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/sizes.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
  26 /* TODO XXX FIXME
  27  *  - subvol delete -> delete when ref goes to 0? delete limits also?
  28  *  - reorganize keys
  29  *  - compressed
  30  *  - sync
  31  *  - copy also limits on subvol creation
  32  *  - limit
  33  *  - caches for ulists
  34  *  - performance benchmarks
  35  *  - check all ioctl parameters
  36  */
  37
  38 /*
  39  * Helpers to access qgroup reservation
  40  *
  41  * Callers should ensure the lock context and type are valid
  42  */
  43
  44 static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
  45 {
  46         u64 ret = 0;
  47         int i;
  48
  49         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  50                 ret += qgroup->rsv.values[i];
  51
  52         return ret;
  53 }
  54
  55 #ifdef CONFIG_BTRFS_DEBUG
  56 static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
  57 {
  58         if (type == BTRFS_QGROUP_RSV_DATA)
  59                 return "data";
  60         if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
  61                 return "meta_pertrans";
  62         if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
  63                 return "meta_prealloc";
  64         return NULL;
  65 }
  66 #endif
  67
  68 static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
  69                            struct btrfs_qgroup *qgroup, u64 num_bytes,
  70                            enum btrfs_qgroup_rsv_type type)
  71 {
  72         trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
  73         qgroup->rsv.values[type] += num_bytes;
  74 }
  75
  76 static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
  77                                struct btrfs_qgroup *qgroup, u64 num_bytes,
  78                                enum btrfs_qgroup_rsv_type type)
  79 {
  80         trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
  81         if (qgroup->rsv.values[type] >= num_bytes) {
  82                 qgroup->rsv.values[type] -= num_bytes;
  83                 return;
  84         }
  85 #ifdef CONFIG_BTRFS_DEBUG
  86         WARN_RATELIMIT(1,
  87                 "qgroup %llu %s reserved space underflow, have %llu to free %llu",
  88                 qgroup->qgroupid, qgroup_rsv_type_str(type),
  89                 qgroup->rsv.values[type], num_bytes);
  90 #endif
  91         qgroup->rsv.values[type] = 0;
  92 }
  93
  94 static void qgroup_rsv_add_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_add(fs_info, dest, src->rsv.values[i], i);
 102 }
 103
 104 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
 105                                          struct btrfs_qgroup *dest,
 106                                           struct btrfs_qgroup *src)
 107 {
 108         int i;
 109
 110         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
 111                 qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
 112 }
 113
 114 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
 115                                            int mod)
 116 {
 117         if (qg->old_refcnt < seq)
 118                 qg->old_refcnt = seq;
 119         qg->old_refcnt += mod;
 120 }
 121
 122 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 123                                            int mod)
 124 {
 125         if (qg->new_refcnt < seq)
 126                 qg->new_refcnt = seq;
 127         qg->new_refcnt += mod;
 128 }
 129
 130 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
 131 {
 132         if (qg->old_refcnt < seq)
 133                 return 0;
 134         return qg->old_refcnt - seq;
 135 }
 136
 137 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
 138 {
 139         if (qg->new_refcnt < seq)
 140                 return 0;
 141         return qg->new_refcnt - seq;
 142 }
 143
 144 /*
 145  * glue structure to represent the relations between qgroups.
 146  */
 147 struct btrfs_qgroup_list {
 148         struct list_head next_group;
 149         struct list_head next_member;
 150         struct btrfs_qgroup *group;
 151         struct btrfs_qgroup *member;
 152 };
 153
 154 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
 155 {
 156         return (u64)(uintptr_t)qg;
 157 }
 158
 159 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
 160 {
 161         return (struct btrfs_qgroup *)(uintptr_t)n->aux;
 162 }
 163
 164 static int
 165 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 166                    int init_flags);
 167 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 168
 169 /* must be called with qgroup_ioctl_lock held */
 170 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 171                                            u64 qgroupid)
 172 {
 173         struct rb_node *n = fs_info->qgroup_tree.rb_node;
 174         struct btrfs_qgroup *qgroup;
 175
 176         while (n) {
 177                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 178                 if (qgroup->qgroupid < qgroupid)
 179                         n = n->rb_left;
 180                 else if (qgroup->qgroupid > qgroupid)
 181                         n = n->rb_right;
 182                 else
 183                         return qgroup;
 184         }
 185         return NULL;
 186 }
 187
 188 /* must be called with qgroup_lock held */
 189 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 190                                           u64 qgroupid)
 191 {
 192         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 193         struct rb_node *parent = NULL;
 194         struct btrfs_qgroup *qgroup;
 195
 196         while (*p) {
 197                 parent = *p;
 198                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 199
 200                 if (qgroup->qgroupid < qgroupid)
 201                         p = &(*p)->rb_left;
 202                 else if (qgroup->qgroupid > qgroupid)
 203                         p = &(*p)->rb_right;
 204                 else
 205                         return qgroup;
 206         }
 207
 208         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 209         if (!qgroup)
 210                 return ERR_PTR(-ENOMEM);
 211
 212         qgroup->qgroupid = qgroupid;
 213         INIT_LIST_HEAD(&qgroup->groups);
 214         INIT_LIST_HEAD(&qgroup->members);
 215         INIT_LIST_HEAD(&qgroup->dirty);
 216
 217         rb_link_node(&qgroup->node, parent, p);
 218         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 219
 220         return qgroup;
 221 }
 222
 223 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
 224 {
 225         struct btrfs_qgroup_list *list;
 226
 227         list_del(&qgroup->dirty);
 228         while (!list_empty(&qgroup->groups)) {
 229                 list = list_first_entry(&qgroup->groups,
 230                                         struct btrfs_qgroup_list, next_group);
 231                 list_del(&list->next_group);
 232                 list_del(&list->next_member);
 233                 kfree(list);
 234         }
 235
 236         while (!list_empty(&qgroup->members)) {
 237                 list = list_first_entry(&qgroup->members,
 238                                         struct btrfs_qgroup_list, next_member);
 239                 list_del(&list->next_group);
 240                 list_del(&list->next_member);
 241                 kfree(list);
 242         }
 243         kfree(qgroup);
 244 }
 245
 246 /* must be called with qgroup_lock held */
 247 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 248 {
 249         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 250
 251         if (!qgroup)
 252                 return -ENOENT;
 253
 254         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 255         __del_qgroup_rb(qgroup);
 256         return 0;
 257 }
 258
 259 /* must be called with qgroup_lock held */
 260 static int add_relation_rb(struct btrfs_fs_info *fs_info,
 261                            u64 memberid, u64 parentid)
 262 {
 263         struct btrfs_qgroup *member;
 264         struct btrfs_qgroup *parent;
 265         struct btrfs_qgroup_list *list;
 266
 267         member = find_qgroup_rb(fs_info, memberid);
 268         parent = find_qgroup_rb(fs_info, parentid);
 269         if (!member || !parent)
 270                 return -ENOENT;
 271
 272         list = kzalloc(sizeof(*list), GFP_ATOMIC);
 273         if (!list)
 274                 return -ENOMEM;
 275
 276         list->group = parent;
 277         list->member = member;
 278         list_add_tail(&list->next_group, &member->groups);
 279         list_add_tail(&list->next_member, &parent->members);
 280
 281         return 0;
 282 }
 283
 284 /* must be called with qgroup_lock held */
 285 static int del_relation_rb(struct btrfs_fs_info *fs_info,
 286                            u64 memberid, u64 parentid)
 287 {
 288         struct btrfs_qgroup *member;
 289         struct btrfs_qgroup *parent;
 290         struct btrfs_qgroup_list *list;
 291
 292         member = find_qgroup_rb(fs_info, memberid);
 293         parent = find_qgroup_rb(fs_info, parentid);
 294         if (!member || !parent)
 295                 return -ENOENT;
 296
 297         list_for_each_entry(list, &member->groups, next_group) {
 298                 if (list->group == parent) {
 299                         list_del(&list->next_group);
 300                         list_del(&list->next_member);
 301                         kfree(list);
 302                         return 0;
 303                 }
 304         }
 305         return -ENOENT;
 306 }
 307
 308 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 309 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 310                                u64 rfer, u64 excl)
 311 {
 312         struct btrfs_qgroup *qgroup;
 313
 314         qgroup = find_qgroup_rb(fs_info, qgroupid);
 315         if (!qgroup)
 316                 return -EINVAL;
 317         if (qgroup->rfer != rfer || qgroup->excl != excl)
 318                 return -EINVAL;
 319         return 0;
 320 }
 321 #endif
 322
 323 /*
 324  * The full config is read in one go, only called from open_ctree()
 325  * It doesn't use any locking, as at this point we're still single-threaded
 326  */
 327 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 328 {
 329         struct btrfs_key key;
 330         struct btrfs_key found_key;
 331         struct btrfs_root *quota_root = fs_info->quota_root;
 332         struct btrfs_path *path = NULL;
 333         struct extent_buffer *l;
 334         int slot;
 335         int ret = 0;
 336         u64 flags = 0;
 337         u64 rescan_progress = 0;
 338
 339         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 340                 return 0;
 341
 342         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 343         if (!fs_info->qgroup_ulist) {
 344                 ret = -ENOMEM;
 345                 goto out;
 346         }
 347
 348         path = btrfs_alloc_path();
 349         if (!path) {
 350                 ret = -ENOMEM;
 351                 goto out;
 352         }
 353
 354         /* default this to quota off, in case no status key is found */
 355         fs_info->qgroup_flags = 0;
 356
 357         /*
 358          * pass 1: read status, all qgroup infos and limits
 359          */
 360         key.objectid = 0;
 361         key.type = 0;
 362         key.offset = 0;
 363         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 364         if (ret)
 365                 goto out;
 366
 367         while (1) {
 368                 struct btrfs_qgroup *qgroup;
 369
 370                 slot = path->slots[0];
 371                 l = path->nodes[0];
 372                 btrfs_item_key_to_cpu(l, &found_key, slot);
 373
 374                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 375                         struct btrfs_qgroup_status_item *ptr;
 376
 377                         ptr = btrfs_item_ptr(l, slot,
 378                                              struct btrfs_qgroup_status_item);
 379
 380                         if (btrfs_qgroup_status_version(l, ptr) !=
 381                             BTRFS_QGROUP_STATUS_VERSION) {
 382                                 btrfs_err(fs_info,
 383                                  "old qgroup version, quota disabled");
 384                                 goto out;
 385                         }
 386                         if (btrfs_qgroup_status_generation(l, ptr) !=
 387                             fs_info->generation) {
 388                                 flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 389                                 btrfs_err(fs_info,
 390                                         "qgroup generation mismatch, marked as inconsistent");
 391                         }
 392                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 393                                                                           ptr);
 394                         rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
 395                         goto next1;
 396                 }
 397
 398                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 399                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 400                         goto next1;
 401
 402                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
 403                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 404                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 405                         btrfs_err(fs_info, "inconsistent qgroup config");
 406                         flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 407                 }
 408                 if (!qgroup) {
 409                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 410                         if (IS_ERR(qgroup)) {
 411                                 ret = PTR_ERR(qgroup);
 412                                 goto out;
 413                         }
 414                 }
 415                 switch (found_key.type) {
 416                 case BTRFS_QGROUP_INFO_KEY: {
 417                         struct btrfs_qgroup_info_item *ptr;
 418
 419                         ptr = btrfs_item_ptr(l, slot,
 420                                              struct btrfs_qgroup_info_item);
 421                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 422                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 423                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 424                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 425                         /* generation currently unused */
 426                         break;
 427                 }
 428                 case BTRFS_QGROUP_LIMIT_KEY: {
 429                         struct btrfs_qgroup_limit_item *ptr;
 430
 431                         ptr = btrfs_item_ptr(l, slot,
 432                                              struct btrfs_qgroup_limit_item);
 433                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 434                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 435                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 436                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 437                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 438                         break;
 439                 }
 440                 }
 441 next1:
 442                 ret = btrfs_next_item(quota_root, path);
 443                 if (ret < 0)
 444                         goto out;
 445                 if (ret)
 446                         break;
 447         }
 448         btrfs_release_path(path);
 449
 450         /*
 451          * pass 2: read all qgroup relations
 452          */
 453         key.objectid = 0;
 454         key.type = BTRFS_QGROUP_RELATION_KEY;
 455         key.offset = 0;
 456         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 457         if (ret)
 458                 goto out;
 459         while (1) {
 460                 slot = path->slots[0];
 461                 l = path->nodes[0];
 462                 btrfs_item_key_to_cpu(l, &found_key, slot);
 463
 464                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 465                         goto next2;
 466
 467                 if (found_key.objectid > found_key.offset) {
 468                         /* parent <- member, not needed to build config */
 469                         /* FIXME should we omit the key completely? */
 470                         goto next2;
 471                 }
 472
 473                 ret = add_relation_rb(fs_info, found_key.objectid,
 474                                       found_key.offset);
 475                 if (ret == -ENOENT) {
 476                         btrfs_warn(fs_info,
 477                                 "orphan qgroup relation 0x%llx->0x%llx",
 478                                 found_key.objectid, found_key.offset);
 479                         ret = 0;        /* ignore the error */
 480                 }
 481                 if (ret)
 482                         goto out;
 483 next2:
 484                 ret = btrfs_next_item(quota_root, path);
 485                 if (ret < 0)
 486                         goto out;
 487                 if (ret)
 488                         break;
 489         }
 490 out:
 491         fs_info->qgroup_flags |= flags;
 492         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
 493                 clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 494         else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
 495                  ret >= 0)
 496                 ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
 497         btrfs_free_path(path);
 498
 499         if (ret < 0) {
 500                 ulist_free(fs_info->qgroup_ulist);
 501                 fs_info->qgroup_ulist = NULL;
 502                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 503         }
 504
 505         return ret < 0 ? ret : 0;
 506 }
 507
 508 /*
 509  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
 510  * first two are in single-threaded paths.And for the third one, we have set
 511  * quota_root to be null with qgroup_lock held before, so it is safe to clean
 512  * up the in-memory structures without qgroup_lock held.
 513  */
 514 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 515 {
 516         struct rb_node *n;
 517         struct btrfs_qgroup *qgroup;
 518
 519         while ((n = rb_first(&fs_info->qgroup_tree))) {
 520                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 521                 rb_erase(n, &fs_info->qgroup_tree);
 522                 __del_qgroup_rb(qgroup);
 523         }
 524         /*
 525          * We call btrfs_free_qgroup_config() when unmounting
 526          * filesystem and disabling quota, so we set qgroup_ulist
 527          * to be null here to avoid double free.
