From 1b7014dfc1584d1f3b10eb91c4f22e0deaca999d Mon Sep 17 00:00:00 2001

From: Lauri Tirkkonen <lotheac@iki.fi>

Date: Tue, 24 Oct 2017 20:40:50 +0300

Subject: [PATCH] nspawn: EROFS for chowning mount points is not fatal (#7122)

This fixes --read-only with --private-users. mkdir_userns_p may return

-EROFS if either mkdir or lchown fails; lchown failing is fine as the

mount point will just be overmounted, and if mkdir fails then the

following mount() will also fail (with ENOENT).

(cherry picked from commit 4f13e534282414b5e58ef31a26cc5c3f06f8cb18)

---

 src/nspawn/nspawn-mount.c | 8 ++++++--

 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/nspawn/nspawn-mount.c b/src/nspawn/nspawn-mount.c

index 531f29cb7b..9b7ceb6bdc 100644

--- a/src/nspawn/nspawn-mount.c

+++ b/src/nspawn/nspawn-mount.c

@@ -598,11 +598,15 @@ int mount_all(const char *dest,

                 r = mkdir_userns_p(dest, where, 0755, mount_settings, uid_shift);

                 if (r < 0 && r != -EEXIST) {

-                        if (fatal)

+                        if (fatal && r != -EROFS)

                                 return log_error_errno(r, "Failed to create directory %s: %m", where);

                         log_debug_errno(r, "Failed to create directory %s: %m", where);

-                        continue;

+                        /* If we failed mkdir() or chown() due to the root

+                         * directory being read only, attempt to mount this fs

+                         * anyway and let mount_verbose log any errors */

+                        if (r != -EROFS)

+                                continue;

                 }

                 o = mount_table[k].options;