From 70215e23a5c77445ed1b62186c069a173c632618 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Sat, 22 Oct 2016 22:16:02 -0400
Subject: [PATCH] core: when restarting services, don't close fds

We would close all the stored fds in service_release_resources(), which of
course broke the whole concept of storing fds over service restart.

Fixes #4408.

(cherry picked from commit f0bfbfac43b7faa68ef1bb2ad659c191b9ec85d2)
(cherry picked from commit 4c271437cd695c31e76adb191013009689a7797c)
Resolves: #1757704
---
 src/core/service.c | 22 +++++++++++++++-------
 src/core/unit.c    |  6 ++++--
 src/core/unit.h    |  2 +-
 3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/src/core/service.c b/src/core/service.c
index e538280bad..3c2f69a003 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -258,7 +258,17 @@ static void service_fd_store_unlink(ServiceFDStore *fs) {
         free(fs);
 }
 
-static void service_release_resources(Unit *u) {
+static void service_release_fd_store(Service *s) {
+        assert(s);
+
+        log_unit_debug(UNIT(s)->id, "Releasing all stored fds");
+        while (s->fd_store)
+                service_fd_store_unlink(s->fd_store);
+
+        assert(s->n_fd_store == 0);
+}
+
+static void service_release_resources(Unit *u, bool inactive) {
         Service *s = SERVICE(u);
 
         assert(s);
@@ -266,12 +276,10 @@ static void service_release_resources(Unit *u) {
         if (!s->fd_store)
                 return;
 
-        log_debug("Releasing all resources for %s", u->id);
-
-        while (s->fd_store)
-                service_fd_store_unlink(s->fd_store);
+        log_unit_debug(u->id, "Releasing resources.");
 
-        assert(s->n_fd_store == 0);
+        if (inactive)
+                service_release_fd_store(s);
 }
 
 static void service_done(Unit *u) {
@@ -319,7 +327,7 @@ static void service_done(Unit *u) {
 
         s->timer_event_source = sd_event_source_unref(s->timer_event_source);
 
-        service_release_resources(u);
+        service_release_resources(u, true);
 }
 
 static int on_fd_store_io(sd_event_source *e, int fd, uint32_t revents, void *userdata) {
diff --git a/src/core/unit.c b/src/core/unit.c
index 0dc66203a4..22e31a76b3 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -285,6 +285,7 @@ int unit_set_description(Unit *u, const char *description) {
 
 bool unit_may_gc(Unit *u) {
         UnitActiveState state;
+        bool inactive;
         assert(u);
 
         /* Checks whether the unit is ready to be unloaded for garbage collection.
@@ -302,16 +303,17 @@ bool unit_may_gc(Unit *u) {
                 return false;
 
         state = unit_active_state(u);
+        inactive = state == UNIT_INACTIVE;
 
         /* If the unit is inactive and failed and no job is queued for
          * it, then release its runtime resources */
         if (UNIT_IS_INACTIVE_OR_FAILED(state) &&
             UNIT_VTABLE(u)->release_resources)
-                UNIT_VTABLE(u)->release_resources(u);
+                UNIT_VTABLE(u)->release_resources(u, inactive);
 
         /* But we keep the unit object around for longer when it is
          * referenced or configured to not be gc'ed */
-        if (state != UNIT_INACTIVE)
+        if (!inactive)
                 return false;
 
         if (UNIT_VTABLE(u)->no_gc)
diff --git a/src/core/unit.h b/src/core/unit.h
index 719fc95260..232be8164f 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -360,7 +360,7 @@ struct UnitVTable {
 
         /* When the unit is not running and no job for it queued we
          * shall release its runtime resources */
-        void (*release_resources)(Unit *u);
+        void (*release_resources)(Unit *u, bool inactive);
 
         /* Return true when this unit is suitable for snapshotting */
         bool (*check_snapshot)(Unit *u);