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 #include "extent_io.h"
  35 #include "qgroup.h"
  36
  37
  38 /* TODO XXX FIXME
  39  *  - subvol delete -> delete when ref goes to 0? delete limits also?
  40  *  - reorganize keys
  41  *  - compressed
  42  *  - sync
  43  *  - copy also limits on subvol creation
  44  *  - limit
  45  *  - caches fuer ulists
  46  *  - performance benchmarks
  47  *  - check all ioctl parameters
  48  */
  49
  50 /*
  51  * one struct for each qgroup, organized in fs_info->qgroup_tree.
  52  */
  53 struct btrfs_qgroup {
  54         u64 qgroupid;
  55
  56         /*
  57          * state
  58          */
  59         u64 rfer;       /* referenced */
  60         u64 rfer_cmpr;  /* referenced compressed */
  61         u64 excl;       /* exclusive */
  62         u64 excl_cmpr;  /* exclusive compressed */
  63
  64         /*
  65          * limits
  66          */
  67         u64 lim_flags;  /* which limits are set */
  68         u64 max_rfer;
  69         u64 max_excl;
  70         u64 rsv_rfer;
  71         u64 rsv_excl;
  72
  73         /*
  74          * reservation tracking
  75          */
  76         u64 reserved;
  77
  78         /*
  79          * lists
  80          */
  81         struct list_head groups;  /* groups this group is member of */
  82         struct list_head members; /* groups that are members of this group */
  83         struct list_head dirty;   /* dirty groups */
  84         struct rb_node node;      /* tree of qgroups */
  85
  86         /*
  87          * temp variables for accounting operations
  88          * Refer to qgroup_shared_accouting() for details.
  89          */
  90         u64 old_refcnt;
  91         u64 new_refcnt;
  92 };
  93
  94 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
  95                                            int mod)
  96 {
  97         if (qg->old_refcnt < seq)
  98                 qg->old_refcnt = seq;
  99         qg->old_refcnt += mod;
 100 }
 101
 102 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 103                                            int mod)
 104 {
 105         if (qg->new_refcnt < seq)
 106                 qg->new_refcnt = seq;
 107         qg->new_refcnt += mod;
 108 }
 109
 110 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
 111 {
 112         if (qg->old_refcnt < seq)
 113                 return 0;
 114         return qg->old_refcnt - seq;
 115 }
 116
 117 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
 118 {
 119         if (qg->new_refcnt < seq)
 120                 return 0;
 121         return qg->new_refcnt - seq;
 122 }
 123
 124 /*
 125  * glue structure to represent the relations between qgroups.
 126  */
 127 struct btrfs_qgroup_list {
 128         struct list_head next_group;
 129         struct list_head next_member;
 130         struct btrfs_qgroup *group;
 131         struct btrfs_qgroup *member;
 132 };
 133
 134 #define ptr_to_u64(x) ((u64)(uintptr_t)x)
 135 #define u64_to_ptr(x) ((struct btrfs_qgroup *)(uintptr_t)x)
 136
 137 static int
 138 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 139                    int init_flags);
 140 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 141
 142 /* must be called with qgroup_ioctl_lock held */
 143 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 144                                            u64 qgroupid)
 145 {
 146         struct rb_node *n = fs_info->qgroup_tree.rb_node;
 147         struct btrfs_qgroup *qgroup;
 148
 149         while (n) {
 150                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 151                 if (qgroup->qgroupid < qgroupid)
 152                         n = n->rb_left;
 153                 else if (qgroup->qgroupid > qgroupid)
 154                         n = n->rb_right;
 155                 else
 156                         return qgroup;
 157         }
 158         return NULL;
 159 }
 160
 161 /* must be called with qgroup_lock held */
 162 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 163                                           u64 qgroupid)
 164 {
 165         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 166         struct rb_node *parent = NULL;
 167         struct btrfs_qgroup *qgroup;
 168
 169         while (*p) {
 170                 parent = *p;
 171                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 172
 173                 if (qgroup->qgroupid < qgroupid)
 174                         p = &(*p)->rb_left;
 175                 else if (qgroup->qgroupid > qgroupid)
 176                         p = &(*p)->rb_right;
 177                 else
 178                         return qgroup;
 179         }
 180
 181         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 182         if (!qgroup)
 183                 return ERR_PTR(-ENOMEM);
 184
 185         qgroup->qgroupid = qgroupid;
 186         INIT_LIST_HEAD(&qgroup->groups);
 187         INIT_LIST_HEAD(&qgroup->members);
 188         INIT_LIST_HEAD(&qgroup->dirty);
 189
 190         rb_link_node(&qgroup->node, parent, p);
 191         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 192
 193         return qgroup;
 194 }
 195
 196 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
 197 {
 198         struct btrfs_qgroup_list *list;
 199
 200         list_del(&qgroup->dirty);
 201         while (!list_empty(&qgroup->groups)) {
 202                 list = list_first_entry(&qgroup->groups,
 203                                         struct btrfs_qgroup_list, next_group);
 204                 list_del(&list->next_group);
 205                 list_del(&list->next_member);
 206                 kfree(list);
 207         }
 208
 209         while (!list_empty(&qgroup->members)) {
 210                 list = list_first_entry(&qgroup->members,
 211                                         struct btrfs_qgroup_list, next_member);
 212                 list_del(&list->next_group);
 213                 list_del(&list->next_member);
 214                 kfree(list);
 215         }
 216         kfree(qgroup);
 217 }
 218
 219 /* must be called with qgroup_lock held */
 220 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 221 {
 222         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 223
 224         if (!qgroup)
 225                 return -ENOENT;
 226
 227         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 228         __del_qgroup_rb(qgroup);
 229         return 0;
 230 }
 231
 232 /* must be called with qgroup_lock held */
 233 static int add_relation_rb(struct btrfs_fs_info *fs_info,
 234                            u64 memberid, u64 parentid)
 235 {
 236         struct btrfs_qgroup *member;
 237         struct btrfs_qgroup *parent;
 238         struct btrfs_qgroup_list *list;
 239
 240         member = find_qgroup_rb(fs_info, memberid);
 241         parent = find_qgroup_rb(fs_info, parentid);
 242         if (!member || !parent)
 243                 return -ENOENT;
 244
 245         list = kzalloc(sizeof(*list), GFP_ATOMIC);
 246         if (!list)
 247                 return -ENOMEM;
 248
 249         list->group = parent;
 250         list->member = member;
 251         list_add_tail(&list->next_group, &member->groups);
 252         list_add_tail(&list->next_member, &parent->members);
 253
 254         return 0;
 255 }
 256
 257 /* must be called with qgroup_lock held */
 258 static int del_relation_rb(struct btrfs_fs_info *fs_info,
 259                            u64 memberid, u64 parentid)
 260 {
 261         struct btrfs_qgroup *member;
 262         struct btrfs_qgroup *parent;
 263         struct btrfs_qgroup_list *list;
 264
 265         member = find_qgroup_rb(fs_info, memberid);
 266         parent = find_qgroup_rb(fs_info, parentid);
 267         if (!member || !parent)
 268                 return -ENOENT;
 269
 270         list_for_each_entry(list, &member->groups, next_group) {
 271                 if (list->group == parent) {
 272                         list_del(&list->next_group);
 273                         list_del(&list->next_member);
 274                         kfree(list);
 275                         return 0;
 276                 }
 277         }
 278         return -ENOENT;
 279 }
 280
 281 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 282 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 283                                u64 rfer, u64 excl)
 284 {
 285         struct btrfs_qgroup *qgroup;
 286
 287         qgroup = find_qgroup_rb(fs_info, qgroupid);
 288         if (!qgroup)
 289                 return -EINVAL;
 290         if (qgroup->rfer != rfer || qgroup->excl != excl)
 291                 return -EINVAL;
 292         return 0;
 293 }
 294 #endif
 295
 296 /*
 297  * The full config is read in one go, only called from open_ctree()
 298  * It doesn't use any locking, as at this point we're still single-threaded
 299  */
 300 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 301 {
 302         struct btrfs_key key;
 303         struct btrfs_key found_key;
 304         struct btrfs_root *quota_root = fs_info->quota_root;
 305         struct btrfs_path *path = NULL;
 306         struct extent_buffer *l;
 307         int slot;
 308         int ret = 0;
 309         u64 flags = 0;
 310         u64 rescan_progress = 0;
 311
 312         if (!fs_info->quota_enabled)
 313                 return 0;
 314
 315         fs_info->qgroup_ulist = ulist_alloc(GFP_NOFS);
 316         if (!fs_info->qgroup_ulist) {
 317                 ret = -ENOMEM;
 318                 goto out;
 319         }
 320
 321         path = btrfs_alloc_path();
 322         if (!path) {
 323                 ret = -ENOMEM;
 324                 goto out;
 325         }
 326
 327         /* default this to quota off, in case no status key is found */
 328         fs_info->qgroup_flags = 0;
 329
 330         /*
 331          * pass 1: read status, all qgroup infos and limits
 332          */
 333         key.objectid = 0;
 334         key.type = 0;
 335         key.offset = 0;
 336         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 337         if (ret)
 338                 goto out;
 339
 340         while (1) {
 341                 struct btrfs_qgroup *qgroup;
 342
 343                 slot = path->slots[0];
 344                 l = path->nodes[0];
 345                 btrfs_item_key_to_cpu(l, &found_key, slot);
 346
 347                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 348                         struct btrfs_qgroup_status_item *ptr;
 349
 350                         ptr = btrfs_item_ptr(l, slot,
 351                                              struct btrfs_qgroup_status_item);
 352
 353                         if (btrfs_qgroup_status_version(l, ptr) !=
 354                             BTRFS_QGROUP_STATUS_VERSION) {
 355                                 btrfs_err(fs_info,
 356                                  "old qgroup version, quota disabled");
 357                                 goto out;
 358                         }
 359                         if (btrfs_qgroup_status_generation(l, ptr) !=
 360                             fs_info->generation) {
 361                                 flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 362                                 btrfs_err(fs_info,
 363                                         "qgroup generation mismatch, "
 364                                         "marked as inconsistent");
 365                         }
 366                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 367                                                                           ptr);
 368                         rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
 369                         goto next1;
 370                 }
 371
 372                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 373                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 374                         goto next1;
 375
 376                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
 377                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 378                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 379                         btrfs_err(fs_info, "inconsistent qgroup config");
 380                         flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 381                 }
 382                 if (!qgroup) {
 383                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 384                         if (IS_ERR(qgroup)) {
 385                                 ret = PTR_ERR(qgroup);
 386                                 goto out;
 387                         }
 388                 }
 389                 switch (found_key.type) {
 390                 case BTRFS_QGROUP_INFO_KEY: {
 391                         struct btrfs_qgroup_info_item *ptr;
 392
 393                         ptr = btrfs_item_ptr(l, slot,
 394                                              struct btrfs_qgroup_info_item);
 395                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 396                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 397                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 398                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 399                         /* generation currently unused */
 400                         break;
 401                 }
 402                 case BTRFS_QGROUP_LIMIT_KEY: {
 403                         struct btrfs_qgroup_limit_item *ptr;
 404
 405                         ptr = btrfs_item_ptr(l, slot,
 406                                              struct btrfs_qgroup_limit_item);
 407                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 408                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 409                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 410                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 411                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 412                         break;
 413                 }
 414                 }
 415 next1:
 416                 ret = btrfs_next_item(quota_root, path);
 417                 if (ret < 0)
 418                         goto out;
 419                 if (ret)
 420                         break;
 421         }
 422         btrfs_release_path(path);
 423
 424         /*
 425          * pass 2: read all qgroup relations
 426          */
 427         key.objectid = 0;
 428         key.type = BTRFS_QGROUP_RELATION_KEY;
 429         key.offset = 0;
 430         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 431         if (ret)
 432                 goto out;
 433         while (1) {
 434                 slot = path->slots[0];
 435                 l = path->nodes[0];
 436                 btrfs_item_key_to_cpu(l, &found_key, slot);
 437
 438                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 439                         goto next2;
 440
 441                 if (found_key.objectid > found_key.offset) {
 442                         /* parent <- member, not needed to build config */
 443                         /* FIXME should we omit the key completely? */
 444                         goto next2;
 445                 }
 446
 447                 ret = add_relation_rb(fs_info, found_key.objectid,
 448                                       found_key.offset);
 449                 if (ret == -ENOENT) {
 450                         btrfs_warn(fs_info,
 451                                 "orphan qgroup relation 0x%llx->0x%llx",
 452                                 found_key.objectid, found_key.offset);
 453                         ret = 0;        /* ignore the error */
 454                 }
 455                 if (ret)
 456                         goto out;
 457 next2:
 458                 ret = btrfs_next_item(quota_root, path);
 459                 if (ret < 0)
 460                         goto out;
 461                 if (ret)
 462                         break;
 463         }
 464 out:
 465         fs_info->qgroup_flags |= flags;
 466         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON)) {
 467                 fs_info->quota_enabled = 0;
 468                 fs_info->pending_quota_state = 0;
 469         } else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
 470                    ret >= 0) {
 471                 ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
 472         }
 473         btrfs_free_path(path);
 474
 475         if (ret < 0) {
 476                 ulist_free(fs_info->qgroup_ulist);
 477                 fs_info->qgroup_ulist = NULL;
 478                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 479         }
 480
 481         return ret < 0 ? ret : 0;
 482 }
 483
 484 /*
 485  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
 486  * first two are in single-threaded paths.And for the third one, we have set
 487  * quota_root to be null with qgroup_lock held before, so it is safe to clean
 488  * up the in-memory structures without qgroup_lock held.
