Re: [PATCH v3 0/2] qapi/throttle: Fix qmp_block_set_io_throttle blocked for too long

[Markus Armbruster <armbru@redhat.com>]

Michael Tokarev <mjt@tls.msk.ru> writes:

> On 26.03.2025 12:26, zoudongjie via wrote:
>> From: Zhu Yangyang <zhuyangyang14@huawei.com>
>> Calling qmp_block_set_io_throttle() will be blocked for a long time
>> when a network disk is configured and the network failure is just about
>> to occur.
>> This series add a timeout parameter for qmp_block_set_io_throttle to control
>> its execution duration.
>> Changelog
>> v3 ---
>>    Unify AIO_WAIT_WHILE_{TIMEOUT/INTERNAL} by replacing AIO_WAIT_WHILE_INTERNAL() with
>>    AIO_WAIT_WHILE_TIMEOUT(..., 0).
>> v2 ----
>>    1. Support 0 in BDRV_POLL_WHILE_TIMEOUT(), 0 means infinite.
>>    2. Use uint64_t timeout_ns instead of int64 timeout to name variables.
>>    3. Use timer_pending() to check for expiry instead of explicitly checking
>>       against the deadline for BDRV_POLL_WHILE_TIMEOUT().
>>    4. Add documentation for bdrv_drained_begin_timeout(), note that bdrv_drained_end()
>>       must be called when -ETIMEDOUT is returned.
>>    5. Add a timeout parameter to the qmp_block_set_io_throttle() instead of hardcoding
>>       the timeout, and the default value is 0, mean an infinite timeout.
>> v1 patch link:
>> https://lore.kernel.org/qemu-devel/20250308101618.721954-1-zoudongjie@huawei.com/
>> Zhu Yangyang (2):
>>    io/block: Refactoring the bdrv_drained_begin() function and implement
>>      a timeout mechanism.
>>    qapi/throttle: add timeout parameter for qmp_block_set_io_throttle()
>
> Hi!
>
> Is this series still relevant?  It's Cc'ed qemu-stable@, but not yet
> applied to master branch..

I understand Zoudongjie intends to respin.

Issues I pointed out:

* Incorrect Since: tag

* Confusing error message

* What other commands could similarly block?

The last one should be investigated, but that need not block the patch.
A partial fix can be better than no fix.