src/login/logind-user.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 //#include <errno.h>
   4 //#include <string.h>
   5 //#include <unistd.h>
   6 #include <stdio_ext.h>
   7
   8 #include "alloc-util.h"
   9 //#include "bus-common-errors.h"
  10 //#include "bus-error.h"
  11 //#include "bus-util.h"
  12 //#include "cgroup-util.h"
  13 #include "clean-ipc.h"
  14 #include "escape.h"
  15 #include "fd-util.h"
  16 #include "fileio.h"
  17 //#include "format-util.h"
  18 //#include "fs-util.h"
  19 //#include "hashmap.h"
  20 //#include "label.h"
  21 //#include "logind-user.h"
  22 #include "mkdir.h"
  23 //#include "parse-util.h"
  24 //#include "path-util.h"
  25 //#include "rm-rf.h"
  26 #include "special.h"
  27 #include "stdio-util.h"
  28 #include "string-table.h"
  29 #include "unit-name.h"
  30 #include "user-util.h"
  31 //#include "util.h"
  32 /// Additional includes needed by elogind
  33 #include "user-runtime-dir.h"
  34
  35 int user_new(User **out, Manager *m, uid_t uid, gid_t gid, const char *name) {
  36         _cleanup_(user_freep) User *u = NULL;
  37         char lu[DECIMAL_STR_MAX(uid_t) + 1];
  38         int r;
  39
  40         assert(out);
  41         assert(m);
  42         assert(name);
  43
  44         u = new0(User, 1);
  45         if (!u)
  46                 return -ENOMEM;
  47
  48         u->manager = m;
  49         u->uid = uid;
  50         u->gid = gid;
  51         xsprintf(lu, UID_FMT, uid);
  52
  53         u->name = strdup(name);
  54         if (!u->name)
  55                 return -ENOMEM;
  56
  57         if (asprintf(&u->state_file, "/run/systemd/users/"UID_FMT, uid) < 0)
  58                 return -ENOMEM;
  59
  60         if (asprintf(&u->runtime_path, "/run/user/"UID_FMT, uid) < 0)
  61                 return -ENOMEM;
  62
  63         r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
  64         if (r < 0)
  65                 return r;
  66
  67         r = unit_name_build("user", lu, ".service", &u->service);
  68         if (r < 0)
  69                 return r;
  70
  71         r = hashmap_put(m->users, UID_TO_PTR(uid), u);
  72         if (r < 0)
  73                 return r;
  74
  75         r = hashmap_put(m->user_units, u->slice, u);
  76         if (r < 0)
  77                 return r;
  78
  79         r = hashmap_put(m->user_units, u->service, u);
  80         if (r < 0)
  81                 return r;
  82
  83         *out = TAKE_PTR(u);
  84
  85         return 0;
  86 }
  87
  88 User *user_free(User *u) {
  89         if (!u)
  90                 return NULL;
  91
  92         if (u->in_gc_queue)
  93                 LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
  94
  95         while (u->sessions)
  96                 session_free(u->sessions);
  97
  98         if (u->service)
  99                 hashmap_remove_value(u->manager->user_units, u->service, u);
 100
 101         if (u->slice)
 102                 hashmap_remove_value(u->manager->user_units, u->slice, u);
 103
 104         hashmap_remove_value(u->manager->users, UID_TO_PTR(u->uid), u);
 105
 106 #if 0 /// elogind neither supports slice nor service jobs.
