fs/btrfs/qgroup.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2011 STRATO.  All rights reserved.
   4  */
   5
   6 #include <linux/sched.h>
   7 #include <linux/pagemap.h>
   8 #include <linux/writeback.h>
   9 #include <linux/blkdev.h>
  10 #include <linux/rbtree.h>
  11 #include <linux/slab.h>
  12 #include <linux/workqueue.h>
  13 #include <linux/btrfs.h>
  14 #include <linux/sched/mm.h>
  15
  16 #include "ctree.h"
  17 #include "transaction.h"
  18 #include "disk-io.h"
  19 #include "locking.h"
  20 #include "ulist.h"
  21 #include "backref.h"
  22 #include "extent_io.h"
  23 #include "qgroup.h"
  24 #include "block-group.h"
  25 #include "sysfs.h"
  26 #include "tree-mod-log.h"
  27
  28 /*
  29  * Helpers to access qgroup reservation
  30  *
  31  * Callers should ensure the lock context and type are valid
  32  */
  33
  34 static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
  35 {
  36         u64 ret = 0;
  37         int i;
  38
  39         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  40                 ret += qgroup->rsv.values[i];
  41
  42         return ret;
  43 }
  44
  45 #ifdef CONFIG_BTRFS_DEBUG
  46 static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
  47 {
  48         if (type == BTRFS_QGROUP_RSV_DATA)
  49                 return "data";
  50         if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
  51                 return "meta_pertrans";
  52         if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
  53                 return "meta_prealloc";
  54         return NULL;
  55 }
  56 #endif
  57
  58 static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
  59                            struct btrfs_qgroup *qgroup, u64 num_bytes,
  60                            enum btrfs_qgroup_rsv_type type)
  61 {
  62         trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
  63         qgroup->rsv.values[type] += num_bytes;
  64 }
  65
  66 static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
  67                                struct btrfs_qgroup *qgroup, u64 num_bytes,
  68                                enum btrfs_qgroup_rsv_type type)
  69 {
  70         trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
  71         if (qgroup->rsv.values[type] >= num_bytes) {
  72                 qgroup->rsv.values[type] -= num_bytes;
  73                 return;
  74         }
  75 #ifdef CONFIG_BTRFS_DEBUG
  76         WARN_RATELIMIT(1,
  77                 "qgroup %llu %s reserved space underflow, have %llu to free %llu",
  78                 qgroup->qgroupid, qgroup_rsv_type_str(type),
  79                 qgroup->rsv.values[type], num_bytes);
  80 #endif
  81         qgroup->rsv.values[type] = 0;
  82 }
  83
  84 static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
  85                                      struct btrfs_qgroup *dest,
  86                                      struct btrfs_qgroup *src)
  87 {
  88         int i;
  89
  90         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  91                 qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
  92 }
  93
  94 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
  95                                          struct btrfs_qgroup *dest,
  96                                           struct btrfs_qgroup *src)
  97 {
  98         int i;
  99
 100         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
 101                 qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
 102 }
 103
 104 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
 105                                            int mod)
 106 {
 107         if (qg->old_refcnt < seq)
 108                 qg->old_refcnt = seq;
 109         qg->old_refcnt += mod;
 110 }
 111
 112 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 113                                            int mod)
 114 {
 115         if (qg->new_refcnt < seq)
 116                 qg->new_refcnt = seq;
 117         qg->new_refcnt += mod;
 118 }
 119
 120 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
 121 {
 122         if (qg->old_refcnt < seq)
 123                 return 0;
 124         return qg->old_refcnt - seq;
 125 }
 126
 127 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
 128 {
 129         if (qg->new_refcnt < seq)
 130                 return 0;
 131         return qg->new_refcnt - seq;
 132 }
 133
 134 /*
 135  * glue structure to represent the relations between qgroups.
 136  */
 137 struct btrfs_qgroup_list {
 138         struct list_head next_group;
 139         struct list_head next_member;
 140         struct btrfs_qgroup *group;
 141         struct btrfs_qgroup *member;
 142 };
 143
 144 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
 145 {
 146         return (u64)(uintptr_t)qg;
 147 }
 148
 149 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
 150 {
 151         return (struct btrfs_qgroup *)(uintptr_t)n->aux;
 152 }
 153
 154 static int
 155 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 156                    int init_flags);
 157 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 158
 159 /* must be called with qgroup_ioctl_lock held */
 160 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 161                                            u64 qgroupid)
 162 {
 163         struct rb_node *n = fs_info->qgroup_tree.rb_node;
 164         struct btrfs_qgroup *qgroup;
 165
 166         while (n) {
 167                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 168                 if (qgroup->qgroupid < qgroupid)
 169                         n = n->rb_left;
 170                 else if (qgroup->qgroupid > qgroupid)
 171                         n = n->rb_right;
 172                 else
 173                         return qgroup;
 174         }
 175         return NULL;
 176 }
 177
 178 /* must be called with qgroup_lock held */
 179 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 180                                           u64 qgroupid)
 181 {
 182         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 183         struct rb_node *parent = NULL;
 184         struct btrfs_qgroup *qgroup;
 185
 186         while (*p) {
 187                 parent = *p;
 188                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 189
 190                 if (qgroup->qgroupid < qgroupid)
 191                         p = &(*p)->rb_left;
 192                 else if (qgroup->qgroupid > qgroupid)
 193                         p = &(*p)->rb_right;
 194                 else
 195                         return qgroup;
 196         }
 197
 198         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 199         if (!qgroup)
 200                 return ERR_PTR(-ENOMEM);
 201
 202         qgroup->qgroupid = qgroupid;
 203         INIT_LIST_HEAD(&qgroup->groups);
 204         INIT_LIST_HEAD(&qgroup->members);
 205         INIT_LIST_HEAD(&qgroup->dirty);
 206
 207         rb_link_node(&qgroup->node, parent, p);
 208         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 209
 210         return qgroup;
 211 }
 212
 213 static void __del_qgroup_rb(struct btrfs_fs_info *fs_info,
 214                             struct btrfs_qgroup *qgroup)
 215 {
 216         struct btrfs_qgroup_list *list;
 217
 218         list_del(&qgroup->dirty);
 219         while (!list_empty(&qgroup->groups)) {
 220                 list = list_first_entry(&qgroup->groups,
 221                                         struct btrfs_qgroup_list, next_group);
 222                 list_del(&list->next_group);
 223                 list_del(&list->next_member);
 224                 kfree(list);
 225         }
 226
 227         while (!list_empty(&qgroup->members)) {
 228                 list = list_first_entry(&qgroup->members,
 229                                         struct btrfs_qgroup_list, next_member);
 230                 list_del(&list->next_group);
 231                 list_del(&list->next_member);
 232                 kfree(list);
 233         }
 234 }
 235
 236 /* must be called with qgroup_lock held */
 237 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 238 {
 239         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 240
 241         if (!qgroup)
 242                 return -ENOENT;
 243
 244         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 245         __del_qgroup_rb(fs_info, qgroup);
 246         return 0;
 247 }
 248
 249 /*
 250  * Add relation specified by two qgroups.
 251  *
 252  * Must be called with qgroup_lock held.
 253  *
 254  * Return: 0        on success
 255  *         -ENOENT  if one of the qgroups is NULL
 256  *         <0       other errors
 257  */
 258 static int __add_relation_rb(struct btrfs_qgroup *member, struct btrfs_qgroup *parent)
 259 {
 260         struct btrfs_qgroup_list *list;
 261
 262         if (!member || !parent)
 263                 return -ENOENT;
 264
 265         list = kzalloc(sizeof(*list), GFP_ATOMIC);
 266         if (!list)
 267                 return -ENOMEM;
 268
 269         list->group = parent;
 270         list->member = member;
 271         list_add_tail(&list->next_group, &member->groups);
 272         list_add_tail(&list->next_member, &parent->members);
 273
 274         return 0;
 275 }
 276
 277 /*
 278  * Add relation specified by two qgroup ids.
 279  *
 280  * Must be called with qgroup_lock held.
 281  *
 282  * Return: 0        on success
 283  *         -ENOENT  if one of the ids does not exist
 284  *         <0       other errors
 285  */
 286 static int add_relation_rb(struct btrfs_fs_info *fs_info, u64 memberid, u64 parentid)
 287 {
 288         struct btrfs_qgroup *member;
 289         struct btrfs_qgroup *parent;
 290
 291         member = find_qgroup_rb(fs_info, memberid);
 292         parent = find_qgroup_rb(fs_info, parentid);
 293
 294         return __add_relation_rb(member, parent);
 295 }
 296
 297 /* Must be called with qgroup_lock held */
 298 static int del_relation_rb(struct btrfs_fs_info *fs_info,
 299                            u64 memberid, u64 parentid)
 300 {
 301         struct btrfs_qgroup *member;
 302         struct btrfs_qgroup *parent;
 303         struct btrfs_qgroup_list *list;
 304
 305         member = find_qgroup_rb(fs_info, memberid);
 306         parent = find_qgroup_rb(fs_info, parentid);
 307         if (!member || !parent)
 308                 return -ENOENT;
 309
 310         list_for_each_entry(list, &member->groups, next_group) {
 311                 if (list->group == parent) {
 312                         list_del(&list->next_group);
 313                         list_del(&list->next_member);
 314                         kfree(list);
 315                         return 0;
 316                 }
 317         }
 318         return -ENOENT;
 319 }
 320
 321 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 322 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 323                                u64 rfer, u64 excl)
 324 {
 325         struct btrfs_qgroup *qgroup;
 326
 327         qgroup = find_qgroup_rb(fs_info, qgroupid);
 328         if (!qgroup)
 329                 return -EINVAL;
 330         if (qgroup->rfer != rfer || qgroup->excl != excl)
 331                 return -EINVAL;
 332         return 0;
 333 }
 334 #endif
 335
 336 static void qgroup_mark_inconsistent(struct btrfs_fs_info *fs_info)
 337 {
 338         fs_info->qgroup_flags |= (BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT |
 339                                   BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN |
 340                                   BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING);
 341 }
 342
 343 /*
 344  * The full config is read in one go, only called from open_ctree()
 345  * It doesn't use any locking, as at this point we're still single-threaded
 346  */
 347 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 348 {
 349         struct btrfs_key key;
 350         struct btrfs_key found_key;
 351         struct btrfs_root *quota_root = fs_info->quota_root;
 352         struct btrfs_path *path = NULL;
 353         struct extent_buffer *l;
 354         int slot;
 355         int ret = 0;
 356         u64 flags = 0;
 357         u64 rescan_progress = 0;
 358
 359         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 360                 return 0;
 361
 362         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 363         if (!fs_info->qgroup_ulist) {
 364                 ret = -ENOMEM;
 365                 goto out;
 366         }
 367
 368         path = btrfs_alloc_path();
 369         if (!path) {
 370                 ret = -ENOMEM;
 371                 goto out;
 372         }
 373
 374         ret = btrfs_sysfs_add_qgroups(fs_info);
 375         if (ret < 0)
 376                 goto out;
 377         /* default this to quota off, in case no status key is found */
 378         fs_info->qgroup_flags = 0;
 379
 380         /*
 381          * pass 1: read status, all qgroup infos and limits
 382          */
 383         key.objectid = 0;
 384         key.type = 0;
 385         key.offset = 0;
 386         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 387         if (ret)
 388                 goto out;
 389
 390         while (1) {
 391                 struct btrfs_qgroup *qgroup;
 392
 393                 slot = path->slots[0];
 394                 l = path->nodes[0];
 395                 btrfs_item_key_to_cpu(l, &found_key, slot);
 396
 397                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 398                         struct btrfs_qgroup_status_item *ptr;
 399
 400                         ptr = btrfs_item_ptr(l, slot,
 401                                              struct btrfs_qgroup_status_item);
 402
 403                         if (btrfs_qgroup_status_version(l, ptr) !=
 404                             BTRFS_QGROUP_STATUS_VERSION) {
 405                                 btrfs_err(fs_info,
 406                                  "old qgroup version, quota disabled");
 407                                 goto out;
 408                         }
 409                         if (btrfs_qgroup_status_generation(l, ptr) !=
 410                             fs_info->generation) {
 411                                 qgroup_mark_inconsistent(fs_info);
 412                                 btrfs_err(fs_info,
 413                                         "qgroup generation mismatch, marked as inconsistent");
 414                         }
 415                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 416                                                                           ptr);
 417                         rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
 418                         goto next1;
 419                 }
 420
 421                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 422                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 423                         goto next1;
 424
 425                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
 426                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 427                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 428                         btrfs_err(fs_info, "inconsistent qgroup config");
 429                         qgroup_mark_inconsistent(fs_info);
 430                 }
 431                 if (!qgroup) {
 432                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 433                         if (IS_ERR(qgroup)) {
 434                                 ret = PTR_ERR(qgroup);
 435                                 goto out;
 436                         }
 437                 }
 438                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
 439                 if (ret < 0)
 440                         goto out;
 441
 442                 switch (found_key.type) {
 443                 case BTRFS_QGROUP_INFO_KEY: {
 444                         struct btrfs_qgroup_info_item *ptr;
 445
 446                         ptr = btrfs_item_ptr(l, slot,
 447                                              struct btrfs_qgroup_info_item);
 448                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 449                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 450                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 451                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 452                         /* generation currently unused */
 453                         break;
 454                 }
 455                 case BTRFS_QGROUP_LIMIT_KEY: {
 456                         struct btrfs_qgroup_limit_item *ptr;
 457
 458                         ptr = btrfs_item_ptr(l, slot,
 459                                              struct btrfs_qgroup_limit_item);
 460                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 461                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 462                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 463                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 464                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 465                         break;
 466                 }
 467                 }
 468 next1:
 469                 ret = btrfs_next_item(quota_root, path);
 470                 if (ret < 0)
 471                         goto out;
 472                 if (ret)
 473                         break;
 474         }
 475         btrfs_release_path(path);
 476
 477         /*
 478          * pass 2: read all qgroup relations
 479          */
 480         key.objectid = 0;
 481         key.type = BTRFS_QGROUP_RELATION_KEY;
 482         key.offset = 0;
 483         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 484         if (ret)
 485                 goto out;
 486         while (1) {
 487                 slot = path->slots[0];
 488                 l = path->nodes[0];
 489                 btrfs_item_key_to_cpu(l, &found_key, slot);
 490
 491                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 492                         goto next2;
 493
 494                 if (found_key.objectid > found_key.offset) {
 495                         /* parent <- member, not needed to build config */
 496                         /* FIXME should we omit the key completely? */
 497                         goto next2;
 498                 }
 499
 500                 ret = add_relation_rb(fs_info, found_key.objectid,
 501                                       found_key.offset);
 502                 if (ret == -ENOENT) {
 503                         btrfs_warn(fs_info,
 504                                 "orphan qgroup relation 0x%llx->0x%llx",
 505                                 found_key.objectid, found_key.offset);
 506                         ret = 0;        /* ignore the error */
 507                 }
 508                 if (ret)
 509                         goto out;
 510 next2:
 511                 ret = btrfs_next_item(quota_root, path);
 512                 if (ret < 0)
 513                         goto out;
 514                 if (ret)
 515                         break;
 516         }
 517 out:
 518         btrfs_free_path(path);
 519         fs_info->qgroup_flags |= flags;
 520         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
 521                 clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 522         else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
 523                  ret >= 0)
 524                 ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
 525
 526         if (ret < 0) {
 527                 ulist_free(fs_info->qgroup_ulist);
 528                 fs_info->qgroup_ulist = NULL;
 529                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 530                 btrfs_sysfs_del_qgroups(fs_info);
 531         }
 532
 533         return ret < 0 ? ret : 0;
 534 }
 535
 536 /*
 537  * Called in close_ctree() when quota is still enabled.  This verifies we don't
 538  * leak some reserved space.
 539  *
 540  * Return false if no reserved space is left.
 541  * Return true if some reserved space is leaked.
 542  */
 543 bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info)
 544 {
 545         struct rb_node *node;
 546         bool ret = false;
 547
 548         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 549                 return ret;
 550         /*
 551          * Since we're unmounting, there is no race and no need to grab qgroup
 552          * lock.  And here we don't go post-order to provide a more user
 553          * friendly sorted result.
 554          */
 555         for (node = rb_first(&fs_info->qgroup_tree); node; node = rb_next(node)) {
 556                 struct btrfs_qgroup *qgroup;
 557                 int i;
 558
 559                 qgroup = rb_entry(node, struct btrfs_qgroup, node);
 560                 for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) {
 561                         if (qgroup->rsv.values[i]) {
 562                                 ret = true;
 563                                 btrfs_warn(fs_info,
 564                 "qgroup %hu/%llu has unreleased space, type %d rsv %llu",
 565                                    btrfs_qgroup_level(qgroup->qgroupid),
 566                                    btrfs_qgroup_subvolid(qgroup->qgroupid),
 567                                    i, qgroup->rsv.values[i]);
 568                         }
 569                 }
 570         }
 571         return ret;
 572 }
 573
 574 /*
 575  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
 576  * first two are in single-threaded paths.And for the third one, we have set
 577  * quota_root to be null with qgroup_lock held before, so it is safe to clean
 578  * up the in-memory structures without qgroup_lock held.
 579  */
 580 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 581 {
 582         struct rb_node *n;
 583         struct btrfs_qgroup *qgroup;
 584
 585         while ((n = rb_first(&fs_info->qgroup_tree))) {
 586                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 587                 rb_erase(n, &fs_info->qgroup_tree);
 588                 __del_qgroup_rb(fs_info, qgroup);
 589                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
 590                 kfree(qgroup);
 591         }
 592         /*
 593          * We call btrfs_free_qgroup_config() when unmounting
 594          * filesystem and disabling quota, so we set qgroup_ulist
 595          * to be null here to avoid double free.
