qgroup.c

   1 /*
   2  * Copyright (C) 2012 STRATO.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include "qgroup.h"
  20 #include <sys/ioctl.h>
  21 #include "ctree.h"
  22 #include "ioctl.h"
  23
  24 struct qgroup_lookup {
  25         struct rb_root root;
  26 };
  27
  28 struct btrfs_qgroup {
  29         struct rb_node rb_node;
  30         u64 qgroupid;
  31
  32         /*
  33          * info_item
  34          */
  35         u64 generation;
  36         u64 rfer;       /*referenced*/
  37         u64 rfer_cmpr;  /*referenced compressed*/
  38         u64 excl;       /*exclusive*/
  39         u64 excl_cmpr;  /*exclusive compressed*/
  40
  41         /*
  42          *limit_item
  43          */
  44         u64 flags;      /*which limits are set*/
  45         u64 max_rfer;
  46         u64 max_excl;
  47         u64 rsv_rfer;
  48         u64 rsv_excl;
  49
  50         /*qgroups this group is member of*/
  51         struct list_head qgroups;
  52         /*qgroups that are members of this group*/
  53         struct list_head members;
  54 };
  55
  56 /*
  57  * glue structure to represent the relations
  58  * between qgroups
  59  */
  60 struct btrfs_qgroup_list {
  61         struct list_head next_qgroup;
  62         struct list_head next_member;
  63         struct btrfs_qgroup *qgroup;
  64         struct btrfs_qgroup *member;
  65 };
  66
  67 /*
  68  * qgroupid,rfer,excl default to set
  69  */
  70 struct {
  71         char *name;
  72         char *column_name;
  73         int need_print;
  74 } btrfs_qgroup_columns[] = {
  75         {
  76                 .name           = "qgroupid",
  77                 .column_name    = "Qgroupid",
  78                 .need_print     = 1,
  79         },
  80         {
  81                 .name           = "rfer",
  82                 .column_name    = "Rfer",
  83                 .need_print     = 1,
  84         },
  85         {
  86                 .name           = "excl",
  87                 .column_name    = "Excl",
  88                 .need_print     = 1,
  89         },
  90         {       .name           = "max_rfer",
  91                 .column_name    = "Max_rfer",
  92                 .need_print     = 0,
  93         },
  94         {
  95                 .name           = "parent",
  96                 .column_name    = "Parent",
  97                 .need_print     = 0,
  98         },
  99         {
 100                 .name           = "child",
 101                 .column_name    = "Child",
 102                 .need_print     = 0,
 103         },
 104         {
 105                 .name           = NULL,
 106                 .column_name    = NULL,
 107                 .need_print     = 0,
 108         },
 109 };
 110
 111 void btrfs_qgroup_setup_print_column(enum btrfs_qgroup_column_enum column)
 112 {
 113         int i;
 114
 115         BUG_ON(column < 0 || column > BTRFS_QGROUP_ALL);
 116
 117         if (column < BTRFS_QGROUP_ALL) {
 118                 btrfs_qgroup_columns[column].need_print = 1;
 119                 return;
 120         }
 121         for (i = 0; i < BTRFS_QGROUP_ALL; i++)
 122                 btrfs_qgroup_columns[i].need_print = 1;
 123 }
 124
 125 static void print_parent_column(struct btrfs_qgroup *qgroup)
 126 {
 127         struct btrfs_qgroup_list *list = NULL;
 128
 129         list_for_each_entry(list, &qgroup->qgroups, next_qgroup) {
 130                 printf("%llu/%llu", (list->qgroup)->qgroupid >> 48,
 131                       ((1ll << 48) - 1) & (list->qgroup)->qgroupid);
 132                 if (!list_is_last(&list->next_qgroup, &qgroup->qgroups))
 133                         printf(",");
 134         }
 135         if (list_empty(&qgroup->qgroups))
 136                 printf("---");
 137 }
 138
 139 static void print_child_column(struct btrfs_qgroup *qgroup)
 140 {
 141         struct btrfs_qgroup_list *list = NULL;
 142
 143         list_for_each_entry(list, &qgroup->members, next_member) {
 144                 printf("%llu/%llu", (list->member)->qgroupid >> 48,
 145                       ((1ll << 48) - 1) & (list->member)->qgroupid);
 146                 if (!list_is_last(&list->next_member, &qgroup->members))
