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TOMOYO Linux Cross Reference
Linux/fs/btrfs/qgroup.c

Version: ~ [ linux-5.13-rc7 ] ~ [ linux-5.12.12 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.45 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.127 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.195 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.237 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.273 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.273 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 /*
  2  * Copyright (C) 2011 STRATO.  All rights reserved.
  3  *
  4  * This program is free software; you can redistribute it and/or
  5  * modify it under the terms of the GNU General Public
  6  * License v2 as published by the Free Software Foundation.
  7  *
  8  * This program is distributed in the hope that it will be useful,
  9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 11  * General Public License for more details.
 12  *
 13  * You should have received a copy of the GNU General Public
 14  * License along with this program; if not, write to the
 15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 16  * Boston, MA 021110-1307, USA.
 17  */
 18 
 19 #include <linux/sched.h>
 20 #include <linux/pagemap.h>
 21 #include <linux/writeback.h>
 22 #include <linux/blkdev.h>
 23 #include <linux/rbtree.h>
 24 #include <linux/slab.h>
 25 #include <linux/workqueue.h>
 26 #include <linux/btrfs.h>
 27 
 28 #include "ctree.h"
 29 #include "transaction.h"
 30 #include "disk-io.h"
 31 #include "locking.h"
 32 #include "ulist.h"
 33 #include "backref.h"
 34 #include "extent_io.h"
 35 #include "qgroup.h"
 36 
 37 
 38 /* TODO XXX FIXME
 39  *  - subvol delete -> delete when ref goes to 0? delete limits also?
 40  *  - reorganize keys
 41  *  - compressed
 42  *  - sync
 43  *  - copy also limits on subvol creation
 44  *  - limit
 45  *  - caches fuer ulists
 46  *  - performance benchmarks
 47  *  - check all ioctl parameters
 48  */
 49 
 50 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
 51                                            int mod)
 52 {
 53         if (qg->old_refcnt < seq)
 54                 qg->old_refcnt = seq;
 55         qg->old_refcnt += mod;
 56 }
 57 
 58 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 59                                            int mod)
 60 {
 61         if (qg->new_refcnt < seq)
 62                 qg->new_refcnt = seq;
 63         qg->new_refcnt += mod;
 64 }
 65 
 66 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
 67 {
 68         if (qg->old_refcnt < seq)
 69                 return 0;
 70         return qg->old_refcnt - seq;
 71 }
 72 
 73 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
 74 {
 75         if (qg->new_refcnt < seq)
 76                 return 0;
 77         return qg->new_refcnt - seq;
 78 }
 79 
 80 /*
 81  * glue structure to represent the relations between qgroups.
 82  */
 83 struct btrfs_qgroup_list {
 84         struct list_head next_group;
 85         struct list_head next_member;
 86         struct btrfs_qgroup *group;
 87         struct btrfs_qgroup *member;
 88 };
 89 
 90 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
 91 {
 92         return (u64)(uintptr_t)qg;
 93 }
 94 
 95 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
 96 {
 97         return (struct btrfs_qgroup *)(uintptr_t)n->aux;
 98 }
 99 
100 static int
101 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
102                    int init_flags);
103 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
104 
105 /* must be called with qgroup_ioctl_lock held */
106 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
107                                            u64 qgroupid)
108 {
109         struct rb_node *n = fs_info->qgroup_tree.rb_node;
110         struct btrfs_qgroup *qgroup;
111 
112         while (n) {
113                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
114                 if (qgroup->qgroupid < qgroupid)
115                         n = n->rb_left;
116                 else if (qgroup->qgroupid > qgroupid)
117                         n = n->rb_right;
118                 else
119                         return qgroup;
120         }
121         return NULL;
122 }
123 
124 /* must be called with qgroup_lock held */
125 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
126                                           u64 qgroupid)
127 {
128         struct rb_node **p = &fs_info->qgroup_tree.rb_node;
129         struct rb_node *parent = NULL;
130         struct btrfs_qgroup *qgroup;
131 
132         while (*p) {
133                 parent = *p;
134                 qgroup = rb_entry(parent, struct btrfs_qgroup, node);
135 
136                 if (qgroup->qgroupid < qgroupid)
137                         p = &(*p)->rb_left;
138                 else if (qgroup->qgroupid > qgroupid)
139                         p = &(*p)->rb_right;
140                 else
141                         return qgroup;
142         }
143 
144         qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
145         if (!qgroup)
146                 return ERR_PTR(-ENOMEM);
147 
148         qgroup->qgroupid = qgroupid;
149         INIT_LIST_HEAD(&qgroup->groups);
150         INIT_LIST_HEAD(&qgroup->members);
151         INIT_LIST_HEAD(&qgroup->dirty);
152 
153         rb_link_node(&qgroup->node, parent, p);
154         rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
155 
156         return qgroup;
157 }
158 
159 static void __del_qgroup_rb(struct btrfs_qgroup *qgroup)
160 {
161         struct btrfs_qgroup_list *list;
162 
163         list_del(&qgroup->dirty);
164         while (!list_empty(&qgroup->groups)) {
165                 list = list_first_entry(&qgroup->groups,
166                                         struct btrfs_qgroup_list, next_group);
167                 list_del(&list->next_group);
168                 list_del(&list->next_member);
169                 kfree(list);
170         }
171 
172         while (!list_empty(&qgroup->members)) {
173                 list = list_first_entry(&qgroup->members,
174                                         struct btrfs_qgroup_list, next_member);
175                 list_del(&list->next_group);
176                 list_del(&list->next_member);
177                 kfree(list);
178         }
179         kfree(qgroup);
180 }
181 
182 /* must be called with qgroup_lock held */
183 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
184 {
185         struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
186 
187         if (!qgroup)
188                 return -ENOENT;
189 
190         rb_erase(&qgroup->node, &fs_info->qgroup_tree);
191         __del_qgroup_rb(qgroup);
192         return 0;
193 }
194 
195 /* must be called with qgroup_lock held */
196 static int add_relation_rb(struct btrfs_fs_info *fs_info,
197                            u64 memberid, u64 parentid)
198 {
199         struct btrfs_qgroup *member;
200         struct btrfs_qgroup *parent;
201         struct btrfs_qgroup_list *list;
202 
203         member = find_qgroup_rb(fs_info, memberid);
204         parent = find_qgroup_rb(fs_info, parentid);
205         if (!member || !parent)
206                 return -ENOENT;
207 
208         list = kzalloc(sizeof(*list), GFP_ATOMIC);
209         if (!list)
210                 return -ENOMEM;
211 
212         list->group = parent;
213         list->member = member;
214         list_add_tail(&list->next_group, &member->groups);
215         list_add_tail(&list->next_member, &parent->members);
216 
217         return 0;
218 }
219 
220 /* must be called with qgroup_lock held */
221 static int del_relation_rb(struct btrfs_fs_info *fs_info,
222                            u64 memberid, u64 parentid)
223 {
224         struct btrfs_qgroup *member;
225         struct btrfs_qgroup *parent;
226         struct btrfs_qgroup_list *list;
227 
228         member = find_qgroup_rb(fs_info, memberid);
229         parent = find_qgroup_rb(fs_info, parentid);
230         if (!member || !parent)
231                 return -ENOENT;
232 
233         list_for_each_entry(list, &member->groups, next_group) {
234                 if (list->group == parent) {
235                         list_del(&list->next_group);
236                         list_del(&list->next_member);
237                         kfree(list);
238                         return 0;
239                 }
240         }
241         return -ENOENT;
242 }
243 
244 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
245 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
246                                u64 rfer, u64 excl)
247 {
248         struct btrfs_qgroup *qgroup;
249 
250         qgroup = find_qgroup_rb(fs_info, qgroupid);
251         if (!qgroup)
252                 return -EINVAL;
253         if (qgroup->rfer != rfer || qgroup->excl != excl)
254                 return -EINVAL;
255         return 0;
256 }
257 #endif
258 
259 /*
260  * The full config is read in one go, only called from open_ctree()
261  * It doesn't use any locking, as at this point we're still single-threaded
262  */
263 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
264 {
265         struct btrfs_key key;
266         struct btrfs_key found_key;
267         struct btrfs_root *quota_root = fs_info->quota_root;
268         struct btrfs_path *path = NULL;
269         struct extent_buffer *l;
270         int slot;
271         int ret = 0;
272         u64 flags = 0;
273         u64 rescan_progress = 0;
274 
275         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
276                 return 0;
277 
278         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
279         if (!fs_info->qgroup_ulist) {
280                 ret = -ENOMEM;
281                 goto out;
282         }
283 
284         path = btrfs_alloc_path();
285         if (!path) {
286                 ret = -ENOMEM;
287                 goto out;
288         }
289 
290         /* default this to quota off, in case no status key is found */
291         fs_info->qgroup_flags = 0;
292 
293         /*
294          * pass 1: read status, all qgroup infos and limits
295          */
296         key.objectid = 0;
297         key.type = 0;
298         key.offset = 0;
299         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
300         if (ret)
301                 goto out;
302 
303         while (1) {
304                 struct btrfs_qgroup *qgroup;
305 
306                 slot = path->slots[0];
307                 l = path->nodes[0];
308                 btrfs_item_key_to_cpu(l, &found_key, slot);
309 
310                 if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
311                         struct btrfs_qgroup_status_item *ptr;
312 
313                         ptr = btrfs_item_ptr(l, slot,
314                                              struct btrfs_qgroup_status_item);
315 
316                         if (btrfs_qgroup_status_version(l, ptr) !=
317                             BTRFS_QGROUP_STATUS_VERSION) {
318                                 btrfs_err(fs_info,
319                                  "old qgroup version, quota disabled");
320                                 goto out;
321                         }
322                         if (btrfs_qgroup_status_generation(l, ptr) !=
323                             fs_info->generation) {
324                                 flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
325                                 btrfs_err(fs_info,
326                                         "qgroup generation mismatch, marked as inconsistent");
327                         }
328                         fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
329                                                                           ptr);
330                         rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
331                         goto next1;
332                 }
333 
334                 if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
335                     found_key.type != BTRFS_QGROUP_LIMIT_KEY)
336                         goto next1;
337 
338                 qgroup = find_qgroup_rb(fs_info, found_key.offset);
339                 if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
340                     (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
341                         btrfs_err(fs_info, "inconsistent qgroup config");
342                         flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
343                 }
344                 if (!qgroup) {
345                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
346                         if (IS_ERR(qgroup)) {
347                                 ret = PTR_ERR(qgroup);
348                                 goto out;
349                         }
350                 }
351                 switch (found_key.type) {
352                 case BTRFS_QGROUP_INFO_KEY: {
353                         struct btrfs_qgroup_info_item *ptr;
354 
355                         ptr = btrfs_item_ptr(l, slot,
356                                              struct btrfs_qgroup_info_item);
357                         qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
358                         qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
359                         qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
360                         qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
361                         /* generation currently unused */
362                         break;
363                 }
364                 case BTRFS_QGROUP_LIMIT_KEY: {
365                         struct btrfs_qgroup_limit_item *ptr;
366 
367                         ptr = btrfs_item_ptr(l, slot,
368                                              struct btrfs_qgroup_limit_item);
369                         qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
370                         qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
371                         qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
372                         qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
373                         qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
374                         break;
375                 }
376                 }
377 next1:
378                 ret = btrfs_next_item(quota_root, path);
379                 if (ret < 0)
380                         goto out;
381                 if (ret)
382                         break;
383         }
384         btrfs_release_path(path);
385 
386         /*
387          * pass 2: read all qgroup relations
388          */
389         key.objectid = 0;
390         key.type = BTRFS_QGROUP_RELATION_KEY;
391         key.offset = 0;
392         ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
393         if (ret)
394                 goto out;
395         while (1) {
396                 slot = path->slots[0];
397                 l = path->nodes[0];
398                 btrfs_item_key_to_cpu(l, &found_key, slot);
399 
400                 if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
401                         goto next2;
402 
403                 if (found_key.objectid > found_key.offset) {
404                         /* parent <- member, not needed to build config */
405                         /* FIXME should we omit the key completely? */
406                         goto next2;
407                 }
408 
409                 ret = add_relation_rb(fs_info, found_key.objectid,
410                                       found_key.offset);
411                 if (ret == -ENOENT) {
412                         btrfs_warn(fs_info,
413                                 "orphan qgroup relation 0x%llx->0x%llx",
414                                 found_key.objectid, found_key.offset);
415                         ret = 0;        /* ignore the error */
416                 }
417                 if (ret)
418                         goto out;
419 next2:
420                 ret = btrfs_next_item(quota_root, path);
421                 if (ret < 0)
422                         goto out;
423                 if (ret)
424                         break;
425         }
426 out:
427         fs_info->qgroup_flags |= flags;
428         if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
429                 clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
430         else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
431                  ret >= 0)
432                 ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
433         btrfs_free_path(path);
434 
435         if (ret < 0) {
436                 ulist_free(fs_info->qgroup_ulist);
437                 fs_info->qgroup_ulist = NULL;
438                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
439         }
440 
441         return ret < 0 ? ret : 0;
442 }
443 
444 /*
445  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
446  * first two are in single-threaded paths.And for the third one, we have set
447  * quota_root to be null with qgroup_lock held before, so it is safe to clean
448  * up the in-memory structures without qgroup_lock held.
