xref: /openbmc/linux/fs/btrfs/qgroup.c (revision 2e554390)
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 
24 
25 /* TODO XXX FIXME
26  *  - subvol delete -> delete when ref goes to 0? delete limits also?
27  *  - reorganize keys
28  *  - compressed
29  *  - sync
30  *  - copy also limits on subvol creation
31  *  - limit
32  *  - caches fuer ulists
33  *  - performance benchmarks
34  *  - check all ioctl parameters
35  */
36 
37 /*
38  * Helpers to access qgroup reservation
39  *
40  * Callers should ensure the lock context and type are valid
41  */
42 
43 static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
44 {
45 	u64 ret = 0;
46 	int i;
47 
48 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
49 		ret += qgroup->rsv.values[i];
50 
51 	return ret;
52 }
53 
54 #ifdef CONFIG_BTRFS_DEBUG
55 static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
56 {
57 	if (type == BTRFS_QGROUP_RSV_DATA)
58 		return "data";
59 	if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
60 		return "meta_pertrans";
61 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
62 		return "meta_prealloc";
63 	return NULL;
64 }
65 #endif
66 
67 static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
68 			   struct btrfs_qgroup *qgroup, u64 num_bytes,
69 			   enum btrfs_qgroup_rsv_type type)
70 {
71 	trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
72 	qgroup->rsv.values[type] += num_bytes;
73 }
74 
75 static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
76 			       struct btrfs_qgroup *qgroup, u64 num_bytes,
77 			       enum btrfs_qgroup_rsv_type type)
78 {
79 	trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
80 	if (qgroup->rsv.values[type] >= num_bytes) {
81 		qgroup->rsv.values[type] -= num_bytes;
82 		return;
83 	}
84 #ifdef CONFIG_BTRFS_DEBUG
85 	WARN_RATELIMIT(1,
86 		"qgroup %llu %s reserved space underflow, have %llu to free %llu",
87 		qgroup->qgroupid, qgroup_rsv_type_str(type),
88 		qgroup->rsv.values[type], num_bytes);
89 #endif
90 	qgroup->rsv.values[type] = 0;
91 }
92 
93 static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
94 				     struct btrfs_qgroup *dest,
95 				     struct btrfs_qgroup *src)
96 {
97 	int i;
98 
99 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
100 		qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
101 }
102 
103 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
104 					 struct btrfs_qgroup *dest,
105 					  struct btrfs_qgroup *src)
106 {
107 	int i;
108 
109 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
110 		qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
111 }
112 
113 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
114 					   int mod)
115 {
116 	if (qg->old_refcnt < seq)
117 		qg->old_refcnt = seq;
118 	qg->old_refcnt += mod;
119 }
120 
121 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
122 					   int mod)
123 {
124 	if (qg->new_refcnt < seq)
125 		qg->new_refcnt = seq;
126 	qg->new_refcnt += mod;
127 }
128 
129 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
130 {
131 	if (qg->old_refcnt < seq)
132 		return 0;
133 	return qg->old_refcnt - seq;
134 }
135 
136 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
137 {
138 	if (qg->new_refcnt < seq)
139 		return 0;
140 	return qg->new_refcnt - seq;
141 }
142 
143 /*
144  * glue structure to represent the relations between qgroups.
145  */
146 struct btrfs_qgroup_list {
147 	struct list_head next_group;
148 	struct list_head next_member;
149 	struct btrfs_qgroup *group;
150 	struct btrfs_qgroup *member;
151 };
152 
153 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
154 {
155 	return (u64)(uintptr_t)qg;
156 }
157 
158 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
159 {
160 	return (struct btrfs_qgroup *)(uintptr_t)n->aux;
161 }
162 
163 static int
164 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
165 		   int init_flags);
166 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
167 
168 /* must be called with qgroup_ioctl_lock held */
169 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
170 					   u64 qgroupid)
171 {
172 	struct rb_node *n = fs_info->qgroup_tree.rb_node;
173 	struct btrfs_qgroup *qgroup;
174 
175 	while (n) {
176 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
177 		if (qgroup->qgroupid < qgroupid)
178 			n = n->rb_left;
179 		else if (qgroup->qgroupid > qgroupid)
180 			n = n->rb_right;
181 		else
182 			return qgroup;
183 	}
184 	return NULL;
185 }
186 
187 /* must be called with qgroup_lock held */
188 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
189 					  u64 qgroupid)
190 {
191 	struct rb_node **p = &fs_info->qgroup_tree.rb_node;
192 	struct rb_node *parent = NULL;
193 	struct btrfs_qgroup *qgroup;
194 
195 	while (*p) {
196 		parent = *p;
197 		qgroup = rb_entry(parent, struct btrfs_qgroup, node);
198 
199 		if (qgroup->qgroupid < qgroupid)
200 			p = &(*p)->rb_left;
201 		else if (qgroup->qgroupid > qgroupid)
202 			p = &(*p)->rb_right;
203 		else
204 			return qgroup;
205 	}
206 
207 	qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
208 	if (!qgroup)
209 		return ERR_PTR(-ENOMEM);
210 
211 	qgroup->qgroupid = qgroupid;
212 	INIT_LIST_HEAD(&qgroup->groups);
213 	INIT_LIST_HEAD(&qgroup->members);
214 	INIT_LIST_HEAD(&qgroup->dirty);
215 
216 	rb_link_node(&qgroup->node, parent, p);
217 	rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
218 
219 	return qgroup;
220 }
221 
222 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
223 {
224 	struct btrfs_qgroup_list *list;
225 
226 	list_del(&qgroup->dirty);
227 	while (!list_empty(&qgroup->groups)) {
228 		list = list_first_entry(&qgroup->groups,
229 					struct btrfs_qgroup_list, next_group);
230 		list_del(&list->next_group);
231 		list_del(&list->next_member);
232 		kfree(list);
233 	}
234 
235 	while (!list_empty(&qgroup->members)) {
236 		list = list_first_entry(&qgroup->members,
237 					struct btrfs_qgroup_list, next_member);
238 		list_del(&list->next_group);
239 		list_del(&list->next_member);
240 		kfree(list);
241 	}
242 	kfree(qgroup);
243 }
244 
245 /* must be called with qgroup_lock held */
246 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
247 {
248 	struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
249 
250 	if (!qgroup)
251 		return -ENOENT;
252 
253 	rb_erase(&qgroup->node, &fs_info->qgroup_tree);
254 	__del_qgroup_rb(qgroup);
255 	return 0;
256 }
257 
258 /* must be called with qgroup_lock held */
259 static int add_relation_rb(struct btrfs_fs_info *fs_info,
260 			   u64 memberid, u64 parentid)
261 {
262 	struct btrfs_qgroup *member;
263 	struct btrfs_qgroup *parent;
264 	struct btrfs_qgroup_list *list;
265 
266 	member = find_qgroup_rb(fs_info, memberid);
267 	parent = find_qgroup_rb(fs_info, parentid);
268 	if (!member || !parent)
269 		return -ENOENT;
270 
271 	list = kzalloc(sizeof(*list), GFP_ATOMIC);
272 	if (!list)
273 		return -ENOMEM;
274 
275 	list->group = parent;
276 	list->member = member;
277 	list_add_tail(&list->next_group, &member->groups);
278 	list_add_tail(&list->next_member, &parent->members);
279 
280 	return 0;
281 }
282 
283 /* must be called with qgroup_lock held */
284 static int del_relation_rb(struct btrfs_fs_info *fs_info,
285 			   u64 memberid, u64 parentid)
286 {
287 	struct btrfs_qgroup *member;
288 	struct btrfs_qgroup *parent;
289 	struct btrfs_qgroup_list *list;
290 
291 	member = find_qgroup_rb(fs_info, memberid);
292 	parent = find_qgroup_rb(fs_info, parentid);
293 	if (!member || !parent)
294 		return -ENOENT;
295 
296 	list_for_each_entry(list, &member->groups, next_group) {
297 		if (list->group == parent) {
298 			list_del(&list->next_group);
299 			list_del(&list->next_member);
300 			kfree(list);
301 			return 0;
302 		}
303 	}
304 	return -ENOENT;
305 }
306 
307 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
308 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
309 			       u64 rfer, u64 excl)
310 {
311 	struct btrfs_qgroup *qgroup;
312 
313 	qgroup = find_qgroup_rb(fs_info, qgroupid);
314 	if (!qgroup)
315 		return -EINVAL;
316 	if (qgroup->rfer != rfer || qgroup->excl != excl)
317 		return -EINVAL;
318 	return 0;
319 }
320 #endif
321 
322 /*
323  * The full config is read in one go, only called from open_ctree()
324  * It doesn't use any locking, as at this point we're still single-threaded
325  */
326 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
327 {
328 	struct btrfs_key key;
329 	struct btrfs_key found_key;
330 	struct btrfs_root *quota_root = fs_info->quota_root;
331 	struct btrfs_path *path = NULL;
332 	struct extent_buffer *l;
333 	int slot;
334 	int ret = 0;
335 	u64 flags = 0;
336 	u64 rescan_progress = 0;
337 
338 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
339 		return 0;
340 
341 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
342 	if (!fs_info->qgroup_ulist) {
343 		ret = -ENOMEM;
344 		goto out;
345 	}
346 
347 	path = btrfs_alloc_path();
348 	if (!path) {
349 		ret = -ENOMEM;
350 		goto out;
351 	}
352 
353 	/* default this to quota off, in case no status key is found */
354 	fs_info->qgroup_flags = 0;
355 
356 	/*
357 	 * pass 1: read status, all qgroup infos and limits
358 	 */
359 	key.objectid = 0;
360 	key.type = 0;
361 	key.offset = 0;
362 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
363 	if (ret)
364 		goto out;
365 
366 	while (1) {
367 		struct btrfs_qgroup *qgroup;
368 
369 		slot = path->slots[0];
370 		l = path->nodes[0];
371 		btrfs_item_key_to_cpu(l, &found_key, slot);
372 
373 		if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
374 			struct btrfs_qgroup_status_item *ptr;
375 
376 			ptr = btrfs_item_ptr(l, slot,
377 					     struct btrfs_qgroup_status_item);
378 
379 			if (btrfs_qgroup_status_version(l, ptr) !=
380 			    BTRFS_QGROUP_STATUS_VERSION) {
381 				btrfs_err(fs_info,
382 				 "old qgroup version, quota disabled");
383 				goto out;
384 			}
385 			if (btrfs_qgroup_status_generation(l, ptr) !=
386 			    fs_info->generation) {
387 				flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
388 				btrfs_err(fs_info,
389 					"qgroup generation mismatch, marked as inconsistent");
390 			}
391 			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
392 									  ptr);
393 			rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
394 			goto next1;
395 		}
396 
397 		if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
398 		    found_key.type != BTRFS_QGROUP_LIMIT_KEY)
399 			goto next1;
400 
401 		qgroup = find_qgroup_rb(fs_info, found_key.offset);
402 		if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
403 		    (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
404 			btrfs_err(fs_info, "inconsistent qgroup config");
405 			flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
406 		}
407 		if (!qgroup) {
408 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
409 			if (IS_ERR(qgroup)) {
410 				ret = PTR_ERR(qgroup);
411 				goto out;
412 			}
413 		}
414 		switch (found_key.type) {
415 		case BTRFS_QGROUP_INFO_KEY: {
416 			struct btrfs_qgroup_info_item *ptr;
417 
418 			ptr = btrfs_item_ptr(l, slot,
419 					     struct btrfs_qgroup_info_item);
420 			qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
421 			qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
422 			qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
423 			qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
424 			/* generation currently unused */
425 			break;
426 		}
427 		case BTRFS_QGROUP_LIMIT_KEY: {
428 			struct btrfs_qgroup_limit_item *ptr;
429 
430 			ptr = btrfs_item_ptr(l, slot,
431 					     struct btrfs_qgroup_limit_item);
432 			qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
433 			qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
434 			qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
435 			qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
436 			qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
437 			break;
438 		}
439 		}
440 next1:
441 		ret = btrfs_next_item(quota_root, path);
442 		if (ret < 0)
443 			goto out;
444 		if (ret)
445 			break;
446 	}
447 	btrfs_release_path(path);
448 
449 	/*
450 	 * pass 2: read all qgroup relations
451 	 */
452 	key.objectid = 0;
453 	key.type = BTRFS_QGROUP_RELATION_KEY;
454 	key.offset = 0;
455 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
456 	if (ret)
457 		goto out;
458 	while (1) {
459 		slot = path->slots[0];
460 		l = path->nodes[0];
461 		btrfs_item_key_to_cpu(l, &found_key, slot);
462 
463 		if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
464 			goto next2;
465 
466 		if (found_key.objectid > found_key.offset) {
467 			/* parent <- member, not needed to build config */
468 			/* FIXME should we omit the key completely? */
469 			goto next2;
470 		}
471 
472 		ret = add_relation_rb(fs_info, found_key.objectid,
473 				      found_key.offset);
474 		if (ret == -ENOENT) {
475 			btrfs_warn(fs_info,
476 				"orphan qgroup relation 0x%llx->0x%llx",
477 				found_key.objectid, found_key.offset);
478 			ret = 0;	/* ignore the error */
479 		}
480 		if (ret)
481 			goto out;
482 next2:
483 		ret = btrfs_next_item(quota_root, path);
484 		if (ret < 0)
485 			goto out;
486 		if (ret)
487 			break;
488 	}
489 out:
490 	fs_info->qgroup_flags |= flags;
491 	if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
492 		clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
493 	else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
494 		 ret >= 0)
495 		ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
496 	btrfs_free_path(path);
497 
498 	if (ret < 0) {
499 		ulist_free(fs_info->qgroup_ulist);
500 		fs_info->qgroup_ulist = NULL;
501 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
502 	}
503 
504 	return ret < 0 ? ret : 0;
505 }
506 
507 /*
508  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
509  * first two are in single-threaded paths.And for the third one, we have set
510  * quota_root to be null with qgroup_lock held before, so it is safe to clean
511  * up the in-memory structures without qgroup_lock held.
