On Fri, Jun 8, 2012 at 6:46 PM, Jeff Cody <jc...@redhat.com> wrote: > On 06/08/2012 12:11 PM, Kevin Wolf wrote: >> Am 08.06.2012 16:32, schrieb Jeff Cody: >>> On 06/08/2012 09:53 AM, Stefan Hajnoczi wrote: >>>> On Fri, Jun 8, 2012 at 2:19 PM, Jeff Cody <jc...@redhat.com> wrote: >>>>> On 06/08/2012 08:42 AM, Stefan Hajnoczi wrote: >>>>>> Let's figure out how to specify block-commit so we're all happy, that >>>>>> way we can avoid duplicating work. Any comments on my notes above? >>>>>> >>>>> >>>>> I think we are almost completely on the same page - devil is in the >>>>> details, of course (for instance, on how to convert the destination base >>>>> from r/o to r/w). >>>> >>>> Great. The atomic r/o -> r/w transition and the commit coroutine can >>>> be implemented on in parallel. Are you happy to implement the atomic >>>> r/o -> r/w transition since you wrote bdrv_append()? Then Zhi Hui can >>>> assume that part already works and focus on implementing the commit >>>> coroutine in the meantime. I'm just suggesting a way to split up the >>>> work, please let me know if you think this is good. >>> >>> I am happy to do it that way. I'll shift my focus to the atomic image >>> reopen in r/w mode. I'll go ahead and post my diagrams and other info >>> for block-commit on the wiki, because I don't think it conflicts with we >>> discussed above (although I will modify my diagrams to not show commit >>> from the top-level image). Of course, feel free to change it as >>> necessary. >> >> I may have mentioned it before, but just in case: I think Supriya's >> bdrv_reopen() patches are a good starting point. I don't know why they >> were never completed, but I think we all agreed on the general design, >> so it should be possible to pick that up. >> >> Though if you have already started with your own work on it, Jeff, I >> expect that it won't be much different because it's basically the same >> transactional approach that you know and that we already used for group >> snapshots. >> > > I will definitely use parts of Supriya's as it makes sense - what I > started work on is similar to bdrv_append() and the current transaction > approach, so there will be plenty in common to reuse, even with some > differences.
I have CCed Supriya who has been working on the reopen patch series. She is close to posting a new version. Stefan
