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_set_state(Slice *t, SliceState state) {
  40         SliceState old_state;
  41         assert(t);
  42
  43         old_state = t->state;
  44         t->state = state;
  45
  46         if (state != old_state)
  47                 log_debug("%s changed %s -> %s",
  48                           UNIT(t)->id,
  49                           slice_state_to_string(old_state),
  50                           slice_state_to_string(state));
  51
  52         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
  53 }
  54
  55 static int slice_add_parent_slice(Slice *s) {
  56         char *a, *dash;
  57         Unit *parent;
  58         int r;
  59
  60         assert(s);
  61
  62         if (UNIT_ISSET(UNIT(s)->slice))
  63                 return 0;
  64
  65         if (unit_has_name(UNIT(s), SPECIAL_ROOT_SLICE))
  66                 return 0;
  67
  68         a = strdupa(UNIT(s)->id);
  69         dash = strrchr(a, '-');
  70         if (dash)
  71                 strcpy(dash, ".slice");
  72         else
  73                 a = (char*) SPECIAL_ROOT_SLICE;
  74
  75         r = manager_load_unit(UNIT(s)->manager, a, NULL, NULL, &parent);
  76         if (r < 0)
  77                 return r;
  78
  79         unit_ref_set(&UNIT(s)->slice, parent);
  80         return 0;
  81 }
  82
  83 static int slice_add_default_dependencies(Slice *s) {
  84         int r;
  85
  86         assert(s);
  87
  88         /* Make sure slices are unloaded on shutdown */
  89         r = unit_add_two_dependencies_by_name(
  90                         UNIT(s),
  91                         UNIT_BEFORE, UNIT_CONFLICTS,
  92                         SPECIAL_SHUTDOWN_TARGET, NULL, true);
  93         if (r < 0)
  94                 return r;
  95
  96         return 0;
  97 }
  98
  99 static int slice_verify(Slice *s) {
 100         assert(s);
 101
 102         if (UNIT(s)->load_state != UNIT_LOADED)
 103                 return 0;
 104
 105         if (UNIT_DEREF(UNIT(s)->slice)) {
 106                 char *a, *dash;
 107
 108                 a = strdupa(UNIT(s)->id);
 109                 dash = strrchr(a, '-');
 110                 if (dash)
 111                         strcpy(dash, ".slice");
 112                 else
 113                         a = (char*) SPECIAL_ROOT_SLICE;
 114
 115                 if (!unit_has_name(UNIT_DEREF(UNIT(s)->slice), a)) {
 116                         log_unit_error(UNIT(s)->id,
 117                                        "%s located outside its parent slice. Refusing.", UNIT(s)->id);
 118                         return -EINVAL;
 119                 }
 120         }
 121
 122         return 0;
 123 }
 124
 125 static int slice_load(Unit *u) {
 126         Slice *s = SLICE(u);
 127         int r;
 128
 129         assert(s);
 130
 131         r = unit_load_fragment_and_dropin_optional(u);
 132         if (r < 0)
 133                 return r;
 134
 135         /* This is a new unit? Then let's add in some extras */
 136         if (u->load_state == UNIT_LOADED) {
 137
 138                 r = unit_patch_contexts(u);
 139                 if (r < 0)
 140                         return r;
 141
 142                 r = slice_add_parent_slice(s);
 143                 if (r < 0)
 144                         return r;
 145
 146                 if (u->default_dependencies) {
 147                         r = slice_add_default_dependencies(s);
 148                         if (r < 0)
 149                                 return r;
 150                 }
 151         }
 152
 153         return slice_verify(s);
 154 }
 155
 156 static int slice_coldplug(Unit *u) {
 157         Slice *t = SLICE(u);
 158
 159         assert(t);
 160         assert(t->state == SLICE_DEAD);
 161
 162         if (t->deserialized_state != t->state)
 163                 slice_set_state(t, t->deserialized_state);
 164
 165         return 0;
 166 }
 167
 168 static void slice_dump(Unit *u, FILE *f, const char *prefix) {
 169         Slice *t = SLICE(u);
 170
 171         assert(t);
 172         assert(f);
 173
 174         fprintf(f,
 175                 "%sSlice State: %s\n",
 176                 prefix, slice_state_to_string(t->state));
 177
 178         cgroup_context_dump(&t->cgroup_context, f, prefix);
 179 }
 180
 181 static int slice_start(Unit *u) {
 182         Slice *t = SLICE(u);
 183
 184         assert(t);
 185         assert(t->state == SLICE_DEAD);
 186
 187         unit_realize_cgroup(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 const char* const slice_state_table[_SLICE_STATE_MAX] = {
 257         [SLICE_DEAD] = "dead",
 258         [SLICE_ACTIVE] = "active"
 259 };
 260
 261 DEFINE_STRING_TABLE_LOOKUP(slice_state, SliceState);
 262
 263 const UnitVTable slice_vtable = {
 264         .object_size = sizeof(Slice),
 265         .cgroup_context_offset = offsetof(Slice, cgroup_context),
 266
 267         .sections =
 268                 "Unit\0"
 269                 "Slice\0"
 270                 "Install\0",
 271         .private_section = "Slice",
 272
 273         .no_alias = true,
 274         .no_instances = true,
 275
 276         .load = slice_load,
 277
 278         .coldplug = slice_coldplug,
 279
 280         .dump = slice_dump,
 281
 282         .start = slice_start,
 283         .stop = slice_stop,
 284
 285         .kill = slice_kill,
 286
 287         .serialize = slice_serialize,
 288         .deserialize_item = slice_deserialize_item,
 289
 290         .active_state = slice_active_state,
 291         .sub_state_to_string = slice_sub_state_to_string,
 292
 293         .bus_interface = "org.freedesktop.systemd1.Slice",
 294         .bus_vtable = bus_slice_vtable,
 295         .bus_set_property = bus_slice_set_property,
 296         .bus_commit_properties = bus_slice_commit_properties,
 297
 298         .status_message_formats = {
 299                 .finished_start_job = {
 300                         [JOB_DONE]       = "Created slice %s.",
 301                         [JOB_DEPENDENCY] = "Dependency failed for %s.",
 302                 },
 303                 .finished_stop_job = {
 304                         [JOB_DONE]       = "Removed slice %s.",
 305                 },
 306         },
 307 };