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 #include <linux/btrfs.h>
  27
  28 #include "ctree.h"
  29 #include "transaction.h"
  30 #include "disk-io.h"
  31 #include "locking.h"
  32 #include "ulist.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 == -ENOENT) {
 383                         printk(KERN_WARNING
 384                                 "btrfs: orphan qgroup relation 0x%llx->0x%llx\n",
 385                                 (unsigned long long)found_key.objectid,
 386                                 (unsigned long long)found_key.offset);
 387                         ret = 0;        /* ignore the error */
 388                 }
 389                 if (ret)
 390                         goto out;
 391 next2:
 392                 ret = btrfs_next_item(quota_root, path);
 393                 if (ret < 0)
 394                         goto out;
 395                 if (ret)
 396                         break;
 397         }
 398 out:
 399         fs_info->qgroup_flags |= flags;
 400         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON)) {
 401                 fs_info->quota_enabled = 0;
 402                 fs_info->pending_quota_state = 0;
 403         }
 404         btrfs_free_path(path);
 405
 406         return ret < 0 ? ret : 0;
 407 }
 408
 409 /*
 410  * This is only called from close_ctree() or open_ctree(), both in single-
 411  * treaded paths. Clean up the in-memory structures. No locking needed.
 412  */
 413 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 414 {
 415         struct rb_node *n;
 416         struct btrfs_qgroup *qgroup;
 417         struct btrfs_qgroup_list *list;
 418
 419         while ((n = rb_first(&fs_info->qgroup_tree))) {
 420                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 421                 rb_erase(n, &fs_info->qgroup_tree);
 422
 423                 WARN_ON(!list_empty(&qgroup->dirty));
 424
 425                 while (!list_empty(&qgroup->groups)) {
 426                         list = list_first_entry(&qgroup->groups,
 427                                                 struct btrfs_qgroup_list,
 428                                                 next_group);
 429                         list_del(&list->next_group);
 430                         list_del(&list->next_member);
 431                         kfree(list);
 432                 }
 433
 434                 while (!list_empty(&qgroup->members)) {
 435                         list = list_first_entry(&qgroup->members,
 436                                                 struct btrfs_qgroup_list,
 437                                                 next_member);
 438                         list_del(&list->next_group);
 439                         list_del(&list->next_member);
 440                         kfree(list);
 441                 }
 442                 kfree(qgroup);
 443         }
 444 }
 445
 446 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
 447                                     struct btrfs_root *quota_root,
 448                                     u64 src, u64 dst)
 449 {
 450         int ret;
 451         struct btrfs_path *path;
 452         struct btrfs_key key;
 453
 454         path = btrfs_alloc_path();
 455         if (!path)
 456                 return -ENOMEM;
 457
 458         key.objectid = src;
 459         key.type = BTRFS_QGROUP_RELATION_KEY;
 460         key.offset = dst;
 461
 462         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 463
 464         btrfs_mark_buffer_dirty(path->nodes[0]);
 465
 466         btrfs_free_path(path);
 467         return ret;
 468 }
 469
 470 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
 471                                     struct btrfs_root *quota_root,
 472                                     u64 src, u64 dst)
 473 {
 474         int ret;
 475         struct btrfs_path *path;
 476         struct btrfs_key key;
 477
 478         path = btrfs_alloc_path();
 479         if (!path)
 480                 return -ENOMEM;
 481
 482         key.objectid = src;
 483         key.type = BTRFS_QGROUP_RELATION_KEY;
 484         key.offset = dst;
 485
 486         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 487         if (ret < 0)
 488                 goto out;
 489
 490         if (ret > 0) {
 491                 ret = -ENOENT;
 492                 goto out;
 493         }
 494
 495         ret = btrfs_del_item(trans, quota_root, path);
 496 out:
 497         btrfs_free_path(path);
 498         return ret;
 499 }
 500
 501 static int add_qgroup_item(struct btrfs_trans_handle *trans,
 502                            struct btrfs_root *quota_root, u64 qgroupid)
 503 {
 504         int ret;
 505         struct btrfs_path *path;
 506         struct btrfs_qgroup_info_item *qgroup_info;
 507         struct btrfs_qgroup_limit_item *qgroup_limit;
 508         struct extent_buffer *leaf;
 509         struct btrfs_key key;
 510
 511         path = btrfs_alloc_path();
 512         if (!path)
 513                 return -ENOMEM;
 514
 515         key.objectid = 0;
 516         key.type = BTRFS_QGROUP_INFO_KEY;
 517         key.offset = qgroupid;
 518
 519         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 520                                       sizeof(*qgroup_info));
 521         if (ret)
 522                 goto out;
 523
 524         leaf = path->nodes[0];
 525         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 526                                  struct btrfs_qgroup_info_item);
 527         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 528         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 529         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 530         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 531         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 532
 533         btrfs_mark_buffer_dirty(leaf);
 534
 535         btrfs_release_path(path);
 536
 537         key.type = BTRFS_QGROUP_LIMIT_KEY;
 538         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 539                                       sizeof(*qgroup_limit));
 540         if (ret)
 541                 goto out;
 542
 543         leaf = path->nodes[0];
 544         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 545                                   struct btrfs_qgroup_limit_item);
 546         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 547         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 548         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 549         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 550         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 551
 552         btrfs_mark_buffer_dirty(leaf);
 553
 554         ret = 0;
 555 out:
 556         btrfs_free_path(path);
 557         return ret;
