core: port unit_fork_helper_process() and unit_fork_and_watch_rm_rf() to PidRef

diff --git a/TODO b/TODO
index bb126377982f8bf0a23c81a164ea91507f8053b0..349e31f1f756d3bcb4fd587bb2c2b401db894710 100644 (file)
--- a/TODO
+++ b/TODO
@@ -174,10 +174,9 @@ Features:
   - pid_is_unwaited() → pidref_is_unwaited()
   - pid_is_alive() → pidref_is_alive()
   - unit_watch_pid() → unit_watch_pidref()
-  - actually wait for POLLIN on piref's pidfd in service logic
+  - actually wait for POLLIN on pidref's pidfd in service logic
   - exec_spawn()
   - serialization of control/main pid in service, socket, mount, swap units
-  - unit_fork_and_watch_rm_rf()
   - cg_pid_get_unit()
   - openpt_allocate_in_namespace()
   - scope dbus PIDs property needs to gain PIDFDs companion

diff --git a/src/core/mount.c b/src/core/mount.c
index 4af2e6810e13bef718a3efbb514b12737b8ec202..08c2ddf9156592185468b5a118a9776d0847e26d 100644 (file)
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -2220,7 +2220,6 @@ static PidRef* mount_control_pid(Unit *u) {
 static int mount_clean(Unit *u, ExecCleanMask mask) {
         _cleanup_strv_free_ char **l = NULL;
         Mount *m = MOUNT(u);
-        pid_t pid;
         int r;
 
         assert(m);
@@ -2245,11 +2244,7 @@ static int mount_clean(Unit *u, ExecCleanMask mask) {
         if (r < 0)
                 goto fail;
 
-        r = unit_fork_and_watch_rm_rf(u, l, &pid);
-        if (r < 0)
-                goto fail;
-
-        r = pidref_set_pid(&m->control_pid, pid);
+        r = unit_fork_and_watch_rm_rf(u, l, &m->control_pid);
         if (r < 0)
                 goto fail;
 

diff --git a/src/core/scope.c b/src/core/scope.c
index 13907855c5062c25667e58a69ffbe789ddab5127..eb3ffba084dcdaadaeb91ab0699e28dbed660cda 100644 (file)
--- a/src/core/scope.c
+++ b/src/core/scope.c
@@ -372,8 +372,8 @@ fail:
 }
 
 static int scope_enter_start_chown(Scope *s) {
+        _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
         Unit *u = UNIT(s);
-        pid_t pid;
         int r;
 
         assert(s);
@@ -383,7 +383,7 @@ static int scope_enter_start_chown(Scope *s) {
         if (r < 0)
                 return r;
 
-        r = unit_fork_helper_process(u, "(sd-chown-cgroup)", &pid);
+        r = unit_fork_helper_process(u, "(sd-chown-cgroup)", &pidref);
         if (r < 0)
                 goto fail;
 
@@ -420,7 +420,7 @@ static int scope_enter_start_chown(Scope *s) {
                 _exit(EXIT_SUCCESS);
         }
 
-        r = unit_watch_pid(UNIT(s), pid, true);
+        r = unit_watch_pid(UNIT(s), pidref.pid, /* exclusive= */ true);
         if (r < 0)
                 goto fail;
 

diff --git a/src/core/service.c b/src/core/service.c
index 0ecfe46cfdfb366b65acaaa507607b71a25386e7..05a2bb6ddf1a58ce6bc9620ae6acb0c49219e35e 100644 (file)
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -4890,7 +4890,6 @@ static int service_clean(Unit *u, ExecCleanMask mask) {
         _cleanup_strv_free_ char **l = NULL;
         bool may_clean_fdstore = false;
         Service *s = SERVICE(u);
-        pid_t pid;
         int r;
 
         assert(s);
@@ -4931,11 +4930,7 @@ static int service_clean(Unit *u, ExecCleanMask mask) {
         if (r < 0)
                 goto fail;
 
