fs/btrfs/qgroup.c

   1 /*
   2  * Copyright (C) 2011 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 <linux/sched.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/writeback.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/rbtree.h>
  24 #include <linux/slab.h>
  25 #include <linux/workqueue.h>
  26
  27 #include "ctree.h"
  28 #include "transaction.h"
  29 #include "disk-io.h"
  30 #include "locking.h"
  31 #include "ulist.h"
  32 #include "ioctl.h"
  33 #include "backref.h"
  34
  35 /* TODO XXX FIXME
  36  *  - subvol delete -> delete when ref goes to 0? delete limits also?
  37  *  - reorganize keys
  38  *  - compressed
  39  *  - sync
  40  *  - rescan
  41  *  - copy also limits on subvol creation
  42  *  - limit
  43  *  - caches fuer ulists
  44  *  - performance benchmarks
  45  *  - check all ioctl parameters
  46  */
  47
  48 /*
  49  * one struct for each qgroup, organized in fs_info->qgroup_tree.
  50  */
  51 struct btrfs_qgroup {
  52         u64 qgroupid;
  53
  54         /*
  55          * state
  56          */
  57         u64 rfer;       /* referenced */
  58         u64 rfer_cmpr;  /* referenced compressed */
  59         u64 excl;       /* exclusive */
  60         u64 excl_cmpr;  /* exclusive compressed */
  61
  62         /*
  63          * limits
  64          */
  65         u64 lim_flags;  /* which limits are set */
  66         u64 max_rfer;
  67         u64 max_excl;
  68         u64 rsv_rfer;
  69         u64 rsv_excl;
  70
  71         /*
  72          * reservation tracking
  73          */
  74         u64 reserved;
  75
  76         /*
  77          * lists
  78          */
  79         struct list_head groups;  /* groups this group is member of */
  80         struct list_head members; /* groups that are members of this group */
  81         struct list_head dirty;   /* dirty groups */
  82         struct rb_node node;      /* tree of qgroups */
  83
  84         /*
  85          * temp variables for accounting operations
  86          */
  87         u64 tag;
  88         u64 refcnt;
  89 };
  90
  91 /*
  92  * glue structure to represent the relations between qgroups.
  93  */
  94 struct btrfs_qgroup_list {
  95         struct list_head next_group;
  96         struct list_head next_member;
  97         struct btrfs_qgroup *group;
  98         struct btrfs_qgroup *member;
  99 };
 100
 101 /* must be called with qgroup_lock held */
 102 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 103                                            u64 qgroupid)
 104 {
 105         struct rb_node *n = fs_info->qgroup_tree.rb_node;
 106         struct btrfs_qgroup *qgroup;
 107
 108         while (n) {
 109                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 110                 if (qgroup->qgroupid < qgroupid)
 111                         n = n->rb_left;
 112                 else if (qgroup->qgroupid > qgroupid)
 113                         n = n->rb_right;
 114                 else
 115                         return qgroup;
 116         }
 117         return NULL;
 118 }
 119
 120 /* must be called with qgroup_lock held */
 121 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 122                                           u64 qgroupid)
 123 {
 124         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 125         struct rb_node *parent = NULL;
 126         struct btrfs_qgroup *qgroup;
 127
 128         while (*p) {
 129                 parent = *p;
 130                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 131
 132                 if (qgroup->qgroupid < qgroupid)
 133                         p = &(*p)->rb_left;
 134                 else if (qgroup->qgroupid > qgroupid)
 135                         p = &(*p)->rb_right;
 136                 else
 137                         return qgroup;
 138         }
 139
 140         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 141         if (!qgroup)
 142                 return ERR_PTR(-ENOMEM);
 143
 144         qgroup->qgroupid = qgroupid;
 145         INIT_LIST_HEAD(&qgroup->groups);
 146         INIT_LIST_HEAD(&qgroup->members);
 147         INIT_LIST_HEAD(&qgroup->dirty);
 148
 149         rb_link_node(&qgroup->node, parent, p);
 150         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 151
 152         return qgroup;
 153 }
 154
 155 /* must be called with qgroup_lock held */
 156 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 157 {
 158         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 159         struct btrfs_qgroup_list *list;
 160
 161         if (!qgroup)
 162                 return -ENOENT;
 163
 164         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 165         list_del(&qgroup->dirty);
 166
 167         while (!list_empty(&qgroup->groups)) {
 168                 list = list_first_entry(&qgroup->groups,
 169                                         struct btrfs_qgroup_list, next_group);
 170                 list_del(&list->next_group);
 171                 list_del(&list->next_member);
 172                 kfree(list);
 173         }
 174
 175         while (!list_empty(&qgroup->members)) {
 176                 list = list_first_entry(&qgroup->members,
 177                                         struct btrfs_qgroup_list, next_member);
 178                 list_del(&list->next_group);
 179                 list_del(&list->next_member);
 180                 kfree(list);
 181         }
 182         kfree(qgroup);
 183
 184         return 0;
 185 }
 186
 187 /* must be called with qgroup_lock held */
 188 static int add_relation_rb(struct btrfs_fs_info *fs_info,
 189                            u64 memberid, u64 parentid)
 190 {
 191         struct btrfs_qgroup *member;
 192         struct btrfs_qgroup *parent;
 193         struct btrfs_qgroup_list *list;
 194
 195         member = find_qgroup_rb(fs_info, memberid);
 196         parent = find_qgroup_rb(fs_info, parentid);
 197         if (!member || !parent)
 198                 return -ENOENT;
 199
 200         list = kzalloc(sizeof(*list), GFP_ATOMIC);
 201         if (!list)
 202                 return -ENOMEM;
 203
 204         list->group = parent;
 205         list->member = member;
 206         list_add_tail(&list->next_group, &member->groups);
 207         list_add_tail(&list->next_member, &parent->members);
 208
 209         return 0;
 210 }
 211
 212 /* must be called with qgroup_lock held */
 213 static int del_relation_rb(struct btrfs_fs_info *fs_info,
 214                            u64 memberid, u64 parentid)
 215 {
 216         struct btrfs_qgroup *member;
 217         struct btrfs_qgroup *parent;
 218         struct btrfs_qgroup_list *list;
 219
 220         member = find_qgroup_rb(fs_info, memberid);
 221         parent = find_qgroup_rb(fs_info, parentid);
 222         if (!member || !parent)
 223                 return -ENOENT;
 224
 225         list_for_each_entry(list, &member->groups, next_group) {
 226                 if (list->group == parent) {
 227                         list_del(&list->next_group);
 228                         list_del(&list->next_member);
 229                         kfree(list);
 230                         return 0;
 231                 }
 232         }
 233         return -ENOENT;
 234 }
 235