 558 }
 559
 560 static int del_qgroup_item(struct btrfs_trans_handle *trans,
 561                            struct btrfs_root *quota_root, u64 qgroupid)
 562 {
 563         int ret;
 564         struct btrfs_path *path;
 565         struct btrfs_key key;
 566
 567         path = btrfs_alloc_path();
 568         if (!path)
 569                 return -ENOMEM;
 570
 571         key.objectid = 0;
 572         key.type = BTRFS_QGROUP_INFO_KEY;
 573         key.offset = qgroupid;
 574         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 575         if (ret < 0)
 576                 goto out;
 577
 578         if (ret > 0) {
 579                 ret = -ENOENT;
 580                 goto out;
 581         }
 582
 583         ret = btrfs_del_item(trans, quota_root, path);
 584         if (ret)
 585                 goto out;
 586
 587         btrfs_release_path(path);
 588
 589         key.type = BTRFS_QGROUP_LIMIT_KEY;
 590         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 591         if (ret < 0)
 592                 goto out;
 593
 594         if (ret > 0) {
 595                 ret = -ENOENT;
 596                 goto out;
 597         }
 598
 599         ret = btrfs_del_item(trans, quota_root, path);
 600
 601 out:
 602         btrfs_free_path(path);
 603         return ret;
 604 }
 605
 606 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 607                                     struct btrfs_root *root, u64 qgroupid,
 608                                     u64 flags, u64 max_rfer, u64 max_excl,
 609                                     u64 rsv_rfer, u64 rsv_excl)
 610 {
 611         struct btrfs_path *path;
 612         struct btrfs_key key;
 613         struct extent_buffer *l;
 614         struct btrfs_qgroup_limit_item *qgroup_limit;
 615         int ret;
 616         int slot;
 617
 618         key.objectid = 0;
 619         key.type = BTRFS_QGROUP_LIMIT_KEY;
 620         key.offset = qgroupid;
 621
 622         path = btrfs_alloc_path();
 623         if (!path)
 624                 return -ENOMEM;
 625
 626         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 627         if (ret > 0)
 628                 ret = -ENOENT;
 629
 630         if (ret)
 631                 goto out;
 632
 633         l = path->nodes[0];
 634         slot = path->slots[0];
 635         qgroup_limit = btrfs_item_ptr(l, path->slots[0],
 636                                       struct btrfs_qgroup_limit_item);
 637         btrfs_set_qgroup_limit_flags(l, qgroup_limit, flags);
 638         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, max_rfer);
 639         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, max_excl);
 640         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, rsv_rfer);
 641         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, rsv_excl);
 642
 643         btrfs_mark_buffer_dirty(l);
 644
 645 out:
 646         btrfs_free_path(path);
 647         return ret;
 648 }
 649
 650 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 651                                    struct btrfs_root *root,
 652                                    struct btrfs_qgroup *qgroup)
 653 {
 654         struct btrfs_path *path;
 655         struct btrfs_key key;
 656         struct extent_buffer *l;
 657         struct btrfs_qgroup_info_item *qgroup_info;
 658         int ret;
 659         int slot;
 660
 661         key.objectid = 0;
 662         key.type = BTRFS_QGROUP_INFO_KEY;
 663         key.offset = qgroup->qgroupid;
 664
 665         path = btrfs_alloc_path();
 666         if (!path)
 667                 return -ENOMEM;
 668
 669         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 670         if (ret > 0)
 671                 ret = -ENOENT;
 672
 673         if (ret)
 674                 goto out;
 675
 676         l = path->nodes[0];
 677         slot = path->slots[0];
 678         qgroup_info = btrfs_item_ptr(l, path->slots[0],
 679                                  struct btrfs_qgroup_info_item);
 680         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 681         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 682         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 683         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 684         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 685
 686         btrfs_mark_buffer_dirty(l);
 687
 688 out:
 689         btrfs_free_path(path);
 690         return ret;
 691 }
 692
 693 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
 694                                      struct btrfs_fs_info *fs_info,
 695                                     struct btrfs_root *root)
 696 {
 697         struct btrfs_path *path;
 698         struct btrfs_key key;
 699         struct extent_buffer *l;
 700         struct btrfs_qgroup_status_item *ptr;
 701         int ret;
 702         int slot;
 703
 704         key.objectid = 0;
 705         key.type = BTRFS_QGROUP_STATUS_KEY;
 706         key.offset = 0;
 707
 708         path = btrfs_alloc_path();
 709         if (!path)
 710                 return -ENOMEM;
 711
 712         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 713         if (ret > 0)
 714                 ret = -ENOENT;
 715
 716         if (ret)
 717                 goto out;
 718
 719         l = path->nodes[0];
 720         slot = path->slots[0];
 721         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 722         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
 723         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 724         /* XXX scan */
 725
 726         btrfs_mark_buffer_dirty(l);
 727
 728 out:
 729         btrfs_free_path(path);
 730         return ret;
 731 }
 732
 733 /*
 734  * called with qgroup_lock held
 735  */
 736 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 737                                   struct btrfs_root *root)
 738 {
 739         struct btrfs_path *path;
 740         struct btrfs_key key;
 741         struct extent_buffer *leaf = NULL;
 742         int ret;
 743         int nr = 0;
 744
 745         path = btrfs_alloc_path();
 746         if (!path)
 747                 return -ENOMEM;
 748
 749         path->leave_spinning = 1;
 750
 751         key.objectid = 0;
 752         key.offset = 0;
 753         key.type = 0;
 754
 755         while (1) {
 756                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 757                 if (ret < 0)
 758                         goto out;
 759                 leaf = path->nodes[0];
 760                 nr = btrfs_header_nritems(leaf);
 761                 if (!nr)
 762                         break;
 763                 /*
 764                  * delete the leaf one by one
 765                  * since the whole tree is going
 766                  * to be deleted.