 107         u->slice_job = mfree(u->slice_job);
 108         u->service_job = mfree(u->service_job);
 109 #endif // 0
 110
 111         u->service = mfree(u->service);
 112         u->slice = mfree(u->slice);
 113         u->runtime_path = mfree(u->runtime_path);
 114         u->state_file = mfree(u->state_file);
 115         u->name = mfree(u->name);
 116
 117         return mfree(u);
 118 }
 119
 120 static int user_save_internal(User *u) {
 121         _cleanup_free_ char *temp_path = NULL;
 122         _cleanup_fclose_ FILE *f = NULL;
 123         int r;
 124
 125         assert(u);
 126         assert(u->state_file);
 127
 128         r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0, MKDIR_WARN_MODE);
 129         if (r < 0)
 130                 goto fail;
 131
 132         r = fopen_temporary(u->state_file, &f, &temp_path);
 133         if (r < 0)
 134                 goto fail;
 135
 136         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 137         (void) fchmod(fileno(f), 0644);
 138
 139         fprintf(f,
 140                 "# This is private data. Do not parse.\n"
 141                 "NAME=%s\n"
 142                 "STATE=%s\n",
 143                 u->name,
 144                 user_state_to_string(user_get_state(u)));
 145
 146         /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
 147         if (u->runtime_path)
 148                 fprintf(f, "RUNTIME=%s\n", u->runtime_path);
 149
 150 #if 0 /// elogind neither supports service nor slice jobs
 151         if (u->service_job)
 152                 fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
 153
 154         if (u->slice_job)
 155                 fprintf(f, "SLICE_JOB=%s\n", u->slice_job);
 156 #endif // 0
 157
 158         if (u->display)
 159                 fprintf(f, "DISPLAY=%s\n", u->display->id);
 160
 161         if (dual_timestamp_is_set(&u->timestamp))
 162                 fprintf(f,
 163                         "REALTIME="USEC_FMT"\n"
 164                         "MONOTONIC="USEC_FMT"\n",
 165                         u->timestamp.realtime,
 166                         u->timestamp.monotonic);
 167
 168         if (u->sessions) {
 169                 Session *i;
 170                 bool first;
 171
 172                 fputs("SESSIONS=", f);
 173                 first = true;
 174                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 175                         if (first)
 176                                 first = false;
 177                         else
 178                                 fputc(' ', f);
 179
 180                         fputs(i->id, f);
 181                 }
 182
 183                 fputs("\nSEATS=", f);
 184                 first = true;
 185                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 186                         if (!i->seat)
 187                                 continue;
 188
 189                         if (first)
 190                                 first = false;
 191                         else
 192                                 fputc(' ', f);
 193
 194                         fputs(i->seat->id, f);
 195                 }
 196
 197                 fputs("\nACTIVE_SESSIONS=", f);
 198                 first = true;
 199                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 200                         if (!session_is_active(i))
 201                                 continue;
 202
 203                         if (first)
 204                                 first = false;
 205                         else
 206                                 fputc(' ', f);
 207
 208                         fputs(i->id, f);
 209                 }
 210
 211                 fputs("\nONLINE_SESSIONS=", f);
 212                 first = true;
 213                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 214                         if (session_get_state(i) == SESSION_CLOSING)
 215                                 continue;
 216
 217                         if (first)
 218                                 first = false;
 219                         else
 220                                 fputc(' ', f);
 221
 222                         fputs(i->id, f);
 223                 }
 224
 225                 fputs("\nACTIVE_SEATS=", f);
 226                 first = true;
 227                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 228                         if (!session_is_active(i) || !i->seat)
 229                                 continue;
 230
 231                         if (first)
 232                                 first = false;
 233                         else
 234                                 fputc(' ', f);
 235
 236                         fputs(i->seat->id, f);
 237                 }
 238
 239                 fputs("\nONLINE_SEATS=", f);
 240                 first = true;
 241                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 242                         if (session_get_state(i) == SESSION_CLOSING || !i->seat)
