sysusers: emit a bit more info at debug level when locking fails

This is the first error message when running unprivileged, and the message is
unspecific, so let's at least add some logging at debug level to make this less
confusing.

3 files changed, 7 insertions, 5 deletions

diff --git a/src/basic/user-util.c b/src/basic/user-util.c
index 17a9b5a8f1..011b29ad02 100644
--- a/src/basic/user-util.c
+++ b/src/basic/user-util.c
@@ -553,18 +553,18 @@ int take_etc_passwd_lock(const char *root) {
          * awfully racy, and thus we just won't do them. */
 
         if (root)
-                path = prefix_roota(root, "/etc/.pwd.lock");
+                path = prefix_roota(root, ETC_PASSWD_LOCK_PATH);
         else
-                path = "/etc/.pwd.lock";
+                path = ETC_PASSWD_LOCK_PATH;
 
         fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600);
         if (fd < 0)
-                return -errno;
+                return log_debug_errno(errno, "Cannot open %s: %m", path);
 
         r = fcntl(fd, F_SETLKW, &flock);
         if (r < 0) {
                 safe_close(fd);
-                return -errno;
+                return log_debug_errno(errno, "Locking %s failed: %m", path);
         }
 
         return fd;
diff --git a/src/basic/user-util.h b/src/basic/user-util.h
index 5f0391f2b8..290d17a0c6 100644
--- a/src/basic/user-util.h
+++ b/src/basic/user-util.h
@@ -63,6 +63,8 @@ int take_etc_passwd_lock(const char *root);
 #define UID_NOBODY ((uid_t) 65534U)
 #define GID_NOBODY ((gid_t) 65534U)
 
+#define ETC_PASSWD_LOCK_PATH "/etc/.pwd.lock"
+
 static inline bool uid_is_dynamic(uid_t uid) {
         return DYNAMIC_UID_MIN <= uid && uid <= DYNAMIC_UID_MAX;
 }
diff --git a/src/sysusers/sysusers.c b/src/sysusers/sysusers.c
index 510d5fa59e..288f6a1665 100644
--- a/src/sysusers/sysusers.c
+++ b/src/sysusers/sysusers.c
@@ -1841,7 +1841,7 @@ int main(int argc, char *argv[]) {
 
         lock = take_etc_passwd_lock(arg_root);
         if (lock < 0) {
-                log_error_errno(lock, "Failed to take lock: %m");
+                log_error_errno(lock, "Failed to take /etc/passwd lock: %m");
                 goto finish;
         }