xref: /openbmc/linux/fs/btrfs/qgroup.c (revision e3d786a3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2011 STRATO.  All rights reserved.
4  */
5 
6 #include <linux/sched.h>
7 #include <linux/pagemap.h>
8 #include <linux/writeback.h>
9 #include <linux/blkdev.h>
10 #include <linux/rbtree.h>
11 #include <linux/slab.h>
12 #include <linux/workqueue.h>
13 #include <linux/btrfs.h>
14 #include <linux/sizes.h>
15 
16 #include "ctree.h"
17 #include "transaction.h"
18 #include "disk-io.h"
19 #include "locking.h"
20 #include "ulist.h"
21 #include "backref.h"
22 #include "extent_io.h"
23 #include "qgroup.h"
24 
25 
26 /* TODO XXX FIXME
27  *  - subvol delete -> delete when ref goes to 0? delete limits also?
28  *  - reorganize keys
29  *  - compressed
30  *  - sync
31  *  - copy also limits on subvol creation
32  *  - limit
33  *  - caches fuer ulists
34  *  - performance benchmarks
35  *  - check all ioctl parameters
36  */
37 
38 /*
39  * Helpers to access qgroup reservation
40  *
41  * Callers should ensure the lock context and type are valid
42  */
43 
44 static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
45 {
46 	u64 ret = 0;
47 	int i;
48 
49 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
50 		ret += qgroup->rsv.values[i];
51 
52 	return ret;
53 }
54 
55 #ifdef CONFIG_BTRFS_DEBUG
56 static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
57 {
58 	if (type == BTRFS_QGROUP_RSV_DATA)
59 		return "data";
60 	if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
61 		return "meta_pertrans";
62 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
63 		return "meta_prealloc";
64 	return NULL;
65 }
66 #endif
67 
68 static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
69 			   struct btrfs_qgroup *qgroup, u64 num_bytes,
70 			   enum btrfs_qgroup_rsv_type type)
71 {
72 	trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
73 	qgroup->rsv.values[type] += num_bytes;
74 }
75 
76 static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
77 			       struct btrfs_qgroup *qgroup, u64 num_bytes,
78 			       enum btrfs_qgroup_rsv_type type)
79 {
80 	trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
81 	if (qgroup->rsv.values[type] >= num_bytes) {
82 		qgroup->rsv.values[type] -= num_bytes;
83 		return;
84 	}
85 #ifdef CONFIG_BTRFS_DEBUG
86 	WARN_RATELIMIT(1,
87 		"qgroup %llu %s reserved space underflow, have %llu to free %llu",
88 		qgroup->qgroupid, qgroup_rsv_type_str(type),
89 		qgroup->rsv.values[type], num_bytes);
90 #endif
91 	qgroup->rsv.values[type] = 0;
92 }
93 
94 static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
95 				     struct btrfs_qgroup *dest,
96 				     struct btrfs_qgroup *src)
97 {
98 	int i;
99 
100 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
101 		qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
102 }
103 
104 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
105 					 struct btrfs_qgroup *dest,
106 					  struct btrfs_qgroup *src)
107 {
108 	int i;
109 
110 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
111 		qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
112 }
113 
114 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
115 					   int mod)
116 {
117 	if (qg->old_refcnt < seq)
118 		qg->old_refcnt = seq;
119 	qg->old_refcnt += mod;
120 }
121 
122 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
123 					   int mod)
124 {
125 	if (qg->new_refcnt < seq)
126 		qg->new_refcnt = seq;
127 	qg->new_refcnt += mod;
128 }
129 
130 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
131 {
132 	if (qg->old_refcnt < seq)
133 		return 0;
134 	return qg->old_refcnt - seq;
135 }
136 
137 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
138 {
139 	if (qg->new_refcnt < seq)
140 		return 0;
141 	return qg->new_refcnt - seq;
142 }
143 
144 /*
145  * glue structure to represent the relations between qgroups.
146  */
147 struct btrfs_qgroup_list {
148 	struct list_head next_group;
149 	struct list_head next_member;
150 	struct btrfs_qgroup *group;
151 	struct btrfs_qgroup *member;
152 };
153 
154 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
155 {
156 	return (u64)(uintptr_t)qg;
157 }
158 
159 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
160 {
161 	return (struct btrfs_qgroup *)(uintptr_t)n->aux;
162 }
163 
164 static int
165 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
166 		   int init_flags);
167 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
168 
169 /* must be called with qgroup_ioctl_lock held */
170 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
171 					   u64 qgroupid)
172 {
173 	struct rb_node *n = fs_info->qgroup_tree.rb_node;
174 	struct btrfs_qgroup *qgroup;
175 
176 	while (n) {
177 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
178 		if (qgroup->qgroupid < qgroupid)
179 			n = n->rb_left;
180 		else if (qgroup->qgroupid > qgroupid)
181 			n = n->rb_right;
182 		else
183 			return qgroup;
184 	}
185 	return NULL;
186 }
187 
188 /* must be called with qgroup_lock held */
189 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
190 					  u64 qgroupid)
191 {
192 	struct rb_node **p = &fs_info->qgroup_tree.rb_node;
193 	struct rb_node *parent = NULL;
194 	struct btrfs_qgroup *qgroup;
195 
196 	while (*p) {
197 		parent = *p;
198 		qgroup = rb_entry(parent, struct btrfs_qgroup, node);
199 
200 		if (qgroup->qgroupid < qgroupid)
201 			p = &(*p)->rb_left;
202 		else if (qgroup->qgroupid > qgroupid)
203 			p = &(*p)->rb_right;
204 		else
205 			return qgroup;
206 	}
207 
208 	qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
209 	if (!qgroup)
210 		return ERR_PTR(-ENOMEM);
211 
212 	qgroup->qgroupid = qgroupid;
213 	INIT_LIST_HEAD(&qgroup->groups);
214 	INIT_LIST_HEAD(&qgroup->members);
215 	INIT_LIST_HEAD(&qgroup->dirty);
216 
217 	rb_link_node(&qgroup->node, parent, p);
218 	rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
219 
220 	return qgroup;
221 }
222 
223 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
224 {
225 	struct btrfs_qgroup_list *list;
226 
227 	list_del(&qgroup->dirty);
228 	while (!list_empty(&qgroup->groups)) {
229 		list = list_first_entry(&qgroup->groups,
230 					struct btrfs_qgroup_list, next_group);
231 		list_del(&list->next_group);
232 		list_del(&list->next_member);
233 		kfree(list);
234 	}
235 
236 	while (!list_empty(&qgroup->members)) {
237 		list = list_first_entry(&qgroup->members,
238 					struct btrfs_qgroup_list, next_member);
239 		list_del(&list->next_group);
240 		list_del(&list->next_member);
241 		kfree(list);
242 	}
243 	kfree(qgroup);
244 }
245 
246 /* must be called with qgroup_lock held */
247 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
248 {
249 	struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
250 
251 	if (!qgroup)
252 		return -ENOENT;
253 
254 	rb_erase(&qgroup->node, &fs_info->qgroup_tree);
255 	__del_qgroup_rb(qgroup);
256 	return 0;
257 }
258 
259 /* must be called with qgroup_lock held */
260 static int add_relation_rb(struct btrfs_fs_info *fs_info,
261 			   u64 memberid, u64 parentid)
262 {
263 	struct btrfs_qgroup *member;
264 	struct btrfs_qgroup *parent;
265 	struct btrfs_qgroup_list *list;
266 
267 	member = find_qgroup_rb(fs_info, memberid);
268 	parent = find_qgroup_rb(fs_info, parentid);
269 	if (!member || !parent)
270 		return -ENOENT;
271 
272 	list = kzalloc(sizeof(*list), GFP_ATOMIC);
273 	if (!list)
274 		return -ENOMEM;
275 
276 	list->group = parent;
277 	list->member = member;
278 	list_add_tail(&list->next_group, &member->groups);
279 	list_add_tail(&list->next_member, &parent->members);
280 
281 	return 0;
282 }
283 
284 /* must be called with qgroup_lock held */
285 static int del_relation_rb(struct btrfs_fs_info *fs_info,
286 			   u64 memberid, u64 parentid)
287 {
288 	struct btrfs_qgroup *member;
289 	struct btrfs_qgroup *parent;
290 	struct btrfs_qgroup_list *list;
291 
292 	member = find_qgroup_rb(fs_info, memberid);
293 	parent = find_qgroup_rb(fs_info, parentid);
294 	if (!member || !parent)
295 		return -ENOENT;
296 
297 	list_for_each_entry(list, &member->groups, next_group) {
298 		if (list->group == parent) {
299 			list_del(&list->next_group);
300 			list_del(&list->next_member);
301 			kfree(list);
302 			return 0;
303 		}
304 	}
305 	return -ENOENT;
306 }
307 
308 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
309 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
310 			       u64 rfer, u64 excl)
311 {
312 	struct btrfs_qgroup *qgroup;
313 
314 	qgroup = find_qgroup_rb(fs_info, qgroupid);
315 	if (!qgroup)
316 		return -EINVAL;
317 	if (qgroup->rfer != rfer || qgroup->excl != excl)
318 		return -EINVAL;
319 	return 0;
320 }
321 #endif
322 
323 /*
324  * The full config is read in one go, only called from open_ctree()
325  * It doesn't use any locking, as at this point we're still single-threaded
326  */
327 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
328 {
329 	struct btrfs_key key;
330 	struct btrfs_key found_key;
331 	struct btrfs_root *quota_root = fs_info->quota_root;
332 	struct btrfs_path *path = NULL;
333 	struct extent_buffer *l;
334 	int slot;
335 	int ret = 0;
336 	u64 flags = 0;
337 	u64 rescan_progress = 0;
338 
339 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
340 		return 0;
341 
342 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
343 	if (!fs_info->qgroup_ulist) {
344 		ret = -ENOMEM;
345 		goto out;
346 	}
347 
348 	path = btrfs_alloc_path();
349 	if (!path) {
350 		ret = -ENOMEM;
351 		goto out;
352 	}
353 
354 	/* default this to quota off, in case no status key is found */
355 	fs_info->qgroup_flags = 0;
356 
357 	/*
358 	 * pass 1: read status, all qgroup infos and limits
359 	 */
360 	key.objectid = 0;
361 	key.type = 0;
362 	key.offset = 0;
363 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
364 	if (ret)
365 		goto out;
366 
367 	while (1) {
368 		struct btrfs_qgroup *qgroup;
369 
370 		slot = path->slots[0];
371 		l = path->nodes[0];
372 		btrfs_item_key_to_cpu(l, &found_key, slot);
373 
374 		if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
375 			struct btrfs_qgroup_status_item *ptr;
376 
377 			ptr = btrfs_item_ptr(l, slot,
378 					     struct btrfs_qgroup_status_item);
379 
380 			if (btrfs_qgroup_status_version(l, ptr) !=
381 			    BTRFS_QGROUP_STATUS_VERSION) {
382 				btrfs_err(fs_info,
383 				 "old qgroup version, quota disabled");
384 				goto out;
385 			}
386 			if (btrfs_qgroup_status_generation(l, ptr) !=
387 			    fs_info->generation) {
388 				flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
389 				btrfs_err(fs_info,
390 					"qgroup generation mismatch, marked as inconsistent");
391 			}
392 			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
393 									  ptr);
394 			rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
395 			goto next1;
396 		}
397 
398 		if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
399 		    found_key.type != BTRFS_QGROUP_LIMIT_KEY)
400 			goto next1;
401 
402 		qgroup = find_qgroup_rb(fs_info, found_key.offset);
403 		if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
404 		    (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
405 			btrfs_err(fs_info, "inconsistent qgroup config");
406 			flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
407 		}
408 		if (!qgroup) {
409 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
410 			if (IS_ERR(qgroup)) {
411 				ret = PTR_ERR(qgroup);
412 				goto out;
413 			}
414 		}
415 		switch (found_key.type) {
416 		case BTRFS_QGROUP_INFO_KEY: {
417 			struct btrfs_qgroup_info_item *ptr;
418 
419 			ptr = btrfs_item_ptr(l, slot,
420 					     struct btrfs_qgroup_info_item);
421 			qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
422 			qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
423 			qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
424 			qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
425 			/* generation currently unused */
426 			break;
427 		}
428 		case BTRFS_QGROUP_LIMIT_KEY: {
429 			struct btrfs_qgroup_limit_item *ptr;
430 
431 			ptr = btrfs_item_ptr(l, slot,
432 					     struct btrfs_qgroup_limit_item);
433 			qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
434 			qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
435 			qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
436 			qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
437 			qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
438 			break;
439 		}
440 		}
441 next1:
442 		ret = btrfs_next_item(quota_root, path);
443 		if (ret < 0)
444 			goto out;
445 		if (ret)
446 			break;
447 	}
448 	btrfs_release_path(path);
449 
450 	/*
451 	 * pass 2: read all qgroup relations
452 	 */
453 	key.objectid = 0;
454 	key.type = BTRFS_QGROUP_RELATION_KEY;
455 	key.offset = 0;
456 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
457 	if (ret)
458 		goto out;
459 	while (1) {
460 		slot = path->slots[0];
461 		l = path->nodes[0];
462 		btrfs_item_key_to_cpu(l, &found_key, slot);
463 
464 		if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
465 			goto next2;
466 
467 		if (found_key.objectid > found_key.offset) {
468 			/* parent <- member, not needed to build config */
469 			/* FIXME should we omit the key completely? */
470 			goto next2;
471 		}
472 
473 		ret = add_relation_rb(fs_info, found_key.objectid,
474 				      found_key.offset);
475 		if (ret == -ENOENT) {
476 			btrfs_warn(fs_info,
477 				"orphan qgroup relation 0x%llx->0x%llx",
478 				found_key.objectid, found_key.offset);
479 			ret = 0;	/* ignore the error */
480 		}
481 		if (ret)
482 			goto out;
483 next2:
484 		ret = btrfs_next_item(quota_root, path);
485 		if (ret < 0)
486 			goto out;
487 		if (ret)
488 			break;
489 	}
490 out:
491 	fs_info->qgroup_flags |= flags;
492 	if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
493 		clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
494 	else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
495 		 ret >= 0)
496 		ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
497 	btrfs_free_path(path);
498 
499 	if (ret < 0) {
500 		ulist_free(fs_info->qgroup_ulist);
501 		fs_info->qgroup_ulist = NULL;
502 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
503 	}
504 
505 	return ret < 0 ? ret : 0;
506 }
507 
508 /*
509  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
510  * first two are in single-threaded paths.And for the third one, we have set
511  * quota_root to be null with qgroup_lock held before, so it is safe to clean
512  * up the in-memory structures without qgroup_lock held.
513  */
514 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
515 {
516 	struct rb_node *n;
517 	struct btrfs_qgroup *qgroup;
518 
519 	while ((n = rb_first(&fs_info->qgroup_tree))) {
520 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
521 		rb_erase(n, &fs_info->qgroup_tree);
522 		__del_qgroup_rb(qgroup);
523 	}
524 	/*
525 	 * we call btrfs_free_qgroup_config() when umounting
526 	 * filesystem and disabling quota, so we set qgroup_ulist
527 	 * to be null here to avoid double free.
