btrfs: qgroup: Fix reserved data space leak if we have multiple reserve calls
[sfrench/cifs-2.6.git] / fs / btrfs / qgroup.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2011 STRATO.  All rights reserved.
4  */
5
6 #include <linux/sched.h>
7 #include <linux/pagemap.h>
8 #include <linux/writeback.h>
9 #include <linux/blkdev.h>
10 #include <linux/rbtree.h>
11 #include <linux/slab.h>
12 #include <linux/workqueue.h>
13 #include <linux/btrfs.h>
14 #include <linux/sizes.h>
15
16 #include "ctree.h"
17 #include "transaction.h"
18 #include "disk-io.h"
19 #include "locking.h"
20 #include "ulist.h"
21 #include "backref.h"
22 #include "extent_io.h"
23 #include "qgroup.h"
24 #include "block-group.h"
25
26 /* TODO XXX FIXME
27  *  - subvol delete -> delete when ref goes to 0? delete limits also?
28  *  - reorganize keys
29  *  - compressed
30  *  - sync
31  *  - copy also limits on subvol creation
32  *  - limit
33  *  - caches for ulists
34  *  - performance benchmarks
35  *  - check all ioctl parameters
36  */
37
38 /*
39  * Helpers to access qgroup reservation
40  *
41  * Callers should ensure the lock context and type are valid
42  */
43
44 static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
45 {
46         u64 ret = 0;
47         int i;
48
49         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
50                 ret += qgroup->rsv.values[i];
51
52         return ret;
53 }
54
55 #ifdef CONFIG_BTRFS_DEBUG
56 static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
57 {
58         if (type == BTRFS_QGROUP_RSV_DATA)
59                 return "data";
60         if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
61                 return "meta_pertrans";
62         if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
63                 return "meta_prealloc";
64         return NULL;
65 }
66 #endif
67
68 static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
69                            struct btrfs_qgroup *qgroup, u64 num_bytes,
70                            enum btrfs_qgroup_rsv_type type)
71 {
72         trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
73         qgroup->rsv.values[type] += num_bytes;
74 }
75
76 static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
77                                struct btrfs_qgroup *qgroup, u64 num_bytes,
78                                enum btrfs_qgroup_rsv_type type)
79 {
80         trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
81         if (qgroup->rsv.values[type] >= num_bytes) {
82                 qgroup->rsv.values[type] -= num_bytes;
83                 return;
84         }
85 #ifdef CONFIG_BTRFS_DEBUG
86         WARN_RATELIMIT(1,
87                 "qgroup %llu %s reserved space underflow, have %llu to free %llu",
88                 qgroup->qgroupid, qgroup_rsv_type_str(type),
89                 qgroup->rsv.values[type], num_bytes);
90 #endif
91         qgroup->rsv.values[type] = 0;
92 }
93
94 static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
95                                      struct btrfs_qgroup *dest,
96                                      struct btrfs_qgroup *src)
97 {
98         int i;
99
100         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
101                 qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
102 }
103
104 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
105                                          struct btrfs_qgroup *dest,
106                                           struct btrfs_qgroup *src)
107 {
108         int i;
109
110         for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
111                 qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
112 }
113
114 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
115                                            int mod)
116 {
117         if (qg->old_refcnt < seq)
118                 qg->old_refcnt = seq;
119         qg->old_refcnt += mod;
120 }
121
122 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
123                                            int mod)
124 {
125         if (qg->new_refcnt < seq)
126                 qg->new_refcnt = seq;
127         qg->new_refcnt += mod;
128 }
129
130 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
131 {
132         if (qg->old_refcnt < seq)
133                 return 0;
134         return qg->old_refcnt - seq;
135 }
136
137 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
138 {
139         if (qg->new_refcnt < seq)
140                 return 0;
141         return qg->new_refcnt - seq;
142 }
143
144 /*
145  * glue structure to represent the relations between qgroups.
146  */
147 struct btrfs_qgroup_list {
148         struct list_head next_group;
149         struct list_head next_member;
150         struct btrfs_qgroup *group;
151         struct btrfs_qgroup *member;
152 };
153
154 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
155 {
156         return (u64)(uintptr_t)qg;
157 }
158
159 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
160 {
161         return (struct btrfs_qgroup *)(uintptr_t)n->aux;
162 }
163
164 static int
165 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
166                    int init_flags);
167 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
168
169 /* must be called with qgroup_ioctl_lock held */
170 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
171                                            u64 qgroupid)
172 {
173         struct rb_node *n = fs_info->qgroup_tree.rb_node;
174         struct btrfs_qgroup *qgroup;
175
176         while (n) {
177                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
178                 if (qgroup->qgroupid < qgroupid)
179                         n = n->rb_left;
180                 else if (qgroup->qgroupid > qgroupid)
181                         n = n->rb_right;
182                 else
183                         return qgroup;
184         }
185         return NULL;
186 }
187
188 /* must be called with qgroup_lock held */
189 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
190                                           u64 qgroupid)
191 {
192         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
193         struct rb_node *parent = NULL;
194         struct btrfs_qgroup *qgroup;
195
196         while (*p) {
197                 parent = *p;
198                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
199
200                 if (qgroup->qgroupid < qgroupid)
201                         p = &(*p)->rb_left;
202                 else if (qgroup->qgroupid > qgroupid)
203                         p = &(*p)->rb_right;
204                 else
205                         return qgroup;
206         }
207
208         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
209         if (!qgroup)
210                 return ERR_PTR(-ENOMEM);
211
212         qgroup->qgroupid = qgroupid;
213         INIT_LIST_HEAD(&qgroup->groups);
214         INIT_LIST_HEAD(&qgroup->members);
215         INIT_LIST_HEAD(&qgroup->dirty);
216
217         rb_link_node(&qgroup->node, parent, p);
218         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
219
220         return qgroup;
221 }
222
223 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
224 {
225         struct btrfs_qgroup_list *list;
226
227         list_del(&qgroup->dirty);
228         while (!list_empty(&qgroup->groups)) {
229                 list = list_first_entry(&qgroup->groups,
230                                         struct btrfs_qgroup_list, next_group);
231                 list_del(&list->next_group);
232                 list_del(&list->next_member);
233                 kfree(list);
234         }
235
236         while (!list_empty(&qgroup->members)) {
237                 list = list_first_entry(&qgroup->members,
238                                         struct btrfs_qgroup_list, next_member);
239                 list_del(&list->next_group);
240                 list_del(&list->next_member);
241                 kfree(list);
242         }
243         kfree(qgroup);
244 }
245
246 /* must be called with qgroup_lock held */
247 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
248 {
249         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
250
251         if (!qgroup)
252                 return -ENOENT;
253
254         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
255         __del_qgroup_rb(qgroup);
256         return 0;
257 }
258
259 /* must be called with qgroup_lock held */
260 static int add_relation_rb(struct btrfs_fs_info *fs_info,
261                            u64 memberid, u64 parentid)
262 {
263         struct btrfs_qgroup *member;
264         struct btrfs_qgroup *parent;
265         struct btrfs_qgroup_list *list;
266
267         member = find_qgroup_rb(fs_info, memberid);
268         parent = find_qgroup_rb(fs_info, parentid);
269         if (!member || !parent)
270                 return -ENOENT;
271
272         list = kzalloc(sizeof(*list), GFP_ATOMIC);
273         if (!list)
274                 return -ENOMEM;
275
276         list->group = parent;
277         list->member = member;
278         list_add_tail(&list->next_group, &member->groups);
279         list_add_tail(&list->next_member, &parent->members);
280
281         return 0;
282 }
283
284 /* must be called with qgroup_lock held */
285 static int del_relation_rb(struct btrfs_fs_info *fs_info,
286                            u64 memberid, u64 parentid)
287 {
288         struct btrfs_qgroup *member;
289         struct btrfs_qgroup *parent;
290         struct btrfs_qgroup_list *list;
291
292         member = find_qgroup_rb(fs_info, memberid);
293         parent = find_qgroup_rb(fs_info, parentid);
294         if (!member || !parent)
295                 return -ENOENT;
296
297         list_for_each_entry(list, &member->groups, next_group) {
298                 if (list->group == parent) {
299                         list_del(&list->next_group);
300                         list_del(&list->next_member);
301                         kfree(list);
302                         return 0;
303                 }
304         }
305         return -ENOENT;
306 }
307
308 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
309 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
310                                u64 rfer, u64 excl)
311 {
312         struct btrfs_qgroup *qgroup;
313
314         qgroup = find_qgroup_rb(fs_info, qgroupid);
315         if (!qgroup)
316                 return -EINVAL;
317         if (qgroup->rfer != rfer || qgroup->excl != excl)
318                 return -EINVAL;
319         return 0;
320 }
321 #endif
322
323 /*
324  * The full config is read in one go, only called from open_ctree()
325  * It doesn't use any locking, as at this point we're still single-threaded
326  */
327 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
328 {
329         struct btrfs_key key;
330         struct btrfs_key found_key;
331         struct btrfs_root *quota_root = fs_info->quota_root;
332         struct btrfs_path *path = NULL;
333         struct extent_buffer *l;
334         int slot;
335         int ret = 0;
336         u64 flags = 0;
337         u64 rescan_progress = 0;
338
339         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
340                 return 0;
341
342         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
343         if (!fs_info->qgroup_ulist) {
344                 ret = -ENOMEM;
345                 goto out;
346         }
347
348         path = btrfs_alloc_path();
349         if (!path) {
350                 ret = -ENOMEM;
351                 goto out;
352         }
353
354         /* default this to quota off, in case no status key is found */
355         fs_info->qgroup_flags = 0;
356
357         /*
358          * pass 1: read status, all qgroup infos and limits
359          */
360         key.objectid = 0;
361         key.type = 0;
362         key.offset = 0;
363         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
364         if (ret)
365                 goto out;
366
367         while (1) {
368                 struct btrfs_qgroup *qgroup;
369
370                 slot = path->slots[0];
371                 l = path->nodes[0];
372                 btrfs_item_key_to_cpu(l, &found_key, slot);
373
374                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
375                         struct btrfs_qgroup_status_item *ptr;
376
377                         ptr = btrfs_item_ptr(l, slot,
378                                              struct btrfs_qgroup_status_item);
379
380                         if (btrfs_qgroup_status_version(l, ptr) !=
381                             BTRFS_QGROUP_STATUS_VERSION) {
382                                 btrfs_err(fs_info,
383                                  "old qgroup version, quota disabled");
384                                 goto out;
385                         }
386                         if (btrfs_qgroup_status_generation(l, ptr) !=
387                             fs_info->generation) {
388                                 flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
389                                 btrfs_err(fs_info,
390                                         "qgroup generation mismatch, marked as inconsistent");
391                         }
392                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
393                                                                           ptr);
394                         rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
395                         goto next1;
396                 }
397
398                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
399                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
400                         goto next1;
401
402                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
403                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
404                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
405                         btrfs_err(fs_info, "inconsistent qgroup config");
406                         flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
407                 }
408                 if (!qgroup) {
409                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
410                         if (IS_ERR(qgroup)) {
411                                 ret = PTR_ERR(qgroup);
412                                 goto out;
413                         }
414                 }
415                 switch (found_key.type) {
416                 case BTRFS_QGROUP_INFO_KEY: {
417                         struct btrfs_qgroup_info_item *ptr;
418
419                         ptr = btrfs_item_ptr(l, slot,
420                                              struct btrfs_qgroup_info_item);
421                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
422                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
423                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
424                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
425                         /* generation currently unused */
426                         break;
427                 }
428                 case BTRFS_QGROUP_LIMIT_KEY: {
429                         struct btrfs_qgroup_limit_item *ptr;
430
431                         ptr = btrfs_item_ptr(l, slot,
432                                              struct btrfs_qgroup_limit_item);
433                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
434                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
435                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
436                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
437                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
438                         break;
439                 }
440                 }
441 next1:
442                 ret = btrfs_next_item(quota_root, path);
443                 if (ret < 0)
444                         goto out;
445                 if (ret)
446                         break;
447         }
448         btrfs_release_path(path);
449
450         /*
451          * pass 2: read all qgroup relations
452          */
453         key.objectid = 0;
454         key.type = BTRFS_QGROUP_RELATION_KEY;
455         key.offset = 0;
456         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
457         if (ret)
458                 goto out;
459         while (1) {
460                 slot = path->slots[0];
461                 l = path->nodes[0];
462                 btrfs_item_key_to_cpu(l, &found_key, slot);
463
464                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
465                         goto next2;
466
467                 if (found_key.objectid > found_key.offset) {
468                         /* parent <- member, not needed to build config */
469                         /* FIXME should we omit the key completely? */
470                         goto next2;
471                 }
472
473                 ret = add_relation_rb(fs_info, found_key.objectid,
474                                       found_key.offset);
475                 if (ret == -ENOENT) {
476                         btrfs_warn(fs_info,
477                                 "orphan qgroup relation 0x%llx->0x%llx",
478                                 found_key.objectid, found_key.offset);
479                         ret = 0;        /* ignore the error */
480                 }
481                 if (ret)
482                         goto out;
483 next2:
484                 ret = btrfs_next_item(quota_root, path);
485                 if (ret < 0)
486                         goto out;
487                 if (ret)
488                         break;
489         }
490 out:
491         fs_info->qgroup_flags |= flags;
492         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
493                 clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
494         else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
495                  ret >= 0)
496                 ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
497         btrfs_free_path(path);
498
499         if (ret < 0) {
500                 ulist_free(fs_info->qgroup_ulist);
501                 fs_info->qgroup_ulist = NULL;
502                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
503         }
504
505         return ret < 0 ? ret : 0;
506 }
507
508 /*
509  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
510  * first two are in single-threaded paths.And for the third one, we have set
511  * quota_root to be null with qgroup_lock held before, so it is safe to clean
512  * up the in-memory structures without qgroup_lock held.
