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, "inconsitent 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         spin_lock(&fs_info->qgroup_lock);
 997         fs_info->quota_enabled = 0;
 998         fs_info->pending_quota_state = 0;
 999         quota_root = fs_info->quota_root;
1000         fs_info->quota_root = NULL;
1001         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1002         spin_unlock(&fs_info->qgroup_lock);
1003
1004         btrfs_free_qgroup_config(fs_info);
1005
1006         ret = btrfs_clean_quota_tree(trans, quota_root);
1007         if (ret)
1008                 goto out;
1009
1010         ret = btrfs_del_root(trans, tree_root, &quota_root->root_key);
1011         if (ret)
1012                 goto out;
1013
1014         list_del(&quota_root->dirty_list);
1015
1016         btrfs_tree_lock(quota_root->node);
1017         clean_tree_block(trans, tree_root->fs_info, quota_root->node);
1018         btrfs_tree_unlock(quota_root->node);
1019         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
1020
1021         free_extent_buffer(quota_root->node);
1022         free_extent_buffer(quota_root->commit_root);
1023         kfree(quota_root);
1024 out:
1025         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1026         return ret;
1027 }
1028
1029 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1030                          struct btrfs_qgroup *qgroup)
1031 {
1032         if (list_empty(&qgroup->dirty))
1033                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1034 }
1035
1036 /*
1037  * The easy accounting, if we are adding/removing the only ref for an extent
1038  * then this qgroup and all of the parent qgroups get their refrence and
1039  * exclusive counts adjusted.
1040  *
1041  * Caller should hold fs_info->qgroup_lock.
1042  */
1043 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1044                                     struct ulist *tmp, u64 ref_root,
1045                                     u64 num_bytes, int sign)
1046 {
1047         struct btrfs_qgroup *qgroup;
1048         struct btrfs_qgroup_list *glist;
1049         struct ulist_node *unode;
1050         struct ulist_iterator uiter;
1051         int ret = 0;
1052
1053         qgroup = find_qgroup_rb(fs_info, ref_root);
1054         if (!qgroup)
1055                 goto out;
1056
1057         qgroup->rfer += sign * num_bytes;
1058         qgroup->rfer_cmpr += sign * num_bytes;
1059
1060         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1061         qgroup->excl += sign * num_bytes;
1062         qgroup->excl_cmpr += sign * num_bytes;
1063         if (sign > 0)
1064                 qgroup->reserved -= num_bytes;
1065
1066         qgroup_dirty(fs_info, qgroup);
1067
1068         /* Get all of the parent groups that contain this qgroup */
1069         list_for_each_entry(glist, &qgroup->groups, next_group) {
1070                 ret = ulist_add(tmp, glist->group->qgroupid,
1071                                 ptr_to_u64(glist->group), GFP_ATOMIC);
1072                 if (ret < 0)
1073                         goto out;
1074         }
1075
1076         /* Iterate all of the parents and adjust their reference counts */
1077         ULIST_ITER_INIT(&uiter);
1078         while ((unode = ulist_next(tmp, &uiter))) {
1079                 qgroup = u64_to_ptr(unode->aux);
1080                 qgroup->rfer += sign * num_bytes;
1081                 qgroup->rfer_cmpr += sign * num_bytes;
1082                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1083                 qgroup->excl += sign * num_bytes;
1084                 if (sign > 0)
1085                         qgroup->reserved -= num_bytes;
1086                 qgroup->excl_cmpr += sign * num_bytes;
1087                 qgroup_dirty(fs_info, qgroup);
1088
1089                 /* Add any parents of the parents */
1090                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1091                         ret = ulist_add(tmp, glist->group->qgroupid,
1092                                         ptr_to_u64(glist->group), GFP_ATOMIC);
1093                         if (ret < 0)
1094                                 goto out;
1095                 }
1096         }
1097         ret = 0;
1098 out:
1099         return ret;
1100 }
1101
1102
1103 /*
1104  * Quick path for updating qgroup with only excl refs.
1105  *
1106  * In that case, just update all parent will be enough.
1107  * Or we needs to do a full rescan.
1108  * Caller should also hold fs_info->qgroup_lock.
1109  *
1110  * Return 0 for quick update, return >0 for need to full rescan
1111  * and mark INCONSISTENT flag.
1112  * Return < 0 for other error.
1113  */
1114 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1115                                    struct ulist *tmp, u64 src, u64 dst,
1116                                    int sign)
1117 {
1118         struct btrfs_qgroup *qgroup;
1119         int ret = 1;
1120         int err = 0;
1121
1122         qgroup = find_qgroup_rb(fs_info, src);
1123         if (!qgroup)
1124                 goto out;
1125         if (qgroup->excl == qgroup->rfer) {
1126                 ret = 0;
1127                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1128                                                qgroup->excl, sign);
1129                 if (err < 0) {
1130                         ret = err;
1131                         goto out;
1132                 }
1133         }
1134 out:
1135         if (ret)
1136                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1137         return ret;
1138 }
1139
1140 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
1141                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1142 {
1143         struct btrfs_root *quota_root;
1144         struct btrfs_qgroup *parent;
1145         struct btrfs_qgroup *member;
1146         struct btrfs_qgroup_list *list;
1147         struct ulist *tmp;
1148         int ret = 0;
1149
1150         /* Check the level of src and dst first */
1151         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1152                 return -EINVAL;
1153
1154         tmp = ulist_alloc(GFP_NOFS);
1155         if (!tmp)
1156                 return -ENOMEM;
1157
1158         mutex_lock(&fs_info->qgroup_ioctl_lock);
1159         quota_root = fs_info->quota_root;
1160         if (!quota_root) {
1161                 ret = -EINVAL;
1162                 goto out;
1163         }
1164         member = find_qgroup_rb(fs_info, src);
1165         parent = find_qgroup_rb(fs_info, dst);
1166         if (!member || !parent) {
1167                 ret = -EINVAL;
1168                 goto out;
