Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750733AbWCVLNH (ORCPT ); Wed, 22 Mar 2006 06:13:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750743AbWCVLNG (ORCPT ); Wed, 22 Mar 2006 06:13:06 -0500 Received: from pat.uio.no ([129.240.130.16]:57853 "EHLO pat.uio.no") by vger.kernel.org with ESMTP id S1750733AbWCVLNE (ORCPT ); Wed, 22 Mar 2006 06:13:04 -0500 Subject: Re: DoS with POSIX file locks? From: Trond Myklebust To: Miklos Szeredi Cc: chrisw@sous-sol.org, matthew@wil.cx, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: <20060320121107.GE8980@parisc-linux.org> <20060320123950.GF8980@parisc-linux.org> <20060320153202.GH8980@parisc-linux.org> <1142878975.7991.13.camel@lade.trondhjem.org> <1142962083.7987.37.camel@lade.trondhjem.org> <20060321191605.GB15997@sorel.sous-sol.org> Content-Type: text/plain Date: Wed, 22 Mar 2006 06:12:47 -0500 Message-Id: <1143025967.12871.9.camel@lade.trondhjem.org> Mime-Version: 1.0 X-Mailer: Evolution 2.4.1 Content-Transfer-Encoding: 7bit X-UiO-Spam-info: not spam, SpamAssassin (score=-5, required 12, autolearn=disabled, UIO_MAIL_IS_INTERNAL -5.00) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 985 Lines: 24 On Wed, 2006-03-22 at 07:21 +0100, Miklos Szeredi wrote: > > i concur with Trond, there's no sane way to get rid of it w/out > > formalizing CLONE_FILES and locks on exec > > Probably there is. It would involve allocating a separate > lock-owner-ID stored in files_struct but separate from it. But it's > more complicated than simply not propagating locks on exec in the > CLONE_FILES case. That doesn't solve the fundamental problem. You would still have to be able to tell a remote server that some locks which previously belonged to one owner are being reallocated to several owners. That is not something that NFS, CIFS, AFS,... support, and I'd be surprised if any of the clustered filesystems support it either. Cheers, Trond - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/