449  */
450 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
451 {
452         struct rb_node *n;
453         struct btrfs_qgroup *qgroup;
454 
455         while ((n = rb_first(&fs_info->qgroup_tree))) {
456                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
457                 rb_erase(n, &fs_info->qgroup_tree);
458                 __del_qgroup_rb(qgroup);
459         }
460         /*
461          * we call btrfs_free_qgroup_config() when umounting
462          * filesystem and disabling quota, so we set qgroup_ulist
463          * to be null here to avoid double free.
464          */
465         ulist_free(fs_info->qgroup_ulist);
466         fs_info->qgroup_ulist = NULL;
467 }
468 
469 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans,
470                                     struct btrfs_root *quota_root,
471                                     u64 src, u64 dst)
472 {
473         int ret;
474         struct btrfs_path *path;
475         struct btrfs_key key;
476 
477         path = btrfs_alloc_path();
478         if (!path)
479                 return -ENOMEM;
480 
481         key.objectid = src;
482         key.type = BTRFS_QGROUP_RELATION_KEY;
483         key.offset = dst;
484 
485         ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
486 
487         btrfs_mark_buffer_dirty(path->nodes[0]);
488 
489         btrfs_free_path(path);
490         return ret;
491 }
492 
493 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans,
494                                     struct btrfs_root *quota_root,
495                                     u64 src, u64 dst)
496 {
497         int ret;
498         struct btrfs_path *path;
499         struct btrfs_key key;
500 
501         path = btrfs_alloc_path();
502         if (!path)
503                 return -ENOMEM;
504 
505         key.objectid = src;
506         key.type = BTRFS_QGROUP_RELATION_KEY;
507         key.offset = dst;
508 
509         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
510         if (ret < 0)
511                 goto out;
512 
513         if (ret > 0) {
514                 ret = -ENOENT;
515                 goto out;
516         }
517 
518         ret = btrfs_del_item(trans, quota_root, path);
519 out:
520         btrfs_free_path(path);
521         return ret;
522 }
523 
524 static int add_qgroup_item(struct btrfs_trans_handle *trans,
525                            struct btrfs_root *quota_root, u64 qgroupid)
526 {
527         int ret;
528         struct btrfs_path *path;
529         struct btrfs_qgroup_info_item *qgroup_info;
530         struct btrfs_qgroup_limit_item *qgroup_limit;
531         struct extent_buffer *leaf;
532         struct btrfs_key key;
533 
534         if (btrfs_is_testing(quota_root->fs_info))
535                 return 0;
536 
537         path = btrfs_alloc_path();
538         if (!path)
539                 return -ENOMEM;
540 
541         key.objectid = 0;
542         key.type = BTRFS_QGROUP_INFO_KEY;
543         key.offset = qgroupid;
544 
545         /*
546          * Avoid a transaction abort by catching -EEXIST here. In that
547          * case, we proceed by re-initializing the existing structure
548          * on disk.
549          */
550 
551         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
552                                       sizeof(*qgroup_info));
553         if (ret && ret != -EEXIST)
554                 goto out;
555 
556         leaf = path->nodes[0];
557         qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
558                                  struct btrfs_qgroup_info_item);
559         btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
560         btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
561         btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
562         btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
563         btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
564 
565         btrfs_mark_buffer_dirty(leaf);
566 
567         btrfs_release_path(path);
568 
569         key.type = BTRFS_QGROUP_LIMIT_KEY;
570         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
571                                       sizeof(*qgroup_limit));
572         if (ret && ret != -EEXIST)
573                 goto out;
574 
575         leaf = path->nodes[0];
576         qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
577                                   struct btrfs_qgroup_limit_item);
578         btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
579         btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
580         btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
581         btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
582         btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
583 
584         btrfs_mark_buffer_dirty(leaf);
585 
586         ret = 0;
587 out:
588         btrfs_free_path(path);
589         return ret;
590 }
591 
592 static int del_qgroup_item(struct btrfs_trans_handle *trans,
593                            struct btrfs_root *quota_root, u64 qgroupid)
594 {
595         int ret;
596         struct btrfs_path *path;
597         struct btrfs_key key;
598 
599         path = btrfs_alloc_path();
600         if (!path)
601                 return -ENOMEM;
602 
603         key.objectid = 0;
604         key.type = BTRFS_QGROUP_INFO_KEY;
605         key.offset = qgroupid;
606         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
607         if (ret < 0)
608                 goto out;
609 
610         if (ret > 0) {
611                 ret = -ENOENT;
612                 goto out;
613         }
614 
615         ret = btrfs_del_item(trans, quota_root, path);
616         if (ret)
617                 goto out;
618 
619         btrfs_release_path(path);
620 
621         key.type = BTRFS_QGROUP_LIMIT_KEY;
622         ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
623         if (ret < 0)
624                 goto out;
625 
626         if (ret > 0) {
627                 ret = -ENOENT;
628                 goto out;
629         }
630 
631         ret = btrfs_del_item(trans, quota_root, path);
632 
633 out:
634         btrfs_free_path(path);
635         return ret;
636 }
637 
638 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
639                                     struct btrfs_root *root,
640                                     struct btrfs_qgroup *qgroup)
641 {
642         struct btrfs_path *path;
643         struct btrfs_key key;
644         struct extent_buffer *l;
645         struct btrfs_qgroup_limit_item *qgroup_limit;
646         int ret;
647         int slot;
648 
649         key.objectid = 0;
650         key.type = BTRFS_QGROUP_LIMIT_KEY;
651         key.offset = qgroup->qgroupid;
652 
653         path = btrfs_alloc_path();
654         if (!path)
655                 return -ENOMEM;
656 
657         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
658         if (ret > 0)
659                 ret = -ENOENT;
660 
661         if (ret)
662                 goto out;
663 
664         l = path->nodes[0];
665         slot = path->slots[0];
666         qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
667         btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
668         btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
669         btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
670         btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
671         btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
672 
673         btrfs_mark_buffer_dirty(l);
674 
675 out:
676         btrfs_free_path(path);
677         return ret;
678 }
679 
680 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
681                                    struct btrfs_root *root,
682                                    struct btrfs_qgroup *qgroup)
683 {
684         struct btrfs_path *path;
685         struct btrfs_key key;
686         struct extent_buffer *l;
687         struct btrfs_qgroup_info_item *qgroup_info;
688         int ret;
689         int slot;
690 
691         if (btrfs_is_testing(root->fs_info))
692                 return 0;
693 
694         key.objectid = 0;
695         key.type = BTRFS_QGROUP_INFO_KEY;
696         key.offset = qgroup->qgroupid;
697 
698         path = btrfs_alloc_path();
699         if (!path)
700                 return -ENOMEM;
701 
702         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
703         if (ret > 0)
704                 ret = -ENOENT;
705 
706         if (ret)
707                 goto out;
708 
709         l = path->nodes[0];
710         slot = path->slots[0];
711         qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
712         btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
713         btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
714         btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
715         btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
716         btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
717 
718         btrfs_mark_buffer_dirty(l);
719 
720 out:
721         btrfs_free_path(path);
722         return ret;
723 }
724 
725 static int update_qgroup_status_item(struct btrfs_trans_handle *trans,
726                                      struct btrfs_fs_info *fs_info,
727                                     struct btrfs_root *root)
728 {
729         struct btrfs_path *path;
730         struct btrfs_key key;
731         struct extent_buffer *l;
732         struct btrfs_qgroup_status_item *ptr;
733         int ret;
734         int slot;
735 
736         key.objectid = 0;
737         key.type = BTRFS_QGROUP_STATUS_KEY;
738         key.offset = 0;
739 
740         path = btrfs_alloc_path();
741         if (!path)
742                 return -ENOMEM;
743 
744         ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
745         if (ret > 0)
746                 ret = -ENOENT;
747 
748         if (ret)
749                 goto out;
750 
751         l = path->nodes[0];
752         slot = path->slots[0];
753         ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
754         btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
755         btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
756         btrfs_set_qgroup_status_rescan(l, ptr,
757                                 fs_info->qgroup_rescan_progress.objectid);
758 
759         btrfs_mark_buffer_dirty(l);
760 
761 out:
762         btrfs_free_path(path);
763         return ret;
764 }
765 
766 /*
767  * called with qgroup_lock held
768  */
769 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
770                                   struct btrfs_root *root)
771 {
772         struct btrfs_path *path;
773         struct btrfs_key key;
774         struct extent_buffer *leaf = NULL;
775         int ret;
776         int nr = 0;
777 
778         path = btrfs_alloc_path();
779         if (!path)
780                 return -ENOMEM;
781 
782         path->leave_spinning = 1;
783 
784         key.objectid = 0;
785         key.offset = 0;
786         key.type = 0;
787 
788         while (1) {
789                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
790                 if (ret < 0)
791                         goto out;
792                 leaf = path->nodes[0];
793                 nr = btrfs_header_nritems(leaf);
794                 if (!nr)
795                         break;
796                 /*
797                  * delete the leaf one by one
798                  * since the whole tree is going
799                  * to be deleted.
