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

[Fam Zheng]

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.
---
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);
+/**
+ *
+ * Destroy the aio context.
+ */
+void aio_context_destroy(AioContext *ctx);
+
/**
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

[Peter Xu]

(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.

[...]

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,