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v6.2
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2011 STRATO.  All rights reserved.
   4 */
   5
   6#include <linux/sched.h>
   7#include <linux/pagemap.h>
   8#include <linux/writeback.h>
   9#include <linux/blkdev.h>
  10#include <linux/rbtree.h>
  11#include <linux/slab.h>
  12#include <linux/workqueue.h>
  13#include <linux/btrfs.h>
  14#include <linux/sched/mm.h>
  15
  16#include "ctree.h"
  17#include "transaction.h"
  18#include "disk-io.h"
  19#include "locking.h"
  20#include "ulist.h"
  21#include "backref.h"
  22#include "extent_io.h"
  23#include "qgroup.h"
  24#include "block-group.h"
  25#include "sysfs.h"
  26#include "tree-mod-log.h"
  27#include "fs.h"
  28#include "accessors.h"
  29#include "extent-tree.h"
  30#include "root-tree.h"
  31#include "tree-checker.h"
 
 
 
 
 
 
 
  32
  33/*
  34 * Helpers to access qgroup reservation
  35 *
  36 * Callers should ensure the lock context and type are valid
  37 */
  38
  39static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
  40{
  41	u64 ret = 0;
  42	int i;
  43
  44	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  45		ret += qgroup->rsv.values[i];
  46
  47	return ret;
  48}
  49
  50#ifdef CONFIG_BTRFS_DEBUG
  51static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
  52{
  53	if (type == BTRFS_QGROUP_RSV_DATA)
  54		return "data";
  55	if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
  56		return "meta_pertrans";
  57	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
  58		return "meta_prealloc";
  59	return NULL;
  60}
  61#endif
  62
  63static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
  64			   struct btrfs_qgroup *qgroup, u64 num_bytes,
  65			   enum btrfs_qgroup_rsv_type type)
  66{
  67	trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
  68	qgroup->rsv.values[type] += num_bytes;
  69}
  70
  71static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
  72			       struct btrfs_qgroup *qgroup, u64 num_bytes,
  73			       enum btrfs_qgroup_rsv_type type)
  74{
  75	trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
  76	if (qgroup->rsv.values[type] >= num_bytes) {
  77		qgroup->rsv.values[type] -= num_bytes;
  78		return;
  79	}
  80#ifdef CONFIG_BTRFS_DEBUG
  81	WARN_RATELIMIT(1,
  82		"qgroup %llu %s reserved space underflow, have %llu to free %llu",
  83		qgroup->qgroupid, qgroup_rsv_type_str(type),
  84		qgroup->rsv.values[type], num_bytes);
  85#endif
  86	qgroup->rsv.values[type] = 0;
  87}
  88
  89static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
  90				     struct btrfs_qgroup *dest,
  91				     struct btrfs_qgroup *src)
  92{
  93	int i;
  94
  95	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  96		qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
  97}
  98
  99static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
 100					 struct btrfs_qgroup *dest,
 101					  struct btrfs_qgroup *src)
 102{
 103	int i;
 104
 105	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
 106		qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
 107}
 108
 109static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
 110					   int mod)
 111{
 112	if (qg->old_refcnt < seq)
 113		qg->old_refcnt = seq;
 114	qg->old_refcnt += mod;
 115}
 116
 117static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 118					   int mod)
 119{
 120	if (qg->new_refcnt < seq)
 121		qg->new_refcnt = seq;
 122	qg->new_refcnt += mod;
 123}
 124
 125static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
 126{
 127	if (qg->old_refcnt < seq)
 128		return 0;
 129	return qg->old_refcnt - seq;
 130}
 131
 132static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
 133{
 134	if (qg->new_refcnt < seq)
 135		return 0;
 136	return qg->new_refcnt - seq;
 137}
 138
 139/*
 140 * glue structure to represent the relations between qgroups.
 141 */
 142struct btrfs_qgroup_list {
 143	struct list_head next_group;
 144	struct list_head next_member;
 145	struct btrfs_qgroup *group;
 146	struct btrfs_qgroup *member;
 147};
 148
 149static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
 150{
 151	return (u64)(uintptr_t)qg;
 152}
 153
 154static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
 155{
 156	return (struct btrfs_qgroup *)(uintptr_t)n->aux;
 157}
 158
 159static int
 160qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 161		   int init_flags);
 162static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 163
 164/* must be called with qgroup_ioctl_lock held */
 165static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 166					   u64 qgroupid)
 167{
 168	struct rb_node *n = fs_info->qgroup_tree.rb_node;
 169	struct btrfs_qgroup *qgroup;
 170
 171	while (n) {
 172		qgroup = rb_entry(n, struct btrfs_qgroup, node);
 173		if (qgroup->qgroupid < qgroupid)
 174			n = n->rb_left;
 175		else if (qgroup->qgroupid > qgroupid)
 176			n = n->rb_right;
 177		else
 178			return qgroup;
 179	}
 180	return NULL;
 181}
 182
 183/* must be called with qgroup_lock held */
 184static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 185					  u64 qgroupid)
 186{
 187	struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 188	struct rb_node *parent = NULL;
 189	struct btrfs_qgroup *qgroup;
 190
 191	while (*p) {
 192		parent = *p;
 193		qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 194
 195		if (qgroup->qgroupid < qgroupid)
 196			p = &(*p)->rb_left;
 197		else if (qgroup->qgroupid > qgroupid)
 198			p = &(*p)->rb_right;
 199		else
 200			return qgroup;
 201	}
 202
 203	qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 204	if (!qgroup)
 205		return ERR_PTR(-ENOMEM);
 206
 207	qgroup->qgroupid = qgroupid;
 208	INIT_LIST_HEAD(&qgroup->groups);
 209	INIT_LIST_HEAD(&qgroup->members);
 210	INIT_LIST_HEAD(&qgroup->dirty);
 211
 212	rb_link_node(&qgroup->node, parent, p);
 213	rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 214
 215	return qgroup;
 216}
 217
 218static void __del_qgroup_rb(struct btrfs_fs_info *fs_info,
 219			    struct btrfs_qgroup *qgroup)
 220{
 221	struct btrfs_qgroup_list *list;
 222
 223	list_del(&qgroup->dirty);
 224	while (!list_empty(&qgroup->groups)) {
 225		list = list_first_entry(&qgroup->groups,
 226					struct btrfs_qgroup_list, next_group);
 227		list_del(&list->next_group);
 228		list_del(&list->next_member);
 229		kfree(list);
 230	}
 231
 232	while (!list_empty(&qgroup->members)) {
 233		list = list_first_entry(&qgroup->members,
 234					struct btrfs_qgroup_list, next_member);
 235		list_del(&list->next_group);
 236		list_del(&list->next_member);
 237		kfree(list);
 238	}
 239}
 240
 241/* must be called with qgroup_lock held */
 242static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 243{
 244	struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 245
 246	if (!qgroup)
 247		return -ENOENT;
 248
 249	rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 250	__del_qgroup_rb(fs_info, qgroup);
 251	return 0;
 252}
 253
 254/*
 255 * Add relation specified by two qgroups.
 256 *
 257 * Must be called with qgroup_lock held.
 258 *
 259 * Return: 0        on success
 260 *         -ENOENT  if one of the qgroups is NULL
 261 *         <0       other errors
 262 */
 263static int __add_relation_rb(struct btrfs_qgroup *member, struct btrfs_qgroup *parent)
 264{
 
 
 265	struct btrfs_qgroup_list *list;
 266
 
 
 267	if (!member || !parent)
 268		return -ENOENT;
 269
 270	list = kzalloc(sizeof(*list), GFP_ATOMIC);
 271	if (!list)
 272		return -ENOMEM;
 273
 274	list->group = parent;
 275	list->member = member;
 276	list_add_tail(&list->next_group, &member->groups);
 277	list_add_tail(&list->next_member, &parent->members);
 278
 279	return 0;
 280}
 281
 282/*
 283 * Add relation specified by two qgroup ids.
 284 *
 285 * Must be called with qgroup_lock held.
 286 *
 287 * Return: 0        on success
 288 *         -ENOENT  if one of the ids does not exist
 289 *         <0       other errors
 290 */
 291static int add_relation_rb(struct btrfs_fs_info *fs_info, u64 memberid, u64 parentid)
 292{
 293	struct btrfs_qgroup *member;
 294	struct btrfs_qgroup *parent;
 295
 296	member = find_qgroup_rb(fs_info, memberid);
 297	parent = find_qgroup_rb(fs_info, parentid);
 298
 299	return __add_relation_rb(member, parent);
 300}
 301
 302/* Must be called with qgroup_lock held */
 303static int del_relation_rb(struct btrfs_fs_info *fs_info,
 304			   u64 memberid, u64 parentid)
 305{
 306	struct btrfs_qgroup *member;
 307	struct btrfs_qgroup *parent;
 308	struct btrfs_qgroup_list *list;
 309
 310	member = find_qgroup_rb(fs_info, memberid);
 311	parent = find_qgroup_rb(fs_info, parentid);
 312	if (!member || !parent)
 313		return -ENOENT;
 314
 315	list_for_each_entry(list, &member->groups, next_group) {
 316		if (list->group == parent) {
 317			list_del(&list->next_group);
 318			list_del(&list->next_member);
 319			kfree(list);
 320			return 0;
 321		}
 322	}
 323	return -ENOENT;
 324}
 325
 326#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 327int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 328			       u64 rfer, u64 excl)
 329{
 330	struct btrfs_qgroup *qgroup;
 331
 332	qgroup = find_qgroup_rb(fs_info, qgroupid);
 333	if (!qgroup)
 334		return -EINVAL;
 335	if (qgroup->rfer != rfer || qgroup->excl != excl)
 336		return -EINVAL;
 337	return 0;
 338}
 339#endif
 340
 341static void qgroup_mark_inconsistent(struct btrfs_fs_info *fs_info)
 342{
 343	fs_info->qgroup_flags |= (BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT |
 344				  BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN |
 345				  BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING);
 346}
 347
 348/*
 349 * The full config is read in one go, only called from open_ctree()
 350 * It doesn't use any locking, as at this point we're still single-threaded
 351 */
 352int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 353{
 354	struct btrfs_key key;
 355	struct btrfs_key found_key;
 356	struct btrfs_root *quota_root = fs_info->quota_root;
 357	struct btrfs_path *path = NULL;
 358	struct extent_buffer *l;
 359	int slot;
 360	int ret = 0;
 361	u64 flags = 0;
 362	u64 rescan_progress = 0;
 363
 364	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 365		return 0;
 366
 367	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 368	if (!fs_info->qgroup_ulist) {
 369		ret = -ENOMEM;
 370		goto out;
 371	}
 372
 373	path = btrfs_alloc_path();
 374	if (!path) {
 375		ret = -ENOMEM;
 376		goto out;
 377	}
 378
 379	ret = btrfs_sysfs_add_qgroups(fs_info);
 380	if (ret < 0)
 381		goto out;
 382	/* default this to quota off, in case no status key is found */
 383	fs_info->qgroup_flags = 0;
 384
 385	/*
 386	 * pass 1: read status, all qgroup infos and limits
 387	 */
 388	key.objectid = 0;
 389	key.type = 0;
 390	key.offset = 0;
 391	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 392	if (ret)
 393		goto out;
 394
 395	while (1) {
 396		struct btrfs_qgroup *qgroup;
 397
 398		slot = path->slots[0];
 399		l = path->nodes[0];
 400		btrfs_item_key_to_cpu(l, &found_key, slot);
 401
 402		if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 403			struct btrfs_qgroup_status_item *ptr;
 404
 405			ptr = btrfs_item_ptr(l, slot,
 406					     struct btrfs_qgroup_status_item);
 407
 408			if (btrfs_qgroup_status_version(l, ptr) !=
 409			    BTRFS_QGROUP_STATUS_VERSION) {
 410				btrfs_err(fs_info,
 411				 "old qgroup version, quota disabled");
 412				goto out;
 413			}
 414			if (btrfs_qgroup_status_generation(l, ptr) !=
 415			    fs_info->generation) {
 416				qgroup_mark_inconsistent(fs_info);
 417				btrfs_err(fs_info,
 418					"qgroup generation mismatch, marked as inconsistent");
 419			}
 420			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 421									  ptr);
 422			rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
 423			goto next1;
 424		}
 425
 426		if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 427		    found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 428			goto next1;
 429
 430		qgroup = find_qgroup_rb(fs_info, found_key.offset);
 431		if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 432		    (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 433			btrfs_err(fs_info, "inconsistent qgroup config");
 434			qgroup_mark_inconsistent(fs_info);
 435		}
 436		if (!qgroup) {
 437			qgroup = add_qgroup_rb(fs_info, found_key.offset);
 438			if (IS_ERR(qgroup)) {
 439				ret = PTR_ERR(qgroup);
 440				goto out;
 441			}
 442		}
 443		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
 444		if (ret < 0)
 445			goto out;
 446
 447		switch (found_key.type) {
 448		case BTRFS_QGROUP_INFO_KEY: {
 449			struct btrfs_qgroup_info_item *ptr;
 450
 451			ptr = btrfs_item_ptr(l, slot,
 452					     struct btrfs_qgroup_info_item);
 453			qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 454			qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 455			qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 456			qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 457			/* generation currently unused */
 458			break;
 459		}
 460		case BTRFS_QGROUP_LIMIT_KEY: {
 461			struct btrfs_qgroup_limit_item *ptr;
 462
 463			ptr = btrfs_item_ptr(l, slot,
 464					     struct btrfs_qgroup_limit_item);
 465			qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 466			qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 467			qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 468			qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 469			qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 470			break;
 471		}
 472		}
 473next1:
 474		ret = btrfs_next_item(quota_root, path);
 475		if (ret < 0)
 476			goto out;
 477		if (ret)
 478			break;
 479	}
 480	btrfs_release_path(path);
 481
 482	/*
 483	 * pass 2: read all qgroup relations
 484	 */
 485	key.objectid = 0;
 486	key.type = BTRFS_QGROUP_RELATION_KEY;
 487	key.offset = 0;
 488	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 489	if (ret)
 490		goto out;
 491	while (1) {
 492		slot = path->slots[0];
 493		l = path->nodes[0];
 494		btrfs_item_key_to_cpu(l, &found_key, slot);
 495
 496		if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 497			goto next2;
 498
 499		if (found_key.objectid > found_key.offset) {
 500			/* parent <- member, not needed to build config */
 501			/* FIXME should we omit the key completely? */
 502			goto next2;
 503		}
 504
 505		ret = add_relation_rb(fs_info, found_key.objectid,
 506				      found_key.offset);
 507		if (ret == -ENOENT) {
 508			btrfs_warn(fs_info,
 509				"orphan qgroup relation 0x%llx->0x%llx",
 510				found_key.objectid, found_key.offset);
 511			ret = 0;	/* ignore the error */
 512		}
 513		if (ret)
 514			goto out;
 515next2:
 516		ret = btrfs_next_item(quota_root, path);
 517		if (ret < 0)
 518			goto out;
 519		if (ret)
 520			break;
 521	}
 522out:
 523	btrfs_free_path(path);
 524	fs_info->qgroup_flags |= flags;
 525	if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
 526		clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 527	else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
 528		 ret >= 0)
 529		ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
 530
 531	if (ret < 0) {
 532		ulist_free(fs_info->qgroup_ulist);
 533		fs_info->qgroup_ulist = NULL;
 534		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 535		btrfs_sysfs_del_qgroups(fs_info);
 536	}
 537
 538	return ret < 0 ? ret : 0;
 539}
 540
 541/*
 542 * Called in close_ctree() when quota is still enabled.  This verifies we don't
 543 * leak some reserved space.
 544 *
 545 * Return false if no reserved space is left.
 546 * Return true if some reserved space is leaked.
 547 */
 548bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info)
 549{
 550	struct rb_node *node;
 551	bool ret = false;
 552
 553	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 554		return ret;
 555	/*
 556	 * Since we're unmounting, there is no race and no need to grab qgroup
 557	 * lock.  And here we don't go post-order to provide a more user
 558	 * friendly sorted result.
 559	 */
 560	for (node = rb_first(&fs_info->qgroup_tree); node; node = rb_next(node)) {
 561		struct btrfs_qgroup *qgroup;
 562		int i;
 563
 564		qgroup = rb_entry(node, struct btrfs_qgroup, node);
 565		for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) {
 566			if (qgroup->rsv.values[i]) {
 567				ret = true;
 568				btrfs_warn(fs_info,
 569		"qgroup %hu/%llu has unreleased space, type %d rsv %llu",
 570				   btrfs_qgroup_level(qgroup->qgroupid),
 571				   btrfs_qgroup_subvolid(qgroup->qgroupid),
 572				   i, qgroup->rsv.values[i]);
 573			}
 574		}
 575	}
 576	return ret;
 577}
 578
 579/*
 580 * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
 581 * first two are in single-threaded paths.And for the third one, we have set
 582 * quota_root to be null with qgroup_lock held before, so it is safe to clean
 583 * up the in-memory structures without qgroup_lock held.
 584 */
 585void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 586{
 587	struct rb_node *n;
 588	struct btrfs_qgroup *qgroup;
 589
 590	while ((n = rb_first(&fs_info->qgroup_tree))) {
 591		qgroup = rb_entry(n, struct btrfs_qgroup, node);
 592		rb_erase(n, &fs_info->qgroup_tree);
 593		__del_qgroup_rb(fs_info, qgroup);
 594		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
 595		kfree(qgroup);
 596	}
 597	/*
 598	 * We call btrfs_free_qgroup_config() when unmounting
 599	 * filesystem and disabling quota, so we set qgroup_ulist
 600	 * to be null here to avoid double free.
 601	 */
 602	ulist_free(fs_info->qgroup_ulist);
 603	fs_info->qgroup_ulist = NULL;
 604	btrfs_sysfs_del_qgroups(fs_info);
 605}
 606
 607static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 608				    u64 dst)
 609{
 610	int ret;
 611	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 612	struct btrfs_path *path;
 613	struct btrfs_key key;
 614
 615	path = btrfs_alloc_path();
 616	if (!path)
 617		return -ENOMEM;
 618
 619	key.objectid = src;
 620	key.type = BTRFS_QGROUP_RELATION_KEY;
 621	key.offset = dst;
 622
 623	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 624
 625	btrfs_mark_buffer_dirty(path->nodes[0]);
 626
 627	btrfs_free_path(path);
 628	return ret;
 629}
 630
 631static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 632				    u64 dst)
 633{
 634	int ret;
 635	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 636	struct btrfs_path *path;
 637	struct btrfs_key key;
 638
 639	path = btrfs_alloc_path();
 640	if (!path)
 641		return -ENOMEM;
 642
 643	key.objectid = src;
 644	key.type = BTRFS_QGROUP_RELATION_KEY;
 645	key.offset = dst;
 646
 647	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 648	if (ret < 0)
 649		goto out;
 650
 651	if (ret > 0) {
 652		ret = -ENOENT;
 653		goto out;
 654	}
 655
 656	ret = btrfs_del_item(trans, quota_root, path);
 657out:
 658	btrfs_free_path(path);
 659	return ret;
 660}
 661
 662static int add_qgroup_item(struct btrfs_trans_handle *trans,
 663			   struct btrfs_root *quota_root, u64 qgroupid)
 664{
 665	int ret;
 666	struct btrfs_path *path;
 667	struct btrfs_qgroup_info_item *qgroup_info;
 668	struct btrfs_qgroup_limit_item *qgroup_limit;
 669	struct extent_buffer *leaf;
 670	struct btrfs_key key;
 671
 672	if (btrfs_is_testing(quota_root->fs_info))
 673		return 0;
 674
 675	path = btrfs_alloc_path();
 676	if (!path)
 677		return -ENOMEM;
 678
 679	key.objectid = 0;
 680	key.type = BTRFS_QGROUP_INFO_KEY;
 681	key.offset = qgroupid;
 682
 683	/*
 684	 * Avoid a transaction abort by catching -EEXIST here. In that
 685	 * case, we proceed by re-initializing the existing structure
 686	 * on disk.
 687	 */
 688
 689	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 690				      sizeof(*qgroup_info));
 691	if (ret && ret != -EEXIST)
 692		goto out;
 693
 694	leaf = path->nodes[0];
 695	qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 696				 struct btrfs_qgroup_info_item);
 697	btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 698	btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 699	btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 700	btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 701	btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 702
 703	btrfs_mark_buffer_dirty(leaf);
 704
 705	btrfs_release_path(path);
 706
 707	key.type = BTRFS_QGROUP_LIMIT_KEY;
 708	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 709				      sizeof(*qgroup_limit));
 710	if (ret && ret != -EEXIST)
 711		goto out;
 712
 713	leaf = path->nodes[0];
 714	qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 715				  struct btrfs_qgroup_limit_item);
 716	btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 717	btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 718	btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 719	btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 720	btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 721
 722	btrfs_mark_buffer_dirty(leaf);
 723
 724	ret = 0;
 725out:
 726	btrfs_free_path(path);
 727	return ret;
 728}
 729
 730static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
 731{
 732	int ret;
 733	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 734	struct btrfs_path *path;
 735	struct btrfs_key key;
 736
 737	path = btrfs_alloc_path();
 738	if (!path)
 739		return -ENOMEM;
 740
 741	key.objectid = 0;
 742	key.type = BTRFS_QGROUP_INFO_KEY;
 743	key.offset = qgroupid;
 744	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 745	if (ret < 0)
 746		goto out;
 747
 748	if (ret > 0) {
 749		ret = -ENOENT;
 750		goto out;
 751	}
 752
 753	ret = btrfs_del_item(trans, quota_root, path);
 754	if (ret)
 755		goto out;
 756
 757	btrfs_release_path(path);
 758
 759	key.type = BTRFS_QGROUP_LIMIT_KEY;
 760	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 761	if (ret < 0)
 762		goto out;
 763
 764	if (ret > 0) {
 765		ret = -ENOENT;
 766		goto out;
 767	}
 768
 769	ret = btrfs_del_item(trans, quota_root, path);
 770
 771out:
 772	btrfs_free_path(path);
 773	return ret;
 774}
 775
 776static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 777				    struct btrfs_qgroup *qgroup)
 778{
 779	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 780	struct btrfs_path *path;
 781	struct btrfs_key key;
 782	struct extent_buffer *l;
 783	struct btrfs_qgroup_limit_item *qgroup_limit;
 784	int ret;
 785	int slot;
 786
 787	key.objectid = 0;
 788	key.type = BTRFS_QGROUP_LIMIT_KEY;
 789	key.offset = qgroup->qgroupid;
 790
 791	path = btrfs_alloc_path();
 792	if (!path)
 793		return -ENOMEM;
 794
 795	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 796	if (ret > 0)
 797		ret = -ENOENT;
 798
 799	if (ret)
 800		goto out;
 801
 802	l = path->nodes[0];
 803	slot = path->slots[0];
 804	qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
 805	btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
 806	btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
 807	btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
 808	btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
 809	btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
 810
 811	btrfs_mark_buffer_dirty(l);
 812
 813out:
 814	btrfs_free_path(path);
 815	return ret;
 816}
 817
 818static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 819				   struct btrfs_qgroup *qgroup)
 820{
 821	struct btrfs_fs_info *fs_info = trans->fs_info;
 822	struct btrfs_root *quota_root = fs_info->quota_root;
 823	struct btrfs_path *path;
 824	struct btrfs_key key;
 825	struct extent_buffer *l;
 826	struct btrfs_qgroup_info_item *qgroup_info;
 827	int ret;
 828	int slot;
 829
 830	if (btrfs_is_testing(fs_info))
 831		return 0;
 832
 833	key.objectid = 0;
 834	key.type = BTRFS_QGROUP_INFO_KEY;
 835	key.offset = qgroup->qgroupid;
 836
 837	path = btrfs_alloc_path();
 838	if (!path)
 839		return -ENOMEM;
 840
 841	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 842	if (ret > 0)
 843		ret = -ENOENT;
 844
 845	if (ret)
 846		goto out;
 847
 848	l = path->nodes[0];
 849	slot = path->slots[0];
 850	qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
 851	btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 852	btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 853	btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 854	btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 855	btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 856
 857	btrfs_mark_buffer_dirty(l);
 858
 859out:
 860	btrfs_free_path(path);
 861	return ret;
 862}
 863
 864static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
 865{
 866	struct btrfs_fs_info *fs_info = trans->fs_info;
 867	struct btrfs_root *quota_root = fs_info->quota_root;
 868	struct btrfs_path *path;
 869	struct btrfs_key key;
 870	struct extent_buffer *l;
 871	struct btrfs_qgroup_status_item *ptr;
 872	int ret;
 873	int slot;
 874
 875	key.objectid = 0;
 876	key.type = BTRFS_QGROUP_STATUS_KEY;
 877	key.offset = 0;
 878
 879	path = btrfs_alloc_path();
 880	if (!path)
 881		return -ENOMEM;
 882
 883	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 884	if (ret > 0)
 885		ret = -ENOENT;
 886
 887	if (ret)
 888		goto out;
 889
 890	l = path->nodes[0];
 891	slot = path->slots[0];
 892	ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 893	btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags &
 894				      BTRFS_QGROUP_STATUS_FLAGS_MASK);
 895	btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 896	btrfs_set_qgroup_status_rescan(l, ptr,
 897				fs_info->qgroup_rescan_progress.objectid);
 898
 899	btrfs_mark_buffer_dirty(l);
 900
 901out:
 902	btrfs_free_path(path);
 903	return ret;
 904}
 905
 906/*
 907 * called with qgroup_lock held
 908 */
 909static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 910				  struct btrfs_root *root)
 911{
 912	struct btrfs_path *path;
 913	struct btrfs_key key;
 914	struct extent_buffer *leaf = NULL;
 915	int ret;
 916	int nr = 0;
 917
 918	path = btrfs_alloc_path();
 919	if (!path)
 920		return -ENOMEM;
 921
 922	key.objectid = 0;
 923	key.offset = 0;
 924	key.type = 0;
 925
 926	while (1) {
 927		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 928		if (ret < 0)
 929			goto out;
 930		leaf = path->nodes[0];
 931		nr = btrfs_header_nritems(leaf);
 932		if (!nr)
 933			break;
 934		/*
 935		 * delete the leaf one by one
 936		 * since the whole tree is going
 937		 * to be deleted.
 938		 */
 939		path->slots[0] = 0;
 940		ret = btrfs_del_items(trans, root, path, 0, nr);
 941		if (ret)
 942			goto out;
 943
 944		btrfs_release_path(path);
 945	}
 946	ret = 0;
 947out:
 948	btrfs_free_path(path);
 949	return ret;
 950}
 951
 952int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
 953{
 954	struct btrfs_root *quota_root;
 955	struct btrfs_root *tree_root = fs_info->tree_root;
 956	struct btrfs_path *path = NULL;
 957	struct btrfs_qgroup_status_item *ptr;
 958	struct extent_buffer *leaf;
 959	struct btrfs_key key;
 960	struct btrfs_key found_key;
 961	struct btrfs_qgroup *qgroup = NULL;
 962	struct btrfs_trans_handle *trans = NULL;
 963	struct ulist *ulist = NULL;
 964	int ret = 0;
 965	int slot;
 966
 967	/*
 968	 * We need to have subvol_sem write locked, to prevent races between
 969	 * concurrent tasks trying to enable quotas, because we will unlock
 970	 * and relock qgroup_ioctl_lock before setting fs_info->quota_root
 971	 * and before setting BTRFS_FS_QUOTA_ENABLED.
 972	 */
 973	lockdep_assert_held_write(&fs_info->subvol_sem);
 974
 975	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
 976		btrfs_err(fs_info,
 977			  "qgroups are currently unsupported in extent tree v2");
 978		return -EINVAL;
 979	}
 980
 981	mutex_lock(&fs_info->qgroup_ioctl_lock);
 982	if (fs_info->quota_root)
 983		goto out;
 984
 985	ulist = ulist_alloc(GFP_KERNEL);
 986	if (!ulist) {
 987		ret = -ENOMEM;
 988		goto out;
 989	}
 990
 991	ret = btrfs_sysfs_add_qgroups(fs_info);
 992	if (ret < 0)
 993		goto out;
 994
 995	/*
 996	 * Unlock qgroup_ioctl_lock before starting the transaction. This is to
 997	 * avoid lock acquisition inversion problems (reported by lockdep) between
 998	 * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we
 999	 * start a transaction.
1000	 * After we started the transaction lock qgroup_ioctl_lock again and
1001	 * check if someone else created the quota root in the meanwhile. If so,
1002	 * just return success and release the transaction handle.
1003	 *
1004	 * Also we don't need to worry about someone else calling
1005	 * btrfs_sysfs_add_qgroups() after we unlock and getting an error because
1006	 * that function returns 0 (success) when the sysfs entries already exist.
1007	 */
1008	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1009
1010	/*
1011	 * 1 for quota root item
1012	 * 1 for BTRFS_QGROUP_STATUS item
1013	 *
1014	 * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
1015	 * per subvolume. However those are not currently reserved since it
1016	 * would be a lot of overkill.
1017	 */
1018	trans = btrfs_start_transaction(tree_root, 2);
1019
1020	mutex_lock(&fs_info->qgroup_ioctl_lock);
1021	if (IS_ERR(trans)) {
1022		ret = PTR_ERR(trans);
1023		trans = NULL;
1024		goto out;
1025	}
1026
1027	if (fs_info->quota_root)
1028		goto out;
1029
1030	fs_info->qgroup_ulist = ulist;
1031	ulist = NULL;
1032
1033	/*
1034	 * initially create the quota tree
1035	 */
1036	quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
1037	if (IS_ERR(quota_root)) {
1038		ret =  PTR_ERR(quota_root);
1039		btrfs_abort_transaction(trans, ret);
1040		goto out;
1041	}
1042
1043	path = btrfs_alloc_path();
1044	if (!path) {
1045		ret = -ENOMEM;
1046		btrfs_abort_transaction(trans, ret);
1047		goto out_free_root;
1048	}
1049
1050	key.objectid = 0;
1051	key.type = BTRFS_QGROUP_STATUS_KEY;
1052	key.offset = 0;
1053
1054	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
1055				      sizeof(*ptr));
1056	if (ret) {
1057		btrfs_abort_transaction(trans, ret);
1058		goto out_free_path;
1059	}
1060
1061	leaf = path->nodes[0];
1062	ptr = btrfs_item_ptr(leaf, path->slots[0],
1063				 struct btrfs_qgroup_status_item);
1064	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
1065	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
1066	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
1067				BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1068	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags &
1069				      BTRFS_QGROUP_STATUS_FLAGS_MASK);
1070	btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
1071
1072	btrfs_mark_buffer_dirty(leaf);
1073
1074	key.objectid = 0;
1075	key.type = BTRFS_ROOT_REF_KEY;
1076	key.offset = 0;
1077
1078	btrfs_release_path(path);
1079	ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
1080	if (ret > 0)
1081		goto out_add_root;
1082	if (ret < 0) {
1083		btrfs_abort_transaction(trans, ret);
1084		goto out_free_path;
1085	}
1086
1087	while (1) {
1088		slot = path->slots[0];
1089		leaf = path->nodes[0];
1090		btrfs_item_key_to_cpu(leaf, &found_key, slot);
1091
1092		if (found_key.type == BTRFS_ROOT_REF_KEY) {
1093
1094			/* Release locks on tree_root before we access quota_root */
1095			btrfs_release_path(path);
1096
1097			ret = add_qgroup_item(trans, quota_root,
1098					      found_key.offset);
1099			if (ret) {
1100				btrfs_abort_transaction(trans, ret);
1101				goto out_free_path;
1102			}
1103
1104			qgroup = add_qgroup_rb(fs_info, found_key.offset);
1105			if (IS_ERR(qgroup)) {
1106				ret = PTR_ERR(qgroup);
1107				btrfs_abort_transaction(trans, ret);
1108				goto out_free_path;
1109			}
1110			ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1111			if (ret < 0) {
1112				btrfs_abort_transaction(trans, ret);
1113				goto out_free_path;
1114			}
1115			ret = btrfs_search_slot_for_read(tree_root, &found_key,
1116							 path, 1, 0);
1117			if (ret < 0) {
1118				btrfs_abort_transaction(trans, ret);
1119				goto out_free_path;
1120			}
1121			if (ret > 0) {
1122				/*
1123				 * Shouldn't happen, but in case it does we
1124				 * don't need to do the btrfs_next_item, just
1125				 * continue.
1126				 */
1127				continue;
1128			}
1129		}
1130		ret = btrfs_next_item(tree_root, path);
1131		if (ret < 0) {
1132			btrfs_abort_transaction(trans, ret);
1133			goto out_free_path;
1134		}
1135		if (ret)
1136			break;
1137	}
1138
1139out_add_root:
1140	btrfs_release_path(path);
1141	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1142	if (ret) {
1143		btrfs_abort_transaction(trans, ret);
1144		goto out_free_path;
1145	}
1146
1147	qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1148	if (IS_ERR(qgroup)) {
1149		ret = PTR_ERR(qgroup);
1150		btrfs_abort_transaction(trans, ret);
1151		goto out_free_path;
1152	}
1153	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1154	if (ret < 0) {
1155		btrfs_abort_transaction(trans, ret);
1156		goto out_free_path;
1157	}
1158
1159	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1160	/*
1161	 * Commit the transaction while not holding qgroup_ioctl_lock, to avoid
1162	 * a deadlock with tasks concurrently doing other qgroup operations, such
1163	 * adding/removing qgroups or adding/deleting qgroup relations for example,
1164	 * because all qgroup operations first start or join a transaction and then
1165	 * lock the qgroup_ioctl_lock mutex.
1166	 * We are safe from a concurrent task trying to enable quotas, by calling
1167	 * this function, since we are serialized by fs_info->subvol_sem.
1168	 */
1169	ret = btrfs_commit_transaction(trans);
1170	trans = NULL;
1171	mutex_lock(&fs_info->qgroup_ioctl_lock);
1172	if (ret)
1173		goto out_free_path;
1174
1175	/*
1176	 * Set quota enabled flag after committing the transaction, to avoid
1177	 * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
1178	 * creation.
1179	 */
1180	spin_lock(&fs_info->qgroup_lock);
1181	fs_info->quota_root = quota_root;
1182	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1183	spin_unlock(&fs_info->qgroup_lock);
1184
1185	ret = qgroup_rescan_init(fs_info, 0, 1);
1186	if (!ret) {
1187	        qgroup_rescan_zero_tracking(fs_info);
1188		fs_info->qgroup_rescan_running = true;
1189	        btrfs_queue_work(fs_info->qgroup_rescan_workers,
1190	                         &fs_info->qgroup_rescan_work);
1191	} else {
1192		/*
1193		 * We have set both BTRFS_FS_QUOTA_ENABLED and
1194		 * BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with
1195		 * -EINPROGRESS. That can happen because someone started the
1196		 * rescan worker by calling quota rescan ioctl before we
1197		 * attempted to initialize the rescan worker. Failure due to
1198		 * quotas disabled in the meanwhile is not possible, because
1199		 * we are holding a write lock on fs_info->subvol_sem, which
1200		 * is also acquired when disabling quotas.
1201		 * Ignore such error, and any other error would need to undo
1202		 * everything we did in the transaction we just committed.
1203		 */
1204		ASSERT(ret == -EINPROGRESS);
1205		ret = 0;
1206	}
1207
1208out_free_path:
1209	btrfs_free_path(path);
1210out_free_root:
1211	if (ret)
1212		btrfs_put_root(quota_root);
1213out:
1214	if (ret) {
1215		ulist_free(fs_info->qgroup_ulist);
1216		fs_info->qgroup_ulist = NULL;
1217		btrfs_sysfs_del_qgroups(fs_info);
1218	}
1219	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1220	if (ret && trans)
1221		btrfs_end_transaction(trans);
1222	else if (trans)
1223		ret = btrfs_end_transaction(trans);
1224	ulist_free(ulist);
1225	return ret;
1226}
1227
1228int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1229{
1230	struct btrfs_root *quota_root;
1231	struct btrfs_trans_handle *trans = NULL;
1232	int ret = 0;
1233
1234	/*
1235	 * We need to have subvol_sem write locked, to prevent races between
1236	 * concurrent tasks trying to disable quotas, because we will unlock
1237	 * and relock qgroup_ioctl_lock across BTRFS_FS_QUOTA_ENABLED changes.
1238	 */
1239	lockdep_assert_held_write(&fs_info->subvol_sem);
1240
1241	mutex_lock(&fs_info->qgroup_ioctl_lock);
1242	if (!fs_info->quota_root)
1243		goto out;
1244
1245	/*
1246	 * Unlock the qgroup_ioctl_lock mutex before waiting for the rescan worker to
1247	 * complete. Otherwise we can deadlock because btrfs_remove_qgroup() needs
1248	 * to lock that mutex while holding a transaction handle and the rescan
1249	 * worker needs to commit a transaction.
1250	 */
1251	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1252
1253	/*
1254	 * Request qgroup rescan worker to complete and wait for it. This wait
1255	 * must be done before transaction start for quota disable since it may
1256	 * deadlock with transaction by the qgroup rescan worker.
1257	 */
1258	clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1259	btrfs_qgroup_wait_for_completion(fs_info, false);
1260
1261	/*
1262	 * 1 For the root item
1263	 *
1264	 * We should also reserve enough items for the quota tree deletion in
1265	 * btrfs_clean_quota_tree but this is not done.
1266	 *
1267	 * Also, we must always start a transaction without holding the mutex
1268	 * qgroup_ioctl_lock, see btrfs_quota_enable().
1269	 */
1270	trans = btrfs_start_transaction(fs_info->tree_root, 1);
1271
1272	mutex_lock(&fs_info->qgroup_ioctl_lock);
1273	if (IS_ERR(trans)) {
1274		ret = PTR_ERR(trans);
1275		trans = NULL;
1276		set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1277		goto out;
1278	}
1279
1280	if (!fs_info->quota_root)
1281		goto out;
1282
 
