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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2011 STRATO.  All rights reserved.
4  */
5 
6 #include <linux/sched.h>
7 #include <linux/pagemap.h>
8 #include <linux/writeback.h>
9 #include <linux/blkdev.h>
10 #include <linux/rbtree.h>
11 #include <linux/slab.h>
12 #include <linux/workqueue.h>
13 #include <linux/btrfs.h>
14 #include <linux/sched/mm.h>
15 
16 #include "ctree.h"
17 #include "transaction.h"
18 #include "disk-io.h"
19 #include "locking.h"
20 #include "ulist.h"
21 #include "backref.h"
22 #include "extent_io.h"
23 #include "qgroup.h"
24 #include "block-group.h"
25 #include "sysfs.h"
26 
27 /* TODO XXX FIXME
28  *  - subvol delete -> delete when ref goes to 0? delete limits also?
29  *  - reorganize keys
30  *  - compressed
31  *  - sync
32  *  - copy also limits on subvol creation
33  *  - limit
34  *  - caches for ulists
35  *  - performance benchmarks
36  *  - check all ioctl parameters
37  */
38 
39 /*
40  * Helpers to access qgroup reservation
41  *
42  * Callers should ensure the lock context and type are valid
43  */
44 
qgroup_rsv_total(const struct btrfs_qgroup * qgroup)45 static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup)
46 {
47 	u64 ret = 0;
48 	int i;
49 
50 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
51 		ret += qgroup->rsv.values[i];
52 
53 	return ret;
54 }
55 
56 #ifdef CONFIG_BTRFS_DEBUG
qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)57 static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type)
58 {
59 	if (type == BTRFS_QGROUP_RSV_DATA)
60 		return "data";
61 	if (type == BTRFS_QGROUP_RSV_META_PERTRANS)
62 		return "meta_pertrans";
63 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
64 		return "meta_prealloc";
65 	return NULL;
66 }
67 #endif
68 
qgroup_rsv_add(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup,u64 num_bytes,enum btrfs_qgroup_rsv_type type)69 static void qgroup_rsv_add(struct btrfs_fs_info *fs_info,
70 			   struct btrfs_qgroup *qgroup, u64 num_bytes,
71 			   enum btrfs_qgroup_rsv_type type)
72 {
73 	trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type);
74 	qgroup->rsv.values[type] += num_bytes;
75 }
76 
qgroup_rsv_release(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup,u64 num_bytes,enum btrfs_qgroup_rsv_type type)77 static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
78 			       struct btrfs_qgroup *qgroup, u64 num_bytes,
79 			       enum btrfs_qgroup_rsv_type type)
80 {
81 	trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type);
82 	if (qgroup->rsv.values[type] >= num_bytes) {
83 		qgroup->rsv.values[type] -= num_bytes;
84 		return;
85 	}
86 #ifdef CONFIG_BTRFS_DEBUG
87 	WARN_RATELIMIT(1,
88 		"qgroup %llu %s reserved space underflow, have %llu to free %llu",
89 		qgroup->qgroupid, qgroup_rsv_type_str(type),
90 		qgroup->rsv.values[type], num_bytes);
91 #endif
92 	qgroup->rsv.values[type] = 0;
93 }
94 
qgroup_rsv_add_by_qgroup(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * dest,struct btrfs_qgroup * src)95 static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
96 				     struct btrfs_qgroup *dest,
97 				     struct btrfs_qgroup *src)
98 {
99 	int i;
100 
101 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
102 		qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i);
103 }
104 
qgroup_rsv_release_by_qgroup(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * dest,struct btrfs_qgroup * src)105 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
106 					 struct btrfs_qgroup *dest,
107 					  struct btrfs_qgroup *src)
108 {
109 	int i;
110 
111 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++)
112 		qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i);
113 }
114 
btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup * qg,u64 seq,int mod)115 static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq,
116 					   int mod)
117 {
118 	if (qg->old_refcnt < seq)
119 		qg->old_refcnt = seq;
120 	qg->old_refcnt += mod;
121 }
122 
btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup * qg,u64 seq,int mod)123 static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
124 					   int mod)
125 {
126 	if (qg->new_refcnt < seq)
127 		qg->new_refcnt = seq;
128 	qg->new_refcnt += mod;
129 }
130 
btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup * qg,u64 seq)131 static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
132 {
133 	if (qg->old_refcnt < seq)
134 		return 0;
135 	return qg->old_refcnt - seq;
136 }
137 
btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup * qg,u64 seq)138 static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
139 {
140 	if (qg->new_refcnt < seq)
141 		return 0;
142 	return qg->new_refcnt - seq;
143 }
144 
145 /*
146  * glue structure to represent the relations between qgroups.
147  */
148 struct btrfs_qgroup_list {
149 	struct list_head next_group;
150 	struct list_head next_member;
151 	struct btrfs_qgroup *group;
152 	struct btrfs_qgroup *member;
153 };
154 
qgroup_to_aux(struct btrfs_qgroup * qg)155 static inline u64 qgroup_to_aux(struct btrfs_qgroup *qg)
156 {
157 	return (u64)(uintptr_t)qg;
158 }
159 
unode_aux_to_qgroup(struct ulist_node * n)160 static inline struct btrfs_qgroup* unode_aux_to_qgroup(struct ulist_node *n)
161 {
162 	return (struct btrfs_qgroup *)(uintptr_t)n->aux;
163 }
164 
165 static int
166 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
167 		   int init_flags);
168 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
169 
170 /* must be called with qgroup_ioctl_lock held */
find_qgroup_rb(struct btrfs_fs_info * fs_info,u64 qgroupid)171 static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
172 					   u64 qgroupid)
173 {
174 	struct rb_node *n = fs_info->qgroup_tree.rb_node;
175 	struct btrfs_qgroup *qgroup;
176 
177 	while (n) {
178 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
179 		if (qgroup->qgroupid < qgroupid)
180 			n = n->rb_left;
181 		else if (qgroup->qgroupid > qgroupid)
182 			n = n->rb_right;
183 		else
184 			return qgroup;
185 	}
186 	return NULL;
187 }
188 
189 /* must be called with qgroup_lock held */
add_qgroup_rb(struct btrfs_fs_info * fs_info,u64 qgroupid)190 static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info,
191 					  u64 qgroupid)
192 {
193 	struct rb_node **p = &fs_info->qgroup_tree.rb_node;
194 	struct rb_node *parent = NULL;
195 	struct btrfs_qgroup *qgroup;
196 
197 	while (*p) {
198 		parent = *p;
199 		qgroup = rb_entry(parent, struct btrfs_qgroup, node);
200 
201 		if (qgroup->qgroupid < qgroupid)
202 			p = &(*p)->rb_left;
203 		else if (qgroup->qgroupid > qgroupid)
204 			p = &(*p)->rb_right;
205 		else
206 			return qgroup;
207 	}
208 
209 	qgroup = kzalloc(sizeof(*qgroup), GFP_ATOMIC);
210 	if (!qgroup)
211 		return ERR_PTR(-ENOMEM);
212 
213 	qgroup->qgroupid = qgroupid;
214 	INIT_LIST_HEAD(&qgroup->groups);
215 	INIT_LIST_HEAD(&qgroup->members);
216 	INIT_LIST_HEAD(&qgroup->dirty);
217 
218 	rb_link_node(&qgroup->node, parent, p);
219 	rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
220 
221 	return qgroup;
222 }
223 
__del_qgroup_rb(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup)224 static void __del_qgroup_rb(struct btrfs_fs_info *fs_info,
225 			    struct btrfs_qgroup *qgroup)
226 {
227 	struct btrfs_qgroup_list *list;
228 
229 	list_del(&qgroup->dirty);
230 	while (!list_empty(&qgroup->groups)) {
231 		list = list_first_entry(&qgroup->groups,
232 					struct btrfs_qgroup_list, next_group);
233 		list_del(&list->next_group);
234 		list_del(&list->next_member);
235 		kfree(list);
236 	}
237 
238 	while (!list_empty(&qgroup->members)) {
239 		list = list_first_entry(&qgroup->members,
240 					struct btrfs_qgroup_list, next_member);
241 		list_del(&list->next_group);
242 		list_del(&list->next_member);
243 		kfree(list);
244 	}
245 }
246 
247 /* must be called with qgroup_lock held */
del_qgroup_rb(struct btrfs_fs_info * fs_info,u64 qgroupid)248 static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
249 {
250 	struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid);
251 
252 	if (!qgroup)
253 		return -ENOENT;
254 
255 	rb_erase(&qgroup->node, &fs_info->qgroup_tree);
256 	__del_qgroup_rb(fs_info, qgroup);
257 	return 0;
258 }
259 
260 /* must be called with qgroup_lock held */
add_relation_rb(struct btrfs_fs_info * fs_info,u64 memberid,u64 parentid)261 static int add_relation_rb(struct btrfs_fs_info *fs_info,
262 			   u64 memberid, u64 parentid)
263 {
264 	struct btrfs_qgroup *member;
265 	struct btrfs_qgroup *parent;
266 	struct btrfs_qgroup_list *list;
267 
268 	member = find_qgroup_rb(fs_info, memberid);
269 	parent = find_qgroup_rb(fs_info, parentid);
270 	if (!member || !parent)
271 		return -ENOENT;
272 
273 	list = kzalloc(sizeof(*list), GFP_ATOMIC);
274 	if (!list)
275 		return -ENOMEM;
276 
277 	list->group = parent;
278 	list->member = member;
279 	list_add_tail(&list->next_group, &member->groups);
280 	list_add_tail(&list->next_member, &parent->members);
281 
282 	return 0;
283 }
284 
285 /* must be called with qgroup_lock held */
del_relation_rb(struct btrfs_fs_info * fs_info,u64 memberid,u64 parentid)286 static int del_relation_rb(struct btrfs_fs_info *fs_info,
287 			   u64 memberid, u64 parentid)
288 {
289 	struct btrfs_qgroup *member;
290 	struct btrfs_qgroup *parent;
291 	struct btrfs_qgroup_list *list;
292 
293 	member = find_qgroup_rb(fs_info, memberid);
294 	parent = find_qgroup_rb(fs_info, parentid);
295 	if (!member || !parent)
296 		return -ENOENT;
297 
298 	list_for_each_entry(list, &member->groups, next_group) {
299 		if (list->group == parent) {
300 			list_del(&list->next_group);
301 			list_del(&list->next_member);
302 			kfree(list);
303 			return 0;
304 		}
305 	}
306 	return -ENOENT;
307 }
308 
309 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
btrfs_verify_qgroup_counts(struct btrfs_fs_info * fs_info,u64 qgroupid,u64 rfer,u64 excl)310 int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
311 			       u64 rfer, u64 excl)
312 {
313 	struct btrfs_qgroup *qgroup;
314 
315 	qgroup = find_qgroup_rb(fs_info, qgroupid);
316 	if (!qgroup)
317 		return -EINVAL;
318 	if (qgroup->rfer != rfer || qgroup->excl != excl)
319 		return -EINVAL;
320 	return 0;
321 }
322 #endif
323 
324 /*
325  * The full config is read in one go, only called from open_ctree()
326  * It doesn't use any locking, as at this point we're still single-threaded
327  */
btrfs_read_qgroup_config(struct btrfs_fs_info * fs_info)328 int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
329 {
330 	struct btrfs_key key;
331 	struct btrfs_key found_key;
332 	struct btrfs_root *quota_root = fs_info->quota_root;
333 	struct btrfs_path *path = NULL;
334 	struct extent_buffer *l;
335 	int slot;
336 	int ret = 0;
337 	u64 flags = 0;
338 	u64 rescan_progress = 0;
339 
340 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
341 		return 0;
342 
343 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
344 	if (!fs_info->qgroup_ulist) {
345 		ret = -ENOMEM;
346 		goto out;
347 	}
348 
349 	path = btrfs_alloc_path();
350 	if (!path) {
351 		ret = -ENOMEM;
352 		goto out;
353 	}
354 
355 	ret = btrfs_sysfs_add_qgroups(fs_info);
356 	if (ret < 0)
357 		goto out;
358 	/* default this to quota off, in case no status key is found */
359 	fs_info->qgroup_flags = 0;
360 
361 	/*
362 	 * pass 1: read status, all qgroup infos and limits
363 	 */
364 	key.objectid = 0;
365 	key.type = 0;
366 	key.offset = 0;
367 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1);
368 	if (ret)
369 		goto out;
370 
371 	while (1) {
372 		struct btrfs_qgroup *qgroup;
373 
374 		slot = path->slots[0];
375 		l = path->nodes[0];
376 		btrfs_item_key_to_cpu(l, &found_key, slot);
377 
378 		if (found_key.type == BTRFS_QGROUP_STATUS_KEY) {
379 			struct btrfs_qgroup_status_item *ptr;
380 
381 			ptr = btrfs_item_ptr(l, slot,
382 					     struct btrfs_qgroup_status_item);
383 
384 			if (btrfs_qgroup_status_version(l, ptr) !=
385 			    BTRFS_QGROUP_STATUS_VERSION) {
386 				btrfs_err(fs_info,
387 				 "old qgroup version, quota disabled");
388 				goto out;
389 			}
390 			if (btrfs_qgroup_status_generation(l, ptr) !=
391 			    fs_info->generation) {
392 				flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
393 				btrfs_err(fs_info,
394 					"qgroup generation mismatch, marked as inconsistent");
395 			}
396 			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l,
397 									  ptr);
398 			rescan_progress = btrfs_qgroup_status_rescan(l, ptr);
399 			goto next1;
400 		}
401 
402 		if (found_key.type != BTRFS_QGROUP_INFO_KEY &&
403 		    found_key.type != BTRFS_QGROUP_LIMIT_KEY)
404 			goto next1;
405 
406 		qgroup = find_qgroup_rb(fs_info, found_key.offset);
407 		if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) ||
408 		    (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) {
409 			btrfs_err(fs_info, "inconsistent qgroup config");
410 			flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
411 		}
412 		if (!qgroup) {
413 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
414 			if (IS_ERR(qgroup)) {
415 				ret = PTR_ERR(qgroup);
416 				goto out;
417 			}
418 		}
419 		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
420 		if (ret < 0)
421 			goto out;
422 
423 		switch (found_key.type) {
424 		case BTRFS_QGROUP_INFO_KEY: {
425 			struct btrfs_qgroup_info_item *ptr;
426 
427 			ptr = btrfs_item_ptr(l, slot,
428 					     struct btrfs_qgroup_info_item);
429 			qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr);
430 			qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr);
431 			qgroup->excl = btrfs_qgroup_info_excl(l, ptr);
432 			qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr);
433 			/* generation currently unused */
434 			break;
435 		}
436 		case BTRFS_QGROUP_LIMIT_KEY: {
437 			struct btrfs_qgroup_limit_item *ptr;
438 
439 			ptr = btrfs_item_ptr(l, slot,
440 					     struct btrfs_qgroup_limit_item);
441 			qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr);
442 			qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr);
443 			qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr);
444 			qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr);
445 			qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr);
446 			break;
447 		}
448 		}
449 next1:
450 		ret = btrfs_next_item(quota_root, path);
451 		if (ret < 0)
452 			goto out;
453 		if (ret)
454 			break;
455 	}
456 	btrfs_release_path(path);
457 
458 	/*
459 	 * pass 2: read all qgroup relations
460 	 */
461 	key.objectid = 0;
462 	key.type = BTRFS_QGROUP_RELATION_KEY;
463 	key.offset = 0;
464 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0);
465 	if (ret)
466 		goto out;
467 	while (1) {
468 		slot = path->slots[0];
469 		l = path->nodes[0];
470 		btrfs_item_key_to_cpu(l, &found_key, slot);
471 
472 		if (found_key.type != BTRFS_QGROUP_RELATION_KEY)
473 			goto next2;
474 
475 		if (found_key.objectid > found_key.offset) {
476 			/* parent <- member, not needed to build config */
477 			/* FIXME should we omit the key completely? */
478 			goto next2;
479 		}
480 
481 		ret = add_relation_rb(fs_info, found_key.objectid,
482 				      found_key.offset);
483 		if (ret == -ENOENT) {
484 			btrfs_warn(fs_info,
485 				"orphan qgroup relation 0x%llx->0x%llx",
486 				found_key.objectid, found_key.offset);
487 			ret = 0;	/* ignore the error */
488 		}
489 		if (ret)
490 			goto out;
491 next2:
492 		ret = btrfs_next_item(quota_root, path);
493 		if (ret < 0)
494 			goto out;
495 		if (ret)
496 			break;
497 	}
498 out:
499 	btrfs_free_path(path);
500 	fs_info->qgroup_flags |= flags;
501 	if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
502 		clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
503 	else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
504 		 ret >= 0)
505 		ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
506 
507 	if (ret < 0) {
508 		ulist_free(fs_info->qgroup_ulist);
509 		fs_info->qgroup_ulist = NULL;
510 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
511 		btrfs_sysfs_del_qgroups(fs_info);
512 	}
513 
514 	return ret < 0 ? ret : 0;
515 }
516 
517 /*
518  * Called in close_ctree() when quota is still enabled.  This verifies we don't
519  * leak some reserved space.
