From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753921Ab0ESQxE (ORCPT ); Wed, 19 May 2010 12:53:04 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:56594 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751883Ab0ESQxB (ORCPT ); Wed, 19 May 2010 12:53:01 -0400 Date: Wed, 19 May 2010 09:49:35 -0700 (PDT) From: Linus Torvalds To: Miklos Szeredi cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, jens.axboe@oracle.com, akpm@linux-foundation.org Subject: Re: [patch] pipe: add support for shrinking and growing pipes In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 19 May 2010, Miklos Szeredi wrote: > > One issue I see is that it's possible to grow pipes indefinitely. > Should this be restricted to privileged users? Yes. But perhaps only if it grows past the default (or perhaps "default*2" or similar). That way a normal user could shrink the pipe buffers, and then grow them again if he wants to. Oh, and I think you need to also require that there be at least two buffers. Otherwise we can't guarantee POSIX behavior, I think. Linus