fs/btrfs/qgroup.c

   1 /*
   2  * Copyright (C) 2011 STRATO.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/sched.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/writeback.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/rbtree.h>
  24 #include <linux/slab.h>
  25 #include <linux/workqueue.h>
  26 #include <linux/btrfs.h>
  27
  28 #include "ctree.h"
  29 #include "transaction.h"
  30 #include "disk-io.h"
  31 #include "locking.h"
  32 #include "ulist.h"
  33 #include "backref.h"
  34 #include "extent_io.h"
  35 #include "qgroup.h"
  36
  37
  38 /* TODO XXX FIXME
  39  *  - subvol delete -> delete when ref goes to 0? delete limits also?
  40  *  - reorganize keys
  41  *  - compressed
  42  *  - sync
  43  *  - copy also limits on subvol creation
  44  *  - limit
  45  *  - caches fuer ulists
  46  *  - performance benchmarks
  47  *  - check all ioctl parameters
  48  */
  49
  50 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
  51                                            int mod)
  52 {
  53         if (qg->old_refcnt < seq)
  54                 qg->old_refcnt = seq;
  55         qg->old_refcnt += mod;
  56 }
  57
  58 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
  59                                            int mod)
  60 {
  61         if (qg->new_refcnt < seq)
  62                 qg->new_refcnt = seq;
  63         qg->new_refcnt += mod;
  64 }
  65
  66 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
  67 {
  68         if (qg->old_refcnt < seq)
  69                 return 0;
  70         return qg->old_refcnt - seq;
  71 }
  72
  73 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
  74 {
  75         if (qg->new_refcnt < seq)
  76                 return 0;
  77         return qg->new_refcnt - seq;
  78 }
  79
  80 /*
  81  * glue structure to represent the relations between qgroups.
  82  */
  83 struct btrfs_qgroup_list {
  84         struct list_head next_group;
  85         struct list_head next_member;
  86         struct btrfs_qgroup *group;
  87         struct btrfs_qgroup *member;
  88 };
  89
  90 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
  91 {
  92         return (u64)(uintptr_t)qg;
  93 }
  94
  95 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
  96 {
  97         return (struct btrfs_qgroup *)(uintptr_t)n->aux;
  98 }
  99
 100 static int
 101 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 102                    int init_flags);
 103 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 104
 105 /* must be called with qgroup_ioctl_lock held */
 106 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 107                                            u64 qgroupid)
 108 {
 109         struct rb_node *n = fs_info->qgroup_tree.rb_node;
 110         struct btrfs_qgroup *qgroup;
 111
 112         while (n) {
 113                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 114                 if (qgroup->qgroupid < qgroupid)
 115                         n = n->rb_left;
 116                 else if (qgroup->qgroupid > qgroupid)
 117                         n = n->rb_right;
 118                 else
 119                         return qgroup;
 120         }
 121         return NULL;
 122 }
 123
 124 /* must be called with qgroup_lock held */
 125 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 126                                           u64 qgroupid)
 127 {
 128         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 129         struct rb_node *parent = NULL;
 130         struct btrfs_qgroup *qgroup;
 131
 132         while (*p) {
 133                 parent = *p;
 134                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 135
 136                 if (qgroup->qgroupid < qgroupid)
 137                         p = &(*p)->rb_left;
 138                 else if (qgroup->qgroupid > qgroupid)
 139                         p = &(*p)->rb_right;
 140                 else
 141                         return qgroup;
 142         }
 143
 144         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 145         if (!qgroup)
 146                 return ERR_PTR(-ENOMEM);
 147
 148         qgroup->qgroupid = qgroupid;
 149         INIT_LIST_HEAD(&qgroup->groups);
 150         INIT_LIST_HEAD(&qgroup->members);
 151         INIT_LIST_HEAD(&qgroup->dirty);
 152
 153         rb_link_node(&qgroup->node, parent, p);
 154         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 155
 156         return qgroup;
 157 }
 158
 159 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
 160 {
 161         struct btrfs_qgroup_list *list;
 162
 163         list_del(&qgroup->dirty);
 164         while (!list_empty(&qgroup->groups)) {
 165                 list = list_first_entry(&qgroup->groups,
 166                                         struct btrfs_qgroup_list, next_group);
 167                 list_del(&list->next_group);
 168                 list_del(&list->next_member);
 169                 kfree(list);
 170         }
 171
 172         while (!list_empty(&qgroup->members)) {
 173                 list = list_first_entry(&qgroup->members,
 174                                         struct btrfs_qgroup_list, next_member);
 175                 list_del(&list->next_group);
 176                 list_del(&list->next_member);
 177                 kfree(list);
 178         }
 179         kfree(qgroup);
 180 }
 181
 182 /* must be called with qgroup_lock held */
 183 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 184 {
 185         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 186
 187         if (!qgroup)
 188                 return -ENOENT;
 189
 190         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 191         __del_qgroup_rb(qgroup);
 192         return 0;
 193 }
 194
 195 /* must be called with qgroup_lock held */
 196 static int add_relation_rb(struct btrfs_fs_info *fs_info,
 197                            u64 memberid, u64 parentid)
 198 {
 199         struct btrfs_qgroup *member;
 200         struct btrfs_qgroup *parent;
 201         struct btrfs_qgroup_list *list;
 202
 203         member = find_qgroup_rb(fs_info, memberid);
 204         parent = find_qgroup_rb(fs_info, parentid);
 205         if (!member || !parent)
 206                 return -ENOENT;
 207
 208         list = kzalloc(sizeof(*list), GFP_ATOMIC);
 209         if (!list)
 210                 return -ENOMEM;
 211
 212         list->group = parent;
 213         list->member = member;
 214         list_add_tail(&list->next_group, &member->groups);
 215         list_add_tail(&list->next_member, &parent->members);
 216
 217         return 0;
 218 }
 219
 220 /* must be called with qgroup_lock held */
 221 static int del_relation_rb(struct btrfs_fs_info *fs_info,
 222                            u64 memberid, u64 parentid)
 223 {
 224         struct btrfs_qgroup *member;
 225         struct btrfs_qgroup *parent;
 226         struct btrfs_qgroup_list *list;
 227
 228         member = find_qgroup_rb(fs_info, memberid);
 229         parent = find_qgroup_rb(fs_info, parentid);
 230         if (!member || !parent)
 231                 return -ENOENT;
 232
 233         list_for_each_entry(list, &member->groups, next_group) {
 234                 if (list->group == parent) {
 235                         list_del(&list->next_group);
 236                         list_del(&list->next_member);
 237                         kfree(list);
 238                         return 0;
 239                 }
 240         }
 241         return -ENOENT;
 242 }
 243
 244 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 245 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 246                                u64 rfer, u64 excl)
 247 {
 248         struct btrfs_qgroup *qgroup;
 249
 250         qgroup = find_qgroup_rb(fs_info, qgroupid);
 251         if (!qgroup)
 252                 return -EINVAL;
 253         if (qgroup->rfer != rfer || qgroup->excl != excl)
 254                 return -EINVAL;
 255         return 0;
 256 }
 257 #endif
 258
 259 /*
 260  * The full config is read in one go, only called from open_ctree()
 261  * It doesn't use any locking, as at this point we're still single-threaded
 262  */
 263 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 264 {
 265         struct btrfs_key key;
 266         struct btrfs_key found_key;
 267         struct btrfs_root *quota_root = fs_info->quota_root;
 268         struct btrfs_path *path = NULL;
 269         struct extent_buffer *l;
 270         int slot;
 271         int ret = 0;
 272         u64 flags = 0;
 273         u64 rescan_progress = 0;
 274
 275         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 276                 return 0;
 277
 278         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 279         if (!fs_info->qgroup_ulist) {
 280                 ret = -ENOMEM;
 281                 goto out;
 282         }
 283
 284         path = btrfs_alloc_path();
 285         if (!path) {
 286                 ret = -ENOMEM;
 287                 goto out;
 288         }
 289
 290         /* default this to quota off, in case no status key is found */
 291         fs_info->qgroup_flags = 0;
 292
 293         /*
 294          * pass 1: read status, all qgroup infos and limits
 295          */
 296         key.objectid = 0;
 297         key.type = 0;
 298         key.offset = 0;
 299         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 300         if (ret)
 301                 goto out;
 302
 303         while (1) {
 304                 struct btrfs_qgroup *qgroup;
 305
 306                 slot = path->slots[0];
 307                 l = path->nodes[0];
 308                 btrfs_item_key_to_cpu(l, &found_key, slot);
 309
 310                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 311                         struct btrfs_qgroup_status_item *ptr;
 312
 313                         ptr = btrfs_item_ptr(l, slot,
 314                                              struct btrfs_qgroup_status_item);
 315
 316                         if (btrfs_qgroup_status_version(l, ptr) !=
 317                             BTRFS_QGROUP_STATUS_VERSION) {
 318                                 btrfs_err(fs_info,
 319                                  "old qgroup version, quota disabled");
 320                                 goto out;
 321                         }
 322                         if (btrfs_qgroup_status_generation(l, ptr) !=
 323                             fs_info->generation) {
 324                                 flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 325                                 btrfs_err(fs_info,
 326                                         "qgroup generation mismatch, marked as inconsistent");
 327                         }
 328                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 329                                                                           ptr);
 330                         rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
 331                         goto next1;
 332                 }
 333
 334                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 335                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 336                         goto next1;
 337
 338                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
 339                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 340                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 341                         btrfs_err(fs_info, "inconsistent qgroup config");
 342                         flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 343                 }
 344                 if (!qgroup) {
 345                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 346                         if (IS_ERR(qgroup)) {
 347                                 ret = PTR_ERR(qgroup);
 348                                 goto out;
 349                         }
 350                 }
 351                 switch (found_key.type) {
 352                 case BTRFS_QGROUP_INFO_KEY: {
 353                         struct btrfs_qgroup_info_item *ptr;
 354
 355                         ptr = btrfs_item_ptr(l, slot,
 356                                              struct btrfs_qgroup_info_item);
 357                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 358                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 359                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 360                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 361                         /* generation currently unused */
 362                         break;
 363                 }
 364                 case BTRFS_QGROUP_LIMIT_KEY: {
 365                         struct btrfs_qgroup_limit_item *ptr;
 366
 367                         ptr = btrfs_item_ptr(l, slot,
 368                                              struct btrfs_qgroup_limit_item);
 369                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 370                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 371                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 372                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 373                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 374                         break;
 375                 }
 376                 }
 377 next1:
 378                 ret = btrfs_next_item(quota_root, path);
 379                 if (ret < 0)
 380                         goto out;
 381                 if (ret)
 382                         break;
 383         }
 384         btrfs_release_path(path);
 385
 386         /*
 387          * pass 2: read all qgroup relations
 388          */
 389         key.objectid = 0;
 390         key.type = BTRFS_QGROUP_RELATION_KEY;
 391         key.offset = 0;
 392         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 393         if (ret)
 394                 goto out;
 395         while (1) {
 396                 slot = path->slots[0];
 397                 l = path->nodes[0];
 398                 btrfs_item_key_to_cpu(l, &found_key, slot);
 399
 400                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 401                         goto next2;
 402
 403                 if (found_key.objectid > found_key.offset) {
 404                         /* parent <- member, not needed to build config */
 405                         /* FIXME should we omit the key completely? */
 406                         goto next2;
 407                 }
 408
 409                 ret = add_relation_rb(fs_info, found_key.objectid,
 410                                       found_key.offset);
 411                 if (ret == -ENOENT) {
 412                         btrfs_warn(fs_info,
 413                                 "orphan qgroup relation 0x%llx->0x%llx",
 414                                 found_key.objectid, found_key.offset);
 415                         ret = 0;        /* ignore the error */
 416                 }
 417                 if (ret)
 418                         goto out;
 419 next2:
 420                 ret = btrfs_next_item(quota_root, path);
 421                 if (ret < 0)
 422                         goto out;
 423                 if (ret)
 424                         break;
 425         }
 426 out:
 427         fs_info->qgroup_flags |= flags;
 428         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
 429                 clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 430         else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
 431                  ret >= 0)
 432                 ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
 433         btrfs_free_path(path);
 434
 435         if (ret < 0) {
 436                 ulist_free(fs_info->qgroup_ulist);
 437                 fs_info->qgroup_ulist = NULL;
 438                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 439         }
 440
 441         return ret < 0 ? ret : 0;
 442 }
 443
 444 /*
 445  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
 446  * first two are in single-threaded paths.And for the third one, we have set
 447  * quota_root to be null with qgroup_lock held before, so it is safe to clean
 448  * up the in-memory structures without qgroup_lock held.