528 	 */
529 	ulist_free(fs_info->qgroup_ulist);
530 	fs_info->qgroup_ulist = NULL;
531 }
532 
533 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
534 				    u64 dst)
535 {
536 	int ret;
537 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
538 	struct btrfs_path *path;
539 	struct btrfs_key key;
540 
541 	path = btrfs_alloc_path();
542 	if (!path)
543 		return -ENOMEM;
544 
545 	key.objectid = src;
546 	key.type = BTRFS_QGROUP_RELATION_KEY;
547 	key.offset = dst;
548 
549 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
550 
551 	btrfs_mark_buffer_dirty(path->nodes[0]);
552 
553 	btrfs_free_path(path);
554 	return ret;
555 }
556 
557 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
558 				    u64 dst)
559 {
560 	int ret;
561 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
562 	struct btrfs_path *path;
563 	struct btrfs_key key;
564 
565 	path = btrfs_alloc_path();
566 	if (!path)
567 		return -ENOMEM;
568 
569 	key.objectid = src;
570 	key.type = BTRFS_QGROUP_RELATION_KEY;
571 	key.offset = dst;
572 
573 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
574 	if (ret < 0)
575 		goto out;
576 
577 	if (ret > 0) {
578 		ret = -ENOENT;
579 		goto out;
580 	}
581 
582 	ret = btrfs_del_item(trans, quota_root, path);
583 out:
584 	btrfs_free_path(path);
585 	return ret;
586 }
587 
588 static int add_qgroup_item(struct btrfs_trans_handle *trans,
589 			   struct btrfs_root *quota_root, u64 qgroupid)
590 {
591 	int ret;
592 	struct btrfs_path *path;
593 	struct btrfs_qgroup_info_item *qgroup_info;
594 	struct btrfs_qgroup_limit_item *qgroup_limit;
595 	struct extent_buffer *leaf;
596 	struct btrfs_key key;
597 
598 	if (btrfs_is_testing(quota_root->fs_info))
599 		return 0;
600 
601 	path = btrfs_alloc_path();
602 	if (!path)
603 		return -ENOMEM;
604 
605 	key.objectid = 0;
606 	key.type = BTRFS_QGROUP_INFO_KEY;
607 	key.offset = qgroupid;
608 
609 	/*
610 	 * Avoid a transaction abort by catching -EEXIST here. In that
611 	 * case, we proceed by re-initializing the existing structure
612 	 * on disk.
613 	 */
614 
615 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
616 				      sizeof(*qgroup_info));
617 	if (ret && ret != -EEXIST)
618 		goto out;
619 
620 	leaf = path->nodes[0];
621 	qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
622 				 struct btrfs_qgroup_info_item);
623 	btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
624 	btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
625 	btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
626 	btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
627 	btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
628 
629 	btrfs_mark_buffer_dirty(leaf);
630 
631 	btrfs_release_path(path);
632 
633 	key.type = BTRFS_QGROUP_LIMIT_KEY;
634 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
635 				      sizeof(*qgroup_limit));
636 	if (ret && ret != -EEXIST)
637 		goto out;
638 
639 	leaf = path->nodes[0];
640 	qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
641 				  struct btrfs_qgroup_limit_item);
642 	btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
643 	btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
644 	btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
645 	btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
646 	btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
647 
648 	btrfs_mark_buffer_dirty(leaf);
649 
650 	ret = 0;
651 out:
652 	btrfs_free_path(path);
653 	return ret;
654 }
655 
656 static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
657 {
658 	int ret;
659 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
660 	struct btrfs_path *path;
661 	struct btrfs_key key;
662 
663 	path = btrfs_alloc_path();
664 	if (!path)
665 		return -ENOMEM;
666 
667 	key.objectid = 0;
668 	key.type = BTRFS_QGROUP_INFO_KEY;
669 	key.offset = qgroupid;
670 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
671 	if (ret < 0)
672 		goto out;
673 
674 	if (ret > 0) {
675 		ret = -ENOENT;
676 		goto out;
677 	}
678 
679 	ret = btrfs_del_item(trans, quota_root, path);
680 	if (ret)
681 		goto out;
682 
683 	btrfs_release_path(path);
684 
685 	key.type = BTRFS_QGROUP_LIMIT_KEY;
686 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
687 	if (ret < 0)
688 		goto out;
689 
690 	if (ret > 0) {
691 		ret = -ENOENT;
692 		goto out;
693 	}
694 
695 	ret = btrfs_del_item(trans, quota_root, path);
696 
697 out:
698 	btrfs_free_path(path);
699 	return ret;
700 }
701 
702 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
703 				    struct btrfs_qgroup *qgroup)
704 {
705 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
706 	struct btrfs_path *path;
707 	struct btrfs_key key;
708 	struct extent_buffer *l;
709 	struct btrfs_qgroup_limit_item *qgroup_limit;
710 	int ret;
711 	int slot;
712 
713 	key.objectid = 0;
714 	key.type = BTRFS_QGROUP_LIMIT_KEY;
715 	key.offset = qgroup->qgroupid;
716 
717 	path = btrfs_alloc_path();
718 	if (!path)
719 		return -ENOMEM;
720 
721 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
722 	if (ret > 0)
723 		ret = -ENOENT;
724 
725 	if (ret)
726 		goto out;
727 
728 	l = path->nodes[0];
729 	slot = path->slots[0];
730 	qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
731 	btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
732 	btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
733 	btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
734 	btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
735 	btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
736 
737 	btrfs_mark_buffer_dirty(l);
738 
739 out:
740 	btrfs_free_path(path);
741 	return ret;
742 }
743 
744 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
745 				   struct btrfs_qgroup *qgroup)
746 {
747 	struct btrfs_fs_info *fs_info = trans->fs_info;
748 	struct btrfs_root *quota_root = fs_info->quota_root;
749 	struct btrfs_path *path;
750 	struct btrfs_key key;
751 	struct extent_buffer *l;
752 	struct btrfs_qgroup_info_item *qgroup_info;
753 	int ret;
754 	int slot;
755 
756 	if (btrfs_is_testing(fs_info))
757 		return 0;
758 
759 	key.objectid = 0;
760 	key.type = BTRFS_QGROUP_INFO_KEY;
761 	key.offset = qgroup->qgroupid;
762 
763 	path = btrfs_alloc_path();
764 	if (!path)
765 		return -ENOMEM;
766 
767 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
768 	if (ret > 0)
769 		ret = -ENOENT;
770 
771 	if (ret)
772 		goto out;
773 
774 	l = path->nodes[0];
775 	slot = path->slots[0];
776 	qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
777 	btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
778 	btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
779 	btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
780 	btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
781 	btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
782 
783 	btrfs_mark_buffer_dirty(l);
784 
785 out:
786 	btrfs_free_path(path);
787 	return ret;
788 }
789 
790 static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
791 {
792 	struct btrfs_fs_info *fs_info = trans->fs_info;
793 	struct btrfs_root *quota_root = fs_info->quota_root;
794 	struct btrfs_path *path;
795 	struct btrfs_key key;
796 	struct extent_buffer *l;
797 	struct btrfs_qgroup_status_item *ptr;
798 	int ret;
799 	int slot;
800 
801 	key.objectid = 0;
802 	key.type = BTRFS_QGROUP_STATUS_KEY;
803 	key.offset = 0;
804 
805 	path = btrfs_alloc_path();
806 	if (!path)
807 		return -ENOMEM;
808 
809 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
810 	if (ret > 0)
811 		ret = -ENOENT;
812 
813 	if (ret)
814 		goto out;
815 
816 	l = path->nodes[0];
817 	slot = path->slots[0];
818 	ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
819 	btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
820 	btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
821 	btrfs_set_qgroup_status_rescan(l, ptr,
822 				fs_info->qgroup_rescan_progress.objectid);
823 
824 	btrfs_mark_buffer_dirty(l);
825 
826 out:
827 	btrfs_free_path(path);
828 	return ret;
829 }
830 
831 /*
832  * called with qgroup_lock held
833  */
834 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
835 				  struct btrfs_root *root)
836 {
837 	struct btrfs_path *path;
838 	struct btrfs_key key;
839 	struct extent_buffer *leaf = NULL;
840 	int ret;
841 	int nr = 0;
842 
843 	path = btrfs_alloc_path();
844 	if (!path)
845 		return -ENOMEM;
846 
847 	path->leave_spinning = 1;
848 
849 	key.objectid = 0;
850 	key.offset = 0;
851 	key.type = 0;
852 
853 	while (1) {
854 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
855 		if (ret < 0)
856 			goto out;
857 		leaf = path->nodes[0];
858 		nr = btrfs_header_nritems(leaf);
859 		if (!nr)
860 			break;
861 		/*
862 		 * delete the leaf one by one
863 		 * since the whole tree is going
864 		 * to be deleted.
865 		 */
866 		path->slots[0] = 0;
867 		ret = btrfs_del_items(trans, root, path, 0, nr);
868 		if (ret)
869 			goto out;
870 
871 		btrfs_release_path(path);
872 	}
873 	ret = 0;
874 out:
875 	btrfs_free_path(path);
876 	return ret;
877 }
878 
879 int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
880 {
881 	struct btrfs_root *quota_root;
882 	struct btrfs_root *tree_root = fs_info->tree_root;
883 	struct btrfs_path *path = NULL;
884 	struct btrfs_qgroup_status_item *ptr;
885 	struct extent_buffer *leaf;
886 	struct btrfs_key key;
887 	struct btrfs_key found_key;
888 	struct btrfs_qgroup *qgroup = NULL;
889 	struct btrfs_trans_handle *trans = NULL;
890 	int ret = 0;
891 	int slot;
892 
893 	mutex_lock(&fs_info->qgroup_ioctl_lock);
894 	if (fs_info->quota_root)
895 		goto out;
896 
897 	/*
898 	 * 1 for quota root item
899 	 * 1 for BTRFS_QGROUP_STATUS item
900 	 *
901 	 * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
902 	 * per subvolume. However those are not currently reserved since it
903 	 * would be a lot of overkill.
904 	 */
905 	trans = btrfs_start_transaction(tree_root, 2);
906 	if (IS_ERR(trans)) {
907 		ret = PTR_ERR(trans);
908 		trans = NULL;
909 		goto out;
910 	}
911 
912 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
913 	if (!fs_info->qgroup_ulist) {
914 		ret = -ENOMEM;
915 		btrfs_abort_transaction(trans, ret);
916 		goto out;
917 	}
918 
919 	/*
920 	 * initially create the quota tree
921 	 */
922 	quota_root = btrfs_create_tree(trans, fs_info,
923 				       BTRFS_QUOTA_TREE_OBJECTID);
924 	if (IS_ERR(quota_root)) {
925 		ret =  PTR_ERR(quota_root);
926 		btrfs_abort_transaction(trans, ret);
927 		goto out;
928 	}
929 
930 	path = btrfs_alloc_path();
931 	if (!path) {
932 		ret = -ENOMEM;
933 		btrfs_abort_transaction(trans, ret);
934 		goto out_free_root;
935 	}
936 
937 	key.objectid = 0;
938 	key.type = BTRFS_QGROUP_STATUS_KEY;
939 	key.offset = 0;
940 
941 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
942 				      sizeof(*ptr));
943 	if (ret) {
944 		btrfs_abort_transaction(trans, ret);
945 		goto out_free_path;
946 	}
947 
948 	leaf = path->nodes[0];
949 	ptr = btrfs_item_ptr(leaf, path->slots[0],
950 				 struct btrfs_qgroup_status_item);
951 	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
952 	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
953 	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
954 				BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
955 	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
956 	btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
957 
958 	btrfs_mark_buffer_dirty(leaf);
959 
960 	key.objectid = 0;
961 	key.type = BTRFS_ROOT_REF_KEY;
962 	key.offset = 0;
963 
964 	btrfs_release_path(path);
965 	ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
966 	if (ret > 0)
967 		goto out_add_root;
968 	if (ret < 0) {
969 		btrfs_abort_transaction(trans, ret);
970 		goto out_free_path;
971 	}
972 
973 	while (1) {
974 		slot = path->slots[0];
975 		leaf = path->nodes[0];
976 		btrfs_item_key_to_cpu(leaf, &found_key, slot);
977 
978 		if (found_key.type == BTRFS_ROOT_REF_KEY) {
979 			ret = add_qgroup_item(trans, quota_root,
980 					      found_key.offset);
981 			if (ret) {
982 				btrfs_abort_transaction(trans, ret);
983 				goto out_free_path;
984 			}
985 
986 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
987 			if (IS_ERR(qgroup)) {
988 				ret = PTR_ERR(qgroup);
989 				btrfs_abort_transaction(trans, ret);
990 				goto out_free_path;
991 			}
992 		}
993 		ret = btrfs_next_item(tree_root, path);
994 		if (ret < 0) {
995 			btrfs_abort_transaction(trans, ret);
996 			goto out_free_path;
997 		}
998 		if (ret)
999 			break;
1000 	}
1001 
1002 out_add_root:
1003 	btrfs_release_path(path);
1004 	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1005 	if (ret) {
1006 		btrfs_abort_transaction(trans, ret);
1007 		goto out_free_path;
1008 	}
1009 
1010 	qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1011 	if (IS_ERR(qgroup)) {
1012 		ret = PTR_ERR(qgroup);
1013 		btrfs_abort_transaction(trans, ret);
1014 		goto out_free_path;
1015 	}
1016 	spin_lock(&fs_info->qgroup_lock);
1017 	fs_info->quota_root = quota_root;
1018 	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1019 	spin_unlock(&fs_info->qgroup_lock);
1020 
1021 	ret = btrfs_commit_transaction(trans);
1022 	trans = NULL;
1023 	if (ret)
1024 		goto out_free_path;
1025 
1026 	ret = qgroup_rescan_init(fs_info, 0, 1);
1027 	if (!ret) {
1028 	        qgroup_rescan_zero_tracking(fs_info);
1029 	        btrfs_queue_work(fs_info->qgroup_rescan_workers,
1030 	                         &fs_info->qgroup_rescan_work);
1031 	}
1032 
1033 out_free_path:
1034 	btrfs_free_path(path);
1035 out_free_root:
1036 	if (ret) {
1037 		free_extent_buffer(quota_root->node);
1038 		free_extent_buffer(quota_root->commit_root);
1039 		kfree(quota_root);
1040 	}
1041 out:
1042 	if (ret) {
1043 		ulist_free(fs_info->qgroup_ulist);
1044 		fs_info->qgroup_ulist = NULL;
1045 		if (trans)
1046 			btrfs_end_transaction(trans);
1047 	}
1048 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1049 	return ret;
1050 }
1051 
1052 int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1053 {
1054 	struct btrfs_root *quota_root;
1055 	struct btrfs_trans_handle *trans = NULL;
1056 	int ret = 0;
1057 
1058 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1059 	if (!fs_info->quota_root)
1060 		goto out;
1061 
1062 	/*
1063 	 * 1 For the root item
1064 	 *
1065 	 * We should also reserve enough items for the quota tree deletion in
1066 	 * btrfs_clean_quota_tree but this is not done.
