[PATCH 1/3] nsfs: move root inode number to uapi

[Christian Brauner <brauner@kernel.org>]

Userspace relies on the root inode numbers to identify the initial
namespaces. That's already a hard dependency. So we cannot change that
anymore. Move the initial inode numbers to a public header.

Link: https://github.com/systemd/systemd/commit/d293fade24b34ccc2f5716b0ff5513e9533cf0c4
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 include/linux/proc_ns.h   | 13 +++++++------
 include/uapi/linux/nsfs.h |  9 +++++++++
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index 5ea470eb4d76..e77a37b23ca7 100644
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -6,6 +6,7 @@
 #define _LINUX_PROC_NS_H
 
 #include <linux/ns_common.h>
+#include <uapi/linux/nsfs.h>
 
 struct pid_namespace;
 struct nsset;
@@ -40,12 +41,12 @@ extern const struct proc_ns_operations timens_for_children_operations;
  */
 enum {
 	PROC_ROOT_INO		= 1,
-	PROC_IPC_INIT_INO	= 0xEFFFFFFFU,
-	PROC_UTS_INIT_INO	= 0xEFFFFFFEU,
-	PROC_USER_INIT_INO	= 0xEFFFFFFDU,
-	PROC_PID_INIT_INO	= 0xEFFFFFFCU,
-	PROC_CGROUP_INIT_INO	= 0xEFFFFFFBU,
-	PROC_TIME_INIT_INO	= 0xEFFFFFFAU,
+	PROC_IPC_INIT_INO	= IPC_NS_INIT_INO,
+	PROC_UTS_INIT_INO	= UTS_NS_INIT_INO,
+	PROC_USER_INIT_INO	= USER_NS_INIT_INO,
+	PROC_PID_INIT_INO	= PID_NS_INIT_INO,
+	PROC_CGROUP_INIT_INO	= CGROUP_NS_INIT_INO,
+	PROC_TIME_INIT_INO	= TIME_NS_INIT_INO,
 };
 
 #ifdef CONFIG_PROC_FS
diff --git a/include/uapi/linux/nsfs.h b/include/uapi/linux/nsfs.h
index 34127653fd00..6683e7ca3996 100644
--- a/include/uapi/linux/nsfs.h
+++ b/include/uapi/linux/nsfs.h
@@ -42,4 +42,13 @@ struct mnt_ns_info {
 /* Get previous namespace. */
 #define NS_MNT_GET_PREV		_IOR(NSIO, 12, struct mnt_ns_info)
 
+enum init_ns_ino {
+	IPC_NS_INIT_INO		= 0xEFFFFFFFU,
+	UTS_NS_INIT_INO		= 0xEFFFFFFEU,
+	USER_NS_INIT_INO	= 0xEFFFFFFDU,
+	PID_NS_INIT_INO		= 0xEFFFFFFCU,
+	CGROUP_NS_INIT_INO	= 0xEFFFFFFBU,
+	TIME_NS_INIT_INO	= 0xEFFFFFFAU,
+};
+
 #endif /* __LINUX_NSFS_H */

-- 
2.47.2