xref: /openbmc/linux/fs/btrfs/qgroup.c (revision 5d0e4d78)
1 /*
2  * Copyright (C) 2011 STRATO.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
25 #include <linux/workqueue.h>
26 #include <linux/btrfs.h>
27 
28 #include "ctree.h"
29 #include "transaction.h"
30 #include "disk-io.h"
31 #include "locking.h"
32 #include "ulist.h"
33 #include "backref.h"
34 #include "extent_io.h"
35 #include "qgroup.h"
36 
37 
38 /* TODO XXX FIXME
39  *  - subvol delete -> delete when ref goes to 0? delete limits also?
40  *  - reorganize keys
41  *  - compressed
42  *  - sync
43  *  - copy also limits on subvol creation
44  *  - limit
45  *  - caches fuer ulists
46  *  - performance benchmarks
47  *  - check all ioctl parameters
48  */
49 
50 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
51 					   int mod)
52 {
53 	if (qg->old_refcnt < seq)
54 		qg->old_refcnt = seq;
55 	qg->old_refcnt += mod;
56 }
57 
58 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
59 					   int mod)
60 {
61 	if (qg->new_refcnt < seq)
62 		qg->new_refcnt = seq;
63 	qg->new_refcnt += mod;
64 }
65 
66 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
67 {
68 	if (qg->old_refcnt < seq)
69 		return 0;
70 	return qg->old_refcnt - seq;
71 }
72 
73 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
74 {
75 	if (qg->new_refcnt < seq)
76 		return 0;
77 	return qg->new_refcnt - seq;
78 }
79 
80 /*
81  * glue structure to represent the relations between qgroups.
82  */
83 struct btrfs_qgroup_list {
84 	struct list_head next_group;
85 	struct list_head next_member;
86 	struct btrfs_qgroup *group;
87 	struct btrfs_qgroup *member;
88 };
89 
90 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
91 {
92 	return (u64)(uintptr_t)qg;
93 }
94 
95 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
96 {
97 	return (struct btrfs_qgroup *)(uintptr_t)n->aux;
98 }
99 
100 static int
101 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
102 		   int init_flags);
103 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
104 
105 /* must be called with qgroup_ioctl_lock held */
106 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
107 					   u64 qgroupid)
108 {
109 	struct rb_node *n = fs_info->qgroup_tree.rb_node;
110 	struct btrfs_qgroup *qgroup;
111 
112 	while (n) {
113 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
114 		if (qgroup->qgroupid < qgroupid)
115 			n = n->rb_left;
116 		else if (qgroup->qgroupid > qgroupid)
117 			n = n->rb_right;
118 		else
119 			return qgroup;
120 	}
121 	return NULL;
122 }
123 
124 /* must be called with qgroup_lock held */
125 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
126 					  u64 qgroupid)
127 {
128 	struct rb_node **p = &fs_info->qgroup_tree.rb_node;
129 	struct rb_node *parent = NULL;
130 	struct btrfs_qgroup *qgroup;
131 
132 	while (*p) {
133 		parent = *p;
134 		qgroup = rb_entry(parent, struct btrfs_qgroup, node);
135 
136 		if (qgroup->qgroupid < qgroupid)
137 			p = &(*p)->rb_left;
138 		else if (qgroup->qgroupid > qgroupid)
139 			p = &(*p)->rb_right;
140 		else
141 			return qgroup;
142 	}
143 
144 	qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
145 	if (!qgroup)
146 		return ERR_PTR(-ENOMEM);
147 
148 	qgroup->qgroupid = qgroupid;
149 	INIT_LIST_HEAD(&qgroup->groups);
150 	INIT_LIST_HEAD(&qgroup->members);
151 	INIT_LIST_HEAD(&qgroup->dirty);
152 
153 	rb_link_node(&qgroup->node, parent, p);
154 	rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
155 
156 	return qgroup;
157 }
158 
159 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
160 {
161 	struct btrfs_qgroup_list *list;
162 
163 	list_del(&qgroup->dirty);
164 	while (!list_empty(&qgroup->groups)) {
165 		list = list_first_entry(&qgroup->groups,
166 					struct btrfs_qgroup_list, next_group);
167 		list_del(&list->next_group);
168 		list_del(&list->next_member);
169 		kfree(list);
170 	}
171 
172 	while (!list_empty(&qgroup->members)) {
173 		list = list_first_entry(&qgroup->members,
174 					struct btrfs_qgroup_list, next_member);
175 		list_del(&list->next_group);
176 		list_del(&list->next_member);
177 		kfree(list);
178 	}
179 	kfree(qgroup);
180 }
181 
182 /* must be called with qgroup_lock held */
183 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
184 {
185 	struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
186 
187 	if (!qgroup)
188 		return -ENOENT;
189 
190 	rb_erase(&qgroup->node, &fs_info->qgroup_tree);
191 	__del_qgroup_rb(qgroup);
192 	return 0;
193 }
194 
195 /* must be called with qgroup_lock held */
196 static int add_relation_rb(struct btrfs_fs_info *fs_info,
197 			   u64 memberid, u64 parentid)
198 {
199 	struct btrfs_qgroup *member;
200 	struct btrfs_qgroup *parent;
201 	struct btrfs_qgroup_list *list;
202 
203 	member = find_qgroup_rb(fs_info, memberid);
204 	parent = find_qgroup_rb(fs_info, parentid);
205 	if (!member || !parent)
206 		return -ENOENT;
207 
208 	list = kzalloc(sizeof(*list), GFP_ATOMIC);
209 	if (!list)
210 		return -ENOMEM;
211 
212 	list->group = parent;
213 	list->member = member;
214 	list_add_tail(&list->next_group, &member->groups);
215 	list_add_tail(&list->next_member, &parent->members);
216 
217 	return 0;
218 }
219 
220 /* must be called with qgroup_lock held */
221 static int del_relation_rb(struct btrfs_fs_info *fs_info,
222 			   u64 memberid, u64 parentid)
223 {
224 	struct btrfs_qgroup *member;
225 	struct btrfs_qgroup *parent;
226 	struct btrfs_qgroup_list *list;
227 
228 	member = find_qgroup_rb(fs_info, memberid);
229 	parent = find_qgroup_rb(fs_info, parentid);
230 	if (!member || !parent)
231 		return -ENOENT;
232 
233 	list_for_each_entry(list, &member->groups, next_group) {
234 		if (list->group == parent) {
235 			list_del(&list->next_group);
236 			list_del(&list->next_member);
237 			kfree(list);
238 			return 0;
239 		}
240 	}
241 	return -ENOENT;
242 }
243 
244 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
245 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
246 			       u64 rfer, u64 excl)
247 {
248 	struct btrfs_qgroup *qgroup;
249 
250 	qgroup = find_qgroup_rb(fs_info, qgroupid);
251 	if (!qgroup)
252 		return -EINVAL;
253 	if (qgroup->rfer != rfer || qgroup->excl != excl)
254 		return -EINVAL;
255 	return 0;
256 }
257 #endif
258 
259 /*
260  * The full config is read in one go, only called from open_ctree()
261  * It doesn't use any locking, as at this point we're still single-threaded
262  */
263 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
264 {
265 	struct btrfs_key key;
266 	struct btrfs_key found_key;
267 	struct btrfs_root *quota_root = fs_info->quota_root;
268 	struct btrfs_path *path = NULL;
269 	struct extent_buffer *l;
270 	int slot;
271 	int ret = 0;
272 	u64 flags = 0;
273 	u64 rescan_progress = 0;
274 
275 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
276 		return 0;
277 
278 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
279 	if (!fs_info->qgroup_ulist) {
280 		ret = -ENOMEM;
281 		goto out;
282 	}
283 
284 	path = btrfs_alloc_path();
285 	if (!path) {
286 		ret = -ENOMEM;
287 		goto out;
288 	}
289 
290 	/* default this to quota off, in case no status key is found */
291 	fs_info->qgroup_flags = 0;
292 
293 	/*
294 	 * pass 1: read status, all qgroup infos and limits
295 	 */
296 	key.objectid = 0;
297 	key.type = 0;
298 	key.offset = 0;
299 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
300 	if (ret)
301 		goto out;
302 
303 	while (1) {
304 		struct btrfs_qgroup *qgroup;
305 
306 		slot = path->slots[0];
307 		l = path->nodes[0];
308 		btrfs_item_key_to_cpu(l, &found_key, slot);
309 
310 		if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
311 			struct btrfs_qgroup_status_item *ptr;
312 
313 			ptr = btrfs_item_ptr(l, slot,
314 					     struct btrfs_qgroup_status_item);
315 
316 			if (btrfs_qgroup_status_version(l, ptr) !=
317 			    BTRFS_QGROUP_STATUS_VERSION) {
318 				btrfs_err(fs_info,
319 				 "old qgroup version, quota disabled");
320 				goto out;
321 			}
322 			if (btrfs_qgroup_status_generation(l, ptr) !=
323 			    fs_info->generation) {
324 				flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
325 				btrfs_err(fs_info,
326 					"qgroup generation mismatch, marked as inconsistent");
327 			}
328 			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
329 									  ptr);
330 			rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
331 			goto next1;
332 		}
333 
334 		if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
335 		    found_key.type != BTRFS_QGROUP_LIMIT_KEY)
336 			goto next1;
337 
338 		qgroup = find_qgroup_rb(fs_info, found_key.offset);
339 		if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
340 		    (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
341 			btrfs_err(fs_info, "inconsistent qgroup config");
342 			flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
343 		}
344 		if (!qgroup) {
345 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
346 			if (IS_ERR(qgroup)) {
347 				ret = PTR_ERR(qgroup);
348 				goto out;
349 			}
350 		}
351 		switch (found_key.type) {
352 		case BTRFS_QGROUP_INFO_KEY: {
353 			struct btrfs_qgroup_info_item *ptr;
354 
355 			ptr = btrfs_item_ptr(l, slot,
356 					     struct btrfs_qgroup_info_item);
357 			qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
358 			qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
359 			qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
360 			qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
361 			/* generation currently unused */
362 			break;
363 		}
364 		case BTRFS_QGROUP_LIMIT_KEY: {
365 			struct btrfs_qgroup_limit_item *ptr;
366 
367 			ptr = btrfs_item_ptr(l, slot,
368 					     struct btrfs_qgroup_limit_item);
369 			qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
370 			qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
371 			qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
372 			qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
373 			qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
374 			break;
375 		}
376 		}
377 next1:
378 		ret = btrfs_next_item(quota_root, path);
379 		if (ret < 0)
380 			goto out;
381 		if (ret)
382 			break;
383 	}
384 	btrfs_release_path(path);
385 
386 	/*
387 	 * pass 2: read all qgroup relations
388 	 */
389 	key.objectid = 0;
390 	key.type = BTRFS_QGROUP_RELATION_KEY;
391 	key.offset = 0;
392 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
393 	if (ret)
394 		goto out;
395 	while (1) {
396 		slot = path->slots[0];
397 		l = path->nodes[0];
398 		btrfs_item_key_to_cpu(l, &found_key, slot);
399 
400 		if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
401 			goto next2;
402 
403 		if (found_key.objectid > found_key.offset) {
404 			/* parent <- member, not needed to build config */
405 			/* FIXME should we omit the key completely? */
406 			goto next2;
407 		}
408 
409 		ret = add_relation_rb(fs_info, found_key.objectid,
410 				      found_key.offset);
411 		if (ret == -ENOENT) {
412 			btrfs_warn(fs_info,
413 				"orphan qgroup relation 0x%llx->0x%llx",
414 				found_key.objectid, found_key.offset);
415 			ret = 0;	/* ignore the error */
416 		}
417 		if (ret)
418 			goto out;
419 next2:
420 		ret = btrfs_next_item(quota_root, path);
421 		if (ret < 0)
422 			goto out;
423 		if (ret)
424 			break;
425 	}
426 out:
427 	fs_info->qgroup_flags |= flags;
428 	if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
429 		clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
430 	else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
431 		 ret >= 0)
432 		ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
433 	btrfs_free_path(path);
434 
435 	if (ret < 0) {
436 		ulist_free(fs_info->qgroup_ulist);
437 		fs_info->qgroup_ulist = NULL;
438 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
439 	}
440 
441 	return ret < 0 ? ret : 0;
442 }
443 
444 /*
445  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
446  * first two are in single-threaded paths.And for the third one, we have set
447  * quota_root to be null with qgroup_lock held before, so it is safe to clean
448  * up the in-memory structures without qgroup_lock held.
