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Merge pull request #12033 from fbuihuu/watched-process-improvments

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Watched process improvments
This commit is contained in:
Zbigniew Jędrzejewski-Szmek
2019-03-20 13:03:06 +01:00
committed by GitHub
parent ec7b77642c 01542056aa
commit a49945e663
14 changed files with 75 additions and 49 deletions
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src/basic/process-util.c
+14
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@@ -934,6 +934,20 @@ int getenv_for_pid(pid_t pid, const char *field, char **ret) {
return 0;
}
int pid_is_my_child(pid_t pid) {
pid_t ppid;
int r;
if (pid <= 1)
return false;
r = get_process_ppid(pid, &ppid);
if (r < 0)
return r;
return ppid == getpid_cached();
}
bool pid_is_unwaited(pid_t pid) {
/* Checks whether a PID is still valid at all, including a zombie */
src/basic/process-util.h
+1
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@@ -69,6 +69,7 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value);
bool pid_is_alive(pid_t pid);
bool pid_is_unwaited(pid_t pid);
int pid_is_my_child(pid_t pid);
int pid_from_same_root_fs(pid_t pid);
bool is_main_thread(void);
src/core/cgroup.c
+3 -6
View File
@@ -2269,7 +2269,7 @@ void unit_prune_cgroup(Unit *u) {
int unit_search_main_pid(Unit *u, pid_t *ret) {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0, npid, mypid;
pid_t pid = 0, npid;
int r;
assert(u);
@@ -2282,15 +2282,12 @@ int unit_search_main_pid(Unit *u, pid_t *ret) {
if (r < 0)
return r;
mypid = getpid_cached();
while (cg_read_pid(f, &npid) > 0) {
pid_t ppid;
if (npid == pid)
continue;
/* Ignore processes that aren't our kids */
if (get_process_ppid(npid, &ppid) >= 0 && ppid != mypid)
if (pid_is_my_child(npid) == 0)
continue;
if (pid != 0)
@@ -2322,7 +2319,7 @@ static int unit_watch_pids_in_path(Unit *u, const char *path) {
pid_t pid;
while ((r = cg_read_pid(f, &pid)) > 0) {
r = unit_watch_pid(u, pid);
r = unit_watch_pid(u, pid, false);
if (r < 0 && ret >= 0)
ret = r;
}
src/core/dbus-scope.c
+1 -1
View File
@@ -106,7 +106,7 @@ static int bus_scope_set_transient_property(
return r;
if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
r = unit_watch_pid(UNIT(s), pid);
r = unit_watch_pid(UNIT(s), pid, false);
if (r < 0 && r != -EEXIST)
return r;
}
src/core/manager.c
+10
View File
@@ -2129,6 +2129,16 @@ void manager_clear_jobs(Manager *m) {
job_finish_and_invalidate(j, JOB_CANCELED, false, false);
}
void manager_unwatch_pid(Manager *m, pid_t pid) {
assert(m);
/* First let's drop the unit keyed as "pid". */
(void) hashmap_remove(m->watch_pids, PID_TO_PTR(pid));
/* Then, let's also drop the array keyed by -pid. */
free(hashmap_remove(m->watch_pids, PID_TO_PTR(-pid)));
}
static int manager_dispatch_run_queue(sd_event_source *source, void *userdata) {
Manager *m = userdata;
Job *j;
src/core/manager.h
+2
View File
@@ -437,6 +437,8 @@ int manager_get_dump_string(Manager *m, char **ret);
void manager_clear_jobs(Manager *m);
void manager_unwatch_pid(Manager *m, pid_t pid);
unsigned manager_dispatch_load_queue(Manager *m);
int manager_default_environment(Manager *m);
src/core/mount.c
+2 -3
View File
@@ -704,7 +704,7 @@ static int mount_coldplug(Unit *u) {
pid_is_unwaited(m->control_pid) &&
MOUNT_STATE_WITH_PROCESS(new_state)) {
r = unit_watch_pid(UNIT(m), m->control_pid);
r = unit_watch_pid(UNIT(m), m->control_pid, false);
if (r < 0)
return r;
@@ -810,9 +810,8 @@ static int mount_spawn(Mount *m, ExecCommand *c, pid_t *_pid) {
if (r < 0)
return r;
r = unit_watch_pid(UNIT(m), pid);
r = unit_watch_pid(UNIT(m), pid, true);
if (r < 0)
/* FIXME: we need to do something here */
return r;
*_pid = pid;
src/core/scope.c
+4 -4
View File
@@ -333,11 +333,11 @@ static int scope_start(Unit *u) {
(void) unit_reset_cpu_accounting(u);
(void) unit_reset_ip_accounting(u);
unit_export_state_files(UNIT(s));
unit_export_state_files(u);
r = unit_attach_pids_to_cgroup(u, UNIT(s)->pids, NULL);
r = unit_attach_pids_to_cgroup(u, u->pids, NULL);
if (r < 0) {
