Systemd/src/login/logind-device.c
Ray Strode ad1bf59c67 logind: ensure seat0 CanGraphical state is written
For non-`seat0` seats, attaching a graphics card to a seat can
lead to it getting created. This is because the graphics device
is a "master device" which means that device is a seat-defining
device.

`seat0` may get created, even before the graphics driver is loaded,
though. This is because the graphics driver is loaded
asynchronously at startup, and `seat0` is the primary seat of
system, associated with the system VTs.

When a graphics card is attached to a seat the `CanGraphical`
property on that seat will flip to `true`.

For seats that haven't been created yet (non-`seat0` seats), this
leads to `seat_start` getting called which ultimately causes the
seat to get serialized to `/run/systemd/seats`.

For `seat0`, which is already created, `seat_start` will return
immediately, which means the updated `CanGraphical` state will
never get written to `/run/systemd/seats`.

The end result is that clients querying `sd_seat_can_graphical`
won't get the correct answer for `seat0` in cases where the
graphics device takes a long time to load until some other peice
of seat state is updated.

This commit fixes the problem by calling `seat_save` explicitly
for already running seats at the time a graphics device is
attached.
2018-10-06 16:52:48 +02:00

107 lines
2.6 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#include <string.h>
#include "alloc-util.h"
#include "logind-device.h"
#include "util.h"
Device* device_new(Manager *m, const char *sysfs, bool master) {
Device *d;
assert(m);
assert(sysfs);
d = new0(Device, 1);
if (!d)
return NULL;
d->sysfs = strdup(sysfs);
if (!d->sysfs)
return mfree(d);
if (hashmap_put(m->devices, d->sysfs, d) < 0) {
free(d->sysfs);
return mfree(d);
}
d->manager = m;
d->master = master;
dual_timestamp_get(&d->timestamp);
return d;
}
static void device_detach(Device *d) {
Seat *s;
SessionDevice *sd;
assert(d);
if (!d->seat)
return;
while ((sd = d->session_devices))
session_device_free(sd);
s = d->seat;
LIST_REMOVE(devices, d->seat->devices, d);
d->seat = NULL;
if (!seat_has_master_device(s)) {
seat_add_to_gc_queue(s);
seat_send_changed(s, "CanGraphical", NULL);
}
}
void device_free(Device *d) {
assert(d);
device_detach(d);
hashmap_remove(d->manager->devices, d->sysfs);
free(d->sysfs);
free(d);
}
void device_attach(Device *d, Seat *s) {
Device *i;
bool had_master;
assert(d);
assert(s);
if (d->seat == s)
return;
if (d->seat)
device_detach(d);
d->seat = s;
had_master = seat_has_master_device(s);
/* We keep the device list sorted by the "master" flag. That is, master
* devices are at the front, other devices at the tail. As there is no
* way to easily add devices at the list-tail, we need to iterate the
* list to find the first non-master device when adding non-master
* devices. We assume there is only a few (normally 1) master devices
* per seat, so we iterate only a few times. */
if (d->master || !s->devices)
LIST_PREPEND(devices, s->devices, d);
else {
LIST_FOREACH(devices, i, s->devices) {
if (!i->devices_next || !i->master) {
LIST_INSERT_AFTER(devices, s->devices, i, d);
break;
}
}
}
if (!had_master && d->master && s->started) {
seat_save(s);
seat_send_changed(s, "CanGraphical", NULL);
}
}