fs/btrfs/qgroup.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2011 STRATO.  All rights reserved.
   4  */
   5
   6 #include <linux/sched.h>
   7 #include <linux/pagemap.h>
   8 #include <linux/writeback.h>
   9 #include <linux/blkdev.h>
  10 #include <linux/rbtree.h>
  11 #include <linux/slab.h>
  12 #include <linux/workqueue.h>
  13 #include <linux/btrfs.h>
  14 #include <linux/sched/mm.h>
  15
  16 #include "ctree.h"
  17 #include "transaction.h"
  18 #include "disk-io.h"
  19 #include "locking.h"
  20 #include "ulist.h"
  21 #include "backref.h"
  22 #include "extent_io.h"
  23 #include "qgroup.h"
  24 #include "block-group.h"
  25 #include "sysfs.h"
  26 #include "tree-mod-log.h"
  27 #include "fs.h"
  28 #include "accessors.h"
  29 #include "extent-tree.h"
  30 #include "root-tree.h"
  31 #include "tree-checker.h"
  32
  33 /*
  34  * Helpers to access qgroup reservation
  35  *
  36  * Callers should ensure the lock context and type are valid
  37  */
  38
  39 static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
  40 {
  41         u64 ret = 0;
  42         int i;
  43
  44         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  45                 ret += qgroup->rsv.values[i];
  46
  47         return ret;
  48 }
  49
  50 #ifdef CONFIG_BTRFS_DEBUG
  51 static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
  52 {
  53         if (type == BTRFS_QGROUP_RSV_DATA)
  54                 return "data";
  55         if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
  56                 return "meta_pertrans";
  57         if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
  58                 return "meta_prealloc";
  59         return NULL;
  60 }
  61 #endif
  62
  63 static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
  64                            struct btrfs_qgroup *qgroup, u64 num_bytes,
  65                            enum btrfs_qgroup_rsv_type type)
  66 {
  67         trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
  68         qgroup->rsv.values[type] += num_bytes;
  69 }
  70
  71 static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
  72                                struct btrfs_qgroup *qgroup, u64 num_bytes,
  73                                enum btrfs_qgroup_rsv_type type)
  74 {
  75         trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
  76         if (qgroup->rsv.values[type] >= num_bytes) {
  77                 qgroup->rsv.values[type] -= num_bytes;
  78                 return;
  79         }
  80 #ifdef CONFIG_BTRFS_DEBUG
  81         WARN_RATELIMIT(1,
  82                 "qgroup %llu %s reserved space underflow, have %llu to free %llu",
  83                 qgroup->qgroupid, qgroup_rsv_type_str(type),
  84                 qgroup->rsv.values[type], num_bytes);
  85 #endif
  86         qgroup->rsv.values[type] = 0;
  87 }
  88
  89 static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
  90                                      struct btrfs_qgroup *dest,
  91                                      struct btrfs_qgroup *src)
  92 {
  93         int i;
  94
  95         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  96                 qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
  97 }
  98
  99 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
 100                                          struct btrfs_qgroup *dest,
 101                                           struct btrfs_qgroup *src)
 102 {
 103         int i;
 104
 105         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
 106                 qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
 107 }
 108
 109 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
 110                                            int mod)
 111 {
 112         if (qg->old_refcnt < seq)
 113                 qg->old_refcnt = seq;
 114         qg->old_refcnt += mod;
 115 }
 116
 117 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 118                                            int mod)
 119 {
 120         if (qg->new_refcnt < seq)
 121                 qg->new_refcnt = seq;
 122         qg->new_refcnt += mod;
 123 }
 124
 125 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
 126 {
 127         if (qg->old_refcnt < seq)
 128                 return 0;
 129         return qg->old_refcnt - seq;
 130 }
 131
 132 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
 133 {
 134         if (qg->new_refcnt < seq)
 135                 return 0;
 136         return qg->new_refcnt - seq;
 137 }
 138
 139 /*
 140  * glue structure to represent the relations between qgroups.
 141  */
 142 struct btrfs_qgroup_list {
 143         struct list_head next_group;
 144         struct list_head next_member;
 145         struct btrfs_qgroup *group;
 146         struct btrfs_qgroup *member;
 147 };
 148
 149 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
 150 {
 151         return (u64)(uintptr_t)qg;
 152 }
 153
 154 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
 155 {
 156         return (struct btrfs_qgroup *)(uintptr_t)n->aux;
 157 }
 158
 159 static int
 160 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 161                    int init_flags);
 162 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 163
 164 /* must be called with qgroup_ioctl_lock held */
 165 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 166                                            u64 qgroupid)
 167 {
 168         struct rb_node *n = fs_info->qgroup_tree.rb_node;
 169         struct btrfs_qgroup *qgroup;
 170
 171         while (n) {
 172                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 173                 if (qgroup->qgroupid < qgroupid)
 174                         n = n->rb_left;
 175                 else if (qgroup->qgroupid > qgroupid)
 176                         n = n->rb_right;
 177                 else
 178                         return qgroup;
 179         }
 180         return NULL;
 181 }
 182
 183 /* must be called with qgroup_lock held */
 184 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 185                                           u64 qgroupid)
 186 {
 187         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 188         struct rb_node *parent = NULL;
 189         struct btrfs_qgroup *qgroup;
 190
 191         while (*p) {
 192                 parent = *p;
 193                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 194
 195                 if (qgroup->qgroupid < qgroupid)
 196                         p = &(*p)->rb_left;
 197                 else if (qgroup->qgroupid > qgroupid)
 198                         p = &(*p)->rb_right;
 199                 else
 200                         return qgroup;
 201         }
 202
 203         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 204         if (!qgroup)
 205                 return ERR_PTR(-ENOMEM);
 206
 207         qgroup->qgroupid = qgroupid;
 208         INIT_LIST_HEAD(&qgroup->groups);
 209         INIT_LIST_HEAD(&qgroup->members);
 210         INIT_LIST_HEAD(&qgroup->dirty);
 211
 212         rb_link_node(&qgroup->node, parent, p);
 213         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 214
 215         return qgroup;
 216 }
 217
 218 static void __del_qgroup_rb(struct btrfs_fs_info *fs_info,
 219                             struct btrfs_qgroup *qgroup)
 220 {
 221         struct btrfs_qgroup_list *list;
 222
 223         list_del(&qgroup->dirty);
 224         while (!list_empty(&qgroup->groups)) {
 225                 list = list_first_entry(&qgroup->groups,
 226                                         struct btrfs_qgroup_list, next_group);
 227                 list_del(&list->next_group);
 228                 list_del(&list->next_member);
 229                 kfree(list);
 230         }
 231
 232         while (!list_empty(&qgroup->members)) {
 233                 list = list_first_entry(&qgroup->members,
 234                                         struct btrfs_qgroup_list, next_member);
 235                 list_del(&list->next_group);
 236                 list_del(&list->next_member);
 237                 kfree(list);
 238         }
 239 }
 240
 241 /* must be called with qgroup_lock held */
 242 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 243 {
 244         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 245
 246         if (!qgroup)
 247                 return -ENOENT;
 248
 249         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 250         __del_qgroup_rb(fs_info, qgroup);
 251         return 0;
 252 }
 253
 254 /*
 255  * Add relation specified by two qgroups.
 256  *
 257  * Must be called with qgroup_lock held.
 258  *
 259  * Return: 0        on success
 260  *         -ENOENT  if one of the qgroups is NULL
 261  *         <0       other errors
 262  */
 263 static int __add_relation_rb(struct btrfs_qgroup *member, struct btrfs_qgroup *parent)
 264 {
 265         struct btrfs_qgroup_list *list;
 266
 267         if (!member || !parent)
 268                 return -ENOENT;
 269
 270         list = kzalloc(sizeof(*list), GFP_ATOMIC);
 271         if (!list)
 272                 return -ENOMEM;
 273
 274         list->group = parent;
 275         list->member = member;
 276         list_add_tail(&list->next_group, &member->groups);
 277         list_add_tail(&list->next_member, &parent->members);
 278
 279         return 0;
 280 }
 281
 282 /*
 283  * Add relation specified by two qgroup ids.
 284  *
 285  * Must be called with qgroup_lock held.
 286  *
 287  * Return: 0        on success
 288  *         -ENOENT  if one of the ids does not exist
 289  *         <0       other errors
 290  */
 291 static int add_relation_rb(struct btrfs_fs_info *fs_info, u64 memberid, u64 parentid)
 292 {
 293         struct btrfs_qgroup *member;
 294         struct btrfs_qgroup *parent;
 295
 296         member = find_qgroup_rb(fs_info, memberid);
 297         parent = find_qgroup_rb(fs_info, parentid);
 298
 299         return __add_relation_rb(member, parent);
 300 }
 301
 302 /* Must be called with qgroup_lock held */
 303 static int del_relation_rb(struct btrfs_fs_info *fs_info,
 304                            u64 memberid, u64 parentid)
 305 {
 306         struct btrfs_qgroup *member;
 307         struct btrfs_qgroup *parent;
 308         struct btrfs_qgroup_list *list;
 309
 310         member = find_qgroup_rb(fs_info, memberid);
 311         parent = find_qgroup_rb(fs_info, parentid);
 312         if (!member || !parent)
 313                 return -ENOENT;
 314
 315         list_for_each_entry(list, &member->groups, next_group) {
 316                 if (list->group == parent) {
 317                         list_del(&list->next_group);
 318                         list_del(&list->next_member);
 319                         kfree(list);
 320                         return 0;
 321                 }
 322         }
 323         return -ENOENT;
 324 }
 325
 326 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 327 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 328                                u64 rfer, u64 excl)
 329 {
 330         struct btrfs_qgroup *qgroup;
 331
 332         qgroup = find_qgroup_rb(fs_info, qgroupid);
 333         if (!qgroup)
 334                 return -EINVAL;
 335         if (qgroup->rfer != rfer || qgroup->excl != excl)
 336                 return -EINVAL;
 337         return 0;
 338 }
 339 #endif
 340
 341 static void qgroup_mark_inconsistent(struct btrfs_fs_info *fs_info)
 342 {
 343         fs_info->qgroup_flags |= (BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT |
 344                                   BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN |
 345                                   BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING);
 346 }
 347
 348 /*
 349  * The full config is read in one go, only called from open_ctree()
 350  * It doesn't use any locking, as at this point we're still single-threaded
 351  */
 352 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 353 {
 354         struct btrfs_key key;
 355         struct btrfs_key found_key;
 356         struct btrfs_root *quota_root = fs_info->quota_root;
 357         struct btrfs_path *path = NULL;
 358         struct extent_buffer *l;
 359         int slot;
 360         int ret = 0;
 361         u64 flags = 0;
 362         u64 rescan_progress = 0;
 363
 364         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 365                 return 0;
 366
 367         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 368         if (!fs_info->qgroup_ulist) {
 369                 ret = -ENOMEM;
 370                 goto out;
 371         }
 372
 373         path = btrfs_alloc_path();
 374         if (!path) {
 375                 ret = -ENOMEM;
 376                 goto out;
 377         }
 378
 379         ret = btrfs_sysfs_add_qgroups(fs_info);
 380         if (ret < 0)
 381                 goto out;
 382         /* default this to quota off, in case no status key is found */
 383         fs_info->qgroup_flags = 0;
 384
 385         /*
 386          * pass 1: read status, all qgroup infos and limits
 387          */
 388         key.objectid = 0;
 389         key.type = 0;
 390         key.offset = 0;
 391         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 392         if (ret)
 393                 goto out;
 394
 395         while (1) {
 396                 struct btrfs_qgroup *qgroup;
 397
 398                 slot = path->slots[0];
 399                 l = path->nodes[0];
 400                 btrfs_item_key_to_cpu(l, &found_key, slot);
 401
 402                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 403                         struct btrfs_qgroup_status_item *ptr;
 404
 405                         ptr = btrfs_item_ptr(l, slot,
 406                                              struct btrfs_qgroup_status_item);
 407
 408                         if (btrfs_qgroup_status_version(l, ptr) !=
 409                             BTRFS_QGROUP_STATUS_VERSION) {
 410                                 btrfs_err(fs_info,
 411                                  "old qgroup version, quota disabled");
 412                                 goto out;
 413                         }
 414                         if (btrfs_qgroup_status_generation(l, ptr) !=
 415                             fs_info->generation) {
 416                                 qgroup_mark_inconsistent(fs_info);
 417                                 btrfs_err(fs_info,
 418                                         "qgroup generation mismatch, marked as inconsistent");
 419                         }
 420                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 421                                                                           ptr);
 422                         rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
 423                         goto next1;
 424                 }
 425
 426                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 427                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 428                         goto next1;
 429
 430                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
 431                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 432                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 433                         btrfs_err(fs_info, "inconsistent qgroup config");
 434                         qgroup_mark_inconsistent(fs_info);
 435                 }
 436                 if (!qgroup) {
 437                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 438                         if (IS_ERR(qgroup)) {
 439                                 ret = PTR_ERR(qgroup);
 440                                 goto out;
 441                         }
 442                 }
 443                 ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
 444                 if (ret < 0)
 445                         goto out;
 446
 447                 switch (found_key.type) {
 448                 case BTRFS_QGROUP_INFO_KEY: {
 449                         struct btrfs_qgroup_info_item *ptr;
 450
 451                         ptr = btrfs_item_ptr(l, slot,
 452                                              struct btrfs_qgroup_info_item);
 453                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 454                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 455                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 456                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 457                         /* generation currently unused */
 458                         break;
 459                 }
 460                 case BTRFS_QGROUP_LIMIT_KEY: {
 461                         struct btrfs_qgroup_limit_item *ptr;
 462
 463                         ptr = btrfs_item_ptr(l, slot,
 464                                              struct btrfs_qgroup_limit_item);
 465                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 466                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 467                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 468                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 469                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 470                         break;
 471                 }
 472                 }
 473 next1:
 474                 ret = btrfs_next_item(quota_root, path);
 475                 if (ret < 0)
 476                         goto out;
 477                 if (ret)
 478                         break;
 479         }
 480         btrfs_release_path(path);
 481
 482         /*
 483          * pass 2: read all qgroup relations
 484          */
 485         key.objectid = 0;
 486         key.type = BTRFS_QGROUP_RELATION_KEY;
 487         key.offset = 0;
 488         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 489         if (ret)
 490                 goto out;
 491         while (1) {
 492                 slot = path->slots[0];
 493                 l = path->nodes[0];
 494                 btrfs_item_key_to_cpu(l, &found_key, slot);
 495
 496                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 497                         goto next2;
 498
 499                 if (found_key.objectid > found_key.offset) {
 500                         /* parent <- member, not needed to build config */
 501                         /* FIXME should we omit the key completely? */
 502                         goto next2;
 503                 }
 504
 505                 ret = add_relation_rb(fs_info, found_key.objectid,
 506                                       found_key.offset);
 507                 if (ret == -ENOENT) {
 508                         btrfs_warn(fs_info,
 509                                 "orphan qgroup relation 0x%llx->0x%llx",
 510                                 found_key.objectid, found_key.offset);
 511                         ret = 0;        /* ignore the error */
 512                 }
 513                 if (ret)
 514                         goto out;
 515 next2:
 516                 ret = btrfs_next_item(quota_root, path);
 517                 if (ret < 0)
 518                         goto out;
 519                 if (ret)
 520                         break;
 521         }
 522 out:
 523         btrfs_free_path(path);
 524         fs_info->qgroup_flags |= flags;
 525         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
 526                 clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 527         else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
 528                  ret >= 0)
 529                 ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
 530
 531         if (ret < 0) {
 532                 ulist_free(fs_info->qgroup_ulist);
 533                 fs_info->qgroup_ulist = NULL;
 534                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 535                 btrfs_sysfs_del_qgroups(fs_info);
 536         }
 537
 538         return ret < 0 ? ret : 0;
 539 }
 540
 541 /*
 542  * Called in close_ctree() when quota is still enabled.  This verifies we don't
 543  * leak some reserved space.
 544  *
 545  * Return false if no reserved space is left.
 546  * Return true if some reserved space is leaked.
 547  */
 548 bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info)
 549 {
 550         struct rb_node *node;
 551         bool ret = false;
 552
 553         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 554                 return ret;
 555         /*
 556          * Since we're unmounting, there is no race and no need to grab qgroup
 557          * lock.  And here we don't go post-order to provide a more user
 558          * friendly sorted result.
 559          */
 560         for (node = rb_first(&fs_info->qgroup_tree); node; node = rb_next(node)) {
 561                 struct btrfs_qgroup *qgroup;
 562                 int i;
 563
 564                 qgroup = rb_entry(node, struct btrfs_qgroup, node);
 565                 for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) {
 566                         if (qgroup->rsv.values[i]) {
 567                                 ret = true;
 568                                 btrfs_warn(fs_info,
 569                 "qgroup %hu/%llu has unreleased space, type %d rsv %llu",
 570                                    btrfs_qgroup_level(qgroup->qgroupid),
 571                                    btrfs_qgroup_subvolid(qgroup->qgroupid),
 572                                    i, qgroup->rsv.values[i]);
 573                         }
 574                 }
 575         }
 576         return ret;
 577 }
 578
 579 /*
 580  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
 581  * first two are in single-threaded paths.And for the third one, we have set
 582  * quota_root to be null with qgroup_lock held before, so it is safe to clean
 583  * up the in-memory structures without qgroup_lock held.
 584  */
 585 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 586 {
 587         struct rb_node *n;
 588         struct btrfs_qgroup *qgroup;
 589
 590         while ((n = rb_first(&fs_info->qgroup_tree))) {
 591                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 592                 rb_erase(n, &fs_info->qgroup_tree);
 593                 __del_qgroup_rb(fs_info, qgroup);
 594                 btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
 595                 kfree(qgroup);
 596         }
 597         /*
 598          * We call btrfs_free_qgroup_config() when unmounting
 599          * filesystem and disabling quota, so we set qgroup_ulist
 600          * to be null here to avoid double free.