449  */
450 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
451 {
452 	struct rb_node *n;
453 	struct btrfs_qgroup *qgroup;
454 
455 	while ((n = rb_first(&fs_info->qgroup_tree))) {
456 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
457 		rb_erase(n, &fs_info->qgroup_tree);
458 		__del_qgroup_rb(qgroup);
459 	}
460 	/*
461 	 * we call btrfs_free_qgroup_config() when umounting
462 	 * filesystem and disabling quota, so we set qgroup_ulist
463 	 * to be null here to avoid double free.
464 	 */
465 	ulist_free(fs_info->qgroup_ulist);
466 	fs_info->qgroup_ulist = NULL;
467 }
468 
469 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
470 				    struct btrfs_root *quota_root,
471 				    u64 src, u64 dst)
472 {
473 	int ret;
474 	struct btrfs_path *path;
475 	struct btrfs_key key;
476 
477 	path = btrfs_alloc_path();
478 	if (!path)
479 		return -ENOMEM;
480 
481 	key.objectid = src;
482 	key.type = BTRFS_QGROUP_RELATION_KEY;
483 	key.offset = dst;
484 
485 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
486 
487 	btrfs_mark_buffer_dirty(path->nodes[0]);
488 
489 	btrfs_free_path(path);
490 	return ret;
491 }
492 
493 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
494 				    struct btrfs_root *quota_root,
495 				    u64 src, u64 dst)
496 {
497 	int ret;
498 	struct btrfs_path *path;
499 	struct btrfs_key key;
500 
501 	path = btrfs_alloc_path();
502 	if (!path)
503 		return -ENOMEM;
504 
505 	key.objectid = src;
506 	key.type = BTRFS_QGROUP_RELATION_KEY;
507 	key.offset = dst;
508 
509 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
510 	if (ret < 0)
511 		goto out;
512 
513 	if (ret > 0) {
514 		ret = -ENOENT;
515 		goto out;
516 	}
517 
518 	ret = btrfs_del_item(trans, quota_root, path);
519 out:
520 	btrfs_free_path(path);
521 	return ret;
522 }
523 
524 static int add_qgroup_item(struct btrfs_trans_handle *trans,
525 			   struct btrfs_root *quota_root, u64 qgroupid)
526 {
527 	int ret;
528 	struct btrfs_path *path;
529 	struct btrfs_qgroup_info_item *qgroup_info;
530 	struct btrfs_qgroup_limit_item *qgroup_limit;
531 	struct extent_buffer *leaf;
532 	struct btrfs_key key;
533 
534 	if (btrfs_is_testing(quota_root->fs_info))
535 		return 0;
536 
537 	path = btrfs_alloc_path();
538 	if (!path)
539 		return -ENOMEM;
540 
541 	key.objectid = 0;
542 	key.type = BTRFS_QGROUP_INFO_KEY;
543 	key.offset = qgroupid;
544 
545 	/*
546 	 * Avoid a transaction abort by catching -EEXIST here. In that
547 	 * case, we proceed by re-initializing the existing structure
548 	 * on disk.
549 	 */
550 
551 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
552 				      sizeof(*qgroup_info));
553 	if (ret && ret != -EEXIST)
554 		goto out;
555 
556 	leaf = path->nodes[0];
557 	qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
558 				 struct btrfs_qgroup_info_item);
559 	btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
560 	btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
561 	btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
562 	btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
563 	btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
564 
565 	btrfs_mark_buffer_dirty(leaf);
566 
567 	btrfs_release_path(path);
568 
569 	key.type = BTRFS_QGROUP_LIMIT_KEY;
570 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
571 				      sizeof(*qgroup_limit));
572 	if (ret && ret != -EEXIST)
573 		goto out;
574 
575 	leaf = path->nodes[0];
576 	qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
577 				  struct btrfs_qgroup_limit_item);
578 	btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
579 	btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
580 	btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
581 	btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
582 	btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
583 
584 	btrfs_mark_buffer_dirty(leaf);
585 
586 	ret = 0;
587 out:
588 	btrfs_free_path(path);
589 	return ret;
590 }
591 
592 static int del_qgroup_item(struct btrfs_trans_handle *trans,
593 			   struct btrfs_root *quota_root, u64 qgroupid)
594 {
595 	int ret;
596 	struct btrfs_path *path;
597 	struct btrfs_key key;
598 
599 	path = btrfs_alloc_path();
600 	if (!path)
601 		return -ENOMEM;
602 
603 	key.objectid = 0;
604 	key.type = BTRFS_QGROUP_INFO_KEY;
605 	key.offset = qgroupid;
606 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
607 	if (ret < 0)
608 		goto out;
609 
610 	if (ret > 0) {
611 		ret = -ENOENT;
612 		goto out;
613 	}
614 
615 	ret = btrfs_del_item(trans, quota_root, path);
616 	if (ret)
617 		goto out;
618 
619 	btrfs_release_path(path);
620 
621 	key.type = BTRFS_QGROUP_LIMIT_KEY;
622 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
623 	if (ret < 0)
624 		goto out;
625 
626 	if (ret > 0) {
627 		ret = -ENOENT;
628 		goto out;
629 	}
630 
631 	ret = btrfs_del_item(trans, quota_root, path);
632 
633 out:
634 	btrfs_free_path(path);
635 	return ret;
636 }
637 
638 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
639 				    struct btrfs_root *root,
640 				    struct btrfs_qgroup *qgroup)
641 {
642 	struct btrfs_path *path;
643 	struct btrfs_key key;
644 	struct extent_buffer *l;
645 	struct btrfs_qgroup_limit_item *qgroup_limit;
646 	int ret;
647 	int slot;
648 
649 	key.objectid = 0;
650 	key.type = BTRFS_QGROUP_LIMIT_KEY;
651 	key.offset = qgroup->qgroupid;
652 
653 	path = btrfs_alloc_path();
654 	if (!path)
655 		return -ENOMEM;
656 
657 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
658 	if (ret > 0)
659 		ret = -ENOENT;
660 
661 	if (ret)
662 		goto out;
663 
664 	l = path->nodes[0];
665 	slot = path->slots[0];
666 	qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
667 	btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
668 	btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
669 	btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
670 	btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
671 	btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
672 
673 	btrfs_mark_buffer_dirty(l);
674 
675 out:
676 	btrfs_free_path(path);
677 	return ret;
678 }
679 
680 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
681 				   struct btrfs_root *root,
682 				   struct btrfs_qgroup *qgroup)
683 {
684 	struct btrfs_path *path;
685 	struct btrfs_key key;
686 	struct extent_buffer *l;
687 	struct btrfs_qgroup_info_item *qgroup_info;
688 	int ret;
689 	int slot;
690 
691 	if (btrfs_is_testing(root->fs_info))
692 		return 0;
693 
694 	key.objectid = 0;
695 	key.type = BTRFS_QGROUP_INFO_KEY;
696 	key.offset = qgroup->qgroupid;
697 
698 	path = btrfs_alloc_path();
699 	if (!path)
700 		return -ENOMEM;
701 
702 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
703 	if (ret > 0)
704 		ret = -ENOENT;
705 
706 	if (ret)
707 		goto out;
708 
709 	l = path->nodes[0];
710 	slot = path->slots[0];
711 	qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
712 	btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
713 	btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
714 	btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
715 	btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
716 	btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
717 
718 	btrfs_mark_buffer_dirty(l);
719 
720 out:
721 	btrfs_free_path(path);
722 	return ret;
723 }
724 
725 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
726 				     struct btrfs_fs_info *fs_info,
727 				    struct btrfs_root *root)
728 {
729 	struct btrfs_path *path;
730 	struct btrfs_key key;
731 	struct extent_buffer *l;
732 	struct btrfs_qgroup_status_item *ptr;
733 	int ret;
734 	int slot;
735 
736 	key.objectid = 0;
737 	key.type = BTRFS_QGROUP_STATUS_KEY;
738 	key.offset = 0;
739 
740 	path = btrfs_alloc_path();
741 	if (!path)
742 		return -ENOMEM;
743 
744 	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
745 	if (ret > 0)
746 		ret = -ENOENT;
747 
748 	if (ret)
749 		goto out;
750 
751 	l = path->nodes[0];
752 	slot = path->slots[0];
753 	ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
754 	btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
755 	btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
756 	btrfs_set_qgroup_status_rescan(l, ptr,
757 				fs_info->qgroup_rescan_progress.objectid);
758 
759 	btrfs_mark_buffer_dirty(l);
760 
761 out:
762 	btrfs_free_path(path);
763 	return ret;
764 }
765 
766 /*
767  * called with qgroup_lock held
768  */
769 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
770 				  struct btrfs_root *root)
771 {
772 	struct btrfs_path *path;
773 	struct btrfs_key key;
774 	struct extent_buffer *leaf = NULL;
775 	int ret;
776 	int nr = 0;
777 
778 	path = btrfs_alloc_path();
779 	if (!path)
780 		return -ENOMEM;
781 
782 	path->leave_spinning = 1;
783 
784 	key.objectid = 0;
785 	key.offset = 0;
786 	key.type = 0;
787 
788 	while (1) {
789 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
790 		if (ret < 0)
791 			goto out;
792 		leaf = path->nodes[0];
793 		nr = btrfs_header_nritems(leaf);
794 		if (!nr)
795 			break;
796 		/*
797 		 * delete the leaf one by one
798 		 * since the whole tree is going
799 		 * to be deleted.