1169         }
1170
1171         /* check if such qgroup relation exist firstly */
1172         list_for_each_entry(list, &member->groups, next_group) {
1173                 if (list->group == parent) {
1174                         ret = -EEXIST;
1175                         goto out;
1176                 }
1177         }
1178
1179         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
1180         if (ret)
1181                 goto out;
1182
1183         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
1184         if (ret) {
1185                 del_qgroup_relation_item(trans, quota_root, src, dst);
1186                 goto out;
1187         }
1188
1189         spin_lock(&fs_info->qgroup_lock);
1190         ret = add_relation_rb(quota_root->fs_info, src, dst);
1191         if (ret < 0) {
1192                 spin_unlock(&fs_info->qgroup_lock);
1193                 goto out;
1194         }
1195         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1196         spin_unlock(&fs_info->qgroup_lock);
1197 out:
1198         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1199         ulist_free(tmp);
1200         return ret;
1201 }
1202
1203 int __del_qgroup_relation(struct btrfs_trans_handle *trans,
1204                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1205 {
1206         struct btrfs_root *quota_root;
1207         struct btrfs_qgroup *parent;
1208         struct btrfs_qgroup *member;
1209         struct btrfs_qgroup_list *list;
1210         struct ulist *tmp;
1211         int ret = 0;
1212         int err;
1213
1214         tmp = ulist_alloc(GFP_NOFS);
1215         if (!tmp)
1216                 return -ENOMEM;
1217
1218         quota_root = fs_info->quota_root;
1219         if (!quota_root) {
1220                 ret = -EINVAL;
1221                 goto out;
1222         }
1223
1224         member = find_qgroup_rb(fs_info, src);
1225         parent = find_qgroup_rb(fs_info, dst);
1226         if (!member || !parent) {
1227                 ret = -EINVAL;
1228                 goto out;
1229         }
1230
1231         /* check if such qgroup relation exist firstly */
1232         list_for_each_entry(list, &member->groups, next_group) {
1233                 if (list->group == parent)
1234                         goto exist;
1235         }
1236         ret = -ENOENT;
1237         goto out;
1238 exist:
1239         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
1240         err = del_qgroup_relation_item(trans, quota_root, dst, src);
1241         if (err && !ret)
1242                 ret = err;
1243
1244         spin_lock(&fs_info->qgroup_lock);
1245         del_relation_rb(fs_info, src, dst);
1246         ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1247         spin_unlock(&fs_info->qgroup_lock);
1248 out:
1249         ulist_free(tmp);
1250         return ret;
1251 }
1252
1253 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
1254                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1255 {
1256         int ret = 0;
1257
1258         mutex_lock(&fs_info->qgroup_ioctl_lock);
1259         ret = __del_qgroup_relation(trans, fs_info, src, dst);
1260         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1261
1262         return ret;
1263 }
1264
1265 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
1266                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1267 {
1268         struct btrfs_root *quota_root;
1269         struct btrfs_qgroup *qgroup;
1270         int ret = 0;
1271
1272         mutex_lock(&fs_info->qgroup_ioctl_lock);
1273         quota_root = fs_info->quota_root;
1274         if (!quota_root) {
1275                 ret = -EINVAL;
1276                 goto out;
1277         }
1278         qgroup = find_qgroup_rb(fs_info, qgroupid);
1279         if (qgroup) {
1280                 ret = -EEXIST;
1281                 goto out;
1282         }
1283
1284         ret = add_qgroup_item(trans, quota_root, qgroupid);
1285         if (ret)
1286                 goto out;
1287
1288         spin_lock(&fs_info->qgroup_lock);
1289         qgroup = add_qgroup_rb(fs_info, qgroupid);
1290         spin_unlock(&fs_info->qgroup_lock);
1291
1292         if (IS_ERR(qgroup))
1293                 ret = PTR_ERR(qgroup);
1294 out:
1295         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1296         return ret;
1297 }
1298
1299 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
1300                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1301 {
1302         struct btrfs_root *quota_root;
1303         struct btrfs_qgroup *qgroup;
1304         struct btrfs_qgroup_list *list;
1305         int ret = 0;
1306
1307         mutex_lock(&fs_info->qgroup_ioctl_lock);
1308         quota_root = fs_info->quota_root;
1309         if (!quota_root) {
1310                 ret = -EINVAL;
1311                 goto out;
1312         }
1313
1314         qgroup = find_qgroup_rb(fs_info, qgroupid);
1315         if (!qgroup) {
1316                 ret = -ENOENT;
1317                 goto out;
1318         } else {
1319                 /* check if there are no children of this qgroup */
1320                 if (!list_empty(&qgroup->members)) {
1321                         ret = -EBUSY;
1322                         goto out;
1323                 }
1324         }
1325         ret = del_qgroup_item(trans, quota_root, qgroupid);
1326
1327         while (!list_empty(&qgroup->groups)) {
1328                 list = list_first_entry(&qgroup->groups,
1329                                         struct btrfs_qgroup_list, next_group);
1330                 ret = __del_qgroup_relation(trans, fs_info,
1331                                            qgroupid,
1332                                            list->group->qgroupid);
1333                 if (ret)
1334                         goto out;
1335         }
1336
1337         spin_lock(&fs_info->qgroup_lock);
1338         del_qgroup_rb(quota_root->fs_info, qgroupid);
1339         spin_unlock(&fs_info->qgroup_lock);
1340 out:
1341         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1342         return ret;
1343 }
1344
1345 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
1346                        struct btrfs_fs_info *fs_info, u64 qgroupid,
1347                        struct btrfs_qgroup_limit *limit)
1348 {
1349         struct btrfs_root *quota_root;
1350         struct btrfs_qgroup *qgroup;
1351         int ret = 0;
1352         /* Sometimes we would want to clear the limit on this qgroup.
1353          * To meet this requirement, we treat the -1 as a special value
1354          * which tell kernel to clear the limit on this qgroup.
