src/core/slice.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21
  22 #include "alloc-util.h"
  23 #include "dbus-slice.h"
  24 #include "log.h"
  25 #include "slice.h"
  26 #include "special.h"
  27 #include "string-util.h"
  28 #include "strv.h"
  29 #include "unit-name.h"
  30 #include "unit.h"
  31
  32 static const UnitActiveState state_translation_table[_SLICE_STATE_MAX] = {
  33         [SLICE_DEAD] = UNIT_INACTIVE,
  34         [SLICE_ACTIVE] = UNIT_ACTIVE
  35 };
  36
  37 static void slice_set_state(Slice *t, SliceState state) {
  38         SliceState old_state;
  39         assert(t);
  40
  41         old_state = t->state;
  42         t->state = state;
  43
  44         if (state != old_state)
  45                 log_debug("%s changed %s -> %s",
  46                           UNIT(t)->id,
  47                           slice_state_to_string(old_state),
  48                           slice_state_to_string(state));
  49
  50         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
  51 }
  52
  53 static int slice_add_parent_slice(Slice *s) {
  54         char *a, *dash;
  55         Unit *parent;
  56         int r;
  57
  58         assert(s);
  59
  60         if (UNIT_ISSET(UNIT(s)->slice))
  61                 return 0;
  62
  63         if (unit_has_name(UNIT(s), SPECIAL_ROOT_SLICE))
  64                 return 0;
  65
  66         a = strdupa(UNIT(s)->id);
  67         dash = strrchr(a, '-');
  68         if (dash)
  69                 strcpy(dash, ".slice");
  70         else
  71                 a = (char*) SPECIAL_ROOT_SLICE;
  72
  73         r = manager_load_unit(UNIT(s)->manager, a, NULL, NULL, &parent);
  74         if (r < 0)
  75                 return r;
  76
  77         unit_ref_set(&UNIT(s)->slice, parent);
  78         return 0;
  79 }
  80
  81 static int slice_add_default_dependencies(Slice *s) {
  82         int r;
  83
  84         assert(s);
  85
  86         if (!UNIT(s)->default_dependencies)
  87                 return 0;
  88
  89         /* Make sure slices are unloaded on shutdown */
  90         r = unit_add_two_dependencies_by_name(
  91                         UNIT(s),
  92                         UNIT_BEFORE, UNIT_CONFLICTS,
  93                         SPECIAL_SHUTDOWN_TARGET, NULL, true);
  94         if (r < 0)
  95                 return r;
  96
  97         return 0;
  98 }
  99
 100 static int slice_verify(Slice *s) {
 101         _cleanup_free_ char *parent = NULL;
 102         int r;
 103
 104         assert(s);
 105
 106         if (UNIT(s)->load_state != UNIT_LOADED)
 107                 return 0;
 108
 109         if (!slice_name_is_valid(UNIT(s)->id)) {
 110                 log_unit_error(UNIT(s), "Slice name %s is not valid. Refusing.", UNIT(s)->id);
 111                 return -EINVAL;
 112         }
 113
 114         r = slice_build_parent_slice(UNIT(s)->id, &parent);
 115         if (r < 0)
 116                 return log_unit_error_errno(UNIT(s), r, "Failed to determine parent slice: %m");
 117
 118         if (parent ? !unit_has_name(UNIT_DEREF(UNIT(s)->slice), parent) : UNIT_ISSET(UNIT(s)->slice)) {
 119                 log_unit_error(UNIT(s), "Located outside of parent slice. Refusing.");
 120                 return -EINVAL;
 121         }
 122
 123         return 0;
 124 }
 125
 126 static int slice_load(Unit *u) {
 127         Slice *s = SLICE(u);
 128         int r;
 129
 130         assert(s);
 131
 132         r = unit_load_fragment_and_dropin_optional(u);
 133         if (r < 0)
 134                 return r;
 135
 136         /* This is a new unit? Then let's add in some extras */
 137         if (u->load_state == UNIT_LOADED) {
 138
 139                 r = unit_patch_contexts(u);
 140                 if (r < 0)
 141                         return r;
 142
 143                 r = slice_add_parent_slice(s);
 144                 if (r < 0)
 145                         return r;
 146
 147                 r = slice_add_default_dependencies(s);
 148                 if (r < 0)
 149                         return r;
 150         }
 151
 152         return slice_verify(s);
 153 }
 154
 155 static int slice_coldplug(Unit *u) {
 156         Slice *t = SLICE(u);
 157
 158         assert(t);
 159         assert(t->state == SLICE_DEAD);
 160
 161         if (t->deserialized_state != t->state)
 162                 slice_set_state(t, t->deserialized_state);
 163
 164         return 0;
 165 }
 166
 167 static void slice_dump(Unit *u, FILE *f, const char *prefix) {
 168         Slice *t = SLICE(u);
 169
 170         assert(t);
 171         assert(f);
 172
 173         fprintf(f,
 174                 "%sSlice State: %s\n",
 175                 prefix, slice_state_to_string(t->state));
 176
 177         cgroup_context_dump(&t->cgroup_context, f, prefix);
 178 }
 179
 180 static int slice_start(Unit *u) {