 528          */
 529         ulist_free(fs_info->qgroup_ulist);
 530         fs_info->qgroup_ulist = NULL;
 531 }
 532
 533 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 534                                     u64 dst)
 535 {
 536         int ret;
 537         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 538         struct btrfs_path *path;
 539         struct btrfs_key key;
 540
 541         path = btrfs_alloc_path();
 542         if (!path)
 543                 return -ENOMEM;
 544
 545         key.objectid = src;
 546         key.type = BTRFS_QGROUP_RELATION_KEY;
 547         key.offset = dst;
 548
 549         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 550
 551         btrfs_mark_buffer_dirty(path->nodes[0]);
 552
 553         btrfs_free_path(path);
 554         return ret;
 555 }
 556
 557 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 558                                     u64 dst)
 559 {
 560         int ret;
 561         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 562         struct btrfs_path *path;
 563         struct btrfs_key key;
 564
 565         path = btrfs_alloc_path();
 566         if (!path)
 567                 return -ENOMEM;
 568
 569         key.objectid = src;
 570         key.type = BTRFS_QGROUP_RELATION_KEY;
 571         key.offset = dst;
 572
 573         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 574         if (ret < 0)
 575                 goto out;
 576
 577         if (ret > 0) {
 578                 ret = -ENOENT;
 579                 goto out;
 580         }
 581
 582         ret = btrfs_del_item(trans, quota_root, path);
 583 out:
 584         btrfs_free_path(path);
 585         return ret;
 586 }
 587
 588 static int add_qgroup_item(struct btrfs_trans_handle *trans,
 589                            struct btrfs_root *quota_root, u64 qgroupid)
 590 {
 591         int ret;
 592         struct btrfs_path *path;
 593         struct btrfs_qgroup_info_item *qgroup_info;
 594         struct btrfs_qgroup_limit_item *qgroup_limit;
 595         struct extent_buffer *leaf;
 596         struct btrfs_key key;
 597
 598         if (btrfs_is_testing(quota_root->fs_info))
 599                 return 0;
 600
 601         path = btrfs_alloc_path();
 602         if (!path)
 603                 return -ENOMEM;
 604
 605         key.objectid = 0;
 606         key.type = BTRFS_QGROUP_INFO_KEY;
 607         key.offset = qgroupid;
 608
 609         /*
 610          * Avoid a transaction abort by catching -EEXIST here. In that
 611          * case, we proceed by re-initializing the existing structure
 612          * on disk.
 613          */
 614
 615         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 616                                       sizeof(*qgroup_info));
 617         if (ret && ret != -EEXIST)
 618                 goto out;
 619
 620         leaf = path->nodes[0];
 621         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 622                                  struct btrfs_qgroup_info_item);
 623         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 624         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 625         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 626         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 627         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 628
 629         btrfs_mark_buffer_dirty(leaf);
 630
 631         btrfs_release_path(path);
 632
 633         key.type = BTRFS_QGROUP_LIMIT_KEY;
 634         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 635                                       sizeof(*qgroup_limit));
 636         if (ret && ret != -EEXIST)
 637                 goto out;
 638
 639         leaf = path->nodes[0];
 640         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 641                                   struct btrfs_qgroup_limit_item);
 642         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 643         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 644         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 645         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 646         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 647
 648         btrfs_mark_buffer_dirty(leaf);
 649
 650         ret = 0;
 651 out:
 652         btrfs_free_path(path);
 653         return ret;
 654 }
 655
 656 static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
 657 {
 658         int ret;
 659         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 660         struct btrfs_path *path;
 661         struct btrfs_key key;
 662
 663         path = btrfs_alloc_path();
 664         if (!path)
 665                 return -ENOMEM;
 666
 667         key.objectid = 0;
 668         key.type = BTRFS_QGROUP_INFO_KEY;
 669         key.offset = qgroupid;
 670         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 671         if (ret < 0)
 672                 goto out;
 673
 674         if (ret > 0) {
 675                 ret = -ENOENT;
 676                 goto out;
 677         }
 678
 679         ret = btrfs_del_item(trans, quota_root, path);
 680         if (ret)
 681                 goto out;
 682
 683         btrfs_release_path(path);
 684
 685         key.type = BTRFS_QGROUP_LIMIT_KEY;
 686         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 687         if (ret < 0)
 688                 goto out;
 689
 690         if (ret > 0) {
 691                 ret = -ENOENT;
 692                 goto out;
 693         }
 694
 695         ret = btrfs_del_item(trans, quota_root, path);
 696
 697 out:
 698         btrfs_free_path(path);
 699         return ret;
 700 }
 701
 702 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 703                                     struct btrfs_qgroup *qgroup)
 704 {
 705         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 706         struct btrfs_path *path;
 707         struct btrfs_key key;
 708         struct extent_buffer *l;
 709         struct btrfs_qgroup_limit_item *qgroup_limit;
 710         int ret;
 711         int slot;
 712
 713         key.objectid = 0;
 714         key.type = BTRFS_QGROUP_LIMIT_KEY;
 715         key.offset = qgroup->qgroupid;
 716
 717         path = btrfs_alloc_path();
 718         if (!path)
 719                 return -ENOMEM;
 720
 721         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 722         if (ret > 0)
 723                 ret = -ENOENT;
 724
 725         if (ret)
 726                 goto out;
 727
 728         l = path->nodes[0];
 729         slot = path->slots[0];
 730         qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
 731         btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
 732         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
 733         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
 734         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
 735         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
 736
 737         btrfs_mark_buffer_dirty(l);
 738
 739 out:
 740         btrfs_free_path(path);
 741         return ret;
 742 }
 743
 744 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 745                                    struct btrfs_qgroup *qgroup)
 746 {
 747         struct btrfs_fs_info *fs_info = trans->fs_info;
 748         struct btrfs_root *quota_root = fs_info->quota_root;
 749         struct btrfs_path *path;
 750         struct btrfs_key key;
 751         struct extent_buffer *l;
 752         struct btrfs_qgroup_info_item *qgroup_info;
 753         int ret;
 754         int slot;
 755
 756         if (btrfs_is_testing(fs_info))
 757                 return 0;
 758
 759         key.objectid = 0;
 760         key.type = BTRFS_QGROUP_INFO_KEY;
 761         key.offset = qgroup->qgroupid;
 762
 763         path = btrfs_alloc_path();
 764         if (!path)
 765                 return -ENOMEM;
 766
 767         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 768         if (ret > 0)
 769                 ret = -ENOENT;
 770
 771         if (ret)
 772                 goto out;
 773
 774         l = path->nodes[0];
 775         slot = path->slots[0];
 776         qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
 777         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 778         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 779         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 780         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 781         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 782
 783         btrfs_mark_buffer_dirty(l);
 784
 785 out:
 786         btrfs_free_path(path);
 787         return ret;
 788 }
 789
 790 static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
 791 {
 792         struct btrfs_fs_info *fs_info = trans->fs_info;
 793         struct btrfs_root *quota_root = fs_info->quota_root;
 794         struct btrfs_path *path;
 795         struct btrfs_key key;
 796         struct extent_buffer *l;
 797         struct btrfs_qgroup_status_item *ptr;
 798         int ret;
 799         int slot;
 800
 801         key.objectid = 0;
 802         key.type = BTRFS_QGROUP_STATUS_KEY;
 803         key.offset = 0;
 804
 805         path = btrfs_alloc_path();
 806         if (!path)
 807                 return -ENOMEM;
 808
 809         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 810         if (ret > 0)
 811                 ret = -ENOENT;
 812
 813         if (ret)
 814                 goto out;
 815
 816         l = path->nodes[0];
 817         slot = path->slots[0];
 818         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 819         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
 820         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 821         btrfs_set_qgroup_status_rescan(l, ptr,
 822                                 fs_info->qgroup_rescan_progress.objectid);
 823
 824         btrfs_mark_buffer_dirty(l);
 825
 826 out:
 827         btrfs_free_path(path);
 828         return ret;
 829 }
 830
 831 /*
 832  * called with qgroup_lock held
 833  */
 834 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 835                                   struct btrfs_root *root)
 836 {
 837         struct btrfs_path *path;
 838         struct btrfs_key key;
 839         struct extent_buffer *leaf = NULL;
 840         int ret;
 841         int nr = 0;
 842
 843         path = btrfs_alloc_path();
 844         if (!path)
 845                 return -ENOMEM;
 846
 847         path->leave_spinning = 1;
 848
 849         key.objectid = 0;
 850         key.offset = 0;
 851         key.type = 0;
 852
 853         while (1) {
 854                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 855                 if (ret < 0)
 856                         goto out;
 857                 leaf = path->nodes[0];
 858                 nr = btrfs_header_nritems(leaf);
 859                 if (!nr)
 860                         break;
 861                 /*
 862                  * delete the leaf one by one
 863                  * since the whole tree is going
 864                  * to be deleted.
 865                  */
 866                 path->slots[0] = 0;
 867                 ret = btrfs_del_items(trans, root, path, 0, nr);
 868                 if (ret)
 869                         goto out;
 870
 871                 btrfs_release_path(path);
 872         }
 873         ret = 0;
 874 out:
 875         btrfs_free_path(path);
 876         return ret;
 877 }
 878
 879 int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
 880 {
 881         struct btrfs_root *quota_root;
 882         struct btrfs_root *tree_root = fs_info->tree_root;
 883         struct btrfs_path *path = NULL;
 884         struct btrfs_qgroup_status_item *ptr;
 885         struct extent_buffer *leaf;
 886         struct btrfs_key key;
 887         struct btrfs_key found_key;
 888         struct btrfs_qgroup *qgroup = NULL;
 889         struct btrfs_trans_handle *trans = NULL;
 890         int ret = 0;
 891         int slot;
 892
 893         mutex_lock(&fs_info->qgroup_ioctl_lock);
 894         if (fs_info->quota_root)
 895                 goto out;
 896
 897         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 898         if (!fs_info->qgroup_ulist) {
 899                 ret = -ENOMEM;
 900                 goto out;
 901         }
 902
 903         /*
 904          * 1 for quota root item
 905          * 1 for BTRFS_QGROUP_STATUS item
 906          *
 907          * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
 908          * per subvolume. However those are not currently reserved since it
 909          * would be a lot of overkill.
 910          */
 911         trans = btrfs_start_transaction(tree_root, 2);
 912         if (IS_ERR(trans)) {
 913                 ret = PTR_ERR(trans);
 914                 trans = NULL;
 915                 goto out;
 916         }
 917
 918         /*
 919          * initially create the quota tree
 920          */
 921         quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
 922         if (IS_ERR(quota_root)) {
 923                 ret =  PTR_ERR(quota_root);
 924                 btrfs_abort_transaction(trans, ret);
 925                 goto out;
 926         }
 927
 928         path = btrfs_alloc_path();
 929         if (!path) {
 930                 ret = -ENOMEM;
 931                 btrfs_abort_transaction(trans, ret);
 932                 goto out_free_root;
 933         }
 934
 935         key.objectid = 0;
 936         key.type = BTRFS_QGROUP_STATUS_KEY;
 937         key.offset = 0;
 938
 939         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 940                                       sizeof(*ptr));
 941         if (ret) {
 942                 btrfs_abort_transaction(trans, ret);
 943                 goto out_free_path;
 944         }
 945
 946         leaf = path->nodes[0];
 947         ptr = btrfs_item_ptr(leaf, path->slots[0],
 948                                  struct btrfs_qgroup_status_item);
 949         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
 950         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
 951         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
 952                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 953         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
 954         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
 955
 956         btrfs_mark_buffer_dirty(leaf);
 957
 958         key.objectid = 0;
 959         key.type = BTRFS_ROOT_REF_KEY;
 960         key.offset = 0;
 961
 962         btrfs_release_path(path);
 963         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
 964         if (ret > 0)
 965                 goto out_add_root;
 966         if (ret < 0) {
 967                 btrfs_abort_transaction(trans, ret);
 968                 goto out_free_path;
 969         }
 970
 971         while (1) {
 972                 slot = path->slots[0];
 973                 leaf = path->nodes[0];
 974                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
 975
 976                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
 977                         ret = add_qgroup_item(trans, quota_root,
 978                                               found_key.offset);
 979                         if (ret) {
 980                                 btrfs_abort_transaction(trans, ret);
 981                                 goto out_free_path;
 982                         }
 983
 984                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 985                         if (IS_ERR(qgroup)) {
 986                                 ret = PTR_ERR(qgroup);
 987                                 btrfs_abort_transaction(trans, ret);
 988                                 goto out_free_path;
 989                         }
 990                 }
 991                 ret = btrfs_next_item(tree_root, path);
 992                 if (ret < 0) {
 993                         btrfs_abort_transaction(trans, ret);
 994                         goto out_free_path;
 995                 }
 996                 if (ret)
 997                         break;
 998         }
 999
1000 out_add_root:
1001         btrfs_release_path(path);
1002         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1003         if (ret) {
1004                 btrfs_abort_transaction(trans, ret);
1005                 goto out_free_path;
1006         }
1007
1008         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1009         if (IS_ERR(qgroup)) {
1010                 ret = PTR_ERR(qgroup);
1011                 btrfs_abort_transaction(trans, ret);
1012                 goto out_free_path;
1013         }
1014
1015         ret = btrfs_commit_transaction(trans);
1016         trans = NULL;
1017         if (ret)
1018                 goto out_free_path;
1019
1020         /*
1021          * Set quota enabled flag after committing the transaction, to avoid
1022          * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
1023          * creation.
1024          */
1025         spin_lock(&fs_info->qgroup_lock);
1026         fs_info->quota_root = quota_root;
1027         set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1028         spin_unlock(&fs_info->qgroup_lock);
1029
1030         ret = qgroup_rescan_init(fs_info, 0, 1);
1031         if (!ret) {
1032                 qgroup_rescan_zero_tracking(fs_info);
1033                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
1034                                  &fs_info->qgroup_rescan_work);
1035         }
1036
1037 out_free_path:
1038         btrfs_free_path(path);
1039 out_free_root:
1040         if (ret) {
1041                 free_extent_buffer(quota_root->node);
1042                 free_extent_buffer(quota_root->commit_root);
1043                 kfree(quota_root);
1044         }
1045 out:
1046         if (ret) {
1047                 ulist_free(fs_info->qgroup_ulist);
1048                 fs_info->qgroup_ulist = NULL;
1049                 if (trans)
1050                         btrfs_end_transaction(trans);
1051         }
1052         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1053         return ret;
1054 }
1055
1056 int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1057 {
1058         struct btrfs_root *quota_root;
1059         struct btrfs_trans_handle *trans = NULL;
1060         int ret = 0;
1061
1062         mutex_lock(&fs_info->qgroup_ioctl_lock);
1063         if (!fs_info->quota_root)
1064                 goto out;
1065
1066         /*
1067          * 1 For the root item
1068          *
1069          * We should also reserve enough items for the quota tree deletion in
1070          * btrfs_clean_quota_tree but this is not done.
1071          */
1072         trans = btrfs_start_transaction(fs_info->tree_root, 1);
1073         if (IS_ERR(trans)) {
1074                 ret = PTR_ERR(trans);
1075                 goto out;
1076         }
1077
1078         clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1079         btrfs_qgroup_wait_for_completion(fs_info, false);
1080         spin_lock(&fs_info->qgroup_lock);
1081         quota_root = fs_info->quota_root;
1082         fs_info->quota_root = NULL;
1083         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1084         spin_unlock(&fs_info->qgroup_lock);
1085
1086         btrfs_free_qgroup_config(fs_info);
1087
1088         ret = btrfs_clean_quota_tree(trans, quota_root);
1089         if (ret) {
1090                 btrfs_abort_transaction(trans, ret);
1091                 goto end_trans;
1092         }
1093
1094         ret = btrfs_del_root(trans, &quota_root->root_key);
1095         if (ret) {
1096                 btrfs_abort_transaction(trans, ret);
1097                 goto end_trans;
1098         }
1099
1100         list_del(&quota_root->dirty_list);
1101
1102         btrfs_tree_lock(quota_root->node);
1103         btrfs_clean_tree_block(quota_root->node);
1104         btrfs_tree_unlock(quota_root->node);
1105         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
1106
1107         free_extent_buffer(quota_root->node);
1108         free_extent_buffer(quota_root->commit_root);
1109         kfree(quota_root);
1110
1111 end_trans:
1112         ret = btrfs_end_transaction(trans);
1113 out:
1114         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1115         return ret;
1116 }
1117
1118 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1119                          struct btrfs_qgroup *qgroup)
1120 {
1121         if (list_empty(&qgroup->dirty))
1122                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1123 }
1124
1125 /*
1126  * The easy accounting, we're updating qgroup relationship whose child qgroup
1127  * only has exclusive extents.