 243                                 continue;
 244
 245                         if (first)
 246                                 first = false;
 247                         else
 248                                 fputc(' ', f);
 249
 250                         fputs(i->seat->id, f);
 251                 }
 252                 fputc('\n', f);
 253         }
 254
 255         r = fflush_and_check(f);
 256         if (r < 0)
 257                 goto fail;
 258
 259         if (rename(temp_path, u->state_file) < 0) {
 260                 r = -errno;
 261                 goto fail;
 262         }
 263
 264         return 0;
 265
 266 fail:
 267         (void) unlink(u->state_file);
 268
 269         if (temp_path)
 270                 (void) unlink(temp_path);
 271
 272         return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
 273 }
 274
 275 int user_save(User *u) {
 276         assert(u);
 277
 278         if (!u->started)
 279                 return 0;
 280
 281         return user_save_internal (u);
 282 }
 283
 284 int user_load(User *u) {
 285         _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL;
 286         Session *s = NULL;
 287         int r;
 288
 289         assert(u);
 290
 291         r = parse_env_file(NULL, u->state_file, NEWLINE,
 292 #if 0 /// elogind neither supports service nor slice jobs
 293                            "SERVICE_JOB", &u->service_job,
 294                            "SLICE_JOB",   &u->slice_job,
 295 #endif // 0
 296                            "DISPLAY",     &display,
 297                            "REALTIME",    &realtime,
 298                            "MONOTONIC",   &monotonic,
 299                            NULL);
 300         if (r < 0) {
 301                 if (r == -ENOENT)
 302                         return 0;
 303
 304                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);
 305         }
 306
 307         if (display)
 308                 s = hashmap_get(u->manager->sessions, display);
 309
 310         if (s && s->display && display_is_local(s->display))
 311                 u->display = s;
 312
 313         if (realtime)
 314                 timestamp_deserialize(realtime, &u->timestamp.realtime);
 315         if (monotonic)
 316                 timestamp_deserialize(monotonic, &u->timestamp.monotonic);
 317
 318         return r;
 319 }
 320
 321 static int user_start_service(User *u) {
 322 #if 0 /// elogind can not ask systemd via dbus to start user services
 323         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 324         char *job;
 325         int r;
 326
 327         assert(u);
 328
 329         u->service_job = mfree(u->service_job);
 330
 331         r = manager_start_unit(
 332                         u->manager,
 333                         u->service,
 334                         &error,
 335                         &job);
 336         if (r < 0)
 337                 /* we don't fail due to this, let's try to continue */
 338                 log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r));
 339         else
 340                 u->service_job = job;
 341 #else
 342         assert(u);
 343
 344         hashmap_put(u->manager->user_units, u->service, u);
 345 #endif // 0
 346
 347         return 0;
 348 }
 349
 350 int user_start(User *u) {
 351         int r;
 352
 353         assert(u);
 354
 355         if (u->started && !u->stopping)
 356                 return 0;
 357
 358         /*
 359          * If u->stopping is set, the user is marked for removal and the slice
 360          * and service stop-jobs are queued. We have to clear that flag before
 361          * queing the start-jobs again. If they succeed, the user object can be
 362          * re-used just fine (pid1 takes care of job-ordering and proper
 363          * restart), but if they fail, we want to force another user_stop() so
 364          * possibly pending units are stopped.
 365          * Note that we don't clear u->started, as we have no clue what state
 366          * the user is in on failure here. Hence, we pretend the user is
 367          * running so it will be properly taken down by GC. However, we clearly
 368          * return an error from user_start() in that case, so no further
 369          * reference to the user is taken.
 370          */
 371         u->stopping = false;
 372
 373 #if 0 /// elogind has to prepare the XDG_RUNTIME_DIR by itself
 374         if (!u->started)
 375                 log_debug("Starting services for new user %s.", u->name);
 376 #else
 377         if (!u->started) {
 378                 log_debug("Starting services for new user %s.", u->name);
 379                 r = user_runtime_dir("start", u);
 380                 if (r < 0)
 381                         return r;
 382         }
 383 #endif // 1
 384
 385         /* Save the user data so far, because pam_systemd will read the
 386          * XDG_RUNTIME_DIR out of it while starting up systemd --user.