 601          */
 602         ulist_free(fs_info->qgroup_ulist);
 603         fs_info->qgroup_ulist = NULL;
 604         btrfs_sysfs_del_qgroups(fs_info);
 605 }
 606
 607 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 608                                     u64 dst)
 609 {
 610         int ret;
 611         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 612         struct btrfs_path *path;
 613         struct btrfs_key key;
 614
 615         path = btrfs_alloc_path();
 616         if (!path)
 617                 return -ENOMEM;
 618
 619         key.objectid = src;
 620         key.type = BTRFS_QGROUP_RELATION_KEY;
 621         key.offset = dst;
 622
 623         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 624
 625         btrfs_mark_buffer_dirty(path->nodes[0]);
 626
 627         btrfs_free_path(path);
 628         return ret;
 629 }
 630
 631 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 632                                     u64 dst)
 633 {
 634         int ret;
 635         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 636         struct btrfs_path *path;
 637         struct btrfs_key key;
 638
 639         path = btrfs_alloc_path();
 640         if (!path)
 641                 return -ENOMEM;
 642
 643         key.objectid = src;
 644         key.type = BTRFS_QGROUP_RELATION_KEY;
 645         key.offset = dst;
 646
 647         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 648         if (ret < 0)
 649                 goto out;
 650
 651         if (ret > 0) {
 652                 ret = -ENOENT;
 653                 goto out;
 654         }
 655
 656         ret = btrfs_del_item(trans, quota_root, path);
 657 out:
 658         btrfs_free_path(path);
 659         return ret;
 660 }
 661
 662 static int add_qgroup_item(struct btrfs_trans_handle *trans,
 663                            struct btrfs_root *quota_root, u64 qgroupid)
 664 {
 665         int ret;
 666         struct btrfs_path *path;
 667         struct btrfs_qgroup_info_item *qgroup_info;
 668         struct btrfs_qgroup_limit_item *qgroup_limit;
 669         struct extent_buffer *leaf;
 670         struct btrfs_key key;
 671
 672         if (btrfs_is_testing(quota_root->fs_info))
 673                 return 0;
 674
 675         path = btrfs_alloc_path();
 676         if (!path)
 677                 return -ENOMEM;
 678
 679         key.objectid = 0;
 680         key.type = BTRFS_QGROUP_INFO_KEY;
 681         key.offset = qgroupid;
 682
 683         /*
 684          * Avoid a transaction abort by catching -EEXIST here. In that
 685          * case, we proceed by re-initializing the existing structure
 686          * on disk.
 687          */
 688
 689         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 690                                       sizeof(*qgroup_info));
 691         if (ret && ret != -EEXIST)
 692                 goto out;
 693
 694         leaf = path->nodes[0];
 695         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 696                                  struct btrfs_qgroup_info_item);
 697         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 698         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 699         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 700         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 701         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 702
 703         btrfs_mark_buffer_dirty(leaf);
 704
 705         btrfs_release_path(path);
 706
 707         key.type = BTRFS_QGROUP_LIMIT_KEY;
 708         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 709                                       sizeof(*qgroup_limit));
 710         if (ret && ret != -EEXIST)
 711                 goto out;
 712
 713         leaf = path->nodes[0];
 714         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 715                                   struct btrfs_qgroup_limit_item);
 716         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 717         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 718         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 719         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 720         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 721
 722         btrfs_mark_buffer_dirty(leaf);
 723
 724         ret = 0;
 725 out:
 726         btrfs_free_path(path);
 727         return ret;
 728 }
 729
 730 static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
 731 {
 732         int ret;
 733         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 734         struct btrfs_path *path;
 735         struct btrfs_key key;
 736
 737         path = btrfs_alloc_path();
 738         if (!path)
 739                 return -ENOMEM;
 740
 741         key.objectid = 0;
 742         key.type = BTRFS_QGROUP_INFO_KEY;
 743         key.offset = qgroupid;
 744         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 745         if (ret < 0)
 746                 goto out;
 747
 748         if (ret > 0) {
 749                 ret = -ENOENT;
 750                 goto out;
 751         }
 752
 753         ret = btrfs_del_item(trans, quota_root, path);
 754         if (ret)
 755                 goto out;
 756
 757         btrfs_release_path(path);
 758
 759         key.type = BTRFS_QGROUP_LIMIT_KEY;
 760         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 761         if (ret < 0)
 762                 goto out;
 763
 764         if (ret > 0) {
 765                 ret = -ENOENT;
 766                 goto out;
 767         }
 768
 769         ret = btrfs_del_item(trans, quota_root, path);
 770
 771 out:
 772         btrfs_free_path(path);
 773         return ret;
 774 }
 775
 776 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 777                                     struct btrfs_qgroup *qgroup)
 778 {
 779         struct btrfs_root *quota_root = trans->fs_info->quota_root;
 780         struct btrfs_path *path;
 781         struct btrfs_key key;
 782         struct extent_buffer *l;
 783         struct btrfs_qgroup_limit_item *qgroup_limit;
 784         int ret;
 785         int slot;
 786
 787         key.objectid = 0;
 788         key.type = BTRFS_QGROUP_LIMIT_KEY;
 789         key.offset = qgroup->qgroupid;
 790
 791         path = btrfs_alloc_path();
 792         if (!path)
 793                 return -ENOMEM;
 794
 795         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 796         if (ret > 0)
 797                 ret = -ENOENT;
 798
 799         if (ret)
 800                 goto out;
 801
 802         l = path->nodes[0];
 803         slot = path->slots[0];
 804         qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
 805         btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
 806         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
 807         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
 808         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
 809         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
 810
 811         btrfs_mark_buffer_dirty(l);
 812
 813 out:
 814         btrfs_free_path(path);
 815         return ret;
 816 }
 817
 818 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 819                                    struct btrfs_qgroup *qgroup)
 820 {
 821         struct btrfs_fs_info *fs_info = trans->fs_info;
 822         struct btrfs_root *quota_root = fs_info->quota_root;
 823         struct btrfs_path *path;
 824         struct btrfs_key key;
 825         struct extent_buffer *l;
 826         struct btrfs_qgroup_info_item *qgroup_info;
 827         int ret;
 828         int slot;
 829
 830         if (btrfs_is_testing(fs_info))
 831                 return 0;
 832
 833         key.objectid = 0;
 834         key.type = BTRFS_QGROUP_INFO_KEY;
 835         key.offset = qgroup->qgroupid;
 836
 837         path = btrfs_alloc_path();
 838         if (!path)
 839                 return -ENOMEM;
 840
 841         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 842         if (ret > 0)
 843                 ret = -ENOENT;
 844
 845         if (ret)
 846                 goto out;
 847
 848         l = path->nodes[0];
 849         slot = path->slots[0];
 850         qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
 851         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 852         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 853         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 854         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 855         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 856
 857         btrfs_mark_buffer_dirty(l);
 858
 859 out:
 860         btrfs_free_path(path);
 861         return ret;
 862 }
 863
 864 static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
 865 {
 866         struct btrfs_fs_info *fs_info = trans->fs_info;
 867         struct btrfs_root *quota_root = fs_info->quota_root;
 868         struct btrfs_path *path;
 869         struct btrfs_key key;
 870         struct extent_buffer *l;
 871         struct btrfs_qgroup_status_item *ptr;
 872         int ret;
 873         int slot;
 874
 875         key.objectid = 0;
 876         key.type = BTRFS_QGROUP_STATUS_KEY;
 877         key.offset = 0;
 878
 879         path = btrfs_alloc_path();
 880         if (!path)
 881                 return -ENOMEM;
 882
 883         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 884         if (ret > 0)
 885                 ret = -ENOENT;
 886
 887         if (ret)
 888                 goto out;
 889
 890         l = path->nodes[0];
 891         slot = path->slots[0];
 892         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 893         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags &
 894                                       BTRFS_QGROUP_STATUS_FLAGS_MASK);
 895         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 896         btrfs_set_qgroup_status_rescan(l, ptr,
 897                                 fs_info->qgroup_rescan_progress.objectid);
 898
 899         btrfs_mark_buffer_dirty(l);
 900
 901 out:
 902         btrfs_free_path(path);
 903         return ret;
 904 }
 905
 906 /*
 907  * called with qgroup_lock held
 908  */
 909 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 910                                   struct btrfs_root *root)
 911 {
 912         struct btrfs_path *path;
 913         struct btrfs_key key;
 914         struct extent_buffer *leaf = NULL;
 915         int ret;
 916         int nr = 0;
 917
 918         path = btrfs_alloc_path();
 919         if (!path)
 920                 return -ENOMEM;
 921
 922         key.objectid = 0;
 923         key.offset = 0;
 924         key.type = 0;
 925
 926         while (1) {
 927                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 928                 if (ret < 0)
 929                         goto out;
 930                 leaf = path->nodes[0];
 931                 nr = btrfs_header_nritems(leaf);
 932                 if (!nr)
 933                         break;
 934                 /*
 935                  * delete the leaf one by one
 936                  * since the whole tree is going
 937                  * to be deleted.
 938                  */
 939                 path->slots[0] = 0;
 940                 ret = btrfs_del_items(trans, root, path, 0, nr);
 941                 if (ret)
 942                         goto out;
 943
 944                 btrfs_release_path(path);
 945         }
 946         ret = 0;
 947 out:
 948         btrfs_free_path(path);
 949         return ret;
 950 }
 951
 952 int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
 953 {
 954         struct btrfs_root *quota_root;
 955         struct btrfs_root *tree_root = fs_info->tree_root;
 956         struct btrfs_path *path = NULL;
 957         struct btrfs_qgroup_status_item *ptr;
 958         struct extent_buffer *leaf;
 959         struct btrfs_key key;
 960         struct btrfs_key found_key;
 961         struct btrfs_qgroup *qgroup = NULL;
 962         struct btrfs_trans_handle *trans = NULL;
 963         struct ulist *ulist = NULL;
 964         int ret = 0;
 965         int slot;
 966
 967         /*
 968          * We need to have subvol_sem write locked, to prevent races between
 969          * concurrent tasks trying to enable quotas, because we will unlock
 970          * and relock qgroup_ioctl_lock before setting fs_info->quota_root
 971          * and before setting BTRFS_FS_QUOTA_ENABLED.
 972          */
 973         lockdep_assert_held_write(&fs_info->subvol_sem);
 974
 975         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
 976                 btrfs_err(fs_info,
 977                           "qgroups are currently unsupported in extent tree v2");
 978                 return -EINVAL;
 979         }
 980
 981         mutex_lock(&fs_info->qgroup_ioctl_lock);
 982         if (fs_info->quota_root)
 983                 goto out;
 984
 985         ulist = ulist_alloc(GFP_KERNEL);
 986         if (!ulist) {
 987                 ret = -ENOMEM;
 988                 goto out;
 989         }
 990
 991         ret = btrfs_sysfs_add_qgroups(fs_info);
 992         if (ret < 0)
 993                 goto out;
 994
 995         /*
 996          * Unlock qgroup_ioctl_lock before starting the transaction. This is to
 997          * avoid lock acquisition inversion problems (reported by lockdep) between
 998          * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we
 999          * start a transaction.
1000          * After we started the transaction lock qgroup_ioctl_lock again and
1001          * check if someone else created the quota root in the meanwhile. If so,
1002          * just return success and release the transaction handle.
1003          *
1004          * Also we don't need to worry about someone else calling
1005          * btrfs_sysfs_add_qgroups() after we unlock and getting an error because
1006          * that function returns 0 (success) when the sysfs entries already exist.
1007          */
1008         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1009
1010         /*
1011          * 1 for quota root item
1012          * 1 for BTRFS_QGROUP_STATUS item
1013          *
1014          * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
1015          * per subvolume. However those are not currently reserved since it
1016          * would be a lot of overkill.
1017          */
1018         trans = btrfs_start_transaction(tree_root, 2);
1019
1020         mutex_lock(&fs_info->qgroup_ioctl_lock);
1021         if (IS_ERR(trans)) {
1022                 ret = PTR_ERR(trans);
1023                 trans = NULL;
1024                 goto out;
1025         }
1026
1027         if (fs_info->quota_root)
1028                 goto out;
1029
1030         fs_info->qgroup_ulist = ulist;
1031         ulist = NULL;
1032
1033         /*
1034          * initially create the quota tree
1035          */
1036         quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
1037         if (IS_ERR(quota_root)) {
1038                 ret =  PTR_ERR(quota_root);
1039                 btrfs_abort_transaction(trans, ret);
1040                 goto out;
1041         }
1042
1043         path = btrfs_alloc_path();
1044         if (!path) {
1045                 ret = -ENOMEM;
1046                 btrfs_abort_transaction(trans, ret);
1047                 goto out_free_root;
1048         }
1049
1050         key.objectid = 0;
1051         key.type = BTRFS_QGROUP_STATUS_KEY;
1052         key.offset = 0;
1053
1054         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
1055                                       sizeof(*ptr));
1056         if (ret) {
1057                 btrfs_abort_transaction(trans, ret);
1058                 goto out_free_path;
1059         }
1060
1061         leaf = path->nodes[0];
1062         ptr = btrfs_item_ptr(leaf, path->slots[0],
1063                                  struct btrfs_qgroup_status_item);
1064         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
1065         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
1066         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
1067                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1068         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags &
1069                                       BTRFS_QGROUP_STATUS_FLAGS_MASK);
1070         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
1071
1072         btrfs_mark_buffer_dirty(leaf);
1073
1074         key.objectid = 0;
1075         key.type = BTRFS_ROOT_REF_KEY;
1076         key.offset = 0;
1077
1078         btrfs_release_path(path);
1079         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
1080         if (ret > 0)
1081                 goto out_add_root;
1082         if (ret < 0) {
1083                 btrfs_abort_transaction(trans, ret);
1084                 goto out_free_path;
1085         }
1086
1087         while (1) {
1088                 slot = path->slots[0];
1089                 leaf = path->nodes[0];
1090                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1091
1092                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
1093
1094                         /* Release locks on tree_root before we access quota_root */
1095                         btrfs_release_path(path);
1096
1097                         ret = add_qgroup_item(trans, quota_root,
1098                                               found_key.offset);
1099                         if (ret) {
1100                                 btrfs_abort_transaction(trans, ret);
1101                                 goto out_free_path;
1102                         }
1103
1104                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
1105                         if (IS_ERR(qgroup)) {
1106                                 ret = PTR_ERR(qgroup);
1107                                 btrfs_abort_transaction(trans, ret);
1108                                 goto out_free_path;
1109                         }
1110                         ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1111                         if (ret < 0) {
1112                                 btrfs_abort_transaction(trans, ret);
1113                                 goto out_free_path;
1114                         }
1115                         ret = btrfs_search_slot_for_read(tree_root, &found_key,
1116                                                          path, 1, 0);
1117                         if (ret < 0) {
1118                                 btrfs_abort_transaction(trans, ret);
1119                                 goto out_free_path;
1120                         }
1121                         if (ret > 0) {
1122                                 /*
1123                                  * Shouldn't happen, but in case it does we
1124                                  * don't need to do the btrfs_next_item, just
1125                                  * continue.
1126                                  */
1127                                 continue;
1128                         }
1129                 }
1130                 ret = btrfs_next_item(tree_root, path);
1131                 if (ret < 0) {
1132                         btrfs_abort_transaction(trans, ret);
1133                         goto out_free_path;
1134                 }
1135                 if (ret)
1136                         break;
1137         }
1138
1139 out_add_root:
1140         btrfs_release_path(path);
1141         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1142         if (ret) {
1143                 btrfs_abort_transaction(trans, ret);
1144                 goto out_free_path;
1145         }
1146
1147         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1148         if (IS_ERR(qgroup)) {
1149                 ret = PTR_ERR(qgroup);
1150                 btrfs_abort_transaction(trans, ret);
1151                 goto out_free_path;
1152         }
1153         ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1154         if (ret < 0) {
1155                 btrfs_abort_transaction(trans, ret);
1156                 goto out_free_path;
1157         }
1158
1159         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1160         /*
1161          * Commit the transaction while not holding qgroup_ioctl_lock, to avoid
1162          * a deadlock with tasks concurrently doing other qgroup operations, such
1163          * adding/removing qgroups or adding/deleting qgroup relations for example,
1164          * because all qgroup operations first start or join a transaction and then
1165          * lock the qgroup_ioctl_lock mutex.
1166          * We are safe from a concurrent task trying to enable quotas, by calling
1167          * this function, since we are serialized by fs_info->subvol_sem.
1168          */
1169         ret = btrfs_commit_transaction(trans);
1170         trans = NULL;
1171         mutex_lock(&fs_info->qgroup_ioctl_lock);
1172         if (ret)
1173                 goto out_free_path;
1174
1175         /*
1176          * Set quota enabled flag after committing the transaction, to avoid
1177          * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
1178          * creation.
1179          */
1180         spin_lock(&fs_info->qgroup_lock);
1181         fs_info->quota_root = quota_root;
1182         set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1183         spin_unlock(&fs_info->qgroup_lock);
1184
1185         ret = qgroup_rescan_init(fs_info, 0, 1);
1186         if (!ret) {
1187                 qgroup_rescan_zero_tracking(fs_info);
1188                 fs_info->qgroup_rescan_running = true;
1189                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
1190                                  &fs_info->qgroup_rescan_work);
1191         } else {
1192                 /*
1193                  * We have set both BTRFS_FS_QUOTA_ENABLED and
1194                  * BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with
1195                  * -EINPROGRESS. That can happen because someone started the
1196                  * rescan worker by calling quota rescan ioctl before we
1197                  * attempted to initialize the rescan worker. Failure due to
1198                  * quotas disabled in the meanwhile is not possible, because
1199                  * we are holding a write lock on fs_info->subvol_sem, which
1200                  * is also acquired when disabling quotas.