800                  */
801                 path->slots[0] = 0;
802                 ret = btrfs_del_items(trans, root, path, 0, nr);
803                 if (ret)
804                         goto out;
805 
806                 btrfs_release_path(path);
807         }
808         ret = 0;
809 out:
810         btrfs_free_path(path);
811         return ret;
812 }
813 
814 int btrfs_quota_enable(struct btrfs_trans_handle *trans,
815                        struct btrfs_fs_info *fs_info)
816 {
817         struct btrfs_root *quota_root;
818         struct btrfs_root *tree_root = fs_info->tree_root;
819         struct btrfs_path *path = NULL;
820         struct btrfs_qgroup_status_item *ptr;
821         struct extent_buffer *leaf;
822         struct btrfs_key key;
823         struct btrfs_key found_key;
824         struct btrfs_qgroup *qgroup = NULL;
825         int ret = 0;
826         int slot;
827 
828         mutex_lock(&fs_info->qgroup_ioctl_lock);
829         if (fs_info->quota_root) {
830                 set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
831                 goto out;
832         }
833 
834         fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
835         if (!fs_info->qgroup_ulist) {
836                 ret = -ENOMEM;
837                 goto out;
838         }
839 
840         /*
841          * initially create the quota tree
842          */
843         quota_root = btrfs_create_tree(trans, fs_info,
844                                        BTRFS_QUOTA_TREE_OBJECTID);
845         if (IS_ERR(quota_root)) {
846                 ret =  PTR_ERR(quota_root);
847                 goto out;
848         }
849 
850         path = btrfs_alloc_path();
851         if (!path) {
852                 ret = -ENOMEM;
853                 goto out_free_root;
854         }
855 
856         key.objectid = 0;
857         key.type = BTRFS_QGROUP_STATUS_KEY;
858         key.offset = 0;
859 
860         ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
861                                       sizeof(*ptr));
862         if (ret)
863                 goto out_free_path;
864 
865         leaf = path->nodes[0];
866         ptr = btrfs_item_ptr(leaf, path->slots[0],
867                                  struct btrfs_qgroup_status_item);
868         btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
869         btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
870         fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
871                                 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
872         btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
873         btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
874 
875         btrfs_mark_buffer_dirty(leaf);
876 
877         key.objectid = 0;
878         key.type = BTRFS_ROOT_REF_KEY;
879         key.offset = 0;
880 
881         btrfs_release_path(path);
882         ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
883         if (ret > 0)
884                 goto out_add_root;
885         if (ret < 0)
886                 goto out_free_path;
887 
888 
889         while (1) {
890                 slot = path->slots[0];
891                 leaf = path->nodes[0];
892                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
893 
894                 if (found_key.type == BTRFS_ROOT_REF_KEY) {
895                         ret = add_qgroup_item(trans, quota_root,
896                                               found_key.offset);
897                         if (ret)
898                                 goto out_free_path;
899 
900                         qgroup = add_qgroup_rb(fs_info, found_key.offset);
901                         if (IS_ERR(qgroup)) {
902                                 ret = PTR_ERR(qgroup);
903                                 goto out_free_path;
904                         }
905                 }
906                 ret = btrfs_next_item(tree_root, path);
907                 if (ret < 0)
908                         goto out_free_path;
909                 if (ret)
910                         break;
911         }
912 
913 out_add_root:
914         btrfs_release_path(path);
915         ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
916         if (ret)
917                 goto out_free_path;
918 
919         qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
920         if (IS_ERR(qgroup)) {
921                 ret = PTR_ERR(qgroup);
922                 goto out_free_path;
923         }
924         spin_lock(&fs_info->qgroup_lock);
925         fs_info->quota_root = quota_root;
926         set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
927         spin_unlock(&fs_info->qgroup_lock);
928 out_free_path:
929         btrfs_free_path(path);
930 out_free_root:
931         if (ret) {
932                 free_extent_buffer(quota_root->node);
933                 free_extent_buffer(quota_root->commit_root);
934                 kfree(quota_root);
935         }
936 out:
937         if (ret) {
938                 ulist_free(fs_info->qgroup_ulist);
939                 fs_info->qgroup_ulist = NULL;
940         }
941         mutex_unlock(&fs_info->qgroup_ioctl_lock);
942         return ret;
943 }
944 
945 int btrfs_quota_disable(struct btrfs_trans_handle *trans,
946                         struct btrfs_fs_info *fs_info)
947 {
948         struct btrfs_root *quota_root;
949         int ret = 0;
950 
951         mutex_lock(&fs_info->qgroup_ioctl_lock);
952         if (!fs_info->quota_root)
953                 goto out;
954         clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
955         btrfs_qgroup_wait_for_completion(fs_info, false);
956         spin_lock(&fs_info->qgroup_lock);
957         quota_root = fs_info->quota_root;
958         fs_info->quota_root = NULL;
959         fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
960         spin_unlock(&fs_info->qgroup_lock);
961 
962         btrfs_free_qgroup_config(fs_info);
963 
964         ret = btrfs_clean_quota_tree(trans, quota_root);
965         if (ret)
966                 goto out;
967 
968         ret = btrfs_del_root(trans, fs_info, &quota_root->root_key);
969         if (ret)
970                 goto out;
971 
972         list_del(&quota_root->dirty_list);
973 
974         btrfs_tree_lock(quota_root->node);
975         clean_tree_block(fs_info, quota_root->node);
976         btrfs_tree_unlock(quota_root->node);
977         btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
978 
979         free_extent_buffer(quota_root->node);
980         free_extent_buffer(quota_root->commit_root);
981         kfree(quota_root);
982 out:
983         mutex_unlock(&fs_info->qgroup_ioctl_lock);
984         return ret;
985 }
986 
987 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
988                          struct btrfs_qgroup *qgroup)
989 {
990         if (list_empty(&qgroup->dirty))
991                 list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
992 }
993 
994 static void report_reserved_underflow(struct btrfs_fs_info *fs_info,
995                                       struct btrfs_qgroup *qgroup,
996                                       u64 num_bytes)
997 {
998 #ifdef CONFIG_BTRFS_DEBUG
999         WARN_ON(qgroup->reserved < num_bytes);
1000         btrfs_debug(fs_info,
1001                 "qgroup %llu reserved space underflow, have: %llu, to free: %llu",
1002                 qgroup->qgroupid, qgroup->reserved, num_bytes);
1003 #endif
1004         qgroup->reserved = 0;
1005 }
1006 /*
1007  * The easy accounting, if we are adding/removing the only ref for an extent
1008  * then this qgroup and all of the parent qgroups get their reference and
1009  * exclusive counts adjusted.
1010  *
1011  * Caller should hold fs_info->qgroup_lock.
1012  */
1013 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1014                                     struct ulist *tmp, u64 ref_root,
1015                                     u64 num_bytes, int sign)
1016 {
1017         struct btrfs_qgroup *qgroup;
1018         struct btrfs_qgroup_list *glist;
1019         struct ulist_node *unode;
1020         struct ulist_iterator uiter;
1021         int ret = 0;
1022 
1023         qgroup = find_qgroup_rb(fs_info, ref_root);
1024         if (!qgroup)
1025                 goto out;
1026 
1027         qgroup->rfer += sign * num_bytes;
1028         qgroup->rfer_cmpr += sign * num_bytes;
1029 
1030         WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1031         qgroup->excl += sign * num_bytes;
1032         qgroup->excl_cmpr += sign * num_bytes;
1033         if (sign > 0) {
1034                 trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes);
1035                 if (qgroup->reserved < num_bytes)
1036                         report_reserved_underflow(fs_info, qgroup, num_bytes);
1037                 else
1038                         qgroup->reserved -= num_bytes;
1039         }
1040 
1041         qgroup_dirty(fs_info, qgroup);
1042 
1043         /* Get all of the parent groups that contain this qgroup */
1044         list_for_each_entry(glist, &qgroup->groups, next_group) {
1045                 ret = ulist_add(tmp, glist->group->qgroupid,
1046                                 qgroup_to_aux(glist->group), GFP_ATOMIC);
1047                 if (ret < 0)
1048                         goto out;
1049         }
1050 
1051         /* Iterate all of the parents and adjust their reference counts */
1052         ULIST_ITER_INIT(&uiter);
1053         while ((unode = ulist_next(tmp, &uiter))) {
1054                 qgroup = unode_aux_to_qgroup(unode);
1055                 qgroup->rfer += sign * num_bytes;
1056                 qgroup->rfer_cmpr += sign * num_bytes;
1057                 WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1058                 qgroup->excl += sign * num_bytes;
1059                 if (sign > 0) {
1060                         trace_qgroup_update_reserve(fs_info, qgroup,
1061                                                     -(s64)num_bytes);
1062                         if (qgroup->reserved < num_bytes)
1063                                 report_reserved_underflow(fs_info, qgroup,
1064                                                           num_bytes);
1065                         else
1066                                 qgroup->reserved -= num_bytes;
1067                 }
1068                 qgroup->excl_cmpr += sign * num_bytes;
1069                 qgroup_dirty(fs_info, qgroup);
1070 
1071                 /* Add any parents of the parents */
1072                 list_for_each_entry(glist, &qgroup->groups, next_group) {
1073                         ret = ulist_add(tmp, glist->group->qgroupid,
1074                                         qgroup_to_aux(glist->group), GFP_ATOMIC);
1075                         if (ret < 0)
1076                                 goto out;
1077                 }
1078         }
1079         ret = 0;
1080 out:
1081         return ret;
1082 }
1083 
1084 
1085 /*
1086  * Quick path for updating qgroup with only excl refs.
1087  *
1088  * In that case, just update all parent will be enough.
1089  * Or we needs to do a full rescan.
1090  * Caller should also hold fs_info->qgroup_lock.
1091  *
1092  * Return 0 for quick update, return >0 for need to full rescan
1093  * and mark INCONSISTENT flag.
1094  * Return < 0 for other error.
1095  */
1096 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1097                                    struct ulist *tmp, u64 src, u64 dst,
1098                                    int sign)
1099 {
1100         struct btrfs_qgroup *qgroup;
1101         int ret = 1;
1102         int err = 0;
1103 
1104         qgroup = find_qgroup_rb(fs_info, src);
1105         if (!qgroup)
1106                 goto out;
1107         if (qgroup->excl == qgroup->rfer) {
1108                 ret = 0;
1109                 err = __qgroup_excl_accounting(fs_info, tmp, dst,
1110                                                qgroup->excl, sign);
1111                 if (err < 0) {
1112                         ret = err;
1113                         goto out;
1114                 }
1115         }
1116 out:
1117         if (ret)
1118                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1119         return ret;
1120 }
1121 
1122 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
1123                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1124 {
1125         struct btrfs_root *quota_root;
1126         struct btrfs_qgroup *parent;
1127         struct btrfs_qgroup *member;
1128         struct btrfs_qgroup_list *list;
1129         struct ulist *tmp;
1130         int ret = 0;
1131 
1132         /* Check the level of src and dst first */
1133         if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1134                 return -EINVAL;
1135 
1136         tmp = ulist_alloc(GFP_KERNEL);
1137         if (!tmp)
1138                 return -ENOMEM;
1139 
1140         mutex_lock(&fs_info->qgroup_ioctl_lock);
1141         quota_root = fs_info->quota_root;
1142         if (!quota_root) {
1143                 ret = -EINVAL;
1144                 goto out;
1145         }
1146         member = find_qgroup_rb(fs_info, src);
1147         parent = find_qgroup_rb(fs_info, dst);
1148         if (!member || !parent) {
1149                 ret = -EINVAL;
1150                 goto out;
1151         }
1152 
1153         /* check if such qgroup relation exist firstly */
1154         list_for_each_entry(list, &member->groups, next_group) {
1155                 if (list->group == parent) {
1156                         ret = -EEXIST;
1157                         goto out;
1158                 }
1159         }
1160 
1161         ret = add_qgroup_relation_item(trans, quota_root, src, dst);
1162         if (ret)
1163                 goto out;
1164 
1165         ret = add_qgroup_relation_item(trans, quota_root, dst, src);
1166         if (ret) {
1167                 del_qgroup_relation_item(trans, quota_root, src, dst);
1168                 goto out;
1169         }
1170 
1171         spin_lock(&fs_info->qgroup_lock);
1172         ret = add_relation_rb(fs_info, src, dst);
1173         if (ret < 0) {
1174                 spin_unlock(&fs_info->qgroup_lock);
1175                 goto out;
1176         }
1177         ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1178         spin_unlock(&fs_info->qgroup_lock);
1179 out:
1180         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1181         ulist_free(tmp);
1182         return ret;
1183 }
1184 
1185 static int __del_qgroup_relation(struct btrfs_trans_handle *trans,
1186                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1187 {
1188         struct btrfs_root *quota_root;
1189         struct btrfs_qgroup *parent;
1190         struct btrfs_qgroup *member;
1191         struct btrfs_qgroup_list *list;
1192         struct ulist *tmp;
1193         int ret = 0;
1194         int err;
1195 
1196         tmp = ulist_alloc(GFP_KERNEL);
1197         if (!tmp)
1198                 return -ENOMEM;
1199 
1200         quota_root = fs_info->quota_root;
1201         if (!quota_root) {
1202                 ret = -EINVAL;
1203                 goto out;
1204         }
1205 
1206         member = find_qgroup_rb(fs_info, src);
1207         parent = find_qgroup_rb(fs_info, dst);
1208         if (!member || !parent) {
1209                 ret = -EINVAL;
1210                 goto out;
1211         }
1212 
1213         /* check if such qgroup relation exist firstly */
1214         list_for_each_entry(list, &member->groups, next_group) {
1215                 if (list->group == parent)
1216                         goto exist;
1217         }
1218         ret = -ENOENT;
1219         goto out;
1220 exist:
1221         ret = del_qgroup_relation_item(trans, quota_root, src, dst);
1222         err = del_qgroup_relation_item(trans, quota_root, dst, src);
1223         if (err && !ret)
1224                 ret = err;
1225 
1226         spin_lock(&fs_info->qgroup_lock);
1227         del_relation_rb(fs_info, src, dst);
1228         ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1229         spin_unlock(&fs_info->qgroup_lock);
1230 out:
1231         ulist_free(tmp);
1232         return ret;
1233 }
1234 
1235 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
1236                               struct btrfs_fs_info *fs_info, u64 src, u64 dst)
1237 {
1238         int ret = 0;
1239 
1240         mutex_lock(&fs_info->qgroup_ioctl_lock);
1241         ret = __del_qgroup_relation(trans, fs_info, src, dst);
1242         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1243 
1244         return ret;
1245 }
1246 
1247 int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
1248                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1249 {
1250         struct btrfs_root *quota_root;
1251         struct btrfs_qgroup *qgroup;
1252         int ret = 0;
1253 
1254         mutex_lock(&fs_info->qgroup_ioctl_lock);
1255         quota_root = fs_info->quota_root;
1256         if (!quota_root) {
1257                 ret = -EINVAL;
1258                 goto out;
1259         }
1260         qgroup = find_qgroup_rb(fs_info, qgroupid);
1261         if (qgroup) {
1262                 ret = -EEXIST;
1263                 goto out;
1264         }
1265 
1266         ret = add_qgroup_item(trans, quota_root, qgroupid);
1267         if (ret)
1268                 goto out;
1269 
1270         spin_lock(&fs_info->qgroup_lock);
1271         qgroup = add_qgroup_rb(fs_info, qgroupid);
1272         spin_unlock(&fs_info->qgroup_lock);
1273 
1274         if (IS_ERR(qgroup))
1275                 ret = PTR_ERR(qgroup);
1276 out:
1277         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1278         return ret;
1279 }
1280 
1281 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
1282                         struct btrfs_fs_info *fs_info, u64 qgroupid)
1283 {
1284         struct btrfs_root *quota_root;
1285         struct btrfs_qgroup *qgroup;
1286         struct btrfs_qgroup_list *list;
1287         int ret = 0;
1288 
1289         mutex_lock(&fs_info->qgroup_ioctl_lock);
1290         quota_root = fs_info->quota_root;
1291         if (!quota_root) {
1292                 ret = -EINVAL;
1293                 goto out;
1294         }
1295 
1296         qgroup = find_qgroup_rb(fs_info, qgroupid);
1297         if (!qgroup) {
1298                 ret = -ENOENT;
1299                 goto out;
1300         } else {
1301                 /* check if there are no children of this qgroup */
1302                 if (!list_empty(&qgroup->members)) {
1303                         ret = -EBUSY;
1304                         goto out;
1305                 }
1306         }
1307         ret = del_qgroup_item(trans, quota_root, qgroupid);
1308         if (ret && ret != -ENOENT)
1309                 goto out;
1310 
1311         while (!list_empty(&qgroup->groups)) {
1312                 list = list_first_entry(&qgroup->groups,
1313                                         struct btrfs_qgroup_list, next_group);
1314                 ret = __del_qgroup_relation(trans, fs_info,
1315                                            qgroupid,
1316                                            list->group->qgroupid);
1317                 if (ret)
1318                         goto out;
1319         }
1320 
1321         spin_lock(&fs_info->qgroup_lock);
1322         del_qgroup_rb(fs_info, qgroupid);
1323         spin_unlock(&fs_info->qgroup_lock);
1324 out:
1325         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1326         return ret;
1327 }
1328 
1329 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
1330                        struct btrfs_fs_info *fs_info, u64 qgroupid,
1331                        struct btrfs_qgroup_limit *limit)
1332 {
1333         struct btrfs_root *quota_root;
1334         struct btrfs_qgroup *qgroup;
1335         int ret = 0;
1336         /* Sometimes we would want to clear the limit on this qgroup.
