chiark / gitweb /
units: rework automatic dependency logic between automounts, mounts, sockets, swaps
[elogind.git] / manager.c
index 9458aa51baec9d61490d121822c937270695e9e1..6913ff400db9dee435779b76fc5e5e6892781f28 100644 (file)
--- a/manager.c
+++ b/manager.c
 #include "unit-name.h"
 #include "dbus-unit.h"
 #include "dbus-job.h"
+#include "missing.h"
+
+/* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
+#define GC_QUEUE_ENTRIES_MAX 16
+
+/* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
+#define GC_QUEUE_USEC_MAX (5*USEC_PER_SEC)
 
 static int enable_special_signals(Manager *m) {
         char fd;
@@ -247,7 +254,7 @@ static int manager_find_paths(Manager *m) {
         }
 
         if (m->running_as == MANAGER_INIT) {
-                /* /etc/init.d/ compativility does not matter to users */
+                /* /etc/init.d/ compatibility does not matter to users */
 
                 if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
                         if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
@@ -330,6 +337,9 @@ int manager_new(ManagerRunningAs running_as, bool confirm_spawn, Manager **_m) {
         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 
+        if (!(m->environment = strv_copy(environ)))
+                goto fail;
+
         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
                 goto fail;
 
@@ -389,6 +399,110 @@ static unsigned manager_dispatch_cleanup_queue(Manager *m) {
         return n;
 }
 
+enum {
+        GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
+        GC_OFFSET_UNSURE,   /* No clue */
+        GC_OFFSET_GOOD,     /* We still need this unit */
+        GC_OFFSET_BAD,      /* We don't need this unit anymore */
+        _GC_OFFSET_MAX
+};
+
+static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
+        Iterator i;
+        Unit *other;
+        bool is_bad;
+
+        assert(u);
+
+        if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
+            u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
+            u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
+                return;
+
+        if (u->meta.in_cleanup_queue)
+                goto bad;
+
+        if (unit_check_gc(u))
+                goto good;
+
+        u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
+
+        is_bad = true;
+
+        SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
+                unit_gc_sweep(other, gc_marker);
+
+                if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
+                        goto good;
+
+                if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
+                        is_bad = false;
+        }
+
+        if (is_bad)
+                goto bad;
+
+        /* We were unable to find anything out about this entry, so
+         * let's investigate it later */
+        u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
+        unit_add_to_gc_queue(u);
+        return;
+
+bad:
+        /* We definitely know that this one is not useful anymore, so
+         * let's mark it for deletion */
+        u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
+        unit_add_to_cleanup_queue(u);
+        return;
+
+good:
+        u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
+}
+
+static unsigned manager_dispatch_gc_queue(Manager *m) {
+        Meta *meta;
+        unsigned n = 0;
+        unsigned gc_marker;
+
+        assert(m);
+
+        if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
+            (m->gc_queue_timestamp <= 0 ||
+             (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
+                return 0;
+
+        log_debug("Running GC...");
+
+        m->gc_marker += _GC_OFFSET_MAX;
+        if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
+                m->gc_marker = 1;
+
+        gc_marker = m->gc_marker;
+
+        while ((meta = m->gc_queue)) {
+                assert(meta->in_gc_queue);
+
+                unit_gc_sweep(UNIT(meta), gc_marker);
+
+                LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
+                meta->in_gc_queue = false;
+
+                n++;
+
+                if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
+                    meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
+                        log_debug("Collecting %s", meta->id);
+                        meta->gc_marker = gc_marker + GC_OFFSET_BAD;
+                        unit_add_to_cleanup_queue(UNIT(meta));
+                }
+        }
+
+        m->n_in_gc_queue = 0;
+        m->gc_queue_timestamp = 0;
+
+        return n;
+}
+
 static void manager_clear_jobs_and_units(Manager *m) {
         Job *j;
         Unit *u;
@@ -434,6 +548,7 @@ void manager_free(Manager *m) {
         strv_free(m->unit_path);
         strv_free(m->sysvinit_path);
         strv_free(m->sysvrcnd_path);
+        strv_free(m->environment);
 
         free(m->cgroup_controller);
         free(m->cgroup_hierarchy);
@@ -925,7 +1040,7 @@ static void transaction_collect_garbage(Manager *m) {
         } while (again);
 }
 
-static int transaction_is_destructive(Manager *m, JobMode mode) {
+static int transaction_is_destructive(Manager *m) {
         Iterator i;
         Job *j;
 
@@ -1004,7 +1119,7 @@ static void transaction_minimize_impact(Manager *m) {
         } while (again);
 }
 
-static int transaction_apply(Manager *m, JobMode mode) {
+static int transaction_apply(Manager *m) {
         Iterator i;
         Job *j;
         int r;
@@ -1124,13 +1239,13 @@ static int transaction_activate(Manager *m, JobMode mode) {
 
         /* Ninth step: check whether we can actually apply this */
         if (mode == JOB_FAIL)
-                if ((r = transaction_is_destructive(m, mode)) < 0) {
+                if ((r = transaction_is_destructive(m)) < 0) {
                         log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
                         goto rollback;
                 }
 