1201                  * Ignore such error, and any other error would need to undo
1202                  * everything we did in the transaction we just committed.
1203                  */
1204                 ASSERT(ret == -EINPROGRESS);
1205                 ret = 0;
1206         }
1207
1208 out_free_path:
1209         btrfs_free_path(path);
1210 out_free_root:
1211         if (ret)
1212                 btrfs_put_root(quota_root);
1213 out:
1214         if (ret) {
1215                 ulist_free(fs_info->qgroup_ulist);
1216                 fs_info->qgroup_ulist = NULL;
1217                 btrfs_sysfs_del_qgroups(fs_info);
1218         }
1219         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1220         if (ret && trans)
1221                 btrfs_end_transaction(trans);
1222         else if (trans)
1223                 ret = btrfs_end_transaction(trans);
1224         ulist_free(ulist);
1225         return ret;
1226 }
1227
1228 int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1229 {
1230         struct btrfs_root *quota_root;
1231         struct btrfs_trans_handle *trans = NULL;
1232         int ret = 0;
1233
1234         /*
1235          * We need to have subvol_sem write locked, to prevent races between
1236          * concurrent tasks trying to disable quotas, because we will unlock
1237          * and relock qgroup_ioctl_lock across BTRFS_FS_QUOTA_ENABLED changes.
1238          */
1239         lockdep_assert_held_write(&fs_info->subvol_sem);
1240
1241         mutex_lock(&fs_info->qgroup_ioctl_lock);
1242         if (!fs_info->quota_root)
1243                 goto out;
1244
1245         /*
1246          * Unlock the qgroup_ioctl_lock mutex before waiting for the rescan worker to
1247          * complete. Otherwise we can deadlock because btrfs_remove_qgroup() needs
1248          * to lock that mutex while holding a transaction handle and the rescan
1249          * worker needs to commit a transaction.
1250          */
1251         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1252
1253         /*
1254          * Request qgroup rescan worker to complete and wait for it. This wait
1255          * must be done before transaction start for quota disable since it may
1256          * deadlock with transaction by the qgroup rescan worker.
1257          */
1258         clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1259         btrfs_qgroup_wait_for_completion(fs_info, false);
1260
1261         /*
1262          * 1 For the root item
1263          *
1264          * We should also reserve enough items for the quota tree deletion in
1265          * btrfs_clean_quota_tree but this is not done.
1266          *
1267          * Also, we must always start a transaction without holding the mutex
1268          * qgroup_ioctl_lock, see btrfs_quota_enable().
1269          */
1270         trans = btrfs_start_transaction(fs_info->tree_root, 1);
1271
1272         mutex_lock(&fs_info->qgroup_ioctl_lock);
1273         if (IS_ERR(trans)) {
1274                 ret = PTR_ERR(trans);
1275                 trans = NULL;
1276                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1277                 goto out;
1278         }
1279
1280         if (!fs_info->quota_root)
1281                 goto out;
1282
1283         spin_lock(&fs_info->qgroup_lock);
1284         quota_root = fs_info->quota_root;
1285         fs_info->quota_root = NULL;
1286         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1287         fs_info->qgroup_drop_subtree_thres = BTRFS_MAX_LEVEL;
1288         spin_unlock(&fs_info->qgroup_lock);
1289
1290         btrfs_free_qgroup_config(fs_info);
1291
1292         ret = btrfs_clean_quota_tree(trans, quota_root);
1293         if (ret) {
1294                 btrfs_abort_transaction(trans, ret);
1295                 goto out;
1296         }
1297
1298         ret = btrfs_del_root(trans, &quota_root->root_key);
1299         if (ret) {
1300                 btrfs_abort_transaction(trans, ret);
1301                 goto out;
1302         }
1303
1304         list_del(&quota_root->dirty_list);
1305
1306         btrfs_tree_lock(quota_root->node);
1307         btrfs_clean_tree_block(quota_root->node);
1308         btrfs_tree_unlock(quota_root->node);
1309         btrfs_free_tree_block(trans, btrfs_root_id(quota_root),
1310                               quota_root->node, 0, 1);
1311
1312         btrfs_put_root(quota_root);
1313
1314 out:
1315         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1316         if (ret && trans)
1317                 btrfs_end_transaction(trans);
1318         else if (trans)
1319                 ret = btrfs_end_transaction(trans);
1320
1321         return ret;
1322 }
1323
1324 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1325                          struct btrfs_qgroup *qgroup)
1326 {
1327         if (list_empty(&qgroup->dirty))
1328                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1329 }
1330
1331 /*
1332  * The easy accounting, we're updating qgroup relationship whose child qgroup
1333  * only has exclusive extents.
1334  *
1335  * In this case, all exclusive extents will also be exclusive for parent, so
1336  * excl/rfer just get added/removed.
1337  *
1338  * So is qgroup reservation space, which should also be added/removed to
1339  * parent.
1340  * Or when child tries to release reservation space, parent will underflow its
1341  * reservation (for relationship adding case).
1342  *
1343  * Caller should hold fs_info->qgroup_lock.
1344  */
1345 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1346                                     struct ulist *tmp, u64 ref_root,
1347                                     struct btrfs_qgroup *src, int sign)
1348 {
1349         struct btrfs_qgroup *qgroup;
1350         struct btrfs_qgroup_list *glist;
1351         struct ulist_node *unode;
1352         struct ulist_iterator uiter;
1353         u64 num_bytes = src->excl;
1354         int ret = 0;
1355
1356         qgroup = find_qgroup_rb(fs_info, ref_root);
1357         if (!qgroup)
1358                 goto out;
1359
1360         qgroup->rfer += sign * num_bytes;
1361         qgroup->rfer_cmpr += sign * num_bytes;
1362
1363         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1364         qgroup->excl += sign * num_bytes;
1365         qgroup->excl_cmpr += sign * num_bytes;
1366
1367         if (sign > 0)
1368                 qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1369         else
1370                 qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1371
1372         qgroup_dirty(fs_info, qgroup);
1373
1374         /* Get all of the parent groups that contain this qgroup */
1375         list_for_each_entry(glist, &qgroup->groups, next_group) {
1376                 ret = ulist_add(tmp, glist->group->qgroupid,
1377                                 qgroup_to_aux(glist->group), GFP_ATOMIC);
1378                 if (ret < 0)
1379                         goto out;
1380         }
1381
1382         /* Iterate all of the parents and adjust their reference counts */
1383         ULIST_ITER_INIT(&uiter);
1384         while ((unode = ulist_next(tmp, &uiter))) {
1385                 qgroup = unode_aux_to_qgroup(unode);
1386                 qgroup->rfer += sign * num_bytes;
1387                 qgroup->rfer_cmpr += sign * num_bytes;
1388                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1389                 qgroup->excl += sign * num_bytes;
1390                 if (sign > 0)
1391                         qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1392                 else
1393                         qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1394                 qgroup->excl_cmpr += sign * num_bytes;
1395                 qgroup_dirty(fs_info, qgroup);
1396
1397                 /* Add any parents of the parents */
1398                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1399                         ret = ulist_add(tmp, glist->group->qgroupid,
1400                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
1401                         if (ret < 0)
1402                                 goto out;
1403                 }
1404         }
1405         ret = 0;
1406 out:
1407         return ret;
1408 }
1409
1410
1411 /*
1412  * Quick path for updating qgroup with only excl refs.
1413  *
1414  * In that case, just update all parent will be enough.
1415  * Or we needs to do a full rescan.
1416  * Caller should also hold fs_info->qgroup_lock.
1417  *
1418  * Return 0 for quick update, return >0 for need to full rescan
1419  * and mark INCONSISTENT flag.
1420  * Return < 0 for other error.
1421  */
1422 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1423                                    struct ulist *tmp, u64 src, u64 dst,
1424                                    int sign)
1425 {
1426         struct btrfs_qgroup *qgroup;
1427         int ret = 1;
1428         int err = 0;
1429
1430         qgroup = find_qgroup_rb(fs_info, src);
1431         if (!qgroup)
1432                 goto out;
1433         if (qgroup->excl == qgroup->rfer) {
1434                 ret = 0;
1435                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1436                                                qgroup, sign);
1437                 if (err < 0) {
1438                         ret = err;
1439                         goto out;
1440                 }
1441         }
1442 out:
1443         if (ret)
1444                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1445         return ret;
1446 }
1447
1448 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1449                               u64 dst)
1450 {
1451         struct btrfs_fs_info *fs_info = trans->fs_info;
1452         struct btrfs_qgroup *parent;
1453         struct btrfs_qgroup *member;
1454         struct btrfs_qgroup_list *list;
1455         struct ulist *tmp;
1456         unsigned int nofs_flag;
1457         int ret = 0;
1458
1459         /* Check the level of src and dst first */
1460         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1461                 return -EINVAL;
1462
1463         /* We hold a transaction handle open, must do a NOFS allocation. */
1464         nofs_flag = memalloc_nofs_save();
1465         tmp = ulist_alloc(GFP_KERNEL);
1466         memalloc_nofs_restore(nofs_flag);
1467         if (!tmp)
1468                 return -ENOMEM;
1469
1470         mutex_lock(&fs_info->qgroup_ioctl_lock);
1471         if (!fs_info->quota_root) {
1472                 ret = -ENOTCONN;
1473                 goto out;
1474         }
1475         member = find_qgroup_rb(fs_info, src);
1476         parent = find_qgroup_rb(fs_info, dst);
1477         if (!member || !parent) {
1478                 ret = -EINVAL;
1479                 goto out;
1480         }
1481
1482         /* check if such qgroup relation exist firstly */
1483         list_for_each_entry(list, &member->groups, next_group) {
1484                 if (list->group == parent) {
1485                         ret = -EEXIST;
1486                         goto out;
1487                 }
1488         }
1489
1490         ret = add_qgroup_relation_item(trans, src, dst);
1491         if (ret)
1492                 goto out;
1493
1494         ret = add_qgroup_relation_item(trans, dst, src);
1495         if (ret) {
1496                 del_qgroup_relation_item(trans, src, dst);
1497                 goto out;
1498         }
1499
1500         spin_lock(&fs_info->qgroup_lock);
1501         ret = __add_relation_rb(member, parent);
1502         if (ret < 0) {
1503                 spin_unlock(&fs_info->qgroup_lock);
1504                 goto out;
1505         }
1506         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1507         spin_unlock(&fs_info->qgroup_lock);
1508 out:
1509         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1510         ulist_free(tmp);
1511         return ret;
1512 }
1513
1514 static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1515                                  u64 dst)
1516 {
1517         struct btrfs_fs_info *fs_info = trans->fs_info;
1518         struct btrfs_qgroup *parent;
1519         struct btrfs_qgroup *member;
1520         struct btrfs_qgroup_list *list;
1521         struct ulist *tmp;
1522         bool found = false;
1523         unsigned int nofs_flag;
1524         int ret = 0;
1525         int ret2;
1526
1527         /* We hold a transaction handle open, must do a NOFS allocation. */
1528         nofs_flag = memalloc_nofs_save();
1529         tmp = ulist_alloc(GFP_KERNEL);
1530         memalloc_nofs_restore(nofs_flag);
1531         if (!tmp)
1532                 return -ENOMEM;
1533
1534         if (!fs_info->quota_root) {
1535                 ret = -ENOTCONN;
1536                 goto out;
1537         }
1538
1539         member = find_qgroup_rb(fs_info, src);
1540         parent = find_qgroup_rb(fs_info, dst);
1541         /*
1542          * The parent/member pair doesn't exist, then try to delete the dead
1543          * relation items only.
1544          */
1545         if (!member || !parent)
1546                 goto delete_item;
1547
1548         /* check if such qgroup relation exist firstly */
1549         list_for_each_entry(list, &member->groups, next_group) {
1550                 if (list->group == parent) {
1551                         found = true;
1552                         break;
1553                 }
1554         }
1555
1556 delete_item:
1557         ret = del_qgroup_relation_item(trans, src, dst);
1558         if (ret < 0 && ret != -ENOENT)
1559                 goto out;
1560         ret2 = del_qgroup_relation_item(trans, dst, src);
1561         if (ret2 < 0 && ret2 != -ENOENT)
1562                 goto out;
1563
1564         /* At least one deletion succeeded, return 0 */
1565         if (!ret || !ret2)
1566                 ret = 0;
1567
1568         if (found) {
1569                 spin_lock(&fs_info->qgroup_lock);
1570                 del_relation_rb(fs_info, src, dst);
1571                 ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1572                 spin_unlock(&fs_info->qgroup_lock);
1573         }
1574 out:
1575         ulist_free(tmp);
1576         return ret;
1577 }
1578
1579 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1580                               u64 dst)
1581 {
1582         struct btrfs_fs_info *fs_info = trans->fs_info;
1583         int ret = 0;
1584
1585         mutex_lock(&fs_info->qgroup_ioctl_lock);
1586         ret = __del_qgroup_relation(trans, src, dst);
1587         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1588
1589         return ret;
1590 }
1591
1592 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1593 {
1594         struct btrfs_fs_info *fs_info = trans->fs_info;
1595         struct btrfs_root *quota_root;
1596         struct btrfs_qgroup *qgroup;
1597         int ret = 0;
1598
1599         mutex_lock(&fs_info->qgroup_ioctl_lock);
1600         if (!fs_info->quota_root) {
1601                 ret = -ENOTCONN;
1602                 goto out;
1603         }
1604         quota_root = fs_info->quota_root;
1605         qgroup = find_qgroup_rb(fs_info, qgroupid);
1606         if (qgroup) {
1607                 ret = -EEXIST;
1608                 goto out;
1609         }
1610
1611         ret = add_qgroup_item(trans, quota_root, qgroupid);
1612         if (ret)
1613                 goto out;
1614
1615         spin_lock(&fs_info->qgroup_lock);
1616         qgroup = add_qgroup_rb(fs_info, qgroupid);
1617         spin_unlock(&fs_info->qgroup_lock);
1618
1619         if (IS_ERR(qgroup)) {
1620                 ret = PTR_ERR(qgroup);
1621                 goto out;
1622         }
1623         ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1624 out:
1625         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1626         return ret;
1627 }
1628
1629 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1630 {
1631         struct btrfs_fs_info *fs_info = trans->fs_info;
1632         struct btrfs_qgroup *qgroup;
1633         struct btrfs_qgroup_list *list;
1634         int ret = 0;
1635
1636         mutex_lock(&fs_info->qgroup_ioctl_lock);
1637         if (!fs_info->quota_root) {
1638                 ret = -ENOTCONN;
1639                 goto out;
1640         }
1641
1642         qgroup = find_qgroup_rb(fs_info, qgroupid);
1643         if (!qgroup) {
1644                 ret = -ENOENT;
1645                 goto out;
1646         }
1647
1648         /* Check if there are no children of this qgroup */
1649         if (!list_empty(&qgroup->members)) {
1650                 ret = -EBUSY;
1651                 goto out;
1652         }
1653
1654         ret = del_qgroup_item(trans, qgroupid);
1655         if (ret && ret != -ENOENT)
1656                 goto out;
1657
1658         while (!list_empty(&qgroup->groups)) {
1659                 list = list_first_entry(&qgroup->groups,
1660                                         struct btrfs_qgroup_list, next_group);
1661                 ret = __del_qgroup_relation(trans, qgroupid,
1662                                             list->group->qgroupid);
1663                 if (ret)
1664                         goto out;
1665         }
1666
1667         spin_lock(&fs_info->qgroup_lock);
1668         del_qgroup_rb(fs_info, qgroupid);
1669         spin_unlock(&fs_info->qgroup_lock);
1670
1671         /*
1672          * Remove the qgroup from sysfs now without holding the qgroup_lock
1673          * spinlock, since the sysfs_remove_group() function needs to take
1674          * the mutex kernfs_mutex through kernfs_remove_by_name_ns().
1675          */
1676         btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1677         kfree(qgroup);
1678 out:
1679         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1680         return ret;
1681 }
1682
1683 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1684                        struct btrfs_qgroup_limit *limit)
1685 {
1686         struct btrfs_fs_info *fs_info = trans->fs_info;
1687         struct btrfs_qgroup *qgroup;
1688         int ret = 0;
1689         /* Sometimes we would want to clear the limit on this qgroup.
1690          * To meet this requirement, we treat the -1 as a special value
1691          * which tell kernel to clear the limit on this qgroup.