 147                         printf(",");
 148         }
 149         if (list_empty(&qgroup->members))
 150                 printf("---");
 151 }
 152
 153 static void print_qgroup_column(struct btrfs_qgroup *qgroup,
 154                                 enum btrfs_qgroup_column_enum column)
 155 {
 156         BUG_ON(column >= BTRFS_QGROUP_ALL || column < 0);
 157
 158         switch (column) {
 159
 160         case BTRFS_QGROUP_QGROUPID:
 161                 printf("%llu/%llu", qgroup->qgroupid >> 48,
 162                        ((1ll << 48) - 1) & qgroup->qgroupid);
 163                 break;
 164         case BTRFS_QGROUP_RFER:
 165                 printf("%lld", qgroup->rfer);
 166                 break;
 167         case BTRFS_QGROUP_EXCL:
 168                 printf("%lld", qgroup->excl);
 169                 break;
 170         case BTRFS_QGROUP_PARENT:
 171                 print_parent_column(qgroup);
 172                 break;
 173         case BTRFS_QGROUP_MAX_RFER:
 174                 printf("%llu", qgroup->max_rfer);
 175                 break;
 176         case BTRFS_QGROUP_CHILD:
 177                 print_child_column(qgroup);
 178                 break;
 179         default:
 180                 break;
 181         }
 182 }
 183
 184 static void print_single_qgroup_default(struct btrfs_qgroup *qgroup)
 185 {
 186         int i;
 187
 188         for (i = 0; i < BTRFS_QGROUP_ALL; i++) {
 189                 if (!btrfs_qgroup_columns[i].need_print)
 190                         continue;
 191                 print_qgroup_column(qgroup, i);
 192
 193                 if (i != BTRFS_QGROUP_ALL - 1)
 194                         printf(" ");
 195         }
 196         printf("\n");
 197 }
 198
 199 static void qgroup_lookup_init(struct qgroup_lookup *tree)
 200 {
 201         tree->root.rb_node = NULL;
 202 }
 203
 204 static int comp_entry_with_qgroupid(struct btrfs_qgroup *entry1,
 205                                     struct btrfs_qgroup *entry2,
 206                                     int is_descending)
 207 {
 208
 209         int ret;
 210
 211         if (entry1->qgroupid > entry2->qgroupid)
 212                 ret = 1;
 213         else if (entry1->qgroupid < entry2->qgroupid)
 214                 ret = -1;
 215         else
 216                 ret = 0;
 217
 218         return is_descending ? -ret : ret;
 219 }
 220
 221 /*
 222  * insert a new root into the tree.  returns the existing root entry
 223  * if one is already there.  qgroupid is used
 224  * as the key
 225  */
 226 static int qgroup_tree_insert(struct qgroup_lookup *root_tree,
 227                               struct btrfs_qgroup *ins)
 228 {
 229
 230         struct rb_node **p = &root_tree->root.rb_node;
 231         struct rb_node *parent = NULL;
 232         struct btrfs_qgroup *curr;
 233         int ret;
 234
 235         while (*p) {
 236                 parent = *p;
 237                 curr = rb_entry(parent, struct btrfs_qgroup, rb_node);
 238
 239                 ret = comp_entry_with_qgroupid(ins, curr, 0);
 240                 if (ret < 0)
 241                         p = &(*p)->rb_left;
 242                 else if (ret > 0)
 243                         p = &(*p)->rb_right;
 244                 else
 245                         return -EEXIST;
 246         }
 247         rb_link_node(&ins->rb_node, parent, p);
 248         rb_insert_color(&ins->rb_node, &root_tree->root);
 249         return 0;
 250 }
 251
 252 /*
 253  *find a given qgroupid in the tree. We return the smallest one,
 254  *rb_next can be used to move forward looking for more if required
 255  */
 256 static struct btrfs_qgroup *qgroup_tree_search(struct qgroup_lookup *root_tree,
 257                                                u64 qgroupid)
 258 {
 259         struct rb_node *n = root_tree->root.rb_node;
 260         struct btrfs_qgroup *entry;
 261         struct btrfs_qgroup tmp;
 262         int ret;
 263
 264         tmp.qgroupid = qgroupid;
 265
 266         while (n) {
 267                 entry = rb_entry(n, struct btrfs_qgroup, rb_node);
 268
 269                 ret = comp_entry_with_qgroupid(&tmp, entry, 0);
 270                 if (ret < 0)
 271                         n = n->rb_left;
 272                 else if (ret > 0)
