Btrfs: fix gcc warnings for 32bit compiles
[linux-3.10.git] / fs / btrfs / qgroup.c
1 /*
2  * Copyright (C) 2011 STRATO.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
25 #include <linux/workqueue.h>
26
27 #include "ctree.h"
28 #include "transaction.h"
29 #include "disk-io.h"
30 #include "locking.h"
31 #include "ulist.h"
32 #include "ioctl.h"
33 #include "backref.h"
34
35 /* TODO XXX FIXME
36  *  - subvol delete -> delete when ref goes to 0? delete limits also?
37  *  - reorganize keys
38  *  - compressed
39  *  - sync
40  *  - rescan
41  *  - copy also limits on subvol creation
42  *  - limit
43  *  - caches fuer ulists
44  *  - performance benchmarks
45  *  - check all ioctl parameters
46  */
47
48 /*
49  * one struct for each qgroup, organized in fs_info->qgroup_tree.
50  */
51 struct btrfs_qgroup {
52         u64 qgroupid;
53
54         /*
55          * state
56          */
57         u64 rfer;       /* referenced */
58         u64 rfer_cmpr;  /* referenced compressed */
59         u64 excl;       /* exclusive */
60         u64 excl_cmpr;  /* exclusive compressed */
61
62         /*
63          * limits
64          */
65         u64 lim_flags;  /* which limits are set */
66         u64 max_rfer;
67         u64 max_excl;
68         u64 rsv_rfer;
69         u64 rsv_excl;
70
71         /*
72          * reservation tracking
73          */
74         u64 reserved;
75
76         /*
77          * lists
78          */
79         struct list_head groups;  /* groups this group is member of */
80         struct list_head members; /* groups that are members of this group */
81         struct list_head dirty;   /* dirty groups */
82         struct rb_node node;      /* tree of qgroups */
83
84         /*
85          * temp variables for accounting operations
86          */
87         u64 tag;
88         u64 refcnt;
89 };
90
91 /*
92  * glue structure to represent the relations between qgroups.
93  */
94 struct btrfs_qgroup_list {
95         struct list_head next_group;
96         struct list_head next_member;
97         struct btrfs_qgroup *group;
98         struct btrfs_qgroup *member;
99 };
100
101 /* must be called with qgroup_lock held */
102 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
103                                            u64 qgroupid)
104 {
105         struct rb_node *n = fs_info->qgroup_tree.rb_node;
106         struct btrfs_qgroup *qgroup;
107
108         while (n) {
109                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
110                 if (qgroup->qgroupid < qgroupid)
111                         n = n->rb_left;
112                 else if (qgroup->qgroupid > qgroupid)
113                         n = n->rb_right;
114                 else
115                         return qgroup;
116         }
117         return NULL;
118 }
119
120 /* must be called with qgroup_lock held */
121 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
122                                           u64 qgroupid)
123 {
124         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
125         struct rb_node *parent = NULL;
126         struct btrfs_qgroup *qgroup;
127
128         while (*p) {
129                 parent = *p;
130                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
131
132                 if (qgroup->qgroupid < qgroupid)
133                         p = &(*p)->rb_left;
134                 else if (qgroup->qgroupid > qgroupid)
135                         p = &(*p)->rb_right;
136                 else
137                         return qgroup;
138         }
139
140         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
141         if (!qgroup)
142                 return ERR_PTR(-ENOMEM);
143
144         qgroup->qgroupid = qgroupid;
145         INIT_LIST_HEAD(&qgroup->groups);
146         INIT_LIST_HEAD(&qgroup->members);
147         INIT_LIST_HEAD(&qgroup->dirty);
148
149         rb_link_node(&qgroup->node, parent, p);
150         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
151
152         return qgroup;
153 }
154
155 /* must be called with qgroup_lock held */
156 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
157 {
158         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
159         struct btrfs_qgroup_list *list;
160
161         if (!qgroup)
162                 return -ENOENT;
163
164         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
165         list_del(&qgroup->dirty);
166
167         while (!list_empty(&qgroup->groups)) {
168                 list = list_first_entry(&qgroup->groups,
169                                         struct btrfs_qgroup_list, next_group);
170                 list_del(&list->next_group);
171                 list_del(&list->next_member);
172                 kfree(list);
173         }
174
175         while (!list_empty(&qgroup->members)) {
176                 list = list_first_entry(&qgroup->members,
177                                         struct btrfs_qgroup_list, next_member);
178                 list_del(&list->next_group);
179                 list_del(&list->next_member);
180                 kfree(list);
181         }
182         kfree(qgroup);
183
184         return 0;
185 }
186
187 /* must be called with qgroup_lock held */
188 static int add_relation_rb(struct btrfs_fs_info *fs_info,
189                            u64 memberid, u64 parentid)
190 {
191         struct btrfs_qgroup *member;
192         struct btrfs_qgroup *parent;
193         struct btrfs_qgroup_list *list;
194
195         member = find_qgroup_rb(fs_info, memberid);
196         parent = find_qgroup_rb(fs_info, parentid);
197         if (!member || !parent)
198                 return -ENOENT;
199
200         list = kzalloc(sizeof(*list), GFP_ATOMIC);
201         if (!list)
202                 return -ENOMEM;
203
204         list->group = parent;
205         list->member = member;
206         list_add_tail(&list->next_group, &member->groups);
207         list_add_tail(&list->next_member, &parent->members);
208
209         return 0;
210 }
211
212 /* must be called with qgroup_lock held */
213 static int del_relation_rb(struct btrfs_fs_info *fs_info,
214                            u64 memberid, u64 parentid)
215 {
216         struct btrfs_qgroup *member;
217         struct btrfs_qgroup *parent;
218         struct btrfs_qgroup_list *list;
219
220         member = find_qgroup_rb(fs_info, memberid);
221         parent = find_qgroup_rb(fs_info, parentid);
222         if (!member || !parent)
223                 return -ENOENT;
224
225         list_for_each_entry(list, &member->groups, next_group) {
226                 if (list->group == parent) {
227                         list_del(&list->next_group);
228                         list_del(&list->next_member);
229                         kfree(list);
230                         return 0;
231                 }
232         }
233         return -ENOENT;
234 }
235
236 /*
237  * The full config is read in one go, only called from open_ctree()