520  *
521  * Return false if no reserved space is left.
522  * Return true if some reserved space is leaked.
523  */
btrfs_check_quota_leak(struct btrfs_fs_info * fs_info)524 bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info)
525 {
526 	struct rb_node *node;
527 	bool ret = false;
528 
529 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
530 		return ret;
531 	/*
532 	 * Since we're unmounting, there is no race and no need to grab qgroup
533 	 * lock.  And here we don't go post-order to provide a more user
534 	 * friendly sorted result.
535 	 */
536 	for (node = rb_first(&fs_info->qgroup_tree); node; node = rb_next(node)) {
537 		struct btrfs_qgroup *qgroup;
538 		int i;
539 
540 		qgroup = rb_entry(node, struct btrfs_qgroup, node);
541 		for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) {
542 			if (qgroup->rsv.values[i]) {
543 				ret = true;
544 				btrfs_warn(fs_info,
545 		"qgroup %hu/%llu has unreleased space, type %d rsv %llu",
546 				   btrfs_qgroup_level(qgroup->qgroupid),
547 				   btrfs_qgroup_subvolid(qgroup->qgroupid),
548 				   i, qgroup->rsv.values[i]);
549 			}
550 		}
551 	}
552 	return ret;
553 }
554 
555 /*
556  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(),
557  * first two are in single-threaded paths.And for the third one, we have set
558  * quota_root to be null with qgroup_lock held before, so it is safe to clean
559  * up the in-memory structures without qgroup_lock held.
560  */
btrfs_free_qgroup_config(struct btrfs_fs_info * fs_info)561 void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info)
562 {
563 	struct rb_node *n;
564 	struct btrfs_qgroup *qgroup;
565 
566 	while ((n = rb_first(&fs_info->qgroup_tree))) {
567 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
568 		rb_erase(n, &fs_info->qgroup_tree);
569 		__del_qgroup_rb(fs_info, qgroup);
570 		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
571 		kfree(qgroup);
572 	}
573 	/*
574 	 * We call btrfs_free_qgroup_config() when unmounting
575 	 * filesystem and disabling quota, so we set qgroup_ulist
576 	 * to be null here to avoid double free.
577 	 */
578 	ulist_free(fs_info->qgroup_ulist);
579 	fs_info->qgroup_ulist = NULL;
580 	btrfs_sysfs_del_qgroups(fs_info);
581 }
582 
add_qgroup_relation_item(struct btrfs_trans_handle * trans,u64 src,u64 dst)583 static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
584 				    u64 dst)
585 {
586 	int ret;
587 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
588 	struct btrfs_path *path;
589 	struct btrfs_key key;
590 
591 	path = btrfs_alloc_path();
592 	if (!path)
593 		return -ENOMEM;
594 
595 	key.objectid = src;
596 	key.type = BTRFS_QGROUP_RELATION_KEY;
597 	key.offset = dst;
598 
599 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0);
600 
601 	btrfs_mark_buffer_dirty(path->nodes[0]);
602 
603 	btrfs_free_path(path);
604 	return ret;
605 }
606 
del_qgroup_relation_item(struct btrfs_trans_handle * trans,u64 src,u64 dst)607 static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src,
608 				    u64 dst)
609 {
610 	int ret;
611 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
612 	struct btrfs_path *path;
613 	struct btrfs_key key;
614 
615 	path = btrfs_alloc_path();
616 	if (!path)
617 		return -ENOMEM;
618 
619 	key.objectid = src;
620 	key.type = BTRFS_QGROUP_RELATION_KEY;
621 	key.offset = dst;
622 
623 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
624 	if (ret < 0)
625 		goto out;
626 
627 	if (ret > 0) {
628 		ret = -ENOENT;
629 		goto out;
630 	}
631 
632 	ret = btrfs_del_item(trans, quota_root, path);
633 out:
634 	btrfs_free_path(path);
635 	return ret;
636 }
637 
add_qgroup_item(struct btrfs_trans_handle * trans,struct btrfs_root * quota_root,u64 qgroupid)638 static int add_qgroup_item(struct btrfs_trans_handle *trans,
639 			   struct btrfs_root *quota_root, u64 qgroupid)
640 {
641 	int ret;
642 	struct btrfs_path *path;
643 	struct btrfs_qgroup_info_item *qgroup_info;
644 	struct btrfs_qgroup_limit_item *qgroup_limit;
645 	struct extent_buffer *leaf;
646 	struct btrfs_key key;
647 
648 	if (btrfs_is_testing(quota_root->fs_info))
649 		return 0;
650 
651 	path = btrfs_alloc_path();
652 	if (!path)
653 		return -ENOMEM;
654 
655 	key.objectid = 0;
656 	key.type = BTRFS_QGROUP_INFO_KEY;
657 	key.offset = qgroupid;
658 
659 	/*
660 	 * Avoid a transaction abort by catching -EEXIST here. In that
661 	 * case, we proceed by re-initializing the existing structure
662 	 * on disk.
663 	 */
664 
665 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
666 				      sizeof(*qgroup_info));
667 	if (ret && ret != -EEXIST)
668 		goto out;
669 
670 	leaf = path->nodes[0];
671 	qgroup_info = btrfs_item_ptr(leaf, path->slots[0],
672 				 struct btrfs_qgroup_info_item);
673 	btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid);
674 	btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0);
675 	btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0);
676 	btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0);
677 	btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0);
678 
679 	btrfs_mark_buffer_dirty(leaf);
680 
681 	btrfs_release_path(path);
682 
683 	key.type = BTRFS_QGROUP_LIMIT_KEY;
684 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
685 				      sizeof(*qgroup_limit));
686 	if (ret && ret != -EEXIST)
687 		goto out;
688 
689 	leaf = path->nodes[0];
690 	qgroup_limit = btrfs_item_ptr(leaf, path->slots[0],
691 				  struct btrfs_qgroup_limit_item);
692 	btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0);
693 	btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0);
694 	btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0);
695 	btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0);
696 	btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0);
697 
698 	btrfs_mark_buffer_dirty(leaf);
699 
700 	ret = 0;
701 out:
702 	btrfs_free_path(path);
703 	return ret;
704 }
705 
del_qgroup_item(struct btrfs_trans_handle * trans,u64 qgroupid)706 static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid)
707 {
708 	int ret;
709 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
710 	struct btrfs_path *path;
711 	struct btrfs_key key;
712 
713 	path = btrfs_alloc_path();
714 	if (!path)
715 		return -ENOMEM;
716 
717 	key.objectid = 0;
718 	key.type = BTRFS_QGROUP_INFO_KEY;
719 	key.offset = qgroupid;
720 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
721 	if (ret < 0)
722 		goto out;
723 
724 	if (ret > 0) {
725 		ret = -ENOENT;
726 		goto out;
727 	}
728 
729 	ret = btrfs_del_item(trans, quota_root, path);
730 	if (ret)
731 		goto out;
732 
733 	btrfs_release_path(path);
734 
735 	key.type = BTRFS_QGROUP_LIMIT_KEY;
736 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1);
737 	if (ret < 0)
738 		goto out;
739 
740 	if (ret > 0) {
741 		ret = -ENOENT;
742 		goto out;
743 	}
744 
745 	ret = btrfs_del_item(trans, quota_root, path);
746 
747 out:
748 	btrfs_free_path(path);
749 	return ret;
750 }
751 
update_qgroup_limit_item(struct btrfs_trans_handle * trans,struct btrfs_qgroup * qgroup)752 static int update_qgroup_limit_item(struct btrfs_trans_handle *trans,
753 				    struct btrfs_qgroup *qgroup)
754 {
755 	struct btrfs_root *quota_root = trans->fs_info->quota_root;
756 	struct btrfs_path *path;
757 	struct btrfs_key key;
758 	struct extent_buffer *l;
759 	struct btrfs_qgroup_limit_item *qgroup_limit;
760 	int ret;
761 	int slot;
762 
763 	key.objectid = 0;
764 	key.type = BTRFS_QGROUP_LIMIT_KEY;
765 	key.offset = qgroup->qgroupid;
766 
767 	path = btrfs_alloc_path();
768 	if (!path)
769 		return -ENOMEM;
770 
771 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
772 	if (ret > 0)
773 		ret = -ENOENT;
774 
775 	if (ret)
776 		goto out;
777 
778 	l = path->nodes[0];
779 	slot = path->slots[0];
780 	qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item);
781 	btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags);
782 	btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer);
783 	btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl);
784 	btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer);
785 	btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl);
786 
787 	btrfs_mark_buffer_dirty(l);
788 
789 out:
790 	btrfs_free_path(path);
791 	return ret;
792 }
793 
update_qgroup_info_item(struct btrfs_trans_handle * trans,struct btrfs_qgroup * qgroup)794 static int update_qgroup_info_item(struct btrfs_trans_handle *trans,
795 				   struct btrfs_qgroup *qgroup)
796 {
797 	struct btrfs_fs_info *fs_info = trans->fs_info;
798 	struct btrfs_root *quota_root = fs_info->quota_root;
799 	struct btrfs_path *path;
800 	struct btrfs_key key;
801 	struct extent_buffer *l;
802 	struct btrfs_qgroup_info_item *qgroup_info;
803 	int ret;
804 	int slot;
805 
806 	if (btrfs_is_testing(fs_info))
807 		return 0;
808 
809 	key.objectid = 0;
810 	key.type = BTRFS_QGROUP_INFO_KEY;
811 	key.offset = qgroup->qgroupid;
812 
813 	path = btrfs_alloc_path();
814 	if (!path)
815 		return -ENOMEM;
816 
817 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
818 	if (ret > 0)
819 		ret = -ENOENT;
820 
821 	if (ret)
822 		goto out;
823 
824 	l = path->nodes[0];
825 	slot = path->slots[0];
826 	qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item);
827 	btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid);
828 	btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer);
829 	btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr);
830 	btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl);
831 	btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr);
832 
833 	btrfs_mark_buffer_dirty(l);
834 
835 out:
836 	btrfs_free_path(path);
837 	return ret;
838 }
839 
update_qgroup_status_item(struct btrfs_trans_handle * trans)840 static int update_qgroup_status_item(struct btrfs_trans_handle *trans)
841 {
842 	struct btrfs_fs_info *fs_info = trans->fs_info;
843 	struct btrfs_root *quota_root = fs_info->quota_root;
844 	struct btrfs_path *path;
845 	struct btrfs_key key;
846 	struct extent_buffer *l;
847 	struct btrfs_qgroup_status_item *ptr;
848 	int ret;
849 	int slot;
850 
851 	key.objectid = 0;
852 	key.type = BTRFS_QGROUP_STATUS_KEY;
853 	key.offset = 0;
854 
855 	path = btrfs_alloc_path();
856 	if (!path)
857 		return -ENOMEM;
858 
859 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1);
860 	if (ret > 0)
861 		ret = -ENOENT;
862 
863 	if (ret)
864 		goto out;
865 
866 	l = path->nodes[0];
867 	slot = path->slots[0];
868 	ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item);
869 	btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags);
870 	btrfs_set_qgroup_status_generation(l, ptr, trans->transid);
871 	btrfs_set_qgroup_status_rescan(l, ptr,
872 				fs_info->qgroup_rescan_progress.objectid);
873 
874 	btrfs_mark_buffer_dirty(l);
875 
876 out:
877 	btrfs_free_path(path);
878 	return ret;
879 }
880 
881 /*
882  * called with qgroup_lock held
883  */
btrfs_clean_quota_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root)884 static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans,
885 				  struct btrfs_root *root)
886 {
887 	struct btrfs_path *path;
888 	struct btrfs_key key;
889 	struct extent_buffer *leaf = NULL;
890 	int ret;
891 	int nr = 0;
892 
893 	path = btrfs_alloc_path();
894 	if (!path)
895 		return -ENOMEM;
896 
897 	path->leave_spinning = 1;
898 
899 	key.objectid = 0;
900 	key.offset = 0;
901 	key.type = 0;
902 
903 	while (1) {
904 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
905 		if (ret < 0)
906 			goto out;
907 		leaf = path->nodes[0];
908 		nr = btrfs_header_nritems(leaf);
909 		if (!nr)
910 			break;
911 		/*
912 		 * delete the leaf one by one
913 		 * since the whole tree is going
914 		 * to be deleted.
915 		 */
916 		path->slots[0] = 0;
917 		ret = btrfs_del_items(trans, root, path, 0, nr);
918 		if (ret)
919 			goto out;
920 
921 		btrfs_release_path(path);
922 	}
923 	ret = 0;
924 out:
925 	btrfs_free_path(path);
926 	return ret;
927 }
928 
btrfs_quota_enable(struct btrfs_fs_info * fs_info)929 int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
930 {
931 	struct btrfs_root *quota_root;
932 	struct btrfs_root *tree_root = fs_info->tree_root;
933 	struct btrfs_path *path = NULL;
934 	struct btrfs_qgroup_status_item *ptr;
935 	struct extent_buffer *leaf;
936 	struct btrfs_key key;
937 	struct btrfs_key found_key;
938 	struct btrfs_qgroup *qgroup = NULL;
939 	struct btrfs_trans_handle *trans = NULL;
940 	struct ulist *ulist = NULL;
941 	int ret = 0;
942 	int slot;
943 
944 	/*
945 	 * We need to have subvol_sem write locked, to prevent races between
946 	 * concurrent tasks trying to enable quotas, because we will unlock
947 	 * and relock qgroup_ioctl_lock before setting fs_info->quota_root
948 	 * and before setting BTRFS_FS_QUOTA_ENABLED.
949 	 */
950 	lockdep_assert_held_write(&fs_info->subvol_sem);
951 
952 	mutex_lock(&fs_info->qgroup_ioctl_lock);
953 	if (fs_info->quota_root)
954 		goto out;
955 
956 	ulist = ulist_alloc(GFP_KERNEL);
957 	if (!ulist) {
958 		ret = -ENOMEM;
959 		goto out;
960 	}
961 
962 	ret = btrfs_sysfs_add_qgroups(fs_info);
963 	if (ret < 0)
964 		goto out;
965 
966 	/*
967 	 * Unlock qgroup_ioctl_lock before starting the transaction. This is to
968 	 * avoid lock acquisition inversion problems (reported by lockdep) between
969 	 * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we
970 	 * start a transaction.
971 	 * After we started the transaction lock qgroup_ioctl_lock again and
972 	 * check if someone else created the quota root in the meanwhile. If so,
973 	 * just return success and release the transaction handle.
974 	 *
975 	 * Also we don't need to worry about someone else calling
976 	 * btrfs_sysfs_add_qgroups() after we unlock and getting an error because
977 	 * that function returns 0 (success) when the sysfs entries already exist.
978 	 */
979 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
980 
981 	/*
982 	 * 1 for quota root item
983 	 * 1 for BTRFS_QGROUP_STATUS item
984 	 *
985 	 * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items
986 	 * per subvolume. However those are not currently reserved since it
987 	 * would be a lot of overkill.