 
1283	spin_lock(&fs_info->qgroup_lock);
1284	quota_root = fs_info->quota_root;
1285	fs_info->quota_root = NULL;
1286	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1287	fs_info->qgroup_drop_subtree_thres = BTRFS_MAX_LEVEL;
1288	spin_unlock(&fs_info->qgroup_lock);
1289
1290	btrfs_free_qgroup_config(fs_info);
1291
1292	ret = btrfs_clean_quota_tree(trans, quota_root);
1293	if (ret) {
1294		btrfs_abort_transaction(trans, ret);
1295		goto out;
1296	}
1297
1298	ret = btrfs_del_root(trans, &quota_root->root_key);
1299	if (ret) {
1300		btrfs_abort_transaction(trans, ret);
1301		goto out;
1302	}
1303
1304	list_del(&quota_root->dirty_list);
1305
1306	btrfs_tree_lock(quota_root->node);
1307	btrfs_clean_tree_block(quota_root->node);
1308	btrfs_tree_unlock(quota_root->node);
1309	btrfs_free_tree_block(trans, btrfs_root_id(quota_root),
1310			      quota_root->node, 0, 1);
1311
1312	btrfs_put_root(quota_root);
1313
1314out:
1315	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1316	if (ret && trans)
1317		btrfs_end_transaction(trans);
1318	else if (trans)
1319		ret = btrfs_end_transaction(trans);
1320
1321	return ret;
1322}
1323
1324static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1325			 struct btrfs_qgroup *qgroup)
1326{
1327	if (list_empty(&qgroup->dirty))
1328		list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1329}
1330
1331/*
1332 * The easy accounting, we're updating qgroup relationship whose child qgroup
1333 * only has exclusive extents.
1334 *
1335 * In this case, all exclusive extents will also be exclusive for parent, so
1336 * excl/rfer just get added/removed.
1337 *
1338 * So is qgroup reservation space, which should also be added/removed to
1339 * parent.
1340 * Or when child tries to release reservation space, parent will underflow its
1341 * reservation (for relationship adding case).
1342 *
1343 * Caller should hold fs_info->qgroup_lock.
1344 */
1345static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1346				    struct ulist *tmp, u64 ref_root,
1347				    struct btrfs_qgroup *src, int sign)
1348{
1349	struct btrfs_qgroup *qgroup;
1350	struct btrfs_qgroup_list *glist;
1351	struct ulist_node *unode;
1352	struct ulist_iterator uiter;
1353	u64 num_bytes = src->excl;
1354	int ret = 0;
1355
1356	qgroup = find_qgroup_rb(fs_info, ref_root);
1357	if (!qgroup)
1358		goto out;
1359
1360	qgroup->rfer += sign * num_bytes;
1361	qgroup->rfer_cmpr += sign * num_bytes;
1362
1363	WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1364	qgroup->excl += sign * num_bytes;
1365	qgroup->excl_cmpr += sign * num_bytes;
1366
1367	if (sign > 0)
1368		qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1369	else
1370		qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1371
1372	qgroup_dirty(fs_info, qgroup);
1373
1374	/* Get all of the parent groups that contain this qgroup */
1375	list_for_each_entry(glist, &qgroup->groups, next_group) {
1376		ret = ulist_add(tmp, glist->group->qgroupid,
1377				qgroup_to_aux(glist->group), GFP_ATOMIC);
1378		if (ret < 0)
1379			goto out;
1380	}
1381
1382	/* Iterate all of the parents and adjust their reference counts */
1383	ULIST_ITER_INIT(&uiter);
1384	while ((unode = ulist_next(tmp, &uiter))) {
1385		qgroup = unode_aux_to_qgroup(unode);
1386		qgroup->rfer += sign * num_bytes;
1387		qgroup->rfer_cmpr += sign * num_bytes;
1388		WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1389		qgroup->excl += sign * num_bytes;
1390		if (sign > 0)
1391			qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1392		else
1393			qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1394		qgroup->excl_cmpr += sign * num_bytes;
1395		qgroup_dirty(fs_info, qgroup);
1396
1397		/* Add any parents of the parents */
1398		list_for_each_entry(glist, &qgroup->groups, next_group) {
1399			ret = ulist_add(tmp, glist->group->qgroupid,
1400					qgroup_to_aux(glist->group), GFP_ATOMIC);
1401			if (ret < 0)
1402				goto out;
1403		}
1404	}
1405	ret = 0;
1406out:
1407	return ret;
1408}
1409
1410
1411/*
1412 * Quick path for updating qgroup with only excl refs.
1413 *
1414 * In that case, just update all parent will be enough.
1415 * Or we needs to do a full rescan.
1416 * Caller should also hold fs_info->qgroup_lock.
1417 *
1418 * Return 0 for quick update, return >0 for need to full rescan
1419 * and mark INCONSISTENT flag.
1420 * Return < 0 for other error.
1421 */
1422static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1423				   struct ulist *tmp, u64 src, u64 dst,
1424				   int sign)
1425{
1426	struct btrfs_qgroup *qgroup;
1427	int ret = 1;
1428	int err = 0;
1429
1430	qgroup = find_qgroup_rb(fs_info, src);
1431	if (!qgroup)
1432		goto out;
1433	if (qgroup->excl == qgroup->rfer) {
1434		ret = 0;
1435		err = __qgroup_excl_accounting(fs_info, tmp, dst,
1436					       qgroup, sign);
1437		if (err < 0) {
1438			ret = err;
1439			goto out;
1440		}
1441	}
1442out:
1443	if (ret)
1444		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1445	return ret;
1446}
1447
1448int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1449			      u64 dst)
1450{
1451	struct btrfs_fs_info *fs_info = trans->fs_info;
1452	struct btrfs_qgroup *parent;
1453	struct btrfs_qgroup *member;
1454	struct btrfs_qgroup_list *list;
1455	struct ulist *tmp;
1456	unsigned int nofs_flag;
1457	int ret = 0;
1458
1459	/* Check the level of src and dst first */
1460	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1461		return -EINVAL;
1462
1463	/* We hold a transaction handle open, must do a NOFS allocation. */
1464	nofs_flag = memalloc_nofs_save();
1465	tmp = ulist_alloc(GFP_KERNEL);
1466	memalloc_nofs_restore(nofs_flag);
1467	if (!tmp)
1468		return -ENOMEM;
1469
1470	mutex_lock(&fs_info->qgroup_ioctl_lock);
1471	if (!fs_info->quota_root) {
1472		ret = -ENOTCONN;
1473		goto out;
1474	}
1475	member = find_qgroup_rb(fs_info, src);
1476	parent = find_qgroup_rb(fs_info, dst);
1477	if (!member || !parent) {
1478		ret = -EINVAL;
1479		goto out;
1480	}
1481
1482	/* check if such qgroup relation exist firstly */
1483	list_for_each_entry(list, &member->groups, next_group) {
1484		if (list->group == parent) {
1485			ret = -EEXIST;
1486			goto out;
1487		}
1488	}
1489
1490	ret = add_qgroup_relation_item(trans, src, dst);
1491	if (ret)
1492		goto out;
1493
1494	ret = add_qgroup_relation_item(trans, dst, src);
1495	if (ret) {
1496		del_qgroup_relation_item(trans, src, dst);
1497		goto out;
1498	}
1499
1500	spin_lock(&fs_info->qgroup_lock);
1501	ret = __add_relation_rb(member, parent);
1502	if (ret < 0) {
1503		spin_unlock(&fs_info->qgroup_lock);
1504		goto out;
1505	}
1506	ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1507	spin_unlock(&fs_info->qgroup_lock);
1508out:
1509	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1510	ulist_free(tmp);
1511	return ret;
1512}
1513
1514static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1515				 u64 dst)
1516{
1517	struct btrfs_fs_info *fs_info = trans->fs_info;
1518	struct btrfs_qgroup *parent;
1519	struct btrfs_qgroup *member;
1520	struct btrfs_qgroup_list *list;
1521	struct ulist *tmp;
1522	bool found = false;
1523	unsigned int nofs_flag;
1524	int ret = 0;
1525	int ret2;
1526
1527	/* We hold a transaction handle open, must do a NOFS allocation. */
1528	nofs_flag = memalloc_nofs_save();
1529	tmp = ulist_alloc(GFP_KERNEL);
1530	memalloc_nofs_restore(nofs_flag);
1531	if (!tmp)
1532		return -ENOMEM;
1533
1534	if (!fs_info->quota_root) {
1535		ret = -ENOTCONN;
1536		goto out;
1537	}
1538
1539	member = find_qgroup_rb(fs_info, src);
1540	parent = find_qgroup_rb(fs_info, dst);
1541	/*
1542	 * The parent/member pair doesn't exist, then try to delete the dead
1543	 * relation items only.
1544	 */
1545	if (!member || !parent)
1546		goto delete_item;
1547
1548	/* check if such qgroup relation exist firstly */
1549	list_for_each_entry(list, &member->groups, next_group) {
1550		if (list->group == parent) {
1551			found = true;
1552			break;
1553		}
1554	}
1555
1556delete_item:
1557	ret = del_qgroup_relation_item(trans, src, dst);
1558	if (ret < 0 && ret != -ENOENT)
1559		goto out;
1560	ret2 = del_qgroup_relation_item(trans, dst, src);
1561	if (ret2 < 0 && ret2 != -ENOENT)
1562		goto out;
1563
1564	/* At least one deletion succeeded, return 0 */
1565	if (!ret || !ret2)
1566		ret = 0;
1567
1568	if (found) {
1569		spin_lock(&fs_info->qgroup_lock);
1570		del_relation_rb(fs_info, src, dst);
1571		ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1572		spin_unlock(&fs_info->qgroup_lock);
1573	}
1574out:
1575	ulist_free(tmp);
1576	return ret;
1577}
1578
1579int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1580			      u64 dst)
1581{
1582	struct btrfs_fs_info *fs_info = trans->fs_info;
1583	int ret = 0;
1584
1585	mutex_lock(&fs_info->qgroup_ioctl_lock);
1586	ret = __del_qgroup_relation(trans, src, dst);
1587	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1588
1589	return ret;
1590}
1591
1592int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1593{
1594	struct btrfs_fs_info *fs_info = trans->fs_info;
1595	struct btrfs_root *quota_root;
1596	struct btrfs_qgroup *qgroup;
1597	int ret = 0;
1598
1599	mutex_lock(&fs_info->qgroup_ioctl_lock);
1600	if (!fs_info->quota_root) {
1601		ret = -ENOTCONN;
1602		goto out;
1603	}
1604	quota_root = fs_info->quota_root;
1605	qgroup = find_qgroup_rb(fs_info, qgroupid);
1606	if (qgroup) {
1607		ret = -EEXIST;
1608		goto out;
1609	}
1610
1611	ret = add_qgroup_item(trans, quota_root, qgroupid);
1612	if (ret)
1613		goto out;
1614
1615	spin_lock(&fs_info->qgroup_lock);
1616	qgroup = add_qgroup_rb(fs_info, qgroupid);
1617	spin_unlock(&fs_info->qgroup_lock);
1618
1619	if (IS_ERR(qgroup)) {
1620		ret = PTR_ERR(qgroup);
1621		goto out;
1622	}
1623	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1624out:
1625	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1626	return ret;
1627}
1628
1629int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1630{
1631	struct btrfs_fs_info *fs_info = trans->fs_info;
1632	struct btrfs_qgroup *qgroup;
1633	struct btrfs_qgroup_list *list;
1634	int ret = 0;
1635
1636	mutex_lock(&fs_info->qgroup_ioctl_lock);
1637	if (!fs_info->quota_root) {
1638		ret = -ENOTCONN;
1639		goto out;
1640	}
1641
1642	qgroup = find_qgroup_rb(fs_info, qgroupid);
1643	if (!qgroup) {
1644		ret = -ENOENT;
1645		goto out;
1646	}
1647
1648	/* Check if there are no children of this qgroup */
1649	if (!list_empty(&qgroup->members)) {
1650		ret = -EBUSY;
1651		goto out;
1652	}
1653
1654	ret = del_qgroup_item(trans, qgroupid);
1655	if (ret && ret != -ENOENT)
1656		goto out;
1657
1658	while (!list_empty(&qgroup->groups)) {
1659		list = list_first_entry(&qgroup->groups,
1660					struct btrfs_qgroup_list, next_group);
1661		ret = __del_qgroup_relation(trans, qgroupid,
1662					    list->group->qgroupid);
1663		if (ret)
1664			goto out;
1665	}
1666
1667	spin_lock(&fs_info->qgroup_lock);
1668	del_qgroup_rb(fs_info, qgroupid);
1669	spin_unlock(&fs_info->qgroup_lock);
1670
1671	/*
1672	 * Remove the qgroup from sysfs now without holding the qgroup_lock
1673	 * spinlock, since the sysfs_remove_group() function needs to take
1674	 * the mutex kernfs_mutex through kernfs_remove_by_name_ns().
1675	 */
1676	btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1677	kfree(qgroup);
1678out:
1679	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1680	return ret;
1681}
1682
1683int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1684		       struct btrfs_qgroup_limit *limit)
1685{
1686	struct btrfs_fs_info *fs_info = trans->fs_info;
1687	struct btrfs_qgroup *qgroup;
1688	int ret = 0;
1689	/* Sometimes we would want to clear the limit on this qgroup.
1690	 * To meet this requirement, we treat the -1 as a special value
1691	 * which tell kernel to clear the limit on this qgroup.
1692	 */
1693	const u64 CLEAR_VALUE = -1;
1694
1695	mutex_lock(&fs_info->qgroup_ioctl_lock);
1696	if (!fs_info->quota_root) {
1697		ret = -ENOTCONN;
1698		goto out;
1699	}
1700
1701	qgroup = find_qgroup_rb(fs_info, qgroupid);
1702	if (!qgroup) {
1703		ret = -ENOENT;
1704		goto out;
1705	}
1706
1707	spin_lock(&fs_info->qgroup_lock);
1708	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1709		if (limit->max_rfer == CLEAR_VALUE) {
1710			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1711			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1712			qgroup->max_rfer = 0;
1713		} else {
1714			qgroup->max_rfer = limit->max_rfer;
1715		}
1716	}
1717	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1718		if (limit->max_excl == CLEAR_VALUE) {
1719			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1720			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1721			qgroup->max_excl = 0;
1722		} else {
1723			qgroup->max_excl = limit->max_excl;
1724		}
1725	}
1726	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1727		if (limit->rsv_rfer == CLEAR_VALUE) {
1728			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1729			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1730			qgroup->rsv_rfer = 0;
1731		} else {
1732			qgroup->rsv_rfer = limit->rsv_rfer;
1733		}
1734	}
1735	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1736		if (limit->rsv_excl == CLEAR_VALUE) {
1737			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1738			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1739			qgroup->rsv_excl = 0;
1740		} else {
1741			qgroup->rsv_excl = limit->rsv_excl;
1742		}
1743	}
1744	qgroup->lim_flags |= limit->flags;
1745
1746	spin_unlock(&fs_info->qgroup_lock);
1747
1748	ret = update_qgroup_limit_item(trans, qgroup);
1749	if (ret) {
1750		qgroup_mark_inconsistent(fs_info);
1751		btrfs_info(fs_info, "unable to update quota limit for %llu",
1752		       qgroupid);
1753	}
1754
1755out:
1756	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1757	return ret;
1758}
1759
1760int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1761				struct btrfs_delayed_ref_root *delayed_refs,
1762				struct btrfs_qgroup_extent_record *record)
1763{
1764	struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1765	struct rb_node *parent_node = NULL;
1766	struct btrfs_qgroup_extent_record *entry;
1767	u64 bytenr = record->bytenr;
1768
1769	lockdep_assert_held(&delayed_refs->lock);
1770	trace_btrfs_qgroup_trace_extent(fs_info, record);
1771
1772	while (*p) {
1773		parent_node = *p;
1774		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1775				 node);
1776		if (bytenr < entry->bytenr) {
1777			p = &(*p)->rb_left;
1778		} else if (bytenr > entry->bytenr) {
1779			p = &(*p)->rb_right;
1780		} else {
1781			if (record->data_rsv && !entry->data_rsv) {
1782				entry->data_rsv = record->data_rsv;
1783				entry->data_rsv_refroot =
1784					record->data_rsv_refroot;
1785			}
1786			return 1;
1787		}
1788	}
1789
1790	rb_link_node(&record->node, parent_node, p);
1791	rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1792	return 0;
1793}
1794
1795int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
1796				   struct btrfs_qgroup_extent_record *qrecord)
1797{
1798	struct btrfs_backref_walk_ctx ctx = { 0 };
 
1799	int ret;
1800
1801	/*
1802	 * We are always called in a context where we are already holding a
1803	 * transaction handle. Often we are called when adding a data delayed
1804	 * reference from btrfs_truncate_inode_items() (truncating or unlinking),
1805	 * in which case we will be holding a write lock on extent buffer from a
1806	 * subvolume tree. In this case we can't allow btrfs_find_all_roots() to
1807	 * acquire fs_info->commit_root_sem, because that is a higher level lock
1808	 * that must be acquired before locking any extent buffers.
1809	 *
1810	 * So we want btrfs_find_all_roots() to not acquire the commit_root_sem
1811	 * but we can't pass it a non-NULL transaction handle, because otherwise
1812	 * it would not use commit roots and would lock extent buffers, causing
1813	 * a deadlock if it ends up trying to read lock the same extent buffer
1814	 * that was previously write locked at btrfs_truncate_inode_items().
1815	 *
1816	 * So pass a NULL transaction handle to btrfs_find_all_roots() and
1817	 * explicitly tell it to not acquire the commit_root_sem - if we are
1818	 * holding a transaction handle we don't need its protection.
1819	 */
1820	ASSERT(trans != NULL);
1821
1822	if (trans->fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)
1823		return 0;
1824
1825	ctx.bytenr = qrecord->bytenr;
1826	ctx.fs_info = trans->fs_info;
1827
1828	ret = btrfs_find_all_roots(&ctx, true);
1829	if (ret < 0) {
1830		qgroup_mark_inconsistent(trans->fs_info);
1831		btrfs_warn(trans->fs_info,
1832"error accounting new delayed refs extent (err code: %d), quota inconsistent",
1833			ret);
1834		return 0;
1835	}
1836
1837	/*
1838	 * Here we don't need to get the lock of
1839	 * trans->transaction->delayed_refs, since inserted qrecord won't
1840	 * be deleted, only qrecord->node may be modified (new qrecord insert)
1841	 *
1842	 * So modifying qrecord->old_roots is safe here
1843	 */
1844	qrecord->old_roots = ctx.roots;
1845	return 0;
1846}
1847
1848int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1849			      u64 num_bytes)
1850{
1851	struct btrfs_fs_info *fs_info = trans->fs_info;
1852	struct btrfs_qgroup_extent_record *record;
1853	struct btrfs_delayed_ref_root *delayed_refs;
1854	int ret;
1855
1856	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1857	    || bytenr == 0 || num_bytes == 0)
1858		return 0;
1859	record = kzalloc(sizeof(*record), GFP_NOFS);
1860	if (!record)
1861		return -ENOMEM;
1862
1863	delayed_refs = &trans->transaction->delayed_refs;
1864	record->bytenr = bytenr;
1865	record->num_bytes = num_bytes;
1866	record->old_roots = NULL;
1867
1868	spin_lock(&delayed_refs->lock);
1869	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1870	spin_unlock(&delayed_refs->lock);
1871	if (ret > 0) {
1872		kfree(record);
1873		return 0;
1874	}
1875	return btrfs_qgroup_trace_extent_post(trans, record);
1876}
1877
1878int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1879				  struct extent_buffer *eb)
1880{
1881	struct btrfs_fs_info *fs_info = trans->fs_info;
1882	int nr = btrfs_header_nritems(eb);
1883	int i, extent_type, ret;
1884	struct btrfs_key key;
1885	struct btrfs_file_extent_item *fi;
1886	u64 bytenr, num_bytes;
1887
1888	/* We can be called directly from walk_up_proc() */
1889	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1890		return 0;
1891
1892	for (i = 0; i < nr; i++) {
1893		btrfs_item_key_to_cpu(eb, &key, i);
1894
1895		if (key.type != BTRFS_EXTENT_DATA_KEY)
1896			continue;
1897
1898		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1899		/* filter out non qgroup-accountable extents  */
1900		extent_type = btrfs_file_extent_type(eb, fi);
1901
1902		if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1903			continue;
1904
1905		bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1906		if (!bytenr)
1907			continue;
1908
1909		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1910
1911		ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes);
 
1912		if (ret)
1913			return ret;
1914	}
1915	cond_resched();
1916	return 0;
1917}
1918
1919/*
1920 * Walk up the tree from the bottom, freeing leaves and any interior
1921 * nodes which have had all slots visited. If a node (leaf or
1922 * interior) is freed, the node above it will have it's slot
1923 * incremented. The root node will never be freed.
1924 *
1925 * At the end of this function, we should have a path which has all
1926 * slots incremented to the next position for a search. If we need to
1927 * read a new node it will be NULL and the node above it will have the
1928 * correct slot selected for a later read.
1929 *
1930 * If we increment the root nodes slot counter past the number of
1931 * elements, 1 is returned to signal completion of the search.
1932 */
1933static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1934{
1935	int level = 0;
1936	int nr, slot;
1937	struct extent_buffer *eb;
1938
1939	if (root_level == 0)
1940		return 1;
1941
1942	while (level <= root_level) {
1943		eb = path->nodes[level];
1944		nr = btrfs_header_nritems(eb);
1945		path->slots[level]++;
1946		slot = path->slots[level];
1947		if (slot >= nr || level == 0) {
1948			/*
1949			 * Don't free the root -  we will detect this
1950			 * condition after our loop and return a
1951			 * positive value for caller to stop walking the tree.
1952			 */
1953			if (level != root_level) {
1954				btrfs_tree_unlock_rw(eb, path->locks[level]);
1955				path->locks[level] = 0;
1956
1957				free_extent_buffer(eb);
1958				path->nodes[level] = NULL;
1959				path->slots[level] = 0;
1960			}
1961		} else {
1962			/*
1963			 * We have a valid slot to walk back down
1964			 * from. Stop here so caller can process these
1965			 * new nodes.
1966			 */
1967			break;
1968		}
1969
1970		level++;
1971	}
1972
1973	eb = path->nodes[root_level];
1974	if (path->slots[root_level] >= btrfs_header_nritems(eb))
1975		return 1;
1976
1977	return 0;
1978}
1979
1980/*
1981 * Helper function to trace a subtree tree block swap.
1982 *
1983 * The swap will happen in highest tree block, but there may be a lot of
1984 * tree blocks involved.
1985 *
1986 * For example:
1987 *  OO = Old tree blocks
1988 *  NN = New tree blocks allocated during balance
1989 *
1990 *           File tree (257)                  Reloc tree for 257
1991 * L2              OO                                NN
1992 *               /    \                            /    \
1993 * L1          OO      OO (a)                    OO      NN (a)
1994 *            / \     / \                       / \     / \
1995 * L0       OO   OO OO   OO                   OO   OO NN   NN
1996 *                  (b)  (c)                          (b)  (c)
1997 *
1998 * When calling qgroup_trace_extent_swap(), we will pass:
1999 * @src_eb = OO(a)
2000 * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
2001 * @dst_level = 0
2002 * @root_level = 1
2003 *
2004 * In that case, qgroup_trace_extent_swap() will search from OO(a) to
2005 * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
2006 *
2007 * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
2008 *
2009 * 1) Tree search from @src_eb
2010 *    It should acts as a simplified btrfs_search_slot().
2011 *    The key for search can be extracted from @dst_path->nodes[dst_level]
2012 *    (first key).
2013 *
2014 * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
2015 *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
2016 *    They should be marked during previous (@dst_level = 1) iteration.
2017 *
2018 * 3) Mark file extents in leaves dirty
2019 *    We don't have good way to pick out new file extents only.
2020 *    So we still follow the old method by scanning all file extents in
2021 *    the leave.
2022 *
2023 * This function can free us from keeping two paths, thus later we only need
2024 * to care about how to iterate all new tree blocks in reloc tree.
2025 */
2026static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
2027				    struct extent_buffer *src_eb,
2028				    struct btrfs_path *dst_path,
2029				    int dst_level, int root_level,
2030				    bool trace_leaf)
2031{
2032	struct btrfs_key key;
2033	struct btrfs_path *src_path;
2034	struct btrfs_fs_info *fs_info = trans->fs_info;
2035	u32 nodesize = fs_info->nodesize;
2036	int cur_level = root_level;
2037	int ret;
2038
2039	BUG_ON(dst_level > root_level);
2040	/* Level mismatch */
2041	if (btrfs_header_level(src_eb) != root_level)
2042		return -EINVAL;
2043
2044	src_path = btrfs_alloc_path();
2045	if (!src_path) {
2046		ret = -ENOMEM;
2047		goto out;
2048	}
2049
2050	if (dst_level)
2051		btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2052	else
2053		btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2054
2055	/* For src_path */
2056	atomic_inc(&src_eb->refs);
2057	src_path->nodes[root_level] = src_eb;
2058	src_path->slots[root_level] = dst_path->slots[root_level];
2059	src_path->locks[root_level] = 0;
2060
2061	/* A simplified version of btrfs_search_slot() */
2062	while (cur_level >= dst_level) {
2063		struct btrfs_key src_key;
2064		struct btrfs_key dst_key;
2065
2066		if (src_path->nodes[cur_level] == NULL) {
2067			struct extent_buffer *eb;
2068			int parent_slot;
2069
2070			eb = src_path->nodes[cur_level + 1];
2071			parent_slot = src_path->slots[cur_level + 1];
2072
2073			eb = btrfs_read_node_slot(eb, parent_slot);
2074			if (IS_ERR(eb)) {
2075				ret = PTR_ERR(eb);
2076				goto out;
2077			}
2078
2079			src_path->nodes[cur_level] = eb;
2080
2081			btrfs_tree_read_lock(eb);
2082			src_path->locks[cur_level] = BTRFS_READ_LOCK;
2083		}
2084
2085		src_path->slots[cur_level] = dst_path->slots[cur_level];
2086		if (cur_level) {
2087			btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
2088					&dst_key, dst_path->slots[cur_level]);
2089			btrfs_node_key_to_cpu(src_path->nodes[cur_level],
2090					&src_key, src_path->slots[cur_level]);
2091		} else {
2092			btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
2093					&dst_key, dst_path->slots[cur_level]);
2094			btrfs_item_key_to_cpu(src_path->nodes[cur_level],
2095					&src_key, src_path->slots[cur_level]);
2096		}
2097		/* Content mismatch, something went wrong */
2098		if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
2099			ret = -ENOENT;
2100			goto out;
2101		}
2102		cur_level--;
2103	}
2104
2105	/*
2106	 * Now both @dst_path and @src_path have been populated, record the tree
2107	 * blocks for qgroup accounting.
2108	 */
2109	ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
2110					nodesize);
2111	if (ret < 0)
2112		goto out;
2113	ret = btrfs_qgroup_trace_extent(trans, dst_path->nodes[dst_level]->start,
2114					nodesize);
 