513  */
514 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
515 {
516         struct rb_node *n;
517         struct btrfs_qgroup *qgroup;
518
519         while ((n = rb_first(&fs_info->qgroup_tree))) {
520                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
521                 rb_erase(n, &fs_info->qgroup_tree);
522                 __del_qgroup_rb(qgroup);
523         }
524         /*
525          * We call btrfs_free_qgroup_config() when unmounting
526          * filesystem and disabling quota, so we set qgroup_ulist
527          * to be null here to avoid double free.
528          */
529         ulist_free(fs_info->qgroup_ulist);
530         fs_info->qgroup_ulist = NULL;
531 }
532
533 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
534                                     u64 dst)
535 {
536         int ret;
537         struct btrfs_root *quota_root = trans->fs_info->quota_root;
538         struct btrfs_path *path;
539         struct btrfs_key key;
540
541         path = btrfs_alloc_path();
542         if (!path)
543                 return -ENOMEM;
544
545         key.objectid = src;
546         key.type = BTRFS_QGROUP_RELATION_KEY;
547         key.offset = dst;
548
549         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
550
551         btrfs_mark_buffer_dirty(path->nodes[0]);
552
553         btrfs_free_path(path);
554         return ret;
555 }
556
557 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
558                                     u64 dst)
559 {
560         int ret;
561         struct btrfs_root *quota_root = trans->fs_info->quota_root;
562         struct btrfs_path *path;
563         struct btrfs_key key;
564
565         path = btrfs_alloc_path();
566         if (!path)
567                 return -ENOMEM;
568
569         key.objectid = src;
570         key.type = BTRFS_QGROUP_RELATION_KEY;
571         key.offset = dst;
572
573         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
574         if (ret < 0)
575                 goto out;
576
577         if (ret > 0) {
578                 ret = -ENOENT;
579                 goto out;
580         }
581
582         ret = btrfs_del_item(trans, quota_root, path);
583 out:
584         btrfs_free_path(path);
585         return ret;
586 }
587
588 static int add_qgroup_item(struct btrfs_trans_handle *trans,
589                            struct btrfs_root *quota_root, u64 qgroupid)
590 {
591         int ret;
592         struct btrfs_path *path;
593         struct btrfs_qgroup_info_item *qgroup_info;
594         struct btrfs_qgroup_limit_item *qgroup_limit;
595         struct extent_buffer *leaf;
596         struct btrfs_key key;
597
598         if (btrfs_is_testing(quota_root->fs_info))
599                 return 0;
600
601         path = btrfs_alloc_path();
602         if (!path)
603                 return -ENOMEM;
604
605         key.objectid = 0;
606         key.type = BTRFS_QGROUP_INFO_KEY;
607         key.offset = qgroupid;
608
609         /*
610          * Avoid a transaction abort by catching -EEXIST here. In that
611          * case, we proceed by re-initializing the existing structure
612          * on disk.
613          */
614
615         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
616                                       sizeof(*qgroup_info));
617         if (ret && ret != -EEXIST)
618                 goto out;
619
620         leaf = path->nodes[0];
621         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
622                                  struct btrfs_qgroup_info_item);
623         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
624         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
625         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
626         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
627         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
628
629         btrfs_mark_buffer_dirty(leaf);
630
631         btrfs_release_path(path);
632
633         key.type = BTRFS_QGROUP_LIMIT_KEY;
634         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
635                                       sizeof(*qgroup_limit));
636         if (ret && ret != -EEXIST)
637                 goto out;
638
639         leaf = path->nodes[0];
640         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
641                                   struct btrfs_qgroup_limit_item);
642         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
643         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
644         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
645         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
646         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
647
648         btrfs_mark_buffer_dirty(leaf);
649
650         ret = 0;
651 out:
652         btrfs_free_path(path);
653         return ret;
654 }
655
656 static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
657 {
658         int ret;
659         struct btrfs_root *quota_root = trans->fs_info->quota_root;
660         struct btrfs_path *path;
661         struct btrfs_key key;
662
663         path = btrfs_alloc_path();
664         if (!path)
665                 return -ENOMEM;
666
667         key.objectid = 0;
668         key.type = BTRFS_QGROUP_INFO_KEY;
669         key.offset = qgroupid;
670         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
671         if (ret < 0)
672                 goto out;
673
674         if (ret > 0) {
675                 ret = -ENOENT;
676                 goto out;
677         }
678
679         ret = btrfs_del_item(trans, quota_root, path);
680         if (ret)
681                 goto out;
682
683         btrfs_release_path(path);
684
685         key.type = BTRFS_QGROUP_LIMIT_KEY;
686         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
687         if (ret < 0)
688                 goto out;
689
690         if (ret > 0) {
691                 ret = -ENOENT;
692                 goto out;
693         }
694
695         ret = btrfs_del_item(trans, quota_root, path);
696
697 out:
698         btrfs_free_path(path);
699         return ret;
700 }
701
702 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
703                                     struct btrfs_qgroup *qgroup)
704 {
705         struct btrfs_root *quota_root = trans->fs_info->quota_root;
706         struct btrfs_path *path;
707         struct btrfs_key key;
708         struct extent_buffer *l;
709         struct btrfs_qgroup_limit_item *qgroup_limit;
710         int ret;
711         int slot;
712
713         key.objectid = 0;
714         key.type = BTRFS_QGROUP_LIMIT_KEY;
715         key.offset = qgroup->qgroupid;
716
717         path = btrfs_alloc_path();
718         if (!path)
719                 return -ENOMEM;
720
721         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
722         if (ret > 0)
723                 ret = -ENOENT;
724
725         if (ret)
726                 goto out;
727
728         l = path->nodes[0];
729         slot = path->slots[0];
730         qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
731         btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
732         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
733         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
734         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
735         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
736
737         btrfs_mark_buffer_dirty(l);
738
739 out:
740         btrfs_free_path(path);
741         return ret;
742 }
743
744 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
745                                    struct btrfs_qgroup *qgroup)
746 {
747         struct btrfs_fs_info *fs_info = trans->fs_info;
748         struct btrfs_root *quota_root = fs_info->quota_root;
749         struct btrfs_path *path;
750         struct btrfs_key key;
751         struct extent_buffer *l;
752         struct btrfs_qgroup_info_item *qgroup_info;
753         int ret;
754         int slot;
755
756         if (btrfs_is_testing(fs_info))
757                 return 0;
758
759         key.objectid = 0;
760         key.type = BTRFS_QGROUP_INFO_KEY;
761         key.offset = qgroup->qgroupid;
762
763         path = btrfs_alloc_path();
764         if (!path)
765                 return -ENOMEM;
766
767         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
768         if (ret > 0)
769                 ret = -ENOENT;
770
771         if (ret)
772                 goto out;
773
774         l = path->nodes[0];
775         slot = path->slots[0];
776         qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
777         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
778         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
779         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
780         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
781         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
782
783         btrfs_mark_buffer_dirty(l);
784
785 out:
786         btrfs_free_path(path);
787         return ret;
788 }
789
790 static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
791 {
792         struct btrfs_fs_info *fs_info = trans->fs_info;
793         struct btrfs_root *quota_root = fs_info->quota_root;
794         struct btrfs_path *path;
795         struct btrfs_key key;
796         struct extent_buffer *l;
797         struct btrfs_qgroup_status_item *ptr;
798         int ret;
799         int slot;
800
801         key.objectid = 0;
802         key.type = BTRFS_QGROUP_STATUS_KEY;
803         key.offset = 0;
804
805         path = btrfs_alloc_path();
806         if (!path)
807                 return -ENOMEM;
808
809         ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
810         if (ret > 0)
811                 ret = -ENOENT;
812
813         if (ret)
814                 goto out;
815
816         l = path->nodes[0];
817         slot = path->slots[0];
818         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
819         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
820         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
821         btrfs_set_qgroup_status_rescan(l, ptr,
822                                 fs_info->qgroup_rescan_progress.objectid);
823
824         btrfs_mark_buffer_dirty(l);
825
826 out:
827         btrfs_free_path(path);
828         return ret;
829 }
830
831 /*
832  * called with qgroup_lock held
833  */
834 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
835                                   struct btrfs_root *root)
836 {
837         struct btrfs_path *path;
838         struct btrfs_key key;
839         struct extent_buffer *leaf = NULL;
840         int ret;
841         int nr = 0;
842
843         path = btrfs_alloc_path();
844         if (!path)
845                 return -ENOMEM;
846
847         path->leave_spinning = 1;
848
849         key.objectid = 0;
850         key.offset = 0;
851         key.type = 0;
852
853         while (1) {
854                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
855                 if (ret < 0)
856                         goto out;
857                 leaf = path->nodes[0];
858                 nr = btrfs_header_nritems(leaf);
859                 if (!nr)
860                         break;
861                 /*
862                  * delete the leaf one by one
863                  * since the whole tree is going
864                  * to be deleted.
865                  */
866                 path->slots[0] = 0;
867                 ret = btrfs_del_items(trans, root, path, 0, nr);
868                 if (ret)
869                         goto out;
870
871                 btrfs_release_path(path);
872         }
873         ret = 0;
874 out:
875         btrfs_free_path(path);
876         return ret;
877 }
878
879 int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
880 {
881         struct btrfs_root *quota_root;
882         struct btrfs_root *tree_root = fs_info->tree_root;
883         struct btrfs_path *path = NULL;
884         struct btrfs_qgroup_status_item *ptr;
885         struct extent_buffer *leaf;
886         struct btrfs_key key;
887         struct btrfs_key found_key;
888         struct btrfs_qgroup *qgroup = NULL;
889         struct btrfs_trans_handle *trans = NULL;
890         int ret = 0;
891         int slot;
892
893         mutex_lock(&fs_info->qgroup_ioctl_lock);
894         if (fs_info->quota_root)
895                 goto out;
896
897         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
898         if (!fs_info->qgroup_ulist) {
899                 ret = -ENOMEM;
900                 goto out;
901         }
902
903         /*
904          * 1 for quota root item
905          * 1 for BTRFS_QGROUP_STATUS item
906          *
907          * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
908          * per subvolume. However those are not currently reserved since it
909          * would be a lot of overkill.
