On 2/18/19 10:18 AM, Kevin Wolf wrote:
> Now that bdrv_set_aio_context() works inside drained sections, it can
> also use the real drain function instead of open coding something
> similar.
>
> Signed-off-by: Kevin Wolf <kw...@redhat.com>
> ---
> block.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/block.c b/block.c
> index aefb5701f5..7024172db8 100644
> --- a/block.c
> +++ b/block.c
> @@ -5268,18 +5268,15 @@ void bdrv_attach_aio_context(BlockDriverState *bs,
> bs->walking_aio_notifiers = false;
> }
>
> +/* The caller must own the AioContext lock for the old AioContext of bs, but
> it
> + * must not own the AioContext lock for new_context. */
Is this comment still accurate, given
> void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
> {
> - AioContext *ctx = bdrv_get_aio_context(bs);
> -
> - if (ctx == new_context) {
> + if (bdrv_get_aio_context(bs) == new_context) {
> return;
> }
the short-circuiting when the old context is the new context?
>
> - aio_disable_external(ctx);
> - bdrv_parent_drained_begin(bs, NULL, false);
> - bdrv_drain(bs); /* ensure there are no in-flight requests */
> -
> + bdrv_drained_begin(bs);
> bdrv_detach_aio_context(bs);
>
> /* This function executes in the old AioContext so acquire the new one in
> @@ -5287,8 +5284,7 @@ void bdrv_set_aio_context(BlockDriverState *bs,
> AioContext *new_context)
> */
> aio_context_acquire(new_context);
> bdrv_attach_aio_context(bs, new_context);
> - bdrv_parent_drained_end(bs, NULL, false);
> - aio_enable_external(ctx);
> + bdrv_drained_end(bs);
> aio_context_release(new_context);
> }
>
>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