-        r = unit_fork_and_watch_rm_rf(u, l, &pid);
-        if (r < 0)
-                goto fail;
-
-        r = pidref_set_pid(&s->control_pid, pid);
+        r = unit_fork_and_watch_rm_rf(u, l, &s->control_pid);
         if (r < 0)
                 goto fail;
 

diff --git a/src/core/socket.c b/src/core/socket.c
index 861e580b3fe05ac7c74014d7b49462b3d33e154c..3304af831dbe24ee2111b40940e1d8c4043d5527 100644 (file)
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -1503,9 +1503,9 @@ static int socket_address_listen_in_cgroup(
                 const SocketAddress *address,
                 const char *label) {
 
+        _cleanup_(pidref_done) PidRef pid = PIDREF_NULL;
         _cleanup_close_pair_ int pair[2] = PIPE_EBADF;
         int fd, r;
-        pid_t pid;
 
         assert(s);
         assert(address);
@@ -1597,7 +1597,7 @@ static int socket_address_listen_in_cgroup(
         fd = receive_one_fd(pair[0], 0);
 
         /* We synchronously wait for the helper, as it shouldn't be slow */
-        r = wait_for_terminate_and_check("(sd-listen)", pid, WAIT_LOG_ABNORMAL);
+        r = wait_for_terminate_and_check("(sd-listen)", pid.pid, WAIT_LOG_ABNORMAL);
         if (r < 0) {
                 safe_close(fd);
                 return r;
@@ -1968,8 +1968,7 @@ static int socket_spawn(Socket *s, ExecCommand *c, PidRef *ret_pid) {
 }
 
 static int socket_chown(Socket *s, PidRef *ret_pid) {
-        _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
-        pid_t pid;
+        _cleanup_(pidref_done) PidRef pid = PIDREF_NULL;
         int r;
 
         assert(s);
@@ -2030,15 +2029,11 @@ static int socket_chown(Socket *s, PidRef *ret_pid) {
                 _exit(EXIT_SUCCESS);
         }
 
-        r = pidref_set_pid(&pidref, pid);
-        if (r < 0)
-                return r;
-
-        r = unit_watch_pid(UNIT(s), pidref.pid, /* exclusive= */ true);
+        r = unit_watch_pid(UNIT(s), pid.pid, /* exclusive= */ true);
         if (r < 0)
                 return r;
 
-        *ret_pid = TAKE_PIDREF(pidref);
+        *ret_pid = TAKE_PIDREF(pid);
         return 0;
 }
 
@@ -2982,9 +2977,9 @@ static int socket_accept_do(Socket *s, int fd) {
 }
 
 static int socket_accept_in_cgroup(Socket *s, SocketPort *p, int fd) {
+        _cleanup_(pidref_done) PidRef pid = PIDREF_NULL;
         _cleanup_close_pair_ int pair[2] = PIPE_EBADF;
         int cfd, r;
-        pid_t pid;
 
         assert(s);
         assert(p);
@@ -3034,7 +3029,7 @@ static int socket_accept_in_cgroup(Socket *s, SocketPort *p, int fd) {
         cfd = receive_one_fd(pair[0], 0);
 
         /* We synchronously wait for the helper, as it shouldn't be slow */
-        r = wait_for_terminate_and_check("(sd-accept)", pid, WAIT_LOG_ABNORMAL);
+        r = wait_for_terminate_and_check("(sd-accept)", pid.pid, WAIT_LOG_ABNORMAL);
         if (r < 0) {
                 safe_close(cfd);
                 return r;
@@ -3417,7 +3412,6 @@ static PidRef *socket_control_pid(Unit *u) {
 static int socket_clean(Unit *u, ExecCleanMask mask) {
         _cleanup_strv_free_ char **l = NULL;
         Socket *s = SOCKET(u);
-        pid_t pid;
         int r;
 
         assert(s);
@@ -3442,11 +3436,7 @@ static int socket_clean(Unit *u, ExecCleanMask mask) {
         if (r < 0)
                 goto fail;
 
