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Date:   Fri, 2 Sep 2022 15:30:10 +0300
From:   "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
To:     Chao Peng <chao.p.peng@linux.intel.com>
Cc:     Hugh Dickins <hughd@google.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>, kvm@vger.kernel.org,
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        Jim Mattson <jmattson@google.com>,
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        Thomas Gleixner <tglx@linutronix.de>,
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        x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
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Subject: Re: [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM
 guest private memory
Message-ID: <20220902123010.zfyv6apmo3v67a2i@box.shutemov.name>
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On Fri, Sep 02, 2022 at 06:27:57PM +0800, Chao Peng wrote:
> > +	if (flags & MFD_INACCESSIBLE) {
> > +		struct file *inaccessible_file;
> > +
> > +		inaccessible_file = memfd_mkinaccessible(file);
> > +		if (IS_ERR(inaccessible_file)) {
> > +			error = PTR_ERR(inaccessible_file);
> > +			goto err_file;
> > +		}
> 
> The new file should alse be marked as O_LARGEFILE otherwise setting the
> initial size greater than 2^31 on the fd will be refused by ftruncate().
> 
> +               inaccessible_file->f_flags |= O_LARGEFILE;
> +

Good catch. Thanks.

I will modify memfd_mkinaccessible() to do this.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov