From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3B68EC433E4 for ; Mon, 13 Jul 2020 07:42:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1384D20720 for ; Mon, 13 Jul 2020 07:42:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728968AbgGMHm4 convert rfc822-to-8bit (ORCPT ); Mon, 13 Jul 2020 03:42:56 -0400 Received: from lithops.sigma-star.at ([195.201.40.130]:41180 "EHLO lithops.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725818AbgGMHmz (ORCPT ); Mon, 13 Jul 2020 03:42:55 -0400 Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id D62F86261CAB; Mon, 13 Jul 2020 09:42:52 +0200 (CEST) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id HEIT-oUNXO2T; Mon, 13 Jul 2020 09:42:52 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id DC4CC6071A74; Mon, 13 Jul 2020 09:42:51 +0200 (CEST) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id Jw1EuLf1JemD; Mon, 13 Jul 2020 09:42:51 +0200 (CEST) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id B4DF4607401D; Mon, 13 Jul 2020 09:42:51 +0200 (CEST) Date: Mon, 13 Jul 2020 09:42:51 +0200 (CEST) From: Richard Weinberger To: linux-kernel Cc: tj@kernel.org, Greg Kroah-Hartman , ebiederm@xmission.com, dan j williams Message-ID: <26112734.125046.1594626171647.JavaMail.zimbra@nod.at> In-Reply-To: <20200704205619.11172-1-richard@nod.at> References: <20200704205619.11172-1-richard@nod.at> Subject: Re: [PATCH] [RFC] kernfs: Allow vm_ops->close() if VMA is never split MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Originating-IP: [195.201.40.130] X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF68 (Linux)/8.8.12_GA_3809) Thread-Topic: kernfs: Allow vm_ops->close() if VMA is never split Thread-Index: 5s35c3UGXLSfPDR9XGUGZynzLnIxuA== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- Ursprüngliche Mail ----- > Von: "richard" > An: "linux-kernel" > CC: tj@kernel.org, "Greg Kroah-Hartman" , ebiederm@xmission.com, "dan j williams" > , "richard" > Gesendet: Samstag, 4. Juli 2020 22:56:19 > Betreff: [PATCH] [RFC] kernfs: Allow vm_ops->close() if VMA is never split > 10 years ago commit a6849fa1f7d7 ("sysfs: Fail bin file mmap if vma close is > implemented.") > removed support for vm_ops->close() for mmap on sysfs. > As far I understand the reason is that due to the wrapping in kernfs > every VMA split operation needs to be tracked to call vm_ops->close() > for all fragments. This is not feasible with reasonable effort. > > Since commit 31383c6865a5 ("mm, hugetlbfs: introduce ->split() to > vm_operations_struct") > we can get notified as soon a VMA is split, this can help to relax the > restriction. > So I propose to allow having a custom close under the condition that a > VMA cannot get split. > > Signed-off-by: Richard Weinberger *friendly ping* Thanks, //richard