1128  *
1129  * In this case, all exclusive extents will also be exclusive for parent, so
1130  * excl/rfer just get added/removed.
1131  *
1132  * So is qgroup reservation space, which should also be added/removed to
1133  * parent.
1134  * Or when child tries to release reservation space, parent will underflow its
1135  * reservation (for relationship adding case).
1136  *
1137  * Caller should hold fs_info->qgroup_lock.
1138  */
1139 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1140                                     struct ulist *tmp, u64 ref_root,
1141                                     struct btrfs_qgroup *src, int sign)
1142 {
1143         struct btrfs_qgroup *qgroup;
1144         struct btrfs_qgroup_list *glist;
1145         struct ulist_node *unode;
1146         struct ulist_iterator uiter;
1147         u64 num_bytes = src->excl;
1148         int ret = 0;
1149
1150         qgroup = find_qgroup_rb(fs_info, ref_root);
1151         if (!qgroup)
1152                 goto out;
1153
1154         qgroup->rfer += sign * num_bytes;
1155         qgroup->rfer_cmpr += sign * num_bytes;
1156
1157         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1158         qgroup->excl += sign * num_bytes;
1159         qgroup->excl_cmpr += sign * num_bytes;
1160
1161         if (sign > 0)
1162                 qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1163         else
1164                 qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1165
1166         qgroup_dirty(fs_info, qgroup);
1167
1168         /* Get all of the parent groups that contain this qgroup */
1169         list_for_each_entry(glist, &qgroup->groups, next_group) {
1170                 ret = ulist_add(tmp, glist->group->qgroupid,
1171                                 qgroup_to_aux(glist->group), GFP_ATOMIC);
1172                 if (ret < 0)
1173                         goto out;
1174         }
1175
1176         /* Iterate all of the parents and adjust their reference counts */
1177         ULIST_ITER_INIT(&uiter);
1178         while ((unode = ulist_next(tmp, &uiter))) {
1179                 qgroup = unode_aux_to_qgroup(unode);
1180                 qgroup->rfer += sign * num_bytes;
1181                 qgroup->rfer_cmpr += sign * num_bytes;
1182                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1183                 qgroup->excl += sign * num_bytes;
1184                 if (sign > 0)
1185                         qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1186                 else
1187                         qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1188                 qgroup->excl_cmpr += sign * num_bytes;
1189                 qgroup_dirty(fs_info, qgroup);
1190
1191                 /* Add any parents of the parents */
1192                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1193                         ret = ulist_add(tmp, glist->group->qgroupid,
1194                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
1195                         if (ret < 0)
1196                                 goto out;
1197                 }
1198         }
1199         ret = 0;
1200 out:
1201         return ret;
1202 }
1203
1204
1205 /*
1206  * Quick path for updating qgroup with only excl refs.
1207  *
1208  * In that case, just update all parent will be enough.
1209  * Or we needs to do a full rescan.
1210  * Caller should also hold fs_info->qgroup_lock.
1211  *
1212  * Return 0 for quick update, return >0 for need to full rescan
1213  * and mark INCONSISTENT flag.
1214  * Return < 0 for other error.
1215  */
1216 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1217                                    struct ulist *tmp, u64 src, u64 dst,
1218                                    int sign)
1219 {
1220         struct btrfs_qgroup *qgroup;
1221         int ret = 1;
1222         int err = 0;
1223
1224         qgroup = find_qgroup_rb(fs_info, src);
1225         if (!qgroup)
1226                 goto out;
1227         if (qgroup->excl == qgroup->rfer) {
1228                 ret = 0;
1229                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1230                                                qgroup, sign);
1231                 if (err < 0) {
1232                         ret = err;
1233                         goto out;
1234                 }
1235         }
1236 out:
1237         if (ret)
1238                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1239         return ret;
1240 }
1241
1242 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1243                               u64 dst)
1244 {
1245         struct btrfs_fs_info *fs_info = trans->fs_info;
1246         struct btrfs_qgroup *parent;
1247         struct btrfs_qgroup *member;
1248         struct btrfs_qgroup_list *list;
1249         struct ulist *tmp;
1250         int ret = 0;
1251
1252         /* Check the level of src and dst first */
1253         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1254                 return -EINVAL;
1255
1256         tmp = ulist_alloc(GFP_KERNEL);
1257         if (!tmp)
1258                 return -ENOMEM;
1259
1260         mutex_lock(&fs_info->qgroup_ioctl_lock);
1261         if (!fs_info->quota_root) {
1262                 ret = -ENOTCONN;
1263                 goto out;
1264         }
1265         member = find_qgroup_rb(fs_info, src);
1266         parent = find_qgroup_rb(fs_info, dst);
1267         if (!member || !parent) {
1268                 ret = -EINVAL;
1269                 goto out;
1270         }
1271
1272         /* check if such qgroup relation exist firstly */
1273         list_for_each_entry(list, &member->groups, next_group) {
1274                 if (list->group == parent) {
1275                         ret = -EEXIST;
1276                         goto out;
1277                 }
1278         }
1279
1280         ret = add_qgroup_relation_item(trans, src, dst);
1281         if (ret)
1282                 goto out;
1283
1284         ret = add_qgroup_relation_item(trans, dst, src);
1285         if (ret) {
1286                 del_qgroup_relation_item(trans, src, dst);
1287                 goto out;
1288         }
1289
1290         spin_lock(&fs_info->qgroup_lock);
1291         ret = add_relation_rb(fs_info, src, dst);
1292         if (ret < 0) {
1293                 spin_unlock(&fs_info->qgroup_lock);
1294                 goto out;
1295         }
1296         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1297         spin_unlock(&fs_info->qgroup_lock);
1298 out:
1299         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1300         ulist_free(tmp);
1301         return ret;
1302 }
1303
1304 static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1305                                  u64 dst)
1306 {
1307         struct btrfs_fs_info *fs_info = trans->fs_info;
1308         struct btrfs_qgroup *parent;
1309         struct btrfs_qgroup *member;
1310         struct btrfs_qgroup_list *list;
1311         struct ulist *tmp;
1312         bool found = false;
1313         int ret = 0;
1314         int ret2;
1315
1316         tmp = ulist_alloc(GFP_KERNEL);
1317         if (!tmp)
1318                 return -ENOMEM;
1319
1320         if (!fs_info->quota_root) {
1321                 ret = -ENOTCONN;
1322                 goto out;
1323         }
1324
1325         member = find_qgroup_rb(fs_info, src);
1326         parent = find_qgroup_rb(fs_info, dst);
1327         /*
1328          * The parent/member pair doesn't exist, then try to delete the dead
1329          * relation items only.
1330          */
1331         if (!member || !parent)
1332                 goto delete_item;
1333
1334         /* check if such qgroup relation exist firstly */
1335         list_for_each_entry(list, &member->groups, next_group) {
1336                 if (list->group == parent) {
1337                         found = true;
1338                         break;
1339                 }
1340         }
1341
1342 delete_item:
1343         ret = del_qgroup_relation_item(trans, src, dst);
1344         if (ret < 0 && ret != -ENOENT)
1345                 goto out;
1346         ret2 = del_qgroup_relation_item(trans, dst, src);
1347         if (ret2 < 0 && ret2 != -ENOENT)
1348                 goto out;
1349
1350         /* At least one deletion succeeded, return 0 */
1351         if (!ret || !ret2)
1352                 ret = 0;
1353
1354         if (found) {
1355                 spin_lock(&fs_info->qgroup_lock);
1356                 del_relation_rb(fs_info, src, dst);
1357                 ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1358                 spin_unlock(&fs_info->qgroup_lock);
1359         }
1360 out:
1361         ulist_free(tmp);
1362         return ret;
1363 }
1364
1365 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1366                               u64 dst)
1367 {
1368         struct btrfs_fs_info *fs_info = trans->fs_info;
1369         int ret = 0;
1370
1371         mutex_lock(&fs_info->qgroup_ioctl_lock);
1372         ret = __del_qgroup_relation(trans, src, dst);
1373         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1374
1375         return ret;
1376 }
1377
1378 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1379 {
1380         struct btrfs_fs_info *fs_info = trans->fs_info;
1381         struct btrfs_root *quota_root;
1382         struct btrfs_qgroup *qgroup;
1383         int ret = 0;
1384
1385         mutex_lock(&fs_info->qgroup_ioctl_lock);
1386         if (!fs_info->quota_root) {
1387                 ret = -ENOTCONN;
1388                 goto out;
1389         }
1390         quota_root = fs_info->quota_root;
1391         qgroup = find_qgroup_rb(fs_info, qgroupid);
1392         if (qgroup) {
1393                 ret = -EEXIST;
1394                 goto out;
1395         }
1396
1397         ret = add_qgroup_item(trans, quota_root, qgroupid);
1398         if (ret)
1399                 goto out;
1400
1401         spin_lock(&fs_info->qgroup_lock);
1402         qgroup = add_qgroup_rb(fs_info, qgroupid);
1403         spin_unlock(&fs_info->qgroup_lock);
1404
1405         if (IS_ERR(qgroup))
1406                 ret = PTR_ERR(qgroup);
1407 out:
1408         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1409         return ret;
1410 }
1411
1412 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1413 {
1414         struct btrfs_fs_info *fs_info = trans->fs_info;
1415         struct btrfs_qgroup *qgroup;
1416         struct btrfs_qgroup_list *list;
1417         int ret = 0;
1418
1419         mutex_lock(&fs_info->qgroup_ioctl_lock);
1420         if (!fs_info->quota_root) {
1421                 ret = -ENOTCONN;
1422                 goto out;
1423         }
1424
1425         qgroup = find_qgroup_rb(fs_info, qgroupid);
1426         if (!qgroup) {
1427                 ret = -ENOENT;
1428                 goto out;
1429         }
1430
1431         /* Check if there are no children of this qgroup */
1432         if (!list_empty(&qgroup->members)) {
1433                 ret = -EBUSY;
1434                 goto out;
1435         }
1436
1437         ret = del_qgroup_item(trans, qgroupid);
1438         if (ret && ret != -ENOENT)
1439                 goto out;
1440
1441         while (!list_empty(&qgroup->groups)) {
1442                 list = list_first_entry(&qgroup->groups,
1443                                         struct btrfs_qgroup_list, next_group);
1444                 ret = __del_qgroup_relation(trans, qgroupid,
1445                                             list->group->qgroupid);
1446                 if (ret)
1447                         goto out;
1448         }
1449
1450         spin_lock(&fs_info->qgroup_lock);
1451         del_qgroup_rb(fs_info, qgroupid);
1452         spin_unlock(&fs_info->qgroup_lock);
1453 out:
1454         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1455         return ret;
1456 }
1457
1458 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1459                        struct btrfs_qgroup_limit *limit)
1460 {
1461         struct btrfs_fs_info *fs_info = trans->fs_info;
1462         struct btrfs_qgroup *qgroup;
1463         int ret = 0;
1464         /* Sometimes we would want to clear the limit on this qgroup.
1465          * To meet this requirement, we treat the -1 as a special value
1466          * which tell kernel to clear the limit on this qgroup.
1467          */
1468         const u64 CLEAR_VALUE = -1;
1469
1470         mutex_lock(&fs_info->qgroup_ioctl_lock);
1471         if (!fs_info->quota_root) {
1472                 ret = -ENOTCONN;
1473                 goto out;
1474         }
1475
1476         qgroup = find_qgroup_rb(fs_info, qgroupid);
1477         if (!qgroup) {
1478                 ret = -ENOENT;
1479                 goto out;
1480         }
1481
1482         spin_lock(&fs_info->qgroup_lock);
1483         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1484                 if (limit->max_rfer == CLEAR_VALUE) {
1485                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1486                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1487                         qgroup->max_rfer = 0;
1488                 } else {
1489                         qgroup->max_rfer = limit->max_rfer;
1490                 }
1491         }
1492         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1493                 if (limit->max_excl == CLEAR_VALUE) {
1494                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1495                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1496                         qgroup->max_excl = 0;
1497                 } else {
1498                         qgroup->max_excl = limit->max_excl;
1499                 }
1500         }
1501         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1502                 if (limit->rsv_rfer == CLEAR_VALUE) {
1503                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1504                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1505                         qgroup->rsv_rfer = 0;
1506                 } else {
1507                         qgroup->rsv_rfer = limit->rsv_rfer;
1508                 }
1509         }
1510         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1511                 if (limit->rsv_excl == CLEAR_VALUE) {
1512                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1513                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1514                         qgroup->rsv_excl = 0;
1515                 } else {
1516                         qgroup->rsv_excl = limit->rsv_excl;
1517                 }
1518         }
1519         qgroup->lim_flags |= limit->flags;
1520
1521         spin_unlock(&fs_info->qgroup_lock);
1522
1523         ret = update_qgroup_limit_item(trans, qgroup);
1524         if (ret) {
1525                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1526                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1527                        qgroupid);
1528         }
1529
1530 out:
1531         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1532         return ret;
1533 }
1534
1535 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1536                                 struct btrfs_delayed_ref_root *delayed_refs,
1537                                 struct btrfs_qgroup_extent_record *record)
1538 {
1539         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1540         struct rb_node *parent_node = NULL;
1541         struct btrfs_qgroup_extent_record *entry;
1542         u64 bytenr = record->bytenr;
1543
1544         lockdep_assert_held(&delayed_refs->lock);
1545         trace_btrfs_qgroup_trace_extent(fs_info, record);
1546
1547         while (*p) {
1548                 parent_node = *p;
1549                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1550                                  node);
1551                 if (bytenr < entry->bytenr) {
1552                         p = &(*p)->rb_left;
1553                 } else if (bytenr > entry->bytenr) {
1554                         p = &(*p)->rb_right;
1555                 } else {
1556                         if (record->data_rsv && !entry->data_rsv) {
1557                                 entry->data_rsv = record->data_rsv;
1558                                 entry->data_rsv_refroot =
1559                                         record->data_rsv_refroot;
1560                         }
1561                         return 1;
1562                 }
1563         }
1564
1565         rb_link_node(&record->node, parent_node, p);
1566         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1567         return 0;
1568 }
1569
1570 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1571                                    struct btrfs_qgroup_extent_record *qrecord)
1572 {
1573         struct ulist *old_root;
1574         u64 bytenr = qrecord->bytenr;
1575         int ret;
1576
1577         ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
1578         if (ret < 0) {
1579                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1580                 btrfs_warn(fs_info,
1581 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1582                         ret);
1583                 return 0;
1584         }
1585
1586         /*
1587          * Here we don't need to get the lock of
1588          * trans->transaction->delayed_refs, since inserted qrecord won't
1589          * be deleted, only qrecord->node may be modified (new qrecord insert)
1590          *
1591          * So modifying qrecord->old_roots is safe here
1592          */
1593         qrecord->old_roots = old_root;
1594         return 0;
1595 }
1596
1597 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1598                               u64 num_bytes, gfp_t gfp_flag)
1599 {
1600         struct btrfs_fs_info *fs_info = trans->fs_info;
1601         struct btrfs_qgroup_extent_record *record;
1602         struct btrfs_delayed_ref_root *delayed_refs;
1603         int ret;
1604
1605         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1606             || bytenr == 0 || num_bytes == 0)
1607                 return 0;
1608         record = kzalloc(sizeof(*record), gfp_flag);
1609         if (!record)
1610                 return -ENOMEM;
1611
1612         delayed_refs = &trans->transaction->delayed_refs;
1613         record->bytenr = bytenr;
1614         record->num_bytes = num_bytes;
1615         record->old_roots = NULL;
1616
1617         spin_lock(&delayed_refs->lock);
1618         ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1619         spin_unlock(&delayed_refs->lock);
1620         if (ret > 0) {
1621                 kfree(record);
1622                 return 0;
1623         }
1624         return btrfs_qgroup_trace_extent_post(fs_info, record);
1625 }
1626
1627 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1628                                   struct extent_buffer *eb)
1629 {
1630         struct btrfs_fs_info *fs_info = trans->fs_info;
1631         int nr = btrfs_header_nritems(eb);
1632         int i, extent_type, ret;
1633         struct btrfs_key key;
1634         struct btrfs_file_extent_item *fi;
1635         u64 bytenr, num_bytes;
1636
1637         /* We can be called directly from walk_up_proc() */
1638         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1639                 return 0;
1640
1641         for (i = 0; i < nr; i++) {
1642                 btrfs_item_key_to_cpu(eb, &key, i);
1643
1644                 if (key.type != BTRFS_EXTENT_DATA_KEY)
1645                         continue;
1646
1647                 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1648                 /* filter out non qgroup-accountable extents  */
1649                 extent_type = btrfs_file_extent_type(eb, fi);
1650
1651                 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1652                         continue;
1653
1654                 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1655                 if (!bytenr)
1656                         continue;
1657
1658                 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1659
1660                 ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes,
1661                                                 GFP_NOFS);
1662                 if (ret)
1663                         return ret;
1664         }
1665         cond_resched();
1666         return 0;
1667 }
1668
1669 /*
1670  * Walk up the tree from the bottom, freeing leaves and any interior
1671  * nodes which have had all slots visited. If a node (leaf or
1672  * interior) is freed, the node above it will have it's slot
1673  * incremented. The root node will never be freed.