 767                  */
 768                 path->slots[0] = 0;
 769                 ret = btrfs_del_items(trans, root, path, 0, nr);
 770                 if (ret)
 771                         goto out;
 772
 773                 btrfs_release_path(path);
 774         }
 775         ret = 0;
 776 out:
 777         root->fs_info->pending_quota_state = 0;
 778         btrfs_free_path(path);
 779         return ret;
 780 }
 781
 782 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
 783                        struct btrfs_fs_info *fs_info)
 784 {
 785         struct btrfs_root *quota_root;
 786         struct btrfs_path *path = NULL;
 787         struct btrfs_qgroup_status_item *ptr;
 788         struct extent_buffer *leaf;
 789         struct btrfs_key key;
 790         int ret = 0;
 791
 792         spin_lock(&fs_info->qgroup_lock);
 793         if (fs_info->quota_root) {
 794                 fs_info->pending_quota_state = 1;
 795                 spin_unlock(&fs_info->qgroup_lock);
 796                 goto out;
 797         }
 798         spin_unlock(&fs_info->qgroup_lock);
 799
 800         /*
 801          * initially create the quota tree
 802          */
 803         quota_root = btrfs_create_tree(trans, fs_info,
 804                                        BTRFS_QUOTA_TREE_OBJECTID);
 805         if (IS_ERR(quota_root)) {
 806                 ret =  PTR_ERR(quota_root);
 807                 goto out;
 808         }
 809
 810         path = btrfs_alloc_path();
 811         if (!path) {
 812                 ret = -ENOMEM;
 813                 goto out_free_root;
 814         }
 815
 816         key.objectid = 0;
 817         key.type = BTRFS_QGROUP_STATUS_KEY;
 818         key.offset = 0;
 819
 820         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 821                                       sizeof(*ptr));
 822         if (ret)
 823                 goto out_free_path;
 824
 825         leaf = path->nodes[0];
 826         ptr = btrfs_item_ptr(leaf, path->slots[0],
 827                                  struct btrfs_qgroup_status_item);
 828         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
 829         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
 830         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
 831                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 832         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
 833         btrfs_set_qgroup_status_scan(leaf, ptr, 0);
 834
 835         btrfs_mark_buffer_dirty(leaf);
 836
 837         spin_lock(&fs_info->qgroup_lock);
 838         fs_info->quota_root = quota_root;
 839         fs_info->pending_quota_state = 1;
 840         spin_unlock(&fs_info->qgroup_lock);
 841 out_free_path:
 842         btrfs_free_path(path);
 843 out_free_root:
 844         if (ret) {
 845                 free_extent_buffer(quota_root->node);
 846                 free_extent_buffer(quota_root->commit_root);
 847                 kfree(quota_root);
 848         }
 849 out:
 850         return ret;
 851 }
 852
 853 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
 854                         struct btrfs_fs_info *fs_info)
 855 {
 856         struct btrfs_root *tree_root = fs_info->tree_root;
 857         struct btrfs_root *quota_root;
 858         int ret = 0;
 859
 860         spin_lock(&fs_info->qgroup_lock);
 861         if (!fs_info->quota_root) {
 862                 spin_unlock(&fs_info->qgroup_lock);
 863                 return 0;
 864         }
 865         fs_info->quota_enabled = 0;
 866         fs_info->pending_quota_state = 0;
 867         quota_root = fs_info->quota_root;
 868         fs_info->quota_root = NULL;
 869         btrfs_free_qgroup_config(fs_info);
 870         spin_unlock(&fs_info->qgroup_lock);
 871
 872         if (!quota_root)
 873                 return -EINVAL;
 874
 875         ret = btrfs_clean_quota_tree(trans, quota_root);
 876         if (ret)
 877                 goto out;
 878
 879         ret = btrfs_del_root(trans, tree_root, &quota_root->root_key);
 880         if (ret)
 881                 goto out;
 882
 883         list_del(&quota_root->dirty_list);
 884
 885         btrfs_tree_lock(quota_root->node);
 886         clean_tree_block(trans, tree_root, quota_root->node);
 887         btrfs_tree_unlock(quota_root->node);
 888         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
 889
 890         free_extent_buffer(quota_root->node);
 891         free_extent_buffer(quota_root->commit_root);
 892         kfree(quota_root);
 893 out:
 894         return ret;
 895 }
 896
 897 int btrfs_quota_rescan(struct btrfs_fs_info *fs_info)
 898 {
 899         /* FIXME */
 900         return 0;
 901 }
 902
 903 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
 904                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
 905 {
 906         struct btrfs_root *quota_root;
 907         int ret = 0;
 908
 909         quota_root = fs_info->quota_root;
 910         if (!quota_root)
 911                 return -EINVAL;
 912
 913         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