2115	if (ret < 0)
2116		goto out;
2117
2118	/* Record leaf file extents */
2119	if (dst_level == 0 && trace_leaf) {
2120		ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
2121		if (ret < 0)
2122			goto out;
2123		ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
2124	}
2125out:
2126	btrfs_free_path(src_path);
2127	return ret;
2128}
2129
2130/*
2131 * Helper function to do recursive generation-aware depth-first search, to
2132 * locate all new tree blocks in a subtree of reloc tree.
2133 *
2134 * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
2135 *         reloc tree
2136 * L2         NN (a)
2137 *          /    \
2138 * L1    OO        NN (b)
2139 *      /  \      /  \
2140 * L0  OO  OO    OO  NN
2141 *               (c) (d)
2142 * If we pass:
2143 * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
2144 * @cur_level = 1
2145 * @root_level = 1
2146 *
2147 * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
2148 * above tree blocks along with their counter parts in file tree.
2149 * While during search, old tree blocks OO(c) will be skipped as tree block swap
2150 * won't affect OO(c).
2151 */
2152static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
2153					   struct extent_buffer *src_eb,
2154					   struct btrfs_path *dst_path,
2155					   int cur_level, int root_level,
2156					   u64 last_snapshot, bool trace_leaf)
2157{
2158	struct btrfs_fs_info *fs_info = trans->fs_info;
2159	struct extent_buffer *eb;
2160	bool need_cleanup = false;
2161	int ret = 0;
2162	int i;
2163
2164	/* Level sanity check */
2165	if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
2166	    root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
2167	    root_level < cur_level) {
2168		btrfs_err_rl(fs_info,
2169			"%s: bad levels, cur_level=%d root_level=%d",
2170			__func__, cur_level, root_level);
2171		return -EUCLEAN;
2172	}
2173
2174	/* Read the tree block if needed */
2175	if (dst_path->nodes[cur_level] == NULL) {
2176		int parent_slot;
2177		u64 child_gen;
2178
2179		/*
2180		 * dst_path->nodes[root_level] must be initialized before
2181		 * calling this function.
2182		 */
2183		if (cur_level == root_level) {
2184			btrfs_err_rl(fs_info,
2185	"%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
2186				__func__, root_level, root_level, cur_level);
2187			return -EUCLEAN;
2188		}
2189
2190		/*
2191		 * We need to get child blockptr/gen from parent before we can
2192		 * read it.
2193		  */
2194		eb = dst_path->nodes[cur_level + 1];
2195		parent_slot = dst_path->slots[cur_level + 1];
2196		child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2197
2198		/* This node is old, no need to trace */
2199		if (child_gen < last_snapshot)
2200			goto out;
2201
2202		eb = btrfs_read_node_slot(eb, parent_slot);
2203		if (IS_ERR(eb)) {
2204			ret = PTR_ERR(eb);
2205			goto out;
2206		}
2207
2208		dst_path->nodes[cur_level] = eb;
2209		dst_path->slots[cur_level] = 0;
2210
2211		btrfs_tree_read_lock(eb);
2212		dst_path->locks[cur_level] = BTRFS_READ_LOCK;
2213		need_cleanup = true;
2214	}
2215
2216	/* Now record this tree block and its counter part for qgroups */
2217	ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
2218				       root_level, trace_leaf);
2219	if (ret < 0)
2220		goto cleanup;
2221
2222	eb = dst_path->nodes[cur_level];
2223
2224	if (cur_level > 0) {
2225		/* Iterate all child tree blocks */
2226		for (i = 0; i < btrfs_header_nritems(eb); i++) {
2227			/* Skip old tree blocks as they won't be swapped */
2228			if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
2229				continue;
2230			dst_path->slots[cur_level] = i;
2231
2232			/* Recursive call (at most 7 times) */
2233			ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
2234					dst_path, cur_level - 1, root_level,
2235					last_snapshot, trace_leaf);
2236			if (ret < 0)
2237				goto cleanup;
2238		}
2239	}
2240
2241cleanup:
2242	if (need_cleanup) {
2243		/* Clean up */
2244		btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2245				     dst_path->locks[cur_level]);
2246		free_extent_buffer(dst_path->nodes[cur_level]);
2247		dst_path->nodes[cur_level] = NULL;
2248		dst_path->slots[cur_level] = 0;
2249		dst_path->locks[cur_level] = 0;
2250	}
2251out:
2252	return ret;
2253}
2254
2255static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2256				struct extent_buffer *src_eb,
2257				struct extent_buffer *dst_eb,
2258				u64 last_snapshot, bool trace_leaf)
2259{
2260	struct btrfs_fs_info *fs_info = trans->fs_info;
2261	struct btrfs_path *dst_path = NULL;
2262	int level;
2263	int ret;
2264
2265	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2266		return 0;
2267
2268	/* Wrong parameter order */
2269	if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
2270		btrfs_err_rl(fs_info,
2271		"%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2272			     btrfs_header_generation(src_eb),
2273			     btrfs_header_generation(dst_eb));
2274		return -EUCLEAN;
2275	}
2276
2277	if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2278		ret = -EIO;
2279		goto out;
2280	}
2281
2282	level = btrfs_header_level(dst_eb);
2283	dst_path = btrfs_alloc_path();
2284	if (!dst_path) {
2285		ret = -ENOMEM;
2286		goto out;
2287	}
2288	/* For dst_path */
2289	atomic_inc(&dst_eb->refs);
2290	dst_path->nodes[level] = dst_eb;
2291	dst_path->slots[level] = 0;
2292	dst_path->locks[level] = 0;
2293
2294	/* Do the generation aware breadth-first search */
2295	ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2296					      level, last_snapshot, trace_leaf);
2297	if (ret < 0)
2298		goto out;
2299	ret = 0;
2300
2301out:
2302	btrfs_free_path(dst_path);
2303	if (ret < 0)
2304		qgroup_mark_inconsistent(fs_info);
2305	return ret;
2306}
2307
2308int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2309			       struct extent_buffer *root_eb,
2310			       u64 root_gen, int root_level)
2311{
2312	struct btrfs_fs_info *fs_info = trans->fs_info;
2313	int ret = 0;
2314	int level;
2315	u8 drop_subptree_thres;
2316	struct extent_buffer *eb = root_eb;
2317	struct btrfs_path *path = NULL;
2318
2319	BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2320	BUG_ON(root_eb == NULL);
2321
2322	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2323		return 0;
2324
2325	spin_lock(&fs_info->qgroup_lock);
2326	drop_subptree_thres = fs_info->qgroup_drop_subtree_thres;
2327	spin_unlock(&fs_info->qgroup_lock);
2328
2329	/*
2330	 * This function only gets called for snapshot drop, if we hit a high
2331	 * node here, it means we are going to change ownership for quite a lot
2332	 * of extents, which will greatly slow down btrfs_commit_transaction().
2333	 *
2334	 * So here if we find a high tree here, we just skip the accounting and
2335	 * mark qgroup inconsistent.
2336	 */
2337	if (root_level >= drop_subptree_thres) {
2338		qgroup_mark_inconsistent(fs_info);
2339		return 0;
2340	}
2341
2342	if (!extent_buffer_uptodate(root_eb)) {
2343		struct btrfs_tree_parent_check check = {
2344			.has_first_key = false,
2345			.transid = root_gen,
2346			.level = root_level
2347		};
2348
2349		ret = btrfs_read_extent_buffer(root_eb, &check);
2350		if (ret)
2351			goto out;
2352	}
2353
2354	if (root_level == 0) {
2355		ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2356		goto out;
2357	}
2358
2359	path = btrfs_alloc_path();
2360	if (!path)
2361		return -ENOMEM;
2362
2363	/*
2364	 * Walk down the tree.  Missing extent blocks are filled in as
2365	 * we go. Metadata is accounted every time we read a new
2366	 * extent block.
2367	 *
2368	 * When we reach a leaf, we account for file extent items in it,
2369	 * walk back up the tree (adjusting slot pointers as we go)
2370	 * and restart the search process.
2371	 */
2372	atomic_inc(&root_eb->refs);	/* For path */
2373	path->nodes[root_level] = root_eb;
2374	path->slots[root_level] = 0;
2375	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2376walk_down:
2377	level = root_level;
2378	while (level >= 0) {
2379		if (path->nodes[level] == NULL) {
2380			int parent_slot;
2381			u64 child_bytenr;
2382
2383			/*
2384			 * We need to get child blockptr from parent before we
2385			 * can read it.
2386			  */
2387			eb = path->nodes[level + 1];
2388			parent_slot = path->slots[level + 1];
2389			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2390
2391			eb = btrfs_read_node_slot(eb, parent_slot);
2392			if (IS_ERR(eb)) {
2393				ret = PTR_ERR(eb);
2394				goto out;
2395			}
2396
2397			path->nodes[level] = eb;
2398			path->slots[level] = 0;
2399
2400			btrfs_tree_read_lock(eb);
2401			path->locks[level] = BTRFS_READ_LOCK;
2402
2403			ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2404							fs_info->nodesize);
 
2405			if (ret)
2406				goto out;
2407		}
2408
2409		if (level == 0) {
2410			ret = btrfs_qgroup_trace_leaf_items(trans,
2411							    path->nodes[level]);
2412			if (ret)
2413				goto out;
2414
2415			/* Nonzero return here means we completed our search */
2416			ret = adjust_slots_upwards(path, root_level);
2417			if (ret)
2418				break;
2419
2420			/* Restart search with new slots */
2421			goto walk_down;
2422		}
2423
2424		level--;
2425	}
2426
2427	ret = 0;
2428out:
2429	btrfs_free_path(path);
2430
2431	return ret;
2432}
2433
2434#define UPDATE_NEW	0
2435#define UPDATE_OLD	1
2436/*
2437 * Walk all of the roots that points to the bytenr and adjust their refcnts.
2438 */
2439static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2440				struct ulist *roots, struct ulist *tmp,
2441				struct ulist *qgroups, u64 seq, int update_old)
2442{
2443	struct ulist_node *unode;
2444	struct ulist_iterator uiter;
2445	struct ulist_node *tmp_unode;
2446	struct ulist_iterator tmp_uiter;
2447	struct btrfs_qgroup *qg;
2448	int ret = 0;
2449
2450	if (!roots)
2451		return 0;
2452	ULIST_ITER_INIT(&uiter);
2453	while ((unode = ulist_next(roots, &uiter))) {
2454		qg = find_qgroup_rb(fs_info, unode->val);
2455		if (!qg)
2456			continue;
2457
2458		ulist_reinit(tmp);
2459		ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2460				GFP_ATOMIC);
2461		if (ret < 0)
2462			return ret;
2463		ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2464		if (ret < 0)
2465			return ret;
2466		ULIST_ITER_INIT(&tmp_uiter);
2467		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2468			struct btrfs_qgroup_list *glist;
2469
2470			qg = unode_aux_to_qgroup(tmp_unode);
2471			if (update_old)
2472				btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2473			else
2474				btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2475			list_for_each_entry(glist, &qg->groups, next_group) {
2476				ret = ulist_add(qgroups, glist->group->qgroupid,
2477						qgroup_to_aux(glist->group),
2478						GFP_ATOMIC);
2479				if (ret < 0)
2480					return ret;
2481				ret = ulist_add(tmp, glist->group->qgroupid,
2482						qgroup_to_aux(glist->group),
2483						GFP_ATOMIC);
2484				if (ret < 0)
2485					return ret;
2486			}
2487		}
2488	}
2489	return 0;
2490}
2491
2492/*
2493 * Update qgroup rfer/excl counters.
2494 * Rfer update is easy, codes can explain themselves.
2495 *
2496 * Excl update is tricky, the update is split into 2 parts.
2497 * Part 1: Possible exclusive <-> sharing detect:
2498 *	|	A	|	!A	|
2499 *  -------------------------------------
2500 *  B	|	*	|	-	|
2501 *  -------------------------------------
2502 *  !B	|	+	|	**	|
2503 *  -------------------------------------
2504 *
2505 * Conditions:
2506 * A:	cur_old_roots < nr_old_roots	(not exclusive before)
2507 * !A:	cur_old_roots == nr_old_roots	(possible exclusive before)
2508 * B:	cur_new_roots < nr_new_roots	(not exclusive now)
2509 * !B:	cur_new_roots == nr_new_roots	(possible exclusive now)
2510 *
2511 * Results:
2512 * +: Possible sharing -> exclusive	-: Possible exclusive -> sharing
2513 * *: Definitely not changed.		**: Possible unchanged.
2514 *
2515 * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2516 *
2517 * To make the logic clear, we first use condition A and B to split
2518 * combination into 4 results.
2519 *
2520 * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2521 * only on variant maybe 0.
2522 *
2523 * Lastly, check result **, since there are 2 variants maybe 0, split them
2524 * again(2x2).
2525 * But this time we don't need to consider other things, the codes and logic
2526 * is easy to understand now.
2527 */
2528static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2529				  struct ulist *qgroups,
2530				  u64 nr_old_roots,
2531				  u64 nr_new_roots,
2532				  u64 num_bytes, u64 seq)
2533{
2534	struct ulist_node *unode;
2535	struct ulist_iterator uiter;
2536	struct btrfs_qgroup *qg;
2537	u64 cur_new_count, cur_old_count;
2538
2539	ULIST_ITER_INIT(&uiter);
2540	while ((unode = ulist_next(qgroups, &uiter))) {
2541		bool dirty = false;
2542
2543		qg = unode_aux_to_qgroup(unode);
2544		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2545		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2546
2547		trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2548					     cur_new_count);
2549
2550		/* Rfer update part */
2551		if (cur_old_count == 0 && cur_new_count > 0) {
2552			qg->rfer += num_bytes;
2553			qg->rfer_cmpr += num_bytes;
2554			dirty = true;
2555		}
2556		if (cur_old_count > 0 && cur_new_count == 0) {
2557			qg->rfer -= num_bytes;
2558			qg->rfer_cmpr -= num_bytes;
2559			dirty = true;
2560		}
2561
2562		/* Excl update part */
2563		/* Exclusive/none -> shared case */
2564		if (cur_old_count == nr_old_roots &&
2565		    cur_new_count < nr_new_roots) {
2566			/* Exclusive -> shared */
2567			if (cur_old_count != 0) {
2568				qg->excl -= num_bytes;
2569				qg->excl_cmpr -= num_bytes;
2570				dirty = true;
2571			}
2572		}
2573
2574		/* Shared -> exclusive/none case */
2575		if (cur_old_count < nr_old_roots &&
2576		    cur_new_count == nr_new_roots) {
2577			/* Shared->exclusive */
2578			if (cur_new_count != 0) {
2579				qg->excl += num_bytes;
2580				qg->excl_cmpr += num_bytes;
2581				dirty = true;
2582			}
2583		}
2584
2585		/* Exclusive/none -> exclusive/none case */
2586		if (cur_old_count == nr_old_roots &&
2587		    cur_new_count == nr_new_roots) {
2588			if (cur_old_count == 0) {
2589				/* None -> exclusive/none */
2590
2591				if (cur_new_count != 0) {
2592					/* None -> exclusive */
2593					qg->excl += num_bytes;
2594					qg->excl_cmpr += num_bytes;
2595					dirty = true;
2596				}
2597				/* None -> none, nothing changed */
2598			} else {
2599				/* Exclusive -> exclusive/none */
2600
2601				if (cur_new_count == 0) {
2602					/* Exclusive -> none */
2603					qg->excl -= num_bytes;
2604					qg->excl_cmpr -= num_bytes;
2605					dirty = true;
2606				}
2607				/* Exclusive -> exclusive, nothing changed */
2608			}
2609		}
2610
2611		if (dirty)
2612			qgroup_dirty(fs_info, qg);
2613	}
2614	return 0;
2615}
2616
2617/*
2618 * Check if the @roots potentially is a list of fs tree roots
2619 *
2620 * Return 0 for definitely not a fs/subvol tree roots ulist
2621 * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2622 *          one as well)
2623 */
2624static int maybe_fs_roots(struct ulist *roots)
2625{
2626	struct ulist_node *unode;
2627	struct ulist_iterator uiter;
2628
2629	/* Empty one, still possible for fs roots */
2630	if (!roots || roots->nnodes == 0)
2631		return 1;
2632
2633	ULIST_ITER_INIT(&uiter);
2634	unode = ulist_next(roots, &uiter);
2635	if (!unode)
2636		return 1;
2637
2638	/*
2639	 * If it contains fs tree roots, then it must belong to fs/subvol
2640	 * trees.
2641	 * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2642	 */
2643	return is_fstree(unode->val);
2644}
2645
2646int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2647				u64 num_bytes, struct ulist *old_roots,
2648				struct ulist *new_roots)
2649{
2650	struct btrfs_fs_info *fs_info = trans->fs_info;
2651	struct ulist *qgroups = NULL;
2652	struct ulist *tmp = NULL;
2653	u64 seq;
2654	u64 nr_new_roots = 0;
2655	u64 nr_old_roots = 0;
2656	int ret = 0;
2657
2658	/*
2659	 * If quotas get disabled meanwhile, the resources need to be freed and
2660	 * we can't just exit here.
2661	 */
2662	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
2663	    fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)
2664		goto out_free;
2665
2666	if (new_roots) {
2667		if (!maybe_fs_roots(new_roots))
2668			goto out_free;
2669		nr_new_roots = new_roots->nnodes;
2670	}
2671	if (old_roots) {
2672		if (!maybe_fs_roots(old_roots))
2673			goto out_free;
2674		nr_old_roots = old_roots->nnodes;
2675	}
2676
2677	/* Quick exit, either not fs tree roots, or won't affect any qgroup */
2678	if (nr_old_roots == 0 && nr_new_roots == 0)
2679		goto out_free;
2680
2681	BUG_ON(!fs_info->quota_root);
2682
2683	trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2684					num_bytes, nr_old_roots, nr_new_roots);
2685
2686	qgroups = ulist_alloc(GFP_NOFS);
2687	if (!qgroups) {
2688		ret = -ENOMEM;
2689		goto out_free;
2690	}
2691	tmp = ulist_alloc(GFP_NOFS);
2692	if (!tmp) {
2693		ret = -ENOMEM;
2694		goto out_free;
2695	}
2696
2697	mutex_lock(&fs_info->qgroup_rescan_lock);
2698	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2699		if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2700			mutex_unlock(&fs_info->qgroup_rescan_lock);
2701			ret = 0;
2702			goto out_free;
2703		}
2704	}
2705	mutex_unlock(&fs_info->qgroup_rescan_lock);
2706
2707	spin_lock(&fs_info->qgroup_lock);
2708	seq = fs_info->qgroup_seq;
2709
2710	/* Update old refcnts using old_roots */
2711	ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2712				   UPDATE_OLD);
2713	if (ret < 0)
2714		goto out;
2715
2716	/* Update new refcnts using new_roots */
2717	ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2718				   UPDATE_NEW);
2719	if (ret < 0)
2720		goto out;
2721
2722	qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2723			       num_bytes, seq);
2724
2725	/*
2726	 * Bump qgroup_seq to avoid seq overlap
2727	 */
2728	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2729out:
2730	spin_unlock(&fs_info->qgroup_lock);
2731out_free:
2732	ulist_free(tmp);
2733	ulist_free(qgroups);
2734	ulist_free(old_roots);
2735	ulist_free(new_roots);
2736	return ret;
2737}
2738
2739int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2740{
2741	struct btrfs_fs_info *fs_info = trans->fs_info;
2742	struct btrfs_qgroup_extent_record *record;
2743	struct btrfs_delayed_ref_root *delayed_refs;
2744	struct ulist *new_roots = NULL;
2745	struct rb_node *node;
2746	u64 num_dirty_extents = 0;
2747	u64 qgroup_to_skip;
2748	int ret = 0;
2749
2750	delayed_refs = &trans->transaction->delayed_refs;
2751	qgroup_to_skip = delayed_refs->qgroup_to_skip;
2752	while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2753		record = rb_entry(node, struct btrfs_qgroup_extent_record,
2754				  node);
2755
2756		num_dirty_extents++;
2757		trace_btrfs_qgroup_account_extents(fs_info, record);
2758
2759		if (!ret && !(fs_info->qgroup_flags &
2760			      BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)) {
2761			struct btrfs_backref_walk_ctx ctx = { 0 };
2762
2763			ctx.bytenr = record->bytenr;
2764			ctx.fs_info = fs_info;
2765
2766			/*
2767			 * Old roots should be searched when inserting qgroup
2768			 * extent record.
2769			 *
2770			 * But for INCONSISTENT (NO_ACCOUNTING) -> rescan case,
2771			 * we may have some record inserted during
2772			 * NO_ACCOUNTING (thus no old_roots populated), but
2773			 * later we start rescan, which clears NO_ACCOUNTING,
2774			 * leaving some inserted records without old_roots
2775			 * populated.
2776			 *
2777			 * Those cases are rare and should not cause too much
2778			 * time spent during commit_transaction().
2779			 */
2780			if (!record->old_roots) {
2781				/* Search commit root to find old_roots */
2782				ret = btrfs_find_all_roots(&ctx, false);
 
 
2783				if (ret < 0)
2784					goto cleanup;
2785				record->old_roots = ctx.roots;
2786				ctx.roots = NULL;
2787			}
2788
2789			/* Free the reserved data space */
2790			btrfs_qgroup_free_refroot(fs_info,
2791					record->data_rsv_refroot,
2792					record->data_rsv,
2793					BTRFS_QGROUP_RSV_DATA);
2794			/*
2795			 * Use BTRFS_SEQ_LAST as time_seq to do special search,
2796			 * which doesn't lock tree or delayed_refs and search
2797			 * current root. It's safe inside commit_transaction().
2798			 */
2799			ctx.trans = trans;
2800			ctx.time_seq = BTRFS_SEQ_LAST;
2801			ret = btrfs_find_all_roots(&ctx, false);
2802			if (ret < 0)
2803				goto cleanup;
2804			new_roots = ctx.roots;
2805			if (qgroup_to_skip) {
2806				ulist_del(new_roots, qgroup_to_skip, 0);
2807				ulist_del(record->old_roots, qgroup_to_skip,
2808					  0);
2809			}
2810			ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2811							  record->num_bytes,
2812							  record->old_roots,
2813							  new_roots);
2814			record->old_roots = NULL;
2815			new_roots = NULL;
2816		}
2817cleanup:
2818		ulist_free(record->old_roots);
2819		ulist_free(new_roots);
2820		new_roots = NULL;
2821		rb_erase(node, &delayed_refs->dirty_extent_root);
2822		kfree(record);
2823
2824	}
2825	trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2826				       num_dirty_extents);
2827	return ret;
2828}
2829
2830/*
2831 * called from commit_transaction. Writes all changed qgroups to disk.
2832 */
2833int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2834{
2835	struct btrfs_fs_info *fs_info = trans->fs_info;
2836	int ret = 0;
2837
2838	if (!fs_info->quota_root)
2839		return ret;
2840
2841	spin_lock(&fs_info->qgroup_lock);
2842	while (!list_empty(&fs_info->dirty_qgroups)) {
2843		struct btrfs_qgroup *qgroup;
2844		qgroup = list_first_entry(&fs_info->dirty_qgroups,
2845					  struct btrfs_qgroup, dirty);
2846		list_del_init(&qgroup->dirty);
2847		spin_unlock(&fs_info->qgroup_lock);
2848		ret = update_qgroup_info_item(trans, qgroup);
2849		if (ret)
2850			qgroup_mark_inconsistent(fs_info);
 
2851		ret = update_qgroup_limit_item(trans, qgroup);
2852		if (ret)
2853			qgroup_mark_inconsistent(fs_info);
 
2854		spin_lock(&fs_info->qgroup_lock);
2855	}
2856	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2857		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2858	else
2859		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2860	spin_unlock(&fs_info->qgroup_lock);
2861
2862	ret = update_qgroup_status_item(trans);
2863	if (ret)
2864		qgroup_mark_inconsistent(fs_info);
2865
2866	return ret;
2867}
2868
2869/*
2870 * Copy the accounting information between qgroups. This is necessary
2871 * when a snapshot or a subvolume is created. Throwing an error will
2872 * cause a transaction abort so we take extra care here to only error
2873 * when a readonly fs is a reasonable outcome.
2874 */
2875int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2876			 u64 objectid, struct btrfs_qgroup_inherit *inherit)
2877{
2878	int ret = 0;
2879	int i;
2880	u64 *i_qgroups;
2881	bool committing = false;
2882	struct btrfs_fs_info *fs_info = trans->fs_info;
2883	struct btrfs_root *quota_root;
2884	struct btrfs_qgroup *srcgroup;
2885	struct btrfs_qgroup *dstgroup;
2886	bool need_rescan = false;
2887	u32 level_size = 0;
2888	u64 nums;
2889
2890	/*
2891	 * There are only two callers of this function.
2892	 *
2893	 * One in create_subvol() in the ioctl context, which needs to hold
2894	 * the qgroup_ioctl_lock.
2895	 *
2896	 * The other one in create_pending_snapshot() where no other qgroup
2897	 * code can modify the fs as they all need to either start a new trans
2898	 * or hold a trans handler, thus we don't need to hold
2899	 * qgroup_ioctl_lock.
2900	 * This would avoid long and complex lock chain and make lockdep happy.
2901	 */
2902	spin_lock(&fs_info->trans_lock);
2903	if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
2904		committing = true;
2905	spin_unlock(&fs_info->trans_lock);
2906
2907	if (!committing)
2908		mutex_lock(&fs_info->qgroup_ioctl_lock);
2909	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2910		goto out;
2911
2912	quota_root = fs_info->quota_root;
2913	if (!quota_root) {
2914		ret = -EINVAL;
2915		goto out;
2916	}
2917
2918	if (inherit) {
2919		i_qgroups = (u64 *)(inherit + 1);
2920		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2921		       2 * inherit->num_excl_copies;
2922		for (i = 0; i < nums; ++i) {
2923			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2924
2925			/*
2926			 * Zero out invalid groups so we can ignore
2927			 * them later.
2928			 */
2929			if (!srcgroup ||
2930			    ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2931				*i_qgroups = 0ULL;
2932
2933			++i_qgroups;
2934		}
2935	}
2936
2937	/*
2938	 * create a tracking group for the subvol itself
2939	 */
2940	ret = add_qgroup_item(trans, quota_root, objectid);
2941	if (ret)
2942		goto out;
2943
2944	/*
2945	 * add qgroup to all inherited groups
2946	 */
2947	if (inherit) {
2948		i_qgroups = (u64 *)(inherit + 1);
2949		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2950			if (*i_qgroups == 0)
2951				continue;
2952			ret = add_qgroup_relation_item(trans, objectid,
2953						       *i_qgroups);
2954			if (ret && ret != -EEXIST)
2955				goto out;
2956			ret = add_qgroup_relation_item(trans, *i_qgroups,
2957						       objectid);
2958			if (ret && ret != -EEXIST)
2959				goto out;
2960		}
2961		ret = 0;
2962	}
2963
2964
2965	spin_lock(&fs_info->qgroup_lock);
2966
2967	dstgroup = add_qgroup_rb(fs_info, objectid);
2968	if (IS_ERR(dstgroup)) {
2969		ret = PTR_ERR(dstgroup);
2970		goto unlock;
2971	}
2972
2973	if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2974		dstgroup->lim_flags = inherit->lim.flags;
2975		dstgroup->max_rfer = inherit->lim.max_rfer;
2976		dstgroup->max_excl = inherit->lim.max_excl;
2977		dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2978		dstgroup->rsv_excl = inherit->lim.rsv_excl;
2979
2980		qgroup_dirty(fs_info, dstgroup);
 
 
 
 
 
 
 
2981	}
2982
2983	if (srcid) {
2984		srcgroup = find_qgroup_rb(fs_info, srcid);
2985		if (!srcgroup)
2986			goto unlock;
2987
2988		/*
2989		 * We call inherit after we clone the root in order to make sure
2990		 * our counts don't go crazy, so at this point the only
2991		 * difference between the two roots should be the root node.
2992		 */
2993		level_size = fs_info->nodesize;
2994		dstgroup->rfer = srcgroup->rfer;
2995		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2996		dstgroup->excl = level_size;
2997		dstgroup->excl_cmpr = level_size;
2998		srcgroup->excl = level_size;
2999		srcgroup->excl_cmpr = level_size;
3000
3001		/* inherit the limit info */
3002		dstgroup->lim_flags = srcgroup->lim_flags;
3003		dstgroup->max_rfer = srcgroup->max_rfer;
3004		dstgroup->max_excl = srcgroup->max_excl;
3005		dstgroup->rsv_rfer = srcgroup->rsv_rfer;
3006		dstgroup->rsv_excl = srcgroup->rsv_excl;
3007
3008		qgroup_dirty(fs_info, dstgroup);
3009		qgroup_dirty(fs_info, srcgroup);
3010	}
3011
3012	if (!inherit)
3013		goto unlock;
3014
3015	i_qgroups = (u64 *)(inherit + 1);
3016	for (i = 0; i < inherit->num_qgroups; ++i) {
3017		if (*i_qgroups) {
3018			ret = add_relation_rb(fs_info, objectid, *i_qgroups);
3019			if (ret)
3020				goto unlock;
3021		}
3022		++i_qgroups;
3023
3024		/*
3025		 * If we're doing a snapshot, and adding the snapshot to a new
3026		 * qgroup, the numbers are guaranteed to be incorrect.
3027		 */
3028		if (srcid)
3029			need_rescan = true;
3030	}
3031
3032	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
3033		struct btrfs_qgroup *src;
3034		struct btrfs_qgroup *dst;
3035
3036		if (!i_qgroups[0] || !i_qgroups[1])
3037			continue;
3038
3039		src = find_qgroup_rb(fs_info, i_qgroups[0]);
3040		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3041
3042		if (!src || !dst) {
3043			ret = -EINVAL;
3044			goto unlock;
3045		}
3046
3047		dst->rfer = src->rfer - level_size;
3048		dst->rfer_cmpr = src->rfer_cmpr - level_size;
3049
3050		/* Manually tweaking numbers certainly needs a rescan */
3051		need_rescan = true;
3052	}
3053	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
3054		struct btrfs_qgroup *src;
3055		struct btrfs_qgroup *dst;
3056
3057		if (!i_qgroups[0] || !i_qgroups[1])
3058			continue;
3059
3060		src = find_qgroup_rb(fs_info, i_qgroups[0]);
3061		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3062
3063		if (!src || !dst) {
3064			ret = -EINVAL;
3065			goto unlock;
3066		}
3067
3068		dst->excl = src->excl + level_size;
3069		dst->excl_cmpr = src->excl_cmpr + level_size;
3070		need_rescan = true;
3071	}
3072
3073unlock:
3074	spin_unlock(&fs_info->qgroup_lock);
3075	if (!ret)
3076		ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup);
3077out:
3078	if (!committing)
3079		mutex_unlock(&fs_info->qgroup_ioctl_lock);
3080	if (need_rescan)
3081		qgroup_mark_inconsistent(fs_info);
3082	return ret;
3083}
3084
3085static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
3086{
3087	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
3088	    qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
3089		return false;
3090
3091	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
3092	    qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
3093		return false;
3094
3095	return true;
3096}
3097
3098static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
3099			  enum btrfs_qgroup_rsv_type type)
3100{
3101	struct btrfs_qgroup *qgroup;
3102	struct btrfs_fs_info *fs_info = root->fs_info;
3103	u64 ref_root = root->root_key.objectid;
3104	int ret = 0;
3105	struct ulist_node *unode;
3106	struct ulist_iterator uiter;
3107
3108	if (!is_fstree(ref_root))
3109		return 0;
3110
3111	if (num_bytes == 0)
3112		return 0;
3113
3114	if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
3115	    capable(CAP_SYS_RESOURCE))
3116		enforce = false;
3117
3118	spin_lock(&fs_info->qgroup_lock);
3119	if (!fs_info->quota_root)
3120		goto out;
3121
3122	qgroup = find_qgroup_rb(fs_info, ref_root);
3123	if (!qgroup)
3124		goto out;
3125
3126	/*
3127	 * in a first step, we check all affected qgroups if any limits would
3128	 * be exceeded
3129	 */
3130	ulist_reinit(fs_info->qgroup_ulist);
3131	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3132			qgroup_to_aux(qgroup), GFP_ATOMIC);
3133	if (ret < 0)
3134		goto out;
3135	ULIST_ITER_INIT(&uiter);
3136	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3137		struct btrfs_qgroup *qg;
3138		struct btrfs_qgroup_list *glist;
3139
3140		qg = unode_aux_to_qgroup(unode);
3141
3142		if (enforce && !qgroup_check_limits(qg, num_bytes)) {
3143			ret = -EDQUOT;
3144			goto out;
3145		}
3146
3147		list_for_each_entry(glist, &qg->groups, next_group) {
3148			ret = ulist_add(fs_info->qgroup_ulist,
3149					glist->group->qgroupid,
3150					qgroup_to_aux(glist->group), GFP_ATOMIC);
3151			if (ret < 0)
3152				goto out;
3153		}
3154	}
3155	ret = 0;
3156	/*
3157	 * no limits exceeded, now record the reservation into all qgroups
3158	 */
3159	ULIST_ITER_INIT(&uiter);
3160	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3161		struct btrfs_qgroup *qg;
3162
3163		qg = unode_aux_to_qgroup(unode);
3164
3165		qgroup_rsv_add(fs_info, qg, num_bytes, type);
3166	}
3167
3168out:
3169	spin_unlock(&fs_info->qgroup_lock);
3170	return ret;
3171}
3172
3173/*
3174 * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
3175 * qgroup).
3176 *
3177 * Will handle all higher level qgroup too.
3178 *
3179 * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
3180 * This special case is only used for META_PERTRANS type.
3181 */
3182void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
3183			       u64 ref_root, u64 num_bytes,
3184			       enum btrfs_qgroup_rsv_type type)
3185{
3186	struct btrfs_qgroup *qgroup;
3187	struct ulist_node *unode;
3188	struct ulist_iterator uiter;
3189	int ret = 0;
3190
3191	if (!is_fstree(ref_root))
3192		return;
3193
3194	if (num_bytes == 0)
3195		return;
3196
3197	if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
3198		WARN(1, "%s: Invalid type to free", __func__);
3199		return;
3200	}
3201	spin_lock(&fs_info->qgroup_lock);
3202
3203	if (!fs_info->quota_root)
3204		goto out;
3205
3206	qgroup = find_qgroup_rb(fs_info, ref_root);
3207	if (!qgroup)
3208		goto out;
3209
3210	if (num_bytes == (u64)-1)
3211		/*
3212		 * We're freeing all pertrans rsv, get reserved value from
3213		 * level 0 qgroup as real num_bytes to free.
3214		 */
3215		num_bytes = qgroup->rsv.values[type];
3216
3217	ulist_reinit(fs_info->qgroup_ulist);
3218	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3219			qgroup_to_aux(qgroup), GFP_ATOMIC);
3220	if (ret < 0)
3221		goto out;
3222	ULIST_ITER_INIT(&uiter);
3223	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3224		struct btrfs_qgroup *qg;
3225		struct btrfs_qgroup_list *glist;
3226
3227		qg = unode_aux_to_qgroup(unode);
3228
3229		qgroup_rsv_release(fs_info, qg, num_bytes, type);
3230
3231		list_for_each_entry(glist, &qg->groups, next_group) {
3232			ret = ulist_add(fs_info->qgroup_ulist,
3233					glist->group->qgroupid,
3234					qgroup_to_aux(glist->group), GFP_ATOMIC);
3235			if (ret < 0)
3236				goto out;
3237		}
3238	}
3239
3240out:
3241	spin_unlock(&fs_info->qgroup_lock);
3242}
3243
3244/*
3245 * Check if the leaf is the last leaf. Which means all node pointers
3246 * are at their last position.
3247 */
3248static bool is_last_leaf(struct btrfs_path *path)
3249{
3250	int i;
3251
3252	for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3253		if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3254			return false;
3255	}
3256	return true;
3257}
3258
3259/*
3260 * returns < 0 on error, 0 when more leafs are to be scanned.
3261 * returns 1 when done.
3262 */
3263static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3264			      struct btrfs_path *path)
3265{
3266	struct btrfs_fs_info *fs_info = trans->fs_info;
3267	struct btrfs_root *extent_root;
3268	struct btrfs_key found;
3269	struct extent_buffer *scratch_leaf = NULL;
 