1692          */
1693         const u64 CLEAR_VALUE = -1;
1694
1695         mutex_lock(&fs_info->qgroup_ioctl_lock);
1696         if (!fs_info->quota_root) {
1697                 ret = -ENOTCONN;
1698                 goto out;
1699         }
1700
1701         qgroup = find_qgroup_rb(fs_info, qgroupid);
1702         if (!qgroup) {
1703                 ret = -ENOENT;
1704                 goto out;
1705         }
1706
1707         spin_lock(&fs_info->qgroup_lock);
1708         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1709                 if (limit->max_rfer == CLEAR_VALUE) {
1710                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1711                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1712                         qgroup->max_rfer = 0;
1713                 } else {
1714                         qgroup->max_rfer = limit->max_rfer;
1715                 }
1716         }
1717         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1718                 if (limit->max_excl == CLEAR_VALUE) {
1719                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1720                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1721                         qgroup->max_excl = 0;
1722                 } else {
1723                         qgroup->max_excl = limit->max_excl;
1724                 }
1725         }
1726         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1727                 if (limit->rsv_rfer == CLEAR_VALUE) {
1728                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1729                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1730                         qgroup->rsv_rfer = 0;
1731                 } else {
1732                         qgroup->rsv_rfer = limit->rsv_rfer;
1733                 }
1734         }
1735         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1736                 if (limit->rsv_excl == CLEAR_VALUE) {
1737                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1738                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1739                         qgroup->rsv_excl = 0;
1740                 } else {
1741                         qgroup->rsv_excl = limit->rsv_excl;
1742                 }
1743         }
1744         qgroup->lim_flags |= limit->flags;
1745
1746         spin_unlock(&fs_info->qgroup_lock);
1747
1748         ret = update_qgroup_limit_item(trans, qgroup);
1749         if (ret) {
1750                 qgroup_mark_inconsistent(fs_info);
1751                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1752                        qgroupid);
1753         }
1754
1755 out:
1756         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1757         return ret;
1758 }
1759
1760 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1761                                 struct btrfs_delayed_ref_root *delayed_refs,
1762                                 struct btrfs_qgroup_extent_record *record)
1763 {
1764         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1765         struct rb_node *parent_node = NULL;
1766         struct btrfs_qgroup_extent_record *entry;
1767         u64 bytenr = record->bytenr;
1768
1769         lockdep_assert_held(&delayed_refs->lock);
1770         trace_btrfs_qgroup_trace_extent(fs_info, record);
1771
1772         while (*p) {
1773                 parent_node = *p;
1774                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1775                                  node);
1776                 if (bytenr < entry->bytenr) {
1777                         p = &(*p)->rb_left;
1778                 } else if (bytenr > entry->bytenr) {
1779                         p = &(*p)->rb_right;
1780                 } else {
1781                         if (record->data_rsv && !entry->data_rsv) {
1782                                 entry->data_rsv = record->data_rsv;
1783                                 entry->data_rsv_refroot =
1784                                         record->data_rsv_refroot;
1785                         }
1786                         return 1;
1787                 }
1788         }
1789
1790         rb_link_node(&record->node, parent_node, p);
1791         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1792         return 0;
1793 }
1794
1795 int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
1796                                    struct btrfs_qgroup_extent_record *qrecord)
1797 {
1798         struct btrfs_backref_walk_ctx ctx = { 0 };
1799         int ret;
1800
1801         /*
1802          * We are always called in a context where we are already holding a
1803          * transaction handle. Often we are called when adding a data delayed
1804          * reference from btrfs_truncate_inode_items() (truncating or unlinking),
1805          * in which case we will be holding a write lock on extent buffer from a
1806          * subvolume tree. In this case we can't allow btrfs_find_all_roots() to
1807          * acquire fs_info->commit_root_sem, because that is a higher level lock
1808          * that must be acquired before locking any extent buffers.
1809          *
1810          * So we want btrfs_find_all_roots() to not acquire the commit_root_sem
1811          * but we can't pass it a non-NULL transaction handle, because otherwise
1812          * it would not use commit roots and would lock extent buffers, causing
1813          * a deadlock if it ends up trying to read lock the same extent buffer
1814          * that was previously write locked at btrfs_truncate_inode_items().
1815          *
1816          * So pass a NULL transaction handle to btrfs_find_all_roots() and
1817          * explicitly tell it to not acquire the commit_root_sem - if we are
1818          * holding a transaction handle we don't need its protection.
1819          */
1820         ASSERT(trans != NULL);
1821
1822         if (trans->fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)
1823                 return 0;
1824
1825         ctx.bytenr = qrecord->bytenr;
1826         ctx.fs_info = trans->fs_info;
1827
1828         ret = btrfs_find_all_roots(&ctx, true);
1829         if (ret < 0) {
1830                 qgroup_mark_inconsistent(trans->fs_info);
1831                 btrfs_warn(trans->fs_info,
1832 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1833                         ret);
1834                 return 0;
1835         }
1836
1837         /*
1838          * Here we don't need to get the lock of
1839          * trans->transaction->delayed_refs, since inserted qrecord won't
1840          * be deleted, only qrecord->node may be modified (new qrecord insert)
1841          *
1842          * So modifying qrecord->old_roots is safe here
1843          */
1844         qrecord->old_roots = ctx.roots;
1845         return 0;
1846 }
1847
1848 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1849                               u64 num_bytes)
1850 {
1851         struct btrfs_fs_info *fs_info = trans->fs_info;
1852         struct btrfs_qgroup_extent_record *record;
1853         struct btrfs_delayed_ref_root *delayed_refs;
1854         int ret;
1855
1856         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1857             || bytenr == 0 || num_bytes == 0)
1858                 return 0;
1859         record = kzalloc(sizeof(*record), GFP_NOFS);
1860         if (!record)
1861                 return -ENOMEM;
1862
1863         delayed_refs = &trans->transaction->delayed_refs;
1864         record->bytenr = bytenr;
1865         record->num_bytes = num_bytes;
1866         record->old_roots = NULL;
1867
1868         spin_lock(&delayed_refs->lock);
1869         ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1870         spin_unlock(&delayed_refs->lock);
1871         if (ret > 0) {
1872                 kfree(record);
1873                 return 0;
1874         }
1875         return btrfs_qgroup_trace_extent_post(trans, record);
1876 }
1877
1878 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1879                                   struct extent_buffer *eb)
1880 {
1881         struct btrfs_fs_info *fs_info = trans->fs_info;
1882         int nr = btrfs_header_nritems(eb);
1883         int i, extent_type, ret;
1884         struct btrfs_key key;
1885         struct btrfs_file_extent_item *fi;
1886         u64 bytenr, num_bytes;
1887
1888         /* We can be called directly from walk_up_proc() */
1889         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1890                 return 0;
1891
1892         for (i = 0; i < nr; i++) {
1893                 btrfs_item_key_to_cpu(eb, &key, i);
1894
1895                 if (key.type != BTRFS_EXTENT_DATA_KEY)
1896                         continue;
1897
1898                 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1899                 /* filter out non qgroup-accountable extents  */
1900                 extent_type = btrfs_file_extent_type(eb, fi);
1901
1902                 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1903                         continue;
1904
1905                 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1906                 if (!bytenr)
1907                         continue;
1908
1909                 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1910
1911                 ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes);
1912                 if (ret)
1913                         return ret;
1914         }
1915         cond_resched();
1916         return 0;
1917 }
1918
1919 /*
1920  * Walk up the tree from the bottom, freeing leaves and any interior
1921  * nodes which have had all slots visited. If a node (leaf or
1922  * interior) is freed, the node above it will have it's slot
1923  * incremented. The root node will never be freed.
1924  *
1925  * At the end of this function, we should have a path which has all
1926  * slots incremented to the next position for a search. If we need to
1927  * read a new node it will be NULL and the node above it will have the
1928  * correct slot selected for a later read.
1929  *
1930  * If we increment the root nodes slot counter past the number of
1931  * elements, 1 is returned to signal completion of the search.
1932  */
1933 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1934 {
1935         int level = 0;
1936         int nr, slot;
1937         struct extent_buffer *eb;
1938
1939         if (root_level == 0)
1940                 return 1;
1941
1942         while (level <= root_level) {
1943                 eb = path->nodes[level];
1944                 nr = btrfs_header_nritems(eb);
1945                 path->slots[level]++;
1946                 slot = path->slots[level];
1947                 if (slot >= nr || level == 0) {
1948                         /*
1949                          * Don't free the root -  we will detect this
1950                          * condition after our loop and return a
1951                          * positive value for caller to stop walking the tree.
1952                          */
1953                         if (level != root_level) {
1954                                 btrfs_tree_unlock_rw(eb, path->locks[level]);
1955                                 path->locks[level] = 0;
1956
1957                                 free_extent_buffer(eb);
1958                                 path->nodes[level] = NULL;
1959                                 path->slots[level] = 0;
1960                         }
1961                 } else {
1962                         /*
1963                          * We have a valid slot to walk back down
1964                          * from. Stop here so caller can process these
1965                          * new nodes.
1966                          */
1967                         break;
1968                 }
1969
1970                 level++;
1971         }
1972
1973         eb = path->nodes[root_level];
1974         if (path->slots[root_level] >= btrfs_header_nritems(eb))
1975                 return 1;
1976
1977         return 0;
1978 }
1979
1980 /*
1981  * Helper function to trace a subtree tree block swap.
1982  *
1983  * The swap will happen in highest tree block, but there may be a lot of
1984  * tree blocks involved.
1985  *
1986  * For example:
1987  *  OO = Old tree blocks
1988  *  NN = New tree blocks allocated during balance
1989  *
1990  *           File tree (257)                  Reloc tree for 257
1991  * L2              OO                                NN
1992  *               /    \                            /    \
1993  * L1          OO      OO (a)                    OO      NN (a)
1994  *            / \     / \                       / \     / \
1995  * L0       OO   OO OO   OO                   OO   OO NN   NN
1996  *                  (b)  (c)                          (b)  (c)
1997  *
1998  * When calling qgroup_trace_extent_swap(), we will pass:
1999  * @src_eb = OO(a)
2000  * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
2001  * @dst_level = 0
2002  * @root_level = 1
2003  *
2004  * In that case, qgroup_trace_extent_swap() will search from OO(a) to
2005  * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
2006  *
2007  * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
2008  *
2009  * 1) Tree search from @src_eb
2010  *    It should acts as a simplified btrfs_search_slot().
2011  *    The key for search can be extracted from @dst_path->nodes[dst_level]
2012  *    (first key).
2013  *
2014  * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
2015  *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
2016  *    They should be marked during previous (@dst_level = 1) iteration.
2017  *
2018  * 3) Mark file extents in leaves dirty
2019  *    We don't have good way to pick out new file extents only.
2020  *    So we still follow the old method by scanning all file extents in
2021  *    the leave.
2022  *
2023  * This function can free us from keeping two paths, thus later we only need
2024  * to care about how to iterate all new tree blocks in reloc tree.
2025  */
2026 static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
2027                                     struct extent_buffer *src_eb,
2028                                     struct btrfs_path *dst_path,
2029                                     int dst_level, int root_level,
2030                                     bool trace_leaf)
2031 {
2032         struct btrfs_key key;
2033         struct btrfs_path *src_path;
2034         struct btrfs_fs_info *fs_info = trans->fs_info;
2035         u32 nodesize = fs_info->nodesize;
2036         int cur_level = root_level;
2037         int ret;
2038
2039         BUG_ON(dst_level > root_level);
2040         /* Level mismatch */
2041         if (btrfs_header_level(src_eb) != root_level)
2042                 return -EINVAL;
2043
2044         src_path = btrfs_alloc_path();
2045         if (!src_path) {
2046                 ret = -ENOMEM;
2047                 goto out;
2048         }
2049
2050         if (dst_level)
2051                 btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2052         else
2053                 btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2054
2055         /* For src_path */
2056         atomic_inc(&src_eb->refs);
2057         src_path->nodes[root_level] = src_eb;
2058         src_path->slots[root_level] = dst_path->slots[root_level];
2059         src_path->locks[root_level] = 0;
2060
2061         /* A simplified version of btrfs_search_slot() */
2062         while (cur_level >= dst_level) {
2063                 struct btrfs_key src_key;
2064                 struct btrfs_key dst_key;
2065
2066                 if (src_path->nodes[cur_level] == NULL) {
2067                         struct extent_buffer *eb;
2068                         int parent_slot;
2069
2070                         eb = src_path->nodes[cur_level + 1];
2071                         parent_slot = src_path->slots[cur_level + 1];
2072
2073                         eb = btrfs_read_node_slot(eb, parent_slot);
2074                         if (IS_ERR(eb)) {
2075                                 ret = PTR_ERR(eb);
2076                                 goto out;
2077                         }
2078
2079                         src_path->nodes[cur_level] = eb;
2080
2081                         btrfs_tree_read_lock(eb);
2082                         src_path->locks[cur_level] = BTRFS_READ_LOCK;
2083                 }
2084
2085                 src_path->slots[cur_level] = dst_path->slots[cur_level];
2086                 if (cur_level) {
2087                         btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
2088                                         &dst_key, dst_path->slots[cur_level]);
2089                         btrfs_node_key_to_cpu(src_path->nodes[cur_level],
2090                                         &src_key, src_path->slots[cur_level]);
2091                 } else {
2092                         btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
2093                                         &dst_key, dst_path->slots[cur_level]);
2094                         btrfs_item_key_to_cpu(src_path->nodes[cur_level],
2095                                         &src_key, src_path->slots[cur_level]);
2096                 }
2097                 /* Content mismatch, something went wrong */
2098                 if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
2099                         ret = -ENOENT;
2100                         goto out;
2101                 }
2102                 cur_level--;
2103         }
2104
2105         /*
2106          * Now both @dst_path and @src_path have been populated, record the tree
2107          * blocks for qgroup accounting.
2108          */
2109         ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
2110                                         nodesize);
2111         if (ret < 0)
2112                 goto out;
2113         ret = btrfs_qgroup_trace_extent(trans, dst_path->nodes[dst_level]->start,
2114                                         nodesize);
2115         if (ret < 0)
2116                 goto out;
2117
2118         /* Record leaf file extents */
2119         if (dst_level == 0 && trace_leaf) {
2120                 ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
2121                 if (ret < 0)
2122                         goto out;
2123                 ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
2124         }
2125 out:
2126         btrfs_free_path(src_path);
2127         return ret;
2128 }
2129
2130 /*
2131  * Helper function to do recursive generation-aware depth-first search, to
2132  * locate all new tree blocks in a subtree of reloc tree.
2133  *
2134  * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
2135  *         reloc tree
2136  * L2         NN (a)
2137  *          /    \
2138  * L1    OO        NN (b)
2139  *      /  \      /  \
2140  * L0  OO  OO    OO  NN
2141  *               (c) (d)
2142  * If we pass:
2143  * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
2144  * @cur_level = 1
2145  * @root_level = 1
2146  *
2147  * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
2148  * above tree blocks along with their counter parts in file tree.
2149  * While during search, old tree blocks OO(c) will be skipped as tree block swap
2150  * won't affect OO(c).
2151  */
2152 static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
2153                                            struct extent_buffer *src_eb,
2154                                            struct btrfs_path *dst_path,
2155                                            int cur_level, int root_level,
2156                                            u64 last_snapshot, bool trace_leaf)
2157 {
2158         struct btrfs_fs_info *fs_info = trans->fs_info;
2159         struct extent_buffer *eb;
2160         bool need_cleanup = false;
2161         int ret = 0;
2162         int i;
2163
2164         /* Level sanity check */
2165         if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
2166             root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
2167             root_level < cur_level) {
2168                 btrfs_err_rl(fs_info,
2169                         "%s: bad levels, cur_level=%d root_level=%d",
2170                         __func__, cur_level, root_level);
2171                 return -EUCLEAN;
2172         }
2173
2174         /* Read the tree block if needed */
2175         if (dst_path->nodes[cur_level] == NULL) {
2176                 int parent_slot;
2177                 u64 child_gen;
2178
2179                 /*
2180                  * dst_path->nodes[root_level] must be initialized before
2181                  * calling this function.
2182                  */
2183                 if (cur_level == root_level) {
2184                         btrfs_err_rl(fs_info,
2185         "%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
2186                                 __func__, root_level, root_level, cur_level);
2187                         return -EUCLEAN;
2188                 }
2189
2190                 /*
2191                  * We need to get child blockptr/gen from parent before we can
2192                  * read it.
2193                   */
2194                 eb = dst_path->nodes[cur_level + 1];
2195                 parent_slot = dst_path->slots[cur_level + 1];
2196                 child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2197
2198                 /* This node is old, no need to trace */
2199                 if (child_gen < last_snapshot)
2200                         goto out;
2201
2202                 eb = btrfs_read_node_slot(eb, parent_slot);
2203                 if (IS_ERR(eb)) {
2204                         ret = PTR_ERR(eb);
2205                         goto out;
2206                 }
2207
2208                 dst_path->nodes[cur_level] = eb;
2209                 dst_path->slots[cur_level] = 0;
2210
2211                 btrfs_tree_read_lock(eb);
2212                 dst_path->locks[cur_level] = BTRFS_READ_LOCK;
2213                 need_cleanup = true;
2214         }
2215
2216         /* Now record this tree block and its counter part for qgroups */
2217         ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
2218                                        root_level, trace_leaf);
2219         if (ret < 0)
2220                 goto cleanup;
2221
2222         eb = dst_path->nodes[cur_level];
2223
2224         if (cur_level > 0) {
2225                 /* Iterate all child tree blocks */
2226                 for (i = 0; i < btrfs_header_nritems(eb); i++) {
2227                         /* Skip old tree blocks as they won't be swapped */
2228                         if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
2229                                 continue;
2230                         dst_path->slots[cur_level] = i;
2231
2232                         /* Recursive call (at most 7 times) */
2233                         ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
2234                                         dst_path, cur_level - 1, root_level,
2235                                         last_snapshot, trace_leaf);
2236                         if (ret < 0)
2237                                 goto cleanup;
2238                 }
2239         }
2240
2241 cleanup:
2242         if (need_cleanup) {
2243                 /* Clean up */
2244                 btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2245                                      dst_path->locks[cur_level]);
2246                 free_extent_buffer(dst_path->nodes[cur_level]);
2247                 dst_path->nodes[cur_level] = NULL;
2248                 dst_path->slots[cur_level] = 0;
2249                 dst_path->locks[cur_level] = 0;
2250         }
2251 out:
2252         return ret;
2253 }
2254
2255 static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2256                                 struct extent_buffer *src_eb,
2257                                 struct extent_buffer *dst_eb,
2258                                 u64 last_snapshot, bool trace_leaf)
2259 {
2260         struct btrfs_fs_info *fs_info = trans->fs_info;
2261         struct btrfs_path *dst_path = NULL;
2262         int level;
2263         int ret;
2264
2265         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2266                 return 0;
2267
2268         /* Wrong parameter order */
2269         if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
2270                 btrfs_err_rl(fs_info,
2271                 "%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2272                              btrfs_header_generation(src_eb),
2273                              btrfs_header_generation(dst_eb));
2274                 return -EUCLEAN;
2275         }
2276
2277         if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2278                 ret = -EIO;
2279                 goto out;
2280         }
2281
2282         level = btrfs_header_level(dst_eb);
2283         dst_path = btrfs_alloc_path();
2284         if (!dst_path) {
2285                 ret = -ENOMEM;
2286                 goto out;
2287         }
2288         /* For dst_path */
2289         atomic_inc(&dst_eb->refs);
2290         dst_path->nodes[level] = dst_eb;
2291         dst_path->slots[level] = 0;
2292         dst_path->locks[level] = 0;
2293
2294         /* Do the generation aware breadth-first search */
2295         ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2296                                               level, last_snapshot, trace_leaf);
2297         if (ret < 0)
2298                 goto out;
2299         ret = 0;
2300
2301 out:
2302         btrfs_free_path(dst_path);
2303         if (ret < 0)
2304                 qgroup_mark_inconsistent(fs_info);
2305         return ret;
2306 }
2307
2308 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2309                                struct extent_buffer *root_eb,
2310                                u64 root_gen, int root_level)
2311 {
2312         struct btrfs_fs_info *fs_info = trans->fs_info;
2313         int ret = 0;
2314         int level;
2315         u8 drop_subptree_thres;
2316         struct extent_buffer *eb = root_eb;
2317         struct btrfs_path *path = NULL;
2318
2319         BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2320         BUG_ON(root_eb == NULL);
2321
2322         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2323                 return 0;
2324
2325         spin_lock(&fs_info->qgroup_lock);
2326         drop_subptree_thres = fs_info->qgroup_drop_subtree_thres;
2327         spin_unlock(&fs_info->qgroup_lock);
2328
2329         /*
2330          * This function only gets called for snapshot drop, if we hit a high
2331          * node here, it means we are going to change ownership for quite a lot
2332          * of extents, which will greatly slow down btrfs_commit_transaction().