910          */
911         trans = btrfs_start_transaction(tree_root, 2);
912         if (IS_ERR(trans)) {
913                 ret = PTR_ERR(trans);
914                 trans = NULL;
915                 goto out;
916         }
917
918         /*
919          * initially create the quota tree
920          */
921         quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
922         if (IS_ERR(quota_root)) {
923                 ret =  PTR_ERR(quota_root);
924                 btrfs_abort_transaction(trans, ret);
925                 goto out;
926         }
927
928         path = btrfs_alloc_path();
929         if (!path) {
930                 ret = -ENOMEM;
931                 btrfs_abort_transaction(trans, ret);
932                 goto out_free_root;
933         }
934
935         key.objectid = 0;
936         key.type = BTRFS_QGROUP_STATUS_KEY;
937         key.offset = 0;
938
939         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
940                                       sizeof(*ptr));
941         if (ret) {
942                 btrfs_abort_transaction(trans, ret);
943                 goto out_free_path;
944         }
945
946         leaf = path->nodes[0];
947         ptr = btrfs_item_ptr(leaf, path->slots[0],
948                                  struct btrfs_qgroup_status_item);
949         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
950         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
951         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
952                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
953         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
954         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
955
956         btrfs_mark_buffer_dirty(leaf);
957
958         key.objectid = 0;
959         key.type = BTRFS_ROOT_REF_KEY;
960         key.offset = 0;
961
962         btrfs_release_path(path);
963         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
964         if (ret > 0)
965                 goto out_add_root;
966         if (ret < 0) {
967                 btrfs_abort_transaction(trans, ret);
968                 goto out_free_path;
969         }
970
971         while (1) {
972                 slot = path->slots[0];
973                 leaf = path->nodes[0];
974                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
975
976                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
977                         ret = add_qgroup_item(trans, quota_root,
978                                               found_key.offset);
979                         if (ret) {
980                                 btrfs_abort_transaction(trans, ret);
981                                 goto out_free_path;
982                         }
983
984                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
985                         if (IS_ERR(qgroup)) {
986                                 ret = PTR_ERR(qgroup);
987                                 btrfs_abort_transaction(trans, ret);
988                                 goto out_free_path;
989                         }
990                 }
991                 ret = btrfs_next_item(tree_root, path);
992                 if (ret < 0) {
993                         btrfs_abort_transaction(trans, ret);
994                         goto out_free_path;
995                 }
996                 if (ret)
997                         break;
998         }
999
1000 out_add_root:
1001         btrfs_release_path(path);
1002         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1003         if (ret) {
1004                 btrfs_abort_transaction(trans, ret);
1005                 goto out_free_path;
1006         }
1007
1008         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1009         if (IS_ERR(qgroup)) {
1010                 ret = PTR_ERR(qgroup);
1011                 btrfs_abort_transaction(trans, ret);
1012                 goto out_free_path;
1013         }
1014
1015         ret = btrfs_commit_transaction(trans);
1016         trans = NULL;
1017         if (ret)
1018                 goto out_free_path;
1019
1020         /*
1021          * Set quota enabled flag after committing the transaction, to avoid
1022          * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
1023          * creation.
1024          */
1025         spin_lock(&fs_info->qgroup_lock);
1026         fs_info->quota_root = quota_root;
1027         set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1028         spin_unlock(&fs_info->qgroup_lock);
1029
1030         ret = qgroup_rescan_init(fs_info, 0, 1);
1031         if (!ret) {
1032                 qgroup_rescan_zero_tracking(fs_info);
1033                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
1034                                  &fs_info->qgroup_rescan_work);
1035         }
1036
1037 out_free_path:
1038         btrfs_free_path(path);
1039 out_free_root:
1040         if (ret) {
1041                 free_extent_buffer(quota_root->node);
1042                 free_extent_buffer(quota_root->commit_root);
1043                 kfree(quota_root);
1044         }
1045 out:
1046         if (ret) {
1047                 ulist_free(fs_info->qgroup_ulist);
1048                 fs_info->qgroup_ulist = NULL;
1049                 if (trans)
1050                         btrfs_end_transaction(trans);
1051         }
1052         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1053         return ret;
1054 }
1055
1056 int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1057 {
1058         struct btrfs_root *quota_root;
1059         struct btrfs_trans_handle *trans = NULL;
1060         int ret = 0;
1061
1062         mutex_lock(&fs_info->qgroup_ioctl_lock);
1063         if (!fs_info->quota_root)
1064                 goto out;
1065
1066         /*
1067          * 1 For the root item
1068          *
1069          * We should also reserve enough items for the quota tree deletion in
1070          * btrfs_clean_quota_tree but this is not done.
1071          */
1072         trans = btrfs_start_transaction(fs_info->tree_root, 1);
1073         if (IS_ERR(trans)) {
1074                 ret = PTR_ERR(trans);
1075                 goto out;
1076         }
1077
1078         clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1079         btrfs_qgroup_wait_for_completion(fs_info, false);
1080         spin_lock(&fs_info->qgroup_lock);
1081         quota_root = fs_info->quota_root;
1082         fs_info->quota_root = NULL;
1083         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1084         spin_unlock(&fs_info->qgroup_lock);
1085
1086         btrfs_free_qgroup_config(fs_info);
1087
1088         ret = btrfs_clean_quota_tree(trans, quota_root);
1089         if (ret) {
1090                 btrfs_abort_transaction(trans, ret);
1091                 goto end_trans;
1092         }
1093
1094         ret = btrfs_del_root(trans, &quota_root->root_key);
1095         if (ret) {
1096                 btrfs_abort_transaction(trans, ret);
1097                 goto end_trans;
1098         }
1099
1100         list_del(&quota_root->dirty_list);
1101
1102         btrfs_tree_lock(quota_root->node);
1103         btrfs_clean_tree_block(quota_root->node);
1104         btrfs_tree_unlock(quota_root->node);
1105         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
1106
1107         free_extent_buffer(quota_root->node);
1108         free_extent_buffer(quota_root->commit_root);
1109         kfree(quota_root);
1110
1111 end_trans:
1112         ret = btrfs_end_transaction(trans);
1113 out:
1114         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1115         return ret;
1116 }
1117
1118 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1119                          struct btrfs_qgroup *qgroup)
1120 {
1121         if (list_empty(&qgroup->dirty))
1122                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1123 }
1124
1125 /*
1126  * The easy accounting, we're updating qgroup relationship whose child qgroup
1127  * only has exclusive extents.
1128  *
1129  * In this case, all exclusive extents will also be exclusive for parent, so
1130  * excl/rfer just get added/removed.
1131  *
1132  * So is qgroup reservation space, which should also be added/removed to
1133  * parent.
1134  * Or when child tries to release reservation space, parent will underflow its
1135  * reservation (for relationship adding case).
1136  *
1137  * Caller should hold fs_info->qgroup_lock.
1138  */
1139 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1140                                     struct ulist *tmp, u64 ref_root,
1141                                     struct btrfs_qgroup *src, int sign)
1142 {
1143         struct btrfs_qgroup *qgroup;
1144         struct btrfs_qgroup_list *glist;
1145         struct ulist_node *unode;
1146         struct ulist_iterator uiter;
1147         u64 num_bytes = src->excl;
1148         int ret = 0;
1149
1150         qgroup = find_qgroup_rb(fs_info, ref_root);
1151         if (!qgroup)
1152                 goto out;
1153
1154         qgroup->rfer += sign * num_bytes;
1155         qgroup->rfer_cmpr += sign * num_bytes;
1156
1157         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1158         qgroup->excl += sign * num_bytes;
1159         qgroup->excl_cmpr += sign * num_bytes;
1160
1161         if (sign > 0)
1162                 qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1163         else
1164                 qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1165
1166         qgroup_dirty(fs_info, qgroup);
1167
1168         /* Get all of the parent groups that contain this qgroup */
1169         list_for_each_entry(glist, &qgroup->groups, next_group) {
1170                 ret = ulist_add(tmp, glist->group->qgroupid,
1171                                 qgroup_to_aux(glist->group), GFP_ATOMIC);
1172                 if (ret < 0)
1173                         goto out;
1174         }
1175
1176         /* Iterate all of the parents and adjust their reference counts */
1177         ULIST_ITER_INIT(&uiter);
1178         while ((unode = ulist_next(tmp, &uiter))) {
1179                 qgroup = unode_aux_to_qgroup(unode);
1180                 qgroup->rfer += sign * num_bytes;
1181                 qgroup->rfer_cmpr += sign * num_bytes;
1182                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1183                 qgroup->excl += sign * num_bytes;
1184                 if (sign > 0)
1185                         qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1186                 else
1187                         qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1188                 qgroup->excl_cmpr += sign * num_bytes;
1189                 qgroup_dirty(fs_info, qgroup);
1190
1191                 /* Add any parents of the parents */
1192                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1193                         ret = ulist_add(tmp, glist->group->qgroupid,
1194                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
1195                         if (ret < 0)
1196                                 goto out;
1197                 }
1198         }
1199         ret = 0;
1200 out:
1201         return ret;
1202 }
1203
1204
1205 /*
1206  * Quick path for updating qgroup with only excl refs.
1207  *
1208  * In that case, just update all parent will be enough.
1209  * Or we needs to do a full rescan.
1210  * Caller should also hold fs_info->qgroup_lock.
1211  *
1212  * Return 0 for quick update, return >0 for need to full rescan
1213  * and mark INCONSISTENT flag.
1214  * Return < 0 for other error.
1215  */
1216 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1217                                    struct ulist *tmp, u64 src, u64 dst,
1218                                    int sign)
1219 {
1220         struct btrfs_qgroup *qgroup;
1221         int ret = 1;
1222         int err = 0;
1223
1224         qgroup = find_qgroup_rb(fs_info, src);
1225         if (!qgroup)
1226                 goto out;
1227         if (qgroup->excl == qgroup->rfer) {
1228                 ret = 0;
1229                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1230                                                qgroup, sign);
1231                 if (err < 0) {
1232                         ret = err;
1233                         goto out;
1234                 }
1235         }
1236 out:
1237         if (ret)
1238                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1239         return ret;
1240 }
1241
1242 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1243                               u64 dst)
1244 {
1245         struct btrfs_fs_info *fs_info = trans->fs_info;
1246         struct btrfs_root *quota_root;
1247         struct btrfs_qgroup *parent;
1248         struct btrfs_qgroup *member;
1249         struct btrfs_qgroup_list *list;
1250         struct ulist *tmp;
1251         int ret = 0;
1252
1253         /* Check the level of src and dst first */
1254         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1255                 return -EINVAL;
1256
1257         tmp = ulist_alloc(GFP_KERNEL);
1258         if (!tmp)
1259                 return -ENOMEM;
1260
1261         mutex_lock(&fs_info->qgroup_ioctl_lock);
1262         quota_root = fs_info->quota_root;
1263         if (!quota_root) {
1264                 ret = -EINVAL;
1265                 goto out;
1266         }
1267         member = find_qgroup_rb(fs_info, src);
1268         parent = find_qgroup_rb(fs_info, dst);
1269         if (!member || !parent) {
1270                 ret = -EINVAL;
1271                 goto out;
1272         }
1273
1274         /* check if such qgroup relation exist firstly */
1275         list_for_each_entry(list, &member->groups, next_group) {
1276                 if (list->group == parent) {
1277                         ret = -EEXIST;
1278                         goto out;
1279                 }
1280         }
1281
1282         ret = add_qgroup_relation_item(trans, src, dst);
1283         if (ret)
1284                 goto out;
1285
1286         ret = add_qgroup_relation_item(trans, dst, src);
1287         if (ret) {
1288                 del_qgroup_relation_item(trans, src, dst);
1289                 goto out;
1290         }
1291
1292         spin_lock(&fs_info->qgroup_lock);
1293         ret = add_relation_rb(fs_info, src, dst);
1294         if (ret < 0) {
1295                 spin_unlock(&fs_info->qgroup_lock);
1296                 goto out;
1297         }
1298         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1299         spin_unlock(&fs_info->qgroup_lock);
1300 out:
1301         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1302         ulist_free(tmp);
1303         return ret;
1304 }
1305
1306 static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1307                                  u64 dst)
1308 {
1309         struct btrfs_fs_info *fs_info = trans->fs_info;
1310         struct btrfs_root *quota_root;
1311         struct btrfs_qgroup *parent;
1312         struct btrfs_qgroup *member;
1313         struct btrfs_qgroup_list *list;
1314         struct ulist *tmp;
1315         bool found = false;
1316         int ret = 0;
1317         int ret2;
1318
1319         tmp = ulist_alloc(GFP_KERNEL);
1320         if (!tmp)
1321                 return -ENOMEM;
1322
1323         quota_root = fs_info->quota_root;
1324         if (!quota_root) {
1325                 ret = -EINVAL;
1326                 goto out;
1327         }
1328
1329         member = find_qgroup_rb(fs_info, src);
1330         parent = find_qgroup_rb(fs_info, dst);
1331         /*
1332          * The parent/member pair doesn't exist, then try to delete the dead
1333          * relation items only.