 914         if (ret)
 915                 return ret;
 916
 917         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
 918         if (ret) {
 919                 del_qgroup_relation_item(trans, quota_root, src, dst);
 920                 return ret;
 921         }
 922
 923         spin_lock(&fs_info->qgroup_lock);
 924         ret = add_relation_rb(quota_root->fs_info, src, dst);
 925         spin_unlock(&fs_info->qgroup_lock);
 926
 927         return ret;
 928 }
 929
 930 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
 931                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
 932 {
 933         struct btrfs_root *quota_root;
 934         int ret = 0;
 935         int err;
 936
 937         quota_root = fs_info->quota_root;
 938         if (!quota_root)
 939                 return -EINVAL;
 940
 941         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
 942         err = del_qgroup_relation_item(trans, quota_root, dst, src);
 943         if (err && !ret)
 944                 ret = err;
 945
 946         spin_lock(&fs_info->qgroup_lock);
 947         del_relation_rb(fs_info, src, dst);
 948
 949         spin_unlock(&fs_info->qgroup_lock);
 950
 951         return ret;
 952 }
 953
 954 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
 955                         struct btrfs_fs_info *fs_info, u64 qgroupid, char *name)
 956 {
 957         struct btrfs_root *quota_root;
 958         struct btrfs_qgroup *qgroup;
 959         int ret = 0;
 960
 961         quota_root = fs_info->quota_root;
 962         if (!quota_root)
 963                 return -EINVAL;
 964
 965         ret = add_qgroup_item(trans, quota_root, qgroupid);
 966
 967         spin_lock(&fs_info->qgroup_lock);
 968         qgroup = add_qgroup_rb(fs_info, qgroupid);
 969         spin_unlock(&fs_info->qgroup_lock);
 970
 971         if (IS_ERR(qgroup))
 972                 ret = PTR_ERR(qgroup);
 973
 974         return ret;
 975 }
 976
 977 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
 978                         struct btrfs_fs_info *fs_info, u64 qgroupid)
 979 {
 980         struct btrfs_root *quota_root;
 981         struct btrfs_qgroup *qgroup;
 982         int ret = 0;
 983
 984         quota_root = fs_info->quota_root;
 985         if (!quota_root)
 986                 return -EINVAL;
 987
 988         /* check if there are no relations to this qgroup */
 989         spin_lock(&fs_info->qgroup_lock);
 990         qgroup = find_qgroup_rb(fs_info, qgroupid);
 991         if (qgroup) {
 992                 if (!list_empty(&qgroup->groups) || !list_empty(&qgroup->members)) {
 993                         spin_unlock(&fs_info->qgroup_lock);
 994                         return -EBUSY;
 995                 }
 996         }
 997         spin_unlock(&fs_info->qgroup_lock);
 998
 999         ret = del_qgroup_item(trans, quota_root, qgroupid);
1000
1001         spin_lock(&fs_info->qgroup_lock);
1002         del_qgroup_rb(quota_root->fs_info, qgroupid);
1003         spin_unlock(&fs_info->qgroup_lock);
1004
1005         return ret;
1006 }
1007
1008 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
1009                        struct btrfs_fs_info *fs_info, u64 qgroupid,
1010                        struct btrfs_qgroup_limit *limit)
1011 {
1012         struct btrfs_root *quota_root = fs_info->quota_root;
1013         struct btrfs_qgroup *qgroup;
1014         int ret = 0;
1015
1016         if (!quota_root)
1017                 return -EINVAL;
1018
1019         ret = update_qgroup_limit_item(trans, quota_root, qgroupid,
1020                                        limit->flags, limit->max_rfer,
1021                                        limit->max_excl, limit->rsv_rfer,
1022                                        limit->rsv_excl);
1023         if (ret) {
1024                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1025                 printk(KERN_INFO "unable to update quota limit for %llu\n",
1026                        (unsigned long long)qgroupid);
1027         }
1028
1029         spin_lock(&fs_info->qgroup_lock);
1030
1031         qgroup = find_qgroup_rb(fs_info, qgroupid);
1032         if (!qgroup) {
1033                 ret = -ENOENT;
1034                 goto unlock;
1035         }
1036         qgroup->lim_flags = limit->flags;
1037         qgroup->max_rfer = limit->max_rfer;
1038         qgroup->max_excl = limit->max_excl;
1039         qgroup->rsv_rfer = limit->rsv_rfer;
1040         qgroup->rsv_excl = limit->rsv_excl;
1041
1042 unlock:
1043         spin_unlock(&fs_info->qgroup_lock);
1044
1045         return ret;
1046 }
1047
1048 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1049                          struct btrfs_qgroup *qgroup)
1050 {
1051         if (list_empty(&qgroup->dirty))
1052                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1053 }
1054
1055 /*
1056  * btrfs_qgroup_record_ref is called when the ref is added or deleted. it puts
1057  * the modification into a list that's later used by btrfs_end_transaction to
1058  * pass the recorded modifications on to btrfs_qgroup_account_ref.