 236 /*
 237  * The full config is read in one go, only called from open_ctree()
 238  * It doesn't use any locking, as at this point we're still single-threaded
 239  */
 240 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 241 {
 242         struct btrfs_key key;
 243         struct btrfs_key found_key;
 244         struct btrfs_root *quota_root = fs_info->quota_root;
 245         struct btrfs_path *path = NULL;
 246         struct extent_buffer *l;
 247         int slot;
 248         int ret = 0;
 249         u64 flags = 0;
 250
 251         if (!fs_info->quota_enabled)
 252                 return 0;
 253
 254         path = btrfs_alloc_path();
 255         if (!path) {
 256                 ret = -ENOMEM;
 257                 goto out;
 258         }
 259
 260         /* default this to quota off, in case no status key is found */
 261         fs_info->qgroup_flags = 0;
 262
 263         /*
 264          * pass 1: read status, all qgroup infos and limits
 265          */
 266         key.objectid = 0;
 267         key.type = 0;
 268         key.offset = 0;
 269         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 270         if (ret)
 271                 goto out;
 272
 273         while (1) {
 274                 struct btrfs_qgroup *qgroup;
 275
 276                 slot = path->slots[0];
 277                 l = path->nodes[0];
 278                 btrfs_item_key_to_cpu(l, &found_key, slot);
 279
 280                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 281                         struct btrfs_qgroup_status_item *ptr;
 282
 283                         ptr = btrfs_item_ptr(l, slot,
 284                                              struct btrfs_qgroup_status_item);
 285
 286                         if (btrfs_qgroup_status_version(l, ptr) !=
 287                             BTRFS_QGROUP_STATUS_VERSION) {
 288                                 printk(KERN_ERR
 289                                  "btrfs: old qgroup version, quota disabled\n");
 290                                 goto out;
 291                         }
 292                         if (btrfs_qgroup_status_generation(l, ptr) !=
 293                             fs_info->generation) {
 294                                 flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 295                                 printk(KERN_ERR
 296                                         "btrfs: qgroup generation mismatch, "
 297                                         "marked as inconsistent\n");
 298                         }
 299                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 300                                                                           ptr);
 301                         /* FIXME read scan element */
 302                         goto next1;
 303                 }
 304
 305                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 306                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 307                         goto next1;
 308
 309                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
 310                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 311                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 312                         printk(KERN_ERR "btrfs: inconsitent qgroup config\n");
 313                         flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 314                 }
 315                 if (!qgroup) {
 316                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 317                         if (IS_ERR(qgroup)) {
 318                                 ret = PTR_ERR(qgroup);
 319                                 goto out;
 320                         }
 321                 }
 322                 switch (found_key.type) {
 323                 case BTRFS_QGROUP_INFO_KEY: {
 324                         struct btrfs_qgroup_info_item *ptr;
 325
 326                         ptr = btrfs_item_ptr(l, slot,
 327                                              struct btrfs_qgroup_info_item);
 328                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 329                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 330                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 331                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 332                         /* generation currently unused */
 333                         break;
 334                 }
 335                 case BTRFS_QGROUP_LIMIT_KEY: {
 336                         struct btrfs_qgroup_limit_item *ptr;
 337
 338                         ptr = btrfs_item_ptr(l, slot,
 339                                              struct btrfs_qgroup_limit_item);
 340                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 341                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 342                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 343                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 344                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 345                         break;
 346                 }
 347                 }
 348 next1:
 349                 ret = btrfs_next_item(quota_root, path);
 350                 if (ret < 0)
 351                         goto out;
 352                 if (ret)
 353                         break;
 354         }
 355         btrfs_release_path(path);
 356
 357         /*
 358          * pass 2: read all qgroup relations
 359          */
 360         key.objectid = 0;
 361         key.type = BTRFS_QGROUP_RELATION_KEY;
 362         key.offset = 0;
 363         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 364         if (ret)
 365                 goto out;
 366         while (1) {
 367                 slot = path->slots[0];
 368                 l = path->nodes[0];
 369                 btrfs_item_key_to_cpu(l, &found_key, slot);
 370
 371                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 372                         goto next2;
 373
 374                 if (found_key.objectid > found_key.offset) {
 375                         /* parent <- member, not needed to build config */
 376                         /* FIXME should we omit the key completely? */
 377                         goto next2;
 378                 }
 379
 380                 ret = add_relation_rb(fs_info, found_key.objectid,
 381                                       found_key.offset);
 382                 if (ret)
 383                         goto out;
 384 next2:
 385                 ret = btrfs_next_item(quota_root, path);
 386                 if (ret < 0)
 387                         goto out;
 388                 if (ret)
 389                         break;
 390         }
 391 out:
 392         fs_info->qgroup_flags |= flags;
 393         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON)) {
 394                 fs_info->quota_enabled = 0;
 395                 fs_info->pending_quota_state = 0;
 396         }
 397         btrfs_free_path(path);
 398
 399         return ret < 0 ? ret : 0;
 400 }
 401
 402 /*
 403  * This is only called from close_ctree() or open_ctree(), both in single-
 404  * treaded paths. Clean up the in-memory structures. No locking needed.