 387          * We need to do user_save_internal() because we have not
 388          * "officially" started yet. */
 389         user_save_internal(u);
 390
 391         /* Spawn user systemd */
 392         r = user_start_service(u);
 393         if (r < 0)
 394                 return r;
 395
 396         if (!u->started) {
 397                 if (!dual_timestamp_is_set(&u->timestamp))
 398                         dual_timestamp_get(&u->timestamp);
 399                 user_send_signal(u, true);
 400                 u->started = true;
 401         }
 402
 403         /* Save new user data */
 404         user_save(u);
 405
 406         return 0;
 407 }
 408
 409 #if 0 /// UNNEEDED by elogind
 410 static int user_stop_slice(User *u) {
 411         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 412         char *job;
 413         int r;
 414
 415         assert(u);
 416
 417         r = manager_stop_unit(u->manager, u->slice, &error, &job);
 418         if (r < 0) {
 419                 log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
 420                 return r;
 421         }
 422
 423         free(u->slice_job);
 424         u->slice_job = job;
 425
 426         return r;
 427 }
 428
 429 static int user_stop_service(User *u) {
 430         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 431         char *job;
 432         int r;
 433
 434         assert(u);
 435
 436         r = manager_stop_unit(u->manager, u->service, &error, &job);
 437         if (r < 0) {
 438                 log_error("Failed to stop user service: %s", bus_error_message(&error, r));
 439                 return r;
 440         }
 441
 442         free_and_replace(u->service_job, job);
 443         return r;
 444 }
 445 #endif // 0
 446
 447 int user_stop(User *u, bool force) {
 448         Session *s;
 449         int r = 0, k;
 450         assert(u);
 451
 452         /* Stop jobs have already been queued */
 453         if (u->stopping) {
 454                 user_save(u);
 455 #if 1 /// elogind must queue this user again
 456                 user_add_to_gc_queue(u);
 457 #endif // 1
 458                 return r;
 459         }
 460
 461         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 462                 k = session_stop(s, force);
 463                 if (k < 0)
 464                         r = k;
 465         }
 466
 467         /* Kill systemd */
 468 #if 0 /// elogind does not support service or slice jobs
 469         k = user_stop_service(u);
 470         if (k < 0)
 471                 r = k;
 472
 473         /* Kill cgroup */
 474         k = user_stop_slice(u);
 475         if (k < 0)
 476                 r = k;
 477 #endif // 0
 478
 479         u->stopping = true;
 480
 481         user_save(u);
 482
 483 #if 1 /// elogind must queue this user again
 484         user_add_to_gc_queue(u);
 485 #endif // 1
 486
 487         return r;
 488 }
 489
 490 int user_finalize(User *u) {
 491         Session *s;
 492         int r = 0, k;
 493
 494         assert(u);
 495
 496         if (u->started)
 497                 log_debug("User %s logged out.", u->name);
 498
 499         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 500                 k = session_finalize(s);
 501                 if (k < 0)
 502                         r = k;
 503         }
 504
 505 #if 1 /// elogind has to remove the XDG_RUNTIME_DIR by itself
 506         /* Kill XDG_RUNTIME_DIR */
 507         k = user_runtime_dir("stop", u);
 508         if (k < 0)
 509                 r = k;
 510 #endif // 1
 511
 512         /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs
 513          * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to
 514          * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such
 515          * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because
 516          * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up,
 517          * and do it only for normal users. */
 518         if (u->manager->remove_ipc && !uid_is_system(u->uid)) {
 519                 k = clean_ipc_by_uid(u->uid);
 520                 if (k < 0)
 521                         r = k;
 522         }
 523
 524         unlink(u->state_file);
 525         user_add_to_gc_queue(u);
 526
 527         if (u->started) {
 528                 user_send_signal(u, false);
 529                 u->started = false;
 530         }
 531
 532         return r;
 533 }
 534
 535 int user_get_idle_hint(User *u, dual_timestamp *t) {
 536         Session *s;
 537         bool idle_hint = true;
 538         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 539
 540         assert(u);
 541
 542         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 543                 dual_timestamp k;
 544                 int ih;
 545
 546                 ih = session_get_idle_hint(s, &k);
