core: port unit_main_pid() + unit_control_pid() to PidRef and drop unit_kill_common()

This ports over unit_main_pid() + unit_control_pid() to return PidRef*
pointers (which also means the underlying UnitVTable function pointers
are changed accordingly).

This then uses te functions to simplify the unit_kill() call, by
avoiding the kill() vtable indirection and instead just suing
unit_main_pid() and unit_control_pid() directly.

diff --git a/TODO b/TODO
index c75d65e0e466ccc144c366aec1ff21d585c467bb..bb126377982f8bf0a23c81a164ea91507f8053b0 100644 (file)
--- a/TODO
+++ b/TODO
@@ -174,9 +174,7 @@ Features:
   - pid_is_unwaited() → pidref_is_unwaited()
   - pid_is_alive() → pidref_is_alive()
   - unit_watch_pid() → unit_watch_pidref()
-  - unit_kill_common()
   - actually wait for POLLIN on piref's pidfd in service logic
-  - unit_main_pid() + unit_control_pid()
   - exec_spawn()
   - serialization of control/main pid in service, socket, mount, swap units
   - unit_fork_and_watch_rm_rf()

diff --git a/src/core/dbus-service.c b/src/core/dbus-service.c
index cc65a5599035d96689b559da1036025c3023ef1d..5bc487bc39925068f315caac6cd3ca089be11b6c 100644 (file)
--- a/src/core/dbus-service.c
+++ b/src/core/dbus-service.c
@@ -134,7 +134,6 @@ static int bus_service_method_mount(sd_bus_message *message, void *userdata, sd_
         int read_only, make_file_or_directory;
         Unit *u = ASSERT_PTR(userdata);
         ExecContext *c;
-        pid_t unit_pid;
         int r;
 
         assert(message);
@@ -192,14 +191,14 @@ static int bus_service_method_mount(sd_bus_message *message, void *userdata, sd_
         if (!exec_needs_mount_namespace(c, NULL, unit_get_exec_runtime(u)))
                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Unit not running in private mount namespace, cannot activate bind mount");
 
-        unit_pid = unit_main_pid(u);
-        if (unit_pid == 0 || !UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u)))
+        PidRef* unit_pid = unit_main_pid(u);
+        if (!pidref_is_set(unit_pid) || !UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u)))
                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Unit is not running");
 
         propagate_directory = strjoina("/run/systemd/propagate/", u->id);
         if (is_image)
                 r = mount_image_in_namespace(
-                                unit_pid,
+                                unit_pid->pid,
                                 propagate_directory,
                                 "/run/systemd/incoming/",
                                 src, dest,
@@ -209,7 +208,7 @@ static int bus_service_method_mount(sd_bus_message *message, void *userdata, sd_
                                 c->mount_image_policy ?: &image_policy_service);
         else
                 r = bind_mount_in_namespace(
-                                unit_pid,
+                                unit_pid->pid,
                                 propagate_directory,
                                 "/run/systemd/incoming/",
                                 src, dest,

diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 1f673fe26d2d72c47a3523f5527fee8515316961..e9b446945aaa60846b043973c8b3292bf6fac9b6 100644 (file)
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -1331,7 +1331,6 @@ int bus_unit_method_get_processes(sd_bus_message *message, void *userdata, sd_bu
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         _cleanup_set_free_ Set *pids = NULL;
         Unit *u = userdata;
-        pid_t pid;
         int r;
 
         assert(message);
@@ -1359,16 +1358,16 @@ int bus_unit_method_get_processes(sd_bus_message *message, void *userdata, sd_bu
         }
 
