Re: [Qemu-devel] [PATCH v2] rbd: print a clear error message when write beyond EOF

[Max Reitz <mreitz@redhat.com>]

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On 2014-12-11 at 10:54, jun muzi wrote:
>
> Jun Li
> 2014-12-11 下午5:13于 "Max Reitz" <mreitz@redhat.com 
> <mailto:mreitz@redhat.com>>写道：
> >
> > On 2014-12-11 at 10:12, Kevin Wolf wrote:
> >>
> >> Am 11.12.2014 um 07:25 hat Jun Li geschrieben:
> >>>
> >>> Currently, as rbd driver do not support dynamic growth when write 
> beyond EOF,
> >>> so just print a clear error message.
> >>>
> >>> Signed-off-by: Jun Li <junmuzi@gmail.com <mailto:junmuzi@gmail.com>>
> >>> ---
> >>> v2:
> >>> Just use rbd_aio_write to realize error detection.
> >>> ---
> >>>   block/rbd.c | 4 ++++
> >>>   1 file changed, 4 insertions(+)
> >>>
> >>> diff --git a/block/rbd.c b/block/rbd.c
> >>> index 5b5a64a..710ee3e 100644
> >>> --- a/block/rbd.c
> >>> +++ b/block/rbd.c
> >>> @@ -661,6 +661,10 @@ static BlockAIOCB 
> *rbd_start_aio(BlockDriverState *bs,
> >>>       }
> >>>         if (r < 0) {
> >>> +        if (r == -EINVAL && cmd == RBD_AIO_WRITE) {
> >>> +            fprintf(stderr, "Image formats that grow on demand "
> >>> +                            "are not supported on rbd.\n");
> >>> +        }
> >>>           goto failed_completion;
> >>>       }
> >>
> >> You can't fill up the log with messages like that. In general, if you
> >> use fprintf() in a function whose call can be triggered by the guest,
> >> you're doing it wrong.
> >>
> >> What needs to be done is to check at open time whether the 
> configuration
> >> works. Max has sent a series to that end a while ago, not sure what its
> >> status is. I think it ended up depending on some blockdev work.
> >
> >
> > Yes, the status is that we need to remove "growable" from the BDS first.
> >
>
> Hi, which serial do you mean? Could you give a link? Thx.
>

Hi, here it is: 
http://lists.nongnu.org/archive/html/qemu-devel/2014-07/msg02088.html

Max

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