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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5A7DC3DA7A for ; Mon, 2 Jan 2023 14:01:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236056AbjABOBv convert rfc822-to-8bit (ORCPT ); Mon, 2 Jan 2023 09:01:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232919AbjABOBq (ORCPT ); Mon, 2 Jan 2023 09:01:46 -0500 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E6B06547 for ; Mon, 2 Jan 2023 06:01:44 -0800 (PST) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-312-47WmmqTFMC28WcHHaiOhtA-1; Mon, 02 Jan 2023 14:01:41 +0000 X-MC-Unique: 47WmmqTFMC28WcHHaiOhtA-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Mon, 2 Jan 2023 14:01:38 +0000 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.044; Mon, 2 Jan 2023 14:01:38 +0000 From: David Laight To: 'Ameer Hamza' , "viro@zeniv.linux.org.uk" , "jlayton@kernel.org" , "chuck.lever@oracle.com" , "arnd@arndb.de" , "guoren@kernel.org" , "palmer@rivosinc.com" , "f.fainelli@gmail.com" , "slark_xiao@163.com" , "richard.henderson@linaro.org" , "ink@jurassic.park.msu.ru" , "mattst88@gmail.com" , "James.Bottomley@HansenPartnership.com" , "deller@gmx.de" , "davem@davemloft.net" CC: "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "awalker@ixsystems.com" , "sparclinux@vger.kernel.org" , "linux-parisc@vger.kernel.org" , "linux-alpha@vger.kernel.org" Subject: RE: [PATCH v2] Add new open(2) flag - O_EMPTY_PATH Thread-Topic: [PATCH v2] Add new open(2) flag - O_EMPTY_PATH Thread-Index: AQHZHXO7YJxmMel9jU25EiVio9tPeK6LKkFQ Date: Mon, 2 Jan 2023 14:01:38 +0000 Message-ID: <4b39cf528148470c934fb5823b35e9d5@AcuMS.aculab.com> References: <202212310842.ysbymPHY-lkp@intel.com> <20221231235618.117201-1-ahamza@ixsystems.com> In-Reply-To: <20221231235618.117201-1-ahamza@ixsystems.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ameer Hamza > Sent: 31 December 2022 23:56 > > This patch adds a new flag O_EMPTY_PATH that allows openat and open > system calls to open a file referenced by fd if the path is empty, > and it is very similar to the FreeBSD O_EMPTY_PATH flag. This can be > beneficial in some cases since it would avoid having to grant /proc > access to things like samba containers for reopening files to change > flags in a race-free way. > But what does it do? (Apart from add code to a common kernel code path.) David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)