1355          */
1356         const u64 CLEAR_VALUE = -1;
1357
1358         mutex_lock(&fs_info->qgroup_ioctl_lock);
1359         quota_root = fs_info->quota_root;
1360         if (!quota_root) {
1361                 ret = -EINVAL;
1362                 goto out;
1363         }
1364
1365         qgroup = find_qgroup_rb(fs_info, qgroupid);
1366         if (!qgroup) {
1367                 ret = -ENOENT;
1368                 goto out;
1369         }
1370
1371         spin_lock(&fs_info->qgroup_lock);
1372         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1373                 if (limit->max_rfer == CLEAR_VALUE) {
1374                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1375                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1376                         qgroup->max_rfer = 0;
1377                 } else {
1378                         qgroup->max_rfer = limit->max_rfer;
1379                 }
1380         }
1381         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1382                 if (limit->max_excl == CLEAR_VALUE) {
1383                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1384                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1385                         qgroup->max_excl = 0;
1386                 } else {
1387                         qgroup->max_excl = limit->max_excl;
1388                 }
1389         }
1390         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1391                 if (limit->rsv_rfer == CLEAR_VALUE) {
1392                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1393                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1394                         qgroup->rsv_rfer = 0;
1395                 } else {
1396                         qgroup->rsv_rfer = limit->rsv_rfer;
1397                 }
1398         }
1399         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1400                 if (limit->rsv_excl == CLEAR_VALUE) {
1401                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1402                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1403                         qgroup->rsv_excl = 0;
1404                 } else {
1405                         qgroup->rsv_excl = limit->rsv_excl;
1406                 }
1407         }
1408         qgroup->lim_flags |= limit->flags;
1409
1410         spin_unlock(&fs_info->qgroup_lock);
1411
1412         ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1413         if (ret) {
1414                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1415                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1416                        qgroupid);
1417         }
1418
1419 out:
1420         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1421         return ret;
1422 }
1423
1424 int btrfs_qgroup_prepare_account_extents(struct btrfs_trans_handle *trans,
1425                                          struct btrfs_fs_info *fs_info)
1426 {
1427         struct btrfs_qgroup_extent_record *record;
1428         struct btrfs_delayed_ref_root *delayed_refs;
1429         struct rb_node *node;
1430         u64 qgroup_to_skip;
1431         int ret = 0;
1432
1433         delayed_refs = &trans->transaction->delayed_refs;
1434         qgroup_to_skip = delayed_refs->qgroup_to_skip;
1435
1436         /*
1437          * No need to do lock, since this function will only be called in
1438          * btrfs_commmit_transaction().
1439          */
1440         node = rb_first(&delayed_refs->dirty_extent_root);
1441         while (node) {
1442                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
1443                                   node);
1444                 ret = btrfs_find_all_roots(NULL, fs_info, record->bytenr, 0,
1445                                            &record->old_roots);
1446                 if (ret < 0)
1447                         break;
1448                 if (qgroup_to_skip)
1449                         ulist_del(record->old_roots, qgroup_to_skip, 0);
1450                 node = rb_next(node);
1451         }
1452         return ret;
1453 }
1454
1455 struct btrfs_qgroup_extent_record
1456 *btrfs_qgroup_insert_dirty_extent(struct btrfs_delayed_ref_root *delayed_refs,
1457                                   struct btrfs_qgroup_extent_record *record)
1458 {
1459         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1460         struct rb_node *parent_node = NULL;
1461         struct btrfs_qgroup_extent_record *entry;
1462         u64 bytenr = record->bytenr;
1463
1464         while (*p) {
1465                 parent_node = *p;
1466                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1467                                  node);
1468                 if (bytenr < entry->bytenr)
1469                         p = &(*p)->rb_left;
1470                 else if (bytenr > entry->bytenr)
1471                         p = &(*p)->rb_right;
1472                 else
1473                         return entry;
1474         }
1475
1476         rb_link_node(&record->node, parent_node, p);
1477         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1478         return NULL;
1479 }
1480
1481 #define UPDATE_NEW      0
1482 #define UPDATE_OLD      1
1483 /*
1484  * Walk all of the roots that points to the bytenr and adjust their refcnts.
1485  */
1486 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
1487                                 struct ulist *roots, struct ulist *tmp,
1488                                 struct ulist *qgroups, u64 seq, int update_old)
1489 {
1490         struct ulist_node *unode;
1491         struct ulist_iterator uiter;
1492         struct ulist_node *tmp_unode;
1493         struct ulist_iterator tmp_uiter;
1494         struct btrfs_qgroup *qg;
1495         int ret = 0;
1496
1497         if (!roots)
1498                 return 0;
1499         ULIST_ITER_INIT(&uiter);
1500         while ((unode = ulist_next(roots, &uiter))) {
1501                 qg = find_qgroup_rb(fs_info, unode->val);
1502                 if (!qg)
1503                         continue;
1504
1505                 ulist_reinit(tmp);
1506                 ret = ulist_add(qgroups, qg->qgroupid, ptr_to_u64(qg),
1507                                 GFP_ATOMIC);
1508                 if (ret < 0)
1509                         return ret;
1510                 ret = ulist_add(tmp, qg->qgroupid, ptr_to_u64(qg), GFP_ATOMIC);
1511                 if (ret < 0)
1512                         return ret;
1513                 ULIST_ITER_INIT(&tmp_uiter);
1514                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1515                         struct btrfs_qgroup_list *glist;
1516
1517                         qg = u64_to_ptr(tmp_unode->aux);
1518                         if (update_old)
1519                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
1520                         else
1521                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
1522                         list_for_each_entry(glist, &qg->groups, next_group) {
1523                                 ret = ulist_add(qgroups, glist->group->qgroupid,
1524                                                 ptr_to_u64(glist->group),
1525                                                 GFP_ATOMIC);
1526                                 if (ret < 0)
1527                                         return ret;
1528                                 ret = ulist_add(tmp, glist->group->qgroupid,
1529                                                 ptr_to_u64(glist->group),
1530                                                 GFP_ATOMIC);
1531                                 if (ret < 0)
1532                                         return ret;
1533                         }
1534                 }
1535         }
1536         return 0;
1537 }
1538
1539 /*
1540  * Update qgroup rfer/excl counters.
1541  * Rfer update is easy, codes can explain themselves.
1542  *
1543  * Excl update is tricky, the update is split into 2 part.
1544  * Part 1: Possible exclusive <-> sharing detect:
1545  *      |       A       |       !A      |
1546  *  -------------------------------------
1547  *  B   |       *       |       -       |
1548  *  -------------------------------------
1549  *  !B  |       +       |       **      |
1550  *  -------------------------------------
1551  *
1552  * Conditions:
1553  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
1554  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
1555  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
1556  * !B:  cur_new_roots == nr_new_roots   (possible exclsuive now)
1557  *
1558  * Results:
1559  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
1560  * *: Definitely not changed.           **: Possible unchanged.