 449  */
 450 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 451 {
 452         struct rb_node *n;
 453         struct btrfs_qgroup *qgroup;
 454
 455         while ((n = rb_first(&fs_info->qgroup_tree))) {
 456                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
 457                 rb_erase(n, &fs_info->qgroup_tree);
 458                 __del_qgroup_rb(qgroup);
 459         }
 460         /*
 461          * we call btrfs_free_qgroup_config() when umounting
 462          * filesystem and disabling quota, so we set qgroup_ulist
 463          * to be null here to avoid double free.
 464          */
 465         ulist_free(fs_info->qgroup_ulist);
 466         fs_info->qgroup_ulist = NULL;
 467 }
 468
 469 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
 470                                     struct btrfs_root *quota_root,
 471                                     u64 src, u64 dst)
 472 {
 473         int ret;
 474         struct btrfs_path *path;
 475         struct btrfs_key key;
 476
 477         path = btrfs_alloc_path();
 478         if (!path)
 479                 return -ENOMEM;
 480
 481         key.objectid = src;
 482         key.type = BTRFS_QGROUP_RELATION_KEY;
 483         key.offset = dst;
 484
 485         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 486
 487         btrfs_mark_buffer_dirty(path->nodes[0]);
 488
 489         btrfs_free_path(path);
 490         return ret;
 491 }
 492
 493 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
 494                                     struct btrfs_root *quota_root,
 495                                     u64 src, u64 dst)
 496 {
 497         int ret;
 498         struct btrfs_path *path;
 499         struct btrfs_key key;
 500
 501         path = btrfs_alloc_path();
 502         if (!path)
 503                 return -ENOMEM;
 504
 505         key.objectid = src;
 506         key.type = BTRFS_QGROUP_RELATION_KEY;
 507         key.offset = dst;
 508
 509         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 510         if (ret < 0)
 511                 goto out;
 512
 513         if (ret > 0) {
 514                 ret = -ENOENT;
 515                 goto out;
 516         }
 517
 518         ret = btrfs_del_item(trans, quota_root, path);
 519 out:
 520         btrfs_free_path(path);
 521         return ret;
 522 }
 523
 524 static int add_qgroup_item(struct btrfs_trans_handle *trans,
 525                            struct btrfs_root *quota_root, u64 qgroupid)
 526 {
 527         int ret;
 528         struct btrfs_path *path;
 529         struct btrfs_qgroup_info_item *qgroup_info;
 530         struct btrfs_qgroup_limit_item *qgroup_limit;
 531         struct extent_buffer *leaf;
 532         struct btrfs_key key;
 533
 534         if (btrfs_is_testing(quota_root->fs_info))
 535                 return 0;
 536
 537         path = btrfs_alloc_path();
 538         if (!path)
 539                 return -ENOMEM;
 540
 541         key.objectid = 0;
 542         key.type = BTRFS_QGROUP_INFO_KEY;
 543         key.offset = qgroupid;
 544
 545         /*
 546          * Avoid a transaction abort by catching -EEXIST here. In that
 547          * case, we proceed by re-initializing the existing structure
 548          * on disk.
 549          */
 550
 551         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 552                                       sizeof(*qgroup_info));
 553         if (ret && ret != -EEXIST)
 554                 goto out;
 555
 556         leaf = path->nodes[0];
 557         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 558                                  struct btrfs_qgroup_info_item);
 559         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 560         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 561         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 562         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 563         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 564
 565         btrfs_mark_buffer_dirty(leaf);
 566
 567         btrfs_release_path(path);
 568
 569         key.type = BTRFS_QGROUP_LIMIT_KEY;
 570         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 571                                       sizeof(*qgroup_limit));
 572         if (ret && ret != -EEXIST)
 573                 goto out;
 574
 575         leaf = path->nodes[0];
 576         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 577                                   struct btrfs_qgroup_limit_item);
 578         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 579         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 580         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 581         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 582         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 583
 584         btrfs_mark_buffer_dirty(leaf);
 585
 586         ret = 0;
 587 out:
 588         btrfs_free_path(path);
 589         return ret;
 590 }
 591
 592 static int del_qgroup_item(struct btrfs_trans_handle *trans,
 593                            struct btrfs_root *quota_root, u64 qgroupid)
 594 {
 595         int ret;
 596         struct btrfs_path *path;
 597         struct btrfs_key key;
 598
 599         path = btrfs_alloc_path();
 600         if (!path)
 601                 return -ENOMEM;
 602
 603         key.objectid = 0;
 604         key.type = BTRFS_QGROUP_INFO_KEY;
 605         key.offset = qgroupid;
 606         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 607         if (ret < 0)
 608                 goto out;
 609
 610         if (ret > 0) {
 611                 ret = -ENOENT;
 612                 goto out;
 613         }
 614
 615         ret = btrfs_del_item(trans, quota_root, path);
 616         if (ret)
 617                 goto out;
 618
 619         btrfs_release_path(path);
 620
 621         key.type = BTRFS_QGROUP_LIMIT_KEY;
 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
 633 out:
 634         btrfs_free_path(path);
 635         return ret;
 636 }
 637
 638 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 639                                     struct btrfs_root *root,
 640                                     struct btrfs_qgroup *qgroup)
 641 {
 642         struct btrfs_path *path;
 643         struct btrfs_key key;
 644         struct extent_buffer *l;
 645         struct btrfs_qgroup_limit_item *qgroup_limit;
 646         int ret;
 647         int slot;
 648
 649         key.objectid = 0;
 650         key.type = BTRFS_QGROUP_LIMIT_KEY;
 651         key.offset = qgroup->qgroupid;
 652
 653         path = btrfs_alloc_path();
 654         if (!path)
 655                 return -ENOMEM;
 656
 657         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 658         if (ret > 0)
 659                 ret = -ENOENT;
 660
 661         if (ret)
 662                 goto out;
 663
 664         l = path->nodes[0];
 665         slot = path->slots[0];
 666         qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
 667         btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
 668         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
 669         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
 670         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
 671         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
 672
 673         btrfs_mark_buffer_dirty(l);
 674
 675 out:
 676         btrfs_free_path(path);
 677         return ret;
 678 }
 679
 680 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 681                                    struct btrfs_root *root,
 682                                    struct btrfs_qgroup *qgroup)
 683 {
 684         struct btrfs_path *path;
 685         struct btrfs_key key;
 686         struct extent_buffer *l;
 687         struct btrfs_qgroup_info_item *qgroup_info;
 688         int ret;
 689         int slot;
 690
 691         if (btrfs_is_testing(root->fs_info))
 692                 return 0;
 693
 694         key.objectid = 0;
 695         key.type = BTRFS_QGROUP_INFO_KEY;
 696         key.offset = qgroup->qgroupid;
 697
 698         path = btrfs_alloc_path();
 699         if (!path)
 700                 return -ENOMEM;
 701
 702         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 703         if (ret > 0)
 704                 ret = -ENOENT;
 705
 706         if (ret)
 707                 goto out;
 708
 709         l = path->nodes[0];
 710         slot = path->slots[0];
 711         qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
 712         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 713         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 714         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 715         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 716         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 717
 718         btrfs_mark_buffer_dirty(l);
 719
 720 out:
 721         btrfs_free_path(path);
 722         return ret;
 723 }
 724
 725 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
 726                                      struct btrfs_fs_info *fs_info,
 727                                     struct btrfs_root *root)
 728 {
 729         struct btrfs_path *path;
 730         struct btrfs_key key;
 731         struct extent_buffer *l;
 732         struct btrfs_qgroup_status_item *ptr;
 733         int ret;
 734         int slot;
 735
 736         key.objectid = 0;
 737         key.type = BTRFS_QGROUP_STATUS_KEY;
 738         key.offset = 0;
 739
 740         path = btrfs_alloc_path();
 741         if (!path)
 742                 return -ENOMEM;
 743
 744         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
 745         if (ret > 0)
 746                 ret = -ENOENT;
 747
 748         if (ret)
 749                 goto out;
 750
 751         l = path->nodes[0];
 752         slot = path->slots[0];
 753         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 754         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
 755         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 756         btrfs_set_qgroup_status_rescan(l, ptr,
 757                                 fs_info->qgroup_rescan_progress.objectid);
 758
 759         btrfs_mark_buffer_dirty(l);
 760
 761 out:
 762         btrfs_free_path(path);
 763         return ret;
 764 }
 765
 766 /*
 767  * called with qgroup_lock held
 768  */
 769 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 770                                   struct btrfs_root *root)
 771 {
 772         struct btrfs_path *path;
 773         struct btrfs_key key;
 774         struct extent_buffer *leaf = NULL;
 775         int ret;
 776         int nr = 0;
 777
 778         path = btrfs_alloc_path();
 779         if (!path)
 780                 return -ENOMEM;
 781
 782         path->leave_spinning = 1;
 783
 784         key.objectid = 0;
 785         key.offset = 0;
 786         key.type = 0;
 787
 788         while (1) {
 789                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 790                 if (ret < 0)
 791                         goto out;
 792                 leaf = path->nodes[0];
 793                 nr = btrfs_header_nritems(leaf);
 794                 if (!nr)
 795                         break;
 796                 /*
 797                  * delete the leaf one by one
 798                  * since the whole tree is going
 799                  * to be deleted.