 596          */
 597         ulist_free(fs_info->qgroup_ulist);
 598         fs_info->qgroup_ulist = NULL;
 599         btrfs_sysfs_del_qgroups(fs_info);
 600 }
 601
 602 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 603                                     u64 dst)
 604 {
 605         int ret;
 606         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 607         struct btrfs_path *path;
 608         struct btrfs_key key;
 609
 610         path = btrfs_alloc_path();
 611         if (!path)
 612                 return -ENOMEM;
 613
 614         key.objectid = src;
 615         key.type = BTRFS_QGROUP_RELATION_KEY;
 616         key.offset = dst;
 617
 618         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 619
 620         btrfs_mark_buffer_dirty(path->nodes[0]);
 621
 622         btrfs_free_path(path);
 623         return ret;
 624 }
 625
 626 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 627                                     u64 dst)
 628 {
 629         int ret;
 630         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 631         struct btrfs_path *path;
 632         struct btrfs_key key;
 633
 634         path = btrfs_alloc_path();
 635         if (!path)
 636                 return -ENOMEM;
 637
 638         key.objectid = src;
 639         key.type = BTRFS_QGROUP_RELATION_KEY;
 640         key.offset = dst;
 641
 642         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 643         if (ret < 0)
 644                 goto out;
 645
 646         if (ret > 0) {
 647                 ret = -ENOENT;
 648                 goto out;
 649         }
 650
 651         ret = btrfs_del_item(trans, quota_root, path);
 652 out:
 653         btrfs_free_path(path);
 654         return ret;
 655 }
 656
 657 static int add_qgroup_item(struct btrfs_trans_handle *trans,
 658                            struct btrfs_root *quota_root, u64 qgroupid)
 659 {
 660         int ret;
 661         struct btrfs_path *path;
 662         struct btrfs_qgroup_info_item *qgroup_info;
 663         struct btrfs_qgroup_limit_item *qgroup_limit;
 664         struct extent_buffer *leaf;
 665         struct btrfs_key key;
 666
 667         if (btrfs_is_testing(quota_root->fs_info))
 668                 return 0;
 669
 670         path = btrfs_alloc_path();
 671         if (!path)
 672                 return -ENOMEM;
 673
 674         key.objectid = 0;
 675         key.type = BTRFS_QGROUP_INFO_KEY;
 676         key.offset = qgroupid;
 677
 678         /*
 679          * Avoid a transaction abort by catching -EEXIST here. In that
 680          * case, we proceed by re-initializing the existing structure
 681          * on disk.
 682          */
 683
 684         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 685                                       sizeof(*qgroup_info));
 686         if (ret && ret != -EEXIST)
 687                 goto out;
 688
 689         leaf = path->nodes[0];
 690         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 691                                  struct btrfs_qgroup_info_item);
 692         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 693         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 694         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 695         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 696         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 697
 698         btrfs_mark_buffer_dirty(leaf);
 699
 700         btrfs_release_path(path);
 701
 702         key.type = BTRFS_QGROUP_LIMIT_KEY;
 703         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 704                                       sizeof(*qgroup_limit));
 705         if (ret && ret != -EEXIST)
 706                 goto out;
 707
 708         leaf = path->nodes[0];
 709         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 710                                   struct btrfs_qgroup_limit_item);
 711         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 712         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 713         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 714         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 715         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 716
 717         btrfs_mark_buffer_dirty(leaf);
 718
 719         ret = 0;
 720 out:
 721         btrfs_free_path(path);
 722         return ret;
 723 }
 724
 725 static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
 726 {
 727         int ret;
 728         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 729         struct btrfs_path *path;
 730         struct btrfs_key key;
 731
 732         path = btrfs_alloc_path();
 733         if (!path)
 734                 return -ENOMEM;
 735
 736         key.objectid = 0;
 737         key.type = BTRFS_QGROUP_INFO_KEY;
 738         key.offset = qgroupid;
 739         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 740         if (ret < 0)
 741                 goto out;
 742
 743         if (ret > 0) {
 744                 ret = -ENOENT;
 745                 goto out;
 746         }
 747
 748         ret = btrfs_del_item(trans, quota_root, path);
 749         if (ret)
 750                 goto out;
 751
 752         btrfs_release_path(path);
 753
 754         key.type = BTRFS_QGROUP_LIMIT_KEY;
 755         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 756         if (ret < 0)
 757                 goto out;
 758
 759         if (ret > 0) {
 760                 ret = -ENOENT;
 761                 goto out;
 762         }
 763
 764         ret = btrfs_del_item(trans, quota_root, path);
 765
 766 out:
 767         btrfs_free_path(path);
 768         return ret;
 769 }
 770
 771 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 772                                     struct btrfs_qgroup *qgroup)
 773 {
 774         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 775         struct btrfs_path *path;
 776         struct btrfs_key key;
 777         struct extent_buffer *l;
 778         struct btrfs_qgroup_limit_item *qgroup_limit;
 779         int ret;
 780         int slot;
 781
 782         key.objectid = 0;
 783         key.type = BTRFS_QGROUP_LIMIT_KEY;
 784         key.offset = qgroup->qgroupid;
 785
 786         path = btrfs_alloc_path();
 787         if (!path)
 788                 return -ENOMEM;
 789
 790         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 791         if (ret > 0)
 792                 ret = -ENOENT;
 793
 794         if (ret)
 795                 goto out;
 796
 797         l = path->nodes[0];
 798         slot = path->slots[0];
 799         qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
 800         btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
 801         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
 802         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
 803         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
 804         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
 805
 806         btrfs_mark_buffer_dirty(l);
 807
 808 out:
 809         btrfs_free_path(path);
 810         return ret;
 811 }
 812
 813 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 814                                    struct btrfs_qgroup *qgroup)
 815 {
 816         struct btrfs_fs_info *fs_info = trans->fs_info;
 817         struct btrfs_root *quota_root = fs_info->quota_root;
 818         struct btrfs_path *path;
 819         struct btrfs_key key;
 820         struct extent_buffer *l;
 821         struct btrfs_qgroup_info_item *qgroup_info;
 822         int ret;
 823         int slot;
 824
 825         if (btrfs_is_testing(fs_info))
 826                 return 0;
 827
 828         key.objectid = 0;
 829         key.type = BTRFS_QGROUP_INFO_KEY;
 830         key.offset = qgroup->qgroupid;
 831
 832         path = btrfs_alloc_path();
 833         if (!path)
 834                 return -ENOMEM;
 835
 836         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 837         if (ret > 0)
 838                 ret = -ENOENT;
 839
 840         if (ret)
 841                 goto out;
 842
 843         l = path->nodes[0];
 844         slot = path->slots[0];
 845         qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
 846         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 847         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 848         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 849         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 850         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 851
 852         btrfs_mark_buffer_dirty(l);
 853
 854 out:
 855         btrfs_free_path(path);
 856         return ret;
 857 }
 858
 859 static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
 860 {
 861         struct btrfs_fs_info *fs_info = trans->fs_info;
 862         struct btrfs_root *quota_root = fs_info->quota_root;
 863         struct btrfs_path *path;
 864         struct btrfs_key key;
 865         struct extent_buffer *l;
 866         struct btrfs_qgroup_status_item *ptr;
 867         int ret;
 868         int slot;
 869
 870         key.objectid = 0;
 871         key.type = BTRFS_QGROUP_STATUS_KEY;
 872         key.offset = 0;
 873
 874         path = btrfs_alloc_path();
 875         if (!path)
 876                 return -ENOMEM;
 877
 878         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 879         if (ret > 0)
 880                 ret = -ENOENT;
 881
 882         if (ret)
 883                 goto out;
 884
 885         l = path->nodes[0];
 886         slot = path->slots[0];
 887         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 888         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags &
 889                                       BTRFS_QGROUP_STATUS_FLAGS_MASK);
 890         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 891         btrfs_set_qgroup_status_rescan(l, ptr,
 892                                 fs_info->qgroup_rescan_progress.objectid);
 893
 894         btrfs_mark_buffer_dirty(l);
 895
 896 out:
 897         btrfs_free_path(path);
 898         return ret;
 899 }
 900
 901 /*
 902  * called with qgroup_lock held
 903  */
 904 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 905                                   struct btrfs_root *root)
 906 {
 907         struct btrfs_path *path;
 908         struct btrfs_key key;
 909         struct extent_buffer *leaf = NULL;
 910         int ret;
 911         int nr = 0;
 912
 913         path = btrfs_alloc_path();
 914         if (!path)
 915                 return -ENOMEM;
 916
 917         key.objectid = 0;
 918         key.offset = 0;
 919         key.type = 0;
 920
 921         while (1) {
 922                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 923                 if (ret < 0)
 924                         goto out;
 925                 leaf = path->nodes[0];
 926                 nr = btrfs_header_nritems(leaf);
 927                 if (!nr)
 928                         break;
 929                 /*
 930                  * delete the leaf one by one
 931                  * since the whole tree is going
 932                  * to be deleted.
 933                  */
 934                 path->slots[0] = 0;
 935                 ret = btrfs_del_items(trans, root, path, 0, nr);
 936                 if (ret)
 937                         goto out;
 938
 939                 btrfs_release_path(path);
 940         }
 941         ret = 0;
 942 out:
 943         btrfs_free_path(path);
 944         return ret;
 945 }
 946
 947 int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
 948 {
 949         struct btrfs_root *quota_root;
 950         struct btrfs_root *tree_root = fs_info->tree_root;
 951         struct btrfs_path *path = NULL;
 952         struct btrfs_qgroup_status_item *ptr;
 953         struct extent_buffer *leaf;
 954         struct btrfs_key key;
 955         struct btrfs_key found_key;
 956         struct btrfs_qgroup *qgroup = NULL;
 957         struct btrfs_trans_handle *trans = NULL;
 958         struct ulist *ulist = NULL;
 959         int ret = 0;
 960         int slot;
 961
 962         /*
 963          * We need to have subvol_sem write locked, to prevent races between
 964          * concurrent tasks trying to enable quotas, because we will unlock
 965          * and relock qgroup_ioctl_lock before setting fs_info->quota_root
 966          * and before setting BTRFS_FS_QUOTA_ENABLED.
 967          */
 968         lockdep_assert_held_write(&fs_info->subvol_sem);
 969
 970         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
 971                 btrfs_err(fs_info,
 972                           "qgroups are currently unsupported in extent tree v2");
 973                 return -EINVAL;
 974         }
 975
 976         mutex_lock(&fs_info->qgroup_ioctl_lock);
 977         if (fs_info->quota_root)
 978                 goto out;
 979
 980         ulist = ulist_alloc(GFP_KERNEL);
 981         if (!ulist) {
 982                 ret = -ENOMEM;
 983                 goto out;
 984         }
 985
 986         ret = btrfs_sysfs_add_qgroups(fs_info);
 987         if (ret < 0)
 988                 goto out;
 989
 990         /*
 991          * Unlock qgroup_ioctl_lock before starting the transaction. This is to
 992          * avoid lock acquisition inversion problems (reported by lockdep) between
 993          * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we
 994          * start a transaction.
 995          * After we started the transaction lock qgroup_ioctl_lock again and
 996          * check if someone else created the quota root in the meanwhile. If so,
 997          * just return success and release the transaction handle.
 998          *
 999          * Also we don't need to worry about someone else calling
1000          * btrfs_sysfs_add_qgroups() after we unlock and getting an error because
1001          * that function returns 0 (success) when the sysfs entries already exist.
1002          */
1003         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1004
1005         /*
1006          * 1 for quota root item
1007          * 1 for BTRFS_QGROUP_STATUS item
1008          *
1009          * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
1010          * per subvolume. However those are not currently reserved since it
1011          * would be a lot of overkill.
1012          */
1013         trans = btrfs_start_transaction(tree_root, 2);
1014
1015         mutex_lock(&fs_info->qgroup_ioctl_lock);
1016         if (IS_ERR(trans)) {
1017                 ret = PTR_ERR(trans);
1018                 trans = NULL;
1019                 goto out;
1020         }
1021
1022         if (fs_info->quota_root)
1023                 goto out;
1024
1025         fs_info->qgroup_ulist = ulist;
1026         ulist = NULL;
1027
1028         /*
1029          * initially create the quota tree
1030          */
1031         quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
1032         if (IS_ERR(quota_root)) {
1033                 ret =  PTR_ERR(quota_root);
1034                 btrfs_abort_transaction(trans, ret);
1035                 goto out;
1036         }
1037
1038         path = btrfs_alloc_path();
1039         if (!path) {
1040                 ret = -ENOMEM;
1041                 btrfs_abort_transaction(trans, ret);
1042                 goto out_free_root;
1043         }
1044
1045         key.objectid = 0;
1046         key.type = BTRFS_QGROUP_STATUS_KEY;
1047         key.offset = 0;
1048
1049         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
1050                                       sizeof(*ptr));
1051         if (ret) {
1052                 btrfs_abort_transaction(trans, ret);
1053                 goto out_free_path;
1054         }
1055
1056         leaf = path->nodes[0];
1057         ptr = btrfs_item_ptr(leaf, path->slots[0],
1058                                  struct btrfs_qgroup_status_item);
1059         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
1060         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
1061         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
1062                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1063         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags &
1064                                       BTRFS_QGROUP_STATUS_FLAGS_MASK);
1065         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
1066
1067         btrfs_mark_buffer_dirty(leaf);
1068
1069         key.objectid = 0;
1070         key.type = BTRFS_ROOT_REF_KEY;
1071         key.offset = 0;
1072
1073         btrfs_release_path(path);
1074         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
1075         if (ret > 0)
1076                 goto out_add_root;
1077         if (ret < 0) {
1078                 btrfs_abort_transaction(trans, ret);
1079                 goto out_free_path;
1080         }
1081
1082         while (1) {
1083                 slot = path->slots[0];
1084                 leaf = path->nodes[0];
1085                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1086
1087                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
1088
1089                         /* Release locks on tree_root before we access quota_root */
1090                         btrfs_release_path(path);
1091
1092                         ret = add_qgroup_item(trans, quota_root,
1093                                               found_key.offset);
1094                         if (ret) {
1095                                 btrfs_abort_transaction(trans, ret);
1096                                 goto out_free_path;
1097                         }
1098
1099                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
1100                         if (IS_ERR(qgroup)) {
1101                                 ret = PTR_ERR(qgroup);
1102                                 btrfs_abort_transaction(trans, ret);
1103                                 goto out_free_path;
1104                         }
1105                         ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1106                         if (ret < 0) {
1107                                 btrfs_abort_transaction(trans, ret);
1108                                 goto out_free_path;
1109                         }
1110                         ret = btrfs_search_slot_for_read(tree_root, &found_key,
1111                                                          path, 1, 0);
1112                         if (ret < 0) {
1113                                 btrfs_abort_transaction(trans, ret);
1114                                 goto out_free_path;
1115                         }
1116                         if (ret > 0) {
1117                                 /*
1118                                  * Shouldn't happen, but in case it does we
1119                                  * don't need to do the btrfs_next_item, just
1120                                  * continue.
1121                                  */
1122                                 continue;
1123                         }
1124                 }
1125                 ret = btrfs_next_item(tree_root, path);
1126                 if (ret < 0) {
1127                         btrfs_abort_transaction(trans, ret);
1128                         goto out_free_path;
1129                 }
1130                 if (ret)
1131                         break;
1132         }
1133
1134 out_add_root:
1135         btrfs_release_path(path);
1136         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1137         if (ret) {
1138                 btrfs_abort_transaction(trans, ret);
1139                 goto out_free_path;
1140         }
1141
1142         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1143         if (IS_ERR(qgroup)) {
1144                 ret = PTR_ERR(qgroup);
1145                 btrfs_abort_transaction(trans, ret);
1146                 goto out_free_path;
1147         }
1148         ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1149         if (ret < 0) {
1150                 btrfs_abort_transaction(trans, ret);
1151                 goto out_free_path;
1152         }
1153
1154         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1155         /*
1156          * Commit the transaction while not holding qgroup_ioctl_lock, to avoid
1157          * a deadlock with tasks concurrently doing other qgroup operations, such
1158          * adding/removing qgroups or adding/deleting qgroup relations for example,
1159          * because all qgroup operations first start or join a transaction and then
1160          * lock the qgroup_ioctl_lock mutex.
1161          * We are safe from a concurrent task trying to enable quotas, by calling
1162          * this function, since we are serialized by fs_info->subvol_sem.
1163          */
1164         ret = btrfs_commit_transaction(trans);
1165         trans = NULL;
1166         mutex_lock(&fs_info->qgroup_ioctl_lock);
1167         if (ret)
1168                 goto out_free_path;
1169
1170         /*
1171          * Set quota enabled flag after committing the transaction, to avoid
1172          * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
1173          * creation.
1174          */
1175         spin_lock(&fs_info->qgroup_lock);
1176         fs_info->quota_root = quota_root;
1177         set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1178         spin_unlock(&fs_info->qgroup_lock);
1179
1180         ret = qgroup_rescan_init(fs_info, 0, 1);
1181         if (!ret) {
1182                 qgroup_rescan_zero_tracking(fs_info);
1183                 fs_info->qgroup_rescan_running = true;
1184                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
1185                                  &fs_info->qgroup_rescan_work);
1186         } else {
1187                 /*
1188                  * We have set both BTRFS_FS_QUOTA_ENABLED and
1189                  * BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with
1190                  * -EINPROGRESS. That can happen because someone started the
1191                  * rescan worker by calling quota rescan ioctl before we
1192                  * attempted to initialize the rescan worker. Failure due to
1193                  * quotas disabled in the meanwhile is not possible, because
1194                  * we are holding a write lock on fs_info->subvol_sem, which
1195                  * is also acquired when disabling quotas.