1337          * To meet this requirement, we treat the -1 as a special value
1338          * which tell kernel to clear the limit on this qgroup.
1339          */
1340         const u64 CLEAR_VALUE = -1;
1341 
1342         mutex_lock(&fs_info->qgroup_ioctl_lock);
1343         quota_root = fs_info->quota_root;
1344         if (!quota_root) {
1345                 ret = -EINVAL;
1346                 goto out;
1347         }
1348 
1349         qgroup = find_qgroup_rb(fs_info, qgroupid);
1350         if (!qgroup) {
1351                 ret = -ENOENT;
1352                 goto out;
1353         }
1354 
1355         spin_lock(&fs_info->qgroup_lock);
1356         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1357                 if (limit->max_rfer == CLEAR_VALUE) {
1358                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1359                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1360                         qgroup->max_rfer = 0;
1361                 } else {
1362                         qgroup->max_rfer = limit->max_rfer;
1363                 }
1364         }
1365         if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1366                 if (limit->max_excl == CLEAR_VALUE) {
1367                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1368                         limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1369                         qgroup->max_excl = 0;
1370                 } else {
1371                         qgroup->max_excl = limit->max_excl;
1372                 }
1373         }
1374         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1375                 if (limit->rsv_rfer == CLEAR_VALUE) {
1376                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1377                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1378                         qgroup->rsv_rfer = 0;
1379                 } else {
1380                         qgroup->rsv_rfer = limit->rsv_rfer;
1381                 }
1382         }
1383         if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1384                 if (limit->rsv_excl == CLEAR_VALUE) {
1385                         qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1386                         limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1387                         qgroup->rsv_excl = 0;
1388                 } else {
1389                         qgroup->rsv_excl = limit->rsv_excl;
1390                 }
1391         }
1392         qgroup->lim_flags |= limit->flags;
1393 
1394         spin_unlock(&fs_info->qgroup_lock);
1395 
1396         ret = update_qgroup_limit_item(trans, quota_root, qgroup);
1397         if (ret) {
1398                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1399                 btrfs_info(fs_info, "unable to update quota limit for %llu",
1400                        qgroupid);
1401         }
1402 
1403 out:
1404         mutex_unlock(&fs_info->qgroup_ioctl_lock);
1405         return ret;
1406 }
1407 
1408 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1409                                 struct btrfs_delayed_ref_root *delayed_refs,
1410                                 struct btrfs_qgroup_extent_record *record)
1411 {
1412         struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1413         struct rb_node *parent_node = NULL;
1414         struct btrfs_qgroup_extent_record *entry;
1415         u64 bytenr = record->bytenr;
1416 
1417         assert_spin_locked(&delayed_refs->lock);
1418         trace_btrfs_qgroup_trace_extent(fs_info, record);
1419 
1420         while (*p) {
1421                 parent_node = *p;
1422                 entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1423                                  node);
1424                 if (bytenr < entry->bytenr)
1425                         p = &(*p)->rb_left;
1426                 else if (bytenr > entry->bytenr)
1427                         p = &(*p)->rb_right;
1428                 else
1429                         return 1;
1430         }
1431 
1432         rb_link_node(&record->node, parent_node, p);
1433         rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1434         return 0;
1435 }
1436 
1437 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1438                                    struct btrfs_qgroup_extent_record *qrecord)
1439 {
1440         struct ulist *old_root;
1441         u64 bytenr = qrecord->bytenr;
1442         int ret;
1443 
1444         ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
1445         if (ret < 0)
1446                 return ret;
1447 
1448         /*
1449          * Here we don't need to get the lock of
1450          * trans->transaction->delayed_refs, since inserted qrecord won't
1451          * be deleted, only qrecord->node may be modified (new qrecord insert)
1452          *
1453          * So modifying qrecord->old_roots is safe here
1454          */
1455         qrecord->old_roots = old_root;
1456         return 0;
1457 }
1458 
1459 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
1460                 struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes,
1461                 gfp_t gfp_flag)
1462 {
1463         struct btrfs_qgroup_extent_record *record;
1464         struct btrfs_delayed_ref_root *delayed_refs;
1465         int ret;
1466 
1467         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1468             || bytenr == 0 || num_bytes == 0)
1469                 return 0;
1470         if (WARN_ON(trans == NULL))
1471                 return -EINVAL;
1472         record = kmalloc(sizeof(*record), gfp_flag);
1473         if (!record)
1474                 return -ENOMEM;
1475 
1476         delayed_refs = &trans->transaction->delayed_refs;
1477         record->bytenr = bytenr;
1478         record->num_bytes = num_bytes;
1479         record->old_roots = NULL;
1480 
1481         spin_lock(&delayed_refs->lock);
1482         ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1483         spin_unlock(&delayed_refs->lock);
1484         if (ret > 0) {
1485                 kfree(record);
1486                 return 0;
1487         }
1488         return btrfs_qgroup_trace_extent_post(fs_info, record);
1489 }
1490 
1491 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1492                                   struct btrfs_fs_info *fs_info,
1493                                   struct extent_buffer *eb)
1494 {
1495         int nr = btrfs_header_nritems(eb);
1496         int i, extent_type, ret;
1497         struct btrfs_key key;
1498         struct btrfs_file_extent_item *fi;
1499         u64 bytenr, num_bytes;
1500 
1501         /* We can be called directly from walk_up_proc() */
1502         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1503                 return 0;
1504 
1505         for (i = 0; i < nr; i++) {
1506                 btrfs_item_key_to_cpu(eb, &key, i);
1507 
1508                 if (key.type != BTRFS_EXTENT_DATA_KEY)
1509                         continue;
1510 
1511                 fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1512                 /* filter out non qgroup-accountable extents  */
1513                 extent_type = btrfs_file_extent_type(eb, fi);
1514 
1515                 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1516                         continue;
1517 
1518                 bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1519                 if (!bytenr)
1520                         continue;
1521 
1522                 num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1523 
1524                 ret = btrfs_qgroup_trace_extent(trans, fs_info, bytenr,
1525                                                 num_bytes, GFP_NOFS);
1526                 if (ret)
1527                         return ret;
1528         }
1529         cond_resched();
1530         return 0;
1531 }
1532 
1533 /*
1534  * Walk up the tree from the bottom, freeing leaves and any interior
1535  * nodes which have had all slots visited. If a node (leaf or
1536  * interior) is freed, the node above it will have it's slot
1537  * incremented. The root node will never be freed.
1538  *
1539  * At the end of this function, we should have a path which has all
1540  * slots incremented to the next position for a search. If we need to
1541  * read a new node it will be NULL and the node above it will have the
1542  * correct slot selected for a later read.
1543  *
1544  * If we increment the root nodes slot counter past the number of
1545  * elements, 1 is returned to signal completion of the search.
1546  */
1547 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1548 {
1549         int level = 0;
1550         int nr, slot;
1551         struct extent_buffer *eb;
1552 
1553         if (root_level == 0)
1554                 return 1;
1555 
1556         while (level <= root_level) {
1557                 eb = path->nodes[level];
1558                 nr = btrfs_header_nritems(eb);
1559                 path->slots[level]++;
1560                 slot = path->slots[level];
1561                 if (slot >= nr || level == 0) {
1562                         /*
1563                          * Don't free the root -  we will detect this
1564                          * condition after our loop and return a
1565                          * positive value for caller to stop walking the tree.
1566                          */
1567                         if (level != root_level) {
1568                                 btrfs_tree_unlock_rw(eb, path->locks[level]);
1569                                 path->locks[level] = 0;
1570 
1571                                 free_extent_buffer(eb);
1572                                 path->nodes[level] = NULL;
1573                                 path->slots[level] = 0;
1574                         }
1575                 } else {
1576                         /*
1577                          * We have a valid slot to walk back down
1578                          * from. Stop here so caller can process these
1579                          * new nodes.
1580                          */
1581                         break;
1582                 }
1583 
1584                 level++;
1585         }
1586 
1587         eb = path->nodes[root_level];
1588         if (path->slots[root_level] >= btrfs_header_nritems(eb))
1589                 return 1;
1590 
1591         return 0;
1592 }
1593 
1594 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
1595                                struct btrfs_root *root,
1596                                struct extent_buffer *root_eb,
1597                                u64 root_gen, int root_level)
1598 {
1599         struct btrfs_fs_info *fs_info = root->fs_info;
1600         int ret = 0;
1601         int level;
1602         struct extent_buffer *eb = root_eb;
1603         struct btrfs_path *path = NULL;
1604 
1605         BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
1606         BUG_ON(root_eb == NULL);
1607 
1608         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1609                 return 0;
1610 
1611         if (!extent_buffer_uptodate(root_eb)) {
1612                 ret = btrfs_read_buffer(root_eb, root_gen);
1613                 if (ret)
1614                         goto out;
1615         }
1616 
1617         if (root_level == 0) {
1618                 ret = btrfs_qgroup_trace_leaf_items(trans, fs_info, root_eb);
1619                 goto out;
1620         }
1621 
1622         path = btrfs_alloc_path();
1623         if (!path)
1624                 return -ENOMEM;
1625 
1626         /*
1627          * Walk down the tree.  Missing extent blocks are filled in as
1628          * we go. Metadata is accounted every time we read a new
1629          * extent block.
1630          *
1631          * When we reach a leaf, we account for file extent items in it,
1632          * walk back up the tree (adjusting slot pointers as we go)
1633          * and restart the search process.
1634          */
1635         extent_buffer_get(root_eb); /* For path */
1636         path->nodes[root_level] = root_eb;
1637         path->slots[root_level] = 0;
1638         path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
1639 walk_down:
1640         level = root_level;
1641         while (level >= 0) {
1642                 if (path->nodes[level] == NULL) {
1643                         int parent_slot;
1644                         u64 child_gen;
1645                         u64 child_bytenr;
1646 
1647                         /*
1648                          * We need to get child blockptr/gen from parent before
1649                          * we can read it.