1059  */
1060 int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans,
1061                             struct btrfs_delayed_ref_node *node,
1062                             struct btrfs_delayed_extent_op *extent_op)
1063 {
1064         struct qgroup_update *u;
1065
1066         BUG_ON(!trans->delayed_ref_elem.seq);
1067         u = kmalloc(sizeof(*u), GFP_NOFS);
1068         if (!u)
1069                 return -ENOMEM;
1070
1071         u->node = node;
1072         u->extent_op = extent_op;
1073         list_add_tail(&u->list, &trans->qgroup_ref_list);
1074
1075         return 0;
1076 }
1077
1078 /*
1079  * btrfs_qgroup_account_ref is called for every ref that is added to or deleted
1080  * from the fs. First, all roots referencing the extent are searched, and
1081  * then the space is accounted accordingly to the different roots. The
1082  * accounting algorithm works in 3 steps documented inline.
1083  */
1084 int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans,
1085                              struct btrfs_fs_info *fs_info,
1086                              struct btrfs_delayed_ref_node *node,
1087                              struct btrfs_delayed_extent_op *extent_op)
1088 {
1089         struct btrfs_key ins;
1090         struct btrfs_root *quota_root;
1091         u64 ref_root;
1092         struct btrfs_qgroup *qgroup;
1093         struct ulist_node *unode;
1094         struct ulist *roots = NULL;
1095         struct ulist *tmp = NULL;
1096         struct ulist_iterator uiter;
1097         u64 seq;
1098         int ret = 0;
1099         int sgn;
1100
1101         if (!fs_info->quota_enabled)
1102                 return 0;
1103
1104         BUG_ON(!fs_info->quota_root);
1105
1106         ins.objectid = node->bytenr;
1107         ins.offset = node->num_bytes;
1108         ins.type = BTRFS_EXTENT_ITEM_KEY;
1109
1110         if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1111             node->type == BTRFS_SHARED_BLOCK_REF_KEY) {
1112                 struct btrfs_delayed_tree_ref *ref;
1113                 ref = btrfs_delayed_node_to_tree_ref(node);
1114                 ref_root = ref->root;
1115         } else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1116                    node->type == BTRFS_SHARED_DATA_REF_KEY) {
1117                 struct btrfs_delayed_data_ref *ref;
1118                 ref = btrfs_delayed_node_to_data_ref(node);
1119                 ref_root = ref->root;
1120         } else {
1121                 BUG();
1122         }
1123
1124         if (!is_fstree(ref_root)) {
1125                 /*
1126                  * non-fs-trees are not being accounted
1127                  */
1128                 return 0;
1129         }
1130
1131         switch (node->action) {
1132         case BTRFS_ADD_DELAYED_REF:
1133         case BTRFS_ADD_DELAYED_EXTENT:
1134                 sgn = 1;
1135                 break;
1136         case BTRFS_DROP_DELAYED_REF:
1137                 sgn = -1;
1138                 break;
1139         case BTRFS_UPDATE_DELAYED_HEAD:
1140                 return 0;
1141         default:
1142                 BUG();
1143         }
1144
1145         /*
1146          * the delayed ref sequence number we pass depends on the direction of
1147          * the operation. for add operations, we pass (node->seq - 1) to skip
1148          * the delayed ref's current sequence number, because we need the state
1149          * of the tree before the add operation. for delete operations, we pass
1150          * (node->seq) to include the delayed ref's current sequence number,
1151          * because we need the state of the tree after the delete operation.