1196                  * Ignore such error, and any other error would need to undo
1197                  * everything we did in the transaction we just committed.
1198                  */
1199                 ASSERT(ret == -EINPROGRESS);
1200                 ret = 0;
1201         }
1202
1203 out_free_path:
1204         btrfs_free_path(path);
1205 out_free_root:
1206         if (ret)
1207                 btrfs_put_root(quota_root);
1208 out:
1209         if (ret) {
1210                 ulist_free(fs_info->qgroup_ulist);
1211                 fs_info->qgroup_ulist = NULL;
1212                 btrfs_sysfs_del_qgroups(fs_info);
1213         }
1214         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1215         if (ret && trans)
1216                 btrfs_end_transaction(trans);
1217         else if (trans)
1218                 ret = btrfs_end_transaction(trans);
1219         ulist_free(ulist);
1220         return ret;
1221 }
1222
1223 int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1224 {
1225         struct btrfs_root *quota_root;
1226         struct btrfs_trans_handle *trans = NULL;
1227         int ret = 0;
1228
1229         /*
1230          * We need to have subvol_sem write locked, to prevent races between
1231          * concurrent tasks trying to disable quotas, because we will unlock
1232          * and relock qgroup_ioctl_lock across BTRFS_FS_QUOTA_ENABLED changes.
1233          */
1234         lockdep_assert_held_write(&fs_info->subvol_sem);
1235
1236         mutex_lock(&fs_info->qgroup_ioctl_lock);
1237         if (!fs_info->quota_root)
1238                 goto out;
1239
1240         /*
1241          * Unlock the qgroup_ioctl_lock mutex before waiting for the rescan worker to
1242          * complete. Otherwise we can deadlock because btrfs_remove_qgroup() needs
1243          * to lock that mutex while holding a transaction handle and the rescan
1244          * worker needs to commit a transaction.
1245          */
1246         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1247
1248         /*
1249          * Request qgroup rescan worker to complete and wait for it. This wait
1250          * must be done before transaction start for quota disable since it may
1251          * deadlock with transaction by the qgroup rescan worker.
1252          */
1253         clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1254         btrfs_qgroup_wait_for_completion(fs_info, false);
1255
1256         /*
1257          * 1 For the root item
1258          *
1259          * We should also reserve enough items for the quota tree deletion in
1260          * btrfs_clean_quota_tree but this is not done.
1261          *
1262          * Also, we must always start a transaction without holding the mutex
1263          * qgroup_ioctl_lock, see btrfs_quota_enable().
1264          */
1265         trans = btrfs_start_transaction(fs_info->tree_root, 1);
1266
1267         mutex_lock(&fs_info->qgroup_ioctl_lock);
1268         if (IS_ERR(trans)) {
1269                 ret = PTR_ERR(trans);
1270                 trans = NULL;
1271                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1272                 goto out;
1273         }
1274
1275         if (!fs_info->quota_root)
1276                 goto out;
1277
1278         spin_lock(&fs_info->qgroup_lock);
1279         quota_root = fs_info->quota_root;
1280         fs_info->quota_root = NULL;
1281         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1282         fs_info->qgroup_drop_subtree_thres = BTRFS_MAX_LEVEL;
1283         spin_unlock(&fs_info->qgroup_lock);
1284
1285         btrfs_free_qgroup_config(fs_info);
1286
1287         ret = btrfs_clean_quota_tree(trans, quota_root);
1288         if (ret) {
1289                 btrfs_abort_transaction(trans, ret);
1290                 goto out;
1291         }
1292
1293         ret = btrfs_del_root(trans, &quota_root->root_key);
1294         if (ret) {
1295                 btrfs_abort_transaction(trans, ret);
1296                 goto out;
1297         }
1298
1299         list_del(&quota_root->dirty_list);
1300
1301         btrfs_tree_lock(quota_root->node);
1302         btrfs_clean_tree_block(quota_root->node);
1303         btrfs_tree_unlock(quota_root->node);
1304         btrfs_free_tree_block(trans, btrfs_root_id(quota_root),
1305                               quota_root->node, 0, 1);
1306
1307         btrfs_put_root(quota_root);
1308
1309 out:
1310         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1311         if (ret && trans)
1312                 btrfs_end_transaction(trans);
1313         else if (trans)
1314                 ret = btrfs_end_transaction(trans);
1315
1316         return ret;
1317 }
1318
1319 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1320                          struct btrfs_qgroup *qgroup)
1321 {
1322         if (list_empty(&qgroup->dirty))
1323                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1324 }
1325
1326 /*
1327  * The easy accounting, we're updating qgroup relationship whose child qgroup
1328  * only has exclusive extents.
1329  *
1330  * In this case, all exclusive extents will also be exclusive for parent, so
1331  * excl/rfer just get added/removed.
1332  *
1333  * So is qgroup reservation space, which should also be added/removed to
1334  * parent.
1335  * Or when child tries to release reservation space, parent will underflow its
1336  * reservation (for relationship adding case).
1337  *
1338  * Caller should hold fs_info->qgroup_lock.
1339  */
1340 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1341                                     struct ulist *tmp, u64 ref_root,
1342                                     struct btrfs_qgroup *src, int sign)
1343 {
1344         struct btrfs_qgroup *qgroup;
1345         struct btrfs_qgroup_list *glist;
1346         struct ulist_node *unode;
1347         struct ulist_iterator uiter;
1348         u64 num_bytes = src->excl;
1349         int ret = 0;
1350
1351         qgroup = find_qgroup_rb(fs_info, ref_root);
1352         if (!qgroup)
1353                 goto out;
1354
1355         qgroup->rfer += sign * num_bytes;
1356         qgroup->rfer_cmpr += sign * num_bytes;
1357
1358         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1359         qgroup->excl += sign * num_bytes;
1360         qgroup->excl_cmpr += sign * num_bytes;
1361
1362         if (sign > 0)
1363                 qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1364         else
1365                 qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1366
1367         qgroup_dirty(fs_info, qgroup);
1368
1369         /* Get all of the parent groups that contain this qgroup */
1370         list_for_each_entry(glist, &qgroup->groups, next_group) {
1371                 ret = ulist_add(tmp, glist->group->qgroupid,
1372                                 qgroup_to_aux(glist->group), GFP_ATOMIC);
1373                 if (ret < 0)
1374                         goto out;
1375         }
1376
1377         /* Iterate all of the parents and adjust their reference counts */
1378         ULIST_ITER_INIT(&uiter);
1379         while ((unode = ulist_next(tmp, &uiter))) {
1380                 qgroup = unode_aux_to_qgroup(unode);
1381                 qgroup->rfer += sign * num_bytes;
1382                 qgroup->rfer_cmpr += sign * num_bytes;
1383                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1384                 qgroup->excl += sign * num_bytes;
1385                 if (sign > 0)
1386                         qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1387                 else
1388                         qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1389                 qgroup->excl_cmpr += sign * num_bytes;
1390                 qgroup_dirty(fs_info, qgroup);
1391
1392                 /* Add any parents of the parents */
1393                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1394                         ret = ulist_add(tmp, glist->group->qgroupid,
1395                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
1396                         if (ret < 0)
1397                                 goto out;
1398                 }
1399         }
1400         ret = 0;
1401 out:
1402         return ret;
1403 }
1404
1405
1406 /*
1407  * Quick path for updating qgroup with only excl refs.
1408  *
1409  * In that case, just update all parent will be enough.
1410  * Or we needs to do a full rescan.
1411  * Caller should also hold fs_info->qgroup_lock.
1412  *
1413  * Return 0 for quick update, return >0 for need to full rescan
1414  * and mark INCONSISTENT flag.
1415  * Return < 0 for other error.
1416  */
1417 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1418                                    struct ulist *tmp, u64 src, u64 dst,
1419                                    int sign)
1420 {
1421         struct btrfs_qgroup *qgroup;
1422         int ret = 1;
1423         int err = 0;
1424
1425         qgroup = find_qgroup_rb(fs_info, src);
1426         if (!qgroup)
1427                 goto out;
1428         if (qgroup->excl == qgroup->rfer) {
1429                 ret = 0;
1430                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1431                                                qgroup, sign);
1432                 if (err < 0) {
1433                         ret = err;
1434                         goto out;
1435                 }
1436         }
1437 out:
1438         if (ret)
1439                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1440         return ret;
1441 }
1442
1443 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1444                               u64 dst)
1445 {
1446         struct btrfs_fs_info *fs_info = trans->fs_info;
1447         struct btrfs_qgroup *parent;
1448         struct btrfs_qgroup *member;
1449         struct btrfs_qgroup_list *list;
1450         struct ulist *tmp;
1451         unsigned int nofs_flag;
1452         int ret = 0;
1453
1454         /* Check the level of src and dst first */
1455         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1456                 return -EINVAL;
1457
1458         /* We hold a transaction handle open, must do a NOFS allocation. */
1459         nofs_flag = memalloc_nofs_save();
1460         tmp = ulist_alloc(GFP_KERNEL);
1461         memalloc_nofs_restore(nofs_flag);
1462         if (!tmp)
1463                 return -ENOMEM;
1464
1465         mutex_lock(&fs_info->qgroup_ioctl_lock);
1466         if (!fs_info->quota_root) {
1467                 ret = -ENOTCONN;
1468                 goto out;
1469         }
1470         member = find_qgroup_rb(fs_info, src);
1471         parent = find_qgroup_rb(fs_info, dst);
1472         if (!member || !parent) {
1473                 ret = -EINVAL;
1474                 goto out;
1475         }
1476
1477         /* check if such qgroup relation exist firstly */
1478         list_for_each_entry(list, &member->groups, next_group) {
1479                 if (list->group == parent) {
1480                         ret = -EEXIST;
1481                         goto out;
1482                 }
1483         }
1484
1485         ret = add_qgroup_relation_item(trans, src, dst);
1486         if (ret)
1487                 goto out;
1488
1489         ret = add_qgroup_relation_item(trans, dst, src);
1490         if (ret) {
1491                 del_qgroup_relation_item(trans, src, dst);
1492                 goto out;
1493         }
1494
1495         spin_lock(&fs_info->qgroup_lock);
1496         ret = __add_relation_rb(member, parent);
1497         if (ret < 0) {
1498                 spin_unlock(&fs_info->qgroup_lock);
1499                 goto out;
1500         }
1501         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1502         spin_unlock(&fs_info->qgroup_lock);
1503 out:
1504         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1505         ulist_free(tmp);
1506         return ret;
1507 }
1508
1509 static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1510                                  u64 dst)
1511 {
1512         struct btrfs_fs_info *fs_info = trans->fs_info;
1513         struct btrfs_qgroup *parent;
1514         struct btrfs_qgroup *member;
1515         struct btrfs_qgroup_list *list;
1516         struct ulist *tmp;
1517         bool found = false;
1518         unsigned int nofs_flag;
1519         int ret = 0;
1520         int ret2;
1521
1522         /* We hold a transaction handle open, must do a NOFS allocation. */
1523         nofs_flag = memalloc_nofs_save();
1524         tmp = ulist_alloc(GFP_KERNEL);
1525         memalloc_nofs_restore(nofs_flag);
1526         if (!tmp)
1527                 return -ENOMEM;
1528
1529         if (!fs_info->quota_root) {
1530                 ret = -ENOTCONN;
1531                 goto out;
1532         }
1533
1534         member = find_qgroup_rb(fs_info, src);
1535         parent = find_qgroup_rb(fs_info, dst);
1536         /*
1537          * The parent/member pair doesn't exist, then try to delete the dead
1538          * relation items only.
1539          */
1540         if (!member || !parent)
1541                 goto delete_item;
1542
1543         /* check if such qgroup relation exist firstly */
1544         list_for_each_entry(list, &member->groups, next_group) {
1545                 if (list->group == parent) {
1546                         found = true;
1547                         break;
1548                 }
1549         }
1550
1551 delete_item:
1552         ret = del_qgroup_relation_item(trans, src, dst);
1553         if (ret < 0 && ret != -ENOENT)
1554                 goto out;
1555         ret2 = del_qgroup_relation_item(trans, dst, src);
1556         if (ret2 < 0 && ret2 != -ENOENT)
1557                 goto out;
1558
1559         /* At least one deletion succeeded, return 0 */
1560         if (!ret || !ret2)
1561                 ret = 0;
1562
1563         if (found) {
1564                 spin_lock(&fs_info->qgroup_lock);
1565                 del_relation_rb(fs_info, src, dst);
1566                 ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1567                 spin_unlock(&fs_info->qgroup_lock);
1568         }
1569 out:
1570         ulist_free(tmp);
1571         return ret;
1572 }
1573
1574 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1575                               u64 dst)
1576 {
1577         struct btrfs_fs_info *fs_info = trans->fs_info;
1578         int ret = 0;
1579
1580         mutex_lock(&fs_info->qgroup_ioctl_lock);
1581         ret = __del_qgroup_relation(trans, src, dst);
1582         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1583
1584         return ret;
1585 }
1586
1587 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1588 {
1589         struct btrfs_fs_info *fs_info = trans->fs_info;
1590         struct btrfs_root *quota_root;
1591         struct btrfs_qgroup *qgroup;
1592         int ret = 0;
1593
1594         mutex_lock(&fs_info->qgroup_ioctl_lock);
1595         if (!fs_info->quota_root) {
1596                 ret = -ENOTCONN;
1597                 goto out;
1598         }
1599         quota_root = fs_info->quota_root;
1600         qgroup = find_qgroup_rb(fs_info, qgroupid);
1601         if (qgroup) {
1602                 ret = -EEXIST;
1603                 goto out;
1604         }
1605
1606         ret = add_qgroup_item(trans, quota_root, qgroupid);
1607         if (ret)
1608                 goto out;
1609
1610         spin_lock(&fs_info->qgroup_lock);
1611         qgroup = add_qgroup_rb(fs_info, qgroupid);
1612         spin_unlock(&fs_info->qgroup_lock);
1613
1614         if (IS_ERR(qgroup)) {
1615                 ret = PTR_ERR(qgroup);
1616                 goto out;
1617         }
1618         ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1619 out:
1620         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1621         return ret;
1622 }
1623
1624 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1625 {
1626         struct btrfs_fs_info *fs_info = trans->fs_info;
1627         struct btrfs_qgroup *qgroup;
1628         struct btrfs_qgroup_list *list;
1629         int ret = 0;
1630
1631         mutex_lock(&fs_info->qgroup_ioctl_lock);
1632         if (!fs_info->quota_root) {
1633                 ret = -ENOTCONN;
1634                 goto out;
1635         }
1636
1637         qgroup = find_qgroup_rb(fs_info, qgroupid);
1638         if (!qgroup) {
1639                 ret = -ENOENT;
1640                 goto out;
1641         }
1642
1643         /* Check if there are no children of this qgroup */
1644         if (!list_empty(&qgroup->members)) {
1645                 ret = -EBUSY;
1646                 goto out;
1647         }
1648
1649         ret = del_qgroup_item(trans, qgroupid);
1650         if (ret && ret != -ENOENT)
1651                 goto out;
1652
1653         while (!list_empty(&qgroup->groups)) {
1654                 list = list_first_entry(&qgroup->groups,
1655                                         struct btrfs_qgroup_list, next_group);
1656                 ret = __del_qgroup_relation(trans, qgroupid,
1657                                             list->group->qgroupid);
1658                 if (ret)
1659                         goto out;
1660         }
1661
1662         spin_lock(&fs_info->qgroup_lock);
1663         del_qgroup_rb(fs_info, qgroupid);
1664         spin_unlock(&fs_info->qgroup_lock);
1665
1666         /*
1667          * Remove the qgroup from sysfs now without holding the qgroup_lock
1668          * spinlock, since the sysfs_remove_group() function needs to take
1669          * the mutex kernfs_mutex through kernfs_remove_by_name_ns().
1670          */
1671         btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1672         kfree(qgroup);
1673 out:
1674         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1675         return ret;
1676 }
1677
1678 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1679                        struct btrfs_qgroup_limit *limit)
1680 {
1681         struct btrfs_fs_info *fs_info = trans->fs_info;
1682         struct btrfs_qgroup *qgroup;
1683         int ret = 0;
1684         /* Sometimes we would want to clear the limit on this qgroup.
1685          * To meet this requirement, we treat the -1 as a special value
1686          * which tell kernel to clear the limit on this qgroup.
