From f7cf3431c7260635d9d2fa0886af05e56261c5df Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 19 May 2015 20:32:44 +0200
Subject: [PATCH] core,nspawn: unify code that moves the root dir

---
 src/shared/util.c | 18 ++++++++++++++++++
 src/shared/util.h |  2 ++
 2 files changed, 20 insertions(+)

diff --git a/src/shared/util.c b/src/shared/util.c
index ceb88d54c..5efb9591a 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -6144,3 +6144,21 @@ int parse_mode(const char *s, mode_t *ret) {
         *ret = (mode_t) l;
         return 0;
 }
+
+int mount_move_root(const char *path) {
+        assert(path);
+
+        if (chdir(path) < 0)
+                return -errno;
+
+        if (mount(path, "/", NULL, MS_MOVE, NULL) < 0)
+                return -errno;
+
+        if (chroot(".") < 0)
+                return -errno;
+
+        if (chdir("/") < 0)
+                return -errno;
+
+        return 0;
+}
diff --git a/src/shared/util.h b/src/shared/util.h
index a6f536754..4cea62758 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -904,3 +904,5 @@ int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char
 char *shell_maybe_quote(const char *s);
 
 int parse_mode(const char *s, mode_t *ret);
+
+int mount_move_root(const char *path);
-- 
2.30.2