Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761581AbYFBNsc (ORCPT ); Mon, 2 Jun 2008 09:48:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761851AbYFBNrg (ORCPT ); Mon, 2 Jun 2008 09:47:36 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:49869 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761822AbYFBNre (ORCPT ); Mon, 2 Jun 2008 09:47:34 -0400 Message-Id: <20080602134439.782528644@theryb.frec.bull.fr> References: <20080602134438.224352910@theryb.frec.bull.fr> User-Agent: quilt/0.46-1 Date: Mon, 02 Jun 2008 15:46:08 +0200 From: Benjamin Thery To: Andrew Morton Cc: Greg Kroah-Hartman , Eric Biederman , Serge Hallyn , linux-kernel@vger.kernel.org, Tejun Heo , Al Viro , Daniel Lezcano , Benjamin Thery Subject: [PATCH 09/10] netns: Enable tagging for net_class directories in sysfs Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5393 Lines: 192 net: Enable tagging for net_class directories in sysfs The problem. Network devices show up in sysfs and with the network namespace active multiple devices with the same name can show up in the same directory, ouch! To avoid that problem and allow existing applications in network namespaces to see the same interface that is currently presented in sysfs, this patch enables the tagging directory support in sysfs. By using the network namespace pointers as tags to separate out the the sysfs directory entries we ensure that we don't have conflicts in the directories and applications only see a limited set of the network devices. Signed-off-by: Eric W. Biederman Signed-off-by: Benjamin Thery --- fs/sysfs/mount.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/sysfs.h | 2 ++ net/Kconfig | 2 +- net/core/net-sysfs.c | 20 ++++++++++++++++++++ 4 files changed, 59 insertions(+), 1 deletion(-) Index: linux-mm/fs/sysfs/mount.c =================================================================== --- linux-mm.orig/fs/sysfs/mount.c +++ linux-mm/fs/sysfs/mount.c @@ -16,6 +16,8 @@ #include #include #include +#include +#include #include "sysfs.h" @@ -78,6 +80,7 @@ static int sysfs_fill_super(struct super root->d_sb = sb; sb->s_root = root; sb->s_fs_info = info; + info->tag.net_ns = hold_net(current->nsproxy->net_ns); return 0; out_err: @@ -95,6 +98,9 @@ static int sysfs_test_super(struct super struct sysfs_super_info *info = sysfs_info(sb); int found = 1; + if (task->nsproxy->net_ns != info->tag.net_ns) + found = 0; + return found; } @@ -131,6 +137,8 @@ static void sysfs_kill_sb(struct super_b struct sysfs_super_info *info = sysfs_info(sb); kill_anon_super(sb); + if (info->tag.net_ns) + release_net(info->tag.net_ns); kfree(info); } @@ -181,6 +189,31 @@ restart: spin_unlock(&sb_lock); } +#ifdef CONFIG_NET +static void sysfs_net_exit(struct net *net) +{ + /* Allow the net namespace to go away while sysfs is still mounted. */ + struct super_block *sb; + mutex_lock(&sysfs_rename_mutex); + sysfs_grab_supers(); + mutex_lock(&sysfs_mutex); + list_for_each_entry(sb, &sysfs_fs_type.fs_supers, s_instances) { + struct sysfs_super_info *info = sysfs_info(sb); + if (info->tag.net_ns != net) + continue; + release_net(info->tag.net_ns); + info->tag.net_ns = NULL; + } + mutex_unlock(&sysfs_mutex); + sysfs_release_supers(); + mutex_unlock(&sysfs_rename_mutex); +} + +static struct pernet_operations sysfs_net_ops = { + .exit = sysfs_net_exit, +}; +#endif + int __init sysfs_init(void) { int err = -ENOMEM; @@ -205,6 +238,9 @@ int __init sysfs_init(void) unregister_filesystem(&sysfs_fs_type); goto out_err; } +#ifdef CONFIG_NET + register_pernet_subsys(&sysfs_net_ops); +#endif } else goto out_err; out: Index: linux-mm/include/linux/sysfs.h =================================================================== --- linux-mm.orig/include/linux/sysfs.h +++ linux-mm/include/linux/sysfs.h @@ -19,6 +19,7 @@ struct kobject; struct module; +struct net; /* FIXME * The *owner field is no longer used, but leave around @@ -79,6 +80,7 @@ struct sysfs_ops { }; struct sysfs_tag_info { + struct net *net_ns; }; struct sysfs_tagged_dir_operations { Index: linux-mm/net/Kconfig =================================================================== --- linux-mm.orig/net/Kconfig +++ linux-mm/net/Kconfig @@ -30,7 +30,7 @@ menu "Networking options" config NET_NS bool "Network namespace support" default n - depends on EXPERIMENTAL && !SYSFS && NAMESPACES + depends on EXPERIMENTAL && NAMESPACES help Allow user space to create what appear to be multiple instances of the network stack. Index: linux-mm/net/core/net-sysfs.c =================================================================== --- linux-mm.orig/net/core/net-sysfs.c +++ linux-mm/net/core/net-sysfs.c @@ -13,7 +13,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -421,6 +423,23 @@ static void netdev_release(struct device kfree((char *)dev - dev->padded); } +static const void *net_sb_tag(struct sysfs_tag_info *info) +{ + return info->net_ns; +} + +static const void *net_kobject_tag(struct kobject *kobj) +{ + struct net_device *dev; + dev = container_of(kobj, struct net_device, dev.kobj); + return dev_net(dev); +} + +static const struct sysfs_tagged_dir_operations net_tagged_dir_operations = { + .sb_tag = net_sb_tag, + .kobject_tag = net_kobject_tag, +}; + static struct class net_class = { .name = "net", .dev_release = netdev_release, @@ -430,6 +449,7 @@ static struct class net_class = { #ifdef CONFIG_HOTPLUG .dev_uevent = netdev_uevent, #endif + .tag_ops = &net_tagged_dir_operations, }; /* Delete sysfs entries but hold kobject reference until after all -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/