From a05c1077911652954c8b9e82cfdc0fc643eca782 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 6 Aug 2018 21:44:45 +0200
Subject: [PATCH] logind: rework how we manage the slice and
user-runtime-dir@.service unit for each user
Instead of managing it explicitly, let's simplify things and rely on
regular Wants=/Requires= dependencies to pull in these units from
user@.service and the session scope, and StopWhenUneeded= to stop these
auxiliary units again. This way, they can be pulled in easily by
unrelated units too.
This simplifies things quite a bit: for each session we now only need to
manage the session scope, and for each user the user@.service, the other
units are not something we need to manage anymore.
This patch also makes sure that if user@.service of a user is masked we
will continue to work, and user-runtime-dir@.service will still be
correctly pulled in, as it is now a dependency of the scope unit.
Fixes: #9461
Replaces: #5546
(cherry picked from commit 25a1ab4ed48b72e974f77a68dcbe3521014787bb)
Related: #1642460
---
src/login/logind-dbus.c | 58 ++++++++--------
src/login/logind-session.c | 64 ++++++++++--------
src/login/logind-session.h | 2 +-
src/login/logind-user.c | 134 ++++++++++++++-----------------------
src/login/logind-user.h | 7 +-
src/login/logind.c | 2 +-
src/login/logind.h | 2 +-
7 files changed, 123 insertions(+), 146 deletions(-)
diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index 4b2c418453..7eba617fff 100644
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -847,7 +847,7 @@ static int method_create_session(sd_bus_message *message, void *userdata, sd_bus
if (r < 0)
goto fail;
- r = session_start(session, message);
+ r = session_start(session, message, error);
if (r < 0)
goto fail;
@@ -3110,24 +3110,20 @@ const sd_bus_vtable manager_vtable[] = {
};
static int session_jobs_reply(Session *s, const char *unit, const char *result) {
- int r = 0;
-
assert(s);
assert(unit);
if (!s->started)
- return r;
+ return 0;
- if (streq(result, "done"))
- r = session_send_create_reply(s, NULL);
- else {
+ if (result && !streq(result, "done")) {
_cleanup_(sd_bus_error_free) sd_bus_error e = SD_BUS_ERROR_NULL;
- sd_bus_error_setf(&e, BUS_ERROR_JOB_FAILED, "Start job for unit %s failed with '%s'", unit, result);
- r = session_send_create_reply(s, &e);
+ sd_bus_error_setf(&e, BUS_ERROR_JOB_FAILED, "Start job for unit '%s' failed with '%s'", unit, result);
+ return session_send_create_reply(s, &e);
}
- return r;
+ return session_send_create_reply(s, NULL);
}
int match_job_removed(sd_bus_message *message, void *userdata, sd_bus_error *error) {
@@ -3160,30 +3156,29 @@ int match_job_removed(sd_bus_message *message, void *userdata, sd_bus_error *err
}
session = hashmap_get(m->session_units, unit);
- if (session && streq_ptr(path, session->scope_job)) {
- session->scope_job = mfree(session->scope_job);
- session_jobs_reply(session, unit, result);
+ if (session) {
+ if (streq_ptr(path, session->scope_job)) {
+ session->scope_job = mfree(session->scope_job);
+ (void) session_jobs_reply(session, unit, result);
+
+ session_save(session);
+ user_save(session->user);
+ }
- session_save(session);
- user_save(session->user);
session_add_to_gc_queue(session);
}
user = hashmap_get(m->user_units, unit);
- if (user &&
- (streq_ptr(path, user->service_job) ||
- streq_ptr(path, user->slice_job))) {
-
- if (streq_ptr(path, user->service_job))
+ if (user) {
+ if (streq_ptr(path, user->service_job)) {
user->service_job = mfree(user->service_job);
- if (streq_ptr(path, user->slice_job))
- user->slice_job = mfree(user->slice_job);
+ LIST_FOREACH(sessions_by_user, session, user->sessions)
+ (void) session_jobs_reply(session, unit, NULL /* don't propagate user service failures to the client */);
- LIST_FOREACH(sessions_by_user, session, user->sessions)
- session_jobs_reply(session, unit, result);
+ user_save(user);
+ }
- user_save(user);
user_add_to_gc_queue(user);
}
@@ -3315,13 +3310,14 @@ int manager_start_scope(
pid_t pid,
const char *slice,
const char *description,
- const char *after,
- const char *after2,
+ char **wants,
+ char **after,
sd_bus_message *more_properties,
sd_bus_error *error,
char **job) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL, *reply = NULL;
+ char **i;
int r;