 800                  */
 801                 path->slots[0] = 0;
 802                 ret = btrfs_del_items(trans, root, path, 0, nr);
 803                 if (ret)
 804                         goto out;
 805
 806                 btrfs_release_path(path);
 807         }
 808         ret = 0;
 809 out:
 810         set_bit(BTRFS_FS_QUOTA_DISABLING, &root->fs_info->flags);
 811         btrfs_free_path(path);
 812         return ret;
 813 }
 814
 815 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
 816                        struct btrfs_fs_info *fs_info)
 817 {
 818         struct btrfs_root *quota_root;
 819         struct btrfs_root *tree_root = fs_info->tree_root;
 820         struct btrfs_path *path = NULL;
 821         struct btrfs_qgroup_status_item *ptr;
 822         struct extent_buffer *leaf;
 823         struct btrfs_key key;
 824         struct btrfs_key found_key;
 825         struct btrfs_qgroup *qgroup = NULL;
 826         int ret = 0;
 827         int slot;
 828
 829         mutex_lock(&fs_info->qgroup_ioctl_lock);
 830         if (fs_info->quota_root) {
 831                 set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
 832                 goto out;
 833         }
 834
 835         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 836         if (!fs_info->qgroup_ulist) {
 837                 ret = -ENOMEM;
 838                 goto out;
 839         }
 840
 841         /*
 842          * initially create the quota tree
 843          */
 844         quota_root = btrfs_create_tree(trans, fs_info,
 845                                        BTRFS_QUOTA_TREE_OBJECTID);
 846         if (IS_ERR(quota_root)) {
 847                 ret =  PTR_ERR(quota_root);
 848                 goto out;
 849         }
 850
 851         path = btrfs_alloc_path();
 852         if (!path) {
 853                 ret = -ENOMEM;
 854                 goto out_free_root;
 855         }
 856
 857         key.objectid = 0;
 858         key.type = BTRFS_QGROUP_STATUS_KEY;
 859         key.offset = 0;
 860
 861         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 862                                       sizeof(*ptr));
 863         if (ret)
 864                 goto out_free_path;
 865
 866         leaf = path->nodes[0];
 867         ptr = btrfs_item_ptr(leaf, path->slots[0],
 868                                  struct btrfs_qgroup_status_item);
 869         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
 870         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
 871         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
 872                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 873         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
 874         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
 875
 876         btrfs_mark_buffer_dirty(leaf);
 877
 878         key.objectid = 0;
 879         key.type = BTRFS_ROOT_REF_KEY;
 880         key.offset = 0;
 881
 882         btrfs_release_path(path);
 883         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
 884         if (ret > 0)
 885                 goto out_add_root;
 886         if (ret < 0)
 887                 goto out_free_path;
 888
 889
 890         while (1) {
 891                 slot = path->slots[0];
 892                 leaf = path->nodes[0];
 893                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
 894
 895                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
 896                         ret = add_qgroup_item(trans, quota_root,
 897                                               found_key.offset);
 898                         if (ret)
 899                                 goto out_free_path;
 900
 901                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 902                         if (IS_ERR(qgroup)) {
 903                                 ret = PTR_ERR(qgroup);
 904                                 goto out_free_path;
 905                         }
 906                 }
 907                 ret = btrfs_next_item(tree_root, path);
 908                 if (ret < 0)
 909                         goto out_free_path;
 910                 if (ret)
 911                         break;
 912         }
 913
 914 out_add_root:
 915         btrfs_release_path(path);
 916         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
 917         if (ret)
 918                 goto out_free_path;
 919
 920         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
 921         if (IS_ERR(qgroup)) {
 922                 ret = PTR_ERR(qgroup);
 923                 goto out_free_path;
 924         }
 925         spin_lock(&fs_info->qgroup_lock);
 926         fs_info->quota_root = quota_root;
 927         set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
 928         spin_unlock(&fs_info->qgroup_lock);
 929 out_free_path:
 930         btrfs_free_path(path);
 931 out_free_root:
 932         if (ret) {
 933                 free_extent_buffer(quota_root->node);
 934                 free_extent_buffer(quota_root->commit_root);
 935                 kfree(quota_root);
 936         }
 937 out:
 938         if (ret) {
 939                 ulist_free(fs_info->qgroup_ulist);
 940                 fs_info->qgroup_ulist = NULL;
 941         }
 942         mutex_unlock(&fs_info->qgroup_ioctl_lock);
 943         return ret;
 944 }
 945
 946 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
 947                         struct btrfs_fs_info *fs_info)
 948 {
 949         struct btrfs_root *quota_root;
 950         int ret = 0;
 951
 952         mutex_lock(&fs_info->qgroup_ioctl_lock);
 953         if (!fs_info->quota_root)
 954                 goto out;
 955         clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 956         set_bit(BTRFS_FS_QUOTA_DISABLING, &fs_info->flags);
 957         btrfs_qgroup_wait_for_completion(fs_info, false);
 958         spin_lock(&fs_info->qgroup_lock);
 959         quota_root = fs_info->quota_root;
 960         fs_info->quota_root = NULL;
 961         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
 962         spin_unlock(&fs_info->qgroup_lock);
 963
 964         btrfs_free_qgroup_config(fs_info);
 965
 966         ret = btrfs_clean_quota_tree(trans, quota_root);
 967         if (ret)
 968                 goto out;
 969
 970         ret = btrfs_del_root(trans, fs_info, &quota_root->root_key);
 971         if (ret)
 972                 goto out;
 973
 974         list_del(&quota_root->dirty_list);
 975
 976         btrfs_tree_lock(quota_root->node);
 977         clean_tree_block(fs_info, quota_root->node);
 978         btrfs_tree_unlock(quota_root->node);
 979         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
 980
 981         free_extent_buffer(quota_root->node);
 982         free_extent_buffer(quota_root->commit_root);
 983         kfree(quota_root);
 984 out:
 985         mutex_unlock(&fs_info->qgroup_ioctl_lock);
 986         return ret;
 987 }
 988
 989 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
 990                          struct btrfs_qgroup *qgroup)
 991 {
 992         if (list_empty(&qgroup->dirty))
 993                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
 994 }
 995
 996 static void report_reserved_underflow(struct btrfs_fs_info *fs_info,
 997                                       struct btrfs_qgroup *qgroup,
 998                                       u64 num_bytes)
 999 {
1000 #ifdef CONFIG_BTRFS_DEBUG
1001         WARN_ON(qgroup->reserved < num_bytes);
1002         btrfs_debug(fs_info,
1003                 "qgroup %llu reserved space underflow, have: %llu, to free: %llu",
1004                 qgroup->qgroupid, qgroup->reserved, num_bytes);
1005 #endif
1006         qgroup->reserved = 0;
1007 }
1008 /*
1009  * The easy accounting, if we are adding/removing the only ref for an extent
1010  * then this qgroup and all of the parent qgroups get their reference and
1011  * exclusive counts adjusted.
1012  *
1013  * Caller should hold fs_info->qgroup_lock.
1014  */
1015 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1016                                     struct ulist *tmp, u64 ref_root,
1017                                     u64 num_bytes, int sign)
1018 {
1019         struct btrfs_qgroup *qgroup;
1020         struct btrfs_qgroup_list *glist;
1021         struct ulist_node *unode;
1022         struct ulist_iterator uiter;
1023         int ret = 0;
1024
1025         qgroup = find_qgroup_rb(fs_info, ref_root);
1026         if (!qgroup)
1027                 goto out;
1028
1029         qgroup->rfer += sign * num_bytes;
1030         qgroup->rfer_cmpr += sign * num_bytes;
1031
1032         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1033         qgroup->excl += sign * num_bytes;
1034         qgroup->excl_cmpr += sign * num_bytes;
1035         if (sign > 0) {
1036                 trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes);
1037                 if (qgroup->reserved < num_bytes)
1038                         report_reserved_underflow(fs_info, qgroup, num_bytes);
1039                 else
1040                         qgroup->reserved -= num_bytes;
1041         }
1042
1043         qgroup_dirty(fs_info, qgroup);
1044
1045         /* Get all of the parent groups that contain this qgroup */
1046         list_for_each_entry(glist, &qgroup->groups, next_group) {
1047                 ret = ulist_add(tmp, glist->group->qgroupid,
1048                                 qgroup_to_aux(glist->group), GFP_ATOMIC);
1049                 if (ret < 0)
1050                         goto out;
1051         }
1052
1053         /* Iterate all of the parents and adjust their reference counts */
1054         ULIST_ITER_INIT(&uiter);
1055         while ((unode = ulist_next(tmp, &uiter))) {
1056                 qgroup = unode_aux_to_qgroup(unode);
1057                 qgroup->rfer += sign * num_bytes;
1058                 qgroup->rfer_cmpr += sign * num_bytes;
1059                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1060                 qgroup->excl += sign * num_bytes;
1061                 if (sign > 0) {
1062                         trace_qgroup_update_reserve(fs_info, qgroup,
1063                                                     -(s64)num_bytes);
1064                         if (qgroup->reserved < num_bytes)
1065                                 report_reserved_underflow(fs_info, qgroup,
1066                                                           num_bytes);
1067                         else
1068                                 qgroup->reserved -= num_bytes;
1069                 }
1070                 qgroup->excl_cmpr += sign * num_bytes;
1071                 qgroup_dirty(fs_info, qgroup);
1072
1073                 /* Add any parents of the parents */
1074                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1075                         ret = ulist_add(tmp, glist->group->qgroupid,
1076                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
1077                         if (ret < 0)
1078                                 goto out;
1079                 }
1080         }
1081         ret = 0;
1082 out:
1083         return ret;
1084 }
1085
1086
1087 /*
1088  * Quick path for updating qgroup with only excl refs.
1089  *
1090  * In that case, just update all parent will be enough.
1091  * Or we needs to do a full rescan.
1092  * Caller should also hold fs_info->qgroup_lock.
1093  *
1094  * Return 0 for quick update, return >0 for need to full rescan
1095  * and mark INCONSISTENT flag.
1096  * Return < 0 for other error.
1097  */
1098 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1099                                    struct ulist *tmp, u64 src, u64 dst,
1100                                    int sign)
1101 {
1102         struct btrfs_qgroup *qgroup;
1103         int ret = 1;
1104         int err = 0;
1105
1106         qgroup = find_qgroup_rb(fs_info, src);
1107         if (!qgroup)
1108                 goto out;
1109         if (qgroup->excl == qgroup->rfer) {
1110                 ret = 0;
1111                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1112                                                qgroup->excl, sign);
1113                 if (err < 0) {
1114                         ret = err;
1115                         goto out;
1116                 }
1117         }
1118 out:
1119         if (ret)
1120                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1121         return ret;
1122 }
1123
1124 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
1125                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1126 {
1127         struct btrfs_root *quota_root;
1128         struct btrfs_qgroup *parent;
1129         struct btrfs_qgroup *member;
1130         struct btrfs_qgroup_list *list;
1131         struct ulist *tmp;
1132         int ret = 0;
1133
1134         /* Check the level of src and dst first */
1135         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1136                 return -EINVAL;
1137
1138         tmp = ulist_alloc(GFP_KERNEL);
1139         if (!tmp)
1140                 return -ENOMEM;
1141
1142         mutex_lock(&fs_info->qgroup_ioctl_lock);
1143         quota_root = fs_info->quota_root;
1144         if (!quota_root) {
1145                 ret = -EINVAL;
1146                 goto out;
1147         }
1148         member = find_qgroup_rb(fs_info, src);
1149         parent = find_qgroup_rb(fs_info, dst);
1150         if (!member || !parent) {
1151                 ret = -EINVAL;
1152                 goto out;
1153         }
1154
1155         /* check if such qgroup relation exist firstly */
1156         list_for_each_entry(list, &member->groups, next_group) {
1157                 if (list->group == parent) {
1158                         ret = -EEXIST;
1159                         goto out;
1160                 }
1161         }
1162
1163         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
1164         if (ret)
1165                 goto out;
1166
1167         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
1168         if (ret) {
1169                 del_qgroup_relation_item(trans, quota_root, src, dst);
1170                 goto out;
1171         }
1172
1173         spin_lock(&fs_info->qgroup_lock);
1174         ret = add_relation_rb(fs_info, src, dst);
1175         if (ret < 0) {
1176                 spin_unlock(&fs_info->qgroup_lock);
1177                 goto out;
1178         }
1179         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1180         spin_unlock(&fs_info->qgroup_lock);
1181 out:
1182         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1183         ulist_free(tmp);
1184         return ret;
1185 }
1186
1187 static int __del_qgroup_relation(struct btrfs_trans_handle *trans,
1188                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1189 {
1190         struct btrfs_root *quota_root;
1191         struct btrfs_qgroup *parent;
1192         struct btrfs_qgroup *member;
1193         struct btrfs_qgroup_list *list;
1194         struct ulist *tmp;
1195         int ret = 0;
1196         int err;
1197
1198         tmp = ulist_alloc(GFP_KERNEL);
1199         if (!tmp)
1200                 return -ENOMEM;
1201
1202         quota_root = fs_info->quota_root;
1203         if (!quota_root) {
1204                 ret = -EINVAL;
1205                 goto out;
1206         }
1207
1208         member = find_qgroup_rb(fs_info, src);
1209         parent = find_qgroup_rb(fs_info, dst);
1210         if (!member || !parent) {
1211                 ret = -EINVAL;
1212                 goto out;
1213         }
1214
1215         /* check if such qgroup relation exist firstly */
1216         list_for_each_entry(list, &member->groups, next_group) {
1217                 if (list->group == parent)
1218                         goto exist;
1219         }
1220         ret = -ENOENT;
1221         goto out;
1222 exist:
1223         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
1224         err = del_qgroup_relation_item(trans, quota_root, dst, src);
1225         if (err && !ret)
1226                 ret = err;
1227
1228         spin_lock(&fs_info->qgroup_lock);
1229         del_relation_rb(fs_info, src, dst);
1230         ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1231         spin_unlock(&fs_info->qgroup_lock);
1232 out:
1233         ulist_free(tmp);
1234         return ret;
1235 }
1236
1237 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
1238                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1239 {
1240         int ret = 0;
1241
1242         mutex_lock(&fs_info->qgroup_ioctl_lock);
1243         ret = __del_qgroup_relation(trans, fs_info, src, dst);
1244         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1245
1246         return ret;
1247 }
1248
1249 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
1250                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1251 {
1252         struct btrfs_root *quota_root;
1253         struct btrfs_qgroup *qgroup;
1254         int ret = 0;
1255
1256         mutex_lock(&fs_info->qgroup_ioctl_lock);
1257         quota_root = fs_info->quota_root;
1258         if (!quota_root) {
1259                 ret = -EINVAL;
1260                 goto out;
1261         }
1262         qgroup = find_qgroup_rb(fs_info, qgroupid);
1263         if (qgroup) {
1264                 ret = -EEXIST;
1265                 goto out;
1266         }
1267
1268         ret = add_qgroup_item(trans, quota_root, qgroupid);
1269         if (ret)
1270                 goto out;
1271
1272         spin_lock(&fs_info->qgroup_lock);
1273         qgroup = add_qgroup_rb(fs_info, qgroupid);
1274         spin_unlock(&fs_info->qgroup_lock);
1275
1276         if (IS_ERR(qgroup))
1277                 ret = PTR_ERR(qgroup);
1278 out:
1279         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1280         return ret;
1281 }
1282
1283 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
1284                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1285 {
1286         struct btrfs_root *quota_root;
1287         struct btrfs_qgroup *qgroup;
1288         struct btrfs_qgroup_list *list;
1289         int ret = 0;
1290
1291         mutex_lock(&fs_info->qgroup_ioctl_lock);
1292         quota_root = fs_info->quota_root;
1293         if (!quota_root) {
1294                 ret = -EINVAL;
1295                 goto out;
1296         }
1297
1298         qgroup = find_qgroup_rb(fs_info, qgroupid);
1299         if (!qgroup) {
1300                 ret = -ENOENT;
1301                 goto out;
1302         } else {
1303                 /* check if there are no children of this qgroup */
1304                 if (!list_empty(&qgroup->members)) {
1305                         ret = -EBUSY;
1306                         goto out;
1307                 }
1308         }
1309         ret = del_qgroup_item(trans, quota_root, qgroupid);
1310
1311         while (!list_empty(&qgroup->groups)) {
1312                 list = list_first_entry(&qgroup->groups,
1313                                         struct btrfs_qgroup_list, next_group);
1314                 ret = __del_qgroup_relation(trans, fs_info,
1315                                            qgroupid,
1316                                            list->group->qgroupid);
1317                 if (ret)
1318                         goto out;
1319         }
1320
1321         spin_lock(&fs_info->qgroup_lock);
1322         del_qgroup_rb(fs_info, qgroupid);
1323         spin_unlock(&fs_info->qgroup_lock);
1324 out:
1325         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1326         return ret;
1327 }
1328
1329 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
1330                        struct btrfs_fs_info *fs_info, u64 qgroupid,
1331                        struct btrfs_qgroup_limit *limit)
1332 {
1333         struct btrfs_root *quota_root;
1334         struct btrfs_qgroup *qgroup;
1335         int ret = 0;
1336         /* Sometimes we would want to clear the limit on this qgroup.