1334          */
1335         if (!member || !parent)
1336                 goto delete_item;
1337
1338         /* check if such qgroup relation exist firstly */
1339         list_for_each_entry(list, &member->groups, next_group) {
1340                 if (list->group == parent) {
1341                         found = true;
1342                         break;
1343                 }
1344         }
1345
1346 delete_item:
1347         ret = del_qgroup_relation_item(trans, src, dst);
1348         if (ret < 0 && ret != -ENOENT)
1349                 goto out;
1350         ret2 = del_qgroup_relation_item(trans, dst, src);
1351         if (ret2 < 0 && ret2 != -ENOENT)
1352                 goto out;
1353
1354         /* At least one deletion succeeded, return 0 */
1355         if (!ret || !ret2)
1356                 ret = 0;
1357
1358         if (found) {
1359                 spin_lock(&fs_info->qgroup_lock);
1360                 del_relation_rb(fs_info, src, dst);
1361                 ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1362                 spin_unlock(&fs_info->qgroup_lock);
1363         }
1364 out:
1365         ulist_free(tmp);
1366         return ret;
1367 }
1368
1369 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1370                               u64 dst)
1371 {
1372         struct btrfs_fs_info *fs_info = trans->fs_info;
1373         int ret = 0;
1374
1375         mutex_lock(&fs_info->qgroup_ioctl_lock);
1376         ret = __del_qgroup_relation(trans, src, dst);
1377         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1378
1379         return ret;
1380 }
1381
1382 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1383 {
1384         struct btrfs_fs_info *fs_info = trans->fs_info;
1385         struct btrfs_root *quota_root;
1386         struct btrfs_qgroup *qgroup;
1387         int ret = 0;
1388
1389         mutex_lock(&fs_info->qgroup_ioctl_lock);
1390         quota_root = fs_info->quota_root;
1391         if (!quota_root) {
1392                 ret = -EINVAL;
1393                 goto out;
1394         }
1395         qgroup = find_qgroup_rb(fs_info, qgroupid);
1396         if (qgroup) {
1397                 ret = -EEXIST;
1398                 goto out;
1399         }
1400
1401         ret = add_qgroup_item(trans, quota_root, qgroupid);
1402         if (ret)
1403                 goto out;
1404
1405         spin_lock(&fs_info->qgroup_lock);
1406         qgroup = add_qgroup_rb(fs_info, qgroupid);
1407         spin_unlock(&fs_info->qgroup_lock);
1408
1409         if (IS_ERR(qgroup))
1410                 ret = PTR_ERR(qgroup);
1411 out:
1412         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1413         return ret;
1414 }
1415
1416 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1417 {
1418         struct btrfs_fs_info *fs_info = trans->fs_info;
1419         struct btrfs_root *quota_root;
1420         struct btrfs_qgroup *qgroup;
1421         struct btrfs_qgroup_list *list;
1422         int ret = 0;
1423
1424         mutex_lock(&fs_info->qgroup_ioctl_lock);
1425         quota_root = fs_info->quota_root;
1426         if (!quota_root) {
1427                 ret = -EINVAL;
1428                 goto out;
1429         }
1430
1431         qgroup = find_qgroup_rb(fs_info, qgroupid);
1432         if (!qgroup) {
1433                 ret = -ENOENT;
1434                 goto out;
1435         }
1436
1437         /* Check if there are no children of this qgroup */
1438         if (!list_empty(&qgroup->members)) {
1439                 ret = -EBUSY;
1440                 goto out;
1441         }
1442
1443         ret = del_qgroup_item(trans, qgroupid);
1444         if (ret && ret != -ENOENT)
1445                 goto out;
1446
1447         while (!list_empty(&qgroup->groups)) {
1448                 list = list_first_entry(&qgroup->groups,
1449                                         struct btrfs_qgroup_list, next_group);
1450                 ret = __del_qgroup_relation(trans, qgroupid,
1451                                             list->group->qgroupid);
1452                 if (ret)
1453                         goto out;
1454         }
1455
1456         spin_lock(&fs_info->qgroup_lock);
1457         del_qgroup_rb(fs_info, qgroupid);
1458         spin_unlock(&fs_info->qgroup_lock);
1459 out:
1460         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1461         return ret;
1462 }
1463
1464 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1465                        struct btrfs_qgroup_limit *limit)
1466 {
1467         struct btrfs_fs_info *fs_info = trans->fs_info;
1468         struct btrfs_root *quota_root;
1469         struct btrfs_qgroup *qgroup;
1470         int ret = 0;
1471         /* Sometimes we would want to clear the limit on this qgroup.
1472          * To meet this requirement, we treat the -1 as a special value
1473          * which tell kernel to clear the limit on this qgroup.
1474          */
1475         const u64 CLEAR_VALUE = -1;
1476
1477         mutex_lock(&fs_info->qgroup_ioctl_lock);
1478         quota_root = fs_info->quota_root;
1479         if (!quota_root) {
1480                 ret = -EINVAL;
1481                 goto out;
1482         }
1483
1484         qgroup = find_qgroup_rb(fs_info, qgroupid);
1485         if (!qgroup) {
1486                 ret = -ENOENT;
1487                 goto out;
1488         }
1489
1490         spin_lock(&fs_info->qgroup_lock);
1491         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1492                 if (limit->max_rfer == CLEAR_VALUE) {
1493                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1494                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1495                         qgroup->max_rfer = 0;
1496                 } else {
1497                         qgroup->max_rfer = limit->max_rfer;
1498                 }
1499         }
1500         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1501                 if (limit->max_excl == CLEAR_VALUE) {
1502                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1503                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1504                         qgroup->max_excl = 0;
1505                 } else {
1506                         qgroup->max_excl = limit->max_excl;
1507                 }
1508         }
1509         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1510                 if (limit->rsv_rfer == CLEAR_VALUE) {
1511                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1512                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1513                         qgroup->rsv_rfer = 0;
1514                 } else {
1515                         qgroup->rsv_rfer = limit->rsv_rfer;
1516                 }
1517         }
1518         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1519                 if (limit->rsv_excl == CLEAR_VALUE) {
1520                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1521                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1522                         qgroup->rsv_excl = 0;
1523                 } else {
1524                         qgroup->rsv_excl = limit->rsv_excl;
1525                 }
1526         }
1527         qgroup->lim_flags |= limit->flags;
1528
1529         spin_unlock(&fs_info->qgroup_lock);
1530
1531         ret = update_qgroup_limit_item(trans, qgroup);
1532         if (ret) {
1533                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1534                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1535                        qgroupid);
1536         }
1537
1538 out:
1539         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1540         return ret;
1541 }
1542
1543 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1544                                 struct btrfs_delayed_ref_root *delayed_refs,
1545                                 struct btrfs_qgroup_extent_record *record)
1546 {
1547         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1548         struct rb_node *parent_node = NULL;
1549         struct btrfs_qgroup_extent_record *entry;
1550         u64 bytenr = record->bytenr;
1551
1552         lockdep_assert_held(&delayed_refs->lock);
1553         trace_btrfs_qgroup_trace_extent(fs_info, record);
1554
1555         while (*p) {
1556                 parent_node = *p;
1557                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1558                                  node);
1559                 if (bytenr < entry->bytenr) {
1560                         p = &(*p)->rb_left;
1561                 } else if (bytenr > entry->bytenr) {
1562                         p = &(*p)->rb_right;
1563                 } else {
1564                         if (record->data_rsv && !entry->data_rsv) {
1565                                 entry->data_rsv = record->data_rsv;
1566                                 entry->data_rsv_refroot =
1567                                         record->data_rsv_refroot;
1568                         }
1569                         return 1;
1570                 }
1571         }
1572
1573         rb_link_node(&record->node, parent_node, p);
1574         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1575         return 0;
1576 }
1577
1578 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1579                                    struct btrfs_qgroup_extent_record *qrecord)
1580 {
1581         struct ulist *old_root;
1582         u64 bytenr = qrecord->bytenr;
1583         int ret;
1584
1585         ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
1586         if (ret < 0) {
1587                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1588                 btrfs_warn(fs_info,
1589 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1590                         ret);
1591                 return 0;
1592         }
1593
1594         /*
1595          * Here we don't need to get the lock of
1596          * trans->transaction->delayed_refs, since inserted qrecord won't
1597          * be deleted, only qrecord->node may be modified (new qrecord insert)
1598          *
1599          * So modifying qrecord->old_roots is safe here
1600          */
1601         qrecord->old_roots = old_root;
1602         return 0;
1603 }
1604
1605 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1606                               u64 num_bytes, gfp_t gfp_flag)
1607 {
1608         struct btrfs_fs_info *fs_info = trans->fs_info;
1609         struct btrfs_qgroup_extent_record *record;
1610         struct btrfs_delayed_ref_root *delayed_refs;
1611         int ret;
1612
1613         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1614             || bytenr == 0 || num_bytes == 0)
1615                 return 0;
1616         record = kzalloc(sizeof(*record), gfp_flag);
1617         if (!record)
1618                 return -ENOMEM;
1619
1620         delayed_refs = &trans->transaction->delayed_refs;
1621         record->bytenr = bytenr;
1622         record->num_bytes = num_bytes;
1623         record->old_roots = NULL;
1624
1625         spin_lock(&delayed_refs->lock);
1626         ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1627         spin_unlock(&delayed_refs->lock);
1628         if (ret > 0) {
1629                 kfree(record);
1630                 return 0;
1631         }
1632         return btrfs_qgroup_trace_extent_post(fs_info, record);
1633 }
1634
1635 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1636                                   struct extent_buffer *eb)
1637 {
1638         struct btrfs_fs_info *fs_info = trans->fs_info;
1639         int nr = btrfs_header_nritems(eb);
1640         int i, extent_type, ret;
1641         struct btrfs_key key;
1642         struct btrfs_file_extent_item *fi;
1643         u64 bytenr, num_bytes;
1644
1645         /* We can be called directly from walk_up_proc() */
1646         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1647                 return 0;
1648
1649         for (i = 0; i < nr; i++) {
1650                 btrfs_item_key_to_cpu(eb, &key, i);
1651
1652                 if (key.type != BTRFS_EXTENT_DATA_KEY)
1653                         continue;
1654
1655                 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1656                 /* filter out non qgroup-accountable extents  */
1657                 extent_type = btrfs_file_extent_type(eb, fi);
1658
1659                 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1660                         continue;
1661
1662                 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1663                 if (!bytenr)
1664                         continue;
1665
1666                 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1667
1668                 ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes,
1669                                                 GFP_NOFS);
1670                 if (ret)
1671                         return ret;
1672         }
1673         cond_resched();
1674         return 0;
1675 }
1676
1677 /*
1678  * Walk up the tree from the bottom, freeing leaves and any interior
1679  * nodes which have had all slots visited. If a node (leaf or
1680  * interior) is freed, the node above it will have it's slot
1681  * incremented. The root node will never be freed.
1682  *
1683  * At the end of this function, we should have a path which has all
1684  * slots incremented to the next position for a search. If we need to
1685  * read a new node it will be NULL and the node above it will have the
1686  * correct slot selected for a later read.
1687  *
1688  * If we increment the root nodes slot counter past the number of
1689  * elements, 1 is returned to signal completion of the search.
1690  */
1691 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1692 {
1693         int level = 0;
1694         int nr, slot;
1695         struct extent_buffer *eb;
1696
1697         if (root_level == 0)
1698                 return 1;
1699
1700         while (level <= root_level) {
1701                 eb = path->nodes[level];
1702                 nr = btrfs_header_nritems(eb);
1703                 path->slots[level]++;
1704                 slot = path->slots[level];
1705                 if (slot >= nr || level == 0) {
1706                         /*
1707                          * Don't free the root -  we will detect this
1708                          * condition after our loop and return a
1709                          * positive value for caller to stop walking the tree.
