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         btrfs_free_path(path);
 811         return ret;
 812 }
 813
 814 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
 815                        struct btrfs_fs_info *fs_info)
 816 {
 817         struct btrfs_root *quota_root;
 818         struct btrfs_root *tree_root = fs_info->tree_root;
 819         struct btrfs_path *path = NULL;
 820         struct btrfs_qgroup_status_item *ptr;
 821         struct extent_buffer *leaf;
 822         struct btrfs_key key;
 823         struct btrfs_key found_key;
 824         struct btrfs_qgroup *qgroup = NULL;
 825         int ret = 0;
 826         int slot;
 827
 828         mutex_lock(&fs_info->qgroup_ioctl_lock);
 829         if (fs_info->quota_root) {
 830                 set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
 831                 goto out;
 832         }
 833
 834         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 835         if (!fs_info->qgroup_ulist) {
 836                 ret = -ENOMEM;
 837                 goto out;
 838         }
 839
 840         /*
 841          * initially create the quota tree
 842          */
 843         quota_root = btrfs_create_tree(trans, fs_info,
 844                                        BTRFS_QUOTA_TREE_OBJECTID);
 845         if (IS_ERR(quota_root)) {
 846                 ret =  PTR_ERR(quota_root);
 847                 goto out;
 848         }
 849
 850         path = btrfs_alloc_path();
 851         if (!path) {
 852                 ret = -ENOMEM;
 853                 goto out_free_root;
 854         }
 855
 856         key.objectid = 0;
 857         key.type = BTRFS_QGROUP_STATUS_KEY;
 858         key.offset = 0;
 859
 860         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 861                                       sizeof(*ptr));
 862         if (ret)
 863                 goto out_free_path;
 864
 865         leaf = path->nodes[0];
 866         ptr = btrfs_item_ptr(leaf, path->slots[0],
 867                                  struct btrfs_qgroup_status_item);
 868         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
 869         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
 870         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
 871                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 872         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
 873         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
 874
 875         btrfs_mark_buffer_dirty(leaf);
 876
 877         key.objectid = 0;
 878         key.type = BTRFS_ROOT_REF_KEY;
 879         key.offset = 0;
 880
 881         btrfs_release_path(path);
 882         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
 883         if (ret > 0)
 884                 goto out_add_root;
 885         if (ret < 0)
 886                 goto out_free_path;
 887
 888
 889         while (1) {
 890                 slot = path->slots[0];
 891                 leaf = path->nodes[0];
 892                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
 893
 894                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
 895                         ret = add_qgroup_item(trans, quota_root,
 896                                               found_key.offset);
 897                         if (ret)
 898                                 goto out_free_path;
 899
 900                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
 901                         if (IS_ERR(qgroup)) {
 902                                 ret = PTR_ERR(qgroup);
 903                                 goto out_free_path;
 904                         }
 905                 }
 906                 ret = btrfs_next_item(tree_root, path);
 907                 if (ret < 0)
 908                         goto out_free_path;
 909                 if (ret)
 910                         break;
 911         }
 912
 913 out_add_root:
 914         btrfs_release_path(path);
 915         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
 916         if (ret)
 917                 goto out_free_path;
 918
 919         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
 920         if (IS_ERR(qgroup)) {
 921                 ret = PTR_ERR(qgroup);
 922                 goto out_free_path;
 923         }
 924         spin_lock(&fs_info->qgroup_lock);
 925         fs_info->quota_root = quota_root;
 926         set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
 927         spin_unlock(&fs_info->qgroup_lock);
 928 out_free_path:
 929         btrfs_free_path(path);
 930 out_free_root:
 931         if (ret) {
 932                 free_extent_buffer(quota_root->node);
 933                 free_extent_buffer(quota_root->commit_root);
 934                 kfree(quota_root);
 935         }
 936 out:
 937         if (ret) {
 938                 ulist_free(fs_info->qgroup_ulist);
 939                 fs_info->qgroup_ulist = NULL;
 940         }
 941         mutex_unlock(&fs_info->qgroup_ioctl_lock);
 942         return ret;
 943 }
 944
 945 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
 946                         struct btrfs_fs_info *fs_info)
 947 {
 948         struct btrfs_root *quota_root;
 949         int ret = 0;
 950
 951         mutex_lock(&fs_info->qgroup_ioctl_lock);
 952         if (!fs_info->quota_root)
 953                 goto out;
 954         clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 955         btrfs_qgroup_wait_for_completion(fs_info, false);
 956         spin_lock(&fs_info->qgroup_lock);
 957         quota_root = fs_info->quota_root;
 958         fs_info->quota_root = NULL;
 959         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
 960         spin_unlock(&fs_info->qgroup_lock);
 961
 962         btrfs_free_qgroup_config(fs_info);
 963
 964         ret = btrfs_clean_quota_tree(trans, quota_root);
 965         if (ret)
 966                 goto out;
 967
 968         ret = btrfs_del_root(trans, fs_info, &quota_root->root_key);
 969         if (ret)
 970                 goto out;
 971
 972         list_del(&quota_root->dirty_list);
 973
 974         btrfs_tree_lock(quota_root->node);
 975         clean_tree_block(fs_info, quota_root->node);
 976         btrfs_tree_unlock(quota_root->node);
 977         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
 978
 979         free_extent_buffer(quota_root->node);
 980         free_extent_buffer(quota_root->commit_root);
 981         kfree(quota_root);
 982 out:
 983         mutex_unlock(&fs_info->qgroup_ioctl_lock);
 984         return ret;
 985 }
 986
 987 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
 988                          struct btrfs_qgroup *qgroup)
 989 {
 990         if (list_empty(&qgroup->dirty))
 991                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
 992 }
 993
 994 static void report_reserved_underflow(struct btrfs_fs_info *fs_info,
 995                                       struct btrfs_qgroup *qgroup,
 996                                       u64 num_bytes)
 997 {
 998 #ifdef CONFIG_BTRFS_DEBUG
 999         WARN_ON(qgroup->reserved < num_bytes);
1000         btrfs_debug(fs_info,
1001                 "qgroup %llu reserved space underflow, have: %llu, to free: %llu",
1002                 qgroup->qgroupid, qgroup->reserved, num_bytes);
1003 #endif
1004         qgroup->reserved = 0;
1005 }
1006 /*
1007  * The easy accounting, if we are adding/removing the only ref for an extent
1008  * then this qgroup and all of the parent qgroups get their reference and
1009  * exclusive counts adjusted.
1010  *
1011  * Caller should hold fs_info->qgroup_lock.
1012  */
1013 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1014                                     struct ulist *tmp, u64 ref_root,
1015                                     u64 num_bytes, int sign)
1016 {
1017         struct btrfs_qgroup *qgroup;
1018         struct btrfs_qgroup_list *glist;
1019         struct ulist_node *unode;
1020         struct ulist_iterator uiter;
1021         int ret = 0;
1022
1023         qgroup = find_qgroup_rb(fs_info, ref_root);
1024         if (!qgroup)
1025                 goto out;
1026
1027         qgroup->rfer += sign * num_bytes;
1028         qgroup->rfer_cmpr += sign * num_bytes;
1029
1030         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1031         qgroup->excl += sign * num_bytes;
1032         qgroup->excl_cmpr += sign * num_bytes;
1033         if (sign > 0) {
1034                 trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes);
1035                 if (qgroup->reserved < num_bytes)
1036                         report_reserved_underflow(fs_info, qgroup, num_bytes);
1037                 else
1038                         qgroup->reserved -= num_bytes;
1039         }
1040
1041         qgroup_dirty(fs_info, qgroup);
1042
1043         /* Get all of the parent groups that contain this qgroup */
1044         list_for_each_entry(glist, &qgroup->groups, next_group) {
1045                 ret = ulist_add(tmp, glist->group->qgroupid,
1046                                 qgroup_to_aux(glist->group), GFP_ATOMIC);
1047                 if (ret < 0)
1048                         goto out;
1049         }
1050
1051         /* Iterate all of the parents and adjust their reference counts */
1052         ULIST_ITER_INIT(&uiter);
1053         while ((unode = ulist_next(tmp, &uiter))) {
1054                 qgroup = unode_aux_to_qgroup(unode);
1055                 qgroup->rfer += sign * num_bytes;
1056                 qgroup->rfer_cmpr += sign * num_bytes;
1057                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1058                 qgroup->excl += sign * num_bytes;
1059                 if (sign > 0) {
1060                         trace_qgroup_update_reserve(fs_info, qgroup,
1061                                                     -(s64)num_bytes);
1062                         if (qgroup->reserved < num_bytes)
1063                                 report_reserved_underflow(fs_info, qgroup,
1064                                                           num_bytes);
1065                         else
1066                                 qgroup->reserved -= num_bytes;
1067                 }
1068                 qgroup->excl_cmpr += sign * num_bytes;
1069                 qgroup_dirty(fs_info, qgroup);
1070
1071                 /* Add any parents of the parents */
1072                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1073                         ret = ulist_add(tmp, glist->group->qgroupid,
1074                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
1075                         if (ret < 0)
1076                                 goto out;
1077                 }
1078         }
1079         ret = 0;
1080 out:
1081         return ret;
1082 }
1083
1084
1085 /*
1086  * Quick path for updating qgroup with only excl refs.