1337          * To meet this requirement, we treat the -1 as a special value
1338          * which tell kernel to clear the limit on this qgroup.
1339          */
1340         const u64 CLEAR_VALUE = -1;
1341
1342         mutex_lock(&fs_info->qgroup_ioctl_lock);
1343         quota_root = fs_info->quota_root;
1344         if (!quota_root) {
1345                 ret = -EINVAL;
1346                 goto out;
1347         }
1348
1349         qgroup = find_qgroup_rb(fs_info, qgroupid);
1350         if (!qgroup) {
1351                 ret = -ENOENT;
1352                 goto out;
1353         }
1354
1355         spin_lock(&fs_info->qgroup_lock);
1356         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1357                 if (limit->max_rfer == CLEAR_VALUE) {
1358                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1359                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1360                         qgroup->max_rfer = 0;
1361                 } else {
1362                         qgroup->max_rfer = limit->max_rfer;
1363                 }
1364         }
1365         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1366                 if (limit->max_excl == CLEAR_VALUE) {
1367                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1368                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1369                         qgroup->max_excl = 0;
1370                 } else {
1371                         qgroup->max_excl = limit->max_excl;
1372                 }
1373         }
1374         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1375                 if (limit->rsv_rfer == CLEAR_VALUE) {
1376                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1377                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1378                         qgroup->rsv_rfer = 0;
1379                 } else {
1380                         qgroup->rsv_rfer = limit->rsv_rfer;
1381                 }
1382         }
1383         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1384                 if (limit->rsv_excl == CLEAR_VALUE) {
1385                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1386                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1387                         qgroup->rsv_excl = 0;
1388                 } else {
1389                         qgroup->rsv_excl = limit->rsv_excl;
1390                 }
1391         }
1392         qgroup->lim_flags |= limit->flags;
1393
1394         spin_unlock(&fs_info->qgroup_lock);
1395
1396         ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1397         if (ret) {
1398                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1399                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1400                        qgroupid);
1401         }
1402
1403 out:
1404         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1405         return ret;
1406 }
1407
1408 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1409                                 struct btrfs_delayed_ref_root *delayed_refs,
1410                                 struct btrfs_qgroup_extent_record *record)
1411 {
1412         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1413         struct rb_node *parent_node = NULL;
1414         struct btrfs_qgroup_extent_record *entry;
1415         u64 bytenr = record->bytenr;
1416
1417         assert_spin_locked(&delayed_refs->lock);
1418         trace_btrfs_qgroup_trace_extent(fs_info, record);
1419
1420         while (*p) {
1421                 parent_node = *p;
1422                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1423                                  node);
1424                 if (bytenr < entry->bytenr)
1425                         p = &(*p)->rb_left;
1426                 else if (bytenr > entry->bytenr)
1427                         p = &(*p)->rb_right;
1428                 else
1429                         return 1;
1430         }
1431
1432         rb_link_node(&record->node, parent_node, p);
1433         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1434         return 0;
1435 }
1436
1437 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1438                                    struct btrfs_qgroup_extent_record *qrecord)
1439 {
1440         struct ulist *old_root;
1441         u64 bytenr = qrecord->bytenr;
1442         int ret;
1443
1444         ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root);
1445         if (ret < 0)
1446                 return ret;
1447
1448         /*
1449          * Here we don't need to get the lock of
1450          * trans->transaction->delayed_refs, since inserted qrecord won't
1451          * be deleted, only qrecord->node may be modified (new qrecord insert)
1452          *
1453          * So modifying qrecord->old_roots is safe here
1454          */
1455         qrecord->old_roots = old_root;
1456         return 0;
1457 }
1458
1459 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
1460                 struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes,
1461                 gfp_t gfp_flag)
1462 {
1463         struct btrfs_qgroup_extent_record *record;
1464         struct btrfs_delayed_ref_root *delayed_refs;
1465         int ret;
1466
1467         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1468             || bytenr == 0 || num_bytes == 0)
1469                 return 0;
1470         if (WARN_ON(trans == NULL))
1471                 return -EINVAL;
1472         record = kmalloc(sizeof(*record), gfp_flag);
1473         if (!record)
1474                 return -ENOMEM;
1475
1476         delayed_refs = &trans->transaction->delayed_refs;
1477         record->bytenr = bytenr;
1478         record->num_bytes = num_bytes;
1479         record->old_roots = NULL;
1480
1481         spin_lock(&delayed_refs->lock);
1482         ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1483         spin_unlock(&delayed_refs->lock);
1484         if (ret > 0) {
1485                 kfree(record);
1486                 return 0;
1487         }
1488         return btrfs_qgroup_trace_extent_post(fs_info, record);
1489 }
1490
1491 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1492                                   struct btrfs_fs_info *fs_info,
1493                                   struct extent_buffer *eb)
1494 {
1495         int nr = btrfs_header_nritems(eb);
1496         int i, extent_type, ret;
1497         struct btrfs_key key;
1498         struct btrfs_file_extent_item *fi;
1499         u64 bytenr, num_bytes;
1500
1501         /* We can be called directly from walk_up_proc() */
1502         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1503                 return 0;
1504
1505         for (i = 0; i < nr; i++) {
1506                 btrfs_item_key_to_cpu(eb, &key, i);
1507
1508                 if (key.type != BTRFS_EXTENT_DATA_KEY)
1509                         continue;
1510
1511                 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1512                 /* filter out non qgroup-accountable extents  */
1513                 extent_type = btrfs_file_extent_type(eb, fi);
1514
1515                 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1516                         continue;
1517
1518                 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1519                 if (!bytenr)
1520                         continue;
1521
1522                 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1523
1524                 ret = btrfs_qgroup_trace_extent(trans, fs_info, bytenr,
1525                                                 num_bytes, GFP_NOFS);
1526                 if (ret)
1527                         return ret;
1528         }
1529         cond_resched();
1530         return 0;
1531 }
1532
1533 /*
1534  * Walk up the tree from the bottom, freeing leaves and any interior
1535  * nodes which have had all slots visited. If a node (leaf or
1536  * interior) is freed, the node above it will have it's slot
1537  * incremented. The root node will never be freed.
1538  *
1539  * At the end of this function, we should have a path which has all
1540  * slots incremented to the next position for a search. If we need to
1541  * read a new node it will be NULL and the node above it will have the
1542  * correct slot selected for a later read.
1543  *
1544  * If we increment the root nodes slot counter past the number of
1545  * elements, 1 is returned to signal completion of the search.
1546  */
1547 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1548 {
1549         int level = 0;
1550         int nr, slot;
1551         struct extent_buffer *eb;
1552
1553         if (root_level == 0)
1554                 return 1;
1555
1556         while (level <= root_level) {
1557                 eb = path->nodes[level];
1558                 nr = btrfs_header_nritems(eb);
1559                 path->slots[level]++;
1560                 slot = path->slots[level];
1561                 if (slot >= nr || level == 0) {
1562                         /*
1563                          * Don't free the root -  we will detect this
1564                          * condition after our loop and return a
1565                          * positive value for caller to stop walking the tree.
1566                          */
1567                         if (level != root_level) {
1568                                 btrfs_tree_unlock_rw(eb, path->locks[level]);
1569                                 path->locks[level] = 0;
1570
1571                                 free_extent_buffer(eb);
1572                                 path->nodes[level] = NULL;
1573                                 path->slots[level] = 0;
1574                         }
1575                 } else {
1576                         /*
1577                          * We have a valid slot to walk back down
1578                          * from. Stop here so caller can process these
1579                          * new nodes.
1580                          */
1581                         break;
1582                 }
1583
1584                 level++;
1585         }
1586
1587         eb = path->nodes[root_level];
1588         if (path->slots[root_level] >= btrfs_header_nritems(eb))
1589                 return 1;
1590
1591         return 0;
1592 }
1593
1594 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
1595                                struct btrfs_root *root,
1596                                struct extent_buffer *root_eb,
1597                                u64 root_gen, int root_level)
1598 {
1599         struct btrfs_fs_info *fs_info = root->fs_info;
1600         int ret = 0;
1601         int level;
1602         struct extent_buffer *eb = root_eb;
1603         struct btrfs_path *path = NULL;
1604
1605         BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
1606         BUG_ON(root_eb == NULL);
1607
1608         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1609                 return 0;
1610
1611         if (!extent_buffer_uptodate(root_eb)) {
1612                 ret = btrfs_read_buffer(root_eb, root_gen);
1613                 if (ret)
1614                         goto out;
1615         }
1616
1617         if (root_level == 0) {
1618                 ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, root_eb);
1619                 goto out;
1620         }
1621
1622         path = btrfs_alloc_path();
1623         if (!path)
1624                 return -ENOMEM;
1625
1626         /*
1627          * Walk down the tree.  Missing extent blocks are filled in as
1628          * we go. Metadata is accounted every time we read a new
1629          * extent block.