238  * It doesn't use any locking, as at this point we're still single-threaded
239  */
240 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
241 {
242         struct btrfs_key key;
243         struct btrfs_key found_key;
244         struct btrfs_root *quota_root = fs_info->quota_root;
245         struct btrfs_path *path = NULL;
246         struct extent_buffer *l;
247         int slot;
248         int ret = 0;
249         u64 flags = 0;
250
251         if (!fs_info->quota_enabled)
252                 return 0;
253
254         path = btrfs_alloc_path();
255         if (!path) {
256                 ret = -ENOMEM;
257                 goto out;
258         }
259
260         /* default this to quota off, in case no status key is found */
261         fs_info->qgroup_flags = 0;
262
263         /*
264          * pass 1: read status, all qgroup infos and limits
265          */
266         key.objectid = 0;
267         key.type = 0;
268         key.offset = 0;
269         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
270         if (ret)
271                 goto out;
272
273         while (1) {
274                 struct btrfs_qgroup *qgroup;
275
276                 slot = path->slots[0];
277                 l = path->nodes[0];
278                 btrfs_item_key_to_cpu(l, &found_key, slot);
279
280                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
281                         struct btrfs_qgroup_status_item *ptr;
282
283                         ptr = btrfs_item_ptr(l, slot,
284                                              struct btrfs_qgroup_status_item);
285
286                         if (btrfs_qgroup_status_version(l, ptr) !=
287                             BTRFS_QGROUP_STATUS_VERSION) {
288                                 printk(KERN_ERR
289                                  "btrfs: old qgroup version, quota disabled\n");
290                                 goto out;
291                         }
292                         if (btrfs_qgroup_status_generation(l, ptr) !=
293                             fs_info->generation) {
294                                 flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
295                                 printk(KERN_ERR
296                                         "btrfs: qgroup generation mismatch, "
297                                         "marked as inconsistent\n");
298                         }
299                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
300                                                                           ptr);
301                         /* FIXME read scan element */
302                         goto next1;
303                 }
304
305                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
306                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
307                         goto next1;
308
309                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
310                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
311                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
312                         printk(KERN_ERR "btrfs: inconsitent qgroup config\n");
313                         flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
314                 }
315                 if (!qgroup) {
316                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
317                         if (IS_ERR(qgroup)) {
318                                 ret = PTR_ERR(qgroup);
319                                 goto out;
320                         }
321                 }
322                 switch (found_key.type) {
323                 case BTRFS_QGROUP_INFO_KEY: {
324                         struct btrfs_qgroup_info_item *ptr;
325
326                         ptr = btrfs_item_ptr(l, slot,
327                                              struct btrfs_qgroup_info_item);
328                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
329                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
330                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
331                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
332                         /* generation currently unused */
333                         break;
334                 }
335                 case BTRFS_QGROUP_LIMIT_KEY: {
336                         struct btrfs_qgroup_limit_item *ptr;
337
338                         ptr = btrfs_item_ptr(l, slot,
339                                              struct btrfs_qgroup_limit_item);
340                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
341                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
342                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
343                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
344                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
345                         break;
346                 }
347                 }
348 next1:
349                 ret = btrfs_next_item(quota_root, path);
350                 if (ret < 0)
351                         goto out;
352                 if (ret)
353                         break;
354         }
355         btrfs_release_path(path);
356
357         /*
358          * pass 2: read all qgroup relations
359          */
360         key.objectid = 0;
361         key.type = BTRFS_QGROUP_RELATION_KEY;
362         key.offset = 0;
363         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
364         if (ret)
365                 goto out;
366         while (1) {
367                 slot = path->slots[0];
368                 l = path->nodes[0];
369                 btrfs_item_key_to_cpu(l, &found_key, slot);
370
371                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
372                         goto next2;
373
374                 if (found_key.objectid > found_key.offset) {
375                         /* parent <- member, not needed to build config */
376                         /* FIXME should we omit the key completely? */
377                         goto next2;
378                 }
379
380                 ret = add_relation_rb(fs_info, found_key.objectid,
381                                       found_key.offset);
382                 if (ret)
383                         goto out;
384 next2:
385                 ret = btrfs_next_item(quota_root, path);
386                 if (ret < 0)
387                         goto out;
388                 if (ret)
389                         break;
390         }
391 out:
392         fs_info->qgroup_flags |= flags;
393         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON)) {
394                 fs_info->quota_enabled = 0;
395                 fs_info->pending_quota_state = 0;
396         }
397         btrfs_free_path(path);
398
399         return ret < 0 ? ret : 0;
400 }
401
402 /*
403  * This is only called from close_ctree() or open_ctree(), both in single-
404  * treaded paths. Clean up the in-memory structures. No locking needed.