log_unit_warning_errno(UNIT(s), r, "Failed to add PIDs to scope's control group: %m");
log_unit_warning_errno(u, r, "Failed to add PIDs to scope's control group: %m");
scope_enter_dead(s, SCOPE_FAILURE_RESOURCES);
return r;
}
@@ -347,7 +347,7 @@ static int scope_start(Unit *u) {
scope_set_state(s, SCOPE_RUNNING);
/* Start watching the PIDs currently in the scope */
(void) unit_enqueue_rewatch_pids(UNIT(s));
(void) unit_enqueue_rewatch_pids(u);
return 1;
}
src/core/service.c
+19 -20
View File
@@ -143,8 +143,6 @@ static void service_unwatch_pid_file(Service *s) {
}
static int service_set_main_pid(Service *s, pid_t pid) {
pid_t ppid;
assert(s);
if (pid <= 1)
@@ -163,12 +161,10 @@ static int service_set_main_pid(Service *s, pid_t pid) {
s->main_pid = pid;
s->main_pid_known = true;
s->main_pid_alien = pid_is_my_child(pid) == 0;
if (get_process_ppid(pid, &ppid) >= 0 && ppid != getpid_cached()) {
if (s->main_pid_alien)
log_unit_warning(UNIT(s), "Supervising process "PID_FMT" which is not our child. We'll most likely not notice when it exits.", pid);
s->main_pid_alien = true;
} else
s->main_pid_alien = false;
return 0;
}
@@ -994,7 +990,7 @@ static int service_load_pid_file(Service *s, bool may_warn) {
if (r < 0)
return r;
r = unit_watch_pid(UNIT(s), pid);
r = unit_watch_pid(UNIT(s), pid, false);
if (r < 0) /* FIXME: we need to do something here */
return log_unit_warning_errno(UNIT(s), r, "Failed to watch PID "PID_FMT" for service: %m", pid);
@@ -1024,7 +1020,7 @@ static void service_search_main_pid(Service *s) {
if (service_set_main_pid(s, pid) < 0)
return;
r = unit_watch_pid(UNIT(s), pid);
r = unit_watch_pid(UNIT(s), pid, false);
if (r < 0)
/* FIXME: we need to do something here */
log_unit_warning_errno(UNIT(s), r, "Failed to watch PID "PID_FMT" from: %m", pid);
@@ -1158,7 +1154,7 @@ static int service_coldplug(Unit *u) {
SERVICE_RUNNING, SERVICE_RELOAD,
SERVICE_STOP, SERVICE_STOP_WATCHDOG, SERVICE_STOP_SIGTERM, SERVICE_STOP_SIGKILL, SERVICE_STOP_POST,
SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL))) {
r = unit_watch_pid(UNIT(s), s->main_pid);
r = unit_watch_pid(UNIT(s), s->main_pid, false);
if (r < 0)
return r;
}
@@ -1170,7 +1166,7 @@ static int service_coldplug(Unit *u) {
SERVICE_RELOAD,
SERVICE_STOP, SERVICE_STOP_WATCHDOG, SERVICE_STOP_SIGTERM, SERVICE_STOP_SIGKILL, SERVICE_STOP_POST,
SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL)) {
r = unit_watch_pid(UNIT(s), s->control_pid);
r = unit_watch_pid(UNIT(s), s->control_pid, false);
if (r < 0)
return r;
}
@@ -1570,8 +1566,8 @@ static int service_spawn(
s->exec_fd_event_source = TAKE_PTR(exec_fd_source);
s->exec_fd_hot = false;
r = unit_watch_pid(UNIT(s), pid);
if (r < 0) /* FIXME: we need to do something here */
r = unit_watch_pid(UNIT(s), pid, true);
if (r < 0)
return r;
*_pid = pid;
@@ -3475,8 +3471,7 @@ static void service_sigchld_event(Unit *u, pid_t pid, int code, int status) {
if (main_pid_good(s) <= 0)
service_enter_stop_post(s, f);
/* If there is still a service
* process around, wait until
/* If there is still a service process around, wait until
* that one quit, too */
break;
@@ -3498,10 +3493,14 @@ static void service_sigchld_event(Unit *u, pid_t pid, int code, int status) {
if (notify_dbus)
unit_add_to_dbus_queue(u);
/* If we get a SIGCHLD event for one of the processes we were interested in, then we look for others to watch,
* under the assumption that we'll sooner or later get a SIGCHLD for them, as the original process we watched
* was probably the parent of them, and they are hence now our children. */
(void) unit_enqueue_rewatch_pids(u);
/* We watch the main/control process otherwise we can't retrieve the unit they
* belong to with cgroupv1. But if they are not our direct child, we won't get a
* SIGCHLD for them. Therefore we need to look for others to watch so we can
* detect when the cgroup becomes empty. Note that the control process is always
* our child so it's pointless to watch all other processes. */
if (!control_pid_good(s))
if (!s->main_pid_known || s->main_pid_alien)
(void) unit_enqueue_rewatch_pids(u);