 489  */
 490 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 491 {
 492         struct rb_node *n;
 493         struct btrfs_qgroup *qgroup;
 494
 495         while ((n = rb_first(&fs_info->qgroup_tree))) {
 496                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 497                 rb_erase(n, &fs_info->qgroup_tree);
 498                 __del_qgroup_rb(qgroup);
 499         }
 500         /*
 501          * we call btrfs_free_qgroup_config() when umounting
 502          * filesystem and disabling quota, so we set qgroup_ulit
 503          * to be null here to avoid double free.
 504          */
 505         ulist_free(fs_info->qgroup_ulist);
 506         fs_info->qgroup_ulist = NULL;
 507 }
 508
 509 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
 510                                     struct btrfs_root *quota_root,
 511                                     u64 src, u64 dst)
 512 {
 513         int ret;
 514         struct btrfs_path *path;
 515         struct btrfs_key key;
 516
 517         path = btrfs_alloc_path();
 518         if (!path)
 519                 return -ENOMEM;
 520
 521         key.objectid = src;
 522         key.type = BTRFS_QGROUP_RELATION_KEY;
 523         key.offset = dst;
 524
 525         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 526
 527         btrfs_mark_buffer_dirty(path->nodes[0]);
 528
 529         btrfs_free_path(path);
 530         return ret;
 531 }
 532
 533 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
 534                                     struct btrfs_root *quota_root,
 535                                     u64 src, u64 dst)
 536 {
 537         int ret;
 538         struct btrfs_path *path;
 539         struct btrfs_key key;
 540
 541         path = btrfs_alloc_path();
 542         if (!path)
 543                 return -ENOMEM;
 544
 545         key.objectid = src;
 546         key.type = BTRFS_QGROUP_RELATION_KEY;
 547         key.offset = dst;
 548
 549         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 550         if (ret < 0)
 551                 goto out;
 552
 553         if (ret > 0) {
 554                 ret = -ENOENT;
 555                 goto out;
 556         }
 557
 558         ret = btrfs_del_item(trans, quota_root, path);
 559 out:
 560         btrfs_free_path(path);
 561         return ret;
 562 }
 563
 564 static int add_qgroup_item(struct btrfs_trans_handle *trans,
 565                            struct btrfs_root *quota_root, u64 qgroupid)
 566 {
 567         int ret;
 568         struct btrfs_path *path;
 569         struct btrfs_qgroup_info_item *qgroup_info;
 570         struct btrfs_qgroup_limit_item *qgroup_limit;
 571         struct extent_buffer *leaf;
 572         struct btrfs_key key;
 573
 574         if (btrfs_test_is_dummy_root(quota_root))
 575                 return 0;
 576
 577         path = btrfs_alloc_path();
 578         if (!path)
 579                 return -ENOMEM;
 580
 581         key.objectid = 0;
 582         key.type = BTRFS_QGROUP_INFO_KEY;
 583         key.offset = qgroupid;
 584
 585         /*
 586          * Avoid a transaction abort by catching -EEXIST here. In that
 587          * case, we proceed by re-initializing the existing structure
 588          * on disk.
 589          */
 590
 591         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 592                                       sizeof(*qgroup_info));
 593         if (ret && ret != -EEXIST)
 594                 goto out;
 595
 596         leaf = path->nodes[0];
 597         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 598                                  struct btrfs_qgroup_info_item);
 599         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 600         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 601         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 602         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 603         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 604
 605         btrfs_mark_buffer_dirty(leaf);
 606
 607         btrfs_release_path(path);
 608
 609         key.type = BTRFS_QGROUP_LIMIT_KEY;
 610         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 611                                       sizeof(*qgroup_limit));
 612         if (ret && ret != -EEXIST)
 613                 goto out;
 614
 615         leaf = path->nodes[0];
 616         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 617                                   struct btrfs_qgroup_limit_item);
 618         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 619         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 620         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 621         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 622         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 623
 624         btrfs_mark_buffer_dirty(leaf);
 625
 626         ret = 0;
 627 out:
 628         btrfs_free_path(path);
 629         return ret;
 630 }
 631
 632 static int del_qgroup_item(struct btrfs_trans_handle *trans,
 633                            struct btrfs_root *quota_root, u64 qgroupid)
 634 {
 635         int ret;
 636         struct btrfs_path *path;
 637         struct btrfs_key key;
 638
 639         path = btrfs_alloc_path();
 640         if (!path)
 641                 return -ENOMEM;
 642
 643         key.objectid = 0;
 644         key.type = BTRFS_QGROUP_INFO_KEY;
 645         key.offset = qgroupid;
 646         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 647         if (ret < 0)
 648                 goto out;
 649
 650         if (ret > 0) {
 651                 ret = -ENOENT;
 652                 goto out;
 653         }
 654
 655         ret = btrfs_del_item(trans, quota_root, path);
 656         if (ret)
 657                 goto out;
 658
 659         btrfs_release_path(path);
 660
 661         key.type = BTRFS_QGROUP_LIMIT_KEY;
 662         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 663         if (ret < 0)
 664                 goto out;
 665
 666         if (ret > 0) {
 667                 ret = -ENOENT;
 668                 goto out;
 669         }
 670
 671         ret = btrfs_del_item(trans, quota_root, path);
 672
 673 out:
 674         btrfs_free_path(path);
 675         return ret;
 676 }
 677
 678 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 679                                     struct btrfs_root *root,
 680                                     struct btrfs_qgroup *qgroup)
 681 {
 682         struct btrfs_path *path;
 683         struct btrfs_key key;
 684         struct extent_buffer *l;
 685         struct btrfs_qgroup_limit_item *qgroup_limit;
 686         int ret;
 687         int slot;
 688
 689         key.objectid = 0;
 690         key.type = BTRFS_QGROUP_LIMIT_KEY;
 691         key.offset = qgroup->qgroupid;
 692
 693         path = btrfs_alloc_path();
 694         if (!path)
 695                 return -ENOMEM;
 696
 697         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 698         if (ret > 0)
 699                 ret = -ENOENT;
 700
 701         if (ret)
 702                 goto out;
 703
 704         l = path->nodes[0];
 705         slot = path->slots[0];
 706         qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
 707         btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
 708         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
 709         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
 710         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
 711         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
 712
 713         btrfs_mark_buffer_dirty(l);
 714
 715 out:
 716         btrfs_free_path(path);
 717         return ret;
 718 }
 719
 720 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 721                                    struct btrfs_root *root,
 722                                    struct btrfs_qgroup *qgroup)
 723 {
 724         struct btrfs_path *path;
 725         struct btrfs_key key;
 726         struct extent_buffer *l;
 727         struct btrfs_qgroup_info_item *qgroup_info;
 728         int ret;
 729         int slot;
 730
 731         if (btrfs_test_is_dummy_root(root))
 732                 return 0;
 733
 734         key.objectid = 0;
 735         key.type = BTRFS_QGROUP_INFO_KEY;
 736         key.offset = qgroup->qgroupid;
 737
 738         path = btrfs_alloc_path();
 739         if (!path)
 740                 return -ENOMEM;
 741
 742         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 743         if (ret > 0)
 744                 ret = -ENOENT;
 745
 746         if (ret)
 747                 goto out;
 748
 749         l = path->nodes[0];
 750         slot = path->slots[0];
 751         qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
 752         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 753         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 754         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 755         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 756         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 757
 758         btrfs_mark_buffer_dirty(l);
 759
 760 out:
 761         btrfs_free_path(path);
 762         return ret;
 763 }
 764
 765 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
 766                                      struct btrfs_fs_info *fs_info,
 767                                     struct btrfs_root *root)
 768 {
 769         struct btrfs_path *path;
 770         struct btrfs_key key;
 771         struct extent_buffer *l;
 772         struct btrfs_qgroup_status_item *ptr;
 773         int ret;
 774         int slot;
 775
 776         key.objectid = 0;
 777         key.type = BTRFS_QGROUP_STATUS_KEY;
 778         key.offset = 0;
 779
 780         path = btrfs_alloc_path();
 781         if (!path)
 782                 return -ENOMEM;
 783
 784         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 785         if (ret > 0)
 786                 ret = -ENOENT;
 787
 788         if (ret)
 789                 goto out;
 790
 791         l = path->nodes[0];
 792         slot = path->slots[0];
 793         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 794         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
 795         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 796         btrfs_set_qgroup_status_rescan(l, ptr,
 797                                 fs_info->qgroup_rescan_progress.objectid);
 798
 799         btrfs_mark_buffer_dirty(l);
 800
 801 out:
 802         btrfs_free_path(path);
 803         return ret;
 804 }
 805
 806 /*
 807  * called with qgroup_lock held
 808  */
 809 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 810                                   struct btrfs_root *root)
 811 {
 812         struct btrfs_path *path;
 813         struct btrfs_key key;
 814         struct extent_buffer *leaf = NULL;
 815         int ret;
 816         int nr = 0;
 817
 818         path = btrfs_alloc_path();
 819         if (!path)
 820                 return -ENOMEM;
 821
 822         path->leave_spinning = 1;
 823
 824         key.objectid = 0;
 825         key.offset = 0;
 826         key.type = 0;
 827
 828         while (1) {
 829                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 830                 if (ret < 0)
 831                         goto out;
 832                 leaf = path->nodes[0];
 833                 nr = btrfs_header_nritems(leaf);
 834                 if (!nr)
 835                         break;
 836                 /*
 837                  * delete the leaf one by one
 838                  * since the whole tree is going
 839                  * to be deleted.