512  */
513 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
514 {
515 	struct rb_node *n;
516 	struct btrfs_qgroup *qgroup;
517 
518 	while ((n = rb_first(&fs_info->qgroup_tree))) {
519 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
520 		rb_erase(n, &fs_info->qgroup_tree);
521 		__del_qgroup_rb(qgroup);
522 	}
523 	/*
524 	 * we call btrfs_free_qgroup_config() when umounting
525 	 * filesystem and disabling quota, so we set qgroup_ulist
526 	 * to be null here to avoid double free.
527 	 */
528 	ulist_free(fs_info->qgroup_ulist);
529 	fs_info->qgroup_ulist = NULL;
530 }
531 
532 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
533 				    struct btrfs_root *quota_root,
534 				    u64 src, u64 dst)
535 {
536 	int ret;
537 	struct btrfs_path *path;
538 	struct btrfs_key key;
539 
540 	path = btrfs_alloc_path();
541 	if (!path)
542 		return -ENOMEM;
543 
544 	key.objectid = src;
545 	key.type = BTRFS_QGROUP_RELATION_KEY;
546 	key.offset = dst;
547 
548 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
549 
550 	btrfs_mark_buffer_dirty(path->nodes[0]);
551 
552 	btrfs_free_path(path);
553 	return ret;
554 }
555 
556 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
557 				    struct btrfs_root *quota_root,
558 				    u64 src, u64 dst)
559 {
560 	int ret;
561 	struct btrfs_path *path;
562 	struct btrfs_key key;
563 
564 	path = btrfs_alloc_path();
565 	if (!path)
566 		return -ENOMEM;
567 
568 	key.objectid = src;
569 	key.type = BTRFS_QGROUP_RELATION_KEY;
570 	key.offset = dst;
571 
572 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
573 	if (ret < 0)
574 		goto out;
575 
576 	if (ret > 0) {
577 		ret = -ENOENT;
578 		goto out;
579 	}
580 
581 	ret = btrfs_del_item(trans, quota_root, path);
582 out:
583 	btrfs_free_path(path);
584 	return ret;
585 }
586 
587 static int add_qgroup_item(struct btrfs_trans_handle *trans,
588 			   struct btrfs_root *quota_root, u64 qgroupid)
589 {
590 	int ret;
591 	struct btrfs_path *path;
592 	struct btrfs_qgroup_info_item *qgroup_info;
593 	struct btrfs_qgroup_limit_item *qgroup_limit;
594 	struct extent_buffer *leaf;
595 	struct btrfs_key key;
596 
597 	if (btrfs_is_testing(quota_root->fs_info))
598 		return 0;
599 
600 	path = btrfs_alloc_path();
601 	if (!path)
602 		return -ENOMEM;
603 
604 	key.objectid = 0;
605 	key.type = BTRFS_QGROUP_INFO_KEY;
606 	key.offset = qgroupid;
607 
608 	/*
609 	 * Avoid a transaction abort by catching -EEXIST here. In that
610 	 * case, we proceed by re-initializing the existing structure
611 	 * on disk.
612 	 */
613 
614 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
615 				      sizeof(*qgroup_info));
616 	if (ret && ret != -EEXIST)
617 		goto out;
618 
619 	leaf = path->nodes[0];
620 	qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
621 				 struct btrfs_qgroup_info_item);
622 	btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
623 	btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
624 	btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
625 	btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
626 	btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
627 
628 	btrfs_mark_buffer_dirty(leaf);
629 
630 	btrfs_release_path(path);
631 
632 	key.type = BTRFS_QGROUP_LIMIT_KEY;
633 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
634 				      sizeof(*qgroup_limit));
635 	if (ret && ret != -EEXIST)
636 		goto out;
637 
638 	leaf = path->nodes[0];
639 	qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
640 				  struct btrfs_qgroup_limit_item);
641 	btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
642 	btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
643 	btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
644 	btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
645 	btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
646 
647 	btrfs_mark_buffer_dirty(leaf);
648 
649 	ret = 0;
650 out:
651 	btrfs_free_path(path);
652 	return ret;
653 }
654 
655 static int del_qgroup_item(struct btrfs_trans_handle *trans,
656 			   struct btrfs_root *quota_root, u64 qgroupid)
657 {
658 	int ret;
659 	struct btrfs_path *path;
660 	struct btrfs_key key;
661 
662 	path = btrfs_alloc_path();
663 	if (!path)
664 		return -ENOMEM;
665 
666 	key.objectid = 0;
667 	key.type = BTRFS_QGROUP_INFO_KEY;
668 	key.offset = qgroupid;
669 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
670 	if (ret < 0)
671 		goto out;
672 
673 	if (ret > 0) {
674 		ret = -ENOENT;
675 		goto out;
676 	}
677 
678 	ret = btrfs_del_item(trans, quota_root, path);
679 	if (ret)
680 		goto out;
681 
682 	btrfs_release_path(path);
683 
684 	key.type = BTRFS_QGROUP_LIMIT_KEY;
685 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
686 	if (ret < 0)
687 		goto out;
688 
689 	if (ret > 0) {
690 		ret = -ENOENT;
691 		goto out;
692 	}
693 
694 	ret = btrfs_del_item(trans, quota_root, path);
695 
696 out:
697 	btrfs_free_path(path);
698 	return ret;
699 }
700 
701 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
702 				    struct btrfs_root *root,
703 				    struct btrfs_qgroup *qgroup)
704 {
705 	struct btrfs_path *path;
706 	struct btrfs_key key;
707 	struct extent_buffer *l;
708 	struct btrfs_qgroup_limit_item *qgroup_limit;
709 	int ret;
710 	int slot;
711 
712 	key.objectid = 0;
713 	key.type = BTRFS_QGROUP_LIMIT_KEY;
714 	key.offset = qgroup->qgroupid;
715 
716 	path = btrfs_alloc_path();
717 	if (!path)
718 		return -ENOMEM;
719 
720 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
721 	if (ret > 0)
722 		ret = -ENOENT;
723 
724 	if (ret)
725 		goto out;
726 
727 	l = path->nodes[0];
728 	slot = path->slots[0];
729 	qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
730 	btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
731 	btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
732 	btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
733 	btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
734 	btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
735 
736 	btrfs_mark_buffer_dirty(l);
737 
738 out:
739 	btrfs_free_path(path);
740 	return ret;
741 }
742 
743 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
744 				   struct btrfs_root *root,
745 				   struct btrfs_qgroup *qgroup)
746 {
747 	struct btrfs_path *path;
748 	struct btrfs_key key;
749 	struct extent_buffer *l;
750 	struct btrfs_qgroup_info_item *qgroup_info;
751 	int ret;
752 	int slot;
753 
754 	if (btrfs_is_testing(root->fs_info))
755 		return 0;
756 
757 	key.objectid = 0;
758 	key.type = BTRFS_QGROUP_INFO_KEY;
759 	key.offset = qgroup->qgroupid;
760 
761 	path = btrfs_alloc_path();
762 	if (!path)
763 		return -ENOMEM;
764 
765 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
766 	if (ret > 0)
767 		ret = -ENOENT;
768 
769 	if (ret)
770 		goto out;
771 
772 	l = path->nodes[0];
773 	slot = path->slots[0];
774 	qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
775 	btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
776 	btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
777 	btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
778 	btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
779 	btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
780 
781 	btrfs_mark_buffer_dirty(l);
782 
783 out:
784 	btrfs_free_path(path);
785 	return ret;
786 }
787 
788 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
789 				     struct btrfs_fs_info *fs_info,
790 				    struct btrfs_root *root)
791 {
792 	struct btrfs_path *path;
793 	struct btrfs_key key;
794 	struct extent_buffer *l;
795 	struct btrfs_qgroup_status_item *ptr;
796 	int ret;
797 	int slot;
798 
799 	key.objectid = 0;
800 	key.type = BTRFS_QGROUP_STATUS_KEY;
801 	key.offset = 0;
802 
803 	path = btrfs_alloc_path();
804 	if (!path)
805 		return -ENOMEM;
806 
807 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
808 	if (ret > 0)
809 		ret = -ENOENT;
810 
811 	if (ret)
812 		goto out;
813 
814 	l = path->nodes[0];
815 	slot = path->slots[0];
816 	ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
817 	btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
818 	btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
819 	btrfs_set_qgroup_status_rescan(l, ptr,
820 				fs_info->qgroup_rescan_progress.objectid);
821 
822 	btrfs_mark_buffer_dirty(l);
823 
824 out:
825 	btrfs_free_path(path);
826 	return ret;
827 }
828 
829 /*
830  * called with qgroup_lock held
831  */
832 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
833 				  struct btrfs_root *root)
834 {
835 	struct btrfs_path *path;
836 	struct btrfs_key key;
837 	struct extent_buffer *leaf = NULL;
838 	int ret;
839 	int nr = 0;
840 
841 	path = btrfs_alloc_path();
842 	if (!path)
843 		return -ENOMEM;
844 
845 	path->leave_spinning = 1;
846 
847 	key.objectid = 0;
848 	key.offset = 0;
849 	key.type = 0;
850 
851 	while (1) {
852 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
853 		if (ret < 0)
854 			goto out;
855 		leaf = path->nodes[0];
856 		nr = btrfs_header_nritems(leaf);
857 		if (!nr)
858 			break;
859 		/*
860 		 * delete the leaf one by one
861 		 * since the whole tree is going
862 		 * to be deleted.
