Apart from the network and mount namespace all other namespaces expose a
stable inode number and userspace has been relying on that for a very
long time now. It's very much heavily used API. Align the network
namespace and use a stable inode number from the reserved procfs inode
number space so this is consistent across all namespaces.
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
include/linux/proc_ns.h | 1 +
include/uapi/linux/nsfs.h | 1 +
net/core/net_namespace.c | 8 ++++++++
3 files changed, 10 insertions(+)
diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index e77a37b23ca7..3ff0bd381704 100644
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -47,6 +47,7 @@ enum {
PROC_PID_INIT_INO = PID_NS_INIT_INO,
PROC_CGROUP_INIT_INO = CGROUP_NS_INIT_INO,
PROC_TIME_INIT_INO = TIME_NS_INIT_INO,
+ PROC_NET_INIT_INO = NET_NS_INIT_INO,
};
#ifdef CONFIG_PROC_FS
diff --git a/include/uapi/linux/nsfs.h b/include/uapi/linux/nsfs.h
index 6683e7ca3996..393778489d85 100644
--- a/include/uapi/linux/nsfs.h
+++ b/include/uapi/linux/nsfs.h
@@ -49,6 +49,7 @@ enum init_ns_ino {
PID_NS_INIT_INO = 0xEFFFFFFCU,
CGROUP_NS_INIT_INO = 0xEFFFFFFBU,
TIME_NS_INIT_INO = 0xEFFFFFFAU,
+ NET_NS_INIT_INO = 0xEFFFFFF9U,
};
#endif /* __LINUX_NSFS_H */
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 42ee7fce3d95..3a962b74080b 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -796,11 +796,19 @@ static __net_init int net_ns_net_init(struct net *net)
#ifdef CONFIG_NET_NS
net->ns.ops = &netns_operations;
#endif
+ if (net == &init_net) {
+ net->ns.inum = PROC_NET_INIT_INO;
+ return 0;
+ }
return ns_alloc_inum(&net->ns);
}
static __net_exit void net_ns_net_exit(struct net *net)
{
+ /*
+ * Initial network namespace doesn't exit so we don't need any
+ * special checks here.
+ */
ns_free_inum(&net->ns);
}
--
2.47.2