2333          *
2334          * So here if we find a high tree here, we just skip the accounting and
2335          * mark qgroup inconsistent.
2336          */
2337         if (root_level >= drop_subptree_thres) {
2338                 qgroup_mark_inconsistent(fs_info);
2339                 return 0;
2340         }
2341
2342         if (!extent_buffer_uptodate(root_eb)) {
2343                 struct btrfs_tree_parent_check check = {
2344                         .has_first_key = false,
2345                         .transid = root_gen,
2346                         .level = root_level
2347                 };
2348
2349                 ret = btrfs_read_extent_buffer(root_eb, &check);
2350                 if (ret)
2351                         goto out;
2352         }
2353
2354         if (root_level == 0) {
2355                 ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2356                 goto out;
2357         }
2358
2359         path = btrfs_alloc_path();
2360         if (!path)
2361                 return -ENOMEM;
2362
2363         /*
2364          * Walk down the tree.  Missing extent blocks are filled in as
2365          * we go. Metadata is accounted every time we read a new
2366          * extent block.
2367          *
2368          * When we reach a leaf, we account for file extent items in it,
2369          * walk back up the tree (adjusting slot pointers as we go)
2370          * and restart the search process.
2371          */
2372         atomic_inc(&root_eb->refs);     /* For path */
2373         path->nodes[root_level] = root_eb;
2374         path->slots[root_level] = 0;
2375         path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2376 walk_down:
2377         level = root_level;
2378         while (level >= 0) {
2379                 if (path->nodes[level] == NULL) {
2380                         int parent_slot;
2381                         u64 child_bytenr;
2382
2383                         /*
2384                          * We need to get child blockptr from parent before we
2385                          * can read it.
2386                           */
2387                         eb = path->nodes[level + 1];
2388                         parent_slot = path->slots[level + 1];
2389                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2390
2391                         eb = btrfs_read_node_slot(eb, parent_slot);
2392                         if (IS_ERR(eb)) {
2393                                 ret = PTR_ERR(eb);
2394                                 goto out;
2395                         }
2396
2397                         path->nodes[level] = eb;
2398                         path->slots[level] = 0;
2399
2400                         btrfs_tree_read_lock(eb);
2401                         path->locks[level] = BTRFS_READ_LOCK;
2402
2403                         ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2404                                                         fs_info->nodesize);
2405                         if (ret)
2406                                 goto out;
2407                 }
2408
2409                 if (level == 0) {
2410                         ret = btrfs_qgroup_trace_leaf_items(trans,
2411                                                             path->nodes[level]);
2412                         if (ret)
2413                                 goto out;
2414
2415                         /* Nonzero return here means we completed our search */
2416                         ret = adjust_slots_upwards(path, root_level);
2417                         if (ret)
2418                                 break;
2419
2420                         /* Restart search with new slots */
2421                         goto walk_down;
2422                 }
2423
2424                 level--;
2425         }
2426
2427         ret = 0;
2428 out:
2429         btrfs_free_path(path);
2430
2431         return ret;
2432 }
2433
2434 #define UPDATE_NEW      0
2435 #define UPDATE_OLD      1
2436 /*
2437  * Walk all of the roots that points to the bytenr and adjust their refcnts.
2438  */
2439 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2440                                 struct ulist *roots, struct ulist *tmp,
2441                                 struct ulist *qgroups, u64 seq, int update_old)
2442 {
2443         struct ulist_node *unode;
2444         struct ulist_iterator uiter;
2445         struct ulist_node *tmp_unode;
2446         struct ulist_iterator tmp_uiter;
2447         struct btrfs_qgroup *qg;
2448         int ret = 0;
2449
2450         if (!roots)
2451                 return 0;
2452         ULIST_ITER_INIT(&uiter);
2453         while ((unode = ulist_next(roots, &uiter))) {
2454                 qg = find_qgroup_rb(fs_info, unode->val);
2455                 if (!qg)
2456                         continue;
2457
2458                 ulist_reinit(tmp);
2459                 ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2460                                 GFP_ATOMIC);
2461                 if (ret < 0)
2462                         return ret;
2463                 ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2464                 if (ret < 0)
2465                         return ret;
2466                 ULIST_ITER_INIT(&tmp_uiter);
2467                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2468                         struct btrfs_qgroup_list *glist;
2469
2470                         qg = unode_aux_to_qgroup(tmp_unode);
2471                         if (update_old)
2472                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2473                         else
2474                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2475                         list_for_each_entry(glist, &qg->groups, next_group) {
2476                                 ret = ulist_add(qgroups, glist->group->qgroupid,
2477                                                 qgroup_to_aux(glist->group),
2478                                                 GFP_ATOMIC);
2479                                 if (ret < 0)
2480                                         return ret;
2481                                 ret = ulist_add(tmp, glist->group->qgroupid,
2482                                                 qgroup_to_aux(glist->group),
2483                                                 GFP_ATOMIC);
2484                                 if (ret < 0)
2485                                         return ret;
2486                         }
2487                 }
2488         }
2489         return 0;
2490 }
2491
2492 /*
2493  * Update qgroup rfer/excl counters.
2494  * Rfer update is easy, codes can explain themselves.
2495  *
2496  * Excl update is tricky, the update is split into 2 parts.
2497  * Part 1: Possible exclusive <-> sharing detect:
2498  *      |       A       |       !A      |
2499  *  -------------------------------------
2500  *  B   |       *       |       -       |
2501  *  -------------------------------------
2502  *  !B  |       +       |       **      |
2503  *  -------------------------------------
2504  *
2505  * Conditions:
2506  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
2507  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
2508  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
2509  * !B:  cur_new_roots == nr_new_roots   (possible exclusive now)
2510  *
2511  * Results:
2512  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
2513  * *: Definitely not changed.           **: Possible unchanged.
2514  *
2515  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2516  *
2517  * To make the logic clear, we first use condition A and B to split
2518  * combination into 4 results.
2519  *
2520  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2521  * only on variant maybe 0.
2522  *
2523  * Lastly, check result **, since there are 2 variants maybe 0, split them
2524  * again(2x2).
2525  * But this time we don't need to consider other things, the codes and logic
2526  * is easy to understand now.
2527  */
2528 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2529                                   struct ulist *qgroups,
2530                                   u64 nr_old_roots,
2531                                   u64 nr_new_roots,
2532                                   u64 num_bytes, u64 seq)
2533 {
2534         struct ulist_node *unode;
2535         struct ulist_iterator uiter;
2536         struct btrfs_qgroup *qg;
2537         u64 cur_new_count, cur_old_count;
2538
2539         ULIST_ITER_INIT(&uiter);
2540         while ((unode = ulist_next(qgroups, &uiter))) {
2541                 bool dirty = false;
2542
2543                 qg = unode_aux_to_qgroup(unode);
2544                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2545                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2546
2547                 trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2548                                              cur_new_count);
2549
2550                 /* Rfer update part */
2551                 if (cur_old_count == 0 && cur_new_count > 0) {
2552                         qg->rfer += num_bytes;
2553                         qg->rfer_cmpr += num_bytes;
2554                         dirty = true;
2555                 }
2556                 if (cur_old_count > 0 && cur_new_count == 0) {
2557                         qg->rfer -= num_bytes;
2558                         qg->rfer_cmpr -= num_bytes;
2559                         dirty = true;
2560                 }
2561
2562                 /* Excl update part */
2563                 /* Exclusive/none -> shared case */
2564                 if (cur_old_count == nr_old_roots &&
2565                     cur_new_count < nr_new_roots) {
2566                         /* Exclusive -> shared */
2567                         if (cur_old_count != 0) {
2568                                 qg->excl -= num_bytes;
2569                                 qg->excl_cmpr -= num_bytes;
2570                                 dirty = true;
2571                         }
2572                 }
2573
2574                 /* Shared -> exclusive/none case */
2575                 if (cur_old_count < nr_old_roots &&
2576                     cur_new_count == nr_new_roots) {
2577                         /* Shared->exclusive */
2578                         if (cur_new_count != 0) {
2579                                 qg->excl += num_bytes;
2580                                 qg->excl_cmpr += num_bytes;
2581                                 dirty = true;
2582                         }
2583                 }
2584
2585                 /* Exclusive/none -> exclusive/none case */
2586                 if (cur_old_count == nr_old_roots &&
2587                     cur_new_count == nr_new_roots) {
2588                         if (cur_old_count == 0) {
2589                                 /* None -> exclusive/none */
2590
2591                                 if (cur_new_count != 0) {
2592                                         /* None -> exclusive */
2593                                         qg->excl += num_bytes;
2594                                         qg->excl_cmpr += num_bytes;
2595                                         dirty = true;
2596                                 }
2597                                 /* None -> none, nothing changed */
2598                         } else {
2599                                 /* Exclusive -> exclusive/none */
2600
2601                                 if (cur_new_count == 0) {
2602                                         /* Exclusive -> none */
2603                                         qg->excl -= num_bytes;
2604                                         qg->excl_cmpr -= num_bytes;
2605                                         dirty = true;
2606                                 }
2607                                 /* Exclusive -> exclusive, nothing changed */
2608                         }
2609                 }
2610
2611                 if (dirty)
2612                         qgroup_dirty(fs_info, qg);
2613         }
2614         return 0;
2615 }
2616
2617 /*
2618  * Check if the @roots potentially is a list of fs tree roots
2619  *
2620  * Return 0 for definitely not a fs/subvol tree roots ulist
2621  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2622  *          one as well)
2623  */
2624 static int maybe_fs_roots(struct ulist *roots)
2625 {
2626         struct ulist_node *unode;
2627         struct ulist_iterator uiter;
2628
2629         /* Empty one, still possible for fs roots */
2630         if (!roots || roots->nnodes == 0)
2631                 return 1;
2632
2633         ULIST_ITER_INIT(&uiter);
2634         unode = ulist_next(roots, &uiter);
2635         if (!unode)
2636                 return 1;
2637
2638         /*
2639          * If it contains fs tree roots, then it must belong to fs/subvol
2640          * trees.
2641          * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2642          */
2643         return is_fstree(unode->val);
2644 }
2645
2646 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2647                                 u64 num_bytes, struct ulist *old_roots,
2648                                 struct ulist *new_roots)
2649 {
2650         struct btrfs_fs_info *fs_info = trans->fs_info;
2651         struct ulist *qgroups = NULL;
2652         struct ulist *tmp = NULL;
2653         u64 seq;
2654         u64 nr_new_roots = 0;
2655         u64 nr_old_roots = 0;
2656         int ret = 0;
2657
2658         /*
2659          * If quotas get disabled meanwhile, the resources need to be freed and
2660          * we can't just exit here.
2661          */
2662         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
2663             fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)
2664                 goto out_free;
2665
2666         if (new_roots) {
2667                 if (!maybe_fs_roots(new_roots))
2668                         goto out_free;
2669                 nr_new_roots = new_roots->nnodes;
2670         }
2671         if (old_roots) {
2672                 if (!maybe_fs_roots(old_roots))
2673                         goto out_free;
2674                 nr_old_roots = old_roots->nnodes;
2675         }
2676
2677         /* Quick exit, either not fs tree roots, or won't affect any qgroup */
2678         if (nr_old_roots == 0 && nr_new_roots == 0)
2679                 goto out_free;
2680
2681         BUG_ON(!fs_info->quota_root);
2682
2683         trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2684                                         num_bytes, nr_old_roots, nr_new_roots);
2685
2686         qgroups = ulist_alloc(GFP_NOFS);
2687         if (!qgroups) {
2688                 ret = -ENOMEM;
2689                 goto out_free;
2690         }
2691         tmp = ulist_alloc(GFP_NOFS);
2692         if (!tmp) {
2693                 ret = -ENOMEM;
2694                 goto out_free;
2695         }
2696
2697         mutex_lock(&fs_info->qgroup_rescan_lock);
2698         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2699                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2700                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2701                         ret = 0;
2702                         goto out_free;
2703                 }
2704         }
2705         mutex_unlock(&fs_info->qgroup_rescan_lock);
2706
2707         spin_lock(&fs_info->qgroup_lock);
2708         seq = fs_info->qgroup_seq;
2709
2710         /* Update old refcnts using old_roots */
2711         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2712                                    UPDATE_OLD);
2713         if (ret < 0)
2714                 goto out;
2715
2716         /* Update new refcnts using new_roots */
2717         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2718                                    UPDATE_NEW);
2719         if (ret < 0)
2720                 goto out;
2721
2722         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2723                                num_bytes, seq);
2724
2725         /*
2726          * Bump qgroup_seq to avoid seq overlap
2727          */
2728         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2729 out:
2730         spin_unlock(&fs_info->qgroup_lock);
2731 out_free:
2732         ulist_free(tmp);
2733         ulist_free(qgroups);
2734         ulist_free(old_roots);
2735         ulist_free(new_roots);
2736         return ret;
2737 }
2738
2739 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2740 {
2741         struct btrfs_fs_info *fs_info = trans->fs_info;
2742         struct btrfs_qgroup_extent_record *record;
2743         struct btrfs_delayed_ref_root *delayed_refs;
2744         struct ulist *new_roots = NULL;
2745         struct rb_node *node;
2746         u64 num_dirty_extents = 0;
2747         u64 qgroup_to_skip;
2748         int ret = 0;
2749
2750         delayed_refs = &trans->transaction->delayed_refs;
2751         qgroup_to_skip = delayed_refs->qgroup_to_skip;
2752         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2753                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
2754                                   node);
2755
2756                 num_dirty_extents++;
2757                 trace_btrfs_qgroup_account_extents(fs_info, record);
2758
2759                 if (!ret && !(fs_info->qgroup_flags &
2760                               BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)) {
2761                         struct btrfs_backref_walk_ctx ctx = { 0 };
2762
2763                         ctx.bytenr = record->bytenr;
2764                         ctx.fs_info = fs_info;
2765
2766                         /*
2767                          * Old roots should be searched when inserting qgroup
2768                          * extent record.
2769                          *
2770                          * But for INCONSISTENT (NO_ACCOUNTING) -> rescan case,
2771                          * we may have some record inserted during
2772                          * NO_ACCOUNTING (thus no old_roots populated), but
2773                          * later we start rescan, which clears NO_ACCOUNTING,
2774                          * leaving some inserted records without old_roots
2775                          * populated.
2776                          *
2777                          * Those cases are rare and should not cause too much
2778                          * time spent during commit_transaction().
2779                          */
2780                         if (!record->old_roots) {
2781                                 /* Search commit root to find old_roots */
2782                                 ret = btrfs_find_all_roots(&ctx, false);
2783                                 if (ret < 0)
2784                                         goto cleanup;
2785                                 record->old_roots = ctx.roots;
2786                                 ctx.roots = NULL;
2787                         }
2788
2789                         /* Free the reserved data space */
2790                         btrfs_qgroup_free_refroot(fs_info,
2791                                         record->data_rsv_refroot,
2792                                         record->data_rsv,
2793                                         BTRFS_QGROUP_RSV_DATA);
2794                         /*
2795                          * Use BTRFS_SEQ_LAST as time_seq to do special search,
2796                          * which doesn't lock tree or delayed_refs and search
2797                          * current root. It's safe inside commit_transaction().
2798                          */
2799                         ctx.trans = trans;
2800                         ctx.time_seq = BTRFS_SEQ_LAST;
2801                         ret = btrfs_find_all_roots(&ctx, false);
2802                         if (ret < 0)
2803                                 goto cleanup;
2804                         new_roots = ctx.roots;
2805                         if (qgroup_to_skip) {
2806                                 ulist_del(new_roots, qgroup_to_skip, 0);
2807                                 ulist_del(record->old_roots, qgroup_to_skip,
2808                                           0);
2809                         }
2810                         ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2811                                                           record->num_bytes,
2812                                                           record->old_roots,
2813                                                           new_roots);
2814                         record->old_roots = NULL;
2815                         new_roots = NULL;
2816                 }
2817 cleanup:
2818                 ulist_free(record->old_roots);
2819                 ulist_free(new_roots);
2820                 new_roots = NULL;
2821                 rb_erase(node, &delayed_refs->dirty_extent_root);
2822                 kfree(record);
2823
2824         }
2825         trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2826                                        num_dirty_extents);
2827         return ret;
2828 }
2829
2830 /*
2831  * called from commit_transaction. Writes all changed qgroups to disk.