1087  *
1088  * In that case, just update all parent will be enough.
1089  * Or we needs to do a full rescan.
1090  * Caller should also hold fs_info->qgroup_lock.
1091  *
1092  * Return 0 for quick update, return >0 for need to full rescan
1093  * and mark INCONSISTENT flag.
1094  * Return < 0 for other error.
1095  */
1096 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1097                                    struct ulist *tmp, u64 src, u64 dst,
1098                                    int sign)
1099 {
1100         struct btrfs_qgroup *qgroup;
1101         int ret = 1;
1102         int err = 0;
1103
1104         qgroup = find_qgroup_rb(fs_info, src);
1105         if (!qgroup)
1106                 goto out;
1107         if (qgroup->excl == qgroup->rfer) {
1108                 ret = 0;
1109                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1110                                                qgroup->excl, sign);
1111                 if (err < 0) {
1112                         ret = err;
1113                         goto out;
1114                 }
1115         }
1116 out:
1117         if (ret)
1118                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1119         return ret;
1120 }
1121
1122 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
1123                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1124 {
1125         struct btrfs_root *quota_root;
1126         struct btrfs_qgroup *parent;
1127         struct btrfs_qgroup *member;
1128         struct btrfs_qgroup_list *list;
1129         struct ulist *tmp;
1130         int ret = 0;
1131
1132         /* Check the level of src and dst first */
1133         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1134                 return -EINVAL;
1135
1136         tmp = ulist_alloc(GFP_KERNEL);
1137         if (!tmp)
1138                 return -ENOMEM;
1139
1140         mutex_lock(&fs_info->qgroup_ioctl_lock);
1141         quota_root = fs_info->quota_root;
1142         if (!quota_root) {
1143                 ret = -EINVAL;
1144                 goto out;
1145         }
1146         member = find_qgroup_rb(fs_info, src);
1147         parent = find_qgroup_rb(fs_info, dst);
1148         if (!member || !parent) {
1149                 ret = -EINVAL;
1150                 goto out;
1151         }
1152
1153         /* check if such qgroup relation exist firstly */
1154         list_for_each_entry(list, &member->groups, next_group) {
1155                 if (list->group == parent) {
1156                         ret = -EEXIST;
1157                         goto out;
1158                 }
1159         }
1160
1161         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
1162         if (ret)
1163                 goto out;
1164
1165         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
1166         if (ret) {
1167                 del_qgroup_relation_item(trans, quota_root, src, dst);
1168                 goto out;
1169         }
1170
1171         spin_lock(&fs_info->qgroup_lock);
1172         ret = add_relation_rb(fs_info, src, dst);
1173         if (ret < 0) {
1174                 spin_unlock(&fs_info->qgroup_lock);
1175                 goto out;
1176         }
1177         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1178         spin_unlock(&fs_info->qgroup_lock);
1179 out:
1180         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1181         ulist_free(tmp);
1182         return ret;
1183 }
1184
1185 static int __del_qgroup_relation(struct btrfs_trans_handle *trans,
1186                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1187 {
1188         struct btrfs_root *quota_root;
1189         struct btrfs_qgroup *parent;
1190         struct btrfs_qgroup *member;
1191         struct btrfs_qgroup_list *list;
1192         struct ulist *tmp;
1193         int ret = 0;
1194         int err;
1195
1196         tmp = ulist_alloc(GFP_KERNEL);
1197         if (!tmp)
1198                 return -ENOMEM;
1199
1200         quota_root = fs_info->quota_root;
1201         if (!quota_root) {
1202                 ret = -EINVAL;
1203                 goto out;
1204         }
1205
1206         member = find_qgroup_rb(fs_info, src);
1207         parent = find_qgroup_rb(fs_info, dst);
1208         if (!member || !parent) {
1209                 ret = -EINVAL;
1210                 goto out;
1211         }
1212
1213         /* check if such qgroup relation exist firstly */
1214         list_for_each_entry(list, &member->groups, next_group) {
1215                 if (list->group == parent)
1216                         goto exist;
1217         }
1218         ret = -ENOENT;
1219         goto out;
1220 exist:
1221         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
1222         err = del_qgroup_relation_item(trans, quota_root, dst, src);
1223         if (err && !ret)
1224                 ret = err;
1225
1226         spin_lock(&fs_info->qgroup_lock);
1227         del_relation_rb(fs_info, src, dst);
1228         ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1229         spin_unlock(&fs_info->qgroup_lock);
1230 out:
1231         ulist_free(tmp);
1232         return ret;
1233 }
1234
1235 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
1236                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1237 {
1238         int ret = 0;
1239
1240         mutex_lock(&fs_info->qgroup_ioctl_lock);
1241         ret = __del_qgroup_relation(trans, fs_info, src, dst);
1242         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1243
1244         return ret;
1245 }
1246
1247 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
1248                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1249 {
1250         struct btrfs_root *quota_root;
1251         struct btrfs_qgroup *qgroup;
1252         int ret = 0;
1253
1254         mutex_lock(&fs_info->qgroup_ioctl_lock);
1255         quota_root = fs_info->quota_root;
1256         if (!quota_root) {
1257                 ret = -EINVAL;
1258                 goto out;
1259         }
1260         qgroup = find_qgroup_rb(fs_info, qgroupid);
1261         if (qgroup) {
1262                 ret = -EEXIST;
1263                 goto out;
1264         }
1265
1266         ret = add_qgroup_item(trans, quota_root, qgroupid);
1267         if (ret)
1268                 goto out;
1269
1270         spin_lock(&fs_info->qgroup_lock);
1271         qgroup = add_qgroup_rb(fs_info, qgroupid);
1272         spin_unlock(&fs_info->qgroup_lock);
1273
1274         if (IS_ERR(qgroup))
1275                 ret = PTR_ERR(qgroup);
1276 out:
1277         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1278         return ret;
1279 }
1280
1281 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
1282                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1283 {
1284         struct btrfs_root *quota_root;
1285         struct btrfs_qgroup *qgroup;
1286         struct btrfs_qgroup_list *list;
1287         int ret = 0;
1288
1289         mutex_lock(&fs_info->qgroup_ioctl_lock);
1290         quota_root = fs_info->quota_root;
1291         if (!quota_root) {
1292                 ret = -EINVAL;
1293                 goto out;
1294         }
1295
1296         qgroup = find_qgroup_rb(fs_info, qgroupid);
1297         if (!qgroup) {
1298                 ret = -ENOENT;
1299                 goto out;
1300         } else {
1301                 /* check if there are no children of this qgroup */
1302                 if (!list_empty(&qgroup->members)) {
1303                         ret = -EBUSY;
1304                         goto out;
1305                 }
1306         }
1307         ret = del_qgroup_item(trans, quota_root, qgroupid);
1308         if (ret && ret != -ENOENT)
1309                 goto out;
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, false);
1445         if (ret < 0) {
1446                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1447                 btrfs_warn(fs_info,
1448 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1449                         ret);
1450                 return 0;
1451         }
1452
1453         /*
1454          * Here we don't need to get the lock of
1455          * trans->transaction->delayed_refs, since inserted qrecord won't
1456          * be deleted, only qrecord->node may be modified (new qrecord insert)
1457          *
1458          * So modifying qrecord->old_roots is safe here
1459          */
1460         qrecord->old_roots = old_root;
1461         return 0;
1462 }
1463
1464 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
1465                 struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes,
1466                 gfp_t gfp_flag)
1467 {
1468         struct btrfs_qgroup_extent_record *record;
1469         struct btrfs_delayed_ref_root *delayed_refs;
1470         int ret;
1471
1472         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1473             || bytenr == 0 || num_bytes == 0)
1474                 return 0;
1475         if (WARN_ON(trans == NULL))
1476                 return -EINVAL;
1477         record = kmalloc(sizeof(*record), gfp_flag);
1478         if (!record)
1479                 return -ENOMEM;
1480
1481         delayed_refs = &trans->transaction->delayed_refs;
1482         record->bytenr = bytenr;
1483         record->num_bytes = num_bytes;
1484         record->old_roots = NULL;
1485
1486         spin_lock(&delayed_refs->lock);
1487         ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1488         spin_unlock(&delayed_refs->lock);
1489         if (ret > 0) {
1490                 kfree(record);
1491                 return 0;
1492         }
1493         return btrfs_qgroup_trace_extent_post(fs_info, record);
1494 }
1495
1496 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1497                                   struct btrfs_fs_info *fs_info,
1498                                   struct extent_buffer *eb)
1499 {
1500         int nr = btrfs_header_nritems(eb);
1501         int i, extent_type, ret;
1502         struct btrfs_key key;
1503         struct btrfs_file_extent_item *fi;
1504         u64 bytenr, num_bytes;
1505
1506         /* We can be called directly from walk_up_proc() */
1507         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1508                 return 0;
1509
1510         for (i = 0; i < nr; i++) {
1511                 btrfs_item_key_to_cpu(eb, &key, i);
1512
1513                 if (key.type != BTRFS_EXTENT_DATA_KEY)
1514                         continue;
1515
1516                 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1517                 /* filter out non qgroup-accountable extents  */
1518                 extent_type = btrfs_file_extent_type(eb, fi);
1519
1520                 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1521                         continue;
1522
1523                 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1524                 if (!bytenr)
1525                         continue;
1526
1527                 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1528
1529                 ret = btrfs_qgroup_trace_extent(trans, fs_info, bytenr,
1530                                                 num_bytes, GFP_NOFS);
1531                 if (ret)
1532                         return ret;
1533         }
1534         cond_resched();
1535         return 0;
1536 }
1537
1538 /*
1539  * Walk up the tree from the bottom, freeing leaves and any interior
1540  * nodes which have had all slots visited. If a node (leaf or
1541  * interior) is freed, the node above it will have it's slot
1542  * incremented. The root node will never be freed.