863 		 */
864 		path->slots[0] = 0;
865 		ret = btrfs_del_items(trans, root, path, 0, nr);
866 		if (ret)
867 			goto out;
868 
869 		btrfs_release_path(path);
870 	}
871 	ret = 0;
872 out:
873 	btrfs_free_path(path);
874 	return ret;
875 }
876 
877 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
878 		       struct btrfs_fs_info *fs_info)
879 {
880 	struct btrfs_root *quota_root;
881 	struct btrfs_root *tree_root = fs_info->tree_root;
882 	struct btrfs_path *path = NULL;
883 	struct btrfs_qgroup_status_item *ptr;
884 	struct extent_buffer *leaf;
885 	struct btrfs_key key;
886 	struct btrfs_key found_key;
887 	struct btrfs_qgroup *qgroup = NULL;
888 	int ret = 0;
889 	int slot;
890 
891 	mutex_lock(&fs_info->qgroup_ioctl_lock);
892 	if (fs_info->quota_root)
893 		goto out;
894 
895 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
896 	if (!fs_info->qgroup_ulist) {
897 		ret = -ENOMEM;
898 		goto out;
899 	}
900 
901 	/*
902 	 * initially create the quota tree
903 	 */
904 	quota_root = btrfs_create_tree(trans, fs_info,
905 				       BTRFS_QUOTA_TREE_OBJECTID);
906 	if (IS_ERR(quota_root)) {
907 		ret =  PTR_ERR(quota_root);
908 		goto out;
909 	}
910 
911 	path = btrfs_alloc_path();
912 	if (!path) {
913 		ret = -ENOMEM;
914 		goto out_free_root;
915 	}
916 
917 	key.objectid = 0;
918 	key.type = BTRFS_QGROUP_STATUS_KEY;
919 	key.offset = 0;
920 
921 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
922 				      sizeof(*ptr));
923 	if (ret)
924 		goto out_free_path;
925 
926 	leaf = path->nodes[0];
927 	ptr = btrfs_item_ptr(leaf, path->slots[0],
928 				 struct btrfs_qgroup_status_item);
929 	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
930 	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
931 	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
932 				BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
933 	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
934 	btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
935 
936 	btrfs_mark_buffer_dirty(leaf);
937 
938 	key.objectid = 0;
939 	key.type = BTRFS_ROOT_REF_KEY;
940 	key.offset = 0;
941 
942 	btrfs_release_path(path);
943 	ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
944 	if (ret > 0)
945 		goto out_add_root;
946 	if (ret < 0)
947 		goto out_free_path;
948 
949 
950 	while (1) {
951 		slot = path->slots[0];
952 		leaf = path->nodes[0];
953 		btrfs_item_key_to_cpu(leaf, &found_key, slot);
954 
955 		if (found_key.type == BTRFS_ROOT_REF_KEY) {
956 			ret = add_qgroup_item(trans, quota_root,
957 					      found_key.offset);
958 			if (ret)
959 				goto out_free_path;
960 
961 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
962 			if (IS_ERR(qgroup)) {
963 				ret = PTR_ERR(qgroup);
964 				goto out_free_path;
965 			}
966 		}
967 		ret = btrfs_next_item(tree_root, path);
968 		if (ret < 0)
969 			goto out_free_path;
970 		if (ret)
971 			break;
972 	}
973 
974 out_add_root:
975 	btrfs_release_path(path);
976 	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
977 	if (ret)
978 		goto out_free_path;
979 
980 	qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
981 	if (IS_ERR(qgroup)) {
982 		ret = PTR_ERR(qgroup);
983 		goto out_free_path;
984 	}
985 	spin_lock(&fs_info->qgroup_lock);
986 	fs_info->quota_root = quota_root;
987 	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
988 	spin_unlock(&fs_info->qgroup_lock);
989 	ret = qgroup_rescan_init(fs_info, 0, 1);
990 	if (!ret) {
991 	        qgroup_rescan_zero_tracking(fs_info);
992 	        btrfs_queue_work(fs_info->qgroup_rescan_workers,
993 	                         &fs_info->qgroup_rescan_work);
994 	}
995 
996 out_free_path:
997 	btrfs_free_path(path);
998 out_free_root:
999 	if (ret) {
1000 		free_extent_buffer(quota_root->node);
1001 		free_extent_buffer(quota_root->commit_root);
1002 		kfree(quota_root);
1003 	}
1004 out:
1005 	if (ret) {
1006 		ulist_free(fs_info->qgroup_ulist);
1007 		fs_info->qgroup_ulist = NULL;
1008 	}
1009 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1010 	return ret;
1011 }
1012 
1013 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
1014 			struct btrfs_fs_info *fs_info)
1015 {
1016 	struct btrfs_root *quota_root;
1017 	int ret = 0;
1018 
1019 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1020 	if (!fs_info->quota_root)
1021 		goto out;
1022 	clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1023 	btrfs_qgroup_wait_for_completion(fs_info, false);
1024 	spin_lock(&fs_info->qgroup_lock);
1025 	quota_root = fs_info->quota_root;
1026 	fs_info->quota_root = NULL;
1027 	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1028 	spin_unlock(&fs_info->qgroup_lock);
1029 
1030 	btrfs_free_qgroup_config(fs_info);
1031 
1032 	ret = btrfs_clean_quota_tree(trans, quota_root);
1033 	if (ret)
1034 		goto out;
1035 
1036 	ret = btrfs_del_root(trans, fs_info, &quota_root->root_key);
1037 	if (ret)
1038 		goto out;
1039 
1040 	list_del(&quota_root->dirty_list);
1041 
1042 	btrfs_tree_lock(quota_root->node);
1043 	clean_tree_block(fs_info, quota_root->node);
1044 	btrfs_tree_unlock(quota_root->node);
1045 	btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
1046 
1047 	free_extent_buffer(quota_root->node);
1048 	free_extent_buffer(quota_root->commit_root);
1049 	kfree(quota_root);
1050 out:
1051 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1052 	return ret;
1053 }
1054 
1055 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1056 			 struct btrfs_qgroup *qgroup)
1057 {
1058 	if (list_empty(&qgroup->dirty))
1059 		list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1060 }
1061 
1062 /*
1063  * The easy accounting, we're updating qgroup relationship whose child qgroup
1064  * only has exclusive extents.
1065  *
1066  * In this case, all exclsuive extents will also be exlusive for parent, so
1067  * excl/rfer just get added/removed.
1068  *
1069  * So is qgroup reservation space, which should also be added/removed to
1070  * parent.
1071  * Or when child tries to release reservation space, parent will underflow its
1072  * reservation (for relationship adding case).
1073  *
1074  * Caller should hold fs_info->qgroup_lock.
1075  */
1076 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1077 				    struct ulist *tmp, u64 ref_root,
1078 				    struct btrfs_qgroup *src, int sign)
1079 {
1080 	struct btrfs_qgroup *qgroup;
1081 	struct btrfs_qgroup_list *glist;
1082 	struct ulist_node *unode;
1083 	struct ulist_iterator uiter;
1084 	u64 num_bytes = src->excl;
1085 	int ret = 0;
1086 
1087 	qgroup = find_qgroup_rb(fs_info, ref_root);
1088 	if (!qgroup)
1089 		goto out;
1090 
1091 	qgroup->rfer += sign * num_bytes;
1092 	qgroup->rfer_cmpr += sign * num_bytes;
1093 
1094 	WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1095 	qgroup->excl += sign * num_bytes;
1096 	qgroup->excl_cmpr += sign * num_bytes;
1097 
1098 	if (sign > 0)
1099 		qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1100 	else
1101 		qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1102 
1103 	qgroup_dirty(fs_info, qgroup);
1104 
1105 	/* Get all of the parent groups that contain this qgroup */
1106 	list_for_each_entry(glist, &qgroup->groups, next_group) {
1107 		ret = ulist_add(tmp, glist->group->qgroupid,
1108 				qgroup_to_aux(glist->group), GFP_ATOMIC);
1109 		if (ret < 0)
1110 			goto out;
1111 	}
1112 
1113 	/* Iterate all of the parents and adjust their reference counts */
1114 	ULIST_ITER_INIT(&uiter);
1115 	while ((unode = ulist_next(tmp, &uiter))) {
1116 		qgroup = unode_aux_to_qgroup(unode);
1117 		qgroup->rfer += sign * num_bytes;
1118 		qgroup->rfer_cmpr += sign * num_bytes;
1119 		WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1120 		qgroup->excl += sign * num_bytes;
1121 		if (sign > 0)
1122 			qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1123 		else
1124 			qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1125 		qgroup->excl_cmpr += sign * num_bytes;
1126 		qgroup_dirty(fs_info, qgroup);
1127 
1128 		/* Add any parents of the parents */
1129 		list_for_each_entry(glist, &qgroup->groups, next_group) {
1130 			ret = ulist_add(tmp, glist->group->qgroupid,
1131 					qgroup_to_aux(glist->group), GFP_ATOMIC);
1132 			if (ret < 0)
1133 				goto out;
1134 		}
1135 	}
1136 	ret = 0;
1137 out:
1138 	return ret;
1139 }
1140 
1141 
1142 /*
1143  * Quick path for updating qgroup with only excl refs.
1144  *
1145  * In that case, just update all parent will be enough.
1146  * Or we needs to do a full rescan.
1147  * Caller should also hold fs_info->qgroup_lock.
1148  *
1149  * Return 0 for quick update, return >0 for need to full rescan
1150  * and mark INCONSISTENT flag.
1151  * Return < 0 for other error.
1152  */
1153 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1154 				   struct ulist *tmp, u64 src, u64 dst,
1155 				   int sign)
1156 {
1157 	struct btrfs_qgroup *qgroup;
1158 	int ret = 1;
1159 	int err = 0;
1160 
1161 	qgroup = find_qgroup_rb(fs_info, src);
1162 	if (!qgroup)
1163 		goto out;
1164 	if (qgroup->excl == qgroup->rfer) {
1165 		ret = 0;
1166 		err = __qgroup_excl_accounting(fs_info, tmp, dst,
1167 					       qgroup, sign);
1168 		if (err < 0) {
1169 			ret = err;
1170 			goto out;
1171 		}
1172 	}
1173 out:
1174 	if (ret)
1175 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1176 	return ret;
1177 }
1178 
1179 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
1180 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1181 {
1182 	struct btrfs_root *quota_root;
1183 	struct btrfs_qgroup *parent;
1184 	struct btrfs_qgroup *member;
1185 	struct btrfs_qgroup_list *list;
1186 	struct ulist *tmp;
1187 	int ret = 0;
1188 
1189 	/* Check the level of src and dst first */
1190 	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1191 		return -EINVAL;
1192 
1193 	tmp = ulist_alloc(GFP_KERNEL);
1194 	if (!tmp)
1195 		return -ENOMEM;
1196 
1197 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1198 	quota_root = fs_info->quota_root;
1199 	if (!quota_root) {
1200 		ret = -EINVAL;
1201 		goto out;
1202 	}
1203 	member = find_qgroup_rb(fs_info, src);
1204 	parent = find_qgroup_rb(fs_info, dst);
1205 	if (!member || !parent) {
1206 		ret = -EINVAL;
1207 		goto out;
1208 	}
1209 
1210 	/* check if such qgroup relation exist firstly */
1211 	list_for_each_entry(list, &member->groups, next_group) {
1212 		if (list->group == parent) {
1213 			ret = -EEXIST;
1214 			goto out;
1215 		}
1216 	}
1217 
1218 	ret = add_qgroup_relation_item(trans, quota_root, src, dst);
1219 	if (ret)
1220 		goto out;
1221 
1222 	ret = add_qgroup_relation_item(trans, quota_root, dst, src);
1223 	if (ret) {
1224 		del_qgroup_relation_item(trans, quota_root, src, dst);
1225 		goto out;
1226 	}
1227 
1228 	spin_lock(&fs_info->qgroup_lock);
1229 	ret = add_relation_rb(fs_info, src, dst);
1230 	if (ret < 0) {
1231 		spin_unlock(&fs_info->qgroup_lock);
1232 		goto out;
1233 	}
1234 	ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1235 	spin_unlock(&fs_info->qgroup_lock);
1236 out:
1237 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1238 	ulist_free(tmp);
1239 	return ret;
1240 }
1241 
1242 static int __del_qgroup_relation(struct btrfs_trans_handle *trans,
1243 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1244 {
1245 	struct btrfs_root *quota_root;
1246 	struct btrfs_qgroup *parent;
1247 	struct btrfs_qgroup *member;
1248 	struct btrfs_qgroup_list *list;
1249 	struct ulist *tmp;
1250 	int ret = 0;
1251 	int err;
1252 
1253 	tmp = ulist_alloc(GFP_KERNEL);
1254 	if (!tmp)
1255 		return -ENOMEM;
1256 
1257 	quota_root = fs_info->quota_root;
1258 	if (!quota_root) {
1259 		ret = -EINVAL;
1260 		goto out;
1261 	}
1262 
1263 	member = find_qgroup_rb(fs_info, src);
1264 	parent = find_qgroup_rb(fs_info, dst);
1265 	if (!member || !parent) {
1266 		ret = -EINVAL;
1267 		goto out;
1268 	}
1269 
1270 	/* check if such qgroup relation exist firstly */
1271 	list_for_each_entry(list, &member->groups, next_group) {
1272 		if (list->group == parent)
1273 			goto exist;
1274 	}
1275 	ret = -ENOENT;
1276 	goto out;
1277 exist:
1278 	ret = del_qgroup_relation_item(trans, quota_root, src, dst);
1279 	err = del_qgroup_relation_item(trans, quota_root, dst, src);
1280 	if (err && !ret)
1281 		ret = err;
1282 
1283 	spin_lock(&fs_info->qgroup_lock);
1284 	del_relation_rb(fs_info, src, dst);
1285 	ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1286 	spin_unlock(&fs_info->qgroup_lock);
1287 out:
1288 	ulist_free(tmp);
1289 	return ret;
1290 }
1291 
1292 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
1293 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1294 {
1295 	int ret = 0;
1296 
1297 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1298 	ret = __del_qgroup_relation(trans, fs_info, src, dst);
1299 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1300 
1301 	return ret;
1302 }
1303 
1304 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
1305 			struct btrfs_fs_info *fs_info, u64 qgroupid)
1306 {
1307 	struct btrfs_root *quota_root;
1308 	struct btrfs_qgroup *qgroup;
1309 	int ret = 0;
1310 
1311 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1312 	quota_root = fs_info->quota_root;
1313 	if (!quota_root) {
1314 		ret = -EINVAL;
1315 		goto out;
1316 	}
1317 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1318 	if (qgroup) {
1319 		ret = -EEXIST;
1320 		goto out;
1321 	}
1322 
1323 	ret = add_qgroup_item(trans, quota_root, qgroupid);
1324 	if (ret)
1325 		goto out;
1326 
1327 	spin_lock(&fs_info->qgroup_lock);
1328 	qgroup = add_qgroup_rb(fs_info, qgroupid);
1329 	spin_unlock(&fs_info->qgroup_lock);
1330 
1331 	if (IS_ERR(qgroup))
1332 		ret = PTR_ERR(qgroup);
1333 out:
1334 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1335 	return ret;
1336 }
1337 
1338 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
1339 			struct btrfs_fs_info *fs_info, u64 qgroupid)
1340 {
1341 	struct btrfs_root *quota_root;
1342 	struct btrfs_qgroup *qgroup;
1343 	struct btrfs_qgroup_list *list;
1344 	int ret = 0;
1345 
1346 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1347 	quota_root = fs_info->quota_root;
1348 	if (!quota_root) {
1349 		ret = -EINVAL;
1350 		goto out;
1351 	}
1352 
1353 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1354 	if (!qgroup) {
1355 		ret = -ENOENT;
1356 		goto out;
1357 	} else {
1358 		/* check if there are no children of this qgroup */
1359 		if (!list_empty(&qgroup->members)) {
1360 			ret = -EBUSY;
1361 			goto out;
1362 		}
1363 	}
1364 	ret = del_qgroup_item(trans, quota_root, qgroupid);
1365 	if (ret && ret != -ENOENT)
1366 		goto out;
1367 
1368 	while (!list_empty(&qgroup->groups)) {
1369 		list = list_first_entry(&qgroup->groups,
1370 					struct btrfs_qgroup_list, next_group);
1371 		ret = __del_qgroup_relation(trans, fs_info,
1372 					   qgroupid,
1373 					   list->group->qgroupid);
1374 		if (ret)
1375 			goto out;
1376 	}
1377 
1378 	spin_lock(&fs_info->qgroup_lock);
1379 	del_qgroup_rb(fs_info, qgroupid);
1380 	spin_unlock(&fs_info->qgroup_lock);
1381 out:
1382 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1383 	return ret;
1384 }
1385 
1386 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
1387 		       struct btrfs_fs_info *fs_info, u64 qgroupid,
1388 		       struct btrfs_qgroup_limit *limit)
1389 {
1390 	struct btrfs_root *quota_root;
1391 	struct btrfs_qgroup *qgroup;
1392 	int ret = 0;
1393 	/* Sometimes we would want to clear the limit on this qgroup.
