From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: From: presotto@plan9.bell-labs.com To: 9fans@cse.psu.edu Subject: Re: [9fans] Ephase question. MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="upas-beyafuporkyaneqpnnyygoojdh" Date: Mon, 12 Aug 2002 21:39:40 -0400 Topicbox-Message-UUID: db04bf7e-eaca-11e9-9e20-41e7f4b1d025 This is a multi-part message in MIME format. --upas-beyafuporkyaneqpnnyygoojdh Content-Disposition: inline Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit This isn't new semantics. If you remove a file that someone else is using, too bad for him. There's nothing sacred about having a file open. If someone else has permissions to do nasty and nefarious things to it, they can. This is very different than Unix. --upas-beyafuporkyaneqpnnyygoojdh Content-Type: message/rfc822 Content-Disposition: inline Received: from plan9.cs.bell-labs.com ([135.104.9.2]) by plan9; Mon Aug 12 21:27:18 EDT 2002 Received: from mail.cse.psu.edu ([130.203.4.6]) by plan9; Mon Aug 12 21:27:17 EDT 2002 Received: from psuvax1.cse.psu.edu (psuvax1.cse.psu.edu [130.203.8.6]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id 04B4D199B9; Mon, 12 Aug 2002 21:27:07 -0400 (EDT) Delivered-To: 9fans@cse.psu.edu Received: from unicorn.math.spbu.ru (unicorn.math.spbu.ru [195.19.226.166]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id 4D5C41998C for <9fans@cse.psu.edu>; Mon, 12 Aug 2002 21:26:20 -0400 (EDT) Received: (from vugluskr@localhost) by unicorn.math.spbu.ru (8.9.3/8.9.3) id FAA10626 for 9fans@cse.psu.edu; Tue, 13 Aug 2002 05:26:18 +0400 From: "Roman V. Shaposhnick" To: 9fans@cse.psu.edu Message-ID: <20020813052618.A10336@unicorn.math.spbu.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0pre3i Subject: [9fans] Ephase question. Sender: 9fans-admin@cse.psu.edu Errors-To: 9fans-admin@cse.psu.edu X-BeenThere: 9fans@cse.psu.edu X-Mailman-Version: 2.0.11 Precedence: bulk Reply-To: 9fans@cse.psu.edu List-Id: Fans of the OS Plan 9 from Bell Labs <9fans.cse.psu.edu> List-Archive: Date: Tue, 13 Aug 2002 05:26:18 +0400 Hi everybody, digging inside 4th edition gave me some very unexpected results in terms of file access semantics in user space. But let me show a scenario first: first-user$ cat > /shared-directory/file blah-blah-blah second-user$ rm /shared-directory/file [first user after hitting ] "phase error -- directory entry not allocated" I was a little bit shocked at first, mainly because I've got so used to UNIX semantics of "once you get it -- it's yours", that I've been taking it for granted in Plan9 as well. Suddenly I can't remember how 3nd and 2nd editions behaved. Before now I was under the impression that regular unopened fids are mostly used for reference counting and once you grab a fid nobody can kill the actual object it refers to, but 4th edition proved me wrong. Even though I still can't understand why it behaves this way. Could somebody explain the rationale behind that to me, please ? And I'm really curios now about what obligations server is supposed to have when it accepts a new fid from a client for a given object. Thanks, Roman. --upas-beyafuporkyaneqpnnyygoojdh--