From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH 0/2] Shared flags Date: Tue, 11 Nov 2008 10:09:40 +0000 Message-ID: <20081111100940.GA8968@shareable.org> References: <49183DF9.9010003@etersoft.ru> <20081111085211.GB2323@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20081111085211.GB2323@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org To: Christoph Hellwig Cc: Pavel Shilovsky , linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org List-Id: linux-api@vger.kernel.org Christoph Hellwig wrote: > On Mon, Nov 10, 2008 at 04:58:17PM +0300, Pavel Shilovsky wrote: > > #define O_DENYREAD 004000000 /* Do not permit read access */ > > #define O_DENYWRITE 010000000 /* Do not permit write access */ > > #define O_DENYDELETE 020000000 /* Do not permit delete or rename operations*/ > (2) you also need to enforce these semantics in the VFS for local > filesystems > > Now if (2) doesn't cause too much overhead I would say it's fine, if not > I would rather avoid it. On the face of it, they look like they have similar denial-of-service potential as mandatory locks. For example, a root process cleaning out /tmp gets stuck because a user process has O_DENYDELETE set. -- Jamie