1687          */
1688         const u64 CLEAR_VALUE = -1;
1689
1690         mutex_lock(&fs_info->qgroup_ioctl_lock);
1691         if (!fs_info->quota_root) {
1692                 ret = -ENOTCONN;
1693                 goto out;
1694         }
1695
1696         qgroup = find_qgroup_rb(fs_info, qgroupid);
1697         if (!qgroup) {
1698                 ret = -ENOENT;
1699                 goto out;
1700         }
1701
1702         spin_lock(&fs_info->qgroup_lock);
1703         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1704                 if (limit->max_rfer == CLEAR_VALUE) {
1705                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1706                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1707                         qgroup->max_rfer = 0;
1708                 } else {
1709                         qgroup->max_rfer = limit->max_rfer;
1710                 }
1711         }
1712         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1713                 if (limit->max_excl == CLEAR_VALUE) {
1714                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1715                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1716                         qgroup->max_excl = 0;
1717                 } else {
1718                         qgroup->max_excl = limit->max_excl;
1719                 }
1720         }
1721         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1722                 if (limit->rsv_rfer == CLEAR_VALUE) {
1723                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1724                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1725                         qgroup->rsv_rfer = 0;
1726                 } else {
1727                         qgroup->rsv_rfer = limit->rsv_rfer;
1728                 }
1729         }
1730         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1731                 if (limit->rsv_excl == CLEAR_VALUE) {
1732                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1733                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1734                         qgroup->rsv_excl = 0;
1735                 } else {
1736                         qgroup->rsv_excl = limit->rsv_excl;
1737                 }
1738         }
1739         qgroup->lim_flags |= limit->flags;
1740
1741         spin_unlock(&fs_info->qgroup_lock);
1742
1743         ret = update_qgroup_limit_item(trans, qgroup);
1744         if (ret) {
1745                 qgroup_mark_inconsistent(fs_info);
1746                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1747                        qgroupid);
1748         }
1749
1750 out:
1751         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1752         return ret;
1753 }
1754
1755 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1756                                 struct btrfs_delayed_ref_root *delayed_refs,
1757                                 struct btrfs_qgroup_extent_record *record)
1758 {
1759         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1760         struct rb_node *parent_node = NULL;
1761         struct btrfs_qgroup_extent_record *entry;
1762         u64 bytenr = record->bytenr;
1763
1764         lockdep_assert_held(&delayed_refs->lock);
1765         trace_btrfs_qgroup_trace_extent(fs_info, record);
1766
1767         while (*p) {
1768                 parent_node = *p;
1769                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1770                                  node);
1771                 if (bytenr < entry->bytenr) {
1772                         p = &(*p)->rb_left;
1773                 } else if (bytenr > entry->bytenr) {
1774                         p = &(*p)->rb_right;
1775                 } else {
1776                         if (record->data_rsv && !entry->data_rsv) {
1777                                 entry->data_rsv = record->data_rsv;
1778                                 entry->data_rsv_refroot =
1779                                         record->data_rsv_refroot;
1780                         }
1781                         return 1;
1782                 }
1783         }
1784
1785         rb_link_node(&record->node, parent_node, p);
1786         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1787         return 0;
1788 }
1789
1790 int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
1791                                    struct btrfs_qgroup_extent_record *qrecord)
1792 {
1793         struct ulist *old_root;
1794         u64 bytenr = qrecord->bytenr;
1795         int ret;
1796
1797         /*
1798          * We are always called in a context where we are already holding a
1799          * transaction handle. Often we are called when adding a data delayed
1800          * reference from btrfs_truncate_inode_items() (truncating or unlinking),
1801          * in which case we will be holding a write lock on extent buffer from a
1802          * subvolume tree. In this case we can't allow btrfs_find_all_roots() to
1803          * acquire fs_info->commit_root_sem, because that is a higher level lock
1804          * that must be acquired before locking any extent buffers.
1805          *
1806          * So we want btrfs_find_all_roots() to not acquire the commit_root_sem
1807          * but we can't pass it a non-NULL transaction handle, because otherwise
1808          * it would not use commit roots and would lock extent buffers, causing
1809          * a deadlock if it ends up trying to read lock the same extent buffer
1810          * that was previously write locked at btrfs_truncate_inode_items().
1811          *
1812          * So pass a NULL transaction handle to btrfs_find_all_roots() and
1813          * explicitly tell it to not acquire the commit_root_sem - if we are
1814          * holding a transaction handle we don't need its protection.
1815          */
1816         ASSERT(trans != NULL);
1817
1818         if (trans->fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)
1819                 return 0;
1820
1821         ret = btrfs_find_all_roots(NULL, trans->fs_info, bytenr, 0, &old_root,
1822                                    true);
1823         if (ret < 0) {
1824                 qgroup_mark_inconsistent(trans->fs_info);
1825                 btrfs_warn(trans->fs_info,
1826 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1827                         ret);
1828                 return 0;
1829         }
1830
1831         /*
1832          * Here we don't need to get the lock of
1833          * trans->transaction->delayed_refs, since inserted qrecord won't
1834          * be deleted, only qrecord->node may be modified (new qrecord insert)
1835          *
1836          * So modifying qrecord->old_roots is safe here
1837          */
1838         qrecord->old_roots = old_root;
1839         return 0;
1840 }
1841
1842 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1843                               u64 num_bytes, gfp_t gfp_flag)
1844 {
1845         struct btrfs_fs_info *fs_info = trans->fs_info;
1846         struct btrfs_qgroup_extent_record *record;
1847         struct btrfs_delayed_ref_root *delayed_refs;
1848         int ret;
1849
1850         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1851             || bytenr == 0 || num_bytes == 0)
1852                 return 0;
1853         record = kzalloc(sizeof(*record), gfp_flag);
1854         if (!record)
1855                 return -ENOMEM;
1856
1857         delayed_refs = &trans->transaction->delayed_refs;
1858         record->bytenr = bytenr;
1859         record->num_bytes = num_bytes;
1860         record->old_roots = NULL;
1861
1862         spin_lock(&delayed_refs->lock);
1863         ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1864         spin_unlock(&delayed_refs->lock);
1865         if (ret > 0) {
1866                 kfree(record);
1867                 return 0;
1868         }
1869         return btrfs_qgroup_trace_extent_post(trans, record);
1870 }
1871
1872 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1873                                   struct extent_buffer *eb)
1874 {
1875         struct btrfs_fs_info *fs_info = trans->fs_info;
1876         int nr = btrfs_header_nritems(eb);
1877         int i, extent_type, ret;
1878         struct btrfs_key key;
1879         struct btrfs_file_extent_item *fi;
1880         u64 bytenr, num_bytes;
1881
1882         /* We can be called directly from walk_up_proc() */
1883         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1884                 return 0;
1885
1886         for (i = 0; i < nr; i++) {
1887                 btrfs_item_key_to_cpu(eb, &key, i);
1888
1889                 if (key.type != BTRFS_EXTENT_DATA_KEY)
1890                         continue;
1891
1892                 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1893                 /* filter out non qgroup-accountable extents  */
1894                 extent_type = btrfs_file_extent_type(eb, fi);
1895
1896                 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1897                         continue;
1898
1899                 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1900                 if (!bytenr)
1901                         continue;
1902
1903                 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1904
1905                 ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes,
1906                                                 GFP_NOFS);
1907                 if (ret)
1908                         return ret;
1909         }
1910         cond_resched();
1911         return 0;
1912 }
1913
1914 /*
1915  * Walk up the tree from the bottom, freeing leaves and any interior
1916  * nodes which have had all slots visited. If a node (leaf or
1917  * interior) is freed, the node above it will have it's slot
1918  * incremented. The root node will never be freed.
1919  *
1920  * At the end of this function, we should have a path which has all
1921  * slots incremented to the next position for a search. If we need to
1922  * read a new node it will be NULL and the node above it will have the
1923  * correct slot selected for a later read.
1924  *
1925  * If we increment the root nodes slot counter past the number of
1926  * elements, 1 is returned to signal completion of the search.
1927  */
1928 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1929 {
1930         int level = 0;
1931         int nr, slot;
1932         struct extent_buffer *eb;
1933
1934         if (root_level == 0)
1935                 return 1;
1936
1937         while (level <= root_level) {
1938                 eb = path->nodes[level];
1939                 nr = btrfs_header_nritems(eb);
1940                 path->slots[level]++;
1941                 slot = path->slots[level];
1942                 if (slot >= nr || level == 0) {
1943                         /*
1944                          * Don't free the root -  we will detect this
1945                          * condition after our loop and return a
1946                          * positive value for caller to stop walking the tree.
1947                          */
1948                         if (level != root_level) {
1949                                 btrfs_tree_unlock_rw(eb, path->locks[level]);
1950                                 path->locks[level] = 0;
1951
1952                                 free_extent_buffer(eb);
1953                                 path->nodes[level] = NULL;
1954                                 path->slots[level] = 0;
1955                         }
1956                 } else {
1957                         /*
1958                          * We have a valid slot to walk back down
1959                          * from. Stop here so caller can process these
1960                          * new nodes.
1961                          */
1962                         break;
1963                 }
1964
1965                 level++;
1966         }
1967
1968         eb = path->nodes[root_level];
1969         if (path->slots[root_level] >= btrfs_header_nritems(eb))
1970                 return 1;
1971
1972         return 0;
1973 }
1974
1975 /*
1976  * Helper function to trace a subtree tree block swap.
1977  *
1978  * The swap will happen in highest tree block, but there may be a lot of
1979  * tree blocks involved.
1980  *
1981  * For example:
1982  *  OO = Old tree blocks
1983  *  NN = New tree blocks allocated during balance
1984  *
1985  *           File tree (257)                  Reloc tree for 257
1986  * L2              OO                                NN
1987  *               /    \                            /    \
1988  * L1          OO      OO (a)                    OO      NN (a)
1989  *            / \     / \                       / \     / \
1990  * L0       OO   OO OO   OO                   OO   OO NN   NN
1991  *                  (b)  (c)                          (b)  (c)
1992  *
1993  * When calling qgroup_trace_extent_swap(), we will pass:
1994  * @src_eb = OO(a)
1995  * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
1996  * @dst_level = 0
1997  * @root_level = 1
1998  *
1999  * In that case, qgroup_trace_extent_swap() will search from OO(a) to
2000  * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
2001  *
2002  * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
2003  *
2004  * 1) Tree search from @src_eb
2005  *    It should acts as a simplified btrfs_search_slot().
2006  *    The key for search can be extracted from @dst_path->nodes[dst_level]
2007  *    (first key).
2008  *
2009  * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
2010  *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
2011  *    They should be marked during previous (@dst_level = 1) iteration.
2012  *
2013  * 3) Mark file extents in leaves dirty
2014  *    We don't have good way to pick out new file extents only.
2015  *    So we still follow the old method by scanning all file extents in
2016  *    the leave.
2017  *
2018  * This function can free us from keeping two paths, thus later we only need
2019  * to care about how to iterate all new tree blocks in reloc tree.
2020  */
2021 static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
2022                                     struct extent_buffer *src_eb,
2023                                     struct btrfs_path *dst_path,
2024                                     int dst_level, int root_level,
2025                                     bool trace_leaf)
2026 {
2027         struct btrfs_key key;
2028         struct btrfs_path *src_path;
2029         struct btrfs_fs_info *fs_info = trans->fs_info;
2030         u32 nodesize = fs_info->nodesize;
2031         int cur_level = root_level;
2032         int ret;
2033
2034         BUG_ON(dst_level > root_level);
2035         /* Level mismatch */
2036         if (btrfs_header_level(src_eb) != root_level)
2037                 return -EINVAL;
2038
2039         src_path = btrfs_alloc_path();
2040         if (!src_path) {
2041                 ret = -ENOMEM;
2042                 goto out;
2043         }
2044
2045         if (dst_level)
2046                 btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2047         else
2048                 btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2049
2050         /* For src_path */
2051         atomic_inc(&src_eb->refs);
2052         src_path->nodes[root_level] = src_eb;
2053         src_path->slots[root_level] = dst_path->slots[root_level];
2054         src_path->locks[root_level] = 0;
2055
2056         /* A simplified version of btrfs_search_slot() */
2057         while (cur_level >= dst_level) {
2058                 struct btrfs_key src_key;
2059                 struct btrfs_key dst_key;
2060
2061                 if (src_path->nodes[cur_level] == NULL) {
2062                         struct extent_buffer *eb;
2063                         int parent_slot;
2064
2065                         eb = src_path->nodes[cur_level + 1];
2066                         parent_slot = src_path->slots[cur_level + 1];
2067
2068                         eb = btrfs_read_node_slot(eb, parent_slot);
2069                         if (IS_ERR(eb)) {
2070                                 ret = PTR_ERR(eb);
2071                                 goto out;
2072                         }
2073
2074                         src_path->nodes[cur_level] = eb;
2075
2076                         btrfs_tree_read_lock(eb);
2077                         src_path->locks[cur_level] = BTRFS_READ_LOCK;
2078                 }
2079
2080                 src_path->slots[cur_level] = dst_path->slots[cur_level];
2081                 if (cur_level) {
2082                         btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
2083                                         &dst_key, dst_path->slots[cur_level]);
2084                         btrfs_node_key_to_cpu(src_path->nodes[cur_level],
2085                                         &src_key, src_path->slots[cur_level]);
2086                 } else {
2087                         btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
2088                                         &dst_key, dst_path->slots[cur_level]);
2089                         btrfs_item_key_to_cpu(src_path->nodes[cur_level],
2090                                         &src_key, src_path->slots[cur_level]);
2091                 }
2092                 /* Content mismatch, something went wrong */
2093                 if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
2094                         ret = -ENOENT;
2095                         goto out;
2096                 }
2097                 cur_level--;
2098         }
2099
2100         /*
2101          * Now both @dst_path and @src_path have been populated, record the tree
2102          * blocks for qgroup accounting.
2103          */
2104         ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
2105                         nodesize, GFP_NOFS);
2106         if (ret < 0)
2107                 goto out;
2108         ret = btrfs_qgroup_trace_extent(trans,
2109                         dst_path->nodes[dst_level]->start,
2110                         nodesize, GFP_NOFS);
2111         if (ret < 0)
2112                 goto out;
2113
2114         /* Record leaf file extents */
2115         if (dst_level == 0 && trace_leaf) {
2116                 ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
2117                 if (ret < 0)
2118                         goto out;
2119                 ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
2120         }
2121 out:
2122         btrfs_free_path(src_path);
2123         return ret;
2124 }
2125
2126 /*
2127  * Helper function to do recursive generation-aware depth-first search, to
2128  * locate all new tree blocks in a subtree of reloc tree.
2129  *
2130  * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
2131  *         reloc tree
2132  * L2         NN (a)
2133  *          /    \
2134  * L1    OO        NN (b)
2135  *      /  \      /  \
2136  * L0  OO  OO    OO  NN
2137  *               (c) (d)
2138  * If we pass:
2139  * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
2140  * @cur_level = 1
2141  * @root_level = 1
2142  *
2143  * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
2144  * above tree blocks along with their counter parts in file tree.
2145  * While during search, old tree blocks OO(c) will be skipped as tree block swap
2146  * won't affect OO(c).
2147  */
2148 static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
2149                                            struct extent_buffer *src_eb,
2150                                            struct btrfs_path *dst_path,
2151                                            int cur_level, int root_level,
2152                                            u64 last_snapshot, bool trace_leaf)
2153 {
2154         struct btrfs_fs_info *fs_info = trans->fs_info;
2155         struct extent_buffer *eb;
2156         bool need_cleanup = false;
2157         int ret = 0;
2158         int i;
2159
2160         /* Level sanity check */
2161         if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
2162             root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
2163             root_level < cur_level) {
2164                 btrfs_err_rl(fs_info,
2165                         "%s: bad levels, cur_level=%d root_level=%d",
2166                         __func__, cur_level, root_level);
2167                 return -EUCLEAN;
2168         }
2169
2170         /* Read the tree block if needed */
2171         if (dst_path->nodes[cur_level] == NULL) {
2172                 int parent_slot;
2173                 u64 child_gen;
2174
2175                 /*
2176                  * dst_path->nodes[root_level] must be initialized before
2177                  * calling this function.
2178                  */
2179                 if (cur_level == root_level) {
2180                         btrfs_err_rl(fs_info,
2181         "%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
2182                                 __func__, root_level, root_level, cur_level);
2183                         return -EUCLEAN;
2184                 }
2185
2186                 /*
2187                  * We need to get child blockptr/gen from parent before we can
2188                  * read it.