3270	u64 num_bytes;
3271	bool done;
3272	int slot;
3273	int ret;
3274
3275	mutex_lock(&fs_info->qgroup_rescan_lock);
3276	extent_root = btrfs_extent_root(fs_info,
3277				fs_info->qgroup_rescan_progress.objectid);
3278	ret = btrfs_search_slot_for_read(extent_root,
3279					 &fs_info->qgroup_rescan_progress,
3280					 path, 1, 0);
3281
3282	btrfs_debug(fs_info,
3283		"current progress key (%llu %u %llu), search_slot ret %d",
3284		fs_info->qgroup_rescan_progress.objectid,
3285		fs_info->qgroup_rescan_progress.type,
3286		fs_info->qgroup_rescan_progress.offset, ret);
3287
3288	if (ret) {
3289		/*
3290		 * The rescan is about to end, we will not be scanning any
3291		 * further blocks. We cannot unset the RESCAN flag here, because
3292		 * we want to commit the transaction if everything went well.
3293		 * To make the live accounting work in this phase, we set our
3294		 * scan progress pointer such that every real extent objectid
3295		 * will be smaller.
3296		 */
3297		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3298		btrfs_release_path(path);
3299		mutex_unlock(&fs_info->qgroup_rescan_lock);
3300		return ret;
3301	}
3302	done = is_last_leaf(path);
3303
3304	btrfs_item_key_to_cpu(path->nodes[0], &found,
3305			      btrfs_header_nritems(path->nodes[0]) - 1);
3306	fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3307
3308	scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3309	if (!scratch_leaf) {
3310		ret = -ENOMEM;
3311		mutex_unlock(&fs_info->qgroup_rescan_lock);
3312		goto out;
3313	}
3314	slot = path->slots[0];
3315	btrfs_release_path(path);
3316	mutex_unlock(&fs_info->qgroup_rescan_lock);
3317
3318	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
3319		struct btrfs_backref_walk_ctx ctx = { 0 };
3320
3321		btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3322		if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3323		    found.type != BTRFS_METADATA_ITEM_KEY)
3324			continue;
3325		if (found.type == BTRFS_METADATA_ITEM_KEY)
3326			num_bytes = fs_info->nodesize;
3327		else
3328			num_bytes = found.offset;
3329
3330		ctx.bytenr = found.objectid;
3331		ctx.fs_info = fs_info;
3332
3333		ret = btrfs_find_all_roots(&ctx, false);
3334		if (ret < 0)
3335			goto out;
3336		/* For rescan, just pass old_roots as NULL */
3337		ret = btrfs_qgroup_account_extent(trans, found.objectid,
3338						  num_bytes, NULL, ctx.roots);
3339		if (ret < 0)
3340			goto out;
3341	}
3342out:
3343	if (scratch_leaf)
3344		free_extent_buffer(scratch_leaf);
3345
3346	if (done && !ret) {
3347		ret = 1;
3348		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3349	}
3350	return ret;
3351}
3352
3353static bool rescan_should_stop(struct btrfs_fs_info *fs_info)
3354{
3355	return btrfs_fs_closing(fs_info) ||
3356		test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state) ||
3357		!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3358			  fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN;
3359}
3360
3361static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3362{
3363	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3364						     qgroup_rescan_work);
3365	struct btrfs_path *path;
3366	struct btrfs_trans_handle *trans = NULL;
3367	int err = -ENOMEM;
3368	int ret = 0;
3369	bool stopped = false;
3370	bool did_leaf_rescans = false;
3371
3372	path = btrfs_alloc_path();
3373	if (!path)
3374		goto out;
3375	/*
3376	 * Rescan should only search for commit root, and any later difference
3377	 * should be recorded by qgroup
3378	 */
3379	path->search_commit_root = 1;
3380	path->skip_locking = 1;
3381
3382	err = 0;
3383	while (!err && !(stopped = rescan_should_stop(fs_info))) {
3384		trans = btrfs_start_transaction(fs_info->fs_root, 0);
3385		if (IS_ERR(trans)) {
3386			err = PTR_ERR(trans);
3387			break;
3388		}
3389
3390		err = qgroup_rescan_leaf(trans, path);
3391		did_leaf_rescans = true;
3392
 
3393		if (err > 0)
3394			btrfs_commit_transaction(trans);
3395		else
3396			btrfs_end_transaction(trans);
3397	}
3398
3399out:
3400	btrfs_free_path(path);
3401
3402	mutex_lock(&fs_info->qgroup_rescan_lock);
3403	if (err > 0 &&
3404	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3405		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3406	} else if (err < 0 || stopped) {
3407		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3408	}
3409	mutex_unlock(&fs_info->qgroup_rescan_lock);
3410
3411	/*
3412	 * Only update status, since the previous part has already updated the
3413	 * qgroup info, and only if we did any actual work. This also prevents
3414	 * race with a concurrent quota disable, which has already set
3415	 * fs_info->quota_root to NULL and cleared BTRFS_FS_QUOTA_ENABLED at
3416	 * btrfs_quota_disable().
3417	 */
3418	if (did_leaf_rescans) {
3419		trans = btrfs_start_transaction(fs_info->quota_root, 1);
3420		if (IS_ERR(trans)) {
3421			err = PTR_ERR(trans);
3422			trans = NULL;
3423			btrfs_err(fs_info,
3424				  "fail to start transaction for status update: %d",
3425				  err);
3426		}
3427	} else {
3428		trans = NULL;
 
 
 
3429	}
3430
3431	mutex_lock(&fs_info->qgroup_rescan_lock);
3432	if (!stopped ||
3433	    fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN)
3434		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3435	if (trans) {
3436		ret = update_qgroup_status_item(trans);
3437		if (ret < 0) {
3438			err = ret;
3439			btrfs_err(fs_info, "fail to update qgroup status: %d",
3440				  err);
3441		}
3442	}
3443	fs_info->qgroup_rescan_running = false;
3444	fs_info->qgroup_flags &= ~BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN;
3445	complete_all(&fs_info->qgroup_rescan_completion);
3446	mutex_unlock(&fs_info->qgroup_rescan_lock);
3447
3448	if (!trans)
3449		return;
3450
3451	btrfs_end_transaction(trans);
3452
3453	if (stopped) {
3454		btrfs_info(fs_info, "qgroup scan paused");
3455	} else if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) {
3456		btrfs_info(fs_info, "qgroup scan cancelled");
3457	} else if (err >= 0) {
3458		btrfs_info(fs_info, "qgroup scan completed%s",
3459			err > 0 ? " (inconsistency flag cleared)" : "");
3460	} else {
3461		btrfs_err(fs_info, "qgroup scan failed with %d", err);
3462	}
3463}
3464
3465/*
3466 * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
3467 * memory required for the rescan context.
3468 */
3469static int
3470qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
3471		   int init_flags)
3472{
3473	int ret = 0;
3474
3475	if (!init_flags) {
3476		/* we're resuming qgroup rescan at mount time */
3477		if (!(fs_info->qgroup_flags &
3478		      BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
3479			btrfs_warn(fs_info,
3480			"qgroup rescan init failed, qgroup rescan is not queued");
3481			ret = -EINVAL;
3482		} else if (!(fs_info->qgroup_flags &
3483			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3484			btrfs_warn(fs_info,
3485			"qgroup rescan init failed, qgroup is not enabled");
3486			ret = -EINVAL;
3487		}
3488
3489		if (ret)
3490			return ret;
3491	}
3492
3493	mutex_lock(&fs_info->qgroup_rescan_lock);
3494
3495	if (init_flags) {
3496		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3497			btrfs_warn(fs_info,
3498				   "qgroup rescan is already in progress");
3499			ret = -EINPROGRESS;
3500		} else if (!(fs_info->qgroup_flags &
3501			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3502			btrfs_warn(fs_info,
3503			"qgroup rescan init failed, qgroup is not enabled");
3504			ret = -EINVAL;
3505		} else if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3506			/* Quota disable is in progress */
3507			ret = -EBUSY;
3508		}
3509
3510		if (ret) {
3511			mutex_unlock(&fs_info->qgroup_rescan_lock);
3512			return ret;
3513		}
3514		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3515	}
3516
3517	memset(&fs_info->qgroup_rescan_progress, 0,
3518		sizeof(fs_info->qgroup_rescan_progress));
3519	fs_info->qgroup_flags &= ~(BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN |
3520				   BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING);
3521	fs_info->qgroup_rescan_progress.objectid = progress_objectid;
3522	init_completion(&fs_info->qgroup_rescan_completion);
3523	mutex_unlock(&fs_info->qgroup_rescan_lock);
3524
3525	btrfs_init_work(&fs_info->qgroup_rescan_work,
3526			btrfs_qgroup_rescan_worker, NULL, NULL);
3527	return 0;
3528}
3529
3530static void
3531qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
3532{
3533	struct rb_node *n;
3534	struct btrfs_qgroup *qgroup;
3535
3536	spin_lock(&fs_info->qgroup_lock);
3537	/* clear all current qgroup tracking information */
3538	for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
3539		qgroup = rb_entry(n, struct btrfs_qgroup, node);
3540		qgroup->rfer = 0;
3541		qgroup->rfer_cmpr = 0;
3542		qgroup->excl = 0;
3543		qgroup->excl_cmpr = 0;
3544		qgroup_dirty(fs_info, qgroup);
3545	}
3546	spin_unlock(&fs_info->qgroup_lock);
3547}
3548
3549int
3550btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
3551{
3552	int ret = 0;
3553	struct btrfs_trans_handle *trans;
3554
3555	ret = qgroup_rescan_init(fs_info, 0, 1);
3556	if (ret)
3557		return ret;
3558
3559	/*
3560	 * We have set the rescan_progress to 0, which means no more
3561	 * delayed refs will be accounted by btrfs_qgroup_account_ref.
3562	 * However, btrfs_qgroup_account_ref may be right after its call
3563	 * to btrfs_find_all_roots, in which case it would still do the
3564	 * accounting.
3565	 * To solve this, we're committing the transaction, which will
3566	 * ensure we run all delayed refs and only after that, we are
3567	 * going to clear all tracking information for a clean start.
3568	 */
3569
3570	trans = btrfs_join_transaction(fs_info->fs_root);
3571	if (IS_ERR(trans)) {
3572		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3573		return PTR_ERR(trans);
3574	}
3575	ret = btrfs_commit_transaction(trans);
3576	if (ret) {
3577		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3578		return ret;
3579	}
3580
3581	qgroup_rescan_zero_tracking(fs_info);
3582
3583	mutex_lock(&fs_info->qgroup_rescan_lock);
3584	fs_info->qgroup_rescan_running = true;
3585	btrfs_queue_work(fs_info->qgroup_rescan_workers,
3586			 &fs_info->qgroup_rescan_work);
3587	mutex_unlock(&fs_info->qgroup_rescan_lock);
3588
3589	return 0;
3590}
3591
3592int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
3593				     bool interruptible)
3594{
3595	int running;
3596	int ret = 0;
3597
3598	mutex_lock(&fs_info->qgroup_rescan_lock);
3599	running = fs_info->qgroup_rescan_running;
3600	mutex_unlock(&fs_info->qgroup_rescan_lock);
3601
3602	if (!running)
3603		return 0;
3604
3605	if (interruptible)
3606		ret = wait_for_completion_interruptible(
3607					&fs_info->qgroup_rescan_completion);
3608	else
3609		wait_for_completion(&fs_info->qgroup_rescan_completion);
3610
3611	return ret;
3612}
3613
3614/*
3615 * this is only called from open_ctree where we're still single threaded, thus
3616 * locking is omitted here.
3617 */
3618void
3619btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
3620{
3621	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3622		mutex_lock(&fs_info->qgroup_rescan_lock);
3623		fs_info->qgroup_rescan_running = true;
3624		btrfs_queue_work(fs_info->qgroup_rescan_workers,
3625				 &fs_info->qgroup_rescan_work);
3626		mutex_unlock(&fs_info->qgroup_rescan_lock);
3627	}
3628}
3629
3630#define rbtree_iterate_from_safe(node, next, start)				\
3631       for (node = start; node && ({ next = rb_next(node); 1;}); node = next)
3632
3633static int qgroup_unreserve_range(struct btrfs_inode *inode,
3634				  struct extent_changeset *reserved, u64 start,
3635				  u64 len)
3636{
3637	struct rb_node *node;
3638	struct rb_node *next;
3639	struct ulist_node *entry;
3640	int ret = 0;
3641
3642	node = reserved->range_changed.root.rb_node;
3643	if (!node)
3644		return 0;
3645	while (node) {
3646		entry = rb_entry(node, struct ulist_node, rb_node);
3647		if (entry->val < start)
3648			node = node->rb_right;
3649		else
3650			node = node->rb_left;
3651	}
3652
3653	if (entry->val > start && rb_prev(&entry->rb_node))
3654		entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node,
3655				 rb_node);
3656
3657	rbtree_iterate_from_safe(node, next, &entry->rb_node) {
3658		u64 entry_start;
3659		u64 entry_end;
3660		u64 entry_len;
3661		int clear_ret;
3662
3663		entry = rb_entry(node, struct ulist_node, rb_node);
3664		entry_start = entry->val;
3665		entry_end = entry->aux;
3666		entry_len = entry_end - entry_start + 1;
3667
3668		if (entry_start >= start + len)
3669			break;
3670		if (entry_start + entry_len <= start)
3671			continue;
3672		/*
3673		 * Now the entry is in [start, start + len), revert the
3674		 * EXTENT_QGROUP_RESERVED bit.
3675		 */
3676		clear_ret = clear_extent_bits(&inode->io_tree, entry_start,
3677					      entry_end, EXTENT_QGROUP_RESERVED);
3678		if (!ret && clear_ret < 0)
3679			ret = clear_ret;
3680
3681		ulist_del(&reserved->range_changed, entry->val, entry->aux);
3682		if (likely(reserved->bytes_changed >= entry_len)) {
3683			reserved->bytes_changed -= entry_len;
3684		} else {
3685			WARN_ON(1);
3686			reserved->bytes_changed = 0;
3687		}
3688	}
3689
3690	return ret;
3691}
3692
3693/*
3694 * Try to free some space for qgroup.
3695 *
3696 * For qgroup, there are only 3 ways to free qgroup space:
3697 * - Flush nodatacow write
3698 *   Any nodatacow write will free its reserved data space at run_delalloc_range().
3699 *   In theory, we should only flush nodatacow inodes, but it's not yet
3700 *   possible, so we need to flush the whole root.
3701 *
3702 * - Wait for ordered extents
3703 *   When ordered extents are finished, their reserved metadata is finally
3704 *   converted to per_trans status, which can be freed by later commit
3705 *   transaction.
3706 *
3707 * - Commit transaction
3708 *   This would free the meta_per_trans space.
3709 *   In theory this shouldn't provide much space, but any more qgroup space
3710 *   is needed.
3711 */
3712static int try_flush_qgroup(struct btrfs_root *root)
3713{
3714	struct btrfs_trans_handle *trans;
3715	int ret;
3716
3717	/* Can't hold an open transaction or we run the risk of deadlocking. */
3718	ASSERT(current->journal_info == NULL);
3719	if (WARN_ON(current->journal_info))
3720		return 0;
3721
3722	/*
3723	 * We don't want to run flush again and again, so if there is a running
3724	 * one, we won't try to start a new flush, but exit directly.
3725	 */
3726	if (test_and_set_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)) {
3727		wait_event(root->qgroup_flush_wait,
3728			!test_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state));
3729		return 0;
3730	}
3731
3732	ret = btrfs_start_delalloc_snapshot(root, true);
3733	if (ret < 0)
3734		goto out;
3735	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
3736
3737	trans = btrfs_join_transaction(root);
3738	if (IS_ERR(trans)) {
3739		ret = PTR_ERR(trans);
3740		goto out;
3741	}
3742
3743	ret = btrfs_commit_transaction(trans);
3744out:
3745	clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state);
3746	wake_up(&root->qgroup_flush_wait);
3747	return ret;
3748}
3749
3750static int qgroup_reserve_data(struct btrfs_inode *inode,
3751			struct extent_changeset **reserved_ret, u64 start,
3752			u64 len)
3753{
3754	struct btrfs_root *root = inode->root;
3755	struct extent_changeset *reserved;
3756	bool new_reserved = false;
3757	u64 orig_reserved;
3758	u64 to_reserve;
3759	int ret;
3760
3761	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
3762	    !is_fstree(root->root_key.objectid) || len == 0)
3763		return 0;
3764
3765	/* @reserved parameter is mandatory for qgroup */
3766	if (WARN_ON(!reserved_ret))
3767		return -EINVAL;
3768	if (!*reserved_ret) {
3769		new_reserved = true;
3770		*reserved_ret = extent_changeset_alloc();
3771		if (!*reserved_ret)
3772			return -ENOMEM;
3773	}
3774	reserved = *reserved_ret;
3775	/* Record already reserved space */
3776	orig_reserved = reserved->bytes_changed;
3777	ret = set_record_extent_bits(&inode->io_tree, start,
3778			start + len -1, EXTENT_QGROUP_RESERVED, reserved);
3779
3780	/* Newly reserved space */
3781	to_reserve = reserved->bytes_changed - orig_reserved;
3782	trace_btrfs_qgroup_reserve_data(&inode->vfs_inode, start, len,
3783					to_reserve, QGROUP_RESERVE);
3784	if (ret < 0)
3785		goto out;
3786	ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
3787	if (ret < 0)
3788		goto cleanup;
3789
3790	return ret;
3791
3792cleanup:
3793	qgroup_unreserve_range(inode, reserved, start, len);
3794out:
3795	if (new_reserved) {
3796		extent_changeset_free(reserved);
3797		*reserved_ret = NULL;
3798	}
3799	return ret;
3800}
3801
3802/*
3803 * Reserve qgroup space for range [start, start + len).
3804 *
3805 * This function will either reserve space from related qgroups or do nothing
3806 * if the range is already reserved.
3807 *
3808 * Return 0 for successful reservation
3809 * Return <0 for error (including -EQUOT)
3810 *
3811 * NOTE: This function may sleep for memory allocation, dirty page flushing and
3812 *	 commit transaction. So caller should not hold any dirty page locked.
3813 */
3814int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
3815			struct extent_changeset **reserved_ret, u64 start,
3816			u64 len)
3817{
3818	int ret;
3819
3820	ret = qgroup_reserve_data(inode, reserved_ret, start, len);
3821	if (ret <= 0 && ret != -EDQUOT)
3822		return ret;
3823
3824	ret = try_flush_qgroup(inode->root);
3825	if (ret < 0)
3826		return ret;
3827	return qgroup_reserve_data(inode, reserved_ret, start, len);
3828}
3829
3830/* Free ranges specified by @reserved, normally in error path */
3831static int qgroup_free_reserved_data(struct btrfs_inode *inode,
3832			struct extent_changeset *reserved, u64 start, u64 len)
3833{
3834	struct btrfs_root *root = inode->root;
3835	struct ulist_node *unode;
3836	struct ulist_iterator uiter;
3837	struct extent_changeset changeset;
3838	int freed = 0;
3839	int ret;
3840
3841	extent_changeset_init(&changeset);
3842	len = round_up(start + len, root->fs_info->sectorsize);
3843	start = round_down(start, root->fs_info->sectorsize);
3844
3845	ULIST_ITER_INIT(&uiter);
3846	while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
3847		u64 range_start = unode->val;
3848		/* unode->aux is the inclusive end */
3849		u64 range_len = unode->aux - range_start + 1;
3850		u64 free_start;
3851		u64 free_len;
3852
3853		extent_changeset_release(&changeset);
3854
3855		/* Only free range in range [start, start + len) */
3856		if (range_start >= start + len ||
3857		    range_start + range_len <= start)
3858			continue;
3859		free_start = max(range_start, start);
3860		free_len = min(start + len, range_start + range_len) -
3861			   free_start;
3862		/*
3863		 * TODO: To also modify reserved->ranges_reserved to reflect
3864		 * the modification.
3865		 *
3866		 * However as long as we free qgroup reserved according to
3867		 * EXTENT_QGROUP_RESERVED, we won't double free.
3868		 * So not need to rush.
3869		 */
3870		ret = clear_record_extent_bits(&inode->io_tree, free_start,
3871				free_start + free_len - 1,
3872				EXTENT_QGROUP_RESERVED, &changeset);
3873		if (ret < 0)
3874			goto out;
3875		freed += changeset.bytes_changed;
3876	}
3877	btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
3878				  BTRFS_QGROUP_RSV_DATA);
3879	ret = freed;
3880out:
3881	extent_changeset_release(&changeset);
3882	return ret;
3883}
3884
3885static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
3886			struct extent_changeset *reserved, u64 start, u64 len,
3887			int free)
3888{
3889	struct extent_changeset changeset;
3890	int trace_op = QGROUP_RELEASE;
3891	int ret;
3892
3893	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &inode->root->fs_info->flags))
3894		return 0;
3895
3896	/* In release case, we shouldn't have @reserved */
3897	WARN_ON(!free && reserved);
3898	if (free && reserved)
3899		return qgroup_free_reserved_data(inode, reserved, start, len);
3900	extent_changeset_init(&changeset);
3901	ret = clear_record_extent_bits(&inode->io_tree, start, start + len -1,
3902				       EXTENT_QGROUP_RESERVED, &changeset);
3903	if (ret < 0)
3904		goto out;
3905
3906	if (free)
3907		trace_op = QGROUP_FREE;
3908	trace_btrfs_qgroup_release_data(&inode->vfs_inode, start, len,
3909					changeset.bytes_changed, trace_op);
3910	if (free)
3911		btrfs_qgroup_free_refroot(inode->root->fs_info,
3912				inode->root->root_key.objectid,
3913				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3914	ret = changeset.bytes_changed;
3915out:
3916	extent_changeset_release(&changeset);
3917	return ret;
3918}
3919
3920/*
3921 * Free a reserved space range from io_tree and related qgroups
3922 *
3923 * Should be called when a range of pages get invalidated before reaching disk.
3924 * Or for error cleanup case.
3925 * if @reserved is given, only reserved range in [@start, @start + @len) will
3926 * be freed.
3927 *
3928 * For data written to disk, use btrfs_qgroup_release_data().
3929 *
3930 * NOTE: This function may sleep for memory allocation.
3931 */
3932int btrfs_qgroup_free_data(struct btrfs_inode *inode,
3933			struct extent_changeset *reserved, u64 start, u64 len)
3934{
3935	return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3936}
3937
3938/*
3939 * Release a reserved space range from io_tree only.
3940 *
3941 * Should be called when a range of pages get written to disk and corresponding
3942 * FILE_EXTENT is inserted into corresponding root.
3943 *
3944 * Since new qgroup accounting framework will only update qgroup numbers at
3945 * commit_transaction() time, its reserved space shouldn't be freed from
3946 * related qgroups.
3947 *
3948 * But we should release the range from io_tree, to allow further write to be
3949 * COWed.
3950 *
3951 * NOTE: This function may sleep for memory allocation.
3952 */
3953int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len)
3954{
3955	return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3956}
3957
3958static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3959			      enum btrfs_qgroup_rsv_type type)
3960{
3961	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3962	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3963		return;
3964	if (num_bytes == 0)
3965		return;
3966
3967	spin_lock(&root->qgroup_meta_rsv_lock);
3968	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3969		root->qgroup_meta_rsv_prealloc += num_bytes;
3970	else
3971		root->qgroup_meta_rsv_pertrans += num_bytes;
3972	spin_unlock(&root->qgroup_meta_rsv_lock);
3973}
3974
3975static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3976			     enum btrfs_qgroup_rsv_type type)
3977{
3978	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3979	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3980		return 0;
3981	if (num_bytes == 0)
3982		return 0;
3983
3984	spin_lock(&root->qgroup_meta_rsv_lock);
3985	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3986		num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3987				  num_bytes);
3988		root->qgroup_meta_rsv_prealloc -= num_bytes;
3989	} else {
3990		num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3991				  num_bytes);
3992		root->qgroup_meta_rsv_pertrans -= num_bytes;
3993	}
3994	spin_unlock(&root->qgroup_meta_rsv_lock);
3995	return num_bytes;
3996}
3997
3998int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3999			      enum btrfs_qgroup_rsv_type type, bool enforce)
4000{
4001	struct btrfs_fs_info *fs_info = root->fs_info;
4002	int ret;
4003
4004	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4005	    !is_fstree(root->root_key.objectid) || num_bytes == 0)
4006		return 0;
4007
4008	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
4009	trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
4010	ret = qgroup_reserve(root, num_bytes, enforce, type);
4011	if (ret < 0)
4012		return ret;
4013	/*
4014	 * Record what we have reserved into root.
4015	 *
4016	 * To avoid quota disabled->enabled underflow.
4017	 * In that case, we may try to free space we haven't reserved
4018	 * (since quota was disabled), so record what we reserved into root.
4019	 * And ensure later release won't underflow this number.
4020	 */
4021	add_root_meta_rsv(root, num_bytes, type);
4022	return ret;
4023}
4024
4025int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
4026				enum btrfs_qgroup_rsv_type type, bool enforce,
4027				bool noflush)
4028{
4029	int ret;
4030
4031	ret = btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4032	if ((ret <= 0 && ret != -EDQUOT) || noflush)
4033		return ret;
4034
4035	ret = try_flush_qgroup(root);
4036	if (ret < 0)
4037		return ret;
4038	return btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4039}
4040
4041void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
4042{
4043	struct btrfs_fs_info *fs_info = root->fs_info;
4044
4045	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4046	    !is_fstree(root->root_key.objectid))
4047		return;
4048
4049	/* TODO: Update trace point to handle such free */
4050	trace_qgroup_meta_free_all_pertrans(root);
4051	/* Special value -1 means to free all reserved space */
4052	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
4053				  BTRFS_QGROUP_RSV_META_PERTRANS);
4054}
4055
4056void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
4057			      enum btrfs_qgroup_rsv_type type)
4058{
4059	struct btrfs_fs_info *fs_info = root->fs_info;
4060
4061	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4062	    !is_fstree(root->root_key.objectid))
4063		return;
4064
4065	/*
4066	 * reservation for META_PREALLOC can happen before quota is enabled,
4067	 * which can lead to underflow.
4068	 * Here ensure we will only free what we really have reserved.
4069	 */
4070	num_bytes = sub_root_meta_rsv(root, num_bytes, type);
4071	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
4072	trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
4073	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
4074				  num_bytes, type);
4075}
4076
4077static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
4078				int num_bytes)
4079{
4080	struct btrfs_qgroup *qgroup;
4081	struct ulist_node *unode;
4082	struct ulist_iterator uiter;
4083	int ret = 0;
4084
4085	if (num_bytes == 0)
4086		return;
4087	if (!fs_info->quota_root)
4088		return;
4089
4090	spin_lock(&fs_info->qgroup_lock);
4091	qgroup = find_qgroup_rb(fs_info, ref_root);
4092	if (!qgroup)
4093		goto out;
4094	ulist_reinit(fs_info->qgroup_ulist);
4095	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
4096		       qgroup_to_aux(qgroup), GFP_ATOMIC);
4097	if (ret < 0)
4098		goto out;
4099	ULIST_ITER_INIT(&uiter);
4100	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
4101		struct btrfs_qgroup *qg;
4102		struct btrfs_qgroup_list *glist;
4103
4104		qg = unode_aux_to_qgroup(unode);
4105
4106		qgroup_rsv_release(fs_info, qg, num_bytes,
4107				BTRFS_QGROUP_RSV_META_PREALLOC);
4108		qgroup_rsv_add(fs_info, qg, num_bytes,
4109				BTRFS_QGROUP_RSV_META_PERTRANS);
4110		list_for_each_entry(glist, &qg->groups, next_group) {
4111			ret = ulist_add(fs_info->qgroup_ulist,
4112					glist->group->qgroupid,
4113					qgroup_to_aux(glist->group), GFP_ATOMIC);
4114			if (ret < 0)
4115				goto out;
4116		}
4117	}
4118out:
4119	spin_unlock(&fs_info->qgroup_lock);
4120}
4121
4122void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
4123{
4124	struct btrfs_fs_info *fs_info = root->fs_info;
4125
4126	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4127	    !is_fstree(root->root_key.objectid))
4128		return;
4129	/* Same as btrfs_qgroup_free_meta_prealloc() */
4130	num_bytes = sub_root_meta_rsv(root, num_bytes,
4131				      BTRFS_QGROUP_RSV_META_PREALLOC);
4132	trace_qgroup_meta_convert(root, num_bytes);
4133	qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
4134}
4135
4136/*
4137 * Check qgroup reserved space leaking, normally at destroy inode
4138 * time
4139 */
4140void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode)
4141{
4142	struct extent_changeset changeset;
4143	struct ulist_node *unode;
4144	struct ulist_iterator iter;
4145	int ret;
4146
4147	extent_changeset_init(&changeset);
4148	ret = clear_record_extent_bits(&inode->io_tree, 0, (u64)-1,
4149			EXTENT_QGROUP_RESERVED, &changeset);
4150
4151	WARN_ON(ret < 0);
4152	if (WARN_ON(changeset.bytes_changed)) {
4153		ULIST_ITER_INIT(&iter);
4154		while ((unode = ulist_next(&changeset.range_changed, &iter))) {
4155			btrfs_warn(inode->root->fs_info,
4156		"leaking qgroup reserved space, ino: %llu, start: %llu, end: %llu",
4157				btrfs_ino(inode), unode->val, unode->aux);
4158		}
4159		btrfs_qgroup_free_refroot(inode->root->fs_info,
4160				inode->root->root_key.objectid,
4161				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
4162
4163	}
4164	extent_changeset_release(&changeset);
4165}
4166
4167void btrfs_qgroup_init_swapped_blocks(
4168	struct btrfs_qgroup_swapped_blocks *swapped_blocks)
4169{
4170	int i;
4171
4172	spin_lock_init(&swapped_blocks->lock);
4173	for (i = 0; i < BTRFS_MAX_LEVEL; i++)
4174		swapped_blocks->blocks[i] = RB_ROOT;
4175	swapped_blocks->swapped = false;
4176}
4177
4178/*
4179 * Delete all swapped blocks record of @root.
4180 * Every record here means we skipped a full subtree scan for qgroup.
4181 *
4182 * Gets called when committing one transaction.
4183 */
4184void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
4185{
4186	struct btrfs_qgroup_swapped_blocks *swapped_blocks;
4187	int i;
4188
4189	swapped_blocks = &root->swapped_blocks;
4190
4191	spin_lock(&swapped_blocks->lock);
4192	if (!swapped_blocks->swapped)
4193		goto out;
4194	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4195		struct rb_root *cur_root = &swapped_blocks->blocks[i];
4196		struct btrfs_qgroup_swapped_block *entry;
4197		struct btrfs_qgroup_swapped_block *next;
4198
4199		rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
4200						     node)
4201			kfree(entry);
4202		swapped_blocks->blocks[i] = RB_ROOT;
4203	}
4204	swapped_blocks->swapped = false;
4205out:
4206	spin_unlock(&swapped_blocks->lock);
4207}
4208
4209/*
4210 * Add subtree roots record into @subvol_root.
4211 *
4212 * @subvol_root:	tree root of the subvolume tree get swapped
4213 * @bg:			block group under balance
4214 * @subvol_parent/slot:	pointer to the subtree root in subvolume tree
4215 * @reloc_parent/slot:	pointer to the subtree root in reloc tree
4216 *			BOTH POINTERS ARE BEFORE TREE SWAP
4217 * @last_snapshot:	last snapshot generation of the subvolume tree
4218 */
4219int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
4220		struct btrfs_root *subvol_root,
4221		struct btrfs_block_group *bg,
4222		struct extent_buffer *subvol_parent, int subvol_slot,
4223		struct extent_buffer *reloc_parent, int reloc_slot,
4224		u64 last_snapshot)
4225{
4226	struct btrfs_fs_info *fs_info = subvol_root->fs_info;
4227	struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
4228	struct btrfs_qgroup_swapped_block *block;
4229	struct rb_node **cur;
4230	struct rb_node *parent = NULL;
4231	int level = btrfs_header_level(subvol_parent) - 1;
4232	int ret = 0;
4233
4234	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4235		return 0;
4236
4237	if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
4238	    btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
4239		btrfs_err_rl(fs_info,
4240		"%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
4241			__func__,
4242			btrfs_node_ptr_generation(subvol_parent, subvol_slot),
4243			btrfs_node_ptr_generation(reloc_parent, reloc_slot));
4244		return -EUCLEAN;
4245	}
4246
4247	block = kmalloc(sizeof(*block), GFP_NOFS);
4248	if (!block) {
4249		ret = -ENOMEM;
4250		goto out;
4251	}
4252
4253	/*
4254	 * @reloc_parent/slot is still before swap, while @block is going to
4255	 * record the bytenr after swap, so we do the swap here.
4256	 */
4257	block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
4258	block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
4259							     reloc_slot);
4260	block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
4261	block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
4262							    subvol_slot);
4263	block->last_snapshot = last_snapshot;
4264	block->level = level;
4265
4266	/*
4267	 * If we have bg == NULL, we're called from btrfs_recover_relocation(),
4268	 * no one else can modify tree blocks thus we qgroup will not change
4269	 * no matter the value of trace_leaf.
4270	 */
4271	if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
4272		block->trace_leaf = true;
4273	else
4274		block->trace_leaf = false;
4275	btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
4276
4277	/* Insert @block into @blocks */
4278	spin_lock(&blocks->lock);
4279	cur = &blocks->blocks[level].rb_node;
4280	while (*cur) {
4281		struct btrfs_qgroup_swapped_block *entry;
4282
4283		parent = *cur;
4284		entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
4285				 node);
4286
4287		if (entry->subvol_bytenr < block->subvol_bytenr) {
4288			cur = &(*cur)->rb_left;
4289		} else if (entry->subvol_bytenr > block->subvol_bytenr) {
4290			cur = &(*cur)->rb_right;
4291		} else {
4292			if (entry->subvol_generation !=
4293					block->subvol_generation ||
4294			    entry->reloc_bytenr != block->reloc_bytenr ||
4295			    entry->reloc_generation !=
4296					block->reloc_generation) {
4297				/*
4298				 * Duplicated but mismatch entry found.
4299				 * Shouldn't happen.
4300				 *
4301				 * Marking qgroup inconsistent should be enough
4302				 * for end users.
4303				 */
4304				WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4305				ret = -EEXIST;
4306			}
4307			kfree(block);
4308			goto out_unlock;
4309		}
4310	}
4311	rb_link_node(&block->node, parent, cur);
4312	rb_insert_color(&block->node, &blocks->blocks[level]);
4313	blocks->swapped = true;
4314out_unlock:
4315	spin_unlock(&blocks->lock);
4316out:
4317	if (ret < 0)
4318		qgroup_mark_inconsistent(fs_info);
 