 840                  */
 841                 path->slots[0] = 0;
 842                 ret = btrfs_del_items(trans, root, path, 0, nr);
 843                 if (ret)
 844                         goto out;
 845
 846                 btrfs_release_path(path);
 847         }
 848         ret = 0;
 849 out:
 850         root->fs_info->pending_quota_state = 0;
 851         btrfs_free_path(path);
 852         return ret;
 853 }
 854
 855 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
 856                        struct btrfs_fs_info *fs_info)
 857 {
 858         struct btrfs_root *quota_root;
 859         struct btrfs_root *tree_root = fs_info->tree_root;
 860         struct btrfs_path *path = NULL;
 861         struct btrfs_qgroup_status_item *ptr;
 862         struct extent_buffer *leaf;
 863         struct btrfs_key key;
 864         struct btrfs_key found_key;
 865         struct btrfs_qgroup *qgroup = NULL;
 866         int ret = 0;
 867         int slot;
 868
 869         mutex_lock(&fs_info->qgroup_ioctl_lock);
 870         if (fs_info->quota_root) {
 871                 fs_info->pending_quota_state = 1;
 872                 goto out;
 873         }
 874
 875         fs_info->qgroup_ulist = ulist_alloc(GFP_NOFS);
 876         if (!fs_info->qgroup_ulist) {
 877                 ret = -ENOMEM;
 878                 goto out;
 879         }
 880
 881         /*
 882          * initially create the quota tree
 883          */
 884         quota_root = btrfs_create_tree(trans, fs_info,
 885                                        BTRFS_QUOTA_TREE_OBJECTID);
 886         if (IS_ERR(quota_root)) {
 887                 ret =  PTR_ERR(quota_root);
 888                 goto out;
 889         }
 890
 891         path = btrfs_alloc_path();
 892         if (!path) {
 893                 ret = -ENOMEM;
 894                 goto out_free_root;
 895         }
 896
 897         key.objectid = 0;
 898         key.type = BTRFS_QGROUP_STATUS_KEY;
 899         key.offset = 0;
 900
 901         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 902                                       sizeof(*ptr));
 903         if (ret)
 904                 goto out_free_path;
 905
 906         leaf = path->nodes[0];
 907         ptr = btrfs_item_ptr(leaf, path->slots[0],
 908                                  struct btrfs_qgroup_status_item);
 909         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
 910         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
 911         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
 912                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 913         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
 914         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
 915
 916         btrfs_mark_buffer_dirty(leaf);
 917
 918         key.objectid = 0;
 919         key.type = BTRFS_ROOT_REF_KEY;
 920         key.offset = 0;
 921
 922         btrfs_release_path(path);
 923         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
 924         if (ret > 0)
 925                 goto out_add_root;
 926         if (ret < 0)
 927                 goto out_free_path;
 928
 929
 930         while (1) {
 931                 slot = path->slots[0];
 932                 leaf = path->nodes[0];
 933                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
 934
 935                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
 936                         ret = add_qgroup_item(trans, quota_root,
 937                                               found_key.offset);
 938                         if (ret)
 939                                 goto out_free_path;
 940
 941                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 942                         if (IS_ERR(qgroup)) {
 943                                 ret = PTR_ERR(qgroup);
 944                                 goto out_free_path;
 945                         }
 946                 }
 947                 ret = btrfs_next_item(tree_root, path);
 948                 if (ret < 0)
 949                         goto out_free_path;
 950                 if (ret)
 951                         break;
 952         }
 953
 954 out_add_root:
 955         btrfs_release_path(path);
 956         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
 957         if (ret)
 958                 goto out_free_path;
 959
 960         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
 961         if (IS_ERR(qgroup)) {
 962                 ret = PTR_ERR(qgroup);
 963                 goto out_free_path;
 964         }
 965         spin_lock(&fs_info->qgroup_lock);
 966         fs_info->quota_root = quota_root;
 967         fs_info->pending_quota_state = 1;
 968         spin_unlock(&fs_info->qgroup_lock);
 969 out_free_path:
 970         btrfs_free_path(path);
 971 out_free_root:
 972         if (ret) {
 973                 free_extent_buffer(quota_root->node);
 974                 free_extent_buffer(quota_root->commit_root);
 975                 kfree(quota_root);
 976         }
 977 out:
 978         if (ret) {
 979                 ulist_free(fs_info->qgroup_ulist);
 980                 fs_info->qgroup_ulist = NULL;
 981         }
 982         mutex_unlock(&fs_info->qgroup_ioctl_lock);
 983         return ret;
 984 }
 985
 986 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
 987                         struct btrfs_fs_info *fs_info)
 988 {
 989         struct btrfs_root *tree_root = fs_info->tree_root;
 990         struct btrfs_root *quota_root;
 991         int ret = 0;
 992
 993         mutex_lock(&fs_info->qgroup_ioctl_lock);
 994         if (!fs_info->quota_root)
 995                 goto out;
 996         fs_info->quota_enabled = 0;
 997         fs_info->pending_quota_state = 0;
 998         btrfs_qgroup_wait_for_completion(fs_info, false);
 999         spin_lock(&fs_info->qgroup_lock);
1000         quota_root = fs_info->quota_root;
1001         fs_info->quota_root = NULL;
1002         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1003         spin_unlock(&fs_info->qgroup_lock);
1004
1005         btrfs_free_qgroup_config(fs_info);
1006
1007         ret = btrfs_clean_quota_tree(trans, quota_root);
1008         if (ret)
1009                 goto out;
1010
1011         ret = btrfs_del_root(trans, tree_root, &quota_root->root_key);
1012         if (ret)
1013                 goto out;
1014
1015         list_del(&quota_root->dirty_list);
1016
1017         btrfs_tree_lock(quota_root->node);
1018         clean_tree_block(trans, tree_root->fs_info, quota_root->node);
1019         btrfs_tree_unlock(quota_root->node);
1020         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
1021
1022         free_extent_buffer(quota_root->node);
1023         free_extent_buffer(quota_root->commit_root);
1024         kfree(quota_root);
1025 out:
1026         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1027         return ret;
1028 }
1029
1030 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1031                          struct btrfs_qgroup *qgroup)
1032 {
1033         if (list_empty(&qgroup->dirty))
1034                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1035 }
1036
1037 /*
1038  * The easy accounting, if we are adding/removing the only ref for an extent
1039  * then this qgroup and all of the parent qgroups get their refrence and
1040  * exclusive counts adjusted.
1041  *
1042  * Caller should hold fs_info->qgroup_lock.
1043  */
1044 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1045                                     struct ulist *tmp, u64 ref_root,
1046                                     u64 num_bytes, int sign)
1047 {
1048         struct btrfs_qgroup *qgroup;
1049         struct btrfs_qgroup_list *glist;
1050         struct ulist_node *unode;
1051         struct ulist_iterator uiter;
1052         int ret = 0;
1053
1054         qgroup = find_qgroup_rb(fs_info, ref_root);
1055         if (!qgroup)
1056                 goto out;
1057
1058         qgroup->rfer += sign * num_bytes;
1059         qgroup->rfer_cmpr += sign * num_bytes;
1060
1061         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1062         qgroup->excl += sign * num_bytes;
1063         qgroup->excl_cmpr += sign * num_bytes;
1064         if (sign > 0)
1065                 qgroup->reserved -= num_bytes;
1066
1067         qgroup_dirty(fs_info, qgroup);
1068
1069         /* Get all of the parent groups that contain this qgroup */
1070         list_for_each_entry(glist, &qgroup->groups, next_group) {
1071                 ret = ulist_add(tmp, glist->group->qgroupid,
1072                                 ptr_to_u64(glist->group), GFP_ATOMIC);
1073                 if (ret < 0)
1074                         goto out;
1075         }
1076
1077         /* Iterate all of the parents and adjust their reference counts */
1078         ULIST_ITER_INIT(&uiter);
1079         while ((unode = ulist_next(tmp, &uiter))) {
1080                 qgroup = u64_to_ptr(unode->aux);
1081                 qgroup->rfer += sign * num_bytes;
1082                 qgroup->rfer_cmpr += sign * num_bytes;
1083                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1084                 qgroup->excl += sign * num_bytes;
1085                 if (sign > 0)
1086                         qgroup->reserved -= num_bytes;
1087                 qgroup->excl_cmpr += sign * num_bytes;
1088                 qgroup_dirty(fs_info, qgroup);
1089
1090                 /* Add any parents of the parents */
1091                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1092                         ret = ulist_add(tmp, glist->group->qgroupid,
1093                                         ptr_to_u64(glist->group), GFP_ATOMIC);
1094                         if (ret < 0)
1095                                 goto out;
1096                 }
1097         }
1098         ret = 0;
1099 out:
1100         return ret;
1101 }
1102
1103
1104 /*
1105  * Quick path for updating qgroup with only excl refs.