 273                         n = n->rb_right;
 274                 else
 275                         return entry;
 276
 277         }
 278         return NULL;
 279 }
 280
 281 static int update_qgroup(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
 282                          u64 generation, u64 rfer, u64 rfer_cmpr, u64 excl,
 283                          u64 excl_cmpr, u64 flags, u64 max_rfer, u64 max_excl,
 284                          u64 rsv_rfer, u64 rsv_excl, struct btrfs_qgroup *pa,
 285                          struct btrfs_qgroup *child)
 286 {
 287         struct btrfs_qgroup *bq;
 288         struct btrfs_qgroup_list *list;
 289
 290         bq = qgroup_tree_search(qgroup_lookup, qgroupid);
 291         if (!bq || bq->qgroupid != qgroupid)
 292                 return -ENOENT;
 293
 294         if (generation)
 295                 bq->generation = generation;
 296         if (rfer)
 297                 bq->rfer = rfer;
 298         if (rfer_cmpr)
 299                 bq->rfer_cmpr = rfer_cmpr;
 300         if (excl)
 301                 bq->excl = excl;
 302         if (excl_cmpr)
 303                 bq->excl_cmpr = excl_cmpr;
 304         if (flags)
 305                 bq->flags = flags;
 306         if (max_rfer)
 307                 bq->max_rfer = max_rfer;
 308         if (max_excl)
 309                 bq->max_excl = max_excl;
 310         if (rsv_rfer)
 311                 bq->rsv_rfer = rsv_rfer;
 312         if (pa && child) {
 313                 list = malloc(sizeof(*list));
 314                 if (!list) {
 315                         fprintf(stderr, "memory allocation failed\n");
 316                         exit(1);
 317                 }
 318                 list->qgroup = pa;
 319                 list->member = child;
 320                 list_add_tail(&list->next_qgroup, &child->qgroups);
 321                 list_add_tail(&list->next_member, &pa->members);
 322         }
 323         return 0;
 324 }
 325
 326 static int add_qgroup(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
 327                       u64 generation, u64 rfer, u64 rfer_cmpr, u64 excl,
 328                       u64 excl_cmpr, u64 flags, u64 max_rfer, u64 max_excl,
 329                       u64 rsv_rfer, u64 rsv_excl, struct btrfs_qgroup *parent,
 330                       struct btrfs_qgroup *child)
 331 {
 332         struct btrfs_qgroup *bq;
 333         struct btrfs_qgroup_list *list;
 334         int ret;
 335
 336         ret = update_qgroup(qgroup_lookup, qgroupid, generation, rfer,
 337                             rfer_cmpr, excl, excl_cmpr, flags, max_rfer,
 338                             max_excl, rsv_rfer, rsv_excl, parent, child);
 339         if (!ret)
 340                 return 0;
 341
 342         bq = malloc(sizeof(*bq));
 343         if (!bq) {
 344                 printf("memory allocation failed\n");
 345                 exit(1);
 346         }
 347         memset(bq, 0, sizeof(*bq));
 348         if (qgroupid) {
 349                 bq->qgroupid = qgroupid;
 350                 INIT_LIST_HEAD(&bq->qgroups);
 351                 INIT_LIST_HEAD(&bq->members);
 352         }
 353         if (generation)
 354                 bq->generation = generation;
 355         if (rfer)
 356                 bq->rfer = rfer;
 357         if (rfer_cmpr)
 358                 bq->rfer_cmpr = rfer_cmpr;
 359         if (excl)
 360                 bq->excl = excl;
 361         if (excl_cmpr)
 362                 bq->excl_cmpr = excl_cmpr;
 363         if (flags)
 364                 bq->flags = flags;
 365         if (max_rfer)
 366                 bq->max_rfer = max_rfer;
 367         if (max_excl)
 368                 bq->max_excl = max_excl;
 369         if (rsv_rfer)
 370                 bq->rsv_rfer = rsv_rfer;
 371         if (parent && child) {
 372                 list = malloc(sizeof(*list));
 373                 if (!list) {
 374                         fprintf(stderr, "memory allocation failed\n");
 375                         exit(1);
 376                 }
 377                 list->qgroup = parent;
 378                 list->member = child;
 379                 list_add_tail(&list->next_qgroup, &child->qgroups);