4319	return ret;
4320}
4321
4322/*
4323 * Check if the tree block is a subtree root, and if so do the needed
4324 * delayed subtree trace for qgroup.
4325 *
4326 * This is called during btrfs_cow_block().
4327 */
4328int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
4329					 struct btrfs_root *root,
4330					 struct extent_buffer *subvol_eb)
4331{
4332	struct btrfs_fs_info *fs_info = root->fs_info;
4333	struct btrfs_tree_parent_check check = { 0 };
4334	struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
4335	struct btrfs_qgroup_swapped_block *block;
4336	struct extent_buffer *reloc_eb = NULL;
4337	struct rb_node *node;
4338	bool found = false;
4339	bool swapped = false;
4340	int level = btrfs_header_level(subvol_eb);
4341	int ret = 0;
4342	int i;
4343
4344	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4345		return 0;
4346	if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
4347		return 0;
4348
4349	spin_lock(&blocks->lock);
4350	if (!blocks->swapped) {
4351		spin_unlock(&blocks->lock);
4352		return 0;
4353	}
4354	node = blocks->blocks[level].rb_node;
4355
4356	while (node) {
4357		block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
4358		if (block->subvol_bytenr < subvol_eb->start) {
4359			node = node->rb_left;
4360		} else if (block->subvol_bytenr > subvol_eb->start) {
4361			node = node->rb_right;
4362		} else {
4363			found = true;
4364			break;
4365		}
4366	}
4367	if (!found) {
4368		spin_unlock(&blocks->lock);
4369		goto out;
4370	}
4371	/* Found one, remove it from @blocks first and update blocks->swapped */
4372	rb_erase(&block->node, &blocks->blocks[level]);
4373	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4374		if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
4375			swapped = true;
4376			break;
4377		}
4378	}
4379	blocks->swapped = swapped;
4380	spin_unlock(&blocks->lock);
4381
4382	check.level = block->level;
4383	check.transid = block->reloc_generation;
4384	check.has_first_key = true;
4385	memcpy(&check.first_key, &block->first_key, sizeof(check.first_key));
4386
4387	/* Read out reloc subtree root */
4388	reloc_eb = read_tree_block(fs_info, block->reloc_bytenr, &check);
 
 
4389	if (IS_ERR(reloc_eb)) {
4390		ret = PTR_ERR(reloc_eb);
4391		reloc_eb = NULL;
4392		goto free_out;
4393	}
4394	if (!extent_buffer_uptodate(reloc_eb)) {
4395		ret = -EIO;
4396		goto free_out;
4397	}
4398
4399	ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
4400			block->last_snapshot, block->trace_leaf);
4401free_out:
4402	kfree(block);
4403	free_extent_buffer(reloc_eb);
4404out:
4405	if (ret < 0) {
4406		btrfs_err_rl(fs_info,
4407			     "failed to account subtree at bytenr %llu: %d",
4408			     subvol_eb->start, ret);
4409		qgroup_mark_inconsistent(fs_info);
4410	}
4411	return ret;
4412}
4413
4414void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans)
4415{
4416	struct btrfs_qgroup_extent_record *entry;
4417	struct btrfs_qgroup_extent_record *next;
4418	struct rb_root *root;
4419
4420	root = &trans->delayed_refs.dirty_extent_root;
4421	rbtree_postorder_for_each_entry_safe(entry, next, root, node) {
4422		ulist_free(entry->old_roots);
4423		kfree(entry);
4424	}
4425}
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2011 STRATO.  All rights reserved.
   4 */
   5
   6#include <linux/sched.h>
   7#include <linux/pagemap.h>
   8#include <linux/writeback.h>
   9#include <linux/blkdev.h>
  10#include <linux/rbtree.h>
  11#include <linux/slab.h>
  12#include <linux/workqueue.h>
  13#include <linux/btrfs.h>
  14#include <linux/sched/mm.h>
  15
  16#include "ctree.h"
  17#include "transaction.h"
  18#include "disk-io.h"
  19#include "locking.h"
  20#include "ulist.h"
  21#include "backref.h"
  22#include "extent_io.h"
  23#include "qgroup.h"
  24#include "block-group.h"
  25#include "sysfs.h"
  26#include "tree-mod-log.h"
  27
  28/* TODO XXX FIXME
  29 *  - subvol delete -> delete when ref goes to 0? delete limits also?
  30 *  - reorganize keys
  31 *  - compressed
  32 *  - sync
  33 *  - copy also limits on subvol creation
  34 *  - limit
  35 *  - caches for ulists
  36 *  - performance benchmarks
  37 *  - check all ioctl parameters
  38 */
  39
  40/*
  41 * Helpers to access qgroup reservation
  42 *
  43 * Callers should ensure the lock context and type are valid
  44 */
  45
  46static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
  47{
  48	u64 ret = 0;
  49	int i;
  50
  51	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
  52		ret += qgroup->rsv.values[i];
  53
  54	return ret;
  55}
  56
  57#ifdef CONFIG_BTRFS_DEBUG
  58static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
  59{
  60	if (type == BTRFS_QGROUP_RSV_DATA)
  61		return "data";
  62	if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
  63		return "meta_pertrans";
  64	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
  65		return "meta_prealloc";
  66	return NULL;
  67}
  68#endif
  69
  70static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
  71			   struct btrfs_qgroup *qgroup, u64 num_bytes,
  72			   enum btrfs_qgroup_rsv_type type)
  73{
  74	trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
  75	qgroup->rsv.values[type] += num_bytes;
  76}
  77
  78static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
  79			       struct btrfs_qgroup *qgroup, u64 num_bytes,
  80			       enum btrfs_qgroup_rsv_type type)
  81{
  82	trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
  83	if (qgroup->rsv.values[type] >= num_bytes) {
  84		qgroup->rsv.values[type] -= num_bytes;
  85		return;
  86	}
  87#ifdef CONFIG_BTRFS_DEBUG
  88	WARN_RATELIMIT(1,
  89		"qgroup %llu %s reserved space underflow, have %llu to free %llu",
  90		qgroup->qgroupid, qgroup_rsv_type_str(type),
  91		qgroup->rsv.values[type], num_bytes);
  92#endif
  93	qgroup->rsv.values[type] = 0;
  94}
  95
  96static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
  97				     struct btrfs_qgroup *dest,
  98				     struct btrfs_qgroup *src)
  99{
 100	int i;
 101
 102	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
 103		qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
 104}
 105
 106static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
 107					 struct btrfs_qgroup *dest,
 108					  struct btrfs_qgroup *src)
 109{
 110	int i;
 111
 112	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
 113		qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
 114}
 115
 116static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
 117					   int mod)
 118{
 119	if (qg->old_refcnt < seq)
 120		qg->old_refcnt = seq;
 121	qg->old_refcnt += mod;
 122}
 123
 124static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 125					   int mod)
 126{
 127	if (qg->new_refcnt < seq)
 128		qg->new_refcnt = seq;
 129	qg->new_refcnt += mod;
 130}
 131
 132static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
 133{
 134	if (qg->old_refcnt < seq)
 135		return 0;
 136	return qg->old_refcnt - seq;
 137}
 138
 139static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
 140{
 141	if (qg->new_refcnt < seq)
 142		return 0;
 143	return qg->new_refcnt - seq;
 144}
 145
 146/*
 147 * glue structure to represent the relations between qgroups.
 148 */
 149struct btrfs_qgroup_list {
 150	struct list_head next_group;
 151	struct list_head next_member;
 152	struct btrfs_qgroup *group;
 153	struct btrfs_qgroup *member;
 154};
 155
 156static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
 157{
 158	return (u64)(uintptr_t)qg;
 159}
 160
 161static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
 162{
 163	return (struct btrfs_qgroup *)(uintptr_t)n->aux;
 164}
 165
 166static int
 167qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 168		   int init_flags);
 169static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 170
 171/* must be called with qgroup_ioctl_lock held */
 172static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
 173					   u64 qgroupid)
 174{
 175	struct rb_node *n = fs_info->qgroup_tree.rb_node;
 176	struct btrfs_qgroup *qgroup;
 177
 178	while (n) {
 179		qgroup = rb_entry(n, struct btrfs_qgroup, node);
 180		if (qgroup->qgroupid < qgroupid)
 181			n = n->rb_left;
 182		else if (qgroup->qgroupid > qgroupid)
 183			n = n->rb_right;
 184		else
 185			return qgroup;
 186	}
 187	return NULL;
 188}
 189
 190/* must be called with qgroup_lock held */
 191static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
 192					  u64 qgroupid)
 193{
 194	struct rb_node **p = &fs_info->qgroup_tree.rb_node;
 195	struct rb_node *parent = NULL;
 196	struct btrfs_qgroup *qgroup;
 197
 198	while (*p) {
 199		parent = *p;
 200		qgroup = rb_entry(parent, struct btrfs_qgroup, node);
 201
 202		if (qgroup->qgroupid < qgroupid)
 203			p = &(*p)->rb_left;
 204		else if (qgroup->qgroupid > qgroupid)
 205			p = &(*p)->rb_right;
 206		else
 207			return qgroup;
 208	}
 209
 210	qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
 211	if (!qgroup)
 212		return ERR_PTR(-ENOMEM);
 213
 214	qgroup->qgroupid = qgroupid;
 215	INIT_LIST_HEAD(&qgroup->groups);
 216	INIT_LIST_HEAD(&qgroup->members);
 217	INIT_LIST_HEAD(&qgroup->dirty);
 218
 219	rb_link_node(&qgroup->node, parent, p);
 220	rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
 221
 222	return qgroup;
 223}
 224
 225static void __del_qgroup_rb(struct btrfs_fs_info *fs_info,
 226			    struct btrfs_qgroup *qgroup)
 227{
 228	struct btrfs_qgroup_list *list;
 229
 230	list_del(&qgroup->dirty);
 231	while (!list_empty(&qgroup->groups)) {
 232		list = list_first_entry(&qgroup->groups,
 233					struct btrfs_qgroup_list, next_group);
 234		list_del(&list->next_group);
 235		list_del(&list->next_member);
 236		kfree(list);
 237	}
 238
 239	while (!list_empty(&qgroup->members)) {
 240		list = list_first_entry(&qgroup->members,
 241					struct btrfs_qgroup_list, next_member);
 242		list_del(&list->next_group);
 243		list_del(&list->next_member);
 244		kfree(list);
 245	}
 246}
 247
 248/* must be called with qgroup_lock held */
 249static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 250{
 251	struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
 252
 253	if (!qgroup)
 254		return -ENOENT;
 255
 256	rb_erase(&qgroup->node, &fs_info->qgroup_tree);
 257	__del_qgroup_rb(fs_info, qgroup);
 258	return 0;
 259}
 260
 261/* must be called with qgroup_lock held */
 262static int add_relation_rb(struct btrfs_fs_info *fs_info,
 263			   u64 memberid, u64 parentid)
 
 
 
 
 
 
 
 264{
 265	struct btrfs_qgroup *member;
 266	struct btrfs_qgroup *parent;
 267	struct btrfs_qgroup_list *list;
 268
 269	member = find_qgroup_rb(fs_info, memberid);
 270	parent = find_qgroup_rb(fs_info, parentid);
 271	if (!member || !parent)
 272		return -ENOENT;
 273
 274	list = kzalloc(sizeof(*list), GFP_ATOMIC);
 275	if (!list)
 276		return -ENOMEM;
 277
 278	list->group = parent;
 279	list->member = member;
 280	list_add_tail(&list->next_group, &member->groups);
 281	list_add_tail(&list->next_member, &parent->members);
 282
 283	return 0;
 284}
 285
 286/* must be called with qgroup_lock held */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 287static int del_relation_rb(struct btrfs_fs_info *fs_info,
 288			   u64 memberid, u64 parentid)
 289{
 290	struct btrfs_qgroup *member;
 291	struct btrfs_qgroup *parent;
 292	struct btrfs_qgroup_list *list;
 293
 294	member = find_qgroup_rb(fs_info, memberid);
 295	parent = find_qgroup_rb(fs_info, parentid);
 296	if (!member || !parent)
 297		return -ENOENT;
 298
 299	list_for_each_entry(list, &member->groups, next_group) {
 300		if (list->group == parent) {
 301			list_del(&list->next_group);
 302			list_del(&list->next_member);
 303			kfree(list);
 304			return 0;
 305		}
 306	}
 307	return -ENOENT;
 308}
 309
 310#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 311int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 312			       u64 rfer, u64 excl)
 313{
 314	struct btrfs_qgroup *qgroup;
 315
 316	qgroup = find_qgroup_rb(fs_info, qgroupid);
 317	if (!qgroup)
 318		return -EINVAL;
 319	if (qgroup->rfer != rfer || qgroup->excl != excl)
 320		return -EINVAL;
 321	return 0;
 322}
 323#endif
 324
 
 
 
 
 
 
 
 325/*
 326 * The full config is read in one go, only called from open_ctree()
 327 * It doesn't use any locking, as at this point we're still single-threaded
 328 */
 329int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 330{
 331	struct btrfs_key key;
 332	struct btrfs_key found_key;
 333	struct btrfs_root *quota_root = fs_info->quota_root;
 334	struct btrfs_path *path = NULL;
 335	struct extent_buffer *l;
 336	int slot;
 337	int ret = 0;
 338	u64 flags = 0;
 339	u64 rescan_progress = 0;
 340
 341	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 342		return 0;
 343
 344	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
 345	if (!fs_info->qgroup_ulist) {
 346		ret = -ENOMEM;
 347		goto out;
 348	}
 349
 350	path = btrfs_alloc_path();
 351	if (!path) {
 352		ret = -ENOMEM;
 353		goto out;
 354	}
 355
 356	ret = btrfs_sysfs_add_qgroups(fs_info);
 357	if (ret < 0)
 358		goto out;
 359	/* default this to quota off, in case no status key is found */
 360	fs_info->qgroup_flags = 0;
 361
 362	/*
 363	 * pass 1: read status, all qgroup infos and limits
 364	 */
 365	key.objectid = 0;
 366	key.type = 0;
 367	key.offset = 0;
 368	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
 369	if (ret)
 370		goto out;
 371
 372	while (1) {
 373		struct btrfs_qgroup *qgroup;
 374
 375		slot = path->slots[0];
 376		l = path->nodes[0];
 377		btrfs_item_key_to_cpu(l, &found_key, slot);
 378
 379		if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
 380			struct btrfs_qgroup_status_item *ptr;
 381
 382			ptr = btrfs_item_ptr(l, slot,
 383					     struct btrfs_qgroup_status_item);
 384
 385			if (btrfs_qgroup_status_version(l, ptr) !=
 386			    BTRFS_QGROUP_STATUS_VERSION) {
 387				btrfs_err(fs_info,
 388				 "old qgroup version, quota disabled");
 389				goto out;
 390			}
 391			if (btrfs_qgroup_status_generation(l, ptr) !=
 392			    fs_info->generation) {
 393				flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 394				btrfs_err(fs_info,
 395					"qgroup generation mismatch, marked as inconsistent");
 396			}
 397			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
 398									  ptr);
 399			rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
 400			goto next1;
 401		}
 402
 403		if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
 404		    found_key.type != BTRFS_QGROUP_LIMIT_KEY)
 405			goto next1;
 406
 407		qgroup = find_qgroup_rb(fs_info, found_key.offset);
 408		if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
 409		    (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
 410			btrfs_err(fs_info, "inconsistent qgroup config");
 411			flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 412		}
 413		if (!qgroup) {
 414			qgroup = add_qgroup_rb(fs_info, found_key.offset);
 415			if (IS_ERR(qgroup)) {
 416				ret = PTR_ERR(qgroup);
 417				goto out;
 418			}
 419		}
 420		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
 421		if (ret < 0)
 422			goto out;
 423
 424		switch (found_key.type) {
 425		case BTRFS_QGROUP_INFO_KEY: {
 426			struct btrfs_qgroup_info_item *ptr;
 427
 428			ptr = btrfs_item_ptr(l, slot,
 429					     struct btrfs_qgroup_info_item);
 430			qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
 431			qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
 432			qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
 433			qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
 434			/* generation currently unused */
 435			break;
 436		}
 437		case BTRFS_QGROUP_LIMIT_KEY: {
 438			struct btrfs_qgroup_limit_item *ptr;
 439
 440			ptr = btrfs_item_ptr(l, slot,
 441					     struct btrfs_qgroup_limit_item);
 442			qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
 443			qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
 444			qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
 445			qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
 446			qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
 447			break;
 448		}
 449		}
 450next1:
 451		ret = btrfs_next_item(quota_root, path);
 452		if (ret < 0)
 453			goto out;
 454		if (ret)
 455			break;
 456	}
 457	btrfs_release_path(path);
 458
 459	/*
 460	 * pass 2: read all qgroup relations
 461	 */
 462	key.objectid = 0;
 463	key.type = BTRFS_QGROUP_RELATION_KEY;
 464	key.offset = 0;
 465	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
 466	if (ret)
 467		goto out;
 468	while (1) {
 469		slot = path->slots[0];
 470		l = path->nodes[0];
 471		btrfs_item_key_to_cpu(l, &found_key, slot);
 472
 473		if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
 474			goto next2;
 475
 476		if (found_key.objectid > found_key.offset) {
 477			/* parent <- member, not needed to build config */
 478			/* FIXME should we omit the key completely? */
 479			goto next2;
 480		}
 481
 482		ret = add_relation_rb(fs_info, found_key.objectid,
 483				      found_key.offset);
 484		if (ret == -ENOENT) {
 485			btrfs_warn(fs_info,
 486				"orphan qgroup relation 0x%llx->0x%llx",
 487				found_key.objectid, found_key.offset);
 488			ret = 0;	/* ignore the error */
 489		}
 490		if (ret)
 491			goto out;
 492next2:
 493		ret = btrfs_next_item(quota_root, path);
 494		if (ret < 0)
 495			goto out;
 496		if (ret)
 497			break;
 498	}
 499out:
 500	btrfs_free_path(path);
 501	fs_info->qgroup_flags |= flags;
 502	if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
 503		clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 504	else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
 505		 ret >= 0)
 506		ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
 507
 508	if (ret < 0) {
 509		ulist_free(fs_info->qgroup_ulist);
 510		fs_info->qgroup_ulist = NULL;
 511		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 512		btrfs_sysfs_del_qgroups(fs_info);
 513	}
 514
 515	return ret < 0 ? ret : 0;
 516}
 517
 518/*
 519 * Called in close_ctree() when quota is still enabled.  This verifies we don't
 520 * leak some reserved space.
 521 *
 522 * Return false if no reserved space is left.
 523 * Return true if some reserved space is leaked.
 524 */
 525bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info)
 526{
 527	struct rb_node *node;
 528	bool ret = false;
 529
 530	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 531		return ret;
 532	/*
 533	 * Since we're unmounting, there is no race and no need to grab qgroup
 534	 * lock.  And here we don't go post-order to provide a more user
 535	 * friendly sorted result.
 536	 */
 537	for (node = rb_first(&fs_info->qgroup_tree); node; node = rb_next(node)) {
 538		struct btrfs_qgroup *qgroup;
 539		int i;
 540
 541		qgroup = rb_entry(node, struct btrfs_qgroup, node);
 542		for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) {
 543			if (qgroup->rsv.values[i]) {
 544				ret = true;
 545				btrfs_warn(fs_info,
 546		"qgroup %hu/%llu has unreleased space, type %d rsv %llu",
 547				   btrfs_qgroup_level(qgroup->qgroupid),
 548				   btrfs_qgroup_subvolid(qgroup->qgroupid),
 549				   i, qgroup->rsv.values[i]);
 550			}
 551		}
 552	}
 553	return ret;
 554}
 555
 556/*
 557 * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
 558 * first two are in single-threaded paths.And for the third one, we have set
 559 * quota_root to be null with qgroup_lock held before, so it is safe to clean
 560 * up the in-memory structures without qgroup_lock held.
 561 */
 562void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
 563{
 564	struct rb_node *n;
 565	struct btrfs_qgroup *qgroup;
 566
 567	while ((n = rb_first(&fs_info->qgroup_tree))) {
 568		qgroup = rb_entry(n, struct btrfs_qgroup, node);
 569		rb_erase(n, &fs_info->qgroup_tree);
 570		__del_qgroup_rb(fs_info, qgroup);
 571		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
 572		kfree(qgroup);
 573	}
 574	/*
 575	 * We call btrfs_free_qgroup_config() when unmounting
 576	 * filesystem and disabling quota, so we set qgroup_ulist
 577	 * to be null here to avoid double free.
 578	 */
 579	ulist_free(fs_info->qgroup_ulist);
 580	fs_info->qgroup_ulist = NULL;
 581	btrfs_sysfs_del_qgroups(fs_info);
 582}
 583
 584static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 585				    u64 dst)
 586{
 587	int ret;
 588	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 589	struct btrfs_path *path;
 590	struct btrfs_key key;
 591
 592	path = btrfs_alloc_path();
 593	if (!path)
 594		return -ENOMEM;
 595
 596	key.objectid = src;
 597	key.type = BTRFS_QGROUP_RELATION_KEY;
 598	key.offset = dst;
 599
 600	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
 601
 602	btrfs_mark_buffer_dirty(path->nodes[0]);
 603
 604	btrfs_free_path(path);
 605	return ret;
 606}
 607
 608static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
 609				    u64 dst)
 610{
 611	int ret;
 612	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 613	struct btrfs_path *path;
 614	struct btrfs_key key;
 615
 616	path = btrfs_alloc_path();
 617	if (!path)
 618		return -ENOMEM;
 619
 620	key.objectid = src;
 621	key.type = BTRFS_QGROUP_RELATION_KEY;
 622	key.offset = dst;
 623
 624	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 625	if (ret < 0)
 626		goto out;
 627
 628	if (ret > 0) {
 629		ret = -ENOENT;
 630		goto out;
 631	}
 632
 633	ret = btrfs_del_item(trans, quota_root, path);
 634out:
 635	btrfs_free_path(path);
 636	return ret;
 637}
 638
 639static int add_qgroup_item(struct btrfs_trans_handle *trans,
 640			   struct btrfs_root *quota_root, u64 qgroupid)
 641{
 642	int ret;
 643	struct btrfs_path *path;
 644	struct btrfs_qgroup_info_item *qgroup_info;
 645	struct btrfs_qgroup_limit_item *qgroup_limit;
 646	struct extent_buffer *leaf;
 647	struct btrfs_key key;
 648
 649	if (btrfs_is_testing(quota_root->fs_info))
 650		return 0;
 651
 652	path = btrfs_alloc_path();
 653	if (!path)
 654		return -ENOMEM;
 655
 656	key.objectid = 0;
 657	key.type = BTRFS_QGROUP_INFO_KEY;
 658	key.offset = qgroupid;
 659
 660	/*
 661	 * Avoid a transaction abort by catching -EEXIST here. In that
 662	 * case, we proceed by re-initializing the existing structure
 663	 * on disk.
 664	 */
 665
 666	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 667				      sizeof(*qgroup_info));
 668	if (ret && ret != -EEXIST)
 669		goto out;
 670
 671	leaf = path->nodes[0];
 672	qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
 673				 struct btrfs_qgroup_info_item);
 674	btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
 675	btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
 676	btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
 677	btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
 678	btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
 679
 680	btrfs_mark_buffer_dirty(leaf);
 681
 682	btrfs_release_path(path);
 683
 684	key.type = BTRFS_QGROUP_LIMIT_KEY;
 685	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
 686				      sizeof(*qgroup_limit));
 687	if (ret && ret != -EEXIST)
 688		goto out;
 689
 690	leaf = path->nodes[0];
 691	qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
 692				  struct btrfs_qgroup_limit_item);
 693	btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
 694	btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
 695	btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
 696	btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
 697	btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
 698
 699	btrfs_mark_buffer_dirty(leaf);
 700
 701	ret = 0;
 702out:
 703	btrfs_free_path(path);
 704	return ret;
 705}
 706
 707static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
 708{
 709	int ret;
 710	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 711	struct btrfs_path *path;
 712	struct btrfs_key key;
 713
 714	path = btrfs_alloc_path();
 715	if (!path)
 716		return -ENOMEM;
 717
 718	key.objectid = 0;
 719	key.type = BTRFS_QGROUP_INFO_KEY;
 720	key.offset = qgroupid;
 721	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 722	if (ret < 0)
 723		goto out;
 724
 725	if (ret > 0) {
 726		ret = -ENOENT;
 727		goto out;
 728	}
 729
 730	ret = btrfs_del_item(trans, quota_root, path);
 731	if (ret)
 732		goto out;
 733
 734	btrfs_release_path(path);
 735
 736	key.type = BTRFS_QGROUP_LIMIT_KEY;
 737	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
 738	if (ret < 0)
 739		goto out;
 740
 741	if (ret > 0) {
 742		ret = -ENOENT;
 743		goto out;
 744	}
 745
 746	ret = btrfs_del_item(trans, quota_root, path);
 747
 748out:
 749	btrfs_free_path(path);
 750	return ret;
 751}
 752
 753static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
 754				    struct btrfs_qgroup *qgroup)
 755{
 756	struct btrfs_root *quota_root = trans->fs_info->quota_root;
 757	struct btrfs_path *path;
 758	struct btrfs_key key;
 759	struct extent_buffer *l;
 760	struct btrfs_qgroup_limit_item *qgroup_limit;
 761	int ret;
 762	int slot;
 763
 764	key.objectid = 0;
 765	key.type = BTRFS_QGROUP_LIMIT_KEY;
 766	key.offset = qgroup->qgroupid;
 767
 768	path = btrfs_alloc_path();
 769	if (!path)
 770		return -ENOMEM;
 771
 772	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 773	if (ret > 0)
 774		ret = -ENOENT;
 775
 776	if (ret)
 777		goto out;
 778
 779	l = path->nodes[0];
 780	slot = path->slots[0];
 781	qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
 782	btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
 783	btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
 784	btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
 785	btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
 786	btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
 787
 788	btrfs_mark_buffer_dirty(l);
 789
 790out:
 791	btrfs_free_path(path);
 792	return ret;
 793}
 794
 795static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
 796				   struct btrfs_qgroup *qgroup)
 797{
 798	struct btrfs_fs_info *fs_info = trans->fs_info;
 799	struct btrfs_root *quota_root = fs_info->quota_root;
 800	struct btrfs_path *path;
 801	struct btrfs_key key;
 802	struct extent_buffer *l;
 803	struct btrfs_qgroup_info_item *qgroup_info;
 804	int ret;
 805	int slot;
 806
 807	if (btrfs_is_testing(fs_info))
 808		return 0;
 809
 810	key.objectid = 0;
 811	key.type = BTRFS_QGROUP_INFO_KEY;
 812	key.offset = qgroup->qgroupid;
 813
 814	path = btrfs_alloc_path();
 815	if (!path)
 816		return -ENOMEM;
 817
 818	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 819	if (ret > 0)
 820		ret = -ENOENT;
 821
 822	if (ret)
 823		goto out;
 824
 825	l = path->nodes[0];
 826	slot = path->slots[0];
 827	qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
 828	btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
 829	btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
 830	btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
 831	btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
 832	btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
 833
 834	btrfs_mark_buffer_dirty(l);
 835
 836out:
 837	btrfs_free_path(path);
 838	return ret;
 839}
 840
 841static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
 842{
 843	struct btrfs_fs_info *fs_info = trans->fs_info;
 844	struct btrfs_root *quota_root = fs_info->quota_root;
 845	struct btrfs_path *path;
 846	struct btrfs_key key;
 847	struct extent_buffer *l;
 848	struct btrfs_qgroup_status_item *ptr;
 849	int ret;
 850	int slot;
 851
 852	key.objectid = 0;
 853	key.type = BTRFS_QGROUP_STATUS_KEY;
 854	key.offset = 0;
 855
 856	path = btrfs_alloc_path();
 857	if (!path)
 858		return -ENOMEM;
 859
 860	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
 861	if (ret > 0)
 862		ret = -ENOENT;
 863
 864	if (ret)
 865		goto out;
 866
 867	l = path->nodes[0];
 868	slot = path->slots[0];
 869	ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
 870	btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
 
 871	btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
 872	btrfs_set_qgroup_status_rescan(l, ptr,
 873				fs_info->qgroup_rescan_progress.objectid);
 874
 875	btrfs_mark_buffer_dirty(l);
 876
 877out:
 878	btrfs_free_path(path);
 879	return ret;
 880}
 881
 882/*
 883 * called with qgroup_lock held
 884 */
 885static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
 886				  struct btrfs_root *root)
 887{
 888	struct btrfs_path *path;
 889	struct btrfs_key key;
 890	struct extent_buffer *leaf = NULL;
 891	int ret;
 892	int nr = 0;
 893
 894	path = btrfs_alloc_path();
 895	if (!path)
 896		return -ENOMEM;
 897
 898	key.objectid = 0;
 899	key.offset = 0;
 900	key.type = 0;
 901
 902	while (1) {
 903		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 904		if (ret < 0)
 905			goto out;
 906		leaf = path->nodes[0];
 907		nr = btrfs_header_nritems(leaf);
 908		if (!nr)
 909			break;
 910		/*
 911		 * delete the leaf one by one
 912		 * since the whole tree is going
 913		 * to be deleted.
 914		 */
 915		path->slots[0] = 0;
 916		ret = btrfs_del_items(trans, root, path, 0, nr);
 917		if (ret)
 918			goto out;
 919
 920		btrfs_release_path(path);
 921	}
 922	ret = 0;
 923out:
 924	btrfs_free_path(path);
 925	return ret;
 926}
 927
 928int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
 929{
 930	struct btrfs_root *quota_root;
 931	struct btrfs_root *tree_root = fs_info->tree_root;
 932	struct btrfs_path *path = NULL;
 933	struct btrfs_qgroup_status_item *ptr;
 934	struct extent_buffer *leaf;
 935	struct btrfs_key key;
 936	struct btrfs_key found_key;
 937	struct btrfs_qgroup *qgroup = NULL;
 938	struct btrfs_trans_handle *trans = NULL;
 939	struct ulist *ulist = NULL;
 940	int ret = 0;
 941	int slot;
 942
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 943	mutex_lock(&fs_info->qgroup_ioctl_lock);
 944	if (fs_info->quota_root)
 945		goto out;
 946
 947	ulist = ulist_alloc(GFP_KERNEL);
 948	if (!ulist) {
 949		ret = -ENOMEM;
 950		goto out;
 951	}
 952
 953	ret = btrfs_sysfs_add_qgroups(fs_info);
 954	if (ret < 0)
 955		goto out;
 956
 957	/*
 958	 * Unlock qgroup_ioctl_lock before starting the transaction. This is to
 959	 * avoid lock acquisition inversion problems (reported by lockdep) between
 960	 * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we
 961	 * start a transaction.
 962	 * After we started the transaction lock qgroup_ioctl_lock again and
 963	 * check if someone else created the quota root in the meanwhile. If so,
 964	 * just return success and release the transaction handle.
 965	 *
 966	 * Also we don't need to worry about someone else calling
 967	 * btrfs_sysfs_add_qgroups() after we unlock and getting an error because
 968	 * that function returns 0 (success) when the sysfs entries already exist.
 969	 */
 970	mutex_unlock(&fs_info->qgroup_ioctl_lock);
 971
 972	/*
 973	 * 1 for quota root item
 974	 * 1 for BTRFS_QGROUP_STATUS item
 975	 *
 976	 * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
 977	 * per subvolume. However those are not currently reserved since it
 978	 * would be a lot of overkill.
 979	 */
 980	trans = btrfs_start_transaction(tree_root, 2);
 981
 982	mutex_lock(&fs_info->qgroup_ioctl_lock);
 983	if (IS_ERR(trans)) {
 984		ret = PTR_ERR(trans);
 985		trans = NULL;
 986		goto out;
 987	}
 988
 989	if (fs_info->quota_root)
 990		goto out;
 991
 992	fs_info->qgroup_ulist = ulist;
 993	ulist = NULL;
 994
 995	/*
 996	 * initially create the quota tree
 997	 */
 998	quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
 999	if (IS_ERR(quota_root)) {
1000		ret =  PTR_ERR(quota_root);
1001		btrfs_abort_transaction(trans, ret);
1002		goto out;
1003	}
1004
1005	path = btrfs_alloc_path();
1006	if (!path) {
1007		ret = -ENOMEM;
1008		btrfs_abort_transaction(trans, ret);
1009		goto out_free_root;
1010	}
1011
1012	key.objectid = 0;
1013	key.type = BTRFS_QGROUP_STATUS_KEY;
1014	key.offset = 0;
1015
1016	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
1017				      sizeof(*ptr));
1018	if (ret) {
1019		btrfs_abort_transaction(trans, ret);
1020		goto out_free_path;
1021	}
1022
1023	leaf = path->nodes[0];
1024	ptr = btrfs_item_ptr(leaf, path->slots[0],
1025				 struct btrfs_qgroup_status_item);
1026	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
1027	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
1028	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
1029				BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1030	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
 
1031	btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
1032
1033	btrfs_mark_buffer_dirty(leaf);
1034
1035	key.objectid = 0;
1036	key.type = BTRFS_ROOT_REF_KEY;
1037	key.offset = 0;
1038
1039	btrfs_release_path(path);
1040	ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
1041	if (ret > 0)
1042		goto out_add_root;
1043	if (ret < 0) {
1044		btrfs_abort_transaction(trans, ret);
1045		goto out_free_path;
1046	}
1047
1048	while (1) {
1049		slot = path->slots[0];
1050		leaf = path->nodes[0];
1051		btrfs_item_key_to_cpu(leaf, &found_key, slot);
1052
1053		if (found_key.type == BTRFS_ROOT_REF_KEY) {
1054
1055			/* Release locks on tree_root before we access quota_root */
1056			btrfs_release_path(path);
1057
1058			ret = add_qgroup_item(trans, quota_root,
1059					      found_key.offset);
1060			if (ret) {
1061				btrfs_abort_transaction(trans, ret);
1062				goto out_free_path;
1063			}
1064
1065			qgroup = add_qgroup_rb(fs_info, found_key.offset);
1066			if (IS_ERR(qgroup)) {
1067				ret = PTR_ERR(qgroup);
1068				btrfs_abort_transaction(trans, ret);
1069				goto out_free_path;
1070			}
1071			ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1072			if (ret < 0) {
1073				btrfs_abort_transaction(trans, ret);
1074				goto out_free_path;
1075			}
1076			ret = btrfs_search_slot_for_read(tree_root, &found_key,
1077							 path, 1, 0);
1078			if (ret < 0) {
1079				btrfs_abort_transaction(trans, ret);
1080				goto out_free_path;
1081			}
1082			if (ret > 0) {
1083				/*
1084				 * Shouldn't happen, but in case it does we
1085				 * don't need to do the btrfs_next_item, just
1086				 * continue.
1087				 */
1088				continue;
1089			}
1090		}
1091		ret = btrfs_next_item(tree_root, path);
1092		if (ret < 0) {
1093			btrfs_abort_transaction(trans, ret);
1094			goto out_free_path;
1095		}
1096		if (ret)
1097			break;
1098	}
1099
1100out_add_root:
1101	btrfs_release_path(path);
1102	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1103	if (ret) {
1104		btrfs_abort_transaction(trans, ret);
1105		goto out_free_path;
1106	}
1107
1108	qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1109	if (IS_ERR(qgroup)) {
1110		ret = PTR_ERR(qgroup);
1111		btrfs_abort_transaction(trans, ret);
1112		goto out_free_path;
1113	}
1114	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1115	if (ret < 0) {
1116		btrfs_abort_transaction(trans, ret);
1117		goto out_free_path;
1118	}
1119
 
