Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-yh0-f52.google.com ([209.85.213.52]:46394 "EHLO mail-yh0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750731Ab3CFBd7 (ORCPT ); Tue, 5 Mar 2013 20:33:59 -0500 Date: Tue, 5 Mar 2013 17:28:00 -0800 From: Tejun Heo To: "Myklebust, Trond" Cc: Jeff Layton , Oleg Nesterov , Mandeep Singh Baines , Ming Lei , "J. Bruce Fields" , Linux Kernel Mailing List , "linux-nfs@vger.kernel.org" , "Rafael J. Wysocki" , Andrew Morton , Ingo Molnar Subject: Re: LOCKDEP: 3.9-rc1: mount.nfs/4272 still has locks held! Message-ID: <20130306012800.GH1227@htj.dyndns.org> References: <20130304092310.1d21100c@tlielax.poochiereds.net> <20130304205307.GA13527@redhat.com> <4FA345DA4F4AE44899BD2B03EEEC2FA9286AEEB0@sacexcmbx05-prd.hq.netapp.com> <20130305082308.6607d4db@tlielax.poochiereds.net> <20130305174648.GF12795@htj.dyndns.org> <20130305174954.GG12795@htj.dyndns.org> <20130305140312.243cb094@tlielax.poochiereds.net> <4FA345DA4F4AE44899BD2B03EEEC2FA9286B1246@sacexcmbx05-prd.hq.netapp.com> <20130306011423.GF1227@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20130306011423.GF1227@htj.dyndns.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Mar 05, 2013 at 05:14:23PM -0800, Tejun Heo wrote: > Then, the operation simply isn't freezable while in progress and > should be on the receiving end of failed-to-freeze error message and > users who depend on suspend/hibernation working properly should be > advised away from using nfs. > > It doesn't really changes anything. The current code is buggy. We're > just not enforcing the rules strictly and people aren't hitting the > bug often enough. Just one more thing. Also, not being able to do retries without side-effect doesn't mean it can't do retries at all. There are syscalls which need to do things differently on re-entry (forgot which one but there are several). They record the necessary state in the restart block and resume from where they left off on re-entry. It sure is hairy but is doable and we already have supporting infrastructure. Not sure whether that would be worthwhile tho. Thanks. -- tejun