1710                          */
1711                         if (level != root_level) {
1712                                 btrfs_tree_unlock_rw(eb, path->locks[level]);
1713                                 path->locks[level] = 0;
1714
1715                                 free_extent_buffer(eb);
1716                                 path->nodes[level] = NULL;
1717                                 path->slots[level] = 0;
1718                         }
1719                 } else {
1720                         /*
1721                          * We have a valid slot to walk back down
1722                          * from. Stop here so caller can process these
1723                          * new nodes.
1724                          */
1725                         break;
1726                 }
1727
1728                 level++;
1729         }
1730
1731         eb = path->nodes[root_level];
1732         if (path->slots[root_level] >= btrfs_header_nritems(eb))
1733                 return 1;
1734
1735         return 0;
1736 }
1737
1738 /*
1739  * Helper function to trace a subtree tree block swap.
1740  *
1741  * The swap will happen in highest tree block, but there may be a lot of
1742  * tree blocks involved.
1743  *
1744  * For example:
1745  *  OO = Old tree blocks
1746  *  NN = New tree blocks allocated during balance
1747  *
1748  *           File tree (257)                  Reloc tree for 257
1749  * L2              OO                                NN
1750  *               /    \                            /    \
1751  * L1          OO      OO (a)                    OO      NN (a)
1752  *            / \     / \                       / \     / \
1753  * L0       OO   OO OO   OO                   OO   OO NN   NN
1754  *                  (b)  (c)                          (b)  (c)
1755  *
1756  * When calling qgroup_trace_extent_swap(), we will pass:
1757  * @src_eb = OO(a)
1758  * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
1759  * @dst_level = 0
1760  * @root_level = 1
1761  *
1762  * In that case, qgroup_trace_extent_swap() will search from OO(a) to
1763  * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
1764  *
1765  * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
1766  *
1767  * 1) Tree search from @src_eb
1768  *    It should acts as a simplified btrfs_search_slot().
1769  *    The key for search can be extracted from @dst_path->nodes[dst_level]
1770  *    (first key).
1771  *
1772  * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
1773  *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
1774  *    They should be marked during previous (@dst_level = 1) iteration.
1775  *
1776  * 3) Mark file extents in leaves dirty
1777  *    We don't have good way to pick out new file extents only.
1778  *    So we still follow the old method by scanning all file extents in
1779  *    the leave.
1780  *
1781  * This function can free us from keeping two paths, thus later we only need
1782  * to care about how to iterate all new tree blocks in reloc tree.
1783  */
1784 static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
1785                                     struct extent_buffer *src_eb,
1786                                     struct btrfs_path *dst_path,
1787                                     int dst_level, int root_level,
1788                                     bool trace_leaf)
1789 {
1790         struct btrfs_key key;
1791         struct btrfs_path *src_path;
1792         struct btrfs_fs_info *fs_info = trans->fs_info;
1793         u32 nodesize = fs_info->nodesize;
1794         int cur_level = root_level;
1795         int ret;
1796
1797         BUG_ON(dst_level > root_level);
1798         /* Level mismatch */
1799         if (btrfs_header_level(src_eb) != root_level)
1800                 return -EINVAL;
1801
1802         src_path = btrfs_alloc_path();
1803         if (!src_path) {
1804                 ret = -ENOMEM;
1805                 goto out;
1806         }
1807
1808         if (dst_level)
1809                 btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1810         else
1811                 btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
1812
1813         /* For src_path */
1814         extent_buffer_get(src_eb);
1815         src_path->nodes[root_level] = src_eb;
1816         src_path->slots[root_level] = dst_path->slots[root_level];
1817         src_path->locks[root_level] = 0;
1818
1819         /* A simplified version of btrfs_search_slot() */
1820         while (cur_level >= dst_level) {
1821                 struct btrfs_key src_key;
1822                 struct btrfs_key dst_key;
1823
1824                 if (src_path->nodes[cur_level] == NULL) {
1825                         struct btrfs_key first_key;
1826                         struct extent_buffer *eb;
1827                         int parent_slot;
1828                         u64 child_gen;
1829                         u64 child_bytenr;
1830
1831                         eb = src_path->nodes[cur_level + 1];
1832                         parent_slot = src_path->slots[cur_level + 1];
1833                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1834                         child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1835                         btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
1836
1837                         eb = read_tree_block(fs_info, child_bytenr, child_gen,
1838                                              cur_level, &first_key);
1839                         if (IS_ERR(eb)) {
1840                                 ret = PTR_ERR(eb);
1841                                 goto out;
1842                         } else if (!extent_buffer_uptodate(eb)) {
1843                                 free_extent_buffer(eb);
1844                                 ret = -EIO;
1845                                 goto out;
1846                         }
1847
1848                         src_path->nodes[cur_level] = eb;
1849
1850                         btrfs_tree_read_lock(eb);
1851                         btrfs_set_lock_blocking_read(eb);
1852                         src_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
1853                 }
1854
1855                 src_path->slots[cur_level] = dst_path->slots[cur_level];
1856                 if (cur_level) {
1857                         btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
1858                                         &dst_key, dst_path->slots[cur_level]);
1859                         btrfs_node_key_to_cpu(src_path->nodes[cur_level],
1860                                         &src_key, src_path->slots[cur_level]);
1861                 } else {
1862                         btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
1863                                         &dst_key, dst_path->slots[cur_level]);
1864                         btrfs_item_key_to_cpu(src_path->nodes[cur_level],
1865                                         &src_key, src_path->slots[cur_level]);
1866                 }
1867                 /* Content mismatch, something went wrong */
1868                 if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
1869                         ret = -ENOENT;
1870                         goto out;
1871                 }
1872                 cur_level--;
1873         }
1874
1875         /*
1876          * Now both @dst_path and @src_path have been populated, record the tree
1877          * blocks for qgroup accounting.
1878          */
1879         ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
1880                         nodesize, GFP_NOFS);
1881         if (ret < 0)
1882                 goto out;
1883         ret = btrfs_qgroup_trace_extent(trans,
1884                         dst_path->nodes[dst_level]->start,
1885                         nodesize, GFP_NOFS);
1886         if (ret < 0)
1887                 goto out;
1888
1889         /* Record leaf file extents */
1890         if (dst_level == 0 && trace_leaf) {
1891                 ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
1892                 if (ret < 0)
1893                         goto out;
1894                 ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
1895         }
1896 out:
1897         btrfs_free_path(src_path);
1898         return ret;
1899 }
1900
1901 /*
1902  * Helper function to do recursive generation-aware depth-first search, to
1903  * locate all new tree blocks in a subtree of reloc tree.
1904  *
1905  * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
1906  *         reloc tree
1907  * L2         NN (a)
1908  *          /    \
1909  * L1    OO        NN (b)
1910  *      /  \      /  \
1911  * L0  OO  OO    OO  NN
1912  *               (c) (d)
1913  * If we pass:
1914  * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
1915  * @cur_level = 1
1916  * @root_level = 1
1917  *
1918  * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
1919  * above tree blocks along with their counter parts in file tree.
1920  * While during search, old tree blocks OO(c) will be skipped as tree block swap
1921  * won't affect OO(c).
1922  */
1923 static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
1924                                            struct extent_buffer *src_eb,
1925                                            struct btrfs_path *dst_path,
1926                                            int cur_level, int root_level,
1927                                            u64 last_snapshot, bool trace_leaf)
1928 {
1929         struct btrfs_fs_info *fs_info = trans->fs_info;
1930         struct extent_buffer *eb;
1931         bool need_cleanup = false;
1932         int ret = 0;
1933         int i;
1934
1935         /* Level sanity check */
1936         if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
1937             root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
1938             root_level < cur_level) {
1939                 btrfs_err_rl(fs_info,
1940                         "%s: bad levels, cur_level=%d root_level=%d",
1941                         __func__, cur_level, root_level);
1942                 return -EUCLEAN;
1943         }
1944
1945         /* Read the tree block if needed */
1946         if (dst_path->nodes[cur_level] == NULL) {
1947                 struct btrfs_key first_key;
1948                 int parent_slot;
1949                 u64 child_gen;
1950                 u64 child_bytenr;
1951
1952                 /*
1953                  * dst_path->nodes[root_level] must be initialized before
1954                  * calling this function.
1955                  */
1956                 if (cur_level == root_level) {
1957                         btrfs_err_rl(fs_info,
1958         "%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
1959                                 __func__, root_level, root_level, cur_level);
1960                         return -EUCLEAN;
1961                 }
1962
1963                 /*
1964                  * We need to get child blockptr/gen from parent before we can
1965                  * read it.
1966                   */
1967                 eb = dst_path->nodes[cur_level + 1];
1968                 parent_slot = dst_path->slots[cur_level + 1];
1969                 child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1970                 child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1971                 btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
1972
1973                 /* This node is old, no need to trace */
1974                 if (child_gen < last_snapshot)
1975                         goto out;
1976
1977                 eb = read_tree_block(fs_info, child_bytenr, child_gen,
1978                                      cur_level, &first_key);
1979                 if (IS_ERR(eb)) {
1980                         ret = PTR_ERR(eb);
1981                         goto out;
1982                 } else if (!extent_buffer_uptodate(eb)) {
1983                         free_extent_buffer(eb);
1984                         ret = -EIO;
1985                         goto out;
1986                 }
1987
1988                 dst_path->nodes[cur_level] = eb;
1989                 dst_path->slots[cur_level] = 0;
1990
1991                 btrfs_tree_read_lock(eb);
1992                 btrfs_set_lock_blocking_read(eb);
1993                 dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
1994                 need_cleanup = true;
1995         }
1996
1997         /* Now record this tree block and its counter part for qgroups */
1998         ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
1999                                        root_level, trace_leaf);
2000         if (ret < 0)
2001                 goto cleanup;
2002
2003         eb = dst_path->nodes[cur_level];
2004
2005         if (cur_level > 0) {
2006                 /* Iterate all child tree blocks */
2007                 for (i = 0; i < btrfs_header_nritems(eb); i++) {
2008                         /* Skip old tree blocks as they won't be swapped */
2009                         if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
2010                                 continue;
2011                         dst_path->slots[cur_level] = i;
2012
2013                         /* Recursive call (at most 7 times) */
2014                         ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
2015                                         dst_path, cur_level - 1, root_level,
2016                                         last_snapshot, trace_leaf);
2017                         if (ret < 0)
2018                                 goto cleanup;
2019                 }
2020         }
2021
2022 cleanup:
2023         if (need_cleanup) {
2024                 /* Clean up */
2025                 btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2026                                      dst_path->locks[cur_level]);
2027                 free_extent_buffer(dst_path->nodes[cur_level]);
2028                 dst_path->nodes[cur_level] = NULL;
2029                 dst_path->slots[cur_level] = 0;
2030                 dst_path->locks[cur_level] = 0;
2031         }
2032 out:
2033         return ret;
2034 }
2035
2036 static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2037                                 struct extent_buffer *src_eb,
2038                                 struct extent_buffer *dst_eb,
2039                                 u64 last_snapshot, bool trace_leaf)
2040 {
2041         struct btrfs_fs_info *fs_info = trans->fs_info;
2042         struct btrfs_path *dst_path = NULL;
2043         int level;
2044         int ret;
2045
2046         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2047                 return 0;
2048
2049         /* Wrong parameter order */
2050         if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
2051                 btrfs_err_rl(fs_info,
2052                 "%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2053                              btrfs_header_generation(src_eb),
2054                              btrfs_header_generation(dst_eb));
2055                 return -EUCLEAN;
2056         }
2057
2058         if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2059                 ret = -EIO;
2060                 goto out;
2061         }
2062
2063         level = btrfs_header_level(dst_eb);
2064         dst_path = btrfs_alloc_path();
2065         if (!dst_path) {
2066                 ret = -ENOMEM;
2067                 goto out;
2068         }
2069         /* For dst_path */
2070         extent_buffer_get(dst_eb);
2071         dst_path->nodes[level] = dst_eb;
2072         dst_path->slots[level] = 0;
2073         dst_path->locks[level] = 0;
2074
2075         /* Do the generation aware breadth-first search */
2076         ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2077                                               level, last_snapshot, trace_leaf);
2078         if (ret < 0)
2079                 goto out;
2080         ret = 0;
2081
2082 out:
2083         btrfs_free_path(dst_path);
2084         if (ret < 0)
2085                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2086         return ret;
2087 }
2088
2089 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2090                                struct extent_buffer *root_eb,
2091                                u64 root_gen, int root_level)
2092 {
2093         struct btrfs_fs_info *fs_info = trans->fs_info;
2094         int ret = 0;
2095         int level;
2096         struct extent_buffer *eb = root_eb;
2097         struct btrfs_path *path = NULL;
2098
2099         BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2100         BUG_ON(root_eb == NULL);
2101
2102         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2103                 return 0;
2104
2105         if (!extent_buffer_uptodate(root_eb)) {
2106                 ret = btrfs_read_buffer(root_eb, root_gen, root_level, NULL);
2107                 if (ret)
2108                         goto out;
2109         }
2110
2111         if (root_level == 0) {
2112                 ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2113                 goto out;
2114         }
2115
2116         path = btrfs_alloc_path();
2117         if (!path)
2118                 return -ENOMEM;
2119
2120         /*
2121          * Walk down the tree.  Missing extent blocks are filled in as
2122          * we go. Metadata is accounted every time we read a new
2123          * extent block.
