Re: [Qemu-devel] [PATCH 04/11] block: Support streaming to an intermediate layer

[Fam Zheng <famz@redhat.com>]

On Fri, 05/15 11:04, Alberto Garcia wrote:
> On Fri 15 May 2015 04:33:19 AM CEST, Fam Zheng wrote:
> 
> >> +    /* Make sure that the image is opened in read-write mode */
> >> +    orig_bs_flags = bdrv_get_flags(bs);
> >> +    if (!(orig_bs_flags & BDRV_O_RDWR)) {
> >> +        if (bdrv_reopen(bs, orig_bs_flags | BDRV_O_RDWR, errp) != 0) {
> >
> > I don't think all bdrv_reopen implementation will guarantee to set errp
> > on error :(. For example:
> >
> >     static int qcow2_reopen_prepare(BDRVReopenState *state,
> >                                     BlockReopenQueue *queue, Error **errp)
> >     {
> 
> bdrv_reopen_prepare() already sets a generic error if the implementation
> (qcow2_reopen_prepare() in this case) doesn't provide one:
> 
>     ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
>     if (ret) {
>         if (local_err != NULL) {
>             error_propagate(errp, local_err);
>         } else {
>             error_setg(errp, "failed while preparing to reopen image '%s'",
>                        reopen_state->bs->filename);
>         }
>         goto error;
>     }
> 

You're right, I missed that. So,

Reviewed-by: Fam Zheng <famz@redhat.com>