 547                 if (ih < 0)
 548                         return ih;
 549
 550                 if (!ih) {
 551                         if (!idle_hint) {
 552                                 if (k.monotonic < ts.monotonic)
 553                                         ts = k;
 554                         } else {
 555                                 idle_hint = false;
 556                                 ts = k;
 557                         }
 558                 } else if (idle_hint) {
 559
 560                         if (k.monotonic > ts.monotonic)
 561                                 ts = k;
 562                 }
 563         }
 564
 565         if (t)
 566                 *t = ts;
 567
 568         return idle_hint;
 569 }
 570
 571 int user_check_linger_file(User *u) {
 572         _cleanup_free_ char *cc = NULL;
 573         char *p = NULL;
 574
 575         cc = cescape(u->name);
 576         if (!cc)
 577                 return -ENOMEM;
 578
 579         p = strjoina("/var/lib/elogind/linger/", cc);
 580
 581         return access(p, F_OK) >= 0;
 582 }
 583
 584 bool user_may_gc(User *u, bool drop_not_started) {
 585         assert(u);
 586
 587         if (drop_not_started && !u->started)
 588                 return true;
 589
 590         if (u->sessions)
 591                 return false;
 592
 593         if (user_check_linger_file(u) > 0)
 594                 return false;
 595
 596 #if 0 /// elogind neither supports service nor slice jobs
 597         if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
 598                 return false;
 599
 600         if (u->service_job && manager_job_is_active(u->manager, u->service_job))
 601                 return false;
 602 #endif // 0
 603
 604         return true;
 605 }
 606
 607 void user_add_to_gc_queue(User *u) {
 608         assert(u);
 609
 610         if (u->in_gc_queue)
 611                 return;
 612
 613         LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
 614         u->in_gc_queue = true;
 615 }
 616
 617 UserState user_get_state(User *u) {
 618         Session *i;
 619
 620         assert(u);
 621
 622         if (u->stopping)
 623                 return USER_CLOSING;
 624
 625 #if 0 /// elogind neither supports service nor slice jobs.
 626         if (!u->started || u->slice_job || u->service_job)
 627 #else
 628         if (!u->started)
 629 #endif // 0
 630                 return USER_OPENING;
 631
 632         if (u->sessions) {
 633                 bool all_closing = true;
 634
 635                 LIST_FOREACH(sessions_by_user, i, u->sessions) {
 636                         SessionState state;
 637
 638                         state = session_get_state(i);
 639                         if (state == SESSION_ACTIVE)
 640                                 return USER_ACTIVE;
 641                         if (state != SESSION_CLOSING)
 642                                 all_closing = false;
 643                 }
 644
 645                 return all_closing ? USER_CLOSING : USER_ONLINE;
 646         }
 647
 648         if (user_check_linger_file(u) > 0)
 649                 return USER_LINGERING;
 650
 651         return USER_CLOSING;
 652 }
 653
 654 int user_kill(User *u, int signo) {
 655 #if 0 /// Without systemd unit support, elogind has to rely on its session system
 656         assert(u);
 657
 658         return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
 659 #else
 660         Session *s;
 661         int res = 0;
 662
 663         assert(u);
 664
 665         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 666                 int r = session_kill(s, KILL_ALL, signo);
 667                 if (res == 0 && r < 0)
 668                         res = r;
 669         }
 670
 671         return res;
 672 #endif // 0
 673 }
 674
 675 static bool elect_display_filter(Session *s) {
 676         /* Return true if the session is a candidate for the user’s ‘primary
 677          * session’ or ‘display’. */
 678         assert(s);
 679
 680         return (s->class == SESSION_USER && !s->stopping);
 681 }
 682
 683 static int elect_display_compare(Session *s1, Session *s2) {
 684         /* Indexed by SessionType. Lower numbers mean more preferred. */
 685         const int type_ranks[_SESSION_TYPE_MAX] = {
 686                 [SESSION_UNSPECIFIED] = 0,
 687                 [SESSION_TTY] = -2,
 688                 [SESSION_X11] = -3,
 689                 [SESSION_WAYLAND] = -3,
 690                 [SESSION_MIR] = -3,
 691                 [SESSION_WEB] = -1,
 692         };
 693
 694         /* Calculate the partial order relationship between s1 and s2,
 695          * returning < 0 if s1 is preferred as the user’s ‘primary session’,
 696          * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
 697          * is preferred.