 405  */
 406 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 407 {
 408         struct rb_node *n;
 409         struct btrfs_qgroup *qgroup;
 410         struct btrfs_qgroup_list *list;
 411
 412         while ((n = rb_first(&fs_info->qgroup_tree))) {
 413                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 414                 rb_erase(n, &fs_info->qgroup_tree);
 415
 416                 WARN_ON(!list_empty(&qgroup->dirty));
 417
 418                 while (!list_empty(&qgroup->groups)) {
 419                         list = list_first_entry(&qgroup->groups,
 420                                                 struct btrfs_qgroup_list,
 421                                                 next_group);
 422                         list_del(&list->next_group);
 423                         list_del(&list->next_member);
 424                         kfree(list);
 425                 }
 426
 427                 while (!list_empty(&qgroup->members)) {
 428                         list = list_first_entry(&qgroup->members,
 429                                                 struct btrfs_qgroup_list,
 430                                                 next_member);
 431                         list_del(&list->next_group);
 432                         list_del(&list->next_member);
 433                         kfree(list);
 434                 }
 435                 kfree(qgroup);
 436         }
 437 }
 438
 439 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
 440                                     struct btrfs_root *quota_root,
 441                                     u64 src, u64 dst)
 442 {
 443         int ret;
 444         struct btrfs_path *path;
 445         struct btrfs_key key;
 446
 447         path = btrfs_alloc_path();
 448         if (!path)
 449                 return -ENOMEM;
 450
 451         key.objectid = src;
 452         key.type = BTRFS_QGROUP_RELATION_KEY;
 453         key.offset = dst;
 454
 455         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 456
 457         btrfs_mark_buffer_dirty(path->nodes[0]);
 458
 459         btrfs_free_path(path);
 460         return ret;
 461 }
 462
 463 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
 464                                     struct btrfs_root *quota_root,
 465                                     u64 src, u64 dst)
 466 {
 467         int ret;
 468         struct btrfs_path *path;
 469         struct btrfs_key key;
 470
 471         path = btrfs_alloc_path();
 472         if (!path)
 473                 return -ENOMEM;
 474
 475         key.objectid = src;
 476         key.type = BTRFS_QGROUP_RELATION_KEY;
 477         key.offset = dst;
 478
 479         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 480         if (ret < 0)
 481                 goto out;
 482
 483         if (ret > 0) {
 484                 ret = -ENOENT;
 485                 goto out;
 486         }
 487
 488         ret = btrfs_del_item(trans, quota_root, path);
 489 out:
 490         btrfs_free_path(path);
 491         return ret;
 492 }
 493
 494 static int add_qgroup_item(struct btrfs_trans_handle *trans,
 495                            struct btrfs_root *quota_root, u64 qgroupid)
 496 {
 497         int ret;
 498         struct btrfs_path *path;
 499         struct btrfs_qgroup_info_item *qgroup_info;
 500         struct btrfs_qgroup_limit_item *qgroup_limit;
 501         struct extent_buffer *leaf;
 502         struct btrfs_key key;
 503
 504         path = btrfs_alloc_path();
 505         if (!path)
 506                 return -ENOMEM;
 507
 508         key.objectid = 0;
 509         key.type = BTRFS_QGROUP_INFO_KEY;
 510         key.offset = qgroupid;
 511
 512         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 513                                       sizeof(*qgroup_info));
 514         if (ret)
 515                 goto out;
 516
 517         leaf = path->nodes[0];
 518         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 519                                  struct btrfs_qgroup_info_item);
 520         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 521         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 522         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 523         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 524         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 525
 526         btrfs_mark_buffer_dirty(leaf);
 527
 528         btrfs_release_path(path);
 529
 530         key.type = BTRFS_QGROUP_LIMIT_KEY;
 531         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 532                                       sizeof(*qgroup_limit));
 533         if (ret)
 534                 goto out;
 535
 536         leaf = path->nodes[0];
 537         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 538                                   struct btrfs_qgroup_limit_item);
 539         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 540         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 541         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 542         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 543         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 544
 545         btrfs_mark_buffer_dirty(leaf);
 546
 547         ret = 0;
 548 out:
 549         btrfs_free_path(path);
 550         return ret;
 551 }
 552
 553 static int del_qgroup_item(struct btrfs_trans_handle *trans,
 554                            struct btrfs_root *quota_root, u64 qgroupid)
 555 {
 556         int ret;
 557         struct btrfs_path *path;
 558         struct btrfs_key key;
 559
 560         path = btrfs_alloc_path();
 561         if (!path)
 562                 return -ENOMEM;
 563
 564         key.objectid = 0;
 565         key.type = BTRFS_QGROUP_INFO_KEY;
 566         key.offset = qgroupid;
 567         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 568         if (ret < 0)
 569                 goto out;
 570
 571         if (ret > 0) {
 572                 ret = -ENOENT;
 573                 goto out;
 574         }
 575
 576         ret = btrfs_del_item(trans, quota_root, path);
 577         if (ret)
 578                 goto out;
 579
 580         btrfs_release_path(path);
 581
 582         key.type = BTRFS_QGROUP_LIMIT_KEY;
 583         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 584         if (ret < 0)
 585                 goto out;
 586
 587         if (ret > 0) {
 588                 ret = -ENOENT;
 589                 goto out;
 590         }
 591
 592         ret = btrfs_del_item(trans, quota_root, path);
 593
 594 out:
 595         btrfs_free_path(path);
 596         return ret;
 597 }
 598
 599 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 600                                     struct btrfs_root *root, u64 qgroupid,
 601                                     u64 flags, u64 max_rfer, u64 max_excl,
 602                                     u64 rsv_rfer, u64 rsv_excl)
 603 {
 604         struct btrfs_path *path;
 605         struct btrfs_key key;
 606         struct extent_buffer *l;
 607         struct btrfs_qgroup_limit_item *qgroup_limit;
 608         int ret;
 609         int slot;
 610
 611         key.objectid = 0;
 612         key.type = BTRFS_QGROUP_LIMIT_KEY;
 613         key.offset = qgroupid;
 614
 615         path = btrfs_alloc_path();
 616         BUG_ON(!path);
 617         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 618         if (ret > 0)
