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