2832  */
2833 int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2834 {
2835         struct btrfs_fs_info *fs_info = trans->fs_info;
2836         int ret = 0;
2837
2838         if (!fs_info->quota_root)
2839                 return ret;
2840
2841         spin_lock(&fs_info->qgroup_lock);
2842         while (!list_empty(&fs_info->dirty_qgroups)) {
2843                 struct btrfs_qgroup *qgroup;
2844                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
2845                                           struct btrfs_qgroup, dirty);
2846                 list_del_init(&qgroup->dirty);
2847                 spin_unlock(&fs_info->qgroup_lock);
2848                 ret = update_qgroup_info_item(trans, qgroup);
2849                 if (ret)
2850                         qgroup_mark_inconsistent(fs_info);
2851                 ret = update_qgroup_limit_item(trans, qgroup);
2852                 if (ret)
2853                         qgroup_mark_inconsistent(fs_info);
2854                 spin_lock(&fs_info->qgroup_lock);
2855         }
2856         if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2857                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2858         else
2859                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2860         spin_unlock(&fs_info->qgroup_lock);
2861
2862         ret = update_qgroup_status_item(trans);
2863         if (ret)
2864                 qgroup_mark_inconsistent(fs_info);
2865
2866         return ret;
2867 }
2868
2869 /*
2870  * Copy the accounting information between qgroups. This is necessary
2871  * when a snapshot or a subvolume is created. Throwing an error will
2872  * cause a transaction abort so we take extra care here to only error
2873  * when a readonly fs is a reasonable outcome.
2874  */
2875 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2876                          u64 objectid, struct btrfs_qgroup_inherit *inherit)
2877 {
2878         int ret = 0;
2879         int i;
2880         u64 *i_qgroups;
2881         bool committing = false;
2882         struct btrfs_fs_info *fs_info = trans->fs_info;
2883         struct btrfs_root *quota_root;
2884         struct btrfs_qgroup *srcgroup;
2885         struct btrfs_qgroup *dstgroup;
2886         bool need_rescan = false;
2887         u32 level_size = 0;
2888         u64 nums;
2889
2890         /*
2891          * There are only two callers of this function.
2892          *
2893          * One in create_subvol() in the ioctl context, which needs to hold
2894          * the qgroup_ioctl_lock.
2895          *
2896          * The other one in create_pending_snapshot() where no other qgroup
2897          * code can modify the fs as they all need to either start a new trans
2898          * or hold a trans handler, thus we don't need to hold
2899          * qgroup_ioctl_lock.
2900          * This would avoid long and complex lock chain and make lockdep happy.
2901          */
2902         spin_lock(&fs_info->trans_lock);
2903         if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
2904                 committing = true;
2905         spin_unlock(&fs_info->trans_lock);
2906
2907         if (!committing)
2908                 mutex_lock(&fs_info->qgroup_ioctl_lock);
2909         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2910                 goto out;
2911
2912         quota_root = fs_info->quota_root;
2913         if (!quota_root) {
2914                 ret = -EINVAL;
2915                 goto out;
2916         }
2917
2918         if (inherit) {
2919                 i_qgroups = (u64 *)(inherit + 1);
2920                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2921                        2 * inherit->num_excl_copies;
2922                 for (i = 0; i < nums; ++i) {
2923                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2924
2925                         /*
2926                          * Zero out invalid groups so we can ignore
2927                          * them later.
2928                          */
2929                         if (!srcgroup ||
2930                             ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2931                                 *i_qgroups = 0ULL;
2932
2933                         ++i_qgroups;
2934                 }
2935         }
2936
2937         /*
2938          * create a tracking group for the subvol itself
2939          */
2940         ret = add_qgroup_item(trans, quota_root, objectid);
2941         if (ret)
2942                 goto out;
2943
2944         /*
2945          * add qgroup to all inherited groups
2946          */
2947         if (inherit) {
2948                 i_qgroups = (u64 *)(inherit + 1);
2949                 for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2950                         if (*i_qgroups == 0)
2951                                 continue;
2952                         ret = add_qgroup_relation_item(trans, objectid,
2953                                                        *i_qgroups);
2954                         if (ret && ret != -EEXIST)
2955                                 goto out;
2956                         ret = add_qgroup_relation_item(trans, *i_qgroups,
2957                                                        objectid);
2958                         if (ret && ret != -EEXIST)
2959                                 goto out;
2960                 }
2961                 ret = 0;
2962         }
2963
2964
2965         spin_lock(&fs_info->qgroup_lock);
2966
2967         dstgroup = add_qgroup_rb(fs_info, objectid);
2968         if (IS_ERR(dstgroup)) {
2969                 ret = PTR_ERR(dstgroup);
2970                 goto unlock;
2971         }
2972
2973         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2974                 dstgroup->lim_flags = inherit->lim.flags;
2975                 dstgroup->max_rfer = inherit->lim.max_rfer;
2976                 dstgroup->max_excl = inherit->lim.max_excl;
2977                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2978                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
2979
2980                 qgroup_dirty(fs_info, dstgroup);
2981         }
2982
2983         if (srcid) {
2984                 srcgroup = find_qgroup_rb(fs_info, srcid);
2985                 if (!srcgroup)
2986                         goto unlock;
2987
2988                 /*
2989                  * We call inherit after we clone the root in order to make sure
2990                  * our counts don't go crazy, so at this point the only
2991                  * difference between the two roots should be the root node.
2992                  */
2993                 level_size = fs_info->nodesize;
2994                 dstgroup->rfer = srcgroup->rfer;
2995                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2996                 dstgroup->excl = level_size;
2997                 dstgroup->excl_cmpr = level_size;
2998                 srcgroup->excl = level_size;
2999                 srcgroup->excl_cmpr = level_size;
3000
3001                 /* inherit the limit info */
3002                 dstgroup->lim_flags = srcgroup->lim_flags;
3003                 dstgroup->max_rfer = srcgroup->max_rfer;
3004                 dstgroup->max_excl = srcgroup->max_excl;
3005                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
3006                 dstgroup->rsv_excl = srcgroup->rsv_excl;
3007
3008                 qgroup_dirty(fs_info, dstgroup);
3009                 qgroup_dirty(fs_info, srcgroup);
3010         }
3011
3012         if (!inherit)
3013                 goto unlock;
3014
3015         i_qgroups = (u64 *)(inherit + 1);
3016         for (i = 0; i < inherit->num_qgroups; ++i) {
3017                 if (*i_qgroups) {
3018                         ret = add_relation_rb(fs_info, objectid, *i_qgroups);
3019                         if (ret)
3020                                 goto unlock;
3021                 }
3022                 ++i_qgroups;
3023
3024                 /*
3025                  * If we're doing a snapshot, and adding the snapshot to a new
3026                  * qgroup, the numbers are guaranteed to be incorrect.
3027                  */
3028                 if (srcid)
3029                         need_rescan = true;
3030         }
3031
3032         for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
3033                 struct btrfs_qgroup *src;
3034                 struct btrfs_qgroup *dst;
3035
3036                 if (!i_qgroups[0] || !i_qgroups[1])
3037                         continue;
3038
3039                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
3040                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3041
3042                 if (!src || !dst) {
3043                         ret = -EINVAL;
3044                         goto unlock;
3045                 }
3046
3047                 dst->rfer = src->rfer - level_size;
3048                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
3049
3050                 /* Manually tweaking numbers certainly needs a rescan */
3051                 need_rescan = true;
3052         }
3053         for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
3054                 struct btrfs_qgroup *src;
3055                 struct btrfs_qgroup *dst;
3056
3057                 if (!i_qgroups[0] || !i_qgroups[1])
3058                         continue;
3059
3060                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
3061                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3062
3063                 if (!src || !dst) {
3064                         ret = -EINVAL;
3065                         goto unlock;
3066                 }
3067
3068                 dst->excl = src->excl + level_size;
3069                 dst->excl_cmpr = src->excl_cmpr + level_size;
3070                 need_rescan = true;
3071         }
3072
3073 unlock:
3074         spin_unlock(&fs_info->qgroup_lock);
3075         if (!ret)
3076                 ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup);
3077 out:
3078         if (!committing)
3079                 mutex_unlock(&fs_info->qgroup_ioctl_lock);
3080         if (need_rescan)
3081                 qgroup_mark_inconsistent(fs_info);
3082         return ret;
3083 }
3084
3085 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
3086 {
3087         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
3088             qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
3089                 return false;
3090
3091         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
3092             qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
3093                 return false;
3094
3095         return true;
3096 }
3097
3098 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
3099                           enum btrfs_qgroup_rsv_type type)
3100 {
3101         struct btrfs_qgroup *qgroup;
3102         struct btrfs_fs_info *fs_info = root->fs_info;
3103         u64 ref_root = root->root_key.objectid;
3104         int ret = 0;
3105         struct ulist_node *unode;
3106         struct ulist_iterator uiter;
3107
3108         if (!is_fstree(ref_root))
3109                 return 0;
3110
3111         if (num_bytes == 0)
3112                 return 0;
3113
3114         if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
3115             capable(CAP_SYS_RESOURCE))
3116                 enforce = false;
3117
3118         spin_lock(&fs_info->qgroup_lock);
3119         if (!fs_info->quota_root)
3120                 goto out;
3121
3122         qgroup = find_qgroup_rb(fs_info, ref_root);
3123         if (!qgroup)
3124                 goto out;
3125
3126         /*
3127          * in a first step, we check all affected qgroups if any limits would
3128          * be exceeded
3129          */
3130         ulist_reinit(fs_info->qgroup_ulist);
3131         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3132                         qgroup_to_aux(qgroup), GFP_ATOMIC);
3133         if (ret < 0)
3134                 goto out;
3135         ULIST_ITER_INIT(&uiter);
3136         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3137                 struct btrfs_qgroup *qg;
3138                 struct btrfs_qgroup_list *glist;
3139
3140                 qg = unode_aux_to_qgroup(unode);
3141
3142                 if (enforce && !qgroup_check_limits(qg, num_bytes)) {
3143                         ret = -EDQUOT;
3144                         goto out;
3145                 }
3146
3147                 list_for_each_entry(glist, &qg->groups, next_group) {
3148                         ret = ulist_add(fs_info->qgroup_ulist,
3149                                         glist->group->qgroupid,
3150                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
3151                         if (ret < 0)
3152                                 goto out;
3153                 }
3154         }
3155         ret = 0;
3156         /*
3157          * no limits exceeded, now record the reservation into all qgroups
3158          */
3159         ULIST_ITER_INIT(&uiter);
3160         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3161                 struct btrfs_qgroup *qg;
3162
3163                 qg = unode_aux_to_qgroup(unode);
3164
3165                 qgroup_rsv_add(fs_info, qg, num_bytes, type);
3166         }
3167
3168 out:
3169         spin_unlock(&fs_info->qgroup_lock);
3170         return ret;
3171 }
3172
3173 /*
3174  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
3175  * qgroup).
3176  *
3177  * Will handle all higher level qgroup too.
3178  *
3179  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
3180  * This special case is only used for META_PERTRANS type.
3181  */
3182 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
3183                                u64 ref_root, u64 num_bytes,
3184                                enum btrfs_qgroup_rsv_type type)
3185 {
3186         struct btrfs_qgroup *qgroup;
3187         struct ulist_node *unode;
3188         struct ulist_iterator uiter;
3189         int ret = 0;
3190
3191         if (!is_fstree(ref_root))
3192                 return;
3193
3194         if (num_bytes == 0)
3195                 return;
3196
3197         if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
3198                 WARN(1, "%s: Invalid type to free", __func__);
3199                 return;
3200         }
3201         spin_lock(&fs_info->qgroup_lock);
3202
3203         if (!fs_info->quota_root)
3204                 goto out;
3205
3206         qgroup = find_qgroup_rb(fs_info, ref_root);
3207         if (!qgroup)
3208                 goto out;
3209
3210         if (num_bytes == (u64)-1)
3211                 /*
3212                  * We're freeing all pertrans rsv, get reserved value from
3213                  * level 0 qgroup as real num_bytes to free.
3214                  */
3215                 num_bytes = qgroup->rsv.values[type];
3216
3217         ulist_reinit(fs_info->qgroup_ulist);
3218         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3219                         qgroup_to_aux(qgroup), GFP_ATOMIC);
3220         if (ret < 0)
3221                 goto out;
3222         ULIST_ITER_INIT(&uiter);
3223         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3224                 struct btrfs_qgroup *qg;
3225                 struct btrfs_qgroup_list *glist;
3226
3227                 qg = unode_aux_to_qgroup(unode);
3228
3229                 qgroup_rsv_release(fs_info, qg, num_bytes, type);
3230
3231                 list_for_each_entry(glist, &qg->groups, next_group) {
3232                         ret = ulist_add(fs_info->qgroup_ulist,
3233                                         glist->group->qgroupid,
3234                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
3235                         if (ret < 0)
3236                                 goto out;
3237                 }
3238         }
3239
3240 out:
3241         spin_unlock(&fs_info->qgroup_lock);
3242 }
3243
3244 /*
3245  * Check if the leaf is the last leaf. Which means all node pointers
3246  * are at their last position.
3247  */
3248 static bool is_last_leaf(struct btrfs_path *path)
3249 {
3250         int i;
3251
3252         for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3253                 if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3254                         return false;
3255         }
3256         return true;
3257 }
3258
3259 /*
3260  * returns < 0 on error, 0 when more leafs are to be scanned.
3261  * returns 1 when done.
3262  */
3263 static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3264                               struct btrfs_path *path)
3265 {
3266         struct btrfs_fs_info *fs_info = trans->fs_info;
3267         struct btrfs_root *extent_root;
3268         struct btrfs_key found;
3269         struct extent_buffer *scratch_leaf = NULL;
3270         u64 num_bytes;
3271         bool done;
3272         int slot;
3273         int ret;
3274
3275         mutex_lock(&fs_info->qgroup_rescan_lock);
3276         extent_root = btrfs_extent_root(fs_info,
3277                                 fs_info->qgroup_rescan_progress.objectid);
3278         ret = btrfs_search_slot_for_read(extent_root,
3279                                          &fs_info->qgroup_rescan_progress,
3280                                          path, 1, 0);
3281
3282         btrfs_debug(fs_info,
3283                 "current progress key (%llu %u %llu), search_slot ret %d",
3284                 fs_info->qgroup_rescan_progress.objectid,
3285                 fs_info->qgroup_rescan_progress.type,
3286                 fs_info->qgroup_rescan_progress.offset, ret);
3287
3288         if (ret) {
3289                 /*
3290                  * The rescan is about to end, we will not be scanning any
3291                  * further blocks. We cannot unset the RESCAN flag here, because
3292                  * we want to commit the transaction if everything went well.
3293                  * To make the live accounting work in this phase, we set our
3294                  * scan progress pointer such that every real extent objectid
3295                  * will be smaller.
3296                  */
3297                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3298                 btrfs_release_path(path);
3299                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3300                 return ret;
3301         }
3302         done = is_last_leaf(path);
3303
3304         btrfs_item_key_to_cpu(path->nodes[0], &found,
3305                               btrfs_header_nritems(path->nodes[0]) - 1);
3306         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3307
3308         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3309         if (!scratch_leaf) {
3310                 ret = -ENOMEM;
3311                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3312                 goto out;
3313         }
3314         slot = path->slots[0];
3315         btrfs_release_path(path);
3316         mutex_unlock(&fs_info->qgroup_rescan_lock);
3317
3318         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
3319                 struct btrfs_backref_walk_ctx ctx = { 0 };
3320
3321                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3322                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3323                     found.type != BTRFS_METADATA_ITEM_KEY)
3324                         continue;
3325                 if (found.type == BTRFS_METADATA_ITEM_KEY)
3326                         num_bytes = fs_info->nodesize;
3327                 else
3328                         num_bytes = found.offset;
3329
3330                 ctx.bytenr = found.objectid;
3331                 ctx.fs_info = fs_info;
3332
3333                 ret = btrfs_find_all_roots(&ctx, false);
3334                 if (ret < 0)
3335                         goto out;
3336                 /* For rescan, just pass old_roots as NULL */
3337                 ret = btrfs_qgroup_account_extent(trans, found.objectid,
3338                                                   num_bytes, NULL, ctx.roots);
3339                 if (ret < 0)
3340                         goto out;
3341         }
3342 out:
3343         if (scratch_leaf)
3344                 free_extent_buffer(scratch_leaf);
3345
3346         if (done && !ret) {
3347                 ret = 1;
3348                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3349         }
3350         return ret;
3351 }
3352
3353 static bool rescan_should_stop(struct btrfs_fs_info *fs_info)
3354 {
3355         return btrfs_fs_closing(fs_info) ||
3356                 test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state) ||
3357                 !test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3358                           fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN;
3359 }
3360
3361 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3362 {
3363         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3364                                                      qgroup_rescan_work);
3365         struct btrfs_path *path;
3366         struct btrfs_trans_handle *trans = NULL;
3367         int err = -ENOMEM;
3368         int ret = 0;
3369         bool stopped = false;
3370         bool did_leaf_rescans = false;
3371
3372         path = btrfs_alloc_path();
3373         if (!path)
3374                 goto out;
3375         /*
3376          * Rescan should only search for commit root, and any later difference
3377          * should be recorded by qgroup
3378          */
3379         path->search_commit_root = 1;
3380         path->skip_locking = 1;
3381
3382         err = 0;
3383         while (!err && !(stopped = rescan_should_stop(fs_info))) {
3384                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
3385                 if (IS_ERR(trans)) {
3386                         err = PTR_ERR(trans);
3387                         break;
3388                 }
3389
3390                 err = qgroup_rescan_leaf(trans, path);
3391                 did_leaf_rescans = true;
3392
3393                 if (err > 0)
3394                         btrfs_commit_transaction(trans);
3395                 else
3396                         btrfs_end_transaction(trans);
3397         }
3398
3399 out:
3400         btrfs_free_path(path);
3401
3402         mutex_lock(&fs_info->qgroup_rescan_lock);
3403         if (err > 0 &&
3404             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3405                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3406         } else if (err < 0 || stopped) {
3407                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3408         }
3409         mutex_unlock(&fs_info->qgroup_rescan_lock);
3410
3411         /*
3412          * Only update status, since the previous part has already updated the
3413          * qgroup info, and only if we did any actual work. This also prevents
3414          * race with a concurrent quota disable, which has already set
3415          * fs_info->quota_root to NULL and cleared BTRFS_FS_QUOTA_ENABLED at
3416          * btrfs_quota_disable().