 619                 ret = -ENOENT;
 620
 621         if (ret)
 622                 goto out;
 623
 624         l = path->nodes[0];
 625         slot = path->slots[0];
 626         qgroup_limit = btrfs_item_ptr(l, path->slots[0],
 627                                       struct btrfs_qgroup_limit_item);
 628         btrfs_set_qgroup_limit_flags(l, qgroup_limit, flags);
 629         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, max_rfer);
 630         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, max_excl);
 631         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, rsv_rfer);
 632         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, rsv_excl);
 633
 634         btrfs_mark_buffer_dirty(l);
 635
 636 out:
 637         btrfs_free_path(path);
 638         return ret;
 639 }
 640
 641 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 642                                    struct btrfs_root *root,
 643                                    struct btrfs_qgroup *qgroup)
 644 {
 645         struct btrfs_path *path;
 646         struct btrfs_key key;
 647         struct extent_buffer *l;
 648         struct btrfs_qgroup_info_item *qgroup_info;
 649         int ret;
 650         int slot;
 651
 652         key.objectid = 0;
 653         key.type = BTRFS_QGROUP_INFO_KEY;
 654         key.offset = qgroup->qgroupid;
 655
 656         path = btrfs_alloc_path();
 657         BUG_ON(!path);
 658         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 659         if (ret > 0)
 660                 ret = -ENOENT;
 661
 662         if (ret)
 663                 goto out;
 664
 665         l = path->nodes[0];
 666         slot = path->slots[0];
 667         qgroup_info = btrfs_item_ptr(l, path->slots[0],
 668                                  struct btrfs_qgroup_info_item);
 669         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 670         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 671         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 672         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 673         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 674
 675         btrfs_mark_buffer_dirty(l);
 676
 677 out:
 678         btrfs_free_path(path);
 679         return ret;
 680 }
 681
 682 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
 683                                      struct btrfs_fs_info *fs_info,
 684                                     struct btrfs_root *root)
 685 {
 686         struct btrfs_path *path;
 687         struct btrfs_key key;
 688         struct extent_buffer *l;
 689         struct btrfs_qgroup_status_item *ptr;
 690         int ret;
 691         int slot;
 692
 693         key.objectid = 0;
 694         key.type = BTRFS_QGROUP_STATUS_KEY;
 695         key.offset = 0;
 696
 697         path = btrfs_alloc_path();
 698         BUG_ON(!path);
 699         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 700         if (ret > 0)
 701                 ret = -ENOENT;
 702
 703         if (ret)
 704                 goto out;
 705
 706         l = path->nodes[0];
 707         slot = path->slots[0];
 708         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 709         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
 710         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 711         /* XXX scan */
 712
 713         btrfs_mark_buffer_dirty(l);
 714
 715 out:
 716         btrfs_free_path(path);
 717         return ret;
 718 }
 719
 720 /*
 721  * called with qgroup_lock held
 722  */
 723 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 724                                   struct btrfs_root *root)
 725 {
 726         struct btrfs_path *path;
 727         struct btrfs_key key;
 728         int ret;
 729
 730         if (!root)
 731                 return -EINVAL;
 732
 733         path = btrfs_alloc_path();
 734         if (!path)
 735                 return -ENOMEM;
 736
 737         while (1) {
 738                 key.objectid = 0;
 739                 key.offset = 0;
 740                 key.type = 0;
 741
 742                 path->leave_spinning = 1;
 743                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 744                 if (ret > 0) {
 745                         if (path->slots[0] == 0)
 746                                 break;
 747                         path->slots[0]--;
 748                 } else if (ret < 0) {
 749                         break;
 750                 }
 751
 752                 ret = btrfs_del_item(trans, root, path);
 753                 if (ret)
 754                         goto out;
 755                 btrfs_release_path(path);
 756         }
 757         ret = 0;
 758 out:
 759         root->fs_info->pending_quota_state = 0;
 760         btrfs_free_path(path);
 761         return ret;
 762 }
 763
 764 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
 765                        struct btrfs_fs_info *fs_info)
 766 {
 767         struct btrfs_root *quota_root;
 768         struct btrfs_path *path = NULL;
 769         struct btrfs_qgroup_status_item *ptr;
 770         struct extent_buffer *leaf;
 771         struct btrfs_key key;
 772         int ret = 0;
 773
 774         spin_lock(&fs_info->qgroup_lock);
 775         if (fs_info->quota_root) {
 776                 fs_info->pending_quota_state = 1;
 777                 spin_unlock(&fs_info->qgroup_lock);
 778                 goto out;
 779         }
 780         spin_unlock(&fs_info->qgroup_lock);
 781
 782         /*
 783          * initially create the quota tree
 784          */
 785         quota_root = btrfs_create_tree(trans, fs_info,
 786                                        BTRFS_QUOTA_TREE_OBJECTID);
 787         if (IS_ERR(quota_root)) {
 788                 ret =  PTR_ERR(quota_root);
 789                 goto out;
 790         }
 791
 792         path = btrfs_alloc_path();
 793         if (!path) {
 794                 ret = -ENOMEM;
 795                 goto out_free_root;
 796         }
 797
 798         key.objectid = 0;
 799         key.type = BTRFS_QGROUP_STATUS_KEY;
 800         key.offset = 0;
 801
 802         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 803                                       sizeof(*ptr));
 804         if (ret)
 805                 goto out_free_path;
 806
 807         leaf = path->nodes[0];
 808         ptr = btrfs_item_ptr(leaf, path->slots[0],
 809                                  struct btrfs_qgroup_status_item);
 810         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
 811         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
 812         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
 813                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 814         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
 815         btrfs_set_qgroup_status_scan(leaf, ptr, 0);
 816
 817         btrfs_mark_buffer_dirty(leaf);
 818
 819         spin_lock(&fs_info->qgroup_lock);
 820         fs_info->quota_root = quota_root;
 821         fs_info->pending_quota_state = 1;
 822         spin_unlock(&fs_info->qgroup_lock);
 823 out_free_path:
 824         btrfs_free_path(path);
 825 out_free_root:
 826         if (ret) {
 827                 free_extent_buffer(quota_root->node);
 828                 free_extent_buffer(quota_root->commit_root);
 829                 kfree(quota_root);
 830         }
 831 out:
