From: James Bottomley Subject: Re: [PATCH v2 0/4] quota: add project quota support Date: Sun, 10 Aug 2014 13:47:24 -0700 Message-ID: <1407703644.8477.1.camel@jarvis.lan> References: <20140808223335.GQ25145@thunk.org> <20140809172427.GF15431@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Li Xi , linux-fsdevel@vger.kernel.org, Ext4 Developers List , viro@zeniv.linux.org.uk, hch@infradead.org, Jan Kara , Andreas Dilger , "Niu, Yawei" To: Theodore Ts'o Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:56405 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751076AbaHJUr1 (ORCPT ); Sun, 10 Aug 2014 16:47:27 -0400 In-Reply-To: <20140809172427.GF15431@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sat, 2014-08-09 at 13:24 -0400, Theodore Ts'o wrote: > The last time I asked why in the world anyone would want to use this > feature, the only use case that I heard was people who were using > containers, and where the all of the project id's were inside a > chroot. Hence, any questions I asked about what happens when a file > gets moved out from the hierarchy were hand-waved away, since inside a > chroot, it could never happen. Actually, I don't believe that's entirely accurate. The performance problem with shared filesystem roots for containers has meant OpenVZ has been using a block root for a while. However, we still support the old shared filesystem root, but for quota's within the chroot, we use a subtree quota system (not a project quota) for which Dmitry Monakhov posted the patches several times a couple of years ago. James