Re: [PATCH v4 1/3] fs: hoist EFSCORRUPTED definition into uapi header

[David Sterba]

On Mon, Jan 21, 2019 at 04:54:54PM -0500, Theodore Y. Ts'o wrote:
> On Fri, Jan 18, 2019 at 05:14:38PM +0100, Jann Horn wrote:
> > Multiple filesystems can already return EFSCORRUPTED errors to userspace;
> > however, so far, definitions of EFSCORRUPTED were in filesystem-private
> > headers.
> > 
> > I wanted to use EUCLEAN to indicate data corruption in the VFS layer;
> > Dave Chinner says that I should instead hoist the definitions of
> > EFSCORRUPTED into the UAPI header and then use EFSCORRUPTED.
> > 
> > This patch is marked for stable backport because it is a prerequisite for
> > the following patch.
> > 
> > Cc: stable@xxxxxxxxxxxxxxx
> > Suggested-by: Dave Chinner <david@xxxxxxxxxxxxx>
> > Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
> 
> Before we enshrine the overloading of EUCLEAN and EFSCORRUPTED, I
> wonder if we should at least consider the option of assigning a new
> error code number for EFSCORRUPTED.  The downside of doing this is
> that for a while, older versions glibc won't have strerror/perror
> translation for the new error code.  On the other hand, I'm not sure
> it will be that much more confusing to the average user than
> "Structure needs cleaning".  :-)
>
> The upside of assigning a new error code is that in a year or two,
> we'll actually have an intelligible error message showing up in log
> files and in user's terminals.

I vote for a new code with a better message than EUCLEAN provides.