 832         return ret;
 833 }
 834
 835 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
 836                         struct btrfs_fs_info *fs_info)
 837 {
 838         struct btrfs_root *tree_root = fs_info->tree_root;
 839         struct btrfs_root *quota_root;
 840         int ret = 0;
 841
 842         spin_lock(&fs_info->qgroup_lock);
 843         fs_info->quota_enabled = 0;
 844         fs_info->pending_quota_state = 0;
 845         quota_root = fs_info->quota_root;
 846         fs_info->quota_root = NULL;
 847         btrfs_free_qgroup_config(fs_info);
 848         spin_unlock(&fs_info->qgroup_lock);
 849
 850         if (!quota_root)
 851                 return -EINVAL;
 852
 853         ret = btrfs_clean_quota_tree(trans, quota_root);
 854         if (ret)
 855                 goto out;
 856
 857         ret = btrfs_del_root(trans, tree_root, &quota_root->root_key);
 858         if (ret)
 859                 goto out;
 860
 861         list_del(&quota_root->dirty_list);
 862
 863         btrfs_tree_lock(quota_root->node);
 864         clean_tree_block(trans, tree_root, quota_root->node);
 865         btrfs_tree_unlock(quota_root->node);
 866         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
 867
 868         free_extent_buffer(quota_root->node);
 869         free_extent_buffer(quota_root->commit_root);
 870         kfree(quota_root);
 871 out:
 872         return ret;
 873 }
 874
 875 int btrfs_quota_rescan(struct btrfs_fs_info *fs_info)
 876 {
 877         /* FIXME */
 878         return 0;
 879 }
 880
 881 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
 882                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
 883 {
 884         struct btrfs_root *quota_root;
 885         int ret = 0;
 886
 887         quota_root = fs_info->quota_root;
 888         if (!quota_root)
 889                 return -EINVAL;
 890
 891         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
 892         if (ret)
 893                 return ret;
 894
 895         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
 896         if (ret) {
 897                 del_qgroup_relation_item(trans, quota_root, src, dst);
 898                 return ret;
 899         }
 900
 901         spin_lock(&fs_info->qgroup_lock);
 902         ret = add_relation_rb(quota_root->fs_info, src, dst);
 903         spin_unlock(&fs_info->qgroup_lock);
 904
 905         return ret;
 906 }
 907
 908 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
 909                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
 910 {
 911         struct btrfs_root *quota_root;
 912         int ret = 0;
 913         int err;
 914
 915         quota_root = fs_info->quota_root;
 916         if (!quota_root)
 917                 return -EINVAL;
 918
 919         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
 920         err = del_qgroup_relation_item(trans, quota_root, dst, src);
 921         if (err && !ret)
 922                 ret = err;
 923
 924         spin_lock(&fs_info->qgroup_lock);
 925         del_relation_rb(fs_info, src, dst);
 926
 927         spin_unlock(&fs_info->qgroup_lock);
 928
 929         return ret;
 930 }
 931
 932 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
 933                         struct btrfs_fs_info *fs_info, u64 qgroupid, char *name)
 934 {
 935         struct btrfs_root *quota_root;
 936         struct btrfs_qgroup *qgroup;
 937         int ret = 0;
 938
 939         quota_root = fs_info->quota_root;
 940         if (!quota_root)
 941                 return -EINVAL;
 942
 943         ret = add_qgroup_item(trans, quota_root, qgroupid);
 944
 945         spin_lock(&fs_info->qgroup_lock);
 946         qgroup = add_qgroup_rb(fs_info, qgroupid);
 947         spin_unlock(&fs_info->qgroup_lock);
 948
 949         if (IS_ERR(qgroup))
 950                 ret = PTR_ERR(qgroup);
 951
 952         return ret;
 953 }
 954
 955 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
 956                         struct btrfs_fs_info *fs_info, u64 qgroupid)
 957 {
 958         struct btrfs_root *quota_root;
 959         int ret = 0;
 960
 961         quota_root = fs_info->quota_root;
 962         if (!quota_root)
 963                 return -EINVAL;
 964
 965         ret = del_qgroup_item(trans, quota_root, qgroupid);
 966
 967         spin_lock(&fs_info->qgroup_lock);
 968         del_qgroup_rb(quota_root->fs_info, qgroupid);
 969
 970         spin_unlock(&fs_info->qgroup_lock);
 971
 972         return ret;
 973 }
 974
 975 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
 976                        struct btrfs_fs_info *fs_info, u64 qgroupid,
 977                        struct btrfs_qgroup_limit *limit)
 978 {
 979         struct btrfs_root *quota_root = fs_info->quota_root;
 980         struct btrfs_qgroup *qgroup;
 981         int ret = 0;
 982
 983         if (!quota_root)
 984                 return -EINVAL;
 985
 986         ret = update_qgroup_limit_item(trans, quota_root, qgroupid,
 987                                        limit->flags, limit->max_rfer,
 988                                        limit->max_excl, limit->rsv_rfer,
 989                                        limit->rsv_excl);
 990         if (ret) {
 991                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 992                 printk(KERN_INFO "unable to update quota limit for %llu\n",
 993                        (unsigned long long)qgroupid);
 994         }
 995
 996         spin_lock(&fs_info->qgroup_lock);
 997
 998         qgroup = find_qgroup_rb(fs_info, qgroupid);
 999         if (!qgroup) {
1000                 ret = -ENOENT;
1001                 goto unlock;
1002         }
1003         qgroup->lim_flags = limit->flags;
1004         qgroup->max_rfer = limit->max_rfer;
1005         qgroup->max_excl = limit->max_excl;
1006         qgroup->rsv_rfer = limit->rsv_rfer;
1007         qgroup->rsv_excl = limit->rsv_excl;
1008
1009 unlock:
1010         spin_unlock(&fs_info->qgroup_lock);
1011
1012         return ret;
1013 }
1014
1015 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1016                          struct btrfs_qgroup *qgroup)
1017 {
1018         if (list_empty(&qgroup->dirty))
1019                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1020 }
1021
1022 /*
1023  * btrfs_qgroup_record_ref is called when the ref is added or deleted. it puts
1024  * the modification into a list that's later used by btrfs_end_transaction to
1025  * pass the recorded modifications on to btrfs_qgroup_account_ref.
1026  */
1027 int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans,
1028                             struct btrfs_delayed_ref_node *node,
1029                             struct btrfs_delayed_extent_op *extent_op)
1030 {
1031         struct qgroup_update *u;
1032
1033         BUG_ON(!trans->delayed_ref_elem.seq);
1034         u = kmalloc(sizeof(*u), GFP_NOFS);
1035         if (!u)
1036                 return -ENOMEM;
1037
1038         u->node = node;
1039         u->extent_op = extent_op;
1040         list_add_tail(&u->list, &trans->qgroup_ref_list);
1041
1042         return 0;
1043 }
1044
1045 /*
1046  * btrfs_qgroup_account_ref is called for every ref that is added to or deleted
1047  * from the fs. First, all roots referencing the extent are searched, and
1048  * then the space is accounted accordingly to the different roots. The
1049  * accounting algorithm works in 3 steps documented inline.
