Re: [Qemu-devel] [PATCH v4 1/9] qapi: Add optional field "name" to block dirty bitmap

[Fam Zheng]

On Thu, 03/27 16:30, Stefan Hajnoczi wrote:
> On Thu, Mar 27, 2014 at 05:09:40PM +0800, Fam Zheng wrote:
> > @@ -5079,18 +5080,45 @@ bool bdrv_qiov_is_aligned(BlockDriverState *bs, 
> > QEMUIOVector *qiov)
> >      return true;
> >  }
> >  
> > -BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int 
> > granularity)
> > +BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char 
> > *name)
> > +{
> > +    BdrvDirtyBitmap *bm;
> > +    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
> > +        if (!strcmp(name, bm->name)) {
> > +            return bm;
> > +        }
> > +    }
> > +    return NULL;
> > +}
> > +
> > +void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap 
> > *bitmap)
> > +{
> > +    g_free(bitmap->name);
> > +    bitmap->name = NULL;
> > +}
> 
> This looks dangerous since strcmp() does not check for NULL pointers.  I
> guess you need to add a check to bdrv_find_dirty_bitmap().

OK.

> 
> > @@ -5120,6 +5149,8 @@ BlockDirtyInfoList 
> > *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
> >          info->count = bdrv_get_dirty_count(bs, bm);
> >          info->granularity =
> >              ((int64_t) BDRV_SECTOR_SIZE << 
> > hbitmap_granularity(bm->bitmap));
> > +        info->has_name = bm->name[0] != '\0';
> > +        info->name = g_strdup(bm->name);
> 
> This looks dangerous too.  What if ->name is NULL?

Will add a check here.

Thanks,
Fam