1067 	 */
1068 	trans = btrfs_start_transaction(fs_info->tree_root, 1);
1069 	if (IS_ERR(trans)) {
1070 		ret = PTR_ERR(trans);
1071 		goto out;
1072 	}
1073 
1074 	clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1075 	btrfs_qgroup_wait_for_completion(fs_info, false);
1076 	spin_lock(&fs_info->qgroup_lock);
1077 	quota_root = fs_info->quota_root;
1078 	fs_info->quota_root = NULL;
1079 	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1080 	spin_unlock(&fs_info->qgroup_lock);
1081 
1082 	btrfs_free_qgroup_config(fs_info);
1083 
1084 	ret = btrfs_clean_quota_tree(trans, quota_root);
1085 	if (ret) {
1086 		btrfs_abort_transaction(trans, ret);
1087 		goto end_trans;
1088 	}
1089 
1090 	ret = btrfs_del_root(trans, &quota_root->root_key);
1091 	if (ret) {
1092 		btrfs_abort_transaction(trans, ret);
1093 		goto end_trans;
1094 	}
1095 
1096 	list_del(&quota_root->dirty_list);
1097 
1098 	btrfs_tree_lock(quota_root->node);
1099 	clean_tree_block(fs_info, quota_root->node);
1100 	btrfs_tree_unlock(quota_root->node);
1101 	btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
1102 
1103 	free_extent_buffer(quota_root->node);
1104 	free_extent_buffer(quota_root->commit_root);
1105 	kfree(quota_root);
1106 
1107 end_trans:
1108 	ret = btrfs_end_transaction(trans);
1109 out:
1110 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1111 	return ret;
1112 }
1113 
1114 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1115 			 struct btrfs_qgroup *qgroup)
1116 {
1117 	if (list_empty(&qgroup->dirty))
1118 		list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1119 }
1120 
1121 /*
1122  * The easy accounting, we're updating qgroup relationship whose child qgroup
1123  * only has exclusive extents.
1124  *
1125  * In this case, all exclsuive extents will also be exlusive for parent, so
1126  * excl/rfer just get added/removed.
1127  *
1128  * So is qgroup reservation space, which should also be added/removed to
1129  * parent.
1130  * Or when child tries to release reservation space, parent will underflow its
1131  * reservation (for relationship adding case).
1132  *
1133  * Caller should hold fs_info->qgroup_lock.
1134  */
1135 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1136 				    struct ulist *tmp, u64 ref_root,
1137 				    struct btrfs_qgroup *src, int sign)
1138 {
1139 	struct btrfs_qgroup *qgroup;
1140 	struct btrfs_qgroup_list *glist;
1141 	struct ulist_node *unode;
1142 	struct ulist_iterator uiter;
1143 	u64 num_bytes = src->excl;
1144 	int ret = 0;
1145 
1146 	qgroup = find_qgroup_rb(fs_info, ref_root);
1147 	if (!qgroup)
1148 		goto out;
1149 
1150 	qgroup->rfer += sign * num_bytes;
1151 	qgroup->rfer_cmpr += sign * num_bytes;
1152 
1153 	WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1154 	qgroup->excl += sign * num_bytes;
1155 	qgroup->excl_cmpr += sign * num_bytes;
1156 
1157 	if (sign > 0)
1158 		qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1159 	else
1160 		qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1161 
1162 	qgroup_dirty(fs_info, qgroup);
1163 
1164 	/* Get all of the parent groups that contain this qgroup */
1165 	list_for_each_entry(glist, &qgroup->groups, next_group) {
1166 		ret = ulist_add(tmp, glist->group->qgroupid,
1167 				qgroup_to_aux(glist->group), GFP_ATOMIC);
1168 		if (ret < 0)
1169 			goto out;
1170 	}
1171 
1172 	/* Iterate all of the parents and adjust their reference counts */
1173 	ULIST_ITER_INIT(&uiter);
1174 	while ((unode = ulist_next(tmp, &uiter))) {
1175 		qgroup = unode_aux_to_qgroup(unode);
1176 		qgroup->rfer += sign * num_bytes;
1177 		qgroup->rfer_cmpr += sign * num_bytes;
1178 		WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1179 		qgroup->excl += sign * num_bytes;
1180 		if (sign > 0)
1181 			qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1182 		else
1183 			qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1184 		qgroup->excl_cmpr += sign * num_bytes;
1185 		qgroup_dirty(fs_info, qgroup);
1186 
1187 		/* Add any parents of the parents */
1188 		list_for_each_entry(glist, &qgroup->groups, next_group) {
1189 			ret = ulist_add(tmp, glist->group->qgroupid,
1190 					qgroup_to_aux(glist->group), GFP_ATOMIC);
1191 			if (ret < 0)
1192 				goto out;
1193 		}
1194 	}
1195 	ret = 0;
1196 out:
1197 	return ret;
1198 }
1199 
1200 
1201 /*
1202  * Quick path for updating qgroup with only excl refs.
1203  *
1204  * In that case, just update all parent will be enough.
1205  * Or we needs to do a full rescan.
1206  * Caller should also hold fs_info->qgroup_lock.
1207  *
1208  * Return 0 for quick update, return >0 for need to full rescan
1209  * and mark INCONSISTENT flag.
1210  * Return < 0 for other error.
1211  */
1212 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1213 				   struct ulist *tmp, u64 src, u64 dst,
1214 				   int sign)
1215 {
1216 	struct btrfs_qgroup *qgroup;
1217 	int ret = 1;
1218 	int err = 0;
1219 
1220 	qgroup = find_qgroup_rb(fs_info, src);
1221 	if (!qgroup)
1222 		goto out;
1223 	if (qgroup->excl == qgroup->rfer) {
1224 		ret = 0;
1225 		err = __qgroup_excl_accounting(fs_info, tmp, dst,
1226 					       qgroup, sign);
1227 		if (err < 0) {
1228 			ret = err;
1229 			goto out;
1230 		}
1231 	}
1232 out:
1233 	if (ret)
1234 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1235 	return ret;
1236 }
1237 
1238 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1239 			      u64 dst)
1240 {
1241 	struct btrfs_fs_info *fs_info = trans->fs_info;
1242 	struct btrfs_root *quota_root;
1243 	struct btrfs_qgroup *parent;
1244 	struct btrfs_qgroup *member;
1245 	struct btrfs_qgroup_list *list;
1246 	struct ulist *tmp;
1247 	int ret = 0;
1248 
1249 	/* Check the level of src and dst first */
1250 	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1251 		return -EINVAL;
1252 
1253 	tmp = ulist_alloc(GFP_KERNEL);
1254 	if (!tmp)
1255 		return -ENOMEM;
1256 
1257 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1258 	quota_root = fs_info->quota_root;
1259 	if (!quota_root) {
1260 		ret = -EINVAL;
1261 		goto out;
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 			ret = -EEXIST;
1274 			goto out;
1275 		}
1276 	}
1277 
1278 	ret = add_qgroup_relation_item(trans, src, dst);
1279 	if (ret)
1280 		goto out;
1281 
1282 	ret = add_qgroup_relation_item(trans, dst, src);
1283 	if (ret) {
1284 		del_qgroup_relation_item(trans, src, dst);
1285 		goto out;
1286 	}
1287 
1288 	spin_lock(&fs_info->qgroup_lock);
1289 	ret = add_relation_rb(fs_info, src, dst);
1290 	if (ret < 0) {
1291 		spin_unlock(&fs_info->qgroup_lock);
1292 		goto out;
1293 	}
1294 	ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1295 	spin_unlock(&fs_info->qgroup_lock);
1296 out:
1297 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1298 	ulist_free(tmp);
1299 	return ret;
1300 }
1301 
1302 static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1303 				 u64 dst)
1304 {
1305 	struct btrfs_fs_info *fs_info = trans->fs_info;
1306 	struct btrfs_root *quota_root;
1307 	struct btrfs_qgroup *parent;
1308 	struct btrfs_qgroup *member;
1309 	struct btrfs_qgroup_list *list;
1310 	struct ulist *tmp;
1311 	int ret = 0;
1312 	int err;
1313 
1314 	tmp = ulist_alloc(GFP_KERNEL);
1315 	if (!tmp)
1316 		return -ENOMEM;
1317 
1318 	quota_root = fs_info->quota_root;
1319 	if (!quota_root) {
1320 		ret = -EINVAL;
1321 		goto out;
1322 	}
1323 
1324 	member = find_qgroup_rb(fs_info, src);
1325 	parent = find_qgroup_rb(fs_info, dst);
1326 	if (!member || !parent) {
1327 		ret = -EINVAL;
1328 		goto out;
1329 	}
1330 
1331 	/* check if such qgroup relation exist firstly */
1332 	list_for_each_entry(list, &member->groups, next_group) {
1333 		if (list->group == parent)
1334 			goto exist;
1335 	}
1336 	ret = -ENOENT;
1337 	goto out;
1338 exist:
1339 	ret = del_qgroup_relation_item(trans, src, dst);
1340 	err = del_qgroup_relation_item(trans, dst, src);
1341 	if (err && !ret)
1342 		ret = err;
1343 
1344 	spin_lock(&fs_info->qgroup_lock);
1345 	del_relation_rb(fs_info, src, dst);
1346 	ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1347 	spin_unlock(&fs_info->qgroup_lock);
1348 out:
1349 	ulist_free(tmp);
1350 	return ret;
1351 }
1352 
1353 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1354 			      u64 dst)
1355 {
1356 	struct btrfs_fs_info *fs_info = trans->fs_info;
1357 	int ret = 0;
1358 
1359 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1360 	ret = __del_qgroup_relation(trans, src, dst);
1361 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1362 
1363 	return ret;
1364 }
1365 
1366 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1367 {
1368 	struct btrfs_fs_info *fs_info = trans->fs_info;
1369 	struct btrfs_root *quota_root;
1370 	struct btrfs_qgroup *qgroup;
1371 	int ret = 0;
1372 
1373 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1374 	quota_root = fs_info->quota_root;
1375 	if (!quota_root) {
1376 		ret = -EINVAL;
1377 		goto out;
1378 	}
1379 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1380 	if (qgroup) {
1381 		ret = -EEXIST;
1382 		goto out;
1383 	}
1384 
1385 	ret = add_qgroup_item(trans, quota_root, qgroupid);
1386 	if (ret)
1387 		goto out;
1388 
1389 	spin_lock(&fs_info->qgroup_lock);
1390 	qgroup = add_qgroup_rb(fs_info, qgroupid);
1391 	spin_unlock(&fs_info->qgroup_lock);
1392 
1393 	if (IS_ERR(qgroup))
1394 		ret = PTR_ERR(qgroup);
1395 out:
1396 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1397 	return ret;
1398 }
1399 
1400 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1401 {
1402 	struct btrfs_fs_info *fs_info = trans->fs_info;
1403 	struct btrfs_root *quota_root;
1404 	struct btrfs_qgroup *qgroup;
1405 	struct btrfs_qgroup_list *list;
1406 	int ret = 0;
1407 
1408 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1409 	quota_root = fs_info->quota_root;
1410 	if (!quota_root) {
1411 		ret = -EINVAL;
1412 		goto out;
1413 	}
1414 
1415 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1416 	if (!qgroup) {
1417 		ret = -ENOENT;
1418 		goto out;
1419 	}
1420 
1421 	/* Check if there are no children of this qgroup */
1422 	if (!list_empty(&qgroup->members)) {
1423 		ret = -EBUSY;
1424 		goto out;
1425 	}
1426 
1427 	ret = del_qgroup_item(trans, qgroupid);
1428 	if (ret && ret != -ENOENT)
1429 		goto out;
1430 
1431 	while (!list_empty(&qgroup->groups)) {
1432 		list = list_first_entry(&qgroup->groups,
1433 					struct btrfs_qgroup_list, next_group);
1434 		ret = __del_qgroup_relation(trans, qgroupid,
1435 					    list->group->qgroupid);
1436 		if (ret)
1437 			goto out;
1438 	}
1439 
1440 	spin_lock(&fs_info->qgroup_lock);
1441 	del_qgroup_rb(fs_info, qgroupid);
1442 	spin_unlock(&fs_info->qgroup_lock);
1443 out:
1444 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1445 	return ret;
1446 }
1447 
1448 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1449 		       struct btrfs_qgroup_limit *limit)
1450 {
1451 	struct btrfs_fs_info *fs_info = trans->fs_info;
1452 	struct btrfs_root *quota_root;
1453 	struct btrfs_qgroup *qgroup;
1454 	int ret = 0;
1455 	/* Sometimes we would want to clear the limit on this qgroup.
1456 	 * To meet this requirement, we treat the -1 as a special value
1457 	 * which tell kernel to clear the limit on this qgroup.
