time-util: introduce common implementation of TFD_TIMER_CANCEL_ON_SET client code

We now use pretty much the same code at three places, let's unify that.

5 files changed, 40 insertions, 44 deletions

diff --git a/src/basic/time-util.c b/src/basic/time-util.c
index 671311e885..031b871640 100644
--- a/src/basic/time-util.c
+++ b/src/basic/time-util.c
@@ -1463,3 +1463,27 @@ bool in_utc_timezone(void) {
 
         return timezone == 0 && daylight == 0;
 }
+
+int time_change_fd(void) {
+
+        /* We only care for the cancellation event, hence we set the timeout to the latest possible value. */
+        static const struct itimerspec its = {
+                .it_value.tv_sec = TIME_T_MAX,
+        };
+
+        _cleanup_close_ int fd;
+
+        assert_cc(sizeof(time_t) == sizeof(TIME_T_MAX));
+
+        /* Uses TFD_TIMER_CANCEL_ON_SET to get notifications whenever CLOCK_REALTIME makes a jump relative to
+         * CLOCK_MONOTONIC. */
+
+        fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
+        if (fd < 0)
+                return -errno;
+
+        if (timerfd_settime(fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0)
+                return -errno;
+
+        return TAKE_FD(fd);
+}
diff --git a/src/basic/time-util.h b/src/basic/time-util.h
index f9c34a3e15..54aebfa36b 100644
--- a/src/basic/time-util.h
+++ b/src/basic/time-util.h
@@ -185,3 +185,5 @@ static inline usec_t usec_sub_signed(usec_t timestamp, int64_t delta) {
 #else
 #error "Yuck, time_t is neither 4 nor 8 bytes wide?"
 #endif
+
+int time_change_fd(void);
diff --git a/src/core/manager.c b/src/core/manager.c
index 0f767d651c..d2f628d2bb 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -353,14 +353,7 @@ static void manager_close_idle_pipe(Manager *m) {
 static int manager_setup_time_change(Manager *m) {
         int r;
 
-        /* We only care for the cancellation event, hence we set the
-         * timeout to the latest possible value. */
-        struct itimerspec its = {
-                .it_value.tv_sec = TIME_T_MAX,
-        };
-
         assert(m);
-        assert_cc(sizeof(time_t) == sizeof(TIME_T_MAX));
 
         if (m->test_run_flags)
                 return 0;
@@ -368,18 +361,9 @@ static int manager_setup_time_change(Manager *m) {
         m->time_change_event_source = sd_event_source_unref(m->time_change_event_source);
         m->time_change_fd = safe_close(m->time_change_fd);
 
-        /* Uses TFD_TIMER_CANCEL_ON_SET to get notifications whenever
-         * CLOCK_REALTIME makes a jump relative to CLOCK_MONOTONIC */
-
-        m->time_change_fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
+        m->time_change_fd = time_change_fd();
         if (m->time_change_fd < 0)
-                return log_error_errno(errno, "Failed to create timerfd: %m");
-
-        if (timerfd_settime(m->time_change_fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0) {
-                log_debug_errno(errno, "Failed to set up TFD_TIMER_CANCEL_ON_SET, ignoring: %m");
-                m->time_change_fd = safe_close(m->time_change_fd);
-                return 0;
-        }
+                return log_error_errno(m->time_change_fd, "Failed to create timer change timer fd: %m");
 
         r = sd_event_add_io(m->event, &m->time_change_event_source, m->time_change_fd, EPOLLIN, manager_dispatch_time_change_fd, m);
         if (r < 0)
diff --git a/src/time-wait-sync/time-wait-sync.c b/src/time-wait-sync/time-wait-sync.c
index 198c055650..37b032b39e 100644
--- a/src/time-wait-sync/time-wait-sync.c
+++ b/src/time-wait-sync/time-wait-sync.c
@@ -115,16 +115,15 @@ static int inotify_handler(sd_event_source *s,
         return 0;
 }
 
-static int clock_state_update(ClockState *sp,
-                              sd_event *event) {
-        static const struct itimerspec its = {
-                .it_value.tv_sec = TIME_T_MAX,
-        };
-        int r;
-        struct timex tx = {};
+static int clock_state_update(
+                ClockState *sp,
+                sd_event *event) {
+
         char buf[MAX((size_t)FORMAT_TIMESTAMP_MAX, STRLEN("unrepresentable"))];
-        usec_t t;
+        struct timex tx = {};
         const char * ts;
+        usec_t t;
+        int r;
 
         clock_state_release_timerfd(sp);
 
@@ -151,18 +150,13 @@ static int clock_state_update(ClockState *sp,
          * it synchronized. When an NTP source is selected it sets the clock again with clock_adjtime(2) which marks it
          * synchronized and also touches /run/systemd/timesync/synchronized which covers the case when the clock wasn't
          * "set". */
-        r = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK | TFD_CLOEXEC);
-        if (r < 0) {
-                log_error_errno(errno, "Failed to create timerfd: %m");
-                goto finish;
-        }
-        sp->timerfd_fd = r;
 
-        r = timerfd_settime(sp->timerfd_fd, TFD_TIMER_ABSTIME | TFD_TIMER_CANCEL_ON_SET, &its, NULL);
+        r = time_change_fd();
         if (r < 0) {
-                log_error_errno(errno, "Failed to set timerfd conditions: %m");
+                log_error_errno(r, "Failed to create timerfd: %m");
                 goto finish;
         }
+        sp->timerfd_fd = r;
 
         r = adjtimex(&tx);
         if (r < 0) {
diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c
index f76f07e655..46036c41f7 100644
--- a/src/timesync/timesyncd-manager.c
+++ b/src/timesync/timesyncd-manager.c
@@ -224,11 +224,6 @@ static int manager_clock_watch(sd_event_source *source, int fd, uint32_t revents
 
 /* wake up when the system time changes underneath us */
 static int manager_clock_watch_setup(Manager *m) {
-
-        struct itimerspec its = {
-                .it_value.tv_sec = TIME_T_MAX
-        };
-
         int r;
 
         assert(m);
@@ -236,12 +231,9 @@ static int manager_clock_watch_setup(Manager *m) {
         m->event_clock_watch = sd_event_source_unref(m->event_clock_watch);
         safe_close(m->clock_watch_fd);
 
-        m->clock_watch_fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
+        m->clock_watch_fd = time_change_fd();
         if (m->clock_watch_fd < 0)
-                return log_error_errno(errno, "Failed to create timerfd: %m");
-
-        if (timerfd_settime(m->clock_watch_fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0)
-                return log_error_errno(errno, "Failed to set up timerfd: %m");
+                return log_error_errno(m->clock_watch_fd, "Failed to create timerfd: %m");
 
         r = sd_event_add_io(m->event, &m->event_clock_watch, m->clock_watch_fd, EPOLLIN, manager_clock_watch, m);
         if (r < 0)