1543  *
1544  * At the end of this function, we should have a path which has all
1545  * slots incremented to the next position for a search. If we need to
1546  * read a new node it will be NULL and the node above it will have the
1547  * correct slot selected for a later read.
1548  *
1549  * If we increment the root nodes slot counter past the number of
1550  * elements, 1 is returned to signal completion of the search.
1551  */
1552 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1553 {
1554         int level = 0;
1555         int nr, slot;
1556         struct extent_buffer *eb;
1557
1558         if (root_level == 0)
1559                 return 1;
1560
1561         while (level <= root_level) {
1562                 eb = path->nodes[level];
1563                 nr = btrfs_header_nritems(eb);
1564                 path->slots[level]++;
1565                 slot = path->slots[level];
1566                 if (slot >= nr || level == 0) {
1567                         /*
1568                          * Don't free the root -  we will detect this
1569                          * condition after our loop and return a
1570                          * positive value for caller to stop walking the tree.
1571                          */
1572                         if (level != root_level) {
1573                                 btrfs_tree_unlock_rw(eb, path->locks[level]);
1574                                 path->locks[level] = 0;
1575
1576                                 free_extent_buffer(eb);
1577                                 path->nodes[level] = NULL;
1578                                 path->slots[level] = 0;
1579                         }
1580                 } else {
1581                         /*
1582                          * We have a valid slot to walk back down
1583                          * from. Stop here so caller can process these
1584                          * new nodes.
1585                          */
1586                         break;
1587                 }
1588
1589                 level++;
1590         }
1591
1592         eb = path->nodes[root_level];
1593         if (path->slots[root_level] >= btrfs_header_nritems(eb))
1594                 return 1;
1595
1596         return 0;
1597 }
1598
1599 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
1600                                struct btrfs_root *root,
1601                                struct extent_buffer *root_eb,
1602                                u64 root_gen, int root_level)
1603 {
1604         struct btrfs_fs_info *fs_info = root->fs_info;
1605         int ret = 0;
1606         int level;
1607         struct extent_buffer *eb = root_eb;
1608         struct btrfs_path *path = NULL;
1609
1610         BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
1611         BUG_ON(root_eb == NULL);
1612
1613         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1614                 return 0;
1615
1616         if (!extent_buffer_uptodate(root_eb)) {
1617                 ret = btrfs_read_buffer(root_eb, root_gen);
1618                 if (ret)
1619                         goto out;
1620         }
1621
1622         if (root_level == 0) {
1623                 ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, root_eb);
1624                 goto out;
1625         }
1626
1627         path = btrfs_alloc_path();
1628         if (!path)
1629                 return -ENOMEM;
1630
1631         /*
1632          * Walk down the tree.  Missing extent blocks are filled in as
1633          * we go. Metadata is accounted every time we read a new
1634          * extent block.
1635          *
1636          * When we reach a leaf, we account for file extent items in it,
1637          * walk back up the tree (adjusting slot pointers as we go)
1638          * and restart the search process.
1639          */
1640         extent_buffer_get(root_eb); /* For path */
1641         path->nodes[root_level] = root_eb;
1642         path->slots[root_level] = 0;
1643         path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
1644 walk_down:
1645         level = root_level;
1646         while (level >= 0) {
1647                 if (path->nodes[level] == NULL) {
1648                         int parent_slot;
1649                         u64 child_gen;
1650                         u64 child_bytenr;
1651
1652                         /*
1653                          * We need to get child blockptr/gen from parent before
1654                          * we can read it.
1655                           */
1656                         eb = path->nodes[level + 1];
1657                         parent_slot = path->slots[level + 1];
1658                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1659                         child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1660
1661                         eb = read_tree_block(fs_info, child_bytenr, child_gen);
1662                         if (IS_ERR(eb)) {
1663                                 ret = PTR_ERR(eb);
1664                                 goto out;
1665                         } else if (!extent_buffer_uptodate(eb)) {
1666                                 free_extent_buffer(eb);
1667                                 ret = -EIO;
1668                                 goto out;
1669                         }
1670
1671                         path->nodes[level] = eb;
1672                         path->slots[level] = 0;
1673
1674                         btrfs_tree_read_lock(eb);
1675                         btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1676                         path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
1677
1678                         ret = btrfs_qgroup_trace_extent(trans, fs_info,
1679                                                         child_bytenr,
1680                                                         fs_info->nodesize,
1681                                                         GFP_NOFS);
1682                         if (ret)
1683                                 goto out;
1684                 }
1685
1686                 if (level == 0) {
1687                         ret = btrfs_qgroup_trace_leaf_items(trans,fs_info,
1688                                                            path->nodes[level]);
1689                         if (ret)
1690                                 goto out;
1691
1692                         /* Nonzero return here means we completed our search */
1693                         ret = adjust_slots_upwards(path, root_level);
1694                         if (ret)
1695                                 break;
1696
1697                         /* Restart search with new slots */
1698                         goto walk_down;
1699                 }
1700
1701                 level--;
1702         }
1703
1704         ret = 0;
1705 out:
1706         btrfs_free_path(path);
1707
1708         return ret;
1709 }
1710
1711 #define UPDATE_NEW      0
1712 #define UPDATE_OLD      1
1713 /*
1714  * Walk all of the roots that points to the bytenr and adjust their refcnts.
1715  */
1716 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
1717                                 struct ulist *roots, struct ulist *tmp,
1718                                 struct ulist *qgroups, u64 seq, int update_old)
1719 {
1720         struct ulist_node *unode;
1721         struct ulist_iterator uiter;
1722         struct ulist_node *tmp_unode;
1723         struct ulist_iterator tmp_uiter;
1724         struct btrfs_qgroup *qg;
1725         int ret = 0;
1726
1727         if (!roots)
1728                 return 0;
1729         ULIST_ITER_INIT(&uiter);
1730         while ((unode = ulist_next(roots, &uiter))) {
1731                 qg = find_qgroup_rb(fs_info, unode->val);
1732                 if (!qg)
1733                         continue;
1734
1735                 ulist_reinit(tmp);
1736                 ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
1737                                 GFP_ATOMIC);
1738                 if (ret < 0)
1739                         return ret;
1740                 ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
1741                 if (ret < 0)
1742                         return ret;
1743                 ULIST_ITER_INIT(&tmp_uiter);
1744                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1745                         struct btrfs_qgroup_list *glist;
1746
1747                         qg = unode_aux_to_qgroup(tmp_unode);
1748                         if (update_old)
1749                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
1750                         else
1751                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
1752                         list_for_each_entry(glist, &qg->groups, next_group) {
1753                                 ret = ulist_add(qgroups, glist->group->qgroupid,
1754                                                 qgroup_to_aux(glist->group),
1755                                                 GFP_ATOMIC);
1756                                 if (ret < 0)
1757                                         return ret;
1758                                 ret = ulist_add(tmp, glist->group->qgroupid,
1759                                                 qgroup_to_aux(glist->group),
1760                                                 GFP_ATOMIC);
1761                                 if (ret < 0)
1762                                         return ret;
1763                         }
1764                 }
1765         }
1766         return 0;
1767 }
1768
1769 /*
1770  * Update qgroup rfer/excl counters.
