From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E3392328627; Mon, 12 Jan 2026 09:10:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768209039; cv=none; b=br0Uld26Gbw6/RN+xMCHIJEnFoTmfnKlESbRko7b7XyyK20DdX/yoPuQoBS7qJy8YOwL108nXPD2zZrF469MCdd7XEP83NC8Cu3upFQsgDUQ6O5HsuGs0AL5w0HFZQCKavgFk5siIpYQndhr4Gw+C7IqwEVcUl+iI365aPYhbuA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768209039; c=relaxed/simple; bh=anQHeyKqkGvMtUYSA1DooDkEFH3wVejNmY4OIw3NEhE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=meTJvSN710WMtpm7ZPRBtP0UzeExpxDPrDuT75pQbUn+YHwtj2NMzH9q1dW2wWI5V+8mCqVvO+O4InWSO5GzQQMMofH1sUHi/x/bsDwghmXWk1twAKglx8cZLmYDDG42KzH5fQrVxnV7Ll8dnd03epedVXpxjS01338XypI7Fww= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZbzVYqFP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZbzVYqFP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B75CC116D0; Mon, 12 Jan 2026 09:10:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768209038; bh=anQHeyKqkGvMtUYSA1DooDkEFH3wVejNmY4OIw3NEhE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZbzVYqFPzcix9RRop5g1a3lPwK0RW1lo5Hk2qugRk2dqccUER0hbhTfxfav4u4KUJ vhT1zdaeCazrYVMeNO9oWNmJJ61DCD/lC6W+sLQCZrd2tWowNxFVLN99KKvyOTbRiM 4ThZaKaZKELNKz1FsvjoMDbqZzfQwB7jLqKT57Z3e71GyWb9xqlSfBboVKSL8XZ6VF CSK+yn7xKdb5nx7HvkYbTqa1B/5u0X9J/ovHRxJB7HGchFBTdDMjsYgw3yiQT4Hdgm 8sKOMJY2G9WJqRuaR5NRLWploez8ETzLoeVrCeSeXcAVq7otgI56REKuMglpF9YvYP fjgpxJa33C0BQ== Date: Mon, 12 Jan 2026 10:10:33 +0100 From: Christian Brauner To: Hongbo Li Cc: hsiangkao@linux.alibaba.com, chao@kernel.org, djwong@kernel.org, amir73il@gmail.com, hch@lst.de, linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v14 03/10] fs: Export alloc_empty_backing_file Message-ID: <20260112-renitent-mitbringen-e94874417a07@brauner> References: <20260109102856.598531-1-lihongbo22@huawei.com> <20260109102856.598531-4-lihongbo22@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260109102856.598531-4-lihongbo22@huawei.com> On Fri, Jan 09, 2026 at 10:28:49AM +0000, Hongbo Li wrote: > There is no need to open nonexistent real files if backing files > couldn't be backed by real files (e.g., EROFS page cache sharing > doesn't need typical real files to open again). > > Therefore, we export the alloc_empty_backing_file() helper, allowing > filesystems to dynamically set the backing file without real file > open. This is particularly useful for obtaining the correct @path > and @inode when calling file_user_path() and file_user_inode(). > > Signed-off-by: Hongbo Li > Reviewed-by: Gao Xiang > Acked-by: Amir Goldstein > --- Acked-by: Christian Brauner