core: don't fail to run services in --user instances if $HOME is missing

Otherwise we cannot even invoke systemd-exit.service anymore, thus not
even exit.

https://bugs.freedesktop.org/show_bug.cgi?id=83100
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=759320

diff --git a/src/core/execute.c b/src/core/execute.c
index 7b071e8c9e2a41045f93e472817cce50c005cae9..1f6072c6aba368f886ec24b604e90c5f3de6e4d5 100644 (file)
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -1617,7 +1617,8 @@ static int exec_child(
                                 return -errno;
                         }
 
-                if (chdir(context->working_directory ? context->working_directory : "/") < 0) {
+                if (chdir(context->working_directory ?: "/") < 0 &&
+                    !context->working_directory_missing_ok) {
                         *exit_status = EXIT_CHDIR;
                         return -errno;
                 }

diff --git a/src/core/execute.h b/src/core/execute.h
index 2c201399e3d987672e9b5cc5249b4b5e1ffd69bb..153867c7b3c8fe9f7f5cebcf93873f6f5b345ceb 100644 (file)
--- a/src/core/execute.h
+++ b/src/core/execute.h
@@ -99,6 +99,7 @@ struct ExecContext {
 
         struct rlimit *rlimit[_RLIMIT_MAX];
         char *working_directory, *root_directory;
+        bool working_directory_missing_ok;
 
         mode_t umask;
         int oom_score_adjust;

diff --git a/src/core/unit.c b/src/core/unit.c
index 67425ba913e0e2ce317ad5b6e852c0983ca7ec36..514b6491ceead8301c679d8e22b3085add7fcad3 100644 (file)
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3178,6 +3178,10 @@ int unit_patch_contexts(Unit *u) {
                         r = get_home_dir(&ec->working_directory);
                         if (r < 0)
                                 return r;
+
+                        /* Allow user services to run, even if the
+                         * home directory is missing */
+                        ec->working_directory_missing_ok = true;
                 }
 
                 if (u->manager->running_as == SYSTEMD_USER &&