1630          *
1631          * When we reach a leaf, we account for file extent items in it,
1632          * walk back up the tree (adjusting slot pointers as we go)
1633          * and restart the search process.
1634          */
1635         extent_buffer_get(root_eb); /* For path */
1636         path->nodes[root_level] = root_eb;
1637         path->slots[root_level] = 0;
1638         path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
1639 walk_down:
1640         level = root_level;
1641         while (level >= 0) {
1642                 if (path->nodes[level] == NULL) {
1643                         int parent_slot;
1644                         u64 child_gen;
1645                         u64 child_bytenr;
1646
1647                         /*
1648                          * We need to get child blockptr/gen from parent before
1649                          * we can read it.
1650                           */
1651                         eb = path->nodes[level + 1];
1652                         parent_slot = path->slots[level + 1];
1653                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1654                         child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1655
1656                         eb = read_tree_block(fs_info, child_bytenr, child_gen);
1657                         if (IS_ERR(eb)) {
1658                                 ret = PTR_ERR(eb);
1659                                 goto out;
1660                         } else if (!extent_buffer_uptodate(eb)) {
1661                                 free_extent_buffer(eb);
1662                                 ret = -EIO;
1663                                 goto out;
1664                         }
1665
1666                         path->nodes[level] = eb;
1667                         path->slots[level] = 0;
1668
1669                         btrfs_tree_read_lock(eb);
1670                         btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1671                         path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
1672
1673                         ret = btrfs_qgroup_trace_extent(trans, fs_info,
1674                                                         child_bytenr,
1675                                                         fs_info->nodesize,
1676                                                         GFP_NOFS);
1677                         if (ret)
1678                                 goto out;
1679                 }
1680
1681                 if (level == 0) {
1682                         ret = btrfs_qgroup_trace_leaf_items(trans,fs_info,
1683                                                            path->nodes[level]);
1684                         if (ret)
1685                                 goto out;
1686
1687                         /* Nonzero return here means we completed our search */
1688                         ret = adjust_slots_upwards(path, root_level);
1689                         if (ret)
1690                                 break;
1691
1692                         /* Restart search with new slots */
1693                         goto walk_down;
1694                 }
1695
1696                 level--;
1697         }
1698
1699         ret = 0;
1700 out:
1701         btrfs_free_path(path);
1702
1703         return ret;
1704 }
1705
1706 #define UPDATE_NEW      0
1707 #define UPDATE_OLD      1
1708 /*
1709  * Walk all of the roots that points to the bytenr and adjust their refcnts.
1710  */
1711 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
1712                                 struct ulist *roots, struct ulist *tmp,
1713                                 struct ulist *qgroups, u64 seq, int update_old)
1714 {
1715         struct ulist_node *unode;
1716         struct ulist_iterator uiter;
1717         struct ulist_node *tmp_unode;
1718         struct ulist_iterator tmp_uiter;
1719         struct btrfs_qgroup *qg;
1720         int ret = 0;
1721
1722         if (!roots)
1723                 return 0;
1724         ULIST_ITER_INIT(&uiter);
1725         while ((unode = ulist_next(roots, &uiter))) {
1726                 qg = find_qgroup_rb(fs_info, unode->val);
1727                 if (!qg)
1728                         continue;
1729
1730                 ulist_reinit(tmp);
1731                 ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
1732                                 GFP_ATOMIC);
1733                 if (ret < 0)
1734                         return ret;
1735                 ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
1736                 if (ret < 0)
1737                         return ret;
1738                 ULIST_ITER_INIT(&tmp_uiter);
1739                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1740                         struct btrfs_qgroup_list *glist;
1741
1742                         qg = unode_aux_to_qgroup(tmp_unode);
1743                         if (update_old)
1744                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
1745                         else
1746                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
1747                         list_for_each_entry(glist, &qg->groups, next_group) {
1748                                 ret = ulist_add(qgroups, glist->group->qgroupid,
1749                                                 qgroup_to_aux(glist->group),
1750                                                 GFP_ATOMIC);
1751                                 if (ret < 0)
1752                                         return ret;
1753                                 ret = ulist_add(tmp, glist->group->qgroupid,
1754                                                 qgroup_to_aux(glist->group),
1755                                                 GFP_ATOMIC);
1756                                 if (ret < 0)
1757                                         return ret;
1758                         }
1759                 }
1760         }
1761         return 0;
1762 }
1763
1764 /*
1765  * Update qgroup rfer/excl counters.
1766  * Rfer update is easy, codes can explain themselves.
1767  *
1768  * Excl update is tricky, the update is split into 2 part.
1769  * Part 1: Possible exclusive <-> sharing detect:
1770  *      |       A       |       !A      |
1771  *  -------------------------------------
1772  *  B   |       *       |       -       |
1773  *  -------------------------------------
1774  *  !B  |       +       |       **      |
1775  *  -------------------------------------
1776  *
1777  * Conditions:
1778  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
1779  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
1780  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
1781  * !B:  cur_new_roots == nr_new_roots   (possible exclusive now)
1782  *
1783  * Results:
1784  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
1785  * *: Definitely not changed.           **: Possible unchanged.
1786  *
1787  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
1788  *
1789  * To make the logic clear, we first use condition A and B to split
1790  * combination into 4 results.
1791  *
1792  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
1793  * only on variant maybe 0.
1794  *
1795  * Lastly, check result **, since there are 2 variants maybe 0, split them
1796  * again(2x2).
1797  * But this time we don't need to consider other things, the codes and logic
1798  * is easy to understand now.
1799  */
1800 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
1801                                   struct ulist *qgroups,
1802                                   u64 nr_old_roots,
1803                                   u64 nr_new_roots,
1804                                   u64 num_bytes, u64 seq)
1805 {
1806         struct ulist_node *unode;
1807         struct ulist_iterator uiter;
1808         struct btrfs_qgroup *qg;
1809         u64 cur_new_count, cur_old_count;
1810
1811         ULIST_ITER_INIT(&uiter);
1812         while ((unode = ulist_next(qgroups, &uiter))) {
1813                 bool dirty = false;
1814
1815                 qg = unode_aux_to_qgroup(unode);
1816                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
1817                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
1818
1819                 trace_qgroup_update_counters(fs_info, qg->qgroupid,
1820                                              cur_old_count, cur_new_count);
1821
1822                 /* Rfer update part */
1823                 if (cur_old_count == 0 && cur_new_count > 0) {
1824                         qg->rfer += num_bytes;
1825                         qg->rfer_cmpr += num_bytes;
1826                         dirty = true;
1827                 }
1828                 if (cur_old_count > 0 && cur_new_count == 0) {
1829                         qg->rfer -= num_bytes;
1830                         qg->rfer_cmpr -= num_bytes;
1831                         dirty = true;
1832                 }
1833
1834                 /* Excl update part */
1835                 /* Exclusive/none -> shared case */
1836                 if (cur_old_count == nr_old_roots &&
1837                     cur_new_count < nr_new_roots) {
1838                         /* Exclusive -> shared */
1839                         if (cur_old_count != 0) {
1840                                 qg->excl -= num_bytes;
1841                                 qg->excl_cmpr -= num_bytes;
1842                                 dirty = true;
1843                         }
1844                 }
1845
1846                 /* Shared -> exclusive/none case */
1847                 if (cur_old_count < nr_old_roots &&
1848                     cur_new_count == nr_new_roots) {
1849                         /* Shared->exclusive */
1850                         if (cur_new_count != 0) {
1851                                 qg->excl += num_bytes;
1852                                 qg->excl_cmpr += num_bytes;
1853                                 dirty = true;
1854                         }
1855                 }
1856
1857                 /* Exclusive/none -> exclusive/none case */
1858                 if (cur_old_count == nr_old_roots &&
1859                     cur_new_count == nr_new_roots) {
1860                         if (cur_old_count == 0) {
1861                                 /* None -> exclusive/none */
1862
1863                                 if (cur_new_count != 0) {
1864                                         /* None -> exclusive */
1865                                         qg->excl += num_bytes;
1866                                         qg->excl_cmpr += num_bytes;
1867                                         dirty = true;
1868                                 }
1869                                 /* None -> none, nothing changed */
1870                         } else {
1871                                 /* Exclusive -> exclusive/none */
1872
1873                                 if (cur_new_count == 0) {
1874                                         /* Exclusive -> none */
1875                                         qg->excl -= num_bytes;
1876                                         qg->excl_cmpr -= num_bytes;
1877                                         dirty = true;
1878                                 }
1879                                 /* Exclusive -> exclusive, nothing changed */
1880                         }
1881                 }
1882
1883                 if (dirty)
1884                         qgroup_dirty(fs_info, qg);
1885         }
1886         return 0;
1887 }
1888
1889 /*
1890  * Check if the @roots potentially is a list of fs tree roots
1891  *
1892  * Return 0 for definitely not a fs/subvol tree roots ulist
1893  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
1894  *          one as well)
1895  */
1896 static int maybe_fs_roots(struct ulist *roots)
1897 {
1898         struct ulist_node *unode;
1899         struct ulist_iterator uiter;
1900
1901         /* Empty one, still possible for fs roots */
1902         if (!roots || roots->nnodes == 0)
1903                 return 1;
1904
1905         ULIST_ITER_INIT(&uiter);
1906         unode = ulist_next(roots, &uiter);
1907         if (!unode)
1908                 return 1;
1909
1910         /*
1911          * If it contains fs tree roots, then it must belong to fs/subvol
1912          * trees.
1913          * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
1914          */
1915         return is_fstree(unode->val);
1916 }
1917
1918 int
1919 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
1920                             struct btrfs_fs_info *fs_info,
1921                             u64 bytenr, u64 num_bytes,
1922                             struct ulist *old_roots, struct ulist *new_roots)
1923 {
1924         struct ulist *qgroups = NULL;
1925         struct ulist *tmp = NULL;
1926         u64 seq;
1927         u64 nr_new_roots = 0;
1928         u64 nr_old_roots = 0;
1929         int ret = 0;
1930
1931         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1932                 return 0;
1933
1934         if (new_roots) {
1935                 if (!maybe_fs_roots(new_roots))
1936                         goto out_free;
1937                 nr_new_roots = new_roots->nnodes;
1938         }
1939         if (old_roots) {
1940                 if (!maybe_fs_roots(old_roots))
1941                         goto out_free;
1942                 nr_old_roots = old_roots->nnodes;
1943         }
1944
1945         /* Quick exit, either not fs tree roots, or won't affect any qgroup */
1946         if (nr_old_roots == 0 && nr_new_roots == 0)
1947                 goto out_free;
1948
1949         BUG_ON(!fs_info->quota_root);
1950
1951         trace_btrfs_qgroup_account_extent(fs_info, bytenr, num_bytes,
1952                                           nr_old_roots, nr_new_roots);
1953
1954         qgroups = ulist_alloc(GFP_NOFS);
1955         if (!qgroups) {
1956                 ret = -ENOMEM;
1957                 goto out_free;
1958         }
1959         tmp = ulist_alloc(GFP_NOFS);
1960         if (!tmp) {
1961                 ret = -ENOMEM;
1962                 goto out_free;
1963         }
1964
1965         mutex_lock(&fs_info->qgroup_rescan_lock);
1966         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
1967                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
1968                         mutex_unlock(&fs_info->qgroup_rescan_lock);
1969                         ret = 0;
1970                         goto out_free;
1971                 }
1972         }
1973         mutex_unlock(&fs_info->qgroup_rescan_lock);
1974
1975         spin_lock(&fs_info->qgroup_lock);
1976         seq = fs_info->qgroup_seq;
1977
1978         /* Update old refcnts using old_roots */
1979         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
1980                                    UPDATE_OLD);
1981         if (ret < 0)
1982                 goto out;
1983
1984         /* Update new refcnts using new_roots */
1985         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
1986                                    UPDATE_NEW);
1987         if (ret < 0)
1988                 goto out;
1989
1990         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
1991                                num_bytes, seq);
1992
1993         /*
1994          * Bump qgroup_seq to avoid seq overlap
1995          */
1996         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
1997 out:
1998         spin_unlock(&fs_info->qgroup_lock);
1999 out_free:
2000         ulist_free(tmp);
2001         ulist_free(qgroups);
2002         ulist_free(old_roots);
2003         ulist_free(new_roots);
2004         return ret;
2005 }
2006
2007 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans,
2008                                  struct btrfs_fs_info *fs_info)
2009 {
2010         struct btrfs_qgroup_extent_record *record;
2011         struct btrfs_delayed_ref_root *delayed_refs;
2012         struct ulist *new_roots = NULL;
2013         struct rb_node *node;
2014         u64 qgroup_to_skip;
2015         int ret = 0;
2016
2017         delayed_refs = &trans->transaction->delayed_refs;
2018         qgroup_to_skip = delayed_refs->qgroup_to_skip;
2019         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2020                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
2021                                   node);
2022
2023                 trace_btrfs_qgroup_account_extents(fs_info, record);
2024
2025                 if (!ret) {
2026                         /*
2027                          * Old roots should be searched when inserting qgroup
2028                          * extent record
2029                          */
2030                         if (WARN_ON(!record->old_roots)) {
2031                                 /* Search commit root to find old_roots */
2032                                 ret = btrfs_find_all_roots(NULL, fs_info,
2033                                                 record->bytenr, 0,
2034                                                 &record->old_roots);
2035                                 if (ret < 0)
2036                                         goto cleanup;
2037                         }
2038
2039                         /*
2040                          * Use SEQ_LAST as time_seq to do special search, which
2041                          * doesn't lock tree or delayed_refs and search current
2042                          * root. It's safe inside commit_transaction().
