Re: [Qemu-devel] [PATCH v4 2/9] qmp: Add dirty-bitmap-add and dirty-bitmap-remove

[Fam Zheng <famz@redhat.com>]

On Thu, 03/27 16:43, Stefan Hajnoczi wrote:
> On Thu, Mar 27, 2014 at 05:09:41PM +0800, Fam Zheng wrote:
> > @@ -1713,6 +1713,66 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
> >      }
> >  }
> >  
> > +void qmp_dirty_bitmap_add(const char *device, const char *name,
> > +                          bool has_granularity, int64_t granularity,
> > +                          Error **errp)
> > +{
> > +    BlockDriverState *bs;
> > +    BdrvDirtyBitmap *bitmap;
> > +
> > +    bs = bdrv_find(device);
> > +    if (!bs) {
> > +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
> > +        return;
> > +    }
> > +
> > +    if (!name || name[0] == '\0') {
> > +        error_setg(errp, "Bitmap name cannot be empty");
> > +        return;
> > +    }
> > +    if (has_granularity) {
> > +        if (granularity & (granularity - 1)) {
> > +            error_setg(errp, "Granularity must be power of 2");
> > +            return;
> > +        }
> 
> granularity must be non-zero, otherwise bdrv_create_dirty_bitmap() hits
> an assertion failure.
> 
> It should probably also be at least 512.

Sure, adding a check.

> 
> > +    } else {
> > +        granularity = 65536;
> > +    }
> > +
> > +    bitmap = bdrv_create_dirty_bitmap(bs, granularity, name, errp);
> > +    if (!bitmap) {
> > +        return;
> > +    }
> 
> Useless error return.

Removing.

> 
> > +}
> > +
> > +void qmp_dirty_bitmap_remove(const char *device, const char *name,
> > +                             Error **errp)
> > +{
> > +    BlockDriverState *bs;
> > +    BdrvDirtyBitmap *bitmap;
> > +
> > +    bs = bdrv_find(device);
> > +    if (!bs) {
> > +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
> > +        return;
> > +    }
> > +
> > +    if (!name || name[0] == '\0') {
> > +        error_setg(errp, "Bitmap name cannot be empty");
> > +        return;
> > +    }
> > +    bitmap = bdrv_find_dirty_bitmap(bs, name);
> > +    if (!bitmap) {
> > +        error_setg(errp, "Dirty bitmap not found: %s", name);
> > +        return;
> > +    }
> > +
> > +    /* Make it invisible to user in case the following
> > +     * bdrv_release_dirty_bitmap doens't free it because of refcnt */
> 
> "doesn't"

Thanks,
Fam