[Qemu-devel] [PATCH v6 1/2] iothread: fix epollfd leak in the process of delIOThread

[Qemu-devel] [PATCH v6 1/2] iothread: fix epollfd leak in the process of delIOThread

[Jie Wang]

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    | 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 = {
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v6 1/2] iothread: fix epollfd leak in the process of delIOThread

[Fam Zheng]

Thanks for the quick iterations. A note on the patch submission:

When sending patch series with git, please use git-send-email's "--thread
--no-chain-reply-to" options, and also create a cover letter using "git
format-patch --cover-letter". Or you can use git-publish. For more complete
information on how to submit patches:

https://wiki.qemu.org/Contribute/SubmitAPatch

In particular, as noted in that page, it is perferred to include revision log in
the cover letter, such as:

    v6: Improve foo.

    v5: Tweak bar.
        Add baz.

    ...

On Thu, 05/17 10:25, 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 <wangjie88@huawei.com>
> ---
>  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);
> +    }

This is changed to aio_epoll_disable in patch 2. It is unnecessary code churn.
Just swap these two patches so that you can avoid it.

> +#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 = {
> -- 
> 1.8.3.1
> 

Fam