assert(manager);
@@ -3359,14 +3355,14 @@ int manager_start_scope(
return r;
}
- if (!isempty(after)) {
- r = sd_bus_message_append(m, "(sv)", "After", "as", 1, after);
+ STRV_FOREACH(i, wants) {
+ r = sd_bus_message_append(m, "(sv)", "Wants", "as", 1, *i);
if (r < 0)
return r;
}
- if (!isempty(after2)) {
- r = sd_bus_message_append(m, "(sv)", "After", "as", 1, after2);
+ STRV_FOREACH(i, after) {
+ r = sd_bus_message_append(m, "(sv)", "After", "as", 1, *i);
if (r < 0)
return r;
}
diff --git a/src/login/logind-session.c b/src/login/logind-session.c
index 960a24d1a7..d56b48a732 100644
--- a/src/login/logind-session.c
+++ b/src/login/logind-session.c
@@ -27,6 +27,7 @@
#include "path-util.h"
#include "process-util.h"
#include "string-table.h"
+#include "strv.h"
#include "terminal-util.h"
#include "user-util.h"
#include "util.h"
@@ -560,17 +561,18 @@ int session_activate(Session *s) {
return 0;
}
-static int session_start_scope(Session *s, sd_bus_message *properties) {
+static int session_start_scope(Session *s, sd_bus_message *properties, sd_bus_error *error) {
int r;
assert(s);
assert(s->user);
if (!s->scope) {
- _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
- char *scope, *job = NULL;
+ _cleanup_free_ char *scope = NULL;
const char *description;
+ s->scope_job = mfree(s->scope_job);
+
scope = strjoin("session-", s->id, ".scope");
if (!scope)
return log_oom();
@@ -583,21 +585,15 @@ static int session_start_scope(Session *s, sd_bus_message *properties) {
s->leader,
s->user->slice,
description,
- "systemd-logind.service",
- "systemd-user-sessions.service",
+ STRV_MAKE(s->user->runtime_dir_service, s->user->service), /* These two have StopWhenUnneeded= set, hence add a dep towards them */
+ STRV_MAKE("systemd-logind.service", "systemd-user-sessions.service", s->user->runtime_dir_service, s->user->service), /* And order us after some more */
properties,
- &error,
- &job);
- if (r < 0) {
- log_error_errno(r, "Failed to start session scope %s: %s", scope, bus_error_message(&error, r));
- free(scope);
- return r;
- } else {
- s->scope = scope;
+ error,
+ &s->scope_job);
+ if (r < 0)
+ return log_error_errno(r, "Failed to start session scope %s: %s", scope, bus_error_message(error, r));
- free(s->scope_job);
- s->scope_job = job;
- }
+ s->scope = TAKE_PTR(scope);
}
if (s->scope)
@@ -606,7 +602,7 @@ static int session_start_scope(Session *s, sd_bus_message *properties) {
return 0;
}
-int session_start(Session *s, sd_bus_message *properties) {
+int session_start(Session *s, sd_bus_message *properties, sd_bus_error *error) {
int r;
assert(s);
@@ -614,6 +610,9 @@ int session_start(Session *s, sd_bus_message *properties) {
if (!s->user)
return -ESTALE;
+ if (s->stopping)
+ return -EINVAL;
+
if (s->started)
return 0;
@@ -621,8 +620,7 @@ int session_start(Session *s, sd_bus_message *properties) {
if (r < 0)
return r;
- /* Create cgroup */
- r = session_start_scope(s, properties);
+ r = session_start_scope(s, properties, error);
if (r < 0)
return r;
@@ -673,21 +671,24 @@ static int session_stop_scope(Session *s, bool force) {
* that is left in the scope is "left-over". Informing systemd about this has the benefit that it will log
* when killing any processes left after this point. */
r = manager_abandon_scope(s->manager, s->scope, &error);
- if (r < 0)
+ if (r < 0) {
log_warning_errno(r, "Failed to abandon session scope, ignoring: %s", bus_error_message(&error, r));
+ sd_bus_error_free(&error);
+ }
+
+ s->scope_job = mfree(s->scope_job);
/* Optionally, let's kill everything that's left now. */
if (force || manager_shall_kill(s->manager, s->user->name)) {
- char *job = NULL;
- r = manager_stop_unit(s->manager, s->scope, &error, &job);
- if (r < 0)
- return log_error_errno(r, "Failed to stop session scope: %s", bus_error_message(&error, r));
+ r = manager_stop_unit(s->manager, s->scope, &error, &s->scope_job);
+ if (r < 0) {
+ if (force)
+ return log_error_errno(r, "Failed to stop session scope: %s", bus_error_message(&error, r));
- free(s->scope_job);
- s->scope_job = job;
+ log_warning_errno(r, "Failed to stop session scope, ignoring: %s", bus_error_message(&error, r));
+ }
} else {
- s->scope_job = mfree(s->scope_job);
/* With no killing, this session is allowed to persist in "closing" state indefinitely.