2043                          */
2044                         ret = btrfs_find_all_roots(trans, fs_info,
2045                                         record->bytenr, SEQ_LAST, &new_roots);
2046                         if (ret < 0)
2047                                 goto cleanup;
2048                         if (qgroup_to_skip) {
2049                                 ulist_del(new_roots, qgroup_to_skip, 0);
2050                                 ulist_del(record->old_roots, qgroup_to_skip,
2051                                           0);
2052                         }
2053                         ret = btrfs_qgroup_account_extent(trans, fs_info,
2054                                         record->bytenr, record->num_bytes,
2055                                         record->old_roots, new_roots);
2056                         record->old_roots = NULL;
2057                         new_roots = NULL;
2058                 }
2059 cleanup:
2060                 ulist_free(record->old_roots);
2061                 ulist_free(new_roots);
2062                 new_roots = NULL;
2063                 rb_erase(node, &delayed_refs->dirty_extent_root);
2064                 kfree(record);
2065
2066         }
2067         return ret;
2068 }
2069
2070 /*
2071  * called from commit_transaction. Writes all changed qgroups to disk.
2072  */
2073 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
2074                       struct btrfs_fs_info *fs_info)
2075 {
2076         struct btrfs_root *quota_root = fs_info->quota_root;
2077         int ret = 0;
2078         int start_rescan_worker = 0;
2079
2080         if (!quota_root)
2081                 goto out;
2082
2083         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
2084             test_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2085                 start_rescan_worker = 1;
2086
2087         if (test_and_clear_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2088                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2089         if (test_and_clear_bit(BTRFS_FS_QUOTA_DISABLING, &fs_info->flags))
2090                 clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2091
2092         spin_lock(&fs_info->qgroup_lock);
2093         while (!list_empty(&fs_info->dirty_qgroups)) {
2094                 struct btrfs_qgroup *qgroup;
2095                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
2096                                           struct btrfs_qgroup, dirty);
2097                 list_del_init(&qgroup->dirty);
2098                 spin_unlock(&fs_info->qgroup_lock);
2099                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
2100                 if (ret)
2101                         fs_info->qgroup_flags |=
2102                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2103                 ret = update_qgroup_limit_item(trans, quota_root, qgroup);
2104                 if (ret)
2105                         fs_info->qgroup_flags |=
2106                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2107                 spin_lock(&fs_info->qgroup_lock);
2108         }
2109         if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2110                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2111         else
2112                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2113         spin_unlock(&fs_info->qgroup_lock);
2114
2115         ret = update_qgroup_status_item(trans, fs_info, quota_root);
2116         if (ret)
2117                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2118
2119         if (!ret && start_rescan_worker) {
2120                 ret = qgroup_rescan_init(fs_info, 0, 1);
2121                 if (!ret) {
2122                         qgroup_rescan_zero_tracking(fs_info);
2123                         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2124                                          &fs_info->qgroup_rescan_work);
2125                 }
2126                 ret = 0;
2127         }
2128
2129 out:
2130
2131         return ret;
2132 }
2133
2134 /*
2135  * Copy the accounting information between qgroups. This is necessary
2136  * when a snapshot or a subvolume is created. Throwing an error will
2137  * cause a transaction abort so we take extra care here to only error
2138  * when a readonly fs is a reasonable outcome.
2139  */
2140 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
2141                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
2142                          struct btrfs_qgroup_inherit *inherit)
2143 {
2144         int ret = 0;
2145         int i;
2146         u64 *i_qgroups;
2147         struct btrfs_root *quota_root = fs_info->quota_root;
2148         struct btrfs_qgroup *srcgroup;
2149         struct btrfs_qgroup *dstgroup;
2150         u32 level_size = 0;
2151         u64 nums;
2152
2153         mutex_lock(&fs_info->qgroup_ioctl_lock);
2154         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2155                 goto out;
2156
2157         if (!quota_root) {
2158                 ret = -EINVAL;
2159                 goto out;
2160         }
2161
2162         if (inherit) {
2163                 i_qgroups = (u64 *)(inherit + 1);
2164                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2165                        2 * inherit->num_excl_copies;
2166                 for (i = 0; i < nums; ++i) {
2167                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2168
2169                         /*
2170                          * Zero out invalid groups so we can ignore
2171                          * them later.
2172                          */
2173                         if (!srcgroup ||
2174                             ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2175                                 *i_qgroups = 0ULL;
2176
2177                         ++i_qgroups;
2178                 }
2179         }
2180
2181         /*
2182          * create a tracking group for the subvol itself
2183          */
2184         ret = add_qgroup_item(trans, quota_root, objectid);
2185         if (ret)
2186                 goto out;
2187
2188         if (srcid) {
2189                 struct btrfs_root *srcroot;
2190                 struct btrfs_key srckey;
2191
2192                 srckey.objectid = srcid;
2193                 srckey.type = BTRFS_ROOT_ITEM_KEY;
2194                 srckey.offset = (u64)-1;
2195                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
2196                 if (IS_ERR(srcroot)) {
2197                         ret = PTR_ERR(srcroot);
2198                         goto out;
2199                 }
2200
2201                 level_size = fs_info->nodesize;
2202         }
2203
2204         /*
2205          * add qgroup to all inherited groups
2206          */
2207         if (inherit) {
2208                 i_qgroups = (u64 *)(inherit + 1);
2209                 for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2210                         if (*i_qgroups == 0)
2211                                 continue;
2212                         ret = add_qgroup_relation_item(trans, quota_root,
2213                                                        objectid, *i_qgroups);
2214                         if (ret && ret != -EEXIST)
2215                                 goto out;
2216                         ret = add_qgroup_relation_item(trans, quota_root,
2217                                                        *i_qgroups, objectid);
2218                         if (ret && ret != -EEXIST)
2219                                 goto out;
2220                 }
2221                 ret = 0;
2222         }
2223
2224
2225         spin_lock(&fs_info->qgroup_lock);
2226
2227         dstgroup = add_qgroup_rb(fs_info, objectid);
2228         if (IS_ERR(dstgroup)) {
2229                 ret = PTR_ERR(dstgroup);
2230                 goto unlock;
2231         }
2232
2233         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2234                 dstgroup->lim_flags = inherit->lim.flags;
2235                 dstgroup->max_rfer = inherit->lim.max_rfer;
2236                 dstgroup->max_excl = inherit->lim.max_excl;
2237                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2238                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
2239
2240                 ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
2241                 if (ret) {
2242                         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2243                         btrfs_info(fs_info,
2244                                    "unable to update quota limit for %llu",
2245                                    dstgroup->qgroupid);
2246                         goto unlock;
2247                 }
2248         }
2249
2250         if (srcid) {
2251                 srcgroup = find_qgroup_rb(fs_info, srcid);
2252                 if (!srcgroup)
2253                         goto unlock;
2254
2255                 /*
2256                  * We call inherit after we clone the root in order to make sure
2257                  * our counts don't go crazy, so at this point the only
2258                  * difference between the two roots should be the root node.
2259                  */
2260                 dstgroup->rfer = srcgroup->rfer;
2261                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2262                 dstgroup->excl = level_size;
2263                 dstgroup->excl_cmpr = level_size;
2264                 srcgroup->excl = level_size;
2265                 srcgroup->excl_cmpr = level_size;
2266
2267                 /* inherit the limit info */
2268                 dstgroup->lim_flags = srcgroup->lim_flags;
2269                 dstgroup->max_rfer = srcgroup->max_rfer;
2270                 dstgroup->max_excl = srcgroup->max_excl;
2271                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2272                 dstgroup->rsv_excl = srcgroup->rsv_excl;
2273
2274                 qgroup_dirty(fs_info, dstgroup);
2275                 qgroup_dirty(fs_info, srcgroup);
2276         }
2277
2278         if (!inherit)
2279                 goto unlock;
2280
2281         i_qgroups = (u64 *)(inherit + 1);
2282         for (i = 0; i < inherit->num_qgroups; ++i) {
2283                 if (*i_qgroups) {
2284                         ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2285                         if (ret)
2286                                 goto unlock;
2287                 }
2288                 ++i_qgroups;
2289         }
2290
2291         for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2292                 struct btrfs_qgroup *src;
2293                 struct btrfs_qgroup *dst;
2294
2295                 if (!i_qgroups[0] || !i_qgroups[1])
2296                         continue;
2297
2298                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2299                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2300
2301                 if (!src || !dst) {
2302                         ret = -EINVAL;
2303                         goto unlock;
2304                 }
2305
2306                 dst->rfer = src->rfer - level_size;
2307                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
2308         }
2309         for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2310                 struct btrfs_qgroup *src;
2311                 struct btrfs_qgroup *dst;
2312
2313                 if (!i_qgroups[0] || !i_qgroups[1])
2314                         continue;
2315
2316                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2317                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2318
2319                 if (!src || !dst) {
2320                         ret = -EINVAL;
2321                         goto unlock;
2322                 }
2323
2324                 dst->excl = src->excl + level_size;
2325                 dst->excl_cmpr = src->excl_cmpr + level_size;
2326         }
2327
2328 unlock:
2329         spin_unlock(&fs_info->qgroup_lock);
2330 out:
2331         mutex_unlock(&fs_info->qgroup_ioctl_lock);
2332         return ret;
2333 }
2334
2335 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
2336 {
2337         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2338             qg->reserved + (s64)qg->rfer + num_bytes > qg->max_rfer)
2339                 return false;
2340
2341         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2342             qg->reserved + (s64)qg->excl + num_bytes > qg->max_excl)
2343                 return false;
2344
2345         return true;
2346 }
2347
2348 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce)
2349 {
2350         struct btrfs_root *quota_root;
2351         struct btrfs_qgroup *qgroup;
2352         struct btrfs_fs_info *fs_info = root->fs_info;
2353         u64 ref_root = root->root_key.objectid;
2354         int ret = 0;
2355         int retried = 0;
2356         struct ulist_node *unode;
2357         struct ulist_iterator uiter;
2358
2359         if (!is_fstree(ref_root))
2360                 return 0;
2361
2362         if (num_bytes == 0)
2363                 return 0;
2364
2365         if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2366             capable(CAP_SYS_RESOURCE))
2367                 enforce = false;
2368
2369 retry:
2370         spin_lock(&fs_info->qgroup_lock);
2371         quota_root = fs_info->quota_root;
2372         if (!quota_root)
2373                 goto out;
2374
2375         qgroup = find_qgroup_rb(fs_info, ref_root);
2376         if (!qgroup)
2377                 goto out;
2378
2379         /*
2380          * in a first step, we check all affected qgroups if any limits would
2381          * be exceeded
2382          */
2383         ulist_reinit(fs_info->qgroup_ulist);
2384         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2385                         (uintptr_t)qgroup, GFP_ATOMIC);
2386         if (ret < 0)
2387                 goto out;
2388         ULIST_ITER_INIT(&uiter);
2389         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2390                 struct btrfs_qgroup *qg;
2391                 struct btrfs_qgroup_list *glist;
2392
2393                 qg = unode_aux_to_qgroup(unode);
2394
2395                 if (enforce && !qgroup_check_limits(qg, num_bytes)) {
2396                         /*
2397                          * Commit the tree and retry, since we may have
2398                          * deletions which would free up space.