405  */
406 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
407 {
408         struct rb_node *n;
409         struct btrfs_qgroup *qgroup;
410         struct btrfs_qgroup_list *list;
411
412         while ((n = rb_first(&fs_info->qgroup_tree))) {
413                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
414                 rb_erase(n, &fs_info->qgroup_tree);
415
416                 WARN_ON(!list_empty(&qgroup->dirty));
417
418                 while (!list_empty(&qgroup->groups)) {
419                         list = list_first_entry(&qgroup->groups,
420                                                 struct btrfs_qgroup_list,
421                                                 next_group);
422                         list_del(&list->next_group);
423                         list_del(&list->next_member);
424                         kfree(list);
425                 }
426
427                 while (!list_empty(&qgroup->members)) {
428                         list = list_first_entry(&qgroup->members,
429                                                 struct btrfs_qgroup_list,
430                                                 next_member);
431                         list_del(&list->next_group);
432                         list_del(&list->next_member);
433                         kfree(list);
434                 }
435                 kfree(qgroup);
436         }
437 }
438
439 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
440                                     struct btrfs_root *quota_root,
441                                     u64 src, u64 dst)
442 {
443         int ret;
444         struct btrfs_path *path;
445         struct btrfs_key key;
446
447         path = btrfs_alloc_path();
448         if (!path)
449                 return -ENOMEM;
450
451         key.objectid = src;
452         key.type = BTRFS_QGROUP_RELATION_KEY;
453         key.offset = dst;
454
455         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
456
457         btrfs_mark_buffer_dirty(path->nodes[0]);
458
459         btrfs_free_path(path);
460         return ret;
461 }
462
463 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
464                                     struct btrfs_root *quota_root,
465                                     u64 src, u64 dst)
466 {
467         int ret;
468         struct btrfs_path *path;
469         struct btrfs_key key;
470
471         path = btrfs_alloc_path();
472         if (!path)
473                 return -ENOMEM;
474
475         key.objectid = src;
476         key.type = BTRFS_QGROUP_RELATION_KEY;
477         key.offset = dst;
478
479         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
480         if (ret < 0)
481                 goto out;
482
483         if (ret > 0) {
484                 ret = -ENOENT;
485                 goto out;
486         }
487
488         ret = btrfs_del_item(trans, quota_root, path);
489 out:
490         btrfs_free_path(path);
491         return ret;
492 }
493
494 static int add_qgroup_item(struct btrfs_trans_handle *trans,
495                            struct btrfs_root *quota_root, u64 qgroupid)
496 {
497         int ret;
498         struct btrfs_path *path;
499         struct btrfs_qgroup_info_item *qgroup_info;
500         struct btrfs_qgroup_limit_item *qgroup_limit;
501         struct extent_buffer *leaf;
502         struct btrfs_key key;
503
504         path = btrfs_alloc_path();
505         if (!path)
506                 return -ENOMEM;
507
508         key.objectid = 0;
509         key.type = BTRFS_QGROUP_INFO_KEY;
510         key.offset = qgroupid;
511
512         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
513                                       sizeof(*qgroup_info));
514         if (ret)
515                 goto out;
516
517         leaf = path->nodes[0];
518         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
519                                  struct btrfs_qgroup_info_item);
520         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
521         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
522         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
523         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
524         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
525
526         btrfs_mark_buffer_dirty(leaf);
527
528         btrfs_release_path(path);
529
530         key.type = BTRFS_QGROUP_LIMIT_KEY;
531         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
532                                       sizeof(*qgroup_limit));
533         if (ret)
534                 goto out;
535
536         leaf = path->nodes[0];
537         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
538                                   struct btrfs_qgroup_limit_item);
539         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
540         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
541         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
542         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
543         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
544
545         btrfs_mark_buffer_dirty(leaf);
546
547         ret = 0;
548 out:
549         btrfs_free_path(path);
550         return ret;
551 }
552
553 static int del_qgroup_item(struct btrfs_trans_handle *trans,
554                            struct btrfs_root *quota_root, u64 qgroupid)
555 {
556         int ret;
557         struct btrfs_path *path;
558         struct btrfs_key key;
559
560         path = btrfs_alloc_path();
561         if (!path)
562                 return -ENOMEM;
563
564         key.objectid = 0;
565         key.type = BTRFS_QGROUP_INFO_KEY;
566         key.offset = qgroupid;
567         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
568         if (ret < 0)
569                 goto out;
570
571         if (ret > 0) {
572                 ret = -ENOENT;
573                 goto out;
574         }
575
576         ret = btrfs_del_item(trans, quota_root, path);
577         if (ret)
578                 goto out;
579
580         btrfs_release_path(path);
581
582         key.type = BTRFS_QGROUP_LIMIT_KEY;
583         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
584         if (ret < 0)
585                 goto out;
586
587         if (ret > 0) {
588                 ret = -ENOENT;
589                 goto out;
590         }
591
592         ret = btrfs_del_item(trans, quota_root, path);
593
594 out:
595         btrfs_free_path(path);
596         return ret;
597 }
598
599 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
600                                     struct btrfs_root *root, u64 qgroupid,
601                                     u64 flags, u64 max_rfer, u64 max_excl,
602                                     u64 rsv_rfer, u64 rsv_excl)
603 {
604         struct btrfs_path *path;
605         struct btrfs_key key;
606         struct extent_buffer *l;
607         struct btrfs_qgroup_limit_item *qgroup_limit;
608         int ret;
609         int slot;
610
611         key.objectid = 0;
612         key.type = BTRFS_QGROUP_LIMIT_KEY;
613         key.offset = qgroupid;
614
615         path = btrfs_alloc_path();
