From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 11 Mar 2021 10:44:03 +0000 (+0100)
Subject: dissect-image: fix volatile images
X-Git-Tag: v248-rc3~6^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=334eb5b0999d51efbc38b775fca92a2556c85830;p=thirdparty%2Fsystemd.git

dissect-image: fix volatile images

This makes sure nspawn's --volatile=yes switch works again: there we
have a read-only image that is overmounted by a tmpfs (with the
exception of /usr). This we need to mkdir all mount points even though
the image is read-only.

Hence, let's drop the optimizatio of avoiding mkdir() on images that are
read-only, it's wrong and misleading here, since the image itself might
be read-only but our mounts are not.
---

diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
index d9053087628..6f9a4576144 100644
--- a/src/shared/dissect-image.c
+++ b/src/shared/dissect-image.c
@@ -1344,12 +1344,10 @@ static int mount_partition(
         }
 
         if (directory) {
-                if (!FLAGS_SET(flags, DISSECT_IMAGE_READ_ONLY)) {
-                        /* Automatically create missing mount points inside the image, if necessary. */
-                        r = mkdir_p_root(where, directory, uid_shift, (gid_t) uid_shift, 0755);
-                        if (r < 0)
-                                return r;
-                }
+                /* Automatically create missing mount points inside the image, if necessary. */
+                r = mkdir_p_root(where, directory, uid_shift, (gid_t) uid_shift, 0755);
+                if (r < 0 && r != -EROFS)
+                        return r;
 
                 r = chase_symlinks(directory, where, CHASE_PREFIX_ROOT, &chased, NULL);
                 if (r < 0)