1771  * Rfer update is easy, codes can explain themselves.
1772  *
1773  * Excl update is tricky, the update is split into 2 part.
1774  * Part 1: Possible exclusive <-> sharing detect:
1775  *      |       A       |       !A      |
1776  *  -------------------------------------
1777  *  B   |       *       |       -       |
1778  *  -------------------------------------
1779  *  !B  |       +       |       **      |
1780  *  -------------------------------------
1781  *
1782  * Conditions:
1783  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
1784  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
1785  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
1786  * !B:  cur_new_roots == nr_new_roots   (possible exclusive now)
1787  *
1788  * Results:
1789  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
1790  * *: Definitely not changed.           **: Possible unchanged.
1791  *
1792  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
1793  *
1794  * To make the logic clear, we first use condition A and B to split
1795  * combination into 4 results.
1796  *
1797  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
1798  * only on variant maybe 0.
1799  *
1800  * Lastly, check result **, since there are 2 variants maybe 0, split them
1801  * again(2x2).
1802  * But this time we don't need to consider other things, the codes and logic
1803  * is easy to understand now.
1804  */
1805 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
1806                                   struct ulist *qgroups,
1807                                   u64 nr_old_roots,
1808                                   u64 nr_new_roots,
1809                                   u64 num_bytes, u64 seq)
1810 {
1811         struct ulist_node *unode;
1812         struct ulist_iterator uiter;
1813         struct btrfs_qgroup *qg;
1814         u64 cur_new_count, cur_old_count;
1815
1816         ULIST_ITER_INIT(&uiter);
1817         while ((unode = ulist_next(qgroups, &uiter))) {
1818                 bool dirty = false;
1819
1820                 qg = unode_aux_to_qgroup(unode);
1821                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
1822                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
1823
1824                 trace_qgroup_update_counters(fs_info, qg->qgroupid,
1825                                              cur_old_count, cur_new_count);
1826
1827                 /* Rfer update part */
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                 if (cur_old_count > 0 && cur_new_count == 0) {
1834                         qg->rfer -= num_bytes;
1835                         qg->rfer_cmpr -= num_bytes;
1836                         dirty = true;
1837                 }
1838
1839                 /* Excl update part */
1840                 /* Exclusive/none -> shared case */
1841                 if (cur_old_count == nr_old_roots &&
1842                     cur_new_count < nr_new_roots) {
1843                         /* Exclusive -> shared */
1844                         if (cur_old_count != 0) {
1845                                 qg->excl -= num_bytes;
1846                                 qg->excl_cmpr -= num_bytes;
1847                                 dirty = true;
1848                         }
1849                 }
1850
1851                 /* Shared -> exclusive/none case */
1852                 if (cur_old_count < nr_old_roots &&
1853                     cur_new_count == nr_new_roots) {
1854                         /* Shared->exclusive */
1855                         if (cur_new_count != 0) {
1856                                 qg->excl += num_bytes;
1857                                 qg->excl_cmpr += num_bytes;
1858                                 dirty = true;
1859                         }
1860                 }
1861
1862                 /* Exclusive/none -> exclusive/none case */
1863                 if (cur_old_count == nr_old_roots &&
1864                     cur_new_count == nr_new_roots) {
1865                         if (cur_old_count == 0) {
1866                                 /* None -> exclusive/none */
1867
1868                                 if (cur_new_count != 0) {
1869                                         /* None -> exclusive */
1870                                         qg->excl += num_bytes;
1871                                         qg->excl_cmpr += num_bytes;
1872                                         dirty = true;
1873                                 }
1874                                 /* None -> none, nothing changed */
1875                         } else {
1876                                 /* Exclusive -> exclusive/none */
1877
1878                                 if (cur_new_count == 0) {
1879                                         /* Exclusive -> none */
1880                                         qg->excl -= num_bytes;
1881                                         qg->excl_cmpr -= num_bytes;
1882                                         dirty = true;
1883                                 }
1884                                 /* Exclusive -> exclusive, nothing changed */
1885                         }
1886                 }
1887
1888                 if (dirty)
1889                         qgroup_dirty(fs_info, qg);
1890         }
1891         return 0;
1892 }
1893
1894 /*
1895  * Check if the @roots potentially is a list of fs tree roots
1896  *
1897  * Return 0 for definitely not a fs/subvol tree roots ulist
1898  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
1899  *          one as well)
1900  */
1901 static int maybe_fs_roots(struct ulist *roots)
1902 {
1903         struct ulist_node *unode;
1904         struct ulist_iterator uiter;
1905
1906         /* Empty one, still possible for fs roots */
1907         if (!roots || roots->nnodes == 0)
1908                 return 1;
1909
1910         ULIST_ITER_INIT(&uiter);
1911         unode = ulist_next(roots, &uiter);
1912         if (!unode)
1913                 return 1;
1914
1915         /*
1916          * If it contains fs tree roots, then it must belong to fs/subvol
1917          * trees.
1918          * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
1919          */
1920         return is_fstree(unode->val);
1921 }
1922
1923 int
1924 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
1925                             struct btrfs_fs_info *fs_info,
1926                             u64 bytenr, u64 num_bytes,
1927                             struct ulist *old_roots, struct ulist *new_roots)
1928 {
1929         struct ulist *qgroups = NULL;
1930         struct ulist *tmp = NULL;
1931         u64 seq;
1932         u64 nr_new_roots = 0;
1933         u64 nr_old_roots = 0;
1934         int ret = 0;
1935
1936         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1937                 return 0;
1938
1939         if (new_roots) {
1940                 if (!maybe_fs_roots(new_roots))
1941                         goto out_free;
1942                 nr_new_roots = new_roots->nnodes;
1943         }
1944         if (old_roots) {
1945                 if (!maybe_fs_roots(old_roots))
1946                         goto out_free;
1947                 nr_old_roots = old_roots->nnodes;
1948         }
1949
1950         /* Quick exit, either not fs tree roots, or won't affect any qgroup */
1951         if (nr_old_roots == 0 && nr_new_roots == 0)
1952                 goto out_free;
1953
1954         BUG_ON(!fs_info->quota_root);
1955
1956         trace_btrfs_qgroup_account_extent(fs_info, bytenr, num_bytes,
1957                                           nr_old_roots, nr_new_roots);
1958
1959         qgroups = ulist_alloc(GFP_NOFS);
1960         if (!qgroups) {
1961                 ret = -ENOMEM;
1962                 goto out_free;
1963         }
1964         tmp = ulist_alloc(GFP_NOFS);
1965         if (!tmp) {
1966                 ret = -ENOMEM;
1967                 goto out_free;
1968         }
1969
1970         mutex_lock(&fs_info->qgroup_rescan_lock);
1971         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
1972                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
1973                         mutex_unlock(&fs_info->qgroup_rescan_lock);
1974                         ret = 0;
1975                         goto out_free;
1976                 }
1977         }
1978         mutex_unlock(&fs_info->qgroup_rescan_lock);
1979
1980         spin_lock(&fs_info->qgroup_lock);
1981         seq = fs_info->qgroup_seq;
1982
1983         /* Update old refcnts using old_roots */
1984         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
1985                                    UPDATE_OLD);
1986         if (ret < 0)
1987                 goto out;
1988
1989         /* Update new refcnts using new_roots */
1990         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
1991                                    UPDATE_NEW);
1992         if (ret < 0)
1993                 goto out;
1994
1995         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
1996                                num_bytes, seq);
1997
1998         /*
1999          * Bump qgroup_seq to avoid seq overlap
2000          */
2001         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2002 out:
2003         spin_unlock(&fs_info->qgroup_lock);
2004 out_free:
2005         ulist_free(tmp);
2006         ulist_free(qgroups);
2007         ulist_free(old_roots);
2008         ulist_free(new_roots);
2009         return ret;
2010 }
2011
2012 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans,
2013                                  struct btrfs_fs_info *fs_info)
2014 {
2015         struct btrfs_qgroup_extent_record *record;
2016         struct btrfs_delayed_ref_root *delayed_refs;
2017         struct ulist *new_roots = NULL;
2018         struct rb_node *node;
2019         u64 qgroup_to_skip;
2020         int ret = 0;
2021
2022         delayed_refs = &trans->transaction->delayed_refs;
2023         qgroup_to_skip = delayed_refs->qgroup_to_skip;
2024         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2025                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
2026                                   node);
2027
2028                 trace_btrfs_qgroup_account_extents(fs_info, record);
2029
2030                 if (!ret) {
2031                         /*
2032                          * Old roots should be searched when inserting qgroup
2033                          * extent record
2034                          */
2035                         if (WARN_ON(!record->old_roots)) {
2036                                 /* Search commit root to find old_roots */
2037                                 ret = btrfs_find_all_roots(NULL, fs_info,
2038                                                 record->bytenr, 0,
2039                                                 &record->old_roots, false);
2040                                 if (ret < 0)
2041                                         goto cleanup;
2042                         }
2043
2044                         /*
2045                          * Use SEQ_LAST as time_seq to do special search, which
2046                          * doesn't lock tree or delayed_refs and search current
2047                          * root. It's safe inside commit_transaction().