* Therefore session stop and session removal may be two distinct events.
@@ -707,8 +708,17 @@ int session_stop(Session *s, bool force) {
assert(s);
+ /* This is called whenever we begin with tearing down a session record. It's called in four cases: explicit API
+ * request via the bus (either directly for the session object or for the seat or user object this session
+ * belongs to; 'force' is true), or due to automatic GC (i.e. scope vanished; 'force' is false), or because the
+ * session FIFO saw an EOF ('force' is false), or because the release timer hit ('force' is false). */
+
if (!s->user)
return -ESTALE;
+ if (!s->started)
+ return 0;
+ if (s->stopping)
+ return 0;
s->timer_event_source = sd_event_source_unref(s->timer_event_source);
diff --git a/src/login/logind-session.h b/src/login/logind-session.h
index 572f2545c1..7d17d9a25f 100644
--- a/src/login/logind-session.h
+++ b/src/login/logind-session.h
@@ -124,7 +124,7 @@ void session_set_idle_hint(Session *s, bool b);
int session_get_locked_hint(Session *s);
void session_set_locked_hint(Session *s, bool b);
int session_create_fifo(Session *s);
-int session_start(Session *s, sd_bus_message *properties);
+int session_start(Session *s, sd_bus_message *properties, sd_bus_error *error);
int session_stop(Session *s, bool force);
int session_finalize(Session *s);
int session_release(Session *s);
diff --git a/src/login/logind-user.c b/src/login/logind-user.c
index 3e4c99bdbd..39fc76f4dc 100644
--- a/src/login/logind-user.c
+++ b/src/login/logind-user.c
@@ -68,6 +68,10 @@ int user_new(User **ret, Manager *m, uid_t uid, gid_t gid, const char *name) {
if (r < 0)
return r;
+ r = unit_name_build("user-runtime-dir", lu, ".service", &u->runtime_dir_service);
+ if (r < 0)
+ return r;
+
r = hashmap_put(m->users, UID_TO_PTR(uid), u);
if (r < 0)
return r;
@@ -80,6 +84,10 @@ int user_new(User **ret, Manager *m, uid_t uid, gid_t gid, const char *name) {
if (r < 0)
return r;
+ r = hashmap_put(m->user_units, u->runtime_dir_service, u);
+ if (r < 0)
+ return r;
+
*ret = TAKE_PTR(u);
return 0;
}
@@ -97,15 +105,18 @@ User *user_free(User *u) {
if (u->service)
hashmap_remove_value(u->manager->user_units, u->service, u);
+ if (u->runtime_dir_service)
+ hashmap_remove_value(u->manager->user_units, u->runtime_dir_service, u);
+
if (u->slice)
hashmap_remove_value(u->manager->user_units, u->slice, u);
hashmap_remove_value(u->manager->users, UID_TO_PTR(u->uid), u);
- u->slice_job = mfree(u->slice_job);
u->service_job = mfree(u->service_job);
u->service = mfree(u->service);
+ u->runtime_dir_service = mfree(u->runtime_dir_service);
u->slice = mfree(u->slice);
u->runtime_path = mfree(u->runtime_path);
u->state_file = mfree(u->state_file);
@@ -149,9 +160,6 @@ static int user_save_internal(User *u) {
if (u->service_job)
fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
- if (u->slice_job)
- fprintf(f, "SLICE_JOB=%s\n", u->slice_job);
-
if (u->display)
fprintf(f, "DISPLAY=%s\n", u->display->id);
@@ -311,66 +319,46 @@ int user_load(User *u) {
return 0;
}
-static int user_start_service(User *u) {
+static void user_start_service(User *u) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
- char *job;
int r;
assert(u);
+ /* Start the service containing the "systemd --user" instance (user@.service). Note that we don't explicitly
+ * start the per-user slice or the systemd-runtime-dir@.service instance, as those are pulled in both by
+ * user@.service and the session scopes as dependencies. */
+
u->service_job = mfree(u->service_job);
- r = manager_start_unit(
- u->manager,
- u->service,
- &error,
- &job);
+ r = manager_start_unit(u->manager, u->service, &error, &u->service_job);
