Re: [Qemu-devel] [PATCH v2 0/2] qemu-img: Allow source cache mode specification

[Max Reitz <mreitz@redhat.com>]

On 14.08.2014 17:30, Kevin Wolf wrote:
> Am 22.07.2014 um 22:58 hat Max Reitz geschrieben:
>> Currently, qemu-img does not allow setting the cache mode for source
>> images. However, it reads images generally only once, therefore a full
>> writeback cache unnecessarily clutters the host cache. In case the user
>> finds this undesirable, there has to be a way of disabling that cache.
>> This series first introduces such a way for check, compare, convert and
>> rebase and then (while at it) adds a cache mode switch to amend (which
>> was missing so far).
>>
>> Peter already tried to add a BDRV_O_SEQUENTIAL mode to qemu-img convert.
>> If we want to add such a mode (which in my opinion would be the logical
>> consequence of this series), we may want to make it just another cache
>> mode which can be selected by the user.
> I would prefer if we used -t in all places where only one image is
> used, so that I don't have to remember that supposedly check -r has only
> an input image, whereas amend has only an output image. But that's
> probably a matter of taste...
>
> If you don't want to change it, the implementation looks okay:
>
> Reviewed-by: Kevin Wolf <kwolf@redhat.com>

In order to get this series in as fast as possible, I won't change it in 
this series anymore.

Maybe we can add support for "-t" and "-T" being usable interchangably 
for such single-image commands in the future, but for now I hope the 
error messages will suffice.

Max