Re: [Qemu-block] [PATCH v3 08/10] block: Allow changing 'discard' on reopen

[Alberto Garcia]

On Mon 24 Sep 2018 03:43:10 PM CEST, Max Reitz wrote:
> On 19.09.18 11:18, Alberto Garcia wrote:
>> On Thu 06 Sep 2018 11:37:08 AM CEST, Alberto Garcia <address@hidden> wrote:
>>> 'discard' is one of the basic BlockdevOptions available for all
>>> drivers, but it's not handled by bdrv_reopen_prepare() so any attempt
>>> to change it results in an error:
>>>
>>>    (qemu) qemu-io virtio0 "reopen -o discard=on"
>>>    Cannot change the option 'discard'
>>>
>>> Since there's no reason why we shouldn't allow changing it and the
>>> implementation is simple let's just do it.
>>>
>>> Signed-off-by: Alberto Garcia <address@hidden>
>> 
>> A side effect of this change that I hadn't noticed when I sent this
>> patch: protocol nodes have the "discard" option set to "unmap" by
>> default (by bdrv_inherited_options()), and that sets the BDRV_O_UNMAP
>> flag.
>> 
>> However that flag is cleared during reopen even though the "discard"
>> option remains there. So thanks to this patch the flag correctly
>> reflects the value of the option after reopen.
>> 
>> Is it worth sending the patch again with an updated commit message that
>> explains this?
>
> I don't know this any better than you. :-)
> I have to admit that personally I don't care too much about overly exact
> commit messages, but I'm probably just wrong.

I decided not to resend the series after all, at least not just for this
change.

Berto