1106  *
1107  * In that case, just update all parent will be enough.
1108  * Or we needs to do a full rescan.
1109  * Caller should also hold fs_info->qgroup_lock.
1110  *
1111  * Return 0 for quick update, return >0 for need to full rescan
1112  * and mark INCONSISTENT flag.
1113  * Return < 0 for other error.
1114  */
1115 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1116                                    struct ulist *tmp, u64 src, u64 dst,
1117                                    int sign)
1118 {
1119         struct btrfs_qgroup *qgroup;
1120         int ret = 1;
1121         int err = 0;
1122
1123         qgroup = find_qgroup_rb(fs_info, src);
1124         if (!qgroup)
1125                 goto out;
1126         if (qgroup->excl == qgroup->rfer) {
1127                 ret = 0;
1128                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1129                                                qgroup->excl, sign);
1130                 if (err < 0) {
1131                         ret = err;
1132                         goto out;
1133                 }
1134         }
1135 out:
1136         if (ret)
1137                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1138         return ret;
1139 }
1140
1141 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
1142                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1143 {
1144         struct btrfs_root *quota_root;
1145         struct btrfs_qgroup *parent;
1146         struct btrfs_qgroup *member;
1147         struct btrfs_qgroup_list *list;
1148         struct ulist *tmp;
1149         int ret = 0;
1150
1151         /* Check the level of src and dst first */
1152         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1153                 return -EINVAL;
1154
1155         tmp = ulist_alloc(GFP_NOFS);
1156         if (!tmp)
1157                 return -ENOMEM;
1158
1159         mutex_lock(&fs_info->qgroup_ioctl_lock);
1160         quota_root = fs_info->quota_root;
1161         if (!quota_root) {
1162                 ret = -EINVAL;
1163                 goto out;
1164         }
1165         member = find_qgroup_rb(fs_info, src);
1166         parent = find_qgroup_rb(fs_info, dst);
1167         if (!member || !parent) {
1168                 ret = -EINVAL;
1169                 goto out;
1170         }
1171
1172         /* check if such qgroup relation exist firstly */
1173         list_for_each_entry(list, &member->groups, next_group) {
1174                 if (list->group == parent) {
1175                         ret = -EEXIST;
1176                         goto out;
1177                 }
1178         }
1179
1180         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
1181         if (ret)
1182                 goto out;
1183
1184         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
1185         if (ret) {
1186                 del_qgroup_relation_item(trans, quota_root, src, dst);
1187                 goto out;
1188         }
1189
1190         spin_lock(&fs_info->qgroup_lock);
1191         ret = add_relation_rb(quota_root->fs_info, src, dst);
1192         if (ret < 0) {
1193                 spin_unlock(&fs_info->qgroup_lock);
1194                 goto out;
1195         }
1196         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1197         spin_unlock(&fs_info->qgroup_lock);
1198 out:
1199         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1200         ulist_free(tmp);
1201         return ret;
1202 }
1203
1204 int __del_qgroup_relation(struct btrfs_trans_handle *trans,
1205                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1206 {
1207         struct btrfs_root *quota_root;
1208         struct btrfs_qgroup *parent;
1209         struct btrfs_qgroup *member;
1210         struct btrfs_qgroup_list *list;
1211         struct ulist *tmp;
1212         int ret = 0;
1213         int err;
1214
1215         tmp = ulist_alloc(GFP_NOFS);
1216         if (!tmp)
1217                 return -ENOMEM;
1218
1219         quota_root = fs_info->quota_root;
1220         if (!quota_root) {
1221                 ret = -EINVAL;
1222                 goto out;
1223         }
1224
1225         member = find_qgroup_rb(fs_info, src);
1226         parent = find_qgroup_rb(fs_info, dst);
1227         if (!member || !parent) {
1228                 ret = -EINVAL;
1229                 goto out;
1230         }
1231
1232         /* check if such qgroup relation exist firstly */
1233         list_for_each_entry(list, &member->groups, next_group) {
1234                 if (list->group == parent)
1235                         goto exist;
1236         }
1237         ret = -ENOENT;
1238         goto out;
1239 exist:
1240         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
1241         err = del_qgroup_relation_item(trans, quota_root, dst, src);
1242         if (err && !ret)
1243                 ret = err;
1244
1245         spin_lock(&fs_info->qgroup_lock);
1246         del_relation_rb(fs_info, src, dst);
1247         ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1248         spin_unlock(&fs_info->qgroup_lock);
1249 out:
1250         ulist_free(tmp);
1251         return ret;
1252 }
1253
1254 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
1255                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1256 {
1257         int ret = 0;
1258
1259         mutex_lock(&fs_info->qgroup_ioctl_lock);
1260         ret = __del_qgroup_relation(trans, fs_info, src, dst);
1261         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1262
1263         return ret;
1264 }
1265
1266 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
1267                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1268 {
1269         struct btrfs_root *quota_root;
1270         struct btrfs_qgroup *qgroup;
1271         int ret = 0;
1272
1273         mutex_lock(&fs_info->qgroup_ioctl_lock);
1274         quota_root = fs_info->quota_root;
1275         if (!quota_root) {
1276                 ret = -EINVAL;
1277                 goto out;
1278         }
1279         qgroup = find_qgroup_rb(fs_info, qgroupid);
1280         if (qgroup) {
1281                 ret = -EEXIST;
1282                 goto out;
1283         }
1284
1285         ret = add_qgroup_item(trans, quota_root, qgroupid);
1286         if (ret)
1287                 goto out;
1288
1289         spin_lock(&fs_info->qgroup_lock);
1290         qgroup = add_qgroup_rb(fs_info, qgroupid);
1291         spin_unlock(&fs_info->qgroup_lock);
1292
1293         if (IS_ERR(qgroup))
1294                 ret = PTR_ERR(qgroup);
1295 out:
1296         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1297         return ret;
1298 }
1299
1300 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
1301                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1302 {
1303         struct btrfs_root *quota_root;
1304         struct btrfs_qgroup *qgroup;
1305         struct btrfs_qgroup_list *list;
1306         int ret = 0;
1307
1308         mutex_lock(&fs_info->qgroup_ioctl_lock);
1309         quota_root = fs_info->quota_root;
1310         if (!quota_root) {
1311                 ret = -EINVAL;
1312                 goto out;
1313         }
1314
1315         qgroup = find_qgroup_rb(fs_info, qgroupid);
1316         if (!qgroup) {
1317                 ret = -ENOENT;
1318                 goto out;
1319         } else {
1320                 /* check if there are no children of this qgroup */
1321                 if (!list_empty(&qgroup->members)) {
1322                         ret = -EBUSY;
1323                         goto out;
1324                 }
1325         }
1326         ret = del_qgroup_item(trans, quota_root, qgroupid);
1327
1328         while (!list_empty(&qgroup->groups)) {
1329                 list = list_first_entry(&qgroup->groups,
1330                                         struct btrfs_qgroup_list, next_group);
1331                 ret = __del_qgroup_relation(trans, fs_info,
1332                                            qgroupid,
1333                                            list->group->qgroupid);
1334                 if (ret)
1335                         goto out;
1336         }
1337
1338         spin_lock(&fs_info->qgroup_lock);
1339         del_qgroup_rb(quota_root->fs_info, qgroupid);
1340         spin_unlock(&fs_info->qgroup_lock);
1341 out:
1342         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1343         return ret;
1344 }
1345
1346 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
1347                        struct btrfs_fs_info *fs_info, u64 qgroupid,
1348                        struct btrfs_qgroup_limit *limit)
1349 {
1350         struct btrfs_root *quota_root;
1351         struct btrfs_qgroup *qgroup;
1352         int ret = 0;
1353         /* Sometimes we would want to clear the limit on this qgroup.
1354          * To meet this requirement, we treat the -1 as a special value
1355          * which tell kernel to clear the limit on this qgroup.
1356          */
1357         const u64 CLEAR_VALUE = -1;
1358
1359         mutex_lock(&fs_info->qgroup_ioctl_lock);
1360         quota_root = fs_info->quota_root;
1361         if (!quota_root) {
1362                 ret = -EINVAL;
1363                 goto out;
1364         }
1365
1366         qgroup = find_qgroup_rb(fs_info, qgroupid);
1367         if (!qgroup) {
1368                 ret = -ENOENT;
1369                 goto out;
1370         }
1371
1372         spin_lock(&fs_info->qgroup_lock);
1373         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1374                 if (limit->max_rfer == CLEAR_VALUE) {
1375                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1376                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1377                         qgroup->max_rfer = 0;
1378                 } else {
1379                         qgroup->max_rfer = limit->max_rfer;
1380                 }
1381         }
1382         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1383                 if (limit->max_excl == CLEAR_VALUE) {
1384                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1385                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1386                         qgroup->max_excl = 0;
1387                 } else {
1388                         qgroup->max_excl = limit->max_excl;
1389                 }
1390         }
1391         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1392                 if (limit->rsv_rfer == CLEAR_VALUE) {
1393                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1394                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1395                         qgroup->rsv_rfer = 0;
1396                 } else {
1397                         qgroup->rsv_rfer = limit->rsv_rfer;
1398                 }
1399         }
1400         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1401                 if (limit->rsv_excl == CLEAR_VALUE) {
1402                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1403                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1404                         qgroup->rsv_excl = 0;
1405                 } else {
1406                         qgroup->rsv_excl = limit->rsv_excl;
1407                 }
1408         }
1409         qgroup->lim_flags |= limit->flags;
1410
1411         spin_unlock(&fs_info->qgroup_lock);
1412
1413         ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1414         if (ret) {
1415                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1416                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1417                        qgroupid);
1418         }
1419
1420 out:
1421         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1422         return ret;
1423 }
1424
1425 int btrfs_qgroup_prepare_account_extents(struct btrfs_trans_handle *trans,
1426                                          struct btrfs_fs_info *fs_info)
1427 {
1428         struct btrfs_qgroup_extent_record *record;
1429         struct btrfs_delayed_ref_root *delayed_refs;
1430         struct rb_node *node;
1431         u64 qgroup_to_skip;
1432         int ret = 0;
1433
1434         delayed_refs = &trans->transaction->delayed_refs;
1435         qgroup_to_skip = delayed_refs->qgroup_to_skip;
1436
1437         /*
1438          * No need to do lock, since this function will only be called in
1439          * btrfs_commmit_transaction().