2399                          */
2400                         if (!retried && qg->reserved > 0) {
2401                                 struct btrfs_trans_handle *trans;
2402
2403                                 spin_unlock(&fs_info->qgroup_lock);
2404                                 ret = btrfs_start_delalloc_inodes(root, 0);
2405                                 if (ret)
2406                                         return ret;
2407                                 btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
2408                                 trans = btrfs_join_transaction(root);
2409                                 if (IS_ERR(trans))
2410                                         return PTR_ERR(trans);
2411                                 ret = btrfs_commit_transaction(trans);
2412                                 if (ret)
2413                                         return ret;
2414                                 retried++;
2415                                 goto retry;
2416                         }
2417                         ret = -EDQUOT;
2418                         goto out;
2419                 }
2420
2421                 list_for_each_entry(glist, &qg->groups, next_group) {
2422                         ret = ulist_add(fs_info->qgroup_ulist,
2423                                         glist->group->qgroupid,
2424                                         (uintptr_t)glist->group, GFP_ATOMIC);
2425                         if (ret < 0)
2426                                 goto out;
2427                 }
2428         }
2429         ret = 0;
2430         /*
2431          * no limits exceeded, now record the reservation into all qgroups
2432          */
2433         ULIST_ITER_INIT(&uiter);
2434         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2435                 struct btrfs_qgroup *qg;
2436
2437                 qg = unode_aux_to_qgroup(unode);
2438
2439                 trace_qgroup_update_reserve(fs_info, qg, num_bytes);
2440                 qg->reserved += num_bytes;
2441         }
2442
2443 out:
2444         spin_unlock(&fs_info->qgroup_lock);
2445         return ret;
2446 }
2447
2448 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2449                                u64 ref_root, u64 num_bytes)
2450 {
2451         struct btrfs_root *quota_root;
2452         struct btrfs_qgroup *qgroup;
2453         struct ulist_node *unode;
2454         struct ulist_iterator uiter;
2455         int ret = 0;
2456
2457         if (!is_fstree(ref_root))
2458                 return;
2459
2460         if (num_bytes == 0)
2461                 return;
2462
2463         spin_lock(&fs_info->qgroup_lock);
2464
2465         quota_root = fs_info->quota_root;
2466         if (!quota_root)
2467                 goto out;
2468
2469         qgroup = find_qgroup_rb(fs_info, ref_root);
2470         if (!qgroup)
2471                 goto out;
2472
2473         ulist_reinit(fs_info->qgroup_ulist);
2474         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2475                         (uintptr_t)qgroup, GFP_ATOMIC);
2476         if (ret < 0)
2477                 goto out;
2478         ULIST_ITER_INIT(&uiter);
2479         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2480                 struct btrfs_qgroup *qg;
2481                 struct btrfs_qgroup_list *glist;
2482
2483                 qg = unode_aux_to_qgroup(unode);
2484
2485                 trace_qgroup_update_reserve(fs_info, qg, -(s64)num_bytes);
2486                 if (qg->reserved < num_bytes)
2487                         report_reserved_underflow(fs_info, qg, num_bytes);
2488                 else
2489                         qg->reserved -= num_bytes;
2490
2491                 list_for_each_entry(glist, &qg->groups, next_group) {
2492                         ret = ulist_add(fs_info->qgroup_ulist,
2493                                         glist->group->qgroupid,
2494                                         (uintptr_t)glist->group, GFP_ATOMIC);
2495                         if (ret < 0)
2496                                 goto out;
2497                 }
2498         }
2499
2500 out:
2501         spin_unlock(&fs_info->qgroup_lock);
2502 }
2503
2504 /*
2505  * returns < 0 on error, 0 when more leafs are to be scanned.
2506  * returns 1 when done.
2507  */
2508 static int
2509 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
2510                    struct btrfs_trans_handle *trans)
2511 {
2512         struct btrfs_key found;
2513         struct extent_buffer *scratch_leaf = NULL;
2514         struct ulist *roots = NULL;
2515         struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
2516         u64 num_bytes;
2517         int slot;
2518         int ret;
2519
2520         mutex_lock(&fs_info->qgroup_rescan_lock);
2521         ret = btrfs_search_slot_for_read(fs_info->extent_root,
2522                                          &fs_info->qgroup_rescan_progress,
2523                                          path, 1, 0);
2524
2525         btrfs_debug(fs_info,
2526                 "current progress key (%llu %u %llu), search_slot ret %d",
2527                 fs_info->qgroup_rescan_progress.objectid,
2528                 fs_info->qgroup_rescan_progress.type,
2529                 fs_info->qgroup_rescan_progress.offset, ret);
2530
2531         if (ret) {
2532                 /*
2533                  * The rescan is about to end, we will not be scanning any
2534                  * further blocks. We cannot unset the RESCAN flag here, because
2535                  * we want to commit the transaction if everything went well.
2536                  * To make the live accounting work in this phase, we set our
2537                  * scan progress pointer such that every real extent objectid
2538                  * will be smaller.
2539                  */
2540                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
2541                 btrfs_release_path(path);
2542                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2543                 return ret;
2544         }
2545
2546         btrfs_item_key_to_cpu(path->nodes[0], &found,
2547                               btrfs_header_nritems(path->nodes[0]) - 1);
2548         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
2549
2550         btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2551         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
2552         if (!scratch_leaf) {
2553                 ret = -ENOMEM;
2554                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2555                 goto out;
2556         }
2557         extent_buffer_get(scratch_leaf);
2558         btrfs_tree_read_lock(scratch_leaf);
2559         btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
2560         slot = path->slots[0];
2561         btrfs_release_path(path);
2562         mutex_unlock(&fs_info->qgroup_rescan_lock);
2563
2564         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
2565                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
2566                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
2567                     found.type != BTRFS_METADATA_ITEM_KEY)
2568                         continue;
2569                 if (found.type == BTRFS_METADATA_ITEM_KEY)
2570                         num_bytes = fs_info->nodesize;
2571                 else
2572                         num_bytes = found.offset;
2573
2574                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
2575                                            &roots);
2576                 if (ret < 0)
2577                         goto out;
2578                 /* For rescan, just pass old_roots as NULL */
2579                 ret = btrfs_qgroup_account_extent(trans, fs_info,
2580                                 found.objectid, num_bytes, NULL, roots);
2581                 if (ret < 0)
2582                         goto out;
2583         }
2584 out:
2585         if (scratch_leaf) {
2586                 btrfs_tree_read_unlock_blocking(scratch_leaf);
2587                 free_extent_buffer(scratch_leaf);
2588         }
2589         btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2590
2591         return ret;
2592 }
2593
2594 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
2595 {
2596         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
2597                                                      qgroup_rescan_work);
2598         struct btrfs_path *path;
2599         struct btrfs_trans_handle *trans = NULL;
2600         int err = -ENOMEM;
2601         int ret = 0;
2602
2603         path = btrfs_alloc_path();
2604         if (!path)
2605                 goto out;
2606
2607         err = 0;
2608         while (!err && !btrfs_fs_closing(fs_info)) {
2609                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
2610                 if (IS_ERR(trans)) {
2611                         err = PTR_ERR(trans);
2612                         break;
2613                 }
2614                 if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
2615                         err = -EINTR;
2616                 } else {
2617                         err = qgroup_rescan_leaf(fs_info, path, trans);
2618                 }
2619                 if (err > 0)
2620                         btrfs_commit_transaction(trans);
2621                 else
2622                         btrfs_end_transaction(trans);
2623         }
2624
2625 out:
2626         btrfs_free_path(path);
2627
2628         mutex_lock(&fs_info->qgroup_rescan_lock);
2629         if (!btrfs_fs_closing(fs_info))
2630                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2631
2632         if (err > 0 &&
2633             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
2634                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2635         } else if (err < 0) {
2636                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2637         }
2638         mutex_unlock(&fs_info->qgroup_rescan_lock);
2639
2640         /*
2641          * only update status, since the previous part has already updated the
2642          * qgroup info.
2643          */
2644         trans = btrfs_start_transaction(fs_info->quota_root, 1);
2645         if (IS_ERR(trans)) {
2646                 err = PTR_ERR(trans);
2647                 btrfs_err(fs_info,
2648                           "fail to start transaction for status update: %d",
2649                           err);
2650                 goto done;
2651         }
2652         ret = update_qgroup_status_item(trans, fs_info, fs_info->quota_root);
2653         if (ret < 0) {
2654                 err = ret;
2655                 btrfs_err(fs_info, "fail to update qgroup status: %d", err);
2656         }
2657         btrfs_end_transaction(trans);
2658
2659         if (btrfs_fs_closing(fs_info)) {
2660                 btrfs_info(fs_info, "qgroup scan paused");
2661         } else if (err >= 0) {
2662                 btrfs_info(fs_info, "qgroup scan completed%s",
2663                         err > 0 ? " (inconsistency flag cleared)" : "");
2664         } else {
2665                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
2666         }
2667
2668 done:
2669         mutex_lock(&fs_info->qgroup_rescan_lock);
2670         fs_info->qgroup_rescan_running = false;
2671         mutex_unlock(&fs_info->qgroup_rescan_lock);
2672         complete_all(&fs_info->qgroup_rescan_completion);
2673 }
2674
2675 /*
2676  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
2677  * memory required for the rescan context.
2678  */
2679 static int
2680 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
2681                    int init_flags)
2682 {
2683         int ret = 0;
2684
2685         if (!init_flags &&
2686             (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
2687              !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
2688                 ret = -EINVAL;
2689                 goto err;
2690         }
2691
2692         mutex_lock(&fs_info->qgroup_rescan_lock);
2693         spin_lock(&fs_info->qgroup_lock);
2694
2695         if (init_flags) {
2696                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2697                         ret = -EINPROGRESS;
2698                 else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
2699                         ret = -EINVAL;
2700
2701                 if (ret) {
2702                         spin_unlock(&fs_info->qgroup_lock);
2703                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2704                         goto err;
2705                 }
2706                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2707         }
2708
2709         memset(&fs_info->qgroup_rescan_progress, 0,
2710                 sizeof(fs_info->qgroup_rescan_progress));
2711         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
2712         init_completion(&fs_info->qgroup_rescan_completion);
2713         fs_info->qgroup_rescan_running = true;
2714
2715         spin_unlock(&fs_info->qgroup_lock);
2716         mutex_unlock(&fs_info->qgroup_rescan_lock);
2717
2718         memset(&fs_info->qgroup_rescan_work, 0,
2719                sizeof(fs_info->qgroup_rescan_work));
2720         btrfs_init_work(&fs_info->qgroup_rescan_work,
2721                         btrfs_qgroup_rescan_helper,
2722                         btrfs_qgroup_rescan_worker, NULL, NULL);
2723
2724         if (ret) {
2725 err:
2726                 btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
2727                 return ret;
2728         }
2729
2730         return 0;
2731 }
2732
2733 static void
2734 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
2735 {
2736         struct rb_node *n;
2737         struct btrfs_qgroup *qgroup;
2738
2739         spin_lock(&fs_info->qgroup_lock);
2740         /* clear all current qgroup tracking information */
2741         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
2742                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
2743                 qgroup->rfer = 0;
2744                 qgroup->rfer_cmpr = 0;
2745                 qgroup->excl = 0;
2746                 qgroup->excl_cmpr = 0;
2747         }
2748         spin_unlock(&fs_info->qgroup_lock);
2749 }
2750
2751 int
2752 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
2753 {
2754         int ret = 0;
2755         struct btrfs_trans_handle *trans;
2756
2757         ret = qgroup_rescan_init(fs_info, 0, 1);
2758         if (ret)
2759                 return ret;
2760
2761         /*
2762          * We have set the rescan_progress to 0, which means no more
2763          * delayed refs will be accounted by btrfs_qgroup_account_ref.