988 	 */
989 	trans = btrfs_start_transaction(tree_root, 2);
990 
991 	mutex_lock(&fs_info->qgroup_ioctl_lock);
992 	if (IS_ERR(trans)) {
993 		ret = PTR_ERR(trans);
994 		trans = NULL;
995 		goto out;
996 	}
997 
998 	if (fs_info->quota_root)
999 		goto out;
1000 
1001 	fs_info->qgroup_ulist = ulist;
1002 	ulist = NULL;
1003 
1004 	/*
1005 	 * initially create the quota tree
1006 	 */
1007 	quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID);
1008 	if (IS_ERR(quota_root)) {
1009 		ret =  PTR_ERR(quota_root);
1010 		btrfs_abort_transaction(trans, ret);
1011 		goto out;
1012 	}
1013 
1014 	path = btrfs_alloc_path();
1015 	if (!path) {
1016 		ret = -ENOMEM;
1017 		btrfs_abort_transaction(trans, ret);
1018 		goto out_free_root;
1019 	}
1020 
1021 	key.objectid = 0;
1022 	key.type = BTRFS_QGROUP_STATUS_KEY;
1023 	key.offset = 0;
1024 
1025 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key,
1026 				      sizeof(*ptr));
1027 	if (ret) {
1028 		btrfs_abort_transaction(trans, ret);
1029 		goto out_free_path;
1030 	}
1031 
1032 	leaf = path->nodes[0];
1033 	ptr = btrfs_item_ptr(leaf, path->slots[0],
1034 				 struct btrfs_qgroup_status_item);
1035 	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);
1036 	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);
1037 	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON |
1038 				BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1039 	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags);
1040 	btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
1041 
1042 	btrfs_mark_buffer_dirty(leaf);
1043 
1044 	key.objectid = 0;
1045 	key.type = BTRFS_ROOT_REF_KEY;
1046 	key.offset = 0;
1047 
1048 	btrfs_release_path(path);
1049 	ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0);
1050 	if (ret > 0)
1051 		goto out_add_root;
1052 	if (ret < 0) {
1053 		btrfs_abort_transaction(trans, ret);
1054 		goto out_free_path;
1055 	}
1056 
1057 	while (1) {
1058 		slot = path->slots[0];
1059 		leaf = path->nodes[0];
1060 		btrfs_item_key_to_cpu(leaf, &found_key, slot);
1061 
1062 		if (found_key.type == BTRFS_ROOT_REF_KEY) {
1063 
1064 			/* Release locks on tree_root before we access quota_root */
1065 			btrfs_release_path(path);
1066 
1067 			ret = add_qgroup_item(trans, quota_root,
1068 					      found_key.offset);
1069 			if (ret) {
1070 				btrfs_abort_transaction(trans, ret);
1071 				goto out_free_path;
1072 			}
1073 
1074 			qgroup = add_qgroup_rb(fs_info, found_key.offset);
1075 			if (IS_ERR(qgroup)) {
1076 				ret = PTR_ERR(qgroup);
1077 				btrfs_abort_transaction(trans, ret);
1078 				goto out_free_path;
1079 			}
1080 			ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1081 			if (ret < 0) {
1082 				btrfs_abort_transaction(trans, ret);
1083 				goto out_free_path;
1084 			}
1085 			ret = btrfs_search_slot_for_read(tree_root, &found_key,
1086 							 path, 1, 0);
1087 			if (ret < 0) {
1088 				btrfs_abort_transaction(trans, ret);
1089 				goto out_free_path;
1090 			}
1091 			if (ret > 0) {
1092 				/*
1093 				 * Shouldn't happen, but in case it does we
1094 				 * don't need to do the btrfs_next_item, just
1095 				 * continue.
1096 				 */
1097 				continue;
1098 			}
1099 		}
1100 		ret = btrfs_next_item(tree_root, path);
1101 		if (ret < 0) {
1102 			btrfs_abort_transaction(trans, ret);
1103 			goto out_free_path;
1104 		}
1105 		if (ret)
1106 			break;
1107 	}
1108 
1109 out_add_root:
1110 	btrfs_release_path(path);
1111 	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID);
1112 	if (ret) {
1113 		btrfs_abort_transaction(trans, ret);
1114 		goto out_free_path;
1115 	}
1116 
1117 	qgroup = add_qgroup_rb(fs_info, BTRFS_FS_TREE_OBJECTID);
1118 	if (IS_ERR(qgroup)) {
1119 		ret = PTR_ERR(qgroup);
1120 		btrfs_abort_transaction(trans, ret);
1121 		goto out_free_path;
1122 	}
1123 	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1124 	if (ret < 0) {
1125 		btrfs_abort_transaction(trans, ret);
1126 		goto out_free_path;
1127 	}
1128 
1129 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1130 	/*
1131 	 * Commit the transaction while not holding qgroup_ioctl_lock, to avoid
1132 	 * a deadlock with tasks concurrently doing other qgroup operations, such
1133 	 * adding/removing qgroups or adding/deleting qgroup relations for example,
1134 	 * because all qgroup operations first start or join a transaction and then
1135 	 * lock the qgroup_ioctl_lock mutex.
1136 	 * We are safe from a concurrent task trying to enable quotas, by calling
1137 	 * this function, since we are serialized by fs_info->subvol_sem.
1138 	 */
1139 	ret = btrfs_commit_transaction(trans);
1140 	trans = NULL;
1141 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1142 	if (ret)
1143 		goto out_free_path;
1144 
1145 	/*
1146 	 * Set quota enabled flag after committing the transaction, to avoid
1147 	 * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot
1148 	 * creation.
1149 	 */
1150 	spin_lock(&fs_info->qgroup_lock);
1151 	fs_info->quota_root = quota_root;
1152 	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1153 	spin_unlock(&fs_info->qgroup_lock);
1154 
1155 	ret = qgroup_rescan_init(fs_info, 0, 1);
1156 	if (!ret) {
1157 	        qgroup_rescan_zero_tracking(fs_info);
1158 		fs_info->qgroup_rescan_running = true;
1159 	        btrfs_queue_work(fs_info->qgroup_rescan_workers,
1160 	                         &fs_info->qgroup_rescan_work);
1161 	} else {
1162 		/*
1163 		 * We have set both BTRFS_FS_QUOTA_ENABLED and
1164 		 * BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with
1165 		 * -EINPROGRESS. That can happen because someone started the
1166 		 * rescan worker by calling quota rescan ioctl before we
1167 		 * attempted to initialize the rescan worker. Failure due to
1168 		 * quotas disabled in the meanwhile is not possible, because
1169 		 * we are holding a write lock on fs_info->subvol_sem, which
1170 		 * is also acquired when disabling quotas.
1171 		 * Ignore such error, and any other error would need to undo
1172 		 * everything we did in the transaction we just committed.
1173 		 */
1174 		ASSERT(ret == -EINPROGRESS);
1175 		ret = 0;
1176 	}
1177 
1178 out_free_path:
1179 	btrfs_free_path(path);
1180 out_free_root:
1181 	if (ret)
1182 		btrfs_put_root(quota_root);
1183 out:
1184 	if (ret) {
1185 		ulist_free(fs_info->qgroup_ulist);
1186 		fs_info->qgroup_ulist = NULL;
1187 		btrfs_sysfs_del_qgroups(fs_info);
1188 	}
1189 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1190 	if (ret && trans)
1191 		btrfs_end_transaction(trans);
1192 	else if (trans)
1193 		ret = btrfs_end_transaction(trans);
1194 	ulist_free(ulist);
1195 	return ret;
1196 }
1197 
btrfs_quota_disable(struct btrfs_fs_info * fs_info)1198 int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
1199 {
1200 	struct btrfs_root *quota_root;
1201 	struct btrfs_trans_handle *trans = NULL;
1202 	int ret = 0;
1203 
1204 	/*
1205 	 * We need to have subvol_sem write locked to prevent races with
1206 	 * snapshot creation.
1207 	 */
1208 	lockdep_assert_held_write(&fs_info->subvol_sem);
1209 
1210 	/*
1211 	 * Lock the cleaner mutex to prevent races with concurrent relocation,
1212 	 * because relocation may be building backrefs for blocks of the quota
1213 	 * root while we are deleting the root. This is like dropping fs roots
1214 	 * of deleted snapshots/subvolumes, we need the same protection.
1215 	 *
1216 	 * This also prevents races between concurrent tasks trying to disable
1217 	 * quotas, because we will unlock and relock qgroup_ioctl_lock across
1218 	 * BTRFS_FS_QUOTA_ENABLED changes.
1219 	 */
1220 	mutex_lock(&fs_info->cleaner_mutex);
1221 
1222 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1223 	if (!fs_info->quota_root)
1224 		goto out;
1225 
1226 	/*
1227 	 * Unlock the qgroup_ioctl_lock mutex before waiting for the rescan worker to
1228 	 * complete. Otherwise we can deadlock because btrfs_remove_qgroup() needs
1229 	 * to lock that mutex while holding a transaction handle and the rescan
1230 	 * worker needs to commit a transaction.
1231 	 */
1232 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1233 
1234 	/*
1235 	 * Request qgroup rescan worker to complete and wait for it. This wait
1236 	 * must be done before transaction start for quota disable since it may
1237 	 * deadlock with transaction by the qgroup rescan worker.
1238 	 */
1239 	clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1240 	btrfs_qgroup_wait_for_completion(fs_info, false);
1241 
1242 	/*
1243 	 * 1 For the root item
1244 	 *
1245 	 * We should also reserve enough items for the quota tree deletion in
1246 	 * btrfs_clean_quota_tree but this is not done.
1247 	 *
1248 	 * Also, we must always start a transaction without holding the mutex
1249 	 * qgroup_ioctl_lock, see btrfs_quota_enable().
1250 	 */
1251 	trans = btrfs_start_transaction(fs_info->tree_root, 1);
1252 
1253 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1254 	if (IS_ERR(trans)) {
1255 		ret = PTR_ERR(trans);
1256 		trans = NULL;
1257 		set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
1258 		goto out;
1259 	}
1260 
1261 	if (!fs_info->quota_root)
1262 		goto out;
1263 
1264 	spin_lock(&fs_info->qgroup_lock);
1265 	quota_root = fs_info->quota_root;
1266 	fs_info->quota_root = NULL;
1267 	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
1268 	spin_unlock(&fs_info->qgroup_lock);
1269 
1270 	btrfs_free_qgroup_config(fs_info);
1271 
1272 	ret = btrfs_clean_quota_tree(trans, quota_root);
1273 	if (ret) {
1274 		btrfs_abort_transaction(trans, ret);
1275 		goto out;
1276 	}
1277 
1278 	ret = btrfs_del_root(trans, &quota_root->root_key);
1279 	if (ret) {
1280 		btrfs_abort_transaction(trans, ret);
1281 		goto out;
1282 	}
1283 
1284 	spin_lock(&fs_info->trans_lock);
1285 	list_del(&quota_root->dirty_list);
1286 	spin_unlock(&fs_info->trans_lock);
1287 
1288 	btrfs_tree_lock(quota_root->node);
1289 	btrfs_clean_tree_block(quota_root->node);
1290 	btrfs_tree_unlock(quota_root->node);
1291 	btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
1292 
1293 	btrfs_put_root(quota_root);
1294 
1295 out:
1296 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1297 	if (ret && trans)
1298 		btrfs_end_transaction(trans);
1299 	else if (trans)
1300 		ret = btrfs_end_transaction(trans);
1301 	mutex_unlock(&fs_info->cleaner_mutex);
1302 
1303 	return ret;
1304 }
1305 
qgroup_dirty(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup)1306 static void qgroup_dirty(struct btrfs_fs_info *fs_info,
1307 			 struct btrfs_qgroup *qgroup)
1308 {
1309 	if (list_empty(&qgroup->dirty))
1310 		list_add(&qgroup->dirty, &fs_info->dirty_qgroups);
1311 }
1312 
1313 /*
1314  * The easy accounting, we're updating qgroup relationship whose child qgroup
1315  * only has exclusive extents.
1316  *
1317  * In this case, all exclusive extents will also be exclusive for parent, so
1318  * excl/rfer just get added/removed.
1319  *
1320  * So is qgroup reservation space, which should also be added/removed to
1321  * parent.
1322  * Or when child tries to release reservation space, parent will underflow its
1323  * reservation (for relationship adding case).
1324  *
1325  * Caller should hold fs_info->qgroup_lock.
1326  */
__qgroup_excl_accounting(struct btrfs_fs_info * fs_info,struct ulist * tmp,u64 ref_root,struct btrfs_qgroup * src,int sign)1327 static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
1328 				    struct ulist *tmp, u64 ref_root,
1329 				    struct btrfs_qgroup *src, int sign)
1330 {
1331 	struct btrfs_qgroup *qgroup;
1332 	struct btrfs_qgroup_list *glist;
1333 	struct ulist_node *unode;
1334 	struct ulist_iterator uiter;
1335 	u64 num_bytes = src->excl;
1336 	int ret = 0;
1337 
1338 	qgroup = find_qgroup_rb(fs_info, ref_root);
1339 	if (!qgroup)
1340 		goto out;
1341 
1342 	qgroup->rfer += sign * num_bytes;
1343 	qgroup->rfer_cmpr += sign * num_bytes;
1344 
1345 	WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1346 	qgroup->excl += sign * num_bytes;
1347 	qgroup->excl_cmpr += sign * num_bytes;
1348 
1349 	if (sign > 0)
1350 		qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1351 	else
1352 		qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1353 
1354 	qgroup_dirty(fs_info, qgroup);
1355 
1356 	/* Get all of the parent groups that contain this qgroup */
1357 	list_for_each_entry(glist, &qgroup->groups, next_group) {
1358 		ret = ulist_add(tmp, glist->group->qgroupid,
1359 				qgroup_to_aux(glist->group), GFP_ATOMIC);
1360 		if (ret < 0)
1361 			goto out;
1362 	}
1363 
1364 	/* Iterate all of the parents and adjust their reference counts */
1365 	ULIST_ITER_INIT(&uiter);
1366 	while ((unode = ulist_next(tmp, &uiter))) {
1367 		qgroup = unode_aux_to_qgroup(unode);
1368 		qgroup->rfer += sign * num_bytes;
1369 		qgroup->rfer_cmpr += sign * num_bytes;
1370 		WARN_ON(sign < 0 && qgroup->excl < num_bytes);
1371 		qgroup->excl += sign * num_bytes;
1372 		if (sign > 0)
1373 			qgroup_rsv_add_by_qgroup(fs_info, qgroup, src);
1374 		else
1375 			qgroup_rsv_release_by_qgroup(fs_info, qgroup, src);
1376 		qgroup->excl_cmpr += sign * num_bytes;
1377 		qgroup_dirty(fs_info, qgroup);
1378 
1379 		/* Add any parents of the parents */
1380 		list_for_each_entry(glist, &qgroup->groups, next_group) {
1381 			ret = ulist_add(tmp, glist->group->qgroupid,
1382 					qgroup_to_aux(glist->group), GFP_ATOMIC);
1383 			if (ret < 0)
1384 				goto out;
1385 		}
1386 	}
1387 	ret = 0;
1388 out:
1389 	return ret;
1390 }
1391 
1392 
1393 /*
1394  * Quick path for updating qgroup with only excl refs.
1395  *
1396  * In that case, just update all parent will be enough.
1397  * Or we needs to do a full rescan.
1398  * Caller should also hold fs_info->qgroup_lock.
1399  *
1400  * Return 0 for quick update, return >0 for need to full rescan
1401  * and mark INCONSISTENT flag.
1402  * Return < 0 for other error.