3417          */
3418         if (did_leaf_rescans) {
3419                 trans = btrfs_start_transaction(fs_info->quota_root, 1);
3420                 if (IS_ERR(trans)) {
3421                         err = PTR_ERR(trans);
3422                         trans = NULL;
3423                         btrfs_err(fs_info,
3424                                   "fail to start transaction for status update: %d",
3425                                   err);
3426                 }
3427         } else {
3428                 trans = NULL;
3429         }
3430
3431         mutex_lock(&fs_info->qgroup_rescan_lock);
3432         if (!stopped ||
3433             fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN)
3434                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3435         if (trans) {
3436                 ret = update_qgroup_status_item(trans);
3437                 if (ret < 0) {
3438                         err = ret;
3439                         btrfs_err(fs_info, "fail to update qgroup status: %d",
3440                                   err);
3441                 }
3442         }
3443         fs_info->qgroup_rescan_running = false;
3444         fs_info->qgroup_flags &= ~BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN;
3445         complete_all(&fs_info->qgroup_rescan_completion);
3446         mutex_unlock(&fs_info->qgroup_rescan_lock);
3447
3448         if (!trans)
3449                 return;
3450
3451         btrfs_end_transaction(trans);
3452
3453         if (stopped) {
3454                 btrfs_info(fs_info, "qgroup scan paused");
3455         } else if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) {
3456                 btrfs_info(fs_info, "qgroup scan cancelled");
3457         } else if (err >= 0) {
3458                 btrfs_info(fs_info, "qgroup scan completed%s",
3459                         err > 0 ? " (inconsistency flag cleared)" : "");
3460         } else {
3461                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
3462         }
3463 }
3464
3465 /*
3466  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
3467  * memory required for the rescan context.
3468  */
3469 static int
3470 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
3471                    int init_flags)
3472 {
3473         int ret = 0;
3474
3475         if (!init_flags) {
3476                 /* we're resuming qgroup rescan at mount time */
3477                 if (!(fs_info->qgroup_flags &
3478                       BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
3479                         btrfs_warn(fs_info,
3480                         "qgroup rescan init failed, qgroup rescan is not queued");
3481                         ret = -EINVAL;
3482                 } else if (!(fs_info->qgroup_flags &
3483                              BTRFS_QGROUP_STATUS_FLAG_ON)) {
3484                         btrfs_warn(fs_info,
3485                         "qgroup rescan init failed, qgroup is not enabled");
3486                         ret = -EINVAL;
3487                 }
3488
3489                 if (ret)
3490                         return ret;
3491         }
3492
3493         mutex_lock(&fs_info->qgroup_rescan_lock);
3494
3495         if (init_flags) {
3496                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3497                         btrfs_warn(fs_info,
3498                                    "qgroup rescan is already in progress");
3499                         ret = -EINPROGRESS;
3500                 } else if (!(fs_info->qgroup_flags &
3501                              BTRFS_QGROUP_STATUS_FLAG_ON)) {
3502                         btrfs_warn(fs_info,
3503                         "qgroup rescan init failed, qgroup is not enabled");
3504                         ret = -EINVAL;
3505                 } else if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3506                         /* Quota disable is in progress */
3507                         ret = -EBUSY;
3508                 }
3509
3510                 if (ret) {
3511                         mutex_unlock(&fs_info->qgroup_rescan_lock);
3512                         return ret;
3513                 }
3514                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3515         }
3516
3517         memset(&fs_info->qgroup_rescan_progress, 0,
3518                 sizeof(fs_info->qgroup_rescan_progress));
3519         fs_info->qgroup_flags &= ~(BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN |
3520                                    BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING);
3521         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
3522         init_completion(&fs_info->qgroup_rescan_completion);
3523         mutex_unlock(&fs_info->qgroup_rescan_lock);
3524
3525         btrfs_init_work(&fs_info->qgroup_rescan_work,
3526                         btrfs_qgroup_rescan_worker, NULL, NULL);
3527         return 0;
3528 }
3529
3530 static void
3531 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
3532 {
3533         struct rb_node *n;
3534         struct btrfs_qgroup *qgroup;
3535
3536         spin_lock(&fs_info->qgroup_lock);
3537         /* clear all current qgroup tracking information */
3538         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
3539                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
3540                 qgroup->rfer = 0;
3541                 qgroup->rfer_cmpr = 0;
3542                 qgroup->excl = 0;
3543                 qgroup->excl_cmpr = 0;
3544                 qgroup_dirty(fs_info, qgroup);
3545         }
3546         spin_unlock(&fs_info->qgroup_lock);
3547 }
3548
3549 int
3550 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
3551 {
3552         int ret = 0;
3553         struct btrfs_trans_handle *trans;
3554
3555         ret = qgroup_rescan_init(fs_info, 0, 1);
3556         if (ret)
3557                 return ret;
3558
3559         /*
3560          * We have set the rescan_progress to 0, which means no more
3561          * delayed refs will be accounted by btrfs_qgroup_account_ref.
3562          * However, btrfs_qgroup_account_ref may be right after its call
3563          * to btrfs_find_all_roots, in which case it would still do the
3564          * accounting.
3565          * To solve this, we're committing the transaction, which will
3566          * ensure we run all delayed refs and only after that, we are
3567          * going to clear all tracking information for a clean start.
3568          */
3569
3570         trans = btrfs_join_transaction(fs_info->fs_root);
3571         if (IS_ERR(trans)) {
3572                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3573                 return PTR_ERR(trans);
3574         }
3575         ret = btrfs_commit_transaction(trans);
3576         if (ret) {
3577                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3578                 return ret;
3579         }
3580
3581         qgroup_rescan_zero_tracking(fs_info);
3582
3583         mutex_lock(&fs_info->qgroup_rescan_lock);
3584         fs_info->qgroup_rescan_running = true;
3585         btrfs_queue_work(fs_info->qgroup_rescan_workers,
3586                          &fs_info->qgroup_rescan_work);
3587         mutex_unlock(&fs_info->qgroup_rescan_lock);
3588
3589         return 0;
3590 }
3591
3592 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
3593                                      bool interruptible)
3594 {
3595         int running;
3596         int ret = 0;
3597
3598         mutex_lock(&fs_info->qgroup_rescan_lock);
3599         running = fs_info->qgroup_rescan_running;
3600         mutex_unlock(&fs_info->qgroup_rescan_lock);
3601
3602         if (!running)
3603                 return 0;
3604
3605         if (interruptible)
3606                 ret = wait_for_completion_interruptible(
3607                                         &fs_info->qgroup_rescan_completion);
3608         else
3609                 wait_for_completion(&fs_info->qgroup_rescan_completion);
3610
3611         return ret;
3612 }
3613
3614 /*
3615  * this is only called from open_ctree where we're still single threaded, thus
3616  * locking is omitted here.
3617  */
3618 void
3619 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
3620 {
3621         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3622                 mutex_lock(&fs_info->qgroup_rescan_lock);
3623                 fs_info->qgroup_rescan_running = true;
3624                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
3625                                  &fs_info->qgroup_rescan_work);
3626                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3627         }
3628 }
3629
3630 #define rbtree_iterate_from_safe(node, next, start)                             \
3631        for (node = start; node && ({ next = rb_next(node); 1;}); node = next)
3632
3633 static int qgroup_unreserve_range(struct btrfs_inode *inode,
3634                                   struct extent_changeset *reserved, u64 start,
3635                                   u64 len)
3636 {
3637         struct rb_node *node;
3638         struct rb_node *next;
3639         struct ulist_node *entry;
3640         int ret = 0;
3641
3642         node = reserved->range_changed.root.rb_node;
3643         if (!node)
3644                 return 0;
3645         while (node) {
3646                 entry = rb_entry(node, struct ulist_node, rb_node);
3647                 if (entry->val < start)
3648                         node = node->rb_right;
3649                 else
3650                         node = node->rb_left;
3651         }
3652
3653         if (entry->val > start && rb_prev(&entry->rb_node))
3654                 entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node,
3655                                  rb_node);
3656
3657         rbtree_iterate_from_safe(node, next, &entry->rb_node) {
3658                 u64 entry_start;
3659                 u64 entry_end;
3660                 u64 entry_len;
3661                 int clear_ret;
3662
3663                 entry = rb_entry(node, struct ulist_node, rb_node);
3664                 entry_start = entry->val;
3665                 entry_end = entry->aux;
3666                 entry_len = entry_end - entry_start + 1;
3667
3668                 if (entry_start >= start + len)
3669                         break;
3670                 if (entry_start + entry_len <= start)
3671                         continue;
3672                 /*
3673                  * Now the entry is in [start, start + len), revert the
3674                  * EXTENT_QGROUP_RESERVED bit.
3675                  */
3676                 clear_ret = clear_extent_bits(&inode->io_tree, entry_start,
3677                                               entry_end, EXTENT_QGROUP_RESERVED);
3678                 if (!ret && clear_ret < 0)
3679                         ret = clear_ret;
3680
3681                 ulist_del(&reserved->range_changed, entry->val, entry->aux);
3682                 if (likely(reserved->bytes_changed >= entry_len)) {
3683                         reserved->bytes_changed -= entry_len;
3684                 } else {
3685                         WARN_ON(1);
3686                         reserved->bytes_changed = 0;
3687                 }
3688         }
3689
3690         return ret;
3691 }
3692
3693 /*
3694  * Try to free some space for qgroup.
3695  *
3696  * For qgroup, there are only 3 ways to free qgroup space:
3697  * - Flush nodatacow write
3698  *   Any nodatacow write will free its reserved data space at run_delalloc_range().
3699  *   In theory, we should only flush nodatacow inodes, but it's not yet
3700  *   possible, so we need to flush the whole root.
3701  *
3702  * - Wait for ordered extents
3703  *   When ordered extents are finished, their reserved metadata is finally
3704  *   converted to per_trans status, which can be freed by later commit
3705  *   transaction.
3706  *
3707  * - Commit transaction
3708  *   This would free the meta_per_trans space.
3709  *   In theory this shouldn't provide much space, but any more qgroup space
3710  *   is needed.
3711  */
3712 static int try_flush_qgroup(struct btrfs_root *root)
3713 {
3714         struct btrfs_trans_handle *trans;
3715         int ret;
3716
3717         /* Can't hold an open transaction or we run the risk of deadlocking. */
3718         ASSERT(current->journal_info == NULL);
3719         if (WARN_ON(current->journal_info))
3720                 return 0;
3721
3722         /*
3723          * We don't want to run flush again and again, so if there is a running
3724          * one, we won't try to start a new flush, but exit directly.
3725          */
3726         if (test_and_set_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)) {
3727                 wait_event(root->qgroup_flush_wait,
3728                         !test_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state));
3729                 return 0;
3730         }
3731
3732         ret = btrfs_start_delalloc_snapshot(root, true);
3733         if (ret < 0)
3734                 goto out;
3735         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
3736
3737         trans = btrfs_join_transaction(root);
3738         if (IS_ERR(trans)) {
3739                 ret = PTR_ERR(trans);
3740                 goto out;
3741         }
3742
3743         ret = btrfs_commit_transaction(trans);
3744 out:
3745         clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state);
3746         wake_up(&root->qgroup_flush_wait);
3747         return ret;
3748 }
3749
3750 static int qgroup_reserve_data(struct btrfs_inode *inode,
3751                         struct extent_changeset **reserved_ret, u64 start,
3752                         u64 len)
3753 {
3754         struct btrfs_root *root = inode->root;
3755         struct extent_changeset *reserved;
3756         bool new_reserved = false;
3757         u64 orig_reserved;
3758         u64 to_reserve;
3759         int ret;
3760
3761         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
3762             !is_fstree(root->root_key.objectid) || len == 0)
3763                 return 0;
3764
3765         /* @reserved parameter is mandatory for qgroup */
3766         if (WARN_ON(!reserved_ret))
3767                 return -EINVAL;
3768         if (!*reserved_ret) {
3769                 new_reserved = true;
3770                 *reserved_ret = extent_changeset_alloc();
3771                 if (!*reserved_ret)
3772                         return -ENOMEM;
3773         }
3774         reserved = *reserved_ret;
3775         /* Record already reserved space */
3776         orig_reserved = reserved->bytes_changed;
3777         ret = set_record_extent_bits(&inode->io_tree, start,
3778                         start + len -1, EXTENT_QGROUP_RESERVED, reserved);
3779
3780         /* Newly reserved space */
3781         to_reserve = reserved->bytes_changed - orig_reserved;
3782         trace_btrfs_qgroup_reserve_data(&inode->vfs_inode, start, len,
3783                                         to_reserve, QGROUP_RESERVE);
3784         if (ret < 0)
3785                 goto out;
3786         ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
3787         if (ret < 0)
3788                 goto cleanup;
3789
3790         return ret;
3791
3792 cleanup:
3793         qgroup_unreserve_range(inode, reserved, start, len);
3794 out:
3795         if (new_reserved) {
3796                 extent_changeset_free(reserved);
3797                 *reserved_ret = NULL;
3798         }
3799         return ret;
3800 }
3801
3802 /*
3803  * Reserve qgroup space for range [start, start + len).
3804  *
3805  * This function will either reserve space from related qgroups or do nothing
3806  * if the range is already reserved.
3807  *
3808  * Return 0 for successful reservation
3809  * Return <0 for error (including -EQUOT)
3810  *
3811  * NOTE: This function may sleep for memory allocation, dirty page flushing and
3812  *       commit transaction. So caller should not hold any dirty page locked.
3813  */
3814 int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
3815                         struct extent_changeset **reserved_ret, u64 start,
3816                         u64 len)
3817 {
3818         int ret;
3819
3820         ret = qgroup_reserve_data(inode, reserved_ret, start, len);
3821         if (ret <= 0 && ret != -EDQUOT)
3822                 return ret;
3823
3824         ret = try_flush_qgroup(inode->root);
3825         if (ret < 0)
3826                 return ret;
3827         return qgroup_reserve_data(inode, reserved_ret, start, len);
3828 }
3829
3830 /* Free ranges specified by @reserved, normally in error path */
3831 static int qgroup_free_reserved_data(struct btrfs_inode *inode,
3832                         struct extent_changeset *reserved, u64 start, u64 len)
3833 {
3834         struct btrfs_root *root = inode->root;
3835         struct ulist_node *unode;
3836         struct ulist_iterator uiter;
3837         struct extent_changeset changeset;
3838         int freed = 0;
3839         int ret;
3840
3841         extent_changeset_init(&changeset);
3842         len = round_up(start + len, root->fs_info->sectorsize);
3843         start = round_down(start, root->fs_info->sectorsize);
3844
3845         ULIST_ITER_INIT(&uiter);
3846         while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
3847                 u64 range_start = unode->val;
3848                 /* unode->aux is the inclusive end */
3849                 u64 range_len = unode->aux - range_start + 1;
3850                 u64 free_start;
3851                 u64 free_len;
3852
3853                 extent_changeset_release(&changeset);
3854
3855                 /* Only free range in range [start, start + len) */
3856                 if (range_start >= start + len ||
3857                     range_start + range_len <= start)
3858                         continue;
3859                 free_start = max(range_start, start);
3860                 free_len = min(start + len, range_start + range_len) -
3861                            free_start;
3862                 /*
3863                  * TODO: To also modify reserved->ranges_reserved to reflect
3864                  * the modification.
3865                  *
3866                  * However as long as we free qgroup reserved according to
3867                  * EXTENT_QGROUP_RESERVED, we won't double free.
3868                  * So not need to rush.
3869                  */
3870                 ret = clear_record_extent_bits(&inode->io_tree, free_start,
3871                                 free_start + free_len - 1,
3872                                 EXTENT_QGROUP_RESERVED, &changeset);
3873                 if (ret < 0)
3874                         goto out;
3875                 freed += changeset.bytes_changed;
3876         }
3877         btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
3878                                   BTRFS_QGROUP_RSV_DATA);
3879         ret = freed;
3880 out:
3881         extent_changeset_release(&changeset);
3882         return ret;
3883 }
3884
3885 static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
3886                         struct extent_changeset *reserved, u64 start, u64 len,
3887                         int free)
3888 {
3889         struct extent_changeset changeset;
3890         int trace_op = QGROUP_RELEASE;
3891         int ret;
3892
3893         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &inode->root->fs_info->flags))
3894                 return 0;
3895
3896         /* In release case, we shouldn't have @reserved */
3897         WARN_ON(!free && reserved);
3898         if (free && reserved)
3899                 return qgroup_free_reserved_data(inode, reserved, start, len);
3900         extent_changeset_init(&changeset);
3901         ret = clear_record_extent_bits(&inode->io_tree, start, start + len -1,
3902                                        EXTENT_QGROUP_RESERVED, &changeset);
3903         if (ret < 0)
3904                 goto out;
3905
3906         if (free)
3907                 trace_op = QGROUP_FREE;
3908         trace_btrfs_qgroup_release_data(&inode->vfs_inode, start, len,
3909                                         changeset.bytes_changed, trace_op);
3910         if (free)
3911                 btrfs_qgroup_free_refroot(inode->root->fs_info,
3912                                 inode->root->root_key.objectid,
3913                                 changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3914         ret = changeset.bytes_changed;
3915 out:
3916         extent_changeset_release(&changeset);
3917         return ret;
3918 }
3919
3920 /*
3921  * Free a reserved space range from io_tree and related qgroups
3922  *
3923  * Should be called when a range of pages get invalidated before reaching disk.