 
 
 
 
 
 
 
 
 
1120	ret = btrfs_commit_transaction(trans);
1121	trans = NULL;
 
1122	if (ret)
1123		goto out_free_path;
1124
1125	/*
1126	 * Set quota enabled flag after committing the transaction, to avoid
1127	 * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
1128	 * creation.
1129	 */
1130	spin_lock(&fs_info->qgroup_lock);
1131	fs_info->quota_root = quota_root;
1132	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1133	spin_unlock(&fs_info->qgroup_lock);
1134
1135	ret = qgroup_rescan_init(fs_info, 0, 1);
1136	if (!ret) {
1137	        qgroup_rescan_zero_tracking(fs_info);
1138		fs_info->qgroup_rescan_running = true;
1139	        btrfs_queue_work(fs_info->qgroup_rescan_workers,
1140	                         &fs_info->qgroup_rescan_work);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1141	}
1142
1143out_free_path:
1144	btrfs_free_path(path);
1145out_free_root:
1146	if (ret)
1147		btrfs_put_root(quota_root);
1148out:
1149	if (ret) {
1150		ulist_free(fs_info->qgroup_ulist);
1151		fs_info->qgroup_ulist = NULL;
1152		btrfs_sysfs_del_qgroups(fs_info);
1153	}
1154	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1155	if (ret && trans)
1156		btrfs_end_transaction(trans);
1157	else if (trans)
1158		ret = btrfs_end_transaction(trans);
1159	ulist_free(ulist);
1160	return ret;
1161}
1162
1163int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1164{
1165	struct btrfs_root *quota_root;
1166	struct btrfs_trans_handle *trans = NULL;
1167	int ret = 0;
1168
 
 
 
 
 
 
 
1169	mutex_lock(&fs_info->qgroup_ioctl_lock);
1170	if (!fs_info->quota_root)
1171		goto out;
 
 
 
 
 
 
 
1172	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1173
1174	/*
 
 
 
 
 
 
 
 
1175	 * 1 For the root item
1176	 *
1177	 * We should also reserve enough items for the quota tree deletion in
1178	 * btrfs_clean_quota_tree but this is not done.
1179	 *
1180	 * Also, we must always start a transaction without holding the mutex
1181	 * qgroup_ioctl_lock, see btrfs_quota_enable().
1182	 */
1183	trans = btrfs_start_transaction(fs_info->tree_root, 1);
1184
1185	mutex_lock(&fs_info->qgroup_ioctl_lock);
1186	if (IS_ERR(trans)) {
1187		ret = PTR_ERR(trans);
1188		trans = NULL;
 
1189		goto out;
1190	}
1191
1192	if (!fs_info->quota_root)
1193		goto out;
1194
1195	clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1196	btrfs_qgroup_wait_for_completion(fs_info, false);
1197	spin_lock(&fs_info->qgroup_lock);
1198	quota_root = fs_info->quota_root;
1199	fs_info->quota_root = NULL;
1200	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
 
1201	spin_unlock(&fs_info->qgroup_lock);
1202
1203	btrfs_free_qgroup_config(fs_info);
1204
1205	ret = btrfs_clean_quota_tree(trans, quota_root);
1206	if (ret) {
1207		btrfs_abort_transaction(trans, ret);
1208		goto out;
1209	}
1210
1211	ret = btrfs_del_root(trans, &quota_root->root_key);
1212	if (ret) {
1213		btrfs_abort_transaction(trans, ret);
1214		goto out;
1215	}
1216
1217	list_del(&quota_root->dirty_list);
1218
1219	btrfs_tree_lock(quota_root->node);
1220	btrfs_clean_tree_block(quota_root->node);
1221	btrfs_tree_unlock(quota_root->node);
1222	btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
 
1223
1224	btrfs_put_root(quota_root);
1225
1226out:
1227	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1228	if (ret && trans)
1229		btrfs_end_transaction(trans);
1230	else if (trans)
1231		ret = btrfs_end_transaction(trans);
1232
1233	return ret;
1234}
1235
1236static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1237			 struct btrfs_qgroup *qgroup)
1238{
1239	if (list_empty(&qgroup->dirty))
1240		list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1241}
1242
1243/*
1244 * The easy accounting, we're updating qgroup relationship whose child qgroup
1245 * only has exclusive extents.
1246 *
1247 * In this case, all exclusive extents will also be exclusive for parent, so
1248 * excl/rfer just get added/removed.
1249 *
1250 * So is qgroup reservation space, which should also be added/removed to
1251 * parent.
1252 * Or when child tries to release reservation space, parent will underflow its
1253 * reservation (for relationship adding case).
1254 *
1255 * Caller should hold fs_info->qgroup_lock.
1256 */
1257static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1258				    struct ulist *tmp, u64 ref_root,
1259				    struct btrfs_qgroup *src, int sign)
1260{
1261	struct btrfs_qgroup *qgroup;
1262	struct btrfs_qgroup_list *glist;
1263	struct ulist_node *unode;
1264	struct ulist_iterator uiter;
1265	u64 num_bytes = src->excl;
1266	int ret = 0;
1267
1268	qgroup = find_qgroup_rb(fs_info, ref_root);
1269	if (!qgroup)
1270		goto out;
1271
1272	qgroup->rfer += sign * num_bytes;
1273	qgroup->rfer_cmpr += sign * num_bytes;
1274
1275	WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1276	qgroup->excl += sign * num_bytes;
1277	qgroup->excl_cmpr += sign * num_bytes;
1278
1279	if (sign > 0)
1280		qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1281	else
1282		qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1283
1284	qgroup_dirty(fs_info, qgroup);
1285
1286	/* Get all of the parent groups that contain this qgroup */
1287	list_for_each_entry(glist, &qgroup->groups, next_group) {
1288		ret = ulist_add(tmp, glist->group->qgroupid,
1289				qgroup_to_aux(glist->group), GFP_ATOMIC);
1290		if (ret < 0)
1291			goto out;
1292	}
1293
1294	/* Iterate all of the parents and adjust their reference counts */
1295	ULIST_ITER_INIT(&uiter);
1296	while ((unode = ulist_next(tmp, &uiter))) {
1297		qgroup = unode_aux_to_qgroup(unode);
1298		qgroup->rfer += sign * num_bytes;
1299		qgroup->rfer_cmpr += sign * num_bytes;
1300		WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1301		qgroup->excl += sign * num_bytes;
1302		if (sign > 0)
1303			qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1304		else
1305			qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1306		qgroup->excl_cmpr += sign * num_bytes;
1307		qgroup_dirty(fs_info, qgroup);
1308
1309		/* Add any parents of the parents */
1310		list_for_each_entry(glist, &qgroup->groups, next_group) {
1311			ret = ulist_add(tmp, glist->group->qgroupid,
1312					qgroup_to_aux(glist->group), GFP_ATOMIC);
1313			if (ret < 0)
1314				goto out;
1315		}
1316	}
1317	ret = 0;
1318out:
1319	return ret;
1320}
1321
1322
1323/*
1324 * Quick path for updating qgroup with only excl refs.
1325 *
1326 * In that case, just update all parent will be enough.
1327 * Or we needs to do a full rescan.
1328 * Caller should also hold fs_info->qgroup_lock.
1329 *
1330 * Return 0 for quick update, return >0 for need to full rescan
1331 * and mark INCONSISTENT flag.
1332 * Return < 0 for other error.
1333 */
1334static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1335				   struct ulist *tmp, u64 src, u64 dst,
1336				   int sign)
1337{
1338	struct btrfs_qgroup *qgroup;
1339	int ret = 1;
1340	int err = 0;
1341
1342	qgroup = find_qgroup_rb(fs_info, src);
1343	if (!qgroup)
1344		goto out;
1345	if (qgroup->excl == qgroup->rfer) {
1346		ret = 0;
1347		err = __qgroup_excl_accounting(fs_info, tmp, dst,
1348					       qgroup, sign);
1349		if (err < 0) {
1350			ret = err;
1351			goto out;
1352		}
1353	}
1354out:
1355	if (ret)
1356		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1357	return ret;
1358}
1359
1360int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1361			      u64 dst)
1362{
1363	struct btrfs_fs_info *fs_info = trans->fs_info;
1364	struct btrfs_qgroup *parent;
1365	struct btrfs_qgroup *member;
1366	struct btrfs_qgroup_list *list;
1367	struct ulist *tmp;
1368	unsigned int nofs_flag;
1369	int ret = 0;
1370
1371	/* Check the level of src and dst first */
1372	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1373		return -EINVAL;
1374
1375	/* We hold a transaction handle open, must do a NOFS allocation. */
1376	nofs_flag = memalloc_nofs_save();
1377	tmp = ulist_alloc(GFP_KERNEL);
1378	memalloc_nofs_restore(nofs_flag);
1379	if (!tmp)
1380		return -ENOMEM;
1381
1382	mutex_lock(&fs_info->qgroup_ioctl_lock);
1383	if (!fs_info->quota_root) {
1384		ret = -ENOTCONN;
1385		goto out;
1386	}
1387	member = find_qgroup_rb(fs_info, src);
1388	parent = find_qgroup_rb(fs_info, dst);
1389	if (!member || !parent) {
1390		ret = -EINVAL;
1391		goto out;
1392	}
1393
1394	/* check if such qgroup relation exist firstly */
1395	list_for_each_entry(list, &member->groups, next_group) {
1396		if (list->group == parent) {
1397			ret = -EEXIST;
1398			goto out;
1399		}
1400	}
1401
1402	ret = add_qgroup_relation_item(trans, src, dst);
1403	if (ret)
1404		goto out;
1405
1406	ret = add_qgroup_relation_item(trans, dst, src);
1407	if (ret) {
1408		del_qgroup_relation_item(trans, src, dst);
1409		goto out;
1410	}
1411
1412	spin_lock(&fs_info->qgroup_lock);
1413	ret = add_relation_rb(fs_info, src, dst);
1414	if (ret < 0) {
1415		spin_unlock(&fs_info->qgroup_lock);
1416		goto out;
1417	}
1418	ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1419	spin_unlock(&fs_info->qgroup_lock);
1420out:
1421	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1422	ulist_free(tmp);
1423	return ret;
1424}
1425
1426static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1427				 u64 dst)
1428{
1429	struct btrfs_fs_info *fs_info = trans->fs_info;
1430	struct btrfs_qgroup *parent;
1431	struct btrfs_qgroup *member;
1432	struct btrfs_qgroup_list *list;
1433	struct ulist *tmp;
1434	bool found = false;
1435	unsigned int nofs_flag;
1436	int ret = 0;
1437	int ret2;
1438
1439	/* We hold a transaction handle open, must do a NOFS allocation. */
1440	nofs_flag = memalloc_nofs_save();
1441	tmp = ulist_alloc(GFP_KERNEL);
1442	memalloc_nofs_restore(nofs_flag);
1443	if (!tmp)
1444		return -ENOMEM;
1445
1446	if (!fs_info->quota_root) {
1447		ret = -ENOTCONN;
1448		goto out;
1449	}
1450
1451	member = find_qgroup_rb(fs_info, src);
1452	parent = find_qgroup_rb(fs_info, dst);
1453	/*
1454	 * The parent/member pair doesn't exist, then try to delete the dead
1455	 * relation items only.
1456	 */
1457	if (!member || !parent)
1458		goto delete_item;
1459
1460	/* check if such qgroup relation exist firstly */
1461	list_for_each_entry(list, &member->groups, next_group) {
1462		if (list->group == parent) {
1463			found = true;
1464			break;
1465		}
1466	}
1467
1468delete_item:
1469	ret = del_qgroup_relation_item(trans, src, dst);
1470	if (ret < 0 && ret != -ENOENT)
1471		goto out;
1472	ret2 = del_qgroup_relation_item(trans, dst, src);
1473	if (ret2 < 0 && ret2 != -ENOENT)
1474		goto out;
1475
1476	/* At least one deletion succeeded, return 0 */
1477	if (!ret || !ret2)
1478		ret = 0;
1479
1480	if (found) {
1481		spin_lock(&fs_info->qgroup_lock);
1482		del_relation_rb(fs_info, src, dst);
1483		ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1484		spin_unlock(&fs_info->qgroup_lock);
1485	}
1486out:
1487	ulist_free(tmp);
1488	return ret;
1489}
1490
1491int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1492			      u64 dst)
1493{
1494	struct btrfs_fs_info *fs_info = trans->fs_info;
1495	int ret = 0;
1496
1497	mutex_lock(&fs_info->qgroup_ioctl_lock);
1498	ret = __del_qgroup_relation(trans, src, dst);
1499	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1500
1501	return ret;
1502}
1503
1504int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1505{
1506	struct btrfs_fs_info *fs_info = trans->fs_info;
1507	struct btrfs_root *quota_root;
1508	struct btrfs_qgroup *qgroup;
1509	int ret = 0;
1510
1511	mutex_lock(&fs_info->qgroup_ioctl_lock);
1512	if (!fs_info->quota_root) {
1513		ret = -ENOTCONN;
1514		goto out;
1515	}
1516	quota_root = fs_info->quota_root;
1517	qgroup = find_qgroup_rb(fs_info, qgroupid);
1518	if (qgroup) {
1519		ret = -EEXIST;
1520		goto out;
1521	}
1522
1523	ret = add_qgroup_item(trans, quota_root, qgroupid);
1524	if (ret)
1525		goto out;
1526
1527	spin_lock(&fs_info->qgroup_lock);
1528	qgroup = add_qgroup_rb(fs_info, qgroupid);
1529	spin_unlock(&fs_info->qgroup_lock);
1530
1531	if (IS_ERR(qgroup)) {
1532		ret = PTR_ERR(qgroup);
1533		goto out;
1534	}
1535	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1536out:
1537	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1538	return ret;
1539}
1540
1541int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1542{
1543	struct btrfs_fs_info *fs_info = trans->fs_info;
1544	struct btrfs_qgroup *qgroup;
1545	struct btrfs_qgroup_list *list;
1546	int ret = 0;
1547
1548	mutex_lock(&fs_info->qgroup_ioctl_lock);
1549	if (!fs_info->quota_root) {
1550		ret = -ENOTCONN;
1551		goto out;
1552	}
1553
1554	qgroup = find_qgroup_rb(fs_info, qgroupid);
1555	if (!qgroup) {
1556		ret = -ENOENT;
1557		goto out;
1558	}
1559
1560	/* Check if there are no children of this qgroup */
1561	if (!list_empty(&qgroup->members)) {
1562		ret = -EBUSY;
1563		goto out;
1564	}
1565
1566	ret = del_qgroup_item(trans, qgroupid);
1567	if (ret && ret != -ENOENT)
1568		goto out;
1569
1570	while (!list_empty(&qgroup->groups)) {
1571		list = list_first_entry(&qgroup->groups,
1572					struct btrfs_qgroup_list, next_group);
1573		ret = __del_qgroup_relation(trans, qgroupid,
1574					    list->group->qgroupid);
1575		if (ret)
1576			goto out;
1577	}
1578
1579	spin_lock(&fs_info->qgroup_lock);
1580	del_qgroup_rb(fs_info, qgroupid);
1581	spin_unlock(&fs_info->qgroup_lock);
1582
1583	/*
1584	 * Remove the qgroup from sysfs now without holding the qgroup_lock
1585	 * spinlock, since the sysfs_remove_group() function needs to take
1586	 * the mutex kernfs_mutex through kernfs_remove_by_name_ns().
1587	 */
1588	btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1589	kfree(qgroup);
1590out:
1591	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1592	return ret;
1593}
1594
1595int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1596		       struct btrfs_qgroup_limit *limit)
1597{
1598	struct btrfs_fs_info *fs_info = trans->fs_info;
1599	struct btrfs_qgroup *qgroup;
1600	int ret = 0;
1601	/* Sometimes we would want to clear the limit on this qgroup.
1602	 * To meet this requirement, we treat the -1 as a special value
1603	 * which tell kernel to clear the limit on this qgroup.
1604	 */
1605	const u64 CLEAR_VALUE = -1;
1606
1607	mutex_lock(&fs_info->qgroup_ioctl_lock);
1608	if (!fs_info->quota_root) {
1609		ret = -ENOTCONN;
1610		goto out;
1611	}
1612
1613	qgroup = find_qgroup_rb(fs_info, qgroupid);
1614	if (!qgroup) {
1615		ret = -ENOENT;
1616		goto out;
1617	}
1618
1619	spin_lock(&fs_info->qgroup_lock);
1620	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1621		if (limit->max_rfer == CLEAR_VALUE) {
1622			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1623			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1624			qgroup->max_rfer = 0;
1625		} else {
1626			qgroup->max_rfer = limit->max_rfer;
1627		}
1628	}
1629	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1630		if (limit->max_excl == CLEAR_VALUE) {
1631			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1632			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1633			qgroup->max_excl = 0;
1634		} else {
1635			qgroup->max_excl = limit->max_excl;
1636		}
1637	}
1638	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1639		if (limit->rsv_rfer == CLEAR_VALUE) {
1640			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1641			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1642			qgroup->rsv_rfer = 0;
1643		} else {
1644			qgroup->rsv_rfer = limit->rsv_rfer;
1645		}
1646	}
1647	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1648		if (limit->rsv_excl == CLEAR_VALUE) {
1649			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1650			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1651			qgroup->rsv_excl = 0;
1652		} else {
1653			qgroup->rsv_excl = limit->rsv_excl;
1654		}
1655	}
1656	qgroup->lim_flags |= limit->flags;
1657
1658	spin_unlock(&fs_info->qgroup_lock);
1659
1660	ret = update_qgroup_limit_item(trans, qgroup);
1661	if (ret) {
1662		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1663		btrfs_info(fs_info, "unable to update quota limit for %llu",
1664		       qgroupid);
1665	}
1666
1667out:
1668	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1669	return ret;
1670}
1671
1672int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1673				struct btrfs_delayed_ref_root *delayed_refs,
1674				struct btrfs_qgroup_extent_record *record)
1675{
1676	struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1677	struct rb_node *parent_node = NULL;
1678	struct btrfs_qgroup_extent_record *entry;
1679	u64 bytenr = record->bytenr;
1680
1681	lockdep_assert_held(&delayed_refs->lock);
1682	trace_btrfs_qgroup_trace_extent(fs_info, record);
1683
1684	while (*p) {
1685		parent_node = *p;
1686		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1687				 node);
1688		if (bytenr < entry->bytenr) {
1689			p = &(*p)->rb_left;
1690		} else if (bytenr > entry->bytenr) {
1691			p = &(*p)->rb_right;
1692		} else {
1693			if (record->data_rsv && !entry->data_rsv) {
1694				entry->data_rsv = record->data_rsv;
1695				entry->data_rsv_refroot =
1696					record->data_rsv_refroot;
1697			}
1698			return 1;
1699		}
1700	}
1701
1702	rb_link_node(&record->node, parent_node, p);
1703	rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1704	return 0;
1705}
1706
1707int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans,
1708				   struct btrfs_qgroup_extent_record *qrecord)
1709{
1710	struct ulist *old_root;
1711	u64 bytenr = qrecord->bytenr;
1712	int ret;
1713
1714	/*
1715	 * We are always called in a context where we are already holding a
1716	 * transaction handle. Often we are called when adding a data delayed
1717	 * reference from btrfs_truncate_inode_items() (truncating or unlinking),
1718	 * in which case we will be holding a write lock on extent buffer from a
1719	 * subvolume tree. In this case we can't allow btrfs_find_all_roots() to
1720	 * acquire fs_info->commit_root_sem, because that is a higher level lock
1721	 * that must be acquired before locking any extent buffers.
1722	 *
1723	 * So we want btrfs_find_all_roots() to not acquire the commit_root_sem
1724	 * but we can't pass it a non-NULL transaction handle, because otherwise
1725	 * it would not use commit roots and would lock extent buffers, causing
1726	 * a deadlock if it ends up trying to read lock the same extent buffer
1727	 * that was previously write locked at btrfs_truncate_inode_items().
1728	 *
1729	 * So pass a NULL transaction handle to btrfs_find_all_roots() and
1730	 * explicitly tell it to not acquire the commit_root_sem - if we are
1731	 * holding a transaction handle we don't need its protection.
1732	 */
1733	ASSERT(trans != NULL);
1734
1735	ret = btrfs_find_all_roots(NULL, trans->fs_info, bytenr, 0, &old_root,
1736				   false, true);
 
 
 
 
 
1737	if (ret < 0) {
1738		trans->fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1739		btrfs_warn(trans->fs_info,
1740"error accounting new delayed refs extent (err code: %d), quota inconsistent",
1741			ret);
1742		return 0;
1743	}
1744
1745	/*
1746	 * Here we don't need to get the lock of
1747	 * trans->transaction->delayed_refs, since inserted qrecord won't
1748	 * be deleted, only qrecord->node may be modified (new qrecord insert)
1749	 *
1750	 * So modifying qrecord->old_roots is safe here
1751	 */
1752	qrecord->old_roots = old_root;
1753	return 0;
1754}
1755
1756int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1757			      u64 num_bytes, gfp_t gfp_flag)
1758{
1759	struct btrfs_fs_info *fs_info = trans->fs_info;
1760	struct btrfs_qgroup_extent_record *record;
1761	struct btrfs_delayed_ref_root *delayed_refs;
1762	int ret;
1763
1764	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1765	    || bytenr == 0 || num_bytes == 0)
1766		return 0;
1767	record = kzalloc(sizeof(*record), gfp_flag);
1768	if (!record)
1769		return -ENOMEM;
1770
1771	delayed_refs = &trans->transaction->delayed_refs;
1772	record->bytenr = bytenr;
1773	record->num_bytes = num_bytes;
1774	record->old_roots = NULL;
1775
1776	spin_lock(&delayed_refs->lock);
1777	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1778	spin_unlock(&delayed_refs->lock);
1779	if (ret > 0) {
1780		kfree(record);
1781		return 0;
1782	}
1783	return btrfs_qgroup_trace_extent_post(trans, record);
1784}
1785
1786int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1787				  struct extent_buffer *eb)
1788{
1789	struct btrfs_fs_info *fs_info = trans->fs_info;
1790	int nr = btrfs_header_nritems(eb);
1791	int i, extent_type, ret;
1792	struct btrfs_key key;
1793	struct btrfs_file_extent_item *fi;
1794	u64 bytenr, num_bytes;
1795
1796	/* We can be called directly from walk_up_proc() */
1797	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1798		return 0;
1799
1800	for (i = 0; i < nr; i++) {
1801		btrfs_item_key_to_cpu(eb, &key, i);
1802
1803		if (key.type != BTRFS_EXTENT_DATA_KEY)
1804			continue;
1805
1806		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1807		/* filter out non qgroup-accountable extents  */
1808		extent_type = btrfs_file_extent_type(eb, fi);
1809
1810		if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1811			continue;
1812
1813		bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1814		if (!bytenr)
1815			continue;
1816
1817		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1818
1819		ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes,
1820						GFP_NOFS);
1821		if (ret)
1822			return ret;
1823	}
1824	cond_resched();
1825	return 0;
1826}
1827
1828/*
1829 * Walk up the tree from the bottom, freeing leaves and any interior
1830 * nodes which have had all slots visited. If a node (leaf or
1831 * interior) is freed, the node above it will have it's slot
1832 * incremented. The root node will never be freed.
1833 *
1834 * At the end of this function, we should have a path which has all
1835 * slots incremented to the next position for a search. If we need to
1836 * read a new node it will be NULL and the node above it will have the
1837 * correct slot selected for a later read.
1838 *
1839 * If we increment the root nodes slot counter past the number of
1840 * elements, 1 is returned to signal completion of the search.
1841 */
1842static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1843{
1844	int level = 0;
1845	int nr, slot;
1846	struct extent_buffer *eb;
1847
1848	if (root_level == 0)
1849		return 1;
1850
1851	while (level <= root_level) {
1852		eb = path->nodes[level];
1853		nr = btrfs_header_nritems(eb);
1854		path->slots[level]++;
1855		slot = path->slots[level];
1856		if (slot >= nr || level == 0) {
1857			/*
1858			 * Don't free the root -  we will detect this
1859			 * condition after our loop and return a
1860			 * positive value for caller to stop walking the tree.
1861			 */
1862			if (level != root_level) {
1863				btrfs_tree_unlock_rw(eb, path->locks[level]);
1864				path->locks[level] = 0;
1865
1866				free_extent_buffer(eb);
1867				path->nodes[level] = NULL;
1868				path->slots[level] = 0;
1869			}
1870		} else {
1871			/*
1872			 * We have a valid slot to walk back down
1873			 * from. Stop here so caller can process these
1874			 * new nodes.
1875			 */
1876			break;
1877		}
1878
1879		level++;
1880	}
1881
1882	eb = path->nodes[root_level];
1883	if (path->slots[root_level] >= btrfs_header_nritems(eb))
1884		return 1;
1885
1886	return 0;
1887}
1888
1889/*
1890 * Helper function to trace a subtree tree block swap.
1891 *
1892 * The swap will happen in highest tree block, but there may be a lot of
1893 * tree blocks involved.
1894 *
1895 * For example:
1896 *  OO = Old tree blocks
1897 *  NN = New tree blocks allocated during balance
1898 *
1899 *           File tree (257)                  Reloc tree for 257
1900 * L2              OO                                NN
1901 *               /    \                            /    \
1902 * L1          OO      OO (a)                    OO      NN (a)
1903 *            / \     / \                       / \     / \
1904 * L0       OO   OO OO   OO                   OO   OO NN   NN
1905 *                  (b)  (c)                          (b)  (c)
1906 *
1907 * When calling qgroup_trace_extent_swap(), we will pass:
1908 * @src_eb = OO(a)
1909 * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
1910 * @dst_level = 0
1911 * @root_level = 1
1912 *
1913 * In that case, qgroup_trace_extent_swap() will search from OO(a) to
1914 * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
1915 *
1916 * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
1917 *
1918 * 1) Tree search from @src_eb
1919 *    It should acts as a simplified btrfs_search_slot().
1920 *    The key for search can be extracted from @dst_path->nodes[dst_level]
1921 *    (first key).
1922 *
1923 * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
1924 *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
1925 *    They should be marked during previous (@dst_level = 1) iteration.
1926 *
1927 * 3) Mark file extents in leaves dirty
1928 *    We don't have good way to pick out new file extents only.
1929 *    So we still follow the old method by scanning all file extents in
1930 *    the leave.
1931 *
1932 * This function can free us from keeping two paths, thus later we only need
1933 * to care about how to iterate all new tree blocks in reloc tree.
1934 */
1935static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
1936				    struct extent_buffer *src_eb,
1937				    struct btrfs_path *dst_path,
1938				    int dst_level, int root_level,
1939				    bool trace_leaf)
1940{
1941	struct btrfs_key key;
1942	struct btrfs_path *src_path;
1943	struct btrfs_fs_info *fs_info = trans->fs_info;
1944	u32 nodesize = fs_info->nodesize;
1945	int cur_level = root_level;
1946	int ret;
1947
1948	BUG_ON(dst_level > root_level);
1949	/* Level mismatch */
1950	if (btrfs_header_level(src_eb) != root_level)
1951		return -EINVAL;
1952
1953	src_path = btrfs_alloc_path();
1954	if (!src_path) {
1955		ret = -ENOMEM;
1956		goto out;
1957	}
1958
1959	if (dst_level)
1960		btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1961	else
1962		btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1963
1964	/* For src_path */
1965	atomic_inc(&src_eb->refs);
1966	src_path->nodes[root_level] = src_eb;
1967	src_path->slots[root_level] = dst_path->slots[root_level];
1968	src_path->locks[root_level] = 0;
1969
1970	/* A simplified version of btrfs_search_slot() */
1971	while (cur_level >= dst_level) {
1972		struct btrfs_key src_key;
1973		struct btrfs_key dst_key;
1974
1975		if (src_path->nodes[cur_level] == NULL) {
1976			struct extent_buffer *eb;
1977			int parent_slot;
1978
1979			eb = src_path->nodes[cur_level + 1];
1980			parent_slot = src_path->slots[cur_level + 1];
1981
1982			eb = btrfs_read_node_slot(eb, parent_slot);
1983			if (IS_ERR(eb)) {
1984				ret = PTR_ERR(eb);
1985				goto out;
1986			}
1987
1988			src_path->nodes[cur_level] = eb;
1989
1990			btrfs_tree_read_lock(eb);
1991			src_path->locks[cur_level] = BTRFS_READ_LOCK;
1992		}
1993
1994		src_path->slots[cur_level] = dst_path->slots[cur_level];
1995		if (cur_level) {
1996			btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
1997					&dst_key, dst_path->slots[cur_level]);
1998			btrfs_node_key_to_cpu(src_path->nodes[cur_level],
1999					&src_key, src_path->slots[cur_level]);
2000		} else {
2001			btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
2002					&dst_key, dst_path->slots[cur_level]);
2003			btrfs_item_key_to_cpu(src_path->nodes[cur_level],
2004					&src_key, src_path->slots[cur_level]);
2005		}
2006		/* Content mismatch, something went wrong */
2007		if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
2008			ret = -ENOENT;
2009			goto out;
2010		}
2011		cur_level--;
2012	}
2013
2014	/*
2015	 * Now both @dst_path and @src_path have been populated, record the tree
2016	 * blocks for qgroup accounting.
2017	 */
2018	ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
2019			nodesize, GFP_NOFS);
2020	if (ret < 0)
2021		goto out;
2022	ret = btrfs_qgroup_trace_extent(trans,
2023			dst_path->nodes[dst_level]->start,
2024			nodesize, GFP_NOFS);
2025	if (ret < 0)
2026		goto out;
2027
2028	/* Record leaf file extents */
2029	if (dst_level == 0 && trace_leaf) {
2030		ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
2031		if (ret < 0)
2032			goto out;
2033		ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
2034	}
2035out:
2036	btrfs_free_path(src_path);
2037	return ret;
2038}
2039
2040/*
2041 * Helper function to do recursive generation-aware depth-first search, to
2042 * locate all new tree blocks in a subtree of reloc tree.
2043 *
2044 * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
2045 *         reloc tree
2046 * L2         NN (a)
2047 *          /    \
2048 * L1    OO        NN (b)
2049 *      /  \      /  \
2050 * L0  OO  OO    OO  NN
2051 *               (c) (d)
2052 * If we pass:
2053 * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
2054 * @cur_level = 1
2055 * @root_level = 1
2056 *
2057 * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
2058 * above tree blocks along with their counter parts in file tree.
2059 * While during search, old tree blocks OO(c) will be skipped as tree block swap
2060 * won't affect OO(c).
2061 */
2062static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
2063					   struct extent_buffer *src_eb,
2064					   struct btrfs_path *dst_path,
2065					   int cur_level, int root_level,
2066					   u64 last_snapshot, bool trace_leaf)
2067{
2068	struct btrfs_fs_info *fs_info = trans->fs_info;
2069	struct extent_buffer *eb;
2070	bool need_cleanup = false;
2071	int ret = 0;
2072	int i;
2073
2074	/* Level sanity check */
2075	if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
2076	    root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
2077	    root_level < cur_level) {
2078		btrfs_err_rl(fs_info,
2079			"%s: bad levels, cur_level=%d root_level=%d",
2080			__func__, cur_level, root_level);
2081		return -EUCLEAN;
2082	}
2083
2084	/* Read the tree block if needed */
2085	if (dst_path->nodes[cur_level] == NULL) {
2086		int parent_slot;
2087		u64 child_gen;
2088
2089		/*
2090		 * dst_path->nodes[root_level] must be initialized before
2091		 * calling this function.
2092		 */
2093		if (cur_level == root_level) {
2094			btrfs_err_rl(fs_info,
2095	"%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
2096				__func__, root_level, root_level, cur_level);
2097			return -EUCLEAN;
2098		}
2099
2100		/*
2101		 * We need to get child blockptr/gen from parent before we can
2102		 * read it.
2103		  */
2104		eb = dst_path->nodes[cur_level + 1];
2105		parent_slot = dst_path->slots[cur_level + 1];
2106		child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2107
2108		/* This node is old, no need to trace */
2109		if (child_gen < last_snapshot)
2110			goto out;
2111
2112		eb = btrfs_read_node_slot(eb, parent_slot);
2113		if (IS_ERR(eb)) {
2114			ret = PTR_ERR(eb);
2115			goto out;
2116		}
2117
2118		dst_path->nodes[cur_level] = eb;
2119		dst_path->slots[cur_level] = 0;
2120
2121		btrfs_tree_read_lock(eb);
2122		dst_path->locks[cur_level] = BTRFS_READ_LOCK;
2123		need_cleanup = true;
2124	}
2125
2126	/* Now record this tree block and its counter part for qgroups */
2127	ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
2128				       root_level, trace_leaf);
2129	if (ret < 0)
2130		goto cleanup;
2131
2132	eb = dst_path->nodes[cur_level];
2133
2134	if (cur_level > 0) {
2135		/* Iterate all child tree blocks */
2136		for (i = 0; i < btrfs_header_nritems(eb); i++) {
2137			/* Skip old tree blocks as they won't be swapped */
2138			if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
2139				continue;
2140			dst_path->slots[cur_level] = i;
2141
2142			/* Recursive call (at most 7 times) */
2143			ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
2144					dst_path, cur_level - 1, root_level,
2145					last_snapshot, trace_leaf);
2146			if (ret < 0)
2147				goto cleanup;
2148		}
2149	}
2150
2151cleanup:
2152	if (need_cleanup) {
2153		/* Clean up */
2154		btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2155				     dst_path->locks[cur_level]);
2156		free_extent_buffer(dst_path->nodes[cur_level]);
2157		dst_path->nodes[cur_level] = NULL;
2158		dst_path->slots[cur_level] = 0;
2159		dst_path->locks[cur_level] = 0;
2160	}
2161out:
2162	return ret;
2163}
2164
2165static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2166				struct extent_buffer *src_eb,
2167				struct extent_buffer *dst_eb,
2168				u64 last_snapshot, bool trace_leaf)
2169{
2170	struct btrfs_fs_info *fs_info = trans->fs_info;
2171	struct btrfs_path *dst_path = NULL;
2172	int level;
2173	int ret;
2174
2175	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2176		return 0;
2177
2178	/* Wrong parameter order */
2179	if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
2180		btrfs_err_rl(fs_info,
2181		"%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2182			     btrfs_header_generation(src_eb),
2183			     btrfs_header_generation(dst_eb));
2184		return -EUCLEAN;
2185	}
2186
2187	if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2188		ret = -EIO;
2189		goto out;
2190	}
2191
2192	level = btrfs_header_level(dst_eb);
2193	dst_path = btrfs_alloc_path();
2194	if (!dst_path) {
2195		ret = -ENOMEM;
2196		goto out;
2197	}
2198	/* For dst_path */
2199	atomic_inc(&dst_eb->refs);
2200	dst_path->nodes[level] = dst_eb;
2201	dst_path->slots[level] = 0;
2202	dst_path->locks[level] = 0;
2203
2204	/* Do the generation aware breadth-first search */
2205	ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2206					      level, last_snapshot, trace_leaf);
2207	if (ret < 0)
2208		goto out;
2209	ret = 0;
2210
2211out:
2212	btrfs_free_path(dst_path);
2213	if (ret < 0)
2214		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2215	return ret;
2216}
2217
2218int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2219			       struct extent_buffer *root_eb,
2220			       u64 root_gen, int root_level)
2221{
2222	struct btrfs_fs_info *fs_info = trans->fs_info;
2223	int ret = 0;
2224	int level;
 