1403  */
quick_update_accounting(struct btrfs_fs_info * fs_info,struct ulist * tmp,u64 src,u64 dst,int sign)1404 static int quick_update_accounting(struct btrfs_fs_info *fs_info,
1405 				   struct ulist *tmp, u64 src, u64 dst,
1406 				   int sign)
1407 {
1408 	struct btrfs_qgroup *qgroup;
1409 	int ret = 1;
1410 	int err = 0;
1411 
1412 	qgroup = find_qgroup_rb(fs_info, src);
1413 	if (!qgroup)
1414 		goto out;
1415 	if (qgroup->excl == qgroup->rfer) {
1416 		ret = 0;
1417 		err = __qgroup_excl_accounting(fs_info, tmp, dst,
1418 					       qgroup, sign);
1419 		if (err < 0) {
1420 			ret = err;
1421 			goto out;
1422 		}
1423 	}
1424 out:
1425 	if (ret)
1426 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1427 	return ret;
1428 }
1429 
btrfs_add_qgroup_relation(struct btrfs_trans_handle * trans,u64 src,u64 dst)1430 int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1431 			      u64 dst)
1432 {
1433 	struct btrfs_fs_info *fs_info = trans->fs_info;
1434 	struct btrfs_qgroup *parent;
1435 	struct btrfs_qgroup *member;
1436 	struct btrfs_qgroup_list *list;
1437 	struct ulist *tmp;
1438 	unsigned int nofs_flag;
1439 	int ret = 0;
1440 
1441 	/* Check the level of src and dst first */
1442 	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
1443 		return -EINVAL;
1444 
1445 	/* We hold a transaction handle open, must do a NOFS allocation. */
1446 	nofs_flag = memalloc_nofs_save();
1447 	tmp = ulist_alloc(GFP_KERNEL);
1448 	memalloc_nofs_restore(nofs_flag);
1449 	if (!tmp)
1450 		return -ENOMEM;
1451 
1452 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1453 	if (!fs_info->quota_root) {
1454 		ret = -ENOTCONN;
1455 		goto out;
1456 	}
1457 	member = find_qgroup_rb(fs_info, src);
1458 	parent = find_qgroup_rb(fs_info, dst);
1459 	if (!member || !parent) {
1460 		ret = -EINVAL;
1461 		goto out;
1462 	}
1463 
1464 	/* check if such qgroup relation exist firstly */
1465 	list_for_each_entry(list, &member->groups, next_group) {
1466 		if (list->group == parent) {
1467 			ret = -EEXIST;
1468 			goto out;
1469 		}
1470 	}
1471 
1472 	ret = add_qgroup_relation_item(trans, src, dst);
1473 	if (ret)
1474 		goto out;
1475 
1476 	ret = add_qgroup_relation_item(trans, dst, src);
1477 	if (ret) {
1478 		del_qgroup_relation_item(trans, src, dst);
1479 		goto out;
1480 	}
1481 
1482 	spin_lock(&fs_info->qgroup_lock);
1483 	ret = add_relation_rb(fs_info, src, dst);
1484 	if (ret < 0) {
1485 		spin_unlock(&fs_info->qgroup_lock);
1486 		goto out;
1487 	}
1488 	ret = quick_update_accounting(fs_info, tmp, src, dst, 1);
1489 	spin_unlock(&fs_info->qgroup_lock);
1490 out:
1491 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1492 	ulist_free(tmp);
1493 	return ret;
1494 }
1495 
__del_qgroup_relation(struct btrfs_trans_handle * trans,u64 src,u64 dst)1496 static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1497 				 u64 dst)
1498 {
1499 	struct btrfs_fs_info *fs_info = trans->fs_info;
1500 	struct btrfs_qgroup *parent;
1501 	struct btrfs_qgroup *member;
1502 	struct btrfs_qgroup_list *list;
1503 	struct ulist *tmp;
1504 	bool found = false;
1505 	unsigned int nofs_flag;
1506 	int ret = 0;
1507 	int ret2;
1508 
1509 	/* We hold a transaction handle open, must do a NOFS allocation. */
1510 	nofs_flag = memalloc_nofs_save();
1511 	tmp = ulist_alloc(GFP_KERNEL);
1512 	memalloc_nofs_restore(nofs_flag);
1513 	if (!tmp)
1514 		return -ENOMEM;
1515 
1516 	if (!fs_info->quota_root) {
1517 		ret = -ENOTCONN;
1518 		goto out;
1519 	}
1520 
1521 	member = find_qgroup_rb(fs_info, src);
1522 	parent = find_qgroup_rb(fs_info, dst);
1523 	/*
1524 	 * The parent/member pair doesn't exist, then try to delete the dead
1525 	 * relation items only.
1526 	 */
1527 	if (!member || !parent)
1528 		goto delete_item;
1529 
1530 	/* check if such qgroup relation exist firstly */
1531 	list_for_each_entry(list, &member->groups, next_group) {
1532 		if (list->group == parent) {
1533 			found = true;
1534 			break;
1535 		}
1536 	}
1537 
1538 delete_item:
1539 	ret = del_qgroup_relation_item(trans, src, dst);
1540 	if (ret < 0 && ret != -ENOENT)
1541 		goto out;
1542 	ret2 = del_qgroup_relation_item(trans, dst, src);
1543 	if (ret2 < 0 && ret2 != -ENOENT)
1544 		goto out;
1545 
1546 	/* At least one deletion succeeded, return 0 */
1547 	if (!ret || !ret2)
1548 		ret = 0;
1549 
1550 	if (found) {
1551 		spin_lock(&fs_info->qgroup_lock);
1552 		del_relation_rb(fs_info, src, dst);
1553 		ret = quick_update_accounting(fs_info, tmp, src, dst, -1);
1554 		spin_unlock(&fs_info->qgroup_lock);
1555 	}
1556 out:
1557 	ulist_free(tmp);
1558 	return ret;
1559 }
1560 
btrfs_del_qgroup_relation(struct btrfs_trans_handle * trans,u64 src,u64 dst)1561 int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
1562 			      u64 dst)
1563 {
1564 	struct btrfs_fs_info *fs_info = trans->fs_info;
1565 	int ret = 0;
1566 
1567 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1568 	ret = __del_qgroup_relation(trans, src, dst);
1569 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1570 
1571 	return ret;
1572 }
1573 
btrfs_create_qgroup(struct btrfs_trans_handle * trans,u64 qgroupid)1574 int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1575 {
1576 	struct btrfs_fs_info *fs_info = trans->fs_info;
1577 	struct btrfs_root *quota_root;
1578 	struct btrfs_qgroup *qgroup;
1579 	int ret = 0;
1580 
1581 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1582 	if (!fs_info->quota_root) {
1583 		ret = -ENOTCONN;
1584 		goto out;
1585 	}
1586 	quota_root = fs_info->quota_root;
1587 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1588 	if (qgroup) {
1589 		ret = -EEXIST;
1590 		goto out;
1591 	}
1592 
1593 	ret = add_qgroup_item(trans, quota_root, qgroupid);
1594 	if (ret)
1595 		goto out;
1596 
1597 	spin_lock(&fs_info->qgroup_lock);
1598 	qgroup = add_qgroup_rb(fs_info, qgroupid);
1599 	spin_unlock(&fs_info->qgroup_lock);
1600 
1601 	if (IS_ERR(qgroup)) {
1602 		ret = PTR_ERR(qgroup);
1603 		goto out;
1604 	}
1605 	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
1606 out:
1607 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1608 	return ret;
1609 }
1610 
qgroup_has_usage(struct btrfs_qgroup * qgroup)1611 static bool qgroup_has_usage(struct btrfs_qgroup *qgroup)
1612 {
1613 	return (qgroup->rfer > 0 || qgroup->rfer_cmpr > 0 ||
1614 		qgroup->excl > 0 || qgroup->excl_cmpr > 0 ||
1615 		qgroup->rsv.values[BTRFS_QGROUP_RSV_DATA] > 0 ||
1616 		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC] > 0 ||
1617 		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS] > 0);
1618 }
1619 
btrfs_remove_qgroup(struct btrfs_trans_handle * trans,u64 qgroupid)1620 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
1621 {
1622 	struct btrfs_fs_info *fs_info = trans->fs_info;
1623 	struct btrfs_qgroup *qgroup;
1624 	struct btrfs_qgroup_list *list;
1625 	int ret = 0;
1626 
1627 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1628 	if (!fs_info->quota_root) {
1629 		ret = -ENOTCONN;
1630 		goto out;
1631 	}
1632 
1633 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1634 	if (!qgroup) {
1635 		ret = -ENOENT;
1636 		goto out;
1637 	}
1638 
1639 	if (is_fstree(qgroupid) && qgroup_has_usage(qgroup)) {
1640 		ret = -EBUSY;
1641 		goto out;
1642 	}
1643 
1644 	/* Check if there are no children of this qgroup */
1645 	if (!list_empty(&qgroup->members)) {
1646 		ret = -EBUSY;
1647 		goto out;
1648 	}
1649 
1650 	ret = del_qgroup_item(trans, qgroupid);
1651 	if (ret && ret != -ENOENT)
1652 		goto out;
1653 
1654 	while (!list_empty(&qgroup->groups)) {
1655 		list = list_first_entry(&qgroup->groups,
1656 					struct btrfs_qgroup_list, next_group);
1657 		ret = __del_qgroup_relation(trans, qgroupid,
1658 					    list->group->qgroupid);
1659 		if (ret)
1660 			goto out;
1661 	}
1662 
1663 	spin_lock(&fs_info->qgroup_lock);
1664 	del_qgroup_rb(fs_info, qgroupid);
1665 	spin_unlock(&fs_info->qgroup_lock);
1666 
1667 	/*
1668 	 * Remove the qgroup from sysfs now without holding the qgroup_lock
1669 	 * spinlock, since the sysfs_remove_group() function needs to take
1670 	 * the mutex kernfs_mutex through kernfs_remove_by_name_ns().
1671 	 */
1672 	btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
1673 	kfree(qgroup);
1674 out:
1675 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1676 	return ret;
1677 }
1678 
btrfs_limit_qgroup(struct btrfs_trans_handle * trans,u64 qgroupid,struct btrfs_qgroup_limit * limit)1679 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
1680 		       struct btrfs_qgroup_limit *limit)
1681 {
1682 	struct btrfs_fs_info *fs_info = trans->fs_info;
1683 	struct btrfs_qgroup *qgroup;
1684 	int ret = 0;
1685 	/* Sometimes we would want to clear the limit on this qgroup.
1686 	 * To meet this requirement, we treat the -1 as a special value
1687 	 * which tell kernel to clear the limit on this qgroup.
1688 	 */
1689 	const u64 CLEAR_VALUE = -1;
1690 
1691 	mutex_lock(&fs_info->qgroup_ioctl_lock);
1692 	if (!fs_info->quota_root) {
1693 		ret = -ENOTCONN;
1694 		goto out;
1695 	}
1696 
1697 	qgroup = find_qgroup_rb(fs_info, qgroupid);
1698 	if (!qgroup) {
1699 		ret = -ENOENT;
1700 		goto out;
1701 	}
1702 
1703 	spin_lock(&fs_info->qgroup_lock);
1704 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) {
1705 		if (limit->max_rfer == CLEAR_VALUE) {
1706 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1707 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER;
1708 			qgroup->max_rfer = 0;
1709 		} else {
1710 			qgroup->max_rfer = limit->max_rfer;
1711 		}
1712 	}
1713 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
1714 		if (limit->max_excl == CLEAR_VALUE) {
1715 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1716 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL;
1717 			qgroup->max_excl = 0;
1718 		} else {
1719 			qgroup->max_excl = limit->max_excl;
1720 		}
1721 	}
1722 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) {
1723 		if (limit->rsv_rfer == CLEAR_VALUE) {
1724 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1725 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER;
1726 			qgroup->rsv_rfer = 0;
1727 		} else {
1728 			qgroup->rsv_rfer = limit->rsv_rfer;
1729 		}
1730 	}
1731 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) {
1732 		if (limit->rsv_excl == CLEAR_VALUE) {
1733 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1734 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL;
1735 			qgroup->rsv_excl = 0;
1736 		} else {
1737 			qgroup->rsv_excl = limit->rsv_excl;
1738 		}
1739 	}
1740 	qgroup->lim_flags |= limit->flags;
1741 
1742 	spin_unlock(&fs_info->qgroup_lock);
1743 
1744 	ret = update_qgroup_limit_item(trans, qgroup);
1745 	if (ret) {
1746 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1747 		btrfs_info(fs_info, "unable to update quota limit for %llu",
1748 		       qgroupid);
1749 	}
1750 
1751 out:
1752 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
1753 	return ret;
1754 }
1755 
btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info * fs_info,struct btrfs_delayed_ref_root * delayed_refs,struct btrfs_qgroup_extent_record * record)1756 int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info,
1757 				struct btrfs_delayed_ref_root *delayed_refs,
1758 				struct btrfs_qgroup_extent_record *record)
1759 {
1760 	struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node;
1761 	struct rb_node *parent_node = NULL;
1762 	struct btrfs_qgroup_extent_record *entry;
1763 	u64 bytenr = record->bytenr;
1764 
1765 	lockdep_assert_held(&delayed_refs->lock);
1766 	trace_btrfs_qgroup_trace_extent(fs_info, record);
1767 
1768 	while (*p) {
1769 		parent_node = *p;
1770 		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record,
1771 				 node);
1772 		if (bytenr < entry->bytenr) {
1773 			p = &(*p)->rb_left;
1774 		} else if (bytenr > entry->bytenr) {
1775 			p = &(*p)->rb_right;
1776 		} else {
1777 			if (record->data_rsv && !entry->data_rsv) {
1778 				entry->data_rsv = record->data_rsv;
1779 				entry->data_rsv_refroot =
1780 					record->data_rsv_refroot;
1781 			}
1782 			return 1;
1783 		}
1784 	}
1785 
1786 	rb_link_node(&record->node, parent_node, p);
1787 	rb_insert_color(&record->node, &delayed_refs->dirty_extent_root);
1788 	return 0;
1789 }
1790 
btrfs_qgroup_trace_extent_post(struct btrfs_fs_info * fs_info,struct btrfs_qgroup_extent_record * qrecord)1791 int btrfs_qgroup_trace_extent_post(struct btrfs_fs_info *fs_info,
1792 				   struct btrfs_qgroup_extent_record *qrecord)
1793 {
1794 	struct ulist *old_root;
1795 	u64 bytenr = qrecord->bytenr;
1796 	int ret;
1797 
1798 	ret = btrfs_find_all_roots(NULL, fs_info, bytenr, 0, &old_root, false);
1799 	if (ret < 0) {
1800 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
1801 		btrfs_warn(fs_info,
1802 "error accounting new delayed refs extent (err code: %d), quota inconsistent",
1803 			ret);
1804 		return 0;
1805 	}
1806 
1807 	/*
1808 	 * Here we don't need to get the lock of
1809 	 * trans->transaction->delayed_refs, since inserted qrecord won't
1810 	 * be deleted, only qrecord->node may be modified (new qrecord insert)
1811 	 *
1812 	 * So modifying qrecord->old_roots is safe here
1813 	 */
1814 	qrecord->old_roots = old_root;
1815 	return 0;
1816 }
1817 
btrfs_qgroup_trace_extent(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes,gfp_t gfp_flag)1818 int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr,
1819 			      u64 num_bytes, gfp_t gfp_flag)
1820 {
1821 	struct btrfs_fs_info *fs_info = trans->fs_info;
1822 	struct btrfs_qgroup_extent_record *record;
1823 	struct btrfs_delayed_ref_root *delayed_refs;
1824 	int ret;
1825 
1826 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)
1827 	    || bytenr == 0 || num_bytes == 0)
1828 		return 0;
1829 	record = kzalloc(sizeof(*record), gfp_flag);
1830 	if (!record)
1831 		return -ENOMEM;
1832 
1833 	delayed_refs = &trans->transaction->delayed_refs;
1834 	record->bytenr = bytenr;
1835 	record->num_bytes = num_bytes;
1836 	record->old_roots = NULL;
1837 
1838 	spin_lock(&delayed_refs->lock);
1839 	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record);
1840 	spin_unlock(&delayed_refs->lock);
1841 	if (ret > 0) {
1842 		kfree(record);
1843 		return 0;
1844 	}
1845 	return btrfs_qgroup_trace_extent_post(fs_info, record);
1846 }
1847 
btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle * trans,struct extent_buffer * eb)1848 int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
1849 				  struct extent_buffer *eb)
1850 {
1851 	struct btrfs_fs_info *fs_info = trans->fs_info;
1852 	int nr = btrfs_header_nritems(eb);
1853 	int i, extent_type, ret;
1854 	struct btrfs_key key;
1855 	struct btrfs_file_extent_item *fi;
1856 	u64 bytenr, num_bytes;
1857 
1858 	/* We can be called directly from walk_up_proc() */
1859 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
1860 		return 0;
1861 
1862 	for (i = 0; i < nr; i++) {
1863 		btrfs_item_key_to_cpu(eb, &key, i);
1864 
1865 		if (key.type != BTRFS_EXTENT_DATA_KEY)
1866 			continue;
1867 
1868 		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
1869 		/* filter out non qgroup-accountable extents  */
1870 		extent_type = btrfs_file_extent_type(eb, fi);
1871 
1872 		if (extent_type == BTRFS_FILE_EXTENT_INLINE)
1873 			continue;
1874 
1875 		bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
1876 		if (!bytenr)
1877 			continue;
1878 
1879 		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
1880 
1881 		ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes,
1882 						GFP_NOFS);
1883 		if (ret)
1884 			return ret;
1885 	}
1886 	cond_resched();
1887 	return 0;
1888 }
1889 
1890 /*
1891  * Walk up the tree from the bottom, freeing leaves and any interior
1892  * nodes which have had all slots visited. If a node (leaf or
1893  * interior) is freed, the node above it will have it's slot
1894  * incremented. The root node will never be freed.