1152          */
1153         ret = btrfs_find_all_roots(trans, fs_info, node->bytenr,
1154                                    sgn > 0 ? node->seq - 1 : node->seq, &roots);
1155         if (ret < 0)
1156                 goto out;
1157
1158         spin_lock(&fs_info->qgroup_lock);
1159         quota_root = fs_info->quota_root;
1160         if (!quota_root)
1161                 goto unlock;
1162
1163         qgroup = find_qgroup_rb(fs_info, ref_root);
1164         if (!qgroup)
1165                 goto unlock;
1166
1167         /*
1168          * step 1: for each old ref, visit all nodes once and inc refcnt
1169          */
1170         tmp = ulist_alloc(GFP_ATOMIC);
1171         if (!tmp) {
1172                 ret = -ENOMEM;
1173                 goto unlock;
1174         }
1175         seq = fs_info->qgroup_seq;
1176         fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */
1177
1178         ULIST_ITER_INIT(&uiter);
1179         while ((unode = ulist_next(roots, &uiter))) {
1180                 struct ulist_node *tmp_unode;
1181                 struct ulist_iterator tmp_uiter;
1182                 struct btrfs_qgroup *qg;
1183
1184                 qg = find_qgroup_rb(fs_info, unode->val);
1185                 if (!qg)
1186                         continue;
1187
1188                 ulist_reinit(tmp);
1189                                                 /* XXX id not needed */
1190                 ulist_add(tmp, qg->qgroupid, (u64)(uintptr_t)qg, GFP_ATOMIC);
1191                 ULIST_ITER_INIT(&tmp_uiter);
1192                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1193                         struct btrfs_qgroup_list *glist;
1194
1195                         qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
1196                         if (qg->refcnt < seq)
1197                                 qg->refcnt = seq + 1;
1198                         else
1199                                 ++qg->refcnt;
1200
1201                         list_for_each_entry(glist, &qg->groups, next_group) {
1202                                 ulist_add(tmp, glist->group->qgroupid,
1203                                           (u64)(uintptr_t)glist->group,
1204                                           GFP_ATOMIC);
1205                         }
1206                 }
1207         }
1208
1209         /*
1210          * step 2: walk from the new root
1211          */
1212         ulist_reinit(tmp);
1213         ulist_add(tmp, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1214         ULIST_ITER_INIT(&uiter);
1215         while ((unode = ulist_next(tmp, &uiter))) {
1216                 struct btrfs_qgroup *qg;
1217                 struct btrfs_qgroup_list *glist;
1218
1219                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1220                 if (qg->refcnt < seq) {
1221                         /* not visited by step 1 */
1222                         qg->rfer += sgn * node->num_bytes;
1223                         qg->rfer_cmpr += sgn * node->num_bytes;
1224                         if (roots->nnodes == 0) {
1225                                 qg->excl += sgn * node->num_bytes;
1226                                 qg->excl_cmpr += sgn * node->num_bytes;
1227                         }
1228                         qgroup_dirty(fs_info, qg);
1229                 }
1230                 WARN_ON(qg->tag >= seq);
1231                 qg->tag = seq;
1232
1233                 list_for_each_entry(glist, &qg->groups, next_group) {
1234                         ulist_add(tmp, glist->group->qgroupid,
1235                                   (uintptr_t)glist->group, GFP_ATOMIC);
1236                 }
1237         }
1238
1239         /*
1240          * step 3: walk again from old refs
1241          */
1242         ULIST_ITER_INIT(&uiter);
1243         while ((unode = ulist_next(roots, &uiter))) {
1244                 struct btrfs_qgroup *qg;
1245                 struct ulist_node *tmp_unode;
1246                 struct ulist_iterator tmp_uiter;
1247
1248                 qg = find_qgroup_rb(fs_info, unode->val);
1249                 if (!qg)
1250                         continue;
1251
1252                 ulist_reinit(tmp);
1253                 ulist_add(tmp, qg->qgroupid, (uintptr_t)qg, GFP_ATOMIC);
1254                 ULIST_ITER_INIT(&tmp_uiter);
1255                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1256                         struct btrfs_qgroup_list *glist;
1257
1258                         qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
1259                         if (qg->tag == seq)
1260                                 continue;
1261
1262                         if (qg->refcnt - seq == roots->nnodes) {
1263                                 qg->excl -= sgn * node->num_bytes;
1264                                 qg->excl_cmpr -= sgn * node->num_bytes;
1265                                 qgroup_dirty(fs_info, qg);
1266                         }
1267
1268                         list_for_each_entry(glist, &qg->groups, next_group) {
1269                                 ulist_add(tmp, glist->group->qgroupid,
1270                                           (uintptr_t)glist->group,
1271                                           GFP_ATOMIC);
1272                         }
1273                 }
1274         }
1275         ret = 0;
1276 unlock:
1277         spin_unlock(&fs_info->qgroup_lock);
1278 out:
1279         ulist_free(roots);
1280         ulist_free(tmp);
1281
1282         return ret;
1283 }
1284
1285 /*
1286  * called from commit_transaction. Writes all changed qgroups to disk.