1394 	 * To meet this requirement, we treat the -1 as a special value
1395 	 * which tell kernel to clear the limit on this qgroup.
1396 	 */
1397 	const u64 CLEAR_VALUE = -1;
1398 
1399 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1400 	quota_root = fs_info->quota_root;
1401 	if (!quota_root) {
1402 		ret = -EINVAL;
1403 		goto out;
1404 	}
1405 
1406 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1407 	if (!qgroup) {
1408 		ret = -ENOENT;
1409 		goto out;
1410 	}
1411 
1412 	spin_lock(&fs_info->qgroup_lock);
1413 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1414 		if (limit->max_rfer == CLEAR_VALUE) {
1415 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1416 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1417 			qgroup->max_rfer = 0;
1418 		} else {
1419 			qgroup->max_rfer = limit->max_rfer;
1420 		}
1421 	}
1422 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1423 		if (limit->max_excl == CLEAR_VALUE) {
1424 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1425 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1426 			qgroup->max_excl = 0;
1427 		} else {
1428 			qgroup->max_excl = limit->max_excl;
1429 		}
1430 	}
1431 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1432 		if (limit->rsv_rfer == CLEAR_VALUE) {
1433 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1434 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1435 			qgroup->rsv_rfer = 0;
1436 		} else {
1437 			qgroup->rsv_rfer = limit->rsv_rfer;
1438 		}
1439 	}
1440 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1441 		if (limit->rsv_excl == CLEAR_VALUE) {
1442 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1443 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1444 			qgroup->rsv_excl = 0;
1445 		} else {
1446 			qgroup->rsv_excl = limit->rsv_excl;
1447 		}
1448 	}
1449 	qgroup->lim_flags |= limit->flags;
1450 
1451 	spin_unlock(&fs_info->qgroup_lock);
1452 
1453 	ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1454 	if (ret) {
1455 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1456 		btrfs_info(fs_info, "unable to update quota limit for %llu",
1457 		       qgroupid);
1458 	}
1459 
1460 out:
1461 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1462 	return ret;
1463 }
1464 
1465 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1466 				struct btrfs_delayed_ref_root *delayed_refs,
1467 				struct btrfs_qgroup_extent_record *record)
1468 {
1469 	struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1470 	struct rb_node *parent_node = NULL;
1471 	struct btrfs_qgroup_extent_record *entry;
1472 	u64 bytenr = record->bytenr;
1473 
1474 	lockdep_assert_held(&delayed_refs->lock);
1475 	trace_btrfs_qgroup_trace_extent(fs_info, record);
1476 
1477 	while (*p) {
1478 		parent_node = *p;
1479 		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1480 				 node);
1481 		if (bytenr < entry->bytenr)
1482 			p = &(*p)->rb_left;
1483 		else if (bytenr > entry->bytenr)
1484 			p = &(*p)->rb_right;
1485 		else
1486 			return 1;
1487 	}
1488 
1489 	rb_link_node(&record->node, parent_node, p);
1490 	rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1491 	return 0;
1492 }
1493 
1494 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1495 				   struct btrfs_qgroup_extent_record *qrecord)
1496 {
1497 	struct ulist *old_root;
1498 	u64 bytenr = qrecord->bytenr;
1499 	int ret;
1500 
1501 	ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
1502 	if (ret < 0) {
1503 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1504 		btrfs_warn(fs_info,
1505 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1506 			ret);
1507 		return 0;
1508 	}
1509 
1510 	/*
1511 	 * Here we don't need to get the lock of
1512 	 * trans->transaction->delayed_refs, since inserted qrecord won't
1513 	 * be deleted, only qrecord->node may be modified (new qrecord insert)
1514 	 *
1515 	 * So modifying qrecord->old_roots is safe here
1516 	 */
1517 	qrecord->old_roots = old_root;
1518 	return 0;
1519 }
1520 
1521 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
1522 		struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes,
1523 		gfp_t gfp_flag)
1524 {
1525 	struct btrfs_qgroup_extent_record *record;
1526 	struct btrfs_delayed_ref_root *delayed_refs;
1527 	int ret;
1528 
1529 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1530 	    || bytenr == 0 || num_bytes == 0)
1531 		return 0;
1532 	if (WARN_ON(trans == NULL))
1533 		return -EINVAL;
1534 	record = kmalloc(sizeof(*record), gfp_flag);
1535 	if (!record)
1536 		return -ENOMEM;
1537 
1538 	delayed_refs = &trans->transaction->delayed_refs;
1539 	record->bytenr = bytenr;
1540 	record->num_bytes = num_bytes;
1541 	record->old_roots = NULL;
1542 
1543 	spin_lock(&delayed_refs->lock);
1544 	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1545 	spin_unlock(&delayed_refs->lock);
1546 	if (ret > 0) {
1547 		kfree(record);
1548 		return 0;
1549 	}
1550 	return btrfs_qgroup_trace_extent_post(fs_info, record);
1551 }
1552 
1553 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1554 				  struct btrfs_fs_info *fs_info,
1555 				  struct extent_buffer *eb)
1556 {
1557 	int nr = btrfs_header_nritems(eb);
1558 	int i, extent_type, ret;
1559 	struct btrfs_key key;
1560 	struct btrfs_file_extent_item *fi;
1561 	u64 bytenr, num_bytes;
1562 
1563 	/* We can be called directly from walk_up_proc() */
1564 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1565 		return 0;
1566 
1567 	for (i = 0; i < nr; i++) {
1568 		btrfs_item_key_to_cpu(eb, &key, i);
1569 
1570 		if (key.type != BTRFS_EXTENT_DATA_KEY)
1571 			continue;
1572 
1573 		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1574 		/* filter out non qgroup-accountable extents  */
1575 		extent_type = btrfs_file_extent_type(eb, fi);
1576 
1577 		if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1578 			continue;
1579 
1580 		bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1581 		if (!bytenr)
1582 			continue;
1583 
1584 		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1585 
1586 		ret = btrfs_qgroup_trace_extent(trans, fs_info, bytenr,
1587 						num_bytes, GFP_NOFS);
1588 		if (ret)
1589 			return ret;
1590 	}
1591 	cond_resched();
1592 	return 0;
1593 }
1594 
1595 /*
1596  * Walk up the tree from the bottom, freeing leaves and any interior
1597  * nodes which have had all slots visited. If a node (leaf or
1598  * interior) is freed, the node above it will have it's slot
1599  * incremented. The root node will never be freed.
1600  *
1601  * At the end of this function, we should have a path which has all
1602  * slots incremented to the next position for a search. If we need to
1603  * read a new node it will be NULL and the node above it will have the
1604  * correct slot selected for a later read.
1605  *
1606  * If we increment the root nodes slot counter past the number of
1607  * elements, 1 is returned to signal completion of the search.
1608  */
1609 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1610 {
1611 	int level = 0;
1612 	int nr, slot;
1613 	struct extent_buffer *eb;
1614 
1615 	if (root_level == 0)
1616 		return 1;
1617 
1618 	while (level <= root_level) {
1619 		eb = path->nodes[level];
1620 		nr = btrfs_header_nritems(eb);
1621 		path->slots[level]++;
1622 		slot = path->slots[level];
1623 		if (slot >= nr || level == 0) {
1624 			/*
1625 			 * Don't free the root -  we will detect this
1626 			 * condition after our loop and return a
1627 			 * positive value for caller to stop walking the tree.
1628 			 */
1629 			if (level != root_level) {
1630 				btrfs_tree_unlock_rw(eb, path->locks[level]);
1631 				path->locks[level] = 0;
1632 
1633 				free_extent_buffer(eb);
1634 				path->nodes[level] = NULL;
1635 				path->slots[level] = 0;
1636 			}
1637 		} else {
1638 			/*
1639 			 * We have a valid slot to walk back down
1640 			 * from. Stop here so caller can process these
1641 			 * new nodes.
1642 			 */
1643 			break;
1644 		}
1645 
1646 		level++;
1647 	}
1648 
1649 	eb = path->nodes[root_level];
1650 	if (path->slots[root_level] >= btrfs_header_nritems(eb))
1651 		return 1;
1652 
1653 	return 0;
1654 }
1655 
1656 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
1657 			       struct btrfs_root *root,
1658 			       struct extent_buffer *root_eb,
1659 			       u64 root_gen, int root_level)
1660 {
1661 	struct btrfs_fs_info *fs_info = root->fs_info;
1662 	int ret = 0;
1663 	int level;
1664 	struct extent_buffer *eb = root_eb;
1665 	struct btrfs_path *path = NULL;
1666 
1667 	BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
1668 	BUG_ON(root_eb == NULL);
1669 
1670 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1671 		return 0;
1672 
1673 	if (!extent_buffer_uptodate(root_eb)) {
1674 		ret = btrfs_read_buffer(root_eb, root_gen, root_level, NULL);
1675 		if (ret)
1676 			goto out;
1677 	}
1678 
1679 	if (root_level == 0) {
1680 		ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, root_eb);
1681 		goto out;
1682 	}
1683 
1684 	path = btrfs_alloc_path();
1685 	if (!path)
1686 		return -ENOMEM;
1687 
1688 	/*
1689 	 * Walk down the tree.  Missing extent blocks are filled in as
1690 	 * we go. Metadata is accounted every time we read a new
1691 	 * extent block.
1692 	 *
1693 	 * When we reach a leaf, we account for file extent items in it,
1694 	 * walk back up the tree (adjusting slot pointers as we go)
1695 	 * and restart the search process.
1696 	 */
1697 	extent_buffer_get(root_eb); /* For path */
1698 	path->nodes[root_level] = root_eb;
1699 	path->slots[root_level] = 0;
1700 	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
1701 walk_down:
1702 	level = root_level;
1703 	while (level >= 0) {
1704 		if (path->nodes[level] == NULL) {
1705 			struct btrfs_key first_key;
1706 			int parent_slot;
1707 			u64 child_gen;
1708 			u64 child_bytenr;
1709 
1710 			/*
1711 			 * We need to get child blockptr/gen from parent before
1712 			 * we can read it.
1713 			  */
1714 			eb = path->nodes[level + 1];
1715 			parent_slot = path->slots[level + 1];
1716 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1717 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1718 			btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
1719 
1720 			eb = read_tree_block(fs_info, child_bytenr, child_gen,
1721 					     level, &first_key);
1722 			if (IS_ERR(eb)) {
1723 				ret = PTR_ERR(eb);
1724 				goto out;
1725 			} else if (!extent_buffer_uptodate(eb)) {
1726 				free_extent_buffer(eb);
1727 				ret = -EIO;
1728 				goto out;
1729 			}
1730 
1731 			path->nodes[level] = eb;
1732 			path->slots[level] = 0;
1733 
1734 			btrfs_tree_read_lock(eb);
1735 			btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1736 			path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
1737 
1738 			ret = btrfs_qgroup_trace_extent(trans, fs_info,
1739 							child_bytenr,
1740 							fs_info->nodesize,
1741 							GFP_NOFS);
1742 			if (ret)
1743 				goto out;
1744 		}
1745 
1746 		if (level == 0) {
1747 			ret = btrfs_qgroup_trace_leaf_items(trans,fs_info,
1748 							   path->nodes[level]);
1749 			if (ret)
1750 				goto out;
1751 
1752 			/* Nonzero return here means we completed our search */
1753 			ret = adjust_slots_upwards(path, root_level);
1754 			if (ret)
1755 				break;
1756 
1757 			/* Restart search with new slots */
1758 			goto walk_down;
1759 		}
1760 
1761 		level--;
1762 	}
1763 
1764 	ret = 0;
1765 out:
1766 	btrfs_free_path(path);
1767 
1768 	return ret;
1769 }
1770 
1771 #define UPDATE_NEW	0
1772 #define UPDATE_OLD	1
1773 /*
1774  * Walk all of the roots that points to the bytenr and adjust their refcnts.
