Re: [PATCH 4/5] vduse-blk: Add vduse-blk resize support

[Yongji Xie]

On Mon, Feb 7, 2022 at 10:18 PM Stefan Hajnoczi <stefanha@redhat.com> wrote:
>
> On Tue, Jan 25, 2022 at 09:17:59PM +0800, Xie Yongji wrote:
> > To support block resize, this uses vduse_dev_update_config()
> > to update the capacity field in configuration space and inject
> > config interrupt on the block resize callback.
> >
> > Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> > ---
> >  block/export/vduse-blk.c | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> >
> > diff --git a/block/export/vduse-blk.c b/block/export/vduse-blk.c
> > index 5a8d289685..83845e9a9a 100644
> > --- a/block/export/vduse-blk.c
> > +++ b/block/export/vduse-blk.c
> > @@ -297,6 +297,23 @@ static void blk_aio_detach(void *opaque)
> >      vblk_exp->export.ctx = NULL;
> >  }
> >
> > +static void vduse_blk_resize(void *opaque)
> > +{
> > +    BlockExport *exp = opaque;
> > +    VduseBlkExport *vblk_exp = container_of(exp, VduseBlkExport, export);
> > +    struct virtio_blk_config config;
> > +
> > +    config.capacity =
> > +            cpu_to_le64(blk_getlength(exp->blk) >> VIRTIO_BLK_SECTOR_BITS);
> > +    vduse_dev_update_config(vblk_exp->dev, sizeof(config.capacity),
> > +                            offsetof(struct virtio_blk_config, capacity),
> > +                            (char *)&config.capacity);
> > +}
> > +
> > +static const BlockDevOps vduse_block_ops = {
> > +    .resize_cb = vduse_blk_resize,
> > +};
> > +
> >  static int vduse_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
> >                                  Error **errp)
> >  {
> > @@ -387,6 +404,8 @@ static int vduse_blk_exp_create(BlockExport *exp, 
> > BlockExportOptions *opts,
> >      blk_add_aio_context_notifier(exp->blk, blk_aio_attached, 
> > blk_aio_detach,
> >                                   vblk_exp);
> >
> > +    blk_set_dev_ops(exp->blk, &vduse_block_ops, exp);
>
> Detach is missing, so BlockBackend->dev_ops will become stale after the
> export is deleted. Please add code to detach when the export is deleted.

OK.

Thanks,
Yongji