         /* The main and control pids might live outside of the cgroup, hence fetch them separately */
-        pid = unit_main_pid(u);
-        if (pid > 0) {
-                r = append_process(reply, NULL, pid, pids);
+        PidRef *pid = unit_main_pid(u);
+        if (pidref_is_set(pid)) {
+                r = append_process(reply, NULL, pid->pid, pids);
                 if (r < 0)
                         return r;
         }
 
         pid = unit_control_pid(u);
-        if (pid > 0) {
-                r = append_process(reply, NULL, pid, pids);
+        if (pidref_is_set(pid)) {
+                r = append_process(reply, NULL, pid->pid, pids);
                 if (r < 0)
                         return r;
         }

diff --git a/src/core/mount.c b/src/core/mount.c
index c156a84c1d3b18a99a88dc47a85e0e5afea466c0..4af2e6810e13bef718a3efbb514b12737b8ec202 100644 (file)
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -2213,20 +2213,8 @@ static void mount_reset_failed(Unit *u) {
         m->clean_result = MOUNT_SUCCESS;
 }
 
-static int mount_kill(Unit *u, KillWho who, int signo, int code, int value, sd_bus_error *error) {
-        Mount *m = MOUNT(u);
-
-        assert(m);
-
-        return unit_kill_common(u, who, signo, code, value, -1, m->control_pid.pid, error);
-}
-
-static int mount_control_pid(Unit *u) {
-        Mount *m = MOUNT(u);
-
-        assert(m);
-
-        return m->control_pid.pid;
+static PidRef* mount_control_pid(Unit *u) {
+        return &ASSERT_PTR(MOUNT(u))->control_pid;
 }
 
 static int mount_clean(Unit *u, ExecCleanMask mask) {
@@ -2358,7 +2346,6 @@ const UnitVTable mount_vtable = {
         .stop = mount_stop,
         .reload = mount_reload,
 
-        .kill = mount_kill,
         .clean = mount_clean,
         .can_clean = mount_can_clean,
 

diff --git a/src/core/scope.c b/src/core/scope.c
index 31ea5c5483264591f4f1cd68833e249ec27feb81..13907855c5062c25667e58a69ffbe789ddab5127 100644 (file)
--- a/src/core/scope.c
+++ b/src/core/scope.c
@@ -533,10 +533,6 @@ static void scope_reset_failed(Unit *u) {
         s->result = SCOPE_SUCCESS;
 }
 
-static int scope_kill(Unit *u, KillWho who, int signo, int code, int value, sd_bus_error *error) {
-        return unit_kill_common(u, who, signo, code, value, -1, -1, error);
-}
-
 static int scope_get_timeout(Unit *u, usec_t *timeout) {
         Scope *s = SCOPE(u);
         usec_t t;
@@ -830,8 +826,6 @@ const UnitVTable scope_vtable = {
         .start = scope_start,
         .stop = scope_stop,
 
-        .kill = scope_kill,
-
         .freeze = unit_freeze_vtable_common,
         .thaw = unit_thaw_vtable_common,
 

diff --git a/src/core/service.c b/src/core/service.c
index 34948fa92340eef248504dc9bb60bf485ba594c7..0ecfe46cfdfb366b65acaaa507607b71a25386e7 100644 (file)
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -4825,28 +4825,12 @@ static void service_reset_failed(Unit *u) {
         s->flush_n_restarts = false;
 }
 
-static int service_kill(Unit *u, KillWho who, int signo, int code, int value, sd_bus_error *error) {
-        Service *s = SERVICE(u);
-
-        assert(s);
-
-        return unit_kill_common(u, who, signo, code, value, s->main_pid.pid, s->control_pid.pid, error);
-}
-
-static int service_main_pid(Unit *u) {
-        Service *s = SERVICE(u);
-
-        assert(s);
-
-        return s->main_pid.pid;
+static PidRef* service_main_pid(Unit *u) {
+        return &ASSERT_PTR(SERVICE(u))->main_pid;
 }
 
-static int service_control_pid(Unit *u) {
-        Service *s = SERVICE(u);
-
-        assert(s);
-
-        return s->control_pid.pid;
+static PidRef* service_control_pid(Unit *u) {
+        return &ASSERT_PTR(SERVICE(u))->control_pid;
 }
 
 static bool service_needs_console(Unit *u) {
@@ -5163,7 +5147,6 @@ const UnitVTable service_vtable = {
 
