Return-Path: Received: from mx2.netapp.com ([216.240.18.37]:54976 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759331Ab0HFS3a (ORCPT ); Fri, 6 Aug 2010 14:29:30 -0400 Message-ID: <4C5C54A3.1010206@netapp.com> Date: Fri, 06 Aug 2010 14:29:55 -0400 From: Bryan Schumaker To: David Howells CC: Trond Myklebust , linux-nfs@vger.kernel.org Subject: Re: [PATCH] NFS use kernel DNS resolver References: <1280970596.2865.28.camel@heimdal.trondhjem.org> <4C59D1A3.5030406@netapp.com> <13523.1281060342@redhat.com> In-Reply-To: <13523.1281060342@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 The patch is below. Thanks! Bryan Use the kernel DNS resolver to translate hostnames to IP addresses. Create a new config option to choose between the legacy DNS resolver and the new resolver. Signed-off-by: Bryan Schumaker diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index a43d07e..10eebc5 100644 --- a/fs/nfs/Kconfig +++ b/fs/nfs/Kconfig @@ -100,3 +100,19 @@ config NFS_FSCACHE help Say Y here if you want NFS data to be cached locally on disc through the general filesystem cache manager + +config NFS_USE_LEGACY_DNS + bool "Use the legacy NFS DNS resolver" + depends on NFS_V4 + help + The kernel now provides a method for translating a host name into an + IP address. Select Y here if you would rather use your own DNS + resolver script. + + If unsure, say N + +config NFS_USE_KERNEL_DNS + bool + depends on NFS_V4 && !NFS_USE_LEGACY_DNS + select DNS_RESOLVER + default y diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c index 76fd235..7e5d3a9 100644 --- a/fs/nfs/dns_resolve.c +++ b/fs/nfs/dns_resolve.c @@ -6,6 +6,37 @@ * Resolves DNS hostnames into valid ip addresses */ +#ifdef CONFIG_NFS_USE_KERNEL_DNS + +#include +#include + +ssize_t nfs_dns_resolve_name(char *name, size_t namelen, + struct sockaddr *sa, size_t salen) +{ + ssize_t ret; + char *ip_addr = NULL; + int ip_len; + + ip_len = dns_query(NULL, name, namelen, NULL, &ip_addr, NULL); + if (ip_len > 0) + ret = rpc_pton(ip_addr, ip_len, sa, salen); + else + ret = -ESRCH; + kfree(ip_addr); + return ret; +} + +inline int nfs_dns_resolver_init(void) +{ + return 0; +} + +inline void nfs_dns_resolver_destroy(void) +{} + +#else + #include #include #include @@ -346,3 +377,4 @@ void nfs_dns_resolver_destroy(void) nfs_cache_unregister(&nfs_dns_resolve); } +#endif diff --git a/fs/nfs/dns_resolve.h b/fs/nfs/dns_resolve.h index a3f0938..199bb55 100644 --- a/fs/nfs/dns_resolve.h +++ b/fs/nfs/dns_resolve.h @@ -6,8 +6,20 @@ #define NFS_DNS_HOSTNAME_MAXLEN (128) + +#ifdef CONFIG_NFS_USE_KERNEL_DNS +static inline int nfs_dns_resolver_init(void) +{ + return 0; +} + +static inline void nfs_dns_resolver_destroy(void) +{} +#else extern int nfs_dns_resolver_init(void); extern void nfs_dns_resolver_destroy(void); +#endif + extern ssize_t nfs_dns_resolve_name(char *name, size_t namelen, struct sockaddr *sa, size_t salen); On 08/05/2010 10:05 PM, David Howells wrote: > Trond Myklebust wrote: > >> David, can you carry this as part of your 'generic DNS resolver' >> patchset? > > Probably. Can you send me a copy of the patch? > > David