1458 	 */
1459 	const u64 CLEAR_VALUE = -1;
1460 
1461 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1462 	quota_root = fs_info->quota_root;
1463 	if (!quota_root) {
1464 		ret = -EINVAL;
1465 		goto out;
1466 	}
1467 
1468 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1469 	if (!qgroup) {
1470 		ret = -ENOENT;
1471 		goto out;
1472 	}
1473 
1474 	spin_lock(&fs_info->qgroup_lock);
1475 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1476 		if (limit->max_rfer == CLEAR_VALUE) {
1477 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1478 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1479 			qgroup->max_rfer = 0;
1480 		} else {
1481 			qgroup->max_rfer = limit->max_rfer;
1482 		}
1483 	}
1484 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1485 		if (limit->max_excl == CLEAR_VALUE) {
1486 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1487 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1488 			qgroup->max_excl = 0;
1489 		} else {
1490 			qgroup->max_excl = limit->max_excl;
1491 		}
1492 	}
1493 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1494 		if (limit->rsv_rfer == CLEAR_VALUE) {
1495 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1496 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1497 			qgroup->rsv_rfer = 0;
1498 		} else {
1499 			qgroup->rsv_rfer = limit->rsv_rfer;
1500 		}
1501 	}
1502 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1503 		if (limit->rsv_excl == CLEAR_VALUE) {
1504 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1505 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1506 			qgroup->rsv_excl = 0;
1507 		} else {
1508 			qgroup->rsv_excl = limit->rsv_excl;
1509 		}
1510 	}
1511 	qgroup->lim_flags |= limit->flags;
1512 
1513 	spin_unlock(&fs_info->qgroup_lock);
1514 
1515 	ret = update_qgroup_limit_item(trans, qgroup);
1516 	if (ret) {
1517 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1518 		btrfs_info(fs_info, "unable to update quota limit for %llu",
1519 		       qgroupid);
1520 	}
1521 
1522 out:
1523 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1524 	return ret;
1525 }
1526 
1527 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1528 				struct btrfs_delayed_ref_root *delayed_refs,
1529 				struct btrfs_qgroup_extent_record *record)
1530 {
1531 	struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1532 	struct rb_node *parent_node = NULL;
1533 	struct btrfs_qgroup_extent_record *entry;
1534 	u64 bytenr = record->bytenr;
1535 
1536 	lockdep_assert_held(&delayed_refs->lock);
1537 	trace_btrfs_qgroup_trace_extent(fs_info, record);
1538 
1539 	while (*p) {
1540 		parent_node = *p;
1541 		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1542 				 node);
1543 		if (bytenr < entry->bytenr)
1544 			p = &(*p)->rb_left;
1545 		else if (bytenr > entry->bytenr)
1546 			p = &(*p)->rb_right;
1547 		else
1548 			return 1;
1549 	}
1550 
1551 	rb_link_node(&record->node, parent_node, p);
1552 	rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1553 	return 0;
1554 }
1555 
1556 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1557 				   struct btrfs_qgroup_extent_record *qrecord)
1558 {
1559 	struct ulist *old_root;
1560 	u64 bytenr = qrecord->bytenr;
1561 	int ret;
1562 
1563 	ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
1564 	if (ret < 0) {
1565 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1566 		btrfs_warn(fs_info,
1567 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1568 			ret);
1569 		return 0;
1570 	}
1571 
1572 	/*
1573 	 * Here we don't need to get the lock of
1574 	 * trans->transaction->delayed_refs, since inserted qrecord won't
1575 	 * be deleted, only qrecord->node may be modified (new qrecord insert)
1576 	 *
1577 	 * So modifying qrecord->old_roots is safe here
1578 	 */
1579 	qrecord->old_roots = old_root;
1580 	return 0;
1581 }
1582 
1583 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1584 			      u64 num_bytes, gfp_t gfp_flag)
1585 {
1586 	struct btrfs_fs_info *fs_info = trans->fs_info;
1587 	struct btrfs_qgroup_extent_record *record;
1588 	struct btrfs_delayed_ref_root *delayed_refs;
1589 	int ret;
1590 
1591 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1592 	    || bytenr == 0 || num_bytes == 0)
1593 		return 0;
1594 	record = kmalloc(sizeof(*record), gfp_flag);
1595 	if (!record)
1596 		return -ENOMEM;
1597 
1598 	delayed_refs = &trans->transaction->delayed_refs;
1599 	record->bytenr = bytenr;
1600 	record->num_bytes = num_bytes;
1601 	record->old_roots = NULL;
1602 
1603 	spin_lock(&delayed_refs->lock);
1604 	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1605 	spin_unlock(&delayed_refs->lock);
1606 	if (ret > 0) {
1607 		kfree(record);
1608 		return 0;
1609 	}
1610 	return btrfs_qgroup_trace_extent_post(fs_info, record);
1611 }
1612 
1613 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1614 				  struct extent_buffer *eb)
1615 {
1616 	struct btrfs_fs_info *fs_info = trans->fs_info;
1617 	int nr = btrfs_header_nritems(eb);
1618 	int i, extent_type, ret;
1619 	struct btrfs_key key;
1620 	struct btrfs_file_extent_item *fi;
1621 	u64 bytenr, num_bytes;
1622 
1623 	/* We can be called directly from walk_up_proc() */
1624 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1625 		return 0;
1626 
1627 	for (i = 0; i < nr; i++) {
1628 		btrfs_item_key_to_cpu(eb, &key, i);
1629 
1630 		if (key.type != BTRFS_EXTENT_DATA_KEY)
1631 			continue;
1632 
1633 		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1634 		/* filter out non qgroup-accountable extents  */
1635 		extent_type = btrfs_file_extent_type(eb, fi);
1636 
1637 		if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1638 			continue;
1639 
1640 		bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1641 		if (!bytenr)
1642 			continue;
1643 
1644 		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1645 
1646 		ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes,
1647 						GFP_NOFS);
1648 		if (ret)
1649 			return ret;
1650 	}
1651 	cond_resched();
1652 	return 0;
1653 }
1654 
1655 /*
1656  * Walk up the tree from the bottom, freeing leaves and any interior
1657  * nodes which have had all slots visited. If a node (leaf or
1658  * interior) is freed, the node above it will have it's slot
1659  * incremented. The root node will never be freed.
1660  *
1661  * At the end of this function, we should have a path which has all
1662  * slots incremented to the next position for a search. If we need to
1663  * read a new node it will be NULL and the node above it will have the
1664  * correct slot selected for a later read.
1665  *
1666  * If we increment the root nodes slot counter past the number of
1667  * elements, 1 is returned to signal completion of the search.
1668  */
1669 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1670 {
1671 	int level = 0;
1672 	int nr, slot;
1673 	struct extent_buffer *eb;
1674 
1675 	if (root_level == 0)
1676 		return 1;
1677 
1678 	while (level <= root_level) {
1679 		eb = path->nodes[level];
1680 		nr = btrfs_header_nritems(eb);
1681 		path->slots[level]++;
1682 		slot = path->slots[level];
1683 		if (slot >= nr || level == 0) {
1684 			/*
1685 			 * Don't free the root -  we will detect this
1686 			 * condition after our loop and return a
1687 			 * positive value for caller to stop walking the tree.
1688 			 */
1689 			if (level != root_level) {
1690 				btrfs_tree_unlock_rw(eb, path->locks[level]);
1691 				path->locks[level] = 0;
1692 
1693 				free_extent_buffer(eb);
1694 				path->nodes[level] = NULL;
1695 				path->slots[level] = 0;
1696 			}
1697 		} else {
1698 			/*
1699 			 * We have a valid slot to walk back down
1700 			 * from. Stop here so caller can process these
1701 			 * new nodes.
1702 			 */
1703 			break;
1704 		}
1705 
1706 		level++;
1707 	}
1708 
1709 	eb = path->nodes[root_level];
1710 	if (path->slots[root_level] >= btrfs_header_nritems(eb))
1711 		return 1;
1712 
1713 	return 0;
1714 }
1715 
1716 /*
1717  * Helper function to trace a subtree tree block swap.
1718  *
1719  * The swap will happen in highest tree block, but there may be a lot of
1720  * tree blocks involved.
1721  *
1722  * For example:
1723  *  OO = Old tree blocks
1724  *  NN = New tree blocks allocated during balance
1725  *
1726  *           File tree (257)                  Reloc tree for 257
1727  * L2              OO                                NN
1728  *               /    \                            /    \
1729  * L1          OO      OO (a)                    OO      NN (a)
1730  *            / \     / \                       / \     / \
1731  * L0       OO   OO OO   OO                   OO   OO NN   NN
1732  *                  (b)  (c)                          (b)  (c)
1733  *
1734  * When calling qgroup_trace_extent_swap(), we will pass:
1735  * @src_eb = OO(a)
1736  * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
1737  * @dst_level = 0
1738  * @root_level = 1
1739  *
1740  * In that case, qgroup_trace_extent_swap() will search from OO(a) to
1741  * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
1742  *
1743  * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
1744  *
1745  * 1) Tree search from @src_eb
1746  *    It should acts as a simplified btrfs_search_slot().
1747  *    The key for search can be extracted from @dst_path->nodes[dst_level]
1748  *    (first key).
1749  *
1750  * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
1751  *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
1752  *    They should be marked during preivous (@dst_level = 1) iteration.
1753  *
1754  * 3) Mark file extents in leaves dirty
1755  *    We don't have good way to pick out new file extents only.
1756  *    So we still follow the old method by scanning all file extents in
1757  *    the leave.
1758  *
1759  * This function can free us from keeping two pathes, thus later we only need
1760  * to care about how to iterate all new tree blocks in reloc tree.
1761  */
1762 static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
1763 				    struct extent_buffer *src_eb,
1764 				    struct btrfs_path *dst_path,
1765 				    int dst_level, int root_level,
1766 				    bool trace_leaf)
1767 {
1768 	struct btrfs_key key;
1769 	struct btrfs_path *src_path;
1770 	struct btrfs_fs_info *fs_info = trans->fs_info;
1771 	u32 nodesize = fs_info->nodesize;
1772 	int cur_level = root_level;
1773 	int ret;
1774 
1775 	BUG_ON(dst_level > root_level);
1776 	/* Level mismatch */
1777 	if (btrfs_header_level(src_eb) != root_level)
1778 		return -EINVAL;
1779 
1780 	src_path = btrfs_alloc_path();
1781 	if (!src_path) {
1782 		ret = -ENOMEM;
1783 		goto out;
1784 	}
1785 
1786 	if (dst_level)
1787 		btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1788 	else
1789 		btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1790 
1791 	/* For src_path */
1792 	extent_buffer_get(src_eb);
1793 	src_path->nodes[root_level] = src_eb;
1794 	src_path->slots[root_level] = dst_path->slots[root_level];
1795 	src_path->locks[root_level] = 0;
1796 
1797 	/* A simplified version of btrfs_search_slot() */
1798 	while (cur_level >= dst_level) {
1799 		struct btrfs_key src_key;
1800 		struct btrfs_key dst_key;
1801 
1802 		if (src_path->nodes[cur_level] == NULL) {
1803 			struct btrfs_key first_key;
1804 			struct extent_buffer *eb;
1805 			int parent_slot;
1806 			u64 child_gen;
1807 			u64 child_bytenr;
1808 
1809 			eb = src_path->nodes[cur_level + 1];
1810 			parent_slot = src_path->slots[cur_level + 1];
1811 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1812 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1813 			btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
1814 
1815 			eb = read_tree_block(fs_info, child_bytenr, child_gen,
1816 					     cur_level, &first_key);
1817 			if (IS_ERR(eb)) {
1818 				ret = PTR_ERR(eb);
1819 				goto out;
1820 			} else if (!extent_buffer_uptodate(eb)) {
1821 				free_extent_buffer(eb);
1822 				ret = -EIO;
1823 				goto out;
1824 			}
1825 
1826 			src_path->nodes[cur_level] = eb;
1827 
1828 			btrfs_tree_read_lock(eb);
1829 			btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1830 			src_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
1831 		}
1832 
1833 		src_path->slots[cur_level] = dst_path->slots[cur_level];
1834 		if (cur_level) {
1835 			btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
1836 					&dst_key, dst_path->slots[cur_level]);
1837 			btrfs_node_key_to_cpu(src_path->nodes[cur_level],
1838 					&src_key, src_path->slots[cur_level]);
1839 		} else {
1840 			btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
1841 					&dst_key, dst_path->slots[cur_level]);
1842 			btrfs_item_key_to_cpu(src_path->nodes[cur_level],
1843 					&src_key, src_path->slots[cur_level]);
1844 		}
1845 		/* Content mismatch, something went wrong */
1846 		if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
1847 			ret = -ENOENT;
1848 			goto out;
1849 		}
1850 		cur_level--;
1851 	}
1852 
1853 	/*
1854 	 * Now both @dst_path and @src_path have been populated, record the tree
1855 	 * blocks for qgroup accounting.
1856 	 */
1857 	ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
1858 			nodesize, GFP_NOFS);
1859 	if (ret < 0)
1860 		goto out;
1861 	ret = btrfs_qgroup_trace_extent(trans,
1862 			dst_path->nodes[dst_level]->start,
1863 			nodesize, GFP_NOFS);
1864 	if (ret < 0)
1865 		goto out;
1866 
1867 	/* Record leaf file extents */
1868 	if (dst_level == 0 && trace_leaf) {
1869 		ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
1870 		if (ret < 0)
1871 			goto out;
1872 		ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
1873 	}
1874 out:
1875 	btrfs_free_path(src_path);
1876 	return ret;
1877 }
1878 
1879 /*
1880  * Helper function to do recursive generation-aware depth-first search, to
1881  * locate all new tree blocks in a subtree of reloc tree.
1882  *
1883  * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
1884  *         reloc tree
1885  * L2         NN (a)
1886  *          /    \
1887  * L1    OO        NN (b)
1888  *      /  \      /  \
1889  * L0  OO  OO    OO  NN
1890  *               (c) (d)
1891  * If we pass:
1892  * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
1893  * @cur_level = 1
1894  * @root_level = 1
1895  *
1896  * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
1897  * above tree blocks along with their counter parts in file tree.
1898  * While during search, old tree blocsk OO(c) will be skiped as tree block swap
1899  * won't affect OO(c).
1900  */
1901 static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
1902 					   struct extent_buffer *src_eb,
1903 					   struct btrfs_path *dst_path,
1904 					   int cur_level, int root_level,
1905 					   u64 last_snapshot, bool trace_leaf)
1906 {
1907 	struct btrfs_fs_info *fs_info = trans->fs_info;
1908 	struct extent_buffer *eb;
1909 	bool need_cleanup = false;
1910 	int ret = 0;
1911 	int i;
1912 
1913 	/* Level sanity check */
1914 	if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL ||
1915 	    root_level < 0 || root_level >= BTRFS_MAX_LEVEL ||
1916 	    root_level < cur_level) {
1917 		btrfs_err_rl(fs_info,
1918 			"%s: bad levels, cur_level=%d root_level=%d",
1919 			__func__, cur_level, root_level);
1920 		return -EUCLEAN;
1921 	}
1922 
1923 	/* Read the tree block if needed */
1924 	if (dst_path->nodes[cur_level] == NULL) {
1925 		struct btrfs_key first_key;
1926 		int parent_slot;
1927 		u64 child_gen;
1928 		u64 child_bytenr;
1929 
1930 		/*
1931 		 * dst_path->nodes[root_level] must be initialized before
1932 		 * calling this function.
1933 		 */
1934 		if (cur_level == root_level) {
1935 			btrfs_err_rl(fs_info,
1936 	"%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
1937 				__func__, root_level, root_level, cur_level);
1938 			return -EUCLEAN;
1939 		}
1940 
1941 		/*
1942 		 * We need to get child blockptr/gen from parent before we can
1943 		 * read it.
1944 		  */
1945 		eb = dst_path->nodes[cur_level + 1];
1946 		parent_slot = dst_path->slots[cur_level + 1];
1947 		child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1948 		child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1949 		btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
1950 
1951 		/* This node is old, no need to trace */
1952 		if (child_gen < last_snapshot)
1953 			goto out;
1954 
1955 		eb = read_tree_block(fs_info, child_bytenr, child_gen,
1956 				     cur_level, &first_key);
1957 		if (IS_ERR(eb)) {
1958 			ret = PTR_ERR(eb);
1959 			goto out;
1960 		} else if (!extent_buffer_uptodate(eb)) {
1961 			free_extent_buffer(eb);
1962 			ret = -EIO;
1963 			goto out;
1964 		}
1965 
1966 		dst_path->nodes[cur_level] = eb;
1967 		dst_path->slots[cur_level] = 0;
1968 
1969 		btrfs_tree_read_lock(eb);
1970 		btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1971 		dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
1972 		need_cleanup = true;
1973 	}
1974 
1975 	/* Now record this tree block and its counter part for qgroups */
1976 	ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
1977 				       root_level, trace_leaf);
1978 	if (ret < 0)
1979 		goto cleanup;
1980 
1981 	eb = dst_path->nodes[cur_level];
1982 
1983 	if (cur_level > 0) {
1984 		/* Iterate all child tree blocks */
1985 		for (i = 0; i < btrfs_header_nritems(eb); i++) {
1986 			/* Skip old tree blocks as they won't be swapped */
1987 			if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
1988 				continue;
1989 			dst_path->slots[cur_level] = i;
1990 
1991 			/* Recursive call (at most 7 times) */
1992 			ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
1993 					dst_path, cur_level - 1, root_level,
1994 					last_snapshot, trace_leaf);
1995 			if (ret < 0)
1996 				goto cleanup;
1997 		}
1998 	}
1999 
2000 cleanup:
2001 	if (need_cleanup) {
2002 		/* Clean up */
2003 		btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2004 				     dst_path->locks[cur_level]);
2005 		free_extent_buffer(dst_path->nodes[cur_level]);
2006 		dst_path->nodes[cur_level] = NULL;
2007 		dst_path->slots[cur_level] = 0;
2008 		dst_path->locks[cur_level] = 0;
2009 	}
2010 out:
2011 	return ret;
2012 }
2013 
2014 /*
2015  * Inform qgroup to trace subtree swap used in balance.
2016  *
2017  * Unlike btrfs_qgroup_trace_subtree(), this function will only trace
2018  * new tree blocks whose generation is equal to (or larger than) @last_snapshot.