         .can_reload = service_can_reload,
 
-        .kill = service_kill,
         .clean = service_clean,
         .can_clean = service_can_clean,
 

diff --git a/src/core/slice.c b/src/core/slice.c
index c6d142cebbaba7626b13bf57ebf8ce06cec35a90..c7701b4017faf90d7a3fd0ee404fd444f2c50340 100644 (file)
--- a/src/core/slice.c
+++ b/src/core/slice.c
@@ -247,10 +247,6 @@ static int slice_stop(Unit *u) {
         return 1;
 }
 
-static int slice_kill(Unit *u, KillWho who, int signo, int code, int value, sd_bus_error *error) {
-        return unit_kill_common(u, who, signo, code, value, -1, -1, error);
-}
-
 static int slice_serialize(Unit *u, FILE *f, FDSet *fds) {
         Slice *s = SLICE(u);
 
@@ -436,8 +432,6 @@ const UnitVTable slice_vtable = {
         .start = slice_start,
         .stop = slice_stop,
 
-        .kill = slice_kill,
-
         .freeze = slice_freeze,
         .thaw = slice_thaw,
         .can_freeze = slice_can_freeze,

diff --git a/src/core/socket.c b/src/core/socket.c
index d885581247c7dc71d452555bfe56f4fd68adf1e7..861e580b3fe05ac7c74014d7b49462b3d33e154c 100644 (file)
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -3382,10 +3382,6 @@ static void socket_trigger_notify(Unit *u, Unit *other) {
                 socket_set_state(s, SOCKET_RUNNING);
 }
 
-static int socket_kill(Unit *u, KillWho who, int signo, int code, int value, sd_bus_error *error) {
-        return unit_kill_common(u, who, signo, code, value, -1, SOCKET(u)->control_pid.pid, error);
-}
-
 static int socket_get_timeout(Unit *u, usec_t *timeout) {
         Socket *s = SOCKET(u);
         usec_t t;
@@ -3414,12 +3410,8 @@ char *socket_fdname(Socket *s) {
         return s->fdname ?: UNIT(s)->id;
 }
 
-static int socket_control_pid(Unit *u) {
-        Socket *s = SOCKET(u);
-
-        assert(s);
-
-        return s->control_pid.pid;
+static PidRef *socket_control_pid(Unit *u) {
+        return &ASSERT_PTR(SOCKET(u))->control_pid;
 }
 
 static int socket_clean(Unit *u, ExecCleanMask mask) {
@@ -3576,7 +3568,6 @@ const UnitVTable socket_vtable = {
         .start = socket_start,
         .stop = socket_stop,
 
-        .kill = socket_kill,
         .clean = socket_clean,
         .can_clean = socket_can_clean,
 

diff --git a/src/core/swap.c b/src/core/swap.c
index d8c08375761f76ed44f75faf06511fe7576cda9c..e06de629da32f759530117115a6d573396af4b11 100644 (file)
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -1476,10 +1476,6 @@ static void swap_reset_failed(Unit *u) {
         s->clean_result = SWAP_SUCCESS;
 }
 
-static int swap_kill(Unit *u, KillWho who, int signo, int code, int value, sd_bus_error *error) {
-        return unit_kill_common(u, who, signo, code, value, -1, SWAP(u)->control_pid.pid, error);
-}
-
 static int swap_get_timeout(Unit *u, usec_t *timeout) {
         Swap *s = SWAP(u);
         usec_t t;
@@ -1516,12 +1512,8 @@ static bool swap_supported(void) {
         return supported;
 }
 