800 		 */
801 		path->slots[0] = 0;
802 		ret = btrfs_del_items(trans, root, path, 0, nr);
803 		if (ret)
804 			goto out;
805 
806 		btrfs_release_path(path);
807 	}
808 	ret = 0;
809 out:
810 	set_bit(BTRFS_FS_QUOTA_DISABLING, &root->fs_info->flags);
811 	btrfs_free_path(path);
812 	return ret;
813 }
814 
815 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
816 		       struct btrfs_fs_info *fs_info)
817 {
818 	struct btrfs_root *quota_root;
819 	struct btrfs_root *tree_root = fs_info->tree_root;
820 	struct btrfs_path *path = NULL;
821 	struct btrfs_qgroup_status_item *ptr;
822 	struct extent_buffer *leaf;
823 	struct btrfs_key key;
824 	struct btrfs_key found_key;
825 	struct btrfs_qgroup *qgroup = NULL;
826 	int ret = 0;
827 	int slot;
828 
829 	mutex_lock(&fs_info->qgroup_ioctl_lock);
830 	if (fs_info->quota_root) {
831 		set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
832 		goto out;
833 	}
834 
835 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
836 	if (!fs_info->qgroup_ulist) {
837 		ret = -ENOMEM;
838 		goto out;
839 	}
840 
841 	/*
842 	 * initially create the quota tree
843 	 */
844 	quota_root = btrfs_create_tree(trans, fs_info,
845 				       BTRFS_QUOTA_TREE_OBJECTID);
846 	if (IS_ERR(quota_root)) {
847 		ret =  PTR_ERR(quota_root);
848 		goto out;
849 	}
850 
851 	path = btrfs_alloc_path();
852 	if (!path) {
853 		ret = -ENOMEM;
854 		goto out_free_root;
855 	}
856 
857 	key.objectid = 0;
858 	key.type = BTRFS_QGROUP_STATUS_KEY;
859 	key.offset = 0;
860 
861 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
862 				      sizeof(*ptr));
863 	if (ret)
864 		goto out_free_path;
865 
866 	leaf = path->nodes[0];
867 	ptr = btrfs_item_ptr(leaf, path->slots[0],
868 				 struct btrfs_qgroup_status_item);
869 	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
870 	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
871 	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
872 				BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
873 	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
874 	btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
875 
876 	btrfs_mark_buffer_dirty(leaf);
877 
878 	key.objectid = 0;
879 	key.type = BTRFS_ROOT_REF_KEY;
880 	key.offset = 0;
881 
882 	btrfs_release_path(path);
883 	ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
884 	if (ret > 0)
885 		goto out_add_root;
886 	if (ret < 0)
887 		goto out_free_path;
888 
889 
890 	while (1) {
891 		slot = path->slots[0];
892 		leaf = path->nodes[0];
893 		btrfs_item_key_to_cpu(leaf, &found_key, slot);
894 
895 		if (found_key.type == BTRFS_ROOT_REF_KEY) {
896 			ret = add_qgroup_item(trans, quota_root,
897 					      found_key.offset);
898 			if (ret)
899 				goto out_free_path;
900 
901 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
902 			if (IS_ERR(qgroup)) {
903 				ret = PTR_ERR(qgroup);
904 				goto out_free_path;
905 			}
906 		}
907 		ret = btrfs_next_item(tree_root, path);
908 		if (ret < 0)
909 			goto out_free_path;
910 		if (ret)
911 			break;
912 	}
913 
914 out_add_root:
915 	btrfs_release_path(path);
916 	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
917 	if (ret)
918 		goto out_free_path;
919 
920 	qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
921 	if (IS_ERR(qgroup)) {
922 		ret = PTR_ERR(qgroup);
923 		goto out_free_path;
924 	}
925 	spin_lock(&fs_info->qgroup_lock);
926 	fs_info->quota_root = quota_root;
927 	set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
928 	spin_unlock(&fs_info->qgroup_lock);
929 out_free_path:
930 	btrfs_free_path(path);
931 out_free_root:
932 	if (ret) {
933 		free_extent_buffer(quota_root->node);
934 		free_extent_buffer(quota_root->commit_root);
935 		kfree(quota_root);
936 	}
937 out:
938 	if (ret) {
939 		ulist_free(fs_info->qgroup_ulist);
940 		fs_info->qgroup_ulist = NULL;
941 	}
942 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
943 	return ret;
944 }
945 
946 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
947 			struct btrfs_fs_info *fs_info)
948 {
949 	struct btrfs_root *tree_root = fs_info->tree_root;
950 	struct btrfs_root *quota_root;
951 	int ret = 0;
952 
953 	mutex_lock(&fs_info->qgroup_ioctl_lock);
954 	if (!fs_info->quota_root)
955 		goto out;
956 	clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
957 	set_bit(BTRFS_FS_QUOTA_DISABLING, &fs_info->flags);
958 	btrfs_qgroup_wait_for_completion(fs_info, false);
959 	spin_lock(&fs_info->qgroup_lock);
960 	quota_root = fs_info->quota_root;
961 	fs_info->quota_root = NULL;
962 	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
963 	spin_unlock(&fs_info->qgroup_lock);
964 
965 	btrfs_free_qgroup_config(fs_info);
966 
967 	ret = btrfs_clean_quota_tree(trans, quota_root);
968 	if (ret)
969 		goto out;
970 
971 	ret = btrfs_del_root(trans, tree_root, &quota_root->root_key);
972 	if (ret)
973 		goto out;
974 
975 	list_del(&quota_root->dirty_list);
976 
977 	btrfs_tree_lock(quota_root->node);
978 	clean_tree_block(fs_info, quota_root->node);
979 	btrfs_tree_unlock(quota_root->node);
980 	btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
981 
982 	free_extent_buffer(quota_root->node);
983 	free_extent_buffer(quota_root->commit_root);
984 	kfree(quota_root);
985 out:
986 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
987 	return ret;
988 }
989 
990 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
991 			 struct btrfs_qgroup *qgroup)
992 {
993 	if (list_empty(&qgroup->dirty))
994 		list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
995 }
996 
997 static void report_reserved_underflow(struct btrfs_fs_info *fs_info,
998 				      struct btrfs_qgroup *qgroup,
999 				      u64 num_bytes)
1000 {
1001 #ifdef CONFIG_BTRFS_DEBUG
1002 	WARN_ON(qgroup->reserved < num_bytes);
1003 	btrfs_debug(fs_info,
1004 		"qgroup %llu reserved space underflow, have: %llu, to free: %llu",
1005 		qgroup->qgroupid, qgroup->reserved, num_bytes);
1006 #endif
1007 	qgroup->reserved = 0;
1008 }
1009 /*
1010  * The easy accounting, if we are adding/removing the only ref for an extent
1011  * then this qgroup and all of the parent qgroups get their reference and
1012  * exclusive counts adjusted.
1013  *
1014  * Caller should hold fs_info->qgroup_lock.
1015  */
1016 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1017 				    struct ulist *tmp, u64 ref_root,
1018 				    u64 num_bytes, int sign)
1019 {
1020 	struct btrfs_qgroup *qgroup;
1021 	struct btrfs_qgroup_list *glist;
1022 	struct ulist_node *unode;
1023 	struct ulist_iterator uiter;
1024 	int ret = 0;
1025 
1026 	qgroup = find_qgroup_rb(fs_info, ref_root);
1027 	if (!qgroup)
1028 		goto out;
1029 
1030 	qgroup->rfer += sign * num_bytes;
1031 	qgroup->rfer_cmpr += sign * num_bytes;
1032 
1033 	WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1034 	qgroup->excl += sign * num_bytes;
1035 	qgroup->excl_cmpr += sign * num_bytes;
1036 	if (sign > 0) {
1037 		trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes);
1038 		if (qgroup->reserved < num_bytes)
1039 			report_reserved_underflow(fs_info, qgroup, num_bytes);
1040 		else
1041 			qgroup->reserved -= num_bytes;
1042 	}
1043 
1044 	qgroup_dirty(fs_info, qgroup);
1045 
1046 	/* Get all of the parent groups that contain this qgroup */
1047 	list_for_each_entry(glist, &qgroup->groups, next_group) {
1048 		ret = ulist_add(tmp, glist->group->qgroupid,
1049 				qgroup_to_aux(glist->group), GFP_ATOMIC);
1050 		if (ret < 0)
1051 			goto out;
1052 	}
1053 
1054 	/* Iterate all of the parents and adjust their reference counts */
1055 	ULIST_ITER_INIT(&uiter);
1056 	while ((unode = ulist_next(tmp, &uiter))) {
1057 		qgroup = unode_aux_to_qgroup(unode);
1058 		qgroup->rfer += sign * num_bytes;
1059 		qgroup->rfer_cmpr += sign * num_bytes;
1060 		WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1061 		qgroup->excl += sign * num_bytes;
1062 		if (sign > 0) {
1063 			trace_qgroup_update_reserve(fs_info, qgroup,
1064 						    -(s64)num_bytes);
1065 			if (qgroup->reserved < num_bytes)
1066 				report_reserved_underflow(fs_info, qgroup,
1067 							  num_bytes);
1068 			else
1069 				qgroup->reserved -= num_bytes;
1070 		}
1071 		qgroup->excl_cmpr += sign * num_bytes;
1072 		qgroup_dirty(fs_info, qgroup);
1073 
1074 		/* Add any parents of the parents */
1075 		list_for_each_entry(glist, &qgroup->groups, next_group) {
1076 			ret = ulist_add(tmp, glist->group->qgroupid,
1077 					qgroup_to_aux(glist->group), GFP_ATOMIC);
1078 			if (ret < 0)
1079 				goto out;
1080 		}
1081 	}
1082 	ret = 0;
1083 out:
1084 	return ret;
1085 }
1086 
1087 
1088 /*
1089  * Quick path for updating qgroup with only excl refs.
1090  *
1091  * In that case, just update all parent will be enough.
1092  * Or we needs to do a full rescan.
1093  * Caller should also hold fs_info->qgroup_lock.
1094  *
1095  * Return 0 for quick update, return >0 for need to full rescan
1096  * and mark INCONSISTENT flag.
1097  * Return < 0 for other error.
1098  */
1099 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1100 				   struct ulist *tmp, u64 src, u64 dst,
1101 				   int sign)
1102 {
1103 	struct btrfs_qgroup *qgroup;
1104 	int ret = 1;
1105 	int err = 0;
1106 
1107 	qgroup = find_qgroup_rb(fs_info, src);
1108 	if (!qgroup)
1109 		goto out;
1110 	if (qgroup->excl == qgroup->rfer) {
1111 		ret = 0;
1112 		err = __qgroup_excl_accounting(fs_info, tmp, dst,
1113 					       qgroup->excl, sign);
1114 		if (err < 0) {
1115 			ret = err;
1116 			goto out;
1117 		}
1118 	}
1119 out:
1120 	if (ret)
1121 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1122 	return ret;
1123 }
1124 
1125 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
1126 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1127 {
1128 	struct btrfs_root *quota_root;
1129 	struct btrfs_qgroup *parent;
1130 	struct btrfs_qgroup *member;
1131 	struct btrfs_qgroup_list *list;
1132 	struct ulist *tmp;
1133 	int ret = 0;
1134 
1135 	/* Check the level of src and dst first */
1136 	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1137 		return -EINVAL;
1138 
1139 	tmp = ulist_alloc(GFP_KERNEL);
1140 	if (!tmp)
1141 		return -ENOMEM;
1142 
1143 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1144 	quota_root = fs_info->quota_root;
1145 	if (!quota_root) {
1146 		ret = -EINVAL;
1147 		goto out;
1148 	}
1149 	member = find_qgroup_rb(fs_info, src);
1150 	parent = find_qgroup_rb(fs_info, dst);
1151 	if (!member || !parent) {
1152 		ret = -EINVAL;
1153 		goto out;
1154 	}
1155 
1156 	/* check if such qgroup relation exist firstly */
1157 	list_for_each_entry(list, &member->groups, next_group) {
1158 		if (list->group == parent) {
1159 			ret = -EEXIST;
1160 			goto out;
1161 		}
1162 	}
1163 
1164 	ret = add_qgroup_relation_item(trans, quota_root, src, dst);
1165 	if (ret)
1166 		goto out;
1167 
1168 	ret = add_qgroup_relation_item(trans, quota_root, dst, src);
1169 	if (ret) {
1170 		del_qgroup_relation_item(trans, quota_root, src, dst);
1171 		goto out;
1172 	}
1173 
1174 	spin_lock(&fs_info->qgroup_lock);
1175 	ret = add_relation_rb(fs_info, src, dst);
1176 	if (ret < 0) {
1177 		spin_unlock(&fs_info->qgroup_lock);
1178 		goto out;
1179 	}
1180 	ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1181 	spin_unlock(&fs_info->qgroup_lock);
1182 out:
1183 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1184 	ulist_free(tmp);
1185 	return ret;
1186 }
1187 
1188 static int __del_qgroup_relation(struct btrfs_trans_handle *trans,
1189 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1190 {
1191 	struct btrfs_root *quota_root;
1192 	struct btrfs_qgroup *parent;
1193 	struct btrfs_qgroup *member;
1194 	struct btrfs_qgroup_list *list;
1195 	struct ulist *tmp;
1196 	int ret = 0;
1197 	int err;
1198 
1199 	tmp = ulist_alloc(GFP_KERNEL);
1200 	if (!tmp)
1201 		return -ENOMEM;
1202 
1203 	quota_root = fs_info->quota_root;
1204 	if (!quota_root) {
1205 		ret = -EINVAL;
1206 		goto out;
1207 	}
1208 
1209 	member = find_qgroup_rb(fs_info, src);
1210 	parent = find_qgroup_rb(fs_info, dst);
1211 	if (!member || !parent) {
1212 		ret = -EINVAL;
1213 		goto out;
1214 	}
1215 
1216 	/* check if such qgroup relation exist firstly */
1217 	list_for_each_entry(list, &member->groups, next_group) {
1218 		if (list->group == parent)
1219 			goto exist;
1220 	}
1221 	ret = -ENOENT;
1222 	goto out;
1223 exist:
1224 	ret = del_qgroup_relation_item(trans, quota_root, src, dst);
1225 	err = del_qgroup_relation_item(trans, quota_root, dst, src);
1226 	if (err && !ret)
1227 		ret = err;
1228 
1229 	spin_lock(&fs_info->qgroup_lock);
1230 	del_relation_rb(fs_info, src, dst);
1231 	ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1232 	spin_unlock(&fs_info->qgroup_lock);
1233 out:
1234 	ulist_free(tmp);
1235 	return ret;
1236 }
1237 
1238 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
1239 			      struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1240 {
1241 	int ret = 0;
1242 
1243 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1244 	ret = __del_qgroup_relation(trans, fs_info, src, dst);
1245 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1246 
1247 	return ret;
1248 }
1249 
1250 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
1251 			struct btrfs_fs_info *fs_info, u64 qgroupid)
1252 {
1253 	struct btrfs_root *quota_root;
1254 	struct btrfs_qgroup *qgroup;
1255 	int ret = 0;
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 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1264 	if (qgroup) {
1265 		ret = -EEXIST;
1266 		goto out;
1267 	}
1268 
1269 	ret = add_qgroup_item(trans, quota_root, qgroupid);
1270 	if (ret)
1271 		goto out;
1272 
1273 	spin_lock(&fs_info->qgroup_lock);
1274 	qgroup = add_qgroup_rb(fs_info, qgroupid);
1275 	spin_unlock(&fs_info->qgroup_lock);
1276 
1277 	if (IS_ERR(qgroup))
1278 		ret = PTR_ERR(qgroup);
1279 out:
1280 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1281 	return ret;
1282 }
1283 
1284 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
1285 			struct btrfs_fs_info *fs_info, u64 qgroupid)
1286 {
1287 	struct btrfs_root *quota_root;
1288 	struct btrfs_qgroup *qgroup;
1289 	struct btrfs_qgroup_list *list;
1290 	int ret = 0;
1291 
1292 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1293 	quota_root = fs_info->quota_root;
1294 	if (!quota_root) {
1295 		ret = -EINVAL;
1296 		goto out;
1297 	}
1298 
1299 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1300 	if (!qgroup) {
1301 		ret = -ENOENT;
1302 		goto out;
1303 	} else {
1304 		/* check if there are no children of this qgroup */
1305 		if (!list_empty(&qgroup->members)) {
1306 			ret = -EBUSY;
1307 			goto out;
1308 		}
1309 	}
1310 	ret = del_qgroup_item(trans, quota_root, qgroupid);
1311 
1312 	while (!list_empty(&qgroup->groups)) {
1313 		list = list_first_entry(&qgroup->groups,
1314 					struct btrfs_qgroup_list, next_group);
1315 		ret = __del_qgroup_relation(trans, fs_info,
1316 					   qgroupid,
1317 					   list->group->qgroupid);
1318 		if (ret)
1319 			goto out;
1320 	}
1321 
1322 	spin_lock(&fs_info->qgroup_lock);
1323 	del_qgroup_rb(fs_info, qgroupid);
1324 	spin_unlock(&fs_info->qgroup_lock);
1325 out:
1326 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1327 	return ret;
1328 }
1329 
1330 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
1331 		       struct btrfs_fs_info *fs_info, u64 qgroupid,
1332 		       struct btrfs_qgroup_limit *limit)
1333 {
1334 	struct btrfs_root *quota_root;
1335 	struct btrfs_qgroup *qgroup;
1336 	int ret = 0;
1337 	/* Sometimes we would want to clear the limit on this qgroup.