2189                   */
2190                 eb = dst_path->nodes[cur_level + 1];
2191                 parent_slot = dst_path->slots[cur_level + 1];
2192                 child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2193
2194                 /* This node is old, no need to trace */
2195                 if (child_gen < last_snapshot)
2196                         goto out;
2197
2198                 eb = btrfs_read_node_slot(eb, parent_slot);
2199                 if (IS_ERR(eb)) {
2200                         ret = PTR_ERR(eb);
2201                         goto out;
2202                 }
2203
2204                 dst_path->nodes[cur_level] = eb;
2205                 dst_path->slots[cur_level] = 0;
2206
2207                 btrfs_tree_read_lock(eb);
2208                 dst_path->locks[cur_level] = BTRFS_READ_LOCK;
2209                 need_cleanup = true;
2210         }
2211
2212         /* Now record this tree block and its counter part for qgroups */
2213         ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
2214                                        root_level, trace_leaf);
2215         if (ret < 0)
2216                 goto cleanup;
2217
2218         eb = dst_path->nodes[cur_level];
2219
2220         if (cur_level > 0) {
2221                 /* Iterate all child tree blocks */
2222                 for (i = 0; i < btrfs_header_nritems(eb); i++) {
2223                         /* Skip old tree blocks as they won't be swapped */
2224                         if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
2225                                 continue;
2226                         dst_path->slots[cur_level] = i;
2227
2228                         /* Recursive call (at most 7 times) */
2229                         ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
2230                                         dst_path, cur_level - 1, root_level,
2231                                         last_snapshot, trace_leaf);
2232                         if (ret < 0)
2233                                 goto cleanup;
2234                 }
2235         }
2236
2237 cleanup:
2238         if (need_cleanup) {
2239                 /* Clean up */
2240                 btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2241                                      dst_path->locks[cur_level]);
2242                 free_extent_buffer(dst_path->nodes[cur_level]);
2243                 dst_path->nodes[cur_level] = NULL;
2244                 dst_path->slots[cur_level] = 0;
2245                 dst_path->locks[cur_level] = 0;
2246         }
2247 out:
2248         return ret;
2249 }
2250
2251 static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2252                                 struct extent_buffer *src_eb,
2253                                 struct extent_buffer *dst_eb,
2254                                 u64 last_snapshot, bool trace_leaf)
2255 {
2256         struct btrfs_fs_info *fs_info = trans->fs_info;
2257         struct btrfs_path *dst_path = NULL;
2258         int level;
2259         int ret;
2260
2261         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2262                 return 0;
2263
2264         /* Wrong parameter order */
2265         if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
2266                 btrfs_err_rl(fs_info,
2267                 "%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2268                              btrfs_header_generation(src_eb),
2269                              btrfs_header_generation(dst_eb));
2270                 return -EUCLEAN;
2271         }
2272
2273         if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2274                 ret = -EIO;
2275                 goto out;
2276         }
2277
2278         level = btrfs_header_level(dst_eb);
2279         dst_path = btrfs_alloc_path();
2280         if (!dst_path) {
2281                 ret = -ENOMEM;
2282                 goto out;
2283         }
2284         /* For dst_path */
2285         atomic_inc(&dst_eb->refs);
2286         dst_path->nodes[level] = dst_eb;
2287         dst_path->slots[level] = 0;
2288         dst_path->locks[level] = 0;
2289
2290         /* Do the generation aware breadth-first search */
2291         ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2292                                               level, last_snapshot, trace_leaf);
2293         if (ret < 0)
2294                 goto out;
2295         ret = 0;
2296
2297 out:
2298         btrfs_free_path(dst_path);
2299         if (ret < 0)
2300                 qgroup_mark_inconsistent(fs_info);
2301         return ret;
2302 }
2303
2304 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2305                                struct extent_buffer *root_eb,
2306                                u64 root_gen, int root_level)
2307 {
2308         struct btrfs_fs_info *fs_info = trans->fs_info;
2309         int ret = 0;
2310         int level;
2311         u8 drop_subptree_thres;
2312         struct extent_buffer *eb = root_eb;
2313         struct btrfs_path *path = NULL;
2314
2315         BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2316         BUG_ON(root_eb == NULL);
2317
2318         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2319                 return 0;
2320
2321         spin_lock(&fs_info->qgroup_lock);
2322         drop_subptree_thres = fs_info->qgroup_drop_subtree_thres;
2323         spin_unlock(&fs_info->qgroup_lock);
2324
2325         /*
2326          * This function only gets called for snapshot drop, if we hit a high
2327          * node here, it means we are going to change ownership for quite a lot
2328          * of extents, which will greatly slow down btrfs_commit_transaction().
2329          *
2330          * So here if we find a high tree here, we just skip the accounting and
2331          * mark qgroup inconsistent.
2332          */
2333         if (root_level >= drop_subptree_thres) {
2334                 qgroup_mark_inconsistent(fs_info);
2335                 return 0;
2336         }
2337
2338         if (!extent_buffer_uptodate(root_eb)) {
2339                 ret = btrfs_read_extent_buffer(root_eb, root_gen, root_level, NULL);
2340                 if (ret)
2341                         goto out;
2342         }
2343
2344         if (root_level == 0) {
2345                 ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2346                 goto out;
2347         }
2348
2349         path = btrfs_alloc_path();
2350         if (!path)
2351                 return -ENOMEM;
2352
2353         /*
2354          * Walk down the tree.  Missing extent blocks are filled in as
2355          * we go. Metadata is accounted every time we read a new
2356          * extent block.
2357          *
2358          * When we reach a leaf, we account for file extent items in it,
2359          * walk back up the tree (adjusting slot pointers as we go)
2360          * and restart the search process.
2361          */
2362         atomic_inc(&root_eb->refs);     /* For path */
2363         path->nodes[root_level] = root_eb;
2364         path->slots[root_level] = 0;
2365         path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2366 walk_down:
2367         level = root_level;
2368         while (level >= 0) {
2369                 if (path->nodes[level] == NULL) {
2370                         int parent_slot;
2371                         u64 child_bytenr;
2372
2373                         /*
2374                          * We need to get child blockptr from parent before we
2375                          * can read it.
2376                           */
2377                         eb = path->nodes[level + 1];
2378                         parent_slot = path->slots[level + 1];
2379                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2380
2381                         eb = btrfs_read_node_slot(eb, parent_slot);
2382                         if (IS_ERR(eb)) {
2383                                 ret = PTR_ERR(eb);
2384                                 goto out;
2385                         }
2386
2387                         path->nodes[level] = eb;
2388                         path->slots[level] = 0;
2389
2390                         btrfs_tree_read_lock(eb);
2391                         path->locks[level] = BTRFS_READ_LOCK;
2392
2393                         ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2394                                                         fs_info->nodesize,
2395                                                         GFP_NOFS);
2396                         if (ret)
2397                                 goto out;
2398                 }
2399
2400                 if (level == 0) {
2401                         ret = btrfs_qgroup_trace_leaf_items(trans,
2402                                                             path->nodes[level]);
2403                         if (ret)
2404                                 goto out;
2405
2406                         /* Nonzero return here means we completed our search */
2407                         ret = adjust_slots_upwards(path, root_level);
2408                         if (ret)
2409                                 break;
2410
2411                         /* Restart search with new slots */
2412                         goto walk_down;
2413                 }
2414
2415                 level--;
2416         }
2417
2418         ret = 0;
2419 out:
2420         btrfs_free_path(path);
2421
2422         return ret;
2423 }
2424
2425 #define UPDATE_NEW      0
2426 #define UPDATE_OLD      1
2427 /*
2428  * Walk all of the roots that points to the bytenr and adjust their refcnts.
2429  */
2430 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2431                                 struct ulist *roots, struct ulist *tmp,
2432                                 struct ulist *qgroups, u64 seq, int update_old)
2433 {
2434         struct ulist_node *unode;
2435         struct ulist_iterator uiter;
2436         struct ulist_node *tmp_unode;
2437         struct ulist_iterator tmp_uiter;
2438         struct btrfs_qgroup *qg;
2439         int ret = 0;
2440
2441         if (!roots)
2442                 return 0;
2443         ULIST_ITER_INIT(&uiter);
2444         while ((unode = ulist_next(roots, &uiter))) {
2445                 qg = find_qgroup_rb(fs_info, unode->val);
2446                 if (!qg)
2447                         continue;
2448
2449                 ulist_reinit(tmp);
2450                 ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2451                                 GFP_ATOMIC);
2452                 if (ret < 0)
2453                         return ret;
2454                 ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2455                 if (ret < 0)
2456                         return ret;
2457                 ULIST_ITER_INIT(&tmp_uiter);
2458                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2459                         struct btrfs_qgroup_list *glist;
2460
2461                         qg = unode_aux_to_qgroup(tmp_unode);
2462                         if (update_old)
2463                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2464                         else
2465                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2466                         list_for_each_entry(glist, &qg->groups, next_group) {
2467                                 ret = ulist_add(qgroups, glist->group->qgroupid,
2468                                                 qgroup_to_aux(glist->group),
2469                                                 GFP_ATOMIC);
2470                                 if (ret < 0)
2471                                         return ret;
2472                                 ret = ulist_add(tmp, glist->group->qgroupid,
2473                                                 qgroup_to_aux(glist->group),
2474                                                 GFP_ATOMIC);
2475                                 if (ret < 0)
2476                                         return ret;
2477                         }
2478                 }
2479         }
2480         return 0;
2481 }
2482
2483 /*
2484  * Update qgroup rfer/excl counters.
2485  * Rfer update is easy, codes can explain themselves.
2486  *
2487  * Excl update is tricky, the update is split into 2 parts.
2488  * Part 1: Possible exclusive <-> sharing detect:
2489  *      |       A       |       !A      |
2490  *  -------------------------------------
2491  *  B   |       *       |       -       |
2492  *  -------------------------------------
2493  *  !B  |       +       |       **      |
2494  *  -------------------------------------
2495  *
2496  * Conditions:
2497  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
2498  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
2499  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
2500  * !B:  cur_new_roots == nr_new_roots   (possible exclusive now)
2501  *
2502  * Results:
2503  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
2504  * *: Definitely not changed.           **: Possible unchanged.
2505  *
2506  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2507  *
2508  * To make the logic clear, we first use condition A and B to split
2509  * combination into 4 results.
2510  *
2511  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2512  * only on variant maybe 0.
2513  *
2514  * Lastly, check result **, since there are 2 variants maybe 0, split them
2515  * again(2x2).
2516  * But this time we don't need to consider other things, the codes and logic
2517  * is easy to understand now.
2518  */
2519 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2520                                   struct ulist *qgroups,
2521                                   u64 nr_old_roots,
2522                                   u64 nr_new_roots,
2523                                   u64 num_bytes, u64 seq)
2524 {
2525         struct ulist_node *unode;
2526         struct ulist_iterator uiter;
2527         struct btrfs_qgroup *qg;
2528         u64 cur_new_count, cur_old_count;
2529
2530         ULIST_ITER_INIT(&uiter);
2531         while ((unode = ulist_next(qgroups, &uiter))) {
2532                 bool dirty = false;
2533
2534                 qg = unode_aux_to_qgroup(unode);
2535                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2536                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2537
2538                 trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2539                                              cur_new_count);
2540
2541                 /* Rfer update part */
2542                 if (cur_old_count == 0 && cur_new_count > 0) {
2543                         qg->rfer += num_bytes;
2544                         qg->rfer_cmpr += num_bytes;
2545                         dirty = true;
2546                 }
2547                 if (cur_old_count > 0 && cur_new_count == 0) {
2548                         qg->rfer -= num_bytes;
2549                         qg->rfer_cmpr -= num_bytes;
2550                         dirty = true;
2551                 }
2552
2553                 /* Excl update part */
2554                 /* Exclusive/none -> shared case */
2555                 if (cur_old_count == nr_old_roots &&
2556                     cur_new_count < nr_new_roots) {
2557                         /* Exclusive -> shared */
2558                         if (cur_old_count != 0) {
2559                                 qg->excl -= num_bytes;
2560                                 qg->excl_cmpr -= num_bytes;
2561                                 dirty = true;
2562                         }
2563                 }
2564
2565                 /* Shared -> exclusive/none case */
2566                 if (cur_old_count < nr_old_roots &&
2567                     cur_new_count == nr_new_roots) {
2568                         /* Shared->exclusive */
2569                         if (cur_new_count != 0) {
2570                                 qg->excl += num_bytes;
2571                                 qg->excl_cmpr += num_bytes;
2572                                 dirty = true;
2573                         }
2574                 }
2575
2576                 /* Exclusive/none -> exclusive/none case */
2577                 if (cur_old_count == nr_old_roots &&
2578                     cur_new_count == nr_new_roots) {
2579                         if (cur_old_count == 0) {
2580                                 /* None -> exclusive/none */
2581
2582                                 if (cur_new_count != 0) {
2583                                         /* None -> exclusive */
2584                                         qg->excl += num_bytes;
2585                                         qg->excl_cmpr += num_bytes;
2586                                         dirty = true;
2587                                 }
2588                                 /* None -> none, nothing changed */
2589                         } else {
2590                                 /* Exclusive -> exclusive/none */
2591
2592                                 if (cur_new_count == 0) {
2593                                         /* Exclusive -> none */
2594                                         qg->excl -= num_bytes;
2595                                         qg->excl_cmpr -= num_bytes;
2596                                         dirty = true;
2597                                 }
2598                                 /* Exclusive -> exclusive, nothing changed */
2599                         }
2600                 }
2601
2602                 if (dirty)
2603                         qgroup_dirty(fs_info, qg);
2604         }
2605         return 0;
2606 }
2607
2608 /*
2609  * Check if the @roots potentially is a list of fs tree roots
2610  *
2611  * Return 0 for definitely not a fs/subvol tree roots ulist
2612  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2613  *          one as well)
2614  */
2615 static int maybe_fs_roots(struct ulist *roots)
2616 {
2617         struct ulist_node *unode;
2618         struct ulist_iterator uiter;
2619
2620         /* Empty one, still possible for fs roots */
2621         if (!roots || roots->nnodes == 0)
2622                 return 1;
2623
2624         ULIST_ITER_INIT(&uiter);
2625         unode = ulist_next(roots, &uiter);
2626         if (!unode)
2627                 return 1;
2628
2629         /*
2630          * If it contains fs tree roots, then it must belong to fs/subvol
2631          * trees.
2632          * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2633          */
2634         return is_fstree(unode->val);
2635 }
2636
2637 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2638                                 u64 num_bytes, struct ulist *old_roots,
2639                                 struct ulist *new_roots)
2640 {
2641         struct btrfs_fs_info *fs_info = trans->fs_info;
2642         struct ulist *qgroups = NULL;
2643         struct ulist *tmp = NULL;
2644         u64 seq;
2645         u64 nr_new_roots = 0;
2646         u64 nr_old_roots = 0;
2647         int ret = 0;
2648
2649         /*
2650          * If quotas get disabled meanwhile, the resources need to be freed and
2651          * we can't just exit here.
2652          */
2653         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
2654             fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)
2655                 goto out_free;
2656
2657         if (new_roots) {
2658                 if (!maybe_fs_roots(new_roots))
2659                         goto out_free;
2660                 nr_new_roots = new_roots->nnodes;
2661         }
2662         if (old_roots) {
2663                 if (!maybe_fs_roots(old_roots))
2664                         goto out_free;
2665                 nr_old_roots = old_roots->nnodes;
2666         }
2667
2668         /* Quick exit, either not fs tree roots, or won't affect any qgroup */
2669         if (nr_old_roots == 0 && nr_new_roots == 0)
2670                 goto out_free;
2671
2672         BUG_ON(!fs_info->quota_root);
2673
2674         trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2675                                         num_bytes, nr_old_roots, nr_new_roots);
2676
2677         qgroups = ulist_alloc(GFP_NOFS);
2678         if (!qgroups) {
2679                 ret = -ENOMEM;
2680                 goto out_free;
2681         }
2682         tmp = ulist_alloc(GFP_NOFS);
2683         if (!tmp) {
2684                 ret = -ENOMEM;
2685                 goto out_free;
2686         }
2687
2688         mutex_lock(&fs_info->qgroup_rescan_lock);
2689         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2690                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2691                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2692                         ret = 0;
2693                         goto out_free;
2694                 }
2695         }
2696         mutex_unlock(&fs_info->qgroup_rescan_lock);
2697
2698         spin_lock(&fs_info->qgroup_lock);
2699         seq = fs_info->qgroup_seq;
2700
2701         /* Update old refcnts using old_roots */
2702         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2703                                    UPDATE_OLD);
2704         if (ret < 0)
2705                 goto out;
2706
2707         /* Update new refcnts using new_roots */
2708         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2709                                    UPDATE_NEW);
2710         if (ret < 0)
2711                 goto out;
2712
2713         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2714                                num_bytes, seq);
2715
2716         /*
2717          * Bump qgroup_seq to avoid seq overlap
2718          */
2719         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2720 out:
2721         spin_unlock(&fs_info->qgroup_lock);
2722 out_free:
2723         ulist_free(tmp);
2724         ulist_free(qgroups);
2725         ulist_free(old_roots);
2726         ulist_free(new_roots);
2727         return ret;
2728 }
2729
2730 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2731 {
2732         struct btrfs_fs_info *fs_info = trans->fs_info;
2733         struct btrfs_qgroup_extent_record *record;
2734         struct btrfs_delayed_ref_root *delayed_refs;
2735         struct ulist *new_roots = NULL;
2736         struct rb_node *node;
2737         u64 num_dirty_extents = 0;
2738         u64 qgroup_to_skip;
2739         int ret = 0;
2740
2741         delayed_refs = &trans->transaction->delayed_refs;
2742         qgroup_to_skip = delayed_refs->qgroup_to_skip;
2743         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2744                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
2745                                   node);
2746
2747                 num_dirty_extents++;
2748                 trace_btrfs_qgroup_account_extents(fs_info, record);
2749
2750                 if (!ret && !(fs_info->qgroup_flags &
2751                               BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)) {
2752                         /*
2753                          * Old roots should be searched when inserting qgroup
2754                          * extent record
2755                          */
2756                         if (WARN_ON(!record->old_roots)) {
2757                                 /* Search commit root to find old_roots */
2758                                 ret = btrfs_find_all_roots(NULL, fs_info,
2759                                                 record->bytenr, 0,
2760                                                 &record->old_roots, false);
2761                                 if (ret < 0)
2762                                         goto cleanup;
2763                         }
2764
2765                         /* Free the reserved data space */
2766                         btrfs_qgroup_free_refroot(fs_info,
2767                                         record->data_rsv_refroot,
2768                                         record->data_rsv,
2769                                         BTRFS_QGROUP_RSV_DATA);
2770                         /*
2771                          * Use BTRFS_SEQ_LAST as time_seq to do special search,
2772                          * which doesn't lock tree or delayed_refs and search
2773                          * current root. It's safe inside commit_transaction().
2774                          */
2775                         ret = btrfs_find_all_roots(trans, fs_info,
2776                            record->bytenr, BTRFS_SEQ_LAST, &new_roots, false);
2777                         if (ret < 0)
2778                                 goto cleanup;
2779                         if (qgroup_to_skip) {
2780                                 ulist_del(new_roots, qgroup_to_skip, 0);
2781                                 ulist_del(record->old_roots, qgroup_to_skip,
2782                                           0);
2783                         }
2784                         ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2785                                                           record->num_bytes,
2786                                                           record->old_roots,
2787                                                           new_roots);
2788                         record->old_roots = NULL;
2789                         new_roots = NULL;
2790                 }
2791 cleanup:
2792                 ulist_free(record->old_roots);
2793                 ulist_free(new_roots);
2794                 new_roots = NULL;
2795                 rb_erase(node, &delayed_refs->dirty_extent_root);
2796                 kfree(record);
2797
2798         }
2799         trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2800                                        num_dirty_extents);
2801         return ret;
2802 }
2803
2804 /*
2805  * called from commit_transaction. Writes all changed qgroups to disk.