1440          */
1441         node = rb_first(&delayed_refs->dirty_extent_root);
1442         while (node) {
1443                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
1444                                   node);
1445                 ret = btrfs_find_all_roots(NULL, fs_info, record->bytenr, 0,
1446                                            &record->old_roots);
1447                 if (ret < 0)
1448                         break;
1449                 if (qgroup_to_skip)
1450                         ulist_del(record->old_roots, qgroup_to_skip, 0);
1451                 node = rb_next(node);
1452         }
1453         return ret;
1454 }
1455
1456 struct btrfs_qgroup_extent_record
1457 *btrfs_qgroup_insert_dirty_extent(struct btrfs_delayed_ref_root *delayed_refs,
1458                                   struct btrfs_qgroup_extent_record *record)
1459 {
1460         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1461         struct rb_node *parent_node = NULL;
1462         struct btrfs_qgroup_extent_record *entry;
1463         u64 bytenr = record->bytenr;
1464
1465         assert_spin_locked(&delayed_refs->lock);
1466
1467         while (*p) {
1468                 parent_node = *p;
1469                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1470                                  node);
1471                 if (bytenr < entry->bytenr)
1472                         p = &(*p)->rb_left;
1473                 else if (bytenr > entry->bytenr)
1474                         p = &(*p)->rb_right;
1475                 else
1476                         return entry;
1477         }
1478
1479         rb_link_node(&record->node, parent_node, p);
1480         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1481         return NULL;
1482 }
1483
1484 #define UPDATE_NEW      0
1485 #define UPDATE_OLD      1
1486 /*
1487  * Walk all of the roots that points to the bytenr and adjust their refcnts.
1488  */
1489 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
1490                                 struct ulist *roots, struct ulist *tmp,
1491                                 struct ulist *qgroups, u64 seq, int update_old)
1492 {
1493         struct ulist_node *unode;
1494         struct ulist_iterator uiter;
1495         struct ulist_node *tmp_unode;
1496         struct ulist_iterator tmp_uiter;
1497         struct btrfs_qgroup *qg;
1498         int ret = 0;
1499
1500         if (!roots)
1501                 return 0;
1502         ULIST_ITER_INIT(&uiter);
1503         while ((unode = ulist_next(roots, &uiter))) {
1504                 qg = find_qgroup_rb(fs_info, unode->val);
1505                 if (!qg)
1506                         continue;
1507
1508                 ulist_reinit(tmp);
1509                 ret = ulist_add(qgroups, qg->qgroupid, ptr_to_u64(qg),
1510                                 GFP_ATOMIC);
1511                 if (ret < 0)
1512                         return ret;
1513                 ret = ulist_add(tmp, qg->qgroupid, ptr_to_u64(qg), GFP_ATOMIC);
1514                 if (ret < 0)
1515                         return ret;
1516                 ULIST_ITER_INIT(&tmp_uiter);
1517                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1518                         struct btrfs_qgroup_list *glist;
1519
1520                         qg = u64_to_ptr(tmp_unode->aux);
1521                         if (update_old)
1522                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
1523                         else
1524                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
1525                         list_for_each_entry(glist, &qg->groups, next_group) {
1526                                 ret = ulist_add(qgroups, glist->group->qgroupid,
1527                                                 ptr_to_u64(glist->group),
1528                                                 GFP_ATOMIC);
1529                                 if (ret < 0)
1530                                         return ret;
1531                                 ret = ulist_add(tmp, glist->group->qgroupid,
1532                                                 ptr_to_u64(glist->group),
1533                                                 GFP_ATOMIC);
1534                                 if (ret < 0)
1535                                         return ret;
1536                         }
1537                 }
1538         }
1539         return 0;
1540 }
1541
1542 /*
1543  * Update qgroup rfer/excl counters.
1544  * Rfer update is easy, codes can explain themselves.
1545  *
1546  * Excl update is tricky, the update is split into 2 part.
1547  * Part 1: Possible exclusive <-> sharing detect:
1548  *      |       A       |       !A      |
1549  *  -------------------------------------
1550  *  B   |       *       |       -       |
1551  *  -------------------------------------
1552  *  !B  |       +       |       **      |
1553  *  -------------------------------------
1554  *
1555  * Conditions:
1556  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
1557  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
1558  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
1559  * !B:  cur_new_roots == nr_new_roots   (possible exclsuive now)
1560  *
1561  * Results:
1562  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
1563  * *: Definitely not changed.           **: Possible unchanged.
1564  *
1565  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
1566  *
1567  * To make the logic clear, we first use condition A and B to split
1568  * combination into 4 results.
1569  *
1570  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
1571  * only on variant maybe 0.
1572  *
1573  * Lastly, check result **, since there are 2 variants maybe 0, split them
1574  * again(2x2).
1575  * But this time we don't need to consider other things, the codes and logic
1576  * is easy to understand now.
1577  */
1578 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
1579                                   struct ulist *qgroups,
1580                                   u64 nr_old_roots,
1581                                   u64 nr_new_roots,
1582                                   u64 num_bytes, u64 seq)
1583 {
1584         struct ulist_node *unode;
1585         struct ulist_iterator uiter;
1586         struct btrfs_qgroup *qg;
1587         u64 cur_new_count, cur_old_count;
1588
1589         ULIST_ITER_INIT(&uiter);
1590         while ((unode = ulist_next(qgroups, &uiter))) {
1591                 bool dirty = false;
1592
1593                 qg = u64_to_ptr(unode->aux);
1594                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
1595                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
1596
1597                 /* Rfer update part */
1598                 if (cur_old_count == 0 && cur_new_count > 0) {
1599                         qg->rfer += num_bytes;
1600                         qg->rfer_cmpr += num_bytes;
1601                         dirty = true;
1602                 }
1603                 if (cur_old_count > 0 && cur_new_count == 0) {
1604                         qg->rfer -= num_bytes;
1605                         qg->rfer_cmpr -= num_bytes;
1606                         dirty = true;
1607                 }
1608
1609                 /* Excl update part */
1610                 /* Exclusive/none -> shared case */
1611                 if (cur_old_count == nr_old_roots &&
1612                     cur_new_count < nr_new_roots) {
1613                         /* Exclusive -> shared */
1614                         if (cur_old_count != 0) {
1615                                 qg->excl -= num_bytes;
1616                                 qg->excl_cmpr -= num_bytes;
1617                                 dirty = true;
1618                         }
1619                 }
1620
1621                 /* Shared -> exclusive/none case */
1622                 if (cur_old_count < nr_old_roots &&
1623                     cur_new_count == nr_new_roots) {
1624                         /* Shared->exclusive */
1625                         if (cur_new_count != 0) {
1626                                 qg->excl += num_bytes;
1627                                 qg->excl_cmpr += num_bytes;
1628                                 dirty = true;
1629                         }
1630                 }
1631
1632                 /* Exclusive/none -> exclusive/none case */
1633                 if (cur_old_count == nr_old_roots &&
1634                     cur_new_count == nr_new_roots) {
1635                         if (cur_old_count == 0) {
1636                                 /* None -> exclusive/none */
1637
1638                                 if (cur_new_count != 0) {
1639                                         /* None -> exclusive */
1640                                         qg->excl += num_bytes;
1641                                         qg->excl_cmpr += num_bytes;
1642                                         dirty = true;
1643                                 }
1644                                 /* None -> none, nothing changed */
1645                         } else {
1646                                 /* Exclusive -> exclusive/none */
1647
1648                                 if (cur_new_count == 0) {
1649                                         /* Exclusive -> none */
1650                                         qg->excl -= num_bytes;
1651                                         qg->excl_cmpr -= num_bytes;
1652                                         dirty = true;
1653                                 }
1654                                 /* Exclusive -> exclusive, nothing changed */
1655                         }
1656                 }
1657
1658                 if (dirty)
1659                         qgroup_dirty(fs_info, qg);
1660         }
1661         return 0;
1662 }
1663
1664 int
1665 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
1666                             struct btrfs_fs_info *fs_info,
1667                             u64 bytenr, u64 num_bytes,
1668                             struct ulist *old_roots, struct ulist *new_roots)
1669 {
1670         struct ulist *qgroups = NULL;
1671         struct ulist *tmp = NULL;
1672         u64 seq;
1673         u64 nr_new_roots = 0;
1674         u64 nr_old_roots = 0;
1675         int ret = 0;
1676
1677         if (new_roots)
1678                 nr_new_roots = new_roots->nnodes;
1679         if (old_roots)
1680                 nr_old_roots = old_roots->nnodes;
1681
1682         if (!fs_info->quota_enabled)
1683                 goto out_free;
1684         BUG_ON(!fs_info->quota_root);
1685
1686         qgroups = ulist_alloc(GFP_NOFS);
1687         if (!qgroups) {
1688                 ret = -ENOMEM;
1689                 goto out_free;
1690         }
1691         tmp = ulist_alloc(GFP_NOFS);
1692         if (!tmp) {
1693                 ret = -ENOMEM;
1694                 goto out_free;
1695         }
1696
1697         mutex_lock(&fs_info->qgroup_rescan_lock);
1698         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
1699                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
1700                         mutex_unlock(&fs_info->qgroup_rescan_lock);
1701                         ret = 0;
1702                         goto out_free;
1703                 }
1704         }
1705         mutex_unlock(&fs_info->qgroup_rescan_lock);
1706
1707         spin_lock(&fs_info->qgroup_lock);
1708         seq = fs_info->qgroup_seq;
1709
1710         /* Update old refcnts using old_roots */
1711         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
1712                                    UPDATE_OLD);
1713         if (ret < 0)
1714                 goto out;
1715
1716         /* Update new refcnts using new_roots */
1717         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
1718                                    UPDATE_NEW);
1719         if (ret < 0)
1720                 goto out;
1721
1722         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
1723                                num_bytes, seq);
1724
1725         /*
1726          * Bump qgroup_seq to avoid seq overlap
1727          */
1728         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
1729 out:
1730         spin_unlock(&fs_info->qgroup_lock);
1731 out_free:
1732         ulist_free(tmp);
1733         ulist_free(qgroups);
1734         ulist_free(old_roots);
1735         ulist_free(new_roots);
1736         return ret;
1737 }
1738
1739 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans,
1740                                  struct btrfs_fs_info *fs_info)
1741 {
1742         struct btrfs_qgroup_extent_record *record;
1743         struct btrfs_delayed_ref_root *delayed_refs;
1744         struct ulist *new_roots = NULL;
1745         struct rb_node *node;
1746         u64 qgroup_to_skip;
1747         int ret = 0;
1748
1749         delayed_refs = &trans->transaction->delayed_refs;
1750         qgroup_to_skip = delayed_refs->qgroup_to_skip;
1751         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
1752                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
1753                                   node);
1754
1755                 if (!ret) {
1756                         /*
1757                          * Use (u64)-1 as time_seq to do special search, which
1758                          * doesn't lock tree or delayed_refs and search current
1759                          * root. It's safe inside commit_transaction().