1895  *
1896  * At the end of this function, we should have a path which has all
1897  * slots incremented to the next position for a search. If we need to
1898  * read a new node it will be NULL and the node above it will have the
1899  * correct slot selected for a later read.
1900  *
1901  * If we increment the root nodes slot counter past the number of
1902  * elements, 1 is returned to signal completion of the search.
1903  */
adjust_slots_upwards(struct btrfs_path * path,int root_level)1904 static int adjust_slots_upwards(struct btrfs_path *path, int root_level)
1905 {
1906 	int level = 0;
1907 	int nr, slot;
1908 	struct extent_buffer *eb;
1909 
1910 	if (root_level == 0)
1911 		return 1;
1912 
1913 	while (level <= root_level) {
1914 		eb = path->nodes[level];
1915 		nr = btrfs_header_nritems(eb);
1916 		path->slots[level]++;
1917 		slot = path->slots[level];
1918 		if (slot >= nr || level == 0) {
1919 			/*
1920 			 * Don't free the root -  we will detect this
1921 			 * condition after our loop and return a
1922 			 * positive value for caller to stop walking the tree.
1923 			 */
1924 			if (level != root_level) {
1925 				btrfs_tree_unlock_rw(eb, path->locks[level]);
1926 				path->locks[level] = 0;
1927 
1928 				free_extent_buffer(eb);
1929 				path->nodes[level] = NULL;
1930 				path->slots[level] = 0;
1931 			}
1932 		} else {
1933 			/*
1934 			 * We have a valid slot to walk back down
1935 			 * from. Stop here so caller can process these
1936 			 * new nodes.
1937 			 */
1938 			break;
1939 		}
1940 
1941 		level++;
1942 	}
1943 
1944 	eb = path->nodes[root_level];
1945 	if (path->slots[root_level] >= btrfs_header_nritems(eb))
1946 		return 1;
1947 
1948 	return 0;
1949 }
1950 
1951 /*
1952  * Helper function to trace a subtree tree block swap.
1953  *
1954  * The swap will happen in highest tree block, but there may be a lot of
1955  * tree blocks involved.
1956  *
1957  * For example:
1958  *  OO = Old tree blocks
1959  *  NN = New tree blocks allocated during balance
1960  *
1961  *           File tree (257)                  Reloc tree for 257
1962  * L2              OO                                NN
1963  *               /    \                            /    \
1964  * L1          OO      OO (a)                    OO      NN (a)
1965  *            / \     / \                       / \     / \
1966  * L0       OO   OO OO   OO                   OO   OO NN   NN
1967  *                  (b)  (c)                          (b)  (c)
1968  *
1969  * When calling qgroup_trace_extent_swap(), we will pass:
1970  * @src_eb = OO(a)
1971  * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ]
1972  * @dst_level = 0
1973  * @root_level = 1
1974  *
1975  * In that case, qgroup_trace_extent_swap() will search from OO(a) to
1976  * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty.
1977  *
1978  * The main work of qgroup_trace_extent_swap() can be split into 3 parts:
1979  *
1980  * 1) Tree search from @src_eb
1981  *    It should acts as a simplified btrfs_search_slot().
1982  *    The key for search can be extracted from @dst_path->nodes[dst_level]
1983  *    (first key).
1984  *
1985  * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty
1986  *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty.
1987  *    They should be marked during previous (@dst_level = 1) iteration.
1988  *
1989  * 3) Mark file extents in leaves dirty
1990  *    We don't have good way to pick out new file extents only.
1991  *    So we still follow the old method by scanning all file extents in
1992  *    the leave.
1993  *
1994  * This function can free us from keeping two paths, thus later we only need
1995  * to care about how to iterate all new tree blocks in reloc tree.
1996  */
qgroup_trace_extent_swap(struct btrfs_trans_handle * trans,struct extent_buffer * src_eb,struct btrfs_path * dst_path,int dst_level,int root_level,bool trace_leaf)1997 static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
1998 				    struct extent_buffer *src_eb,
1999 				    struct btrfs_path *dst_path,
2000 				    int dst_level, int root_level,
2001 				    bool trace_leaf)
2002 {
2003 	struct btrfs_key key;
2004 	struct btrfs_path *src_path;
2005 	struct btrfs_fs_info *fs_info = trans->fs_info;
2006 	u32 nodesize = fs_info->nodesize;
2007 	int cur_level = root_level;
2008 	int ret;
2009 
2010 	BUG_ON(dst_level > root_level);
2011 	/* Level mismatch */
2012 	if (btrfs_header_level(src_eb) != root_level)
2013 		return -EINVAL;
2014 
2015 	src_path = btrfs_alloc_path();
2016 	if (!src_path) {
2017 		ret = -ENOMEM;
2018 		goto out;
2019 	}
2020 
2021 	if (dst_level)
2022 		btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2023 	else
2024 		btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0);
2025 
2026 	/* For src_path */
2027 	atomic_inc(&src_eb->refs);
2028 	src_path->nodes[root_level] = src_eb;
2029 	src_path->slots[root_level] = dst_path->slots[root_level];
2030 	src_path->locks[root_level] = 0;
2031 
2032 	/* A simplified version of btrfs_search_slot() */
2033 	while (cur_level >= dst_level) {
2034 		struct btrfs_key src_key;
2035 		struct btrfs_key dst_key;
2036 
2037 		if (src_path->nodes[cur_level] == NULL) {
2038 			struct btrfs_key first_key;
2039 			struct extent_buffer *eb;
2040 			int parent_slot;
2041 			u64 child_gen;
2042 			u64 child_bytenr;
2043 
2044 			eb = src_path->nodes[cur_level + 1];
2045 			parent_slot = src_path->slots[cur_level + 1];
2046 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2047 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2048 			btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
2049 
2050 			eb = read_tree_block(fs_info, child_bytenr, child_gen,
2051 					     cur_level, &first_key);
2052 			if (IS_ERR(eb)) {
2053 				ret = PTR_ERR(eb);
2054 				goto out;
2055 			} else if (!extent_buffer_uptodate(eb)) {
2056 				free_extent_buffer(eb);
2057 				ret = -EIO;
2058 				goto out;
2059 			}
2060 
2061 			src_path->nodes[cur_level] = eb;
2062 
2063 			btrfs_tree_read_lock(eb);
2064 			btrfs_set_lock_blocking_read(eb);
2065 			src_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
2066 		}
2067 
2068 		src_path->slots[cur_level] = dst_path->slots[cur_level];
2069 		if (cur_level) {
2070 			btrfs_node_key_to_cpu(dst_path->nodes[cur_level],
2071 					&dst_key, dst_path->slots[cur_level]);
2072 			btrfs_node_key_to_cpu(src_path->nodes[cur_level],
2073 					&src_key, src_path->slots[cur_level]);
2074 		} else {
2075 			btrfs_item_key_to_cpu(dst_path->nodes[cur_level],
2076 					&dst_key, dst_path->slots[cur_level]);
2077 			btrfs_item_key_to_cpu(src_path->nodes[cur_level],
2078 					&src_key, src_path->slots[cur_level]);
2079 		}
2080 		/* Content mismatch, something went wrong */
2081 		if (btrfs_comp_cpu_keys(&dst_key, &src_key)) {
2082 			ret = -ENOENT;
2083 			goto out;
2084 		}
2085 		cur_level--;
2086 	}
2087 
2088 	/*
2089 	 * Now both @dst_path and @src_path have been populated, record the tree
2090 	 * blocks for qgroup accounting.
2091 	 */
2092 	ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start,
2093 			nodesize, GFP_NOFS);
2094 	if (ret < 0)
2095 		goto out;
2096 	ret = btrfs_qgroup_trace_extent(trans,
2097 			dst_path->nodes[dst_level]->start,
2098 			nodesize, GFP_NOFS);
2099 	if (ret < 0)
2100 		goto out;
2101 
2102 	/* Record leaf file extents */
2103 	if (dst_level == 0 && trace_leaf) {
2104 		ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]);
2105 		if (ret < 0)
2106 			goto out;
2107 		ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]);
2108 	}
2109 out:
2110 	btrfs_free_path(src_path);
2111 	return ret;
2112 }
2113 
2114 /*
2115  * Helper function to do recursive generation-aware depth-first search, to
2116  * locate all new tree blocks in a subtree of reloc tree.
2117  *
2118  * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot)
2119  *         reloc tree
2120  * L2         NN (a)
2121  *          /    \
2122  * L1    OO        NN (b)
2123  *      /  \      /  \
2124  * L0  OO  OO    OO  NN
2125  *               (c) (d)
2126  * If we pass:
2127  * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ],
2128  * @cur_level = 1
2129  * @root_level = 1
2130  *
2131  * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace
2132  * above tree blocks along with their counter parts in file tree.
2133  * While during search, old tree blocks OO(c) will be skipped as tree block swap
2134  * won't affect OO(c).
2135  */
qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle * trans,struct extent_buffer * src_eb,struct btrfs_path * dst_path,int cur_level,int root_level,u64 last_snapshot,bool trace_leaf)2136 static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans,
2137 					   struct extent_buffer *src_eb,
2138 					   struct btrfs_path *dst_path,
2139 					   int cur_level, int root_level,
2140 					   u64 last_snapshot, bool trace_leaf)
2141 {
2142 	struct btrfs_fs_info *fs_info = trans->fs_info;
2143 	struct extent_buffer *eb;
2144 	bool need_cleanup = false;
2145 	int ret = 0;
2146 	int i;
2147 
2148 	/* Level sanity check */
2149 	if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
2150 	    root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
2151 	    root_level < cur_level) {
2152 		btrfs_err_rl(fs_info,
2153 			"%s: bad levels, cur_level=%d root_level=%d",
2154 			__func__, cur_level, root_level);
2155 		return -EUCLEAN;
2156 	}
2157 
2158 	/* Read the tree block if needed */
2159 	if (dst_path->nodes[cur_level] == NULL) {
2160 		struct btrfs_key first_key;
2161 		int parent_slot;
2162 		u64 child_gen;
2163 		u64 child_bytenr;
2164 
2165 		/*
2166 		 * dst_path->nodes[root_level] must be initialized before
2167 		 * calling this function.
2168 		 */
2169 		if (cur_level == root_level) {
2170 			btrfs_err_rl(fs_info,
2171 	"%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d",
2172 				__func__, root_level, root_level, cur_level);
2173 			return -EUCLEAN;
2174 		}
2175 
2176 		/*
2177 		 * We need to get child blockptr/gen from parent before we can
2178 		 * read it.
2179 		  */
2180 		eb = dst_path->nodes[cur_level + 1];
2181 		parent_slot = dst_path->slots[cur_level + 1];
2182 		child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2183 		child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2184 		btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
2185 
2186 		/* This node is old, no need to trace */
2187 		if (child_gen < last_snapshot)
2188 			goto out;
2189 
2190 		eb = read_tree_block(fs_info, child_bytenr, child_gen,
2191 				     cur_level, &first_key);
2192 		if (IS_ERR(eb)) {
2193 			ret = PTR_ERR(eb);
2194 			goto out;
2195 		} else if (!extent_buffer_uptodate(eb)) {
2196 			free_extent_buffer(eb);
2197 			ret = -EIO;
2198 			goto out;
2199 		}
2200 
2201 		dst_path->nodes[cur_level] = eb;
2202 		dst_path->slots[cur_level] = 0;
2203 
2204 		btrfs_tree_read_lock(eb);
2205 		btrfs_set_lock_blocking_read(eb);
2206 		dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING;
2207 		need_cleanup = true;
2208 	}
2209 
2210 	/* Now record this tree block and its counter part for qgroups */
2211 	ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level,
2212 				       root_level, trace_leaf);
2213 	if (ret < 0)
2214 		goto cleanup;
2215 
2216 	eb = dst_path->nodes[cur_level];
2217 
2218 	if (cur_level > 0) {
2219 		/* Iterate all child tree blocks */
2220 		for (i = 0; i < btrfs_header_nritems(eb); i++) {
2221 			/* Skip old tree blocks as they won't be swapped */
2222 			if (btrfs_node_ptr_generation(eb, i) < last_snapshot)
2223 				continue;
2224 			dst_path->slots[cur_level] = i;
2225 
2226 			/* Recursive call (at most 7 times) */
2227 			ret = qgroup_trace_new_subtree_blocks(trans, src_eb,
2228 					dst_path, cur_level - 1, root_level,
2229 					last_snapshot, trace_leaf);
2230 			if (ret < 0)
2231 				goto cleanup;
2232 		}
2233 	}
2234 
2235 cleanup:
2236 	if (need_cleanup) {
2237 		/* Clean up */
2238 		btrfs_tree_unlock_rw(dst_path->nodes[cur_level],
2239 				     dst_path->locks[cur_level]);
2240 		free_extent_buffer(dst_path->nodes[cur_level]);
2241 		dst_path->nodes[cur_level] = NULL;
2242 		dst_path->slots[cur_level] = 0;
2243 		dst_path->locks[cur_level] = 0;
2244 	}
2245 out:
2246 	return ret;
2247 }
2248 
qgroup_trace_subtree_swap(struct btrfs_trans_handle * trans,struct extent_buffer * src_eb,struct extent_buffer * dst_eb,u64 last_snapshot,bool trace_leaf)2249 static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
2250 				struct extent_buffer *src_eb,
2251 				struct extent_buffer *dst_eb,
2252 				u64 last_snapshot, bool trace_leaf)
2253 {
2254 	struct btrfs_fs_info *fs_info = trans->fs_info;
2255 	struct btrfs_path *dst_path = NULL;
2256 	int level;
2257 	int ret;
2258 
2259 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2260 		return 0;
2261 
2262 	/* Wrong parameter order */
2263 	if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
2264 		btrfs_err_rl(fs_info,
2265 		"%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
2266 			     btrfs_header_generation(src_eb),
2267 			     btrfs_header_generation(dst_eb));
2268 		return -EUCLEAN;
2269 	}
2270 
2271 	if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
2272 		ret = -EIO;
2273 		goto out;
2274 	}
2275 
2276 	level = btrfs_header_level(dst_eb);
2277 	dst_path = btrfs_alloc_path();
2278 	if (!dst_path) {
2279 		ret = -ENOMEM;
2280 		goto out;
2281 	}
2282 	/* For dst_path */
2283 	atomic_inc(&dst_eb->refs);
2284 	dst_path->nodes[level] = dst_eb;
2285 	dst_path->slots[level] = 0;
2286 	dst_path->locks[level] = 0;
2287 
2288 	/* Do the generation aware breadth-first search */
2289 	ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
2290 					      level, last_snapshot, trace_leaf);
2291 	if (ret < 0)
2292 		goto out;
2293 	ret = 0;
2294 
2295 out:
2296 	btrfs_free_path(dst_path);
2297 	if (ret < 0)
2298 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2299 	return ret;
2300 }
2301 
btrfs_qgroup_trace_subtree(struct btrfs_trans_handle * trans,struct extent_buffer * root_eb,u64 root_gen,int root_level)2302 int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
2303 			       struct extent_buffer *root_eb,
2304 			       u64 root_gen, int root_level)
2305 {
2306 	struct btrfs_fs_info *fs_info = trans->fs_info;
2307 	int ret = 0;
2308 	int level;
2309 	struct extent_buffer *eb = root_eb;
2310 	struct btrfs_path *path = NULL;
2311 
2312 	BUG_ON(root_level < 0 || root_level >= BTRFS_MAX_LEVEL);
2313 	BUG_ON(root_eb == NULL);
2314 
2315 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2316 		return 0;
2317 
2318 	if (!extent_buffer_uptodate(root_eb)) {
2319 		ret = btrfs_read_buffer(root_eb, root_gen, root_level, NULL);
2320 		if (ret)
2321 			goto out;
2322 	}
2323 
2324 	if (root_level == 0) {
2325 		ret = btrfs_qgroup_trace_leaf_items(trans, root_eb);
2326 		goto out;
2327 	}
2328 
2329 	path = btrfs_alloc_path();
2330 	if (!path)
2331 		return -ENOMEM;
2332 
2333 	/*
2334 	 * Walk down the tree.  Missing extent blocks are filled in as
2335 	 * we go. Metadata is accounted every time we read a new
2336 	 * extent block.