-static int swap_control_pid(Unit *u) {
-        Swap *s = SWAP(u);
-
-        assert(s);
-
-        return s->control_pid.pid;
+static PidRef* swap_control_pid(Unit *u) {
+        return &ASSERT_PTR(SWAP(u))->control_pid;
 }
 
 static int swap_clean(Unit *u, ExecCleanMask mask) {
@@ -1638,7 +1630,6 @@ const UnitVTable swap_vtable = {
         .start = swap_start,
         .stop = swap_stop,
 
-        .kill = swap_kill,
         .clean = swap_clean,
         .can_clean = swap_can_clean,
 

diff --git a/src/core/unit.c b/src/core/unit.c
index c542e4f504267242b8c8bd14456fdca1caa37312..c17e0990184a1c7345a319512faf6b21f2a72a4d 100644 (file)
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -2943,7 +2943,7 @@ void unit_unwatch_all_pids(Unit *u) {
 }
 
 static void unit_tidy_watch_pids(Unit *u) {
-        pid_t except1, except2;
+        PidRef *except1, *except2;
         void *e;
 
         assert(u);
@@ -2956,7 +2956,8 @@ static void unit_tidy_watch_pids(Unit *u) {
         SET_FOREACH(e, u->pids) {
                 pid_t pid = PTR_TO_PID(e);
 
-                if (pid == except1 || pid == except2)
+                if ((pidref_is_set(except1) && pid == except1->pid) ||
+                    (pidref_is_set(except2) && pid == except2->pid))
                         continue;
 
                 if (!pid_is_unwaited(pid))
@@ -3958,18 +3959,6 @@ bool unit_will_restart(Unit *u) {
         return UNIT_VTABLE(u)->will_restart(u);
 }
 
-int unit_kill(Unit *u, KillWho w, int signo, int code, int value, sd_bus_error *error) {
-        assert(u);
-        assert(w >= 0 && w < _KILL_WHO_MAX);
-        assert(SIGNAL_VALID(signo));
-        assert(IN_SET(code, SI_USER, SI_QUEUE));
-
-        if (!UNIT_VTABLE(u)->kill)
-                return -EOPNOTSUPP;
-
-        return UNIT_VTABLE(u)->kill(u, w, signo, code, value, error);
-}
-
 void unit_notify_cgroup_oom(Unit *u, bool managed_oom) {
         assert(u);
 
@@ -4012,35 +4001,34 @@ static int kill_common_log(pid_t pid, int signo, void *userdata) {
         return 1;
 }
 
-static int kill_or_sigqueue(pid_t pid, int signo, int code, int value) {
-        assert(pid > 0);
+static int kill_or_sigqueue(PidRef* pidref, int signo, int code, int value) {
+        assert(pidref_is_set(pidref));
         assert(SIGNAL_VALID(signo));
 
         switch (code) {
 
         case SI_USER:
-                log_debug("Killing " PID_FMT " with signal SIG%s.", pid, signal_to_string(signo));
-                return RET_NERRNO(kill(pid, signo));
+                log_debug("Killing " PID_FMT " with signal SIG%s.", pidref->pid, signal_to_string(signo));
+                return pidref_kill(pidref, signo);
 
         case SI_QUEUE:
-                log_debug("Enqueuing value %i to " PID_FMT " on signal SIG%s.", value, pid, signal_to_string(signo));
-                return RET_NERRNO(sigqueue(pid, signo, (const union sigval) { .sival_int = value }));
+                log_debug("Enqueuing value %i to " PID_FMT " on signal SIG%s.", value, pidref->pid, signal_to_string(signo));
+                return pidref_sigqueue(pidref, signo, value);
 
         default:
                 assert_not_reached();
         }
 }
 
-int unit_kill_common(
+int unit_kill(
                 Unit *u,
                 KillWho who,
                 int signo,
                 int code,
                 int value,
-                pid_t main_pid,
-                pid_t control_pid,
                 sd_bus_error *error) {
 
+        PidRef *main_pid, *control_pid;
         bool killed = false;
         int ret = 0, r;
 