1760                          */
1761                         ret = btrfs_find_all_roots(trans, fs_info,
1762                                         record->bytenr, (u64)-1, &new_roots);
1763                         if (ret < 0)
1764                                 goto cleanup;
1765                         if (qgroup_to_skip)
1766                                 ulist_del(new_roots, qgroup_to_skip, 0);
1767                         ret = btrfs_qgroup_account_extent(trans, fs_info,
1768                                         record->bytenr, record->num_bytes,
1769                                         record->old_roots, new_roots);
1770                         record->old_roots = NULL;
1771                         new_roots = NULL;
1772                 }
1773 cleanup:
1774                 ulist_free(record->old_roots);
1775                 ulist_free(new_roots);
1776                 new_roots = NULL;
1777                 rb_erase(node, &delayed_refs->dirty_extent_root);
1778                 kfree(record);
1779
1780         }
1781         return ret;
1782 }
1783
1784 /*
1785  * called from commit_transaction. Writes all changed qgroups to disk.
1786  */
1787 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
1788                       struct btrfs_fs_info *fs_info)
1789 {
1790         struct btrfs_root *quota_root = fs_info->quota_root;
1791         int ret = 0;
1792         int start_rescan_worker = 0;
1793
1794         if (!quota_root)
1795                 goto out;
1796
1797         if (!fs_info->quota_enabled && fs_info->pending_quota_state)
1798                 start_rescan_worker = 1;
1799
1800         fs_info->quota_enabled = fs_info->pending_quota_state;
1801
1802         spin_lock(&fs_info->qgroup_lock);
1803         while (!list_empty(&fs_info->dirty_qgroups)) {
1804                 struct btrfs_qgroup *qgroup;
1805                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
1806                                           struct btrfs_qgroup, dirty);
1807                 list_del_init(&qgroup->dirty);
1808                 spin_unlock(&fs_info->qgroup_lock);
1809                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
1810                 if (ret)
1811                         fs_info->qgroup_flags |=
1812                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1813                 ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1814                 if (ret)
1815                         fs_info->qgroup_flags |=
1816                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1817                 spin_lock(&fs_info->qgroup_lock);
1818         }
1819         if (fs_info->quota_enabled)
1820                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
1821         else
1822                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1823         spin_unlock(&fs_info->qgroup_lock);
1824
1825         ret = update_qgroup_status_item(trans, fs_info, quota_root);
1826         if (ret)
1827                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1828
1829         if (!ret && start_rescan_worker) {
1830                 ret = qgroup_rescan_init(fs_info, 0, 1);
1831                 if (!ret) {
1832                         qgroup_rescan_zero_tracking(fs_info);
1833                         btrfs_queue_work(fs_info->qgroup_rescan_workers,
1834                                          &fs_info->qgroup_rescan_work);
1835                 }
1836                 ret = 0;
1837         }
1838
1839 out:
1840
1841         return ret;
1842 }
1843
1844 /*
1845  * copy the acounting information between qgroups. This is necessary when a
1846  * snapshot or a subvolume is created
1847  */
1848 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
1849                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
1850                          struct btrfs_qgroup_inherit *inherit)
1851 {
1852         int ret = 0;
1853         int i;
1854         u64 *i_qgroups;
1855         struct btrfs_root *quota_root = fs_info->quota_root;
1856         struct btrfs_qgroup *srcgroup;
1857         struct btrfs_qgroup *dstgroup;
1858         u32 level_size = 0;
1859         u64 nums;
1860
1861         mutex_lock(&fs_info->qgroup_ioctl_lock);
1862         if (!fs_info->quota_enabled)
1863                 goto out;
1864
1865         if (!quota_root) {
1866                 ret = -EINVAL;
1867                 goto out;
1868         }
1869
1870         if (inherit) {
1871                 i_qgroups = (u64 *)(inherit + 1);
1872                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
1873                        2 * inherit->num_excl_copies;
1874                 for (i = 0; i < nums; ++i) {
1875                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
1876                         if (!srcgroup) {
1877                                 ret = -EINVAL;
1878                                 goto out;
1879                         }
1880
1881                         if ((srcgroup->qgroupid >> 48) <= (objectid >> 48)) {
1882                                 ret = -EINVAL;
1883                                 goto out;
1884                         }
1885                         ++i_qgroups;
1886                 }
1887         }
1888
1889         /*
1890          * create a tracking group for the subvol itself
1891          */
1892         ret = add_qgroup_item(trans, quota_root, objectid);
1893         if (ret)
1894                 goto out;
1895
1896         if (srcid) {
1897                 struct btrfs_root *srcroot;
1898                 struct btrfs_key srckey;
1899
1900                 srckey.objectid = srcid;
1901                 srckey.type = BTRFS_ROOT_ITEM_KEY;
1902                 srckey.offset = (u64)-1;
1903                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
1904                 if (IS_ERR(srcroot)) {
1905                         ret = PTR_ERR(srcroot);
1906                         goto out;
1907                 }
1908
1909                 rcu_read_lock();
1910                 level_size = srcroot->nodesize;
1911                 rcu_read_unlock();
1912         }
1913
1914         /*
1915          * add qgroup to all inherited groups
1916          */
1917         if (inherit) {
1918                 i_qgroups = (u64 *)(inherit + 1);
1919                 for (i = 0; i < inherit->num_qgroups; ++i) {
1920                         ret = add_qgroup_relation_item(trans, quota_root,
1921                                                        objectid, *i_qgroups);
1922                         if (ret)
1923                                 goto out;
1924                         ret = add_qgroup_relation_item(trans, quota_root,
1925                                                        *i_qgroups, objectid);
1926                         if (ret)
1927                                 goto out;
1928                         ++i_qgroups;
1929                 }
1930         }
1931
1932
1933         spin_lock(&fs_info->qgroup_lock);
1934
1935         dstgroup = add_qgroup_rb(fs_info, objectid);
1936         if (IS_ERR(dstgroup)) {
1937                 ret = PTR_ERR(dstgroup);
1938                 goto unlock;
1939         }
1940
1941         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
1942                 dstgroup->lim_flags = inherit->lim.flags;
1943                 dstgroup->max_rfer = inherit->lim.max_rfer;
1944                 dstgroup->max_excl = inherit->lim.max_excl;
1945                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
1946                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
1947
1948                 ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
1949                 if (ret) {
1950                         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1951                         btrfs_info(fs_info, "unable to update quota limit for %llu",
1952                                dstgroup->qgroupid);
1953                         goto unlock;
1954                 }
1955         }
1956
1957         if (srcid) {
1958                 srcgroup = find_qgroup_rb(fs_info, srcid);
1959                 if (!srcgroup)
1960                         goto unlock;
1961
1962                 /*
1963                  * We call inherit after we clone the root in order to make sure
1964                  * our counts don't go crazy, so at this point the only
1965                  * difference between the two roots should be the root node.
1966                  */
1967                 dstgroup->rfer = srcgroup->rfer;
1968                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
1969                 dstgroup->excl = level_size;
1970                 dstgroup->excl_cmpr = level_size;
1971                 srcgroup->excl = level_size;
1972                 srcgroup->excl_cmpr = level_size;
1973
1974                 /* inherit the limit info */
1975                 dstgroup->lim_flags = srcgroup->lim_flags;
1976                 dstgroup->max_rfer = srcgroup->max_rfer;
1977                 dstgroup->max_excl = srcgroup->max_excl;
1978                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
1979                 dstgroup->rsv_excl = srcgroup->rsv_excl;
1980
1981                 qgroup_dirty(fs_info, dstgroup);
1982                 qgroup_dirty(fs_info, srcgroup);
1983         }
1984
1985         if (!inherit)
1986                 goto unlock;
1987
1988         i_qgroups = (u64 *)(inherit + 1);
1989         for (i = 0; i < inherit->num_qgroups; ++i) {
1990                 ret = add_relation_rb(quota_root->fs_info, objectid,
1991                                       *i_qgroups);
1992                 if (ret)
1993                         goto unlock;
1994                 ++i_qgroups;
1995         }
1996
1997         for (i = 0; i <  inherit->num_ref_copies; ++i) {
1998                 struct btrfs_qgroup *src;
1999                 struct btrfs_qgroup *dst;
2000
2001                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2002                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2003
2004                 if (!src || !dst) {
2005                         ret = -EINVAL;
2006                         goto unlock;
2007                 }
2008
2009                 dst->rfer = src->rfer - level_size;
2010                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
2011                 i_qgroups += 2;
2012         }
2013         for (i = 0; i <  inherit->num_excl_copies; ++i) {
2014                 struct btrfs_qgroup *src;
2015                 struct btrfs_qgroup *dst;
2016
2017                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2018                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2019
2020                 if (!src || !dst) {
2021                         ret = -EINVAL;
2022                         goto unlock;
2023                 }
2024
2025                 dst->excl = src->excl + level_size;
2026                 dst->excl_cmpr = src->excl_cmpr + level_size;
2027                 i_qgroups += 2;
2028         }
2029
2030 unlock:
2031         spin_unlock(&fs_info->qgroup_lock);
2032 out:
2033         mutex_unlock(&fs_info->qgroup_ioctl_lock);
2034         return ret;
2035 }
2036
2037 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
2038 {
2039         struct btrfs_root *quota_root;
2040         struct btrfs_qgroup *qgroup;
2041         struct btrfs_fs_info *fs_info = root->fs_info;
2042         u64 ref_root = root->root_key.objectid;
2043         int ret = 0;
2044         struct ulist_node *unode;
2045         struct ulist_iterator uiter;
2046
2047         if (!is_fstree(ref_root))
2048                 return 0;
2049
2050         if (num_bytes == 0)
2051                 return 0;
2052
2053         spin_lock(&fs_info->qgroup_lock);
2054         quota_root = fs_info->quota_root;
2055         if (!quota_root)
2056                 goto out;
2057
2058         qgroup = find_qgroup_rb(fs_info, ref_root);
2059         if (!qgroup)
2060                 goto out;
2061
2062         /*
2063          * in a first step, we check all affected qgroups if any limits would