1050  */
1051 int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans,
1052                              struct btrfs_fs_info *fs_info,
1053                              struct btrfs_delayed_ref_node *node,
1054                              struct btrfs_delayed_extent_op *extent_op)
1055 {
1056         struct btrfs_key ins;
1057         struct btrfs_root *quota_root;
1058         u64 ref_root;
1059         struct btrfs_qgroup *qgroup;
1060         struct ulist_node *unode;
1061         struct ulist *roots = NULL;
1062         struct ulist *tmp = NULL;
1063         struct ulist_iterator uiter;
1064         u64 seq;
1065         int ret = 0;
1066         int sgn;
1067
1068         if (!fs_info->quota_enabled)
1069                 return 0;
1070
1071         BUG_ON(!fs_info->quota_root);
1072
1073         ins.objectid = node->bytenr;
1074         ins.offset = node->num_bytes;
1075         ins.type = BTRFS_EXTENT_ITEM_KEY;
1076
1077         if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1078             node->type == BTRFS_SHARED_BLOCK_REF_KEY) {
1079                 struct btrfs_delayed_tree_ref *ref;
1080                 ref = btrfs_delayed_node_to_tree_ref(node);
1081                 ref_root = ref->root;
1082         } else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1083                    node->type == BTRFS_SHARED_DATA_REF_KEY) {
1084                 struct btrfs_delayed_data_ref *ref;
1085                 ref = btrfs_delayed_node_to_data_ref(node);
1086                 ref_root = ref->root;
1087         } else {
1088                 BUG();
1089         }
1090
1091         if (!is_fstree(ref_root)) {
1092                 /*
1093                  * non-fs-trees are not being accounted
1094                  */
1095                 return 0;
1096         }
1097
1098         switch (node->action) {
1099         case BTRFS_ADD_DELAYED_REF:
1100         case BTRFS_ADD_DELAYED_EXTENT:
1101                 sgn = 1;
1102                 break;
1103         case BTRFS_DROP_DELAYED_REF:
1104                 sgn = -1;
1105                 break;
1106         case BTRFS_UPDATE_DELAYED_HEAD:
1107                 return 0;
1108         default:
1109                 BUG();
1110         }
1111
1112         /*
1113          * the delayed ref sequence number we pass depends on the direction of
1114          * the operation. for add operations, we pass (node->seq - 1) to skip
1115          * the delayed ref's current sequence number, because we need the state
1116          * of the tree before the add operation. for delete operations, we pass
1117          * (node->seq) to include the delayed ref's current sequence number,
1118          * because we need the state of the tree after the delete operation.
1119          */
1120         ret = btrfs_find_all_roots(trans, fs_info, node->bytenr,
1121                                    sgn > 0 ? node->seq - 1 : node->seq, &roots);
1122         if (ret < 0)
1123                 goto out;
1124
1125         spin_lock(&fs_info->qgroup_lock);
1126         quota_root = fs_info->quota_root;
1127         if (!quota_root)
1128                 goto unlock;
1129
1130         qgroup = find_qgroup_rb(fs_info, ref_root);
1131         if (!qgroup)
1132                 goto unlock;
1133
1134         /*
1135          * step 1: for each old ref, visit all nodes once and inc refcnt
1136          */
1137         tmp = ulist_alloc(GFP_ATOMIC);
1138         if (!tmp) {
1139                 ret = -ENOMEM;
1140                 goto unlock;
1141         }
1142         seq = fs_info->qgroup_seq;
1143         fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */
1144
1145         ULIST_ITER_INIT(&uiter);
1146         while ((unode = ulist_next(roots, &uiter))) {
1147                 struct ulist_node *tmp_unode;
1148                 struct ulist_iterator tmp_uiter;
1149                 struct btrfs_qgroup *qg;
1150
1151                 qg = find_qgroup_rb(fs_info, unode->val);
1152                 if (!qg)
1153                         continue;
1154
1155                 ulist_reinit(tmp);
1156                                                 /* XXX id not needed */
1157                 ulist_add(tmp, qg->qgroupid, (u64)(uintptr_t)qg, GFP_ATOMIC);
1158                 ULIST_ITER_INIT(&tmp_uiter);
1159                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1160                         struct btrfs_qgroup_list *glist;
1161
1162                         qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
1163                         if (qg->refcnt < seq)
1164                                 qg->refcnt = seq + 1;
1165                         else
1166                                 ++qg->refcnt;
1167
1168                         list_for_each_entry(glist, &qg->groups, next_group) {
1169                                 ulist_add(tmp, glist->group->qgroupid,
1170                                           (u64)(uintptr_t)glist->group,
1171                                           GFP_ATOMIC);
1172                         }
1173                 }
1174         }
1175
1176         /*
1177          * step 2: walk from the new root
1178          */
1179         ulist_reinit(tmp);
1180         ulist_add(tmp, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1181         ULIST_ITER_INIT(&uiter);
1182         while ((unode = ulist_next(tmp, &uiter))) {
1183                 struct btrfs_qgroup *qg;
1184                 struct btrfs_qgroup_list *glist;
1185
1186                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1187                 if (qg->refcnt < seq) {
1188                         /* not visited by step 1 */
1189                         qg->rfer += sgn * node->num_bytes;
1190                         qg->rfer_cmpr += sgn * node->num_bytes;
1191                         if (roots->nnodes == 0) {
1192                                 qg->excl += sgn * node->num_bytes;
1193                                 qg->excl_cmpr += sgn * node->num_bytes;
1194                         }
1195                         qgroup_dirty(fs_info, qg);
1196                 }
1197                 WARN_ON(qg->tag >= seq);
1198                 qg->tag = seq;
1199
1200                 list_for_each_entry(glist, &qg->groups, next_group) {
1201                         ulist_add(tmp, glist->group->qgroupid,
1202                                   (uintptr_t)glist->group, GFP_ATOMIC);
1203                 }
1204         }
1205
1206         /*
1207          * step 3: walk again from old refs
1208          */
1209         ULIST_ITER_INIT(&uiter);
1210         while ((unode = ulist_next(roots, &uiter))) {
1211                 struct btrfs_qgroup *qg;
1212                 struct ulist_node *tmp_unode;
1213                 struct ulist_iterator tmp_uiter;
1214
1215                 qg = find_qgroup_rb(fs_info, unode->val);
1216                 if (!qg)
1217                         continue;
1218
1219                 ulist_reinit(tmp);
1220                 ulist_add(tmp, qg->qgroupid, (uintptr_t)qg, GFP_ATOMIC);
1221                 ULIST_ITER_INIT(&tmp_uiter);
1222                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1223                         struct btrfs_qgroup_list *glist;
1224
1225                         qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
1226                         if (qg->tag == seq)
1227                                 continue;
1228
1229                         if (qg->refcnt - seq == roots->nnodes) {
1230                                 qg->excl -= sgn * node->num_bytes;
1231                                 qg->excl_cmpr -= sgn * node->num_bytes;
1232                                 qgroup_dirty(fs_info, qg);
1233                         }
1234
1235                         list_for_each_entry(glist, &qg->groups, next_group) {
1236                                 ulist_add(tmp, glist->group->qgroupid,
1237                                           (uintptr_t)glist->group,
1238                                           GFP_ATOMIC);
1239                         }
1240                 }
1241         }
1242         ret = 0;
1243 unlock:
1244         spin_unlock(&fs_info->qgroup_lock);
1245 out:
1246         ulist_free(roots);
1247         ulist_free(tmp);
1248
1249         return ret;
1250 }
1251
1252 /*
1253  * called from commit_transaction. Writes all changed qgroups to disk.
