[PATCH 6/8] Revert "netns: Fix device renaming for sysfs"

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To: Greg KH <greg@...>
Cc: Greg Kroah-Hartman <gregkh@...>, Andrew Morton <akpm@...>, Tejun Heo <htejun@...>, Daniel Lezcano <dlezcano@...>, <linux-kernel@...>, Al Viro <viro@...>, Linux Containers <containers@...>, Benjamin Thery <benjamin.thery@...>, <netdev@...>
Date: Thursday, August 21, 2008 - 2:38 am

This reverts commit aaf8cdc34ddba08122f02217d9d684e2f9f5d575.

Drivers like the ipw2100 call device_create_group when they
are initialized and device_remove_group when they are shutdown.
Moving them between namespaces deletes their sysfs groups early.

In particular the following call chain results.
netdev_unregister_kobject -> device_del -> kobject_del -> sysfs_remove_dir
With sysfs_remove_dir recursively deleting all of it's subdirectories,
and nothing adding them back.

Ouch!

Therefore we need to call something that ultimate calls sysfs_mv_dir
as that sysfs function can move sysfs directories between namespaces
without deleting their subdirectories or their contents.   Allowing
us to avoid placing extra boiler plate into every driver that does
something interesting with sysfs.

Currently the function that provides that capability is device_rename.
That is the code works without nasty side effects as originally written.

So remove the misguided fix for moving devices between namespaces.  The
bug in the kobject layer that inspired it has now been recognized and
fixed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 net/core/dev.c       |    4 +---
 net/core/net-sysfs.c |    7 +------
 net/core/net-sysfs.h |    1 -
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 600bb23..a7e236c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3989,7 +3989,6 @@ int register_netdevice(struct net_device *dev)
 	if (dev->features & NETIF_F_SG)
 		dev->features |= NETIF_F_GSO;
 
-	netdev_initialize_kobject(dev);
 	ret = netdev_register_kobject(dev);
 	if (ret)
 		goto err_uninit;
@@ -4451,8 +4450,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
-	err = netdev_register_kobject(dev);
+	err = device_rename(&dev->dev, dev->name);
 	WARN_ON(err);
 
 	/* Add the device back in the hashes */
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index c1f4e0d..c9968f1 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -449,6 +449,7 @@ int netdev_register_kobject(struct net_device *net)
 	struct device *dev = &(net->dev);
 	struct attribute_group **groups = net->sysfs_groups;
 
+	device_initialize(dev);
 	dev->class = &net_class;
 	dev->platform_data = net;
 	dev->groups = groups;
@@ -481,12 +482,6 @@ void netdev_class_remove_file(struct class_attribute *class_attr)
 EXPORT_SYMBOL(netdev_class_create_file);
 EXPORT_SYMBOL(netdev_class_remove_file);
 
-void netdev_initialize_kobject(struct net_device *net)
-{
-	struct device *device = &(net->dev);
-	device_initialize(device);
-}
-
 int netdev_kobject_init(void)
 {
 	return class_register(&net_class);
diff --git a/net/core/net-sysfs.h b/net/core/net-sysfs.h
index 14e7524..805555e 100644
--- a/net/core/net-sysfs.h
+++ b/net/core/net-sysfs.h
@@ -4,5 +4,4 @@
 int netdev_kobject_init(void);
 int netdev_register_kobject(struct net_device *);
 void netdev_unregister_kobject(struct net_device *);
-void netdev_initialize_kobject(struct net_device *);
 #endif
-- 
1.5.3.rc6.17.g1911

