Re: [PATCH v3 20/20] aio: remove aio_disable_external() API

[Philippe Mathieu-Daudé]

On 20/4/23 13:37, Stefan Hajnoczi wrote:
> All callers now pass is_external=false to aio_set_fd_handler() and
> aio_set_event_notifier(). The aio_disable_external() API that
> temporarily disables fd handlers that were registered is_external=true
> is therefore dead code.
>
> Remove aio_disable_external(), aio_enable_external(), and the
> is_external arguments to aio_set_fd_handler() and
> aio_set_event_notifier().
>
> The entire test-fdmon-epoll test is removed because its sole purpose was
> testing aio_disable_external().
>
> Parts of this patch were generated using the following coccinelle
> (https://coccinelle.lip6.fr/) semantic patch:
>
>    @@
>    expression ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, 
> opaque;
>    @@
>    - aio_set_fd_handler(ctx, fd, is_external, io_read, io_write, io_poll, 
> io_poll_ready, opaque)
>    + aio_set_fd_handler(ctx, fd, io_read, io_write, io_poll, io_poll_ready, 
> opaque)
>
>    @@
>    expression ctx, notifier, is_external, io_read, io_poll, io_poll_ready;
>    @@
>    - aio_set_event_notifier(ctx, notifier, is_external, io_read, io_poll, 
> io_poll_ready)
>    + aio_set_event_notifier(ctx, notifier, io_read, io_poll, io_poll_ready)
>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   include/block/aio.h           | 55 --------------------------
>   util/aio-posix.h              |  1 -
>   block.c                       |  7 ----
>   block/blkio.c                 | 15 +++----
>   block/curl.c                  | 10 ++---
>   block/export/fuse.c           |  8 ++--
>   block/export/vduse-blk.c      | 10 ++---
>   block/io.c                    |  2 -
>   block/io_uring.c              |  4 +-
>   block/iscsi.c                 |  3 +-
>   block/linux-aio.c             |  4 +-
>   block/nfs.c                   |  5 +--
>   block/nvme.c                  |  8 ++--
>   block/ssh.c                   |  4 +-
>   block/win32-aio.c             |  6 +--
>   hw/i386/kvm/xen_xenstore.c    |  2 +-
>   hw/virtio/virtio.c            |  6 +--
>   hw/xen/xen-bus.c              |  8 ++--
>   io/channel-command.c          |  6 +--
>   io/channel-file.c             |  3 +-
>   io/channel-socket.c           |  3 +-
>   migration/rdma.c              | 16 ++++----
>   tests/unit/test-aio.c         | 27 +------------
>   tests/unit/test-fdmon-epoll.c | 73 -----------------------------------
>   util/aio-posix.c              | 20 +++-------
>   util/aio-win32.c              |  8 +---
>   util/async.c                  |  3 +-
>   util/fdmon-epoll.c            | 10 -----
>   util/fdmon-io_uring.c         |  8 +---
>   util/fdmon-poll.c             |  3 +-
>   util/main-loop.c              |  7 ++--
>   util/qemu-coroutine-io.c      |  7 ++--
>   util/vhost-user-server.c      | 11 +++---
>   tests/unit/meson.build        |  3 --
>   34 files changed, 76 insertions(+), 290 deletions(-)
>   delete mode 100644 tests/unit/test-fdmon-epoll.c


> -/**
> - * aio_disable_external:
> - * @ctx: the aio context
> - *
> - * Disable the further processing of external clients.
> - */
> -static inline void aio_disable_external(AioContext *ctx)
> -{
> -    qatomic_inc(&ctx->external_disable_cnt);
> -}
> -
> -/**
> - * aio_enable_external:
> - * @ctx: the aio context
> - *
> - * Enable the processing of external clients.
> - */
> -static inline void aio_enable_external(AioContext *ctx)
> -{
> -    int old;
> -
> -    old = qatomic_fetch_dec(&ctx->external_disable_cnt);
> -    assert(old > 0);
> -    if (old == 1) {
> -        /* Kick event loop so it re-arms file descriptors */
> -        aio_notify(ctx);
> -    }
> -}
> -
> -/**
> - * aio_external_disabled:
> - * @ctx: the aio context
> - *
> - * Return true if the external clients are disabled.
> - */
> -static inline bool aio_external_disabled(AioContext *ctx)
> -{
> -    return qatomic_read(&ctx->external_disable_cnt);
> -}

Missing:

-- >8 --
diff --git a/include/block/aio.h b/include/block/aio.h
index d4ce01ea08..266be26f8e 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -224,6 +224,4 @@ struct AioContext {
     QEMUTimerListGroup tlg;

-    int external_disable_cnt;
-
     /* Number of AioHandlers without .io_poll() */
     int poll_disable_cnt;
diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c
index d9d3807062..5c89169e46 100644
--- a/tests/unit/test-bdrv-drain.c
+++ b/tests/unit/test-bdrv-drain.c
@@ -436,5 +436,4 @@ static void test_graph_change_drain_all(void)
     g_assert_cmpint(bs_b->quiesce_counter, ==, 0);
     g_assert_cmpint(b_s->drain_count, ==, 0);
-    g_assert_cmpint(qemu_get_aio_context()->external_disable_cnt, ==, 0);

     bdrv_unref(bs_b);
---

Once cleaned:
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>