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Date:   Sun, 23 Jan 2022 23:41:41 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     dan.j.williams@intel.com, willy@infradead.org, jack@suse.cz,
        viro@zeniv.linux.org.uk, akpm@linux-foundation.org,
        apopple@nvidia.com, shy828301@gmail.com, rcampbell@nvidia.com,
        hughd@google.com, xiyuyang19@fudan.edu.cn,
        kirill.shutemov@linux.intel.com, zwisler@kernel.org,
        linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH 4/5] dax: fix missing writeprotect the pte entry
Message-ID: <Ye5YNbBbVymwfPB0@infradead.org>
References: <20220121075515.79311-1-songmuchun@bytedance.com>
 <20220121075515.79311-4-songmuchun@bytedance.com>
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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?

> +	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.