1561  *
1562  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
1563  *
1564  * To make the logic clear, we first use condition A and B to split
1565  * combination into 4 results.
1566  *
1567  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
1568  * only on variant maybe 0.
1569  *
1570  * Lastly, check result **, since there are 2 variants maybe 0, split them
1571  * again(2x2).
1572  * But this time we don't need to consider other things, the codes and logic
1573  * is easy to understand now.
1574  */
1575 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
1576                                   struct ulist *qgroups,
1577                                   u64 nr_old_roots,
1578                                   u64 nr_new_roots,
1579                                   u64 num_bytes, u64 seq)
1580 {
1581         struct ulist_node *unode;
1582         struct ulist_iterator uiter;
1583         struct btrfs_qgroup *qg;
1584         u64 cur_new_count, cur_old_count;
1585
1586         ULIST_ITER_INIT(&uiter);
1587         while ((unode = ulist_next(qgroups, &uiter))) {
1588                 bool dirty = false;
1589
1590                 qg = u64_to_ptr(unode->aux);
1591                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
1592                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
1593
1594                 /* Rfer update part */
1595                 if (cur_old_count == 0 && cur_new_count > 0) {
1596                         qg->rfer += num_bytes;
1597                         qg->rfer_cmpr += num_bytes;
1598                         dirty = true;
1599                 }
1600                 if (cur_old_count > 0 && cur_new_count == 0) {
1601                         qg->rfer -= num_bytes;
1602                         qg->rfer_cmpr -= num_bytes;
1603                         dirty = true;
1604                 }
1605
1606                 /* Excl update part */
1607                 /* Exclusive/none -> shared case */
1608                 if (cur_old_count == nr_old_roots &&
1609                     cur_new_count < nr_new_roots) {
1610                         /* Exclusive -> shared */
1611                         if (cur_old_count != 0) {
1612                                 qg->excl -= num_bytes;
1613                                 qg->excl_cmpr -= num_bytes;
1614                                 dirty = true;
1615                         }
1616                 }
1617
1618                 /* Shared -> exclusive/none case */
1619                 if (cur_old_count < nr_old_roots &&
1620                     cur_new_count == nr_new_roots) {
1621                         /* Shared->exclusive */
1622                         if (cur_new_count != 0) {
1623                                 qg->excl += num_bytes;
1624                                 qg->excl_cmpr += num_bytes;
1625                                 dirty = true;
1626                         }
1627                 }
1628
1629                 /* Exclusive/none -> exclusive/none case */
1630                 if (cur_old_count == nr_old_roots &&
1631                     cur_new_count == nr_new_roots) {
1632                         if (cur_old_count == 0) {
1633                                 /* None -> exclusive/none */
1634
1635                                 if (cur_new_count != 0) {
1636                                         /* None -> exclusive */
1637                                         qg->excl += num_bytes;
1638                                         qg->excl_cmpr += num_bytes;
1639                                         dirty = true;
1640                                 }
1641                                 /* None -> none, nothing changed */
1642                         } else {
1643                                 /* Exclusive -> exclusive/none */
1644
1645                                 if (cur_new_count == 0) {
1646                                         /* Exclusive -> none */
1647                                         qg->excl -= num_bytes;
1648                                         qg->excl_cmpr -= num_bytes;
1649                                         dirty = true;
1650                                 }
1651                                 /* Exclusive -> exclusive, nothing changed */
1652                         }
1653                 }
1654                 if (dirty)
1655                         qgroup_dirty(fs_info, qg);
1656         }
1657         return 0;
1658 }
1659
1660 int
1661 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
1662                             struct btrfs_fs_info *fs_info,
1663                             u64 bytenr, u64 num_bytes,
1664                             struct ulist *old_roots, struct ulist *new_roots)
1665 {
1666         struct ulist *qgroups = NULL;
1667         struct ulist *tmp = NULL;
1668         u64 seq;
1669         u64 nr_new_roots = 0;
1670         u64 nr_old_roots = 0;
1671         int ret = 0;
1672
1673         if (new_roots)
1674                 nr_new_roots = new_roots->nnodes;
1675         if (old_roots)
1676                 nr_old_roots = old_roots->nnodes;
1677
1678         if (!fs_info->quota_enabled)
1679                 goto out_free;
1680         BUG_ON(!fs_info->quota_root);
1681
1682         qgroups = ulist_alloc(GFP_NOFS);
1683         if (!qgroups) {
1684                 ret = -ENOMEM;
1685                 goto out_free;
1686         }
1687         tmp = ulist_alloc(GFP_NOFS);
1688         if (!tmp) {
1689                 ret = -ENOMEM;
1690                 goto out_free;
1691         }
1692
1693         mutex_lock(&fs_info->qgroup_rescan_lock);
1694         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
1695                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
1696                         mutex_unlock(&fs_info->qgroup_rescan_lock);
1697                         ret = 0;
1698                         goto out_free;
1699                 }
1700         }
1701         mutex_unlock(&fs_info->qgroup_rescan_lock);
1702
1703         spin_lock(&fs_info->qgroup_lock);
1704         seq = fs_info->qgroup_seq;
1705
1706         /* Update old refcnts using old_roots */
1707         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
1708                                    UPDATE_OLD);
1709         if (ret < 0)
1710                 goto out;
1711
1712         /* Update new refcnts using new_roots */
1713         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
1714                                    UPDATE_NEW);
1715         if (ret < 0)
1716                 goto out;
1717
1718         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
1719                                num_bytes, seq);
1720
1721         /*
1722          * Bump qgroup_seq to avoid seq overlap
1723          */
1724         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
1725 out:
1726         spin_unlock(&fs_info->qgroup_lock);
1727 out_free:
1728         ulist_free(tmp);
1729         ulist_free(qgroups);
1730         ulist_free(old_roots);
1731         ulist_free(new_roots);
1732         return ret;
1733 }
1734
1735 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans,
1736                                  struct btrfs_fs_info *fs_info)
1737 {
1738         struct btrfs_qgroup_extent_record *record;
1739         struct btrfs_delayed_ref_root *delayed_refs;
1740         struct ulist *new_roots = NULL;
1741         struct rb_node *node;
1742         u64 qgroup_to_skip;
1743         int ret = 0;
1744
1745         delayed_refs = &trans->transaction->delayed_refs;
1746         qgroup_to_skip = delayed_refs->qgroup_to_skip;
1747         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
1748                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
1749                                   node);
1750
1751                 if (!ret) {
1752                         /*
1753                          * Use (u64)-1 as time_seq to do special search, which
1754                          * doesn't lock tree or delayed_refs and search current
1755                          * root. It's safe inside commit_transaction().