2124          *
2125          * When we reach a leaf, we account for file extent items in it,
2126          * walk back up the tree (adjusting slot pointers as we go)
2127          * and restart the search process.
2128          */
2129         extent_buffer_get(root_eb); /* For path */
2130         path->nodes[root_level] = root_eb;
2131         path->slots[root_level] = 0;
2132         path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2133 walk_down:
2134         level = root_level;
2135         while (level >= 0) {
2136                 if (path->nodes[level] == NULL) {
2137                         struct btrfs_key first_key;
2138                         int parent_slot;
2139                         u64 child_gen;
2140                         u64 child_bytenr;
2141
2142                         /*
2143                          * We need to get child blockptr/gen from parent before
2144                          * we can read it.
2145                           */
2146                         eb = path->nodes[level + 1];
2147                         parent_slot = path->slots[level + 1];
2148                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2149                         child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2150                         btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
2151
2152                         eb = read_tree_block(fs_info, child_bytenr, child_gen,
2153                                              level, &first_key);
2154                         if (IS_ERR(eb)) {
2155                                 ret = PTR_ERR(eb);
2156                                 goto out;
2157                         } else if (!extent_buffer_uptodate(eb)) {
2158                                 free_extent_buffer(eb);
2159                                 ret = -EIO;
2160                                 goto out;
2161                         }
2162
2163                         path->nodes[level] = eb;
2164                         path->slots[level] = 0;
2165
2166                         btrfs_tree_read_lock(eb);
2167                         btrfs_set_lock_blocking_read(eb);
2168                         path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
2169
2170                         ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2171                                                         fs_info->nodesize,
2172                                                         GFP_NOFS);
2173                         if (ret)
2174                                 goto out;
2175                 }
2176
2177                 if (level == 0) {
2178                         ret = btrfs_qgroup_trace_leaf_items(trans,
2179                                                             path->nodes[level]);
2180                         if (ret)
2181                                 goto out;
2182
2183                         /* Nonzero return here means we completed our search */
2184                         ret = adjust_slots_upwards(path, root_level);
2185                         if (ret)
2186                                 break;
2187
2188                         /* Restart search with new slots */
2189                         goto walk_down;
2190                 }
2191
2192                 level--;
2193         }
2194
2195         ret = 0;
2196 out:
2197         btrfs_free_path(path);
2198
2199         return ret;
2200 }
2201
2202 #define UPDATE_NEW      0
2203 #define UPDATE_OLD      1
2204 /*
2205  * Walk all of the roots that points to the bytenr and adjust their refcnts.
2206  */
2207 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2208                                 struct ulist *roots, struct ulist *tmp,
2209                                 struct ulist *qgroups, u64 seq, int update_old)
2210 {
2211         struct ulist_node *unode;
2212         struct ulist_iterator uiter;
2213         struct ulist_node *tmp_unode;
2214         struct ulist_iterator tmp_uiter;
2215         struct btrfs_qgroup *qg;
2216         int ret = 0;
2217
2218         if (!roots)
2219                 return 0;
2220         ULIST_ITER_INIT(&uiter);
2221         while ((unode = ulist_next(roots, &uiter))) {
2222                 qg = find_qgroup_rb(fs_info, unode->val);
2223                 if (!qg)
2224                         continue;
2225
2226                 ulist_reinit(tmp);
2227                 ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2228                                 GFP_ATOMIC);
2229                 if (ret < 0)
2230                         return ret;
2231                 ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2232                 if (ret < 0)
2233                         return ret;
2234                 ULIST_ITER_INIT(&tmp_uiter);
2235                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2236                         struct btrfs_qgroup_list *glist;
2237
2238                         qg = unode_aux_to_qgroup(tmp_unode);
2239                         if (update_old)
2240                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2241                         else
2242                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2243                         list_for_each_entry(glist, &qg->groups, next_group) {
2244                                 ret = ulist_add(qgroups, glist->group->qgroupid,
2245                                                 qgroup_to_aux(glist->group),
2246                                                 GFP_ATOMIC);
2247                                 if (ret < 0)
2248                                         return ret;
2249                                 ret = ulist_add(tmp, glist->group->qgroupid,
2250                                                 qgroup_to_aux(glist->group),
2251                                                 GFP_ATOMIC);
2252                                 if (ret < 0)
2253                                         return ret;
2254                         }
2255                 }
2256         }
2257         return 0;
2258 }
2259
2260 /*
2261  * Update qgroup rfer/excl counters.
2262  * Rfer update is easy, codes can explain themselves.
2263  *
2264  * Excl update is tricky, the update is split into 2 part.
2265  * Part 1: Possible exclusive <-> sharing detect:
2266  *      |       A       |       !A      |
2267  *  -------------------------------------
2268  *  B   |       *       |       -       |
2269  *  -------------------------------------
2270  *  !B  |       +       |       **      |
2271  *  -------------------------------------
2272  *
2273  * Conditions:
2274  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
2275  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
2276  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
2277  * !B:  cur_new_roots == nr_new_roots   (possible exclusive now)
2278  *
2279  * Results:
2280  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
2281  * *: Definitely not changed.           **: Possible unchanged.
2282  *
2283  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2284  *
2285  * To make the logic clear, we first use condition A and B to split
2286  * combination into 4 results.
2287  *
2288  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2289  * only on variant maybe 0.
2290  *
2291  * Lastly, check result **, since there are 2 variants maybe 0, split them
2292  * again(2x2).
2293  * But this time we don't need to consider other things, the codes and logic
2294  * is easy to understand now.
2295  */
2296 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2297                                   struct ulist *qgroups,
2298                                   u64 nr_old_roots,
2299                                   u64 nr_new_roots,
2300                                   u64 num_bytes, u64 seq)
2301 {
2302         struct ulist_node *unode;
2303         struct ulist_iterator uiter;
2304         struct btrfs_qgroup *qg;
2305         u64 cur_new_count, cur_old_count;
2306
2307         ULIST_ITER_INIT(&uiter);
2308         while ((unode = ulist_next(qgroups, &uiter))) {
2309                 bool dirty = false;
2310
2311                 qg = unode_aux_to_qgroup(unode);
2312                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2313                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2314
2315                 trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2316                                              cur_new_count);
2317
2318                 /* Rfer update part */
2319                 if (cur_old_count == 0 && cur_new_count > 0) {
2320                         qg->rfer += num_bytes;
2321                         qg->rfer_cmpr += num_bytes;
2322                         dirty = true;
2323                 }
2324                 if (cur_old_count > 0 && cur_new_count == 0) {
2325                         qg->rfer -= num_bytes;
2326                         qg->rfer_cmpr -= num_bytes;
2327                         dirty = true;
2328                 }
2329
2330                 /* Excl update part */
2331                 /* Exclusive/none -> shared case */
2332                 if (cur_old_count == nr_old_roots &&
2333                     cur_new_count < nr_new_roots) {
2334                         /* Exclusive -> shared */
2335                         if (cur_old_count != 0) {
2336                                 qg->excl -= num_bytes;
2337                                 qg->excl_cmpr -= num_bytes;
2338                                 dirty = true;
2339                         }
2340                 }
2341
2342                 /* Shared -> exclusive/none case */
2343                 if (cur_old_count < nr_old_roots &&
2344                     cur_new_count == nr_new_roots) {
2345                         /* Shared->exclusive */
2346                         if (cur_new_count != 0) {
2347                                 qg->excl += num_bytes;
2348                                 qg->excl_cmpr += num_bytes;
2349                                 dirty = true;
2350                         }
2351                 }
2352
2353                 /* Exclusive/none -> exclusive/none case */
2354                 if (cur_old_count == nr_old_roots &&
2355                     cur_new_count == nr_new_roots) {
2356                         if (cur_old_count == 0) {
2357                                 /* None -> exclusive/none */
2358
2359                                 if (cur_new_count != 0) {
2360                                         /* None -> exclusive */
2361                                         qg->excl += num_bytes;
2362                                         qg->excl_cmpr += num_bytes;
2363                                         dirty = true;
2364                                 }
2365                                 /* None -> none, nothing changed */
2366                         } else {
2367                                 /* Exclusive -> exclusive/none */
2368
2369                                 if (cur_new_count == 0) {
2370                                         /* Exclusive -> none */
2371                                         qg->excl -= num_bytes;
2372                                         qg->excl_cmpr -= num_bytes;
2373                                         dirty = true;
2374                                 }
2375                                 /* Exclusive -> exclusive, nothing changed */
2376                         }
2377                 }
2378
2379                 if (dirty)
2380                         qgroup_dirty(fs_info, qg);
2381         }
2382         return 0;
2383 }
2384
2385 /*
2386  * Check if the @roots potentially is a list of fs tree roots
2387  *
2388  * Return 0 for definitely not a fs/subvol tree roots ulist
2389  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2390  *          one as well)
2391  */
2392 static int maybe_fs_roots(struct ulist *roots)
2393 {
2394         struct ulist_node *unode;
2395         struct ulist_iterator uiter;
2396
2397         /* Empty one, still possible for fs roots */
2398         if (!roots || roots->nnodes == 0)
2399                 return 1;
2400
2401         ULIST_ITER_INIT(&uiter);
2402         unode = ulist_next(roots, &uiter);
2403         if (!unode)
2404                 return 1;
2405
2406         /*
2407          * If it contains fs tree roots, then it must belong to fs/subvol
2408          * trees.