1338 	 * To meet this requirement, we treat the -1 as a special value
1339 	 * which tell kernel to clear the limit on this qgroup.
1340 	 */
1341 	const u64 CLEAR_VALUE = -1;
1342 
1343 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1344 	quota_root = fs_info->quota_root;
1345 	if (!quota_root) {
1346 		ret = -EINVAL;
1347 		goto out;
1348 	}
1349 
1350 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1351 	if (!qgroup) {
1352 		ret = -ENOENT;
1353 		goto out;
1354 	}
1355 
1356 	spin_lock(&fs_info->qgroup_lock);
1357 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1358 		if (limit->max_rfer == CLEAR_VALUE) {
1359 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1360 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1361 			qgroup->max_rfer = 0;
1362 		} else {
1363 			qgroup->max_rfer = limit->max_rfer;
1364 		}
1365 	}
1366 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1367 		if (limit->max_excl == CLEAR_VALUE) {
1368 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1369 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1370 			qgroup->max_excl = 0;
1371 		} else {
1372 			qgroup->max_excl = limit->max_excl;
1373 		}
1374 	}
1375 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1376 		if (limit->rsv_rfer == CLEAR_VALUE) {
1377 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1378 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1379 			qgroup->rsv_rfer = 0;
1380 		} else {
1381 			qgroup->rsv_rfer = limit->rsv_rfer;
1382 		}
1383 	}
1384 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1385 		if (limit->rsv_excl == CLEAR_VALUE) {
1386 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1387 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1388 			qgroup->rsv_excl = 0;
1389 		} else {
1390 			qgroup->rsv_excl = limit->rsv_excl;
1391 		}
1392 	}
1393 	qgroup->lim_flags |= limit->flags;
1394 
1395 	spin_unlock(&fs_info->qgroup_lock);
1396 
1397 	ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1398 	if (ret) {
1399 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1400 		btrfs_info(fs_info, "unable to update quota limit for %llu",
1401 		       qgroupid);
1402 	}
1403 
1404 out:
1405 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1406 	return ret;
1407 }
1408 
1409 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1410 				struct btrfs_delayed_ref_root *delayed_refs,
1411 				struct btrfs_qgroup_extent_record *record)
1412 {
1413 	struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1414 	struct rb_node *parent_node = NULL;
1415 	struct btrfs_qgroup_extent_record *entry;
1416 	u64 bytenr = record->bytenr;
1417 
1418 	assert_spin_locked(&delayed_refs->lock);
1419 	trace_btrfs_qgroup_trace_extent(fs_info, record);
1420 
1421 	while (*p) {
1422 		parent_node = *p;
1423 		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1424 				 node);
1425 		if (bytenr < entry->bytenr)
1426 			p = &(*p)->rb_left;
1427 		else if (bytenr > entry->bytenr)
1428 			p = &(*p)->rb_right;
1429 		else
1430 			return 1;
1431 	}
1432 
1433 	rb_link_node(&record->node, parent_node, p);
1434 	rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1435 	return 0;
1436 }
1437 
1438 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1439 				   struct btrfs_qgroup_extent_record *qrecord)
1440 {
1441 	struct ulist *old_root;
1442 	u64 bytenr = qrecord->bytenr;
1443 	int ret;
1444 
1445 	ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root);
1446 	if (ret < 0)
1447 		return ret;
1448 
1449 	/*
1450 	 * Here we don't need to get the lock of
1451 	 * trans->transaction->delayed_refs, since inserted qrecord won't
1452 	 * be deleted, only qrecord->node may be modified (new qrecord insert)
1453 	 *
1454 	 * So modifying qrecord->old_roots is safe here
1455 	 */
1456 	qrecord->old_roots = old_root;
1457 	return 0;
1458 }
1459 
1460 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
1461 		struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes,
1462 		gfp_t gfp_flag)
1463 {
1464 	struct btrfs_qgroup_extent_record *record;
1465 	struct btrfs_delayed_ref_root *delayed_refs;
1466 	int ret;
1467 
1468 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1469 	    || bytenr == 0 || num_bytes == 0)
1470 		return 0;
1471 	if (WARN_ON(trans == NULL))
1472 		return -EINVAL;
1473 	record = kmalloc(sizeof(*record), gfp_flag);
1474 	if (!record)
1475 		return -ENOMEM;
1476 
1477 	delayed_refs = &trans->transaction->delayed_refs;
1478 	record->bytenr = bytenr;
1479 	record->num_bytes = num_bytes;
1480 	record->old_roots = NULL;
1481 
1482 	spin_lock(&delayed_refs->lock);
1483 	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1484 	spin_unlock(&delayed_refs->lock);
1485 	if (ret > 0) {
1486 		kfree(record);
1487 		return 0;
1488 	}
1489 	return btrfs_qgroup_trace_extent_post(fs_info, record);
1490 }
1491 
1492 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1493 				  struct btrfs_fs_info *fs_info,
1494 				  struct extent_buffer *eb)
1495 {
1496 	int nr = btrfs_header_nritems(eb);
1497 	int i, extent_type, ret;
1498 	struct btrfs_key key;
1499 	struct btrfs_file_extent_item *fi;
1500 	u64 bytenr, num_bytes;
1501 
1502 	/* We can be called directly from walk_up_proc() */
1503 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1504 		return 0;
1505 
1506 	for (i = 0; i < nr; i++) {
1507 		btrfs_item_key_to_cpu(eb, &key, i);
1508 
1509 		if (key.type != BTRFS_EXTENT_DATA_KEY)
1510 			continue;
1511 
1512 		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1513 		/* filter out non qgroup-accountable extents  */
1514 		extent_type = btrfs_file_extent_type(eb, fi);
1515 
1516 		if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1517 			continue;
1518 
1519 		bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1520 		if (!bytenr)
1521 			continue;
1522 
1523 		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1524 
1525 		ret = btrfs_qgroup_trace_extent(trans, fs_info, bytenr,
1526 						num_bytes, GFP_NOFS);
1527 		if (ret)
1528 			return ret;
1529 	}
1530 	cond_resched();
1531 	return 0;
1532 }
1533 
1534 /*
1535  * Walk up the tree from the bottom, freeing leaves and any interior
1536  * nodes which have had all slots visited. If a node (leaf or
1537  * interior) is freed, the node above it will have it's slot
1538  * incremented. The root node will never be freed.
1539  *
1540  * At the end of this function, we should have a path which has all
1541  * slots incremented to the next position for a search. If we need to
1542  * read a new node it will be NULL and the node above it will have the
1543  * correct slot selected for a later read.
1544  *
1545  * If we increment the root nodes slot counter past the number of
1546  * elements, 1 is returned to signal completion of the search.
1547  */
1548 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1549 {
1550 	int level = 0;
1551 	int nr, slot;
1552 	struct extent_buffer *eb;
1553 
1554 	if (root_level == 0)
1555 		return 1;
1556 
1557 	while (level <= root_level) {
1558 		eb = path->nodes[level];
1559 		nr = btrfs_header_nritems(eb);
1560 		path->slots[level]++;
1561 		slot = path->slots[level];
1562 		if (slot >= nr || level == 0) {
1563 			/*
1564 			 * Don't free the root -  we will detect this
1565 			 * condition after our loop and return a
1566 			 * positive value for caller to stop walking the tree.
1567 			 */
1568 			if (level != root_level) {
1569 				btrfs_tree_unlock_rw(eb, path->locks[level]);
1570 				path->locks[level] = 0;
1571 
1572 				free_extent_buffer(eb);
1573 				path->nodes[level] = NULL;
1574 				path->slots[level] = 0;
1575 			}
1576 		} else {
1577 			/*
1578 			 * We have a valid slot to walk back down
1579 			 * from. Stop here so caller can process these
1580 			 * new nodes.
1581 			 */
1582 			break;
1583 		}
1584 
1585 		level++;
1586 	}
1587 
1588 	eb = path->nodes[root_level];
1589 	if (path->slots[root_level] >= btrfs_header_nritems(eb))
1590 		return 1;
1591 
1592 	return 0;
1593 }
1594 
1595 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
1596 			       struct btrfs_root *root,
1597 			       struct extent_buffer *root_eb,
1598 			       u64 root_gen, int root_level)
1599 {
1600 	struct btrfs_fs_info *fs_info = root->fs_info;
1601 	int ret = 0;
1602 	int level;
1603 	struct extent_buffer *eb = root_eb;
1604 	struct btrfs_path *path = NULL;
1605 
1606 	BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL);
1607 	BUG_ON(root_eb == NULL);
1608 
1609 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1610 		return 0;
1611 
1612 	if (!extent_buffer_uptodate(root_eb)) {
1613 		ret = btrfs_read_buffer(root_eb, root_gen);
1614 		if (ret)
1615 			goto out;
1616 	}
1617 
1618 	if (root_level == 0) {
1619 		ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, root_eb);
1620 		goto out;
1621 	}
1622 
1623 	path = btrfs_alloc_path();
1624 	if (!path)
1625 		return -ENOMEM;
1626 
1627 	/*
1628 	 * Walk down the tree.  Missing extent blocks are filled in as
1629 	 * we go. Metadata is accounted every time we read a new
1630 	 * extent block.
1631 	 *
1632 	 * When we reach a leaf, we account for file extent items in it,
1633 	 * walk back up the tree (adjusting slot pointers as we go)
1634 	 * and restart the search process.
1635 	 */
1636 	extent_buffer_get(root_eb); /* For path */
1637 	path->nodes[root_level] = root_eb;
1638 	path->slots[root_level] = 0;
1639 	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
1640 walk_down:
1641 	level = root_level;
1642 	while (level >= 0) {
1643 		if (path->nodes[level] == NULL) {
1644 			int parent_slot;
1645 			u64 child_gen;
1646 			u64 child_bytenr;
1647 
1648 			/*
1649 			 * We need to get child blockptr/gen from parent before
1650 			 * we can read it.
