Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:60485 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932184AbbLGQmF (ORCPT ); Mon, 7 Dec 2015 11:42:05 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 40D8767C20 for ; Mon, 7 Dec 2015 16:42:05 +0000 (UTC) From: Scott Mayhew To: steved@redhat.com Cc: linux-nfs@vger.kernel.org Subject: [nfs-utils PATCH] statd: make statd_canonical_name emit a warning if the presentation address maps to an empty hostname Date: Mon, 7 Dec 2015 11:42:03 -0500 Message-Id: <1449506523-21897-1-git-send-email-smayhew@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Certain name resolution misconfigurations (for example, a hosts file entry with an ip address but no hostnames) can cause get_nameinfo() to return an empty string in buf, which will lead to this cryptic failure: Dec 7 09:37:44 hostname rpc.statd[8024]: Failed to insert: creating /var/lib/nfs/statd/sm/: Is a directory Dec 7 09:37:44 hostname rpc.statd[8024]: STAT_FAIL to hostname.example.com for SM_MON of 192.168.1.2 Dec 7 09:37:44 hostname kernel: lockd: cannot monitor 192.168.1.2 It's better in that case to just go ahead and use the presentation address and log a more helpful warning: Dec 7 10:24:52 hostname rpc.statd[14224]: get_nameinfo returned empty hostname for 10.10.183.219. Fix your name resolution! Signed-off-by: Scott Mayhew --- utils/statd/hostname.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c index c61087c..86d11ca 100644 --- a/utils/statd/hostname.c +++ b/utils/statd/hostname.c @@ -211,6 +211,12 @@ statd_canonical_name(const char *hostname) /* OK to use presentation address, * if no reverse map exists */ return strdup(hostname); + else if (buf[0] == '\0') { + xlog_warn("get_nameinfo returned empty hostname for " + "%s. Fix your name resolution!", + hostname); + return strdup(hostname); + } return strdup(buf); } -- 2.4.3