2409          * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2410          */
2411         return is_fstree(unode->val);
2412 }
2413
2414 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2415                                 u64 num_bytes, struct ulist *old_roots,
2416                                 struct ulist *new_roots)
2417 {
2418         struct btrfs_fs_info *fs_info = trans->fs_info;
2419         struct ulist *qgroups = NULL;
2420         struct ulist *tmp = NULL;
2421         u64 seq;
2422         u64 nr_new_roots = 0;
2423         u64 nr_old_roots = 0;
2424         int ret = 0;
2425
2426         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2427                 return 0;
2428
2429         if (new_roots) {
2430                 if (!maybe_fs_roots(new_roots))
2431                         goto out_free;
2432                 nr_new_roots = new_roots->nnodes;
2433         }
2434         if (old_roots) {
2435                 if (!maybe_fs_roots(old_roots))
2436                         goto out_free;
2437                 nr_old_roots = old_roots->nnodes;
2438         }
2439
2440         /* Quick exit, either not fs tree roots, or won't affect any qgroup */
2441         if (nr_old_roots == 0 && nr_new_roots == 0)
2442                 goto out_free;
2443
2444         BUG_ON(!fs_info->quota_root);
2445
2446         trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2447                                         num_bytes, nr_old_roots, nr_new_roots);
2448
2449         qgroups = ulist_alloc(GFP_NOFS);
2450         if (!qgroups) {
2451                 ret = -ENOMEM;
2452                 goto out_free;
2453         }
2454         tmp = ulist_alloc(GFP_NOFS);
2455         if (!tmp) {
2456                 ret = -ENOMEM;
2457                 goto out_free;
2458         }
2459
2460         mutex_lock(&fs_info->qgroup_rescan_lock);
2461         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2462                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2463                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2464                         ret = 0;
2465                         goto out_free;
2466                 }
2467         }
2468         mutex_unlock(&fs_info->qgroup_rescan_lock);
2469
2470         spin_lock(&fs_info->qgroup_lock);
2471         seq = fs_info->qgroup_seq;
2472
2473         /* Update old refcnts using old_roots */
2474         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2475                                    UPDATE_OLD);
2476         if (ret < 0)
2477                 goto out;
2478
2479         /* Update new refcnts using new_roots */
2480         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2481                                    UPDATE_NEW);
2482         if (ret < 0)
2483                 goto out;
2484
2485         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2486                                num_bytes, seq);
2487
2488         /*
2489          * Bump qgroup_seq to avoid seq overlap
2490          */
2491         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2492 out:
2493         spin_unlock(&fs_info->qgroup_lock);
2494 out_free:
2495         ulist_free(tmp);
2496         ulist_free(qgroups);
2497         ulist_free(old_roots);
2498         ulist_free(new_roots);
2499         return ret;
2500 }
2501
2502 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2503 {
2504         struct btrfs_fs_info *fs_info = trans->fs_info;
2505         struct btrfs_qgroup_extent_record *record;
2506         struct btrfs_delayed_ref_root *delayed_refs;
2507         struct ulist *new_roots = NULL;
2508         struct rb_node *node;
2509         u64 num_dirty_extents = 0;
2510         u64 qgroup_to_skip;
2511         int ret = 0;
2512
2513         delayed_refs = &trans->transaction->delayed_refs;
2514         qgroup_to_skip = delayed_refs->qgroup_to_skip;
2515         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2516                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
2517                                   node);
2518
2519                 num_dirty_extents++;
2520                 trace_btrfs_qgroup_account_extents(fs_info, record);
2521
2522                 if (!ret) {
2523                         /*
2524                          * Old roots should be searched when inserting qgroup
2525                          * extent record
2526                          */
2527                         if (WARN_ON(!record->old_roots)) {
2528                                 /* Search commit root to find old_roots */
2529                                 ret = btrfs_find_all_roots(NULL, fs_info,
2530                                                 record->bytenr, 0,
2531                                                 &record->old_roots, false);
2532                                 if (ret < 0)
2533                                         goto cleanup;
2534                         }
2535
2536                         /* Free the reserved data space */
2537                         btrfs_qgroup_free_refroot(fs_info,
2538                                         record->data_rsv_refroot,
2539                                         record->data_rsv,
2540                                         BTRFS_QGROUP_RSV_DATA);
2541                         /*
2542                          * Use SEQ_LAST as time_seq to do special search, which
2543                          * doesn't lock tree or delayed_refs and search current
2544                          * root. It's safe inside commit_transaction().
2545                          */
2546                         ret = btrfs_find_all_roots(trans, fs_info,
2547                                 record->bytenr, SEQ_LAST, &new_roots, false);
2548                         if (ret < 0)
2549                                 goto cleanup;
2550                         if (qgroup_to_skip) {
2551                                 ulist_del(new_roots, qgroup_to_skip, 0);
2552                                 ulist_del(record->old_roots, qgroup_to_skip,
2553                                           0);
2554                         }
2555                         ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2556                                                           record->num_bytes,
2557                                                           record->old_roots,
2558                                                           new_roots);
2559                         record->old_roots = NULL;
2560                         new_roots = NULL;
2561                 }
2562 cleanup:
2563                 ulist_free(record->old_roots);
2564                 ulist_free(new_roots);
2565                 new_roots = NULL;
2566                 rb_erase(node, &delayed_refs->dirty_extent_root);
2567                 kfree(record);
2568
2569         }
2570         trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2571                                        num_dirty_extents);
2572         return ret;
2573 }
2574
2575 /*
2576  * called from commit_transaction. Writes all changed qgroups to disk.
2577  */
2578 int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2579 {
2580         struct btrfs_fs_info *fs_info = trans->fs_info;
2581         struct btrfs_root *quota_root = fs_info->quota_root;
2582         int ret = 0;
2583
2584         if (!quota_root)
2585                 return ret;
2586
2587         spin_lock(&fs_info->qgroup_lock);
2588         while (!list_empty(&fs_info->dirty_qgroups)) {
2589                 struct btrfs_qgroup *qgroup;
2590                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
2591                                           struct btrfs_qgroup, dirty);
2592                 list_del_init(&qgroup->dirty);
2593                 spin_unlock(&fs_info->qgroup_lock);
2594                 ret = update_qgroup_info_item(trans, qgroup);
2595                 if (ret)
2596                         fs_info->qgroup_flags |=
2597                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2598                 ret = update_qgroup_limit_item(trans, qgroup);
2599                 if (ret)
2600                         fs_info->qgroup_flags |=
2601                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2602                 spin_lock(&fs_info->qgroup_lock);
2603         }
2604         if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2605                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2606         else
2607                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2608         spin_unlock(&fs_info->qgroup_lock);
2609
2610         ret = update_qgroup_status_item(trans);
2611         if (ret)
2612                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2613
2614         return ret;
2615 }
2616
2617 /*
2618  * Copy the accounting information between qgroups. This is necessary
2619  * when a snapshot or a subvolume is created. Throwing an error will
2620  * cause a transaction abort so we take extra care here to only error
2621  * when a readonly fs is a reasonable outcome.
2622  */
2623 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2624                          u64 objectid, struct btrfs_qgroup_inherit *inherit)
2625 {
2626         int ret = 0;
2627         int i;
2628         u64 *i_qgroups;
2629         bool committing = false;
2630         struct btrfs_fs_info *fs_info = trans->fs_info;
2631         struct btrfs_root *quota_root;
2632         struct btrfs_qgroup *srcgroup;
2633         struct btrfs_qgroup *dstgroup;
2634         u32 level_size = 0;
2635         u64 nums;
2636
2637         /*
2638          * There are only two callers of this function.
2639          *
2640          * One in create_subvol() in the ioctl context, which needs to hold
2641          * the qgroup_ioctl_lock.
2642          *
2643          * The other one in create_pending_snapshot() where no other qgroup
2644          * code can modify the fs as they all need to either start a new trans
2645          * or hold a trans handler, thus we don't need to hold
2646          * qgroup_ioctl_lock.
2647          * This would avoid long and complex lock chain and make lockdep happy.
2648          */
2649         spin_lock(&fs_info->trans_lock);
2650         if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
2651                 committing = true;
2652         spin_unlock(&fs_info->trans_lock);
2653
2654         if (!committing)
2655                 mutex_lock(&fs_info->qgroup_ioctl_lock);
2656         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2657                 goto out;
2658
2659         quota_root = fs_info->quota_root;
2660         if (!quota_root) {
2661                 ret = -EINVAL;
2662                 goto out;
2663         }
2664
2665         if (inherit) {
2666                 i_qgroups = (u64 *)(inherit + 1);
2667                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2668                        2 * inherit->num_excl_copies;
2669                 for (i = 0; i < nums; ++i) {
2670                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2671
2672                         /*
2673                          * Zero out invalid groups so we can ignore
2674                          * them later.
2675                          */
2676                         if (!srcgroup ||
2677                             ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2678                                 *i_qgroups = 0ULL;
2679
2680                         ++i_qgroups;
2681                 }
2682         }
2683
2684         /*
2685          * create a tracking group for the subvol itself
2686          */
2687         ret = add_qgroup_item(trans, quota_root, objectid);
2688         if (ret)
2689                 goto out;
2690
2691         /*
2692          * add qgroup to all inherited groups
2693          */
2694         if (inherit) {
2695                 i_qgroups = (u64 *)(inherit + 1);
2696                 for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2697                         if (*i_qgroups == 0)
2698                                 continue;
2699                         ret = add_qgroup_relation_item(trans, objectid,
2700                                                        *i_qgroups);
2701                         if (ret && ret != -EEXIST)
2702                                 goto out;
2703                         ret = add_qgroup_relation_item(trans, *i_qgroups,
2704                                                        objectid);
2705                         if (ret && ret != -EEXIST)
2706                                 goto out;
2707                 }
2708                 ret = 0;
2709         }
2710
2711
2712         spin_lock(&fs_info->qgroup_lock);
2713
2714         dstgroup = add_qgroup_rb(fs_info, objectid);
2715         if (IS_ERR(dstgroup)) {
2716                 ret = PTR_ERR(dstgroup);
2717                 goto unlock;
2718         }
2719
2720         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2721                 dstgroup->lim_flags = inherit->lim.flags;
2722                 dstgroup->max_rfer = inherit->lim.max_rfer;
2723                 dstgroup->max_excl = inherit->lim.max_excl;
2724                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2725                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
2726
2727                 ret = update_qgroup_limit_item(trans, dstgroup);
2728                 if (ret) {
2729                         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2730                         btrfs_info(fs_info,
2731                                    "unable to update quota limit for %llu",
2732                                    dstgroup->qgroupid);
2733                         goto unlock;
2734                 }
2735         }
2736
2737         if (srcid) {
2738                 srcgroup = find_qgroup_rb(fs_info, srcid);
2739                 if (!srcgroup)
2740                         goto unlock;
2741
2742                 /*
2743                  * We call inherit after we clone the root in order to make sure
2744                  * our counts don't go crazy, so at this point the only
2745                  * difference between the two roots should be the root node.
2746                  */
2747                 level_size = fs_info->nodesize;
2748                 dstgroup->rfer = srcgroup->rfer;
2749                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2750                 dstgroup->excl = level_size;
2751                 dstgroup->excl_cmpr = level_size;
2752                 srcgroup->excl = level_size;
2753                 srcgroup->excl_cmpr = level_size;
2754
2755                 /* inherit the limit info */
2756                 dstgroup->lim_flags = srcgroup->lim_flags;
2757                 dstgroup->max_rfer = srcgroup->max_rfer;
2758                 dstgroup->max_excl = srcgroup->max_excl;
2759                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2760                 dstgroup->rsv_excl = srcgroup->rsv_excl;
2761
2762                 qgroup_dirty(fs_info, dstgroup);
2763                 qgroup_dirty(fs_info, srcgroup);
2764         }
2765
2766         if (!inherit)
2767                 goto unlock;
2768
2769         i_qgroups = (u64 *)(inherit + 1);
2770         for (i = 0; i < inherit->num_qgroups; ++i) {
2771                 if (*i_qgroups) {
2772                         ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2773                         if (ret)
2774                                 goto unlock;
2775                 }
2776                 ++i_qgroups;
2777         }
2778
2779         for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2780                 struct btrfs_qgroup *src;
2781                 struct btrfs_qgroup *dst;
2782
2783                 if (!i_qgroups[0] || !i_qgroups[1])
2784                         continue;
2785
2786                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2787                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2788
2789                 if (!src || !dst) {
2790                         ret = -EINVAL;
2791                         goto unlock;
2792                 }
2793
2794                 dst->rfer = src->rfer - level_size;
2795                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
2796         }
2797         for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2798                 struct btrfs_qgroup *src;
2799                 struct btrfs_qgroup *dst;
2800
2801                 if (!i_qgroups[0] || !i_qgroups[1])
2802                         continue;
2803
2804                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2805                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2806
2807                 if (!src || !dst) {
2808                         ret = -EINVAL;
2809                         goto unlock;
2810                 }
2811
2812                 dst->excl = src->excl + level_size;
2813                 dst->excl_cmpr = src->excl_cmpr + level_size;
2814         }
2815
2816 unlock:
2817         spin_unlock(&fs_info->qgroup_lock);
2818 out:
2819         if (!committing)
2820                 mutex_unlock(&fs_info->qgroup_ioctl_lock);
2821         return ret;
2822 }
2823
2824 /*
2825  * Two limits to commit transaction in advance.
2826  *
2827  * For RATIO, it will be 1/RATIO of the remaining limit as threshold.
2828  * For SIZE, it will be in byte unit as threshold.
2829  */
2830 #define QGROUP_FREE_RATIO               32
2831 #define QGROUP_FREE_SIZE                SZ_32M
2832 static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
2833                                 const struct btrfs_qgroup *qg, u64 num_bytes)
2834 {
2835         u64 free;
2836         u64 threshold;
2837
2838         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2839             qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
2840                 return false;
2841
2842         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2843             qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
2844                 return false;
2845
2846         /*
2847          * Even if we passed the check, it's better to check if reservation
2848          * for meta_pertrans is pushing us near limit.