2337 	 *
2338 	 * When we reach a leaf, we account for file extent items in it,
2339 	 * walk back up the tree (adjusting slot pointers as we go)
2340 	 * and restart the search process.
2341 	 */
2342 	atomic_inc(&root_eb->refs);	/* For path */
2343 	path->nodes[root_level] = root_eb;
2344 	path->slots[root_level] = 0;
2345 	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
2346 walk_down:
2347 	level = root_level;
2348 	while (level >= 0) {
2349 		if (path->nodes[level] == NULL) {
2350 			struct btrfs_key first_key;
2351 			int parent_slot;
2352 			u64 child_gen;
2353 			u64 child_bytenr;
2354 
2355 			/*
2356 			 * We need to get child blockptr/gen from parent before
2357 			 * we can read it.
2358 			  */
2359 			eb = path->nodes[level + 1];
2360 			parent_slot = path->slots[level + 1];
2361 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
2362 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
2363 			btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
2364 
2365 			eb = read_tree_block(fs_info, child_bytenr, child_gen,
2366 					     level, &first_key);
2367 			if (IS_ERR(eb)) {
2368 				ret = PTR_ERR(eb);
2369 				goto out;
2370 			} else if (!extent_buffer_uptodate(eb)) {
2371 				free_extent_buffer(eb);
2372 				ret = -EIO;
2373 				goto out;
2374 			}
2375 
2376 			path->nodes[level] = eb;
2377 			path->slots[level] = 0;
2378 
2379 			btrfs_tree_read_lock(eb);
2380 			btrfs_set_lock_blocking_read(eb);
2381 			path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
2382 
2383 			ret = btrfs_qgroup_trace_extent(trans, child_bytenr,
2384 							fs_info->nodesize,
2385 							GFP_NOFS);
2386 			if (ret)
2387 				goto out;
2388 		}
2389 
2390 		if (level == 0) {
2391 			ret = btrfs_qgroup_trace_leaf_items(trans,
2392 							    path->nodes[level]);
2393 			if (ret)
2394 				goto out;
2395 
2396 			/* Nonzero return here means we completed our search */
2397 			ret = adjust_slots_upwards(path, root_level);
2398 			if (ret)
2399 				break;
2400 
2401 			/* Restart search with new slots */
2402 			goto walk_down;
2403 		}
2404 
2405 		level--;
2406 	}
2407 
2408 	ret = 0;
2409 out:
2410 	btrfs_free_path(path);
2411 
2412 	return ret;
2413 }
2414 
2415 #define UPDATE_NEW	0
2416 #define UPDATE_OLD	1
2417 /*
2418  * Walk all of the roots that points to the bytenr and adjust their refcnts.
2419  */
qgroup_update_refcnt(struct btrfs_fs_info * fs_info,struct ulist * roots,struct ulist * tmp,struct ulist * qgroups,u64 seq,int update_old)2420 static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,
2421 				struct ulist *roots, struct ulist *tmp,
2422 				struct ulist *qgroups, u64 seq, int update_old)
2423 {
2424 	struct ulist_node *unode;
2425 	struct ulist_iterator uiter;
2426 	struct ulist_node *tmp_unode;
2427 	struct ulist_iterator tmp_uiter;
2428 	struct btrfs_qgroup *qg;
2429 	int ret = 0;
2430 
2431 	if (!roots)
2432 		return 0;
2433 	ULIST_ITER_INIT(&uiter);
2434 	while ((unode = ulist_next(roots, &uiter))) {
2435 		qg = find_qgroup_rb(fs_info, unode->val);
2436 		if (!qg)
2437 			continue;
2438 
2439 		ulist_reinit(tmp);
2440 		ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),
2441 				GFP_ATOMIC);
2442 		if (ret < 0)
2443 			return ret;
2444 		ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);
2445 		if (ret < 0)
2446 			return ret;
2447 		ULIST_ITER_INIT(&tmp_uiter);
2448 		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
2449 			struct btrfs_qgroup_list *glist;
2450 
2451 			qg = unode_aux_to_qgroup(tmp_unode);
2452 			if (update_old)
2453 				btrfs_qgroup_update_old_refcnt(qg, seq, 1);
2454 			else
2455 				btrfs_qgroup_update_new_refcnt(qg, seq, 1);
2456 			list_for_each_entry(glist, &qg->groups, next_group) {
2457 				ret = ulist_add(qgroups, glist->group->qgroupid,
2458 						qgroup_to_aux(glist->group),
2459 						GFP_ATOMIC);
2460 				if (ret < 0)
2461 					return ret;
2462 				ret = ulist_add(tmp, glist->group->qgroupid,
2463 						qgroup_to_aux(glist->group),
2464 						GFP_ATOMIC);
2465 				if (ret < 0)
2466 					return ret;
2467 			}
2468 		}
2469 	}
2470 	return 0;
2471 }
2472 
2473 /*
2474  * Update qgroup rfer/excl counters.
2475  * Rfer update is easy, codes can explain themselves.
2476  *
2477  * Excl update is tricky, the update is split into 2 parts.
2478  * Part 1: Possible exclusive <-> sharing detect:
2479  *	|	A	|	!A	|
2480  *  -------------------------------------
2481  *  B	|	*	|	-	|
2482  *  -------------------------------------
2483  *  !B	|	+	|	**	|
2484  *  -------------------------------------
2485  *
2486  * Conditions:
2487  * A:	cur_old_roots < nr_old_roots	(not exclusive before)
2488  * !A:	cur_old_roots == nr_old_roots	(possible exclusive before)
2489  * B:	cur_new_roots < nr_new_roots	(not exclusive now)
2490  * !B:	cur_new_roots == nr_new_roots	(possible exclusive now)
2491  *
2492  * Results:
2493  * +: Possible sharing -> exclusive	-: Possible exclusive -> sharing
2494  * *: Definitely not changed.		**: Possible unchanged.
2495  *
2496  * For !A and !B condition, the exception is cur_old/new_roots == 0 case.
2497  *
2498  * To make the logic clear, we first use condition A and B to split
2499  * combination into 4 results.
2500  *
2501  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them
2502  * only on variant maybe 0.
2503  *
2504  * Lastly, check result **, since there are 2 variants maybe 0, split them
2505  * again(2x2).
2506  * But this time we don't need to consider other things, the codes and logic
2507  * is easy to understand now.
2508  */
qgroup_update_counters(struct btrfs_fs_info * fs_info,struct ulist * qgroups,u64 nr_old_roots,u64 nr_new_roots,u64 num_bytes,u64 seq)2509 static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
2510 				  struct ulist *qgroups,
2511 				  u64 nr_old_roots,
2512 				  u64 nr_new_roots,
2513 				  u64 num_bytes, u64 seq)
2514 {
2515 	struct ulist_node *unode;
2516 	struct ulist_iterator uiter;
2517 	struct btrfs_qgroup *qg;
2518 	u64 cur_new_count, cur_old_count;
2519 
2520 	ULIST_ITER_INIT(&uiter);
2521 	while ((unode = ulist_next(qgroups, &uiter))) {
2522 		bool dirty = false;
2523 
2524 		qg = unode_aux_to_qgroup(unode);
2525 		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
2526 		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
2527 
2528 		trace_qgroup_update_counters(fs_info, qg, cur_old_count,
2529 					     cur_new_count);
2530 
2531 		/* Rfer update part */
2532 		if (cur_old_count == 0 && cur_new_count > 0) {
2533 			qg->rfer += num_bytes;
2534 			qg->rfer_cmpr += num_bytes;
2535 			dirty = true;
2536 		}
2537 		if (cur_old_count > 0 && cur_new_count == 0) {
2538 			qg->rfer -= num_bytes;
2539 			qg->rfer_cmpr -= num_bytes;
2540 			dirty = true;
2541 		}
2542 
2543 		/* Excl update part */
2544 		/* Exclusive/none -> shared case */
2545 		if (cur_old_count == nr_old_roots &&
2546 		    cur_new_count < nr_new_roots) {
2547 			/* Exclusive -> shared */
2548 			if (cur_old_count != 0) {
2549 				qg->excl -= num_bytes;
2550 				qg->excl_cmpr -= num_bytes;
2551 				dirty = true;
2552 			}
2553 		}
2554 
2555 		/* Shared -> exclusive/none case */
2556 		if (cur_old_count < nr_old_roots &&
2557 		    cur_new_count == nr_new_roots) {
2558 			/* Shared->exclusive */
2559 			if (cur_new_count != 0) {
2560 				qg->excl += num_bytes;
2561 				qg->excl_cmpr += num_bytes;
2562 				dirty = true;
2563 			}
2564 		}
2565 
2566 		/* Exclusive/none -> exclusive/none case */
2567 		if (cur_old_count == nr_old_roots &&
2568 		    cur_new_count == nr_new_roots) {
2569 			if (cur_old_count == 0) {
2570 				/* None -> exclusive/none */
2571 
2572 				if (cur_new_count != 0) {
2573 					/* None -> exclusive */
2574 					qg->excl += num_bytes;
2575 					qg->excl_cmpr += num_bytes;
2576 					dirty = true;
2577 				}
2578 				/* None -> none, nothing changed */
2579 			} else {
2580 				/* Exclusive -> exclusive/none */
2581 
2582 				if (cur_new_count == 0) {
2583 					/* Exclusive -> none */
2584 					qg->excl -= num_bytes;
2585 					qg->excl_cmpr -= num_bytes;
2586 					dirty = true;
2587 				}
2588 				/* Exclusive -> exclusive, nothing changed */
2589 			}
2590 		}
2591 
2592 		if (dirty)
2593 			qgroup_dirty(fs_info, qg);
2594 	}
2595 	return 0;
2596 }
2597 
2598 /*
2599  * Check if the @roots potentially is a list of fs tree roots
2600  *
2601  * Return 0 for definitely not a fs/subvol tree roots ulist
2602  * Return 1 for possible fs/subvol tree roots in the list (considering an empty
2603  *          one as well)
2604  */
maybe_fs_roots(struct ulist * roots)2605 static int maybe_fs_roots(struct ulist *roots)
2606 {
2607 	struct ulist_node *unode;
2608 	struct ulist_iterator uiter;
2609 
2610 	/* Empty one, still possible for fs roots */
2611 	if (!roots || roots->nnodes == 0)
2612 		return 1;
2613 
2614 	ULIST_ITER_INIT(&uiter);
2615 	unode = ulist_next(roots, &uiter);
2616 	if (!unode)
2617 		return 1;
2618 
2619 	/*
2620 	 * If it contains fs tree roots, then it must belong to fs/subvol
2621 	 * trees.
2622 	 * If it contains a non-fs tree, it won't be shared with fs/subvol trees.
2623 	 */
2624 	return is_fstree(unode->val);
2625 }
2626 
btrfs_qgroup_account_extent(struct btrfs_trans_handle * trans,u64 bytenr,u64 num_bytes,struct ulist * old_roots,struct ulist * new_roots)2627 int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
2628 				u64 num_bytes, struct ulist *old_roots,
2629 				struct ulist *new_roots)
2630 {
2631 	struct btrfs_fs_info *fs_info = trans->fs_info;
2632 	struct ulist *qgroups = NULL;
2633 	struct ulist *tmp = NULL;
2634 	u64 seq;
2635 	u64 nr_new_roots = 0;
2636 	u64 nr_old_roots = 0;
2637 	int ret = 0;
2638 
2639 	/*
2640 	 * If quotas get disabled meanwhile, the resouces need to be freed and
2641 	 * we can't just exit here.
2642 	 */
2643 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2644 		goto out_free;
2645 
2646 	if (new_roots) {
2647 		if (!maybe_fs_roots(new_roots))
2648 			goto out_free;
2649 		nr_new_roots = new_roots->nnodes;
2650 	}
2651 	if (old_roots) {
2652 		if (!maybe_fs_roots(old_roots))
2653 			goto out_free;
2654 		nr_old_roots = old_roots->nnodes;
2655 	}
2656 
2657 	/* Quick exit, either not fs tree roots, or won't affect any qgroup */
2658 	if (nr_old_roots == 0 && nr_new_roots == 0)
2659 		goto out_free;
2660 
2661 	BUG_ON(!fs_info->quota_root);
2662 
2663 	trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,
2664 					num_bytes, nr_old_roots, nr_new_roots);
2665 
2666 	qgroups = ulist_alloc(GFP_NOFS);
2667 	if (!qgroups) {
2668 		ret = -ENOMEM;
2669 		goto out_free;
2670 	}
2671 	tmp = ulist_alloc(GFP_NOFS);
2672 	if (!tmp) {
2673 		ret = -ENOMEM;
2674 		goto out_free;
2675 	}
2676 
2677 	mutex_lock(&fs_info->qgroup_rescan_lock);
2678 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
2679 		if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
2680 			mutex_unlock(&fs_info->qgroup_rescan_lock);
2681 			ret = 0;
2682 			goto out_free;
2683 		}
2684 	}
2685 	mutex_unlock(&fs_info->qgroup_rescan_lock);
2686 
2687 	spin_lock(&fs_info->qgroup_lock);
2688 	seq = fs_info->qgroup_seq;
2689 
2690 	/* Update old refcnts using old_roots */
2691 	ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,
2692 				   UPDATE_OLD);
2693 	if (ret < 0)
2694 		goto out;
2695 
2696 	/* Update new refcnts using new_roots */
2697 	ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,
2698 				   UPDATE_NEW);
2699 	if (ret < 0)
2700 		goto out;
2701 
2702 	qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,
2703 			       num_bytes, seq);
2704 
2705 	/*
2706 	 * Bump qgroup_seq to avoid seq overlap
2707 	 */
2708 	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;
2709 out:
2710 	spin_unlock(&fs_info->qgroup_lock);
2711 out_free:
2712 	ulist_free(tmp);
2713 	ulist_free(qgroups);
2714 	ulist_free(old_roots);
2715 	ulist_free(new_roots);
2716 	return ret;
2717 }
2718 
btrfs_qgroup_account_extents(struct btrfs_trans_handle * trans)2719 int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans)
2720 {
2721 	struct btrfs_fs_info *fs_info = trans->fs_info;
2722 	struct btrfs_qgroup_extent_record *record;
2723 	struct btrfs_delayed_ref_root *delayed_refs;
2724 	struct ulist *new_roots = NULL;
2725 	struct rb_node *node;
2726 	u64 num_dirty_extents = 0;
2727 	u64 qgroup_to_skip;
2728 	int ret = 0;
2729 
2730 	delayed_refs = &trans->transaction->delayed_refs;
2731 	qgroup_to_skip = delayed_refs->qgroup_to_skip;
2732 	while ((node = rb_first(&delayed_refs->dirty_extent_root))) {
2733 		record = rb_entry(node, struct btrfs_qgroup_extent_record,
2734 				  node);
2735 
2736 		num_dirty_extents++;
2737 		trace_btrfs_qgroup_account_extents(fs_info, record);
2738 
2739 		if (!ret) {
2740 			/*
2741 			 * Old roots should be searched when inserting qgroup
2742 			 * extent record
2743 			 */
2744 			if (WARN_ON(!record->old_roots)) {
2745 				/* Search commit root to find old_roots */
2746 				ret = btrfs_find_all_roots(NULL, fs_info,
2747 						record->bytenr, 0,
2748 						&record->old_roots, false);
2749 				if (ret < 0)
2750 					goto cleanup;
2751 			}
2752 
2753 			/* Free the reserved data space */
2754 			btrfs_qgroup_free_refroot(fs_info,
2755 					record->data_rsv_refroot,
2756 					record->data_rsv,
2757 					BTRFS_QGROUP_RSV_DATA);
2758 			/*
2759 			 * Use SEQ_LAST as time_seq to do special search, which
2760 			 * doesn't lock tree or delayed_refs and search current
2761 			 * root. It's safe inside commit_transaction().