1650                           */
1651                         eb = path->nodes[level + 1];
1652                         parent_slot = path->slots[level + 1];
1653                         child_bytenr = btrfs_node_blockptr(eb, parent_slot);
1654                         child_gen = btrfs_node_ptr_generation(eb, parent_slot);
1655 
1656                         eb = read_tree_block(fs_info, child_bytenr, child_gen);
1657                         if (IS_ERR(eb)) {
1658                                 ret = PTR_ERR(eb);
1659                                 goto out;
1660                         } else if (!extent_buffer_uptodate(eb)) {
1661                                 free_extent_buffer(eb);
1662                                 ret = -EIO;
1663                                 goto out;
1664                         }
1665 
1666                         path->nodes[level] = eb;
1667                         path->slots[level] = 0;
1668 
1669                         btrfs_tree_read_lock(eb);
1670                         btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1671                         path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
1672 
1673                         ret = btrfs_qgroup_trace_extent(trans, fs_info,
1674                                                         child_bytenr,
1675                                                         fs_info->nodesize,
1676                                                         GFP_NOFS);
1677                         if (ret)
1678                                 goto out;
1679                 }
1680 
1681                 if (level == 0) {
1682                         ret = btrfs_qgroup_trace_leaf_items(trans,fs_info,
1683                                                            path->nodes[level]);
1684                         if (ret)
1685                                 goto out;
1686 
1687                         /* Nonzero return here means we completed our search */
1688                         ret = adjust_slots_upwards(path, root_level);
1689                         if (ret)
1690                                 break;
1691 
1692                         /* Restart search with new slots */
1693                         goto walk_down;
1694                 }
1695 
1696                 level--;
1697         }
1698 
1699         ret = 0;
1700 out:
1701         btrfs_free_path(path);
1702 
1703         return ret;
1704 }
1705 
1706 #define UPDATE_NEW      0
1707 #define UPDATE_OLD      1
1708 /*
1709  * Walk all of the roots that points to the bytenr and adjust their refcnts.
1710  */
1711 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
1712                                 struct ulist *roots, struct ulist *tmp,
1713                                 struct ulist *qgroups, u64 seq, int update_old)
1714 {
1715         struct ulist_node *unode;
1716         struct ulist_iterator uiter;
1717         struct ulist_node *tmp_unode;
1718         struct ulist_iterator tmp_uiter;
1719         struct btrfs_qgroup *qg;
1720         int ret = 0;
1721 
1722         if (!roots)
1723                 return 0;
1724         ULIST_ITER_INIT(&uiter);
1725         while ((unode = ulist_next(roots, &uiter))) {
1726                 qg = find_qgroup_rb(fs_info, unode->val);
1727                 if (!qg)
1728                         continue;
1729 
1730                 ulist_reinit(tmp);
1731                 ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
1732                                 GFP_ATOMIC);
1733                 if (ret < 0)
1734                         return ret;
1735                 ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
1736                 if (ret < 0)
1737                         return ret;
1738                 ULIST_ITER_INIT(&tmp_uiter);
1739                 while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
1740                         struct btrfs_qgroup_list *glist;
1741 
1742                         qg = unode_aux_to_qgroup(tmp_unode);
1743                         if (update_old)
1744                                 btrfs_qgroup_update_old_refcnt(qg, seq, 1);
1745                         else
1746                                 btrfs_qgroup_update_new_refcnt(qg, seq, 1);
1747                         list_for_each_entry(glist, &qg->groups, next_group) {
1748                                 ret = ulist_add(qgroups, glist->group->qgroupid,
1749                                                 qgroup_to_aux(glist->group),
1750                                                 GFP_ATOMIC);
1751                                 if (ret < 0)
1752                                         return ret;
1753                                 ret = ulist_add(tmp, glist->group->qgroupid,
1754                                                 qgroup_to_aux(glist->group),
1755                                                 GFP_ATOMIC);
1756                                 if (ret < 0)
1757                                         return ret;
1758                         }
1759                 }
1760         }
1761         return 0;
1762 }
1763 
1764 /*
1765  * Update qgroup rfer/excl counters.
1766  * Rfer update is easy, codes can explain themselves.
1767  *
1768  * Excl update is tricky, the update is split into 2 part.
1769  * Part 1: Possible exclusive <-> sharing detect:
1770  *      |       A       |       !A      |
1771  *  -------------------------------------
1772  *  B   |       *       |       -       |
1773  *  -------------------------------------
1774  *  !B  |       +       |       **      |
1775  *  -------------------------------------
1776  *
1777  * Conditions:
1778  * A:   cur_old_roots < nr_old_roots    (not exclusive before)
1779  * !A:  cur_old_roots == nr_old_roots   (possible exclusive before)
1780  * B:   cur_new_roots < nr_new_roots    (not exclusive now)
1781  * !B:  cur_new_roots == nr_new_roots   (possible exclusive now)
1782  *
1783  * Results:
1784  * +: Possible sharing -> exclusive     -: Possible exclusive -> sharing
1785  * *: Definitely not changed.           **: Possible unchanged.
1786  *
1787  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
1788  *
1789  * To make the logic clear, we first use condition A and B to split
1790  * combination into 4 results.
1791  *
1792  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
1793  * only on variant maybe 0.
1794  *
1795  * Lastly, check result **, since there are 2 variants maybe 0, split them
1796  * again(2x2).
1797  * But this time we don't need to consider other things, the codes and logic
1798  * is easy to understand now.
1799  */
1800 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
1801                                   struct ulist *qgroups,
1802                                   u64 nr_old_roots,
1803                                   u64 nr_new_roots,
1804                                   u64 num_bytes, u64 seq)
1805 {
1806         struct ulist_node *unode;
1807         struct ulist_iterator uiter;
1808         struct btrfs_qgroup *qg;
1809         u64 cur_new_count, cur_old_count;
1810 
1811         ULIST_ITER_INIT(&uiter);
1812         while ((unode = ulist_next(qgroups, &uiter))) {
1813                 bool dirty = false;
1814 
1815                 qg = unode_aux_to_qgroup(unode);
1816                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
1817                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
1818 
1819                 trace_qgroup_update_counters(fs_info, qg->qgroupid,
1820                                              cur_old_count, cur_new_count);
1821 
1822                 /* Rfer update part */
1823                 if (cur_old_count == 0 && cur_new_count > 0) {
1824                         qg->rfer += num_bytes;
1825                         qg->rfer_cmpr += num_bytes;
1826                         dirty = true;
1827                 }
1828                 if (cur_old_count > 0 && cur_new_count == 0) {
1829                         qg->rfer -= num_bytes;
1830                         qg->rfer_cmpr -= num_bytes;
1831                         dirty = true;
1832                 }
1833 
1834                 /* Excl update part */
1835                 /* Exclusive/none -> shared case */
1836                 if (cur_old_count == nr_old_roots &&
1837                     cur_new_count < nr_new_roots) {
1838                         /* Exclusive -> shared */
1839                         if (cur_old_count != 0) {
1840                                 qg->excl -= num_bytes;
1841                                 qg->excl_cmpr -= num_bytes;
1842                                 dirty = true;
1843                         }
1844                 }
1845 
1846                 /* Shared -> exclusive/none case */
1847                 if (cur_old_count < nr_old_roots &&
1848                     cur_new_count == nr_new_roots) {
1849                         /* Shared->exclusive */
1850                         if (cur_new_count != 0) {
1851                                 qg->excl += num_bytes;
1852                                 qg->excl_cmpr += num_bytes;
1853                                 dirty = true;
1854                         }
1855                 }
1856 
1857                 /* Exclusive/none -> exclusive/none case */
1858                 if (cur_old_count == nr_old_roots &&
1859                     cur_new_count == nr_new_roots) {
1860                         if (cur_old_count == 0) {
1861                                 /* None -> exclusive/none */
1862 
1863                                 if (cur_new_count != 0) {
1864                                         /* None -> exclusive */
1865                                         qg->excl += num_bytes;
1866                                         qg->excl_cmpr += num_bytes;
1867                                         dirty = true;
1868                                 }
1869                                 /* None -> none, nothing changed */
1870                         } else {
1871                                 /* Exclusive -> exclusive/none */
1872 
1873                                 if (cur_new_count == 0) {
1874                                         /* Exclusive -> none */
1875                                         qg->excl -= num_bytes;
1876                                         qg->excl_cmpr -= num_bytes;
1877                                         dirty = true;
1878                                 }
1879                                 /* Exclusive -> exclusive, nothing changed */
1880                         }
1881                 }
1882 
1883                 if (dirty)
1884                         qgroup_dirty(fs_info, qg);
1885         }
1886         return 0;
1887 }
1888 
1889 /*
1890  * Check if the @roots potentially is a list of fs tree roots
1891  *
1892  * Return 0 for definitely not a fs/subvol tree roots ulist
1893  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
1894  *          one as well)
1895  */
1896 static int maybe_fs_roots(struct ulist *roots)
1897 {
1898         struct ulist_node *unode;
1899         struct ulist_iterator uiter;
1900 
1901         /* Empty one, still possible for fs roots */
1902         if (!roots || roots->nnodes == 0)
1903                 return 1;
1904 
1905         ULIST_ITER_INIT(&uiter);
1906         unode = ulist_next(roots, &uiter);
1907         if (!unode)
1908                 return 1;
1909 
1910         /*
1911          * If it contains fs tree roots, then it must belong to fs/subvol
1912          * trees.
1913          * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
1914          */
1915         return is_fstree(unode->val);
1916 }
1917 
1918 int
1919 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
1920                             struct btrfs_fs_info *fs_info,
1921                             u64 bytenr, u64 num_bytes,
1922                             struct ulist *old_roots, struct ulist *new_roots)
1923 {
1924         struct ulist *qgroups = NULL;
1925         struct ulist *tmp = NULL;
1926         u64 seq;
1927         u64 nr_new_roots = 0;
1928         u64 nr_old_roots = 0;
1929         int ret = 0;
1930 
1931         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1932                 return 0;
1933 
1934         if (new_roots) {
1935                 if (!maybe_fs_roots(new_roots))
1936                         goto out_free;
1937                 nr_new_roots = new_roots->nnodes;
1938         }
1939         if (old_roots) {
1940                 if (!maybe_fs_roots(old_roots))
1941                         goto out_free;
1942                 nr_old_roots = old_roots->nnodes;
1943         }
1944 
1945         /* Quick exit, either not fs tree roots, or won't affect any qgroup */
1946         if (nr_old_roots == 0 && nr_new_roots == 0)
1947                 goto out_free;
1948 
1949         BUG_ON(!fs_info->quota_root);
1950 
1951         trace_btrfs_qgroup_account_extent(fs_info, bytenr, num_bytes,
1952                                           nr_old_roots, nr_new_roots);
1953 
1954         qgroups = ulist_alloc(GFP_NOFS);
1955         if (!qgroups) {
1956                 ret = -ENOMEM;
1957                 goto out_free;
1958         }
1959         tmp = ulist_alloc(GFP_NOFS);
1960         if (!tmp) {
1961                 ret = -ENOMEM;
1962                 goto out_free;
1963         }
1964 
1965         mutex_lock(&fs_info->qgroup_rescan_lock);
1966         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
1967                 if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
1968                         mutex_unlock(&fs_info->qgroup_rescan_lock);
1969                         ret = 0;
1970                         goto out_free;
1971                 }
1972         }
1973         mutex_unlock(&fs_info->qgroup_rescan_lock);
1974 
1975         spin_lock(&fs_info->qgroup_lock);
1976         seq = fs_info->qgroup_seq;
1977 
1978         /* Update old refcnts using old_roots */
1979         ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
1980                                    UPDATE_OLD);
1981         if (ret < 0)
1982                 goto out;
1983 
1984         /* Update new refcnts using new_roots */
1985         ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
1986                                    UPDATE_NEW);
1987         if (ret < 0)
1988                 goto out;
1989 
1990         qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
1991                                num_bytes, seq);
1992 
1993         /*
1994          * Bump qgroup_seq to avoid seq overlap
1995          */
1996         fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
1997 out:
1998         spin_unlock(&fs_info->qgroup_lock);
1999 out_free:
2000         ulist_free(tmp);
2001         ulist_free(qgroups);
2002         ulist_free(old_roots);
2003         ulist_free(new_roots);
2004         return ret;
2005 }
2006 
2007 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans,
2008                                  struct btrfs_fs_info *fs_info)
2009 {
2010         struct btrfs_qgroup_extent_record *record;
2011         struct btrfs_delayed_ref_root *delayed_refs;
2012         struct ulist *new_roots = NULL;
2013         struct rb_node *node;
2014         u64 qgroup_to_skip;
2015         int ret = 0;
2016 
2017         delayed_refs = &trans->transaction->delayed_refs;
2018         qgroup_to_skip = delayed_refs->qgroup_to_skip;
2019         while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2020                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
2021                                   node);
2022 
2023                 trace_btrfs_qgroup_account_extents(fs_info, record);
2024 
2025                 if (!ret) {
2026                         /*
2027                          * Old roots should be searched when inserting qgroup
2028                          * extent record
2029                          */
2030                         if (WARN_ON(!record->old_roots)) {
2031                                 /* Search commit root to find old_roots */
2032                                 ret = btrfs_find_all_roots(NULL, fs_info,
2033                                                 record->bytenr, 0,
2034                                                 &record->old_roots, false);
2035                                 if (ret < 0)
2036                                         goto cleanup;
2037                         }
2038 
2039                         /*
2040                          * Use SEQ_LAST as time_seq to do special search, which
2041                          * doesn't lock tree or delayed_refs and search current
2042                          * root. It's safe inside commit_transaction().