1756                          */
1757                         ret = btrfs_find_all_roots(trans, fs_info,
1758                                         record->bytenr, (u64)-1, &new_roots);
1759                         if (ret < 0)
1760                                 goto cleanup;
1761                         if (qgroup_to_skip)
1762                                 ulist_del(new_roots, qgroup_to_skip, 0);
1763                         ret = btrfs_qgroup_account_extent(trans, fs_info,
1764                                         record->bytenr, record->num_bytes,
1765                                         record->old_roots, new_roots);
1766                         record->old_roots = NULL;
1767                         new_roots = NULL;
1768                 }
1769 cleanup:
1770                 ulist_free(record->old_roots);
1771                 ulist_free(new_roots);
1772                 new_roots = NULL;
1773                 rb_erase(node, &delayed_refs->dirty_extent_root);
1774                 kfree(record);
1775
1776         }
1777         return ret;
1778 }
1779
1780 /*
1781  * called from commit_transaction. Writes all changed qgroups to disk.
1782  */
1783 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
1784                       struct btrfs_fs_info *fs_info)
1785 {
1786         struct btrfs_root *quota_root = fs_info->quota_root;
1787         int ret = 0;
1788         int start_rescan_worker = 0;
1789
1790         if (!quota_root)
1791                 goto out;
1792
1793         if (!fs_info->quota_enabled && fs_info->pending_quota_state)
1794                 start_rescan_worker = 1;
1795
1796         fs_info->quota_enabled = fs_info->pending_quota_state;
1797
1798         spin_lock(&fs_info->qgroup_lock);
1799         while (!list_empty(&fs_info->dirty_qgroups)) {
1800                 struct btrfs_qgroup *qgroup;
1801                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
1802                                           struct btrfs_qgroup, dirty);
1803                 list_del_init(&qgroup->dirty);
1804                 spin_unlock(&fs_info->qgroup_lock);
1805                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
1806                 if (ret)
1807                         fs_info->qgroup_flags |=
1808                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1809                 ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1810                 if (ret)
1811                         fs_info->qgroup_flags |=
1812                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1813                 spin_lock(&fs_info->qgroup_lock);
1814         }
1815         if (fs_info->quota_enabled)
1816                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
1817         else
1818                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1819         spin_unlock(&fs_info->qgroup_lock);
1820
1821         ret = update_qgroup_status_item(trans, fs_info, quota_root);
1822         if (ret)
1823                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1824
1825         if (!ret && start_rescan_worker) {
1826                 ret = qgroup_rescan_init(fs_info, 0, 1);
1827                 if (!ret) {
1828                         qgroup_rescan_zero_tracking(fs_info);
1829                         btrfs_queue_work(fs_info->qgroup_rescan_workers,
1830                                          &fs_info->qgroup_rescan_work);
1831                 }
1832                 ret = 0;
1833         }
1834
1835 out:
1836
1837         return ret;
1838 }
1839
1840 /*
1841  * copy the acounting information between qgroups. This is necessary when a
1842  * snapshot or a subvolume is created
1843  */
1844 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
1845                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
1846                          struct btrfs_qgroup_inherit *inherit)
1847 {
1848         int ret = 0;
1849         int i;
1850         u64 *i_qgroups;
1851         struct btrfs_root *quota_root = fs_info->quota_root;
1852         struct btrfs_qgroup *srcgroup;
1853         struct btrfs_qgroup *dstgroup;
1854         u32 level_size = 0;
1855         u64 nums;
1856
1857         mutex_lock(&fs_info->qgroup_ioctl_lock);
1858         if (!fs_info->quota_enabled)
1859                 goto out;
1860
1861         if (!quota_root) {
1862                 ret = -EINVAL;
1863                 goto out;
1864         }
1865
1866         if (inherit) {
1867                 i_qgroups = (u64 *)(inherit + 1);
1868                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
1869                        2 * inherit->num_excl_copies;
1870                 for (i = 0; i < nums; ++i) {
1871                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
1872                         if (!srcgroup) {
1873                                 ret = -EINVAL;
1874                                 goto out;
1875                         }
1876
1877                         if ((srcgroup->qgroupid >> 48) <= (objectid >> 48)) {
1878                                 ret = -EINVAL;
1879                                 goto out;
1880                         }
1881                         ++i_qgroups;
1882                 }
1883         }
1884
1885         /*
1886          * create a tracking group for the subvol itself
1887          */
1888         ret = add_qgroup_item(trans, quota_root, objectid);
1889         if (ret)
1890                 goto out;
1891
1892         if (srcid) {
1893                 struct btrfs_root *srcroot;
1894                 struct btrfs_key srckey;
1895
1896                 srckey.objectid = srcid;
1897                 srckey.type = BTRFS_ROOT_ITEM_KEY;
1898                 srckey.offset = (u64)-1;
1899                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
1900                 if (IS_ERR(srcroot)) {
1901                         ret = PTR_ERR(srcroot);
1902                         goto out;
1903                 }
1904
1905                 rcu_read_lock();
1906                 level_size = srcroot->nodesize;
1907                 rcu_read_unlock();
1908         }
1909
1910         /*
1911          * add qgroup to all inherited groups
1912          */
1913         if (inherit) {
1914                 i_qgroups = (u64 *)(inherit + 1);
1915                 for (i = 0; i < inherit->num_qgroups; ++i) {
1916                         ret = add_qgroup_relation_item(trans, quota_root,
1917                                                        objectid, *i_qgroups);
1918                         if (ret)
1919                                 goto out;
1920                         ret = add_qgroup_relation_item(trans, quota_root,
1921                                                        *i_qgroups, objectid);
1922                         if (ret)
1923                                 goto out;
1924                         ++i_qgroups;
1925                 }
1926         }
1927
1928
1929         spin_lock(&fs_info->qgroup_lock);
1930
1931         dstgroup = add_qgroup_rb(fs_info, objectid);
1932         if (IS_ERR(dstgroup)) {
1933                 ret = PTR_ERR(dstgroup);
1934                 goto unlock;
1935         }
1936
1937         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
1938                 dstgroup->lim_flags = inherit->lim.flags;
1939                 dstgroup->max_rfer = inherit->lim.max_rfer;
1940                 dstgroup->max_excl = inherit->lim.max_excl;
1941                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
1942                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
1943
1944                 ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
1945                 if (ret) {
1946                         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1947                         btrfs_info(fs_info, "unable to update quota limit for %llu",
1948                                dstgroup->qgroupid);
1949                         goto unlock;
1950                 }
1951         }
1952
1953         if (srcid) {
1954                 srcgroup = find_qgroup_rb(fs_info, srcid);
1955                 if (!srcgroup)
1956                         goto unlock;
1957
1958                 /*
1959                  * We call inherit after we clone the root in order to make sure
1960                  * our counts don't go crazy, so at this point the only
1961                  * difference between the two roots should be the root node.
