update-utmp: reconnect after sleep when PID1 is reexecuting

Fixes #27167.
This commit is contained in:
Yu Watanabe
2023-05-24 20:06:10 +09:00
parent 87ae54533c
commit fcb2343175
+46 -21
View File
@@ -20,6 +20,7 @@
#include "macro.h"
#include "main-func.h"
#include "process-util.h"
#include "random-util.h"
#include "special.h"
#include "stdio-util.h"
#include "strv.h"
@@ -76,35 +77,59 @@ static int get_current_runlevel(Context *c) {
{ '3', SPECIAL_MULTI_USER_TARGET },
{ '1', SPECIAL_RESCUE_TARGET },
};
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
int r;
assert(c);
for (size_t i = 0; i < ELEMENTSOF(table); i++) {
_cleanup_free_ char *state = NULL, *path = NULL;
for (unsigned n_attempts = 0;;) {
FOREACH_ARRAY(e, table, ELEMENTSOF(table)) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_free_ char *state = NULL, *path = NULL;
path = unit_dbus_path_from_name(table[i].special);
if (!path)
return log_oom();
path = unit_dbus_path_from_name(e->special);
if (!path)
return log_oom();
r = sd_bus_get_property_string(
c->bus,
"org.freedesktop.systemd1",
path,
"org.freedesktop.systemd1.Unit",
"ActiveState",
&error,
&state);
r = sd_bus_get_property_string(
c->bus,
"org.freedesktop.systemd1",
path,
"org.freedesktop.systemd1.Unit",
"ActiveState",
&error,
&state);
if ((r == -ENOTCONN ||
sd_bus_error_has_names(&error,
SD_BUS_ERROR_NO_REPLY,
SD_BUS_ERROR_DISCONNECTED)) &&
++n_attempts < 64) {
/* systemd might have dropped off momentarily, let's not make this an error,
* and wait some random time. Let's pick a random time in the range 0ms…250ms,
* linearly scaled by the number of failed attempts. */
usec_t usec = random_u64_range(UINT64_C(10) * USEC_PER_MSEC +
UINT64_C(240) * USEC_PER_MSEC * n_attempts/64);
log_debug_errno(r, "Failed to get state of %s, retrying after %s: %s",
e->special, FORMAT_TIMESPAN(usec, USEC_PER_MSEC), bus_error_message(&error, r));
(void) usleep(usec);
goto reconnect;
}
if (r < 0)
return log_warning_errno(r, "Failed to get state of %s: %s", e->special, bus_error_message(&error, r));
if (STR_IN_SET(state, "active", "reloading"))
return e->runlevel;
}
return 0;
reconnect:
c->bus = sd_bus_flush_close_unref(c->bus);
r = bus_connect_system_systemd(&c->bus);
if (r < 0)
return log_warning_errno(r, "Failed to get state: %s", bus_error_message(&error, r));
if (STR_IN_SET(state, "active", "reloading"))
return table[i].runlevel;
return log_error_errno(r, "Failed to reconnect to system bus: %m");
}
return 0;
}
static int on_reboot(int argc, char *argv[], void *userdata) {