         /* Tenth step: apply changes */
-        if ((r = transaction_apply(m, mode)) < 0) {
+        if ((r = transaction_apply(m)) < 0) {
                 log_debug("Failed to apply transaction: %s", strerror(-r));
                 goto rollback;
         }
@@ -1304,6 +1419,38 @@ fail:
         return r;
 }
 
+static int transaction_add_isolate_jobs(Manager *m) {
+        Iterator i;
+        Unit *u;
+        char *k;
+        int r;
+
+        assert(m);
+
+        HASHMAP_FOREACH_KEY(u, k, m->units, i) {
+
+                /* ignore aliases */
+                if (u->meta.id != k)
+                        continue;
+
+                if (UNIT_VTABLE(u)->no_isolate)
+                        continue;
+
+                /* No need to stop inactive jobs */
+                if (unit_active_state(u) == UNIT_INACTIVE)
+                        continue;
+
+                /* Is there already something listed for this? */
+                if (hashmap_get(m->transaction_jobs, u))
+                        continue;
+
+                if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, NULL)) < 0)
+                        log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
+        }
+
+        return 0;
+}
+
 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, Job **_ret) {
         int r;
         Job *ret;
@@ -1313,6 +1460,9 @@ int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool ove
         assert(unit);
         assert(mode < _JOB_MODE_MAX);
 
+        if (mode == JOB_ISOLATE && type != JOB_START)
+                return -EINVAL;
+
         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
 
         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, &ret)) < 0) {
@@ -1320,6 +1470,12 @@ int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool ove
                 return r;
         }
 
+        if (mode == JOB_ISOLATE)
+                if ((r = transaction_add_isolate_jobs(m)) < 0) {
+                        transaction_abort(m);
+                        return r;
+                }
+
         if ((r = transaction_activate(m, mode)) < 0)
                 return r;
 
@@ -1385,15 +1541,15 @@ unsigned manager_dispatch_load_queue(Manager *m) {
         return n;
 }
 
-int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
+int manager_load_unit_prepare(Manager *m, const char *name, const char *path, Unit **_ret) {
         Unit *ret;
         int r;
 
         assert(m);
         assert(name || path);
 
-        /* This will load the service information files, but not actually
-         * start any services or anything. */
+        /* This will prepare the unit for loading, but not actually
+         * load anything from disk. */
 
         if (path && !is_path(path))
                 return -EINVAL;
@@ -1426,6 +1582,24 @@ int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_re
         unit_add_to_load_queue(ret);
         unit_add_to_dbus_queue(ret);
 
+        if (_ret)
+                *_ret = ret;
+
+        return 0;
+}
+
+int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
+        Unit *ret;
+        int r;
+
+        assert(m);
+
+        /* This will load the service information files, but not actually
+         * start any services or anything. */
+
+        if ((r = manager_load_unit_prepare(m, name, path, &ret)) < 0)
+                return r;
+
         manager_dispatch_load_queue(m);
 
         if (_ret)
@@ -1614,9 +1788,17 @@ static int manager_process_signal_fd(Manager *m) {
                         sigchld = true;
                         break;
 
-                case SIGINT:
                 case SIGTERM:
+                        if (m->running_as == MANAGER_INIT)
+                                /* This is for compatibility with the
+                                 * original sysvinit */
+                                m->exit_code = MANAGER_REEXECUTE;
+                        else
+                                m->exit_code = MANAGER_EXIT;
+
+                        return 0;
 
+                case SIGINT:
                         if (m->running_as == MANAGER_INIT) {
                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
                                 break;
@@ -1626,7 +1808,6 @@ static int manager_process_signal_fd(Manager *m) {
                         return 0;
 
                 case SIGWINCH:
-
                         if (m->running_as == MANAGER_INIT)
                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
 
@@ -1640,12 +1821,7 @@ static int manager_process_signal_fd(Manager *m) {
                         /* This is a nop on non-init */
                         break;
 
-                case SIGUSR1:
-                        manager_dump_units(m, stdout, "\t");
-                        manager_dump_jobs(m, stdout, "\t");
-                        break;
-
-                case SIGUSR2:  {
+                case SIGUSR1: {
                         Unit *u;
 
                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
@@ -1664,6 +1840,11 @@ static int manager_process_signal_fd(Manager *m) {
                         break;
                 }
 
+                case SIGUSR2:
+                        manager_dump_units(m, stdout, "\t");
+                        manager_dump_jobs(m, stdout, "\t");
+                        break;
+
                 case SIGHUP:
                         m->exit_code = MANAGER_RELOAD;
                         break;
@@ -1770,6 +1951,9 @@ int manager_loop(Manager *m) {
                 if (manager_dispatch_cleanup_queue(m) > 0)
                         continue;
 
+                if (manager_dispatch_gc_queue(m) > 0)
+                        continue;
+
                 if (manager_dispatch_load_queue(m) > 0)
                         continue;
 
@@ -1784,7 +1968,7 @@ int manager_loop(Manager *m) {
 
                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
 
-                        if (errno == -EINTR)
+                        if (errno == EINTR)
                                 continue;
 
                         return -errno;