1674  *
1675  * At the end of this function, we should have a path which has all
1676  * slots incremented to the next position for a search. If we need to
1677  * read a new node it will be NULL and the node above it will have the
1678  * correct slot selected for a later read.
1679  *
1680  * If we increment the root nodes slot counter past the number of
1681  * elements, 1 is returned to signal completion of the search.
1682  */
1683 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1684 {
1685         int level = 0;
1686         int nr, slot;
1687         struct extent_buffer *eb;
1688
1689         if (root_level == 0)
1690                 return 1;
1691
1692         while (level <= root_level) {
1693                 eb = path->nodes[level];
1694                 nr = btrfs_header_nritems(eb);
1695                 path->slots[level]++;
1696                 slot = path->slots[level];
1697                 if (slot >= nr || level == 0) {
1698                         /*
1699                          * Don't free the root -  we will detect this
1700                          * condition after our loop and return a
1701                          * positive value for caller to stop walking the tree.
1702                          */
1703                         if (level != root_level) {
1704                                 btrfs_tree_unlock_rw(eb, path->locks[level]);
1705                                 path->locks[level] = 0;
1706
1707                                 free_extent_buffer(eb);
1708                                 path->nodes[level] = NULL;
1709                                 path->slots[level] = 0;
1710                         }
1711                 } else {
1712                         /*
1713                          * We have a valid slot to walk back down
1714                          * from. Stop here so caller can process these
1715                          * new nodes.
1716                          */
1717                         break;
1718                 }
1719
1720                 level++;
1721         }
1722
1723         eb = path->nodes[root_level];
1724         if (path->slots[root_level] >= btrfs_header_nritems(eb))
1725                 return 1;
1726
1727         return 0;
1728 }
1729
1730 /*
1731  * Helper function to trace a subtree tree block swap.
1732  *
1733  * The swap will happen in highest tree block, but there may be a lot of
1734  * tree blocks involved.
1735  *
1736  * For example:
1737  *  OO = Old tree blocks
1738  *  NN = New tree blocks allocated during balance
1739  *
1740  *           File tree (257)                  Reloc tree for 257
1741  * L2              OO                                NN
1742  *               /    \                            /    \
1743  * L1          OO      OO (a)                    OO      NN (a)
1744  *            / \     / \                       / \     / \
1745  * L0       OO   OO OO   OO                   OO   OO NN   NN
1746  *                  (b)  (c)                          (b)  (c)
1747  *
1748  * When calling qgroup_trace_extent_swap(), we will pass:
1749  * @src_eb = OO(a)
1750  * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
1751  * @dst_level = 0
1752  * @root_level = 1
1753  *
1754  * In that case, qgroup_trace_extent_swap() will search from OO(a) to
1755  * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
1756  *
1757  * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
1758  *
1759  * 1) Tree search from @src_eb
1760  *    It should acts as a simplified btrfs_search_slot().
1761  *    The key for search can be extracted from @dst_path->nodes[dst_level]
1762  *    (first key).
1763  *
1764  * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
1765  *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
1766  *    They should be marked during previous (@dst_level = 1) iteration.
1767  *
1768  * 3) Mark file extents in leaves dirty
1769  *    We don't have good way to pick out new file extents only.
1770  *    So we still follow the old method by scanning all file extents in
1771  *    the leave.
1772  *
1773  * This function can free us from keeping two paths, thus later we only need
1774  * to care about how to iterate all new tree blocks in reloc tree.
1775  */
1776 static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
1777                                     struct extent_buffer *src_eb,
1778                                     struct btrfs_path *dst_path,
1779                                     int dst_level, int root_level,
1780                                     bool trace_leaf)
1781 {
1782         struct btrfs_key key;
1783         struct btrfs_path *src_path;
1784         struct btrfs_fs_info *fs_info = trans->fs_info;
1785         u32 nodesize = fs_info->nodesize;
1786         int cur_level = root_level;
1787         int ret;
1788
1789         BUG_ON(dst_level > root_level);
1790         /* Level mismatch */
1791         if (btrfs_header_level(src_eb) != root_level)
1792                 return -EINVAL;
1793
1794         src_path = btrfs_alloc_path();
1795         if (!src_path) {
1796                 ret = -ENOMEM;
1797                 goto out;
1798         }
1799
1800         if (dst_level)
1801                 btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1802         else
1803                 btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1804
1805         /* For src_path */
1806         atomic_inc(&src_eb->refs);
1807         src_path->nodes[root_level] = src_eb;
1808         src_path->slots[root_level] = dst_path->slots[root_level];
1809         src_path->locks[root_level] = 0;
1810
1811         /* A simplified version of btrfs_search_slot() */
1812         while (cur_level >= dst_level) {
1813                 struct btrfs_key src_key;
1814                 struct btrfs_key dst_key;
1815
1816                 if (src_path->nodes[cur_level] == NULL) {
1817                         struct btrfs_key first_key;
1818                         struct extent_buffer *eb;
1819                         int parent_slot;
1820                         u64 child_gen;
1821                         u64 child_bytenr;
1822
1823                         eb = src_path->nodes[cur_level + 1];
1824                         parent_slot = src_path->slots[cur_level + 1];
1825                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1826                         child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1827                         btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
1828
1829                         eb = read_tree_block(fs_info, child_bytenr, child_gen,
1830                                              cur_level, &first_key);
1831                         if (IS_ERR(eb)) {
1832                                 ret = PTR_ERR(eb);
1833                                 goto out;
1834                         } else if (!extent_buffer_uptodate(eb)) {
1835                                 free_extent_buffer(eb);
1836                                 ret = -EIO;
1837                                 goto out;
1838                         }
1839
1840                         src_path->nodes[cur_level] = eb;
1841
1842                         btrfs_tree_read_lock(eb);
1843                         btrfs_set_lock_blocking_read(eb);
1844                         src_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
1845                 }
1846
1847                 src_path->slots[cur_level] = dst_path->slots[cur_level];
1848                 if (cur_level) {
1849                         btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
1850                                         &dst_key, dst_path->slots[cur_level]);
1851                         btrfs_node_key_to_cpu(src_path->nodes[cur_level],
1852                                         &src_key, src_path->slots[cur_level]);
1853                 } else {
1854                         btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
1855                                         &dst_key, dst_path->slots[cur_level]);
1856                         btrfs_item_key_to_cpu(src_path->nodes[cur_level],
1857                                         &src_key, src_path->slots[cur_level]);
1858                 }
1859                 /* Content mismatch, something went wrong */
1860                 if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
1861                         ret = -ENOENT;
1862                         goto out;
1863                 }
1864                 cur_level--;
1865         }
1866
1867         /*
1868          * Now both @dst_path and @src_path have been populated, record the tree
1869          * blocks for qgroup accounting.
1870          */
1871         ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
1872                         nodesize, GFP_NOFS);
1873         if (ret < 0)
1874                 goto out;
1875         ret = btrfs_qgroup_trace_extent(trans,
1876                         dst_path->nodes[dst_level]->start,
1877                         nodesize, GFP_NOFS);
1878         if (ret < 0)
1879                 goto out;
1880
1881         /* Record leaf file extents */
1882         if (dst_level == 0 && trace_leaf) {
1883                 ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
1884                 if (ret < 0)
1885                         goto out;
1886                 ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
1887         }
1888 out:
1889         btrfs_free_path(src_path);
1890         return ret;
1891 }
1892
1893 /*
1894  * Helper function to do recursive generation-aware depth-first search, to
1895  * locate all new tree blocks in a subtree of reloc tree.
1896  *
1897  * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
1898  *         reloc tree
1899  * L2         NN (a)
1900  *          /    \
1901  * L1    OO        NN (b)
1902  *      /  \      /  \
1903  * L0  OO  OO    OO  NN
1904  *               (c) (d)
1905  * If we pass:
1906  * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
1907  * @cur_level = 1
1908  * @root_level = 1
1909  *
1910  * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
1911  * above tree blocks along with their counter parts in file tree.
1912  * While during search, old tree blocks OO(c) will be skipped as tree block swap
1913  * won't affect OO(c).
1914  */
1915 static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
1916                                            struct extent_buffer *src_eb,
1917                                            struct btrfs_path *dst_path,
1918                                            int cur_level, int root_level,
1919                                            u64 last_snapshot, bool trace_leaf)
1920 {
1921         struct btrfs_fs_info *fs_info = trans->fs_info;
1922         struct extent_buffer *eb;
1923         bool need_cleanup = false;
1924         int ret = 0;
1925         int i;
1926
1927         /* Level sanity check */
1928         if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
1929             root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
1930             root_level < cur_level) {
1931                 btrfs_err_rl(fs_info,
1932                         "%s: bad levels, cur_level=%d root_level=%d",
1933                         __func__, cur_level, root_level);
1934                 return -EUCLEAN;
1935         }
1936
1937         /* Read the tree block if needed */
1938         if (dst_path->nodes[cur_level] == NULL) {
1939                 struct btrfs_key first_key;
1940                 int parent_slot;
1941                 u64 child_gen;
1942                 u64 child_bytenr;
1943
1944                 /*
1945                  * dst_path->nodes[root_level] must be initialized before
1946                  * calling this function.
1947                  */
1948                 if (cur_level == root_level) {
1949                         btrfs_err_rl(fs_info,
1950         "%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
1951                                 __func__, root_level, root_level, cur_level);
1952                         return -EUCLEAN;
1953                 }
1954
1955                 /*
1956                  * We need to get child blockptr/gen from parent before we can
1957                  * read it.
1958                   */
1959                 eb = dst_path->nodes[cur_level + 1];
1960                 parent_slot = dst_path->slots[cur_level + 1];
1961                 child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1962                 child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1963                 btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
1964
1965                 /* This node is old, no need to trace */
1966                 if (child_gen < last_snapshot)
1967                         goto out;
1968
1969                 eb = read_tree_block(fs_info, child_bytenr, child_gen,
1970                                      cur_level, &first_key);
1971                 if (IS_ERR(eb)) {
1972                         ret = PTR_ERR(eb);
1973                         goto out;
1974                 } else if (!extent_buffer_uptodate(eb)) {
1975                         free_extent_buffer(eb);
1976                         ret = -EIO;
1977                         goto out;
1978                 }
1979
1980                 dst_path->nodes[cur_level] = eb;
1981                 dst_path->slots[cur_level] = 0;
1982
1983                 btrfs_tree_read_lock(eb);
1984                 btrfs_set_lock_blocking_read(eb);
1985                 dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
1986                 need_cleanup = true;
1987         }
1988
1989         /* Now record this tree block and its counter part for qgroups */
1990         ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
1991                                        root_level, trace_leaf);
1992         if (ret < 0)
1993                 goto cleanup;
1994
1995         eb = dst_path->nodes[cur_level];
1996
1997         if (cur_level > 0) {
1998                 /* Iterate all child tree blocks */
1999                 for (i = 0; i < btrfs_header_nritems(eb); i++) {
2000                         /* Skip old tree blocks as they won't be swapped */
2001                         if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
2002                                 continue;
2003                         dst_path->slots[cur_level] = i;
2004
2005                         /* Recursive call (at most 7 times) */
2006                         ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
2007                                         dst_path, cur_level - 1, root_level,
2008                                         last_snapshot, trace_leaf);
2009                         if (ret < 0)
2010                                 goto cleanup;
2011                 }
2012         }
2013
2014 cleanup:
2015         if (need_cleanup) {
2016                 /* Clean up */
2017                 btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2018                                      dst_path->locks[cur_level]);
2019                 free_extent_buffer(dst_path->nodes[cur_level]);
2020                 dst_path->nodes[cur_level] = NULL;
2021                 dst_path->slots[cur_level] = 0;
2022                 dst_path->locks[cur_level] = 0;
2023         }
2024 out:
2025         return ret;
2026 }
2027
2028 static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2029                                 struct extent_buffer *src_eb,
2030                                 struct extent_buffer *dst_eb,
2031                                 u64 last_snapshot, bool trace_leaf)
2032 {
2033         struct btrfs_fs_info *fs_info = trans->fs_info;
2034         struct btrfs_path *dst_path = NULL;
2035         int level;
2036         int ret;
2037
2038         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2039                 return 0;
2040
2041         /* Wrong parameter order */
2042         if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
2043                 btrfs_err_rl(fs_info,
2044                 "%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2045                              btrfs_header_generation(src_eb),
2046                              btrfs_header_generation(dst_eb));
2047                 return -EUCLEAN;
2048         }
2049
2050         if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2051                 ret = -EIO;
2052                 goto out;
2053         }
2054
2055         level = btrfs_header_level(dst_eb);
2056         dst_path = btrfs_alloc_path();
2057         if (!dst_path) {
2058                 ret = -ENOMEM;
2059                 goto out;
2060         }
2061         /* For dst_path */
2062         atomic_inc(&dst_eb->refs);
2063         dst_path->nodes[level] = dst_eb;
2064         dst_path->slots[level] = 0;
2065         dst_path->locks[level] = 0;
2066
2067         /* Do the generation aware breadth-first search */
2068         ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2069                                               level, last_snapshot, trace_leaf);
2070         if (ret < 0)
2071                 goto out;
2072         ret = 0;
2073
2074 out:
2075         btrfs_free_path(dst_path);
2076         if (ret < 0)
2077                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2078         return ret;
2079 }
2080
2081 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2082                                struct extent_buffer *root_eb,
2083                                u64 root_gen, int root_level)
2084 {
2085         struct btrfs_fs_info *fs_info = trans->fs_info;
2086         int ret = 0;
2087         int level;
2088         struct extent_buffer *eb = root_eb;
2089         struct btrfs_path *path = NULL;
2090
2091         BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2092         BUG_ON(root_eb == NULL);
2093
2094         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2095                 return 0;
2096
2097         if (!extent_buffer_uptodate(root_eb)) {
2098                 ret = btrfs_read_buffer(root_eb, root_gen, root_level, NULL);
2099                 if (ret)
2100                         goto out;
2101         }
2102
2103         if (root_level == 0) {
2104                 ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2105                 goto out;
2106         }
2107
2108         path = btrfs_alloc_path();
2109         if (!path)
2110                 return -ENOMEM;
2111
2112         /*
2113          * Walk down the tree.  Missing extent blocks are filled in as
2114          * we go. Metadata is accounted every time we read a new
2115          * extent block.