2806  */
2807 int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2808 {
2809         struct btrfs_fs_info *fs_info = trans->fs_info;
2810         int ret = 0;
2811
2812         if (!fs_info->quota_root)
2813                 return ret;
2814
2815         spin_lock(&fs_info->qgroup_lock);
2816         while (!list_empty(&fs_info->dirty_qgroups)) {
2817                 struct btrfs_qgroup *qgroup;
2818                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
2819                                           struct btrfs_qgroup, dirty);
2820                 list_del_init(&qgroup->dirty);
2821                 spin_unlock(&fs_info->qgroup_lock);
2822                 ret = update_qgroup_info_item(trans, qgroup);
2823                 if (ret)
2824                         qgroup_mark_inconsistent(fs_info);
2825                 ret = update_qgroup_limit_item(trans, qgroup);
2826                 if (ret)
2827                         qgroup_mark_inconsistent(fs_info);
2828                 spin_lock(&fs_info->qgroup_lock);
2829         }
2830         if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2831                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2832         else
2833                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2834         spin_unlock(&fs_info->qgroup_lock);
2835
2836         ret = update_qgroup_status_item(trans);
2837         if (ret)
2838                 qgroup_mark_inconsistent(fs_info);
2839
2840         return ret;
2841 }
2842
2843 /*
2844  * Copy the accounting information between qgroups. This is necessary
2845  * when a snapshot or a subvolume is created. Throwing an error will
2846  * cause a transaction abort so we take extra care here to only error
2847  * when a readonly fs is a reasonable outcome.
2848  */
2849 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2850                          u64 objectid, struct btrfs_qgroup_inherit *inherit)
2851 {
2852         int ret = 0;
2853         int i;
2854         u64 *i_qgroups;
2855         bool committing = false;
2856         struct btrfs_fs_info *fs_info = trans->fs_info;
2857         struct btrfs_root *quota_root;
2858         struct btrfs_qgroup *srcgroup;
2859         struct btrfs_qgroup *dstgroup;
2860         bool need_rescan = false;
2861         u32 level_size = 0;
2862         u64 nums;
2863
2864         /*
2865          * There are only two callers of this function.
2866          *
2867          * One in create_subvol() in the ioctl context, which needs to hold
2868          * the qgroup_ioctl_lock.
2869          *
2870          * The other one in create_pending_snapshot() where no other qgroup
2871          * code can modify the fs as they all need to either start a new trans
2872          * or hold a trans handler, thus we don't need to hold
2873          * qgroup_ioctl_lock.
2874          * This would avoid long and complex lock chain and make lockdep happy.
2875          */
2876         spin_lock(&fs_info->trans_lock);
2877         if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
2878                 committing = true;
2879         spin_unlock(&fs_info->trans_lock);
2880
2881         if (!committing)
2882                 mutex_lock(&fs_info->qgroup_ioctl_lock);
2883         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2884                 goto out;
2885
2886         quota_root = fs_info->quota_root;
2887         if (!quota_root) {
2888                 ret = -EINVAL;
2889                 goto out;
2890         }
2891
2892         if (inherit) {
2893                 i_qgroups = (u64 *)(inherit + 1);
2894                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2895                        2 * inherit->num_excl_copies;
2896                 for (i = 0; i < nums; ++i) {
2897                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2898
2899                         /*
2900                          * Zero out invalid groups so we can ignore
2901                          * them later.
2902                          */
2903                         if (!srcgroup ||
2904                             ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2905                                 *i_qgroups = 0ULL;
2906
2907                         ++i_qgroups;
2908                 }
2909         }
2910
2911         /*
2912          * create a tracking group for the subvol itself
2913          */
2914         ret = add_qgroup_item(trans, quota_root, objectid);
2915         if (ret)
2916                 goto out;
2917
2918         /*
2919          * add qgroup to all inherited groups
2920          */
2921         if (inherit) {
2922                 i_qgroups = (u64 *)(inherit + 1);
2923                 for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2924                         if (*i_qgroups == 0)
2925                                 continue;
2926                         ret = add_qgroup_relation_item(trans, objectid,
2927                                                        *i_qgroups);
2928                         if (ret && ret != -EEXIST)
2929                                 goto out;
2930                         ret = add_qgroup_relation_item(trans, *i_qgroups,
2931                                                        objectid);
2932                         if (ret && ret != -EEXIST)
2933                                 goto out;
2934                 }
2935                 ret = 0;
2936         }
2937
2938
2939         spin_lock(&fs_info->qgroup_lock);
2940
2941         dstgroup = add_qgroup_rb(fs_info, objectid);
2942         if (IS_ERR(dstgroup)) {
2943                 ret = PTR_ERR(dstgroup);
2944                 goto unlock;
2945         }
2946
2947         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2948                 dstgroup->lim_flags = inherit->lim.flags;
2949                 dstgroup->max_rfer = inherit->lim.max_rfer;
2950                 dstgroup->max_excl = inherit->lim.max_excl;
2951                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2952                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
2953
2954                 ret = update_qgroup_limit_item(trans, dstgroup);
2955                 if (ret) {
2956                         qgroup_mark_inconsistent(fs_info);
2957                         btrfs_info(fs_info,
2958                                    "unable to update quota limit for %llu",
2959                                    dstgroup->qgroupid);
2960                         goto unlock;
2961                 }
2962         }
2963
2964         if (srcid) {
2965                 srcgroup = find_qgroup_rb(fs_info, srcid);
2966                 if (!srcgroup)
2967                         goto unlock;
2968
2969                 /*
2970                  * We call inherit after we clone the root in order to make sure
2971                  * our counts don't go crazy, so at this point the only
2972                  * difference between the two roots should be the root node.
2973                  */
2974                 level_size = fs_info->nodesize;
2975                 dstgroup->rfer = srcgroup->rfer;
2976                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2977                 dstgroup->excl = level_size;
2978                 dstgroup->excl_cmpr = level_size;
2979                 srcgroup->excl = level_size;
2980                 srcgroup->excl_cmpr = level_size;
2981
2982                 /* inherit the limit info */
2983                 dstgroup->lim_flags = srcgroup->lim_flags;
2984                 dstgroup->max_rfer = srcgroup->max_rfer;
2985                 dstgroup->max_excl = srcgroup->max_excl;
2986                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2987                 dstgroup->rsv_excl = srcgroup->rsv_excl;
2988
2989                 qgroup_dirty(fs_info, dstgroup);
2990                 qgroup_dirty(fs_info, srcgroup);
2991         }
2992
2993         if (!inherit)
2994                 goto unlock;
2995
2996         i_qgroups = (u64 *)(inherit + 1);
2997         for (i = 0; i < inherit->num_qgroups; ++i) {
2998                 if (*i_qgroups) {
2999                         ret = add_relation_rb(fs_info, objectid, *i_qgroups);
3000                         if (ret)
3001                                 goto unlock;
3002                 }
3003                 ++i_qgroups;
3004
3005                 /*
3006                  * If we're doing a snapshot, and adding the snapshot to a new
3007                  * qgroup, the numbers are guaranteed to be incorrect.
3008                  */
3009                 if (srcid)
3010                         need_rescan = true;
3011         }
3012
3013         for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
3014                 struct btrfs_qgroup *src;
3015                 struct btrfs_qgroup *dst;
3016
3017                 if (!i_qgroups[0] || !i_qgroups[1])
3018                         continue;
3019
3020                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
3021                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3022
3023                 if (!src || !dst) {
3024                         ret = -EINVAL;
3025                         goto unlock;
3026                 }
3027
3028                 dst->rfer = src->rfer - level_size;
3029                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
3030
3031                 /* Manually tweaking numbers certainly needs a rescan */
3032                 need_rescan = true;
3033         }
3034         for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
3035                 struct btrfs_qgroup *src;
3036                 struct btrfs_qgroup *dst;
3037
3038                 if (!i_qgroups[0] || !i_qgroups[1])
3039                         continue;
3040
3041                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
3042                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3043
3044                 if (!src || !dst) {
3045                         ret = -EINVAL;
3046                         goto unlock;
3047                 }
3048
3049                 dst->excl = src->excl + level_size;
3050                 dst->excl_cmpr = src->excl_cmpr + level_size;
3051                 need_rescan = true;
3052         }
3053
3054 unlock:
3055         spin_unlock(&fs_info->qgroup_lock);
3056         if (!ret)
3057                 ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup);
3058 out:
3059         if (!committing)
3060                 mutex_unlock(&fs_info->qgroup_ioctl_lock);
3061         if (need_rescan)
3062                 qgroup_mark_inconsistent(fs_info);
3063         return ret;
3064 }
3065
3066 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
3067 {
3068         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
3069             qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
3070                 return false;
3071
3072         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
3073             qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
3074                 return false;
3075
3076         return true;
3077 }
3078
3079 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
3080                           enum btrfs_qgroup_rsv_type type)
3081 {
3082         struct btrfs_qgroup *qgroup;
3083         struct btrfs_fs_info *fs_info = root->fs_info;
3084         u64 ref_root = root->root_key.objectid;
3085         int ret = 0;
3086         struct ulist_node *unode;
3087         struct ulist_iterator uiter;
3088
3089         if (!is_fstree(ref_root))
3090                 return 0;
3091
3092         if (num_bytes == 0)
3093                 return 0;
3094
3095         if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
3096             capable(CAP_SYS_RESOURCE))
3097                 enforce = false;
3098
3099         spin_lock(&fs_info->qgroup_lock);
3100         if (!fs_info->quota_root)
3101                 goto out;
3102
3103         qgroup = find_qgroup_rb(fs_info, ref_root);
3104         if (!qgroup)
3105                 goto out;
3106
3107         /*
3108          * in a first step, we check all affected qgroups if any limits would
3109          * be exceeded
3110          */
3111         ulist_reinit(fs_info->qgroup_ulist);
3112         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3113                         qgroup_to_aux(qgroup), GFP_ATOMIC);
3114         if (ret < 0)
3115                 goto out;
3116         ULIST_ITER_INIT(&uiter);
3117         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3118                 struct btrfs_qgroup *qg;
3119                 struct btrfs_qgroup_list *glist;
3120
3121                 qg = unode_aux_to_qgroup(unode);
3122
3123                 if (enforce && !qgroup_check_limits(qg, num_bytes)) {
3124                         ret = -EDQUOT;
3125                         goto out;
3126                 }
3127
3128                 list_for_each_entry(glist, &qg->groups, next_group) {
3129                         ret = ulist_add(fs_info->qgroup_ulist,
3130                                         glist->group->qgroupid,
3131                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
3132                         if (ret < 0)
3133                                 goto out;
3134                 }
3135         }
3136         ret = 0;
3137         /*
3138          * no limits exceeded, now record the reservation into all qgroups
3139          */
3140         ULIST_ITER_INIT(&uiter);
3141         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3142                 struct btrfs_qgroup *qg;
3143
3144                 qg = unode_aux_to_qgroup(unode);
3145
3146                 qgroup_rsv_add(fs_info, qg, num_bytes, type);
3147         }
3148
3149 out:
3150         spin_unlock(&fs_info->qgroup_lock);
3151         return ret;
3152 }
3153
3154 /*
3155  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
3156  * qgroup).
3157  *
3158  * Will handle all higher level qgroup too.
3159  *
3160  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
3161  * This special case is only used for META_PERTRANS type.
3162  */
3163 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
3164                                u64 ref_root, u64 num_bytes,
3165                                enum btrfs_qgroup_rsv_type type)
3166 {
3167         struct btrfs_qgroup *qgroup;
3168         struct ulist_node *unode;
3169         struct ulist_iterator uiter;
3170         int ret = 0;
3171
3172         if (!is_fstree(ref_root))
3173                 return;
3174
3175         if (num_bytes == 0)
3176                 return;
3177
3178         if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
3179                 WARN(1, "%s: Invalid type to free", __func__);
3180                 return;
3181         }
3182         spin_lock(&fs_info->qgroup_lock);
3183
3184         if (!fs_info->quota_root)
3185                 goto out;
3186
3187         qgroup = find_qgroup_rb(fs_info, ref_root);
3188         if (!qgroup)
3189                 goto out;
3190
3191         if (num_bytes == (u64)-1)
3192                 /*
3193                  * We're freeing all pertrans rsv, get reserved value from
3194                  * level 0 qgroup as real num_bytes to free.
3195                  */
3196                 num_bytes = qgroup->rsv.values[type];
3197
3198         ulist_reinit(fs_info->qgroup_ulist);
3199         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3200                         qgroup_to_aux(qgroup), GFP_ATOMIC);
3201         if (ret < 0)
3202                 goto out;
3203         ULIST_ITER_INIT(&uiter);
3204         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3205                 struct btrfs_qgroup *qg;
3206                 struct btrfs_qgroup_list *glist;
3207
3208                 qg = unode_aux_to_qgroup(unode);
3209
3210                 qgroup_rsv_release(fs_info, qg, num_bytes, type);
3211
3212                 list_for_each_entry(glist, &qg->groups, next_group) {
3213                         ret = ulist_add(fs_info->qgroup_ulist,
3214                                         glist->group->qgroupid,
3215                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
3216                         if (ret < 0)
3217                                 goto out;
3218                 }
3219         }
3220
3221 out:
3222         spin_unlock(&fs_info->qgroup_lock);
3223 }
3224
3225 /*
3226  * Check if the leaf is the last leaf. Which means all node pointers
3227  * are at their last position.
3228  */
3229 static bool is_last_leaf(struct btrfs_path *path)
3230 {
3231         int i;
3232
3233         for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3234                 if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3235                         return false;
3236         }
3237         return true;
3238 }
3239
3240 /*
3241  * returns < 0 on error, 0 when more leafs are to be scanned.
3242  * returns 1 when done.
3243  */
3244 static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3245                               struct btrfs_path *path)
3246 {
3247         struct btrfs_fs_info *fs_info = trans->fs_info;
3248         struct btrfs_root *extent_root;
3249         struct btrfs_key found;
3250         struct extent_buffer *scratch_leaf = NULL;
3251         struct ulist *roots = NULL;
3252         u64 num_bytes;
3253         bool done;
3254         int slot;
3255         int ret;
3256
3257         mutex_lock(&fs_info->qgroup_rescan_lock);
3258         extent_root = btrfs_extent_root(fs_info,
3259                                 fs_info->qgroup_rescan_progress.objectid);
3260         ret = btrfs_search_slot_for_read(extent_root,
3261                                          &fs_info->qgroup_rescan_progress,
3262                                          path, 1, 0);
3263
3264         btrfs_debug(fs_info,
3265                 "current progress key (%llu %u %llu), search_slot ret %d",
3266                 fs_info->qgroup_rescan_progress.objectid,
3267                 fs_info->qgroup_rescan_progress.type,
3268                 fs_info->qgroup_rescan_progress.offset, ret);
3269
3270         if (ret) {
3271                 /*
3272                  * The rescan is about to end, we will not be scanning any
3273                  * further blocks. We cannot unset the RESCAN flag here, because
3274                  * we want to commit the transaction if everything went well.
3275                  * To make the live accounting work in this phase, we set our
3276                  * scan progress pointer such that every real extent objectid
3277                  * will be smaller.
3278                  */
3279                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3280                 btrfs_release_path(path);
3281                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3282                 return ret;
3283         }
3284         done = is_last_leaf(path);
3285
3286         btrfs_item_key_to_cpu(path->nodes[0], &found,
3287                               btrfs_header_nritems(path->nodes[0]) - 1);
3288         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3289
3290         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3291         if (!scratch_leaf) {
3292                 ret = -ENOMEM;
3293                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3294                 goto out;
3295         }
3296         slot = path->slots[0];
3297         btrfs_release_path(path);
3298         mutex_unlock(&fs_info->qgroup_rescan_lock);
3299
3300         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
3301                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3302                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3303                     found.type != BTRFS_METADATA_ITEM_KEY)
3304                         continue;
3305                 if (found.type == BTRFS_METADATA_ITEM_KEY)
3306                         num_bytes = fs_info->nodesize;
3307                 else
3308                         num_bytes = found.offset;
3309
3310                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
3311                                            &roots, false);
3312                 if (ret < 0)
3313                         goto out;
3314                 /* For rescan, just pass old_roots as NULL */
3315                 ret = btrfs_qgroup_account_extent(trans, found.objectid,
3316                                                   num_bytes, NULL, roots);
3317                 if (ret < 0)
3318                         goto out;
3319         }
3320 out:
3321         if (scratch_leaf)
3322                 free_extent_buffer(scratch_leaf);
3323
3324         if (done && !ret) {
3325                 ret = 1;
3326                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3327         }
3328         return ret;
3329 }
3330
3331 static bool rescan_should_stop(struct btrfs_fs_info *fs_info)
3332 {
3333         return btrfs_fs_closing(fs_info) ||
3334                 test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state) ||
3335                 !test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3336                           fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN;
3337 }
3338
3339 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3340 {
3341         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3342                                                      qgroup_rescan_work);
3343         struct btrfs_path *path;
3344         struct btrfs_trans_handle *trans = NULL;
3345         int err = -ENOMEM;
3346         int ret = 0;
3347         bool stopped = false;
3348
3349         path = btrfs_alloc_path();
3350         if (!path)
3351                 goto out;
3352         /*
3353          * Rescan should only search for commit root, and any later difference
3354          * should be recorded by qgroup
3355          */
3356         path->search_commit_root = 1;
3357         path->skip_locking = 1;
3358
3359         err = 0;
3360         while (!err && !(stopped = rescan_should_stop(fs_info))) {
3361                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
3362                 if (IS_ERR(trans)) {
3363                         err = PTR_ERR(trans);
3364                         break;
3365                 }
3366
3367                 err = qgroup_rescan_leaf(trans, path);
3368
3369                 if (err > 0)
3370                         btrfs_commit_transaction(trans);
3371                 else
3372                         btrfs_end_transaction(trans);
3373         }
3374
3375 out:
3376         btrfs_free_path(path);
3377
3378         mutex_lock(&fs_info->qgroup_rescan_lock);
3379         if (err > 0 &&
3380             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3381                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3382         } else if (err < 0 || stopped) {
3383                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3384         }
3385         mutex_unlock(&fs_info->qgroup_rescan_lock);
3386
3387         /*
3388          * only update status, since the previous part has already updated the
3389          * qgroup info.
