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Date: Wed, 6 Jul 2016 06:57:21 +1000
From: Dave Chinner <david@fromorbit.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jan Kara <jack@suse.cz>, Seth Forshee <seth.forshee@canonical.com>,
	Jann Horn <jannh@google.com>,
	Linux API <linux-api@vger.kernel.org>,
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	linux-fsdevel@vger.kernel.org, Djalal Harouni <tixxdz@gmail.com>
Subject: Re: [PATCH v2 review 09/11] quota: Handle quota data stored in
 s_user_ns.
Message-ID: <20160705205721.GG27480@dastard>
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On Tue, Jul 05, 2016 at 10:34:49AM -0500, Eric W. Biederman wrote:
> The more I think of it the more I think that sounds like wisdom.
> Dropping this patch and replacing it by one that just does:
> 
> diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
> index d8fb0fd3ff6f..9c9890fe18b7 100644
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -2273,6 +2273,11 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
>                 error = -EINVAL;
>                 goto out_fmt;
>         }
> +       /* Filesystems outside of init_user_ns not yet supported */
> +       if (sb->s_user_ns != &init_user_ns) {
> +               error = -EINVAL;
> +               goto out_fmt;
> +       }
>         /* Usage always has to be set... */
>         if (!(flags & DQUOT_USAGE_ENABLED)) {
>                 error = -EINVAL;
> 
> 
> seems a lot more appropriate at this point.  That is enough to give a
> great big hint there is something that needs to be done but won't
> embrittle the code with untested corner cases.

You'll need to propagate that to all filesystems that have their own
quota implemenation, too.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com