2043                          */
2044                         ret = btrfs_find_all_roots(trans, fs_info,
2045                                 record->bytenr, SEQ_LAST, &new_roots, false);
2046                         if (ret < 0)
2047                                 goto cleanup;
2048                         if (qgroup_to_skip) {
2049                                 ulist_del(new_roots, qgroup_to_skip, 0);
2050                                 ulist_del(record->old_roots, qgroup_to_skip,
2051                                           0);
2052                         }
2053                         ret = btrfs_qgroup_account_extent(trans, fs_info,
2054                                         record->bytenr, record->num_bytes,
2055                                         record->old_roots, new_roots);
2056                         record->old_roots = NULL;
2057                         new_roots = NULL;
2058                 }
2059 cleanup:
2060                 ulist_free(record->old_roots);
2061                 ulist_free(new_roots);
2062                 new_roots = NULL;
2063                 rb_erase(node, &delayed_refs->dirty_extent_root);
2064                 kfree(record);
2065 
2066         }
2067         return ret;
2068 }
2069 
2070 /*
2071  * called from commit_transaction. Writes all changed qgroups to disk.
2072  */
2073 int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
2074                       struct btrfs_fs_info *fs_info)
2075 {
2076         struct btrfs_root *quota_root = fs_info->quota_root;
2077         int ret = 0;
2078         int start_rescan_worker = 0;
2079 
2080         if (!quota_root)
2081                 goto out;
2082 
2083         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
2084             test_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2085                 start_rescan_worker = 1;
2086 
2087         if (test_and_clear_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
2088                 set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
2089 
2090         spin_lock(&fs_info->qgroup_lock);
2091         while (!list_empty(&fs_info->dirty_qgroups)) {
2092                 struct btrfs_qgroup *qgroup;
2093                 qgroup = list_first_entry(&fs_info->dirty_qgroups,
2094                                           struct btrfs_qgroup, dirty);
2095                 list_del_init(&qgroup->dirty);
2096                 spin_unlock(&fs_info->qgroup_lock);
2097                 ret = update_qgroup_info_item(trans, quota_root, qgroup);
2098                 if (ret)
2099                         fs_info->qgroup_flags |=
2100                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2101                 ret = update_qgroup_limit_item(trans, quota_root, qgroup);
2102                 if (ret)
2103                         fs_info->qgroup_flags |=
2104                                         BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2105                 spin_lock(&fs_info->qgroup_lock);
2106         }
2107         if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2108                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2109         else
2110                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2111         spin_unlock(&fs_info->qgroup_lock);
2112 
2113         ret = update_qgroup_status_item(trans, fs_info, quota_root);
2114         if (ret)
2115                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2116 
2117         if (!ret && start_rescan_worker) {
2118                 ret = qgroup_rescan_init(fs_info, 0, 1);
2119                 if (!ret) {
2120                         qgroup_rescan_zero_tracking(fs_info);
2121                         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2122                                          &fs_info->qgroup_rescan_work);
2123                 }
2124                 ret = 0;
2125         }
2126 
2127 out:
2128 
2129         return ret;
2130 }
2131 
2132 /*
2133  * Copy the accounting information between qgroups. This is necessary
2134  * when a snapshot or a subvolume is created. Throwing an error will
2135  * cause a transaction abort so we take extra care here to only error
2136  * when a readonly fs is a reasonable outcome.
2137  */
2138 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
2139                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
2140                          struct btrfs_qgroup_inherit *inherit)
2141 {
2142         int ret = 0;
2143         int i;
2144         u64 *i_qgroups;
2145         struct btrfs_root *quota_root = fs_info->quota_root;
2146         struct btrfs_qgroup *srcgroup;
2147         struct btrfs_qgroup *dstgroup;
2148         u32 level_size = 0;
2149         u64 nums;
2150 
2151         mutex_lock(&fs_info->qgroup_ioctl_lock);
2152         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2153                 goto out;
2154 
2155         if (!quota_root) {
2156                 ret = -EINVAL;
2157                 goto out;
2158         }
2159 
2160         if (inherit) {
2161                 i_qgroups = (u64 *)(inherit + 1);
2162                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2163                        2 * inherit->num_excl_copies;
2164                 for (i = 0; i < nums; ++i) {
2165                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2166 
2167                         /*
2168                          * Zero out invalid groups so we can ignore
2169                          * them later.
2170                          */
2171                         if (!srcgroup ||
2172                             ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2173                                 *i_qgroups = 0ULL;
2174 
2175                         ++i_qgroups;
2176                 }
2177         }
2178 
2179         /*
2180          * create a tracking group for the subvol itself
2181          */
2182         ret = add_qgroup_item(trans, quota_root, objectid);
2183         if (ret)
2184                 goto out;
2185 
2186         if (srcid) {
2187                 struct btrfs_root *srcroot;
2188                 struct btrfs_key srckey;
2189 
2190                 srckey.objectid = srcid;
2191                 srckey.type = BTRFS_ROOT_ITEM_KEY;
2192                 srckey.offset = (u64)-1;
2193                 srcroot = btrfs_read_fs_root_no_name(fs_info, &srckey);
2194                 if (IS_ERR(srcroot)) {
2195                         ret = PTR_ERR(srcroot);
2196                         goto out;
2197                 }
2198 
2199                 level_size = fs_info->nodesize;
2200         }
2201 
2202         /*
2203          * add qgroup to all inherited groups
2204          */
2205         if (inherit) {
2206                 i_qgroups = (u64 *)(inherit + 1);
2207                 for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2208                         if (*i_qgroups == 0)
2209                                 continue;
2210                         ret = add_qgroup_relation_item(trans, quota_root,
2211                                                        objectid, *i_qgroups);
2212                         if (ret && ret != -EEXIST)
2213                                 goto out;
2214                         ret = add_qgroup_relation_item(trans, quota_root,
2215                                                        *i_qgroups, objectid);
2216                         if (ret && ret != -EEXIST)
2217                                 goto out;
2218                 }
2219                 ret = 0;
2220         }
2221 
2222 
2223         spin_lock(&fs_info->qgroup_lock);
2224 
2225         dstgroup = add_qgroup_rb(fs_info, objectid);
2226         if (IS_ERR(dstgroup)) {
2227                 ret = PTR_ERR(dstgroup);
2228                 goto unlock;
2229         }
2230 
2231         if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2232                 dstgroup->lim_flags = inherit->lim.flags;
2233                 dstgroup->max_rfer = inherit->lim.max_rfer;
2234                 dstgroup->max_excl = inherit->lim.max_excl;
2235                 dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2236                 dstgroup->rsv_excl = inherit->lim.rsv_excl;
2237 
2238                 ret = update_qgroup_limit_item(trans, quota_root, dstgroup);
2239                 if (ret) {
2240                         fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2241                         btrfs_info(fs_info,
2242                                    "unable to update quota limit for %llu",
2243                                    dstgroup->qgroupid);
2244                         goto unlock;
2245                 }
2246         }
2247 
2248         if (srcid) {
2249                 srcgroup = find_qgroup_rb(fs_info, srcid);
2250                 if (!srcgroup)
2251                         goto unlock;
2252 
2253                 /*
2254                  * We call inherit after we clone the root in order to make sure
2255                  * our counts don't go crazy, so at this point the only
2256                  * difference between the two roots should be the root node.
2257                  */
2258                 dstgroup->rfer = srcgroup->rfer;
2259                 dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2260                 dstgroup->excl = level_size;
2261                 dstgroup->excl_cmpr = level_size;
2262                 srcgroup->excl = level_size;
2263                 srcgroup->excl_cmpr = level_size;
2264 
2265                 /* inherit the limit info */
2266                 dstgroup->lim_flags = srcgroup->lim_flags;
2267                 dstgroup->max_rfer = srcgroup->max_rfer;
2268                 dstgroup->max_excl = srcgroup->max_excl;
2269                 dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2270                 dstgroup->rsv_excl = srcgroup->rsv_excl;
2271 
2272                 qgroup_dirty(fs_info, dstgroup);
2273                 qgroup_dirty(fs_info, srcgroup);
2274         }
2275 
2276         if (!inherit)
2277                 goto unlock;
2278 
2279         i_qgroups = (u64 *)(inherit + 1);
2280         for (i = 0; i < inherit->num_qgroups; ++i) {
2281                 if (*i_qgroups) {
2282                         ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2283                         if (ret)
2284                                 goto unlock;
2285                 }
2286                 ++i_qgroups;
2287         }
2288 
2289         for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
2290                 struct btrfs_qgroup *src;
2291                 struct btrfs_qgroup *dst;
2292 
2293                 if (!i_qgroups[0] || !i_qgroups[1])
2294                         continue;
2295 
2296                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2297                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2298 
2299                 if (!src || !dst) {
2300                         ret = -EINVAL;
2301                         goto unlock;
2302                 }
2303 
2304                 dst->rfer = src->rfer - level_size;
2305                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
2306         }
2307         for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
2308                 struct btrfs_qgroup *src;
2309                 struct btrfs_qgroup *dst;
2310 
2311                 if (!i_qgroups[0] || !i_qgroups[1])
2312                         continue;
2313 
2314                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
2315                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
2316 
2317                 if (!src || !dst) {
2318                         ret = -EINVAL;
2319                         goto unlock;
2320                 }
2321 
2322                 dst->excl = src->excl + level_size;
2323                 dst->excl_cmpr = src->excl_cmpr + level_size;
2324         }
2325 
2326 unlock:
2327         spin_unlock(&fs_info->qgroup_lock);
2328 out:
2329         mutex_unlock(&fs_info->qgroup_ioctl_lock);
2330         return ret;
2331 }
2332 
2333 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
2334 {
2335         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
2336             qg->reserved + (s64)qg->rfer + num_bytes > qg->max_rfer)
2337                 return false;
2338 
2339         if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
2340             qg->reserved + (s64)qg->excl + num_bytes > qg->max_excl)
2341                 return false;
2342 
2343         return true;
2344 }
2345 
2346 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce)
2347 {
2348         struct btrfs_root *quota_root;
2349         struct btrfs_qgroup *qgroup;
2350         struct btrfs_fs_info *fs_info = root->fs_info;
2351         u64 ref_root = root->root_key.objectid;
2352         int ret = 0;
2353         int retried = 0;
2354         struct ulist_node *unode;
2355         struct ulist_iterator uiter;
2356 
2357         if (!is_fstree(ref_root))
2358                 return 0;
2359 
2360         if (num_bytes == 0)
2361                 return 0;
2362 
2363         if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
2364             capable(CAP_SYS_RESOURCE))
2365                 enforce = false;
2366 
2367 retry:
2368         spin_lock(&fs_info->qgroup_lock);
2369         quota_root = fs_info->quota_root;
2370         if (!quota_root)
2371                 goto out;
2372 
2373         qgroup = find_qgroup_rb(fs_info, ref_root);
2374         if (!qgroup)
2375                 goto out;
2376 
2377         /*
2378          * in a first step, we check all affected qgroups if any limits would
2379          * be exceeded
2380          */
2381         ulist_reinit(fs_info->qgroup_ulist);
2382         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2383                         (uintptr_t)qgroup, GFP_ATOMIC);
2384         if (ret < 0)
2385                 goto out;
2386         ULIST_ITER_INIT(&uiter);
2387         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2388                 struct btrfs_qgroup *qg;
2389                 struct btrfs_qgroup_list *glist;
2390 
2391                 qg = unode_aux_to_qgroup(unode);
2392 
2393                 if (enforce && !qgroup_check_limits(qg, num_bytes)) {
2394                         /*
2395                          * Commit the tree and retry, since we may have
2396                          * deletions which would free up space.