2048                          */
2049                         ret = btrfs_find_all_roots(trans, fs_info,
2050                                 record->bytenr, SEQ_LAST, &new_roots, false);
2051                         if (ret < 0)
2052                                 goto cleanup;
2053                         if (qgroup_to_skip) {
2054                                 ulist_del(new_roots, qgroup_to_skip, 0);
2055                                 ulist_del(record->old_roots, qgroup_to_skip,
2056                                           0);
2057                         }
2058                         ret = btrfs_qgroup_account_extent(trans, fs_info,
2059                                         record->bytenr, record->num_bytes,
2060                                         record->old_roots, new_roots);
2061                         record->old_roots = NULL;
2062                         new_roots = NULL;
2063                 }
2064 cleanup:
2065                 ulist_free(record->old_roots);
2066                 ulist_free(new_roots);
2067                 new_roots = NULL;
2068                 rb_erase(node, &delayed_refs->dirty_extent_root);
2069                 kfree(record);
2070
2071         }
2072         return ret;
2073 }
2074
2075 /*
2076  * called from commit_transaction. Writes all changed qgroups to disk.
2077  */
2078 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
2079                       struct btrfs_fs_info *fs_info)
2080 {
2081         struct btrfs_root *quota_root = fs_info->quota_root;
2082         int ret = 0;
2083         int start_rescan_worker = 0;
2084
2085         if (!quota_root)
2086                 goto out;
2087
2088         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
2089             test_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2090                 start_rescan_worker = 1;
2091
2092         if (test_and_clear_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2093                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2094
2095         spin_lock(&fs_info->qgroup_lock);
2096         while (!list_empty(&fs_info->dirty_qgroups)) {
2097                 struct btrfs_qgroup *qgroup;
2098                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
2099                                           struct btrfs_qgroup, dirty);
2100                 list_del_init(&qgroup->dirty);
2101                 spin_unlock(&fs_info->qgroup_lock);
2102                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
2103                 if (ret)
2104                         fs_info->qgroup_flags |=
2105                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2106                 ret = update_qgroup_limit_item(trans, quota_root, qgroup);
2107                 if (ret)
2108                         fs_info->qgroup_flags |=
2109                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2110                 spin_lock(&fs_info->qgroup_lock);
2111         }
2112         if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2113                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2114         else
2115                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2116         spin_unlock(&fs_info->qgroup_lock);
2117
2118         ret = update_qgroup_status_item(trans, fs_info, quota_root);
2119         if (ret)
2120                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2121
2122         if (!ret && start_rescan_worker) {
2123                 ret = qgroup_rescan_init(fs_info, 0, 1);
2124                 if (!ret) {
2125                         qgroup_rescan_zero_tracking(fs_info);
2126                         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2127                                          &fs_info->qgroup_rescan_work);
2128                 }
2129                 ret = 0;
2130         }
2131
2132 out:
2133
2134         return ret;
2135 }
2136
2137 /*
2138  * Copy the accounting information between qgroups. This is necessary
2139  * when a snapshot or a subvolume is created. Throwing an error will
2140  * cause a transaction abort so we take extra care here to only error
2141  * when a readonly fs is a reasonable outcome.
2142  */
2143 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
2144                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
2145                          struct btrfs_qgroup_inherit *inherit)
2146 {
2147         int ret = 0;
2148         int i;
2149         u64 *i_qgroups;
2150         struct btrfs_root *quota_root = fs_info->quota_root;
2151         struct btrfs_qgroup *srcgroup;
2152         struct btrfs_qgroup *dstgroup;
2153         u32 level_size = 0;
2154         u64 nums;
2155
2156         mutex_lock(&fs_info->qgroup_ioctl_lock);
2157         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2158                 goto out;
2159
2160         if (!quota_root) {
2161                 ret = -EINVAL;
2162                 goto out;
2163         }
2164
2165         if (inherit) {
2166                 i_qgroups = (u64 *)(inherit + 1);
2167                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2168                        2 * inherit->num_excl_copies;
2169                 for (i = 0; i < nums; ++i) {
2170                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2171
2172                         /*
2173                          * Zero out invalid groups so we can ignore
2174                          * them later.
2175                          */
2176                         if (!srcgroup ||
2177                             ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2178                                 *i_qgroups = 0ULL;
2179
2180                         ++i_qgroups;
2181                 }
2182         }
2183
2184         /*
2185          * create a tracking group for the subvol itself
2186          */
2187         ret = add_qgroup_item(trans, quota_root, objectid);
2188         if (ret)
2189                 goto out;
2190
2191         if (srcid) {
2192                 struct btrfs_root *srcroot;
2193                 struct btrfs_key srckey;
2194
2195                 srckey.objectid = srcid;
2196                 srckey.type = BTRFS_ROOT_ITEM_KEY;
2197                 srckey.offset = (u64)-1;
2198                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
2199                 if (IS_ERR(srcroot)) {
2200                         ret = PTR_ERR(srcroot);
2201                         goto out;
2202                 }
2203
2204                 level_size = fs_info->nodesize;
2205         }
2206
2207         /*
2208          * add qgroup to all inherited groups
2209          */
2210         if (inherit) {
2211                 i_qgroups = (u64 *)(inherit + 1);
2212                 for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2213                         if (*i_qgroups == 0)
2214                                 continue;
2215                         ret = add_qgroup_relation_item(trans, quota_root,
2216                                                        objectid, *i_qgroups);
2217                         if (ret && ret != -EEXIST)
2218                                 goto out;
2219                         ret = add_qgroup_relation_item(trans, quota_root,
2220                                                        *i_qgroups, objectid);
2221                         if (ret && ret != -EEXIST)
2222                                 goto out;
2223                 }
2224                 ret = 0;
2225         }
2226
2227
2228         spin_lock(&fs_info->qgroup_lock);
2229
2230         dstgroup = add_qgroup_rb(fs_info, objectid);
2231         if (IS_ERR(dstgroup)) {
2232                 ret = PTR_ERR(dstgroup);
2233                 goto unlock;
2234         }
2235
2236         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2237                 dstgroup->lim_flags = inherit->lim.flags;
2238                 dstgroup->max_rfer = inherit->lim.max_rfer;
2239                 dstgroup->max_excl = inherit->lim.max_excl;
2240                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2241                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
2242
2243                 ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
2244                 if (ret) {
2245                         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2246                         btrfs_info(fs_info,
2247                                    "unable to update quota limit for %llu",
2248                                    dstgroup->qgroupid);
2249                         goto unlock;
2250                 }
2251         }
2252
2253         if (srcid) {
2254                 srcgroup = find_qgroup_rb(fs_info, srcid);
2255                 if (!srcgroup)
2256                         goto unlock;
2257
2258                 /*
2259                  * We call inherit after we clone the root in order to make sure
2260                  * our counts don't go crazy, so at this point the only
2261                  * difference between the two roots should be the root node.