2225	struct extent_buffer *eb = root_eb;
2226	struct btrfs_path *path = NULL;
2227
2228	BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2229	BUG_ON(root_eb == NULL);
2230
2231	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2232		return 0;
2233
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2234	if (!extent_buffer_uptodate(root_eb)) {
2235		ret = btrfs_read_buffer(root_eb, root_gen, root_level, NULL);
 
 
 
 
 
 
2236		if (ret)
2237			goto out;
2238	}
2239
2240	if (root_level == 0) {
2241		ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2242		goto out;
2243	}
2244
2245	path = btrfs_alloc_path();
2246	if (!path)
2247		return -ENOMEM;
2248
2249	/*
2250	 * Walk down the tree.  Missing extent blocks are filled in as
2251	 * we go. Metadata is accounted every time we read a new
2252	 * extent block.
2253	 *
2254	 * When we reach a leaf, we account for file extent items in it,
2255	 * walk back up the tree (adjusting slot pointers as we go)
2256	 * and restart the search process.
2257	 */
2258	atomic_inc(&root_eb->refs);	/* For path */
2259	path->nodes[root_level] = root_eb;
2260	path->slots[root_level] = 0;
2261	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2262walk_down:
2263	level = root_level;
2264	while (level >= 0) {
2265		if (path->nodes[level] == NULL) {
2266			int parent_slot;
2267			u64 child_bytenr;
2268
2269			/*
2270			 * We need to get child blockptr from parent before we
2271			 * can read it.
2272			  */
2273			eb = path->nodes[level + 1];
2274			parent_slot = path->slots[level + 1];
2275			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2276
2277			eb = btrfs_read_node_slot(eb, parent_slot);
2278			if (IS_ERR(eb)) {
2279				ret = PTR_ERR(eb);
2280				goto out;
2281			}
2282
2283			path->nodes[level] = eb;
2284			path->slots[level] = 0;
2285
2286			btrfs_tree_read_lock(eb);
2287			path->locks[level] = BTRFS_READ_LOCK;
2288
2289			ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2290							fs_info->nodesize,
2291							GFP_NOFS);
2292			if (ret)
2293				goto out;
2294		}
2295
2296		if (level == 0) {
2297			ret = btrfs_qgroup_trace_leaf_items(trans,
2298							    path->nodes[level]);
2299			if (ret)
2300				goto out;
2301
2302			/* Nonzero return here means we completed our search */
2303			ret = adjust_slots_upwards(path, root_level);
2304			if (ret)
2305				break;
2306
2307			/* Restart search with new slots */
2308			goto walk_down;
2309		}
2310
2311		level--;
2312	}
2313
2314	ret = 0;
2315out:
2316	btrfs_free_path(path);
2317
2318	return ret;
2319}
2320
2321#define UPDATE_NEW	0
2322#define UPDATE_OLD	1
2323/*
2324 * Walk all of the roots that points to the bytenr and adjust their refcnts.
2325 */
2326static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2327				struct ulist *roots, struct ulist *tmp,
2328				struct ulist *qgroups, u64 seq, int update_old)
2329{
2330	struct ulist_node *unode;
2331	struct ulist_iterator uiter;
2332	struct ulist_node *tmp_unode;
2333	struct ulist_iterator tmp_uiter;
2334	struct btrfs_qgroup *qg;
2335	int ret = 0;
2336
2337	if (!roots)
2338		return 0;
2339	ULIST_ITER_INIT(&uiter);
2340	while ((unode = ulist_next(roots, &uiter))) {
2341		qg = find_qgroup_rb(fs_info, unode->val);
2342		if (!qg)
2343			continue;
2344
2345		ulist_reinit(tmp);
2346		ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2347				GFP_ATOMIC);
2348		if (ret < 0)
2349			return ret;
2350		ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2351		if (ret < 0)
2352			return ret;
2353		ULIST_ITER_INIT(&tmp_uiter);
2354		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2355			struct btrfs_qgroup_list *glist;
2356
2357			qg = unode_aux_to_qgroup(tmp_unode);
2358			if (update_old)
2359				btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2360			else
2361				btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2362			list_for_each_entry(glist, &qg->groups, next_group) {
2363				ret = ulist_add(qgroups, glist->group->qgroupid,
2364						qgroup_to_aux(glist->group),
2365						GFP_ATOMIC);
2366				if (ret < 0)
2367					return ret;
2368				ret = ulist_add(tmp, glist->group->qgroupid,
2369						qgroup_to_aux(glist->group),
2370						GFP_ATOMIC);
2371				if (ret < 0)
2372					return ret;
2373			}
2374		}
2375	}
2376	return 0;
2377}
2378
2379/*
2380 * Update qgroup rfer/excl counters.
2381 * Rfer update is easy, codes can explain themselves.
2382 *
2383 * Excl update is tricky, the update is split into 2 parts.
2384 * Part 1: Possible exclusive <-> sharing detect:
2385 *	|	A	|	!A	|
2386 *  -------------------------------------
2387 *  B	|	*	|	-	|
2388 *  -------------------------------------
2389 *  !B	|	+	|	**	|
2390 *  -------------------------------------
2391 *
2392 * Conditions:
2393 * A:	cur_old_roots < nr_old_roots	(not exclusive before)
2394 * !A:	cur_old_roots == nr_old_roots	(possible exclusive before)
2395 * B:	cur_new_roots < nr_new_roots	(not exclusive now)
2396 * !B:	cur_new_roots == nr_new_roots	(possible exclusive now)
2397 *
2398 * Results:
2399 * +: Possible sharing -> exclusive	-: Possible exclusive -> sharing
2400 * *: Definitely not changed.		**: Possible unchanged.
2401 *
2402 * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2403 *
2404 * To make the logic clear, we first use condition A and B to split
2405 * combination into 4 results.
2406 *
2407 * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2408 * only on variant maybe 0.
2409 *
2410 * Lastly, check result **, since there are 2 variants maybe 0, split them
2411 * again(2x2).
2412 * But this time we don't need to consider other things, the codes and logic
2413 * is easy to understand now.
2414 */
2415static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2416				  struct ulist *qgroups,
2417				  u64 nr_old_roots,
2418				  u64 nr_new_roots,
2419				  u64 num_bytes, u64 seq)
2420{
2421	struct ulist_node *unode;
2422	struct ulist_iterator uiter;
2423	struct btrfs_qgroup *qg;
2424	u64 cur_new_count, cur_old_count;
2425
2426	ULIST_ITER_INIT(&uiter);
2427	while ((unode = ulist_next(qgroups, &uiter))) {
2428		bool dirty = false;
2429
2430		qg = unode_aux_to_qgroup(unode);
2431		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2432		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2433
2434		trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2435					     cur_new_count);
2436
2437		/* Rfer update part */
2438		if (cur_old_count == 0 && cur_new_count > 0) {
2439			qg->rfer += num_bytes;
2440			qg->rfer_cmpr += num_bytes;
2441			dirty = true;
2442		}
2443		if (cur_old_count > 0 && cur_new_count == 0) {
2444			qg->rfer -= num_bytes;
2445			qg->rfer_cmpr -= num_bytes;
2446			dirty = true;
2447		}
2448
2449		/* Excl update part */
2450		/* Exclusive/none -> shared case */
2451		if (cur_old_count == nr_old_roots &&
2452		    cur_new_count < nr_new_roots) {
2453			/* Exclusive -> shared */
2454			if (cur_old_count != 0) {
2455				qg->excl -= num_bytes;
2456				qg->excl_cmpr -= num_bytes;
2457				dirty = true;
2458			}
2459		}
2460
2461		/* Shared -> exclusive/none case */
2462		if (cur_old_count < nr_old_roots &&
2463		    cur_new_count == nr_new_roots) {
2464			/* Shared->exclusive */
2465			if (cur_new_count != 0) {
2466				qg->excl += num_bytes;
2467				qg->excl_cmpr += num_bytes;
2468				dirty = true;
2469			}
2470		}
2471
2472		/* Exclusive/none -> exclusive/none case */
2473		if (cur_old_count == nr_old_roots &&
2474		    cur_new_count == nr_new_roots) {
2475			if (cur_old_count == 0) {
2476				/* None -> exclusive/none */
2477
2478				if (cur_new_count != 0) {
2479					/* None -> exclusive */
2480					qg->excl += num_bytes;
2481					qg->excl_cmpr += num_bytes;
2482					dirty = true;
2483				}
2484				/* None -> none, nothing changed */
2485			} else {
2486				/* Exclusive -> exclusive/none */
2487
2488				if (cur_new_count == 0) {
2489					/* Exclusive -> none */
2490					qg->excl -= num_bytes;
2491					qg->excl_cmpr -= num_bytes;
2492					dirty = true;
2493				}
2494				/* Exclusive -> exclusive, nothing changed */
2495			}
2496		}
2497
2498		if (dirty)
2499			qgroup_dirty(fs_info, qg);
2500	}
2501	return 0;
2502}
2503
2504/*
2505 * Check if the @roots potentially is a list of fs tree roots
2506 *
2507 * Return 0 for definitely not a fs/subvol tree roots ulist
2508 * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2509 *          one as well)
2510 */
2511static int maybe_fs_roots(struct ulist *roots)
2512{
2513	struct ulist_node *unode;
2514	struct ulist_iterator uiter;
2515
2516	/* Empty one, still possible for fs roots */
2517	if (!roots || roots->nnodes == 0)
2518		return 1;
2519
2520	ULIST_ITER_INIT(&uiter);
2521	unode = ulist_next(roots, &uiter);
2522	if (!unode)
2523		return 1;
2524
2525	/*
2526	 * If it contains fs tree roots, then it must belong to fs/subvol
2527	 * trees.
2528	 * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2529	 */
2530	return is_fstree(unode->val);
2531}
2532
2533int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2534				u64 num_bytes, struct ulist *old_roots,
2535				struct ulist *new_roots)
2536{
2537	struct btrfs_fs_info *fs_info = trans->fs_info;
2538	struct ulist *qgroups = NULL;
2539	struct ulist *tmp = NULL;
2540	u64 seq;
2541	u64 nr_new_roots = 0;
2542	u64 nr_old_roots = 0;
2543	int ret = 0;
2544
2545	/*
2546	 * If quotas get disabled meanwhile, the resources need to be freed and
2547	 * we can't just exit here.
2548	 */
2549	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 
2550		goto out_free;
2551
2552	if (new_roots) {
2553		if (!maybe_fs_roots(new_roots))
2554			goto out_free;
2555		nr_new_roots = new_roots->nnodes;
2556	}
2557	if (old_roots) {
2558		if (!maybe_fs_roots(old_roots))
2559			goto out_free;
2560		nr_old_roots = old_roots->nnodes;
2561	}
2562
2563	/* Quick exit, either not fs tree roots, or won't affect any qgroup */
2564	if (nr_old_roots == 0 && nr_new_roots == 0)
2565		goto out_free;
2566
2567	BUG_ON(!fs_info->quota_root);
2568
2569	trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2570					num_bytes, nr_old_roots, nr_new_roots);
2571
2572	qgroups = ulist_alloc(GFP_NOFS);
2573	if (!qgroups) {
2574		ret = -ENOMEM;
2575		goto out_free;
2576	}
2577	tmp = ulist_alloc(GFP_NOFS);
2578	if (!tmp) {
2579		ret = -ENOMEM;
2580		goto out_free;
2581	}
2582
2583	mutex_lock(&fs_info->qgroup_rescan_lock);
2584	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2585		if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2586			mutex_unlock(&fs_info->qgroup_rescan_lock);
2587			ret = 0;
2588			goto out_free;
2589		}
2590	}
2591	mutex_unlock(&fs_info->qgroup_rescan_lock);
2592
2593	spin_lock(&fs_info->qgroup_lock);
2594	seq = fs_info->qgroup_seq;
2595
2596	/* Update old refcnts using old_roots */
2597	ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2598				   UPDATE_OLD);
2599	if (ret < 0)
2600		goto out;
2601
2602	/* Update new refcnts using new_roots */
2603	ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2604				   UPDATE_NEW);
2605	if (ret < 0)
2606		goto out;
2607
2608	qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2609			       num_bytes, seq);
2610
2611	/*
2612	 * Bump qgroup_seq to avoid seq overlap
2613	 */
2614	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2615out:
2616	spin_unlock(&fs_info->qgroup_lock);
2617out_free:
2618	ulist_free(tmp);
2619	ulist_free(qgroups);
2620	ulist_free(old_roots);
2621	ulist_free(new_roots);
2622	return ret;
2623}
2624
2625int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2626{
2627	struct btrfs_fs_info *fs_info = trans->fs_info;
2628	struct btrfs_qgroup_extent_record *record;
2629	struct btrfs_delayed_ref_root *delayed_refs;
2630	struct ulist *new_roots = NULL;
2631	struct rb_node *node;
2632	u64 num_dirty_extents = 0;
2633	u64 qgroup_to_skip;
2634	int ret = 0;
2635
2636	delayed_refs = &trans->transaction->delayed_refs;
2637	qgroup_to_skip = delayed_refs->qgroup_to_skip;
2638	while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2639		record = rb_entry(node, struct btrfs_qgroup_extent_record,
2640				  node);
2641
2642		num_dirty_extents++;
2643		trace_btrfs_qgroup_account_extents(fs_info, record);
2644
2645		if (!ret) {
 
 
 
 
 
 
2646			/*
2647			 * Old roots should be searched when inserting qgroup
2648			 * extent record
 
 
 
 
 
 
 
 
 
 
2649			 */
2650			if (WARN_ON(!record->old_roots)) {
2651				/* Search commit root to find old_roots */
2652				ret = btrfs_find_all_roots(NULL, fs_info,
2653						record->bytenr, 0,
2654						&record->old_roots, false, false);
2655				if (ret < 0)
2656					goto cleanup;
 
 
2657			}
2658
2659			/* Free the reserved data space */
2660			btrfs_qgroup_free_refroot(fs_info,
2661					record->data_rsv_refroot,
2662					record->data_rsv,
2663					BTRFS_QGROUP_RSV_DATA);
2664			/*
2665			 * Use BTRFS_SEQ_LAST as time_seq to do special search,
2666			 * which doesn't lock tree or delayed_refs and search
2667			 * current root. It's safe inside commit_transaction().
2668			 */
2669			ret = btrfs_find_all_roots(trans, fs_info,
2670			   record->bytenr, BTRFS_SEQ_LAST, &new_roots, false, false);
 
2671			if (ret < 0)
2672				goto cleanup;
 
2673			if (qgroup_to_skip) {
2674				ulist_del(new_roots, qgroup_to_skip, 0);
2675				ulist_del(record->old_roots, qgroup_to_skip,
2676					  0);
2677			}
2678			ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2679							  record->num_bytes,
2680							  record->old_roots,
2681							  new_roots);
2682			record->old_roots = NULL;
2683			new_roots = NULL;
2684		}
2685cleanup:
2686		ulist_free(record->old_roots);
2687		ulist_free(new_roots);
2688		new_roots = NULL;
2689		rb_erase(node, &delayed_refs->dirty_extent_root);
2690		kfree(record);
2691
2692	}
2693	trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2694				       num_dirty_extents);
2695	return ret;
2696}
2697
2698/*
2699 * called from commit_transaction. Writes all changed qgroups to disk.
2700 */
2701int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2702{
2703	struct btrfs_fs_info *fs_info = trans->fs_info;
2704	int ret = 0;
2705
2706	if (!fs_info->quota_root)
2707		return ret;
2708
2709	spin_lock(&fs_info->qgroup_lock);
2710	while (!list_empty(&fs_info->dirty_qgroups)) {
2711		struct btrfs_qgroup *qgroup;
2712		qgroup = list_first_entry(&fs_info->dirty_qgroups,
2713					  struct btrfs_qgroup, dirty);
2714		list_del_init(&qgroup->dirty);
2715		spin_unlock(&fs_info->qgroup_lock);
2716		ret = update_qgroup_info_item(trans, qgroup);
2717		if (ret)
2718			fs_info->qgroup_flags |=
2719					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2720		ret = update_qgroup_limit_item(trans, qgroup);
2721		if (ret)
2722			fs_info->qgroup_flags |=
2723					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2724		spin_lock(&fs_info->qgroup_lock);
2725	}
2726	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2727		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2728	else
2729		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2730	spin_unlock(&fs_info->qgroup_lock);
2731
2732	ret = update_qgroup_status_item(trans);
2733	if (ret)
2734		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2735
2736	return ret;
2737}
2738
2739/*
2740 * Copy the accounting information between qgroups. This is necessary
2741 * when a snapshot or a subvolume is created. Throwing an error will
2742 * cause a transaction abort so we take extra care here to only error
2743 * when a readonly fs is a reasonable outcome.
2744 */
2745int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2746			 u64 objectid, struct btrfs_qgroup_inherit *inherit)
2747{
2748	int ret = 0;
2749	int i;
2750	u64 *i_qgroups;
2751	bool committing = false;
2752	struct btrfs_fs_info *fs_info = trans->fs_info;
2753	struct btrfs_root *quota_root;
2754	struct btrfs_qgroup *srcgroup;
2755	struct btrfs_qgroup *dstgroup;
2756	bool need_rescan = false;
2757	u32 level_size = 0;
2758	u64 nums;
2759
2760	/*
2761	 * There are only two callers of this function.
2762	 *
2763	 * One in create_subvol() in the ioctl context, which needs to hold
2764	 * the qgroup_ioctl_lock.
2765	 *
2766	 * The other one in create_pending_snapshot() where no other qgroup
2767	 * code can modify the fs as they all need to either start a new trans
2768	 * or hold a trans handler, thus we don't need to hold
2769	 * qgroup_ioctl_lock.
2770	 * This would avoid long and complex lock chain and make lockdep happy.
2771	 */
2772	spin_lock(&fs_info->trans_lock);
2773	if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
2774		committing = true;
2775	spin_unlock(&fs_info->trans_lock);
2776
2777	if (!committing)
2778		mutex_lock(&fs_info->qgroup_ioctl_lock);
2779	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2780		goto out;
2781
2782	quota_root = fs_info->quota_root;
2783	if (!quota_root) {
2784		ret = -EINVAL;
2785		goto out;
2786	}
2787
2788	if (inherit) {
2789		i_qgroups = (u64 *)(inherit + 1);
2790		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2791		       2 * inherit->num_excl_copies;
2792		for (i = 0; i < nums; ++i) {
2793			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2794
2795			/*
2796			 * Zero out invalid groups so we can ignore
2797			 * them later.
2798			 */
2799			if (!srcgroup ||
2800			    ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2801				*i_qgroups = 0ULL;
2802
2803			++i_qgroups;
2804		}
2805	}
2806
2807	/*
2808	 * create a tracking group for the subvol itself
2809	 */
2810	ret = add_qgroup_item(trans, quota_root, objectid);
2811	if (ret)
2812		goto out;
2813
2814	/*
2815	 * add qgroup to all inherited groups
2816	 */
2817	if (inherit) {
2818		i_qgroups = (u64 *)(inherit + 1);
2819		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2820			if (*i_qgroups == 0)
2821				continue;
2822			ret = add_qgroup_relation_item(trans, objectid,
2823						       *i_qgroups);
2824			if (ret && ret != -EEXIST)
2825				goto out;
2826			ret = add_qgroup_relation_item(trans, *i_qgroups,
2827						       objectid);
2828			if (ret && ret != -EEXIST)
2829				goto out;
2830		}
2831		ret = 0;
2832	}
2833
2834
2835	spin_lock(&fs_info->qgroup_lock);
2836
2837	dstgroup = add_qgroup_rb(fs_info, objectid);
2838	if (IS_ERR(dstgroup)) {
2839		ret = PTR_ERR(dstgroup);
2840		goto unlock;
2841	}
2842
2843	if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2844		dstgroup->lim_flags = inherit->lim.flags;
2845		dstgroup->max_rfer = inherit->lim.max_rfer;
2846		dstgroup->max_excl = inherit->lim.max_excl;
2847		dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2848		dstgroup->rsv_excl = inherit->lim.rsv_excl;
2849
2850		ret = update_qgroup_limit_item(trans, dstgroup);
2851		if (ret) {
2852			fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2853			btrfs_info(fs_info,
2854				   "unable to update quota limit for %llu",
2855				   dstgroup->qgroupid);
2856			goto unlock;
2857		}
2858	}
2859
2860	if (srcid) {
2861		srcgroup = find_qgroup_rb(fs_info, srcid);
2862		if (!srcgroup)
2863			goto unlock;
2864
2865		/*
2866		 * We call inherit after we clone the root in order to make sure
2867		 * our counts don't go crazy, so at this point the only
2868		 * difference between the two roots should be the root node.
2869		 */
2870		level_size = fs_info->nodesize;
2871		dstgroup->rfer = srcgroup->rfer;
2872		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2873		dstgroup->excl = level_size;
2874		dstgroup->excl_cmpr = level_size;
2875		srcgroup->excl = level_size;
2876		srcgroup->excl_cmpr = level_size;
2877
2878		/* inherit the limit info */
2879		dstgroup->lim_flags = srcgroup->lim_flags;
2880		dstgroup->max_rfer = srcgroup->max_rfer;
2881		dstgroup->max_excl = srcgroup->max_excl;
2882		dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2883		dstgroup->rsv_excl = srcgroup->rsv_excl;
2884
2885		qgroup_dirty(fs_info, dstgroup);
2886		qgroup_dirty(fs_info, srcgroup);
2887	}
2888
2889	if (!inherit)
2890		goto unlock;
2891
2892	i_qgroups = (u64 *)(inherit + 1);
2893	for (i = 0; i < inherit->num_qgroups; ++i) {
2894		if (*i_qgroups) {
2895			ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2896			if (ret)
2897				goto unlock;
2898		}
2899		++i_qgroups;
2900
2901		/*
2902		 * If we're doing a snapshot, and adding the snapshot to a new
2903		 * qgroup, the numbers are guaranteed to be incorrect.
2904		 */
2905		if (srcid)
2906			need_rescan = true;
2907	}
2908
2909	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2910		struct btrfs_qgroup *src;
2911		struct btrfs_qgroup *dst;
2912
2913		if (!i_qgroups[0] || !i_qgroups[1])
2914			continue;
2915
2916		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2917		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2918
2919		if (!src || !dst) {
2920			ret = -EINVAL;
2921			goto unlock;
2922		}
2923
2924		dst->rfer = src->rfer - level_size;
2925		dst->rfer_cmpr = src->rfer_cmpr - level_size;
2926
2927		/* Manually tweaking numbers certainly needs a rescan */
2928		need_rescan = true;
2929	}
2930	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2931		struct btrfs_qgroup *src;
2932		struct btrfs_qgroup *dst;
2933
2934		if (!i_qgroups[0] || !i_qgroups[1])
2935			continue;
2936
2937		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2938		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2939
2940		if (!src || !dst) {
2941			ret = -EINVAL;
2942			goto unlock;
2943		}
2944
2945		dst->excl = src->excl + level_size;
2946		dst->excl_cmpr = src->excl_cmpr + level_size;
2947		need_rescan = true;
2948	}
2949
2950unlock:
2951	spin_unlock(&fs_info->qgroup_lock);
2952	if (!ret)
2953		ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup);
2954out:
2955	if (!committing)
2956		mutex_unlock(&fs_info->qgroup_ioctl_lock);
2957	if (need_rescan)
2958		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2959	return ret;
2960}
2961
2962static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
2963{
2964	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2965	    qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
2966		return false;
2967
2968	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2969	    qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
2970		return false;
2971
2972	return true;
2973}
2974
2975static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
2976			  enum btrfs_qgroup_rsv_type type)
2977{
2978	struct btrfs_qgroup *qgroup;
2979	struct btrfs_fs_info *fs_info = root->fs_info;
2980	u64 ref_root = root->root_key.objectid;
2981	int ret = 0;
2982	struct ulist_node *unode;
2983	struct ulist_iterator uiter;
2984
2985	if (!is_fstree(ref_root))
2986		return 0;
2987
2988	if (num_bytes == 0)
2989		return 0;
2990
2991	if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2992	    capable(CAP_SYS_RESOURCE))
2993		enforce = false;
2994
2995	spin_lock(&fs_info->qgroup_lock);
2996	if (!fs_info->quota_root)
2997		goto out;
2998
2999	qgroup = find_qgroup_rb(fs_info, ref_root);
3000	if (!qgroup)
3001		goto out;
3002
3003	/*
3004	 * in a first step, we check all affected qgroups if any limits would
3005	 * be exceeded
3006	 */
3007	ulist_reinit(fs_info->qgroup_ulist);
3008	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3009			qgroup_to_aux(qgroup), GFP_ATOMIC);
3010	if (ret < 0)
3011		goto out;
3012	ULIST_ITER_INIT(&uiter);
3013	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3014		struct btrfs_qgroup *qg;
3015		struct btrfs_qgroup_list *glist;
3016
3017		qg = unode_aux_to_qgroup(unode);
3018
3019		if (enforce && !qgroup_check_limits(qg, num_bytes)) {
3020			ret = -EDQUOT;
3021			goto out;
3022		}
3023
3024		list_for_each_entry(glist, &qg->groups, next_group) {
3025			ret = ulist_add(fs_info->qgroup_ulist,
3026					glist->group->qgroupid,
3027					qgroup_to_aux(glist->group), GFP_ATOMIC);
3028			if (ret < 0)
3029				goto out;
3030		}
3031	}
3032	ret = 0;
3033	/*
3034	 * no limits exceeded, now record the reservation into all qgroups
3035	 */
3036	ULIST_ITER_INIT(&uiter);
3037	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3038		struct btrfs_qgroup *qg;
3039
3040		qg = unode_aux_to_qgroup(unode);
3041
3042		qgroup_rsv_add(fs_info, qg, num_bytes, type);
3043	}
3044
3045out:
3046	spin_unlock(&fs_info->qgroup_lock);
3047	return ret;
3048}
3049
3050/*
3051 * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
3052 * qgroup).
3053 *
3054 * Will handle all higher level qgroup too.
3055 *
3056 * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
3057 * This special case is only used for META_PERTRANS type.
3058 */
3059void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
3060			       u64 ref_root, u64 num_bytes,
3061			       enum btrfs_qgroup_rsv_type type)
3062{
3063	struct btrfs_qgroup *qgroup;
3064	struct ulist_node *unode;
3065	struct ulist_iterator uiter;
3066	int ret = 0;
3067
3068	if (!is_fstree(ref_root))
3069		return;
3070
3071	if (num_bytes == 0)
3072		return;
3073
3074	if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
3075		WARN(1, "%s: Invalid type to free", __func__);
3076		return;
3077	}
3078	spin_lock(&fs_info->qgroup_lock);
3079
3080	if (!fs_info->quota_root)
3081		goto out;
3082
3083	qgroup = find_qgroup_rb(fs_info, ref_root);
3084	if (!qgroup)
3085		goto out;
3086
3087	if (num_bytes == (u64)-1)
3088		/*
3089		 * We're freeing all pertrans rsv, get reserved value from
3090		 * level 0 qgroup as real num_bytes to free.
3091		 */
3092		num_bytes = qgroup->rsv.values[type];
3093
3094	ulist_reinit(fs_info->qgroup_ulist);
3095	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3096			qgroup_to_aux(qgroup), GFP_ATOMIC);
3097	if (ret < 0)
3098		goto out;
3099	ULIST_ITER_INIT(&uiter);
3100	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3101		struct btrfs_qgroup *qg;
3102		struct btrfs_qgroup_list *glist;
3103
3104		qg = unode_aux_to_qgroup(unode);
3105
3106		qgroup_rsv_release(fs_info, qg, num_bytes, type);
3107
3108		list_for_each_entry(glist, &qg->groups, next_group) {
3109			ret = ulist_add(fs_info->qgroup_ulist,
3110					glist->group->qgroupid,
3111					qgroup_to_aux(glist->group), GFP_ATOMIC);
3112			if (ret < 0)
3113				goto out;
3114		}
3115	}
3116
3117out:
3118	spin_unlock(&fs_info->qgroup_lock);
3119}
3120
3121/*
3122 * Check if the leaf is the last leaf. Which means all node pointers
3123 * are at their last position.
3124 */
3125static bool is_last_leaf(struct btrfs_path *path)
3126{
3127	int i;
3128
3129	for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3130		if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3131			return false;
3132	}
3133	return true;
3134}
3135
3136/*
3137 * returns < 0 on error, 0 when more leafs are to be scanned.
3138 * returns 1 when done.
3139 */
3140static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3141			      struct btrfs_path *path)
3142{
3143	struct btrfs_fs_info *fs_info = trans->fs_info;
 
3144	struct btrfs_key found;
3145	struct extent_buffer *scratch_leaf = NULL;
3146	struct ulist *roots = NULL;
3147	u64 num_bytes;
3148	bool done;
3149	int slot;
3150	int ret;
3151
3152	mutex_lock(&fs_info->qgroup_rescan_lock);
3153	ret = btrfs_search_slot_for_read(fs_info->extent_root,
 
 
3154					 &fs_info->qgroup_rescan_progress,
3155					 path, 1, 0);
3156
3157	btrfs_debug(fs_info,
3158		"current progress key (%llu %u %llu), search_slot ret %d",
3159		fs_info->qgroup_rescan_progress.objectid,
3160		fs_info->qgroup_rescan_progress.type,
3161		fs_info->qgroup_rescan_progress.offset, ret);
3162
3163	if (ret) {
3164		/*
3165		 * The rescan is about to end, we will not be scanning any
3166		 * further blocks. We cannot unset the RESCAN flag here, because
3167		 * we want to commit the transaction if everything went well.
3168		 * To make the live accounting work in this phase, we set our
3169		 * scan progress pointer such that every real extent objectid
3170		 * will be smaller.
3171		 */
3172		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3173		btrfs_release_path(path);
3174		mutex_unlock(&fs_info->qgroup_rescan_lock);
3175		return ret;
3176	}
3177	done = is_last_leaf(path);
3178
3179	btrfs_item_key_to_cpu(path->nodes[0], &found,
3180			      btrfs_header_nritems(path->nodes[0]) - 1);
3181	fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3182
3183	scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3184	if (!scratch_leaf) {
3185		ret = -ENOMEM;
3186		mutex_unlock(&fs_info->qgroup_rescan_lock);
3187		goto out;
3188	}
3189	slot = path->slots[0];
3190	btrfs_release_path(path);
3191	mutex_unlock(&fs_info->qgroup_rescan_lock);
3192
3193	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
 
 
3194		btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3195		if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3196		    found.type != BTRFS_METADATA_ITEM_KEY)
3197			continue;
3198		if (found.type == BTRFS_METADATA_ITEM_KEY)
3199			num_bytes = fs_info->nodesize;
3200		else
3201			num_bytes = found.offset;
3202
3203		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
3204					   &roots, false, false);
 
 
3205		if (ret < 0)
3206			goto out;
3207		/* For rescan, just pass old_roots as NULL */
3208		ret = btrfs_qgroup_account_extent(trans, found.objectid,
3209						  num_bytes, NULL, roots);
3210		if (ret < 0)
3211			goto out;
3212	}
3213out:
3214	if (scratch_leaf)
3215		free_extent_buffer(scratch_leaf);
3216
3217	if (done && !ret) {
3218		ret = 1;
3219		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3220	}
3221	return ret;
3222}
3223
3224static bool rescan_should_stop(struct btrfs_fs_info *fs_info)
3225{
3226	return btrfs_fs_closing(fs_info) ||
3227		test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
 
 
3228}
3229
3230static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3231{
3232	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3233						     qgroup_rescan_work);
3234	struct btrfs_path *path;
3235	struct btrfs_trans_handle *trans = NULL;
3236	int err = -ENOMEM;
3237	int ret = 0;
3238	bool stopped = false;
 
3239
3240	path = btrfs_alloc_path();
3241	if (!path)
3242		goto out;
3243	/*
3244	 * Rescan should only search for commit root, and any later difference
3245	 * should be recorded by qgroup
3246	 */
3247	path->search_commit_root = 1;
3248	path->skip_locking = 1;
3249
3250	err = 0;
3251	while (!err && !(stopped = rescan_should_stop(fs_info))) {
3252		trans = btrfs_start_transaction(fs_info->fs_root, 0);
3253		if (IS_ERR(trans)) {
3254			err = PTR_ERR(trans);
3255			break;
3256		}
3257		if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3258			err = -EINTR;
3259		} else {
3260			err = qgroup_rescan_leaf(trans, path);
3261		}
3262		if (err > 0)
3263			btrfs_commit_transaction(trans);
3264		else
3265			btrfs_end_transaction(trans);
3266	}
3267
3268out:
3269	btrfs_free_path(path);
3270
3271	mutex_lock(&fs_info->qgroup_rescan_lock);
3272	if (err > 0 &&
3273	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3274		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3275	} else if (err < 0) {
3276		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3277	}
3278	mutex_unlock(&fs_info->qgroup_rescan_lock);
3279
3280	/*
3281	 * only update status, since the previous part has already updated the
3282	 * qgroup info.
 
