tree-wide: warn when a directory path already exists but has bad mode/owner/type

When we are attempting to create directory somewhere in the bowels of /var/lib
and get an error that it already exists, it can be quite hard to diagnose what
is wrong (especially for a user who is not aware that the directory must have
the specified owner, and permissions not looser than what was requested). Let's
print a warning in most cases. A warning is appropriate, because such state is
usually a sign of borked installation and needs to be resolved by the adminstrator.

$ build/test-fs-util

Path "/tmp/test-readlink_and_make_absolute" already exists and is not a directory, refusing.
   (or)
Directory "/tmp/test-readlink_and_make_absolute" already exists, but has mode 0775 that is too permissive (0755 was requested), refusing.
   (or)
Directory "/tmp/test-readlink_and_make_absolute" already exists, but is owned by 1001:1000 (1000:1000 was requested), refusing.

Assertion 'mkdir_safe(tempdir, 0755, getuid(), getgid(), MKDIR_WARN_MODE) >= 0' failed at ../src/test/test-fs-util.c:320, function test_readlink_and_make_absolute(). Aborting.

No functional change except for the new log lines.

1 files changed, 4 insertions, 4 deletions

diff --git a/src/network/networkd.c b/src/network/networkd.c
index 1d87d5ae05..5fd82552ee 100644
--- a/src/network/networkd.c
+++ b/src/network/networkd.c
@@ -56,7 +56,7 @@ int main(int argc, char *argv[]) {
         /* Create runtime directory. This is not necessary when networkd is
          * started with "RuntimeDirectory=systemd/netif", or after
          * systemd-tmpfiles-setup.service. */
-        r = mkdir_safe_label("/run/systemd/netif", 0755, uid, gid, 0);
+        r = mkdir_safe_label("/run/systemd/netif", 0755, uid, gid, MKDIR_WARN_MODE);
         if (r < 0)
                 log_warning_errno(r, "Could not create runtime directory: %m");
 
@@ -75,15 +75,15 @@ int main(int argc, char *argv[]) {
         /* Always create the directories people can create inotify watches in.
          * It is necessary to create the following subdirectories after drop_privileges()
          * to support old kernels not supporting AmbientCapabilities=. */
-        r = mkdir_safe_label("/run/systemd/netif/links", 0755, uid, gid, 0);
+        r = mkdir_safe_label("/run/systemd/netif/links", 0755, uid, gid, MKDIR_WARN_MODE);
         if (r < 0)
                 log_warning_errno(r, "Could not create runtime directory 'links': %m");
 
-        r = mkdir_safe_label("/run/systemd/netif/leases", 0755, uid, gid, 0);
+        r = mkdir_safe_label("/run/systemd/netif/leases", 0755, uid, gid, MKDIR_WARN_MODE);
         if (r < 0)
                 log_warning_errno(r, "Could not create runtime directory 'leases': %m");
 
-        r = mkdir_safe_label("/run/systemd/netif/lldp", 0755, uid, gid, 0);
+        r = mkdir_safe_label("/run/systemd/netif/lldp", 0755, uid, gid, MKDIR_WARN_MODE);
         if (r < 0)
                 log_warning_errno(r, "Could not create runtime directory 'lldp': %m");