2262                  */
2263                 dstgroup->rfer = srcgroup->rfer;
2264                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2265                 dstgroup->excl = level_size;
2266                 dstgroup->excl_cmpr = level_size;
2267                 srcgroup->excl = level_size;
2268                 srcgroup->excl_cmpr = level_size;
2269
2270                 /* inherit the limit info */
2271                 dstgroup->lim_flags = srcgroup->lim_flags;
2272                 dstgroup->max_rfer = srcgroup->max_rfer;
2273                 dstgroup->max_excl = srcgroup->max_excl;
2274                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2275                 dstgroup->rsv_excl = srcgroup->rsv_excl;
2276
2277                 qgroup_dirty(fs_info, dstgroup);
2278                 qgroup_dirty(fs_info, srcgroup);
2279         }
2280
2281         if (!inherit)
2282                 goto unlock;
2283
2284         i_qgroups = (u64 *)(inherit + 1);
2285         for (i = 0; i < inherit->num_qgroups; ++i) {
2286                 if (*i_qgroups) {
2287                         ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2288                         if (ret)
2289                                 goto unlock;
2290                 }
2291                 ++i_qgroups;
2292         }
2293
2294         for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2295                 struct btrfs_qgroup *src;
2296                 struct btrfs_qgroup *dst;
2297
2298                 if (!i_qgroups[0] || !i_qgroups[1])
2299                         continue;
2300
2301                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2302                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2303
2304                 if (!src || !dst) {
2305                         ret = -EINVAL;
2306                         goto unlock;
2307                 }
2308
2309                 dst->rfer = src->rfer - level_size;
2310                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
2311         }
2312         for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2313                 struct btrfs_qgroup *src;
2314                 struct btrfs_qgroup *dst;
2315
2316                 if (!i_qgroups[0] || !i_qgroups[1])
2317                         continue;
2318
2319                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2320                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2321
2322                 if (!src || !dst) {
2323                         ret = -EINVAL;
2324                         goto unlock;
2325                 }
2326
2327                 dst->excl = src->excl + level_size;
2328                 dst->excl_cmpr = src->excl_cmpr + level_size;
2329         }
2330
2331 unlock:
2332         spin_unlock(&fs_info->qgroup_lock);
2333 out:
2334         mutex_unlock(&fs_info->qgroup_ioctl_lock);
2335         return ret;
2336 }
2337
2338 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
2339 {
2340         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2341             qg->reserved + (s64)qg->rfer + num_bytes > qg->max_rfer)
2342                 return false;
2343
2344         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2345             qg->reserved + (s64)qg->excl + num_bytes > qg->max_excl)
2346                 return false;
2347
2348         return true;
2349 }
2350
2351 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce)
2352 {
2353         struct btrfs_root *quota_root;
2354         struct btrfs_qgroup *qgroup;
2355         struct btrfs_fs_info *fs_info = root->fs_info;
2356         u64 ref_root = root->root_key.objectid;
2357         int ret = 0;
2358         int retried = 0;
2359         struct ulist_node *unode;
2360         struct ulist_iterator uiter;
2361
2362         if (!is_fstree(ref_root))
2363                 return 0;
2364
2365         if (num_bytes == 0)
2366                 return 0;
2367
2368         if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2369             capable(CAP_SYS_RESOURCE))
2370                 enforce = false;
2371
2372 retry:
2373         spin_lock(&fs_info->qgroup_lock);
2374         quota_root = fs_info->quota_root;
2375         if (!quota_root)
2376                 goto out;
2377
2378         qgroup = find_qgroup_rb(fs_info, ref_root);
2379         if (!qgroup)
2380                 goto out;
2381
2382         /*
2383          * in a first step, we check all affected qgroups if any limits would
2384          * be exceeded
2385          */
2386         ulist_reinit(fs_info->qgroup_ulist);
2387         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2388                         (uintptr_t)qgroup, GFP_ATOMIC);
2389         if (ret < 0)
2390                 goto out;
2391         ULIST_ITER_INIT(&uiter);
2392         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2393                 struct btrfs_qgroup *qg;
2394                 struct btrfs_qgroup_list *glist;
2395
2396                 qg = unode_aux_to_qgroup(unode);
2397
2398                 if (enforce && !qgroup_check_limits(qg, num_bytes)) {
2399                         /*
2400                          * Commit the tree and retry, since we may have
2401                          * deletions which would free up space.
2402                          */
2403                         if (!retried && qg->reserved > 0) {
2404                                 struct btrfs_trans_handle *trans;
2405
2406                                 spin_unlock(&fs_info->qgroup_lock);
2407                                 ret = btrfs_start_delalloc_inodes(root, 0);
2408                                 if (ret)
2409                                         return ret;
2410                                 btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
2411                                 trans = btrfs_join_transaction(root);
2412                                 if (IS_ERR(trans))
2413                                         return PTR_ERR(trans);
2414                                 ret = btrfs_commit_transaction(trans);
2415                                 if (ret)
2416                                         return ret;
2417                                 retried++;
2418                                 goto retry;
2419                         }
2420                         ret = -EDQUOT;
2421                         goto out;
2422                 }
2423
2424                 list_for_each_entry(glist, &qg->groups, next_group) {
2425                         ret = ulist_add(fs_info->qgroup_ulist,
2426                                         glist->group->qgroupid,
2427                                         (uintptr_t)glist->group, GFP_ATOMIC);
2428                         if (ret < 0)
2429                                 goto out;
2430                 }
2431         }
2432         ret = 0;
2433         /*
2434          * no limits exceeded, now record the reservation into all qgroups
2435          */
2436         ULIST_ITER_INIT(&uiter);
2437         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2438                 struct btrfs_qgroup *qg;
2439
2440                 qg = unode_aux_to_qgroup(unode);
2441
2442                 trace_qgroup_update_reserve(fs_info, qg, num_bytes);
2443                 qg->reserved += num_bytes;
2444         }
2445
2446 out:
2447         spin_unlock(&fs_info->qgroup_lock);
2448         return ret;
2449 }
2450
2451 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2452                                u64 ref_root, u64 num_bytes)
2453 {
2454         struct btrfs_root *quota_root;
2455         struct btrfs_qgroup *qgroup;
2456         struct ulist_node *unode;
2457         struct ulist_iterator uiter;
2458         int ret = 0;
2459
2460         if (!is_fstree(ref_root))
2461                 return;
2462
2463         if (num_bytes == 0)
2464                 return;
2465
2466         spin_lock(&fs_info->qgroup_lock);
2467
2468         quota_root = fs_info->quota_root;
2469         if (!quota_root)
2470                 goto out;
2471
2472         qgroup = find_qgroup_rb(fs_info, ref_root);
2473         if (!qgroup)
2474                 goto out;
2475
2476         ulist_reinit(fs_info->qgroup_ulist);
2477         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2478                         (uintptr_t)qgroup, GFP_ATOMIC);
2479         if (ret < 0)
2480                 goto out;
2481         ULIST_ITER_INIT(&uiter);
2482         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2483                 struct btrfs_qgroup *qg;
2484                 struct btrfs_qgroup_list *glist;
2485
2486                 qg = unode_aux_to_qgroup(unode);
2487
2488                 trace_qgroup_update_reserve(fs_info, qg, -(s64)num_bytes);
2489                 if (qg->reserved < num_bytes)
2490                         report_reserved_underflow(fs_info, qg, num_bytes);
2491                 else
2492                         qg->reserved -= num_bytes;
2493
2494                 list_for_each_entry(glist, &qg->groups, next_group) {
2495                         ret = ulist_add(fs_info->qgroup_ulist,
2496                                         glist->group->qgroupid,
2497                                         (uintptr_t)glist->group, GFP_ATOMIC);
2498                         if (ret < 0)
2499                                 goto out;
2500                 }
2501         }
2502
2503 out:
2504         spin_unlock(&fs_info->qgroup_lock);
2505 }
2506
2507 /*
2508  * returns < 0 on error, 0 when more leafs are to be scanned.
2509  * returns 1 when done.
2510  */
2511 static int
2512 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
2513                    struct btrfs_trans_handle *trans)
2514 {
2515         struct btrfs_key found;
2516         struct extent_buffer *scratch_leaf = NULL;
2517         struct ulist *roots = NULL;
2518         struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
2519         u64 num_bytes;
2520         int slot;
2521         int ret;
2522
2523         mutex_lock(&fs_info->qgroup_rescan_lock);
2524         ret = btrfs_search_slot_for_read(fs_info->extent_root,
2525                                          &fs_info->qgroup_rescan_progress,
2526                                          path, 1, 0);
2527
2528         btrfs_debug(fs_info,
2529                 "current progress key (%llu %u %llu), search_slot ret %d",
2530                 fs_info->qgroup_rescan_progress.objectid,
2531                 fs_info->qgroup_rescan_progress.type,
2532                 fs_info->qgroup_rescan_progress.offset, ret);
2533
2534         if (ret) {
2535                 /*
2536                  * The rescan is about to end, we will not be scanning any
2537                  * further blocks. We cannot unset the RESCAN flag here, because
2538                  * we want to commit the transaction if everything went well.
2539                  * To make the live accounting work in this phase, we set our
2540                  * scan progress pointer such that every real extent objectid
2541                  * will be smaller.