1775  */
1776 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
1777 				struct ulist *roots, struct ulist *tmp,
1778 				struct ulist *qgroups, u64 seq, int update_old)
1779 {
1780 	struct ulist_node *unode;
1781 	struct ulist_iterator uiter;
1782 	struct ulist_node *tmp_unode;
1783 	struct ulist_iterator tmp_uiter;
1784 	struct btrfs_qgroup *qg;
1785 	int ret = 0;
1786 
1787 	if (!roots)
1788 		return 0;
1789 	ULIST_ITER_INIT(&uiter);
1790 	while ((unode = ulist_next(roots, &uiter))) {
1791 		qg = find_qgroup_rb(fs_info, unode->val);
1792 		if (!qg)
1793 			continue;
1794 
1795 		ulist_reinit(tmp);
1796 		ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
1797 				GFP_ATOMIC);
1798 		if (ret < 0)
1799 			return ret;
1800 		ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
1801 		if (ret < 0)
1802 			return ret;
1803 		ULIST_ITER_INIT(&tmp_uiter);
1804 		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1805 			struct btrfs_qgroup_list *glist;
1806 
1807 			qg = unode_aux_to_qgroup(tmp_unode);
1808 			if (update_old)
1809 				btrfs_qgroup_update_old_refcnt(qg, seq, 1);
1810 			else
1811 				btrfs_qgroup_update_new_refcnt(qg, seq, 1);
1812 			list_for_each_entry(glist, &qg->groups, next_group) {
1813 				ret = ulist_add(qgroups, glist->group->qgroupid,
1814 						qgroup_to_aux(glist->group),
1815 						GFP_ATOMIC);
1816 				if (ret < 0)
1817 					return ret;
1818 				ret = ulist_add(tmp, glist->group->qgroupid,
1819 						qgroup_to_aux(glist->group),
1820 						GFP_ATOMIC);
1821 				if (ret < 0)
1822 					return ret;
1823 			}
1824 		}
1825 	}
1826 	return 0;
1827 }
1828 
1829 /*
1830  * Update qgroup rfer/excl counters.
1831  * Rfer update is easy, codes can explain themselves.
1832  *
1833  * Excl update is tricky, the update is split into 2 part.
1834  * Part 1: Possible exclusive <-> sharing detect:
1835  *	|	A	|	!A	|
1836  *  -------------------------------------
1837  *  B	|	*	|	-	|
1838  *  -------------------------------------
1839  *  !B	|	+	|	**	|
1840  *  -------------------------------------
1841  *
1842  * Conditions:
1843  * A:	cur_old_roots < nr_old_roots	(not exclusive before)
1844  * !A:	cur_old_roots == nr_old_roots	(possible exclusive before)
1845  * B:	cur_new_roots < nr_new_roots	(not exclusive now)
1846  * !B:	cur_new_roots == nr_new_roots	(possible exclusive now)
1847  *
1848  * Results:
1849  * +: Possible sharing -> exclusive	-: Possible exclusive -> sharing
1850  * *: Definitely not changed.		**: Possible unchanged.
1851  *
1852  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
1853  *
1854  * To make the logic clear, we first use condition A and B to split
1855  * combination into 4 results.
1856  *
1857  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
1858  * only on variant maybe 0.
1859  *
1860  * Lastly, check result **, since there are 2 variants maybe 0, split them
1861  * again(2x2).
1862  * But this time we don't need to consider other things, the codes and logic
1863  * is easy to understand now.
1864  */
1865 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
1866 				  struct ulist *qgroups,
1867 				  u64 nr_old_roots,
1868 				  u64 nr_new_roots,
1869 				  u64 num_bytes, u64 seq)
1870 {
1871 	struct ulist_node *unode;
1872 	struct ulist_iterator uiter;
1873 	struct btrfs_qgroup *qg;
1874 	u64 cur_new_count, cur_old_count;
1875 
1876 	ULIST_ITER_INIT(&uiter);
1877 	while ((unode = ulist_next(qgroups, &uiter))) {
1878 		bool dirty = false;
1879 
1880 		qg = unode_aux_to_qgroup(unode);
1881 		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
1882 		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
1883 
1884 		trace_qgroup_update_counters(fs_info, qg->qgroupid,
1885 					     cur_old_count, cur_new_count);
1886 
1887 		/* Rfer update part */
1888 		if (cur_old_count == 0 && cur_new_count > 0) {
1889 			qg->rfer += num_bytes;
1890 			qg->rfer_cmpr += num_bytes;
1891 			dirty = true;
1892 		}
1893 		if (cur_old_count > 0 && cur_new_count == 0) {
1894 			qg->rfer -= num_bytes;
1895 			qg->rfer_cmpr -= num_bytes;
1896 			dirty = true;
1897 		}
1898 
1899 		/* Excl update part */
1900 		/* Exclusive/none -> shared case */
1901 		if (cur_old_count == nr_old_roots &&
1902 		    cur_new_count < nr_new_roots) {
1903 			/* Exclusive -> shared */
1904 			if (cur_old_count != 0) {
1905 				qg->excl -= num_bytes;
1906 				qg->excl_cmpr -= num_bytes;
1907 				dirty = true;
1908 			}
1909 		}
1910 
1911 		/* Shared -> exclusive/none case */
1912 		if (cur_old_count < nr_old_roots &&
1913 		    cur_new_count == nr_new_roots) {
1914 			/* Shared->exclusive */
1915 			if (cur_new_count != 0) {
1916 				qg->excl += num_bytes;
1917 				qg->excl_cmpr += num_bytes;
1918 				dirty = true;
1919 			}
1920 		}
1921 
1922 		/* Exclusive/none -> exclusive/none case */
1923 		if (cur_old_count == nr_old_roots &&
1924 		    cur_new_count == nr_new_roots) {
1925 			if (cur_old_count == 0) {
1926 				/* None -> exclusive/none */
1927 
1928 				if (cur_new_count != 0) {
1929 					/* None -> exclusive */
1930 					qg->excl += num_bytes;
1931 					qg->excl_cmpr += num_bytes;
1932 					dirty = true;
1933 				}
1934 				/* None -> none, nothing changed */
1935 			} else {
1936 				/* Exclusive -> exclusive/none */
1937 
1938 				if (cur_new_count == 0) {
1939 					/* Exclusive -> none */
1940 					qg->excl -= num_bytes;
1941 					qg->excl_cmpr -= num_bytes;
1942 					dirty = true;
1943 				}
1944 				/* Exclusive -> exclusive, nothing changed */
1945 			}
1946 		}
1947 
1948 		if (dirty)
1949 			qgroup_dirty(fs_info, qg);
1950 	}
1951 	return 0;
1952 }
1953 
1954 /*
1955  * Check if the @roots potentially is a list of fs tree roots
1956  *
1957  * Return 0 for definitely not a fs/subvol tree roots ulist
1958  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
1959  *          one as well)
1960  */
1961 static int maybe_fs_roots(struct ulist *roots)
1962 {
1963 	struct ulist_node *unode;
1964 	struct ulist_iterator uiter;
1965 
1966 	/* Empty one, still possible for fs roots */
1967 	if (!roots || roots->nnodes == 0)
1968 		return 1;
1969 
1970 	ULIST_ITER_INIT(&uiter);
1971 	unode = ulist_next(roots, &uiter);
1972 	if (!unode)
1973 		return 1;
1974 
1975 	/*
1976 	 * If it contains fs tree roots, then it must belong to fs/subvol
1977 	 * trees.
1978 	 * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
1979 	 */
1980 	return is_fstree(unode->val);
1981 }
1982 
1983 int
1984 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
1985 			    struct btrfs_fs_info *fs_info,
1986 			    u64 bytenr, u64 num_bytes,
1987 			    struct ulist *old_roots, struct ulist *new_roots)
1988 {
1989 	struct ulist *qgroups = NULL;
1990 	struct ulist *tmp = NULL;
1991 	u64 seq;
1992 	u64 nr_new_roots = 0;
1993 	u64 nr_old_roots = 0;
1994 	int ret = 0;
1995 
1996 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1997 		return 0;
1998 
1999 	if (new_roots) {
2000 		if (!maybe_fs_roots(new_roots))
2001 			goto out_free;
2002 		nr_new_roots = new_roots->nnodes;
2003 	}
2004 	if (old_roots) {
2005 		if (!maybe_fs_roots(old_roots))
2006 			goto out_free;
2007 		nr_old_roots = old_roots->nnodes;
2008 	}
2009 
2010 	/* Quick exit, either not fs tree roots, or won't affect any qgroup */
2011 	if (nr_old_roots == 0 && nr_new_roots == 0)
2012 		goto out_free;
2013 
2014 	BUG_ON(!fs_info->quota_root);
2015 
2016 	trace_btrfs_qgroup_account_extent(fs_info, bytenr, num_bytes,
2017 					  nr_old_roots, nr_new_roots);
2018 
2019 	qgroups = ulist_alloc(GFP_NOFS);
2020 	if (!qgroups) {
2021 		ret = -ENOMEM;
2022 		goto out_free;
2023 	}
2024 	tmp = ulist_alloc(GFP_NOFS);
2025 	if (!tmp) {
2026 		ret = -ENOMEM;
2027 		goto out_free;
2028 	}
2029 
2030 	mutex_lock(&fs_info->qgroup_rescan_lock);
2031 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2032 		if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2033 			mutex_unlock(&fs_info->qgroup_rescan_lock);
2034 			ret = 0;
2035 			goto out_free;
2036 		}
2037 	}
2038 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2039 
2040 	spin_lock(&fs_info->qgroup_lock);
2041 	seq = fs_info->qgroup_seq;
2042 
2043 	/* Update old refcnts using old_roots */
2044 	ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2045 				   UPDATE_OLD);
2046 	if (ret < 0)
2047 		goto out;
2048 
2049 	/* Update new refcnts using new_roots */
2050 	ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2051 				   UPDATE_NEW);
2052 	if (ret < 0)
2053 		goto out;
2054 
2055 	qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2056 			       num_bytes, seq);
2057 
2058 	/*
2059 	 * Bump qgroup_seq to avoid seq overlap
2060 	 */
2061 	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2062 out:
2063 	spin_unlock(&fs_info->qgroup_lock);
2064 out_free:
2065 	ulist_free(tmp);
2066 	ulist_free(qgroups);
2067 	ulist_free(old_roots);
2068 	ulist_free(new_roots);
2069 	return ret;
2070 }
2071 
2072 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2073 {
2074 	struct btrfs_fs_info *fs_info = trans->fs_info;
2075 	struct btrfs_qgroup_extent_record *record;
2076 	struct btrfs_delayed_ref_root *delayed_refs;
2077 	struct ulist *new_roots = NULL;
2078 	struct rb_node *node;
2079 	u64 qgroup_to_skip;
2080 	int ret = 0;
2081 
2082 	delayed_refs = &trans->transaction->delayed_refs;
2083 	qgroup_to_skip = delayed_refs->qgroup_to_skip;
2084 	while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2085 		record = rb_entry(node, struct btrfs_qgroup_extent_record,
2086 				  node);
2087 
2088 		trace_btrfs_qgroup_account_extents(fs_info, record);
2089 
2090 		if (!ret) {
2091 			/*
2092 			 * Old roots should be searched when inserting qgroup
2093 			 * extent record
2094 			 */
2095 			if (WARN_ON(!record->old_roots)) {
2096 				/* Search commit root to find old_roots */
2097 				ret = btrfs_find_all_roots(NULL, fs_info,
2098 						record->bytenr, 0,
2099 						&record->old_roots, false);
2100 				if (ret < 0)
2101 					goto cleanup;
2102 			}
2103 
2104 			/*
2105 			 * Use SEQ_LAST as time_seq to do special search, which
2106 			 * doesn't lock tree or delayed_refs and search current
2107 			 * root. It's safe inside commit_transaction().