--
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Messages in current thread:
Re: [PATCH 06/11] sysfs: Implement sysfs tagged directory su..., Eric W. Biederman, (Thu Jun 26, 4:21 pm)
Re: [PATCH 06/11] sysfs: Implement sysfs tagged directory su..., Eric W. Biederman, (Mon Jun 30, 2:56 pm)
Re: [PATCH 06/11] sysfs: Implement sysfs tagged directory su..., Eric W. Biederman, (Tue Jul 1, 11:53 pm)
Re: [PATCH 06/11] sysfs: Implement sysfs tagged directory su..., Eric W. Biederman, (Wed Jul 2, 12:49 pm)
[PATCH 00/15] sysfs support for namespaces, Eric W. Biederman, (Thu Jul 3, 8:48 pm)
Re: [PATCH 00/15] sysfs support for namespaces, Eric W. Biederman, (Sun Jul 6, 12:42 am)
Re: [PATCH 00/15] sysfs support for namespaces, Cornelia Huck, (Mon Jul 7, 7:41 am)
Re: [PATCH 00/15] sysfs support for namespaces, Eric W. Biederman, (Mon Jul 7, 8:22 am)
Re: [PATCH 00/15] sysfs support for namespaces, Eric W. Biederman, (Thu Jul 3, 9:27 pm)
[PATCH 02/15] sysfs: Support for preventing unmounts., Eric W. Biederman, (Thu Jul 3, 9:07 pm)
[PATCH 03/15] sysfs: sysfs_get_dentry add a sb parameter, Eric W. Biederman, (Thu Jul 3, 9:08 pm)
[PATCH 04/15] sysfs: Implement __sysfs_get_dentry, Eric W. Biederman, (Thu Jul 3, 9:09 pm)
[PATCH 05/15] sysfs: Rename Support multiple superblocks, Eric W. Biederman, (Thu Jul 3, 9:10 pm)
[PATCH 06/15] Introduce sysfs_sd_setattr and fix sysfs_chmod, Eric W. Biederman, (Thu Jul 3, 9:11 pm)
[PATCH 08/15] sysfs: Make sysfs_mount static once again., Eric W. Biederman, (Thu Jul 3, 9:14 pm)
[PATCH 0/8] sysfs namespace support, Eric W. Biederman, (Thu Aug 21, 2:31 am)
[PATCH 1/8] sysfs: Implement sysfs tagged directory support., Eric W. Biederman, (Thu Aug 21, 2:33 am)
Re: [PATCH 1/8] sysfs: Implement sysfs tagged directory supp..., Eric W. Biederman, (Mon Oct 13, 11:20 pm)
[PATCH 2/8] sysfs: Merge sysfs_rename_dir and sysfs_move_dir, Eric W. Biederman, (Thu Aug 21, 2:34 am)
[PATCH 3/8] sysfs: Implement sysfs_delete_link and sysfs_ren..., Eric W. Biederman, (Thu Aug 21, 2:35 am)
[PATCH 4/8] driver core: Implement tagged directory support ..., Eric W. Biederman, (Thu Aug 21, 2:37 am)
[PATCH 5/8] sysfs: Remove sysfs_create_link_nowarn, Eric W. Biederman, (Thu Aug 21, 2:36 am)
[PATCH 6/8] Revert "netns: Fix device renaming for sysfs", Eric W. Biederman, (Thu Aug 21, 2:38 am)
[PATCH 7/8] netns: Enable tagging for net_class directories ..., Eric W. Biederman, (Thu Aug 21, 2:39 am)
[PATCH 8/8] sysfs: user namespaces: fix bug with clone(CLONE..., Eric W. Biederman, (Thu Aug 21, 2:40 am)
Re: [PATCH 0/8] sysfs namespace support, David Miller, (Thu Aug 21, 2:37 am)
Re: [PATCH 09/15] sysfs: Implement sysfs tagged directory su..., Eric W. Biederman, (Wed Aug 20, 2:58 am)
Re: [PATCH 12/15] driver core: Implement tagged directory su..., Eric W. Biederman, (Sun Jul 13, 9:54 pm)
Re: [PATCH 12/15] driver core: Implement tagged directory su..., Eric W. Biederman, (Fri Jul 18, 4:19 pm)
Re: [PATCH 12/15] driver core: Implement tagged directory su..., Eric W. Biederman, (Wed Jul 16, 1:41 am)
Re: [PATCH 12/15] driver core: Implement tagged directory su..., Eric W. Biederman, (Wed Jul 16, 2:32 am)
Re: [PATCH 12/15] driver core: Implement tagged directory su..., Eric W. Biederman, (Wed Jul 16, 5:09 pm)
Re: [PATCH 12/15] driver core: Implement tagged directory su..., Eric W. Biederman, (Wed Jul 16, 3:07 pm)
[PATCH 13/15] Revert "netns: Fix device renaming for sysfs", Eric W. Biederman, (Thu Jul 3, 9:21 pm)