Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751632AbdFIHFJ (ORCPT ); Fri, 9 Jun 2017 03:05:09 -0400 Received: from mail.linux-iscsi.org ([67.23.28.174]:48636 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751524AbdFIHFG (ORCPT ); Fri, 9 Jun 2017 03:05:06 -0400 Message-ID: <1496991903.28997.74.camel@haakon3.risingtidesystems.com> Subject: Re: [PATCH] configfs: Fix race between create_link and configfs_rmdir From: "Nicholas A. Bellinger" To: "Bryant G. Ly" Cc: Christoph Hellwig , target-devel , linux-fsdevel , linux-scsi , lkml , Joel Becker Date: Fri, 09 Jun 2017 00:05:03 -0700 In-Reply-To: References: <1496897514-20142-1-git-send-email-nab@linux-iscsi.org> <20170608072129.GA13433@lst.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1076 Lines: 25 On Thu, 2017-06-08 at 07:34 -0500, Bryant G. Ly wrote: > > Thanks Nic, > > > > applied to the configfs-for-next tree. I'm not entirely sure if we > > should bother adding this to 4.12 or if it hits rarely enough? > > > It hits for us pretty often when we have a GPFS setup with 10 hosts and 1k+ vms. > > That is how we discovered the bug in the first place. > Using a DATERA workload with 1K unique multi-tenant backend devices and 1K unique iscsi-target IQNs per node, I've never tripped across this particular bug.. However, our userspace built atop rtslib is enforcing tenant shutdown of individual rmdir(2) of /sys/kernel/config/target/$FABRIC/$WWN/$TPGT/, before rmdir(2) of /sys/kernel/config/target/core/$HBA/$DEV/ occurs. Based on Bryant's original backtrace with targetcli, it looks like the Novalink user-space is not enforcing this requirement across user-space processes doing fabric port symlink and backend device shutdown. That said it probably doesn't need a special v4.12-rc PULL, but based on Bryant's feedback it certainly does deserve a stable CC'.