2116          *
2117          * When we reach a leaf, we account for file extent items in it,
2118          * walk back up the tree (adjusting slot pointers as we go)
2119          * and restart the search process.
2120          */
2121         atomic_inc(&root_eb->refs);     /* For path */
2122         path->nodes[root_level] = root_eb;
2123         path->slots[root_level] = 0;
2124         path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2125 walk_down:
2126         level = root_level;
2127         while (level >= 0) {
2128                 if (path->nodes[level] == NULL) {
2129                         struct btrfs_key first_key;
2130                         int parent_slot;
2131                         u64 child_gen;
2132                         u64 child_bytenr;
2133
2134                         /*
2135                          * We need to get child blockptr/gen from parent before
2136                          * we can read it.
2137                           */
2138                         eb = path->nodes[level + 1];
2139                         parent_slot = path->slots[level + 1];
2140                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2141                         child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2142                         btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
2143
2144                         eb = read_tree_block(fs_info, child_bytenr, child_gen,
2145                                              level, &first_key);
2146                         if (IS_ERR(eb)) {
2147                                 ret = PTR_ERR(eb);
2148                                 goto out;
2149                         } else if (!extent_buffer_uptodate(eb)) {
2150                                 free_extent_buffer(eb);
2151                                 ret = -EIO;
2152                                 goto out;
2153                         }
2154
2155                         path->nodes[level] = eb;
2156                         path->slots[level] = 0;
2157
2158                         btrfs_tree_read_lock(eb);
2159                         btrfs_set_lock_blocking_read(eb);
2160                         path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
2161
2162                         ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2163                                                         fs_info->nodesize,
2164                                                         GFP_NOFS);
2165                         if (ret)
2166                                 goto out;
2167                 }
2168
2169                 if (level == 0) {
2170                         ret = btrfs_qgroup_trace_leaf_items(trans,
2171                                                             path->nodes[level]);
2172                         if (ret)
2173                                 goto out;
2174
2175                         /* Nonzero return here means we completed our search */
2176                         ret = adjust_slots_upwards(path, root_level);
2177                         if (ret)
2178                                 break;
2179
2180                         /* Restart search with new slots */
2181                         goto walk_down;
2182                 }
2183
2184                 level--;
2185         }
2186
2187         ret = 0;
2188 out:
2189         btrfs_free_path(path);
2190
2191         return ret;
2192 }
2193
2194 #define UPDATE_NEW      0
2195 #define UPDATE_OLD      1
2196 /*
2197  * Walk all of the roots that points to the bytenr and adjust their refcnts.
2198  */
2199 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2200                                 struct ulist *roots, struct ulist *tmp,
2201                                 struct ulist *qgroups, u64 seq, int update_old)
2202 {
2203         struct ulist_node *unode;
2204         struct ulist_iterator uiter;
2205         struct ulist_node *tmp_unode;
2206         struct ulist_iterator tmp_uiter;
2207         struct btrfs_qgroup *qg;
2208         int ret = 0;
2209
2210         if (!roots)
2211                 return 0;
2212         ULIST_ITER_INIT(&uiter);
2213         while ((unode = ulist_next(roots, &uiter))) {
2214                 qg = find_qgroup_rb(fs_info, unode->val);
2215                 if (!qg)
2216                         continue;
2217
2218                 ulist_reinit(tmp);
2219                 ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2220                                 GFP_ATOMIC);
2221                 if (ret < 0)
2222                         return ret;
2223                 ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2224                 if (ret < 0)
2225                         return ret;
2226                 ULIST_ITER_INIT(&tmp_uiter);
2227                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2228                         struct btrfs_qgroup_list *glist;
2229
2230                         qg = unode_aux_to_qgroup(tmp_unode);
2231                         if (update_old)
2232                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2233                         else
2234                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2235                         list_for_each_entry(glist, &qg->groups, next_group) {
2236                                 ret = ulist_add(qgroups, glist->group->qgroupid,
2237                                                 qgroup_to_aux(glist->group),
2238                                                 GFP_ATOMIC);
2239                                 if (ret < 0)
2240                                         return ret;
2241                                 ret = ulist_add(tmp, glist->group->qgroupid,
2242                                                 qgroup_to_aux(glist->group),
2243                                                 GFP_ATOMIC);
2244                                 if (ret < 0)
2245                                         return ret;
2246                         }
2247                 }
2248         }
2249         return 0;
2250 }
2251
2252 /*
2253  * Update qgroup rfer/excl counters.
2254  * Rfer update is easy, codes can explain themselves.
2255  *
2256  * Excl update is tricky, the update is split into 2 part.
2257  * Part 1: Possible exclusive <-> sharing detect:
2258  *      |       A       |       !A      |
2259  *  -------------------------------------
2260  *  B   |       *       |       -       |
2261  *  -------------------------------------
2262  *  !B  |       +       |       **      |
2263  *  -------------------------------------
2264  *
2265  * Conditions:
2266  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
2267  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
2268  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
2269  * !B:  cur_new_roots == nr_new_roots   (possible exclusive now)
2270  *
2271  * Results:
2272  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
2273  * *: Definitely not changed.           **: Possible unchanged.
2274  *
2275  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2276  *
2277  * To make the logic clear, we first use condition A and B to split
2278  * combination into 4 results.
2279  *
2280  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2281  * only on variant maybe 0.
2282  *
2283  * Lastly, check result **, since there are 2 variants maybe 0, split them
2284  * again(2x2).
2285  * But this time we don't need to consider other things, the codes and logic
2286  * is easy to understand now.
2287  */
2288 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2289                                   struct ulist *qgroups,
2290                                   u64 nr_old_roots,
2291                                   u64 nr_new_roots,
2292                                   u64 num_bytes, u64 seq)
2293 {
2294         struct ulist_node *unode;
2295         struct ulist_iterator uiter;
2296         struct btrfs_qgroup *qg;
2297         u64 cur_new_count, cur_old_count;
2298
2299         ULIST_ITER_INIT(&uiter);
2300         while ((unode = ulist_next(qgroups, &uiter))) {
2301                 bool dirty = false;
2302
2303                 qg = unode_aux_to_qgroup(unode);
2304                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2305                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2306
2307                 trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2308                                              cur_new_count);
2309
2310                 /* Rfer update part */
2311                 if (cur_old_count == 0 && cur_new_count > 0) {
2312                         qg->rfer += num_bytes;
2313                         qg->rfer_cmpr += num_bytes;
2314                         dirty = true;
2315                 }
2316                 if (cur_old_count > 0 && cur_new_count == 0) {
2317                         qg->rfer -= num_bytes;
2318                         qg->rfer_cmpr -= num_bytes;
2319                         dirty = true;
2320                 }
2321
2322                 /* Excl update part */
2323                 /* Exclusive/none -> shared case */
2324                 if (cur_old_count == nr_old_roots &&
2325                     cur_new_count < nr_new_roots) {
2326                         /* Exclusive -> shared */
2327                         if (cur_old_count != 0) {
2328                                 qg->excl -= num_bytes;
2329                                 qg->excl_cmpr -= num_bytes;
2330                                 dirty = true;
2331                         }
2332                 }
2333
2334                 /* Shared -> exclusive/none case */
2335                 if (cur_old_count < nr_old_roots &&
2336                     cur_new_count == nr_new_roots) {
2337                         /* Shared->exclusive */
2338                         if (cur_new_count != 0) {
2339                                 qg->excl += num_bytes;
2340                                 qg->excl_cmpr += num_bytes;
2341                                 dirty = true;
2342                         }
2343                 }
2344
2345                 /* Exclusive/none -> exclusive/none case */
2346                 if (cur_old_count == nr_old_roots &&
2347                     cur_new_count == nr_new_roots) {
2348                         if (cur_old_count == 0) {
2349                                 /* None -> exclusive/none */
2350
2351                                 if (cur_new_count != 0) {
2352                                         /* None -> exclusive */
2353                                         qg->excl += num_bytes;
2354                                         qg->excl_cmpr += num_bytes;
2355                                         dirty = true;
2356                                 }
2357                                 /* None -> none, nothing changed */
2358                         } else {
2359                                 /* Exclusive -> exclusive/none */
2360
2361                                 if (cur_new_count == 0) {
2362                                         /* Exclusive -> none */
2363                                         qg->excl -= num_bytes;
2364                                         qg->excl_cmpr -= num_bytes;
2365                                         dirty = true;
2366                                 }
2367                                 /* Exclusive -> exclusive, nothing changed */
2368                         }
2369                 }
2370
2371                 if (dirty)
2372                         qgroup_dirty(fs_info, qg);
2373         }
2374         return 0;
2375 }
2376
2377 /*
2378  * Check if the @roots potentially is a list of fs tree roots
2379  *
2380  * Return 0 for definitely not a fs/subvol tree roots ulist
2381  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2382  *          one as well)
2383  */
2384 static int maybe_fs_roots(struct ulist *roots)
2385 {
2386         struct ulist_node *unode;
2387         struct ulist_iterator uiter;
2388
2389         /* Empty one, still possible for fs roots */
2390         if (!roots || roots->nnodes == 0)
2391                 return 1;
2392
2393         ULIST_ITER_INIT(&uiter);
2394         unode = ulist_next(roots, &uiter);
2395         if (!unode)
2396                 return 1;
2397
2398         /*
2399          * If it contains fs tree roots, then it must belong to fs/subvol
2400          * trees.
2401          * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2402          */
2403         return is_fstree(unode->val);
2404 }
2405
2406 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2407                                 u64 num_bytes, struct ulist *old_roots,
2408                                 struct ulist *new_roots)
2409 {
2410         struct btrfs_fs_info *fs_info = trans->fs_info;
2411         struct ulist *qgroups = NULL;
2412         struct ulist *tmp = NULL;
2413         u64 seq;
2414         u64 nr_new_roots = 0;
2415         u64 nr_old_roots = 0;
2416         int ret = 0;
2417
2418         /*
2419          * If quotas get disabled meanwhile, the resouces need to be freed and
2420          * we can't just exit here.
2421          */
2422         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2423                 goto out_free;
2424
2425         if (new_roots) {
2426                 if (!maybe_fs_roots(new_roots))
2427                         goto out_free;
2428                 nr_new_roots = new_roots->nnodes;
2429         }
2430         if (old_roots) {
2431                 if (!maybe_fs_roots(old_roots))
2432                         goto out_free;
2433                 nr_old_roots = old_roots->nnodes;
2434         }
2435
2436         /* Quick exit, either not fs tree roots, or won't affect any qgroup */
2437         if (nr_old_roots == 0 && nr_new_roots == 0)
2438                 goto out_free;
2439
2440         BUG_ON(!fs_info->quota_root);
2441
2442         trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2443                                         num_bytes, nr_old_roots, nr_new_roots);
2444
2445         qgroups = ulist_alloc(GFP_NOFS);
2446         if (!qgroups) {
2447                 ret = -ENOMEM;
2448                 goto out_free;
2449         }
2450         tmp = ulist_alloc(GFP_NOFS);
2451         if (!tmp) {
2452                 ret = -ENOMEM;
2453                 goto out_free;
2454         }
2455
2456         mutex_lock(&fs_info->qgroup_rescan_lock);
2457         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2458                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2459                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2460                         ret = 0;
2461                         goto out_free;
2462                 }
2463         }
2464         mutex_unlock(&fs_info->qgroup_rescan_lock);
2465
2466         spin_lock(&fs_info->qgroup_lock);
2467         seq = fs_info->qgroup_seq;
2468
2469         /* Update old refcnts using old_roots */
2470         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2471                                    UPDATE_OLD);
2472         if (ret < 0)
2473                 goto out;
2474
2475         /* Update new refcnts using new_roots */
2476         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2477                                    UPDATE_NEW);
2478         if (ret < 0)
2479                 goto out;
2480
2481         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2482                                num_bytes, seq);
2483
2484         /*
2485          * Bump qgroup_seq to avoid seq overlap
2486          */
2487         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2488 out:
2489         spin_unlock(&fs_info->qgroup_lock);
2490 out_free:
2491         ulist_free(tmp);
2492         ulist_free(qgroups);
2493         ulist_free(old_roots);
2494         ulist_free(new_roots);
2495         return ret;
2496 }
2497
2498 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2499 {
2500         struct btrfs_fs_info *fs_info = trans->fs_info;
2501         struct btrfs_qgroup_extent_record *record;
2502         struct btrfs_delayed_ref_root *delayed_refs;
2503         struct ulist *new_roots = NULL;
2504         struct rb_node *node;
2505         u64 num_dirty_extents = 0;
2506         u64 qgroup_to_skip;
2507         int ret = 0;
2508
2509         delayed_refs = &trans->transaction->delayed_refs;
2510         qgroup_to_skip = delayed_refs->qgroup_to_skip;
2511         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2512                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
2513                                   node);
2514
2515                 num_dirty_extents++;
2516                 trace_btrfs_qgroup_account_extents(fs_info, record);
2517
2518                 if (!ret) {
2519                         /*
2520                          * Old roots should be searched when inserting qgroup
2521                          * extent record
2522                          */
2523                         if (WARN_ON(!record->old_roots)) {
2524                                 /* Search commit root to find old_roots */
2525                                 ret = btrfs_find_all_roots(NULL, fs_info,
2526                                                 record->bytenr, 0,
2527                                                 &record->old_roots, false);
2528                                 if (ret < 0)
2529                                         goto cleanup;
2530                         }
2531
2532                         /* Free the reserved data space */
2533                         btrfs_qgroup_free_refroot(fs_info,
2534                                         record->data_rsv_refroot,
2535                                         record->data_rsv,
2536                                         BTRFS_QGROUP_RSV_DATA);
2537                         /*
2538                          * Use SEQ_LAST as time_seq to do special search, which
2539                          * doesn't lock tree or delayed_refs and search current
2540                          * root. It's safe inside commit_transaction().
2541                          */
2542                         ret = btrfs_find_all_roots(trans, fs_info,
2543                                 record->bytenr, SEQ_LAST, &new_roots, false);
2544                         if (ret < 0)
2545                                 goto cleanup;
2546                         if (qgroup_to_skip) {
2547                                 ulist_del(new_roots, qgroup_to_skip, 0);
2548                                 ulist_del(record->old_roots, qgroup_to_skip,
2549                                           0);
2550                         }
2551                         ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2552                                                           record->num_bytes,
2553                                                           record->old_roots,
2554                                                           new_roots);
2555                         record->old_roots = NULL;
2556                         new_roots = NULL;
2557                 }
2558 cleanup:
2559                 ulist_free(record->old_roots);
2560                 ulist_free(new_roots);
2561                 new_roots = NULL;
2562                 rb_erase(node, &delayed_refs->dirty_extent_root);
2563                 kfree(record);
2564
2565         }
2566         trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2567                                        num_dirty_extents);
2568         return ret;
2569 }
2570
2571 /*
2572  * called from commit_transaction. Writes all changed qgroups to disk.