@@ -4054,24 +4042,30 @@ int unit_kill_common(
         assert(SIGNAL_VALID(signo));
         assert(IN_SET(code, SI_USER, SI_QUEUE));
 
+        main_pid = unit_main_pid(u);
+        control_pid = unit_control_pid(u);
+
+        if (!UNIT_HAS_CGROUP_CONTEXT(u) && !main_pid && !control_pid)
+                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Unit type does not support process killing.");
+
         if (IN_SET(who, KILL_MAIN, KILL_MAIN_FAIL)) {
-                if (main_pid < 0)
+                if (!main_pid)
                         return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_PROCESS, "%s units have no main processes", unit_type_to_string(u->type));
-                if (main_pid == 0)
+                if (!pidref_is_set(main_pid))
                         return sd_bus_error_set_const(error, BUS_ERROR_NO_SUCH_PROCESS, "No main process to kill");
         }
 
         if (IN_SET(who, KILL_CONTROL, KILL_CONTROL_FAIL)) {
-                if (control_pid < 0)
+                if (!control_pid)
                         return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_PROCESS, "%s units have no control processes", unit_type_to_string(u->type));
-                if (control_pid == 0)
+                if (!pidref_is_set(control_pid))
                         return sd_bus_error_set_const(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
         }
 
-        if (control_pid > 0 &&
+        if (pidref_is_set(control_pid) &&
             IN_SET(who, KILL_CONTROL, KILL_CONTROL_FAIL, KILL_ALL, KILL_ALL_FAIL)) {
                 _cleanup_free_ char *comm = NULL;
-                (void) get_process_comm(control_pid, &comm);
+                (void) get_process_comm(control_pid->pid, &comm);
 
                 r = kill_or_sigqueue(control_pid, signo, code, value);
                 if (r < 0) {
@@ -4081,23 +4075,23 @@ int unit_kill_common(
                         sd_bus_error_set_errnof(
                                         error, r,
                                         "Failed to send signal SIG%s to control process " PID_FMT " (%s): %m",
-                                        signal_to_string(signo), control_pid, strna(comm));
+                                        signal_to_string(signo), control_pid->pid, strna(comm));
                         log_unit_warning_errno(
                                         u, r,
                                         "Failed to send signal SIG%s to control process " PID_FMT " (%s) on client request: %m",
-                                        signal_to_string(signo), control_pid, strna(comm));
+                                        signal_to_string(signo), control_pid->pid, strna(comm));
                 } else {
                         log_unit_info(u, "Sent signal SIG%s to control process " PID_FMT " (%s) on client request.",
-                                      signal_to_string(signo), control_pid, strna(comm));
+                                      signal_to_string(signo), control_pid->pid, strna(comm));
                         killed = true;
                 }
         }
 
-        if (main_pid > 0 &&
+        if (pidref_is_set(main_pid) &&
             IN_SET(who, KILL_MAIN, KILL_MAIN_FAIL, KILL_ALL, KILL_ALL_FAIL)) {
 
                 _cleanup_free_ char *comm = NULL;
-                (void) get_process_comm(main_pid, &comm);
+                (void) get_process_comm(main_pid->pid, &comm);
 
                 r = kill_or_sigqueue(main_pid, signo, code, value);
                 if (r < 0) {
@@ -4107,17 +4101,17 @@ int unit_kill_common(
                                 sd_bus_error_set_errnof(
                                                 error, r,
                                                 "Failed to send signal SIG%s to main process " PID_FMT " (%s): %m",
-                                                signal_to_string(signo), main_pid, strna(comm));
+                                                signal_to_string(signo), main_pid->pid, strna(comm));
                         }
 
                         log_unit_warning_errno(
                                         u, r,
                                         "Failed to send signal SIG%s to main process " PID_FMT " (%s) on client request: %m",
-                                        signal_to_string(signo), main_pid, strna(comm));
+                                        signal_to_string(signo), main_pid->pid, strna(comm));
 