1651 			  */
1652 			eb = path->nodes[level + 1];
1653 			parent_slot = path->slots[level + 1];
1654 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1655 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1656 
1657 			eb = read_tree_block(fs_info, child_bytenr, child_gen);
1658 			if (IS_ERR(eb)) {
1659 				ret = PTR_ERR(eb);
1660 				goto out;
1661 			} else if (!extent_buffer_uptodate(eb)) {
1662 				free_extent_buffer(eb);
1663 				ret = -EIO;
1664 				goto out;
1665 			}
1666 
1667 			path->nodes[level] = eb;
1668 			path->slots[level] = 0;
1669 
1670 			btrfs_tree_read_lock(eb);
1671 			btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1672 			path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
1673 
1674 			ret = btrfs_qgroup_trace_extent(trans, fs_info,
1675 							child_bytenr,
1676 							fs_info->nodesize,
1677 							GFP_NOFS);
1678 			if (ret)
1679 				goto out;
1680 		}
1681 
1682 		if (level == 0) {
1683 			ret = btrfs_qgroup_trace_leaf_items(trans,fs_info,
1684 							   path->nodes[level]);
1685 			if (ret)
1686 				goto out;
1687 
1688 			/* Nonzero return here means we completed our search */
1689 			ret = adjust_slots_upwards(path, root_level);
1690 			if (ret)
1691 				break;
1692 
1693 			/* Restart search with new slots */
1694 			goto walk_down;
1695 		}
1696 
1697 		level--;
1698 	}
1699 
1700 	ret = 0;
1701 out:
1702 	btrfs_free_path(path);
1703 
1704 	return ret;
1705 }
1706 
1707 #define UPDATE_NEW	0
1708 #define UPDATE_OLD	1
1709 /*
1710  * Walk all of the roots that points to the bytenr and adjust their refcnts.
1711  */
1712 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
1713 				struct ulist *roots, struct ulist *tmp,
1714 				struct ulist *qgroups, u64 seq, int update_old)
1715 {
1716 	struct ulist_node *unode;
1717 	struct ulist_iterator uiter;
1718 	struct ulist_node *tmp_unode;
1719 	struct ulist_iterator tmp_uiter;
1720 	struct btrfs_qgroup *qg;
1721 	int ret = 0;
1722 
1723 	if (!roots)
1724 		return 0;
1725 	ULIST_ITER_INIT(&uiter);
1726 	while ((unode = ulist_next(roots, &uiter))) {
1727 		qg = find_qgroup_rb(fs_info, unode->val);
1728 		if (!qg)
1729 			continue;
1730 
1731 		ulist_reinit(tmp);
1732 		ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
1733 				GFP_ATOMIC);
1734 		if (ret < 0)
1735 			return ret;
1736 		ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
1737 		if (ret < 0)
1738 			return ret;
1739 		ULIST_ITER_INIT(&tmp_uiter);
1740 		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1741 			struct btrfs_qgroup_list *glist;
1742 
1743 			qg = unode_aux_to_qgroup(tmp_unode);
1744 			if (update_old)
1745 				btrfs_qgroup_update_old_refcnt(qg, seq, 1);
1746 			else
1747 				btrfs_qgroup_update_new_refcnt(qg, seq, 1);
1748 			list_for_each_entry(glist, &qg->groups, next_group) {
1749 				ret = ulist_add(qgroups, glist->group->qgroupid,
1750 						qgroup_to_aux(glist->group),
1751 						GFP_ATOMIC);
1752 				if (ret < 0)
1753 					return ret;
1754 				ret = ulist_add(tmp, glist->group->qgroupid,
1755 						qgroup_to_aux(glist->group),
1756 						GFP_ATOMIC);
1757 				if (ret < 0)
1758 					return ret;
1759 			}
1760 		}
1761 	}
1762 	return 0;
1763 }
1764 
1765 /*
1766  * Update qgroup rfer/excl counters.
1767  * Rfer update is easy, codes can explain themselves.
1768  *
1769  * Excl update is tricky, the update is split into 2 part.
1770  * Part 1: Possible exclusive <-> sharing detect:
1771  *	|	A	|	!A	|
1772  *  -------------------------------------
1773  *  B	|	*	|	-	|
1774  *  -------------------------------------
1775  *  !B	|	+	|	**	|
1776  *  -------------------------------------
1777  *
1778  * Conditions:
1779  * A:	cur_old_roots < nr_old_roots	(not exclusive before)
1780  * !A:	cur_old_roots == nr_old_roots	(possible exclusive before)
1781  * B:	cur_new_roots < nr_new_roots	(not exclusive now)
1782  * !B:	cur_new_roots == nr_new_roots	(possible exclusive now)
1783  *
1784  * Results:
1785  * +: Possible sharing -> exclusive	-: Possible exclusive -> sharing
1786  * *: Definitely not changed.		**: Possible unchanged.
1787  *
1788  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
1789  *
1790  * To make the logic clear, we first use condition A and B to split
1791  * combination into 4 results.
1792  *
1793  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
1794  * only on variant maybe 0.
1795  *
1796  * Lastly, check result **, since there are 2 variants maybe 0, split them
1797  * again(2x2).
1798  * But this time we don't need to consider other things, the codes and logic
1799  * is easy to understand now.
1800  */
1801 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
1802 				  struct ulist *qgroups,
1803 				  u64 nr_old_roots,
1804 				  u64 nr_new_roots,
1805 				  u64 num_bytes, u64 seq)
1806 {
1807 	struct ulist_node *unode;
1808 	struct ulist_iterator uiter;
1809 	struct btrfs_qgroup *qg;
1810 	u64 cur_new_count, cur_old_count;
1811 
1812 	ULIST_ITER_INIT(&uiter);
1813 	while ((unode = ulist_next(qgroups, &uiter))) {
1814 		bool dirty = false;
1815 
1816 		qg = unode_aux_to_qgroup(unode);
1817 		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
1818 		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
1819 
1820 		trace_qgroup_update_counters(fs_info, qg->qgroupid,
1821 					     cur_old_count, cur_new_count);
1822 
1823 		/* Rfer update part */
1824 		if (cur_old_count == 0 && cur_new_count > 0) {
1825 			qg->rfer += num_bytes;
1826 			qg->rfer_cmpr += num_bytes;
1827 			dirty = true;
1828 		}
1829 		if (cur_old_count > 0 && cur_new_count == 0) {
1830 			qg->rfer -= num_bytes;
1831 			qg->rfer_cmpr -= num_bytes;
1832 			dirty = true;
1833 		}
1834 
1835 		/* Excl update part */
1836 		/* Exclusive/none -> shared case */
1837 		if (cur_old_count == nr_old_roots &&
1838 		    cur_new_count < nr_new_roots) {
1839 			/* Exclusive -> shared */
1840 			if (cur_old_count != 0) {
1841 				qg->excl -= num_bytes;
1842 				qg->excl_cmpr -= num_bytes;
1843 				dirty = true;
1844 			}
1845 		}
1846 
1847 		/* Shared -> exclusive/none case */
1848 		if (cur_old_count < nr_old_roots &&
1849 		    cur_new_count == nr_new_roots) {
1850 			/* Shared->exclusive */
1851 			if (cur_new_count != 0) {
1852 				qg->excl += num_bytes;
1853 				qg->excl_cmpr += num_bytes;
1854 				dirty = true;
1855 			}
1856 		}
1857 
1858 		/* Exclusive/none -> exclusive/none case */
1859 		if (cur_old_count == nr_old_roots &&
1860 		    cur_new_count == nr_new_roots) {
1861 			if (cur_old_count == 0) {
1862 				/* None -> exclusive/none */
1863 
1864 				if (cur_new_count != 0) {
1865 					/* None -> exclusive */
1866 					qg->excl += num_bytes;
1867 					qg->excl_cmpr += num_bytes;
1868 					dirty = true;
1869 				}
1870 				/* None -> none, nothing changed */
1871 			} else {
1872 				/* Exclusive -> exclusive/none */
1873 
1874 				if (cur_new_count == 0) {
1875 					/* Exclusive -> none */
1876 					qg->excl -= num_bytes;
1877 					qg->excl_cmpr -= num_bytes;
1878 					dirty = true;
1879 				}
1880 				/* Exclusive -> exclusive, nothing changed */
1881 			}
1882 		}
1883 
1884 		if (dirty)
1885 			qgroup_dirty(fs_info, qg);
1886 	}
1887 	return 0;
1888 }
1889 
1890 /*
1891  * Check if the @roots potentially is a list of fs tree roots
1892  *
1893  * Return 0 for definitely not a fs/subvol tree roots ulist
1894  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
1895  *          one as well)
1896  */
1897 static int maybe_fs_roots(struct ulist *roots)
1898 {
1899 	struct ulist_node *unode;
1900 	struct ulist_iterator uiter;
1901 
1902 	/* Empty one, still possible for fs roots */
1903 	if (!roots || roots->nnodes == 0)
1904 		return 1;
1905 
1906 	ULIST_ITER_INIT(&uiter);
1907 	unode = ulist_next(roots, &uiter);
1908 	if (!unode)
1909 		return 1;
1910 
1911 	/*
1912 	 * If it contains fs tree roots, then it must belong to fs/subvol
1913 	 * trees.
1914 	 * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
1915 	 */
1916 	return is_fstree(unode->val);
1917 }
1918 
1919 int
1920 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
1921 			    struct btrfs_fs_info *fs_info,
1922 			    u64 bytenr, u64 num_bytes,
1923 			    struct ulist *old_roots, struct ulist *new_roots)
1924 {
1925 	struct ulist *qgroups = NULL;
1926 	struct ulist *tmp = NULL;
1927 	u64 seq;
1928 	u64 nr_new_roots = 0;
1929 	u64 nr_old_roots = 0;
1930 	int ret = 0;
1931 
1932 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1933 		return 0;
1934 
1935 	if (new_roots) {
1936 		if (!maybe_fs_roots(new_roots))
1937 			goto out_free;
1938 		nr_new_roots = new_roots->nnodes;
1939 	}
1940 	if (old_roots) {
1941 		if (!maybe_fs_roots(old_roots))
1942 			goto out_free;
1943 		nr_old_roots = old_roots->nnodes;
1944 	}
1945 
1946 	/* Quick exit, either not fs tree roots, or won't affect any qgroup */
1947 	if (nr_old_roots == 0 && nr_new_roots == 0)
1948 		goto out_free;
1949 
1950 	BUG_ON(!fs_info->quota_root);
1951 
1952 	trace_btrfs_qgroup_account_extent(fs_info, bytenr, num_bytes,
1953 					  nr_old_roots, nr_new_roots);
1954 
1955 	qgroups = ulist_alloc(GFP_NOFS);
1956 	if (!qgroups) {
1957 		ret = -ENOMEM;
1958 		goto out_free;
1959 	}
1960 	tmp = ulist_alloc(GFP_NOFS);
1961 	if (!tmp) {
1962 		ret = -ENOMEM;
1963 		goto out_free;
1964 	}
1965 
1966 	mutex_lock(&fs_info->qgroup_rescan_lock);
1967 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
1968 		if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
1969 			mutex_unlock(&fs_info->qgroup_rescan_lock);
1970 			ret = 0;
1971 			goto out_free;
1972 		}
1973 	}
1974 	mutex_unlock(&fs_info->qgroup_rescan_lock);
1975 
1976 	spin_lock(&fs_info->qgroup_lock);
1977 	seq = fs_info->qgroup_seq;
1978 
1979 	/* Update old refcnts using old_roots */
1980 	ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
1981 				   UPDATE_OLD);
1982 	if (ret < 0)
1983 		goto out;
1984 
1985 	/* Update new refcnts using new_roots */
1986 	ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
1987 				   UPDATE_NEW);
1988 	if (ret < 0)
1989 		goto out;
1990 
1991 	qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
1992 			       num_bytes, seq);
1993 
1994 	/*
1995 	 * Bump qgroup_seq to avoid seq overlap
1996 	 */
1997 	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
1998 out:
1999 	spin_unlock(&fs_info->qgroup_lock);
2000 out_free:
2001 	ulist_free(tmp);
2002 	ulist_free(qgroups);
2003 	ulist_free(old_roots);
2004 	ulist_free(new_roots);
2005 	return ret;
2006 }
2007 
2008 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans,
2009 				 struct btrfs_fs_info *fs_info)
2010 {
2011 	struct btrfs_qgroup_extent_record *record;
2012 	struct btrfs_delayed_ref_root *delayed_refs;
2013 	struct ulist *new_roots = NULL;
2014 	struct rb_node *node;
2015 	u64 qgroup_to_skip;
2016 	int ret = 0;
2017 
2018 	delayed_refs = &trans->transaction->delayed_refs;
2019 	qgroup_to_skip = delayed_refs->qgroup_to_skip;
2020 	while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2021 		record = rb_entry(node, struct btrfs_qgroup_extent_record,
2022 				  node);
2023 
2024 		trace_btrfs_qgroup_account_extents(fs_info, record);
2025 
2026 		if (!ret) {
2027 			/*
2028 			 * Old roots should be searched when inserting qgroup
2029 			 * extent record
2030 			 */
2031 			if (WARN_ON(!record->old_roots)) {
2032 				/* Search commit root to find old_roots */
2033 				ret = btrfs_find_all_roots(NULL, fs_info,
2034 						record->bytenr, 0,
2035 						&record->old_roots);
2036 				if (ret < 0)
2037 					goto cleanup;
2038 			}
2039 
2040 			/*
2041 			 * Use SEQ_LAST as time_seq to do special search, which
2042 			 * doesn't lock tree or delayed_refs and search current
2043 			 * root. It's safe inside commit_transaction().