2542                  */
2543                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
2544                 btrfs_release_path(path);
2545                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2546                 return ret;
2547         }
2548
2549         btrfs_item_key_to_cpu(path->nodes[0], &found,
2550                               btrfs_header_nritems(path->nodes[0]) - 1);
2551         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
2552
2553         btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2554         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
2555         if (!scratch_leaf) {
2556                 ret = -ENOMEM;
2557                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2558                 goto out;
2559         }
2560         extent_buffer_get(scratch_leaf);
2561         btrfs_tree_read_lock(scratch_leaf);
2562         btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
2563         slot = path->slots[0];
2564         btrfs_release_path(path);
2565         mutex_unlock(&fs_info->qgroup_rescan_lock);
2566
2567         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
2568                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
2569                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
2570                     found.type != BTRFS_METADATA_ITEM_KEY)
2571                         continue;
2572                 if (found.type == BTRFS_METADATA_ITEM_KEY)
2573                         num_bytes = fs_info->nodesize;
2574                 else
2575                         num_bytes = found.offset;
2576
2577                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
2578                                            &roots, false);
2579                 if (ret < 0)
2580                         goto out;
2581                 /* For rescan, just pass old_roots as NULL */
2582                 ret = btrfs_qgroup_account_extent(trans, fs_info,
2583                                 found.objectid, num_bytes, NULL, roots);
2584                 if (ret < 0)
2585                         goto out;
2586         }
2587 out:
2588         if (scratch_leaf) {
2589                 btrfs_tree_read_unlock_blocking(scratch_leaf);
2590                 free_extent_buffer(scratch_leaf);
2591         }
2592         btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2593
2594         return ret;
2595 }
2596
2597 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
2598 {
2599         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
2600                                                      qgroup_rescan_work);
2601         struct btrfs_path *path;
2602         struct btrfs_trans_handle *trans = NULL;
2603         int err = -ENOMEM;
2604         int ret = 0;
2605
2606         path = btrfs_alloc_path();
2607         if (!path)
2608                 goto out;
2609
2610         err = 0;
2611         while (!err && !btrfs_fs_closing(fs_info)) {
2612                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
2613                 if (IS_ERR(trans)) {
2614                         err = PTR_ERR(trans);
2615                         break;
2616                 }
2617                 if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
2618                         err = -EINTR;
2619                 } else {
2620                         err = qgroup_rescan_leaf(fs_info, path, trans);
2621                 }
2622                 if (err > 0)
2623                         btrfs_commit_transaction(trans);
2624                 else
2625                         btrfs_end_transaction(trans);
2626         }
2627
2628 out:
2629         btrfs_free_path(path);
2630
2631         mutex_lock(&fs_info->qgroup_rescan_lock);
2632         if (!btrfs_fs_closing(fs_info))
2633                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2634
2635         if (err > 0 &&
2636             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
2637                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2638         } else if (err < 0) {
2639                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2640         }
2641         mutex_unlock(&fs_info->qgroup_rescan_lock);
2642
2643         /*
2644          * only update status, since the previous part has already updated the
2645          * qgroup info.
2646          */
2647         trans = btrfs_start_transaction(fs_info->quota_root, 1);
2648         if (IS_ERR(trans)) {
2649                 err = PTR_ERR(trans);
2650                 btrfs_err(fs_info,
2651                           "fail to start transaction for status update: %d",
2652                           err);
2653                 goto done;
2654         }
2655         ret = update_qgroup_status_item(trans, fs_info, fs_info->quota_root);
2656         if (ret < 0) {
2657                 err = ret;
2658                 btrfs_err(fs_info, "fail to update qgroup status: %d", err);
2659         }
2660         btrfs_end_transaction(trans);
2661
2662         if (btrfs_fs_closing(fs_info)) {
2663                 btrfs_info(fs_info, "qgroup scan paused");
2664         } else if (err >= 0) {
2665                 btrfs_info(fs_info, "qgroup scan completed%s",
2666                         err > 0 ? " (inconsistency flag cleared)" : "");
2667         } else {
2668                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
2669         }
2670
2671 done:
2672         mutex_lock(&fs_info->qgroup_rescan_lock);
2673         fs_info->qgroup_rescan_running = false;
2674         mutex_unlock(&fs_info->qgroup_rescan_lock);
2675         complete_all(&fs_info->qgroup_rescan_completion);
2676 }
2677
2678 /*
2679  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
2680  * memory required for the rescan context.
2681  */
2682 static int
2683 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
2684                    int init_flags)
2685 {
2686         int ret = 0;
2687
2688         if (!init_flags &&
2689             (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
2690              !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
2691                 ret = -EINVAL;
2692                 goto err;
2693         }
2694
2695         mutex_lock(&fs_info->qgroup_rescan_lock);
2696         spin_lock(&fs_info->qgroup_lock);
2697
2698         if (init_flags) {
2699                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2700                         ret = -EINPROGRESS;
2701                 else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
2702                         ret = -EINVAL;
2703
2704                 if (ret) {
2705                         spin_unlock(&fs_info->qgroup_lock);
2706                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2707                         goto err;
2708                 }
2709                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2710         }
2711
2712         memset(&fs_info->qgroup_rescan_progress, 0,
2713                 sizeof(fs_info->qgroup_rescan_progress));
2714         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
2715         init_completion(&fs_info->qgroup_rescan_completion);
2716         fs_info->qgroup_rescan_running = true;
2717
2718         spin_unlock(&fs_info->qgroup_lock);
2719         mutex_unlock(&fs_info->qgroup_rescan_lock);
2720
2721         memset(&fs_info->qgroup_rescan_work, 0,
2722                sizeof(fs_info->qgroup_rescan_work));
2723         btrfs_init_work(&fs_info->qgroup_rescan_work,
2724                         btrfs_qgroup_rescan_helper,
2725                         btrfs_qgroup_rescan_worker, NULL, NULL);
2726
2727         if (ret) {
2728 err:
2729                 btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
2730                 return ret;
2731         }
2732
2733         return 0;
2734 }
2735
2736 static void
2737 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
2738 {
2739         struct rb_node *n;
2740         struct btrfs_qgroup *qgroup;
2741
2742         spin_lock(&fs_info->qgroup_lock);
2743         /* clear all current qgroup tracking information */
2744         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
2745                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
2746                 qgroup->rfer = 0;
2747                 qgroup->rfer_cmpr = 0;
2748                 qgroup->excl = 0;
2749                 qgroup->excl_cmpr = 0;
2750         }
2751         spin_unlock(&fs_info->qgroup_lock);
2752 }
2753
2754 int
2755 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
2756 {
2757         int ret = 0;
2758         struct btrfs_trans_handle *trans;
2759
2760         ret = qgroup_rescan_init(fs_info, 0, 1);
2761         if (ret)
2762                 return ret;
2763
2764         /*
2765          * We have set the rescan_progress to 0, which means no more
2766          * delayed refs will be accounted by btrfs_qgroup_account_ref.
2767          * However, btrfs_qgroup_account_ref may be right after its call
2768          * to btrfs_find_all_roots, in which case it would still do the
2769          * accounting.
2770          * To solve this, we're committing the transaction, which will
2771          * ensure we run all delayed refs and only after that, we are
2772          * going to clear all tracking information for a clean start.
2773          */
2774
2775         trans = btrfs_join_transaction(fs_info->fs_root);
2776         if (IS_ERR(trans)) {
2777                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2778                 return PTR_ERR(trans);
2779         }
2780         ret = btrfs_commit_transaction(trans);
2781         if (ret) {
2782                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2783                 return ret;
2784         }
2785
2786         qgroup_rescan_zero_tracking(fs_info);
2787
2788         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2789                          &fs_info->qgroup_rescan_work);
2790
2791         return 0;
2792 }
2793
2794 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
2795                                      bool interruptible)
2796 {
2797         int running;
2798         int ret = 0;
2799
2800         mutex_lock(&fs_info->qgroup_rescan_lock);
2801         spin_lock(&fs_info->qgroup_lock);
2802         running = fs_info->qgroup_rescan_running;
2803         spin_unlock(&fs_info->qgroup_lock);
2804         mutex_unlock(&fs_info->qgroup_rescan_lock);
2805
2806         if (!running)
2807                 return 0;
2808
2809         if (interruptible)
2810                 ret = wait_for_completion_interruptible(
2811                                         &fs_info->qgroup_rescan_completion);
2812         else
2813                 wait_for_completion(&fs_info->qgroup_rescan_completion);
2814
2815         return ret;
2816 }
2817
2818 /*
2819  * this is only called from open_ctree where we're still single threaded, thus
2820  * locking is omitted here.
2821  */
2822 void
2823 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
2824 {
2825         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2826                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
2827                                  &fs_info->qgroup_rescan_work);
2828 }
2829
2830 /*
2831  * Reserve qgroup space for range [start, start + len).
2832  *
2833  * This function will either reserve space from related qgroups or doing
2834  * nothing if the range is already reserved.
2835  *
2836  * Return 0 for successful reserve
2837  * Return <0 for error (including -EQUOT)
2838  *
2839  * NOTE: this function may sleep for memory allocation.
2840  *       if btrfs_qgroup_reserve_data() is called multiple times with
2841  *       same @reserved, caller must ensure when error happens it's OK
2842  *       to free *ALL* reserved space.
