Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:52469 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934845AbcCPSVA (ORCPT ); Wed, 16 Mar 2016 14:21:00 -0400 Subject: Re: [PATCH nfs-utils v2] statd: Don't unregister statd service on failing to execute callout To: Toshiaki Makita References: <1455582968-4474-1-git-send-email-makita.toshiaki@lab.ntt.co.jp> Cc: Chuck Lever , linux-nfs@vger.kernel.org From: Steve Dickson Message-ID: <56E9A40A.5040405@RedHat.com> Date: Wed, 16 Mar 2016 14:20:58 -0400 MIME-Version: 1.0 In-Reply-To: <1455582968-4474-1-git-send-email-makita.toshiaki@lab.ntt.co.jp> Content-Type: text/plain; charset=windows-1252 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 02/15/2016 07:36 PM, Toshiaki Makita wrote: > statd calls atexit(statd_unregister) to unregister statd service on exit, > which actually has a side-effect that ha_callout() unregisters statd > service even when the child callout process exits on execl() failure. > > Certain clustering software's deployment script adds -H option with its > specified file non-existent, when it is configured not to use callout. > In other words, -H seems to be used no matter if callout is needed or not, > but when callout is unnecessary, the specified callout program is not > deployed. > This causes statd not to work once a lock is requested by its NFS client, > as execl() in ha_callout() results in ENOENT and exit() of the child > process calls exit-handler statd_unregister(). Eventually, the NFS client > gets stuck with messages "lockd: cannot monitor xxx" on the NFS server. > > Also, execl() could fail for other reasons like ENFILE or EIO as well. > > A forked child must not unregister the statd RPC server, so use > _exit(), which does not call any exit-handlers, instead of exit(). > > Signed-off-by: Toshiaki Makita > Reviewed-by: Chuck Lever Committed.... steved. > --- > v2: > - Simplified changelog. > > support/include/ha-callout.h | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/support/include/ha-callout.h b/support/include/ha-callout.h > index 1164336..a454bdb 100644 > --- a/support/include/ha-callout.h > +++ b/support/include/ha-callout.h > @@ -47,7 +47,7 @@ ha_callout(char *event, char *arg1, char *arg2, int arg3) > arg3 < 0 ? NULL : buf, > NULL); > perror("execl"); > - exit(2); > + _exit(2); > case -1: perror("fork"); > break; > default: pid = waitpid(pid, &ret, 0); >