616         BUG_ON(!path);
617         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
618         if (ret > 0)
619                 ret = -ENOENT;
620
621         if (ret)
622                 goto out;
623
624         l = path->nodes[0];
625         slot = path->slots[0];
626         qgroup_limit = btrfs_item_ptr(l, path->slots[0],
627                                       struct btrfs_qgroup_limit_item);
628         btrfs_set_qgroup_limit_flags(l, qgroup_limit, flags);
629         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, max_rfer);
630         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, max_excl);
631         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, rsv_rfer);
632         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, rsv_excl);
633
634         btrfs_mark_buffer_dirty(l);
635
636 out:
637         btrfs_free_path(path);
638         return ret;
639 }
640
641 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
642                                    struct btrfs_root *root,
643                                    struct btrfs_qgroup *qgroup)
644 {
645         struct btrfs_path *path;
646         struct btrfs_key key;
647         struct extent_buffer *l;
648         struct btrfs_qgroup_info_item *qgroup_info;
649         int ret;
650         int slot;
651
652         key.objectid = 0;
653         key.type = BTRFS_QGROUP_INFO_KEY;
654         key.offset = qgroup->qgroupid;
655
656         path = btrfs_alloc_path();
657         BUG_ON(!path);
658         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
659         if (ret > 0)
660                 ret = -ENOENT;
661
662         if (ret)
663                 goto out;
664
665         l = path->nodes[0];
666         slot = path->slots[0];
667         qgroup_info = btrfs_item_ptr(l, path->slots[0],
668                                  struct btrfs_qgroup_info_item);
669         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
670         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
671         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
672         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
673         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
674
675         btrfs_mark_buffer_dirty(l);
676
677 out:
678         btrfs_free_path(path);
679         return ret;
680 }
681
682 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
683                                      struct btrfs_fs_info *fs_info,
684                                     struct btrfs_root *root)
685 {
686         struct btrfs_path *path;
687         struct btrfs_key key;
688         struct extent_buffer *l;
689         struct btrfs_qgroup_status_item *ptr;
690         int ret;
691         int slot;
692
693         key.objectid = 0;
694         key.type = BTRFS_QGROUP_STATUS_KEY;
695         key.offset = 0;
696
697         path = btrfs_alloc_path();
698         BUG_ON(!path);
699         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
700         if (ret > 0)
701                 ret = -ENOENT;
702
703         if (ret)
704                 goto out;
705
706         l = path->nodes[0];
707         slot = path->slots[0];
708         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
709         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
710         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
711         /* XXX scan */
712
713         btrfs_mark_buffer_dirty(l);
714
715 out:
716         btrfs_free_path(path);
717         return ret;
718 }
719
720 /*
721  * called with qgroup_lock held
722  */
723 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
724                                   struct btrfs_root *root)
725 {
726         struct btrfs_path *path;
727         struct btrfs_key key;
728         int ret;
729
730         if (!root)
731                 return -EINVAL;
732
733         path = btrfs_alloc_path();
734         if (!path)
735                 return -ENOMEM;
736
737         while (1) {
738                 key.objectid = 0;
739                 key.offset = 0;
740                 key.type = 0;
741
742                 path->leave_spinning = 1;
743                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
744                 if (ret > 0) {
745                         if (path->slots[0] == 0)
746                                 break;
747                         path->slots[0]--;
748                 } else if (ret < 0) {
749                         break;
750                 }
751
752                 ret = btrfs_del_item(trans, root, path);
753                 if (ret)
754                         goto out;
755                 btrfs_release_path(path);
756         }
757         ret = 0;
758 out:
759         root->fs_info->pending_quota_state = 0;
760         btrfs_free_path(path);
761         return ret;
762 }
763
764 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
765                        struct btrfs_fs_info *fs_info)
766 {
767         struct btrfs_root *quota_root;
768         struct btrfs_path *path = NULL;
769         struct btrfs_qgroup_status_item *ptr;
770         struct extent_buffer *leaf;
771         struct btrfs_key key;
772         int ret = 0;
773
774         spin_lock(&fs_info->qgroup_lock);
775         if (fs_info->quota_root) {
776                 fs_info->pending_quota_state = 1;
777                 spin_unlock(&fs_info->qgroup_lock);
778                 goto out;
779         }
780         spin_unlock(&fs_info->qgroup_lock);
781
782         /*
783          * initially create the quota tree
784          */
785         quota_root = btrfs_create_tree(trans, fs_info,
786                                        BTRFS_QUOTA_TREE_OBJECTID);
787         if (IS_ERR(quota_root)) {
788                 ret =  PTR_ERR(quota_root);
789                 goto out;
790         }
791
792         path = btrfs_alloc_path();
793         if (!path)
794                 return -ENOMEM;
795
796         key.objectid = 0;
797         key.type = BTRFS_QGROUP_STATUS_KEY;
798         key.offset = 0;
799
800         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
801                                       sizeof(*ptr));
802         if (ret)
803                 goto out;
804
805         leaf = path->nodes[0];
806         ptr = btrfs_item_ptr(leaf, path->slots[0],
807                                  struct btrfs_qgroup_status_item);
808         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
809         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
810         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
811                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
812         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
813         btrfs_set_qgroup_status_scan(leaf, ptr, 0);
814
815         btrfs_mark_buffer_dirty(leaf);
816
817         spin_lock(&fs_info->qgroup_lock);
818         fs_info->quota_root = quota_root;
819         fs_info->pending_quota_state = 1;
820         spin_unlock(&fs_info->qgroup_lock);
821 out:
822         btrfs_free_path(path);
823         return ret;
824 }
825
826 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
