Re: [Qemu-block] segfault in parallel blockjobs (iotest 30)

[Alberto Garcia]

On Wed 08 Nov 2017 03:45:38 PM CET, Alberto Garcia wrote:

> I'm thinking that perhaps we should add the pause point directly to
> block_job_defer_to_main_loop(), to prevent any block job from running
> the exit function when it's paused.

I was trying this and unfortunately this breaks the mirror job at least
(reproduced with a simple block-commit on the topmost node, which uses
commit_active_start() -> mirror_start_job()).

So what happens is that mirror_run() always calls bdrv_drained_begin()
before returning, pausing the block job. The closing bdrv_drained_end()
call is at the end of mirror_exit(), already in the main loop.

So the mirror job is always calling block_job_defer_to_main_loop() and
mirror_exit() when the job is paused.

Berto