Re: [PATCH v2 0/3] xen-blk{front,back}: Fix the broken semantic and flow of feature-persistent

[SeongJae Park <sj@xxxxxxxxxx>]

On Wed, 31 Aug 2022 16:58:21 +0000 SeongJae Park <sj@xxxxxxxxxx> wrote:

> Changes from v1
> (https://lore.kernel.org/xen-devel/20220825161511.94922-1-sj@xxxxxxxxxx/)
> - Fix the wrong feature_persistent caching position of blkfront
> - Set blkfront's feature_persistent field setting with simple '&&'
>   instead of 'if' (Pratyush Yadav)
> 
> This patchset fixes misuse of the 'feature-persistent' advertisement
> semantic (patches 1 and 2), and the wrong timing of the
> 'feature_persistent' value caching, which made persistent grants feature
> always disabled.

Please note that I have some problem in my test setup and therefore was unable
to fully test this patchset.  I am posting this though, as the impact of the
bug is not trivial (always disabling persistent grants), and to make testing of
my proposed fix from others easier.  Hope to get someone's test results or code
review of this patchset even before I fix my test setup problem.

Juergen, I didn't add your 'Reviewed-by:'s to the first two patches of this
series because I changed some of the description for making it clear which bug
and commit it is really fixing.  Specifically, I wordsmithed the working and
changed 'Fixed:' tag.  Code change is almost same, though.


Thanks,
SJ

> 
> SeongJae Park (3):
>   xen-blkback: Advertise feature-persistent as user requested
>   xen-blkfront: Advertise feature-persistent as user requested
>   xen-blkfront: Cache feature_persistent value before advertisement
> 
>  drivers/block/xen-blkback/common.h |  3 +++
>  drivers/block/xen-blkback/xenbus.c |  6 ++++--
>  drivers/block/xen-blkfront.c       | 20 ++++++++++++--------
>  3 files changed, 19 insertions(+), 10 deletions(-)
> 
> -- 
> 2.25.1
>