2019  *
2020  * Will go down the tree block pointed by @dst_eb (pointed by @dst_parent and
2021  * @dst_slot), and find any tree blocks whose generation is at @last_snapshot,
2022  * and then go down @src_eb (pointed by @src_parent and @src_slot) to find
2023  * the conterpart of the tree block, then mark both tree blocks as qgroup dirty,
2024  * and skip all tree blocks whose generation is smaller than last_snapshot.
2025  *
2026  * This would skip tons of tree blocks of original btrfs_qgroup_trace_subtree(),
2027  * which could be the cause of very slow balance if the file tree is large.
2028  *
2029  * @src_parent, @src_slot: pointer to src (file tree) eb.
2030  * @dst_parent, @dst_slot: pointer to dst (reloc tree) eb.
2031  */
2032 int btrfs_qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2033 				struct btrfs_block_group_cache *bg_cache,
2034 				struct extent_buffer *src_parent, int src_slot,
2035 				struct extent_buffer *dst_parent, int dst_slot,
2036 				u64 last_snapshot)
2037 {
2038 	struct btrfs_fs_info *fs_info = trans->fs_info;
2039 	struct btrfs_path *dst_path = NULL;
2040 	struct btrfs_key first_key;
2041 	struct extent_buffer *src_eb = NULL;
2042 	struct extent_buffer *dst_eb = NULL;
2043 	bool trace_leaf = false;
2044 	u64 child_gen;
2045 	u64 child_bytenr;
2046 	int level;
2047 	int ret;
2048 
2049 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2050 		return 0;
2051 
2052 	/* Check parameter order */
2053 	if (btrfs_node_ptr_generation(src_parent, src_slot) >
2054 	    btrfs_node_ptr_generation(dst_parent, dst_slot)) {
2055 		btrfs_err_rl(fs_info,
2056 		"%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2057 			btrfs_node_ptr_generation(src_parent, src_slot),
2058 			btrfs_node_ptr_generation(dst_parent, dst_slot));
2059 		return -EUCLEAN;
2060 	}
2061 
2062 	/*
2063 	 * Only trace leaf if we're relocating data block groups, this could
2064 	 * reduce tons of data extents tracing for meta/sys bg relocation.
2065 	 */
2066 	if (bg_cache->flags & BTRFS_BLOCK_GROUP_DATA)
2067 		trace_leaf = true;
2068 	/* Read out real @src_eb, pointed by @src_parent and @src_slot */
2069 	child_bytenr = btrfs_node_blockptr(src_parent, src_slot);
2070 	child_gen = btrfs_node_ptr_generation(src_parent, src_slot);
2071 	btrfs_node_key_to_cpu(src_parent, &first_key, src_slot);
2072 
2073 	src_eb = read_tree_block(fs_info, child_bytenr, child_gen,
2074 			btrfs_header_level(src_parent) - 1, &first_key);
2075 	if (IS_ERR(src_eb)) {
2076 		ret = PTR_ERR(src_eb);
2077 		goto out;
2078 	}
2079 
2080 	/* Read out real @dst_eb, pointed by @src_parent and @src_slot */
2081 	child_bytenr = btrfs_node_blockptr(dst_parent, dst_slot);
2082 	child_gen = btrfs_node_ptr_generation(dst_parent, dst_slot);
2083 	btrfs_node_key_to_cpu(dst_parent, &first_key, dst_slot);
2084 
2085 	dst_eb = read_tree_block(fs_info, child_bytenr, child_gen,
2086 			btrfs_header_level(dst_parent) - 1, &first_key);
2087 	if (IS_ERR(dst_eb)) {
2088 		ret = PTR_ERR(dst_eb);
2089 		goto out;
2090 	}
2091 
2092 	if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2093 		ret = -EINVAL;
2094 		goto out;
2095 	}
2096 
2097 	level = btrfs_header_level(dst_eb);
2098 	dst_path = btrfs_alloc_path();
2099 	if (!dst_path) {
2100 		ret = -ENOMEM;
2101 		goto out;
2102 	}
2103 
2104 	/* For dst_path */
2105 	extent_buffer_get(dst_eb);
2106 	dst_path->nodes[level] = dst_eb;
2107 	dst_path->slots[level] = 0;
2108 	dst_path->locks[level] = 0;
2109 
2110 	/* Do the generation-aware breadth-first search */
2111 	ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2112 					      level, last_snapshot, trace_leaf);
2113 	if (ret < 0)
2114 		goto out;
2115 	ret = 0;
2116 
2117 out:
2118 	free_extent_buffer(src_eb);
2119 	free_extent_buffer(dst_eb);
2120 	btrfs_free_path(dst_path);
2121 	if (ret < 0)
2122 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2123 	return ret;
2124 }
2125 
2126 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2127 			       struct extent_buffer *root_eb,
2128 			       u64 root_gen, int root_level)
2129 {
2130 	struct btrfs_fs_info *fs_info = trans->fs_info;
2131 	int ret = 0;
2132 	int level;
2133 	struct extent_buffer *eb = root_eb;
2134 	struct btrfs_path *path = NULL;
2135 
2136 	BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2137 	BUG_ON(root_eb == NULL);
2138 
2139 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2140 		return 0;
2141 
2142 	if (!extent_buffer_uptodate(root_eb)) {
2143 		ret = btrfs_read_buffer(root_eb, root_gen, root_level, NULL);
2144 		if (ret)
2145 			goto out;
2146 	}
2147 
2148 	if (root_level == 0) {
2149 		ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2150 		goto out;
2151 	}
2152 
2153 	path = btrfs_alloc_path();
2154 	if (!path)
2155 		return -ENOMEM;
2156 
2157 	/*
2158 	 * Walk down the tree.  Missing extent blocks are filled in as
2159 	 * we go. Metadata is accounted every time we read a new
2160 	 * extent block.
2161 	 *
2162 	 * When we reach a leaf, we account for file extent items in it,
2163 	 * walk back up the tree (adjusting slot pointers as we go)
2164 	 * and restart the search process.
2165 	 */
2166 	extent_buffer_get(root_eb); /* For path */
2167 	path->nodes[root_level] = root_eb;
2168 	path->slots[root_level] = 0;
2169 	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2170 walk_down:
2171 	level = root_level;
2172 	while (level >= 0) {
2173 		if (path->nodes[level] == NULL) {
2174 			struct btrfs_key first_key;
2175 			int parent_slot;
2176 			u64 child_gen;
2177 			u64 child_bytenr;
2178 
2179 			/*
2180 			 * We need to get child blockptr/gen from parent before
2181 			 * we can read it.
2182 			  */
2183 			eb = path->nodes[level + 1];
2184 			parent_slot = path->slots[level + 1];
2185 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2186 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2187 			btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
2188 
2189 			eb = read_tree_block(fs_info, child_bytenr, child_gen,
2190 					     level, &first_key);
2191 			if (IS_ERR(eb)) {
2192 				ret = PTR_ERR(eb);
2193 				goto out;
2194 			} else if (!extent_buffer_uptodate(eb)) {
2195 				free_extent_buffer(eb);
2196 				ret = -EIO;
2197 				goto out;
2198 			}
2199 
2200 			path->nodes[level] = eb;
2201 			path->slots[level] = 0;
2202 
2203 			btrfs_tree_read_lock(eb);
2204 			btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
2205 			path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
2206 
2207 			ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2208 							fs_info->nodesize,
2209 							GFP_NOFS);
2210 			if (ret)
2211 				goto out;
2212 		}
2213 
2214 		if (level == 0) {
2215 			ret = btrfs_qgroup_trace_leaf_items(trans,
2216 							    path->nodes[level]);
2217 			if (ret)
2218 				goto out;
2219 
2220 			/* Nonzero return here means we completed our search */
2221 			ret = adjust_slots_upwards(path, root_level);
2222 			if (ret)
2223 				break;
2224 
2225 			/* Restart search with new slots */
2226 			goto walk_down;
2227 		}
2228 
2229 		level--;
2230 	}
2231 
2232 	ret = 0;
2233 out:
2234 	btrfs_free_path(path);
2235 
2236 	return ret;
2237 }
2238 
2239 #define UPDATE_NEW	0
2240 #define UPDATE_OLD	1
2241 /*
2242  * Walk all of the roots that points to the bytenr and adjust their refcnts.
2243  */
2244 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2245 				struct ulist *roots, struct ulist *tmp,
2246 				struct ulist *qgroups, u64 seq, int update_old)
2247 {
2248 	struct ulist_node *unode;
2249 	struct ulist_iterator uiter;
2250 	struct ulist_node *tmp_unode;
2251 	struct ulist_iterator tmp_uiter;
2252 	struct btrfs_qgroup *qg;
2253 	int ret = 0;
2254 
2255 	if (!roots)
2256 		return 0;
2257 	ULIST_ITER_INIT(&uiter);
2258 	while ((unode = ulist_next(roots, &uiter))) {
2259 		qg = find_qgroup_rb(fs_info, unode->val);
2260 		if (!qg)
2261 			continue;
2262 
2263 		ulist_reinit(tmp);
2264 		ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2265 				GFP_ATOMIC);
2266 		if (ret < 0)
2267 			return ret;
2268 		ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2269 		if (ret < 0)
2270 			return ret;
2271 		ULIST_ITER_INIT(&tmp_uiter);
2272 		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2273 			struct btrfs_qgroup_list *glist;
2274 
2275 			qg = unode_aux_to_qgroup(tmp_unode);
2276 			if (update_old)
2277 				btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2278 			else
2279 				btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2280 			list_for_each_entry(glist, &qg->groups, next_group) {
2281 				ret = ulist_add(qgroups, glist->group->qgroupid,
2282 						qgroup_to_aux(glist->group),
2283 						GFP_ATOMIC);
2284 				if (ret < 0)
2285 					return ret;
2286 				ret = ulist_add(tmp, glist->group->qgroupid,
2287 						qgroup_to_aux(glist->group),
2288 						GFP_ATOMIC);
2289 				if (ret < 0)
2290 					return ret;
2291 			}
2292 		}
2293 	}
2294 	return 0;
2295 }
2296 
2297 /*
2298  * Update qgroup rfer/excl counters.
2299  * Rfer update is easy, codes can explain themselves.
2300  *
2301  * Excl update is tricky, the update is split into 2 part.
2302  * Part 1: Possible exclusive <-> sharing detect:
2303  *	|	A	|	!A	|
2304  *  -------------------------------------
2305  *  B	|	*	|	-	|
2306  *  -------------------------------------
2307  *  !B	|	+	|	**	|
2308  *  -------------------------------------
2309  *
2310  * Conditions:
2311  * A:	cur_old_roots < nr_old_roots	(not exclusive before)
2312  * !A:	cur_old_roots == nr_old_roots	(possible exclusive before)
2313  * B:	cur_new_roots < nr_new_roots	(not exclusive now)
2314  * !B:	cur_new_roots == nr_new_roots	(possible exclusive now)
2315  *
2316  * Results:
2317  * +: Possible sharing -> exclusive	-: Possible exclusive -> sharing
2318  * *: Definitely not changed.		**: Possible unchanged.
2319  *
2320  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2321  *
2322  * To make the logic clear, we first use condition A and B to split
2323  * combination into 4 results.
2324  *
2325  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2326  * only on variant maybe 0.
2327  *
2328  * Lastly, check result **, since there are 2 variants maybe 0, split them
2329  * again(2x2).
2330  * But this time we don't need to consider other things, the codes and logic
2331  * is easy to understand now.
2332  */
2333 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2334 				  struct ulist *qgroups,
2335 				  u64 nr_old_roots,
2336 				  u64 nr_new_roots,
2337 				  u64 num_bytes, u64 seq)
2338 {
2339 	struct ulist_node *unode;
2340 	struct ulist_iterator uiter;
2341 	struct btrfs_qgroup *qg;
2342 	u64 cur_new_count, cur_old_count;
2343 
2344 	ULIST_ITER_INIT(&uiter);
2345 	while ((unode = ulist_next(qgroups, &uiter))) {
2346 		bool dirty = false;
2347 
2348 		qg = unode_aux_to_qgroup(unode);
2349 		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2350 		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2351 
2352 		trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2353 					     cur_new_count);
2354 
2355 		/* Rfer update part */
2356 		if (cur_old_count == 0 && cur_new_count > 0) {
2357 			qg->rfer += num_bytes;
2358 			qg->rfer_cmpr += num_bytes;
2359 			dirty = true;
2360 		}
2361 		if (cur_old_count > 0 && cur_new_count == 0) {
2362 			qg->rfer -= num_bytes;
2363 			qg->rfer_cmpr -= num_bytes;
2364 			dirty = true;
2365 		}
2366 
2367 		/* Excl update part */
2368 		/* Exclusive/none -> shared case */
2369 		if (cur_old_count == nr_old_roots &&
2370 		    cur_new_count < nr_new_roots) {
2371 			/* Exclusive -> shared */
2372 			if (cur_old_count != 0) {
2373 				qg->excl -= num_bytes;
2374 				qg->excl_cmpr -= num_bytes;
2375 				dirty = true;
2376 			}
2377 		}
2378 
2379 		/* Shared -> exclusive/none case */
2380 		if (cur_old_count < nr_old_roots &&
2381 		    cur_new_count == nr_new_roots) {
2382 			/* Shared->exclusive */
2383 			if (cur_new_count != 0) {
2384 				qg->excl += num_bytes;
2385 				qg->excl_cmpr += num_bytes;
2386 				dirty = true;
2387 			}
2388 		}
2389 
2390 		/* Exclusive/none -> exclusive/none case */
2391 		if (cur_old_count == nr_old_roots &&
2392 		    cur_new_count == nr_new_roots) {
2393 			if (cur_old_count == 0) {
2394 				/* None -> exclusive/none */
2395 
2396 				if (cur_new_count != 0) {
2397 					/* None -> exclusive */
2398 					qg->excl += num_bytes;
2399 					qg->excl_cmpr += num_bytes;
2400 					dirty = true;
2401 				}
2402 				/* None -> none, nothing changed */
2403 			} else {
2404 				/* Exclusive -> exclusive/none */
2405 
2406 				if (cur_new_count == 0) {
2407 					/* Exclusive -> none */
2408 					qg->excl -= num_bytes;
2409 					qg->excl_cmpr -= num_bytes;
2410 					dirty = true;
2411 				}
2412 				/* Exclusive -> exclusive, nothing changed */
2413 			}
2414 		}
2415 
2416 		if (dirty)
2417 			qgroup_dirty(fs_info, qg);
2418 	}
2419 	return 0;
2420 }
2421 
2422 /*
2423  * Check if the @roots potentially is a list of fs tree roots
2424  *
2425  * Return 0 for definitely not a fs/subvol tree roots ulist
2426  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2427  *          one as well)
2428  */
2429 static int maybe_fs_roots(struct ulist *roots)
2430 {
2431 	struct ulist_node *unode;
2432 	struct ulist_iterator uiter;
2433 
2434 	/* Empty one, still possible for fs roots */
2435 	if (!roots || roots->nnodes == 0)
2436 		return 1;
2437 
2438 	ULIST_ITER_INIT(&uiter);
2439 	unode = ulist_next(roots, &uiter);
2440 	if (!unode)
2441 		return 1;
2442 
2443 	/*
2444 	 * If it contains fs tree roots, then it must belong to fs/subvol
2445 	 * trees.