 380                 list_add_tail(&list->next_member, &parent->members);
 381         }
 382         ret = qgroup_tree_insert(qgroup_lookup, bq);
 383         if (ret) {
 384                 printf("failed to insert tree %llu\n",
 385                        bq->qgroupid);
 386                 exit(1);
 387         }
 388         return ret;
 389 }
 390
 391 void __free_btrfs_qgroup(struct btrfs_qgroup *bq)
 392 {
 393         struct btrfs_qgroup_list *list;
 394         while (!list_empty(&bq->qgroups)) {
 395                 list = list_entry((&bq->qgroups)->next,
 396                                   struct btrfs_qgroup_list,
 397                                   next_qgroup);
 398                 list_del(&list->next_qgroup);
 399                 list_del(&list->next_member);
 400                 free(list);
 401         }
 402         while (!list_empty(&bq->members)) {
 403                 list = list_entry((&bq->members)->next,
 404                                   struct btrfs_qgroup_list,
 405                                   next_member);
 406                 list_del(&list->next_qgroup);
 407                 list_del(&list->next_member);
 408                 free(list);
 409         }
 410         free(bq);
 411 }
 412
 413 void __free_all_qgroups(struct qgroup_lookup *root_tree)
 414 {
 415         struct btrfs_qgroup *entry;
 416         struct rb_node *n;
 417
 418         n = rb_first(&root_tree->root);
 419         while (n) {
 420                 entry = rb_entry(n, struct btrfs_qgroup, rb_node);
 421                 rb_erase(n, &root_tree->root);
 422                 __free_btrfs_qgroup(entry);
 423
 424                 n = rb_first(&root_tree->root);
 425         }
 426 }
 427
 428 static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 429 {
 430         int ret;
 431         struct btrfs_ioctl_search_args args;
 432         struct btrfs_ioctl_search_key *sk = &args.key;
 433         struct btrfs_ioctl_search_header *sh;
 434         unsigned long off = 0;
 435         unsigned int i;
 436         int e;
 437         struct btrfs_qgroup_info_item *info;
 438         struct btrfs_qgroup_limit_item *limit;
 439         struct btrfs_qgroup *bq;
 440         struct btrfs_qgroup *bq1;
 441         u64 a1;
 442         u64 a2;
 443         u64 a3;
 444         u64 a4;
 445         u64 a5;
 446
 447         memset(&args, 0, sizeof(args));
 448
 449         sk->tree_id = BTRFS_QUOTA_TREE_OBJECTID;
 450         sk->max_type = BTRFS_QGROUP_RELATION_KEY;
 451         sk->min_type = BTRFS_QGROUP_INFO_KEY;
 452         sk->max_objectid = (u64)-1;
 453         sk->max_offset = (u64)-1;
 454         sk->max_transid = (u64)-1;
 455         sk->nr_items = 4096;
 456
 457         qgroup_lookup_init(qgroup_lookup);
 458
 459         while (1) {
 460                 ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
 461                 e = errno;
 462                 if (ret < 0) {
 463                         fprintf(stderr,
 464                                 "ERROR: can't perform the search - %s\n",
 465                                 strerror(e));
 466                         return ret;
 467                 }
 468                 /* the ioctl returns the number of item it found in nr_items */
 469                 if (sk->nr_items == 0)
 470                         break;
 471
 472                 off = 0;
 473                 /*
 474                  * for each item, pull the key out of the header and then
 475                  * read the root_ref item it contains
 476                  */
 477                 for (i = 0; i < sk->nr_items; i++) {
 478                         sh = (struct btrfs_ioctl_search_header *)(args.buf +
 479                                                                   off);
 480                         off += sizeof(*sh);
 481
 482                         if (sh->type == BTRFS_QGROUP_INFO_KEY) {
 483                                 info = (struct btrfs_qgroup_info_item *)
 484                                        (args.buf + off);
 485                                 a1 = btrfs_stack_qgroup_info_generation(info);
 486                                 a2 = btrfs_stack_qgroup_info_referenced(info);
 487                                 a3 =