-        r = unit_fork_and_watch_rm_rf(u, l, &pid);
-        if (r < 0)
-                goto fail;
-
-        r = pidref_set_pid(&s->control_pid, pid);
+        r = unit_fork_and_watch_rm_rf(u, l, &s->control_pid);
         if (r < 0)
                 goto fail;
 

diff --git a/src/core/swap.c b/src/core/swap.c
index e06de629da32f759530117115a6d573396af4b11..aa04b99462275948feaaf4b22cdf4a8f569d9da3 100644 (file)
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -1519,7 +1519,6 @@ static PidRef* swap_control_pid(Unit *u) {
 static int swap_clean(Unit *u, ExecCleanMask mask) {
         _cleanup_strv_free_ char **l = NULL;
         Swap *s = SWAP(u);
-        pid_t pid;
         int r;
 
         assert(s);
@@ -1544,11 +1543,7 @@ static int swap_clean(Unit *u, ExecCleanMask mask) {
         if (r < 0)
                 goto fail;
 
-        r = unit_fork_and_watch_rm_rf(u, l, &pid);
-        if (r < 0)
-                goto fail;
-
-        r = pidref_set_pid(&s->control_pid, pid);
+        r = unit_fork_and_watch_rm_rf(u, l, &s->control_pid);
         if (r < 0)
                 goto fail;
 

diff --git a/src/core/unit.c b/src/core/unit.c
index c17e0990184a1c7345a319512faf6b21f2a72a4d..5fd66e7b6e042bde4759fe0e98e029a1fa07345e 100644 (file)
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -5319,7 +5319,8 @@ int unit_set_exec_params(Unit *u, ExecParameters *p) {
         return 0;
 }
 
-int unit_fork_helper_process(Unit *u, const char *name, pid_t *ret) {
+int unit_fork_helper_process(Unit *u, const char *name, PidRef *ret) {
+        pid_t pid;
         int r;
 
         assert(u);
@@ -5330,9 +5331,24 @@ int unit_fork_helper_process(Unit *u, const char *name, pid_t *ret) {
 
         (void) unit_realize_cgroup(u);
 
-        r = safe_fork(name, FORK_REOPEN_LOG|FORK_DEATHSIG, ret);
-        if (r != 0)
+        r = safe_fork(name, FORK_REOPEN_LOG|FORK_DEATHSIG, &pid);
+        if (r < 0)
+                return r;
+        if (r > 0) {
+                _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
+                int q;
+
+                /* Parent */
+
+                q = pidref_set_pid(&pidref, pid);
+                if (q < 0)
+                        return q;
+
+                *ret = TAKE_PIDREF(pidref);
                 return r;
+        }
+
+        /* Child */
 
         (void) default_signals(SIGNALS_CRASH_HANDLER, SIGNALS_IGNORE);
         (void) ignore_signals(SIGPIPE);
@@ -5348,8 +5364,8 @@ int unit_fork_helper_process(Unit *u, const char *name, pid_t *ret) {
         return 0;
 }
 
-int unit_fork_and_watch_rm_rf(Unit *u, char **paths, pid_t *ret_pid) {
-        pid_t pid;
+int unit_fork_and_watch_rm_rf(Unit *u, char **paths, PidRef *ret_pid) {
+        _cleanup_(pidref_done) PidRef pid = PIDREF_NULL;
         int r;
 
         assert(u);
@@ -5372,11 +5388,11 @@ int unit_fork_and_watch_rm_rf(Unit *u, char **paths, pid_t *ret_pid) {
                 _exit(ret);
         }
 
-        r = unit_watch_pid(u, pid, true);
+        r = unit_watch_pid(u, pid.pid, /* exclusive= */ true);
         if (r < 0)
                 return r;
 
-        *ret_pid = pid;
+        *ret_pid = TAKE_PIDREF(pid);
         return 0;
 }
 

diff --git a/src/core/unit.h b/src/core/unit.h
index d0d713f612681683d535b0359e647b80bd87d600..f1a80cc8912201ff896b0173b231286a8efc8fd0 100644 (file)
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -1024,8 +1024,8 @@ bool unit_shall_confirm_spawn(Unit *u);
 
 int unit_set_exec_params(Unit *s, ExecParameters *p);
 
-int unit_fork_helper_process(Unit *u, const char *name, pid_t *ret);
-int unit_fork_and_watch_rm_rf(Unit *u, char **paths, pid_t *ret_pid);
+int unit_fork_helper_process(Unit *u, const char *name, PidRef *ret);
+int unit_fork_and_watch_rm_rf(Unit *u, char **paths, PidRef *ret);
 
 void unit_remove_dependencies(Unit *u, UnitDependencyMask mask);