Re: clone ioctl return values

[Chris Mason <clm@fb.com>]

On Tue, Nov 17, 2015 at 02:54:33AM -0800, Christoph Hellwig wrote:
> On Mon, Nov 16, 2015 at 04:28:22PM -0800, Darrick J. Wong wrote:
> > >  Try to reflink a device
> > > -XFS_IOC_CLONE_RANGE: Invalid argument
> > > +/mnt/test/test-157/dev1: No such device or address
> > 
> > Huh.  How did you get -ENODEV here?  I ran this on 4.3 and got -EINVAL.
> 
> This is current 4.4-rc.  The error seems accidental I think.
> 
> > Errrgh, the golden output of this test reflects the changes to the input
> > checking in Anna/Peng's copy_file_range/clone_file_range patches.
> > 
> > So, I guess the question is, should I reset the golden output to whatever
> > btrfs spits out before that patchset, and we'll consider the alterations
> > to be bugs/regressions/whatever that ought to be fixed in their patches?
> 
> Some bits in btrfs don't seem kosher.  But it would be good to
> explicitly send patches for btrfs to adopt to what might make more
> sense, and then follow it in the other implementations.

Btrfs does check for directories, but we should really be checking for
regular files too.  In the end, we only copy extents that would
correspond with regular files, so we're sneaking by.

-chris