2044 			 */
2045 			ret = btrfs_find_all_roots(trans, fs_info,
2046 					record->bytenr, SEQ_LAST, &new_roots);
2047 			if (ret < 0)
2048 				goto cleanup;
2049 			if (qgroup_to_skip) {
2050 				ulist_del(new_roots, qgroup_to_skip, 0);
2051 				ulist_del(record->old_roots, qgroup_to_skip,
2052 					  0);
2053 			}
2054 			ret = btrfs_qgroup_account_extent(trans, fs_info,
2055 					record->bytenr, record->num_bytes,
2056 					record->old_roots, new_roots);
2057 			record->old_roots = NULL;
2058 			new_roots = NULL;
2059 		}
2060 cleanup:
2061 		ulist_free(record->old_roots);
2062 		ulist_free(new_roots);
2063 		new_roots = NULL;
2064 		rb_erase(node, &delayed_refs->dirty_extent_root);
2065 		kfree(record);
2066 
2067 	}
2068 	return ret;
2069 }
2070 
2071 /*
2072  * called from commit_transaction. Writes all changed qgroups to disk.
2073  */
2074 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
2075 		      struct btrfs_fs_info *fs_info)
2076 {
2077 	struct btrfs_root *quota_root = fs_info->quota_root;
2078 	int ret = 0;
2079 	int start_rescan_worker = 0;
2080 
2081 	if (!quota_root)
2082 		goto out;
2083 
2084 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
2085 	    test_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2086 		start_rescan_worker = 1;
2087 
2088 	if (test_and_clear_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2089 		set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2090 	if (test_and_clear_bit(BTRFS_FS_QUOTA_DISABLING, &fs_info->flags))
2091 		clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2092 
2093 	spin_lock(&fs_info->qgroup_lock);
2094 	while (!list_empty(&fs_info->dirty_qgroups)) {
2095 		struct btrfs_qgroup *qgroup;
2096 		qgroup = list_first_entry(&fs_info->dirty_qgroups,
2097 					  struct btrfs_qgroup, dirty);
2098 		list_del_init(&qgroup->dirty);
2099 		spin_unlock(&fs_info->qgroup_lock);
2100 		ret = update_qgroup_info_item(trans, quota_root, qgroup);
2101 		if (ret)
2102 			fs_info->qgroup_flags |=
2103 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2104 		ret = update_qgroup_limit_item(trans, quota_root, qgroup);
2105 		if (ret)
2106 			fs_info->qgroup_flags |=
2107 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2108 		spin_lock(&fs_info->qgroup_lock);
2109 	}
2110 	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2111 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2112 	else
2113 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2114 	spin_unlock(&fs_info->qgroup_lock);
2115 
2116 	ret = update_qgroup_status_item(trans, fs_info, quota_root);
2117 	if (ret)
2118 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2119 
2120 	if (!ret && start_rescan_worker) {
2121 		ret = qgroup_rescan_init(fs_info, 0, 1);
2122 		if (!ret) {
2123 			qgroup_rescan_zero_tracking(fs_info);
2124 			btrfs_queue_work(fs_info->qgroup_rescan_workers,
2125 					 &fs_info->qgroup_rescan_work);
2126 		}
2127 		ret = 0;
2128 	}
2129 
2130 out:
2131 
2132 	return ret;
2133 }
2134 
2135 /*
2136  * Copy the accounting information between qgroups. This is necessary
2137  * when a snapshot or a subvolume is created. Throwing an error will
2138  * cause a transaction abort so we take extra care here to only error
2139  * when a readonly fs is a reasonable outcome.
2140  */
2141 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
2142 			 struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
2143 			 struct btrfs_qgroup_inherit *inherit)
2144 {
2145 	int ret = 0;
2146 	int i;
2147 	u64 *i_qgroups;
2148 	struct btrfs_root *quota_root = fs_info->quota_root;
2149 	struct btrfs_qgroup *srcgroup;
2150 	struct btrfs_qgroup *dstgroup;
2151 	u32 level_size = 0;
2152 	u64 nums;
2153 
2154 	mutex_lock(&fs_info->qgroup_ioctl_lock);
2155 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2156 		goto out;
2157 
2158 	if (!quota_root) {
2159 		ret = -EINVAL;
2160 		goto out;
2161 	}
2162 
2163 	if (inherit) {
2164 		i_qgroups = (u64 *)(inherit + 1);
2165 		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2166 		       2 * inherit->num_excl_copies;
2167 		for (i = 0; i < nums; ++i) {
2168 			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2169 
2170 			/*
2171 			 * Zero out invalid groups so we can ignore
2172 			 * them later.
2173 			 */
2174 			if (!srcgroup ||
2175 			    ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2176 				*i_qgroups = 0ULL;
2177 
2178 			++i_qgroups;
2179 		}
2180 	}
2181 
2182 	/*
2183 	 * create a tracking group for the subvol itself
2184 	 */
2185 	ret = add_qgroup_item(trans, quota_root, objectid);
2186 	if (ret)
2187 		goto out;
2188 
2189 	if (srcid) {
2190 		struct btrfs_root *srcroot;
2191 		struct btrfs_key srckey;
2192 
2193 		srckey.objectid = srcid;
2194 		srckey.type = BTRFS_ROOT_ITEM_KEY;
2195 		srckey.offset = (u64)-1;
2196 		srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
2197 		if (IS_ERR(srcroot)) {
2198 			ret = PTR_ERR(srcroot);
2199 			goto out;
2200 		}
2201 
2202 		level_size = fs_info->nodesize;
2203 	}
2204 
2205 	/*
2206 	 * add qgroup to all inherited groups
2207 	 */
2208 	if (inherit) {
2209 		i_qgroups = (u64 *)(inherit + 1);
2210 		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2211 			if (*i_qgroups == 0)
2212 				continue;
2213 			ret = add_qgroup_relation_item(trans, quota_root,
2214 						       objectid, *i_qgroups);
2215 			if (ret && ret != -EEXIST)
2216 				goto out;
2217 			ret = add_qgroup_relation_item(trans, quota_root,
2218 						       *i_qgroups, objectid);
2219 			if (ret && ret != -EEXIST)
2220 				goto out;
2221 		}
2222 		ret = 0;
2223 	}
2224 
2225 
2226 	spin_lock(&fs_info->qgroup_lock);
2227 
2228 	dstgroup = add_qgroup_rb(fs_info, objectid);
2229 	if (IS_ERR(dstgroup)) {
2230 		ret = PTR_ERR(dstgroup);
2231 		goto unlock;
2232 	}
2233 
2234 	if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2235 		dstgroup->lim_flags = inherit->lim.flags;
2236 		dstgroup->max_rfer = inherit->lim.max_rfer;
2237 		dstgroup->max_excl = inherit->lim.max_excl;
2238 		dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2239 		dstgroup->rsv_excl = inherit->lim.rsv_excl;
2240 
2241 		ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
2242 		if (ret) {
2243 			fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2244 			btrfs_info(fs_info,
2245 				   "unable to update quota limit for %llu",
2246 				   dstgroup->qgroupid);
2247 			goto unlock;
2248 		}
2249 	}
2250 
2251 	if (srcid) {
2252 		srcgroup = find_qgroup_rb(fs_info, srcid);
2253 		if (!srcgroup)
2254 			goto unlock;
2255 
2256 		/*
2257 		 * We call inherit after we clone the root in order to make sure
2258 		 * our counts don't go crazy, so at this point the only
2259 		 * difference between the two roots should be the root node.
2260 		 */
2261 		dstgroup->rfer = srcgroup->rfer;
2262 		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2263 		dstgroup->excl = level_size;
2264 		dstgroup->excl_cmpr = level_size;
2265 		srcgroup->excl = level_size;
2266 		srcgroup->excl_cmpr = level_size;
2267 
2268 		/* inherit the limit info */
2269 		dstgroup->lim_flags = srcgroup->lim_flags;
2270 		dstgroup->max_rfer = srcgroup->max_rfer;
2271 		dstgroup->max_excl = srcgroup->max_excl;
2272 		dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2273 		dstgroup->rsv_excl = srcgroup->rsv_excl;
2274 
2275 		qgroup_dirty(fs_info, dstgroup);
2276 		qgroup_dirty(fs_info, srcgroup);
2277 	}
2278 
2279 	if (!inherit)
2280 		goto unlock;
2281 
2282 	i_qgroups = (u64 *)(inherit + 1);
2283 	for (i = 0; i < inherit->num_qgroups; ++i) {
2284 		if (*i_qgroups) {
2285 			ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2286 			if (ret)
2287 				goto unlock;
2288 		}
2289 		++i_qgroups;
2290 	}
2291 
2292 	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2293 		struct btrfs_qgroup *src;
2294 		struct btrfs_qgroup *dst;
2295 
2296 		if (!i_qgroups[0] || !i_qgroups[1])
2297 			continue;
2298 
2299 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2300 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2301 
2302 		if (!src || !dst) {
2303 			ret = -EINVAL;
2304 			goto unlock;
2305 		}
2306 
2307 		dst->rfer = src->rfer - level_size;
2308 		dst->rfer_cmpr = src->rfer_cmpr - level_size;
2309 	}
2310 	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2311 		struct btrfs_qgroup *src;
2312 		struct btrfs_qgroup *dst;
2313 
2314 		if (!i_qgroups[0] || !i_qgroups[1])
2315 			continue;
2316 
2317 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
2318 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2319 
2320 		if (!src || !dst) {
2321 			ret = -EINVAL;
2322 			goto unlock;
2323 		}
2324 
2325 		dst->excl = src->excl + level_size;
2326 		dst->excl_cmpr = src->excl_cmpr + level_size;
2327 	}
2328 
2329 unlock:
2330 	spin_unlock(&fs_info->qgroup_lock);
2331 out:
2332 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
2333 	return ret;
2334 }
2335 
2336 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
2337 {
2338 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2339 	    qg->reserved + (s64)qg->rfer + num_bytes > qg->max_rfer)
2340 		return false;
2341 
2342 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2343 	    qg->reserved + (s64)qg->excl + num_bytes > qg->max_excl)
2344 		return false;
2345 
2346 	return true;
2347 }
2348 
2349 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce)
2350 {
2351 	struct btrfs_root *quota_root;
2352 	struct btrfs_qgroup *qgroup;
2353 	struct btrfs_fs_info *fs_info = root->fs_info;
2354 	u64 ref_root = root->root_key.objectid;
2355 	int ret = 0;
2356 	int retried = 0;
2357 	struct ulist_node *unode;
2358 	struct ulist_iterator uiter;
2359 
2360 	if (!is_fstree(ref_root))
2361 		return 0;
2362 
2363 	if (num_bytes == 0)
2364 		return 0;
2365 
2366 	if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2367 	    capable(CAP_SYS_RESOURCE))
2368 		enforce = false;
2369 
2370 retry:
2371 	spin_lock(&fs_info->qgroup_lock);
2372 	quota_root = fs_info->quota_root;
2373 	if (!quota_root)
2374 		goto out;
2375 
2376 	qgroup = find_qgroup_rb(fs_info, ref_root);
2377 	if (!qgroup)
2378 		goto out;
2379 
2380 	/*
2381 	 * in a first step, we check all affected qgroups if any limits would
2382 	 * be exceeded
2383 	 */
2384 	ulist_reinit(fs_info->qgroup_ulist);
2385 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2386 			(uintptr_t)qgroup, GFP_ATOMIC);
2387 	if (ret < 0)
2388 		goto out;
2389 	ULIST_ITER_INIT(&uiter);
2390 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2391 		struct btrfs_qgroup *qg;
2392 		struct btrfs_qgroup_list *glist;
2393 
2394 		qg = unode_aux_to_qgroup(unode);
2395 
2396 		if (enforce && !qgroup_check_limits(qg, num_bytes)) {
2397 			/*
2398 			 * Commit the tree and retry, since we may have
2399 			 * deletions which would free up space.
