Re: ext4 quota tests fail with CONFIG_QFMT_V2=n

[Omar Sandoval <osandov@osandov.com>]

On Wed, Jan 17, 2018 at 11:08:19PM -0500, Theodore Ts'o wrote:
> On Wed, Jan 17, 2018 at 06:16:10PM -0800, Omar Sandoval wrote:
> > > I'd like to ask a different question, which is there a reason to
> > > support CONFIG_QFMT_V1 && !CONFIG_QFMT_V2?  Maybe we should just
> > > always enable CONFIG_QFMT_V2, and simplify the test matrix?
> > 
> > FWIW,
> > 
> > # CONFIG_QFMT_V1 is not set
> > # CONFIG_QFMT_V2 is not set
> > 
> > on this kernel.
> 
> Huh.... I don't think that's a valid kernel configuration at all.  Or
> rather, it's allowed by Kconfig, but it shouldn't be, since without
> any quota formats enabled, the quota code is completely useless, and
> you might as well not compile it in, as near as I can tell.
> 
> Was this configuration one that you were deliberately using; and if
> so, what for?   Or was it one that was created accidentally?

It's not intentional. I'm assuming what happened here is we disabled any
modules we weren't using, but CONFIG_QUOTA happened to stay on. Is it
also the case for XFS that quotas are useless without qfmt-v2?

> In any case, ext4's quota feature has to have the V2 quota format
> enabled, or it's not going to work properly.  We should remove
> EXT4_FEATURE_RO_COMPAT_QUOTA from the list of supported features if
> CONFIG_QUOTA or CONFIG_QFMT_V2 are not set.
> 
> 					- Ted