 488                                   btrfs_stack_qgroup_info_referenced_compressed
 489                                   (info);
 490                                 a4 = btrfs_stack_qgroup_info_exclusive(info);
 491                                 a5 =
 492                                   btrfs_stack_qgroup_info_exclusive_compressed
 493                                   (info);
 494                                 add_qgroup(qgroup_lookup, sh->offset, a1, a2,
 495                                            a3, a4, a5, 0, 0, 0, 0, 0, 0, 0);
 496                         } else if (sh->type == BTRFS_QGROUP_LIMIT_KEY) {
 497                                 limit = (struct btrfs_qgroup_limit_item *)
 498                                     (args.buf + off);
 499
 500                                 a1 = btrfs_stack_qgroup_limit_flags(limit);
 501                                 a2 = btrfs_stack_qgroup_limit_max_referenced
 502                                      (limit);
 503                                 a3 = btrfs_stack_qgroup_limit_max_exclusive
 504                                      (limit);
 505                                 a4 = btrfs_stack_qgroup_limit_rsv_referenced
 506                                      (limit);
 507                                 a5 = btrfs_stack_qgroup_limit_rsv_exclusive
 508                                      (limit);
 509                                 add_qgroup(qgroup_lookup, sh->offset, 0, 0,
 510                                            0, 0, 0, a1, a2, a3, a4, a5, 0, 0);
 511                         } else if (sh->type == BTRFS_QGROUP_RELATION_KEY) {
 512                                 if (sh->offset < sh->objectid)
 513                                         goto skip;
 514                                 bq = qgroup_tree_search(qgroup_lookup,
 515                                                         sh->offset);
 516                                 if (!bq)
 517                                         goto skip;
 518                                 bq1 = qgroup_tree_search(qgroup_lookup,
 519                                                          sh->objectid);
 520                                 if (!bq1)
 521                                         goto skip;
 522                                 add_qgroup(qgroup_lookup, sh->offset, 0, 0,
 523                                            0, 0, 0, 0, 0, 0, 0, 0, bq, bq1);
 524                         } else
 525                                 goto done;
 526 skip:
 527                         off += sh->len;
 528
 529                         /*
 530                          * record the mins in sk so we can make sure the
 531                          * next search doesn't repeat this root
 532                          */
 533                         sk->min_type = sh->type;
 534                         sk->min_offset = sh->offset;
 535                         sk->min_objectid = sh->objectid;
 536                 }
 537                 sk->nr_items = 4096;
 538                 /*
 539                  * this iteration is done, step forward one qgroup for the next
 540                  * ioctl
 541                  */
 542                 if (sk->min_offset < (u64)-1)
 543                         sk->min_offset++;
 544                 else
 545                         break;
 546         }
 547
 548 done:
 549         return ret;
 550 }
 551
 552 static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup)
 553 {
 554
 555         struct rb_node *n;
 556         struct btrfs_qgroup *entry;
 557
 558         n = rb_first(&qgroup_lookup->root);
 559         while (n) {
 560                 entry = rb_entry(n, struct btrfs_qgroup, rb_node);
 561                 print_single_qgroup_default(entry);
 562                 n = rb_next(n);
 563         }
 564 }
 565
 566 int btrfs_show_qgroups(int fd)
 567 {
 568
 569         struct qgroup_lookup qgroup_lookup;
 570         int ret;
 571
 572         ret = __qgroups_search(fd, &qgroup_lookup);
 573         if (ret)
 574                 return ret;
 575
 576         print_all_qgroups(&qgroup_lookup);
 577         __free_all_qgroups(&qgroup_lookup);
 578
 579         return ret;
 580 }
 581
 582 u64 parse_qgroupid(char *p)
 583 {