if (r < 0)
/* we don't fail due to this, let's try to continue */
log_full_errno(sd_bus_error_has_name(&error, BUS_ERROR_UNIT_MASKED) ? LOG_DEBUG : LOG_WARNING, r,
"Failed to start user service '%s', ignoring: %s", u->service, bus_error_message(&error, r));
- else
- u->service_job = job;
-
- return 0;
}
int user_start(User *u) {
- int r;
-
assert(u);
if (u->started && !u->stopping)
return 0;
- /*
- * If u->stopping is set, the user is marked for removal and the slice
- * and service stop-jobs are queued. We have to clear that flag before
- * queing the start-jobs again. If they succeed, the user object can be
- * re-used just fine (pid1 takes care of job-ordering and proper
- * restart), but if they fail, we want to force another user_stop() so
- * possibly pending units are stopped.
- * Note that we don't clear u->started, as we have no clue what state
- * the user is in on failure here. Hence, we pretend the user is
- * running so it will be properly taken down by GC. However, we clearly
- * return an error from user_start() in that case, so no further
- * reference to the user is taken.
- */
+ /* If u->stopping is set, the user is marked for removal and service stop-jobs are queued. We have to clear
+ * that flag before queing the start-jobs again. If they succeed, the user object can be re-used just fine
+ * (pid1 takes care of job-ordering and proper restart), but if they fail, we want to force another user_stop()
+ * so possibly pending units are stopped. */
u->stopping = false;
if (!u->started)
log_debug("Starting services for new user %s.", u->name);
- /* Save the user data so far, because pam_systemd will read the
- * XDG_RUNTIME_DIR out of it while starting up systemd --user.
- * We need to do user_save_internal() because we have not
- * "officially" started yet. */
+ /* Save the user data so far, because pam_systemd will read the XDG_RUNTIME_DIR out of it while starting up
+ * systemd --user. We need to do user_save_internal() because we have not "officially" started yet. */
user_save_internal(u);
- /* Spawn user systemd */
- r = user_start_service(u);
- if (r < 0)
- return r;
+ /* Start user@UID.service */
+ user_start_service(u);
if (!u->started) {
if (!dual_timestamp_is_set(&u->timestamp))
@@ -385,68 +373,50 @@ int user_start(User *u) {
return 0;
}
-static int user_stop_slice(User *u) {
+static void user_stop_service(User *u) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
- char *job;
int r;
assert(u);
+ assert(u->service);
- r = manager_stop_unit(u->manager, u->slice, &error, &job);
- if (r < 0) {
- log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
- return r;
- }
+ /* The reverse of user_start_service(). Note that we only stop user@UID.service here, and let StopWhenUnneeded=
+ * deal with the slice and the user-runtime-dir@.service instance. */
- free(u->slice_job);
- u->slice_job = job;
-
- return r;
-}
-
-static int user_stop_service(User *u) {
- _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
- char *job;
- int r;
-
- assert(u);
-
- r = manager_stop_unit(u->manager, u->service, &error, &job);
- if (r < 0) {
- log_error("Failed to stop user service: %s", bus_error_message(&error, r));
- return r;
- }
+ u->service_job = mfree(u->service_job);
- free_and_replace(u->service_job, job);
- return r;
+ r = manager_stop_unit(u->manager, u->service, &error, &u->service_job);
+ if (r < 0)
+ log_warning_errno(r, "Failed to stop user service '%s', ignoring: %s", u->service, bus_error_message(&error, r));
}
int user_stop(User *u, bool force) {
Session *s;
- int r = 0, k;
+ int r = 0;
assert(u);