2108 			 */
2109 			ret = btrfs_find_all_roots(trans, fs_info,
2110 				record->bytenr, SEQ_LAST, &new_roots, false);
2111 			if (ret < 0)
2112 				goto cleanup;
2113 			if (qgroup_to_skip) {
2114 				ulist_del(new_roots, qgroup_to_skip, 0);
2115 				ulist_del(record->old_roots, qgroup_to_skip,
2116 					  0);
2117 			}
2118 			ret = btrfs_qgroup_account_extent(trans, fs_info,
2119 					record->bytenr, record->num_bytes,
2120 					record->old_roots, new_roots);
2121 			record->old_roots = NULL;
2122 			new_roots = NULL;
2123 		}
2124 cleanup:
2125 		ulist_free(record->old_roots);
2126 		ulist_free(new_roots);
2127 		new_roots = NULL;
2128 		rb_erase(node, &delayed_refs->dirty_extent_root);
2129 		kfree(record);
2130 
2131 	}
2132 	return ret;
2133 }
2134 
2135 /*
2136  * called from commit_transaction. Writes all changed qgroups to disk.
2137  */
2138 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
2139 		      struct btrfs_fs_info *fs_info)
2140 {
2141 	struct btrfs_root *quota_root = fs_info->quota_root;
2142 	int ret = 0;
2143 
2144 	if (!quota_root)
2145 		return ret;
2146 
2147 	spin_lock(&fs_info->qgroup_lock);
2148 	while (!list_empty(&fs_info->dirty_qgroups)) {
2149 		struct btrfs_qgroup *qgroup;
2150 		qgroup = list_first_entry(&fs_info->dirty_qgroups,
2151 					  struct btrfs_qgroup, dirty);
2152 		list_del_init(&qgroup->dirty);
2153 		spin_unlock(&fs_info->qgroup_lock);
2154 		ret = update_qgroup_info_item(trans, quota_root, qgroup);
2155 		if (ret)
2156 			fs_info->qgroup_flags |=
2157 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2158 		ret = update_qgroup_limit_item(trans, quota_root, qgroup);
2159 		if (ret)
2160 			fs_info->qgroup_flags |=
2161 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2162 		spin_lock(&fs_info->qgroup_lock);
2163 	}
2164 	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2165 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2166 	else
2167 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2168 	spin_unlock(&fs_info->qgroup_lock);
2169 
2170 	ret = update_qgroup_status_item(trans, fs_info, quota_root);
2171 	if (ret)
2172 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2173 
2174 	return ret;
2175 }
2176 
2177 /*
2178  * Copy the accounting information between qgroups. This is necessary
2179  * when a snapshot or a subvolume is created. Throwing an error will
2180  * cause a transaction abort so we take extra care here to only error
2181  * when a readonly fs is a reasonable outcome.
2182  */
2183 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
2184 			 struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
2185 			 struct btrfs_qgroup_inherit *inherit)
2186 {
2187 	int ret = 0;
2188 	int i;
2189 	u64 *i_qgroups;
2190 	struct btrfs_root *quota_root = fs_info->quota_root;
2191 	struct btrfs_qgroup *srcgroup;
2192 	struct btrfs_qgroup *dstgroup;
2193 	u32 level_size = 0;
2194 	u64 nums;
2195 
2196 	mutex_lock(&fs_info->qgroup_ioctl_lock);
2197 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2198 		goto out;
2199 
2200 	if (!quota_root) {
2201 		ret = -EINVAL;
2202 		goto out;
2203 	}
2204 
2205 	if (inherit) {
2206 		i_qgroups = (u64 *)(inherit + 1);
2207 		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2208 		       2 * inherit->num_excl_copies;
2209 		for (i = 0; i < nums; ++i) {
2210 			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2211 
2212 			/*
2213 			 * Zero out invalid groups so we can ignore
2214 			 * them later.
2215 			 */
2216 			if (!srcgroup ||
2217 			    ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2218 				*i_qgroups = 0ULL;
2219 
2220 			++i_qgroups;
2221 		}
2222 	}
2223 
2224 	/*
2225 	 * create a tracking group for the subvol itself
2226 	 */
2227 	ret = add_qgroup_item(trans, quota_root, objectid);
2228 	if (ret)
2229 		goto out;
2230 
2231 	if (srcid) {
2232 		struct btrfs_root *srcroot;
2233 		struct btrfs_key srckey;
2234 
2235 		srckey.objectid = srcid;
2236 		srckey.type = BTRFS_ROOT_ITEM_KEY;
2237 		srckey.offset = (u64)-1;
2238 		srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
2239 		if (IS_ERR(srcroot)) {
2240 			ret = PTR_ERR(srcroot);
2241 			goto out;
2242 		}
2243 
2244 		level_size = fs_info->nodesize;
2245 	}
2246 
2247 	/*
2248 	 * add qgroup to all inherited groups
2249 	 */
2250 	if (inherit) {
2251 		i_qgroups = (u64 *)(inherit + 1);
2252 		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2253 			if (*i_qgroups == 0)
2254 				continue;
2255 			ret = add_qgroup_relation_item(trans, quota_root,
2256 						       objectid, *i_qgroups);
2257 			if (ret && ret != -EEXIST)
2258 				goto out;
2259 			ret = add_qgroup_relation_item(trans, quota_root,
2260 						       *i_qgroups, objectid);
2261 			if (ret && ret != -EEXIST)
2262 				goto out;
2263 		}
2264 		ret = 0;
2265 	}
2266 
2267 
2268 	spin_lock(&fs_info->qgroup_lock);
2269 
2270 	dstgroup = add_qgroup_rb(fs_info, objectid);
2271 	if (IS_ERR(dstgroup)) {
2272 		ret = PTR_ERR(dstgroup);
2273 		goto unlock;
2274 	}
2275 
2276 	if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2277 		dstgroup->lim_flags = inherit->lim.flags;
2278 		dstgroup->max_rfer = inherit->lim.max_rfer;
2279 		dstgroup->max_excl = inherit->lim.max_excl;
2280 		dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2281 		dstgroup->rsv_excl = inherit->lim.rsv_excl;
2282 
2283 		ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
2284 		if (ret) {
2285 			fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2286 			btrfs_info(fs_info,
2287 				   "unable to update quota limit for %llu",
2288 				   dstgroup->qgroupid);
2289 			goto unlock;
2290 		}
2291 	}
2292 
2293 	if (srcid) {
2294 		srcgroup = find_qgroup_rb(fs_info, srcid);
2295 		if (!srcgroup)
2296 			goto unlock;
2297 
2298 		/*
2299 		 * We call inherit after we clone the root in order to make sure
2300 		 * our counts don't go crazy, so at this point the only
2301 		 * difference between the two roots should be the root node.
2302 		 */
2303 		dstgroup->rfer = srcgroup->rfer;
2304 		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2305 		dstgroup->excl = level_size;
2306 		dstgroup->excl_cmpr = level_size;
2307 		srcgroup->excl = level_size;
2308 		srcgroup->excl_cmpr = level_size;
2309 
2310 		/* inherit the limit info */
2311 		dstgroup->lim_flags = srcgroup->lim_flags;
2312 		dstgroup->max_rfer = srcgroup->max_rfer;
2313 		dstgroup->max_excl = srcgroup->max_excl;
2314 		dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2315 		dstgroup->rsv_excl = srcgroup->rsv_excl;
2316 
2317 		qgroup_dirty(fs_info, dstgroup);
2318 		qgroup_dirty(fs_info, srcgroup);
2319 	}
2320 
2321 	if (!inherit)
2322 		goto unlock;
2323 
2324 	i_qgroups = (u64 *)(inherit + 1);
2325 	for (i = 0; i < inherit->num_qgroups; ++i) {
2326 		if (*i_qgroups) {
2327 			ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2328 			if (ret)
2329 				goto unlock;
2330 		}
2331 		++i_qgroups;
2332 	}
2333 
2334 	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2335 		struct btrfs_qgroup *src;
2336 		struct btrfs_qgroup *dst;
2337 
2338 		if (!i_qgroups[0] || !i_qgroups[1])
2339 			continue;
2340 
2341 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2342 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2343 
2344 		if (!src || !dst) {
2345 			ret = -EINVAL;
2346 			goto unlock;
2347 		}
2348 
2349 		dst->rfer = src->rfer - level_size;
2350 		dst->rfer_cmpr = src->rfer_cmpr - level_size;
2351 	}
2352 	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2353 		struct btrfs_qgroup *src;
2354 		struct btrfs_qgroup *dst;
2355 
2356 		if (!i_qgroups[0] || !i_qgroups[1])
2357 			continue;
2358 
2359 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2360 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2361 
2362 		if (!src || !dst) {
2363 			ret = -EINVAL;
2364 			goto unlock;
2365 		}
2366 
2367 		dst->excl = src->excl + level_size;
2368 		dst->excl_cmpr = src->excl_cmpr + level_size;
2369 	}
2370 
2371 unlock:
2372 	spin_unlock(&fs_info->qgroup_lock);
2373 out:
2374 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
2375 	return ret;
2376 }
2377 
2378 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
2379 {
2380 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2381 	    qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
2382 		return false;
2383 
2384 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2385 	    qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
2386 		return false;
2387 
2388 	return true;
2389 }
2390 
2391 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
2392 			  enum btrfs_qgroup_rsv_type type)
2393 {
2394 	struct btrfs_root *quota_root;
2395 	struct btrfs_qgroup *qgroup;
2396 	struct btrfs_fs_info *fs_info = root->fs_info;
2397 	u64 ref_root = root->root_key.objectid;
2398 	int ret = 0;
2399 	struct ulist_node *unode;
2400 	struct ulist_iterator uiter;
2401 
2402 	if (!is_fstree(ref_root))
2403 		return 0;
2404 
2405 	if (num_bytes == 0)
2406 		return 0;
2407 
2408 	if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2409 	    capable(CAP_SYS_RESOURCE))
2410 		enforce = false;
2411 
2412 	spin_lock(&fs_info->qgroup_lock);
2413 	quota_root = fs_info->quota_root;
2414 	if (!quota_root)
2415 		goto out;
2416 
2417 	qgroup = find_qgroup_rb(fs_info, ref_root);
2418 	if (!qgroup)
2419 		goto out;
2420 
2421 	/*
2422 	 * in a first step, we check all affected qgroups if any limits would
2423 	 * be exceeded
2424 	 */
2425 	ulist_reinit(fs_info->qgroup_ulist);
2426 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2427 			qgroup_to_aux(qgroup), GFP_ATOMIC);
2428 	if (ret < 0)
2429 		goto out;
2430 	ULIST_ITER_INIT(&uiter);
2431 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2432 		struct btrfs_qgroup *qg;
2433 		struct btrfs_qgroup_list *glist;
2434 
2435 		qg = unode_aux_to_qgroup(unode);
2436 
2437 		if (enforce && !qgroup_check_limits(qg, num_bytes)) {
2438 			ret = -EDQUOT;
2439 			goto out;
2440 		}
2441 
2442 		list_for_each_entry(glist, &qg->groups, next_group) {
2443 			ret = ulist_add(fs_info->qgroup_ulist,
2444 					glist->group->qgroupid,
2445 					qgroup_to_aux(glist->group), GFP_ATOMIC);
2446 			if (ret < 0)
2447 				goto out;
2448 		}
2449 	}
2450 	ret = 0;
2451 	/*
2452 	 * no limits exceeded, now record the reservation into all qgroups
2453 	 */
2454 	ULIST_ITER_INIT(&uiter);
2455 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2456 		struct btrfs_qgroup *qg;
2457 
2458 		qg = unode_aux_to_qgroup(unode);
2459 
2460 		trace_qgroup_update_reserve(fs_info, qg, num_bytes, type);
2461 		qgroup_rsv_add(fs_info, qg, num_bytes, type);
2462 	}
2463 
2464 out:
2465 	spin_unlock(&fs_info->qgroup_lock);
2466 	return ret;
2467 }
2468 
2469 /*
2470  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
2471  * qgroup).
2472  *
2473  * Will handle all higher level qgroup too.
2474  *
2475  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
2476  * This special case is only used for META_PERTRANS type.
2477  */
2478 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2479 			       u64 ref_root, u64 num_bytes,
2480 			       enum btrfs_qgroup_rsv_type type)
2481 {
2482 	struct btrfs_root *quota_root;
2483 	struct btrfs_qgroup *qgroup;
2484 	struct ulist_node *unode;
2485 	struct ulist_iterator uiter;
2486 	int ret = 0;
2487 
2488 	if (!is_fstree(ref_root))
2489 		return;
2490 
2491 	if (num_bytes == 0)
2492 		return;
2493 
2494 	if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
2495 		WARN(1, "%s: Invalid type to free", __func__);
2496 		return;
2497 	}
2498 	spin_lock(&fs_info->qgroup_lock);
2499 
2500 	quota_root = fs_info->quota_root;
2501 	if (!quota_root)
2502 		goto out;
2503 
2504 	qgroup = find_qgroup_rb(fs_info, ref_root);
2505 	if (!qgroup)
2506 		goto out;
2507 
2508 	if (num_bytes == (u64)-1)
2509 		/*
2510 		 * We're freeing all pertrans rsv, get reserved value from
2511 		 * level 0 qgroup as real num_bytes to free.
