pid1: expose "extrinsic" status of swaps and mounts

The only visible change from this is that we show Extrinsic: yes/no
in dumps for swap units (this was already done for mount units).

4 files changed, 52 insertions, 32 deletions

diff --git a/src/core/mount.c b/src/core/mount.c
index dbbb73f3d5..07c038b345 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -412,8 +412,9 @@ static int mount_add_quota_dependencies(Mount *m) {
         return 0;
 }
 
-static bool mount_is_extrinsic(Mount *m) {
+static bool mount_is_extrinsic(Unit *u) {
         MountParameters *p;
+        Mount *m = MOUNT(u);
         assert(m);
 
         /* Returns true for all units that are "magic" and should be excluded from the usual
@@ -422,10 +423,7 @@ static bool mount_is_extrinsic(Mount *m) {
          * ourselves but it's fine if the user operates on them with us. */
 
         /* We only automatically manage mounts if we are in system mode */
-        if (!MANAGER_IS_SYSTEM(UNIT(m)->manager))
-                return true;
-
-        if (UNIT(m)->perpetual) /* All perpetual units never change state */
+        if (MANAGER_IS_USER(u->manager))
                 return true;
 
         p = get_mount_parameters(m);
@@ -493,7 +491,7 @@ static int mount_add_default_dependencies(Mount *m) {
          * guaranteed to stay mounted the whole time, since our system is on it.  Also, don't
          * bother with anything mounted below virtual file systems, it's also going to be virtual,
          * and hence not worth the effort. */
-        if (mount_is_extrinsic(m))
+        if (mount_is_extrinsic(UNIT(m)))
                 return 0;
 
         p = get_mount_parameters(m);
@@ -790,7 +788,7 @@ static void mount_dump(Unit *u, FILE *f, const char *prefix) {
                 prefix, p ? strna(p->options) : "n/a",
                 prefix, yes_no(m->from_proc_self_mountinfo),
                 prefix, yes_no(m->from_fragment),
-                prefix, yes_no(mount_is_extrinsic(m)),
+                prefix, yes_no(mount_is_extrinsic(u)),
                 prefix, m->directory_mode,
                 prefix, yes_no(m->sloppy_options),
                 prefix, yes_no(m->lazy_unmount),
@@ -2161,6 +2159,7 @@ const UnitVTable mount_vtable = {
         .will_restart = unit_will_restart_default,
 
         .may_gc = mount_may_gc,
+        .is_extrinsic = mount_is_extrinsic,
 
         .sigchld_event = mount_sigchld_event,
 
diff --git a/src/core/swap.c b/src/core/swap.c
index fa600a9797..2d3d488a7b 100644
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -56,6 +56,35 @@ static bool SWAP_STATE_WITH_PROCESS(SwapState state) {
                       SWAP_CLEANING);
 }
 
+_pure_ static UnitActiveState swap_active_state(Unit *u) {
+        assert(u);
+
+        return state_translation_table[SWAP(u)->state];
+}
+
+_pure_ static const char *swap_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return swap_state_to_string(SWAP(u)->state);
+}
+
+_pure_ static bool swap_may_gc(Unit *u) {
+        Swap *s = SWAP(u);
+
+        assert(s);
+
+        if (s->from_proc_swaps)
+                return false;
+
+        return true;
+}
+
+_pure_ static bool swap_is_extrinsic(Unit *u) {
+        assert(SWAP(u));
+
+        return MANAGER_IS_USER(u->manager);
+}
+
 static void swap_unset_proc_swaps(Swap *s) {
         assert(s);
 
@@ -610,13 +639,15 @@ static void swap_dump(Unit *u, FILE *f, const char *prefix) {
                 "%sClean Result: %s\n"
                 "%sWhat: %s\n"
                 "%sFrom /proc/swaps: %s\n"
-                "%sFrom fragment: %s\n",
+                "%sFrom fragment: %s\n"
+                "%sExtrinsic: %s\n",
                 prefix, swap_state_to_string(s->state),
                 prefix, swap_result_to_string(s->result),
                 prefix, swap_result_to_string(s->clean_result),
                 prefix, s->what,
                 prefix, yes_no(s->from_proc_swaps),
-                prefix, yes_no(s->from_fragment));
+                prefix, yes_no(s->from_fragment),
+                prefix, yes_no(swap_is_extrinsic(u)));
 
         if (s->devnode)
                 fprintf(f, "%sDevice Node: %s\n", prefix, s->devnode);
@@ -1028,29 +1059,6 @@ static int swap_deserialize_item(Unit *u, const char *key, const char *value, FD
         return 0;
 }
 
-_pure_ static UnitActiveState swap_active_state(Unit *u) {
-        assert(u);
-
-        return state_translation_table[SWAP(u)->state];
-}
-
-_pure_ static const char *swap_sub_state_to_string(Unit *u) {
-        assert(u);
-
-        return swap_state_to_string(SWAP(u)->state);
-}
-
-_pure_ static bool swap_may_gc(Unit *u) {
-        Swap *s = SWAP(u);
-
-        assert(s);
-
-        if (s->from_proc_swaps)
-                return false;
-
-        return true;
-}
-
 static void swap_sigchld_event(Unit *u, pid_t pid, int code, int status) {
         Swap *s = SWAP(u);
         SwapResult f;
@@ -1649,6 +1657,7 @@ const UnitVTable swap_vtable = {
         .will_restart = unit_will_restart_default,
 
         .may_gc = swap_may_gc,
+        .is_extrinsic = swap_is_extrinsic,
 
         .sigchld_event = swap_sigchld_event,
 
diff --git a/src/core/unit.c b/src/core/unit.c
index 40578cb3fa..f80d9f4099 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -1988,6 +1988,10 @@ int unit_stop(Unit *u) {
 bool unit_can_stop(Unit *u) {
         assert(u);
 
+        /* Note: if we return true here, it does not mean that the unit may be successfully stopped.
+         * Extrinsic units follow external state and they may stop following external state changes
+         * (hence we return true here), but an attempt to do this through the manager will fail. */
+
         if (!unit_type_supported(u->type))
                 return false;
 
diff --git a/src/core/unit.h b/src/core/unit.h
index 1e6d7ccf6b..991a05bafe 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -531,6 +531,9 @@ typedef struct UnitVTable {
          * even though nothing references it and it isn't active in any way. */
         bool (*may_gc)(Unit *u);
 
+        /* Return true when the unit is not controlled by the manager (e.g. extrinsic mounts). */
+        bool (*is_extrinsic)(Unit *u);
+
         /* When the unit is not running and no job for it queued we shall release its runtime resources */
         void (*release_resources)(Unit *u);
 
@@ -684,6 +687,11 @@ int unit_set_description(Unit *u, const char *description);
 
 bool unit_may_gc(Unit *u);
 
+static inline bool unit_is_extrinsic(Unit *u) {
+        return u->perpetual ||
+                (UNIT_VTABLE(u)->is_extrinsic && UNIT_VTABLE(u)->is_extrinsic(u));
+}
+
 void unit_add_to_load_queue(Unit *u);
 void unit_add_to_dbus_queue(Unit *u);
 void unit_add_to_cleanup_queue(Unit *u);