2400 			 */
2401 			if (!retried && qg->reserved > 0) {
2402 				struct btrfs_trans_handle *trans;
2403 
2404 				spin_unlock(&fs_info->qgroup_lock);
2405 				ret = btrfs_start_delalloc_inodes(root, 0);
2406 				if (ret)
2407 					return ret;
2408 				btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
2409 				trans = btrfs_join_transaction(root);
2410 				if (IS_ERR(trans))
2411 					return PTR_ERR(trans);
2412 				ret = btrfs_commit_transaction(trans);
2413 				if (ret)
2414 					return ret;
2415 				retried++;
2416 				goto retry;
2417 			}
2418 			ret = -EDQUOT;
2419 			goto out;
2420 		}
2421 
2422 		list_for_each_entry(glist, &qg->groups, next_group) {
2423 			ret = ulist_add(fs_info->qgroup_ulist,
2424 					glist->group->qgroupid,
2425 					(uintptr_t)glist->group, GFP_ATOMIC);
2426 			if (ret < 0)
2427 				goto out;
2428 		}
2429 	}
2430 	ret = 0;
2431 	/*
2432 	 * no limits exceeded, now record the reservation into all qgroups
2433 	 */
2434 	ULIST_ITER_INIT(&uiter);
2435 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2436 		struct btrfs_qgroup *qg;
2437 
2438 		qg = unode_aux_to_qgroup(unode);
2439 
2440 		trace_qgroup_update_reserve(fs_info, qg, num_bytes);
2441 		qg->reserved += num_bytes;
2442 	}
2443 
2444 out:
2445 	spin_unlock(&fs_info->qgroup_lock);
2446 	return ret;
2447 }
2448 
2449 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2450 			       u64 ref_root, u64 num_bytes)
2451 {
2452 	struct btrfs_root *quota_root;
2453 	struct btrfs_qgroup *qgroup;
2454 	struct ulist_node *unode;
2455 	struct ulist_iterator uiter;
2456 	int ret = 0;
2457 
2458 	if (!is_fstree(ref_root))
2459 		return;
2460 
2461 	if (num_bytes == 0)
2462 		return;
2463 
2464 	spin_lock(&fs_info->qgroup_lock);
2465 
2466 	quota_root = fs_info->quota_root;
2467 	if (!quota_root)
2468 		goto out;
2469 
2470 	qgroup = find_qgroup_rb(fs_info, ref_root);
2471 	if (!qgroup)
2472 		goto out;
2473 
2474 	ulist_reinit(fs_info->qgroup_ulist);
2475 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2476 			(uintptr_t)qgroup, GFP_ATOMIC);
2477 	if (ret < 0)
2478 		goto out;
2479 	ULIST_ITER_INIT(&uiter);
2480 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2481 		struct btrfs_qgroup *qg;
2482 		struct btrfs_qgroup_list *glist;
2483 
2484 		qg = unode_aux_to_qgroup(unode);
2485 
2486 		trace_qgroup_update_reserve(fs_info, qg, -(s64)num_bytes);
2487 		if (qg->reserved < num_bytes)
2488 			report_reserved_underflow(fs_info, qg, num_bytes);
2489 		else
2490 			qg->reserved -= num_bytes;
2491 
2492 		list_for_each_entry(glist, &qg->groups, next_group) {
2493 			ret = ulist_add(fs_info->qgroup_ulist,
2494 					glist->group->qgroupid,
2495 					(uintptr_t)glist->group, GFP_ATOMIC);
2496 			if (ret < 0)
2497 				goto out;
2498 		}
2499 	}
2500 
2501 out:
2502 	spin_unlock(&fs_info->qgroup_lock);
2503 }
2504 
2505 /*
2506  * returns < 0 on error, 0 when more leafs are to be scanned.
2507  * returns 1 when done.
2508  */
2509 static int
2510 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
2511 		   struct btrfs_trans_handle *trans)
2512 {
2513 	struct btrfs_key found;
2514 	struct extent_buffer *scratch_leaf = NULL;
2515 	struct ulist *roots = NULL;
2516 	struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
2517 	u64 num_bytes;
2518 	int slot;
2519 	int ret;
2520 
2521 	mutex_lock(&fs_info->qgroup_rescan_lock);
2522 	ret = btrfs_search_slot_for_read(fs_info->extent_root,
2523 					 &fs_info->qgroup_rescan_progress,
2524 					 path, 1, 0);
2525 
2526 	btrfs_debug(fs_info,
2527 		"current progress key (%llu %u %llu), search_slot ret %d",
2528 		fs_info->qgroup_rescan_progress.objectid,
2529 		fs_info->qgroup_rescan_progress.type,
2530 		fs_info->qgroup_rescan_progress.offset, ret);
2531 
2532 	if (ret) {
2533 		/*
2534 		 * The rescan is about to end, we will not be scanning any
2535 		 * further blocks. We cannot unset the RESCAN flag here, because
2536 		 * we want to commit the transaction if everything went well.
2537 		 * To make the live accounting work in this phase, we set our
2538 		 * scan progress pointer such that every real extent objectid
2539 		 * will be smaller.
2540 		 */
2541 		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
2542 		btrfs_release_path(path);
2543 		mutex_unlock(&fs_info->qgroup_rescan_lock);
2544 		return ret;
2545 	}
2546 
2547 	btrfs_item_key_to_cpu(path->nodes[0], &found,
2548 			      btrfs_header_nritems(path->nodes[0]) - 1);
2549 	fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
2550 
2551 	btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2552 	scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
2553 	if (!scratch_leaf) {
2554 		ret = -ENOMEM;
2555 		mutex_unlock(&fs_info->qgroup_rescan_lock);
2556 		goto out;
2557 	}
2558 	extent_buffer_get(scratch_leaf);
2559 	btrfs_tree_read_lock(scratch_leaf);
2560 	btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
2561 	slot = path->slots[0];
2562 	btrfs_release_path(path);
2563 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2564 
2565 	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
2566 		btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
2567 		if (found.type != BTRFS_EXTENT_ITEM_KEY &&
2568 		    found.type != BTRFS_METADATA_ITEM_KEY)
2569 			continue;
2570 		if (found.type == BTRFS_METADATA_ITEM_KEY)
2571 			num_bytes = fs_info->nodesize;
2572 		else
2573 			num_bytes = found.offset;
2574 
2575 		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
2576 					   &roots);
2577 		if (ret < 0)
2578 			goto out;
2579 		/* For rescan, just pass old_roots as NULL */
2580 		ret = btrfs_qgroup_account_extent(trans, fs_info,
2581 				found.objectid, num_bytes, NULL, roots);
2582 		if (ret < 0)
2583 			goto out;
2584 	}
2585 out:
2586 	if (scratch_leaf) {
2587 		btrfs_tree_read_unlock_blocking(scratch_leaf);
2588 		free_extent_buffer(scratch_leaf);
2589 	}
2590 	btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2591 
2592 	return ret;
2593 }
2594 
2595 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
2596 {
2597 	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
2598 						     qgroup_rescan_work);
2599 	struct btrfs_path *path;
2600 	struct btrfs_trans_handle *trans = NULL;
2601 	int err = -ENOMEM;
2602 	int ret = 0;
2603 
2604 	path = btrfs_alloc_path();
2605 	if (!path)
2606 		goto out;
2607 
2608 	err = 0;
2609 	while (!err && !btrfs_fs_closing(fs_info)) {
2610 		trans = btrfs_start_transaction(fs_info->fs_root, 0);
2611 		if (IS_ERR(trans)) {
2612 			err = PTR_ERR(trans);
2613 			break;
2614 		}
2615 		if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
2616 			err = -EINTR;
2617 		} else {
2618 			err = qgroup_rescan_leaf(fs_info, path, trans);
2619 		}
2620 		if (err > 0)
2621 			btrfs_commit_transaction(trans);
2622 		else
2623 			btrfs_end_transaction(trans);
2624 	}
2625 
2626 out:
2627 	btrfs_free_path(path);
2628 
2629 	mutex_lock(&fs_info->qgroup_rescan_lock);
2630 	if (!btrfs_fs_closing(fs_info))
2631 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2632 
2633 	if (err > 0 &&
2634 	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
2635 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2636 	} else if (err < 0) {
2637 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2638 	}
2639 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2640 
2641 	/*
2642 	 * only update status, since the previous part has already updated the
2643 	 * qgroup info.
2644 	 */
2645 	trans = btrfs_start_transaction(fs_info->quota_root, 1);
2646 	if (IS_ERR(trans)) {
2647 		err = PTR_ERR(trans);
2648 		btrfs_err(fs_info,
2649 			  "fail to start transaction for status update: %d\n",
2650 			  err);
2651 		goto done;
2652 	}
2653 	ret = update_qgroup_status_item(trans, fs_info, fs_info->quota_root);
2654 	if (ret < 0) {
2655 		err = ret;
2656 		btrfs_err(fs_info, "fail to update qgroup status: %d", err);
2657 	}
2658 	btrfs_end_transaction(trans);
2659 
2660 	if (btrfs_fs_closing(fs_info)) {
2661 		btrfs_info(fs_info, "qgroup scan paused");
2662 	} else if (err >= 0) {
2663 		btrfs_info(fs_info, "qgroup scan completed%s",
2664 			err > 0 ? " (inconsistency flag cleared)" : "");
2665 	} else {
2666 		btrfs_err(fs_info, "qgroup scan failed with %d", err);
2667 	}
2668 
2669 done:
2670 	mutex_lock(&fs_info->qgroup_rescan_lock);
2671 	fs_info->qgroup_rescan_running = false;
2672 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2673 	complete_all(&fs_info->qgroup_rescan_completion);
2674 }
2675 
2676 /*
2677  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
2678  * memory required for the rescan context.
2679  */
2680 static int
2681 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
2682 		   int init_flags)
2683 {
2684 	int ret = 0;
2685 
2686 	if (!init_flags &&
2687 	    (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
2688 	     !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
2689 		ret = -EINVAL;
2690 		goto err;
2691 	}
2692 
2693 	mutex_lock(&fs_info->qgroup_rescan_lock);
2694 	spin_lock(&fs_info->qgroup_lock);
2695 
2696 	if (init_flags) {
2697 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2698 			ret = -EINPROGRESS;
2699 		else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
2700 			ret = -EINVAL;
2701 
2702 		if (ret) {
2703 			spin_unlock(&fs_info->qgroup_lock);
2704 			mutex_unlock(&fs_info->qgroup_rescan_lock);
2705 			goto err;
2706 		}
2707 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2708 	}
2709 
2710 	memset(&fs_info->qgroup_rescan_progress, 0,
2711 		sizeof(fs_info->qgroup_rescan_progress));
2712 	fs_info->qgroup_rescan_progress.objectid = progress_objectid;
2713 	init_completion(&fs_info->qgroup_rescan_completion);
2714 	fs_info->qgroup_rescan_running = true;
2715 
2716 	spin_unlock(&fs_info->qgroup_lock);
2717 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2718 
2719 	memset(&fs_info->qgroup_rescan_work, 0,
2720 	       sizeof(fs_info->qgroup_rescan_work));
2721 	btrfs_init_work(&fs_info->qgroup_rescan_work,
2722 			btrfs_qgroup_rescan_helper,
2723 			btrfs_qgroup_rescan_worker, NULL, NULL);
2724 
2725 	if (ret) {
2726 err:
2727 		btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
2728 		return ret;
2729 	}
2730 
2731 	return 0;
2732 }
2733 
2734 static void
2735 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
2736 {
2737 	struct rb_node *n;
2738 	struct btrfs_qgroup *qgroup;
2739 
2740 	spin_lock(&fs_info->qgroup_lock);
2741 	/* clear all current qgroup tracking information */
2742 	for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
2743 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
2744 		qgroup->rfer = 0;
2745 		qgroup->rfer_cmpr = 0;
2746 		qgroup->excl = 0;
2747 		qgroup->excl_cmpr = 0;
2748 	}
2749 	spin_unlock(&fs_info->qgroup_lock);
2750 }
2751 
2752 int
2753 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
2754 {
2755 	int ret = 0;
2756 	struct btrfs_trans_handle *trans;
2757 
2758 	ret = qgroup_rescan_init(fs_info, 0, 1);
2759 	if (ret)
2760 		return ret;
2761 
2762 	/*
2763 	 * We have set the rescan_progress to 0, which means no more
2764 	 * delayed refs will be accounted by btrfs_qgroup_account_ref.