2397                          */
2398                         if (!retried && qg->reserved > 0) {
2399                                 struct btrfs_trans_handle *trans;
2400 
2401                                 spin_unlock(&fs_info->qgroup_lock);
2402                                 ret = btrfs_start_delalloc_inodes(root, 0);
2403                                 if (ret)
2404                                         return ret;
2405                                 btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
2406                                 trans = btrfs_join_transaction(root);
2407                                 if (IS_ERR(trans))
2408                                         return PTR_ERR(trans);
2409                                 ret = btrfs_commit_transaction(trans);
2410                                 if (ret)
2411                                         return ret;
2412                                 retried++;
2413                                 goto retry;
2414                         }
2415                         ret = -EDQUOT;
2416                         goto out;
2417                 }
2418 
2419                 list_for_each_entry(glist, &qg->groups, next_group) {
2420                         ret = ulist_add(fs_info->qgroup_ulist,
2421                                         glist->group->qgroupid,
2422                                         (uintptr_t)glist->group, GFP_ATOMIC);
2423                         if (ret < 0)
2424                                 goto out;
2425                 }
2426         }
2427         ret = 0;
2428         /*
2429          * no limits exceeded, now record the reservation into all qgroups
2430          */
2431         ULIST_ITER_INIT(&uiter);
2432         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2433                 struct btrfs_qgroup *qg;
2434 
2435                 qg = unode_aux_to_qgroup(unode);
2436 
2437                 trace_qgroup_update_reserve(fs_info, qg, num_bytes);
2438                 qg->reserved += num_bytes;
2439         }
2440 
2441 out:
2442         spin_unlock(&fs_info->qgroup_lock);
2443         return ret;
2444 }
2445 
2446 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
2447                                u64 ref_root, u64 num_bytes)
2448 {
2449         struct btrfs_root *quota_root;
2450         struct btrfs_qgroup *qgroup;
2451         struct ulist_node *unode;
2452         struct ulist_iterator uiter;
2453         int ret = 0;
2454 
2455         if (!is_fstree(ref_root))
2456                 return;
2457 
2458         if (num_bytes == 0)
2459                 return;
2460 
2461         spin_lock(&fs_info->qgroup_lock);
2462 
2463         quota_root = fs_info->quota_root;
2464         if (!quota_root)
2465                 goto out;
2466 
2467         qgroup = find_qgroup_rb(fs_info, ref_root);
2468         if (!qgroup)
2469                 goto out;
2470 
2471         ulist_reinit(fs_info->qgroup_ulist);
2472         ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
2473                         (uintptr_t)qgroup, GFP_ATOMIC);
2474         if (ret < 0)
2475                 goto out;
2476         ULIST_ITER_INIT(&uiter);
2477         while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
2478                 struct btrfs_qgroup *qg;
2479                 struct btrfs_qgroup_list *glist;
2480 
2481                 qg = unode_aux_to_qgroup(unode);
2482 
2483                 trace_qgroup_update_reserve(fs_info, qg, -(s64)num_bytes);
2484                 if (qg->reserved < num_bytes)
2485                         report_reserved_underflow(fs_info, qg, num_bytes);
2486                 else
2487                         qg->reserved -= num_bytes;
2488 
2489                 list_for_each_entry(glist, &qg->groups, next_group) {
2490                         ret = ulist_add(fs_info->qgroup_ulist,
2491                                         glist->group->qgroupid,
2492                                         (uintptr_t)glist->group, GFP_ATOMIC);
2493                         if (ret < 0)
2494                                 goto out;
2495                 }
2496         }
2497 
2498 out:
2499         spin_unlock(&fs_info->qgroup_lock);
2500 }
2501 
2502 /*
2503  * returns < 0 on error, 0 when more leafs are to be scanned.
2504  * returns 1 when done.
2505  */
2506 static int
2507 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
2508                    struct btrfs_trans_handle *trans)
2509 {
2510         struct btrfs_key found;
2511         struct extent_buffer *scratch_leaf = NULL;
2512         struct ulist *roots = NULL;
2513         struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
2514         u64 num_bytes;
2515         int slot;
2516         int ret;
2517 
2518         mutex_lock(&fs_info->qgroup_rescan_lock);
2519         ret = btrfs_search_slot_for_read(fs_info->extent_root,
2520                                          &fs_info->qgroup_rescan_progress,
2521                                          path, 1, 0);
2522 
2523         btrfs_debug(fs_info,
2524                 "current progress key (%llu %u %llu), search_slot ret %d",
2525                 fs_info->qgroup_rescan_progress.objectid,
2526                 fs_info->qgroup_rescan_progress.type,
2527                 fs_info->qgroup_rescan_progress.offset, ret);
2528 
2529         if (ret) {
2530                 /*
2531                  * The rescan is about to end, we will not be scanning any
2532                  * further blocks. We cannot unset the RESCAN flag here, because
2533                  * we want to commit the transaction if everything went well.
2534                  * To make the live accounting work in this phase, we set our
2535                  * scan progress pointer such that every real extent objectid
2536                  * will be smaller.
2537                  */
2538                 fs_info->qgroup_rescan_progress.objectid = (u64)-1;
2539                 btrfs_release_path(path);
2540                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2541                 return ret;
2542         }
2543 
2544         btrfs_item_key_to_cpu(path->nodes[0], &found,
2545                               btrfs_header_nritems(path->nodes[0]) - 1);
2546         fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
2547 
2548         btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2549         scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
2550         if (!scratch_leaf) {
2551                 ret = -ENOMEM;
2552                 mutex_unlock(&fs_info->qgroup_rescan_lock);
2553                 goto out;
2554         }
2555         extent_buffer_get(scratch_leaf);
2556         btrfs_tree_read_lock(scratch_leaf);
2557         btrfs_set_lock_blocking_rw(scratch_leaf, BTRFS_READ_LOCK);
2558         slot = path->slots[0];
2559         btrfs_release_path(path);
2560         mutex_unlock(&fs_info->qgroup_rescan_lock);
2561 
2562         for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
2563                 btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
2564                 if (found.type != BTRFS_EXTENT_ITEM_KEY &&
2565                     found.type != BTRFS_METADATA_ITEM_KEY)
2566                         continue;
2567                 if (found.type == BTRFS_METADATA_ITEM_KEY)
2568                         num_bytes = fs_info->nodesize;
2569                 else
2570                         num_bytes = found.offset;
2571 
2572                 ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
2573                                            &roots, false);
2574                 if (ret < 0)
2575                         goto out;
2576                 /* For rescan, just pass old_roots as NULL */
2577                 ret = btrfs_qgroup_account_extent(trans, fs_info,
2578                                 found.objectid, num_bytes, NULL, roots);
2579                 if (ret < 0)
2580                         goto out;
2581         }
2582 out:
2583         if (scratch_leaf) {
2584                 btrfs_tree_read_unlock_blocking(scratch_leaf);
2585                 free_extent_buffer(scratch_leaf);
2586         }
2587         btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
2588 
2589         return ret;
2590 }
2591 
2592 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
2593 {
2594         struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
2595                                                      qgroup_rescan_work);
2596         struct btrfs_path *path;
2597         struct btrfs_trans_handle *trans = NULL;
2598         int err = -ENOMEM;
2599         int ret = 0;
2600 
2601         path = btrfs_alloc_path();
2602         if (!path)
2603                 goto out;
2604 
2605         err = 0;
2606         while (!err && !btrfs_fs_closing(fs_info)) {
2607                 trans = btrfs_start_transaction(fs_info->fs_root, 0);
2608                 if (IS_ERR(trans)) {
2609                         err = PTR_ERR(trans);
2610                         break;
2611                 }
2612                 if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
2613                         err = -EINTR;
2614                 } else {
2615                         err = qgroup_rescan_leaf(fs_info, path, trans);
2616                 }
2617                 if (err > 0)
2618                         btrfs_commit_transaction(trans);
2619                 else
2620                         btrfs_end_transaction(trans);
2621         }
2622 
2623 out:
2624         btrfs_free_path(path);
2625 
2626         mutex_lock(&fs_info->qgroup_rescan_lock);
2627         if (!btrfs_fs_closing(fs_info))
2628                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2629 
2630         if (err > 0 &&
2631             fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
2632                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2633         } else if (err < 0) {
2634                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2635         }
2636         mutex_unlock(&fs_info->qgroup_rescan_lock);
2637 
2638         /*
2639          * only update status, since the previous part has already updated the
2640          * qgroup info.
2641          */
2642         trans = btrfs_start_transaction(fs_info->quota_root, 1);
2643         if (IS_ERR(trans)) {
2644                 err = PTR_ERR(trans);
2645                 btrfs_err(fs_info,
2646                           "fail to start transaction for status update: %d",
2647                           err);
2648                 goto done;
2649         }
2650         ret = update_qgroup_status_item(trans, fs_info, fs_info->quota_root);
2651         if (ret < 0) {
2652                 err = ret;
2653                 btrfs_err(fs_info, "fail to update qgroup status: %d", err);
2654         }
2655         btrfs_end_transaction(trans);
2656 
2657         if (btrfs_fs_closing(fs_info)) {
2658                 btrfs_info(fs_info, "qgroup scan paused");
2659         } else if (err >= 0) {
2660                 btrfs_info(fs_info, "qgroup scan completed%s",
2661                         err > 0 ? " (inconsistency flag cleared)" : "");
2662         } else {
2663                 btrfs_err(fs_info, "qgroup scan failed with %d", err);
2664         }
2665 
2666 done:
2667         mutex_lock(&fs_info->qgroup_rescan_lock);
2668         fs_info->qgroup_rescan_running = false;
2669         mutex_unlock(&fs_info->qgroup_rescan_lock);
2670         complete_all(&fs_info->qgroup_rescan_completion);
2671 }
2672 
2673 /*
2674  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
2675  * memory required for the rescan context.
2676  */
2677 static int
2678 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
2679                    int init_flags)
2680 {
2681         int ret = 0;
2682 
2683         if (!init_flags &&
2684             (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) ||
2685              !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))) {
2686                 ret = -EINVAL;
2687                 goto err;
2688         }
2689 
2690         mutex_lock(&fs_info->qgroup_rescan_lock);
2691         spin_lock(&fs_info->qgroup_lock);
2692 
2693         if (init_flags) {
2694                 if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2695                         ret = -EINPROGRESS;
2696                 else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
2697                         ret = -EINVAL;
2698 
2699                 if (ret) {
2700                         spin_unlock(&fs_info->qgroup_lock);
2701                         mutex_unlock(&fs_info->qgroup_rescan_lock);
2702                         goto err;
2703                 }
2704                 fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2705         }
2706 
2707         memset(&fs_info->qgroup_rescan_progress, 0,
2708                 sizeof(fs_info->qgroup_rescan_progress));
2709         fs_info->qgroup_rescan_progress.objectid = progress_objectid;
2710         init_completion(&fs_info->qgroup_rescan_completion);
2711         fs_info->qgroup_rescan_running = true;
2712 
2713         spin_unlock(&fs_info->qgroup_lock);
2714         mutex_unlock(&fs_info->qgroup_rescan_lock);
2715 
2716         memset(&fs_info->qgroup_rescan_work, 0,
2717                sizeof(fs_info->qgroup_rescan_work));
2718         btrfs_init_work(&fs_info->qgroup_rescan_work,
2719                         btrfs_qgroup_rescan_helper,
2720                         btrfs_qgroup_rescan_worker, NULL, NULL);
2721 
2722         if (ret) {
2723 err:
2724                 btrfs_info(fs_info, "qgroup_rescan_init failed with %d", ret);
2725                 return ret;
2726         }
2727 
2728         return 0;
2729 }
2730 
2731 static void
2732 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
2733 {
2734         struct rb_node *n;
2735         struct btrfs_qgroup *qgroup;
2736 
2737         spin_lock(&fs_info->qgroup_lock);
2738         /* clear all current qgroup tracking information */
2739         for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
2740                 qgroup = rb_entry(n, struct btrfs_qgroup, node);
2741                 qgroup->rfer = 0;
2742                 qgroup->rfer_cmpr = 0;
2743                 qgroup->excl = 0;
2744                 qgroup->excl_cmpr = 0;
2745         }
2746         spin_unlock(&fs_info->qgroup_lock);
2747 }
2748 
2749 int
2750 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
2751 {
2752         int ret = 0;
2753         struct btrfs_trans_handle *trans;
2754 
2755         ret = qgroup_rescan_init(fs_info, 0, 1);
2756         if (ret)
2757                 return ret;
2758 
2759         /*
2760          * We have set the rescan_progress to 0, which means no more
2761          * delayed refs will be accounted by btrfs_qgroup_account_ref.
