Re: [PATCH v3] block/backup-top: fix flags handling

[Vladimir Sementsov-Ogievskiy]

07.02.2020 19:30, Max Reitz wrote:
> On 07.02.20 17:12, Vladimir Sementsov-Ogievskiy wrote:
> > backup-top "supports" write-unchanged, by skipping CBW operation in
> > backup_top_co_pwritev. But it forgets to do the same in
> > backup_top_co_pwrite_zeroes, as well as declare support for
> > BDRV_REQ_WRITE_UNCHANGED.
> >
> > Fix this, and, while being here, declare also support for flags
> > supported by source child.
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> > ---
> >
> > v3: rebase on master, keep state initialization after check top != NULL.
> >
> > v2: restrict flags propagation like it is done in other filters [Eric]
> >      move state variable initialization to the top
> >   block/backup-top.c | 31 ++++++++++++++++++++-----------
> >   1 file changed, 20 insertions(+), 11 deletions(-)
> >
> > diff --git a/block/backup-top.c b/block/backup-top.c
> > index fa78f3256d..1bfb360bd3 100644
> > --- a/block/backup-top.c
> > +++ b/block/backup-top.c
>
> [...]
>
> > @@ -196,8 +200,13 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState 
> > *source,
> >           return NULL;
> >       }
> >   
> > -    top->total_sectors = source->total_sectors;
> >       state = top->opaque;
> > +    top->total_sectors = source->total_sectors;
>
> This looks a bit accidental, but, well, whatever.

I failed to restrict myself in a wish to keep all "top->.. =" initializers went 
together :)
Hmm, I could "state =" intializer to go after them. But it's good to keep it at 
top too.

> Thanks, applied to my block branch:
>
> https://git.xanclic.moe/XanClic/qemu/commits/branch/block


Thanks!


--
Best regards,
Vladimir