2765 	 * However, btrfs_qgroup_account_ref may be right after its call
2766 	 * to btrfs_find_all_roots, in which case it would still do the
2767 	 * accounting.
2768 	 * To solve this, we're committing the transaction, which will
2769 	 * ensure we run all delayed refs and only after that, we are
2770 	 * going to clear all tracking information for a clean start.
2771 	 */
2772 
2773 	trans = btrfs_join_transaction(fs_info->fs_root);
2774 	if (IS_ERR(trans)) {
2775 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2776 		return PTR_ERR(trans);
2777 	}
2778 	ret = btrfs_commit_transaction(trans);
2779 	if (ret) {
2780 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2781 		return ret;
2782 	}
2783 
2784 	qgroup_rescan_zero_tracking(fs_info);
2785 
2786 	btrfs_queue_work(fs_info->qgroup_rescan_workers,
2787 			 &fs_info->qgroup_rescan_work);
2788 
2789 	return 0;
2790 }
2791 
2792 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
2793 				     bool interruptible)
2794 {
2795 	int running;
2796 	int ret = 0;
2797 
2798 	mutex_lock(&fs_info->qgroup_rescan_lock);
2799 	spin_lock(&fs_info->qgroup_lock);
2800 	running = fs_info->qgroup_rescan_running;
2801 	spin_unlock(&fs_info->qgroup_lock);
2802 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2803 
2804 	if (!running)
2805 		return 0;
2806 
2807 	if (interruptible)
2808 		ret = wait_for_completion_interruptible(
2809 					&fs_info->qgroup_rescan_completion);
2810 	else
2811 		wait_for_completion(&fs_info->qgroup_rescan_completion);
2812 
2813 	return ret;
2814 }
2815 
2816 /*
2817  * this is only called from open_ctree where we're still single threaded, thus
2818  * locking is omitted here.
2819  */
2820 void
2821 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
2822 {
2823 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2824 		btrfs_queue_work(fs_info->qgroup_rescan_workers,
2825 				 &fs_info->qgroup_rescan_work);
2826 }
2827 
2828 /*
2829  * Reserve qgroup space for range [start, start + len).
2830  *
2831  * This function will either reserve space from related qgroups or doing
2832  * nothing if the range is already reserved.
2833  *
2834  * Return 0 for successful reserve
2835  * Return <0 for error (including -EQUOT)
2836  *
2837  * NOTE: this function may sleep for memory allocation.
2838  *       if btrfs_qgroup_reserve_data() is called multiple times with
2839  *       same @reserved, caller must ensure when error happens it's OK
2840  *       to free *ALL* reserved space.
2841  */
2842 int btrfs_qgroup_reserve_data(struct inode *inode,
2843 			struct extent_changeset **reserved_ret, u64 start,
2844 			u64 len)
2845 {
2846 	struct btrfs_root *root = BTRFS_I(inode)->root;
2847 	struct ulist_node *unode;
2848 	struct ulist_iterator uiter;
2849 	struct extent_changeset *reserved;
2850 	u64 orig_reserved;
2851 	u64 to_reserve;
2852 	int ret;
2853 
2854 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
2855 	    !is_fstree(root->objectid) || len == 0)
2856 		return 0;
2857 
2858 	/* @reserved parameter is mandatory for qgroup */
2859 	if (WARN_ON(!reserved_ret))
2860 		return -EINVAL;
2861 	if (!*reserved_ret) {
2862 		*reserved_ret = extent_changeset_alloc();
2863 		if (!*reserved_ret)
2864 			return -ENOMEM;
2865 	}
2866 	reserved = *reserved_ret;
2867 	/* Record already reserved space */
2868 	orig_reserved = reserved->bytes_changed;
2869 	ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2870 			start + len -1, EXTENT_QGROUP_RESERVED, reserved);
2871 
2872 	/* Newly reserved space */
2873 	to_reserve = reserved->bytes_changed - orig_reserved;
2874 	trace_btrfs_qgroup_reserve_data(inode, start, len,
2875 					to_reserve, QGROUP_RESERVE);
2876 	if (ret < 0)
2877 		goto cleanup;
2878 	ret = qgroup_reserve(root, to_reserve, true);
2879 	if (ret < 0)
2880 		goto cleanup;
2881 
2882 	return ret;
2883 
2884 cleanup:
2885 	/* cleanup *ALL* already reserved ranges */
2886 	ULIST_ITER_INIT(&uiter);
2887 	while ((unode = ulist_next(&reserved->range_changed, &uiter)))
2888 		clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
2889 				 unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL,
2890 				 GFP_NOFS);
2891 	extent_changeset_release(reserved);
2892 	return ret;
2893 }
2894 
2895 /* Free ranges specified by @reserved, normally in error path */
2896 static int qgroup_free_reserved_data(struct inode *inode,
2897 			struct extent_changeset *reserved, u64 start, u64 len)
2898 {
2899 	struct btrfs_root *root = BTRFS_I(inode)->root;
2900 	struct ulist_node *unode;
2901 	struct ulist_iterator uiter;
2902 	struct extent_changeset changeset;
2903 	int freed = 0;
2904 	int ret;
2905 
2906 	extent_changeset_init(&changeset);
2907 	len = round_up(start + len, root->fs_info->sectorsize);
2908 	start = round_down(start, root->fs_info->sectorsize);
2909 
2910 	ULIST_ITER_INIT(&uiter);
2911 	while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
2912 		u64 range_start = unode->val;
2913 		/* unode->aux is the inclusive end */
2914 		u64 range_len = unode->aux - range_start + 1;
2915 		u64 free_start;
2916 		u64 free_len;
2917 
2918 		extent_changeset_release(&changeset);
2919 
2920 		/* Only free range in range [start, start + len) */
2921 		if (range_start >= start + len ||
2922 		    range_start + range_len <= start)
2923 			continue;
2924 		free_start = max(range_start, start);
2925 		free_len = min(start + len, range_start + range_len) -
2926 			   free_start;
2927 		/*
2928 		 * TODO: To also modify reserved->ranges_reserved to reflect
2929 		 * the modification.
2930 		 *
2931 		 * However as long as we free qgroup reserved according to
2932 		 * EXTENT_QGROUP_RESERVED, we won't double free.
2933 		 * So not need to rush.
2934 		 */
2935 		ret = clear_record_extent_bits(&BTRFS_I(inode)->io_failure_tree,
2936 				free_start, free_start + free_len - 1,
2937 				EXTENT_QGROUP_RESERVED, &changeset);
2938 		if (ret < 0)
2939 			goto out;
2940 		freed += changeset.bytes_changed;
2941 	}
2942 	btrfs_qgroup_free_refroot(root->fs_info, root->objectid, freed);
2943 	ret = freed;
2944 out:
2945 	extent_changeset_release(&changeset);
2946 	return ret;
2947 }
2948 
2949 static int __btrfs_qgroup_release_data(struct inode *inode,
2950 			struct extent_changeset *reserved, u64 start, u64 len,
2951 			int free)
2952 {
2953 	struct extent_changeset changeset;
2954 	int trace_op = QGROUP_RELEASE;
2955 	int ret;
2956 
2957 	/* In release case, we shouldn't have @reserved */
2958 	WARN_ON(!free && reserved);
2959 	if (free && reserved)
2960 		return qgroup_free_reserved_data(inode, reserved, start, len);
2961 	extent_changeset_init(&changeset);
2962 	ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2963 			start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
2964 	if (ret < 0)
2965 		goto out;
2966 
2967 	if (free)
2968 		trace_op = QGROUP_FREE;
2969 	trace_btrfs_qgroup_release_data(inode, start, len,
2970 					changeset.bytes_changed, trace_op);
2971 	if (free)
2972 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
2973 				BTRFS_I(inode)->root->objectid,
2974 				changeset.bytes_changed);
2975 	ret = changeset.bytes_changed;
2976 out:
2977 	extent_changeset_release(&changeset);
2978 	return ret;
2979 }
2980 
2981 /*
2982  * Free a reserved space range from io_tree and related qgroups
2983  *
2984  * Should be called when a range of pages get invalidated before reaching disk.
2985  * Or for error cleanup case.
2986  * if @reserved is given, only reserved range in [@start, @start + @len) will
2987  * be freed.
2988  *
2989  * For data written to disk, use btrfs_qgroup_release_data().
2990  *
2991  * NOTE: This function may sleep for memory allocation.
2992  */
2993 int btrfs_qgroup_free_data(struct inode *inode,
2994 			struct extent_changeset *reserved, u64 start, u64 len)
2995 {
2996 	return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
2997 }
2998 
2999 /*
3000  * Release a reserved space range from io_tree only.
3001  *
3002  * Should be called when a range of pages get written to disk and corresponding
3003  * FILE_EXTENT is inserted into corresponding root.
3004  *
3005  * Since new qgroup accounting framework will only update qgroup numbers at
3006  * commit_transaction() time, its reserved space shouldn't be freed from
3007  * related qgroups.
3008  *
3009  * But we should release the range from io_tree, to allow further write to be
3010  * COWed.
3011  *
3012  * NOTE: This function may sleep for memory allocation.
3013  */
3014 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
3015 {
3016 	return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3017 }
3018 
3019 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3020 			      bool enforce)
3021 {
3022 	struct btrfs_fs_info *fs_info = root->fs_info;
3023 	int ret;
3024 
3025 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3026 	    !is_fstree(root->objectid) || num_bytes == 0)
3027 		return 0;
3028 
3029 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3030 	trace_qgroup_meta_reserve(root, (s64)num_bytes);
3031 	ret = qgroup_reserve(root, num_bytes, enforce);
3032 	if (ret < 0)
3033 		return ret;
3034 	atomic64_add(num_bytes, &root->qgroup_meta_rsv);
3035 	return ret;
3036 }
3037 
3038 void btrfs_qgroup_free_meta_all(struct btrfs_root *root)
3039 {
3040 	struct btrfs_fs_info *fs_info = root->fs_info;
3041 	u64 reserved;
3042 
3043 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3044 	    !is_fstree(root->objectid))
3045 		return;
3046 
3047 	reserved = atomic64_xchg(&root->qgroup_meta_rsv, 0);
3048 	if (reserved == 0)
3049 		return;
3050 	trace_qgroup_meta_reserve(root, -(s64)reserved);
3051 	btrfs_qgroup_free_refroot(fs_info, root->objectid, reserved);
3052 }
3053 
3054 void btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes)
3055 {
3056 	struct btrfs_fs_info *fs_info = root->fs_info;
3057 
3058 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3059 	    !is_fstree(root->objectid))
3060 		return;
3061 
3062 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3063 	WARN_ON(atomic64_read(&root->qgroup_meta_rsv) < num_bytes);
3064 	atomic64_sub(num_bytes, &root->qgroup_meta_rsv);
3065 	trace_qgroup_meta_reserve(root, -(s64)num_bytes);
3066 	btrfs_qgroup_free_refroot(fs_info, root->objectid, num_bytes);
3067 }
3068 
3069 /*
3070  * Check qgroup reserved space leaking, normally at destroy inode
3071  * time
3072  */
3073 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
3074 {
3075 	struct extent_changeset changeset;
3076 	struct ulist_node *unode;
3077 	struct ulist_iterator iter;
3078 	int ret;
3079 
3080 	extent_changeset_init(&changeset);
3081 	ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
3082 			EXTENT_QGROUP_RESERVED, &changeset);
3083 
3084 	WARN_ON(ret < 0);
3085 	if (WARN_ON(changeset.bytes_changed)) {
3086 		ULIST_ITER_INIT(&iter);
3087 		while ((unode = ulist_next(&changeset.range_changed, &iter))) {
3088 			btrfs_warn(BTRFS_I(inode)->root->fs_info,
3089 				"leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
3090 				inode->i_ino, unode->val, unode->aux);
3091 		}
3092 		btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3093 				BTRFS_I(inode)->root->objectid,
3094 				changeset.bytes_changed);
3095 
3096 	}
3097 	extent_changeset_release(&changeset);
3098 }
3099