2064          * be exceeded
2065          */
2066         ulist_reinit(fs_info->qgroup_ulist);
2067         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2068                         (uintptr_t)qgroup, GFP_ATOMIC);
2069         if (ret < 0)
2070                 goto out;
2071         ULIST_ITER_INIT(&uiter);
2072         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2073                 struct btrfs_qgroup *qg;
2074                 struct btrfs_qgroup_list *glist;
2075
2076                 qg = u64_to_ptr(unode->aux);
2077
2078                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2079                     qg->reserved + (s64)qg->rfer + num_bytes >
2080                     qg->max_rfer) {
2081                         ret = -EDQUOT;
2082                         goto out;
2083                 }
2084
2085                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2086                     qg->reserved + (s64)qg->excl + num_bytes >
2087                     qg->max_excl) {
2088                         ret = -EDQUOT;
2089                         goto out;
2090                 }
2091
2092                 list_for_each_entry(glist, &qg->groups, next_group) {
2093                         ret = ulist_add(fs_info->qgroup_ulist,
2094                                         glist->group->qgroupid,
2095                                         (uintptr_t)glist->group, GFP_ATOMIC);
2096                         if (ret < 0)
2097                                 goto out;
2098                 }
2099         }
2100         ret = 0;
2101         /*
2102          * no limits exceeded, now record the reservation into all qgroups
2103          */
2104         ULIST_ITER_INIT(&uiter);
2105         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2106                 struct btrfs_qgroup *qg;
2107
2108                 qg = u64_to_ptr(unode->aux);
2109
2110                 qg->reserved += num_bytes;
2111         }
2112
2113 out:
2114         spin_unlock(&fs_info->qgroup_lock);
2115         return ret;
2116 }
2117
2118 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2119                                u64 ref_root, u64 num_bytes)
2120 {
2121         struct btrfs_root *quota_root;
2122         struct btrfs_qgroup *qgroup;
2123         struct ulist_node *unode;
2124         struct ulist_iterator uiter;
2125         int ret = 0;
2126
2127         if (!is_fstree(ref_root))
2128                 return;
2129
2130         if (num_bytes == 0)
2131                 return;
2132
2133         spin_lock(&fs_info->qgroup_lock);
2134
2135         quota_root = fs_info->quota_root;
2136         if (!quota_root)
2137                 goto out;
2138
2139         qgroup = find_qgroup_rb(fs_info, ref_root);
2140         if (!qgroup)
2141                 goto out;
2142
2143         ulist_reinit(fs_info->qgroup_ulist);
2144         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2145                         (uintptr_t)qgroup, GFP_ATOMIC);
2146         if (ret < 0)
2147                 goto out;
2148         ULIST_ITER_INIT(&uiter);
2149         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2150                 struct btrfs_qgroup *qg;
2151                 struct btrfs_qgroup_list *glist;
2152
2153                 qg = u64_to_ptr(unode->aux);
2154
2155                 qg->reserved -= num_bytes;
2156
2157                 list_for_each_entry(glist, &qg->groups, next_group) {
2158                         ret = ulist_add(fs_info->qgroup_ulist,
2159                                         glist->group->qgroupid,
2160                                         (uintptr_t)glist->group, GFP_ATOMIC);
2161                         if (ret < 0)
2162                                 goto out;
2163                 }
2164         }
2165
2166 out:
2167         spin_unlock(&fs_info->qgroup_lock);
2168 }
2169
2170 static inline void qgroup_free(struct btrfs_root *root, u64 num_bytes)
2171 {
2172         return btrfs_qgroup_free_refroot(root->fs_info, root->objectid,
2173                                          num_bytes);
2174 }
2175 void assert_qgroups_uptodate(struct btrfs_trans_handle *trans)
2176 {
2177         if (list_empty(&trans->qgroup_ref_list) && !trans->delayed_ref_elem.seq)
2178                 return;
2179         btrfs_err(trans->root->fs_info,
2180                 "qgroups not uptodate in trans handle %p:  list is%s empty, "
2181                 "seq is %#x.%x",
2182                 trans, list_empty(&trans->qgroup_ref_list) ? "" : " not",
2183                 (u32)(trans->delayed_ref_elem.seq >> 32),
2184                 (u32)trans->delayed_ref_elem.seq);
2185         BUG();
2186 }
2187
2188 /*
2189  * returns < 0 on error, 0 when more leafs are to be scanned.
2190  * returns 1 when done.
2191  */
2192 static int
2193 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
2194                    struct btrfs_trans_handle *trans)
2195 {
2196         struct btrfs_key found;
2197         struct extent_buffer *scratch_leaf = NULL;
2198         struct ulist *roots = NULL;
2199         struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
2200         u64 num_bytes;
2201         int slot;
2202         int ret;
2203
2204         mutex_lock(&fs_info->qgroup_rescan_lock);
2205         ret = btrfs_search_slot_for_read(fs_info->extent_root,
2206                                          &fs_info->qgroup_rescan_progress,
2207                                          path, 1, 0);
2208
2209         pr_debug("current progress key (%llu %u %llu), search_slot ret %d\n",
2210                  fs_info->qgroup_rescan_progress.objectid,
2211                  fs_info->qgroup_rescan_progress.type,
2212                  fs_info->qgroup_rescan_progress.offset, ret);
2213
2214         if (ret) {
2215                 /*
2216                  * The rescan is about to end, we will not be scanning any
2217                  * further blocks. We cannot unset the RESCAN flag here, because
2218                  * we want to commit the transaction if everything went well.
2219                  * To make the live accounting work in this phase, we set our
2220                  * scan progress pointer such that every real extent objectid
2221                  * will be smaller.
2222                  */
2223                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
2224                 btrfs_release_path(path);
2225                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2226                 return ret;
2227         }
2228
2229         btrfs_item_key_to_cpu(path->nodes[0], &found,
2230                               btrfs_header_nritems(path->nodes[0]) - 1);
2231         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
2232
2233         btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2234         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
2235         if (!scratch_leaf) {
2236                 ret = -ENOMEM;
2237                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2238                 goto out;
2239         }
2240         extent_buffer_get(scratch_leaf);
2241         btrfs_tree_read_lock(scratch_leaf);
2242         btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
2243         slot = path->slots[0];
2244         btrfs_release_path(path);
2245         mutex_unlock(&fs_info->qgroup_rescan_lock);
2246
2247         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
2248                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
2249                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
2250                     found.type != BTRFS_METADATA_ITEM_KEY)
2251                         continue;
2252                 if (found.type == BTRFS_METADATA_ITEM_KEY)
2253                         num_bytes = fs_info->extent_root->nodesize;
2254                 else
2255                         num_bytes = found.offset;
2256
2257                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
2258                                            &roots);
2259                 if (ret < 0)
2260                         goto out;
2261                 /* For rescan, just pass old_roots as NULL */
2262                 ret = btrfs_qgroup_account_extent(trans, fs_info,
2263                                 found.objectid, num_bytes, NULL, roots);
2264                 if (ret < 0)
2265                         goto out;
2266         }
2267 out:
2268         if (scratch_leaf) {
2269                 btrfs_tree_read_unlock_blocking(scratch_leaf);
2270                 free_extent_buffer(scratch_leaf);
2271         }
2272         btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2273
2274         return ret;
2275 }
2276
2277 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
2278 {
2279         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
2280                                                      qgroup_rescan_work);
2281         struct btrfs_path *path;
2282         struct btrfs_trans_handle *trans = NULL;
2283         int err = -ENOMEM;
2284         int ret = 0;
2285
2286         path = btrfs_alloc_path();
2287         if (!path)
2288                 goto out;
2289
2290         err = 0;
2291         while (!err && !btrfs_fs_closing(fs_info)) {
2292                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
2293                 if (IS_ERR(trans)) {
2294                         err = PTR_ERR(trans);
2295                         break;
2296                 }
2297                 if (!fs_info->quota_enabled) {
2298                         err = -EINTR;
2299                 } else {
2300                         err = qgroup_rescan_leaf(fs_info, path, trans);
2301                 }
2302                 if (err > 0)
2303                         btrfs_commit_transaction(trans, fs_info->fs_root);
2304                 else
2305                         btrfs_end_transaction(trans, fs_info->fs_root);
2306         }
2307
2308 out:
2309         btrfs_free_path(path);
2310
2311         mutex_lock(&fs_info->qgroup_rescan_lock);
2312         if (!btrfs_fs_closing(fs_info))
2313                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2314
2315         if (err > 0 &&
2316             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
2317                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2318         } else if (err < 0) {
2319                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2320         }
2321         mutex_unlock(&fs_info->qgroup_rescan_lock);
2322
2323         /*
2324          * only update status, since the previous part has alreay updated the
2325          * qgroup info.
2326          */
2327         trans = btrfs_start_transaction(fs_info->quota_root, 1);
2328         if (IS_ERR(trans)) {
2329                 err = PTR_ERR(trans);
2330                 btrfs_err(fs_info,
2331                           "fail to start transaction for status update: %d\n",
2332                           err);
2333                 goto done;
2334         }
2335         ret = update_qgroup_status_item(trans, fs_info, fs_info->quota_root);
2336         if (ret < 0) {
2337                 err = ret;
2338                 btrfs_err(fs_info, "fail to update qgroup status: %d\n", err);
2339         }
2340         btrfs_end_transaction(trans, fs_info->quota_root);
2341
2342         if (btrfs_fs_closing(fs_info)) {
2343                 btrfs_info(fs_info, "qgroup scan paused");
2344         } else if (err >= 0) {
2345                 btrfs_info(fs_info, "qgroup scan completed%s",
2346                         err > 0 ? " (inconsistency flag cleared)" : "");
2347         } else {
2348                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
2349         }
2350
2351 done:
2352         mutex_lock(&fs_info->qgroup_rescan_lock);
2353         fs_info->qgroup_rescan_running = false;
2354         mutex_unlock(&fs_info->qgroup_rescan_lock);
2355         complete_all(&fs_info->qgroup_rescan_completion);
2356 }
2357
2358 /*
2359  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
2360  * memory required for the rescan context.