827                         struct btrfs_fs_info *fs_info)
828 {
829         struct btrfs_root *tree_root = fs_info->tree_root;
830         struct btrfs_root *quota_root;
831         int ret = 0;
832
833         spin_lock(&fs_info->qgroup_lock);
834         fs_info->quota_enabled = 0;
835         fs_info->pending_quota_state = 0;
836         quota_root = fs_info->quota_root;
837         fs_info->quota_root = NULL;
838         btrfs_free_qgroup_config(fs_info);
839         spin_unlock(&fs_info->qgroup_lock);
840
841         if (!quota_root)
842                 return -EINVAL;
843
844         ret = btrfs_clean_quota_tree(trans, quota_root);
845         if (ret)
846                 goto out;
847
848         ret = btrfs_del_root(trans, tree_root, &quota_root->root_key);
849         if (ret)
850                 goto out;
851
852         list_del(&quota_root->dirty_list);
853
854         btrfs_tree_lock(quota_root->node);
855         clean_tree_block(trans, tree_root, quota_root->node);
856         btrfs_tree_unlock(quota_root->node);
857         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
858
859         free_extent_buffer(quota_root->node);
860         free_extent_buffer(quota_root->commit_root);
861         kfree(quota_root);
862 out:
863         return ret;
864 }
865
866 int btrfs_quota_rescan(struct btrfs_fs_info *fs_info)
867 {
868         /* FIXME */
869         return 0;
870 }
871
872 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
873                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
874 {
875         struct btrfs_root *quota_root;
876         int ret = 0;
877
878         quota_root = fs_info->quota_root;
879         if (!quota_root)
880                 return -EINVAL;
881
882         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
883         if (ret)
884                 return ret;
885
886         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
887         if (ret) {
888                 del_qgroup_relation_item(trans, quota_root, src, dst);
889                 return ret;
890         }
891
892         spin_lock(&fs_info->qgroup_lock);
893         ret = add_relation_rb(quota_root->fs_info, src, dst);
894         spin_unlock(&fs_info->qgroup_lock);
895
896         return ret;
897 }
898
899 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
900                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
901 {
902         struct btrfs_root *quota_root;
903         int ret = 0;
904         int err;
905
906         quota_root = fs_info->quota_root;
907         if (!quota_root)
908                 return -EINVAL;
909
910         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
911         err = del_qgroup_relation_item(trans, quota_root, dst, src);
912         if (err && !ret)
913                 ret = err;
914
915         spin_lock(&fs_info->qgroup_lock);
916         del_relation_rb(fs_info, src, dst);
917
918         spin_unlock(&fs_info->qgroup_lock);
919
920         return ret;
921 }
922
923 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
924                         struct btrfs_fs_info *fs_info, u64 qgroupid, char *name)
925 {
926         struct btrfs_root *quota_root;
927         struct btrfs_qgroup *qgroup;
928         int ret = 0;
929
930         quota_root = fs_info->quota_root;
931         if (!quota_root)
932                 return -EINVAL;
933
934         ret = add_qgroup_item(trans, quota_root, qgroupid);
935
936         spin_lock(&fs_info->qgroup_lock);
937         qgroup = add_qgroup_rb(fs_info, qgroupid);
938         spin_unlock(&fs_info->qgroup_lock);
939
940         if (IS_ERR(qgroup))
941                 ret = PTR_ERR(qgroup);
942
943         return ret;
944 }
945
946 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
947                         struct btrfs_fs_info *fs_info, u64 qgroupid)
948 {
949         struct btrfs_root *quota_root;
950         int ret = 0;
951
952         quota_root = fs_info->quota_root;
953         if (!quota_root)
954                 return -EINVAL;
955
956         ret = del_qgroup_item(trans, quota_root, qgroupid);
957
958         spin_lock(&fs_info->qgroup_lock);
959         del_qgroup_rb(quota_root->fs_info, qgroupid);
960
961         spin_unlock(&fs_info->qgroup_lock);
962
963         return ret;
964 }
965
966 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
967                        struct btrfs_fs_info *fs_info, u64 qgroupid,
968                        struct btrfs_qgroup_limit *limit)
969 {
970         struct btrfs_root *quota_root = fs_info->quota_root;
971         struct btrfs_qgroup *qgroup;
972         int ret = 0;
973
974         if (!quota_root)
975                 return -EINVAL;
976
977         ret = update_qgroup_limit_item(trans, quota_root, qgroupid,
978                                        limit->flags, limit->max_rfer,
979                                        limit->max_excl, limit->rsv_rfer,
980                                        limit->rsv_excl);
981         if (ret) {
982                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
983                 printk(KERN_INFO "unable to update quota limit for %llu\n",
984                        (unsigned long long)qgroupid);
985         }
986
987         spin_lock(&fs_info->qgroup_lock);
988
989         qgroup = find_qgroup_rb(fs_info, qgroupid);
990         if (!qgroup) {
991                 ret = -ENOENT;
992                 goto unlock;
993         }
994         qgroup->lim_flags = limit->flags;
995         qgroup->max_rfer = limit->max_rfer;
996         qgroup->max_excl = limit->max_excl;
997         qgroup->rsv_rfer = limit->rsv_rfer;
998         qgroup->rsv_excl = limit->rsv_excl;
999
1000 unlock:
1001         spin_unlock(&fs_info->qgroup_lock);
1002
1003         return ret;
1004 }
1005
1006 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1007                          struct btrfs_qgroup *qgroup)
1008 {
1009         if (list_empty(&qgroup->dirty))
1010                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1011 }
1012
1013 /*
1014  * btrfs_qgroup_record_ref is called when the ref is added or deleted. it puts
1015  * the modification into a list that's later used by btrfs_end_transaction to
1016  * pass the recorded modifications on to btrfs_qgroup_account_ref.
1017  */
1018 int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans,
1019                             struct btrfs_delayed_ref_node *node,
1020                             struct btrfs_delayed_extent_op *extent_op)
1021 {
1022         struct qgroup_update *u;
1023
1024         BUG_ON(!trans->delayed_ref_elem.seq);
1025         u = kmalloc(sizeof(*u), GFP_NOFS);
1026         if (!u)
1027                 return -ENOMEM;
1028
1029         u->node = node;
1030         u->extent_op = extent_op;
1031         list_add_tail(&u->list, &trans->qgroup_ref_list);
1032
1033         return 0;
1034 }
1035
1036 /*
1037  * btrfs_qgroup_account_ref is called for every ref that is added to or deleted
1038  * from the fs. First, all roots referencing the extent are searched, and
1039  * then the space is accounted accordingly to the different roots. The
1040  * accounting algorithm works in 3 steps documented inline.
