Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220318074529.5261-1-songmuchun@bytedance.com>
 <20220318074529.5261-6-songmuchun@bytedance.com> <YjmK0aaCu/FI/t7T@infradead.org>
In-Reply-To: <YjmK0aaCu/FI/t7T@infradead.org>
From:   Muchun Song <songmuchun@bytedance.com>
Date:   Tue, 22 Mar 2022 16:46:59 +0800
Message-ID: <CAMZfGtVBqVwHpoaotp+HF8+Sh-U3onKBBbQY69UT9SrGGOKVtQ@mail.gmail.com>
Subject: Re: [PATCH v5 5/6] dax: fix missing writeprotect the pte entry
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Dan Williams <dan.j.williams@intel.com>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alistair Popple <apopple@nvidia.com>,
        Yang Shi <shy828301@gmail.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        Hugh Dickins <hughd@google.com>,
        Xiyu Yang <xiyuyang19@fudan.edu.cn>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Ross Zwisler <zwisler@kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux NVDIMM <nvdimm@lists.linux.dev>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        Xiongchun duan <duanxiongchun@bytedance.com>,
        Muchun Song <smuchun@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Mar 22, 2022 at 4:37 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> > +static void dax_entry_mkclean(struct address_space *mapping, unsigned long pfn,
> > +                           unsigned long npfn, pgoff_t start)
> >  {
> >       struct vm_area_struct *vma;
> > +     pgoff_t end = start + npfn - 1;
> >
> >       i_mmap_lock_read(mapping);
> > +     vma_interval_tree_foreach(vma, &mapping->i_mmap, start, end) {
> > +             pfn_mkclean_range(pfn, npfn, start, vma);
> >               cond_resched();
> >       }
> >       i_mmap_unlock_read(mapping);
>
>
> Is there any point in even keeping this helper vs just open coding it
> in the only caller below?

Good point. I'll fold dax_entry_mkclean() into the caller.

>
> Otherwise looks good:
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Thanks.