Re: [PULL v3 00/50] Block layer patches

[Peter Maydell]

On Mon, 19 Dec 2022 at 23:55, Fabiano Rosas <farosas@suse.de> wrote:
> With today's master at c15dc499cc (Merge tag 'pull-misc-20221218'
> of https://gitlab.com/rth7680/qemu into staging, 2022-12-19),
>
> I get a test failure:
>
> $ make check-avocado 
> AVOCADO_TESTS=../tests/avocado/reverse_debugging.py:ReverseDebugging_X86_64.test_x86_64_pc
> ...
> Output: qemu-system-x86_64: ../block/block-backend.c:2572:
> blk_root_drained_poll: Assertion `blk->quiesce_counter' failed.
>
> Bisect points to this patch
> da0bd74434 (block: Factor out bdrv_drain_all_begin_nopoll(), 2022-12-07)

Yep, that does seem to be the commit that introduces the
regression. The problem is that the refactoring has broken
the early-return if replay_events_enabled() is true --
before the refactor that 'return' used to return direcly
from bdrv_drain_all_begin(); now it only returns from
bdrv_drain_all_begin_nopoll() and doesn't cause the
calling bdrv_drain_all_begin() to return early, so
execution continues into the following code when it should
not.

-- PMM