2512 		 */
2513 		num_bytes = qgroup->rsv.values[type];
2514 
2515 	ulist_reinit(fs_info->qgroup_ulist);
2516 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2517 			qgroup_to_aux(qgroup), GFP_ATOMIC);
2518 	if (ret < 0)
2519 		goto out;
2520 	ULIST_ITER_INIT(&uiter);
2521 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2522 		struct btrfs_qgroup *qg;
2523 		struct btrfs_qgroup_list *glist;
2524 
2525 		qg = unode_aux_to_qgroup(unode);
2526 
2527 		trace_qgroup_update_reserve(fs_info, qg, -(s64)num_bytes, type);
2528 		qgroup_rsv_release(fs_info, qg, num_bytes, type);
2529 
2530 		list_for_each_entry(glist, &qg->groups, next_group) {
2531 			ret = ulist_add(fs_info->qgroup_ulist,
2532 					glist->group->qgroupid,
2533 					qgroup_to_aux(glist->group), GFP_ATOMIC);
2534 			if (ret < 0)
2535 				goto out;
2536 		}
2537 	}
2538 
2539 out:
2540 	spin_unlock(&fs_info->qgroup_lock);
2541 }
2542 
2543 /*
2544  * returns < 0 on error, 0 when more leafs are to be scanned.
2545  * returns 1 when done.
2546  */
2547 static int
2548 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
2549 		   struct btrfs_trans_handle *trans)
2550 {
2551 	struct btrfs_key found;
2552 	struct extent_buffer *scratch_leaf = NULL;
2553 	struct ulist *roots = NULL;
2554 	struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
2555 	u64 num_bytes;
2556 	int slot;
2557 	int ret;
2558 
2559 	mutex_lock(&fs_info->qgroup_rescan_lock);
2560 	ret = btrfs_search_slot_for_read(fs_info->extent_root,
2561 					 &fs_info->qgroup_rescan_progress,
2562 					 path, 1, 0);
2563 
2564 	btrfs_debug(fs_info,
2565 		"current progress key (%llu %u %llu), search_slot ret %d",
2566 		fs_info->qgroup_rescan_progress.objectid,
2567 		fs_info->qgroup_rescan_progress.type,
2568 		fs_info->qgroup_rescan_progress.offset, ret);
2569 
2570 	if (ret) {
2571 		/*
2572 		 * The rescan is about to end, we will not be scanning any
2573 		 * further blocks. We cannot unset the RESCAN flag here, because
2574 		 * we want to commit the transaction if everything went well.
2575 		 * To make the live accounting work in this phase, we set our
2576 		 * scan progress pointer such that every real extent objectid
2577 		 * will be smaller.
2578 		 */
2579 		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
2580 		btrfs_release_path(path);
2581 		mutex_unlock(&fs_info->qgroup_rescan_lock);
2582 		return ret;
2583 	}
2584 
2585 	btrfs_item_key_to_cpu(path->nodes[0], &found,
2586 			      btrfs_header_nritems(path->nodes[0]) - 1);
2587 	fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
2588 
2589 	btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2590 	scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
2591 	if (!scratch_leaf) {
2592 		ret = -ENOMEM;
2593 		mutex_unlock(&fs_info->qgroup_rescan_lock);
2594 		goto out;
2595 	}
2596 	extent_buffer_get(scratch_leaf);
2597 	btrfs_tree_read_lock(scratch_leaf);
2598 	btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
2599 	slot = path->slots[0];
2600 	btrfs_release_path(path);
2601 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2602 
2603 	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
2604 		btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
2605 		if (found.type != BTRFS_EXTENT_ITEM_KEY &&
2606 		    found.type != BTRFS_METADATA_ITEM_KEY)
2607 			continue;
2608 		if (found.type == BTRFS_METADATA_ITEM_KEY)
2609 			num_bytes = fs_info->nodesize;
2610 		else
2611 			num_bytes = found.offset;
2612 
2613 		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
2614 					   &roots, false);
2615 		if (ret < 0)
2616 			goto out;
2617 		/* For rescan, just pass old_roots as NULL */
2618 		ret = btrfs_qgroup_account_extent(trans, fs_info,
2619 				found.objectid, num_bytes, NULL, roots);
2620 		if (ret < 0)
2621 			goto out;
2622 	}
2623 out:
2624 	if (scratch_leaf) {
2625 		btrfs_tree_read_unlock_blocking(scratch_leaf);
2626 		free_extent_buffer(scratch_leaf);
2627 	}
2628 	btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2629 
2630 	return ret;
2631 }
2632 
2633 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
2634 {
2635 	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
2636 						     qgroup_rescan_work);
2637 	struct btrfs_path *path;
2638 	struct btrfs_trans_handle *trans = NULL;
2639 	int err = -ENOMEM;
2640 	int ret = 0;
2641 
2642 	path = btrfs_alloc_path();
2643 	if (!path)
2644 		goto out;
2645 
2646 	err = 0;
2647 	while (!err && !btrfs_fs_closing(fs_info)) {
2648 		trans = btrfs_start_transaction(fs_info->fs_root, 0);
2649 		if (IS_ERR(trans)) {
2650 			err = PTR_ERR(trans);
2651 			break;
2652 		}
2653 		if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
2654 			err = -EINTR;
2655 		} else {
2656 			err = qgroup_rescan_leaf(fs_info, path, trans);
2657 		}
2658 		if (err > 0)
2659 			btrfs_commit_transaction(trans);
2660 		else
2661 			btrfs_end_transaction(trans);
2662 	}
2663 
2664 out:
2665 	btrfs_free_path(path);
2666 
2667 	mutex_lock(&fs_info->qgroup_rescan_lock);
2668 	if (!btrfs_fs_closing(fs_info))
2669 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2670 
2671 	if (err > 0 &&
2672 	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
2673 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2674 	} else if (err < 0) {
2675 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2676 	}
2677 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2678 
2679 	/*
2680 	 * only update status, since the previous part has already updated the
2681 	 * qgroup info.
2682 	 */
2683 	trans = btrfs_start_transaction(fs_info->quota_root, 1);
2684 	if (IS_ERR(trans)) {
2685 		err = PTR_ERR(trans);
2686 		btrfs_err(fs_info,
2687 			  "fail to start transaction for status update: %d",
2688 			  err);
2689 		goto done;
2690 	}
2691 	ret = update_qgroup_status_item(trans, fs_info, fs_info->quota_root);
2692 	if (ret < 0) {
2693 		err = ret;
2694 		btrfs_err(fs_info, "fail to update qgroup status: %d", err);
2695 	}
2696 	btrfs_end_transaction(trans);
2697 
2698 	if (btrfs_fs_closing(fs_info)) {
2699 		btrfs_info(fs_info, "qgroup scan paused");
2700 	} else if (err >= 0) {
2701 		btrfs_info(fs_info, "qgroup scan completed%s",
2702 			err > 0 ? " (inconsistency flag cleared)" : "");
2703 	} else {
2704 		btrfs_err(fs_info, "qgroup scan failed with %d", err);
2705 	}
2706 
2707 done:
2708 	mutex_lock(&fs_info->qgroup_rescan_lock);
2709 	fs_info->qgroup_rescan_running = false;
2710 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2711 	complete_all(&fs_info->qgroup_rescan_completion);
2712 }
2713 
2714 /*
2715  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
2716  * memory required for the rescan context.
2717  */
2718 static int
2719 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
2720 		   int init_flags)
2721 {
2722 	int ret = 0;
2723 
2724 	if (!init_flags &&
2725 	    (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
2726 	     !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
2727 		ret = -EINVAL;
2728 		goto err;
2729 	}
2730 
2731 	mutex_lock(&fs_info->qgroup_rescan_lock);
2732 	spin_lock(&fs_info->qgroup_lock);
2733 
2734 	if (init_flags) {
2735 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2736 			ret = -EINPROGRESS;
2737 		else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
2738 			ret = -EINVAL;
2739 
2740 		if (ret) {
2741 			spin_unlock(&fs_info->qgroup_lock);
2742 			mutex_unlock(&fs_info->qgroup_rescan_lock);
2743 			goto err;
2744 		}
2745 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2746 	}
2747 
2748 	memset(&fs_info->qgroup_rescan_progress, 0,
2749 		sizeof(fs_info->qgroup_rescan_progress));
2750 	fs_info->qgroup_rescan_progress.objectid = progress_objectid;
2751 	init_completion(&fs_info->qgroup_rescan_completion);
2752 	fs_info->qgroup_rescan_running = true;
2753 
2754 	spin_unlock(&fs_info->qgroup_lock);
2755 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2756 
2757 	memset(&fs_info->qgroup_rescan_work, 0,
2758 	       sizeof(fs_info->qgroup_rescan_work));
2759 	btrfs_init_work(&fs_info->qgroup_rescan_work,
2760 			btrfs_qgroup_rescan_helper,
2761 			btrfs_qgroup_rescan_worker, NULL, NULL);
2762 
2763 	if (ret) {
2764 err:
2765 		btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
2766 		return ret;
2767 	}
2768 
2769 	return 0;
2770 }
2771 
2772 static void
2773 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
2774 {
2775 	struct rb_node *n;
2776 	struct btrfs_qgroup *qgroup;
2777 
2778 	spin_lock(&fs_info->qgroup_lock);
2779 	/* clear all current qgroup tracking information */
2780 	for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
2781 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
2782 		qgroup->rfer = 0;
2783 		qgroup->rfer_cmpr = 0;
2784 		qgroup->excl = 0;
2785 		qgroup->excl_cmpr = 0;
2786 	}
2787 	spin_unlock(&fs_info->qgroup_lock);
2788 }
2789 
2790 int
2791 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
2792 {
2793 	int ret = 0;
2794 	struct btrfs_trans_handle *trans;
2795 
2796 	ret = qgroup_rescan_init(fs_info, 0, 1);
2797 	if (ret)
2798 		return ret;
2799 
2800 	/*
2801 	 * We have set the rescan_progress to 0, which means no more
2802 	 * delayed refs will be accounted by btrfs_qgroup_account_ref.
2803 	 * However, btrfs_qgroup_account_ref may be right after its call
2804 	 * to btrfs_find_all_roots, in which case it would still do the
2805 	 * accounting.
2806 	 * To solve this, we're committing the transaction, which will
2807 	 * ensure we run all delayed refs and only after that, we are
2808 	 * going to clear all tracking information for a clean start.
2809 	 */
2810 
2811 	trans = btrfs_join_transaction(fs_info->fs_root);
2812 	if (IS_ERR(trans)) {
2813 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2814 		return PTR_ERR(trans);
2815 	}
2816 	ret = btrfs_commit_transaction(trans);
2817 	if (ret) {
2818 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2819 		return ret;
2820 	}
2821 
2822 	qgroup_rescan_zero_tracking(fs_info);
2823 
2824 	btrfs_queue_work(fs_info->qgroup_rescan_workers,
2825 			 &fs_info->qgroup_rescan_work);
2826 
2827 	return 0;
2828 }
2829 
2830 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
2831 				     bool interruptible)
2832 {
2833 	int running;
2834 	int ret = 0;
2835 
2836 	mutex_lock(&fs_info->qgroup_rescan_lock);
2837 	spin_lock(&fs_info->qgroup_lock);
2838 	running = fs_info->qgroup_rescan_running;
2839 	spin_unlock(&fs_info->qgroup_lock);
2840 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2841 
2842 	if (!running)
2843 		return 0;
2844 
2845 	if (interruptible)
2846 		ret = wait_for_completion_interruptible(
2847 					&fs_info->qgroup_rescan_completion);
2848 	else
2849 		wait_for_completion(&fs_info->qgroup_rescan_completion);
2850 
2851 	return ret;
2852 }
2853 
2854 /*
2855  * this is only called from open_ctree where we're still single threaded, thus
2856  * locking is omitted here.
2857  */
2858 void
2859 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
2860 {
2861 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2862 		btrfs_queue_work(fs_info->qgroup_rescan_workers,
2863 				 &fs_info->qgroup_rescan_work);
2864 }
2865 
2866 /*
2867  * Reserve qgroup space for range [start, start + len).
2868  *
2869  * This function will either reserve space from related qgroups or doing
2870  * nothing if the range is already reserved.
2871  *
2872  * Return 0 for successful reserve
2873  * Return <0 for error (including -EQUOT)
2874  *
2875  * NOTE: this function may sleep for memory allocation.
2876  *       if btrfs_qgroup_reserve_data() is called multiple times with
2877  *       same @reserved, caller must ensure when error happens it's OK
2878  *       to free *ALL* reserved space.