                 } else {
                         log_unit_info(u, "Sent signal SIG%s to main process " PID_FMT " (%s) on client request.",
-                                      signal_to_string(signo), main_pid, strna(comm));
+                                      signal_to_string(signo), main_pid->pid, strna(comm));
                         killed = true;
                 }
         }
@@ -4129,7 +4123,7 @@ int unit_kill_common(
                 _cleanup_set_free_ Set *pid_set = NULL;
 
                 /* Exclude the main/control pids from being killed via the cgroup */
-                pid_set = unit_pid_set(main_pid, control_pid);
+                pid_set = unit_pid_set(main_pid ? main_pid->pid : 0, control_pid ? control_pid->pid : 0);
                 if (!pid_set)
                         return log_oom();
 
@@ -5120,22 +5114,22 @@ bool unit_is_pristine(Unit *u) {
                !u->merged_into;
 }
 
-pid_t unit_control_pid(Unit *u) {
+PidRef* unit_control_pid(Unit *u) {
         assert(u);
 
         if (UNIT_VTABLE(u)->control_pid)
                 return UNIT_VTABLE(u)->control_pid(u);
 
-        return 0;
+        return NULL;
 }
 
-pid_t unit_main_pid(Unit *u) {
+PidRef* unit_main_pid(Unit *u) {
         assert(u);
 
         if (UNIT_VTABLE(u)->main_pid)
                 return UNIT_VTABLE(u)->main_pid(u);
 
-        return 0;
+        return NULL;
 }
 
 static void unit_unref_uid_internal(

diff --git a/src/core/unit.h b/src/core/unit.h
index 7ce61eb5fd14f2bf7de36bc72a4a36fb4b385a31..d0d713f612681683d535b0359e647b80bd87d600 100644 (file)
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -625,8 +625,6 @@ typedef struct UnitVTable {
         int (*stop)(Unit *u);
         int (*reload)(Unit *u);
 
-        int (*kill)(Unit *u, KillWho w, int signo, int code, int value, sd_bus_error *error);
-
         /* Clear out the various runtime/state/cache/logs/configuration data */
         int (*clean)(Unit *u, ExecCleanMask m);
 
@@ -720,10 +718,10 @@ typedef struct UnitVTable {
         usec_t (*get_timeout_start_usec)(Unit *u);
 
         /* Returns the main PID if there is any defined, or 0. */
-        pid_t (*main_pid)(Unit *u);
+        PidRef* (*main_pid)(Unit *u);
 
-        /* Returns the main PID if there is any defined, or 0. */
-        pid_t (*control_pid)(Unit *u);
+        /* Returns the control PID if there is any defined, or 0. */
+        PidRef* (*control_pid)(Unit *u);
 
         /* Returns true if the unit currently needs access to the console */
         bool (*needs_console)(Unit *u);
@@ -914,7 +912,6 @@ int unit_stop(Unit *u);
 int unit_reload(Unit *u);
 
 int unit_kill(Unit *u, KillWho w, int signo, int code, int value, sd_bus_error *error);
-int unit_kill_common(Unit *u, KillWho who, int signo, int code, int value, pid_t main_pid, pid_t control_pid, sd_bus_error *error);
 
 void unit_notify_cgroup_oom(Unit *u, bool managed_oom);
 
@@ -1007,8 +1004,8 @@ bool unit_is_unneeded(Unit *u);
 bool unit_is_upheld_by_active(Unit *u, Unit **ret_culprit);
 bool unit_is_bound_by_inactive(Unit *u, Unit **ret_culprit);
 
-pid_t unit_control_pid(Unit *u);
-pid_t unit_main_pid(Unit *u);
+PidRef* unit_control_pid(Unit *u);
+PidRef* unit_main_pid(Unit *u);
 
 void unit_warn_if_dir_nonempty(Unit *u, const char* where);
 int unit_fail_if_noncanonical(Unit *u, const char* where);