1962                  */
1963                 dstgroup->rfer = srcgroup->rfer;
1964                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
1965                 dstgroup->excl = level_size;
1966                 dstgroup->excl_cmpr = level_size;
1967                 srcgroup->excl = level_size;
1968                 srcgroup->excl_cmpr = level_size;
1969
1970                 /* inherit the limit info */
1971                 dstgroup->lim_flags = srcgroup->lim_flags;
1972                 dstgroup->max_rfer = srcgroup->max_rfer;
1973                 dstgroup->max_excl = srcgroup->max_excl;
1974                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
1975                 dstgroup->rsv_excl = srcgroup->rsv_excl;
1976
1977                 qgroup_dirty(fs_info, dstgroup);
1978                 qgroup_dirty(fs_info, srcgroup);
1979         }
1980
1981         if (!inherit)
1982                 goto unlock;
1983
1984         i_qgroups = (u64 *)(inherit + 1);
1985         for (i = 0; i < inherit->num_qgroups; ++i) {
1986                 ret = add_relation_rb(quota_root->fs_info, objectid,
1987                                       *i_qgroups);
1988                 if (ret)
1989                         goto unlock;
1990                 ++i_qgroups;
1991         }
1992
1993         for (i = 0; i <  inherit->num_ref_copies; ++i) {
1994                 struct btrfs_qgroup *src;
1995                 struct btrfs_qgroup *dst;
1996
1997                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
1998                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
1999
2000                 if (!src || !dst) {
2001                         ret = -EINVAL;
2002                         goto unlock;
2003                 }
2004
2005                 dst->rfer = src->rfer - level_size;
2006                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
2007                 i_qgroups += 2;
2008         }
2009         for (i = 0; i <  inherit->num_excl_copies; ++i) {
2010                 struct btrfs_qgroup *src;
2011                 struct btrfs_qgroup *dst;
2012
2013                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2014                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2015
2016                 if (!src || !dst) {
2017                         ret = -EINVAL;
2018                         goto unlock;
2019                 }
2020
2021                 dst->excl = src->excl + level_size;
2022                 dst->excl_cmpr = src->excl_cmpr + level_size;
2023                 i_qgroups += 2;
2024         }
2025
2026 unlock:
2027         spin_unlock(&fs_info->qgroup_lock);
2028 out:
2029         mutex_unlock(&fs_info->qgroup_ioctl_lock);
2030         return ret;
2031 }
2032
2033 int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
2034 {
2035         struct btrfs_root *quota_root;
2036         struct btrfs_qgroup *qgroup;
2037         struct btrfs_fs_info *fs_info = root->fs_info;
2038         u64 ref_root = root->root_key.objectid;
2039         int ret = 0;
2040         struct ulist_node *unode;
2041         struct ulist_iterator uiter;
2042
2043         if (!is_fstree(ref_root))
2044                 return 0;
2045
2046         if (num_bytes == 0)
2047                 return 0;
2048
2049         spin_lock(&fs_info->qgroup_lock);
2050         quota_root = fs_info->quota_root;
2051         if (!quota_root)
2052                 goto out;
2053
2054         qgroup = find_qgroup_rb(fs_info, ref_root);
2055         if (!qgroup)
2056                 goto out;
2057
2058         /*
2059          * in a first step, we check all affected qgroups if any limits would
2060          * be exceeded
2061          */
2062         ulist_reinit(fs_info->qgroup_ulist);
2063         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2064                         (uintptr_t)qgroup, GFP_ATOMIC);
2065         if (ret < 0)
2066                 goto out;
2067         ULIST_ITER_INIT(&uiter);
2068         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2069                 struct btrfs_qgroup *qg;
2070                 struct btrfs_qgroup_list *glist;
2071
2072                 qg = u64_to_ptr(unode->aux);
2073
2074                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2075                     qg->reserved + (s64)qg->rfer + num_bytes >
2076                     qg->max_rfer) {
2077                         ret = -EDQUOT;
2078                         goto out;
2079                 }
2080
2081                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2082                     qg->reserved + (s64)qg->excl + num_bytes >
2083                     qg->max_excl) {
2084                         ret = -EDQUOT;
2085                         goto out;
2086                 }
2087
2088                 list_for_each_entry(glist, &qg->groups, next_group) {
2089                         ret = ulist_add(fs_info->qgroup_ulist,
2090                                         glist->group->qgroupid,
2091                                         (uintptr_t)glist->group, GFP_ATOMIC);
2092                         if (ret < 0)
2093                                 goto out;
2094                 }
2095         }
2096         ret = 0;
2097         /*
2098          * no limits exceeded, now record the reservation into all qgroups
2099          */
2100         ULIST_ITER_INIT(&uiter);
2101         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2102                 struct btrfs_qgroup *qg;
2103
2104                 qg = u64_to_ptr(unode->aux);
2105
2106                 qg->reserved += num_bytes;
2107         }
2108
2109 out:
2110         spin_unlock(&fs_info->qgroup_lock);
2111         return ret;
2112 }
2113
2114 void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes)
2115 {
2116         struct btrfs_root *quota_root;
2117         struct btrfs_qgroup *qgroup;
2118         struct btrfs_fs_info *fs_info = root->fs_info;
2119         struct ulist_node *unode;
2120         struct ulist_iterator uiter;
2121         u64 ref_root = root->root_key.objectid;
2122         int ret = 0;
2123
2124         if (!is_fstree(ref_root))
2125                 return;
2126
2127         if (num_bytes == 0)
2128                 return;
2129
2130         spin_lock(&fs_info->qgroup_lock);
2131
2132         quota_root = fs_info->quota_root;
2133         if (!quota_root)
2134                 goto out;
2135
2136         qgroup = find_qgroup_rb(fs_info, ref_root);
2137         if (!qgroup)
2138                 goto out;
2139
2140         ulist_reinit(fs_info->qgroup_ulist);
2141         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2142                         (uintptr_t)qgroup, GFP_ATOMIC);
2143         if (ret < 0)
2144                 goto out;
2145         ULIST_ITER_INIT(&uiter);
2146         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2147                 struct btrfs_qgroup *qg;
