Re: [RFC PATCH] test-bdrv-drain: keep graph manipulations out of coroutines

[Emanuele Giuseppe Esposito]

Am 02/12/2022 um 18:22 schrieb Paolo Bonzini:
> On 12/2/22 14:42, Emanuele Giuseppe Esposito wrote:
>>
>>
>> Am 02/12/2022 um 14:27 schrieb Paolo Bonzini:
>>> Changes to the BlockDriverState graph will have to take the
>>> corresponding lock for writing, and therefore cannot be done
>>> inside a coroutine.  Move them outside the test body.
>>>
>>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>>> ---
>>>   tests/unit/test-bdrv-drain.c | 63 ++++++++++++++++++++++++++----------
>>>   1 file changed, 46 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c
>>> index 6ae44116fe79..d85083dd4f9e 100644
>>> --- a/tests/unit/test-bdrv-drain.c
>>> +++ b/tests/unit/test-bdrv-drain.c
>>> @@ -199,25 +199,40 @@ static void do_drain_end_unlocked(enum
>>> drain_type drain_type, BlockDriverState *
>>>       }
>>>   }
>>>   +static BlockBackend *blk;
>>> +static BlockDriverState *bs, *backing;
>>> +
>>> +static void test_drv_cb_init(void)
>>> +{
>>> +    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
>>> +    bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
>>> +                              &error_abort);
>>> +    blk_insert_bs(blk, bs, &error_abort);
>>> +
>>> +    backing = bdrv_new_open_driver(&bdrv_test, "backing", 0,
>>> &error_abort);
>>> +    bdrv_set_backing_hd(bs, backing, &error_abort);
>>> +}
>>> +
>>> +static void test_drv_cb_fini(void)
>>
>> fini stands for "finito"? :)
> 
> No, for finish :)
> http://ftp.math.utah.edu/u/ma/hohn/linux/misc/elf/node3.html

Cool :)
> 
>> Anyways, an alternative solution for this is also here (probably coming
>> from you too):
>> https://lists.nongnu.org/archive/html/qemu-devel/2022-03/msg03517.html
> 
> Much better.  At least patches 7-8 from that series have to be salvaged,
> possibly 10 as well.

Serie sent:
20221205121029.1089209-1-eesposit@redhat.com/">https://patchew.org/QEMU/20221205121029.1089209-1-eesposit@redhat.com/

Yes theoretically also patch 9, but I think there's no need to respin
them. If someone is interested they are there.

Thank you,
Emanuele
> 
> Paolo
>