Re: [Qemu-devel] [PATCH] commit: Add NULL check for overlay_bs

[Kevin Wolf <kwolf@redhat.com>]

Am 10.07.2017 um 14:09 hat Peter Maydell geschrieben:
> On 10 July 2017 at 12:45, Kevin Wolf <kwolf@redhat.com> wrote:
> > I can't see how overlay_bs could become NULL with the current code, but
> > other code in this function already checks it and we can make Coverity
> > happy with this check, so let's add it.
> >
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> >  block/commit.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/block/commit.c b/block/commit.c
> > index 774a8a5..50e7950 100644
> > --- a/block/commit.c
> > +++ b/block/commit.c
> > @@ -90,7 +90,9 @@ static void commit_complete(BlockJob *job, void *opaque)
> >
> >      /* Make sure overlay_bs and top stay around until bdrv_set_backing_hd() */
> >      bdrv_ref(top);
> > -    bdrv_ref(overlay_bs);
> > +    if (overlay_bs) {
> > +        bdrv_ref(overlay_bs);
> > +    }
> >
> >      /* Remove base node parent that still uses BLK_PERM_WRITE/RESIZE before
> >       * the normal backing chain can be restored. */
> 
> Commit 19ebd13ed45ad5d5f2 which added the bdrv_ref() call
> was cc qemu-stable; should we cc this fix too, or are you
> happy that it's definitely not actually triggerable in stable?

Okay, I'll add the CC, better safe than sorry.

Kevin