[dm-devel] [PATCH] Just inform and dont warn when DM_DEV_REMOVE is tried on a open device
Nikanth Karthikesan
knikanth at suse.de
Tue Apr 20 08:43:15 UTC 2010
On Tuesday 20 April 2010 13:30:18 Milan Broz wrote:
> On 04/20/2010 09:16 AM, Nikanth Karthikesan wrote:
> > Dont warn when DM_DEV_REMOVE ioctl is tried on a open device.
> >
> > On openSUSE when cryptsetup and udev interact, cryptsetup sometimes tries
> > to remove a dm device currently opened by blkid, which is not a serious
> > issue to print a kernel warning. The application should retry if -EBUSY
> > is returned. So let us make it an informational message instead.
> >
> > - DMWARN("unable to remove open device %s", hc->name);
> > + DMINFO("unable to remove open device %s", hc->name);
>
> NAK.
>
> Firstly, it is security problem if someone from udev rules tries to open
> temporary-cryptsetup device, it contains only private key material.
>
Okay.
> Secondly, it must be solved on application level and not paper kernel using
> patches which hides errors.
>
Agreed, it must be solved in the application level.
/me wonders whether this is an error worth a warning from kernel? Returning
-EBUSY seems enough. May be a KERN_INFO message... But yes rest of DM prints
warnings for these kind of events.
> FYI there is already patch in upstream cryptsetup which uses udev cookie
> mechanism. It still cannot solve artificial change events (which causes
> scan from rules randomly), but should help here. (will be in cryptsetup
> 1.1.1)
>
Oh, ok. Thanks for the pointer.
Thanks
Nikanth
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