1041  */
1042 int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans,
1043                              struct btrfs_fs_info *fs_info,
1044                              struct btrfs_delayed_ref_node *node,
1045                              struct btrfs_delayed_extent_op *extent_op)
1046 {
1047         struct btrfs_key ins;
1048         struct btrfs_root *quota_root;
1049         u64 ref_root;
1050         struct btrfs_qgroup *qgroup;
1051         struct ulist_node *unode;
1052         struct ulist *roots = NULL;
1053         struct ulist *tmp = NULL;
1054         struct ulist_iterator uiter;
1055         u64 seq;
1056         int ret = 0;
1057         int sgn;
1058
1059         if (!fs_info->quota_enabled)
1060                 return 0;
1061
1062         BUG_ON(!fs_info->quota_root);
1063
1064         ins.objectid = node->bytenr;
1065         ins.offset = node->num_bytes;
1066         ins.type = BTRFS_EXTENT_ITEM_KEY;
1067
1068         if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
1069             node->type == BTRFS_SHARED_BLOCK_REF_KEY) {
1070                 struct btrfs_delayed_tree_ref *ref;
1071                 ref = btrfs_delayed_node_to_tree_ref(node);
1072                 ref_root = ref->root;
1073         } else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
1074                    node->type == BTRFS_SHARED_DATA_REF_KEY) {
1075                 struct btrfs_delayed_data_ref *ref;
1076                 ref = btrfs_delayed_node_to_data_ref(node);
1077                 ref_root = ref->root;
1078         } else {
1079                 BUG();
1080         }
1081
1082         if (!is_fstree(ref_root)) {
1083                 /*
1084                  * non-fs-trees are not being accounted
1085                  */
1086                 return 0;
1087         }
1088
1089         switch (node->action) {
1090         case BTRFS_ADD_DELAYED_REF:
1091         case BTRFS_ADD_DELAYED_EXTENT:
1092                 sgn = 1;
1093                 break;
1094         case BTRFS_DROP_DELAYED_REF:
1095                 sgn = -1;
1096                 break;
1097         case BTRFS_UPDATE_DELAYED_HEAD:
1098                 return 0;
1099         default:
1100                 BUG();
1101         }
1102
1103         /*
1104          * the delayed ref sequence number we pass depends on the direction of
1105          * the operation. for add operations, we pass (node->seq - 1) to skip
1106          * the delayed ref's current sequence number, because we need the state
1107          * of the tree before the add operation. for delete operations, we pass
1108          * (node->seq) to include the delayed ref's current sequence number,
1109          * because we need the state of the tree after the delete operation.
1110          */
1111         ret = btrfs_find_all_roots(trans, fs_info, node->bytenr,
1112                                    sgn > 0 ? node->seq - 1 : node->seq, &roots);
1113         if (ret < 0)
1114                 goto out;
1115
1116         spin_lock(&fs_info->qgroup_lock);
1117         quota_root = fs_info->quota_root;
1118         if (!quota_root)
1119                 goto unlock;
1120
1121         qgroup = find_qgroup_rb(fs_info, ref_root);
1122         if (!qgroup)
1123                 goto unlock;
1124
1125         /*
1126          * step 1: for each old ref, visit all nodes once and inc refcnt
1127          */
1128         tmp = ulist_alloc(GFP_ATOMIC);
1129         if (!tmp) {
1130                 ret = -ENOMEM;
1131                 goto unlock;
1132         }
1133         seq = fs_info->qgroup_seq;
1134         fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */
1135
1136         ULIST_ITER_INIT(&uiter);
1137         while ((unode = ulist_next(roots, &uiter))) {
1138                 struct ulist_node *tmp_unode;
1139                 struct ulist_iterator tmp_uiter;
1140                 struct btrfs_qgroup *qg;
1141
1142                 qg = find_qgroup_rb(fs_info, unode->val);
1143                 if (!qg)
1144                         continue;
1145
1146                 ulist_reinit(tmp);
1147                                                 /* XXX id not needed */
1148                 ulist_add(tmp, qg->qgroupid, (u64)(uintptr_t)qg, GFP_ATOMIC);
1149                 ULIST_ITER_INIT(&tmp_uiter);
1150                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1151                         struct btrfs_qgroup_list *glist;
1152
1153                         qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
1154                         if (qg->refcnt < seq)
1155                                 qg->refcnt = seq + 1;
1156                         else
1157                                 ++qg->refcnt;
1158
1159                         list_for_each_entry(glist, &qg->groups, next_group) {
1160                                 ulist_add(tmp, glist->group->qgroupid,
1161                                           (u64)(uintptr_t)glist->group,
1162                                           GFP_ATOMIC);
1163                         }
1164                 }
1165         }
1166
1167         /*
1168          * step 2: walk from the new root
1169          */
1170         ulist_reinit(tmp);
1171         ulist_add(tmp, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1172         ULIST_ITER_INIT(&uiter);
1173         while ((unode = ulist_next(tmp, &uiter))) {
1174                 struct btrfs_qgroup *qg;
1175                 struct btrfs_qgroup_list *glist;
1176
1177                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1178                 if (qg->refcnt < seq) {
1179                         /* not visited by step 1 */
1180                         qg->rfer += sgn * node->num_bytes;
1181                         qg->rfer_cmpr += sgn * node->num_bytes;
1182                         if (roots->nnodes == 0) {
1183                                 qg->excl += sgn * node->num_bytes;
1184                                 qg->excl_cmpr += sgn * node->num_bytes;
1185                         }
1186                         qgroup_dirty(fs_info, qg);
1187                 }
1188                 WARN_ON(qg->tag >= seq);
1189                 qg->tag = seq;
1190
1191                 list_for_each_entry(glist, &qg->groups, next_group) {
1192                         ulist_add(tmp, glist->group->qgroupid,
1193                                   (uintptr_t)glist->group, GFP_ATOMIC);
1194                 }
1195         }
1196
1197         /*
1198          * step 3: walk again from old refs
1199          */
1200         ULIST_ITER_INIT(&uiter);
1201         while ((unode = ulist_next(roots, &uiter))) {
1202                 struct btrfs_qgroup *qg;
1203                 struct ulist_node *tmp_unode;
1204                 struct ulist_iterator tmp_uiter;
1205
1206                 qg = find_qgroup_rb(fs_info, unode->val);
1207                 if (!qg)
1208                         continue;
1209
1210                 ulist_reinit(tmp);
1211                 ulist_add(tmp, qg->qgroupid, (uintptr_t)qg, GFP_ATOMIC);
1212                 ULIST_ITER_INIT(&tmp_uiter);
1213                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1214                         struct btrfs_qgroup_list *glist;
1215
1216                         qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
1217                         if (qg->tag == seq)
1218                                 continue;
1219
1220                         if (qg->refcnt - seq == roots->nnodes) {
1221                                 qg->excl -= sgn * node->num_bytes;
1222                                 qg->excl_cmpr -= sgn * node->num_bytes;
1223                                 qgroup_dirty(fs_info, qg);
1224                         }
1225
1226                         list_for_each_entry(glist, &qg->groups, next_group) {
1227                                 ulist_add(tmp, glist->group->qgroupid,
1228                                           (uintptr_t)glist->group,
1229                                           GFP_ATOMIC);
1230                         }
1231                 }
1232         }
1233         ret = 0;
1234 unlock:
1235         spin_unlock(&fs_info->qgroup_lock);
1236 out:
1237         ulist_free(roots);
1238         ulist_free(tmp);
1239
1240         return ret;
1241 }
1242
1243 /*
1244  * called from commit_transaction. Writes all changed qgroups to disk.
