Re: [Qemu-block] [Qemu-devel] [PATCH 0/3] qemu-img: Allow rebase with no input base

[Vladimir Sementsov-Ogievskiy]

13.04.2019 19:11, Max Reitz wrote:
> Ping again
> 
> (I feel like I just need to start merging unreviewed patches until I
> break something (can't take that long) so you get so scared of my
> patches that you at least refuse them outright)

Could you resend before?

> 
> On 13.07.18 13:14, Max Reitz wrote:
>> This series allows using qemu-img rebase on images that do not have a
>> backing file.  Right now, this fails with the rather cryptic error
>> message:
>>
>> $ qemu-img rebase -b base.qcow2 foo.qcow2
>> qemu-img: Could not open old backing file '': The 'file' block driver 
>> requires a file name
>>
>> Yeah, well, OK.
>>
>> With how rebase currently works, this would lead to the overlay being
>> filled with zeroes, however.  This is where patch 2 comes in and instead
>> makes rebase use blk_pwrite_zeroes() whenever it handles an area past
>> the input’s backing file’s EOF.
>>
>> (Note that additionally we could try to punch holes in the overlay
>> whenever it matches the new backing file, but that’s something I’ll put
>> off for later.  (We don’t even have a reliable method for punching holes
>> into an overlay yet, although I would like to have such because it could
>> make active commit more efficient.))
>>
>>
>> And patch 3 adds the usual test.
>>
>>
>> Max Reitz (3):
>>    qemu-img: Allow rebase with no input base
>>    qemu-img: Use zero writes after source backing EOF
>>    iotests: Add test for rebase without input base
>>
>>   qemu-img.c                 | 72 +++++++++++++++++++++++---------------
>>   tests/qemu-iotests/024     | 70 ++++++++++++++++++++++++++++++++++++
>>   tests/qemu-iotests/024.out | 37 ++++++++++++++++++++
>>   3 files changed, 150 insertions(+), 29 deletions(-)
>>
> 
> 


-- 
Best regards,
Vladimir