2446 	 * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2447 	 */
2448 	return is_fstree(unode->val);
2449 }
2450 
2451 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2452 				u64 num_bytes, struct ulist *old_roots,
2453 				struct ulist *new_roots)
2454 {
2455 	struct btrfs_fs_info *fs_info = trans->fs_info;
2456 	struct ulist *qgroups = NULL;
2457 	struct ulist *tmp = NULL;
2458 	u64 seq;
2459 	u64 nr_new_roots = 0;
2460 	u64 nr_old_roots = 0;
2461 	int ret = 0;
2462 
2463 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2464 		return 0;
2465 
2466 	if (new_roots) {
2467 		if (!maybe_fs_roots(new_roots))
2468 			goto out_free;
2469 		nr_new_roots = new_roots->nnodes;
2470 	}
2471 	if (old_roots) {
2472 		if (!maybe_fs_roots(old_roots))
2473 			goto out_free;
2474 		nr_old_roots = old_roots->nnodes;
2475 	}
2476 
2477 	/* Quick exit, either not fs tree roots, or won't affect any qgroup */
2478 	if (nr_old_roots == 0 && nr_new_roots == 0)
2479 		goto out_free;
2480 
2481 	BUG_ON(!fs_info->quota_root);
2482 
2483 	trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2484 					num_bytes, nr_old_roots, nr_new_roots);
2485 
2486 	qgroups = ulist_alloc(GFP_NOFS);
2487 	if (!qgroups) {
2488 		ret = -ENOMEM;
2489 		goto out_free;
2490 	}
2491 	tmp = ulist_alloc(GFP_NOFS);
2492 	if (!tmp) {
2493 		ret = -ENOMEM;
2494 		goto out_free;
2495 	}
2496 
2497 	mutex_lock(&fs_info->qgroup_rescan_lock);
2498 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2499 		if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2500 			mutex_unlock(&fs_info->qgroup_rescan_lock);
2501 			ret = 0;
2502 			goto out_free;
2503 		}
2504 	}
2505 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2506 
2507 	spin_lock(&fs_info->qgroup_lock);
2508 	seq = fs_info->qgroup_seq;
2509 
2510 	/* Update old refcnts using old_roots */
2511 	ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2512 				   UPDATE_OLD);
2513 	if (ret < 0)
2514 		goto out;
2515 
2516 	/* Update new refcnts using new_roots */
2517 	ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2518 				   UPDATE_NEW);
2519 	if (ret < 0)
2520 		goto out;
2521 
2522 	qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2523 			       num_bytes, seq);
2524 
2525 	/*
2526 	 * Bump qgroup_seq to avoid seq overlap
2527 	 */
2528 	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2529 out:
2530 	spin_unlock(&fs_info->qgroup_lock);
2531 out_free:
2532 	ulist_free(tmp);
2533 	ulist_free(qgroups);
2534 	ulist_free(old_roots);
2535 	ulist_free(new_roots);
2536 	return ret;
2537 }
2538 
2539 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2540 {
2541 	struct btrfs_fs_info *fs_info = trans->fs_info;
2542 	struct btrfs_qgroup_extent_record *record;
2543 	struct btrfs_delayed_ref_root *delayed_refs;
2544 	struct ulist *new_roots = NULL;
2545 	struct rb_node *node;
2546 	u64 num_dirty_extents = 0;
2547 	u64 qgroup_to_skip;
2548 	int ret = 0;
2549 
2550 	delayed_refs = &trans->transaction->delayed_refs;
2551 	qgroup_to_skip = delayed_refs->qgroup_to_skip;
2552 	while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2553 		record = rb_entry(node, struct btrfs_qgroup_extent_record,
2554 				  node);
2555 
2556 		num_dirty_extents++;
2557 		trace_btrfs_qgroup_account_extents(fs_info, record);
2558 
2559 		if (!ret) {
2560 			/*
2561 			 * Old roots should be searched when inserting qgroup
2562 			 * extent record
2563 			 */
2564 			if (WARN_ON(!record->old_roots)) {
2565 				/* Search commit root to find old_roots */
2566 				ret = btrfs_find_all_roots(NULL, fs_info,
2567 						record->bytenr, 0,
2568 						&record->old_roots, false);
2569 				if (ret < 0)
2570 					goto cleanup;
2571 			}
2572 
2573 			/*
2574 			 * Use SEQ_LAST as time_seq to do special search, which
2575 			 * doesn't lock tree or delayed_refs and search current
2576 			 * root. It's safe inside commit_transaction().
2577 			 */
2578 			ret = btrfs_find_all_roots(trans, fs_info,
2579 				record->bytenr, SEQ_LAST, &new_roots, false);
2580 			if (ret < 0)
2581 				goto cleanup;
2582 			if (qgroup_to_skip) {
2583 				ulist_del(new_roots, qgroup_to_skip, 0);
2584 				ulist_del(record->old_roots, qgroup_to_skip,
2585 					  0);
2586 			}
2587 			ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2588 							  record->num_bytes,
2589 							  record->old_roots,
2590 							  new_roots);
2591 			record->old_roots = NULL;
2592 			new_roots = NULL;
2593 		}
2594 cleanup:
2595 		ulist_free(record->old_roots);
2596 		ulist_free(new_roots);
2597 		new_roots = NULL;
2598 		rb_erase(node, &delayed_refs->dirty_extent_root);
2599 		kfree(record);
2600 
2601 	}
2602 	trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2603 				       num_dirty_extents);
2604 	return ret;
2605 }
2606 
2607 /*
2608  * called from commit_transaction. Writes all changed qgroups to disk.
2609  */
2610 int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2611 {
2612 	struct btrfs_fs_info *fs_info = trans->fs_info;
2613 	struct btrfs_root *quota_root = fs_info->quota_root;
2614 	int ret = 0;
2615 
2616 	if (!quota_root)
2617 		return ret;
2618 
2619 	spin_lock(&fs_info->qgroup_lock);
2620 	while (!list_empty(&fs_info->dirty_qgroups)) {
2621 		struct btrfs_qgroup *qgroup;
2622 		qgroup = list_first_entry(&fs_info->dirty_qgroups,
2623 					  struct btrfs_qgroup, dirty);
2624 		list_del_init(&qgroup->dirty);
2625 		spin_unlock(&fs_info->qgroup_lock);
2626 		ret = update_qgroup_info_item(trans, qgroup);
2627 		if (ret)
2628 			fs_info->qgroup_flags |=
2629 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2630 		ret = update_qgroup_limit_item(trans, qgroup);
2631 		if (ret)
2632 			fs_info->qgroup_flags |=
2633 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2634 		spin_lock(&fs_info->qgroup_lock);
2635 	}
2636 	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2637 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2638 	else
2639 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2640 	spin_unlock(&fs_info->qgroup_lock);
2641 
2642 	ret = update_qgroup_status_item(trans);
2643 	if (ret)
2644 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2645 
2646 	return ret;
2647 }
2648 
2649 /*
2650  * Copy the accounting information between qgroups. This is necessary
2651  * when a snapshot or a subvolume is created. Throwing an error will
2652  * cause a transaction abort so we take extra care here to only error
2653  * when a readonly fs is a reasonable outcome.
2654  */
2655 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2656 			 u64 objectid, struct btrfs_qgroup_inherit *inherit)
2657 {
2658 	int ret = 0;
2659 	int i;
2660 	u64 *i_qgroups;
2661 	struct btrfs_fs_info *fs_info = trans->fs_info;
2662 	struct btrfs_root *quota_root = fs_info->quota_root;
2663 	struct btrfs_qgroup *srcgroup;
2664 	struct btrfs_qgroup *dstgroup;
2665 	u32 level_size = 0;
2666 	u64 nums;
2667 
2668 	mutex_lock(&fs_info->qgroup_ioctl_lock);
2669 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2670 		goto out;
2671 
2672 	if (!quota_root) {
2673 		ret = -EINVAL;
2674 		goto out;
2675 	}
2676 
2677 	if (inherit) {
2678 		i_qgroups = (u64 *)(inherit + 1);
2679 		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2680 		       2 * inherit->num_excl_copies;
2681 		for (i = 0; i < nums; ++i) {
2682 			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2683 
2684 			/*
2685 			 * Zero out invalid groups so we can ignore
2686 			 * them later.
2687 			 */
2688 			if (!srcgroup ||
2689 			    ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2690 				*i_qgroups = 0ULL;
2691 
2692 			++i_qgroups;
2693 		}
2694 	}
2695 
2696 	/*
2697 	 * create a tracking group for the subvol itself
2698 	 */
2699 	ret = add_qgroup_item(trans, quota_root, objectid);
2700 	if (ret)
2701 		goto out;
2702 
2703 	/*
2704 	 * add qgroup to all inherited groups
2705 	 */
2706 	if (inherit) {
2707 		i_qgroups = (u64 *)(inherit + 1);
2708 		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2709 			if (*i_qgroups == 0)
2710 				continue;
2711 			ret = add_qgroup_relation_item(trans, objectid,
2712 						       *i_qgroups);
2713 			if (ret && ret != -EEXIST)
2714 				goto out;
2715 			ret = add_qgroup_relation_item(trans, *i_qgroups,
2716 						       objectid);
2717 			if (ret && ret != -EEXIST)
2718 				goto out;
2719 		}
2720 		ret = 0;
2721 	}
2722 
2723 
2724 	spin_lock(&fs_info->qgroup_lock);
2725 
2726 	dstgroup = add_qgroup_rb(fs_info, objectid);
2727 	if (IS_ERR(dstgroup)) {
2728 		ret = PTR_ERR(dstgroup);
2729 		goto unlock;
2730 	}
2731 
2732 	if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2733 		dstgroup->lim_flags = inherit->lim.flags;
2734 		dstgroup->max_rfer = inherit->lim.max_rfer;
2735 		dstgroup->max_excl = inherit->lim.max_excl;
2736 		dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2737 		dstgroup->rsv_excl = inherit->lim.rsv_excl;
2738 
2739 		ret = update_qgroup_limit_item(trans, dstgroup);
2740 		if (ret) {
2741 			fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2742 			btrfs_info(fs_info,
2743 				   "unable to update quota limit for %llu",
2744 				   dstgroup->qgroupid);
2745 			goto unlock;
2746 		}
2747 	}
2748 
2749 	if (srcid) {
2750 		srcgroup = find_qgroup_rb(fs_info, srcid);
2751 		if (!srcgroup)
2752 			goto unlock;
2753 
2754 		/*
2755 		 * We call inherit after we clone the root in order to make sure
2756 		 * our counts don't go crazy, so at this point the only
2757 		 * difference between the two roots should be the root node.
2758 		 */
2759 		level_size = fs_info->nodesize;
2760 		dstgroup->rfer = srcgroup->rfer;
2761 		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2762 		dstgroup->excl = level_size;
2763 		dstgroup->excl_cmpr = level_size;
2764 		srcgroup->excl = level_size;
2765 		srcgroup->excl_cmpr = level_size;
2766 
2767 		/* inherit the limit info */
2768 		dstgroup->lim_flags = srcgroup->lim_flags;
2769 		dstgroup->max_rfer = srcgroup->max_rfer;
2770 		dstgroup->max_excl = srcgroup->max_excl;
2771 		dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2772 		dstgroup->rsv_excl = srcgroup->rsv_excl;
2773 
2774 		qgroup_dirty(fs_info, dstgroup);
2775 		qgroup_dirty(fs_info, srcgroup);
2776 	}
2777 
2778 	if (!inherit)
2779 		goto unlock;
2780 
2781 	i_qgroups = (u64 *)(inherit + 1);
2782 	for (i = 0; i < inherit->num_qgroups; ++i) {
2783 		if (*i_qgroups) {
2784 			ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2785 			if (ret)
2786 				goto unlock;
2787 		}
2788 		++i_qgroups;
2789 	}
2790 
2791 	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2792 		struct btrfs_qgroup *src;
2793 		struct btrfs_qgroup *dst;
2794 
2795 		if (!i_qgroups[0] || !i_qgroups[1])
2796 			continue;
2797 
2798 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2799 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2800 
2801 		if (!src || !dst) {
2802 			ret = -EINVAL;
2803 			goto unlock;
2804 		}
2805 
2806 		dst->rfer = src->rfer - level_size;
2807 		dst->rfer_cmpr = src->rfer_cmpr - level_size;
2808 	}
2809 	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2810 		struct btrfs_qgroup *src;
2811 		struct btrfs_qgroup *dst;
2812 
2813 		if (!i_qgroups[0] || !i_qgroups[1])
2814 			continue;
2815 
2816 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2817 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2818 
2819 		if (!src || !dst) {
2820 			ret = -EINVAL;
2821 			goto unlock;
2822 		}
2823 
2824 		dst->excl = src->excl + level_size;
2825 		dst->excl_cmpr = src->excl_cmpr + level_size;
2826 	}
2827 
2828 unlock:
2829 	spin_unlock(&fs_info->qgroup_lock);
2830 out:
2831 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
2832 	return ret;
2833 }
2834 
2835 /*
2836  * Two limits to commit transaction in advance.
2837  *
2838  * For RATIO, it will be 1/RATIO of the remaining limit
2839  * (excluding data and prealloc meta) as threshold.
2840  * For SIZE, it will be in byte unit as threshold.
2841  */
2842 #define QGROUP_PERTRANS_RATIO		32
2843 #define QGROUP_PERTRANS_SIZE		SZ_32M
2844 static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
2845 				const struct btrfs_qgroup *qg, u64 num_bytes)
2846 {
2847 	u64 limit;
2848 	u64 threshold;
2849 
2850 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2851 	    qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
2852 		return false;
2853 
2854 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2855 	    qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
2856 		return false;
2857 
2858 	/*
2859 	 * Even if we passed the check, it's better to check if reservation
2860 	 * for meta_pertrans is pushing us near limit.
2861 	 * If there is too much pertrans reservation or it's near the limit,
2862 	 * let's try commit transaction to free some, using transaction_kthread
2863 	 */
2864 	if ((qg->lim_flags & (BTRFS_QGROUP_LIMIT_MAX_RFER |
2865 			      BTRFS_QGROUP_LIMIT_MAX_EXCL))) {
2866 		if (qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL)
2867 			limit = qg->max_excl;
2868 		else
2869 			limit = qg->max_rfer;
2870 		threshold = (limit - qg->rsv.values[BTRFS_QGROUP_RSV_DATA] -
2871 			    qg->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC]) /
2872 			    QGROUP_PERTRANS_RATIO;
2873 		threshold = min_t(u64, threshold, QGROUP_PERTRANS_SIZE);
2874 
2875 		/*
2876 		 * Use transaction_kthread to commit transaction, so we no
2877 		 * longer need to bother nested transaction nor lock context.
