namespace: rework namespace support

- don't use pivot_root() anymore, just reuse root hierarchy
- first create all mounts, then mark them read-only so that we get the
  right behaviour when people want writable mounts inside of
  read-only mounts
- don't pass invalid combinations of MS_ constants to the kernel

1 files changed, 6 insertions, 0 deletions

diff --git a/src/core/switch-root.c b/src/core/switch-root.c
index efc7d345e1..150332a858 100644
--- a/src/core/switch-root.c
+++ b/src/core/switch-root.c
@@ -115,6 +115,12 @@ int switch_root(const char *new_root) {
                 goto fail;
         }
 
+        if (chdir("/") < 0) {
+                r = -errno;
+                log_error("Failed to change directory: %m");
+                goto fail;
+        }
+
         if (old_root_fd >= 0) {
                 struct stat rb;