2148                 struct btrfs_qgroup_list *glist;
2149
2150                 qg = u64_to_ptr(unode->aux);
2151
2152                 qg->reserved -= num_bytes;
2153
2154                 list_for_each_entry(glist, &qg->groups, next_group) {
2155                         ret = ulist_add(fs_info->qgroup_ulist,
2156                                         glist->group->qgroupid,
2157                                         (uintptr_t)glist->group, GFP_ATOMIC);
2158                         if (ret < 0)
2159                                 goto out;
2160                 }
2161         }
2162
2163 out:
2164         spin_unlock(&fs_info->qgroup_lock);
2165 }
2166
2167 void assert_qgroups_uptodate(struct btrfs_trans_handle *trans)
2168 {
2169         if (list_empty(&trans->qgroup_ref_list) && !trans->delayed_ref_elem.seq)
2170                 return;
2171         btrfs_err(trans->root->fs_info,
2172                 "qgroups not uptodate in trans handle %p:  list is%s empty, "
2173                 "seq is %#x.%x",
2174                 trans, list_empty(&trans->qgroup_ref_list) ? "" : " not",
2175                 (u32)(trans->delayed_ref_elem.seq >> 32),
2176                 (u32)trans->delayed_ref_elem.seq);
2177         BUG();
2178 }
2179
2180 /*
2181  * returns < 0 on error, 0 when more leafs are to be scanned.
2182  * returns 1 when done.
2183  */
2184 static int
2185 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
2186                    struct btrfs_trans_handle *trans,
2187                    struct extent_buffer *scratch_leaf)
2188 {
2189         struct btrfs_key found;
2190         struct ulist *roots = NULL;
2191         struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
2192         u64 num_bytes;
2193         int slot;
2194         int ret;
2195
2196         path->leave_spinning = 1;
2197         mutex_lock(&fs_info->qgroup_rescan_lock);
2198         ret = btrfs_search_slot_for_read(fs_info->extent_root,
2199                                          &fs_info->qgroup_rescan_progress,
2200                                          path, 1, 0);
2201
2202         pr_debug("current progress key (%llu %u %llu), search_slot ret %d\n",
2203                  fs_info->qgroup_rescan_progress.objectid,
2204                  fs_info->qgroup_rescan_progress.type,
2205                  fs_info->qgroup_rescan_progress.offset, ret);
2206
2207         if (ret) {
2208                 /*
2209                  * The rescan is about to end, we will not be scanning any
2210                  * further blocks. We cannot unset the RESCAN flag here, because
2211                  * we want to commit the transaction if everything went well.
2212                  * To make the live accounting work in this phase, we set our
2213                  * scan progress pointer such that every real extent objectid
2214                  * will be smaller.
2215                  */
2216                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
2217                 btrfs_release_path(path);
2218                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2219                 return ret;
2220         }
2221
2222         btrfs_item_key_to_cpu(path->nodes[0], &found,
2223                               btrfs_header_nritems(path->nodes[0]) - 1);
2224         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
2225
2226         btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2227         memcpy(scratch_leaf, path->nodes[0], sizeof(*scratch_leaf));
2228         slot = path->slots[0];
2229         btrfs_release_path(path);
2230         mutex_unlock(&fs_info->qgroup_rescan_lock);
2231
2232         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
2233                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
2234                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
2235                     found.type != BTRFS_METADATA_ITEM_KEY)
2236                         continue;
2237                 if (found.type == BTRFS_METADATA_ITEM_KEY)
2238                         num_bytes = fs_info->extent_root->nodesize;
2239                 else
2240                         num_bytes = found.offset;
2241
2242                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
2243                                            &roots);
2244                 if (ret < 0)
2245                         goto out;
2246                 /* For rescan, just pass old_roots as NULL */
2247                 ret = btrfs_qgroup_account_extent(trans, fs_info,
2248                                 found.objectid, num_bytes, NULL, roots);
2249                 if (ret < 0)
2250                         goto out;
2251         }
2252 out:
2253         btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2254
2255         return ret;
2256 }
2257
2258 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
2259 {
2260         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
2261                                                      qgroup_rescan_work);
2262         struct btrfs_path *path;
2263         struct btrfs_trans_handle *trans = NULL;
2264         struct extent_buffer *scratch_leaf = NULL;
2265         int err = -ENOMEM;
2266         int ret = 0;
2267
2268         path = btrfs_alloc_path();
2269         if (!path)
2270                 goto out;
2271         scratch_leaf = kmalloc(sizeof(*scratch_leaf), GFP_NOFS);
2272         if (!scratch_leaf)
2273                 goto out;
2274
2275         err = 0;
2276         while (!err) {
2277                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
2278                 if (IS_ERR(trans)) {
2279                         err = PTR_ERR(trans);
2280                         break;
2281                 }
2282                 if (!fs_info->quota_enabled) {
2283                         err = -EINTR;
2284                 } else {
2285                         err = qgroup_rescan_leaf(fs_info, path, trans,
2286                                                  scratch_leaf);
2287                 }
2288                 if (err > 0)
2289                         btrfs_commit_transaction(trans, fs_info->fs_root);
2290                 else
2291                         btrfs_end_transaction(trans, fs_info->fs_root);
2292         }
2293
2294 out:
2295         kfree(scratch_leaf);
2296         btrfs_free_path(path);
2297
2298         mutex_lock(&fs_info->qgroup_rescan_lock);
2299         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2300
2301         if (err > 0 &&
2302             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
2303                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2304         } else if (err < 0) {
2305                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2306         }
2307         mutex_unlock(&fs_info->qgroup_rescan_lock);
2308
2309         /*
2310          * only update status, since the previous part has alreay updated the
2311          * qgroup info.