2878 		 */
2879 		if (qg->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS] > threshold)
2880 			btrfs_commit_transaction_locksafe(fs_info);
2881 	}
2882 
2883 	return true;
2884 }
2885 
2886 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
2887 			  enum btrfs_qgroup_rsv_type type)
2888 {
2889 	struct btrfs_root *quota_root;
2890 	struct btrfs_qgroup *qgroup;
2891 	struct btrfs_fs_info *fs_info = root->fs_info;
2892 	u64 ref_root = root->root_key.objectid;
2893 	int ret = 0;
2894 	struct ulist_node *unode;
2895 	struct ulist_iterator uiter;
2896 
2897 	if (!is_fstree(ref_root))
2898 		return 0;
2899 
2900 	if (num_bytes == 0)
2901 		return 0;
2902 
2903 	if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2904 	    capable(CAP_SYS_RESOURCE))
2905 		enforce = false;
2906 
2907 	spin_lock(&fs_info->qgroup_lock);
2908 	quota_root = fs_info->quota_root;
2909 	if (!quota_root)
2910 		goto out;
2911 
2912 	qgroup = find_qgroup_rb(fs_info, ref_root);
2913 	if (!qgroup)
2914 		goto out;
2915 
2916 	/*
2917 	 * in a first step, we check all affected qgroups if any limits would
2918 	 * be exceeded
2919 	 */
2920 	ulist_reinit(fs_info->qgroup_ulist);
2921 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2922 			qgroup_to_aux(qgroup), GFP_ATOMIC);
2923 	if (ret < 0)
2924 		goto out;
2925 	ULIST_ITER_INIT(&uiter);
2926 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2927 		struct btrfs_qgroup *qg;
2928 		struct btrfs_qgroup_list *glist;
2929 
2930 		qg = unode_aux_to_qgroup(unode);
2931 
2932 		if (enforce && !qgroup_check_limits(fs_info, qg, num_bytes)) {
2933 			ret = -EDQUOT;
2934 			goto out;
2935 		}
2936 
2937 		list_for_each_entry(glist, &qg->groups, next_group) {
2938 			ret = ulist_add(fs_info->qgroup_ulist,
2939 					glist->group->qgroupid,
2940 					qgroup_to_aux(glist->group), GFP_ATOMIC);
2941 			if (ret < 0)
2942 				goto out;
2943 		}
2944 	}
2945 	ret = 0;
2946 	/*
2947 	 * no limits exceeded, now record the reservation into all qgroups
2948 	 */
2949 	ULIST_ITER_INIT(&uiter);
2950 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2951 		struct btrfs_qgroup *qg;
2952 
2953 		qg = unode_aux_to_qgroup(unode);
2954 
2955 		trace_qgroup_update_reserve(fs_info, qg, num_bytes, type);
2956 		qgroup_rsv_add(fs_info, qg, num_bytes, type);
2957 	}
2958 
2959 out:
2960 	spin_unlock(&fs_info->qgroup_lock);
2961 	return ret;
2962 }
2963 
2964 /*
2965  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
2966  * qgroup).
2967  *
2968  * Will handle all higher level qgroup too.
2969  *
2970  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
2971  * This special case is only used for META_PERTRANS type.
2972  */
2973 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2974 			       u64 ref_root, u64 num_bytes,
2975 			       enum btrfs_qgroup_rsv_type type)
2976 {
2977 	struct btrfs_root *quota_root;
2978 	struct btrfs_qgroup *qgroup;
2979 	struct ulist_node *unode;
2980 	struct ulist_iterator uiter;
2981 	int ret = 0;
2982 
2983 	if (!is_fstree(ref_root))
2984 		return;
2985 
2986 	if (num_bytes == 0)
2987 		return;
2988 
2989 	if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
2990 		WARN(1, "%s: Invalid type to free", __func__);
2991 		return;
2992 	}
2993 	spin_lock(&fs_info->qgroup_lock);
2994 
2995 	quota_root = fs_info->quota_root;
2996 	if (!quota_root)
2997 		goto out;
2998 
2999 	qgroup = find_qgroup_rb(fs_info, ref_root);
3000 	if (!qgroup)
3001 		goto out;
3002 
3003 	if (num_bytes == (u64)-1)
3004 		/*
3005 		 * We're freeing all pertrans rsv, get reserved value from
3006 		 * level 0 qgroup as real num_bytes to free.
3007 		 */
3008 		num_bytes = qgroup->rsv.values[type];
3009 
3010 	ulist_reinit(fs_info->qgroup_ulist);
3011 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3012 			qgroup_to_aux(qgroup), GFP_ATOMIC);
3013 	if (ret < 0)
3014 		goto out;
3015 	ULIST_ITER_INIT(&uiter);
3016 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3017 		struct btrfs_qgroup *qg;
3018 		struct btrfs_qgroup_list *glist;
3019 
3020 		qg = unode_aux_to_qgroup(unode);
3021 
3022 		trace_qgroup_update_reserve(fs_info, qg, -(s64)num_bytes, type);
3023 		qgroup_rsv_release(fs_info, qg, num_bytes, type);
3024 
3025 		list_for_each_entry(glist, &qg->groups, next_group) {
3026 			ret = ulist_add(fs_info->qgroup_ulist,
3027 					glist->group->qgroupid,
3028 					qgroup_to_aux(glist->group), GFP_ATOMIC);
3029 			if (ret < 0)
3030 				goto out;
3031 		}
3032 	}
3033 
3034 out:
3035 	spin_unlock(&fs_info->qgroup_lock);
3036 }
3037 
3038 /*
3039  * Check if the leaf is the last leaf. Which means all node pointers
3040  * are at their last position.
3041  */
3042 static bool is_last_leaf(struct btrfs_path *path)
3043 {
3044 	int i;
3045 
3046 	for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3047 		if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3048 			return false;
3049 	}
3050 	return true;
3051 }
3052 
3053 /*
3054  * returns < 0 on error, 0 when more leafs are to be scanned.
3055  * returns 1 when done.
3056  */
3057 static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3058 			      struct btrfs_path *path)
3059 {
3060 	struct btrfs_fs_info *fs_info = trans->fs_info;
3061 	struct btrfs_key found;
3062 	struct extent_buffer *scratch_leaf = NULL;
3063 	struct ulist *roots = NULL;
3064 	u64 num_bytes;
3065 	bool done;
3066 	int slot;
3067 	int ret;
3068 
3069 	mutex_lock(&fs_info->qgroup_rescan_lock);
3070 	ret = btrfs_search_slot_for_read(fs_info->extent_root,
3071 					 &fs_info->qgroup_rescan_progress,
3072 					 path, 1, 0);
3073 
3074 	btrfs_debug(fs_info,
3075 		"current progress key (%llu %u %llu), search_slot ret %d",
3076 		fs_info->qgroup_rescan_progress.objectid,
3077 		fs_info->qgroup_rescan_progress.type,
3078 		fs_info->qgroup_rescan_progress.offset, ret);
3079 
3080 	if (ret) {
3081 		/*
3082 		 * The rescan is about to end, we will not be scanning any
3083 		 * further blocks. We cannot unset the RESCAN flag here, because
3084 		 * we want to commit the transaction if everything went well.
3085 		 * To make the live accounting work in this phase, we set our
3086 		 * scan progress pointer such that every real extent objectid
3087 		 * will be smaller.
3088 		 */
3089 		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3090 		btrfs_release_path(path);
3091 		mutex_unlock(&fs_info->qgroup_rescan_lock);
3092 		return ret;
3093 	}
3094 	done = is_last_leaf(path);
3095 
3096 	btrfs_item_key_to_cpu(path->nodes[0], &found,
3097 			      btrfs_header_nritems(path->nodes[0]) - 1);
3098 	fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3099 
3100 	scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3101 	if (!scratch_leaf) {
3102 		ret = -ENOMEM;
3103 		mutex_unlock(&fs_info->qgroup_rescan_lock);
3104 		goto out;
3105 	}
3106 	extent_buffer_get(scratch_leaf);
3107 	btrfs_tree_read_lock(scratch_leaf);
3108 	btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
3109 	slot = path->slots[0];
3110 	btrfs_release_path(path);
3111 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3112 
3113 	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
3114 		btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3115 		if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3116 		    found.type != BTRFS_METADATA_ITEM_KEY)
3117 			continue;
3118 		if (found.type == BTRFS_METADATA_ITEM_KEY)
3119 			num_bytes = fs_info->nodesize;
3120 		else
3121 			num_bytes = found.offset;
3122 
3123 		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
3124 					   &roots, false);
3125 		if (ret < 0)
3126 			goto out;
3127 		/* For rescan, just pass old_roots as NULL */
3128 		ret = btrfs_qgroup_account_extent(trans, found.objectid,
3129 						  num_bytes, NULL, roots);
3130 		if (ret < 0)
3131 			goto out;
3132 	}
3133 out:
3134 	if (scratch_leaf) {
3135 		btrfs_tree_read_unlock_blocking(scratch_leaf);
3136 		free_extent_buffer(scratch_leaf);
3137 	}
3138 
3139 	if (done && !ret) {
3140 		ret = 1;
3141 		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3142 	}
3143 	return ret;
3144 }
3145 
3146 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3147 {
3148 	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3149 						     qgroup_rescan_work);
3150 	struct btrfs_path *path;
3151 	struct btrfs_trans_handle *trans = NULL;
3152 	int err = -ENOMEM;
3153 	int ret = 0;
3154 
3155 	path = btrfs_alloc_path();
3156 	if (!path)
3157 		goto out;
3158 	/*
3159 	 * Rescan should only search for commit root, and any later difference
3160 	 * should be recorded by qgroup
3161 	 */
3162 	path->search_commit_root = 1;
3163 	path->skip_locking = 1;
3164 
3165 	err = 0;
3166 	while (!err && !btrfs_fs_closing(fs_info)) {
3167 		trans = btrfs_start_transaction(fs_info->fs_root, 0);
3168 		if (IS_ERR(trans)) {
3169 			err = PTR_ERR(trans);
3170 			break;
3171 		}
3172 		if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3173 			err = -EINTR;
3174 		} else {
3175 			err = qgroup_rescan_leaf(trans, path);
3176 		}
3177 		if (err > 0)
3178 			btrfs_commit_transaction(trans);
3179 		else
3180 			btrfs_end_transaction(trans);
3181 	}
3182 
3183 out:
3184 	btrfs_free_path(path);
3185 
3186 	mutex_lock(&fs_info->qgroup_rescan_lock);
3187 	if (!btrfs_fs_closing(fs_info))
3188 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3189 
3190 	if (err > 0 &&
3191 	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3192 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3193 	} else if (err < 0) {
3194 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3195 	}
3196 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3197 
3198 	/*
3199 	 * only update status, since the previous part has already updated the
3200 	 * qgroup info.
3201 	 */
3202 	trans = btrfs_start_transaction(fs_info->quota_root, 1);
3203 	if (IS_ERR(trans)) {
3204 		err = PTR_ERR(trans);
3205 		btrfs_err(fs_info,
3206 			  "fail to start transaction for status update: %d",
3207 			  err);
3208 		goto done;
3209 	}
3210 	ret = update_qgroup_status_item(trans);
3211 	if (ret < 0) {
3212 		err = ret;
3213 		btrfs_err(fs_info, "fail to update qgroup status: %d", err);
3214 	}
3215 	btrfs_end_transaction(trans);
3216 
3217 	if (btrfs_fs_closing(fs_info)) {
3218 		btrfs_info(fs_info, "qgroup scan paused");
3219 	} else if (err >= 0) {
3220 		btrfs_info(fs_info, "qgroup scan completed%s",
3221 			err > 0 ? " (inconsistency flag cleared)" : "");
3222 	} else {
3223 		btrfs_err(fs_info, "qgroup scan failed with %d", err);
3224 	}
3225 
3226 done:
3227 	mutex_lock(&fs_info->qgroup_rescan_lock);
3228 	fs_info->qgroup_rescan_running = false;
3229 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3230 	complete_all(&fs_info->qgroup_rescan_completion);
3231 }
3232 
3233 /*
3234  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
3235  * memory required for the rescan context.
3236  */
3237 static int
3238 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
3239 		   int init_flags)
3240 {
3241 	int ret = 0;
3242 
3243 	if (!init_flags) {
3244 		/* we're resuming qgroup rescan at mount time */
3245 		if (!(fs_info->qgroup_flags &
3246 		      BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
3247 			btrfs_warn(fs_info,
3248 			"qgroup rescan init failed, qgroup is not enabled");
3249 			ret = -EINVAL;
3250 		} else if (!(fs_info->qgroup_flags &
3251 			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3252 			btrfs_warn(fs_info,
3253 			"qgroup rescan init failed, qgroup rescan is not queued");
3254 			ret = -EINVAL;
3255 		}
3256 
3257 		if (ret)
3258 			return ret;
3259 	}
3260 
3261 	mutex_lock(&fs_info->qgroup_rescan_lock);
3262 	spin_lock(&fs_info->qgroup_lock);
3263 
3264 	if (init_flags) {
3265 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3266 			btrfs_warn(fs_info,
3267 				   "qgroup rescan is already in progress");
3268 			ret = -EINPROGRESS;
3269 		} else if (!(fs_info->qgroup_flags &
3270 			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3271 			btrfs_warn(fs_info,
3272 			"qgroup rescan init failed, qgroup is not enabled");
3273 			ret = -EINVAL;
3274 		}
3275 
3276 		if (ret) {
3277 			spin_unlock(&fs_info->qgroup_lock);
3278 			mutex_unlock(&fs_info->qgroup_rescan_lock);
3279 			return ret;
3280 		}
3281 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3282 	}
3283 
3284 	memset(&fs_info->qgroup_rescan_progress, 0,
3285 		sizeof(fs_info->qgroup_rescan_progress));
3286 	fs_info->qgroup_rescan_progress.objectid = progress_objectid;
3287 	init_completion(&fs_info->qgroup_rescan_completion);
3288 	fs_info->qgroup_rescan_running = true;
3289 
3290 	spin_unlock(&fs_info->qgroup_lock);
3291 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3292 
3293 	memset(&fs_info->qgroup_rescan_work, 0,
3294 	       sizeof(fs_info->qgroup_rescan_work));
3295 	btrfs_init_work(&fs_info->qgroup_rescan_work,
3296 			btrfs_qgroup_rescan_helper,
3297 			btrfs_qgroup_rescan_worker, NULL, NULL);
3298 	return 0;
3299 }
3300 
3301 static void
3302 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
3303 {
3304 	struct rb_node *n;
3305 	struct btrfs_qgroup *qgroup;
3306 
3307 	spin_lock(&fs_info->qgroup_lock);
3308 	/* clear all current qgroup tracking information */
3309 	for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
3310 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
3311 		qgroup->rfer = 0;
3312 		qgroup->rfer_cmpr = 0;
3313 		qgroup->excl = 0;
3314 		qgroup->excl_cmpr = 0;
3315 		qgroup_dirty(fs_info, qgroup);
3316 	}
3317 	spin_unlock(&fs_info->qgroup_lock);
3318 }
3319 
3320 int
3321 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
3322 {
3323 	int ret = 0;
3324 	struct btrfs_trans_handle *trans;
3325 
3326 	ret = qgroup_rescan_init(fs_info, 0, 1);
3327 	if (ret)
3328 		return ret;
3329 
3330 	/*
3331 	 * We have set the rescan_progress to 0, which means no more
3332 	 * delayed refs will be accounted by btrfs_qgroup_account_ref.
3333 	 * However, btrfs_qgroup_account_ref may be right after its call
3334 	 * to btrfs_find_all_roots, in which case it would still do the
3335 	 * accounting.
3336 	 * To solve this, we're committing the transaction, which will
3337 	 * ensure we run all delayed refs and only after that, we are
3338 	 * going to clear all tracking information for a clean start.