1254  */
1255 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
1256                       struct btrfs_fs_info *fs_info)
1257 {
1258         struct btrfs_root *quota_root = fs_info->quota_root;
1259         int ret = 0;
1260
1261         if (!quota_root)
1262                 goto out;
1263
1264         fs_info->quota_enabled = fs_info->pending_quota_state;
1265
1266         spin_lock(&fs_info->qgroup_lock);
1267         while (!list_empty(&fs_info->dirty_qgroups)) {
1268                 struct btrfs_qgroup *qgroup;
1269                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
1270                                           struct btrfs_qgroup, dirty);
1271                 list_del_init(&qgroup->dirty);
1272                 spin_unlock(&fs_info->qgroup_lock);
1273                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
1274                 if (ret)
1275                         fs_info->qgroup_flags |=
1276                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1277                 spin_lock(&fs_info->qgroup_lock);
1278         }
1279         if (fs_info->quota_enabled)
1280                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
1281         else
1282                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1283         spin_unlock(&fs_info->qgroup_lock);
1284
1285         ret = update_qgroup_status_item(trans, fs_info, quota_root);
1286         if (ret)
1287                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1288
1289 out:
1290
1291         return ret;
1292 }
1293
1294 /*
1295  * copy the acounting information between qgroups. This is necessary when a
1296  * snapshot or a subvolume is created
1297  */
1298 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
1299                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
1300                          struct btrfs_qgroup_inherit *inherit)
1301 {
1302         int ret = 0;
1303         int i;
1304         u64 *i_qgroups;
1305         struct btrfs_root *quota_root = fs_info->quota_root;
1306         struct btrfs_qgroup *srcgroup;
1307         struct btrfs_qgroup *dstgroup;
1308         u32 level_size = 0;
1309
1310         if (!fs_info->quota_enabled)
1311                 return 0;
1312
1313         if (!quota_root)
1314                 return -EINVAL;
1315
1316         /*
1317          * create a tracking group for the subvol itself
1318          */
1319         ret = add_qgroup_item(trans, quota_root, objectid);
1320         if (ret)
1321                 goto out;
1322
1323         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
1324                 ret = update_qgroup_limit_item(trans, quota_root, objectid,
1325                                                inherit->lim.flags,
1326                                                inherit->lim.max_rfer,
1327                                                inherit->lim.max_excl,
1328                                                inherit->lim.rsv_rfer,
1329                                                inherit->lim.rsv_excl);
1330                 if (ret)
1331                         goto out;
1332         }
1333
1334         if (srcid) {
1335                 struct btrfs_root *srcroot;
1336                 struct btrfs_key srckey;
1337                 int srcroot_level;
1338
1339                 srckey.objectid = srcid;
1340                 srckey.type = BTRFS_ROOT_ITEM_KEY;
1341                 srckey.offset = (u64)-1;
1342                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
1343                 if (IS_ERR(srcroot)) {
1344                         ret = PTR_ERR(srcroot);
1345                         goto out;
1346                 }
1347
1348                 rcu_read_lock();
1349                 srcroot_level = btrfs_header_level(srcroot->node);
1350                 level_size = btrfs_level_size(srcroot, srcroot_level);
1351                 rcu_read_unlock();
1352         }
1353
1354         /*
1355          * add qgroup to all inherited groups
1356          */
1357         if (inherit) {
1358                 i_qgroups = (u64 *)(inherit + 1);
1359                 for (i = 0; i < inherit->num_qgroups; ++i) {
1360                         ret = add_qgroup_relation_item(trans, quota_root,
1361                                                        objectid, *i_qgroups);
1362                         if (ret)
1363                                 goto out;
1364                         ret = add_qgroup_relation_item(trans, quota_root,
1365                                                        *i_qgroups, objectid);
1366                         if (ret)
1367                                 goto out;
1368                         ++i_qgroups;
1369                 }
1370         }
1371
1372
1373         spin_lock(&fs_info->qgroup_lock);
1374
1375         dstgroup = add_qgroup_rb(fs_info, objectid);
1376         if (IS_ERR(dstgroup)) {
1377                 ret = PTR_ERR(dstgroup);
1378                 goto unlock;
1379         }
1380
1381         if (srcid) {
1382                 srcgroup = find_qgroup_rb(fs_info, srcid);
1383                 if (!srcgroup)
1384                         goto unlock;
1385                 dstgroup->rfer = srcgroup->rfer - level_size;
1386                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr - level_size;
1387                 srcgroup->excl = level_size;
1388                 srcgroup->excl_cmpr = level_size;
1389                 qgroup_dirty(fs_info, dstgroup);
1390                 qgroup_dirty(fs_info, srcgroup);
1391         }
1392
1393         if (!inherit)
1394                 goto unlock;
1395
1396         i_qgroups = (u64 *)(inherit + 1);
1397         for (i = 0; i < inherit->num_qgroups; ++i) {
1398                 ret = add_relation_rb(quota_root->fs_info, objectid,
1399                                       *i_qgroups);
1400                 if (ret)
1401                         goto unlock;
1402                 ++i_qgroups;
1403         }
1404
1405         for (i = 0; i <  inherit->num_ref_copies; ++i) {
1406                 struct btrfs_qgroup *src;
1407                 struct btrfs_qgroup *dst;
1408
1409                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
1410                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
1411
1412                 if (!src || !dst) {
1413                         ret = -EINVAL;
1414                         goto unlock;
1415                 }
1416
1417                 dst->rfer = src->rfer - level_size;
1418                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
1419                 i_qgroups += 2;
1420         }
1421         for (i = 0; i <  inherit->num_excl_copies; ++i) {
1422                 struct btrfs_qgroup *src;
1423                 struct btrfs_qgroup *dst;
1424
1425                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
1426                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
1427
1428                 if (!src || !dst) {
1429                         ret = -EINVAL;
1430                         goto unlock;
1431                 }
1432
1433                 dst->excl = src->excl + level_size;
1434                 dst->excl_cmpr = src->excl_cmpr + level_size;
1435                 i_qgroups += 2;
1436         }
1437
1438 unlock:
1439         spin_unlock(&fs_info->qgroup_lock);
1440 out:
1441         return ret;
1442 }
1443
1444 /*
1445  * reserve some space for a qgroup and all its parents. The reservation takes
1446  * place with start_transaction or dealloc_reserve, similar to ENOSPC
1447  * accounting. If not enough space is available, EDQUOT is returned.
