fstab-generator: Support root on tmpfs (or other deviceless FS)

This allows for stateless systems.

2 files changed, 30 insertions, 0 deletions

diff --git a/src/shared/util.c b/src/shared/util.c
index ad548da82a..2d50f73dc4 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -1713,6 +1713,35 @@ bool fstype_is_network(const char *fstype) {
         return nulstr_contains(table, fstype);
 }
 
+bool fstype_is_deviceless(const char *fstype) {
+        static const char table[] =
+                "autofs\0"
+                "bdev\0"
+                "cgroup\0"
+                "configfs\0"
+                "cpuset\0"
+                "debugfs\0"
+                "devpts\0"
+                "devtmpfs\0"
+                "efivarfs\0"
+                "hugetlbfs\0"
+                "mqueue\0"
+                "overlayfs\0"
+                "pipefs\0"
+                "proc\0"
+                "pstore\0"
+                "ramfs\0"
+                "rootfs\0"
+                "rpc_pipefs\0"
+                "securityfs\0"
+                "sockfs\0"
+                "sysfs\0"
+                "tmpfs\0";
+
+        return !isempty(fstype) && (
+                nulstr_contains(table, fstype) || fstype_is_network(fstype));
+}
+
 int chvt(int vt) {
         _cleanup_close_ int fd;
 
diff --git a/src/shared/util.h b/src/shared/util.h
index 29e85bb7e1..b5f44b8a1f 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -409,6 +409,7 @@ int fd_cloexec(int fd, bool cloexec);
 int close_all_fds(const int except[], unsigned n_except);
 
 bool fstype_is_network(const char *fstype);
+bool fstype_is_deviceless(const char *fstype);
 
 int chvt(int vt);