[Devel] [PATCH RHEL9 COMMIT] ve/net: Don't skip device_rename for non-root Container netns

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-162.6.1.vz9.18.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-162.6.1.vz9.18.11
------>
commit f0a628066967fab032ca5d9309223d7e287dfddd
Author: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
Date:   Wed Feb 22 20:19:23 2023 +0800

    ve/net: Don't skip device_rename for non-root Container netns
    
    This patch effectively reverts the commit:
      2e365f4fbe5d ("ve/net: allow to rename devices in non-ve namespaces")
    
    The patch says that it allows to rename devices, but instead it skips
    call to device_rename() for non-root netnses of the container.
    Ending up with not renamed sysfs link for the renamed device.
    
    And if such inconsistent device with different device name and sysfs
    name is moved to root netns of Container the systemd-udevd gets an event
    notification about it with mixed names.
    
    Systemd obviously does not expect this and goes mad if at the same time
    old moved device name intersects with some other device name in root
    netns of Container, thus systemd disables this other device (e.g. eth0
    and breaks Container network).
    
    The original patch from vz6
      diff-ve-net-allow-to-rename-devices-in-non-ve-namespaces
    seems just to be a crutch for
      diff-ve-vedev-dont-call-netdev_fixup_sysfs-if-device_add-was-not-called
    so that sysfs entries of vedev don't break on netns creation.
    
    But as we don't have the latter (in vz7 device cgroups eliminated all
    crunches of that kind - https://jira.sw.ru/browse/PSBM-17918)
    now we also don't need the former.
    
    https://jira.sw.ru/browse/PSBM-145324
    
    Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
---
 include/linux/ve.h |  1 -
 kernel/ve/ve.c     | 15 ---------------
 net/core/dev.c     | 22 ----------------------
 3 files changed, 38 deletions(-)

diff --git a/include/linux/ve.h b/include/linux/ve.h
index a023d9a8d14a..678cd9b6a94a 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -218,7 +218,6 @@ extern int vz_security_protocol_check(struct net *net, int protocol);
 
 int ve_net_hide_sysctl(struct net *net);
 
-extern struct net *ve_get_net_ns(struct ve_struct* ve);
 extern bool is_ve_init_net(const struct net *net);
 
 #else	/* CONFIG_VE */
diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c
index 80865161670e..55d45b5f2fbf 100644
--- a/kernel/ve/ve.c
+++ b/kernel/ve/ve.c
@@ -32,7 +32,6 @@
 #include <linux/ctype.h>
 #include <linux/tty.h>
 #include <linux/device.h>
-#include <net/net_namespace.h>
 
 #include <uapi/linux/vzcalluser.h>
 #include <net/rtnetlink.h>
@@ -283,20 +282,6 @@ int ve_net_hide_sysctl(struct net *net)
 }
 EXPORT_SYMBOL(ve_net_hide_sysctl);
 
-struct net *ve_get_net_ns(struct ve_struct* ve)
-{
-	struct nsproxy *ve_ns;
-	struct net *net_ns;
-
-	rcu_read_lock();
-	ve_ns = rcu_dereference(ve->ve_ns);
-	net_ns = ve_ns ? get_net(ve_ns->net_ns) : NULL;
-	rcu_read_unlock();
-
-	return net_ns;
-}
-EXPORT_SYMBOL(ve_get_net_ns);
-
 bool is_ve_init_net(const struct net *net)
 {
 	struct ve_struct *ve = net->owner_ve;
diff --git a/net/core/dev.c b/net/core/dev.c
index 826584477edb..e901c0b28387 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1135,20 +1135,6 @@ static int dev_get_valid_name(struct net *net, struct net_device *dev,
 	return 0;
 }
 
-#ifdef CONFIG_VE
-static bool ve_dev_can_rename(struct net_device *dev)
-{
-	struct net *net;
-	bool can;
-
-	net = ve_get_net_ns(dev_net(dev)->owner_ve);
-	can = !net || net == dev_net(dev);
-	if (net)
-		put_net(net);
-	return can;
-}
-#endif
-
 /**
  *	dev_change_name - change name of a device
  *	@dev: device
@@ -1208,11 +1194,6 @@ int dev_change_name(struct net_device *dev, const char *newname)
 	dev->name_assign_type = NET_NAME_RENAMED;
 
 rollback:
-#ifdef CONFIG_VE
-	if (!ve_dev_can_rename(dev))
-		goto skip_rename;
-#endif
-
 	ret = device_rename(&dev->dev, dev->name);
 	if (ret) {
 		memcpy(dev->name, oldname, IFNAMSIZ);
@@ -1221,9 +1202,6 @@ int dev_change_name(struct net_device *dev, const char *newname)
 		return ret;
 	}
 
-#ifdef CONFIG_VE
-skip_rename:
-#endif
 	up_write(&devnet_rename_sem);
 
 	netdev_adjacent_rename_links(dev, oldname);