2849          * If there is too much pertrans reservation or it's near the limit,
2850          * let's try commit transaction to free some, using transaction_kthread
2851          */
2852         if ((qg->lim_flags & (BTRFS_QGROUP_LIMIT_MAX_RFER |
2853                               BTRFS_QGROUP_LIMIT_MAX_EXCL))) {
2854                 if (qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
2855                         free = qg->max_excl - qgroup_rsv_total(qg) - qg->excl;
2856                         threshold = min_t(u64, qg->max_excl / QGROUP_FREE_RATIO,
2857                                           QGROUP_FREE_SIZE);
2858                 } else {
2859                         free = qg->max_rfer - qgroup_rsv_total(qg) - qg->rfer;
2860                         threshold = min_t(u64, qg->max_rfer / QGROUP_FREE_RATIO,
2861                                           QGROUP_FREE_SIZE);
2862                 }
2863
2864                 /*
2865                  * Use transaction_kthread to commit transaction, so we no
2866                  * longer need to bother nested transaction nor lock context.
2867                  */
2868                 if (free < threshold)
2869                         btrfs_commit_transaction_locksafe(fs_info);
2870         }
2871
2872         return true;
2873 }
2874
2875 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
2876                           enum btrfs_qgroup_rsv_type type)
2877 {
2878         struct btrfs_root *quota_root;
2879         struct btrfs_qgroup *qgroup;
2880         struct btrfs_fs_info *fs_info = root->fs_info;
2881         u64 ref_root = root->root_key.objectid;
2882         int ret = 0;
2883         struct ulist_node *unode;
2884         struct ulist_iterator uiter;
2885
2886         if (!is_fstree(ref_root))
2887                 return 0;
2888
2889         if (num_bytes == 0)
2890                 return 0;
2891
2892         if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2893             capable(CAP_SYS_RESOURCE))
2894                 enforce = false;
2895
2896         spin_lock(&fs_info->qgroup_lock);
2897         quota_root = fs_info->quota_root;
2898         if (!quota_root)
2899                 goto out;
2900
2901         qgroup = find_qgroup_rb(fs_info, ref_root);
2902         if (!qgroup)
2903                 goto out;
2904
2905         /*
2906          * in a first step, we check all affected qgroups if any limits would
2907          * be exceeded
2908          */
2909         ulist_reinit(fs_info->qgroup_ulist);
2910         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2911                         qgroup_to_aux(qgroup), GFP_ATOMIC);
2912         if (ret < 0)
2913                 goto out;
2914         ULIST_ITER_INIT(&uiter);
2915         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2916                 struct btrfs_qgroup *qg;
2917                 struct btrfs_qgroup_list *glist;
2918
2919                 qg = unode_aux_to_qgroup(unode);
2920
2921                 if (enforce && !qgroup_check_limits(fs_info, qg, num_bytes)) {
2922                         ret = -EDQUOT;
2923                         goto out;
2924                 }
2925
2926                 list_for_each_entry(glist, &qg->groups, next_group) {
2927                         ret = ulist_add(fs_info->qgroup_ulist,
2928                                         glist->group->qgroupid,
2929                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
2930                         if (ret < 0)
2931                                 goto out;
2932                 }
2933         }
2934         ret = 0;
2935         /*
2936          * no limits exceeded, now record the reservation into all qgroups
2937          */
2938         ULIST_ITER_INIT(&uiter);
2939         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2940                 struct btrfs_qgroup *qg;
2941
2942                 qg = unode_aux_to_qgroup(unode);
2943
2944                 qgroup_rsv_add(fs_info, qg, num_bytes, type);
2945         }
2946
2947 out:
2948         spin_unlock(&fs_info->qgroup_lock);
2949         return ret;
2950 }
2951
2952 /*
2953  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
2954  * qgroup).
2955  *
2956  * Will handle all higher level qgroup too.
2957  *
2958  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
2959  * This special case is only used for META_PERTRANS type.
2960  */
2961 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2962                                u64 ref_root, u64 num_bytes,
2963                                enum btrfs_qgroup_rsv_type type)
2964 {
2965         struct btrfs_root *quota_root;
2966         struct btrfs_qgroup *qgroup;
2967         struct ulist_node *unode;
2968         struct ulist_iterator uiter;
2969         int ret = 0;
2970
2971         if (!is_fstree(ref_root))
2972                 return;
2973
2974         if (num_bytes == 0)
2975                 return;
2976
2977         if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
2978                 WARN(1, "%s: Invalid type to free", __func__);
2979                 return;
2980         }
2981         spin_lock(&fs_info->qgroup_lock);
2982
2983         quota_root = fs_info->quota_root;
2984         if (!quota_root)
2985                 goto out;
2986
2987         qgroup = find_qgroup_rb(fs_info, ref_root);
2988         if (!qgroup)
2989                 goto out;
2990
2991         if (num_bytes == (u64)-1)
2992                 /*
2993                  * We're freeing all pertrans rsv, get reserved value from
2994                  * level 0 qgroup as real num_bytes to free.
2995                  */
2996                 num_bytes = qgroup->rsv.values[type];
2997
2998         ulist_reinit(fs_info->qgroup_ulist);
2999         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3000                         qgroup_to_aux(qgroup), GFP_ATOMIC);
3001         if (ret < 0)
3002                 goto out;
3003         ULIST_ITER_INIT(&uiter);
3004         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3005                 struct btrfs_qgroup *qg;
3006                 struct btrfs_qgroup_list *glist;
3007
3008                 qg = unode_aux_to_qgroup(unode);
3009
3010                 qgroup_rsv_release(fs_info, qg, num_bytes, type);
3011
3012                 list_for_each_entry(glist, &qg->groups, next_group) {
3013                         ret = ulist_add(fs_info->qgroup_ulist,
3014                                         glist->group->qgroupid,
3015                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
3016                         if (ret < 0)
3017                                 goto out;
3018                 }
3019         }
3020
3021 out:
3022         spin_unlock(&fs_info->qgroup_lock);
3023 }
3024
3025 /*
3026  * Check if the leaf is the last leaf. Which means all node pointers
3027  * are at their last position.
3028  */
3029 static bool is_last_leaf(struct btrfs_path *path)
3030 {
3031         int i;
3032
3033         for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3034                 if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3035                         return false;
3036         }
3037         return true;
3038 }
3039
3040 /*
3041  * returns < 0 on error, 0 when more leafs are to be scanned.
3042  * returns 1 when done.
3043  */
3044 static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3045                               struct btrfs_path *path)
3046 {
3047         struct btrfs_fs_info *fs_info = trans->fs_info;
3048         struct btrfs_key found;
3049         struct extent_buffer *scratch_leaf = NULL;
3050         struct ulist *roots = NULL;
3051         u64 num_bytes;
3052         bool done;
3053         int slot;
3054         int ret;
3055
3056         mutex_lock(&fs_info->qgroup_rescan_lock);
3057         ret = btrfs_search_slot_for_read(fs_info->extent_root,
3058                                          &fs_info->qgroup_rescan_progress,
3059                                          path, 1, 0);
3060
3061         btrfs_debug(fs_info,
3062                 "current progress key (%llu %u %llu), search_slot ret %d",
3063                 fs_info->qgroup_rescan_progress.objectid,
3064                 fs_info->qgroup_rescan_progress.type,
3065                 fs_info->qgroup_rescan_progress.offset, ret);
3066
3067         if (ret) {
3068                 /*
3069                  * The rescan is about to end, we will not be scanning any
3070                  * further blocks. We cannot unset the RESCAN flag here, because
3071                  * we want to commit the transaction if everything went well.
3072                  * To make the live accounting work in this phase, we set our
3073                  * scan progress pointer such that every real extent objectid
3074                  * will be smaller.
3075                  */
3076                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3077                 btrfs_release_path(path);
3078                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3079                 return ret;
3080         }
3081         done = is_last_leaf(path);
3082
3083         btrfs_item_key_to_cpu(path->nodes[0], &found,
3084                               btrfs_header_nritems(path->nodes[0]) - 1);
3085         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3086
3087         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3088         if (!scratch_leaf) {
3089                 ret = -ENOMEM;
3090                 mutex_unlock(&fs_info->qgroup_rescan_lock);
3091                 goto out;
3092         }
3093         slot = path->slots[0];
3094         btrfs_release_path(path);
3095         mutex_unlock(&fs_info->qgroup_rescan_lock);
3096
3097         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
3098                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3099                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3100                     found.type != BTRFS_METADATA_ITEM_KEY)
3101                         continue;
3102                 if (found.type == BTRFS_METADATA_ITEM_KEY)
3103                         num_bytes = fs_info->nodesize;
3104                 else
3105                         num_bytes = found.offset;
3106
3107                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
3108                                            &roots, false);
3109                 if (ret < 0)
3110                         goto out;
3111                 /* For rescan, just pass old_roots as NULL */
3112                 ret = btrfs_qgroup_account_extent(trans, found.objectid,
3113                                                   num_bytes, NULL, roots);
3114                 if (ret < 0)
3115                         goto out;
3116         }
3117 out:
3118         if (scratch_leaf)
3119                 free_extent_buffer(scratch_leaf);
3120
3121         if (done && !ret) {
3122                 ret = 1;
3123                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3124         }
3125         return ret;
3126 }
3127
3128 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3129 {
3130         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3131                                                      qgroup_rescan_work);
3132         struct btrfs_path *path;
3133         struct btrfs_trans_handle *trans = NULL;
3134         int err = -ENOMEM;
3135         int ret = 0;
3136
3137         path = btrfs_alloc_path();
3138         if (!path)
3139                 goto out;
3140         /*
3141          * Rescan should only search for commit root, and any later difference
3142          * should be recorded by qgroup
3143          */
3144         path->search_commit_root = 1;
3145         path->skip_locking = 1;
3146
3147         err = 0;
3148         while (!err && !btrfs_fs_closing(fs_info)) {
3149                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
3150                 if (IS_ERR(trans)) {
3151                         err = PTR_ERR(trans);
3152                         break;
3153                 }
3154                 if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3155                         err = -EINTR;
3156                 } else {
3157                         err = qgroup_rescan_leaf(trans, path);
3158                 }
3159                 if (err > 0)
3160                         btrfs_commit_transaction(trans);
3161                 else
3162                         btrfs_end_transaction(trans);
3163         }
3164
3165 out:
3166         btrfs_free_path(path);
3167
3168         mutex_lock(&fs_info->qgroup_rescan_lock);
3169         if (err > 0 &&
3170             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3171                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3172         } else if (err < 0) {
3173                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3174         }
3175         mutex_unlock(&fs_info->qgroup_rescan_lock);
3176
3177         /*
3178          * only update status, since the previous part has already updated the
3179          * qgroup info.
3180          */
3181         trans = btrfs_start_transaction(fs_info->quota_root, 1);
3182         if (IS_ERR(trans)) {
3183                 err = PTR_ERR(trans);
3184                 trans = NULL;
3185                 btrfs_err(fs_info,
3186                           "fail to start transaction for status update: %d",
3187                           err);
3188         }
3189
3190         mutex_lock(&fs_info->qgroup_rescan_lock);
3191         if (!btrfs_fs_closing(fs_info))
3192                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3193         if (trans) {
3194                 ret = update_qgroup_status_item(trans);
3195                 if (ret < 0) {
3196                         err = ret;
3197                         btrfs_err(fs_info, "fail to update qgroup status: %d",
3198                                   err);
3199                 }
3200         }
3201         fs_info->qgroup_rescan_running = false;
3202         complete_all(&fs_info->qgroup_rescan_completion);
3203         mutex_unlock(&fs_info->qgroup_rescan_lock);
3204
3205         if (!trans)
3206                 return;
3207
3208         btrfs_end_transaction(trans);
3209
3210         if (btrfs_fs_closing(fs_info)) {
3211                 btrfs_info(fs_info, "qgroup scan paused");
3212         } else if (err >= 0) {
3213                 btrfs_info(fs_info, "qgroup scan completed%s",
3214                         err > 0 ? " (inconsistency flag cleared)" : "");
3215         } else {
3216                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
3217         }