From 67d29b19ff4e53d58879b14c2e79a3bda419576f Mon Sep 17 00:00:00 2001

From: Ray Strode <rstrode@redhat.com>

Date: Fri, 22 Jun 2018 15:26:03 -0400

Subject: [PATCH 11/51] manager: don't bail if session disappears out from

 under us

It's entirely possible for a session returned by

sd_seat_get_sessions to disappear immediately after the

sd_seat_get_sessions call returns.  This is especially

likely at logout time where the session will briefly be

in the "closing" state before getting reaped.

If that happens when we're looking for a greeter session, we

stop looking for a greeter session and bail out all confused.

This commit fixes the confusion by gracefully handling the

session disappearing by just proceeding to the next session

in the list.

---

 daemon/gdm-manager.c | 10 ++++++++++

 1 file changed, 10 insertions(+)

diff --git a/daemon/gdm-manager.c b/daemon/gdm-manager.c

index a6f13dec7..ede22e771 100644

--- a/daemon/gdm-manager.c

+++ b/daemon/gdm-manager.c

@@ -1349,87 +1349,97 @@ maybe_start_pending_initial_login (GdmManager *manager,

         g_free (user_session_seat_id);

 }

 static gboolean

 get_login_window_session_id (const char  *seat_id,

                              char       **session_id)

 {

         gboolean   ret;

         int        res, i;

         char     **sessions;

         char      *service_id;

         char      *service_class;

         char      *state;

         res = sd_seat_get_sessions (seat_id, &sessions, NULL, NULL);

         if (res < 0) {

                 g_debug ("Failed to determine sessions: %s", strerror (-res));

                 return FALSE;

         }

         if (sessions == NULL || sessions[0] == NULL) {

                 *session_id = NULL;

                 ret = FALSE;

                 goto out;

         }

         for (i = 0; sessions[i]; i ++) {

                 res = sd_session_get_class (sessions[i], &service_class);

                 if (res < 0) {

+                        if (res == -ENOENT) {

+                                free (service_class);

+                                continue;

+                        }

+

                         g_debug ("failed to determine class of session %s: %s", sessions[i], strerror (-res));

                         ret = FALSE;

                         goto out;

                 }

                 if (strcmp (service_class, "greeter") != 0) {

                         free (service_class);

                         continue;

                 }

                 free (service_class);

                 ret = sd_session_get_state (sessions[i], &state);

                 if (ret < 0) {

+                        if (res == -ENOENT)

+                                continue;

+

                         g_debug ("failed to determine state of session %s: %s", sessions[i], strerror (-res));

                         ret = FALSE;

                         goto out;

                 }

                 if (g_strcmp0 (state, "closing") == 0) {

                         free (state);

                         continue;

                 }

                 free (state);

                 res = sd_session_get_service (sessions[i], &service_id);

                 if (res < 0) {

+                        if (res == -ENOENT)

+                                continue;

                         g_debug ("failed to determine service of session %s: %s", sessions[i], strerror (-res));

                         ret = FALSE;

                         goto out;

                 }

                 if (strcmp (service_id, "gdm-launch-environment") == 0) {

                         *session_id = g_strdup (sessions[i]);

                         ret = TRUE;

                         free (service_id);

                         goto out;

                 }

                 free (service_id);

         }

         *session_id = NULL;

         ret = FALSE;

 out:

         if (sessions) {

                 for (i = 0; sessions[i]; i ++) {

                         free (sessions[i]);

                 }

                 free (sessions);

         }

         return ret;

 }

-- 

2.27.0