From patchwork Wed Nov 2 00:25:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 9408361 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A692A60585 for ; Wed, 2 Nov 2016 00:25:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 96EE629BB8 for ; Wed, 2 Nov 2016 00:25:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8BAC129C0D; Wed, 2 Nov 2016 00:25:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_TVD_MIME_EPI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1279D29BB8 for ; Wed, 2 Nov 2016 00:25:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755047AbcKBAZx (ORCPT ); Tue, 1 Nov 2016 20:25:53 -0400 Received: from mx2.suse.de ([195.135.220.15]:48654 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755056AbcKBAZw (ORCPT ); Tue, 1 Nov 2016 20:25:52 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id BECA0ABFC; Wed, 2 Nov 2016 00:25:50 +0000 (UTC) From: NeilBrown To: Steve Dickson Date: Wed, 02 Nov 2016 11:25:43 +1100 Cc: Linux NFS Mailing List Subject: [PATCH nfs-utils v2] nfs-server-generator: avoid using external services. In-Reply-To: References: <8737k0215d.fsf@notabene.neil.brown.name> <4a004767-e7cd-d427-706e-4e144b7bdbbb@RedHat.com> <87wpgnq8jx.fsf@notabene.neil.brown.name> User-Agent: Notmuch/0.22.1 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-suse-linux-gnu) Message-ID: <87lgx2ram0.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP nfs-server-generator is run very early when a lot of services are not yet started, so it mustn't depend on them. Currently it can try to use hostname lookup and syslog. Using hostname lookup can cause errors and when these are logged via syslog, it can cause the generator to block indefinitely Hostname-lookup is not needed, as we don't use the host issue, and sending message to stderr is sufficient for the generator. Disabling syslog is easy - call a function that sets a static variable. Disabling hostname lookup requires adding an "ignore_hosts" flags to export_read and export_d_read(). Signed-off-by: NeilBrown --- Hi Steve, I decided that you were right and the interface wasn't really very nice. And it wasn't that hard to make a more sensible interface. So I did that. Less need for comments, but I put an appropriate comment in anyway. Thanks, NeilBrown support/export/export.c | 13 +++++++++---- support/include/exportfs.h | 4 ++-- systemd/nfs-server-generator.c | 4 ++-- utils/exportfs/exportfs.c | 4 ++-- 4 files changed, 15 insertions(+), 10 deletions(-) diff --git a/support/export/export.c b/support/export/export.c index 0b8a858c2c74..15e91cb3eb71 100644 --- a/support/export/export.c +++ b/support/export/export.c @@ -70,11 +70,15 @@ static void warn_duplicated_exports(nfs_export *exp, struct exportent *eep) /** * export_read - read entries from /etc/exports * @fname: name of file to read from + * @ignore_hosts: don't check validity of host names * * Returns number of read entries. + * @ignore_hosts can be set when the host names won't be used + * and when getting delays or errors due to problems with + * hostname looking is not acceptable. */ int -export_read(char *fname) +export_read(char *fname, int ignore_hosts) { struct exportent *eep; nfs_export *exp; @@ -83,7 +87,7 @@ export_read(char *fname) setexportent(fname, "r"); while ((eep = getexportent(0,1)) != NULL) { - exp = export_lookup(eep->e_hostname, eep->e_path, 0); + exp = export_lookup(eep->e_hostname, eep->e_path, ignore_hosts); if (!exp) { if (export_create(eep, 0)) /* possible complaints already logged */ @@ -100,13 +104,14 @@ export_read(char *fname) /** * export_d_read - read entries from /etc/exports. * @fname: name of directory to read from + * @ignore_hosts: don't check validity of host names * * Returns number of read entries. * Based on mnt_table_parse_dir() in * util-linux-ng/shlibs/mount/src/tab_parse.c */ int -export_d_read(const char *dname) +export_d_read(const char *dname, int ignore_hosts) { int n = 0, i; struct dirent **namelist = NULL; @@ -150,7 +155,7 @@ export_d_read(const char *dname) continue; } - volumes += export_read(fname); + volumes += export_read(fname, ignore_hosts); } for (i = 0; i < n; i++) diff --git a/support/include/exportfs.h b/support/include/exportfs.h index f033329b5fd2..32d4fe95fd7e 100644 --- a/support/include/exportfs.h +++ b/support/include/exportfs.h @@ -134,8 +134,8 @@ struct addrinfo * client_resolve(const struct sockaddr *sap); int client_member(const char *client, const char *name); -int export_read(char *fname); -int export_d_read(const char *dname); +int export_read(char *fname, int ignore_hosts); +int export_d_read(const char *dname, int ignore_hosts); void export_reset(nfs_export *); nfs_export * export_lookup(char *hname, char *path, int caconical); nfs_export * export_find(const struct addrinfo *ai, diff --git a/systemd/nfs-server-generator.c b/systemd/nfs-server-generator.c index af8bb52bfbd7..44895f1f8582 100644 --- a/systemd/nfs-server-generator.c +++ b/systemd/nfs-server-generator.c @@ -102,8 +102,8 @@ int main(int argc, char *argv[]) path = malloc(strlen(argv[1]) + sizeof(dirbase) + sizeof(filebase)); if (!path) exit(2); - if (export_read(_PATH_EXPORTS) + - export_d_read(_PATH_EXPORTS_D) == 0) + if (export_read(_PATH_EXPORTS, 1) + + export_d_read(_PATH_EXPORTS_D, 1) == 0) /* Nothing is exported, so nothing to do */ exit(0); diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c index 4ac2c15ae13e..5136810029d0 100644 --- a/utils/exportfs/exportfs.c +++ b/utils/exportfs/exportfs.c @@ -183,8 +183,8 @@ main(int argc, char **argv) atexit(release_lockfile); if (f_export && ! f_ignore) { - if (! (export_read(_PATH_EXPORTS) + - export_d_read(_PATH_EXPORTS_D))) { + if (! (export_read(_PATH_EXPORTS, 0) + + export_d_read(_PATH_EXPORTS_D, 0))) { if (f_verbose) xlog(L_WARNING, "No file systems exported!"); }