Re: [PATCH 01/12] block-coroutine-wrapper: Take AioContext lock in no_co_wrappers

[Stefan Hajnoczi <stefanha@redhat.com>]

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On Thu, May 25, 2023 at 02:47:02PM +0200, Kevin Wolf wrote:
> All of the functions that currently take a BlockDriverState, BdrvChild
> or BlockBackend as their first parameter expect the associated
> AioContext to be locked when they are called. In the case of
> no_co_wrappers, they are called from bottom halves directly in the main
> loop, so no other caller can be expected to take the lock for them. This
> can result in assertion failures because a lock that isn't taken is
> released in nested event loops.
> 
> Looking at the first parameter is already done by co_wrappers to decide
> where the coroutine should run, so doing the same in no_co_wrappers is
> only consistent. Take the lock in the generated bottom halves to fix the
> problem.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  include/block/block-common.h       |  3 +++
>  block/block-backend.c              |  7 ++++++-
>  scripts/block-coroutine-wrapper.py | 25 +++++++++++++++----------
>  3 files changed, 24 insertions(+), 11 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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