From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout10.his.huawei.com (canpmsgout10.his.huawei.com [113.46.200.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 266033B28D; Mon, 19 Jan 2026 01:23:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.225 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768785827; cv=none; b=qbIK0NahkHoWnV5gFU31BWlLk6a8177/bXMZOfmKN9Yj0i78HGHE3KSRorcRNhuH+NNBeRfhDLMTvd0YYY1xFzj1/WxsmgDnTgHmr+NBONyFF2rS5qjVpJCoG5zRacn8w45dQpzp+jxy9QDTBBs48y7T3td6l6UZWx5tvFy3Jd4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768785827; c=relaxed/simple; bh=RWiszc1RJ1JBInh4yUYC+PGB1Hc+m/WqkB61cgLQwVc=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=a3dyEgy/mRNVQD1nT8geqjxOB8u4ZR/TFzvxy9EBdJ6p1TMOeB7C4/bJP2FJO/RGjw3sydin+aKElwyTkkHMVTFPY0DmA7hNHo7jTLj0gTlrW/SAx0k2kAD/cN3ZaMzFIm2FFj+6qMGDfl1cvd9c+7v6f+bhhnEmdukQW+95+js= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=5sx6wMC/; arc=none smtp.client-ip=113.46.200.225 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="5sx6wMC/" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=gba2ktAjy+g71eevs0XUENyEHWbD0Qkbdb1/QKJXxK0=; b=5sx6wMC/nc8WBo/cRYm/rpR6NqMoGK1/b5Dh82yOsbRZBDc5767PZtHZfUv8w2lvELDWgZARO lcxMYVF89CRW8F+V6ErvUK40hkRwkROchxRRpvwq/QShXniCu6BE9vEDijul5IDmackJNTY23I3 aZGv4isjWr+h+/A1qplP81Y= Received: from mail.maildlp.com (unknown [172.19.162.92]) by canpmsgout10.his.huawei.com (SkyGuard) with ESMTPS id 4dvXgz0W98z1K9D6; Mon, 19 Jan 2026 09:20:15 +0800 (CST) Received: from kwepemr500015.china.huawei.com (unknown [7.202.195.162]) by mail.maildlp.com (Postfix) with ESMTPS id 6735340565; Mon, 19 Jan 2026 09:23:35 +0800 (CST) Received: from [10.67.111.104] (10.67.111.104) by kwepemr500015.china.huawei.com (7.202.195.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 19 Jan 2026 09:23:34 +0800 Message-ID: Date: Mon, 19 Jan 2026 09:23:34 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v15 0/9] erofs: Introduce page cache sharing feature Content-Language: en-US To: Gao Xiang , Christoph Hellwig CC: , , , , , , References: <20260116095550.627082-1-lihongbo22@huawei.com> <20260116153656.GA21174@lst.de> From: Hongbo Li In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemr500015.china.huawei.com (7.202.195.162) Thanks for comments and attention. So in short: Two files with identical content fingerprints (user-defined, such as sha256) will share the same page cache which associated with an anonymous inode. Data operations are redirected to the anonymous inode while metadata operations (include locating the data position on disk) are still performed on the original inode(realinode). Sorry for the ambiguous annotation, and I will refine the cover-letter in next iteration to make it clear as possible. Thanks, Hongbo On 2026/1/17 0:43, Gao Xiang wrote: > > > On 2026/1/16 23:36, Christoph Hellwig wrote: > >> >> Also do you have a git tree for the whole feature? > > I prepared a test tree for Hongbo but it's v14: > https://git.kernel.org/pub/scm/linux/kernel/git/xiang/linux.git/log/?h=erofs/pagecache-share > > I think v15 is almost close to the final status, > I hope Hongbo addresses your comment and I will > review the remaining parts too and apply to > linux-next at the beginning of next week. > > Thanks, > Gao Xiang