2312          */
2313         trans = btrfs_start_transaction(fs_info->quota_root, 1);
2314         if (IS_ERR(trans)) {
2315                 err = PTR_ERR(trans);
2316                 btrfs_err(fs_info,
2317                           "fail to start transaction for status update: %d\n",
2318                           err);
2319                 goto done;
2320         }
2321         ret = update_qgroup_status_item(trans, fs_info, fs_info->quota_root);
2322         if (ret < 0) {
2323                 err = ret;
2324                 btrfs_err(fs_info, "fail to update qgroup status: %d\n", err);
2325         }
2326         btrfs_end_transaction(trans, fs_info->quota_root);
2327
2328         if (err >= 0) {
2329                 btrfs_info(fs_info, "qgroup scan completed%s",
2330                         err > 0 ? " (inconsistency flag cleared)" : "");
2331         } else {
2332                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
2333         }
2334
2335 done:
2336         complete_all(&fs_info->qgroup_rescan_completion);
2337 }
2338
2339 /*
2340  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
2341  * memory required for the rescan context.
2342  */
2343 static int
2344 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
2345                    int init_flags)
2346 {
2347         int ret = 0;
2348
2349         if (!init_flags &&
2350             (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
2351              !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
2352                 ret = -EINVAL;
2353                 goto err;
2354         }
2355
2356         mutex_lock(&fs_info->qgroup_rescan_lock);
2357         spin_lock(&fs_info->qgroup_lock);
2358
2359         if (init_flags) {
2360                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2361                         ret = -EINPROGRESS;
2362                 else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
2363                         ret = -EINVAL;
2364
2365                 if (ret) {
2366                         spin_unlock(&fs_info->qgroup_lock);
2367                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2368                         goto err;
2369                 }
2370                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2371         }
2372
2373         memset(&fs_info->qgroup_rescan_progress, 0,
2374                 sizeof(fs_info->qgroup_rescan_progress));
2375         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
2376
2377         spin_unlock(&fs_info->qgroup_lock);
2378         mutex_unlock(&fs_info->qgroup_rescan_lock);
2379
2380         init_completion(&fs_info->qgroup_rescan_completion);
2381
2382         memset(&fs_info->qgroup_rescan_work, 0,
2383                sizeof(fs_info->qgroup_rescan_work));
2384         btrfs_init_work(&fs_info->qgroup_rescan_work,
2385                         btrfs_qgroup_rescan_helper,
2386                         btrfs_qgroup_rescan_worker, NULL, NULL);
2387
2388         if (ret) {
2389 err:
2390                 btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
2391                 return ret;
2392         }
2393
2394         return 0;
2395 }
2396
2397 static void
2398 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
2399 {
2400         struct rb_node *n;
2401         struct btrfs_qgroup *qgroup;
2402
2403         spin_lock(&fs_info->qgroup_lock);
2404         /* clear all current qgroup tracking information */
2405         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
2406                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
2407                 qgroup->rfer = 0;
2408                 qgroup->rfer_cmpr = 0;
2409                 qgroup->excl = 0;
2410                 qgroup->excl_cmpr = 0;
2411         }
2412         spin_unlock(&fs_info->qgroup_lock);
2413 }
2414
2415 int
2416 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
2417 {
2418         int ret = 0;
2419         struct btrfs_trans_handle *trans;
2420
2421         ret = qgroup_rescan_init(fs_info, 0, 1);
2422         if (ret)
2423                 return ret;
2424
2425         /*
2426          * We have set the rescan_progress to 0, which means no more
2427          * delayed refs will be accounted by btrfs_qgroup_account_ref.
2428          * However, btrfs_qgroup_account_ref may be right after its call
2429          * to btrfs_find_all_roots, in which case it would still do the
2430          * accounting.
2431          * To solve this, we're committing the transaction, which will
2432          * ensure we run all delayed refs and only after that, we are
2433          * going to clear all tracking information for a clean start.
2434          */
2435
2436         trans = btrfs_join_transaction(fs_info->fs_root);
2437         if (IS_ERR(trans)) {
2438                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2439                 return PTR_ERR(trans);
2440         }
2441         ret = btrfs_commit_transaction(trans, fs_info->fs_root);
2442         if (ret) {
2443                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2444                 return ret;
2445         }
2446
2447         qgroup_rescan_zero_tracking(fs_info);
2448
2449         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2450                          &fs_info->qgroup_rescan_work);
2451
2452         return 0;
2453 }
2454
2455 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info)
2456 {
2457         int running;
2458         int ret = 0;
2459
2460         mutex_lock(&fs_info->qgroup_rescan_lock);
2461         spin_lock(&fs_info->qgroup_lock);
2462         running = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2463         spin_unlock(&fs_info->qgroup_lock);
2464         mutex_unlock(&fs_info->qgroup_rescan_lock);
2465
2466         if (running)
2467                 ret = wait_for_completion_interruptible(
2468                                         &fs_info->qgroup_rescan_completion);
2469
2470         return ret;
2471 }
2472
2473 /*
2474  * this is only called from open_ctree where we're still single threaded, thus
2475  * locking is omitted here.
2476  */
2477 void
2478 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
2479 {
2480         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2481                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
2482                                  &fs_info->qgroup_rescan_work);
2483 }