Re: [PATCH 5/6] shmem: quota support

[Carlos Maiolino <cem@kernel.org>]

On Fri, Jul 14, 2023 at 03:48:12PM +0200, Christian Brauner wrote:
> On Fri, Jul 14, 2023 at 02:26:44PM +0200, Carlos Maiolino wrote:
> > > >
> > > > @@ -3736,6 +3853,18 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
> > > >  		ctx->noswap = true;
> > > >  		ctx->seen |= SHMEM_SEEN_NOSWAP;
> > > >  		break;
> > > > +	case Opt_quota:
> > > > +		ctx->seen |= SHMEM_SEEN_QUOTA;
> > > > +		ctx->quota_types |= (QTYPE_MASK_USR | QTYPE_MASK_GRP);
> > > > +		break;
> > > > +	case Opt_usrquota:
> > > > +		ctx->seen |= SHMEM_SEEN_QUOTA;
> > > > +		ctx->quota_types |= QTYPE_MASK_USR;
> > > > +		break;
> > > > +	case Opt_grpquota:
> > > > +		ctx->seen |= SHMEM_SEEN_QUOTA;
> > > > +		ctx->quota_types |= QTYPE_MASK_GRP;
> > > > +		break;
> > > >  	}
> > > >  	return 0;
> > >
> > > I mentioned this in an earlier review; following the sequence:
> > >
> > > if (ctx->seen & SHMEM_SEEN_QUOTA)
> > > -> shmem_enable_quotas()
> > >    -> dquot_load_quota_sb()
> > >
> > > to then figure out that in dquot_load_quota_sb() we fail if
> > > sb->s_user_ns != &init_user_ns is too subtle for a filesystem that's
> > > mountable by unprivileged users. Every few months someone will end up
> > > stumbling upon this code and wonder where it's blocked. There isn't even
> > > a comment in the code.
> >
> > I was just going to rebase these updated changes on top of linux-next, and I
> > realized the patches are already there. Wouldn't it be better if I send a
> > follow-up patch on top of linux-next, applying these changes, as a Fixes: tag?
> 
> I would just resend and fold the fix into the patch. There's no good
> reason to make this a separate patch imho.

sounds good. Thanks