2573  */
2574 int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2575 {
2576         struct btrfs_fs_info *fs_info = trans->fs_info;
2577         int ret = 0;
2578
2579         if (!fs_info->quota_root)
2580                 return ret;
2581
2582         spin_lock(&fs_info->qgroup_lock);
2583         while (!list_empty(&fs_info->dirty_qgroups)) {
2584                 struct btrfs_qgroup *qgroup;
2585                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
2586                                           struct btrfs_qgroup, dirty);
2587                 list_del_init(&qgroup->dirty);
2588                 spin_unlock(&fs_info->qgroup_lock);
2589                 ret = update_qgroup_info_item(trans, qgroup);
2590                 if (ret)
2591                         fs_info->qgroup_flags |=
2592                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2593                 ret = update_qgroup_limit_item(trans, qgroup);
2594                 if (ret)
2595                         fs_info->qgroup_flags |=
2596                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2597                 spin_lock(&fs_info->qgroup_lock);
2598         }
2599         if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2600                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2601         else
2602                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2603         spin_unlock(&fs_info->qgroup_lock);
2604
2605         ret = update_qgroup_status_item(trans);
2606         if (ret)
2607                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2608
2609         return ret;
2610 }
2611
2612 /*
2613  * Copy the accounting information between qgroups. This is necessary
2614  * when a snapshot or a subvolume is created. Throwing an error will
2615  * cause a transaction abort so we take extra care here to only error
2616  * when a readonly fs is a reasonable outcome.
2617  */
2618 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2619                          u64 objectid, struct btrfs_qgroup_inherit *inherit)
2620 {
2621         int ret = 0;
2622         int i;
2623         u64 *i_qgroups;
2624         bool committing = false;
2625         struct btrfs_fs_info *fs_info = trans->fs_info;
2626         struct btrfs_root *quota_root;
2627         struct btrfs_qgroup *srcgroup;
2628         struct btrfs_qgroup *dstgroup;
2629         u32 level_size = 0;
2630         u64 nums;
2631
2632         /*
2633          * There are only two callers of this function.
2634          *
2635          * One in create_subvol() in the ioctl context, which needs to hold
2636          * the qgroup_ioctl_lock.
2637          *
2638          * The other one in create_pending_snapshot() where no other qgroup
2639          * code can modify the fs as they all need to either start a new trans
2640          * or hold a trans handler, thus we don't need to hold
2641          * qgroup_ioctl_lock.
2642          * This would avoid long and complex lock chain and make lockdep happy.
2643          */
2644         spin_lock(&fs_info->trans_lock);
2645         if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
2646                 committing = true;
2647         spin_unlock(&fs_info->trans_lock);
2648
2649         if (!committing)
2650                 mutex_lock(&fs_info->qgroup_ioctl_lock);
2651         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2652                 goto out;
2653
2654         quota_root = fs_info->quota_root;
2655         if (!quota_root) {
2656                 ret = -EINVAL;
2657                 goto out;
2658         }
2659
2660         if (inherit) {
2661                 i_qgroups = (u64 *)(inherit + 1);
2662                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2663                        2 * inherit->num_excl_copies;
2664                 for (i = 0; i < nums; ++i) {
2665                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2666
2667                         /*
2668                          * Zero out invalid groups so we can ignore
2669                          * them later.
2670                          */
2671                         if (!srcgroup ||
2672                             ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2673                                 *i_qgroups = 0ULL;
2674
2675                         ++i_qgroups;
2676                 }
2677         }
2678
2679         /*
2680          * create a tracking group for the subvol itself
2681          */
2682         ret = add_qgroup_item(trans, quota_root, objectid);
2683         if (ret)
2684                 goto out;
2685
2686         /*
2687          * add qgroup to all inherited groups
2688          */
2689         if (inherit) {
2690                 i_qgroups = (u64 *)(inherit + 1);
2691                 for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2692                         if (*i_qgroups == 0)
2693                                 continue;
2694                         ret = add_qgroup_relation_item(trans, objectid,
2695                                                        *i_qgroups);
2696                         if (ret && ret != -EEXIST)
2697                                 goto out;
2698                         ret = add_qgroup_relation_item(trans, *i_qgroups,
2699                                                        objectid);
2700                         if (ret && ret != -EEXIST)
2701                                 goto out;
2702                 }
2703                 ret = 0;
2704         }
2705
2706
2707         spin_lock(&fs_info->qgroup_lock);
2708
2709         dstgroup = add_qgroup_rb(fs_info, objectid);
2710         if (IS_ERR(dstgroup)) {
2711                 ret = PTR_ERR(dstgroup);
2712                 goto unlock;
2713         }
2714
2715         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2716                 dstgroup->lim_flags = inherit->lim.flags;
2717                 dstgroup->max_rfer = inherit->lim.max_rfer;
2718                 dstgroup->max_excl = inherit->lim.max_excl;
2719                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2720                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
2721
2722                 ret = update_qgroup_limit_item(trans, dstgroup);
2723                 if (ret) {
2724                         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2725                         btrfs_info(fs_info,
2726                                    "unable to update quota limit for %llu",
2727                                    dstgroup->qgroupid);
2728                         goto unlock;
2729                 }
2730         }
2731
2732         if (srcid) {
2733                 srcgroup = find_qgroup_rb(fs_info, srcid);
2734                 if (!srcgroup)
2735                         goto unlock;
2736
2737                 /*
2738                  * We call inherit after we clone the root in order to make sure
2739                  * our counts don't go crazy, so at this point the only
2740                  * difference between the two roots should be the root node.
2741                  */
2742                 level_size = fs_info->nodesize;
2743                 dstgroup->rfer = srcgroup->rfer;
2744                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2745                 dstgroup->excl = level_size;
2746                 dstgroup->excl_cmpr = level_size;
2747                 srcgroup->excl = level_size;
2748                 srcgroup->excl_cmpr = level_size;
2749
2750                 /* inherit the limit info */
2751                 dstgroup->lim_flags = srcgroup->lim_flags;
2752                 dstgroup->max_rfer = srcgroup->max_rfer;
2753                 dstgroup->max_excl = srcgroup->max_excl;
2754                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2755                 dstgroup->rsv_excl = srcgroup->rsv_excl;
2756
2757                 qgroup_dirty(fs_info, dstgroup);
2758                 qgroup_dirty(fs_info, srcgroup);
2759         }
2760
2761         if (!inherit)
2762                 goto unlock;
2763
2764         i_qgroups = (u64 *)(inherit + 1);
2765         for (i = 0; i < inherit->num_qgroups; ++i) {
2766                 if (*i_qgroups) {
2767                         ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2768                         if (ret)
2769                                 goto unlock;
2770                 }
2771                 ++i_qgroups;
2772         }
2773
2774         for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2775                 struct btrfs_qgroup *src;
2776                 struct btrfs_qgroup *dst;
2777
2778                 if (!i_qgroups[0] || !i_qgroups[1])
2779                         continue;
2780
2781                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2782                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2783
2784                 if (!src || !dst) {
2785                         ret = -EINVAL;
2786                         goto unlock;
2787                 }
2788
2789                 dst->rfer = src->rfer - level_size;
2790                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
2791         }
2792         for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2793                 struct btrfs_qgroup *src;
2794                 struct btrfs_qgroup *dst;
2795
2796                 if (!i_qgroups[0] || !i_qgroups[1])
2797                         continue;
2798
2799                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2800                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2801
2802                 if (!src || !dst) {
2803                         ret = -EINVAL;
2804                         goto unlock;
2805                 }
2806
2807                 dst->excl = src->excl + level_size;
2808                 dst->excl_cmpr = src->excl_cmpr + level_size;
2809         }
2810
2811 unlock:
2812         spin_unlock(&fs_info->qgroup_lock);
2813 out:
2814         if (!committing)
2815                 mutex_unlock(&fs_info->qgroup_ioctl_lock);
2816         return ret;
2817 }
2818
2819 /*
2820  * Two limits to commit transaction in advance.
2821  *
2822  * For RATIO, it will be 1/RATIO of the remaining limit as threshold.
2823  * For SIZE, it will be in byte unit as threshold.
2824  */
2825 #define QGROUP_FREE_RATIO               32
2826 #define QGROUP_FREE_SIZE                SZ_32M
2827 static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
2828                                 const struct btrfs_qgroup *qg, u64 num_bytes)
2829 {
2830         u64 free;
2831         u64 threshold;
2832
2833         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2834             qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
2835                 return false;
2836
2837         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2838             qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
2839                 return false;
2840
2841         /*
2842          * Even if we passed the check, it's better to check if reservation
2843          * for meta_pertrans is pushing us near limit.
2844          * If there is too much pertrans reservation or it's near the limit,
2845          * let's try commit transaction to free some, using transaction_kthread
2846          */
2847         if ((qg->lim_flags & (BTRFS_QGROUP_LIMIT_MAX_RFER |
2848                               BTRFS_QGROUP_LIMIT_MAX_EXCL))) {
2849                 if (qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
2850                         free = qg->max_excl - qgroup_rsv_total(qg) - qg->excl;
2851                         threshold = min_t(u64, qg->max_excl / QGROUP_FREE_RATIO,
2852                                           QGROUP_FREE_SIZE);
2853                 } else {
2854                         free = qg->max_rfer - qgroup_rsv_total(qg) - qg->rfer;
2855                         threshold = min_t(u64, qg->max_rfer / QGROUP_FREE_RATIO,
2856                                           QGROUP_FREE_SIZE);
2857                 }
2858
2859                 /*
2860                  * Use transaction_kthread to commit transaction, so we no
2861                  * longer need to bother nested transaction nor lock context.
2862                  */
2863                 if (free < threshold)
2864                         btrfs_commit_transaction_locksafe(fs_info);
2865         }
2866
2867         return true;
2868 }
2869
2870 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
2871                           enum btrfs_qgroup_rsv_type type)
2872 {
2873         struct btrfs_qgroup *qgroup;
2874         struct btrfs_fs_info *fs_info = root->fs_info;
2875         u64 ref_root = root->root_key.objectid;
2876         int ret = 0;
2877         struct ulist_node *unode;
2878         struct ulist_iterator uiter;
2879
2880         if (!is_fstree(ref_root))
2881                 return 0;
2882
2883         if (num_bytes == 0)
2884                 return 0;
2885
2886         if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2887             capable(CAP_SYS_RESOURCE))
2888                 enforce = false;
2889
2890         spin_lock(&fs_info->qgroup_lock);
2891         if (!fs_info->quota_root)
2892                 goto out;
2893
2894         qgroup = find_qgroup_rb(fs_info, ref_root);
2895         if (!qgroup)
2896                 goto out;
2897
2898         /*
2899          * in a first step, we check all affected qgroups if any limits would
2900          * be exceeded
2901          */
2902         ulist_reinit(fs_info->qgroup_ulist);
2903         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2904                         qgroup_to_aux(qgroup), GFP_ATOMIC);
2905         if (ret < 0)
2906                 goto out;
2907         ULIST_ITER_INIT(&uiter);
2908         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2909                 struct btrfs_qgroup *qg;
2910                 struct btrfs_qgroup_list *glist;
2911
2912                 qg = unode_aux_to_qgroup(unode);
2913
2914                 if (enforce && !qgroup_check_limits(fs_info, qg, num_bytes)) {
2915                         ret = -EDQUOT;
2916                         goto out;
2917                 }
2918
2919                 list_for_each_entry(glist, &qg->groups, next_group) {
2920                         ret = ulist_add(fs_info->qgroup_ulist,
2921                                         glist->group->qgroupid,
2922                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
2923                         if (ret < 0)
2924                                 goto out;
2925                 }
2926         }
2927         ret = 0;
2928         /*
2929          * no limits exceeded, now record the reservation into all qgroups
2930          */
2931         ULIST_ITER_INIT(&uiter);
2932         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2933                 struct btrfs_qgroup *qg;
2934
2935                 qg = unode_aux_to_qgroup(unode);
2936
2937                 qgroup_rsv_add(fs_info, qg, num_bytes, type);
2938         }
2939
2940 out:
2941         spin_unlock(&fs_info->qgroup_lock);
2942         return ret;
2943 }
2944
2945 /*
2946  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
2947  * qgroup).
2948  *
2949  * Will handle all higher level qgroup too.
2950  *
2951  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
2952  * This special case is only used for META_PERTRANS type.
2953  */
2954 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2955                                u64 ref_root, u64 num_bytes,
2956                                enum btrfs_qgroup_rsv_type type)
2957 {
2958         struct btrfs_qgroup *qgroup;
2959         struct ulist_node *unode;
2960         struct ulist_iterator uiter;
2961         int ret = 0;
2962
2963         if (!is_fstree(ref_root))
2964                 return;
2965
2966         if (num_bytes == 0)
2967                 return;
2968
2969         if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
2970                 WARN(1, "%s: Invalid type to free", __func__);
2971                 return;
2972         }
2973         spin_lock(&fs_info->qgroup_lock);
2974
2975         if (!fs_info->quota_root)
2976                 goto out;
2977
2978         qgroup = find_qgroup_rb(fs_info, ref_root);
2979         if (!qgroup)
2980                 goto out;
2981
2982         if (num_bytes == (u64)-1)
2983                 /*
2984                  * We're freeing all pertrans rsv, get reserved value from
2985                  * level 0 qgroup as real num_bytes to free.
2986                  */
2987                 num_bytes = qgroup->rsv.values[type];
2988
2989         ulist_reinit(fs_info->qgroup_ulist);
2990         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2991                         qgroup_to_aux(qgroup), GFP_ATOMIC);
2992         if (ret < 0)
2993                 goto out;
2994         ULIST_ITER_INIT(&uiter);
2995         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2996                 struct btrfs_qgroup *qg;
2997                 struct btrfs_qgroup_list *glist;
2998
2999                 qg = unode_aux_to_qgroup(unode);
3000
3001                 qgroup_rsv_release(fs_info, qg, num_bytes, type);
3002
3003                 list_for_each_entry(glist, &qg->groups, next_group) {
3004                         ret = ulist_add(fs_info->qgroup_ulist,
3005                                         glist->group->qgroupid,
3006                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
3007                         if (ret < 0)
3008                                 goto out;
3009                 }
3010         }
3011
3012 out:
3013         spin_unlock(&fs_info->qgroup_lock);
3014 }
3015
3016 /*
3017  * Check if the leaf is the last leaf. Which means all node pointers
3018  * are at their last position.
3019  */
3020 static bool is_last_leaf(struct btrfs_path *path)
3021 {
3022         int i;
3023
3024         for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3025                 if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3026                         return false;
3027         }
3028         return true;
3029 }
3030
3031 /*
3032  * returns < 0 on error, 0 when more leafs are to be scanned.
3033  * returns 1 when done.
3034  */
3035 static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3036                               struct btrfs_path *path)
3037 {
3038         struct btrfs_fs_info *fs_info = trans->fs_info;
3039         struct btrfs_key found;
3040         struct extent_buffer *scratch_leaf = NULL;
3041         struct ulist *roots = NULL;
3042         u64 num_bytes;
3043         bool done;
3044         int slot;
3045         int ret;
3046
3047         mutex_lock(&fs_info->qgroup_rescan_lock);
3048         ret = btrfs_search_slot_for_read(fs_info->extent_root,
3049                                          &fs_info->qgroup_rescan_progress,
3050                                          path, 1, 0);
3051
3052         btrfs_debug(fs_info,
3053                 "current progress key (%llu %u %llu), search_slot ret %d",
3054                 fs_info->qgroup_rescan_progress.objectid,
3055                 fs_info->qgroup_rescan_progress.type,
3056                 fs_info->qgroup_rescan_progress.offset, ret);
3057
3058         if (ret) {
3059                 /*
3060                  * The rescan is about to end, we will not be scanning any
3061                  * further blocks. We cannot unset the RESCAN flag here, because
3062                  * we want to commit the transaction if everything went well.
3063                  * To make the live accounting work in this phase, we set our
3064                  * scan progress pointer such that every real extent objectid
3065                  * will be smaller.