1245  */
1246 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
1247                       struct btrfs_fs_info *fs_info)
1248 {
1249         struct btrfs_root *quota_root = fs_info->quota_root;
1250         int ret = 0;
1251
1252         if (!quota_root)
1253                 goto out;
1254
1255         fs_info->quota_enabled = fs_info->pending_quota_state;
1256
1257         spin_lock(&fs_info->qgroup_lock);
1258         while (!list_empty(&fs_info->dirty_qgroups)) {
1259                 struct btrfs_qgroup *qgroup;
1260                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
1261                                           struct btrfs_qgroup, dirty);
1262                 list_del_init(&qgroup->dirty);
1263                 spin_unlock(&fs_info->qgroup_lock);
1264                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
1265                 if (ret)
1266                         fs_info->qgroup_flags |=
1267                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1268                 spin_lock(&fs_info->qgroup_lock);
1269         }
1270         if (fs_info->quota_enabled)
1271                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
1272         else
1273                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1274         spin_unlock(&fs_info->qgroup_lock);
1275
1276         ret = update_qgroup_status_item(trans, fs_info, quota_root);
1277         if (ret)
1278                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1279
1280 out:
1281
1282         return ret;
1283 }
1284
1285 /*
1286  * copy the acounting information between qgroups. This is necessary when a
1287  * snapshot or a subvolume is created
1288  */
1289 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
1290                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
1291                          struct btrfs_qgroup_inherit *inherit)
1292 {
1293         int ret = 0;
1294         int i;
1295         u64 *i_qgroups;
1296         struct btrfs_root *quota_root = fs_info->quota_root;
1297         struct btrfs_qgroup *srcgroup;
1298         struct btrfs_qgroup *dstgroup;
1299         u32 level_size = 0;
1300
1301         if (!fs_info->quota_enabled)
1302                 return 0;
1303
1304         if (!quota_root)
1305                 return -EINVAL;
1306
1307         /*
1308          * create a tracking group for the subvol itself
1309          */
1310         ret = add_qgroup_item(trans, quota_root, objectid);
1311         if (ret)
1312                 goto out;
1313
1314         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
1315                 ret = update_qgroup_limit_item(trans, quota_root, objectid,
1316                                                inherit->lim.flags,
1317                                                inherit->lim.max_rfer,
1318                                                inherit->lim.max_excl,
1319                                                inherit->lim.rsv_rfer,
1320                                                inherit->lim.rsv_excl);
1321                 if (ret)
1322                         goto out;
1323         }
1324
1325         if (srcid) {
1326                 struct btrfs_root *srcroot;
1327                 struct btrfs_key srckey;
1328                 int srcroot_level;
1329
1330                 srckey.objectid = srcid;
1331                 srckey.type = BTRFS_ROOT_ITEM_KEY;
1332                 srckey.offset = (u64)-1;
1333                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
1334                 if (IS_ERR(srcroot)) {
1335                         ret = PTR_ERR(srcroot);
1336                         goto out;
1337                 }
1338
1339                 rcu_read_lock();
1340                 srcroot_level = btrfs_header_level(srcroot->node);
1341                 level_size = btrfs_level_size(srcroot, srcroot_level);
1342                 rcu_read_unlock();
1343         }
1344
1345         /*
1346          * add qgroup to all inherited groups
1347          */
1348         if (inherit) {
1349                 i_qgroups = (u64 *)(inherit + 1);
1350                 for (i = 0; i < inherit->num_qgroups; ++i) {
1351                         ret = add_qgroup_relation_item(trans, quota_root,
1352                                                        objectid, *i_qgroups);
1353                         if (ret)
1354                                 goto out;
1355                         ret = add_qgroup_relation_item(trans, quota_root,
1356                                                        *i_qgroups, objectid);
1357                         if (ret)
1358                                 goto out;
1359                         ++i_qgroups;
1360                 }
1361         }
1362
1363
1364         spin_lock(&fs_info->qgroup_lock);
1365
1366         dstgroup = add_qgroup_rb(fs_info, objectid);
1367         if (IS_ERR(dstgroup)) {
1368                 ret = PTR_ERR(dstgroup);
1369                 goto unlock;
1370         }
1371
1372         if (srcid) {
1373                 srcgroup = find_qgroup_rb(fs_info, srcid);
1374                 if (!srcgroup)
1375                         goto unlock;
1376                 dstgroup->rfer = srcgroup->rfer - level_size;
1377                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr - level_size;
1378                 srcgroup->excl = level_size;
1379                 srcgroup->excl_cmpr = level_size;
1380                 qgroup_dirty(fs_info, dstgroup);
1381                 qgroup_dirty(fs_info, srcgroup);
1382         }
1383
1384         if (!inherit)
1385                 goto unlock;
1386
1387         i_qgroups = (u64 *)(inherit + 1);
1388         for (i = 0; i < inherit->num_qgroups; ++i) {
1389                 ret = add_relation_rb(quota_root->fs_info, objectid,
1390                                       *i_qgroups);
1391                 if (ret)
1392                         goto unlock;
1393                 ++i_qgroups;
1394         }
1395
1396         for (i = 0; i <  inherit->num_ref_copies; ++i) {
1397                 struct btrfs_qgroup *src;
1398                 struct btrfs_qgroup *dst;
1399
1400                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
1401                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
1402
1403                 if (!src || !dst) {
1404                         ret = -EINVAL;
1405                         goto unlock;
1406                 }
1407
1408                 dst->rfer = src->rfer - level_size;
1409                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
1410                 i_qgroups += 2;
1411         }
1412         for (i = 0; i <  inherit->num_excl_copies; ++i) {
1413                 struct btrfs_qgroup *src;
1414                 struct btrfs_qgroup *dst;
1415
1416                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
1417                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
1418
1419                 if (!src || !dst) {
1420                         ret = -EINVAL;
1421                         goto unlock;
1422                 }
1423
1424                 dst->excl = src->excl + level_size;
1425                 dst->excl_cmpr = src->excl_cmpr + level_size;
1426                 i_qgroups += 2;
1427         }
1428
1429 unlock:
1430         spin_unlock(&fs_info->qgroup_lock);
1431 out:
1432         return ret;
1433 }
1434
1435 /*
1436  * reserve some space for a qgroup and all its parents. The reservation takes
1437  * place with start_transaction or dealloc_reserve, similar to ENOSPC
1438  * accounting. If not enough space is available, EDQUOT is returned.