2879  */
2880 int btrfs_qgroup_reserve_data(struct inode *inode,
2881 			struct extent_changeset **reserved_ret, u64 start,
2882 			u64 len)
2883 {
2884 	struct btrfs_root *root = BTRFS_I(inode)->root;
2885 	struct ulist_node *unode;
2886 	struct ulist_iterator uiter;
2887 	struct extent_changeset *reserved;
2888 	u64 orig_reserved;
2889 	u64 to_reserve;
2890 	int ret;
2891 
2892 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
2893 	    !is_fstree(root->objectid) || len == 0)
2894 		return 0;
2895 
2896 	/* @reserved parameter is mandatory for qgroup */
2897 	if (WARN_ON(!reserved_ret))
2898 		return -EINVAL;
2899 	if (!*reserved_ret) {
2900 		*reserved_ret = extent_changeset_alloc();
2901 		if (!*reserved_ret)
2902 			return -ENOMEM;
2903 	}
2904 	reserved = *reserved_ret;
2905 	/* Record already reserved space */
2906 	orig_reserved = reserved->bytes_changed;
2907 	ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2908 			start + len -1, EXTENT_QGROUP_RESERVED, reserved);
2909 
2910 	/* Newly reserved space */
2911 	to_reserve = reserved->bytes_changed - orig_reserved;
2912 	trace_btrfs_qgroup_reserve_data(inode, start, len,
2913 					to_reserve, QGROUP_RESERVE);
2914 	if (ret < 0)
2915 		goto cleanup;
2916 	ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
2917 	if (ret < 0)
2918 		goto cleanup;
2919 
2920 	return ret;
2921 
2922 cleanup:
2923 	/* cleanup *ALL* already reserved ranges */
2924 	ULIST_ITER_INIT(&uiter);
2925 	while ((unode = ulist_next(&reserved->range_changed, &uiter)))
2926 		clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
2927 				 unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL);
2928 	extent_changeset_release(reserved);
2929 	return ret;
2930 }
2931 
2932 /* Free ranges specified by @reserved, normally in error path */
2933 static int qgroup_free_reserved_data(struct inode *inode,
2934 			struct extent_changeset *reserved, u64 start, u64 len)
2935 {
2936 	struct btrfs_root *root = BTRFS_I(inode)->root;
2937 	struct ulist_node *unode;
2938 	struct ulist_iterator uiter;
2939 	struct extent_changeset changeset;
2940 	int freed = 0;
2941 	int ret;
2942 
2943 	extent_changeset_init(&changeset);
2944 	len = round_up(start + len, root->fs_info->sectorsize);
2945 	start = round_down(start, root->fs_info->sectorsize);
2946 
2947 	ULIST_ITER_INIT(&uiter);
2948 	while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
2949 		u64 range_start = unode->val;
2950 		/* unode->aux is the inclusive end */
2951 		u64 range_len = unode->aux - range_start + 1;
2952 		u64 free_start;
2953 		u64 free_len;
2954 
2955 		extent_changeset_release(&changeset);
2956 
2957 		/* Only free range in range [start, start + len) */
2958 		if (range_start >= start + len ||
2959 		    range_start + range_len <= start)
2960 			continue;
2961 		free_start = max(range_start, start);
2962 		free_len = min(start + len, range_start + range_len) -
2963 			   free_start;
2964 		/*
2965 		 * TODO: To also modify reserved->ranges_reserved to reflect
2966 		 * the modification.
2967 		 *
2968 		 * However as long as we free qgroup reserved according to
2969 		 * EXTENT_QGROUP_RESERVED, we won't double free.
2970 		 * So not need to rush.
2971 		 */
2972 		ret = clear_record_extent_bits(&BTRFS_I(inode)->io_failure_tree,
2973 				free_start, free_start + free_len - 1,
2974 				EXTENT_QGROUP_RESERVED, &changeset);
2975 		if (ret < 0)
2976 			goto out;
2977 		freed += changeset.bytes_changed;
2978 	}
2979 	btrfs_qgroup_free_refroot(root->fs_info, root->objectid, freed,
2980 				  BTRFS_QGROUP_RSV_DATA);
2981 	ret = freed;
2982 out:
2983 	extent_changeset_release(&changeset);
2984 	return ret;
2985 }
2986 
2987 static int __btrfs_qgroup_release_data(struct inode *inode,
2988 			struct extent_changeset *reserved, u64 start, u64 len,
2989 			int free)
2990 {
2991 	struct extent_changeset changeset;
2992 	int trace_op = QGROUP_RELEASE;
2993 	int ret;
2994 
2995 	/* In release case, we shouldn't have @reserved */
2996 	WARN_ON(!free && reserved);
2997 	if (free && reserved)
2998 		return qgroup_free_reserved_data(inode, reserved, start, len);
2999 	extent_changeset_init(&changeset);
3000 	ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
3001 			start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
3002 	if (ret < 0)
3003 		goto out;
3004 
3005 	if (free)
3006 		trace_op = QGROUP_FREE;
3007 	trace_btrfs_qgroup_release_data(inode, start, len,
3008 					changeset.bytes_changed, trace_op);
3009 	if (free)
3010 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3011 				BTRFS_I(inode)->root->objectid,
3012 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3013 	ret = changeset.bytes_changed;
3014 out:
3015 	extent_changeset_release(&changeset);
3016 	return ret;
3017 }
3018 
3019 /*
3020  * Free a reserved space range from io_tree and related qgroups
3021  *
3022  * Should be called when a range of pages get invalidated before reaching disk.
3023  * Or for error cleanup case.
3024  * if @reserved is given, only reserved range in [@start, @start + @len) will
3025  * be freed.
3026  *
3027  * For data written to disk, use btrfs_qgroup_release_data().
3028  *
3029  * NOTE: This function may sleep for memory allocation.
3030  */
3031 int btrfs_qgroup_free_data(struct inode *inode,
3032 			struct extent_changeset *reserved, u64 start, u64 len)
3033 {
3034 	return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3035 }
3036 
3037 /*
3038  * Release a reserved space range from io_tree only.
3039  *
3040  * Should be called when a range of pages get written to disk and corresponding
3041  * FILE_EXTENT is inserted into corresponding root.
3042  *
3043  * Since new qgroup accounting framework will only update qgroup numbers at
3044  * commit_transaction() time, its reserved space shouldn't be freed from
3045  * related qgroups.
3046  *
3047  * But we should release the range from io_tree, to allow further write to be
3048  * COWed.
3049  *
3050  * NOTE: This function may sleep for memory allocation.
3051  */
3052 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
3053 {
3054 	return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3055 }
3056 
3057 static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3058 			      enum btrfs_qgroup_rsv_type type)
3059 {
3060 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3061 	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3062 		return;
3063 	if (num_bytes == 0)
3064 		return;
3065 
3066 	spin_lock(&root->qgroup_meta_rsv_lock);
3067 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3068 		root->qgroup_meta_rsv_prealloc += num_bytes;
3069 	else
3070 		root->qgroup_meta_rsv_pertrans += num_bytes;
3071 	spin_unlock(&root->qgroup_meta_rsv_lock);
3072 }
3073 
3074 static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3075 			     enum btrfs_qgroup_rsv_type type)
3076 {
3077 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3078 	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3079 		return 0;
3080 	if (num_bytes == 0)
3081 		return 0;
3082 
3083 	spin_lock(&root->qgroup_meta_rsv_lock);
3084 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3085 		num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3086 				  num_bytes);
3087 		root->qgroup_meta_rsv_prealloc -= num_bytes;
3088 	} else {
3089 		num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3090 				  num_bytes);
3091 		root->qgroup_meta_rsv_pertrans -= num_bytes;
3092 	}
3093 	spin_unlock(&root->qgroup_meta_rsv_lock);
3094 	return num_bytes;
3095 }
3096 
3097 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3098 				enum btrfs_qgroup_rsv_type type, bool enforce)
3099 {
3100 	struct btrfs_fs_info *fs_info = root->fs_info;
3101 	int ret;
3102 
3103 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3104 	    !is_fstree(root->objectid) || num_bytes == 0)
3105 		return 0;
3106 
3107 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3108 	trace_qgroup_meta_reserve(root, type, (s64)num_bytes);
3109 	ret = qgroup_reserve(root, num_bytes, enforce, type);
3110 	if (ret < 0)
3111 		return ret;
3112 	/*
3113 	 * Record what we have reserved into root.
3114 	 *
3115 	 * To avoid quota disabled->enabled underflow.
3116 	 * In that case, we may try to free space we haven't reserved
3117 	 * (since quota was disabled), so record what we reserved into root.
3118 	 * And ensure later release won't underflow this number.
3119 	 */
3120 	add_root_meta_rsv(root, num_bytes, type);
3121 	return ret;
3122 }
3123 
3124 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
3125 {
3126 	struct btrfs_fs_info *fs_info = root->fs_info;
3127 
3128 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3129 	    !is_fstree(root->objectid))
3130 		return;
3131 
3132 	/* TODO: Update trace point to handle such free */
3133 	trace_qgroup_meta_free_all_pertrans(root);
3134 	/* Special value -1 means to free all reserved space */
3135 	btrfs_qgroup_free_refroot(fs_info, root->objectid, (u64)-1,
3136 				  BTRFS_QGROUP_RSV_META_PERTRANS);
3137 }
3138 
3139 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
3140 			      enum btrfs_qgroup_rsv_type type)
3141 {
3142 	struct btrfs_fs_info *fs_info = root->fs_info;
3143 
3144 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3145 	    !is_fstree(root->objectid))
3146 		return;
3147 
3148 	/*
3149 	 * reservation for META_PREALLOC can happen before quota is enabled,
3150 	 * which can lead to underflow.
3151 	 * Here ensure we will only free what we really have reserved.
3152 	 */
3153 	num_bytes = sub_root_meta_rsv(root, num_bytes, type);
3154 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3155 	trace_qgroup_meta_reserve(root, type, -(s64)num_bytes);
3156 	btrfs_qgroup_free_refroot(fs_info, root->objectid, num_bytes, type);
3157 }
3158 
3159 static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
3160 				int num_bytes)
3161 {
3162 	struct btrfs_root *quota_root = fs_info->quota_root;
3163 	struct btrfs_qgroup *qgroup;
3164 	struct ulist_node *unode;
3165 	struct ulist_iterator uiter;
3166 	int ret = 0;
3167 
3168 	if (num_bytes == 0)
3169 		return;
3170 	if (!quota_root)
3171 		return;
3172 
3173 	spin_lock(&fs_info->qgroup_lock);
3174 	qgroup = find_qgroup_rb(fs_info, ref_root);
3175 	if (!qgroup)
3176 		goto out;
3177 	ulist_reinit(fs_info->qgroup_ulist);
3178 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3179 		       qgroup_to_aux(qgroup), GFP_ATOMIC);
3180 	if (ret < 0)
3181 		goto out;
3182 	ULIST_ITER_INIT(&uiter);
3183 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3184 		struct btrfs_qgroup *qg;
3185 		struct btrfs_qgroup_list *glist;
3186 
3187 		qg = unode_aux_to_qgroup(unode);
3188 
3189 		qgroup_rsv_release(fs_info, qg, num_bytes,
3190 				BTRFS_QGROUP_RSV_META_PREALLOC);
3191 		qgroup_rsv_add(fs_info, qg, num_bytes,
3192 				BTRFS_QGROUP_RSV_META_PERTRANS);
3193 		list_for_each_entry(glist, &qg->groups, next_group) {
3194 			ret = ulist_add(fs_info->qgroup_ulist,
3195 					glist->group->qgroupid,
3196 					qgroup_to_aux(glist->group), GFP_ATOMIC);
3197 			if (ret < 0)
3198 				goto out;
3199 		}
3200 	}
3201 out:
3202 	spin_unlock(&fs_info->qgroup_lock);
3203 }
3204 
3205 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
3206 {
3207 	struct btrfs_fs_info *fs_info = root->fs_info;
3208 
3209 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3210 	    !is_fstree(root->objectid))
3211 		return;
3212 	/* Same as btrfs_qgroup_free_meta_prealloc() */
3213 	num_bytes = sub_root_meta_rsv(root, num_bytes,
3214 				      BTRFS_QGROUP_RSV_META_PREALLOC);
3215 	trace_qgroup_meta_convert(root, num_bytes);
3216 	qgroup_convert_meta(fs_info, root->objectid, num_bytes);
3217 }
3218 
3219 /*
3220  * Check qgroup reserved space leaking, normally at destroy inode
3221  * time
3222  */
3223 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
3224 {
3225 	struct extent_changeset changeset;
3226 	struct ulist_node *unode;
3227 	struct ulist_iterator iter;
3228 	int ret;
3229 
3230 	extent_changeset_init(&changeset);
3231 	ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
3232 			EXTENT_QGROUP_RESERVED, &changeset);
3233 
3234 	WARN_ON(ret < 0);
3235 	if (WARN_ON(changeset.bytes_changed)) {
3236 		ULIST_ITER_INIT(&iter);
3237 		while ((unode = ulist_next(&changeset.range_changed, &iter))) {
3238 			btrfs_warn(BTRFS_I(inode)->root->fs_info,
3239 				"leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
3240 				inode->i_ino, unode->val, unode->aux);
3241 		}
3242 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3243 				BTRFS_I(inode)->root->objectid,
3244 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3245 
3246 	}
3247 	extent_changeset_release(&changeset);
3248 }
3249