2843  */
2844 int btrfs_qgroup_reserve_data(struct inode *inode,
2845                         struct extent_changeset **reserved_ret, u64 start,
2846                         u64 len)
2847 {
2848         struct btrfs_root *root = BTRFS_I(inode)->root;
2849         struct ulist_node *unode;
2850         struct ulist_iterator uiter;
2851         struct extent_changeset *reserved;
2852         u64 orig_reserved;
2853         u64 to_reserve;
2854         int ret;
2855
2856         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
2857             !is_fstree(root->objectid) || len == 0)
2858                 return 0;
2859
2860         /* @reserved parameter is mandatory for qgroup */
2861         if (WARN_ON(!reserved_ret))
2862                 return -EINVAL;
2863         if (!*reserved_ret) {
2864                 *reserved_ret = extent_changeset_alloc();
2865                 if (!*reserved_ret)
2866                         return -ENOMEM;
2867         }
2868         reserved = *reserved_ret;
2869         /* Record already reserved space */
2870         orig_reserved = reserved->bytes_changed;
2871         ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2872                         start + len -1, EXTENT_QGROUP_RESERVED, reserved);
2873
2874         /* Newly reserved space */
2875         to_reserve = reserved->bytes_changed - orig_reserved;
2876         trace_btrfs_qgroup_reserve_data(inode, start, len,
2877                                         to_reserve, QGROUP_RESERVE);
2878         if (ret < 0)
2879                 goto cleanup;
2880         ret = qgroup_reserve(root, to_reserve, true);
2881         if (ret < 0)
2882                 goto cleanup;
2883
2884         return ret;
2885
2886 cleanup:
2887         /* cleanup *ALL* already reserved ranges */
2888         ULIST_ITER_INIT(&uiter);
2889         while ((unode = ulist_next(&reserved->range_changed, &uiter)))
2890                 clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
2891                                  unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL);
2892         extent_changeset_release(reserved);
2893         return ret;
2894 }
2895
2896 /* Free ranges specified by @reserved, normally in error path */
2897 static int qgroup_free_reserved_data(struct inode *inode,
2898                         struct extent_changeset *reserved, u64 start, u64 len)
2899 {
2900         struct btrfs_root *root = BTRFS_I(inode)->root;
2901         struct ulist_node *unode;
2902         struct ulist_iterator uiter;
2903         struct extent_changeset changeset;
2904         int freed = 0;
2905         int ret;
2906
2907         extent_changeset_init(&changeset);
2908         len = round_up(start + len, root->fs_info->sectorsize);
2909         start = round_down(start, root->fs_info->sectorsize);
2910
2911         ULIST_ITER_INIT(&uiter);
2912         while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
2913                 u64 range_start = unode->val;
2914                 /* unode->aux is the inclusive end */
2915                 u64 range_len = unode->aux - range_start + 1;
2916                 u64 free_start;
2917                 u64 free_len;
2918
2919                 extent_changeset_release(&changeset);
2920
2921                 /* Only free range in range [start, start + len) */
2922                 if (range_start >= start + len ||
2923                     range_start + range_len <= start)
2924                         continue;
2925                 free_start = max(range_start, start);
2926                 free_len = min(start + len, range_start + range_len) -
2927                            free_start;
2928                 /*
2929                  * TODO: To also modify reserved->ranges_reserved to reflect
2930                  * the modification.
2931                  *
2932                  * However as long as we free qgroup reserved according to
2933                  * EXTENT_QGROUP_RESERVED, we won't double free.
2934                  * So not need to rush.
2935                  */
2936                 ret = clear_record_extent_bits(&BTRFS_I(inode)->io_failure_tree,
2937                                 free_start, free_start + free_len - 1,
2938                                 EXTENT_QGROUP_RESERVED, &changeset);
2939                 if (ret < 0)
2940                         goto out;
2941                 freed += changeset.bytes_changed;
2942         }
2943         btrfs_qgroup_free_refroot(root->fs_info, root->objectid, freed);
2944         ret = freed;
2945 out:
2946         extent_changeset_release(&changeset);
2947         return ret;
2948 }
2949
2950 static int __btrfs_qgroup_release_data(struct inode *inode,
2951                         struct extent_changeset *reserved, u64 start, u64 len,
2952                         int free)
2953 {
2954         struct extent_changeset changeset;
2955         int trace_op = QGROUP_RELEASE;
2956         int ret;
2957
2958         /* In release case, we shouldn't have @reserved */
2959         WARN_ON(!free && reserved);
2960         if (free && reserved)
2961                 return qgroup_free_reserved_data(inode, reserved, start, len);
2962         extent_changeset_init(&changeset);
2963         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2964                         start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
2965         if (ret < 0)
2966                 goto out;
2967
2968         if (free)
2969                 trace_op = QGROUP_FREE;
2970         trace_btrfs_qgroup_release_data(inode, start, len,
2971                                         changeset.bytes_changed, trace_op);
2972         if (free)
2973                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
2974                                 BTRFS_I(inode)->root->objectid,
2975                                 changeset.bytes_changed);
2976         ret = changeset.bytes_changed;
2977 out:
2978         extent_changeset_release(&changeset);
2979         return ret;
2980 }
2981
2982 /*
2983  * Free a reserved space range from io_tree and related qgroups
2984  *
2985  * Should be called when a range of pages get invalidated before reaching disk.
2986  * Or for error cleanup case.
2987  * if @reserved is given, only reserved range in [@start, @start + @len) will
2988  * be freed.
2989  *
2990  * For data written to disk, use btrfs_qgroup_release_data().
2991  *
2992  * NOTE: This function may sleep for memory allocation.
2993  */
2994 int btrfs_qgroup_free_data(struct inode *inode,
2995                         struct extent_changeset *reserved, u64 start, u64 len)
2996 {
2997         return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
2998 }
2999
3000 /*
3001  * Release a reserved space range from io_tree only.
3002  *
3003  * Should be called when a range of pages get written to disk and corresponding
3004  * FILE_EXTENT is inserted into corresponding root.
3005  *
3006  * Since new qgroup accounting framework will only update qgroup numbers at
3007  * commit_transaction() time, its reserved space shouldn't be freed from
3008  * related qgroups.
3009  *
3010  * But we should release the range from io_tree, to allow further write to be
3011  * COWed.
3012  *
3013  * NOTE: This function may sleep for memory allocation.
3014  */
3015 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
3016 {
3017         return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3018 }
3019
3020 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3021                               bool enforce)
3022 {
3023         struct btrfs_fs_info *fs_info = root->fs_info;
3024         int ret;
3025
3026         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3027             !is_fstree(root->objectid) || num_bytes == 0)
3028                 return 0;
3029
3030         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3031         trace_qgroup_meta_reserve(root, (s64)num_bytes);
3032         ret = qgroup_reserve(root, num_bytes, enforce);
3033         if (ret < 0)
3034                 return ret;
3035         atomic64_add(num_bytes, &root->qgroup_meta_rsv);
3036         return ret;
3037 }
3038
3039 void btrfs_qgroup_free_meta_all(struct btrfs_root *root)
3040 {
3041         struct btrfs_fs_info *fs_info = root->fs_info;
3042         u64 reserved;
3043
3044         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3045             !is_fstree(root->objectid))
3046                 return;
3047
3048         reserved = atomic64_xchg(&root->qgroup_meta_rsv, 0);
3049         if (reserved == 0)
3050                 return;
3051         trace_qgroup_meta_reserve(root, -(s64)reserved);
3052         btrfs_qgroup_free_refroot(fs_info, root->objectid, reserved);
3053 }
3054
3055 void btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes)
3056 {
3057         struct btrfs_fs_info *fs_info = root->fs_info;
3058
3059         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3060             !is_fstree(root->objectid))
3061                 return;
3062
3063         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3064         WARN_ON(atomic64_read(&root->qgroup_meta_rsv) < num_bytes);
3065         atomic64_sub(num_bytes, &root->qgroup_meta_rsv);
3066         trace_qgroup_meta_reserve(root, -(s64)num_bytes);
3067         btrfs_qgroup_free_refroot(fs_info, root->objectid, num_bytes);
3068 }
3069
3070 /*
3071  * Check qgroup reserved space leaking, normally at destroy inode
3072  * time
3073  */
3074 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
3075 {
3076         struct extent_changeset changeset;
3077         struct ulist_node *unode;
3078         struct ulist_iterator iter;
3079         int ret;
3080
3081         extent_changeset_init(&changeset);
3082         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
3083                         EXTENT_QGROUP_RESERVED, &changeset);
3084
3085         WARN_ON(ret < 0);
3086         if (WARN_ON(changeset.bytes_changed)) {
3087                 ULIST_ITER_INIT(&iter);
3088                 while ((unode = ulist_next(&changeset.range_changed, &iter))) {
3089                         btrfs_warn(BTRFS_I(inode)->root->fs_info,
3090                                 "leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
3091                                 inode->i_ino, unode->val, unode->aux);
3092                 }
3093                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3094                                 BTRFS_I(inode)->root->objectid,
3095                                 changeset.bytes_changed);
3096
3097         }
3098         extent_changeset_release(&changeset);
3099 }