3390          */
3391         trans = btrfs_start_transaction(fs_info->quota_root, 1);
3392         if (IS_ERR(trans)) {
3393                 err = PTR_ERR(trans);
3394                 trans = NULL;
3395                 btrfs_err(fs_info,
3396                           "fail to start transaction for status update: %d",
3397                           err);
3398         }
3399
3400         mutex_lock(&fs_info->qgroup_rescan_lock);
3401         if (!stopped ||
3402             fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN)
3403                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3404         if (trans) {
3405                 ret = update_qgroup_status_item(trans);
3406                 if (ret < 0) {
3407                         err = ret;
3408                         btrfs_err(fs_info, "fail to update qgroup status: %d",
3409                                   err);
3410                 }
3411         }
3412         fs_info->qgroup_rescan_running = false;
3413         fs_info->qgroup_flags &= ~BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN;
3414         complete_all(&fs_info->qgroup_rescan_completion);
3415         mutex_unlock(&fs_info->qgroup_rescan_lock);
3416
3417         if (!trans)
3418                 return;
3419
3420         btrfs_end_transaction(trans);
3421
3422         if (stopped) {
3423                 btrfs_info(fs_info, "qgroup scan paused");
3424         } else if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) {
3425                 btrfs_info(fs_info, "qgroup scan cancelled");
3426         } else if (err >= 0) {
3427                 btrfs_info(fs_info, "qgroup scan completed%s",
3428                         err > 0 ? " (inconsistency flag cleared)" : "");
3429         } else {
3430                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
3431         }
3432 }
3433
3434 /*
3435  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
3436  * memory required for the rescan context.
3437  */
3438 static int
3439 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
3440                    int init_flags)
3441 {
3442         int ret = 0;
3443
3444         if (!init_flags) {
3445                 /* we're resuming qgroup rescan at mount time */
3446                 if (!(fs_info->qgroup_flags &
3447                       BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
3448                         btrfs_warn(fs_info,
3449                         "qgroup rescan init failed, qgroup rescan is not queued");
3450                         ret = -EINVAL;
3451                 } else if (!(fs_info->qgroup_flags &
3452                              BTRFS_QGROUP_STATUS_FLAG_ON)) {
3453                         btrfs_warn(fs_info,
3454                         "qgroup rescan init failed, qgroup is not enabled");
3455                         ret = -EINVAL;
3456                 }
3457
3458                 if (ret)
3459                         return ret;
3460         }
3461
3462         mutex_lock(&fs_info->qgroup_rescan_lock);
3463
3464         if (init_flags) {
3465                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3466                         btrfs_warn(fs_info,
3467                                    "qgroup rescan is already in progress");
3468                         ret = -EINPROGRESS;
3469                 } else if (!(fs_info->qgroup_flags &
3470                              BTRFS_QGROUP_STATUS_FLAG_ON)) {
3471                         btrfs_warn(fs_info,
3472                         "qgroup rescan init failed, qgroup is not enabled");
3473                         ret = -EINVAL;
3474                 } else if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3475                         /* Quota disable is in progress */
3476                         ret = -EBUSY;
3477                 }
3478
3479                 if (ret) {
3480                         mutex_unlock(&fs_info->qgroup_rescan_lock);
3481                         return ret;
3482                 }
3483                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3484         }
3485
3486         memset(&fs_info->qgroup_rescan_progress, 0,
3487                 sizeof(fs_info->qgroup_rescan_progress));
3488         fs_info->qgroup_flags &= ~(BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN |
3489                                    BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING);
3490         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
3491         init_completion(&fs_info->qgroup_rescan_completion);
3492         mutex_unlock(&fs_info->qgroup_rescan_lock);
3493
3494         btrfs_init_work(&fs_info->qgroup_rescan_work,
3495                         btrfs_qgroup_rescan_worker, NULL, NULL);
3496         return 0;
3497 }
3498
3499 static void
3500 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
3501 {
3502         struct rb_node *n;
3503         struct btrfs_qgroup *qgroup;
3504
3505         spin_lock(&fs_info->qgroup_lock);
3506         /* clear all current qgroup tracking information */
3507         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
3508                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
3509                 qgroup->rfer = 0;
3510                 qgroup->rfer_cmpr = 0;
3511                 qgroup->excl = 0;
3512                 qgroup->excl_cmpr = 0;
3513                 qgroup_dirty(fs_info, qgroup);
3514         }
3515         spin_unlock(&fs_info->qgroup_lock);
3516 }
3517
3518 int
3519 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
3520 {
3521         int ret = 0;
3522         struct btrfs_trans_handle *trans;
3523
3524         ret = qgroup_rescan_init(fs_info, 0, 1);
3525         if (ret)
3526                 return ret;
3527
3528         /*
3529          * We have set the rescan_progress to 0, which means no more
3530          * delayed refs will be accounted by btrfs_qgroup_account_ref.
3531          * However, btrfs_qgroup_account_ref may be right after its call
3532          * to btrfs_find_all_roots, in which case it would still do the
3533          * accounting.
3534          * To solve this, we're committing the transaction, which will
3535          * ensure we run all delayed refs and only after that, we are
3536          * going to clear all tracking information for a clean start.
3537          */
3538
3539         trans = btrfs_join_transaction(fs_info->fs_root);
3540         if (IS_ERR(trans)) {
3541                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3542                 return PTR_ERR(trans);
3543         }
3544         ret = btrfs_commit_transaction(trans);
3545         if (ret) {
3546                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3547                 return ret;
3548         }
3549
3550         qgroup_rescan_zero_tracking(fs_info);
3551
3552         mutex_lock(&fs_info->qgroup_rescan_lock);
3553         fs_info->qgroup_rescan_running = true;
3554         btrfs_queue_work(fs_info->qgroup_rescan_workers,
3555                          &fs_info->qgroup_rescan_work);
3556         mutex_unlock(&fs_info->qgroup_rescan_lock);
3557
3558         return 0;
3559 }
3560
3561 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
3562                                      bool interruptible)
3563 {
3564         int running;
3565         int ret = 0;
3566
3567         mutex_lock(&fs_info->qgroup_rescan_lock);
3568         running = fs_info->qgroup_rescan_running;
3569         mutex_unlock(&fs_info->qgroup_rescan_lock);
3570
3571         if (!running)
3572                 return 0;
3573
3574         if (interruptible)
3575                 ret = wait_for_completion_interruptible(
3576                                         &fs_info->qgroup_rescan_completion);
3577         else
3578                 wait_for_completion(&fs_info->qgroup_rescan_completion);
3579
3580         return ret;
3581 }
3582
3583 /*
3584  * this is only called from open_ctree where we're still single threaded, thus
3585  * locking is omitted here.
3586  */
3587 void
3588 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
3589 {
3590         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3591                 mutex_lock(&fs_info->qgroup_rescan_lock);
3592                 fs_info->qgroup_rescan_running = true;
3593                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
3594                                  &fs_info->qgroup_rescan_work);
3595                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3596         }
3597 }
3598
3599 #define rbtree_iterate_from_safe(node, next, start)                             \
3600        for (node = start; node && ({ next = rb_next(node); 1;}); node = next)
3601
3602 static int qgroup_unreserve_range(struct btrfs_inode *inode,
3603                                   struct extent_changeset *reserved, u64 start,
3604                                   u64 len)
3605 {
3606         struct rb_node *node;
3607         struct rb_node *next;
3608         struct ulist_node *entry;
3609         int ret = 0;
3610
3611         node = reserved->range_changed.root.rb_node;
3612         if (!node)
3613                 return 0;
3614         while (node) {
3615                 entry = rb_entry(node, struct ulist_node, rb_node);
3616                 if (entry->val < start)
3617                         node = node->rb_right;
3618                 else
3619                         node = node->rb_left;
3620         }
3621
3622         if (entry->val > start && rb_prev(&entry->rb_node))
3623                 entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node,
3624                                  rb_node);
3625
3626         rbtree_iterate_from_safe(node, next, &entry->rb_node) {
3627                 u64 entry_start;
3628                 u64 entry_end;
3629                 u64 entry_len;
3630                 int clear_ret;
3631
3632                 entry = rb_entry(node, struct ulist_node, rb_node);
3633                 entry_start = entry->val;
3634                 entry_end = entry->aux;
3635                 entry_len = entry_end - entry_start + 1;
3636
3637                 if (entry_start >= start + len)
3638                         break;
3639                 if (entry_start + entry_len <= start)
3640                         continue;
3641                 /*
3642                  * Now the entry is in [start, start + len), revert the
3643                  * EXTENT_QGROUP_RESERVED bit.
3644                  */
3645                 clear_ret = clear_extent_bits(&inode->io_tree, entry_start,
3646                                               entry_end, EXTENT_QGROUP_RESERVED);
3647                 if (!ret && clear_ret < 0)
3648                         ret = clear_ret;
3649
3650                 ulist_del(&reserved->range_changed, entry->val, entry->aux);
3651                 if (likely(reserved->bytes_changed >= entry_len)) {
3652                         reserved->bytes_changed -= entry_len;
3653                 } else {
3654                         WARN_ON(1);
3655                         reserved->bytes_changed = 0;
3656                 }
3657         }
3658
3659         return ret;
3660 }
3661
3662 /*
3663  * Try to free some space for qgroup.
3664  *
3665  * For qgroup, there are only 3 ways to free qgroup space:
3666  * - Flush nodatacow write
3667  *   Any nodatacow write will free its reserved data space at run_delalloc_range().
3668  *   In theory, we should only flush nodatacow inodes, but it's not yet
3669  *   possible, so we need to flush the whole root.
3670  *
3671  * - Wait for ordered extents
3672  *   When ordered extents are finished, their reserved metadata is finally
3673  *   converted to per_trans status, which can be freed by later commit
3674  *   transaction.
3675  *
3676  * - Commit transaction
3677  *   This would free the meta_per_trans space.
3678  *   In theory this shouldn't provide much space, but any more qgroup space
3679  *   is needed.
3680  */
3681 static int try_flush_qgroup(struct btrfs_root *root)
3682 {
3683         struct btrfs_trans_handle *trans;
3684         int ret;
3685
3686         /* Can't hold an open transaction or we run the risk of deadlocking. */
3687         ASSERT(current->journal_info == NULL);
3688         if (WARN_ON(current->journal_info))
3689                 return 0;
3690
3691         /*
3692          * We don't want to run flush again and again, so if there is a running
3693          * one, we won't try to start a new flush, but exit directly.
3694          */
3695         if (test_and_set_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)) {
3696                 wait_event(root->qgroup_flush_wait,
3697                         !test_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state));
3698                 return 0;
3699         }
3700
3701         ret = btrfs_start_delalloc_snapshot(root, true);
3702         if (ret < 0)
3703                 goto out;
3704         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
3705
3706         trans = btrfs_join_transaction(root);
3707         if (IS_ERR(trans)) {
3708                 ret = PTR_ERR(trans);
3709                 goto out;
3710         }
3711
3712         ret = btrfs_commit_transaction(trans);
3713 out:
3714         clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state);
3715         wake_up(&root->qgroup_flush_wait);
3716         return ret;
3717 }
3718
3719 static int qgroup_reserve_data(struct btrfs_inode *inode,
3720                         struct extent_changeset **reserved_ret, u64 start,
3721                         u64 len)
3722 {
3723         struct btrfs_root *root = inode->root;
3724         struct extent_changeset *reserved;
3725         bool new_reserved = false;
3726         u64 orig_reserved;
3727         u64 to_reserve;
3728         int ret;
3729
3730         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
3731             !is_fstree(root->root_key.objectid) || len == 0)
3732                 return 0;
3733
3734         /* @reserved parameter is mandatory for qgroup */
3735         if (WARN_ON(!reserved_ret))
3736                 return -EINVAL;
3737         if (!*reserved_ret) {
3738                 new_reserved = true;
3739                 *reserved_ret = extent_changeset_alloc();
3740                 if (!*reserved_ret)
3741                         return -ENOMEM;
3742         }
3743         reserved = *reserved_ret;
3744         /* Record already reserved space */
3745         orig_reserved = reserved->bytes_changed;
3746         ret = set_record_extent_bits(&inode->io_tree, start,
3747                         start + len -1, EXTENT_QGROUP_RESERVED, reserved);
3748
3749         /* Newly reserved space */
3750         to_reserve = reserved->bytes_changed - orig_reserved;
3751         trace_btrfs_qgroup_reserve_data(&inode->vfs_inode, start, len,
3752                                         to_reserve, QGROUP_RESERVE);
3753         if (ret < 0)
3754                 goto out;
3755         ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
3756         if (ret < 0)
3757                 goto cleanup;
3758
3759         return ret;
3760
3761 cleanup:
3762         qgroup_unreserve_range(inode, reserved, start, len);
3763 out:
3764         if (new_reserved) {
3765                 extent_changeset_free(reserved);
3766                 *reserved_ret = NULL;
3767         }
3768         return ret;
3769 }
3770
3771 /*
3772  * Reserve qgroup space for range [start, start + len).
3773  *
3774  * This function will either reserve space from related qgroups or do nothing
3775  * if the range is already reserved.
3776  *
3777  * Return 0 for successful reservation
3778  * Return <0 for error (including -EQUOT)
3779  *
3780  * NOTE: This function may sleep for memory allocation, dirty page flushing and
3781  *       commit transaction. So caller should not hold any dirty page locked.
3782  */
3783 int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
3784                         struct extent_changeset **reserved_ret, u64 start,
3785                         u64 len)
3786 {
3787         int ret;
3788
3789         ret = qgroup_reserve_data(inode, reserved_ret, start, len);
3790         if (ret <= 0 && ret != -EDQUOT)
3791                 return ret;
3792
3793         ret = try_flush_qgroup(inode->root);
3794         if (ret < 0)
3795                 return ret;
3796         return qgroup_reserve_data(inode, reserved_ret, start, len);
3797 }
3798
3799 /* Free ranges specified by @reserved, normally in error path */
3800 static int qgroup_free_reserved_data(struct btrfs_inode *inode,
3801                         struct extent_changeset *reserved, u64 start, u64 len)
3802 {
3803         struct btrfs_root *root = inode->root;
3804         struct ulist_node *unode;
3805         struct ulist_iterator uiter;
3806         struct extent_changeset changeset;
3807         int freed = 0;
3808         int ret;
3809
3810         extent_changeset_init(&changeset);
3811         len = round_up(start + len, root->fs_info->sectorsize);
3812         start = round_down(start, root->fs_info->sectorsize);
3813
3814         ULIST_ITER_INIT(&uiter);
3815         while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
3816                 u64 range_start = unode->val;
3817                 /* unode->aux is the inclusive end */
3818                 u64 range_len = unode->aux - range_start + 1;
3819                 u64 free_start;
3820                 u64 free_len;
3821
3822                 extent_changeset_release(&changeset);
3823
3824                 /* Only free range in range [start, start + len) */
3825                 if (range_start >= start + len ||
3826                     range_start + range_len <= start)
3827                         continue;
3828                 free_start = max(range_start, start);
3829                 free_len = min(start + len, range_start + range_len) -
3830                            free_start;
3831                 /*
3832                  * TODO: To also modify reserved->ranges_reserved to reflect
3833                  * the modification.
3834                  *
3835                  * However as long as we free qgroup reserved according to
3836                  * EXTENT_QGROUP_RESERVED, we won't double free.
3837                  * So not need to rush.
3838                  */
3839                 ret = clear_record_extent_bits(&inode->io_tree, free_start,
3840                                 free_start + free_len - 1,
3841                                 EXTENT_QGROUP_RESERVED, &changeset);
3842                 if (ret < 0)
3843                         goto out;
3844                 freed += changeset.bytes_changed;
3845         }
3846         btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
3847                                   BTRFS_QGROUP_RSV_DATA);
3848         ret = freed;
3849 out:
3850         extent_changeset_release(&changeset);
3851         return ret;
3852 }
3853
3854 static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
3855                         struct extent_changeset *reserved, u64 start, u64 len,
3856                         int free)
3857 {
3858         struct extent_changeset changeset;
3859         int trace_op = QGROUP_RELEASE;
3860         int ret;
3861
3862         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &inode->root->fs_info->flags))
3863                 return 0;
3864
3865         /* In release case, we shouldn't have @reserved */
3866         WARN_ON(!free && reserved);
3867         if (free && reserved)
3868                 return qgroup_free_reserved_data(inode, reserved, start, len);
3869         extent_changeset_init(&changeset);
3870         ret = clear_record_extent_bits(&inode->io_tree, start, start + len -1,
3871                                        EXTENT_QGROUP_RESERVED, &changeset);
3872         if (ret < 0)
3873                 goto out;
3874
3875         if (free)
3876                 trace_op = QGROUP_FREE;
3877         trace_btrfs_qgroup_release_data(&inode->vfs_inode, start, len,
3878                                         changeset.bytes_changed, trace_op);
3879         if (free)
3880                 btrfs_qgroup_free_refroot(inode->root->fs_info,
3881                                 inode->root->root_key.objectid,
3882                                 changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3883         ret = changeset.bytes_changed;
3884 out:
3885         extent_changeset_release(&changeset);
3886         return ret;
3887 }
3888
3889 /*
3890  * Free a reserved space range from io_tree and related qgroups
3891  *
3892  * Should be called when a range of pages get invalidated before reaching disk.