3066                  */
3067                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3068                 btrfs_release_path(path);
3069                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3070                 return ret;
3071         }
3072         done = is_last_leaf(path);
3073
3074         btrfs_item_key_to_cpu(path->nodes[0], &found,
3075                               btrfs_header_nritems(path->nodes[0]) - 1);
3076         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3077
3078         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3079         if (!scratch_leaf) {
3080                 ret = -ENOMEM;
3081                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3082                 goto out;
3083         }
3084         slot = path->slots[0];
3085         btrfs_release_path(path);
3086         mutex_unlock(&fs_info->qgroup_rescan_lock);
3087
3088         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
3089                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3090                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3091                     found.type != BTRFS_METADATA_ITEM_KEY)
3092                         continue;
3093                 if (found.type == BTRFS_METADATA_ITEM_KEY)
3094                         num_bytes = fs_info->nodesize;
3095                 else
3096                         num_bytes = found.offset;
3097
3098                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
3099                                            &roots, false);
3100                 if (ret < 0)
3101                         goto out;
3102                 /* For rescan, just pass old_roots as NULL */
3103                 ret = btrfs_qgroup_account_extent(trans, found.objectid,
3104                                                   num_bytes, NULL, roots);
3105                 if (ret < 0)
3106                         goto out;
3107         }
3108 out:
3109         if (scratch_leaf)
3110                 free_extent_buffer(scratch_leaf);
3111
3112         if (done && !ret) {
3113                 ret = 1;
3114                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3115         }
3116         return ret;
3117 }
3118
3119 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3120 {
3121         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3122                                                      qgroup_rescan_work);
3123         struct btrfs_path *path;
3124         struct btrfs_trans_handle *trans = NULL;
3125         int err = -ENOMEM;
3126         int ret = 0;
3127
3128         path = btrfs_alloc_path();
3129         if (!path)
3130                 goto out;
3131         /*
3132          * Rescan should only search for commit root, and any later difference
3133          * should be recorded by qgroup
3134          */
3135         path->search_commit_root = 1;
3136         path->skip_locking = 1;
3137
3138         err = 0;
3139         while (!err && !btrfs_fs_closing(fs_info)) {
3140                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
3141                 if (IS_ERR(trans)) {
3142                         err = PTR_ERR(trans);
3143                         break;
3144                 }
3145                 if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3146                         err = -EINTR;
3147                 } else {
3148                         err = qgroup_rescan_leaf(trans, path);
3149                 }
3150                 if (err > 0)
3151                         btrfs_commit_transaction(trans);
3152                 else
3153                         btrfs_end_transaction(trans);
3154         }
3155
3156 out:
3157         btrfs_free_path(path);
3158
3159         mutex_lock(&fs_info->qgroup_rescan_lock);
3160         if (err > 0 &&
3161             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3162                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3163         } else if (err < 0) {
3164                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3165         }
3166         mutex_unlock(&fs_info->qgroup_rescan_lock);
3167
3168         /*
3169          * only update status, since the previous part has already updated the
3170          * qgroup info.
3171          */
3172         trans = btrfs_start_transaction(fs_info->quota_root, 1);
3173         if (IS_ERR(trans)) {
3174                 err = PTR_ERR(trans);
3175                 trans = NULL;
3176                 btrfs_err(fs_info,
3177                           "fail to start transaction for status update: %d",
3178                           err);
3179         }
3180
3181         mutex_lock(&fs_info->qgroup_rescan_lock);
3182         if (!btrfs_fs_closing(fs_info))
3183                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3184         if (trans) {
3185                 ret = update_qgroup_status_item(trans);
3186                 if (ret < 0) {
3187                         err = ret;
3188                         btrfs_err(fs_info, "fail to update qgroup status: %d",
3189                                   err);
3190                 }
3191         }
3192         fs_info->qgroup_rescan_running = false;
3193         complete_all(&fs_info->qgroup_rescan_completion);
3194         mutex_unlock(&fs_info->qgroup_rescan_lock);
3195
3196         if (!trans)
3197                 return;
3198
3199         btrfs_end_transaction(trans);
3200
3201         if (btrfs_fs_closing(fs_info)) {
3202                 btrfs_info(fs_info, "qgroup scan paused");
3203         } else if (err >= 0) {
3204                 btrfs_info(fs_info, "qgroup scan completed%s",
3205                         err > 0 ? " (inconsistency flag cleared)" : "");
3206         } else {
3207                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
3208         }
3209 }
3210
3211 /*
3212  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
3213  * memory required for the rescan context.
3214  */
3215 static int
3216 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
3217                    int init_flags)
3218 {
3219         int ret = 0;
3220
3221         if (!init_flags) {
3222                 /* we're resuming qgroup rescan at mount time */
3223                 if (!(fs_info->qgroup_flags &
3224                       BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
3225                         btrfs_warn(fs_info,
3226                         "qgroup rescan init failed, qgroup rescan is not queued");
3227                         ret = -EINVAL;
3228                 } else if (!(fs_info->qgroup_flags &
3229                              BTRFS_QGROUP_STATUS_FLAG_ON)) {
3230                         btrfs_warn(fs_info,
3231                         "qgroup rescan init failed, qgroup is not enabled");
3232                         ret = -EINVAL;
3233                 }
3234
3235                 if (ret)
3236                         return ret;
3237         }
3238
3239         mutex_lock(&fs_info->qgroup_rescan_lock);
3240         spin_lock(&fs_info->qgroup_lock);
3241
3242         if (init_flags) {
3243                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3244                         btrfs_warn(fs_info,
3245                                    "qgroup rescan is already in progress");
3246                         ret = -EINPROGRESS;
3247                 } else if (!(fs_info->qgroup_flags &
3248                              BTRFS_QGROUP_STATUS_FLAG_ON)) {
3249                         btrfs_warn(fs_info,
3250                         "qgroup rescan init failed, qgroup is not enabled");
3251                         ret = -EINVAL;
3252                 }
3253
3254                 if (ret) {
3255                         spin_unlock(&fs_info->qgroup_lock);
3256                         mutex_unlock(&fs_info->qgroup_rescan_lock);
3257                         return ret;
3258                 }
3259                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3260         }
3261
3262         memset(&fs_info->qgroup_rescan_progress, 0,
3263                 sizeof(fs_info->qgroup_rescan_progress));
3264         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
3265         init_completion(&fs_info->qgroup_rescan_completion);
3266         fs_info->qgroup_rescan_running = true;
3267
3268         spin_unlock(&fs_info->qgroup_lock);
3269         mutex_unlock(&fs_info->qgroup_rescan_lock);
3270
3271         btrfs_init_work(&fs_info->qgroup_rescan_work,
3272                         btrfs_qgroup_rescan_worker, NULL, NULL);
3273         return 0;
3274 }
3275
3276 static void
3277 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
3278 {
3279         struct rb_node *n;
3280         struct btrfs_qgroup *qgroup;
3281
3282         spin_lock(&fs_info->qgroup_lock);
3283         /* clear all current qgroup tracking information */
3284         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
3285                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
3286                 qgroup->rfer = 0;
3287                 qgroup->rfer_cmpr = 0;
3288                 qgroup->excl = 0;
3289                 qgroup->excl_cmpr = 0;
3290                 qgroup_dirty(fs_info, qgroup);
3291         }
3292         spin_unlock(&fs_info->qgroup_lock);
3293 }
3294
3295 int
3296 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
3297 {
3298         int ret = 0;
3299         struct btrfs_trans_handle *trans;
3300
3301         ret = qgroup_rescan_init(fs_info, 0, 1);
3302         if (ret)
3303                 return ret;
3304
3305         /*
3306          * We have set the rescan_progress to 0, which means no more
3307          * delayed refs will be accounted by btrfs_qgroup_account_ref.
3308          * However, btrfs_qgroup_account_ref may be right after its call
3309          * to btrfs_find_all_roots, in which case it would still do the
3310          * accounting.
3311          * To solve this, we're committing the transaction, which will
3312          * ensure we run all delayed refs and only after that, we are
3313          * going to clear all tracking information for a clean start.
3314          */
3315
3316         trans = btrfs_join_transaction(fs_info->fs_root);
3317         if (IS_ERR(trans)) {
3318                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3319                 return PTR_ERR(trans);
3320         }
3321         ret = btrfs_commit_transaction(trans);
3322         if (ret) {
3323                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3324                 return ret;
3325         }
3326
3327         qgroup_rescan_zero_tracking(fs_info);
3328
3329         btrfs_queue_work(fs_info->qgroup_rescan_workers,
3330                          &fs_info->qgroup_rescan_work);
3331
3332         return 0;
3333 }
3334
3335 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
3336                                      bool interruptible)
3337 {
3338         int running;
3339         int ret = 0;
3340
3341         mutex_lock(&fs_info->qgroup_rescan_lock);
3342         spin_lock(&fs_info->qgroup_lock);
3343         running = fs_info->qgroup_rescan_running;
3344         spin_unlock(&fs_info->qgroup_lock);
3345         mutex_unlock(&fs_info->qgroup_rescan_lock);
3346
3347         if (!running)
3348                 return 0;
3349
3350         if (interruptible)
3351                 ret = wait_for_completion_interruptible(
3352                                         &fs_info->qgroup_rescan_completion);
3353         else
3354                 wait_for_completion(&fs_info->qgroup_rescan_completion);
3355
3356         return ret;
3357 }
3358
3359 /*
3360  * this is only called from open_ctree where we're still single threaded, thus
3361  * locking is omitted here.
3362  */
3363 void
3364 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
3365 {
3366         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
3367                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
3368                                  &fs_info->qgroup_rescan_work);
3369 }
3370
3371 /*
3372  * Reserve qgroup space for range [start, start + len).
3373  *
3374  * This function will either reserve space from related qgroups or doing
3375  * nothing if the range is already reserved.
3376  *
3377  * Return 0 for successful reserve
3378  * Return <0 for error (including -EQUOT)
3379  *
3380  * NOTE: this function may sleep for memory allocation.
3381  *       if btrfs_qgroup_reserve_data() is called multiple times with
3382  *       same @reserved, caller must ensure when error happens it's OK
3383  *       to free *ALL* reserved space.
3384  */
3385 int btrfs_qgroup_reserve_data(struct inode *inode,
3386                         struct extent_changeset **reserved_ret, u64 start,
3387                         u64 len)
3388 {
3389         struct btrfs_root *root = BTRFS_I(inode)->root;
3390         struct ulist_node *unode;
3391         struct ulist_iterator uiter;
3392         struct extent_changeset *reserved;
3393         u64 orig_reserved;
3394         u64 to_reserve;
3395         int ret;
3396
3397         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
3398             !is_fstree(root->root_key.objectid) || len == 0)
3399                 return 0;
3400
3401         /* @reserved parameter is mandatory for qgroup */
3402         if (WARN_ON(!reserved_ret))
3403                 return -EINVAL;
3404         if (!*reserved_ret) {
3405                 *reserved_ret = extent_changeset_alloc();
3406                 if (!*reserved_ret)
3407                         return -ENOMEM;
3408         }
3409         reserved = *reserved_ret;
3410         /* Record already reserved space */
3411         orig_reserved = reserved->bytes_changed;
3412         ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
3413                         start + len -1, EXTENT_QGROUP_RESERVED, reserved);
3414
3415         /* Newly reserved space */
3416         to_reserve = reserved->bytes_changed - orig_reserved;
3417         trace_btrfs_qgroup_reserve_data(inode, start, len,
3418                                         to_reserve, QGROUP_RESERVE);
3419         if (ret < 0)
3420                 goto cleanup;
3421         ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
3422         if (ret < 0)
3423                 goto cleanup;
3424
3425         return ret;
3426
3427 cleanup:
3428         /* cleanup *ALL* already reserved ranges */
3429         ULIST_ITER_INIT(&uiter);
3430         while ((unode = ulist_next(&reserved->range_changed, &uiter)))
3431                 clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
3432                                  unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL);
3433         /* Also free data bytes of already reserved one */
3434         btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid,
3435                                   orig_reserved, BTRFS_QGROUP_RSV_DATA);
3436         extent_changeset_release(reserved);
3437         return ret;
3438 }
3439
3440 /* Free ranges specified by @reserved, normally in error path */
3441 static int qgroup_free_reserved_data(struct inode *inode,
3442                         struct extent_changeset *reserved, u64 start, u64 len)
3443 {
3444         struct btrfs_root *root = BTRFS_I(inode)->root;
3445         struct ulist_node *unode;
3446         struct ulist_iterator uiter;
3447         struct extent_changeset changeset;
3448         int freed = 0;
3449         int ret;
3450
3451         extent_changeset_init(&changeset);
3452         len = round_up(start + len, root->fs_info->sectorsize);
3453         start = round_down(start, root->fs_info->sectorsize);
3454
3455         ULIST_ITER_INIT(&uiter);
3456         while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
3457                 u64 range_start = unode->val;
3458                 /* unode->aux is the inclusive end */
3459                 u64 range_len = unode->aux - range_start + 1;
3460                 u64 free_start;
3461                 u64 free_len;
3462
3463                 extent_changeset_release(&changeset);
3464
3465                 /* Only free range in range [start, start + len) */
3466                 if (range_start >= start + len ||
3467                     range_start + range_len <= start)
3468                         continue;
3469                 free_start = max(range_start, start);
3470                 free_len = min(start + len, range_start + range_len) -
3471                            free_start;
3472                 /*
3473                  * TODO: To also modify reserved->ranges_reserved to reflect
3474                  * the modification.
3475                  *
3476                  * However as long as we free qgroup reserved according to
3477                  * EXTENT_QGROUP_RESERVED, we won't double free.
3478                  * So not need to rush.
3479                  */
3480                 ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree,
3481                                 free_start, free_start + free_len - 1,
3482                                 EXTENT_QGROUP_RESERVED, &changeset);
3483                 if (ret < 0)
3484                         goto out;
3485                 freed += changeset.bytes_changed;
3486         }
3487         btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
3488                                   BTRFS_QGROUP_RSV_DATA);
3489         ret = freed;
3490 out:
3491         extent_changeset_release(&changeset);
3492         return ret;
3493 }
3494
3495 static int __btrfs_qgroup_release_data(struct inode *inode,
3496                         struct extent_changeset *reserved, u64 start, u64 len,
3497                         int free)
3498 {
3499         struct extent_changeset changeset;
3500         int trace_op = QGROUP_RELEASE;
3501         int ret;
3502
3503         if (!test_bit(BTRFS_FS_QUOTA_ENABLED,
3504                       &BTRFS_I(inode)->root->fs_info->flags))
3505                 return 0;
3506
3507         /* In release case, we shouldn't have @reserved */
3508         WARN_ON(!free && reserved);
3509         if (free && reserved)
3510                 return qgroup_free_reserved_data(inode, reserved, start, len);
3511         extent_changeset_init(&changeset);
3512         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
3513                         start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
3514         if (ret < 0)
3515                 goto out;
3516
3517         if (free)
3518                 trace_op = QGROUP_FREE;
3519         trace_btrfs_qgroup_release_data(inode, start, len,
3520                                         changeset.bytes_changed, trace_op);
3521         if (free)
3522                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3523                                 BTRFS_I(inode)->root->root_key.objectid,
3524                                 changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3525         ret = changeset.bytes_changed;
3526 out:
3527         extent_changeset_release(&changeset);
3528         return ret;
3529 }
3530
3531 /*
3532  * Free a reserved space range from io_tree and related qgroups
3533  *
3534  * Should be called when a range of pages get invalidated before reaching disk.
3535  * Or for error cleanup case.