3924  * Or for error cleanup case.
3925  * if @reserved is given, only reserved range in [@start, @start + @len) will
3926  * be freed.
3927  *
3928  * For data written to disk, use btrfs_qgroup_release_data().
3929  *
3930  * NOTE: This function may sleep for memory allocation.
3931  */
3932 int btrfs_qgroup_free_data(struct btrfs_inode *inode,
3933                         struct extent_changeset *reserved, u64 start, u64 len)
3934 {
3935         return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3936 }
3937
3938 /*
3939  * Release a reserved space range from io_tree only.
3940  *
3941  * Should be called when a range of pages get written to disk and corresponding
3942  * FILE_EXTENT is inserted into corresponding root.
3943  *
3944  * Since new qgroup accounting framework will only update qgroup numbers at
3945  * commit_transaction() time, its reserved space shouldn't be freed from
3946  * related qgroups.
3947  *
3948  * But we should release the range from io_tree, to allow further write to be
3949  * COWed.
3950  *
3951  * NOTE: This function may sleep for memory allocation.
3952  */
3953 int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len)
3954 {
3955         return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3956 }
3957
3958 static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3959                               enum btrfs_qgroup_rsv_type type)
3960 {
3961         if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3962             type != BTRFS_QGROUP_RSV_META_PERTRANS)
3963                 return;
3964         if (num_bytes == 0)
3965                 return;
3966
3967         spin_lock(&root->qgroup_meta_rsv_lock);
3968         if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3969                 root->qgroup_meta_rsv_prealloc += num_bytes;
3970         else
3971                 root->qgroup_meta_rsv_pertrans += num_bytes;
3972         spin_unlock(&root->qgroup_meta_rsv_lock);
3973 }
3974
3975 static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3976                              enum btrfs_qgroup_rsv_type type)
3977 {
3978         if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3979             type != BTRFS_QGROUP_RSV_META_PERTRANS)
3980                 return 0;
3981         if (num_bytes == 0)
3982                 return 0;
3983
3984         spin_lock(&root->qgroup_meta_rsv_lock);
3985         if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3986                 num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3987                                   num_bytes);
3988                 root->qgroup_meta_rsv_prealloc -= num_bytes;
3989         } else {
3990                 num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3991                                   num_bytes);
3992                 root->qgroup_meta_rsv_pertrans -= num_bytes;
3993         }
3994         spin_unlock(&root->qgroup_meta_rsv_lock);
3995         return num_bytes;
3996 }
3997
3998 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3999                               enum btrfs_qgroup_rsv_type type, bool enforce)
4000 {
4001         struct btrfs_fs_info *fs_info = root->fs_info;
4002         int ret;
4003
4004         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4005             !is_fstree(root->root_key.objectid) || num_bytes == 0)
4006                 return 0;
4007
4008         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
4009         trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
4010         ret = qgroup_reserve(root, num_bytes, enforce, type);
4011         if (ret < 0)
4012                 return ret;
4013         /*
4014          * Record what we have reserved into root.
4015          *
4016          * To avoid quota disabled->enabled underflow.
4017          * In that case, we may try to free space we haven't reserved
4018          * (since quota was disabled), so record what we reserved into root.
4019          * And ensure later release won't underflow this number.
4020          */
4021         add_root_meta_rsv(root, num_bytes, type);
4022         return ret;
4023 }
4024
4025 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
4026                                 enum btrfs_qgroup_rsv_type type, bool enforce,
4027                                 bool noflush)
4028 {
4029         int ret;
4030
4031         ret = btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4032         if ((ret <= 0 && ret != -EDQUOT) || noflush)
4033                 return ret;
4034
4035         ret = try_flush_qgroup(root);
4036         if (ret < 0)
4037                 return ret;
4038         return btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4039 }
4040
4041 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
4042 {
4043         struct btrfs_fs_info *fs_info = root->fs_info;
4044
4045         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4046             !is_fstree(root->root_key.objectid))
4047                 return;
4048
4049         /* TODO: Update trace point to handle such free */
4050         trace_qgroup_meta_free_all_pertrans(root);
4051         /* Special value -1 means to free all reserved space */
4052         btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
4053                                   BTRFS_QGROUP_RSV_META_PERTRANS);
4054 }
4055
4056 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
4057                               enum btrfs_qgroup_rsv_type type)
4058 {
4059         struct btrfs_fs_info *fs_info = root->fs_info;
4060
4061         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4062             !is_fstree(root->root_key.objectid))
4063                 return;
4064
4065         /*
4066          * reservation for META_PREALLOC can happen before quota is enabled,
4067          * which can lead to underflow.
4068          * Here ensure we will only free what we really have reserved.
4069          */
4070         num_bytes = sub_root_meta_rsv(root, num_bytes, type);
4071         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
4072         trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
4073         btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
4074                                   num_bytes, type);
4075 }
4076
4077 static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
4078                                 int num_bytes)
4079 {
4080         struct btrfs_qgroup *qgroup;
4081         struct ulist_node *unode;
4082         struct ulist_iterator uiter;
4083         int ret = 0;
4084
4085         if (num_bytes == 0)
4086                 return;
4087         if (!fs_info->quota_root)
4088                 return;
4089
4090         spin_lock(&fs_info->qgroup_lock);
4091         qgroup = find_qgroup_rb(fs_info, ref_root);
4092         if (!qgroup)
4093                 goto out;
4094         ulist_reinit(fs_info->qgroup_ulist);
4095         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
4096                        qgroup_to_aux(qgroup), GFP_ATOMIC);
4097         if (ret < 0)
4098                 goto out;
4099         ULIST_ITER_INIT(&uiter);
4100         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
4101                 struct btrfs_qgroup *qg;
4102                 struct btrfs_qgroup_list *glist;
4103
4104                 qg = unode_aux_to_qgroup(unode);
4105
4106                 qgroup_rsv_release(fs_info, qg, num_bytes,
4107                                 BTRFS_QGROUP_RSV_META_PREALLOC);
4108                 qgroup_rsv_add(fs_info, qg, num_bytes,
4109                                 BTRFS_QGROUP_RSV_META_PERTRANS);
4110                 list_for_each_entry(glist, &qg->groups, next_group) {
4111                         ret = ulist_add(fs_info->qgroup_ulist,
4112                                         glist->group->qgroupid,
4113                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
4114                         if (ret < 0)
4115                                 goto out;
4116                 }
4117         }
4118 out:
4119         spin_unlock(&fs_info->qgroup_lock);
4120 }
4121
4122 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
4123 {
4124         struct btrfs_fs_info *fs_info = root->fs_info;
4125
4126         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4127             !is_fstree(root->root_key.objectid))
4128                 return;
4129         /* Same as btrfs_qgroup_free_meta_prealloc() */
4130         num_bytes = sub_root_meta_rsv(root, num_bytes,
4131                                       BTRFS_QGROUP_RSV_META_PREALLOC);
4132         trace_qgroup_meta_convert(root, num_bytes);
4133         qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
4134 }
4135
4136 /*
4137  * Check qgroup reserved space leaking, normally at destroy inode
4138  * time
4139  */
4140 void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode)
4141 {
4142         struct extent_changeset changeset;
4143         struct ulist_node *unode;
4144         struct ulist_iterator iter;
4145         int ret;
4146
4147         extent_changeset_init(&changeset);
4148         ret = clear_record_extent_bits(&inode->io_tree, 0, (u64)-1,
4149                         EXTENT_QGROUP_RESERVED, &changeset);
4150
4151         WARN_ON(ret < 0);
4152         if (WARN_ON(changeset.bytes_changed)) {
4153                 ULIST_ITER_INIT(&iter);
4154                 while ((unode = ulist_next(&changeset.range_changed, &iter))) {
4155                         btrfs_warn(inode->root->fs_info,
4156                 "leaking qgroup reserved space, ino: %llu, start: %llu, end: %llu",
4157                                 btrfs_ino(inode), unode->val, unode->aux);
4158                 }
4159                 btrfs_qgroup_free_refroot(inode->root->fs_info,
4160                                 inode->root->root_key.objectid,
4161                                 changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
4162
4163         }
4164         extent_changeset_release(&changeset);
4165 }
4166
4167 void btrfs_qgroup_init_swapped_blocks(
4168         struct btrfs_qgroup_swapped_blocks *swapped_blocks)
4169 {
4170         int i;
4171
4172         spin_lock_init(&swapped_blocks->lock);
4173         for (i = 0; i < BTRFS_MAX_LEVEL; i++)
4174                 swapped_blocks->blocks[i] = RB_ROOT;
4175         swapped_blocks->swapped = false;
4176 }
4177
4178 /*
4179  * Delete all swapped blocks record of @root.
4180  * Every record here means we skipped a full subtree scan for qgroup.
4181  *
4182  * Gets called when committing one transaction.
4183  */
4184 void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
4185 {
4186         struct btrfs_qgroup_swapped_blocks *swapped_blocks;
4187         int i;
4188
4189         swapped_blocks = &root->swapped_blocks;
4190
4191         spin_lock(&swapped_blocks->lock);
4192         if (!swapped_blocks->swapped)
4193                 goto out;
4194         for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4195                 struct rb_root *cur_root = &swapped_blocks->blocks[i];
4196                 struct btrfs_qgroup_swapped_block *entry;
4197                 struct btrfs_qgroup_swapped_block *next;
4198
4199                 rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
4200                                                      node)
4201                         kfree(entry);
4202                 swapped_blocks->blocks[i] = RB_ROOT;
4203         }
4204         swapped_blocks->swapped = false;
4205 out:
4206         spin_unlock(&swapped_blocks->lock);
4207 }
4208
4209 /*
4210  * Add subtree roots record into @subvol_root.
4211  *
4212  * @subvol_root:        tree root of the subvolume tree get swapped
4213  * @bg:                 block group under balance
4214  * @subvol_parent/slot: pointer to the subtree root in subvolume tree
4215  * @reloc_parent/slot:  pointer to the subtree root in reloc tree
4216  *                      BOTH POINTERS ARE BEFORE TREE SWAP
4217  * @last_snapshot:      last snapshot generation of the subvolume tree
4218  */
4219 int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
4220                 struct btrfs_root *subvol_root,
4221                 struct btrfs_block_group *bg,
4222                 struct extent_buffer *subvol_parent, int subvol_slot,
4223                 struct extent_buffer *reloc_parent, int reloc_slot,
4224                 u64 last_snapshot)
4225 {
4226         struct btrfs_fs_info *fs_info = subvol_root->fs_info;
4227         struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
4228         struct btrfs_qgroup_swapped_block *block;
4229         struct rb_node **cur;
4230         struct rb_node *parent = NULL;
4231         int level = btrfs_header_level(subvol_parent) - 1;
4232         int ret = 0;
4233
4234         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4235                 return 0;
4236
4237         if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
4238             btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
4239                 btrfs_err_rl(fs_info,
4240                 "%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
4241                         __func__,
4242                         btrfs_node_ptr_generation(subvol_parent, subvol_slot),
4243                         btrfs_node_ptr_generation(reloc_parent, reloc_slot));
4244                 return -EUCLEAN;
4245         }
4246
4247         block = kmalloc(sizeof(*block), GFP_NOFS);
4248         if (!block) {
4249                 ret = -ENOMEM;
4250                 goto out;
4251         }
4252
4253         /*
4254          * @reloc_parent/slot is still before swap, while @block is going to
4255          * record the bytenr after swap, so we do the swap here.
4256          */
4257         block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
4258         block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
4259                                                              reloc_slot);
4260         block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
4261         block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
4262                                                             subvol_slot);
4263         block->last_snapshot = last_snapshot;
4264         block->level = level;
4265
4266         /*
4267          * If we have bg == NULL, we're called from btrfs_recover_relocation(),
4268          * no one else can modify tree blocks thus we qgroup will not change
4269          * no matter the value of trace_leaf.
4270          */
4271         if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
4272                 block->trace_leaf = true;
4273         else
4274                 block->trace_leaf = false;
4275         btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
4276
4277         /* Insert @block into @blocks */
4278         spin_lock(&blocks->lock);
4279         cur = &blocks->blocks[level].rb_node;
4280         while (*cur) {
4281                 struct btrfs_qgroup_swapped_block *entry;
4282
4283                 parent = *cur;
4284                 entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
4285                                  node);
4286
4287                 if (entry->subvol_bytenr < block->subvol_bytenr) {
4288                         cur = &(*cur)->rb_left;
4289                 } else if (entry->subvol_bytenr > block->subvol_bytenr) {
4290                         cur = &(*cur)->rb_right;
4291                 } else {
4292                         if (entry->subvol_generation !=
4293                                         block->subvol_generation ||
4294                             entry->reloc_bytenr != block->reloc_bytenr ||
4295                             entry->reloc_generation !=
4296                                         block->reloc_generation) {
4297                                 /*
4298                                  * Duplicated but mismatch entry found.
4299                                  * Shouldn't happen.
4300                                  *
4301                                  * Marking qgroup inconsistent should be enough
4302                                  * for end users.
4303                                  */
4304                                 WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4305                                 ret = -EEXIST;
4306                         }
4307                         kfree(block);
4308                         goto out_unlock;
4309                 }
4310         }
4311         rb_link_node(&block->node, parent, cur);
4312         rb_insert_color(&block->node, &blocks->blocks[level]);
4313         blocks->swapped = true;
4314 out_unlock:
4315         spin_unlock(&blocks->lock);
4316 out:
4317         if (ret < 0)
4318                 qgroup_mark_inconsistent(fs_info);
4319         return ret;
4320 }
4321
4322 /*
4323  * Check if the tree block is a subtree root, and if so do the needed
4324  * delayed subtree trace for qgroup.
4325  *
4326  * This is called during btrfs_cow_block().
4327  */
4328 int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
4329                                          struct btrfs_root *root,
4330                                          struct extent_buffer *subvol_eb)
4331 {
4332         struct btrfs_fs_info *fs_info = root->fs_info;
4333         struct btrfs_tree_parent_check check = { 0 };
4334         struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
4335         struct btrfs_qgroup_swapped_block *block;
4336         struct extent_buffer *reloc_eb = NULL;
4337         struct rb_node *node;
4338         bool found = false;
4339         bool swapped = false;
4340         int level = btrfs_header_level(subvol_eb);
4341         int ret = 0;
4342         int i;
4343
4344         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4345                 return 0;
4346         if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
4347                 return 0;
4348
4349         spin_lock(&blocks->lock);
4350         if (!blocks->swapped) {
4351                 spin_unlock(&blocks->lock);
4352                 return 0;
4353         }
4354         node = blocks->blocks[level].rb_node;
4355
4356         while (node) {
4357                 block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
4358                 if (block->subvol_bytenr < subvol_eb->start) {
4359                         node = node->rb_left;
4360                 } else if (block->subvol_bytenr > subvol_eb->start) {
4361                         node = node->rb_right;
4362                 } else {
4363                         found = true;
4364                         break;
4365                 }
4366         }
4367         if (!found) {
4368                 spin_unlock(&blocks->lock);
4369                 goto out;
4370         }
4371         /* Found one, remove it from @blocks first and update blocks->swapped */
4372         rb_erase(&block->node, &blocks->blocks[level]);
4373         for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4374                 if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
4375                         swapped = true;
4376                         break;
4377                 }
4378         }
4379         blocks->swapped = swapped;
4380         spin_unlock(&blocks->lock);
4381
4382         check.level = block->level;
4383         check.transid = block->reloc_generation;
4384         check.has_first_key = true;
4385         memcpy(&check.first_key, &block->first_key, sizeof(check.first_key));
4386
4387         /* Read out reloc subtree root */
4388         reloc_eb = read_tree_block(fs_info, block->reloc_bytenr, &check);
4389         if (IS_ERR(reloc_eb)) {
4390                 ret = PTR_ERR(reloc_eb);
4391                 reloc_eb = NULL;
4392                 goto free_out;
4393         }
4394         if (!extent_buffer_uptodate(reloc_eb)) {
4395                 ret = -EIO;
4396                 goto free_out;
4397         }
4398
4399         ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
4400                         block->last_snapshot, block->trace_leaf);
4401 free_out:
4402         kfree(block);
4403         free_extent_buffer(reloc_eb);
4404 out:
4405         if (ret < 0) {
4406                 btrfs_err_rl(fs_info,
4407                              "failed to account subtree at bytenr %llu: %d",
4408                              subvol_eb->start, ret);
4409                 qgroup_mark_inconsistent(fs_info);
4410         }
4411         return ret;
4412 }
4413
4414 void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans)
4415 {
4416         struct btrfs_qgroup_extent_record *entry;
4417         struct btrfs_qgroup_extent_record *next;
4418         struct rb_root *root;
4419
4420         root = &trans->delayed_refs.dirty_extent_root;
4421         rbtree_postorder_for_each_entry_safe(entry, next, root, node) {
4422                 ulist_free(entry->old_roots);
4423                 kfree(entry);
4424         }
4425 }