2762 			 */
2763 			ret = btrfs_find_all_roots(trans, fs_info,
2764 				record->bytenr, SEQ_LAST, &new_roots, false);
2765 			if (ret < 0)
2766 				goto cleanup;
2767 			if (qgroup_to_skip) {
2768 				ulist_del(new_roots, qgroup_to_skip, 0);
2769 				ulist_del(record->old_roots, qgroup_to_skip,
2770 					  0);
2771 			}
2772 			ret = btrfs_qgroup_account_extent(trans, record->bytenr,
2773 							  record->num_bytes,
2774 							  record->old_roots,
2775 							  new_roots);
2776 			record->old_roots = NULL;
2777 			new_roots = NULL;
2778 		}
2779 cleanup:
2780 		ulist_free(record->old_roots);
2781 		ulist_free(new_roots);
2782 		new_roots = NULL;
2783 		rb_erase(node, &delayed_refs->dirty_extent_root);
2784 		kfree(record);
2785 
2786 	}
2787 	trace_qgroup_num_dirty_extents(fs_info, trans->transid,
2788 				       num_dirty_extents);
2789 	return ret;
2790 }
2791 
2792 /*
2793  * Writes all changed qgroups to disk.
2794  * Called by the transaction commit path and the qgroup assign ioctl.
2795  */
btrfs_run_qgroups(struct btrfs_trans_handle * trans)2796 int btrfs_run_qgroups(struct btrfs_trans_handle *trans)
2797 {
2798 	struct btrfs_fs_info *fs_info = trans->fs_info;
2799 	int ret = 0;
2800 
2801 	/*
2802 	 * In case we are called from the qgroup assign ioctl, assert that we
2803 	 * are holding the qgroup_ioctl_lock, otherwise we can race with a quota
2804 	 * disable operation (ioctl) and access a freed quota root.
2805 	 */
2806 	if (trans->transaction->state != TRANS_STATE_COMMIT_DOING)
2807 		lockdep_assert_held(&fs_info->qgroup_ioctl_lock);
2808 
2809 	if (!fs_info->quota_root)
2810 		return ret;
2811 
2812 	spin_lock(&fs_info->qgroup_lock);
2813 	while (!list_empty(&fs_info->dirty_qgroups)) {
2814 		struct btrfs_qgroup *qgroup;
2815 		qgroup = list_first_entry(&fs_info->dirty_qgroups,
2816 					  struct btrfs_qgroup, dirty);
2817 		list_del_init(&qgroup->dirty);
2818 		spin_unlock(&fs_info->qgroup_lock);
2819 		ret = update_qgroup_info_item(trans, qgroup);
2820 		if (ret)
2821 			fs_info->qgroup_flags |=
2822 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2823 		ret = update_qgroup_limit_item(trans, qgroup);
2824 		if (ret)
2825 			fs_info->qgroup_flags |=
2826 					BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2827 		spin_lock(&fs_info->qgroup_lock);
2828 	}
2829 	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2830 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON;
2831 	else
2832 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON;
2833 	spin_unlock(&fs_info->qgroup_lock);
2834 
2835 	ret = update_qgroup_status_item(trans);
2836 	if (ret)
2837 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
2838 
2839 	return ret;
2840 }
2841 
2842 /*
2843  * Copy the accounting information between qgroups. This is necessary
2844  * when a snapshot or a subvolume is created. Throwing an error will
2845  * cause a transaction abort so we take extra care here to only error
2846  * when a readonly fs is a reasonable outcome.
2847  */
btrfs_qgroup_inherit(struct btrfs_trans_handle * trans,u64 srcid,u64 objectid,struct btrfs_qgroup_inherit * inherit)2848 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
2849 			 u64 objectid, struct btrfs_qgroup_inherit *inherit)
2850 {
2851 	int ret = 0;
2852 	int i;
2853 	u64 *i_qgroups;
2854 	bool committing = false;
2855 	struct btrfs_fs_info *fs_info = trans->fs_info;
2856 	struct btrfs_root *quota_root;
2857 	struct btrfs_qgroup *srcgroup;
2858 	struct btrfs_qgroup *dstgroup;
2859 	bool need_rescan = false;
2860 	u32 level_size = 0;
2861 	u64 nums;
2862 
2863 	/*
2864 	 * There are only two callers of this function.
2865 	 *
2866 	 * One in create_subvol() in the ioctl context, which needs to hold
2867 	 * the qgroup_ioctl_lock.
2868 	 *
2869 	 * The other one in create_pending_snapshot() where no other qgroup
2870 	 * code can modify the fs as they all need to either start a new trans
2871 	 * or hold a trans handler, thus we don't need to hold
2872 	 * qgroup_ioctl_lock.
2873 	 * This would avoid long and complex lock chain and make lockdep happy.
2874 	 */
2875 	spin_lock(&fs_info->trans_lock);
2876 	if (trans->transaction->state == TRANS_STATE_COMMIT_DOING)
2877 		committing = true;
2878 	spin_unlock(&fs_info->trans_lock);
2879 
2880 	if (!committing)
2881 		mutex_lock(&fs_info->qgroup_ioctl_lock);
2882 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
2883 		goto out;
2884 
2885 	quota_root = fs_info->quota_root;
2886 	if (!quota_root) {
2887 		ret = -EINVAL;
2888 		goto out;
2889 	}
2890 
2891 	if (inherit) {
2892 		i_qgroups = (u64 *)(inherit + 1);
2893 		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
2894 		       2 * inherit->num_excl_copies;
2895 		for (i = 0; i < nums; ++i) {
2896 			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
2897 
2898 			/*
2899 			 * Zero out invalid groups so we can ignore
2900 			 * them later.
2901 			 */
2902 			if (!srcgroup ||
2903 			    ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
2904 				*i_qgroups = 0ULL;
2905 
2906 			++i_qgroups;
2907 		}
2908 	}
2909 
2910 	/*
2911 	 * create a tracking group for the subvol itself
2912 	 */
2913 	ret = add_qgroup_item(trans, quota_root, objectid);
2914 	if (ret)
2915 		goto out;
2916 
2917 	/*
2918 	 * add qgroup to all inherited groups
2919 	 */
2920 	if (inherit) {
2921 		i_qgroups = (u64 *)(inherit + 1);
2922 		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
2923 			if (*i_qgroups == 0)
2924 				continue;
2925 			ret = add_qgroup_relation_item(trans, objectid,
2926 						       *i_qgroups);
2927 			if (ret && ret != -EEXIST)
2928 				goto out;
2929 			ret = add_qgroup_relation_item(trans, *i_qgroups,
2930 						       objectid);
2931 			if (ret && ret != -EEXIST)
2932 				goto out;
2933 		}
2934 		ret = 0;
2935 	}
2936 
2937 
2938 	spin_lock(&fs_info->qgroup_lock);
2939 
2940 	dstgroup = add_qgroup_rb(fs_info, objectid);
2941 	if (IS_ERR(dstgroup)) {
2942 		ret = PTR_ERR(dstgroup);
2943 		goto unlock;
2944 	}
2945 
2946 	if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) {
2947 		dstgroup->lim_flags = inherit->lim.flags;
2948 		dstgroup->max_rfer = inherit->lim.max_rfer;
2949 		dstgroup->max_excl = inherit->lim.max_excl;
2950 		dstgroup->rsv_rfer = inherit->lim.rsv_rfer;
2951 		dstgroup->rsv_excl = inherit->lim.rsv_excl;
2952 
2953 		qgroup_dirty(fs_info, dstgroup);
2954 	}
2955 
2956 	if (srcid) {
2957 		srcgroup = find_qgroup_rb(fs_info, srcid);
2958 		if (!srcgroup)
2959 			goto unlock;
2960 
2961 		/*
2962 		 * We call inherit after we clone the root in order to make sure
2963 		 * our counts don't go crazy, so at this point the only
2964 		 * difference between the two roots should be the root node.
2965 		 */
2966 		level_size = fs_info->nodesize;
2967 		dstgroup->rfer = srcgroup->rfer;
2968 		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
2969 		dstgroup->excl = level_size;
2970 		dstgroup->excl_cmpr = level_size;
2971 		srcgroup->excl = level_size;
2972 		srcgroup->excl_cmpr = level_size;
2973 
2974 		/* inherit the limit info */
2975 		dstgroup->lim_flags = srcgroup->lim_flags;
2976 		dstgroup->max_rfer = srcgroup->max_rfer;
2977 		dstgroup->max_excl = srcgroup->max_excl;
2978 		dstgroup->rsv_rfer = srcgroup->rsv_rfer;
2979 		dstgroup->rsv_excl = srcgroup->rsv_excl;
2980 
2981 		qgroup_dirty(fs_info, dstgroup);
2982 		qgroup_dirty(fs_info, srcgroup);
2983 	}
2984 
2985 	if (!inherit)
2986 		goto unlock;
2987 
2988 	i_qgroups = (u64 *)(inherit + 1);
2989 	for (i = 0; i < inherit->num_qgroups; ++i) {
2990 		if (*i_qgroups) {
2991 			ret = add_relation_rb(fs_info, objectid, *i_qgroups);
2992 			if (ret)
2993 				goto unlock;
2994 		}
2995 		++i_qgroups;
2996 
2997 		/*
2998 		 * If we're doing a snapshot, and adding the snapshot to a new
2999 		 * qgroup, the numbers are guaranteed to be incorrect.
3000 		 */
3001 		if (srcid)
3002 			need_rescan = true;
3003 	}
3004 
3005 	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
3006 		struct btrfs_qgroup *src;
3007 		struct btrfs_qgroup *dst;
3008 
3009 		if (!i_qgroups[0] || !i_qgroups[1])
3010 			continue;
3011 
3012 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
3013 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3014 
3015 		if (!src || !dst) {
3016 			ret = -EINVAL;
3017 			goto unlock;
3018 		}
3019 
3020 		dst->rfer = src->rfer - level_size;
3021 		dst->rfer_cmpr = src->rfer_cmpr - level_size;
3022 
3023 		/* Manually tweaking numbers certainly needs a rescan */
3024 		need_rescan = true;
3025 	}
3026 	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
3027 		struct btrfs_qgroup *src;
3028 		struct btrfs_qgroup *dst;
3029 
3030 		if (!i_qgroups[0] || !i_qgroups[1])
3031 			continue;
3032 
3033 		src = find_qgroup_rb(fs_info, i_qgroups[0]);
3034 		dst = find_qgroup_rb(fs_info, i_qgroups[1]);
3035 
3036 		if (!src || !dst) {
3037 			ret = -EINVAL;
3038 			goto unlock;
3039 		}
3040 
3041 		dst->excl = src->excl + level_size;
3042 		dst->excl_cmpr = src->excl_cmpr + level_size;
3043 		need_rescan = true;
3044 	}
3045 
3046 unlock:
3047 	spin_unlock(&fs_info->qgroup_lock);
3048 	if (!ret)
3049 		ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup);
3050 out:
3051 	if (!committing)
3052 		mutex_unlock(&fs_info->qgroup_ioctl_lock);
3053 	if (need_rescan)
3054 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3055 	return ret;
3056 }
3057 
qgroup_check_limits(const struct btrfs_qgroup * qg,u64 num_bytes)3058 static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
3059 {
3060 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
3061 	    qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
3062 		return false;
3063 
3064 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
3065 	    qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
3066 		return false;
3067 
3068 	return true;
3069 }
3070 
qgroup_reserve(struct btrfs_root * root,u64 num_bytes,bool enforce,enum btrfs_qgroup_rsv_type type)3071 static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
3072 			  enum btrfs_qgroup_rsv_type type)
3073 {
3074 	struct btrfs_qgroup *qgroup;
3075 	struct btrfs_fs_info *fs_info = root->fs_info;
3076 	u64 ref_root = root->root_key.objectid;
3077 	int ret = 0;
3078 	struct ulist_node *unode;
3079 	struct ulist_iterator uiter;
3080 
3081 	if (!is_fstree(ref_root))
3082 		return 0;
3083 
3084 	if (num_bytes == 0)
3085 		return 0;
3086 
3087 	if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) &&
3088 	    capable(CAP_SYS_RESOURCE))
3089 		enforce = false;
3090 
3091 	spin_lock(&fs_info->qgroup_lock);
3092 	if (!fs_info->quota_root)
3093 		goto out;
3094 
3095 	qgroup = find_qgroup_rb(fs_info, ref_root);
3096 	if (!qgroup)
3097 		goto out;
3098 
3099 	/*
3100 	 * in a first step, we check all affected qgroups if any limits would
3101 	 * be exceeded
3102 	 */
3103 	ulist_reinit(fs_info->qgroup_ulist);
3104 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3105 			qgroup_to_aux(qgroup), GFP_ATOMIC);
3106 	if (ret < 0)
3107 		goto out;
3108 	ULIST_ITER_INIT(&uiter);
3109 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3110 		struct btrfs_qgroup *qg;
3111 		struct btrfs_qgroup_list *glist;
3112 
3113 		qg = unode_aux_to_qgroup(unode);
3114 
3115 		if (enforce && !qgroup_check_limits(qg, num_bytes)) {
3116 			ret = -EDQUOT;
3117 			goto out;
3118 		}
3119 
3120 		list_for_each_entry(glist, &qg->groups, next_group) {
3121 			ret = ulist_add(fs_info->qgroup_ulist,
3122 					glist->group->qgroupid,
3123 					qgroup_to_aux(glist->group), GFP_ATOMIC);
3124 			if (ret < 0)
3125 				goto out;
3126 		}
3127 	}
3128 	ret = 0;
3129 	/*
3130 	 * no limits exceeded, now record the reservation into all qgroups
3131 	 */
3132 	ULIST_ITER_INIT(&uiter);
3133 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3134 		struct btrfs_qgroup *qg;
3135 
3136 		qg = unode_aux_to_qgroup(unode);
3137 
3138 		qgroup_rsv_add(fs_info, qg, num_bytes, type);
3139 	}
3140 
3141 out:
3142 	spin_unlock(&fs_info->qgroup_lock);
3143 	return ret;
3144 }
3145 
3146 /*
3147  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0
3148  * qgroup).
3149  *
3150  * Will handle all higher level qgroup too.
3151  *
3152  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup.
3153  * This special case is only used for META_PERTRANS type.
3154  */
btrfs_qgroup_free_refroot(struct btrfs_fs_info * fs_info,u64 ref_root,u64 num_bytes,enum btrfs_qgroup_rsv_type type)3155 void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
3156 			       u64 ref_root, u64 num_bytes,
3157 			       enum btrfs_qgroup_rsv_type type)
3158 {
3159 	struct btrfs_qgroup *qgroup;
3160 	struct ulist_node *unode;
3161 	struct ulist_iterator uiter;
3162 	int ret = 0;
3163 
3164 	if (!is_fstree(ref_root))
3165 		return;
3166 
3167 	if (num_bytes == 0)
3168 		return;
3169 
3170 	if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) {
3171 		WARN(1, "%s: Invalid type to free", __func__);
3172 		return;
3173 	}
3174 	spin_lock(&fs_info->qgroup_lock);
3175 
3176 	if (!fs_info->quota_root)
3177 		goto out;
3178 
3179 	qgroup = find_qgroup_rb(fs_info, ref_root);
3180 	if (!qgroup)
3181 		goto out;
3182 
3183 	if (num_bytes == (u64)-1)
3184 		/*
3185 		 * We're freeing all pertrans rsv, get reserved value from
3186 		 * level 0 qgroup as real num_bytes to free.