3536  * if @reserved is given, only reserved range in [@start, @start + @len) will
3537  * be freed.
3538  *
3539  * For data written to disk, use btrfs_qgroup_release_data().
3540  *
3541  * NOTE: This function may sleep for memory allocation.
3542  */
3543 int btrfs_qgroup_free_data(struct inode *inode,
3544                         struct extent_changeset *reserved, u64 start, u64 len)
3545 {
3546         return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3547 }
3548
3549 /*
3550  * Release a reserved space range from io_tree only.
3551  *
3552  * Should be called when a range of pages get written to disk and corresponding
3553  * FILE_EXTENT is inserted into corresponding root.
3554  *
3555  * Since new qgroup accounting framework will only update qgroup numbers at
3556  * commit_transaction() time, its reserved space shouldn't be freed from
3557  * related qgroups.
3558  *
3559  * But we should release the range from io_tree, to allow further write to be
3560  * COWed.
3561  *
3562  * NOTE: This function may sleep for memory allocation.
3563  */
3564 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
3565 {
3566         return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3567 }
3568
3569 static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3570                               enum btrfs_qgroup_rsv_type type)
3571 {
3572         if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3573             type != BTRFS_QGROUP_RSV_META_PERTRANS)
3574                 return;
3575         if (num_bytes == 0)
3576                 return;
3577
3578         spin_lock(&root->qgroup_meta_rsv_lock);
3579         if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3580                 root->qgroup_meta_rsv_prealloc += num_bytes;
3581         else
3582                 root->qgroup_meta_rsv_pertrans += num_bytes;
3583         spin_unlock(&root->qgroup_meta_rsv_lock);
3584 }
3585
3586 static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3587                              enum btrfs_qgroup_rsv_type type)
3588 {
3589         if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3590             type != BTRFS_QGROUP_RSV_META_PERTRANS)
3591                 return 0;
3592         if (num_bytes == 0)
3593                 return 0;
3594
3595         spin_lock(&root->qgroup_meta_rsv_lock);
3596         if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3597                 num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3598                                   num_bytes);
3599                 root->qgroup_meta_rsv_prealloc -= num_bytes;
3600         } else {
3601                 num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3602                                   num_bytes);
3603                 root->qgroup_meta_rsv_pertrans -= num_bytes;
3604         }
3605         spin_unlock(&root->qgroup_meta_rsv_lock);
3606         return num_bytes;
3607 }
3608
3609 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3610                                 enum btrfs_qgroup_rsv_type type, bool enforce)
3611 {
3612         struct btrfs_fs_info *fs_info = root->fs_info;
3613         int ret;
3614
3615         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3616             !is_fstree(root->root_key.objectid) || num_bytes == 0)
3617                 return 0;
3618
3619         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3620         trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
3621         ret = qgroup_reserve(root, num_bytes, enforce, type);
3622         if (ret < 0)
3623                 return ret;
3624         /*
3625          * Record what we have reserved into root.
3626          *
3627          * To avoid quota disabled->enabled underflow.
3628          * In that case, we may try to free space we haven't reserved
3629          * (since quota was disabled), so record what we reserved into root.
3630          * And ensure later release won't underflow this number.
3631          */
3632         add_root_meta_rsv(root, num_bytes, type);
3633         return ret;
3634 }
3635
3636 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
3637 {
3638         struct btrfs_fs_info *fs_info = root->fs_info;
3639
3640         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3641             !is_fstree(root->root_key.objectid))
3642                 return;
3643
3644         /* TODO: Update trace point to handle such free */
3645         trace_qgroup_meta_free_all_pertrans(root);
3646         /* Special value -1 means to free all reserved space */
3647         btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
3648                                   BTRFS_QGROUP_RSV_META_PERTRANS);
3649 }
3650
3651 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
3652                               enum btrfs_qgroup_rsv_type type)
3653 {
3654         struct btrfs_fs_info *fs_info = root->fs_info;
3655
3656         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3657             !is_fstree(root->root_key.objectid))
3658                 return;
3659
3660         /*
3661          * reservation for META_PREALLOC can happen before quota is enabled,
3662          * which can lead to underflow.
3663          * Here ensure we will only free what we really have reserved.
3664          */
3665         num_bytes = sub_root_meta_rsv(root, num_bytes, type);
3666         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3667         trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
3668         btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
3669                                   num_bytes, type);
3670 }
3671
3672 static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
3673                                 int num_bytes)
3674 {
3675         struct btrfs_qgroup *qgroup;
3676         struct ulist_node *unode;
3677         struct ulist_iterator uiter;
3678         int ret = 0;
3679
3680         if (num_bytes == 0)
3681                 return;
3682         if (!fs_info->quota_root)
3683                 return;
3684
3685         spin_lock(&fs_info->qgroup_lock);
3686         qgroup = find_qgroup_rb(fs_info, ref_root);
3687         if (!qgroup)
3688                 goto out;
3689         ulist_reinit(fs_info->qgroup_ulist);
3690         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3691                        qgroup_to_aux(qgroup), GFP_ATOMIC);
3692         if (ret < 0)
3693                 goto out;
3694         ULIST_ITER_INIT(&uiter);
3695         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3696                 struct btrfs_qgroup *qg;
3697                 struct btrfs_qgroup_list *glist;
3698
3699                 qg = unode_aux_to_qgroup(unode);
3700
3701                 qgroup_rsv_release(fs_info, qg, num_bytes,
3702                                 BTRFS_QGROUP_RSV_META_PREALLOC);
3703                 qgroup_rsv_add(fs_info, qg, num_bytes,
3704                                 BTRFS_QGROUP_RSV_META_PERTRANS);
3705                 list_for_each_entry(glist, &qg->groups, next_group) {
3706                         ret = ulist_add(fs_info->qgroup_ulist,
3707                                         glist->group->qgroupid,
3708                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
3709                         if (ret < 0)
3710                                 goto out;
3711                 }
3712         }
3713 out:
3714         spin_unlock(&fs_info->qgroup_lock);
3715 }
3716
3717 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
3718 {
3719         struct btrfs_fs_info *fs_info = root->fs_info;
3720
3721         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3722             !is_fstree(root->root_key.objectid))
3723                 return;
3724         /* Same as btrfs_qgroup_free_meta_prealloc() */
3725         num_bytes = sub_root_meta_rsv(root, num_bytes,
3726                                       BTRFS_QGROUP_RSV_META_PREALLOC);
3727         trace_qgroup_meta_convert(root, num_bytes);
3728         qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
3729 }
3730
3731 /*
3732  * Check qgroup reserved space leaking, normally at destroy inode
3733  * time
3734  */
3735 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
3736 {
3737         struct extent_changeset changeset;
3738         struct ulist_node *unode;
3739         struct ulist_iterator iter;
3740         int ret;
3741
3742         extent_changeset_init(&changeset);
3743         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
3744                         EXTENT_QGROUP_RESERVED, &changeset);
3745
3746         WARN_ON(ret < 0);
3747         if (WARN_ON(changeset.bytes_changed)) {
3748                 ULIST_ITER_INIT(&iter);
3749                 while ((unode = ulist_next(&changeset.range_changed, &iter))) {
3750                         btrfs_warn(BTRFS_I(inode)->root->fs_info,
3751                                 "leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
3752                                 inode->i_ino, unode->val, unode->aux);
3753                 }
3754                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3755                                 BTRFS_I(inode)->root->root_key.objectid,
3756                                 changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3757
3758         }
3759         extent_changeset_release(&changeset);
3760 }
3761
3762 void btrfs_qgroup_init_swapped_blocks(
3763         struct btrfs_qgroup_swapped_blocks *swapped_blocks)
3764 {
3765         int i;
3766
3767         spin_lock_init(&swapped_blocks->lock);
3768         for (i = 0; i < BTRFS_MAX_LEVEL; i++)
3769                 swapped_blocks->blocks[i] = RB_ROOT;
3770         swapped_blocks->swapped = false;
3771 }
3772
3773 /*
3774  * Delete all swapped blocks record of @root.
3775  * Every record here means we skipped a full subtree scan for qgroup.
3776  *
3777  * Gets called when committing one transaction.
3778  */
3779 void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
3780 {
3781         struct btrfs_qgroup_swapped_blocks *swapped_blocks;
3782         int i;
3783
3784         swapped_blocks = &root->swapped_blocks;
3785
3786         spin_lock(&swapped_blocks->lock);
3787         if (!swapped_blocks->swapped)
3788                 goto out;
3789         for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3790                 struct rb_root *cur_root = &swapped_blocks->blocks[i];
3791                 struct btrfs_qgroup_swapped_block *entry;
3792                 struct btrfs_qgroup_swapped_block *next;
3793
3794                 rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
3795                                                      node)
3796                         kfree(entry);
3797                 swapped_blocks->blocks[i] = RB_ROOT;
3798         }
3799         swapped_blocks->swapped = false;
3800 out:
3801         spin_unlock(&swapped_blocks->lock);
3802 }
3803
3804 /*
3805  * Add subtree roots record into @subvol_root.
3806  *
3807  * @subvol_root:        tree root of the subvolume tree get swapped
3808  * @bg:                 block group under balance
3809  * @subvol_parent/slot: pointer to the subtree root in subvolume tree
3810  * @reloc_parent/slot:  pointer to the subtree root in reloc tree
3811  *                      BOTH POINTERS ARE BEFORE TREE SWAP
3812  * @last_snapshot:      last snapshot generation of the subvolume tree
3813  */
3814 int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
3815                 struct btrfs_root *subvol_root,
3816                 struct btrfs_block_group *bg,
3817                 struct extent_buffer *subvol_parent, int subvol_slot,
3818                 struct extent_buffer *reloc_parent, int reloc_slot,
3819                 u64 last_snapshot)
3820 {
3821         struct btrfs_fs_info *fs_info = subvol_root->fs_info;
3822         struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
3823         struct btrfs_qgroup_swapped_block *block;
3824         struct rb_node **cur;
3825         struct rb_node *parent = NULL;
3826         int level = btrfs_header_level(subvol_parent) - 1;
3827         int ret = 0;
3828
3829         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
3830                 return 0;
3831
3832         if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
3833             btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
3834                 btrfs_err_rl(fs_info,
3835                 "%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
3836                         __func__,
3837                         btrfs_node_ptr_generation(subvol_parent, subvol_slot),
3838                         btrfs_node_ptr_generation(reloc_parent, reloc_slot));
3839                 return -EUCLEAN;
3840         }
3841
3842         block = kmalloc(sizeof(*block), GFP_NOFS);
3843         if (!block) {
3844                 ret = -ENOMEM;
3845                 goto out;
3846         }
3847
3848         /*
3849          * @reloc_parent/slot is still before swap, while @block is going to
3850          * record the bytenr after swap, so we do the swap here.
3851          */
3852         block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
3853         block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
3854                                                              reloc_slot);
3855         block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
3856         block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
3857                                                             subvol_slot);
3858         block->last_snapshot = last_snapshot;
3859         block->level = level;
3860
3861         /*
3862          * If we have bg == NULL, we're called from btrfs_recover_relocation(),
3863          * no one else can modify tree blocks thus we qgroup will not change
3864          * no matter the value of trace_leaf.
3865          */
3866         if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
3867                 block->trace_leaf = true;
3868         else
3869                 block->trace_leaf = false;
3870         btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
3871
3872         /* Insert @block into @blocks */
3873         spin_lock(&blocks->lock);
3874         cur = &blocks->blocks[level].rb_node;
3875         while (*cur) {
3876                 struct btrfs_qgroup_swapped_block *entry;
3877
3878                 parent = *cur;
3879                 entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
3880                                  node);
3881
3882                 if (entry->subvol_bytenr < block->subvol_bytenr) {
3883                         cur = &(*cur)->rb_left;
3884                 } else if (entry->subvol_bytenr > block->subvol_bytenr) {
3885                         cur = &(*cur)->rb_right;
3886                 } else {
3887                         if (entry->subvol_generation !=
3888                                         block->subvol_generation ||
3889                             entry->reloc_bytenr != block->reloc_bytenr ||
3890                             entry->reloc_generation !=
3891                                         block->reloc_generation) {
3892                                 /*
3893                                  * Duplicated but mismatch entry found.
3894                                  * Shouldn't happen.
3895                                  *
3896                                  * Marking qgroup inconsistent should be enough
3897                                  * for end users.
3898                                  */
3899                                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
3900                                 ret = -EEXIST;
3901                         }
3902                         kfree(block);
3903                         goto out_unlock;
3904                 }
3905         }
3906         rb_link_node(&block->node, parent, cur);
3907         rb_insert_color(&block->node, &blocks->blocks[level]);
3908         blocks->swapped = true;
3909 out_unlock:
3910         spin_unlock(&blocks->lock);
3911 out:
3912         if (ret < 0)
3913                 fs_info->qgroup_flags |=
3914                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3915         return ret;
3916 }
3917
3918 /*
3919  * Check if the tree block is a subtree root, and if so do the needed
3920  * delayed subtree trace for qgroup.
3921  *
3922  * This is called during btrfs_cow_block().
3923  */
3924 int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
3925                                          struct btrfs_root *root,
3926                                          struct extent_buffer *subvol_eb)
3927 {
3928         struct btrfs_fs_info *fs_info = root->fs_info;
3929         struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
3930         struct btrfs_qgroup_swapped_block *block;
3931         struct extent_buffer *reloc_eb = NULL;
3932         struct rb_node *node;
3933         bool found = false;
3934         bool swapped = false;
3935         int level = btrfs_header_level(subvol_eb);
3936         int ret = 0;
3937         int i;
3938
3939         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
3940                 return 0;
3941         if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
3942                 return 0;
3943
3944         spin_lock(&blocks->lock);
3945         if (!blocks->swapped) {
3946                 spin_unlock(&blocks->lock);
3947                 return 0;
3948         }
3949         node = blocks->blocks[level].rb_node;
3950
3951         while (node) {
3952                 block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
3953                 if (block->subvol_bytenr < subvol_eb->start) {
3954                         node = node->rb_left;
3955                 } else if (block->subvol_bytenr > subvol_eb->start) {
3956                         node = node->rb_right;
3957                 } else {
3958                         found = true;
3959                         break;
3960                 }
3961         }
3962         if (!found) {
3963                 spin_unlock(&blocks->lock);
3964                 goto out;
3965         }
3966         /* Found one, remove it from @blocks first and update blocks->swapped */
3967         rb_erase(&block->node, &blocks->blocks[level]);
3968         for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3969                 if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
3970                         swapped = true;
3971                         break;
3972                 }
3973         }
3974         blocks->swapped = swapped;
3975         spin_unlock(&blocks->lock);
3976
3977         /* Read out reloc subtree root */
3978         reloc_eb = read_tree_block(fs_info, block->reloc_bytenr,
3979                                    block->reloc_generation, block->level,
3980                                    &block->first_key);
3981         if (IS_ERR(reloc_eb)) {
3982                 ret = PTR_ERR(reloc_eb);
3983                 reloc_eb = NULL;
3984                 goto free_out;
3985         }
3986         if (!extent_buffer_uptodate(reloc_eb)) {
3987                 ret = -EIO;
3988                 goto free_out;
3989         }
3990
3991         ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
3992                         block->last_snapshot, block->trace_leaf);
3993 free_out:
3994         kfree(block);
3995         free_extent_buffer(reloc_eb);
3996 out:
3997         if (ret < 0) {
3998                 btrfs_err_rl(fs_info,
3999                              "failed to account subtree at bytenr %llu: %d",
4000                              subvol_eb->start, ret);
4001                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
4002         }
4003         return ret;
4004 }