3339 	 */
3340 
3341 	trans = btrfs_join_transaction(fs_info->fs_root);
3342 	if (IS_ERR(trans)) {
3343 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3344 		return PTR_ERR(trans);
3345 	}
3346 	ret = btrfs_commit_transaction(trans);
3347 	if (ret) {
3348 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3349 		return ret;
3350 	}
3351 
3352 	qgroup_rescan_zero_tracking(fs_info);
3353 
3354 	btrfs_queue_work(fs_info->qgroup_rescan_workers,
3355 			 &fs_info->qgroup_rescan_work);
3356 
3357 	return 0;
3358 }
3359 
3360 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
3361 				     bool interruptible)
3362 {
3363 	int running;
3364 	int ret = 0;
3365 
3366 	mutex_lock(&fs_info->qgroup_rescan_lock);
3367 	spin_lock(&fs_info->qgroup_lock);
3368 	running = fs_info->qgroup_rescan_running;
3369 	spin_unlock(&fs_info->qgroup_lock);
3370 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3371 
3372 	if (!running)
3373 		return 0;
3374 
3375 	if (interruptible)
3376 		ret = wait_for_completion_interruptible(
3377 					&fs_info->qgroup_rescan_completion);
3378 	else
3379 		wait_for_completion(&fs_info->qgroup_rescan_completion);
3380 
3381 	return ret;
3382 }
3383 
3384 /*
3385  * this is only called from open_ctree where we're still single threaded, thus
3386  * locking is omitted here.
3387  */
3388 void
3389 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
3390 {
3391 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
3392 		btrfs_queue_work(fs_info->qgroup_rescan_workers,
3393 				 &fs_info->qgroup_rescan_work);
3394 }
3395 
3396 /*
3397  * Reserve qgroup space for range [start, start + len).
3398  *
3399  * This function will either reserve space from related qgroups or doing
3400  * nothing if the range is already reserved.
3401  *
3402  * Return 0 for successful reserve
3403  * Return <0 for error (including -EQUOT)
3404  *
3405  * NOTE: this function may sleep for memory allocation.
3406  *       if btrfs_qgroup_reserve_data() is called multiple times with
3407  *       same @reserved, caller must ensure when error happens it's OK
3408  *       to free *ALL* reserved space.
3409  */
3410 int btrfs_qgroup_reserve_data(struct inode *inode,
3411 			struct extent_changeset **reserved_ret, u64 start,
3412 			u64 len)
3413 {
3414 	struct btrfs_root *root = BTRFS_I(inode)->root;
3415 	struct ulist_node *unode;
3416 	struct ulist_iterator uiter;
3417 	struct extent_changeset *reserved;
3418 	u64 orig_reserved;
3419 	u64 to_reserve;
3420 	int ret;
3421 
3422 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
3423 	    !is_fstree(root->root_key.objectid) || len == 0)
3424 		return 0;
3425 
3426 	/* @reserved parameter is mandatory for qgroup */
3427 	if (WARN_ON(!reserved_ret))
3428 		return -EINVAL;
3429 	if (!*reserved_ret) {
3430 		*reserved_ret = extent_changeset_alloc();
3431 		if (!*reserved_ret)
3432 			return -ENOMEM;
3433 	}
3434 	reserved = *reserved_ret;
3435 	/* Record already reserved space */
3436 	orig_reserved = reserved->bytes_changed;
3437 	ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
3438 			start + len -1, EXTENT_QGROUP_RESERVED, reserved);
3439 
3440 	/* Newly reserved space */
3441 	to_reserve = reserved->bytes_changed - orig_reserved;
3442 	trace_btrfs_qgroup_reserve_data(inode, start, len,
3443 					to_reserve, QGROUP_RESERVE);
3444 	if (ret < 0)
3445 		goto cleanup;
3446 	ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
3447 	if (ret < 0)
3448 		goto cleanup;
3449 
3450 	return ret;
3451 
3452 cleanup:
3453 	/* cleanup *ALL* already reserved ranges */
3454 	ULIST_ITER_INIT(&uiter);
3455 	while ((unode = ulist_next(&reserved->range_changed, &uiter)))
3456 		clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
3457 				 unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL);
3458 	extent_changeset_release(reserved);
3459 	return ret;
3460 }
3461 
3462 /* Free ranges specified by @reserved, normally in error path */
3463 static int qgroup_free_reserved_data(struct inode *inode,
3464 			struct extent_changeset *reserved, u64 start, u64 len)
3465 {
3466 	struct btrfs_root *root = BTRFS_I(inode)->root;
3467 	struct ulist_node *unode;
3468 	struct ulist_iterator uiter;
3469 	struct extent_changeset changeset;
3470 	int freed = 0;
3471 	int ret;
3472 
3473 	extent_changeset_init(&changeset);
3474 	len = round_up(start + len, root->fs_info->sectorsize);
3475 	start = round_down(start, root->fs_info->sectorsize);
3476 
3477 	ULIST_ITER_INIT(&uiter);
3478 	while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
3479 		u64 range_start = unode->val;
3480 		/* unode->aux is the inclusive end */
3481 		u64 range_len = unode->aux - range_start + 1;
3482 		u64 free_start;
3483 		u64 free_len;
3484 
3485 		extent_changeset_release(&changeset);
3486 
3487 		/* Only free range in range [start, start + len) */
3488 		if (range_start >= start + len ||
3489 		    range_start + range_len <= start)
3490 			continue;
3491 		free_start = max(range_start, start);
3492 		free_len = min(start + len, range_start + range_len) -
3493 			   free_start;
3494 		/*
3495 		 * TODO: To also modify reserved->ranges_reserved to reflect
3496 		 * the modification.
3497 		 *
3498 		 * However as long as we free qgroup reserved according to
3499 		 * EXTENT_QGROUP_RESERVED, we won't double free.
3500 		 * So not need to rush.
3501 		 */
3502 		ret = clear_record_extent_bits(&BTRFS_I(inode)->io_failure_tree,
3503 				free_start, free_start + free_len - 1,
3504 				EXTENT_QGROUP_RESERVED, &changeset);
3505 		if (ret < 0)
3506 			goto out;
3507 		freed += changeset.bytes_changed;
3508 	}
3509 	btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
3510 				  BTRFS_QGROUP_RSV_DATA);
3511 	ret = freed;
3512 out:
3513 	extent_changeset_release(&changeset);
3514 	return ret;
3515 }
3516 
3517 static int __btrfs_qgroup_release_data(struct inode *inode,
3518 			struct extent_changeset *reserved, u64 start, u64 len,
3519 			int free)
3520 {
3521 	struct extent_changeset changeset;
3522 	int trace_op = QGROUP_RELEASE;
3523 	int ret;
3524 
3525 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED,
3526 		      &BTRFS_I(inode)->root->fs_info->flags))
3527 		return 0;
3528 
3529 	/* In release case, we shouldn't have @reserved */
3530 	WARN_ON(!free && reserved);
3531 	if (free && reserved)
3532 		return qgroup_free_reserved_data(inode, reserved, start, len);
3533 	extent_changeset_init(&changeset);
3534 	ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
3535 			start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
3536 	if (ret < 0)
3537 		goto out;
3538 
3539 	if (free)
3540 		trace_op = QGROUP_FREE;
3541 	trace_btrfs_qgroup_release_data(inode, start, len,
3542 					changeset.bytes_changed, trace_op);
3543 	if (free)
3544 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3545 				BTRFS_I(inode)->root->root_key.objectid,
3546 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3547 	ret = changeset.bytes_changed;
3548 out:
3549 	extent_changeset_release(&changeset);
3550 	return ret;
3551 }
3552 
3553 /*
3554  * Free a reserved space range from io_tree and related qgroups
3555  *
3556  * Should be called when a range of pages get invalidated before reaching disk.
3557  * Or for error cleanup case.
3558  * if @reserved is given, only reserved range in [@start, @start + @len) will
3559  * be freed.
3560  *
3561  * For data written to disk, use btrfs_qgroup_release_data().
3562  *
3563  * NOTE: This function may sleep for memory allocation.
3564  */
3565 int btrfs_qgroup_free_data(struct inode *inode,
3566 			struct extent_changeset *reserved, u64 start, u64 len)
3567 {
3568 	return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3569 }
3570 
3571 /*
3572  * Release a reserved space range from io_tree only.
3573  *
3574  * Should be called when a range of pages get written to disk and corresponding
3575  * FILE_EXTENT is inserted into corresponding root.
3576  *
3577  * Since new qgroup accounting framework will only update qgroup numbers at
3578  * commit_transaction() time, its reserved space shouldn't be freed from
3579  * related qgroups.
3580  *
3581  * But we should release the range from io_tree, to allow further write to be
3582  * COWed.
3583  *
3584  * NOTE: This function may sleep for memory allocation.
3585  */
3586 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
3587 {
3588 	return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3589 }
3590 
3591 static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3592 			      enum btrfs_qgroup_rsv_type type)
3593 {
3594 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3595 	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3596 		return;
3597 	if (num_bytes == 0)
3598 		return;
3599 
3600 	spin_lock(&root->qgroup_meta_rsv_lock);
3601 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3602 		root->qgroup_meta_rsv_prealloc += num_bytes;
3603 	else
3604 		root->qgroup_meta_rsv_pertrans += num_bytes;
3605 	spin_unlock(&root->qgroup_meta_rsv_lock);
3606 }
3607 
3608 static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3609 			     enum btrfs_qgroup_rsv_type type)
3610 {
3611 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3612 	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3613 		return 0;
3614 	if (num_bytes == 0)
3615 		return 0;
3616 
3617 	spin_lock(&root->qgroup_meta_rsv_lock);
3618 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3619 		num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3620 				  num_bytes);
3621 		root->qgroup_meta_rsv_prealloc -= num_bytes;
3622 	} else {
3623 		num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3624 				  num_bytes);
3625 		root->qgroup_meta_rsv_pertrans -= num_bytes;
3626 	}
3627 	spin_unlock(&root->qgroup_meta_rsv_lock);
3628 	return num_bytes;
3629 }
3630 
3631 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3632 				enum btrfs_qgroup_rsv_type type, bool enforce)
3633 {
3634 	struct btrfs_fs_info *fs_info = root->fs_info;
3635 	int ret;
3636 
3637 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3638 	    !is_fstree(root->root_key.objectid) || num_bytes == 0)
3639 		return 0;
3640 
3641 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3642 	trace_qgroup_meta_reserve(root, type, (s64)num_bytes);
3643 	ret = qgroup_reserve(root, num_bytes, enforce, type);
3644 	if (ret < 0)
3645 		return ret;
3646 	/*
3647 	 * Record what we have reserved into root.
3648 	 *
3649 	 * To avoid quota disabled->enabled underflow.
3650 	 * In that case, we may try to free space we haven't reserved
3651 	 * (since quota was disabled), so record what we reserved into root.
3652 	 * And ensure later release won't underflow this number.
3653 	 */
3654 	add_root_meta_rsv(root, num_bytes, type);
3655 	return ret;
3656 }
3657 
3658 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
3659 {
3660 	struct btrfs_fs_info *fs_info = root->fs_info;
3661 
3662 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3663 	    !is_fstree(root->root_key.objectid))
3664 		return;
3665 
3666 	/* TODO: Update trace point to handle such free */
3667 	trace_qgroup_meta_free_all_pertrans(root);
3668 	/* Special value -1 means to free all reserved space */
3669 	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
3670 				  BTRFS_QGROUP_RSV_META_PERTRANS);
3671 }
3672 
3673 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
3674 			      enum btrfs_qgroup_rsv_type type)
3675 {
3676 	struct btrfs_fs_info *fs_info = root->fs_info;
3677 
3678 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3679 	    !is_fstree(root->root_key.objectid))
3680 		return;
3681 
3682 	/*
3683 	 * reservation for META_PREALLOC can happen before quota is enabled,
3684 	 * which can lead to underflow.
3685 	 * Here ensure we will only free what we really have reserved.
3686 	 */
3687 	num_bytes = sub_root_meta_rsv(root, num_bytes, type);
3688 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3689 	trace_qgroup_meta_reserve(root, type, -(s64)num_bytes);
3690 	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
3691 				  num_bytes, type);
3692 }
3693 
3694 static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
3695 				int num_bytes)
3696 {
3697 	struct btrfs_root *quota_root = fs_info->quota_root;
3698 	struct btrfs_qgroup *qgroup;
3699 	struct ulist_node *unode;
3700 	struct ulist_iterator uiter;
3701 	int ret = 0;
3702 
3703 	if (num_bytes == 0)
3704 		return;
3705 	if (!quota_root)
3706 		return;
3707 
3708 	spin_lock(&fs_info->qgroup_lock);
3709 	qgroup = find_qgroup_rb(fs_info, ref_root);
3710 	if (!qgroup)
3711 		goto out;
3712 	ulist_reinit(fs_info->qgroup_ulist);
3713 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3714 		       qgroup_to_aux(qgroup), GFP_ATOMIC);
3715 	if (ret < 0)
3716 		goto out;
3717 	ULIST_ITER_INIT(&uiter);
3718 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3719 		struct btrfs_qgroup *qg;
3720 		struct btrfs_qgroup_list *glist;
3721 
3722 		qg = unode_aux_to_qgroup(unode);
3723 
3724 		qgroup_rsv_release(fs_info, qg, num_bytes,
3725 				BTRFS_QGROUP_RSV_META_PREALLOC);
3726 		qgroup_rsv_add(fs_info, qg, num_bytes,
3727 				BTRFS_QGROUP_RSV_META_PERTRANS);
3728 		list_for_each_entry(glist, &qg->groups, next_group) {
3729 			ret = ulist_add(fs_info->qgroup_ulist,
3730 					glist->group->qgroupid,
3731 					qgroup_to_aux(glist->group), GFP_ATOMIC);
3732 			if (ret < 0)
3733 				goto out;
3734 		}
3735 	}
3736 out:
3737 	spin_unlock(&fs_info->qgroup_lock);
3738 }
3739 
3740 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
3741 {
3742 	struct btrfs_fs_info *fs_info = root->fs_info;
3743 
3744 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3745 	    !is_fstree(root->root_key.objectid))
3746 		return;
3747 	/* Same as btrfs_qgroup_free_meta_prealloc() */
3748 	num_bytes = sub_root_meta_rsv(root, num_bytes,
3749 				      BTRFS_QGROUP_RSV_META_PREALLOC);
3750 	trace_qgroup_meta_convert(root, num_bytes);
3751 	qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
3752 }
3753 
3754 /*
3755  * Check qgroup reserved space leaking, normally at destroy inode
3756  * time
3757  */
3758 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
3759 {
3760 	struct extent_changeset changeset;
3761 	struct ulist_node *unode;
3762 	struct ulist_iterator iter;
3763 	int ret;
3764 
3765 	extent_changeset_init(&changeset);
3766 	ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
3767 			EXTENT_QGROUP_RESERVED, &changeset);
3768 
3769 	WARN_ON(ret < 0);
3770 	if (WARN_ON(changeset.bytes_changed)) {
3771 		ULIST_ITER_INIT(&iter);
3772 		while ((unode = ulist_next(&changeset.range_changed, &iter))) {
3773 			btrfs_warn(BTRFS_I(inode)->root->fs_info,
3774 				"leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
3775 				inode->i_ino, unode->val, unode->aux);
3776 		}
3777 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3778 				BTRFS_I(inode)->root->root_key.objectid,
3779 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3780 
3781 	}
3782 	extent_changeset_release(&changeset);
3783 }
3784