 698          *
 699          * s1 or s2 may be NULL. */
 700         if (!s1 && !s2)
 701                 return 0;
 702
 703         if ((s1 == NULL) != (s2 == NULL))
 704                 return (s1 == NULL) - (s2 == NULL);
 705
 706         if (s1->stopping != s2->stopping)
 707                 return s1->stopping - s2->stopping;
 708
 709         if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
 710                 return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
 711
 712         if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
 713                 return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
 714
 715         if (s1->type != s2->type)
 716                 return type_ranks[s1->type] - type_ranks[s2->type];
 717
 718         return 0;
 719 }
 720
 721 void user_elect_display(User *u) {
 722         Session *s;
 723
 724         assert(u);
 725
 726         /* This elects a primary session for each user, which we call
 727          * the "display". We try to keep the assignment stable, but we
 728          * "upgrade" to better choices. */
 729         log_debug("Electing new display for user %s", u->name);
 730
 731         LIST_FOREACH(sessions_by_user, s, u->sessions) {
 732                 if (!elect_display_filter(s)) {
 733                         log_debug("Ignoring session %s", s->id);
 734                         continue;
 735                 }
 736
 737                 if (elect_display_compare(s, u->display) < 0) {
 738                         log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
 739                         u->display = s;
 740                 }
 741         }
 742 }
 743
 744 static const char* const user_state_table[_USER_STATE_MAX] = {
 745         [USER_OFFLINE] = "offline",
 746         [USER_OPENING] = "opening",
 747         [USER_LINGERING] = "lingering",
 748         [USER_ONLINE] = "online",
 749         [USER_ACTIVE] = "active",
 750         [USER_CLOSING] = "closing"
 751 };
 752
 753 DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
 754
 755 int config_parse_tmpfs_size(
 756                 const char* unit,
 757                 const char *filename,
 758                 unsigned line,
 759                 const char *section,
 760                 unsigned section_line,
 761                 const char *lvalue,
 762                 int ltype,
 763                 const char *rvalue,
 764                 void *data,
 765                 void *userdata) {
 766
 767         uint64_t *sz = data;
 768         int r;
 769
 770         assert(filename);
 771         assert(lvalue);
 772         assert(rvalue);
 773         assert(data);
 774
 775         /* First, try to parse as percentage */
 776         r = parse_percent(rvalue);
 777         if (r > 0 && r < 100)
 778                 *sz = physical_memory_scale(r, 100U);
 779         else {
 780                 uint64_t k;
 781
 782                 /* If the passed argument was not a percentage, or out of range, parse as byte size */
 783
 784                 r = parse_size(rvalue, 1024, &k);
 785                 if (r < 0 || k <= 0 || (uint64_t) (size_t) k != k) {
 786                         log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue);
 787                         return 0;
 788                 }
 789
 790                 *sz = PAGE_ALIGN((size_t) k);
 791         }
 792
 793         return 0;
 794 }
 795
 796 int config_parse_compat_user_tasks_max(
 797                 const char *unit,
 798                 const char *filename,
 799                 unsigned line,
 800                 const char *section,
 801                 unsigned section_line,
 802                 const char *lvalue,
 803                 int ltype,
 804                 const char *rvalue,
 805                 void *data,
 806                 void *userdata) {
 807
 808         assert(filename);
 809         assert(lvalue);
 810         assert(rvalue);
 811         assert(data);
 812
 813         log_syntax(unit, LOG_NOTICE, filename, line, 0,
 814                    "Support for option %s= has been removed.",
 815                    lvalue);
 816         log_info("Hint: try creating /etc/elogind/system/user-.slice/50-limits.conf with:\n"
 817                  "        [Slice]\n"
 818                  "        TasksMax=%s",
 819                  rvalue);
 820         return 0;
 821 }