Re: [PATCH 3/6] block: convert bdrv_graph_wrlock() to AIO_WAIT_WHILE_UNLOCKED()

[Philippe Mathieu-Daudé]

On 1/3/23 21:57, Stefan Hajnoczi wrote:
> The following conversion is safe and does not change behavior:
>
>       GLOBAL_STATE_CODE();
>       ...
>    -  AIO_WAIT_WHILE(qemu_get_aio_context(), ...);
>    +  AIO_WAIT_WHILE_UNLOCKED(NULL, ...);
>
> Since we're in GLOBAL_STATE_CODE(), qemu_get_aio_context() is our home
> thread's AioContext. Thus AIO_WAIT_WHILE() does not unlock the
> AioContext:
>
>    if (ctx_ && in_aio_context_home_thread(ctx_)) {                \
>        while ((cond)) {                                           \
>            aio_poll(ctx_, true);                                  \
>            waited_ = true;                                        \
>        }                                                          \
>
> And that means AIO_WAIT_WHILE_UNLOCKED(NULL, ...) can be substituted.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   block/graph-lock.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

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