From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-97.freemail.mail.aliyun.com (out30-97.freemail.mail.aliyun.com [115.124.30.97]) (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 0EC2A2C21EA; Sun, 16 Nov 2025 11:54:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.97 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763294098; cv=none; b=tzRnGroe4oVnce34MTifXwgKimg9EnwZtyls9/oJWxj/6uHZwk9YESpX0V8B6bFghIeB09AxzMs6BPgAZCt2FbG1wjtNqB3HQorKjVFUDs0YG7K7F3ommHZnQ+fHwU2OgDtc59aJfHoGNMXSRPotqKE92r1AeJnRc1QY0lRB+Ns= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763294098; c=relaxed/simple; bh=xtk8UQzrIzPbNaQvN2j0/EIZALpVBPnp+tlD9FHVG/I=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ErzzTkEL2dc1+maZSCOEUCzBzRlN8YvYC2lDWUxyuTIdV1WohEpegR85CSVXB2iBaDbXg5h3x0MnLZZEJIHA5cEP/2e1jB47kzcZsU7nLwyKVtA8naWTtaTRgjZE4h4oLHxKJSfWg5pZ911yz1Jg0K+GJlgC5R/oAX9JfT/qpzs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=W6/ozjk2; arc=none smtp.client-ip=115.124.30.97 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="W6/ozjk2" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1763294087; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=4v60toLnC7F9DIrdXiLX89QoxpYhFyqY7LCwty780Vs=; b=W6/ozjk2T9hvtvLrA8ogA8Zl0Qx0bZOVmgMjyDf3BouuKiDuwlRNtk6jaSj7neF/bA7rXxyiHZHKvB9x/I7bEAr4FctO3sIMStrVPMd4aYhxn43dCtpVBaz9coTeg0vK+quQStq2epd3pZZrYdoczhDhYJso6XjvRO234Q22tiU= Received: from 30.170.196.81(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0WsSHQp._1763294083 cluster:ay36) by smtp.aliyun-inc.com; Sun, 16 Nov 2025 19:54:44 +0800 Message-ID: <9e121004-fa70-4461-932b-9d30fd3733cc@linux.alibaba.com> Date: Sun, 16 Nov 2025 19:54:43 +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 v8 1/9] iomap: stash iomap read ctx in the private field of iomap_iter To: Hongbo Li , chao@kernel.org, brauner@kernel.org, djwong@kernel.org, amir73il@gmail.com, joannelkoong@gmail.com Cc: linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20251114095516.207555-1-lihongbo22@huawei.com> <20251114095516.207555-2-lihongbo22@huawei.com> From: Gao Xiang In-Reply-To: <20251114095516.207555-2-lihongbo22@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025/11/14 17:55, Hongbo Li wrote: > It's useful to get filesystem-specific information using the > existing private field in the @iomap_iter passed to iomap_{begin,end} > for advanced usage for iomap buffered reads, which is much like the > current iomap DIO. > > For example, EROFS needs it to: > > - implement an efficient page cache sharing feature, since iomap > needs to apply to anon inode page cache but we'd like to get the > backing inode/fs instead, so filesystem-specific private data is > needed to keep such information; > > - pass in both struct page * and void * for inline data to avoid > kmap_to_page() usage (which is bogus). > > Signed-off-by: Hongbo Li LGTM, and I think the case 2) is useful even without the main feature: Reviewed-by: Gao Xiang Thanks, Gao Xiang