From 7d9e4212490f7c42d419de4befb438e173380da7 Mon Sep 17 00:00:00 2001

From: Alan Jenkins <alan.christopher.jenkins@gmail.com>

Date: Mon, 21 Aug 2017 17:28:35 +0100

Subject: [PATCH] logind: respect "delay" inhibitors in scheduled shutdowns

There is no justification not to wait an extra (default) 5 seconds, for

a more graceful shutdown of user programs.  Again, you don't get to ignore

delay inhibitors for unscheduled shutdowns, short of

`systemctl poweroff -f`.

It is simplest if we move the test for `m->shutdown_dry_run` into

manager_scheduled_shutdown_handler().

However we need to not add such delays during a "dry run".  Otherwise, we

would still have to be considered "in progress" for some seconds after our

admin has seen the final wall message.  If they go to `poweroff`, we would

have blocked them with a misleading error message.  Note this `poweroff`

will still process delay inhibitors as needed.  If the admin planned to

use a more forceful method... eh.  It's their responsibility to assess

whether that's safe.

There is an argument that the alternative behaviour could be used (racily!)

to kludge around them not being able to shutdown to "single user mode".  If

we cared about that case, we would have easily preserved non-racy support

for it in `shutdown`.

Additionally, though I think this code does read more easily by reducing

inconsistencies, we didn't come up with any use case for delay inhibitors

v.s. shutdown.[1]  The SIGTERM v.s. SIGKILL delay is more general, and we

allow a whole 90 seconds for it, not just 5.  So I don't think keeping this

approach bears a risk of significant damage.

[1] https://www.freedesktop.org/wiki/Software/systemd/inhibit/

(cherry picked from commit df75a1a8aa5420335a56093077fa8cfcbfffac78)

---

 src/login/logind-dbus.c | 91 ++++++++++++++++++++++++++-----------------------

 1 file changed, 48 insertions(+), 43 deletions(-)

diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c

index 3f05c86f5c..1fd64d32b7 100644

--- a/src/login/logind-dbus.c

+++ b/src/login/logind-dbus.c

@@ -1399,7 +1399,6 @@ static int have_multiple_sessions(

 static int bus_manager_log_shutdown(

                 Manager *m,

-                InhibitWhat w,

                 const char *unit_name) {

         const char *p, *q;

@@ -1407,9 +1406,6 @@ static int bus_manager_log_shutdown(

         assert(m);

         assert(unit_name);

-        if (w != INHIBIT_SHUTDOWN)

-                return 0;

-

         if (streq(unit_name, SPECIAL_POWEROFF_TARGET)) {

                 p = "MESSAGE=System is powering down";

                 q = "SHUTDOWN=power-off";

@@ -1484,21 +1480,6 @@ int manager_set_lid_switch_ignore(Manager *m, usec_t until) {

         return r;

 }

-static void reset_scheduled_shutdown(Manager *m) {

-        m->scheduled_shutdown_timeout_source = sd_event_source_unref(m->scheduled_shutdown_timeout_source);

-        m->wall_message_timeout_source = sd_event_source_unref(m->wall_message_timeout_source);

-        m->nologin_timeout_source = sd_event_source_unref(m->nologin_timeout_source);

-        m->scheduled_shutdown_type = mfree(m->scheduled_shutdown_type);

-        m->scheduled_shutdown_timeout = 0;

-        m->shutdown_dry_run = false;

-

-        if (m->unlink_nologin) {

-                (void) unlink("/run/nologin");

-                m->unlink_nologin = false;

-        }

-        (void) unlink("/run/systemd/shutdown/scheduled");

-}

-

 static int execute_shutdown_or_sleep(

                 Manager *m,

                 InhibitWhat w,

@@ -1515,32 +1496,28 @@ static int execute_shutdown_or_sleep(

         assert(w < _INHIBIT_WHAT_MAX);

         assert(unit_name);

-        bus_manager_log_shutdown(m, w, unit_name);

+        if (w == INHIBIT_SHUTDOWN)

+                bus_manager_log_shutdown(m, unit_name);

-        if (m->shutdown_dry_run) {

-                log_info("Running in dry run, suppressing action.");

-                reset_scheduled_shutdown(m);

-        } else {

-                r = sd_bus_call_method(

-                                m->bus,

-                                "org.freedesktop.systemd1",

-                                "/org/freedesktop/systemd1",

-                                "org.freedesktop.systemd1.Manager",

-                                "StartUnit",

-                                error,

-                                &reply,

-                                "ss", unit_name, "replace-irreversibly");

-                if (r < 0)

-                        return r;

+        r = sd_bus_call_method(

+                        m->bus,

+                        "org.freedesktop.systemd1",

+                        "/org/freedesktop/systemd1",

+                        "org.freedesktop.systemd1.Manager",

+                        "StartUnit",

+                        error,

+                        &reply,

+                        "ss", unit_name, "replace-irreversibly");

+        if (r < 0)

+                return r;

-                r = sd_bus_message_read(reply, "o", &p);

-                if (r < 0)

-                        return r;

+        r = sd_bus_message_read(reply, "o", &p);

+        if (r < 0)

+                return r;

-                c = strdup(p);

-                if (!c)

-                        return -ENOMEM;

-        }

+        c = strdup(p);

+        if (!c)

+                return -ENOMEM;

         m->action_unit = unit_name;

         free(m->action_job);

@@ -1924,6 +1901,21 @@ fail:

         return log_error_errno(r, "Failed to write information about scheduled shutdowns: %m");

 }

+static void reset_scheduled_shutdown(Manager *m) {

+        m->scheduled_shutdown_timeout_source = sd_event_source_unref(m->scheduled_shutdown_timeout_source);

+        m->wall_message_timeout_source = sd_event_source_unref(m->wall_message_timeout_source);

+        m->nologin_timeout_source = sd_event_source_unref(m->nologin_timeout_source);

+        m->scheduled_shutdown_type = mfree(m->scheduled_shutdown_type);

+        m->scheduled_shutdown_timeout = 0;

+        m->shutdown_dry_run = false;

+

+        if (m->unlink_nologin) {

+                (void) unlink("/run/nologin");

+                m->unlink_nologin = false;

+        }

+        (void) unlink("/run/systemd/shutdown/scheduled");

+}

+

 static int manager_scheduled_shutdown_handler(

                         sd_event_source *s,

                         uint64_t usec,

@@ -1952,7 +1944,20 @@ static int manager_scheduled_shutdown_handler(

                 return -EALREADY;

         }

-        r = execute_shutdown_or_sleep(m, INHIBIT_SHUTDOWN, target, &error);

+        if (m->shutdown_dry_run) {

+                /* We do not process delay inhibitors here.  Otherwise, we

+                 * would have to be considered "in progress" (like the check

+                 * above) for some seconds after our admin has seen the final

+                 * wall message. */

+

+                bus_manager_log_shutdown(m, target);

+                log_info("Running in dry run, suppressing action.");

+                reset_scheduled_shutdown(m);

+

+                return 0;

+        }

+

+        r = bus_manager_shutdown_or_sleep_now_or_later(m, target, INHIBIT_SHUTDOWN, &error);

         if (r < 0)

                 return log_error_errno(r, "Scheduled shutdown to %s failed: %m", target);