Re: [PATCH] mmc: block: remove the check for whole block device for ioctl.

[fengwei.yin]

On 2016/3/16 19:48, Jon Hunter wrote:
> On 15/03/16 23:44, fengwei.yin wrote:
> > On 2016/3/15 22:31, Christoph Hellwig wrote:
> > > On Tue, Mar 15, 2016 at 11:26:07AM -0400, Yin, Fengwei wrote:
> > > > From: Fengwei Yin <fengwei.yin@xxxxxxxxxx>
> > > >
> > > > a5f5774c55a2e3ed75f4d6c5556b7bfcb726e6f0 introduced the whole block
> > > > device checking for MMC_IOC_CMD while the old code has no such check.
> > > >
> > > > It breaks some ioctl call like BLKROSET from user space. An example
> > > > is "adb remount" cmd. It prints out following error message:
> > > > "remount of /system failed; couldn't make block device XXXX writable: \
> > > > Operation not permitted."
> > > > while the command worked fine.
> > > >
> > > > This change move the whole block device checking only for
> > > > MMC_IOC_MULTI_CMD.
> > >
> > > I think mmc_blk_ioctl_cmd will need this as well, as will probably
> > > do any new ioctl.
> > >
> > > So I think the right fix is to simply return -EINVAL instead of
> > > EPERM if on a partition, which will make all the block layer ioctls
> > > works fine.
> > Fair enough.
> >
> > I will wait for one more day for further comments to the patch. And update
> > the patch tomorrow. Thanks a lot for looking into the patch.
>
> There is already a patch in the works for this [0].
>
> Cheers
> Jon
>
> [0] http://marc.info/?l=linux-mmc&m=145812340114153&w=2

Thanks a lot for the information. I will drop my patch.

Regards
Yin, Fengwei

>