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 <20220121075515.79311-4-songmuchun@bytedance.com> <Ye5YNbBbVymwfPB0@infradead.org>
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From:   Muchun Song <songmuchun@bytedance.com>
Date:   Mon, 24 Jan 2022 17:07:38 +0800
Message-ID: <CAMZfGtUb+xF9nFd21g8tagjRTCYg7R=HOVmXvVZhbtx8im3FDQ@mail.gmail.com>
Subject: Re: [PATCH 4/5] 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>, apopple@nvidia.com,
        Yang Shi <shy828301@gmail.com>, rcampbell@nvidia.com,
        Hugh Dickins <hughd@google.com>,
        Xiyu Yang <xiyuyang19@fudan.edu.cn>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        zwisler@kernel.org, linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        nvdimm@lists.linux.dev, LKML <linux-kernel@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>
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On Mon, Jan 24, 2022 at 3:41 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Fri, Jan 21, 2022 at 03:55:14PM +0800, Muchun Song wrote:
> > Reuse some infrastructure of page_mkclean_one() to let DAX can handle
> > similar case to fix this issue.
>
> Can you split out some of the infrastructure changes into proper
> well-documented preparation patches?

Will do. I'll introduce page_vma_mkclean_one in a prepared patch
and then fix the DAX issue in a separate patch. Thanks for your
suggestions.

>
> > +     pgoff_t pgoff_end = pgoff_start + npfn - 1;
> >
> >       i_mmap_lock_read(mapping);
> > -     vma_interval_tree_foreach(vma, &mapping->i_mmap, index, index) {
> > -             struct mmu_notifier_range range;
> > -             unsigned long address;
> > -
> > +     vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff_start, pgoff_end) {
>
> Please avoid the overly long lines here.  Just using start and end
> might be an easy option.
>

Will do.

Thanks.