2764          * However, btrfs_qgroup_account_ref may be right after its call
2765          * to btrfs_find_all_roots, in which case it would still do the
2766          * accounting.
2767          * To solve this, we're committing the transaction, which will
2768          * ensure we run all delayed refs and only after that, we are
2769          * going to clear all tracking information for a clean start.
2770          */
2771
2772         trans = btrfs_join_transaction(fs_info->fs_root);
2773         if (IS_ERR(trans)) {
2774                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2775                 return PTR_ERR(trans);
2776         }
2777         ret = btrfs_commit_transaction(trans);
2778         if (ret) {
2779                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2780                 return ret;
2781         }
2782
2783         qgroup_rescan_zero_tracking(fs_info);
2784
2785         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2786                          &fs_info->qgroup_rescan_work);
2787
2788         return 0;
2789 }
2790
2791 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
2792                                      bool interruptible)
2793 {
2794         int running;
2795         int ret = 0;
2796
2797         mutex_lock(&fs_info->qgroup_rescan_lock);
2798         spin_lock(&fs_info->qgroup_lock);
2799         running = fs_info->qgroup_rescan_running;
2800         spin_unlock(&fs_info->qgroup_lock);
2801         mutex_unlock(&fs_info->qgroup_rescan_lock);
2802
2803         if (!running)
2804                 return 0;
2805
2806         if (interruptible)
2807                 ret = wait_for_completion_interruptible(
2808                                         &fs_info->qgroup_rescan_completion);
2809         else
2810                 wait_for_completion(&fs_info->qgroup_rescan_completion);
2811
2812         return ret;
2813 }
2814
2815 /*
2816  * this is only called from open_ctree where we're still single threaded, thus
2817  * locking is omitted here.
2818  */
2819 void
2820 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
2821 {
2822         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2823                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
2824                                  &fs_info->qgroup_rescan_work);
2825 }
2826
2827 /*
2828  * Reserve qgroup space for range [start, start + len).
2829  *
2830  * This function will either reserve space from related qgroups or doing
2831  * nothing if the range is already reserved.
2832  *
2833  * Return 0 for successful reserve
2834  * Return <0 for error (including -EQUOT)
2835  *
2836  * NOTE: this function may sleep for memory allocation.
2837  *       if btrfs_qgroup_reserve_data() is called multiple times with
2838  *       same @reserved, caller must ensure when error happens it's OK
2839  *       to free *ALL* reserved space.
2840  */
2841 int btrfs_qgroup_reserve_data(struct inode *inode,
2842                         struct extent_changeset **reserved_ret, u64 start,
2843                         u64 len)
2844 {
2845         struct btrfs_root *root = BTRFS_I(inode)->root;
2846         struct ulist_node *unode;
2847         struct ulist_iterator uiter;
2848         struct extent_changeset *reserved;
2849         u64 orig_reserved;
2850         u64 to_reserve;
2851         int ret;
2852
2853         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
2854             !is_fstree(root->objectid) || len == 0)
2855                 return 0;
2856
2857         /* @reserved parameter is mandatory for qgroup */
2858         if (WARN_ON(!reserved_ret))
2859                 return -EINVAL;
2860         if (!*reserved_ret) {
2861                 *reserved_ret = extent_changeset_alloc();
2862                 if (!*reserved_ret)
2863                         return -ENOMEM;
2864         }
2865         reserved = *reserved_ret;
2866         /* Record already reserved space */
2867         orig_reserved = reserved->bytes_changed;
2868         ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2869                         start + len -1, EXTENT_QGROUP_RESERVED, reserved);
2870
2871         /* Newly reserved space */
2872         to_reserve = reserved->bytes_changed - orig_reserved;
2873         trace_btrfs_qgroup_reserve_data(inode, start, len,
2874                                         to_reserve, QGROUP_RESERVE);
2875         if (ret < 0)
2876                 goto cleanup;
2877         ret = qgroup_reserve(root, to_reserve, true);
2878         if (ret < 0)
2879                 goto cleanup;
2880
2881         return ret;
2882
2883 cleanup:
2884         /* cleanup *ALL* already reserved ranges */
2885         ULIST_ITER_INIT(&uiter);
2886         while ((unode = ulist_next(&reserved->range_changed, &uiter)))
2887                 clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
2888                                  unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL,
2889                                  GFP_NOFS);
2890         extent_changeset_release(reserved);
2891         return ret;
2892 }
2893
2894 /* Free ranges specified by @reserved, normally in error path */
2895 static int qgroup_free_reserved_data(struct inode *inode,
2896                         struct extent_changeset *reserved, u64 start, u64 len)
2897 {
2898         struct btrfs_root *root = BTRFS_I(inode)->root;
2899         struct ulist_node *unode;
2900         struct ulist_iterator uiter;
2901         struct extent_changeset changeset;
2902         int freed = 0;
2903         int ret;
2904
2905         extent_changeset_init(&changeset);
2906         len = round_up(start + len, root->fs_info->sectorsize);
2907         start = round_down(start, root->fs_info->sectorsize);
2908
2909         ULIST_ITER_INIT(&uiter);
2910         while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
2911                 u64 range_start = unode->val;
2912                 /* unode->aux is the inclusive end */
2913                 u64 range_len = unode->aux - range_start + 1;
2914                 u64 free_start;
2915                 u64 free_len;
2916
2917                 extent_changeset_release(&changeset);
2918
2919                 /* Only free range in range [start, start + len) */
2920                 if (range_start >= start + len ||
2921                     range_start + range_len <= start)
2922                         continue;
2923                 free_start = max(range_start, start);
2924                 free_len = min(start + len, range_start + range_len) -
2925                            free_start;
2926                 /*
2927                  * TODO: To also modify reserved->ranges_reserved to reflect
2928                  * the modification.
2929                  *
2930                  * However as long as we free qgroup reserved according to
2931                  * EXTENT_QGROUP_RESERVED, we won't double free.
2932                  * So not need to rush.
2933                  */
2934                 ret = clear_record_extent_bits(&BTRFS_I(inode)->io_failure_tree,
2935                                 free_start, free_start + free_len - 1,
2936                                 EXTENT_QGROUP_RESERVED, &changeset);
2937                 if (ret < 0)
2938                         goto out;
2939                 freed += changeset.bytes_changed;
2940         }
2941         btrfs_qgroup_free_refroot(root->fs_info, root->objectid, freed);
2942         ret = freed;
2943 out:
2944         extent_changeset_release(&changeset);
2945         return ret;
2946 }
2947
2948 static int __btrfs_qgroup_release_data(struct inode *inode,
2949                         struct extent_changeset *reserved, u64 start, u64 len,
2950                         int free)
2951 {
2952         struct extent_changeset changeset;
2953         int trace_op = QGROUP_RELEASE;
2954         int ret;
2955
2956         /* In release case, we shouldn't have @reserved */
2957         WARN_ON(!free && reserved);
2958         if (free && reserved)
2959                 return qgroup_free_reserved_data(inode, reserved, start, len);
2960         extent_changeset_init(&changeset);
2961         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2962                         start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
2963         if (ret < 0)
2964                 goto out;
2965
2966         if (free)
2967                 trace_op = QGROUP_FREE;
2968         trace_btrfs_qgroup_release_data(inode, start, len,
2969                                         changeset.bytes_changed, trace_op);
2970         if (free)
2971                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
2972                                 BTRFS_I(inode)->root->objectid,
2973                                 changeset.bytes_changed);
2974         ret = changeset.bytes_changed;
2975 out:
2976         extent_changeset_release(&changeset);
2977         return ret;
2978 }
2979
2980 /*
2981  * Free a reserved space range from io_tree and related qgroups
2982  *
2983  * Should be called when a range of pages get invalidated before reaching disk.
2984  * Or for error cleanup case.
2985  * if @reserved is given, only reserved range in [@start, @start + @len) will
2986  * be freed.
2987  *
2988  * For data written to disk, use btrfs_qgroup_release_data().
2989  *
2990  * NOTE: This function may sleep for memory allocation.
2991  */
2992 int btrfs_qgroup_free_data(struct inode *inode,
2993                         struct extent_changeset *reserved, u64 start, u64 len)
2994 {
2995         return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
2996 }
2997
2998 /*
2999  * Release a reserved space range from io_tree only.
3000  *
3001  * Should be called when a range of pages get written to disk and corresponding
3002  * FILE_EXTENT is inserted into corresponding root.
3003  *
3004  * Since new qgroup accounting framework will only update qgroup numbers at
3005  * commit_transaction() time, its reserved space shouldn't be freed from
3006  * related qgroups.
3007  *
3008  * But we should release the range from io_tree, to allow further write to be
3009  * COWed.
3010  *
3011  * NOTE: This function may sleep for memory allocation.
3012  */
3013 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
3014 {
3015         return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3016 }
3017
3018 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3019                               bool enforce)
3020 {
3021         struct btrfs_fs_info *fs_info = root->fs_info;
3022         int ret;
3023
3024         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3025             !is_fstree(root->objectid) || num_bytes == 0)
3026                 return 0;
3027
3028         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3029         trace_qgroup_meta_reserve(root, (s64)num_bytes);
3030         ret = qgroup_reserve(root, num_bytes, enforce);
3031         if (ret < 0)
3032                 return ret;
3033         atomic64_add(num_bytes, &root->qgroup_meta_rsv);
3034         return ret;
3035 }
3036
3037 void btrfs_qgroup_free_meta_all(struct btrfs_root *root)
3038 {
3039         struct btrfs_fs_info *fs_info = root->fs_info;
3040         u64 reserved;
3041
3042         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3043             !is_fstree(root->objectid))
3044                 return;
3045
3046         reserved = atomic64_xchg(&root->qgroup_meta_rsv, 0);
3047         if (reserved == 0)
3048                 return;
3049         trace_qgroup_meta_reserve(root, -(s64)reserved);
3050         btrfs_qgroup_free_refroot(fs_info, root->objectid, reserved);
3051 }
3052
3053 void btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes)
3054 {
3055         struct btrfs_fs_info *fs_info = root->fs_info;
3056
3057         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3058             !is_fstree(root->objectid))
3059                 return;
3060
3061         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3062         WARN_ON(atomic64_read(&root->qgroup_meta_rsv) < num_bytes);
3063         atomic64_sub(num_bytes, &root->qgroup_meta_rsv);
3064         trace_qgroup_meta_reserve(root, -(s64)num_bytes);
3065         btrfs_qgroup_free_refroot(fs_info, root->objectid, num_bytes);
3066 }
3067
3068 /*
3069  * Check qgroup reserved space leaking, normally at destroy inode
3070  * time
3071  */
3072 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
3073 {
3074         struct extent_changeset changeset;
3075         struct ulist_node *unode;
3076         struct ulist_iterator iter;
3077         int ret;
3078
3079         extent_changeset_init(&changeset);
3080         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
3081                         EXTENT_QGROUP_RESERVED, &changeset);
3082
3083         WARN_ON(ret < 0);
3084         if (WARN_ON(changeset.bytes_changed)) {
3085                 ULIST_ITER_INIT(&iter);
3086                 while ((unode = ulist_next(&changeset.range_changed, &iter))) {
3087                         btrfs_warn(BTRFS_I(inode)->root->fs_info,
3088                                 "leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
3089                                 inode->i_ino, unode->val, unode->aux);
3090                 }
3091                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3092                                 BTRFS_I(inode)->root->objectid,
3093                                 changeset.bytes_changed);
3094
3095         }
3096         extent_changeset_release(&changeset);
3097 }