> 
> 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 <wangjie88@huawei.com>
> ---
>  include/block/aio.h | 8 ++++++++
>  util/aio-posix.c    | 7 +++++++
>  util/aio-win32.c    | 4 ++++
>  util/async.c        | 1 +
>  4 files changed, 20 insertions(+)
> 
> diff --git a/include/block/aio.h b/include/block/aio.h
> index a1d6b9e249..ae6f354e6c 100644
> --- a/include/block/aio.h
> +++ b/include/block/aio.h
> @@ -554,6 +554,14 @@ 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
> diff --git a/util/aio-posix.c b/util/aio-posix.c
> index d8f0cb4af8..bd81455851 100644
> --- a/util/aio-posix.c
> +++ b/util/aio-posix.c
> @@ -713,6 +713,13 @@ void aio_context_setup(AioContext *ctx)
>  #endif
>  }
>  
> +void aio_context_destroy(AioContext *ctx)
> +{
> +#ifdef CONFIG_EPOLL_CREATE1
> +    close(ctx->epollfd);

In aio_context_setup, epoll_create1 could fail. Putting this inside an "if
(ctx->epllfd >= 0)" condition is cleaner, I think. 

> +#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 a67b00c6ad..e676a8d9b2 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 4dd9d95a9e..03f62787f2 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 = {
> -- 
> 2.15.0.windows.1
>

Re: [Qemu-devel] [PATCH v2] iothread: fix epollfd leak in the process of delIOThread

Posted by Peter Xu 5 years, 11 months ago

On Wed, May 16, 2018 at 02:39:44PM +0800, Jie Wang wrote:
> From: w00251574 <wangjie88@huawei.com>

(Maybe you'd prefer to still use "Jie Wang" here? :)

> 
> 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 <wangjie88@huawei.com>

[...]

> diff --git a/util/aio-posix.c b/util/aio-posix.c
> index d8f0cb4af8..bd81455851 100644
> --- a/util/aio-posix.c
> +++ b/util/aio-posix.c
> @@ -713,6 +713,13 @@ void aio_context_setup(AioContext *ctx)
>  #endif
>  }
>  
> +void aio_context_destroy(AioContext *ctx)
> +{
> +#ifdef CONFIG_EPOLL_CREATE1
> +    close(ctx->epollfd);

Would it be better to call aio_epoll_disable() here?  Otherwise it
looks good to me.

> +#endif
> +}
> +

Regards,

-- 
Peter Xu