 
 
3283	 */
3284	trans = btrfs_start_transaction(fs_info->quota_root, 1);
3285	if (IS_ERR(trans)) {
3286		err = PTR_ERR(trans);
 
 
 
 
 
 
 
3287		trans = NULL;
3288		btrfs_err(fs_info,
3289			  "fail to start transaction for status update: %d",
3290			  err);
3291	}
3292
3293	mutex_lock(&fs_info->qgroup_rescan_lock);
3294	if (!stopped)
 
3295		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3296	if (trans) {
3297		ret = update_qgroup_status_item(trans);
3298		if (ret < 0) {
3299			err = ret;
3300			btrfs_err(fs_info, "fail to update qgroup status: %d",
3301				  err);
3302		}
3303	}
3304	fs_info->qgroup_rescan_running = false;
 
3305	complete_all(&fs_info->qgroup_rescan_completion);
3306	mutex_unlock(&fs_info->qgroup_rescan_lock);
3307
3308	if (!trans)
3309		return;
3310
3311	btrfs_end_transaction(trans);
3312
3313	if (stopped) {
3314		btrfs_info(fs_info, "qgroup scan paused");
 
 
3315	} else if (err >= 0) {
3316		btrfs_info(fs_info, "qgroup scan completed%s",
3317			err > 0 ? " (inconsistency flag cleared)" : "");
3318	} else {
3319		btrfs_err(fs_info, "qgroup scan failed with %d", err);
3320	}
3321}
3322
3323/*
3324 * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
3325 * memory required for the rescan context.
3326 */
3327static int
3328qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
3329		   int init_flags)
3330{
3331	int ret = 0;
3332
3333	if (!init_flags) {
3334		/* we're resuming qgroup rescan at mount time */
3335		if (!(fs_info->qgroup_flags &
3336		      BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
3337			btrfs_warn(fs_info,
3338			"qgroup rescan init failed, qgroup rescan is not queued");
3339			ret = -EINVAL;
3340		} else if (!(fs_info->qgroup_flags &
3341			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3342			btrfs_warn(fs_info,
3343			"qgroup rescan init failed, qgroup is not enabled");
3344			ret = -EINVAL;
3345		}
3346
3347		if (ret)
3348			return ret;
3349	}
3350
3351	mutex_lock(&fs_info->qgroup_rescan_lock);
3352
3353	if (init_flags) {
3354		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3355			btrfs_warn(fs_info,
3356				   "qgroup rescan is already in progress");
3357			ret = -EINPROGRESS;
3358		} else if (!(fs_info->qgroup_flags &
3359			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3360			btrfs_warn(fs_info,
3361			"qgroup rescan init failed, qgroup is not enabled");
3362			ret = -EINVAL;
 
 
 
3363		}
3364
3365		if (ret) {
3366			mutex_unlock(&fs_info->qgroup_rescan_lock);
3367			return ret;
3368		}
3369		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3370	}
3371
3372	memset(&fs_info->qgroup_rescan_progress, 0,
3373		sizeof(fs_info->qgroup_rescan_progress));
 
 
3374	fs_info->qgroup_rescan_progress.objectid = progress_objectid;
3375	init_completion(&fs_info->qgroup_rescan_completion);
3376	mutex_unlock(&fs_info->qgroup_rescan_lock);
3377
3378	btrfs_init_work(&fs_info->qgroup_rescan_work,
3379			btrfs_qgroup_rescan_worker, NULL, NULL);
3380	return 0;
3381}
3382
3383static void
3384qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
3385{
3386	struct rb_node *n;
3387	struct btrfs_qgroup *qgroup;
3388
3389	spin_lock(&fs_info->qgroup_lock);
3390	/* clear all current qgroup tracking information */
3391	for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
3392		qgroup = rb_entry(n, struct btrfs_qgroup, node);
3393		qgroup->rfer = 0;
3394		qgroup->rfer_cmpr = 0;
3395		qgroup->excl = 0;
3396		qgroup->excl_cmpr = 0;
3397		qgroup_dirty(fs_info, qgroup);
3398	}
3399	spin_unlock(&fs_info->qgroup_lock);
3400}
3401
3402int
3403btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
3404{
3405	int ret = 0;
3406	struct btrfs_trans_handle *trans;
3407
3408	ret = qgroup_rescan_init(fs_info, 0, 1);
3409	if (ret)
3410		return ret;
3411
3412	/*
3413	 * We have set the rescan_progress to 0, which means no more
3414	 * delayed refs will be accounted by btrfs_qgroup_account_ref.
3415	 * However, btrfs_qgroup_account_ref may be right after its call
3416	 * to btrfs_find_all_roots, in which case it would still do the
3417	 * accounting.
3418	 * To solve this, we're committing the transaction, which will
3419	 * ensure we run all delayed refs and only after that, we are
3420	 * going to clear all tracking information for a clean start.
3421	 */
3422
3423	trans = btrfs_join_transaction(fs_info->fs_root);
3424	if (IS_ERR(trans)) {
3425		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3426		return PTR_ERR(trans);
3427	}
3428	ret = btrfs_commit_transaction(trans);
3429	if (ret) {
3430		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3431		return ret;
3432	}
3433
3434	qgroup_rescan_zero_tracking(fs_info);
3435
3436	mutex_lock(&fs_info->qgroup_rescan_lock);
3437	fs_info->qgroup_rescan_running = true;
3438	btrfs_queue_work(fs_info->qgroup_rescan_workers,
3439			 &fs_info->qgroup_rescan_work);
3440	mutex_unlock(&fs_info->qgroup_rescan_lock);
3441
3442	return 0;
3443}
3444
3445int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
3446				     bool interruptible)
3447{
3448	int running;
3449	int ret = 0;
3450
3451	mutex_lock(&fs_info->qgroup_rescan_lock);
3452	running = fs_info->qgroup_rescan_running;
3453	mutex_unlock(&fs_info->qgroup_rescan_lock);
3454
3455	if (!running)
3456		return 0;
3457
3458	if (interruptible)
3459		ret = wait_for_completion_interruptible(
3460					&fs_info->qgroup_rescan_completion);
3461	else
3462		wait_for_completion(&fs_info->qgroup_rescan_completion);
3463
3464	return ret;
3465}
3466
3467/*
3468 * this is only called from open_ctree where we're still single threaded, thus
3469 * locking is omitted here.
3470 */
3471void
3472btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
3473{
3474	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3475		mutex_lock(&fs_info->qgroup_rescan_lock);
3476		fs_info->qgroup_rescan_running = true;
3477		btrfs_queue_work(fs_info->qgroup_rescan_workers,
3478				 &fs_info->qgroup_rescan_work);
3479		mutex_unlock(&fs_info->qgroup_rescan_lock);
3480	}
3481}
3482
3483#define rbtree_iterate_from_safe(node, next, start)				\
3484       for (node = start; node && ({ next = rb_next(node); 1;}); node = next)
3485
3486static int qgroup_unreserve_range(struct btrfs_inode *inode,
3487				  struct extent_changeset *reserved, u64 start,
3488				  u64 len)
3489{
3490	struct rb_node *node;
3491	struct rb_node *next;
3492	struct ulist_node *entry;
3493	int ret = 0;
3494
3495	node = reserved->range_changed.root.rb_node;
3496	if (!node)
3497		return 0;
3498	while (node) {
3499		entry = rb_entry(node, struct ulist_node, rb_node);
3500		if (entry->val < start)
3501			node = node->rb_right;
3502		else
3503			node = node->rb_left;
3504	}
3505
3506	if (entry->val > start && rb_prev(&entry->rb_node))
3507		entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node,
3508				 rb_node);
3509
3510	rbtree_iterate_from_safe(node, next, &entry->rb_node) {
3511		u64 entry_start;
3512		u64 entry_end;
3513		u64 entry_len;
3514		int clear_ret;
3515
3516		entry = rb_entry(node, struct ulist_node, rb_node);
3517		entry_start = entry->val;
3518		entry_end = entry->aux;
3519		entry_len = entry_end - entry_start + 1;
3520
3521		if (entry_start >= start + len)
3522			break;
3523		if (entry_start + entry_len <= start)
3524			continue;
3525		/*
3526		 * Now the entry is in [start, start + len), revert the
3527		 * EXTENT_QGROUP_RESERVED bit.
3528		 */
3529		clear_ret = clear_extent_bits(&inode->io_tree, entry_start,
3530					      entry_end, EXTENT_QGROUP_RESERVED);
3531		if (!ret && clear_ret < 0)
3532			ret = clear_ret;
3533
3534		ulist_del(&reserved->range_changed, entry->val, entry->aux);
3535		if (likely(reserved->bytes_changed >= entry_len)) {
3536			reserved->bytes_changed -= entry_len;
3537		} else {
3538			WARN_ON(1);
3539			reserved->bytes_changed = 0;
3540		}
3541	}
3542
3543	return ret;
3544}
3545
3546/*
3547 * Try to free some space for qgroup.
3548 *
3549 * For qgroup, there are only 3 ways to free qgroup space:
3550 * - Flush nodatacow write
3551 *   Any nodatacow write will free its reserved data space at run_delalloc_range().
3552 *   In theory, we should only flush nodatacow inodes, but it's not yet
3553 *   possible, so we need to flush the whole root.
3554 *
3555 * - Wait for ordered extents
3556 *   When ordered extents are finished, their reserved metadata is finally
3557 *   converted to per_trans status, which can be freed by later commit
3558 *   transaction.
3559 *
3560 * - Commit transaction
3561 *   This would free the meta_per_trans space.
3562 *   In theory this shouldn't provide much space, but any more qgroup space
3563 *   is needed.
3564 */
3565static int try_flush_qgroup(struct btrfs_root *root)
3566{
3567	struct btrfs_trans_handle *trans;
3568	int ret;
3569
3570	/* Can't hold an open transaction or we run the risk of deadlocking. */
3571	ASSERT(current->journal_info == NULL);
3572	if (WARN_ON(current->journal_info))
3573		return 0;
3574
3575	/*
3576	 * We don't want to run flush again and again, so if there is a running
3577	 * one, we won't try to start a new flush, but exit directly.
3578	 */
3579	if (test_and_set_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)) {
3580		wait_event(root->qgroup_flush_wait,
3581			!test_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state));
3582		return 0;
3583	}
3584
3585	ret = btrfs_start_delalloc_snapshot(root, true);
3586	if (ret < 0)
3587		goto out;
3588	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
3589
3590	trans = btrfs_join_transaction(root);
3591	if (IS_ERR(trans)) {
3592		ret = PTR_ERR(trans);
3593		goto out;
3594	}
3595
3596	ret = btrfs_commit_transaction(trans);
3597out:
3598	clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state);
3599	wake_up(&root->qgroup_flush_wait);
3600	return ret;
3601}
3602
3603static int qgroup_reserve_data(struct btrfs_inode *inode,
3604			struct extent_changeset **reserved_ret, u64 start,
3605			u64 len)
3606{
3607	struct btrfs_root *root = inode->root;
3608	struct extent_changeset *reserved;
3609	bool new_reserved = false;
3610	u64 orig_reserved;
3611	u64 to_reserve;
3612	int ret;
3613
3614	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
3615	    !is_fstree(root->root_key.objectid) || len == 0)
3616		return 0;
3617
3618	/* @reserved parameter is mandatory for qgroup */
3619	if (WARN_ON(!reserved_ret))
3620		return -EINVAL;
3621	if (!*reserved_ret) {
3622		new_reserved = true;
3623		*reserved_ret = extent_changeset_alloc();
3624		if (!*reserved_ret)
3625			return -ENOMEM;
3626	}
3627	reserved = *reserved_ret;
3628	/* Record already reserved space */
3629	orig_reserved = reserved->bytes_changed;
3630	ret = set_record_extent_bits(&inode->io_tree, start,
3631			start + len -1, EXTENT_QGROUP_RESERVED, reserved);
3632
3633	/* Newly reserved space */
3634	to_reserve = reserved->bytes_changed - orig_reserved;
3635	trace_btrfs_qgroup_reserve_data(&inode->vfs_inode, start, len,
3636					to_reserve, QGROUP_RESERVE);
3637	if (ret < 0)
3638		goto out;
3639	ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
3640	if (ret < 0)
3641		goto cleanup;
3642
3643	return ret;
3644
3645cleanup:
3646	qgroup_unreserve_range(inode, reserved, start, len);
3647out:
3648	if (new_reserved) {
3649		extent_changeset_free(reserved);
3650		*reserved_ret = NULL;
3651	}
3652	return ret;
3653}
3654
3655/*
3656 * Reserve qgroup space for range [start, start + len).
3657 *
3658 * This function will either reserve space from related qgroups or do nothing
3659 * if the range is already reserved.
3660 *
3661 * Return 0 for successful reservation
3662 * Return <0 for error (including -EQUOT)
3663 *
3664 * NOTE: This function may sleep for memory allocation, dirty page flushing and
3665 *	 commit transaction. So caller should not hold any dirty page locked.
3666 */
3667int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
3668			struct extent_changeset **reserved_ret, u64 start,
3669			u64 len)
3670{
3671	int ret;
3672
3673	ret = qgroup_reserve_data(inode, reserved_ret, start, len);
3674	if (ret <= 0 && ret != -EDQUOT)
3675		return ret;
3676
3677	ret = try_flush_qgroup(inode->root);
3678	if (ret < 0)
3679		return ret;
3680	return qgroup_reserve_data(inode, reserved_ret, start, len);
3681}
3682
3683/* Free ranges specified by @reserved, normally in error path */
3684static int qgroup_free_reserved_data(struct btrfs_inode *inode,
3685			struct extent_changeset *reserved, u64 start, u64 len)
3686{
3687	struct btrfs_root *root = inode->root;
3688	struct ulist_node *unode;
3689	struct ulist_iterator uiter;
3690	struct extent_changeset changeset;
3691	int freed = 0;
3692	int ret;
3693
3694	extent_changeset_init(&changeset);
3695	len = round_up(start + len, root->fs_info->sectorsize);
3696	start = round_down(start, root->fs_info->sectorsize);
3697
3698	ULIST_ITER_INIT(&uiter);
3699	while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
3700		u64 range_start = unode->val;
3701		/* unode->aux is the inclusive end */
3702		u64 range_len = unode->aux - range_start + 1;
3703		u64 free_start;
3704		u64 free_len;
3705
3706		extent_changeset_release(&changeset);
3707
3708		/* Only free range in range [start, start + len) */
3709		if (range_start >= start + len ||
3710		    range_start + range_len <= start)
3711			continue;
3712		free_start = max(range_start, start);
3713		free_len = min(start + len, range_start + range_len) -
3714			   free_start;
3715		/*
3716		 * TODO: To also modify reserved->ranges_reserved to reflect
3717		 * the modification.
3718		 *
3719		 * However as long as we free qgroup reserved according to
3720		 * EXTENT_QGROUP_RESERVED, we won't double free.
3721		 * So not need to rush.
3722		 */
3723		ret = clear_record_extent_bits(&inode->io_tree, free_start,
3724				free_start + free_len - 1,
3725				EXTENT_QGROUP_RESERVED, &changeset);
3726		if (ret < 0)
3727			goto out;
3728		freed += changeset.bytes_changed;
3729	}
3730	btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
3731				  BTRFS_QGROUP_RSV_DATA);
3732	ret = freed;
3733out:
3734	extent_changeset_release(&changeset);
3735	return ret;
3736}
3737
3738static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
3739			struct extent_changeset *reserved, u64 start, u64 len,
3740			int free)
3741{
3742	struct extent_changeset changeset;
3743	int trace_op = QGROUP_RELEASE;
3744	int ret;
3745
3746	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &inode->root->fs_info->flags))
3747		return 0;
3748
3749	/* In release case, we shouldn't have @reserved */
3750	WARN_ON(!free && reserved);
3751	if (free && reserved)
3752		return qgroup_free_reserved_data(inode, reserved, start, len);
3753	extent_changeset_init(&changeset);
3754	ret = clear_record_extent_bits(&inode->io_tree, start, start + len -1,
3755				       EXTENT_QGROUP_RESERVED, &changeset);
3756	if (ret < 0)
3757		goto out;
3758
3759	if (free)
3760		trace_op = QGROUP_FREE;
3761	trace_btrfs_qgroup_release_data(&inode->vfs_inode, start, len,
3762					changeset.bytes_changed, trace_op);
3763	if (free)
3764		btrfs_qgroup_free_refroot(inode->root->fs_info,
3765				inode->root->root_key.objectid,
3766				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3767	ret = changeset.bytes_changed;
3768out:
3769	extent_changeset_release(&changeset);
3770	return ret;
3771}
3772
3773/*
3774 * Free a reserved space range from io_tree and related qgroups
3775 *
3776 * Should be called when a range of pages get invalidated before reaching disk.
3777 * Or for error cleanup case.
3778 * if @reserved is given, only reserved range in [@start, @start + @len) will
3779 * be freed.
3780 *
3781 * For data written to disk, use btrfs_qgroup_release_data().
3782 *
3783 * NOTE: This function may sleep for memory allocation.
3784 */
3785int btrfs_qgroup_free_data(struct btrfs_inode *inode,
3786			struct extent_changeset *reserved, u64 start, u64 len)
3787{
3788	return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3789}
3790
3791/*
3792 * Release a reserved space range from io_tree only.
3793 *
3794 * Should be called when a range of pages get written to disk and corresponding
3795 * FILE_EXTENT is inserted into corresponding root.
3796 *
3797 * Since new qgroup accounting framework will only update qgroup numbers at
3798 * commit_transaction() time, its reserved space shouldn't be freed from
3799 * related qgroups.
3800 *
3801 * But we should release the range from io_tree, to allow further write to be
3802 * COWed.
3803 *
3804 * NOTE: This function may sleep for memory allocation.
3805 */
3806int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len)
3807{
3808	return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3809}
3810
3811static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3812			      enum btrfs_qgroup_rsv_type type)
3813{
3814	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3815	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3816		return;
3817	if (num_bytes == 0)
3818		return;
3819
3820	spin_lock(&root->qgroup_meta_rsv_lock);
3821	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3822		root->qgroup_meta_rsv_prealloc += num_bytes;
3823	else
3824		root->qgroup_meta_rsv_pertrans += num_bytes;
3825	spin_unlock(&root->qgroup_meta_rsv_lock);
3826}
3827
3828static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3829			     enum btrfs_qgroup_rsv_type type)
3830{
3831	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3832	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3833		return 0;
3834	if (num_bytes == 0)
3835		return 0;
3836
3837	spin_lock(&root->qgroup_meta_rsv_lock);
3838	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3839		num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3840				  num_bytes);
3841		root->qgroup_meta_rsv_prealloc -= num_bytes;
3842	} else {
3843		num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3844				  num_bytes);
3845		root->qgroup_meta_rsv_pertrans -= num_bytes;
3846	}
3847	spin_unlock(&root->qgroup_meta_rsv_lock);
3848	return num_bytes;
3849}
3850
3851int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3852			      enum btrfs_qgroup_rsv_type type, bool enforce)
3853{
3854	struct btrfs_fs_info *fs_info = root->fs_info;
3855	int ret;
3856
3857	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3858	    !is_fstree(root->root_key.objectid) || num_bytes == 0)
3859		return 0;
3860
3861	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3862	trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
3863	ret = qgroup_reserve(root, num_bytes, enforce, type);
3864	if (ret < 0)
3865		return ret;
3866	/*
3867	 * Record what we have reserved into root.
3868	 *
3869	 * To avoid quota disabled->enabled underflow.
3870	 * In that case, we may try to free space we haven't reserved
3871	 * (since quota was disabled), so record what we reserved into root.
3872	 * And ensure later release won't underflow this number.
3873	 */
3874	add_root_meta_rsv(root, num_bytes, type);
3875	return ret;
3876}
3877
3878int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3879				enum btrfs_qgroup_rsv_type type, bool enforce)
 
3880{
3881	int ret;
3882
3883	ret = btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
3884	if (ret <= 0 && ret != -EDQUOT)
3885		return ret;
3886
3887	ret = try_flush_qgroup(root);
3888	if (ret < 0)
3889		return ret;
3890	return btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
3891}
3892
3893void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
3894{
3895	struct btrfs_fs_info *fs_info = root->fs_info;
3896
3897	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3898	    !is_fstree(root->root_key.objectid))
3899		return;
3900
3901	/* TODO: Update trace point to handle such free */
3902	trace_qgroup_meta_free_all_pertrans(root);
3903	/* Special value -1 means to free all reserved space */
3904	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
3905				  BTRFS_QGROUP_RSV_META_PERTRANS);
3906}
3907
3908void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
3909			      enum btrfs_qgroup_rsv_type type)
3910{
3911	struct btrfs_fs_info *fs_info = root->fs_info;
3912
3913	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3914	    !is_fstree(root->root_key.objectid))
3915		return;
3916
3917	/*
3918	 * reservation for META_PREALLOC can happen before quota is enabled,
3919	 * which can lead to underflow.
3920	 * Here ensure we will only free what we really have reserved.
3921	 */
3922	num_bytes = sub_root_meta_rsv(root, num_bytes, type);
3923	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3924	trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
3925	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
3926				  num_bytes, type);
3927}
3928
3929static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
3930				int num_bytes)
3931{
3932	struct btrfs_qgroup *qgroup;
3933	struct ulist_node *unode;
3934	struct ulist_iterator uiter;
3935	int ret = 0;
3936
3937	if (num_bytes == 0)
3938		return;
3939	if (!fs_info->quota_root)
3940		return;
3941
3942	spin_lock(&fs_info->qgroup_lock);
3943	qgroup = find_qgroup_rb(fs_info, ref_root);
3944	if (!qgroup)
3945		goto out;
3946	ulist_reinit(fs_info->qgroup_ulist);
3947	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3948		       qgroup_to_aux(qgroup), GFP_ATOMIC);
3949	if (ret < 0)
3950		goto out;
3951	ULIST_ITER_INIT(&uiter);
3952	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3953		struct btrfs_qgroup *qg;
3954		struct btrfs_qgroup_list *glist;
3955
3956		qg = unode_aux_to_qgroup(unode);
3957
3958		qgroup_rsv_release(fs_info, qg, num_bytes,
3959				BTRFS_QGROUP_RSV_META_PREALLOC);
3960		qgroup_rsv_add(fs_info, qg, num_bytes,
3961				BTRFS_QGROUP_RSV_META_PERTRANS);
3962		list_for_each_entry(glist, &qg->groups, next_group) {
3963			ret = ulist_add(fs_info->qgroup_ulist,
3964					glist->group->qgroupid,
3965					qgroup_to_aux(glist->group), GFP_ATOMIC);
3966			if (ret < 0)
3967				goto out;
3968		}
3969	}
3970out:
3971	spin_unlock(&fs_info->qgroup_lock);
3972}
3973
3974void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
3975{
3976	struct btrfs_fs_info *fs_info = root->fs_info;
3977
3978	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3979	    !is_fstree(root->root_key.objectid))
3980		return;
3981	/* Same as btrfs_qgroup_free_meta_prealloc() */
3982	num_bytes = sub_root_meta_rsv(root, num_bytes,
3983				      BTRFS_QGROUP_RSV_META_PREALLOC);
3984	trace_qgroup_meta_convert(root, num_bytes);
3985	qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
3986}
3987
3988/*
3989 * Check qgroup reserved space leaking, normally at destroy inode
3990 * time
3991 */
3992void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode)
3993{
3994	struct extent_changeset changeset;
3995	struct ulist_node *unode;
3996	struct ulist_iterator iter;
3997	int ret;
3998
3999	extent_changeset_init(&changeset);
4000	ret = clear_record_extent_bits(&inode->io_tree, 0, (u64)-1,
4001			EXTENT_QGROUP_RESERVED, &changeset);
4002
4003	WARN_ON(ret < 0);
4004	if (WARN_ON(changeset.bytes_changed)) {
4005		ULIST_ITER_INIT(&iter);
4006		while ((unode = ulist_next(&changeset.range_changed, &iter))) {
4007			btrfs_warn(inode->root->fs_info,
4008		"leaking qgroup reserved space, ino: %llu, start: %llu, end: %llu",
4009				btrfs_ino(inode), unode->val, unode->aux);
4010		}
4011		btrfs_qgroup_free_refroot(inode->root->fs_info,
4012				inode->root->root_key.objectid,
4013				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
4014
4015	}
4016	extent_changeset_release(&changeset);
4017}
4018
4019void btrfs_qgroup_init_swapped_blocks(
4020	struct btrfs_qgroup_swapped_blocks *swapped_blocks)
4021{
4022	int i;
4023
4024	spin_lock_init(&swapped_blocks->lock);
4025	for (i = 0; i < BTRFS_MAX_LEVEL; i++)
4026		swapped_blocks->blocks[i] = RB_ROOT;
4027	swapped_blocks->swapped = false;
4028}
4029
4030/*
4031 * Delete all swapped blocks record of @root.
4032 * Every record here means we skipped a full subtree scan for qgroup.
4033 *
4034 * Gets called when committing one transaction.
4035 */
4036void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
4037{
4038	struct btrfs_qgroup_swapped_blocks *swapped_blocks;
4039	int i;
4040
4041	swapped_blocks = &root->swapped_blocks;
4042
4043	spin_lock(&swapped_blocks->lock);
4044	if (!swapped_blocks->swapped)
4045		goto out;
4046	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4047		struct rb_root *cur_root = &swapped_blocks->blocks[i];
4048		struct btrfs_qgroup_swapped_block *entry;
4049		struct btrfs_qgroup_swapped_block *next;
4050
4051		rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
4052						     node)
4053			kfree(entry);
4054		swapped_blocks->blocks[i] = RB_ROOT;
4055	}
4056	swapped_blocks->swapped = false;
4057out:
4058	spin_unlock(&swapped_blocks->lock);
4059}
4060
4061/*
4062 * Add subtree roots record into @subvol_root.
4063 *
4064 * @subvol_root:	tree root of the subvolume tree get swapped
4065 * @bg:			block group under balance
4066 * @subvol_parent/slot:	pointer to the subtree root in subvolume tree
4067 * @reloc_parent/slot:	pointer to the subtree root in reloc tree
4068 *			BOTH POINTERS ARE BEFORE TREE SWAP
4069 * @last_snapshot:	last snapshot generation of the subvolume tree
4070 */
4071int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
4072		struct btrfs_root *subvol_root,
4073		struct btrfs_block_group *bg,
4074		struct extent_buffer *subvol_parent, int subvol_slot,
4075		struct extent_buffer *reloc_parent, int reloc_slot,
4076		u64 last_snapshot)
4077{
4078	struct btrfs_fs_info *fs_info = subvol_root->fs_info;
4079	struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
4080	struct btrfs_qgroup_swapped_block *block;
4081	struct rb_node **cur;
4082	struct rb_node *parent = NULL;
4083	int level = btrfs_header_level(subvol_parent) - 1;
4084	int ret = 0;
4085
4086	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4087		return 0;
4088
4089	if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
4090	    btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
4091		btrfs_err_rl(fs_info,
4092		"%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
4093			__func__,
4094			btrfs_node_ptr_generation(subvol_parent, subvol_slot),
4095			btrfs_node_ptr_generation(reloc_parent, reloc_slot));
4096		return -EUCLEAN;
4097	}
4098
4099	block = kmalloc(sizeof(*block), GFP_NOFS);
4100	if (!block) {
4101		ret = -ENOMEM;
4102		goto out;
4103	}
4104
4105	/*
4106	 * @reloc_parent/slot is still before swap, while @block is going to
4107	 * record the bytenr after swap, so we do the swap here.
4108	 */
4109	block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
4110	block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
4111							     reloc_slot);
4112	block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
4113	block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
4114							    subvol_slot);
4115	block->last_snapshot = last_snapshot;
4116	block->level = level;
4117
4118	/*
4119	 * If we have bg == NULL, we're called from btrfs_recover_relocation(),
4120	 * no one else can modify tree blocks thus we qgroup will not change
4121	 * no matter the value of trace_leaf.
4122	 */
4123	if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
4124		block->trace_leaf = true;
4125	else
4126		block->trace_leaf = false;
4127	btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
4128
4129	/* Insert @block into @blocks */
4130	spin_lock(&blocks->lock);
4131	cur = &blocks->blocks[level].rb_node;
4132	while (*cur) {
4133		struct btrfs_qgroup_swapped_block *entry;
4134
4135		parent = *cur;
4136		entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
4137				 node);
4138
4139		if (entry->subvol_bytenr < block->subvol_bytenr) {
4140			cur = &(*cur)->rb_left;
4141		} else if (entry->subvol_bytenr > block->subvol_bytenr) {
4142			cur = &(*cur)->rb_right;
4143		} else {
4144			if (entry->subvol_generation !=
4145					block->subvol_generation ||
4146			    entry->reloc_bytenr != block->reloc_bytenr ||
4147			    entry->reloc_generation !=
4148					block->reloc_generation) {
4149				/*
4150				 * Duplicated but mismatch entry found.
4151				 * Shouldn't happen.
4152				 *
4153				 * Marking qgroup inconsistent should be enough
4154				 * for end users.
4155				 */
4156				WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4157				ret = -EEXIST;
4158			}
4159			kfree(block);
4160			goto out_unlock;
4161		}
4162	}
4163	rb_link_node(&block->node, parent, cur);
4164	rb_insert_color(&block->node, &blocks->blocks[level]);
4165	blocks->swapped = true;
4166out_unlock:
4167	spin_unlock(&blocks->lock);
4168out:
4169	if (ret < 0)
4170		fs_info->qgroup_flags |=
4171			BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
4172	return ret;
4173}
4174
4175/*
4176 * Check if the tree block is a subtree root, and if so do the needed
4177 * delayed subtree trace for qgroup.
4178 *
4179 * This is called during btrfs_cow_block().
4180 */
4181int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
4182					 struct btrfs_root *root,
4183					 struct extent_buffer *subvol_eb)
4184{
4185	struct btrfs_fs_info *fs_info = root->fs_info;
 
4186	struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
4187	struct btrfs_qgroup_swapped_block *block;
4188	struct extent_buffer *reloc_eb = NULL;
4189	struct rb_node *node;
4190	bool found = false;
4191	bool swapped = false;
4192	int level = btrfs_header_level(subvol_eb);
4193	int ret = 0;
4194	int i;
4195
4196	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4197		return 0;
4198	if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
4199		return 0;
4200
4201	spin_lock(&blocks->lock);
4202	if (!blocks->swapped) {
4203		spin_unlock(&blocks->lock);
4204		return 0;
4205	}
4206	node = blocks->blocks[level].rb_node;
4207
4208	while (node) {
4209		block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
4210		if (block->subvol_bytenr < subvol_eb->start) {
4211			node = node->rb_left;
4212		} else if (block->subvol_bytenr > subvol_eb->start) {
4213			node = node->rb_right;
4214		} else {
4215			found = true;
4216			break;
4217		}
4218	}
4219	if (!found) {
4220		spin_unlock(&blocks->lock);
4221		goto out;
4222	}
4223	/* Found one, remove it from @blocks first and update blocks->swapped */
4224	rb_erase(&block->node, &blocks->blocks[level]);
4225	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4226		if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
4227			swapped = true;
4228			break;
4229		}
4230	}
4231	blocks->swapped = swapped;
4232	spin_unlock(&blocks->lock);
4233
 
 
 
 
 
4234	/* Read out reloc subtree root */
4235	reloc_eb = read_tree_block(fs_info, block->reloc_bytenr, 0,
4236				   block->reloc_generation, block->level,
4237				   &block->first_key);
4238	if (IS_ERR(reloc_eb)) {
4239		ret = PTR_ERR(reloc_eb);
4240		reloc_eb = NULL;
4241		goto free_out;
4242	}
4243	if (!extent_buffer_uptodate(reloc_eb)) {
4244		ret = -EIO;
4245		goto free_out;
4246	}
4247
4248	ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
4249			block->last_snapshot, block->trace_leaf);
4250free_out:
4251	kfree(block);
4252	free_extent_buffer(reloc_eb);
4253out:
4254	if (ret < 0) {
4255		btrfs_err_rl(fs_info,
4256			     "failed to account subtree at bytenr %llu: %d",
4257			     subvol_eb->start, ret);
4258		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
4259	}
4260	return ret;
4261}
4262
4263void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans)
4264{
4265	struct btrfs_qgroup_extent_record *entry;
4266	struct btrfs_qgroup_extent_record *next;
4267	struct rb_root *root;
4268
4269	root = &trans->delayed_refs.dirty_extent_root;
4270	rbtree_postorder_for_each_entry_safe(entry, next, root, node) {
4271		ulist_free(entry->old_roots);
4272		kfree(entry);
4273	}
4274}