From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from bombadil.infradead.org ([198.137.202.9]:59271 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751805AbaDUPBO (ORCPT ); Mon, 21 Apr 2014 11:01:14 -0400 Date: Mon, 21 Apr 2014 08:01:13 -0700 From: Christoph Hellwig To: Trond Myklebust Cc: Bruce Fields , linux-nfs@vger.kernel.org Subject: Re: [PATCH 00/70] NFSd lock scalability patches Message-ID: <20140421150113.GA24334@infradead.org> References: <1397846704-14567-1-git-send-email-trond.myklebust@primarydata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1397846704-14567-1-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: I think the series introduces some find vs alloc races where a function first tries to find an existing structure in a lookup structure, then allocates a new one, but doesn't check for another allocation that could have happened in the meantime. - lookup_or_create_lock_state for lock stateids - I can't find any protection for the creation/addition of files and open stateids in the whole open machinery (nfsd4_open, nfsd4_process_open1 and nfsd4_process_open2), but I also generally have trouble following that code. - similarly I can't find much of a protection against this sort of race for the various state owners.