core: add Unit.Markers property

The property is never set by systemd, only reset after a stop or restart or
reload. It may externally be set to mark the unit for a later restart/reload.

I wasn't sure whether to configure the property only for the types where this
makes sense (Service, Swap, etc). But Restart() method is defined on the unit,
and also having this always under the same property name is more convenient.

1 files changed, 56 insertions, 0 deletions

diff --git a/src/core/unit-serialize.c b/src/core/unit-serialize.c
index ea4a57907e..3f099248ce 100644
--- a/src/core/unit-serialize.c
+++ b/src/core/unit-serialize.c
@@ -28,6 +28,45 @@ static int serialize_cgroup_mask(FILE *f, const char *key, CGroupMask mask) {
         return serialize_item(f, key, s);
 }
 
+/* Make sure out values fit in the bitfield. */
+assert_cc(_UNIT_MARKER_MAX <= sizeof(((Unit){}).markers) * 8);
+
+static int serialize_markers(FILE *f, unsigned markers) {
+        assert(f);
+
+        if (markers == 0)
+                return 0;
+
+        fputs("markers=", f);
+        for (UnitMarker m = 0; m < _UNIT_MARKER_MAX; m++)
+                if (FLAGS_SET(markers, 1u << m))
+                        fputs(unit_marker_to_string(m), f);
+        fputc('\n', f);
+        return 0;
+}
+
+static int deserialize_markers(Unit *u, const char *value) {
+        assert(u);
+        assert(value);
+        int r;
+
+        for (const char *p = value;;) {
+                _cleanup_free_ char *word = NULL;
+
+                r = extract_first_word(&p, &word, NULL, 0);
+                if (r <= 0)
+                        return r;
+
+                UnitMarker m = unit_marker_from_string(word);
+                if (m < 0) {
+                        log_unit_debug_errno(u, m, "Unknown unit marker \"%s\", ignoring.", word);
+                        continue;
+                }
+
+                u->markers |= 1u << m;
+        }
+}
+
 static const char *const ip_accounting_metric_field[_CGROUP_IP_ACCOUNTING_METRIC_MAX] = {
         [CGROUP_IP_INGRESS_BYTES] = "ip-accounting-ingress-bytes",
         [CGROUP_IP_INGRESS_PACKETS] = "ip-accounting-ingress-packets",
@@ -121,6 +160,7 @@ int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs) {
                 (void) serialize_item_format(f, "invocation-id", SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(u->invocation_id));
 
         (void) serialize_item_format(f, "freezer-state", "%s", freezer_state_to_string(unit_freezer_state(u)));
+        (void) serialize_markers(f, u->markers);
 
         bus_track_serialize(u->bus_track, f, "ref");
 
@@ -365,6 +405,13 @@ int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
                 } else if (MATCH_DESERIALIZE("freezer-state", l, v, freezer_state_from_string, u->freezer_state))
                         continue;
 
+                else if (streq(l, "markers")) {
+                        r = deserialize_markers(u, v);
+                        if (r < 0)
+                                log_unit_debug_errno(u, r, "Failed to deserialize \"%s=%s\", ignoring: %m", l, v);
+                        continue;
+                }
+
                 /* Check if this is an IP accounting metric serialization field */
                 m = string_table_lookup(ip_accounting_metric_field, ELEMENTSOF(ip_accounting_metric_field), l);
                 if (m >= 0) {
@@ -559,6 +606,15 @@ void unit_dump(Unit *u, FILE *f, const char *prefix) {
                 prefix, strna(u->cgroup_path),
                 prefix, yes_no(u->cgroup_realized));
 
+        if (u->markers != 0) {
+                fprintf(f, "%s\tMarkers:", prefix);
+
+                for (UnitMarker marker = 0; marker < _UNIT_MARKER_MAX; marker++)
+                        if (FLAGS_SET(u->markers, 1u << marker))
+                                fprintf(f, " %s", unit_marker_to_string(marker));
+                fputs("\n", f);
+        }
+
         if (u->cgroup_realized_mask != 0) {
                 _cleanup_free_ char *s = NULL;
                 (void) cg_mask_to_string(u->cgroup_realized_mask, &s);