 584         char *s = strchr(p, '/');
 585         char *ptr_src_end = p + strlen(p);
 586         char *ptr_parse_end = NULL;
 587         u64 level;
 588         u64 id;
 589
 590         if (!s) {
 591                 id = strtoull(p, &ptr_parse_end, 10);
 592                 if (ptr_parse_end != ptr_src_end)
 593                         goto err;
 594                 return id;
 595         }
 596         level = strtoull(p, &ptr_parse_end, 10);
 597         if (ptr_parse_end != s)
 598                 goto err;
 599
 600         id = strtoull(s+1, &ptr_parse_end, 10);
 601         if (ptr_parse_end != ptr_src_end)
 602                 goto  err;
 603
 604         return (level << 48) | id;
 605 err:
 606         fprintf(stderr, "ERROR:invalid qgroupid\n");
 607         exit(-1);
 608 }
 609
 610 int qgroup_inherit_size(struct btrfs_qgroup_inherit *p)
 611 {
 612         return sizeof(*p) + sizeof(p->qgroups[0]) *
 613                             (p->num_qgroups + 2 * p->num_ref_copies +
 614                              2 * p->num_excl_copies);
 615 }
 616
 617 static int
 618 qgroup_inherit_realloc(struct btrfs_qgroup_inherit **inherit, int n, int pos)
 619 {
 620         struct btrfs_qgroup_inherit *out;
 621         int nitems = 0;
 622
 623         if (*inherit) {
 624                 nitems = (*inherit)->num_qgroups +
 625                          (*inherit)->num_ref_copies +
 626                          (*inherit)->num_excl_copies;
 627         }
 628
 629         out = calloc(sizeof(*out) + sizeof(out->qgroups[0]) * (nitems + n), 1);
 630         if (out == NULL) {
 631                 fprintf(stderr, "ERROR: Not enough memory\n");
 632                 return 13;
 633         }
 634
 635         if (*inherit) {
 636                 struct btrfs_qgroup_inherit *i = *inherit;
 637                 int s = sizeof(out->qgroups[0]);
 638
 639                 out->num_qgroups = i->num_qgroups;
 640                 out->num_ref_copies = i->num_ref_copies;
 641                 out->num_excl_copies = i->num_excl_copies;
 642                 memcpy(out->qgroups, i->qgroups, pos * s);
 643                 memcpy(out->qgroups + pos + n, i->qgroups + pos,
 644                        (nitems - pos) * s);
 645         }
 646         free(*inherit);
 647         *inherit = out;
 648
 649         return 0;
 650 }
 651
 652 int qgroup_inherit_add_group(struct btrfs_qgroup_inherit **inherit, char *arg)
 653 {
 654         int ret;
 655         u64 qgroupid = parse_qgroupid(arg);
 656         int pos = 0;
 657
 658         if (qgroupid == 0) {
 659                 fprintf(stderr, "ERROR: bad qgroup specification\n");
 660                 return 12;
 661         }
 662
 663         if (*inherit)
 664                 pos = (*inherit)->num_qgroups;
 665         ret = qgroup_inherit_realloc(inherit, 1, pos);
 666         if (ret)
 667                 return ret;
 668
 669         (*inherit)->qgroups[(*inherit)->num_qgroups++] = qgroupid;
 670
 671         return 0;
 672 }
 673
 674 int qgroup_inherit_add_copy(struct btrfs_qgroup_inherit **inherit, char *arg,
 675                             int type)
 676 {
 677         int ret;
 678         u64 qgroup_src;
 679         u64 qgroup_dst;
 680         char *p;
 681         int pos = 0;
 682
 683         p = strchr(arg, ':');
 684         if (!p) {
 685 bad:
 686                 fprintf(stderr, "ERROR: bad copy specification\n");
 687                 return 12;
 688         }
 689         *p = 0;
 690         qgroup_src = parse_qgroupid(arg);
 691         qgroup_dst = parse_qgroupid(p + 1);
 692         *p = ':';
 693
 694         if (!qgroup_src || !qgroup_dst)
 695                 goto bad;
 696
 697         if (*inherit)
 698                 pos = (*inherit)->num_qgroups +
 699                       (*inherit)->num_ref_copies * 2 * type;
 700
 701         ret = qgroup_inherit_realloc(inherit, 2, pos);
 702         if (ret)
 703                 return ret;
 704
 705         (*inherit)->qgroups[pos++] = qgroup_src;
 706         (*inherit)->qgroups[pos++] = qgroup_dst;
 707
 708         if (!type)
 709                 ++(*inherit)->num_ref_copies;
 710         else
 711                 ++(*inherit)->num_excl_copies;
 712
 713         return 0;
 714 }