2762          * However, btrfs_qgroup_account_ref may be right after its call
2763          * to btrfs_find_all_roots, in which case it would still do the
2764          * accounting.
2765          * To solve this, we're committing the transaction, which will
2766          * ensure we run all delayed refs and only after that, we are
2767          * going to clear all tracking information for a clean start.
2768          */
2769 
2770         trans = btrfs_join_transaction(fs_info->fs_root);
2771         if (IS_ERR(trans)) {
2772                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2773                 return PTR_ERR(trans);
2774         }
2775         ret = btrfs_commit_transaction(trans);
2776         if (ret) {
2777                 fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
2778                 return ret;
2779         }
2780 
2781         qgroup_rescan_zero_tracking(fs_info);
2782 
2783         btrfs_queue_work(fs_info->qgroup_rescan_workers,
2784                          &fs_info->qgroup_rescan_work);
2785 
2786         return 0;
2787 }
2788 
2789 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
2790                                      bool interruptible)
2791 {
2792         int running;
2793         int ret = 0;
2794 
2795         mutex_lock(&fs_info->qgroup_rescan_lock);
2796         spin_lock(&fs_info->qgroup_lock);
2797         running = fs_info->qgroup_rescan_running;
2798         spin_unlock(&fs_info->qgroup_lock);
2799         mutex_unlock(&fs_info->qgroup_rescan_lock);
2800 
2801         if (!running)
2802                 return 0;
2803 
2804         if (interruptible)
2805                 ret = wait_for_completion_interruptible(
2806                                         &fs_info->qgroup_rescan_completion);
2807         else
2808                 wait_for_completion(&fs_info->qgroup_rescan_completion);
2809 
2810         return ret;
2811 }
2812 
2813 /*
2814  * this is only called from open_ctree where we're still single threaded, thus
2815  * locking is omitted here.
2816  */
2817 void
2818 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
2819 {
2820         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
2821                 btrfs_queue_work(fs_info->qgroup_rescan_workers,
2822                                  &fs_info->qgroup_rescan_work);
2823 }
2824 
2825 /*
2826  * Reserve qgroup space for range [start, start + len).
2827  *
2828  * This function will either reserve space from related qgroups or doing
2829  * nothing if the range is already reserved.
2830  *
2831  * Return 0 for successful reserve
2832  * Return <0 for error (including -EQUOT)
2833  *
2834  * NOTE: this function may sleep for memory allocation.
2835  *       if btrfs_qgroup_reserve_data() is called multiple times with
2836  *       same @reserved, caller must ensure when error happens it's OK
2837  *       to free *ALL* reserved space.
2838  */
2839 int btrfs_qgroup_reserve_data(struct inode *inode,
2840                         struct extent_changeset **reserved_ret, u64 start,
2841                         u64 len)
2842 {
2843         struct btrfs_root *root = BTRFS_I(inode)->root;
2844         struct ulist_node *unode;
2845         struct ulist_iterator uiter;
2846         struct extent_changeset *reserved;
2847         u64 orig_reserved;
2848         u64 to_reserve;
2849         int ret;
2850 
2851         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
2852             !is_fstree(root->objectid) || len == 0)
2853                 return 0;
2854 
2855         /* @reserved parameter is mandatory for qgroup */
2856         if (WARN_ON(!reserved_ret))
2857                 return -EINVAL;
2858         if (!*reserved_ret) {
2859                 *reserved_ret = extent_changeset_alloc();
2860                 if (!*reserved_ret)
2861                         return -ENOMEM;
2862         }
2863         reserved = *reserved_ret;
2864         /* Record already reserved space */
2865         orig_reserved = reserved->bytes_changed;
2866         ret = set_record_extent_bits(&BTRFS_I(inode)->io_tree, start,
2867                         start + len -1, EXTENT_QGROUP_RESERVED, reserved);
2868 
2869         /* Newly reserved space */
2870         to_reserve = reserved->bytes_changed - orig_reserved;
2871         trace_btrfs_qgroup_reserve_data(inode, start, len,
2872                                         to_reserve, QGROUP_RESERVE);
2873         if (ret < 0)
2874                 goto cleanup;
2875         ret = qgroup_reserve(root, to_reserve, true);
2876         if (ret < 0)
2877                 goto cleanup;
2878 
2879         return ret;
2880 
2881 cleanup:
2882         /* cleanup *ALL* already reserved ranges */
2883         ULIST_ITER_INIT(&uiter);
2884         while ((unode = ulist_next(&reserved->range_changed, &uiter)))
2885                 clear_extent_bit(&BTRFS_I(inode)->io_tree, unode->val,
2886                                  unode->aux, EXTENT_QGROUP_RESERVED, 0, 0, NULL,
2887                                  GFP_NOFS);
2888         extent_changeset_release(reserved);
2889         return ret;
2890 }
2891 
2892 /* Free ranges specified by @reserved, normally in error path */
2893 static int qgroup_free_reserved_data(struct inode *inode,
2894                         struct extent_changeset *reserved, u64 start, u64 len)
2895 {
2896         struct btrfs_root *root = BTRFS_I(inode)->root;
2897         struct ulist_node *unode;
2898         struct ulist_iterator uiter;
2899         struct extent_changeset changeset;
2900         int freed = 0;
2901         int ret;
2902 
2903         extent_changeset_init(&changeset);
2904         len = round_up(start + len, root->fs_info->sectorsize);
2905         start = round_down(start, root->fs_info->sectorsize);
2906 
2907         ULIST_ITER_INIT(&uiter);
2908         while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
2909                 u64 range_start = unode->val;
2910                 /* unode->aux is the inclusive end */
2911                 u64 range_len = unode->aux - range_start + 1;
2912                 u64 free_start;
2913                 u64 free_len;
2914 
2915                 extent_changeset_release(&changeset);
2916 
2917                 /* Only free range in range [start, start + len) */
2918                 if (range_start >= start + len ||
2919                     range_start + range_len <= start)
2920                         continue;
2921                 free_start = max(range_start, start);
2922                 free_len = min(start + len, range_start + range_len) -
2923                            free_start;
2924                 /*
2925                  * TODO: To also modify reserved->ranges_reserved to reflect
2926                  * the modification.
2927                  *
2928                  * However as long as we free qgroup reserved according to
2929                  * EXTENT_QGROUP_RESERVED, we won't double free.
2930                  * So not need to rush.
2931                  */
2932                 ret = clear_record_extent_bits(&BTRFS_I(inode)->io_failure_tree,
2933                                 free_start, free_start + free_len - 1,
2934                                 EXTENT_QGROUP_RESERVED, &changeset);
2935                 if (ret < 0)
2936                         goto out;
2937                 freed += changeset.bytes_changed;
2938         }
2939         btrfs_qgroup_free_refroot(root->fs_info, root->objectid, freed);
2940         ret = freed;
2941 out:
2942         extent_changeset_release(&changeset);
2943         return ret;
2944 }
2945 
2946 static int __btrfs_qgroup_release_data(struct inode *inode,
2947                         struct extent_changeset *reserved, u64 start, u64 len,
2948                         int free)
2949 {
2950         struct extent_changeset changeset;
2951         int trace_op = QGROUP_RELEASE;
2952         int ret;
2953 
2954         /* In release case, we shouldn't have @reserved */
2955         WARN_ON(!free && reserved);
2956         if (free && reserved)
2957                 return qgroup_free_reserved_data(inode, reserved, start, len);
2958         extent_changeset_init(&changeset);
2959         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, start, 
2960                         start + len -1, EXTENT_QGROUP_RESERVED, &changeset);
2961         if (ret < 0)
2962                 goto out;
2963 
2964         if (free)
2965                 trace_op = QGROUP_FREE;
2966         trace_btrfs_qgroup_release_data(inode, start, len,
2967                                         changeset.bytes_changed, trace_op);
2968         if (free)
2969                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
2970                                 BTRFS_I(inode)->root->objectid,
2971                                 changeset.bytes_changed);
2972         ret = changeset.bytes_changed;
2973 out:
2974         extent_changeset_release(&changeset);
2975         return ret;
2976 }
2977 
2978 /*
2979  * Free a reserved space range from io_tree and related qgroups
2980  *
2981  * Should be called when a range of pages get invalidated before reaching disk.
2982  * Or for error cleanup case.
2983  * if @reserved is given, only reserved range in [@start, @start + @len) will
2984  * be freed.
2985  *
2986  * For data written to disk, use btrfs_qgroup_release_data().
2987  *
2988  * NOTE: This function may sleep for memory allocation.
2989  */
2990 int btrfs_qgroup_free_data(struct inode *inode,
2991                         struct extent_changeset *reserved, u64 start, u64 len)
2992 {
2993         return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
2994 }
2995 
2996 /*
2997  * Release a reserved space range from io_tree only.
2998  *
2999  * Should be called when a range of pages get written to disk and corresponding
3000  * FILE_EXTENT is inserted into corresponding root.
3001  *
3002  * Since new qgroup accounting framework will only update qgroup numbers at
3003  * commit_transaction() time, its reserved space shouldn't be freed from
3004  * related qgroups.
3005  *
3006  * But we should release the range from io_tree, to allow further write to be
3007  * COWed.
3008  *
3009  * NOTE: This function may sleep for memory allocation.
3010  */
3011 int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len)
3012 {
3013         return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3014 }
3015 
3016 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3017                               bool enforce)
3018 {
3019         struct btrfs_fs_info *fs_info = root->fs_info;
3020         int ret;
3021 
3022         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3023             !is_fstree(root->objectid) || num_bytes == 0)
3024                 return 0;
3025 
3026         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3027         trace_qgroup_meta_reserve(root, (s64)num_bytes);
3028         ret = qgroup_reserve(root, num_bytes, enforce);
3029         if (ret < 0)
3030                 return ret;
3031         atomic64_add(num_bytes, &root->qgroup_meta_rsv);
3032         return ret;
3033 }
3034 
3035 void btrfs_qgroup_free_meta_all(struct btrfs_root *root)
3036 {
3037         struct btrfs_fs_info *fs_info = root->fs_info;
3038         u64 reserved;
3039 
3040         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3041             !is_fstree(root->objectid))
3042                 return;
3043 
3044         reserved = atomic64_xchg(&root->qgroup_meta_rsv, 0);
3045         if (reserved == 0)
3046                 return;
3047         trace_qgroup_meta_reserve(root, -(s64)reserved);
3048         btrfs_qgroup_free_refroot(fs_info, root->objectid, reserved);
3049 }
3050 
3051 void btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes)
3052 {
3053         struct btrfs_fs_info *fs_info = root->fs_info;
3054 
3055         if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3056             !is_fstree(root->objectid))
3057                 return;
3058 
3059         BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3060         WARN_ON(atomic64_read(&root->qgroup_meta_rsv) < num_bytes);
3061         atomic64_sub(num_bytes, &root->qgroup_meta_rsv);
3062         trace_qgroup_meta_reserve(root, -(s64)num_bytes);
3063         btrfs_qgroup_free_refroot(fs_info, root->objectid, num_bytes);
3064 }
3065 
3066 /*
3067  * Check qgroup reserved space leaking, normally at destroy inode
3068  * time
3069  */
3070 void btrfs_qgroup_check_reserved_leak(struct inode *inode)
3071 {
3072         struct extent_changeset changeset;
3073         struct ulist_node *unode;
3074         struct ulist_iterator iter;
3075         int ret;
3076 
3077         extent_changeset_init(&changeset);
3078         ret = clear_record_extent_bits(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
3079                         EXTENT_QGROUP_RESERVED, &changeset);
3080 
3081         WARN_ON(ret < 0);
3082         if (WARN_ON(changeset.bytes_changed)) {
3083                 ULIST_ITER_INIT(&iter);
3084                 while ((unode = ulist_next(&changeset.range_changed, &iter))) {
3085                         btrfs_warn(BTRFS_I(inode)->root->fs_info,
3086                                 "leaking qgroup reserved space, ino: %lu, start: %llu, end: %llu",
3087                                 inode->i_ino, unode->val, unode->aux);
3088                 }
3089                 btrfs_qgroup_free_refroot(BTRFS_I(inode)->root->fs_info,
3090                                 BTRFS_I(inode)->root->objectid,
3091                                 changeset.bytes_changed);
3092 
3093         }
3094         extent_changeset_release(&changeset);
3095 }
3096 

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