 181         Slice *t = SLICE(u);
 182
 183         assert(t);
 184         assert(t->state == SLICE_DEAD);
 185
 186         (void) unit_realize_cgroup(u);
 187         (void) unit_reset_cpu_usage(u);
 188
 189         slice_set_state(t, SLICE_ACTIVE);
 190         return 1;
 191 }
 192
 193 static int slice_stop(Unit *u) {
 194         Slice *t = SLICE(u);
 195
 196         assert(t);
 197         assert(t->state == SLICE_ACTIVE);
 198
 199         /* We do not need to destroy the cgroup explicitly,
 200          * unit_notify() will do that for us anyway. */
 201
 202         slice_set_state(t, SLICE_DEAD);
 203         return 1;
 204 }
 205
 206 static int slice_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 207         return unit_kill_common(u, who, signo, -1, -1, error);
 208 }
 209
 210 static int slice_serialize(Unit *u, FILE *f, FDSet *fds) {
 211         Slice *s = SLICE(u);
 212
 213         assert(s);
 214         assert(f);
 215         assert(fds);
 216
 217         unit_serialize_item(u, f, "state", slice_state_to_string(s->state));
 218         return 0;
 219 }
 220
 221 static int slice_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 222         Slice *s = SLICE(u);
 223
 224         assert(u);
 225         assert(key);
 226         assert(value);
 227         assert(fds);
 228
 229         if (streq(key, "state")) {
 230                 SliceState state;
 231
 232                 state = slice_state_from_string(value);
 233                 if (state < 0)
 234                         log_debug("Failed to parse state value %s", value);
 235                 else
 236                         s->deserialized_state = state;
 237
 238         } else
 239                 log_debug("Unknown serialization key '%s'", key);
 240
 241         return 0;
 242 }
 243
 244 _pure_ static UnitActiveState slice_active_state(Unit *u) {
 245         assert(u);
 246
 247         return state_translation_table[SLICE(u)->state];
 248 }
 249
 250 _pure_ static const char *slice_sub_state_to_string(Unit *u) {
 251         assert(u);
 252
 253         return slice_state_to_string(SLICE(u)->state);
 254 }
 255
 256 static void slice_enumerate(Manager *m) {
 257         Unit *u;
 258         int r;
 259
 260         assert(m);
 261
 262         u = manager_get_unit(m, SPECIAL_ROOT_SLICE);
 263         if (!u) {
 264                 u = unit_new(m, sizeof(Slice));
 265                 if (!u)  {
 266                         log_oom();
 267                         return;
 268                 }
 269
 270                 r = unit_add_name(u, SPECIAL_ROOT_SLICE);
 271                 if (r < 0) {
 272                         unit_free(u);
 273                         log_error_errno(r, "Failed to add -.slice name");
 274                         return;
 275                 }
 276         }
 277
 278         u->default_dependencies = false;
 279         u->no_gc = true;
 280         u->ignore_on_isolate = true;
 281         u->refuse_manual_start = true;
 282         u->refuse_manual_stop = true;
 283         SLICE(u)->deserialized_state = SLICE_ACTIVE;
 284
 285         if (!u->description)
 286                 u->description = strdup("Root Slice");
 287         if (!u->documentation)
 288                 (void) strv_extend(&u->documentation, "man:systemd.special(7)");
 289
 290         unit_add_to_load_queue(u);
 291         unit_add_to_dbus_queue(u);
 292 }
 293
 294 const UnitVTable slice_vtable = {
 295         .object_size = sizeof(Slice),
 296         .cgroup_context_offset = offsetof(Slice, cgroup_context),
 297
 298         .sections =
 299                 "Unit\0"
 300                 "Slice\0"
 301                 "Install\0",
 302         .private_section = "Slice",
 303
 304         .no_alias = true,
 305         .no_instances = true,
 306         .can_transient = true,
 307
 308         .load = slice_load,
 309
 310         .coldplug = slice_coldplug,
 311
 312         .dump = slice_dump,
 313
 314         .start = slice_start,
 315         .stop = slice_stop,
 316
 317         .kill = slice_kill,
 318
 319         .serialize = slice_serialize,
 320         .deserialize_item = slice_deserialize_item,
 321
 322         .active_state = slice_active_state,
 323         .sub_state_to_string = slice_sub_state_to_string,
 324
 325         .bus_vtable = bus_slice_vtable,
 326         .bus_set_property = bus_slice_set_property,
 327         .bus_commit_properties = bus_slice_commit_properties,
 328
 329         .enumerate = slice_enumerate,
 330
 331         .status_message_formats = {
 332                 .finished_start_job = {
 333                         [JOB_DONE]       = "Created slice %s.",
 334                 },
 335                 .finished_stop_job = {
 336                         [JOB_DONE]       = "Removed slice %s.",
 337                 },
 338         },
 339 };