1287  */
1288 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
1289                       struct btrfs_fs_info *fs_info)
1290 {
1291         struct btrfs_root *quota_root = fs_info->quota_root;
1292         int ret = 0;
1293
1294         if (!quota_root)
1295                 goto out;
1296
1297         fs_info->quota_enabled = fs_info->pending_quota_state;
1298
1299         spin_lock(&fs_info->qgroup_lock);
1300         while (!list_empty(&fs_info->dirty_qgroups)) {
1301                 struct btrfs_qgroup *qgroup;
1302                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
1303                                           struct btrfs_qgroup, dirty);
1304                 list_del_init(&qgroup->dirty);
1305                 spin_unlock(&fs_info->qgroup_lock);
1306                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
1307                 if (ret)
1308                         fs_info->qgroup_flags |=
1309                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1310                 spin_lock(&fs_info->qgroup_lock);
1311         }
1312         if (fs_info->quota_enabled)
1313                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
1314         else
1315                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1316         spin_unlock(&fs_info->qgroup_lock);
1317
1318         ret = update_qgroup_status_item(trans, fs_info, quota_root);
1319         if (ret)
1320                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1321
1322 out:
1323
1324         return ret;
1325 }
1326
1327 /*
1328  * copy the acounting information between qgroups. This is necessary when a
1329  * snapshot or a subvolume is created
1330  */
1331 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
1332                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
1333                          struct btrfs_qgroup_inherit *inherit)
1334 {
1335         int ret = 0;
1336         int i;
1337         u64 *i_qgroups;
1338         struct btrfs_root *quota_root = fs_info->quota_root;
1339         struct btrfs_qgroup *srcgroup;
1340         struct btrfs_qgroup *dstgroup;
1341         u32 level_size = 0;
1342
1343         if (!fs_info->quota_enabled)
1344                 return 0;
1345
1346         if (!quota_root)
1347                 return -EINVAL;
1348
1349         /*
1350          * create a tracking group for the subvol itself
1351          */
1352         ret = add_qgroup_item(trans, quota_root, objectid);
1353         if (ret)
1354                 goto out;
1355
1356         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
1357                 ret = update_qgroup_limit_item(trans, quota_root, objectid,
1358                                                inherit->lim.flags,
1359                                                inherit->lim.max_rfer,
1360                                                inherit->lim.max_excl,
1361                                                inherit->lim.rsv_rfer,
1362                                                inherit->lim.rsv_excl);
1363                 if (ret)
1364                         goto out;
1365         }
1366
1367         if (srcid) {
1368                 struct btrfs_root *srcroot;
1369                 struct btrfs_key srckey;
1370                 int srcroot_level;
1371
1372                 srckey.objectid = srcid;
1373                 srckey.type = BTRFS_ROOT_ITEM_KEY;
1374                 srckey.offset = (u64)-1;
1375                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
1376                 if (IS_ERR(srcroot)) {
1377                         ret = PTR_ERR(srcroot);
1378                         goto out;
1379                 }
1380
1381                 rcu_read_lock();
1382                 srcroot_level = btrfs_header_level(srcroot->node);
1383                 level_size = btrfs_level_size(srcroot, srcroot_level);
1384                 rcu_read_unlock();
1385         }
1386
1387         /*
1388          * add qgroup to all inherited groups
1389          */
1390         if (inherit) {
1391                 i_qgroups = (u64 *)(inherit + 1);
1392                 for (i = 0; i < inherit->num_qgroups; ++i) {
1393                         ret = add_qgroup_relation_item(trans, quota_root,
1394                                                        objectid, *i_qgroups);
1395                         if (ret)
1396                                 goto out;
1397                         ret = add_qgroup_relation_item(trans, quota_root,
1398                                                        *i_qgroups, objectid);
1399                         if (ret)
1400                                 goto out;
1401                         ++i_qgroups;
1402                 }
1403         }
1404
1405
1406         spin_lock(&fs_info->qgroup_lock);
1407
1408         dstgroup = add_qgroup_rb(fs_info, objectid);
1409         if (IS_ERR(dstgroup)) {
1410                 ret = PTR_ERR(dstgroup);
1411                 goto unlock;
1412         }
1413
1414         if (srcid) {
1415                 srcgroup = find_qgroup_rb(fs_info, srcid);
1416                 if (!srcgroup)
1417                         goto unlock;
1418                 dstgroup->rfer = srcgroup->rfer - level_size;
1419                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr - level_size;
1420                 srcgroup->excl = level_size;
1421                 srcgroup->excl_cmpr = level_size;
1422                 qgroup_dirty(fs_info, dstgroup);
1423                 qgroup_dirty(fs_info, srcgroup);
1424         }
1425
1426         if (!inherit)
1427                 goto unlock;
1428
1429         i_qgroups = (u64 *)(inherit + 1);
1430         for (i = 0; i < inherit->num_qgroups; ++i) {
1431                 ret = add_relation_rb(quota_root->fs_info, objectid,
1432                                       *i_qgroups);
1433                 if (ret)
1434                         goto unlock;
1435                 ++i_qgroups;
1436         }
1437
1438         for (i = 0; i <  inherit->num_ref_copies; ++i) {
1439                 struct btrfs_qgroup *src;
1440                 struct btrfs_qgroup *dst;
1441
1442                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
1443                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
1444
1445                 if (!src || !dst) {
1446                         ret = -EINVAL;
1447                         goto unlock;
1448                 }
1449
1450                 dst->rfer = src->rfer - level_size;
1451                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
1452                 i_qgroups += 2;
1453         }
1454         for (i = 0; i <  inherit->num_excl_copies; ++i) {
1455                 struct btrfs_qgroup *src;
1456                 struct btrfs_qgroup *dst;
1457
1458                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
1459                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
1460
1461                 if (!src || !dst) {
1462                         ret = -EINVAL;
1463                         goto unlock;
1464                 }
1465
1466                 dst->excl = src->excl + level_size;
1467                 dst->excl_cmpr = src->excl_cmpr + level_size;
1468                 i_qgroups += 2;
1469         }
1470
1471 unlock:
1472         spin_unlock(&fs_info->qgroup_lock);
1473 out:
1474         return ret;
1475 }
1476
1477 /*
1478  * reserve some space for a qgroup and all its parents. The reservation takes
1479  * place with start_transaction or dealloc_reserve, similar to ENOSPC
1480  * accounting. If not enough space is available, EDQUOT is returned.
