Make initrd.target the default target in the initrd

First, rename root-fs.target to initrd-root-fs.target to clarify its usage.

Mount units with "x-initrd-rootfs.mount" are now ordered before
initrd-root-fs.target. As we sometimes construct /sysroot mounts in
/etc/fstab in the initrd, we want these to be mounted before the
initrd-root-fs.target is active.

initrd.target can be the default target in the initrd.

                             (normal startup)
                                    :
                                    :
                                    v
                              basic.target
                                    |
             ______________________/|
            /                       |
            |                  sysroot.mount
            |                       |
            |                       v
            |             initrd-root-fs.target
            |                       |
            |                       v
            |            initrd-parse-etc.service
(custom initrd services)            |
            |                       v
            |            (sysroot-usr.mount and
            |             various mounts marked
            |               with fstab option
            |                x-initrd.mount)
            |                       |
            |                       v
            |                initrd-fs.target
            |                       |
            \______________________ |
                                   \|
                                    v
                               initrd.target
                                    |
                                    v
                          initrd-cleanup.service
                               isolates to
                         initrd-switch-root.target
                                    |
                                    v
             ______________________/|
            /                       |
            |        initrd-udevadm-cleanup-db.service
            |                       |
(custom initrd services)            |
            |                       |
            \______________________ |
                                   \|
                                    v
                        initrd-switch-root.target
                                    |
                                    v
                        initrd-switch-root.service
                                    |
                                    v
                               switch-root

2 files changed, 11 insertions, 2 deletions

diff --git a/src/core/special.h b/src/core/special.h
index 52e593b690..c7b856e2bd 100644
--- a/src/core/special.h
+++ b/src/core/special.h
@@ -49,7 +49,7 @@
 #define SPECIAL_LOCAL_FS_TARGET "local-fs.target"
 #define SPECIAL_LOCAL_FS_PRE_TARGET "local-fs-pre.target"
 #define SPECIAL_INITRD_FS_TARGET "initrd-fs.target"
-#define SPECIAL_ROOT_FS_TARGET "root-fs.target"
+#define SPECIAL_INITRD_ROOT_FS_TARGET "initrd-root-fs.target"
 #define SPECIAL_REMOTE_FS_TARGET "remote-fs.target"       /* LSB's $remote_fs */
 #define SPECIAL_REMOTE_FS_PRE_TARGET "remote-fs-pre.target"
 #define SPECIAL_SWAP_TARGET "swap.target"
diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
index b4fb1344e6..cf85d3189a 100644
--- a/src/fstab-generator/fstab-generator.c
+++ b/src/fstab-generator/fstab-generator.c
@@ -199,6 +199,12 @@ static bool mount_in_initrd(struct mntent *me) {
                 streq(me->mnt_dir, "/usr");
 }
 
+static bool mount_is_rootfs(struct mntent *me) {
+        assert(me);
+
+        return hasmntopt(me, "x-initrd-rootfs.mount");
+}
+
 static int add_mount(const char *what, const char *where, const char *type, const char *opts,
                      int passno, bool noauto, bool nofail, bool automount, bool isbind,
                      const char *pre, const char *post, const char *source) {
@@ -434,6 +440,9 @@ static int parse_fstab(const char *prefix, bool initrd) {
                         if (initrd) {
                                 post = SPECIAL_INITRD_FS_TARGET;
                                 pre = NULL;
+                        } else if (mount_is_rootfs(me)) {
+                                post = SPECIAL_INITRD_ROOT_FS_TARGET;
+                                pre = NULL;
                         } else if (mount_is_network(me)) {
                                 post = SPECIAL_REMOTE_FS_TARGET;
                                 pre = SPECIAL_REMOTE_FS_PRE_TARGET;
@@ -525,7 +534,7 @@ static int parse_new_root_from_proc_cmdline(void) {
 
         log_debug("Found entry what=%s where=/sysroot type=%s", what, type);
         r = add_mount(what, "/sysroot", type, opts, 0, false, false, false,
-                      false, NULL, SPECIAL_ROOT_FS_TARGET, "/proc/cmdline");
+                      false, NULL, SPECIAL_INITRD_ROOT_FS_TARGET, "/proc/cmdline");
 
         return (r < 0) ? r : 0;
 }