From owner-freebsd-hackers@freebsd.org Thu Nov 12 08:30:16 2015 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id BA9F4A2C380 for ; Thu, 12 Nov 2015 08:30:16 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 31F121CB4; Thu, 12 Nov 2015 08:30:16 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kostik@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id tAC8U7ZF094917 (version=TLSv1 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Thu, 12 Nov 2015 10:30:07 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua tAC8U7ZF094917 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id tAC8U6ik094914; Thu, 12 Nov 2015 10:30:06 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Thu, 12 Nov 2015 10:30:06 +0200 From: Konstantin Belousov To: Conrad Meyer Cc: Ivan Radovanovic , FreeBSD Hackers Subject: Re: Detecting new file name after receiving kevent's NOTE_RENAME Message-ID: <20151112083006.GH2257@kib.kiev.ua> References: <5641A2A5.7070909@gmail.com> <20151110081421.GL2257@kib.kiev.ua> <56426054.2070007@gmail.com> <20151111105656.GX2257@kib.kiev.ua> <20151111193612.GG2257@kib.kiev.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Nov 2015 08:30:16 -0000 On Wed, Nov 11, 2015 at 12:01:22PM -0800, Conrad Meyer wrote: > On Wed, Nov 11, 2015 at 11:36 AM, Konstantin Belousov > wrote: > > VOP_VPTOCNP() still must get the data somewhere. It is usually easy to > > provide the name for a synthetic file system, where the data is fully > > controlled by the filesystem. Also, it is always possible to provide the > > name for a directory on any unix-like filesystem, due to dotdot. Both > > cases are what handled by fs-specific implementations of VOP_VPTOCNP() > > and by the default code. > > > > For the rest, you e.g. must be able to answer with the name for regular > > inode on UFS, given the inode number. If you can provide such code, I > > will be quite amazed. > > I'm not sure what you're talking about. To have a NOTE_RENAME monitor > as originally discussed, the userspace program must have an fd open to > the vnode. With a vnode, the boring generic vn_fullpath and > vop_stdvptocnp can find a whole path using .. and directory traversal. > It may not be fast, but it is possible. I have no idea what you are talking about either. How dotdot algorithm can be used to find the parent directory for a regular inode ?