3893  * Or for error cleanup case.
3894  * if @reserved is given, only reserved range in [@start, @start + @len) will
3895  * be freed.
3896  *
3897  * For data written to disk, use btrfs_qgroup_release_data().
3898  *
3899  * NOTE: This function may sleep for memory allocation.
3900  */
3901 int btrfs_qgroup_free_data(struct btrfs_inode *inode,
3902                         struct extent_changeset *reserved, u64 start, u64 len)
3903 {
3904         return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3905 }
3906
3907 /*
3908  * Release a reserved space range from io_tree only.
3909  *
3910  * Should be called when a range of pages get written to disk and corresponding
3911  * FILE_EXTENT is inserted into corresponding root.
3912  *
3913  * Since new qgroup accounting framework will only update qgroup numbers at
3914  * commit_transaction() time, its reserved space shouldn't be freed from
3915  * related qgroups.
3916  *
3917  * But we should release the range from io_tree, to allow further write to be
3918  * COWed.
3919  *
3920  * NOTE: This function may sleep for memory allocation.
3921  */
3922 int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len)
3923 {
3924         return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3925 }
3926
3927 static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3928                               enum btrfs_qgroup_rsv_type type)
3929 {
3930         if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3931             type != BTRFS_QGROUP_RSV_META_PERTRANS)
3932                 return;
3933         if (num_bytes == 0)
3934                 return;
3935
3936         spin_lock(&root->qgroup_meta_rsv_lock);
3937         if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3938                 root->qgroup_meta_rsv_prealloc += num_bytes;
3939         else
3940                 root->qgroup_meta_rsv_pertrans += num_bytes;
3941         spin_unlock(&root->qgroup_meta_rsv_lock);
3942 }
3943
3944 static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3945                              enum btrfs_qgroup_rsv_type type)
3946 {
3947         if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3948             type != BTRFS_QGROUP_RSV_META_PERTRANS)
3949                 return 0;
3950         if (num_bytes == 0)
3951                 return 0;
3952
3953         spin_lock(&root->qgroup_meta_rsv_lock);
3954         if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3955                 num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3956                                   num_bytes);
3957                 root->qgroup_meta_rsv_prealloc -= num_bytes;
3958         } else {
3959                 num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3960                                   num_bytes);
3961                 root->qgroup_meta_rsv_pertrans -= num_bytes;
3962         }
3963         spin_unlock(&root->qgroup_meta_rsv_lock);
3964         return num_bytes;
3965 }
3966
3967 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3968                               enum btrfs_qgroup_rsv_type type, bool enforce)
3969 {
3970         struct btrfs_fs_info *fs_info = root->fs_info;
3971         int ret;
3972
3973         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3974             !is_fstree(root->root_key.objectid) || num_bytes == 0)
3975                 return 0;
3976
3977         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3978         trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
3979         ret = qgroup_reserve(root, num_bytes, enforce, type);
3980         if (ret < 0)
3981                 return ret;
3982         /*
3983          * Record what we have reserved into root.
3984          *
3985          * To avoid quota disabled->enabled underflow.
3986          * In that case, we may try to free space we haven't reserved
3987          * (since quota was disabled), so record what we reserved into root.
3988          * And ensure later release won't underflow this number.
3989          */
3990         add_root_meta_rsv(root, num_bytes, type);
3991         return ret;
3992 }
3993
3994 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3995                                 enum btrfs_qgroup_rsv_type type, bool enforce,
3996                                 bool noflush)
3997 {
3998         int ret;
3999
4000         ret = btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4001         if ((ret <= 0 && ret != -EDQUOT) || noflush)
4002                 return ret;
4003
4004         ret = try_flush_qgroup(root);
4005         if (ret < 0)
4006                 return ret;
4007         return btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4008 }
4009
4010 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
4011 {
4012         struct btrfs_fs_info *fs_info = root->fs_info;
4013
4014         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4015             !is_fstree(root->root_key.objectid))
4016                 return;
4017
4018         /* TODO: Update trace point to handle such free */
4019         trace_qgroup_meta_free_all_pertrans(root);
4020         /* Special value -1 means to free all reserved space */
4021         btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
4022                                   BTRFS_QGROUP_RSV_META_PERTRANS);
4023 }
4024
4025 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
4026                               enum btrfs_qgroup_rsv_type type)
4027 {
4028         struct btrfs_fs_info *fs_info = root->fs_info;
4029
4030         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4031             !is_fstree(root->root_key.objectid))
4032                 return;
4033
4034         /*
4035          * reservation for META_PREALLOC can happen before quota is enabled,
4036          * which can lead to underflow.
4037          * Here ensure we will only free what we really have reserved.
4038          */
4039         num_bytes = sub_root_meta_rsv(root, num_bytes, type);
4040         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
4041         trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
4042         btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
4043                                   num_bytes, type);
4044 }
4045
4046 static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
4047                                 int num_bytes)
4048 {
4049         struct btrfs_qgroup *qgroup;
4050         struct ulist_node *unode;
4051         struct ulist_iterator uiter;
4052         int ret = 0;
4053
4054         if (num_bytes == 0)
4055                 return;
4056         if (!fs_info->quota_root)
4057                 return;
4058
4059         spin_lock(&fs_info->qgroup_lock);
4060         qgroup = find_qgroup_rb(fs_info, ref_root);
4061         if (!qgroup)
4062                 goto out;
4063         ulist_reinit(fs_info->qgroup_ulist);
4064         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
4065                        qgroup_to_aux(qgroup), GFP_ATOMIC);
4066         if (ret < 0)
4067                 goto out;
4068         ULIST_ITER_INIT(&uiter);
4069         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
4070                 struct btrfs_qgroup *qg;
4071                 struct btrfs_qgroup_list *glist;
4072
4073                 qg = unode_aux_to_qgroup(unode);
4074
4075                 qgroup_rsv_release(fs_info, qg, num_bytes,
4076                                 BTRFS_QGROUP_RSV_META_PREALLOC);
4077                 qgroup_rsv_add(fs_info, qg, num_bytes,
4078                                 BTRFS_QGROUP_RSV_META_PERTRANS);
4079                 list_for_each_entry(glist, &qg->groups, next_group) {
4080                         ret = ulist_add(fs_info->qgroup_ulist,
4081                                         glist->group->qgroupid,
4082                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
4083                         if (ret < 0)
4084                                 goto out;
4085                 }
4086         }
4087 out:
4088         spin_unlock(&fs_info->qgroup_lock);
4089 }
4090
4091 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
4092 {
4093         struct btrfs_fs_info *fs_info = root->fs_info;
4094
4095         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4096             !is_fstree(root->root_key.objectid))
4097                 return;
4098         /* Same as btrfs_qgroup_free_meta_prealloc() */
4099         num_bytes = sub_root_meta_rsv(root, num_bytes,
4100                                       BTRFS_QGROUP_RSV_META_PREALLOC);
4101         trace_qgroup_meta_convert(root, num_bytes);
4102         qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
4103 }
4104
4105 /*
4106  * Check qgroup reserved space leaking, normally at destroy inode
4107  * time
4108  */
4109 void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode)
4110 {
4111         struct extent_changeset changeset;
4112         struct ulist_node *unode;
4113         struct ulist_iterator iter;
4114         int ret;
4115
4116         extent_changeset_init(&changeset);
4117         ret = clear_record_extent_bits(&inode->io_tree, 0, (u64)-1,
4118                         EXTENT_QGROUP_RESERVED, &changeset);
4119
4120         WARN_ON(ret < 0);
4121         if (WARN_ON(changeset.bytes_changed)) {
4122                 ULIST_ITER_INIT(&iter);
4123                 while ((unode = ulist_next(&changeset.range_changed, &iter))) {
4124                         btrfs_warn(inode->root->fs_info,
4125                 "leaking qgroup reserved space, ino: %llu, start: %llu, end: %llu",
4126                                 btrfs_ino(inode), unode->val, unode->aux);
4127                 }
4128                 btrfs_qgroup_free_refroot(inode->root->fs_info,
4129                                 inode->root->root_key.objectid,
4130                                 changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
4131
4132         }
4133         extent_changeset_release(&changeset);
4134 }
4135
4136 void btrfs_qgroup_init_swapped_blocks(
4137         struct btrfs_qgroup_swapped_blocks *swapped_blocks)
4138 {
4139         int i;
4140
4141         spin_lock_init(&swapped_blocks->lock);
4142         for (i = 0; i < BTRFS_MAX_LEVEL; i++)
4143                 swapped_blocks->blocks[i] = RB_ROOT;
4144         swapped_blocks->swapped = false;
4145 }
4146
4147 /*
4148  * Delete all swapped blocks record of @root.
4149  * Every record here means we skipped a full subtree scan for qgroup.
4150  *
4151  * Gets called when committing one transaction.
4152  */
4153 void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
4154 {
4155         struct btrfs_qgroup_swapped_blocks *swapped_blocks;
4156         int i;
4157
4158         swapped_blocks = &root->swapped_blocks;
4159
4160         spin_lock(&swapped_blocks->lock);
4161         if (!swapped_blocks->swapped)
4162                 goto out;
4163         for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4164                 struct rb_root *cur_root = &swapped_blocks->blocks[i];
4165                 struct btrfs_qgroup_swapped_block *entry;
4166                 struct btrfs_qgroup_swapped_block *next;
4167
4168                 rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
4169                                                      node)
4170                         kfree(entry);
4171                 swapped_blocks->blocks[i] = RB_ROOT;
4172         }
4173         swapped_blocks->swapped = false;
4174 out:
4175         spin_unlock(&swapped_blocks->lock);
4176 }
4177
4178 /*
4179  * Add subtree roots record into @subvol_root.
4180  *
4181  * @subvol_root:        tree root of the subvolume tree get swapped
4182  * @bg:                 block group under balance
4183  * @subvol_parent/slot: pointer to the subtree root in subvolume tree
4184  * @reloc_parent/slot:  pointer to the subtree root in reloc tree
4185  *                      BOTH POINTERS ARE BEFORE TREE SWAP
4186  * @last_snapshot:      last snapshot generation of the subvolume tree
4187  */
4188 int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
4189                 struct btrfs_root *subvol_root,
4190                 struct btrfs_block_group *bg,
4191                 struct extent_buffer *subvol_parent, int subvol_slot,
4192                 struct extent_buffer *reloc_parent, int reloc_slot,
4193                 u64 last_snapshot)
4194 {
4195         struct btrfs_fs_info *fs_info = subvol_root->fs_info;
4196         struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
4197         struct btrfs_qgroup_swapped_block *block;
4198         struct rb_node **cur;
4199         struct rb_node *parent = NULL;
4200         int level = btrfs_header_level(subvol_parent) - 1;
4201         int ret = 0;
4202
4203         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4204                 return 0;
4205
4206         if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
4207             btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
4208                 btrfs_err_rl(fs_info,
4209                 "%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
4210                         __func__,
4211                         btrfs_node_ptr_generation(subvol_parent, subvol_slot),
4212                         btrfs_node_ptr_generation(reloc_parent, reloc_slot));
4213                 return -EUCLEAN;
4214         }
4215
4216         block = kmalloc(sizeof(*block), GFP_NOFS);
4217         if (!block) {
4218                 ret = -ENOMEM;
4219                 goto out;
4220         }
4221
4222         /*
4223          * @reloc_parent/slot is still before swap, while @block is going to
4224          * record the bytenr after swap, so we do the swap here.
4225          */
4226         block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
4227         block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
4228                                                              reloc_slot);
4229         block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
4230         block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
4231                                                             subvol_slot);
4232         block->last_snapshot = last_snapshot;
4233         block->level = level;
4234
4235         /*
4236          * If we have bg == NULL, we're called from btrfs_recover_relocation(),
4237          * no one else can modify tree blocks thus we qgroup will not change
4238          * no matter the value of trace_leaf.
4239          */
4240         if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
4241                 block->trace_leaf = true;
4242         else
4243                 block->trace_leaf = false;
4244         btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
4245
4246         /* Insert @block into @blocks */
4247         spin_lock(&blocks->lock);
4248         cur = &blocks->blocks[level].rb_node;
4249         while (*cur) {
4250                 struct btrfs_qgroup_swapped_block *entry;
4251
4252                 parent = *cur;
4253                 entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
4254                                  node);
4255
4256                 if (entry->subvol_bytenr < block->subvol_bytenr) {
4257                         cur = &(*cur)->rb_left;
4258                 } else if (entry->subvol_bytenr > block->subvol_bytenr) {
4259                         cur = &(*cur)->rb_right;
4260                 } else {
4261                         if (entry->subvol_generation !=
4262                                         block->subvol_generation ||
4263                             entry->reloc_bytenr != block->reloc_bytenr ||
4264                             entry->reloc_generation !=
4265                                         block->reloc_generation) {
4266                                 /*
4267                                  * Duplicated but mismatch entry found.
4268                                  * Shouldn't happen.
4269                                  *
4270                                  * Marking qgroup inconsistent should be enough
4271                                  * for end users.
4272                                  */
4273                                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4274                                 ret = -EEXIST;
4275                         }
4276                         kfree(block);
4277                         goto out_unlock;
4278                 }
4279         }
4280         rb_link_node(&block->node, parent, cur);
4281         rb_insert_color(&block->node, &blocks->blocks[level]);
4282         blocks->swapped = true;
4283 out_unlock:
4284         spin_unlock(&blocks->lock);
4285 out:
4286         if (ret < 0)
4287                 qgroup_mark_inconsistent(fs_info);
4288         return ret;
4289 }
4290
4291 /*
4292  * Check if the tree block is a subtree root, and if so do the needed
4293  * delayed subtree trace for qgroup.
4294  *
4295  * This is called during btrfs_cow_block().
4296  */
4297 int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
4298                                          struct btrfs_root *root,
4299                                          struct extent_buffer *subvol_eb)
4300 {
4301         struct btrfs_fs_info *fs_info = root->fs_info;
4302         struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
4303         struct btrfs_qgroup_swapped_block *block;
4304         struct extent_buffer *reloc_eb = NULL;
4305         struct rb_node *node;
4306         bool found = false;
4307         bool swapped = false;
4308         int level = btrfs_header_level(subvol_eb);
4309         int ret = 0;
4310         int i;
4311
4312         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4313                 return 0;
4314         if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
4315                 return 0;
4316
4317         spin_lock(&blocks->lock);
4318         if (!blocks->swapped) {
4319                 spin_unlock(&blocks->lock);
4320                 return 0;
4321         }
4322         node = blocks->blocks[level].rb_node;
4323
4324         while (node) {
4325                 block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
4326                 if (block->subvol_bytenr < subvol_eb->start) {
4327                         node = node->rb_left;
4328                 } else if (block->subvol_bytenr > subvol_eb->start) {
4329                         node = node->rb_right;
4330                 } else {
4331                         found = true;
4332                         break;
4333                 }
4334         }
4335         if (!found) {
4336                 spin_unlock(&blocks->lock);
4337                 goto out;
4338         }
4339         /* Found one, remove it from @blocks first and update blocks->swapped */
4340         rb_erase(&block->node, &blocks->blocks[level]);
4341         for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4342                 if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
4343                         swapped = true;
4344                         break;
4345                 }
4346         }
4347         blocks->swapped = swapped;
4348         spin_unlock(&blocks->lock);
4349
4350         /* Read out reloc subtree root */
4351         reloc_eb = read_tree_block(fs_info, block->reloc_bytenr, 0,
4352                                    block->reloc_generation, block->level,
4353                                    &block->first_key);
4354         if (IS_ERR(reloc_eb)) {
4355                 ret = PTR_ERR(reloc_eb);
4356                 reloc_eb = NULL;
4357                 goto free_out;
4358         }
4359         if (!extent_buffer_uptodate(reloc_eb)) {
4360                 ret = -EIO;
4361                 goto free_out;
4362         }
4363
4364         ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
4365                         block->last_snapshot, block->trace_leaf);
4366 free_out:
4367         kfree(block);
4368         free_extent_buffer(reloc_eb);
4369 out:
4370         if (ret < 0) {
4371                 btrfs_err_rl(fs_info,
4372                              "failed to account subtree at bytenr %llu: %d",
4373                              subvol_eb->start, ret);
4374                 qgroup_mark_inconsistent(fs_info);
4375         }
4376         return ret;
4377 }
4378
4379 void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans)
4380 {
4381         struct btrfs_qgroup_extent_record *entry;
4382         struct btrfs_qgroup_extent_record *next;
4383         struct rb_root *root;
4384
4385         root = &trans->delayed_refs.dirty_extent_root;
4386         rbtree_postorder_for_each_entry_safe(entry, next, root, node) {
4387                 ulist_free(entry->old_roots);
4388                 kfree(entry);
4389         }
4390 }