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