1439  * We assume that the requested space is new for all qgroups.
1440  */
1441 int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
1442 {
1443         struct btrfs_root *quota_root;
1444         struct btrfs_qgroup *qgroup;
1445         struct btrfs_fs_info *fs_info = root->fs_info;
1446         u64 ref_root = root->root_key.objectid;
1447         int ret = 0;
1448         struct ulist *ulist = NULL;
1449         struct ulist_node *unode;
1450         struct ulist_iterator uiter;
1451
1452         if (!is_fstree(ref_root))
1453                 return 0;
1454
1455         if (num_bytes == 0)
1456                 return 0;
1457
1458         spin_lock(&fs_info->qgroup_lock);
1459         quota_root = fs_info->quota_root;
1460         if (!quota_root)
1461                 goto out;
1462
1463         qgroup = find_qgroup_rb(fs_info, ref_root);
1464         if (!qgroup)
1465                 goto out;
1466
1467         /*
1468          * in a first step, we check all affected qgroups if any limits would
1469          * be exceeded
1470          */
1471         ulist = ulist_alloc(GFP_ATOMIC);
1472         ulist_add(ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1473         ULIST_ITER_INIT(&uiter);
1474         while ((unode = ulist_next(ulist, &uiter))) {
1475                 struct btrfs_qgroup *qg;
1476                 struct btrfs_qgroup_list *glist;
1477
1478                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1479
1480                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
1481                     qg->reserved + qg->rfer + num_bytes >
1482                     qg->max_rfer)
1483                         ret = -EDQUOT;
1484
1485                 if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
1486                     qg->reserved + qg->excl + num_bytes >
1487                     qg->max_excl)
1488                         ret = -EDQUOT;
1489
1490                 list_for_each_entry(glist, &qg->groups, next_group) {
1491                         ulist_add(ulist, glist->group->qgroupid,
1492                                   (uintptr_t)glist->group, GFP_ATOMIC);
1493                 }
1494         }
1495         if (ret)
1496                 goto out;
1497
1498         /*
1499          * no limits exceeded, now record the reservation into all qgroups
1500          */
1501         ULIST_ITER_INIT(&uiter);
1502         while ((unode = ulist_next(ulist, &uiter))) {
1503                 struct btrfs_qgroup *qg;
1504
1505                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1506
1507                 qg->reserved += num_bytes;
1508         }
1509
1510 out:
1511         spin_unlock(&fs_info->qgroup_lock);
1512         ulist_free(ulist);
1513
1514         return ret;
1515 }
1516
1517 void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes)
1518 {
1519         struct btrfs_root *quota_root;
1520         struct btrfs_qgroup *qgroup;
1521         struct btrfs_fs_info *fs_info = root->fs_info;
1522         struct ulist *ulist = NULL;
1523         struct ulist_node *unode;
1524         struct ulist_iterator uiter;
1525         u64 ref_root = root->root_key.objectid;
1526
1527         if (!is_fstree(ref_root))
1528                 return;
1529
1530         if (num_bytes == 0)
1531                 return;
1532
1533         spin_lock(&fs_info->qgroup_lock);
1534
1535         quota_root = fs_info->quota_root;
1536         if (!quota_root)
1537                 goto out;
1538
1539         qgroup = find_qgroup_rb(fs_info, ref_root);
1540         if (!qgroup)
1541                 goto out;
1542
1543         ulist = ulist_alloc(GFP_ATOMIC);
1544         ulist_add(ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
1545         ULIST_ITER_INIT(&uiter);
1546         while ((unode = ulist_next(ulist, &uiter))) {
1547                 struct btrfs_qgroup *qg;
1548                 struct btrfs_qgroup_list *glist;
1549
1550                 qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
1551
1552                 qg->reserved -= num_bytes;
1553
1554                 list_for_each_entry(glist, &qg->groups, next_group) {
1555                         ulist_add(ulist, glist->group->qgroupid,
1556                                   (uintptr_t)glist->group, GFP_ATOMIC);
1557                 }
1558         }
1559
1560 out:
1561         spin_unlock(&fs_info->qgroup_lock);
1562         ulist_free(ulist);
1563 }
1564
1565 void assert_qgroups_uptodate(struct btrfs_trans_handle *trans)
1566 {
1567         if (list_empty(&trans->qgroup_ref_list) && !trans->delayed_ref_elem.seq)
1568                 return;
1569         printk(KERN_ERR "btrfs: qgroups not uptodate in trans handle %p: list is%s empty, seq is %llu\n",
1570                 trans, list_empty(&trans->qgroup_ref_list) ? "" : " not",
1571                 trans->delayed_ref_elem.seq);
1572         BUG();
1573 }