1481  * We assume that the requested space is new for all qgroups.
1482  */
1483 int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
1484 {
1485         struct btrfs_root *quota_root;
1486         struct btrfs_qgroup *qgroup;
1487         struct btrfs_fs_info *fs_info = root->fs_info;
1488         u64 ref_root = root->root_key.objectid;
1489         int ret = 0;
1490         struct ulist *ulist = NULL;
1491         struct ulist_node *unode;
1492         struct ulist_iterator uiter;
1493
1494         if (!is_fstree(ref_root))
1495                 return 0;
1496
1497         if (num_bytes == 0)
1498                 return 0;
1499
1500         spin_lock(&fs_info->qgroup_lock);
1501         quota_root = fs_info->quota_root;
1502         if (!quota_root)
1503                 goto out;
1504
1505         qgroup = find_qgroup_rb(fs_info, ref_root);
1506         if (!qgroup)
1507                 goto out;
1508
1509         /*
1510          * in a first step, we check all affected qgroups if any limits would
1511          * be exceeded
1512          */
1513         ulist = ulist_alloc(GFP_ATOMIC);
1514         if (!ulist) {
1515                 ret = -ENOMEM;
1516                 goto out;
1517         }
1518         ulist_add(ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1519         ULIST_ITER_INIT(&uiter);
1520         while ((unode = ulist_next(ulist, &uiter))) {
1521                 struct btrfs_qgroup *qg;
1522                 struct btrfs_qgroup_list *glist;
1523
1524                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1525
1526                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
1527                     qg->reserved + qg->rfer + num_bytes >
1528                     qg->max_rfer)
1529                         ret = -EDQUOT;
1530
1531                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
1532                     qg->reserved + qg->excl + num_bytes >
1533                     qg->max_excl)
1534                         ret = -EDQUOT;
1535
1536                 list_for_each_entry(glist, &qg->groups, next_group) {
1537                         ulist_add(ulist, glist->group->qgroupid,
1538                                   (uintptr_t)glist->group, GFP_ATOMIC);
1539                 }
1540         }
1541         if (ret)
1542                 goto out;
1543
1544         /*
1545          * no limits exceeded, now record the reservation into all qgroups
1546          */
1547         ULIST_ITER_INIT(&uiter);
1548         while ((unode = ulist_next(ulist, &uiter))) {
1549                 struct btrfs_qgroup *qg;
1550
1551                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1552
1553                 qg->reserved += num_bytes;
1554         }
1555
1556 out:
1557         spin_unlock(&fs_info->qgroup_lock);
1558         ulist_free(ulist);
1559
1560         return ret;
1561 }
1562
1563 void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes)
1564 {
1565         struct btrfs_root *quota_root;
1566         struct btrfs_qgroup *qgroup;
1567         struct btrfs_fs_info *fs_info = root->fs_info;
1568         struct ulist *ulist = NULL;
1569         struct ulist_node *unode;
1570         struct ulist_iterator uiter;
1571         u64 ref_root = root->root_key.objectid;
1572
1573         if (!is_fstree(ref_root))
1574                 return;
1575
1576         if (num_bytes == 0)
1577                 return;
1578
1579         spin_lock(&fs_info->qgroup_lock);
1580
1581         quota_root = fs_info->quota_root;
1582         if (!quota_root)
1583                 goto out;
1584
1585         qgroup = find_qgroup_rb(fs_info, ref_root);
1586         if (!qgroup)
1587                 goto out;
1588
1589         ulist = ulist_alloc(GFP_ATOMIC);
1590         if (!ulist) {
1591                 btrfs_std_error(fs_info, -ENOMEM);
1592                 goto out;
1593         }
1594         ulist_add(ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1595         ULIST_ITER_INIT(&uiter);
1596         while ((unode = ulist_next(ulist, &uiter))) {
1597                 struct btrfs_qgroup *qg;
1598                 struct btrfs_qgroup_list *glist;
1599
1600                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1601
1602                 qg->reserved -= num_bytes;
1603
1604                 list_for_each_entry(glist, &qg->groups, next_group) {
1605                         ulist_add(ulist, glist->group->qgroupid,
1606                                   (uintptr_t)glist->group, GFP_ATOMIC);
1607                 }
1608         }
1609
1610 out:
1611         spin_unlock(&fs_info->qgroup_lock);
1612         ulist_free(ulist);
1613 }
1614
1615 void assert_qgroups_uptodate(struct btrfs_trans_handle *trans)
1616 {
1617         if (list_empty(&trans->qgroup_ref_list) && !trans->delayed_ref_elem.seq)
1618                 return;
1619         printk(KERN_ERR "btrfs: qgroups not uptodate in trans handle %p: list is%s empty, seq is %llu\n",
1620                 trans, list_empty(&trans->qgroup_ref_list) ? "" : " not",
1621                 trans->delayed_ref_elem.seq);
1622         BUG();
1623 }