2361  */
2362 static int
2363 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
2364                    int init_flags)
2365 {
2366         int ret = 0;
2367
2368         if (!init_flags &&
2369             (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
2370              !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
2371                 ret = -EINVAL;
2372                 goto err;
2373         }
2374
2375         mutex_lock(&fs_info->qgroup_rescan_lock);
2376         spin_lock(&fs_info->qgroup_lock);
2377
2378         if (init_flags) {
2379                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2380                         ret = -EINPROGRESS;
2381                 else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
2382                         ret = -EINVAL;
2383
2384                 if (ret) {
2385                         spin_unlock(&fs_info->qgroup_lock);
2386                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2387                         goto err;
2388                 }
2389                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2390         }
2391
2392         memset(&fs_info->qgroup_rescan_progress, 0,
2393                 sizeof(fs_info->qgroup_rescan_progress));
2394         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
2395         init_completion(&fs_info->qgroup_rescan_completion);
2396         fs_info->qgroup_rescan_running = true;
2397
2398         spin_unlock(&fs_info->qgroup_lock);
2399         mutex_unlock(&fs_info->qgroup_rescan_lock);
2400
2401         memset(&fs_info->qgroup_rescan_work, 0,
2402                sizeof(fs_info->qgroup_rescan_work));
2403         btrfs_init_work(&fs_info->qgroup_rescan_work,
2404                         btrfs_qgroup_rescan_helper,
2405                         btrfs_qgroup_rescan_worker, NULL, NULL);
2406
2407         if (ret) {
2408 err:
2409                 btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
2410                 return ret;
2411         }
2412
2413         return 0;
2414 }
2415
2416 static void
2417 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
2418 {
2419         struct rb_node *n;
2420         struct btrfs_qgroup *qgroup;
2421
2422         spin_lock(&fs_info->qgroup_lock);
2423         /* clear all current qgroup tracking information */
2424         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
2425                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
2426                 qgroup->rfer = 0;
2427                 qgroup->rfer_cmpr = 0;
2428                 qgroup->excl = 0;
2429                 qgroup->excl_cmpr = 0;
2430         }
2431         spin_unlock(&fs_info->qgroup_lock);
2432 }
2433
2434 int
2435 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
2436 {
2437         int ret = 0;
2438         struct btrfs_trans_handle *trans;
2439
2440         ret = qgroup_rescan_init(fs_info, 0, 1);
2441         if (ret)
2442                 return ret;
2443
2444         /*
2445          * We have set the rescan_progress to 0, which means no more
2446          * delayed refs will be accounted by btrfs_qgroup_account_ref.
2447          * However, btrfs_qgroup_account_ref may be right after its call
2448          * to btrfs_find_all_roots, in which case it would still do the
2449          * accounting.
2450          * To solve this, we're committing the transaction, which will
2451          * ensure we run all delayed refs and only after that, we are
2452          * going to clear all tracking information for a clean start.
2453          */
2454
2455         trans = btrfs_join_transaction(fs_info->fs_root);
2456         if (IS_ERR(trans)) {
2457                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2458                 return PTR_ERR(trans);
2459         }
2460         ret = btrfs_commit_transaction(trans, fs_info->fs_root);
2461         if (ret) {
2462                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2463                 return ret;
2464         }
2465
2466         qgroup_rescan_zero_tracking(fs_info);
2467
2468         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2469                          &fs_info->qgroup_rescan_work);
2470
2471         return 0;
2472 }
2473
2474 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
2475                                      bool interruptible)
2476 {
2477         int running;
2478         int ret = 0;
2479
2480         mutex_lock(&fs_info->qgroup_rescan_lock);
2481         spin_lock(&fs_info->qgroup_lock);
2482         running = fs_info->qgroup_rescan_running;
2483         spin_unlock(&fs_info->qgroup_lock);
2484         mutex_unlock(&fs_info->qgroup_rescan_lock);
2485
2486         if (!running)
2487                 return 0;
2488
2489         if (interruptible)
2490                 ret = wait_for_completion_interruptible(
2491                                         &fs_info->qgroup_rescan_completion);
2492         else
2493                 wait_for_completion(&fs_info->qgroup_rescan_completion);
2494
2495         return ret;
2496 }
2497
2498 /*
2499  * this is only called from open_ctree where we're still single threaded, thus
2500  * locking is omitted here.
2501  */
2502 void
2503 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
2504 {
2505         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2506                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
2507                                  &fs_info->qgroup_rescan_work);
2508 }
2509
2510 /*
2511  * Reserve qgroup space for range [start, start + len).
2512  *
2513  * This function will either reserve space from related qgroups or doing
2514  * nothing if the range is already reserved.
2515  *
2516  * Return 0 for successful reserve
2517  * Return <0 for error (including -EQUOT)
2518  *
2519  * NOTE: this function may sleep for memory allocation.
2520  */
2521 int btrfs_qgroup_reserve_data(struct inode *inode, u64 start, u64 len)
2522 {
2523         struct btrfs_root *root = BTRFS_I(inode)->root;
2524         struct extent_changeset changeset;
2525         struct ulist_node *unode;
2526         struct ulist_iterator uiter;
2527         int ret;
2528
2529         if (!root->fs_info->quota_enabled || !is_fstree(root->objectid) ||
2530             len == 0)
2531                 return 0;
2532
2533         changeset.bytes_changed = 0;
2534         changeset.range_changed = ulist_alloc(GFP_NOFS);
2535         ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2536                         start + len -1, EXTENT_QGROUP_RESERVED, GFP_NOFS,
2537                         &changeset);
2538         trace_btrfs_qgroup_reserve_data(inode, start, len,
2539                                         changeset.bytes_changed,
2540                                         QGROUP_RESERVE);
2541         if (ret < 0)
2542                 goto cleanup;
2543         ret = qgroup_reserve(root, changeset.bytes_changed);
2544         if (ret < 0)
2545                 goto cleanup;
2546
2547         ulist_free(changeset.range_changed);
2548         return ret;
2549
2550 cleanup:
2551         /* cleanup already reserved ranges */
2552         ULIST_ITER_INIT(&uiter);
2553         while ((unode = ulist_next(changeset.range_changed, &uiter)))
2554                 clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
2555                                  unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL,
2556                                  GFP_NOFS);
2557         ulist_free(changeset.range_changed);
2558         return ret;
2559 }
2560
2561 static int __btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len,
2562                                        int free)
2563 {
2564         struct extent_changeset changeset;
2565         int trace_op = QGROUP_RELEASE;
2566         int ret;
2567
2568         changeset.bytes_changed = 0;
2569         changeset.range_changed = ulist_alloc(GFP_NOFS);
2570         if (!changeset.range_changed)
2571                 return -ENOMEM;
2572
2573         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2574                         start + len -1, EXTENT_QGROUP_RESERVED, GFP_NOFS,
2575                         &changeset);
2576         if (ret < 0)
2577                 goto out;
2578
2579         if (free) {
2580                 qgroup_free(BTRFS_I(inode)->root, changeset.bytes_changed);
2581                 trace_op = QGROUP_FREE;
2582         }
2583         trace_btrfs_qgroup_release_data(inode, start, len,
2584                                         changeset.bytes_changed, trace_op);
2585 out:
2586         ulist_free(changeset.range_changed);
2587         return ret;
2588 }
2589
2590 /*
2591  * Free a reserved space range from io_tree and related qgroups
2592  *
2593  * Should be called when a range of pages get invalidated before reaching disk.
2594  * Or for error cleanup case.
2595  *
2596  * For data written to disk, use btrfs_qgroup_release_data().
2597  *
2598  * NOTE: This function may sleep for memory allocation.
2599  */
2600 int btrfs_qgroup_free_data(struct inode *inode, u64 start, u64 len)
2601 {
2602         return __btrfs_qgroup_release_data(inode, start, len, 1);
2603 }
2604
2605 /*
2606  * Release a reserved space range from io_tree only.
2607  *
2608  * Should be called when a range of pages get written to disk and corresponding
2609  * FILE_EXTENT is inserted into corresponding root.
2610  *
2611  * Since new qgroup accounting framework will only update qgroup numbers at
2612  * commit_transaction() time, its reserved space shouldn't be freed from
2613  * related qgroups.
2614  *
2615  * But we should release the range from io_tree, to allow further write to be
2616  * COWed.
2617  *
2618  * NOTE: This function may sleep for memory allocation.
2619  */
2620 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
2621 {
2622         return __btrfs_qgroup_release_data(inode, start, len, 0);
2623 }
2624
2625 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes)
2626 {
2627         int ret;
2628
2629         if (!root->fs_info->quota_enabled || !is_fstree(root->objectid) ||
2630             num_bytes == 0)
2631                 return 0;
2632
2633         BUG_ON(num_bytes != round_down(num_bytes, root->nodesize));
2634         ret = qgroup_reserve(root, num_bytes);
2635         if (ret < 0)
2636                 return ret;
2637         atomic_add(num_bytes, &root->qgroup_meta_rsv);
2638         return ret;
2639 }
2640
2641 void btrfs_qgroup_free_meta_all(struct btrfs_root *root)
2642 {
2643         int reserved;
2644
2645         if (!root->fs_info->quota_enabled || !is_fstree(root->objectid))
2646                 return;
2647
2648         reserved = atomic_xchg(&root->qgroup_meta_rsv, 0);
2649         if (reserved == 0)
2650                 return;
2651         qgroup_free(root, reserved);
2652 }
2653
2654 void btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes)
2655 {
2656         if (!root->fs_info->quota_enabled || !is_fstree(root->objectid))
2657                 return;
2658
2659         BUG_ON(num_bytes != round_down(num_bytes, root->nodesize));
2660         WARN_ON(atomic_read(&root->qgroup_meta_rsv) < num_bytes);
2661         atomic_sub(num_bytes, &root->qgroup_meta_rsv);
2662         qgroup_free(root, num_bytes);
2663 }
2664
2665 /*
2666  * Check qgroup reserved space leaking, normally at destory inode
2667  * time
2668  */
2669 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
2670 {
2671         struct extent_changeset changeset;
2672         struct ulist_node *unode;
2673         struct ulist_iterator iter;
2674         int ret;
2675
2676         changeset.bytes_changed = 0;
2677         changeset.range_changed = ulist_alloc(GFP_NOFS);
2678         if (WARN_ON(!changeset.range_changed))
2679                 return;
2680
2681         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
2682                         EXTENT_QGROUP_RESERVED, GFP_NOFS, &changeset);
2683
2684         WARN_ON(ret < 0);
2685         if (WARN_ON(changeset.bytes_changed)) {
2686                 ULIST_ITER_INIT(&iter);
2687                 while ((unode = ulist_next(changeset.range_changed, &iter))) {
2688                         btrfs_warn(BTRFS_I(inode)->root->fs_info,
2689                                 "leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
2690                                 inode->i_ino, unode->val, unode->aux);
2691                 }
2692                 qgroup_free(BTRFS_I(inode)->root, changeset.bytes_changed);
2693         }
2694         ulist_free(changeset.range_changed);
2695 }