automount: If an automount unit is masked, don't react to activation anymore

Otherwise we'll hit an assert sooner or later.

Closes: #856035

debian/patches/automount-if-an-automount-unit-is-masked-don-t-react-to-a.patch

+From: Lennart Poettering <lennart@poettering.net>
+Date: Wed, 1 Mar 2017 04:03:48 +0100
+Subject: automount: if an automount unit is masked,
+ don't react to activation anymore (#5445)
+
+Otherwise we'll hit an assert sooner or later.
+
+This requires us to initialize ->where even if we come back in "masked"
+mode, as otherwise we don't know how to operate on the automount and
+detach it.
+
+Fixes: #5441
+(backported from commit e350ca3f1ecb6672b74cd25d09ef23c7b309aa5a)
+---
+ src/core/automount.c | 67 +++++++++++++++++++++++++++++++++++-----------------
+ 1 file changed, 45 insertions(+), 22 deletions(-)
+
+diff --git a/src/core/automount.c b/src/core/automount.c
+index 73a8ce1..4392635 100644
+--- a/src/core/automount.c
++++ b/src/core/automount.c
+@@ -87,17 +87,19 @@ static void unmount_autofs(Automount *a) {
+         if (a->pipe_fd < 0)
+                 return;
+ 
+-        automount_send_ready(a, -EHOSTDOWN);
+ 
+         a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
+         a->pipe_fd = safe_close(a->pipe_fd);
+ 
+-        /* If we reload/reexecute things we keep the mount point
+-         * around */
+-        if (a->where &&
+-            (UNIT(a)->manager->exit_code != MANAGER_RELOAD &&
+-             UNIT(a)->manager->exit_code != MANAGER_REEXECUTE))
+-                repeat_unmount(a->where);
++        /* If we reload/reexecute things we keep the mount point around */
++        if (!IN_SET(UNIT(a)->manager->exit_code, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
++
++                automount_send_ready(a, -EHOSTDOWN);
++
++                if (a->where) {
++                        repeat_unmount(a->where);
++                }
++        }
+ }
+ 
+ static void automount_done(Unit *u) {
+@@ -169,6 +171,21 @@ static int automount_verify(Automount *a) {
+         return 0;
+ }
+ 
++static int automount_set_where(Automount *a) {
++
++        assert(a);
++
++        if (a->where)
++                return 0;
++
++        a->where = unit_name_to_path(UNIT(a)->id);
++        if (!a->where)
++                return -ENOMEM;
++
++        path_kill_slashes(a->where);
++        return 1;
++}
++
+ static int automount_load(Unit *u) {
+         Automount *a = AUTOMOUNT(u);
+         int r;
+@@ -184,13 +201,9 @@ static int automount_load(Unit *u) {
+         if (u->load_state == UNIT_LOADED) {
+                 Unit *x;
+ 
+-                if (!a->where) {
+-                        a->where = unit_name_to_path(u->id);
+-                        if (!a->where)
+-                                return -ENOMEM;
+-                }
+-
+-                path_kill_slashes(a->where);
++                r = automount_set_where(a);
++                if (r < 0)
++                        return r;
+ 
+                 r = unit_load_related_unit(u, ".mount", &x);
+                 if (r < 0)
+@@ -242,21 +255,25 @@ static int automount_coldplug(Unit *u) {
+         assert(a);
+         assert(a->state == AUTOMOUNT_DEAD);
+ 
+-        if (a->deserialized_state != a->state) {
++        if (a->deserialized_state == a->state)
++                return 0;
++
++        if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
++
++                r = automount_set_where(a);
++                if (r < 0)
++                        return r;
+ 
+                 r = open_dev_autofs(u->manager);
+                 if (r < 0)
+                         return r;
+ 
+-                if (a->deserialized_state == AUTOMOUNT_WAITING ||
+-                    a->deserialized_state == AUTOMOUNT_RUNNING) {
++                assert(a->pipe_fd >= 0);
+ 
+-                        assert(a->pipe_fd >= 0);
++                r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
++                if (r < 0)
++                        return r;
+ 
+-                        r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
+-                        if (r < 0)
+-                                return r;
+-                }
+ 
+                 automount_set_state(a, a->deserialized_state);
+         }
+@@ -548,6 +565,12 @@ static void automount_enter_runnning(Automount *a) {
+ 
+         assert(a);
+ 
++        /* If the user masked our unit in the meantime, fail */
++        if (UNIT(a)->load_state != UNIT_LOADED) {
++                log_error_unit(UNIT(a)->id, "Suppressing automount event since unit is no longer loaded.");
++                goto fail;
++        }
++
+         /* We don't take mount requests anymore if we are supposed to
+          * shut down anyway */
+         if (unit_stop_pending(UNIT(a))) {

debian/patches/series

@@ -173,6 +173,7 @@ systemctl-when-reading-legacy-t-argument-for-shutdown-don.patch
 bus-fix-bus_print_property-to-use-int-for-booleans.patch
 service-allow-services-of-Type-oneshot-that-specify-no-Ex.patch
 core-if-the-start-command-vanishes-during-runtime-don-t-h.patch
+automount-if-an-automount-unit-is-masked-don-t-react-to-a.patch
 
 ## Debian specific patches:
 Add-back-support-for-Debian-specific-config-files.patch