- /* Stop jobs have already been queued */
- if (u->stopping) {
+ /* This is called whenever we begin with tearing down a user record. It's called in two cases: explicit API
+ * request to do so via the bus (in which case 'force' is true) and automatically due to GC, if there's no
+ * session left pinning it (in which case 'force' is false). Note that this just initiates tearing down of the
+ * user, the User object will remain in memory until user_finalize() is called, see below. */
+
+ if (!u->started)
+ return 0;
+
+ if (u->stopping) { /* Stop jobs have already been queued */
user_save(u);
- return r;
+ return 0;
}
LIST_FOREACH(sessions_by_user, s, u->sessions) {
+ int k;
+
k = session_stop(s, force);
if (k < 0)
r = k;
}
- /* Kill systemd */
- k = user_stop_service(u);
- if (k < 0)
- r = k;
-
- /* Kill cgroup */
- k = user_stop_slice(u);
- if (k < 0)
- r = k;
+ user_stop_service(u);
u->stopping = true;
@@ -461,6 +431,9 @@ int user_finalize(User *u) {
assert(u);
+ /* Called when the user is really ready to be freed, i.e. when all unit stop jobs and suchlike for it are
+ * done. This is called as a result of an earlier user_done() when all jobs are completed. */
+
if (u->started)
log_debug("User %s logged out.", u->name);
@@ -554,9 +527,6 @@ bool user_may_gc(User *u, bool drop_not_started) {
if (user_check_linger_file(u) > 0)
return false;
- if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
- return false;
-
if (u->service_job && manager_job_is_active(u->manager, u->service_job))
return false;
@@ -581,7 +551,7 @@ UserState user_get_state(User *u) {
if (u->stopping)
return USER_CLOSING;
- if (!u->started || u->slice_job || u->service_job)
+ if (!u->started || u->service_job)
return USER_OPENING;
if (u->sessions) {
diff --git a/src/login/logind-user.h b/src/login/logind-user.h
index 03e020b870..5e1f7b813a 100644
--- a/src/login/logind-user.h
+++ b/src/login/logind-user.h
@@ -25,11 +25,12 @@ struct User {
char *name;
char *state_file;
char *runtime_path;
- char *slice;
- char *service;
+
+ char *slice; /* user-UID.slice */
+ char *service; /* user@UID.service */
+ char *runtime_dir_service; /* user-runtime-dir@UID.service */
char *service_job;
- char *slice_job;
Session *display;
diff --git a/src/login/logind.c b/src/login/logind.c
index 1b366cd55f..6c208c8e89 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -1158,7 +1158,7 @@ static int manager_startup(Manager *m) {
user_start(user);
HASHMAP_FOREACH(session, m->sessions, i)
- session_start(session, NULL);
+ (void) session_start(session, NULL, NULL);
HASHMAP_FOREACH(inhibitor, m->inhibitors, i)
inhibitor_start(inhibitor);
diff --git a/src/login/logind.h b/src/login/logind.h
index a6ebc9e152..ae4d74076b 100644
--- a/src/login/logind.h
+++ b/src/login/logind.h
@@ -161,7 +161,7 @@ int bus_manager_shutdown_or_sleep_now_or_later(Manager *m, const char *unit_name
int manager_send_changed(Manager *manager, const char *property, ...) _sentinel_;
-int manager_start_scope(Manager *manager, const char *scope, pid_t pid, const char *slice, const char *description, const char *after, const char *after2, sd_bus_message *more_properties, sd_bus_error *error, char **job);
+int manager_start_scope(Manager *manager, const char *scope, pid_t pid, const char *slice, const char *description, char **wants, char **after, sd_bus_message *more_properties, sd_bus_error *error, char **job);
int manager_start_unit(Manager *manager, const char *unit, sd_bus_error *error, char **job);
int manager_stop_unit(Manager *manager, const char *unit, sd_bus_error *error, char **job);
int manager_abandon_scope(Manager *manager, const char *scope, sd_bus_error *error);