}
static int service_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
@@ -3709,7 +3708,7 @@ static void service_notify_message(
if (r > 0) {
service_set_main_pid(s, new_main_pid);
r = unit_watch_pid(UNIT(s), new_main_pid);
r = unit_watch_pid(UNIT(s), new_main_pid, false);
if (r < 0)
log_unit_warning_errno(UNIT(s), r, "Failed to watch new main PID "PID_FMT" for service: %m", new_main_pid);
@@ -3927,7 +3926,7 @@ static void service_bus_name_owner_change(
log_unit_debug(u, "D-Bus name %s is now owned by process " PID_FMT, name, pid);
service_set_main_pid(s, pid);
unit_watch_pid(UNIT(s), pid);
unit_watch_pid(UNIT(s), pid, false);
}
}
}
src/core/socket.c
+3 -4
View File
@@ -1852,7 +1852,7 @@ static int socket_coldplug(Unit *u) {
SOCKET_FINAL_SIGTERM,
SOCKET_FINAL_SIGKILL)) {
r = unit_watch_pid(UNIT(s), s->control_pid);
r = unit_watch_pid(UNIT(s), s->control_pid, false);
if (r < 0)
return r;
@@ -1938,9 +1938,8 @@ static int socket_spawn(Socket *s, ExecCommand *c, pid_t *_pid) {
if (r < 0)
return r;
r = unit_watch_pid(UNIT(s), pid);
r = unit_watch_pid(UNIT(s), pid, true);
if (r < 0)
/* FIXME: we need to do something here */
return r;
*_pid = pid;
@@ -2009,7 +2008,7 @@ static int socket_chown(Socket *s, pid_t *_pid) {
_exit(EXIT_SUCCESS);
}
r = unit_watch_pid(UNIT(s), pid);
r = unit_watch_pid(UNIT(s), pid, true);
if (r < 0)
goto fail;
src/core/swap.c
+2 -3
View File
@@ -550,7 +550,7 @@ static int swap_coldplug(Unit *u) {
pid_is_unwaited(s->control_pid) &&
SWAP_STATE_WITH_PROCESS(new_state)) {
r = unit_watch_pid(UNIT(s), s->control_pid);
r = unit_watch_pid(UNIT(s), s->control_pid, false);
if (r < 0)
return r;
@@ -657,9 +657,8 @@ static int swap_spawn(Swap *s, ExecCommand *c, pid_t *_pid) {
if (r < 0)
goto fail;
r = unit_watch_pid(UNIT(s), pid);
r = unit_watch_pid(UNIT(s), pid, true);
if (r < 0)
/* FIXME: we need to do something here */
goto fail;
*_pid = pid;
src/core/unit.c
+7 -1
View File
@@ -2525,7 +2525,7 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, UnitNotifyFlag
unit_add_to_gc_queue(u);
}
int unit_watch_pid(Unit *u, pid_t pid) {
int unit_watch_pid(Unit *u, pid_t pid, bool exclusive) {
int r;
assert(u);
@@ -2533,6 +2533,12 @@ int unit_watch_pid(Unit *u, pid_t pid) {
/* Watch a specific PID */
/* Caller might be sure that this PID belongs to this unit only. Let's take this
* opportunity to remove any stalled references to this PID as they can be created
* easily (when watching a process which is not our direct child). */
if (exclusive)
manager_unwatch_pid(u->manager, pid);
r = set_ensure_allocated(&u->pids, NULL);
if (r < 0)
return r;
src/core/unit.h
+1 -1
View File
@@ -678,7 +678,7 @@ typedef enum UnitNotifyFlags {
void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, UnitNotifyFlags flags);
int unit_watch_pid(Unit *u, pid_t pid);
int unit_watch_pid(Unit *u, pid_t pid, bool exclusive);
void unit_unwatch_pid(Unit *u, pid_t pid);
void unit_unwatch_all_pids(Unit *u);
src/test/test-watch-pid.c
+6 -6
View File
@@ -42,25 +42,25 @@ int main(int argc, char *argv[]) {
assert_se(hashmap_isempty(m->watch_pids));
assert_se(manager_get_unit_by_pid(m, 4711) == NULL);
assert_se(unit_watch_pid(a, 4711) >= 0);
assert_se(unit_watch_pid(a, 4711, false) >= 0);
assert_se(manager_get_unit_by_pid(m, 4711) == a);
assert_se(unit_watch_pid(a, 4711) >= 0);
assert_se(unit_watch_pid(a, 4711, false) >= 0);
assert_se(manager_get_unit_by_pid(m, 4711) == a);
assert_se(unit_watch_pid(b, 4711) >= 0);
assert_se(unit_watch_pid(b, 4711, false) >= 0);
u = manager_get_unit_by_pid(m, 4711);
assert_se(u == a || u == b);
assert_se(unit_watch_pid(b, 4711) >= 0);
assert_se(unit_watch_pid(b, 4711, false) >= 0);
u = manager_get_unit_by_pid(m, 4711);
assert_se(u == a || u == b);
assert_se(unit_watch_pid(c, 4711) >= 0);
assert_se(unit_watch_pid(c, 4711, false) >= 0);
u = manager_get_unit_by_pid(m, 4711);
assert_se(u == a || u == b || u == c);
assert_se(unit_watch_pid(c, 4711) >= 0);
assert_se(unit_watch_pid(c, 4711, false) >= 0);
u = manager_get_unit_by_pid(m, 4711);
assert_se(u == a || u == b || u == c);