src/core/slice.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23 #include <signal.h>
  24 #include <unistd.h>
  25
  26 #include "unit.h"
  27 #include "slice.h"
  28 #include "load-fragment.h"
  29 #include "log.h"
  30 #include "dbus-slice.h"
  31 #include "special.h"
  32 #include "unit-name.h"
  33
  34 static const UnitActiveState state_translation_table[_SLICE_STATE_MAX] = {
  35         [SLICE_DEAD] = UNIT_INACTIVE,
  36         [SLICE_ACTIVE] = UNIT_ACTIVE
  37 };
  38
  39 static void slice_init(Unit *u) {
  40         Slice *s = SLICE(u);
  41
  42         assert(u);
  43         assert(u->load_state == UNIT_STUB);
  44
  45         cgroup_context_init(&s->cgroup_context);
  46         unit_cgroup_context_init_defaults(u, &s->cgroup_context);
  47 }
  48
  49 static void slice_done(Unit *u) {
  50         Slice *s = SLICE(u);
  51
  52         assert(u);
  53
  54         cgroup_context_done(&s->cgroup_context);
  55 }
  56
  57 static void slice_set_state(Slice *t, SliceState state) {
  58         SliceState old_state;
  59         assert(t);
  60
  61         old_state = t->state;
  62         t->state = state;
  63
  64         if (state != old_state)
  65                 log_debug("%s changed %s -> %s",
  66                           UNIT(t)->id,
  67                           slice_state_to_string(old_state),
  68                           slice_state_to_string(state));
  69
  70         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
  71 }
  72
  73 static int slice_add_parent_slice(Slice *s) {
  74         char *a, *dash;
  75         Unit *parent;
  76         int r;
  77
  78         assert(s);
  79
  80         if (UNIT_ISSET(UNIT(s)->slice))
  81                 return 0;
  82
  83         if (unit_has_name(UNIT(s), SPECIAL_ROOT_SLICE))
  84                 return 0;
  85
  86         a = strdupa(UNIT(s)->id);
  87         dash = strrchr(a, '-');
  88         if (dash)
  89                 strcpy(dash, ".slice");
  90         else
  91                 a = (char*) SPECIAL_ROOT_SLICE;
  92
  93         r = manager_load_unit(UNIT(s)->manager, a, NULL, NULL, &parent);
  94         if (r < 0)
  95                 return r;
  96
  97         unit_ref_set(&UNIT(s)->slice, parent);
  98         return 0;
  99 }
 100
 101 static int slice_add_default_dependencies(Slice *s) {
 102         int r;
 103
 104         assert(s);
 105
 106         /* Make sure slices are unloaded on shutdown */
 107         r = unit_add_two_dependencies_by_name(
 108                         UNIT(s),
 109                         UNIT_BEFORE, UNIT_CONFLICTS,
 110                         SPECIAL_SHUTDOWN_TARGET, NULL, true);
 111         if (r < 0)
 112                 return r;
 113
 114         return 0;
 115 }
 116
 117 static int slice_verify(Slice *s) {
 118         assert(s);
 119
 120         if (UNIT(s)->load_state != UNIT_LOADED)
 121                 return 0;
 122
 123         if (UNIT_DEREF(UNIT(s)->slice)) {
 124                 char *a, *dash;
 125
 126                 a = strdupa(UNIT(s)->id);
 127                 dash = strrchr(a, '-');
 128                 if (dash)
 129                         strcpy(dash, ".slice");
 130                 else
 131                         a = (char*) SPECIAL_ROOT_SLICE;
 132
 133                 if (!unit_has_name(UNIT_DEREF(UNIT(s)->slice), a)) {
 134                         log_error_unit(UNIT(s)->id,
 135                                        "%s located outside its parent slice. Refusing.", UNIT(s)->id);
 136                         return -EINVAL;
 137                 }
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int slice_load(Unit *u) {
 144         Slice *s = SLICE(u);
 145         int r;
 146
 147         assert(s);
 148
 149         r = unit_load_fragment_and_dropin_optional(u);
 150         if (r < 0)
 151                 return r;
 152
 153         /* This is a new unit? Then let's add in some extras */
 154         if (u->load_state == UNIT_LOADED) {
 155
 156                 r = slice_add_parent_slice(s);
 157                 if (r < 0)
 158                         return r;
 159
 160                 if (u->default_dependencies) {
 161                         r = slice_add_default_dependencies(s);
 162                         if (r < 0)
 163                                 return r;
 164                 }
 165         }
 166
 167         return slice_verify(s);
 168 }
 169
 170 static int slice_coldplug(Unit *u) {
 171         Slice *t = SLICE(u);
 172
 173         assert(t);
