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Date:   Fri, 23 Jul 2021 16:05:29 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Gao Xiang <hsiangkao@linux.alibaba.com>,
        linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        "Darrick J . Wong" <djwong@kernel.org>,
        Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
Subject: Re: [PATCH v6] iomap: support tail packing inline read
Message-ID: <YPrauRjG7+vCw7f9@casper.infradead.org>
References: <20210722031729.51628-1-hsiangkao@linux.alibaba.com>
 <20210722053947.GA28594@lst.de>
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On Thu, Jul 22, 2021 at 07:39:47AM +0200, Christoph Hellwig wrote:
> @@ -675,7 +676,7 @@ static size_t iomap_write_end_inline(struct inode *inode, struct page *page,
>  
>  	flush_dcache_page(page);
>  	addr = kmap_atomic(page);
> -	memcpy(iomap->inline_data + pos, addr + pos, copied);
> +	memcpy(iomap_inline_buf(iomap, pos), addr + pos, copied);

This is wrong; pos can be > PAGE_SIZE, so this needs to be
addr + offset_in_page(pos).