1448  * We assume that the requested space is new for all qgroups.
1449  */
1450 int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
1451 {
1452         struct btrfs_root *quota_root;
1453         struct btrfs_qgroup *qgroup;
1454         struct btrfs_fs_info *fs_info = root->fs_info;
1455         u64 ref_root = root->root_key.objectid;
1456         int ret = 0;
1457         struct ulist *ulist = NULL;
1458         struct ulist_node *unode;
1459         struct ulist_iterator uiter;
1460
1461         if (!is_fstree(ref_root))
1462                 return 0;
1463
1464         if (num_bytes == 0)
1465                 return 0;
1466
1467         spin_lock(&fs_info->qgroup_lock);
1468         quota_root = fs_info->quota_root;
1469         if (!quota_root)
1470                 goto out;
1471
1472         qgroup = find_qgroup_rb(fs_info, ref_root);
1473         if (!qgroup)
1474                 goto out;
1475
1476         /*
1477          * in a first step, we check all affected qgroups if any limits would
1478          * be exceeded
1479          */
1480         ulist = ulist_alloc(GFP_ATOMIC);
1481         if (!ulist) {
1482                 ret = -ENOMEM;
1483                 goto out;
1484         }
1485         ulist_add(ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1486         ULIST_ITER_INIT(&uiter);
1487         while ((unode = ulist_next(ulist, &uiter))) {
1488                 struct btrfs_qgroup *qg;
1489                 struct btrfs_qgroup_list *glist;
1490
1491                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1492
1493                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
1494                     qg->reserved + qg->rfer + num_bytes >
1495                     qg->max_rfer)
1496                         ret = -EDQUOT;
1497
1498                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
1499                     qg->reserved + qg->excl + num_bytes >
1500                     qg->max_excl)
1501                         ret = -EDQUOT;
1502
1503                 list_for_each_entry(glist, &qg->groups, next_group) {
1504                         ulist_add(ulist, glist->group->qgroupid,
1505                                   (uintptr_t)glist->group, GFP_ATOMIC);
1506                 }
1507         }
1508         if (ret)
1509                 goto out;
1510
1511         /*
1512          * no limits exceeded, now record the reservation into all qgroups
1513          */
1514         ULIST_ITER_INIT(&uiter);
1515         while ((unode = ulist_next(ulist, &uiter))) {
1516                 struct btrfs_qgroup *qg;
1517
1518                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1519
1520                 qg->reserved += num_bytes;
1521         }
1522
1523 out:
1524         spin_unlock(&fs_info->qgroup_lock);
1525         ulist_free(ulist);
1526
1527         return ret;
1528 }
1529
1530 void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes)
1531 {
1532         struct btrfs_root *quota_root;
1533         struct btrfs_qgroup *qgroup;
1534         struct btrfs_fs_info *fs_info = root->fs_info;
1535         struct ulist *ulist = NULL;
1536         struct ulist_node *unode;
1537         struct ulist_iterator uiter;
1538         u64 ref_root = root->root_key.objectid;
1539
1540         if (!is_fstree(ref_root))
1541                 return;
1542
1543         if (num_bytes == 0)
1544                 return;
1545
1546         spin_lock(&fs_info->qgroup_lock);
1547
1548         quota_root = fs_info->quota_root;
1549         if (!quota_root)
1550                 goto out;
1551
1552         qgroup = find_qgroup_rb(fs_info, ref_root);
1553         if (!qgroup)
1554                 goto out;
1555
1556         ulist = ulist_alloc(GFP_ATOMIC);
1557         if (!ulist) {
1558                 btrfs_std_error(fs_info, -ENOMEM);
1559                 goto out;
1560         }
1561         ulist_add(ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1562         ULIST_ITER_INIT(&uiter);
1563         while ((unode = ulist_next(ulist, &uiter))) {
1564                 struct btrfs_qgroup *qg;
1565                 struct btrfs_qgroup_list *glist;
1566
1567                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1568
1569                 qg->reserved -= num_bytes;
1570
1571                 list_for_each_entry(glist, &qg->groups, next_group) {
1572                         ulist_add(ulist, glist->group->qgroupid,
1573                                   (uintptr_t)glist->group, GFP_ATOMIC);
1574                 }
1575         }
1576
1577 out:
1578         spin_unlock(&fs_info->qgroup_lock);
1579         ulist_free(ulist);
1580 }
1581
1582 void assert_qgroups_uptodate(struct btrfs_trans_handle *trans)
1583 {
1584         if (list_empty(&trans->qgroup_ref_list) && !trans->delayed_ref_elem.seq)
1585                 return;
1586         printk(KERN_ERR "btrfs: qgroups not uptodate in trans handle %p: list is%s empty, seq is %llu\n",
1587                 trans, list_empty(&trans->qgroup_ref_list) ? "" : " not",
1588                 trans->delayed_ref_elem.seq);
1589         BUG();
1590 }