 174         assert(t->state == SLICE_DEAD);
 175
 176         if (t->deserialized_state != t->state)
 177                 slice_set_state(t, t->deserialized_state);
 178
 179         return 0;
 180 }
 181
 182 static void slice_dump(Unit *u, FILE *f, const char *prefix) {
 183         Slice *t = SLICE(u);
 184
 185         assert(t);
 186         assert(f);
 187
 188         fprintf(f,
 189                 "%sSlice State: %s\n",
 190                 prefix, slice_state_to_string(t->state));
 191
 192         cgroup_context_dump(&t->cgroup_context, f, prefix);
 193 }
 194
 195 static int slice_start(Unit *u) {
 196         Slice *t = SLICE(u);
 197
 198         assert(t);
 199         assert(t->state == SLICE_DEAD);
 200
 201         unit_realize_cgroup(u);
 202
 203         slice_set_state(t, SLICE_ACTIVE);
 204         return 0;
 205 }
 206
 207 static int slice_stop(Unit *u) {
 208         Slice *t = SLICE(u);
 209
 210         assert(t);
 211         assert(t->state == SLICE_ACTIVE);
 212
 213         /* We do not need to destroy the cgroup explicitly,
 214          * unit_notify() will do that for us anyway. */
 215
 216         slice_set_state(t, SLICE_DEAD);
 217         return 0;
 218 }
 219
 220 static int slice_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 221         return unit_kill_common(u, who, signo, -1, -1, error);
 222 }
 223
 224 static int slice_serialize(Unit *u, FILE *f, FDSet *fds) {
 225         Slice *s = SLICE(u);
 226
 227         assert(s);
 228         assert(f);
 229         assert(fds);
 230
 231         unit_serialize_item(u, f, "state", slice_state_to_string(s->state));
 232         return 0;
 233 }
 234
 235 static int slice_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 236         Slice *s = SLICE(u);
 237
 238         assert(u);
 239         assert(key);
 240         assert(value);
 241         assert(fds);
 242
 243         if (streq(key, "state")) {
 244                 SliceState state;
 245
 246                 state = slice_state_from_string(value);
 247                 if (state < 0)
 248                         log_debug("Failed to parse state value %s", value);
 249                 else
 250                         s->deserialized_state = state;
 251
 252         } else
 253                 log_debug("Unknown serialization key '%s'", key);
 254
 255         return 0;
 256 }
 257
 258 _pure_ static UnitActiveState slice_active_state(Unit *u) {
 259         assert(u);
 260
 261         return state_translation_table[SLICE(u)->state];
 262 }
 263
 264 _pure_ static const char *slice_sub_state_to_string(Unit *u) {
 265         assert(u);
 266
 267         return slice_state_to_string(SLICE(u)->state);
 268 }
 269
 270 static const char* const slice_state_table[_SLICE_STATE_MAX] = {
 271         [SLICE_DEAD] = "dead",
 272         [SLICE_ACTIVE] = "active"
 273 };
 274
 275 DEFINE_STRING_TABLE_LOOKUP(slice_state, SliceState);
 276
 277 const UnitVTable slice_vtable = {
 278         .object_size = sizeof(Slice),
 279         .cgroup_context_offset = offsetof(Slice, cgroup_context),
 280
 281         .sections =
 282                 "Unit\0"
 283                 "Slice\0"
 284                 "Install\0",
 285         .private_section = "Slice",
 286
 287         .no_alias = true,
 288         .no_instances = true,
 289
 290         .init = slice_init,
 291         .load = slice_load,
 292         .done = slice_done,
 293
 294         .coldplug = slice_coldplug,
 295
 296         .dump = slice_dump,
 297
 298         .start = slice_start,
 299         .stop = slice_stop,
 300
 301         .kill = slice_kill,
 302
 303         .serialize = slice_serialize,
 304         .deserialize_item = slice_deserialize_item,
 305
 306         .active_state = slice_active_state,
 307         .sub_state_to_string = slice_sub_state_to_string,
 308
 309         .bus_interface = "org.freedesktop.systemd1.Slice",
 310         .bus_vtable = bus_slice_vtable,
 311         .bus_set_property = bus_slice_set_property,
 312         .bus_commit_properties = bus_slice_commit_properties,
 313
 314         .status_message_formats = {
 315                 .finished_start_job = {
 316                         [JOB_DONE]       = "Created slice %s.",
 317                         [JOB_DEPENDENCY] = "Dependency failed for %s.",
 318                 },
 319                 .finished_stop_job = {
 320                         [JOB_DONE]       = "Removed slice %s.",
 321                 },
 322         },
 323 };