3187 		 */
3188 		num_bytes = qgroup->rsv.values[type];
3189 
3190 	ulist_reinit(fs_info->qgroup_ulist);
3191 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
3192 			qgroup_to_aux(qgroup), GFP_ATOMIC);
3193 	if (ret < 0)
3194 		goto out;
3195 	ULIST_ITER_INIT(&uiter);
3196 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
3197 		struct btrfs_qgroup *qg;
3198 		struct btrfs_qgroup_list *glist;
3199 
3200 		qg = unode_aux_to_qgroup(unode);
3201 
3202 		qgroup_rsv_release(fs_info, qg, num_bytes, type);
3203 
3204 		list_for_each_entry(glist, &qg->groups, next_group) {
3205 			ret = ulist_add(fs_info->qgroup_ulist,
3206 					glist->group->qgroupid,
3207 					qgroup_to_aux(glist->group), GFP_ATOMIC);
3208 			if (ret < 0)
3209 				goto out;
3210 		}
3211 	}
3212 
3213 out:
3214 	spin_unlock(&fs_info->qgroup_lock);
3215 }
3216 
3217 /*
3218  * Check if the leaf is the last leaf. Which means all node pointers
3219  * are at their last position.
3220  */
is_last_leaf(struct btrfs_path * path)3221 static bool is_last_leaf(struct btrfs_path *path)
3222 {
3223 	int i;
3224 
3225 	for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
3226 		if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1)
3227 			return false;
3228 	}
3229 	return true;
3230 }
3231 
3232 /*
3233  * returns < 0 on error, 0 when more leafs are to be scanned.
3234  * returns 1 when done.
3235  */
qgroup_rescan_leaf(struct btrfs_trans_handle * trans,struct btrfs_path * path)3236 static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans,
3237 			      struct btrfs_path *path)
3238 {
3239 	struct btrfs_fs_info *fs_info = trans->fs_info;
3240 	struct btrfs_key found;
3241 	struct extent_buffer *scratch_leaf = NULL;
3242 	struct ulist *roots = NULL;
3243 	u64 num_bytes;
3244 	bool done;
3245 	int slot;
3246 	int ret;
3247 
3248 	mutex_lock(&fs_info->qgroup_rescan_lock);
3249 	ret = btrfs_search_slot_for_read(fs_info->extent_root,
3250 					 &fs_info->qgroup_rescan_progress,
3251 					 path, 1, 0);
3252 
3253 	btrfs_debug(fs_info,
3254 		"current progress key (%llu %u %llu), search_slot ret %d",
3255 		fs_info->qgroup_rescan_progress.objectid,
3256 		fs_info->qgroup_rescan_progress.type,
3257 		fs_info->qgroup_rescan_progress.offset, ret);
3258 
3259 	if (ret) {
3260 		/*
3261 		 * The rescan is about to end, we will not be scanning any
3262 		 * further blocks. We cannot unset the RESCAN flag here, because
3263 		 * we want to commit the transaction if everything went well.
3264 		 * To make the live accounting work in this phase, we set our
3265 		 * scan progress pointer such that every real extent objectid
3266 		 * will be smaller.
3267 		 */
3268 		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3269 		btrfs_release_path(path);
3270 		mutex_unlock(&fs_info->qgroup_rescan_lock);
3271 		return ret;
3272 	}
3273 	done = is_last_leaf(path);
3274 
3275 	btrfs_item_key_to_cpu(path->nodes[0], &found,
3276 			      btrfs_header_nritems(path->nodes[0]) - 1);
3277 	fs_info->qgroup_rescan_progress.objectid = found.objectid + 1;
3278 
3279 	scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]);
3280 	if (!scratch_leaf) {
3281 		ret = -ENOMEM;
3282 		mutex_unlock(&fs_info->qgroup_rescan_lock);
3283 		goto out;
3284 	}
3285 	slot = path->slots[0];
3286 	btrfs_release_path(path);
3287 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3288 
3289 	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
3290 		btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
3291 		if (found.type != BTRFS_EXTENT_ITEM_KEY &&
3292 		    found.type != BTRFS_METADATA_ITEM_KEY)
3293 			continue;
3294 		if (found.type == BTRFS_METADATA_ITEM_KEY)
3295 			num_bytes = fs_info->nodesize;
3296 		else
3297 			num_bytes = found.offset;
3298 
3299 		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
3300 					   &roots, false);
3301 		if (ret < 0)
3302 			goto out;
3303 		/* For rescan, just pass old_roots as NULL */
3304 		ret = btrfs_qgroup_account_extent(trans, found.objectid,
3305 						  num_bytes, NULL, roots);
3306 		if (ret < 0)
3307 			goto out;
3308 	}
3309 out:
3310 	if (scratch_leaf)
3311 		free_extent_buffer(scratch_leaf);
3312 
3313 	if (done && !ret) {
3314 		ret = 1;
3315 		fs_info->qgroup_rescan_progress.objectid = (u64)-1;
3316 	}
3317 	return ret;
3318 }
3319 
rescan_should_stop(struct btrfs_fs_info * fs_info)3320 static bool rescan_should_stop(struct btrfs_fs_info *fs_info)
3321 {
3322 	return btrfs_fs_closing(fs_info) ||
3323 		test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state) ||
3324 		!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
3325 }
3326 
btrfs_qgroup_rescan_worker(struct btrfs_work * work)3327 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
3328 {
3329 	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
3330 						     qgroup_rescan_work);
3331 	struct btrfs_path *path;
3332 	struct btrfs_trans_handle *trans = NULL;
3333 	int err = -ENOMEM;
3334 	int ret = 0;
3335 	bool stopped = false;
3336 	bool did_leaf_rescans = false;
3337 
3338 	path = btrfs_alloc_path();
3339 	if (!path)
3340 		goto out;
3341 	/*
3342 	 * Rescan should only search for commit root, and any later difference
3343 	 * should be recorded by qgroup
3344 	 */
3345 	path->search_commit_root = 1;
3346 	path->skip_locking = 1;
3347 
3348 	err = 0;
3349 	while (!err && !(stopped = rescan_should_stop(fs_info))) {
3350 		trans = btrfs_start_transaction(fs_info->fs_root, 0);
3351 		if (IS_ERR(trans)) {
3352 			err = PTR_ERR(trans);
3353 			break;
3354 		}
3355 
3356 		err = qgroup_rescan_leaf(trans, path);
3357 		did_leaf_rescans = true;
3358 
3359 		if (err > 0)
3360 			btrfs_commit_transaction(trans);
3361 		else
3362 			btrfs_end_transaction(trans);
3363 	}
3364 
3365 out:
3366 	btrfs_free_path(path);
3367 
3368 	mutex_lock(&fs_info->qgroup_rescan_lock);
3369 	if (err > 0 &&
3370 	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
3371 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3372 	} else if (err < 0 || stopped) {
3373 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
3374 	}
3375 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3376 
3377 	/*
3378 	 * Only update status, since the previous part has already updated the
3379 	 * qgroup info, and only if we did any actual work. This also prevents
3380 	 * race with a concurrent quota disable, which has already set
3381 	 * fs_info->quota_root to NULL and cleared BTRFS_FS_QUOTA_ENABLED at
3382 	 * btrfs_quota_disable().
3383 	 */
3384 	if (did_leaf_rescans) {
3385 		trans = btrfs_start_transaction(fs_info->quota_root, 1);
3386 		if (IS_ERR(trans)) {
3387 			err = PTR_ERR(trans);
3388 			trans = NULL;
3389 			btrfs_err(fs_info,
3390 				  "fail to start transaction for status update: %d",
3391 				  err);
3392 		}
3393 	} else {
3394 		trans = NULL;
3395 	}
3396 
3397 	mutex_lock(&fs_info->qgroup_rescan_lock);
3398 	if (!stopped)
3399 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3400 	if (trans) {
3401 		ret = update_qgroup_status_item(trans);
3402 		if (ret < 0) {
3403 			err = ret;
3404 			btrfs_err(fs_info, "fail to update qgroup status: %d",
3405 				  err);
3406 		}
3407 	}
3408 	fs_info->qgroup_rescan_running = false;
3409 	complete_all(&fs_info->qgroup_rescan_completion);
3410 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3411 
3412 	if (!trans)
3413 		return;
3414 
3415 	btrfs_end_transaction(trans);
3416 
3417 	if (stopped) {
3418 		btrfs_info(fs_info, "qgroup scan paused");
3419 	} else if (err >= 0) {
3420 		btrfs_info(fs_info, "qgroup scan completed%s",
3421 			err > 0 ? " (inconsistency flag cleared)" : "");
3422 	} else {
3423 		btrfs_err(fs_info, "qgroup scan failed with %d", err);
3424 	}
3425 }
3426 
3427 /*
3428  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all
3429  * memory required for the rescan context.
3430  */
3431 static int
qgroup_rescan_init(struct btrfs_fs_info * fs_info,u64 progress_objectid,int init_flags)3432 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
3433 		   int init_flags)
3434 {
3435 	int ret = 0;
3436 
3437 	if (!init_flags) {
3438 		/* we're resuming qgroup rescan at mount time */
3439 		if (!(fs_info->qgroup_flags &
3440 		      BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
3441 			btrfs_warn(fs_info,
3442 			"qgroup rescan init failed, qgroup rescan is not queued");
3443 			ret = -EINVAL;
3444 		} else if (!(fs_info->qgroup_flags &
3445 			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3446 			btrfs_warn(fs_info,
3447 			"qgroup rescan init failed, qgroup is not enabled");
3448 			ret = -EINVAL;
3449 		}
3450 
3451 		if (ret)
3452 			return ret;
3453 	}
3454 
3455 	mutex_lock(&fs_info->qgroup_rescan_lock);
3456 
3457 	if (init_flags) {
3458 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3459 			btrfs_warn(fs_info,
3460 				   "qgroup rescan is already in progress");
3461 			ret = -EINPROGRESS;
3462 		} else if (!(fs_info->qgroup_flags &
3463 			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
3464 			btrfs_warn(fs_info,
3465 			"qgroup rescan init failed, qgroup is not enabled");
3466 			ret = -EINVAL;
3467 		} else if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
3468 			/* Quota disable is in progress */
3469 			ret = -EBUSY;
3470 		}
3471 
3472 		if (ret) {
3473 			mutex_unlock(&fs_info->qgroup_rescan_lock);
3474 			return ret;
3475 		}
3476 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3477 	}
3478 
3479 	memset(&fs_info->qgroup_rescan_progress, 0,
3480 		sizeof(fs_info->qgroup_rescan_progress));
3481 	fs_info->qgroup_rescan_progress.objectid = progress_objectid;
3482 	init_completion(&fs_info->qgroup_rescan_completion);
3483 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3484 
3485 	btrfs_init_work(&fs_info->qgroup_rescan_work,
3486 			btrfs_qgroup_rescan_worker, NULL, NULL);
3487 	return 0;
3488 }
3489 
3490 static void
qgroup_rescan_zero_tracking(struct btrfs_fs_info * fs_info)3491 qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info)
3492 {
3493 	struct rb_node *n;
3494 	struct btrfs_qgroup *qgroup;
3495 
3496 	spin_lock(&fs_info->qgroup_lock);
3497 	/* clear all current qgroup tracking information */
3498 	for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) {
3499 		qgroup = rb_entry(n, struct btrfs_qgroup, node);
3500 		qgroup->rfer = 0;
3501 		qgroup->rfer_cmpr = 0;
3502 		qgroup->excl = 0;
3503 		qgroup->excl_cmpr = 0;
3504 		qgroup_dirty(fs_info, qgroup);
3505 	}
3506 	spin_unlock(&fs_info->qgroup_lock);
3507 }
3508 
3509 int
btrfs_qgroup_rescan(struct btrfs_fs_info * fs_info)3510 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
3511 {
3512 	int ret = 0;
3513 	struct btrfs_trans_handle *trans;
3514 
3515 	ret = qgroup_rescan_init(fs_info, 0, 1);
3516 	if (ret)
3517 		return ret;
3518 
3519 	/*
3520 	 * We have set the rescan_progress to 0, which means no more
3521 	 * delayed refs will be accounted by btrfs_qgroup_account_ref.
3522 	 * However, btrfs_qgroup_account_ref may be right after its call
3523 	 * to btrfs_find_all_roots, in which case it would still do the
3524 	 * accounting.
3525 	 * To solve this, we're committing the transaction, which will
3526 	 * ensure we run all delayed refs and only after that, we are
3527 	 * going to clear all tracking information for a clean start.
3528 	 */
3529 
3530 	trans = btrfs_join_transaction(fs_info->fs_root);
3531 	if (IS_ERR(trans)) {
3532 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3533 		return PTR_ERR(trans);
3534 	}
3535 	ret = btrfs_commit_transaction(trans);
3536 	if (ret) {
3537 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
3538 		return ret;
3539 	}
3540 
3541 	qgroup_rescan_zero_tracking(fs_info);
3542 
3543 	mutex_lock(&fs_info->qgroup_rescan_lock);
3544 	fs_info->qgroup_rescan_running = true;
3545 	btrfs_queue_work(fs_info->qgroup_rescan_workers,
3546 			 &fs_info->qgroup_rescan_work);
3547 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3548 
3549 	return 0;
3550 }
3551 
btrfs_qgroup_wait_for_completion(struct btrfs_fs_info * fs_info,bool interruptible)3552 int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
3553 				     bool interruptible)
3554 {
3555 	int running;
3556 	int ret = 0;
3557 
3558 	mutex_lock(&fs_info->qgroup_rescan_lock);
3559 	running = fs_info->qgroup_rescan_running;
3560 	mutex_unlock(&fs_info->qgroup_rescan_lock);
3561 
3562 	if (!running)
3563 		return 0;
3564 
3565 	if (interruptible)
3566 		ret = wait_for_completion_interruptible(
3567 					&fs_info->qgroup_rescan_completion);
3568 	else
3569 		wait_for_completion(&fs_info->qgroup_rescan_completion);
3570 
3571 	return ret;
3572 }
3573 
3574 /*
3575  * this is only called from open_ctree where we're still single threaded, thus
3576  * locking is omitted here.
3577  */
3578 void
btrfs_qgroup_rescan_resume(struct btrfs_fs_info * fs_info)3579 btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
3580 {
3581 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3582 		mutex_lock(&fs_info->qgroup_rescan_lock);
3583 		fs_info->qgroup_rescan_running = true;
3584 		btrfs_queue_work(fs_info->qgroup_rescan_workers,
3585 				 &fs_info->qgroup_rescan_work);
3586 		mutex_unlock(&fs_info->qgroup_rescan_lock);
3587 	}
3588 }
3589 
3590 #define rbtree_iterate_from_safe(node, next, start)				\
3591        for (node = start; node && ({ next = rb_next(node); 1;}); node = next)
3592 
qgroup_unreserve_range(struct btrfs_inode * inode,struct extent_changeset * reserved,u64 start,u64 len)3593 static int qgroup_unreserve_range(struct btrfs_inode *inode,
3594 				  struct extent_changeset *reserved, u64 start,
3595 				  u64 len)
3596 {
3597 	struct rb_node *node;
3598 	struct rb_node *next;
3599 	struct ulist_node *entry;
3600 	int ret = 0;
3601 
3602 	node = reserved->range_changed.root.rb_node;
3603 	if (!node)
3604 		return 0;
3605 	while (node) {
3606 		entry = rb_entry(node, struct ulist_node, rb_node);
3607 		if (entry->val < start)
3608 			node = node->rb_right;
3609 		else
3610 			node = node->rb_left;
3611 	}
3612 
3613 	if (entry->val > start && rb_prev(&entry->rb_node))
3614 		entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node,
3615 				 rb_node);
3616 
3617 	rbtree_iterate_from_safe(node, next, &entry->rb_node) {
3618 		u64 entry_start;
3619 		u64 entry_end;
3620 		u64 entry_len;
3621 		int clear_ret;
3622 
3623 		entry = rb_entry(node, struct ulist_node, rb_node);
3624 		entry_start = entry->val;
3625 		entry_end = entry->aux;
3626 		entry_len = entry_end - entry_start + 1;
3627 
3628 		if (entry_start >= start + len)
3629 			break;
3630 		if (entry_start + entry_len <= start)
3631 			continue;
3632 		/*
3633 		 * Now the entry is in [start, start + len), revert the
3634 		 * EXTENT_QGROUP_RESERVED bit.
3635 		 */
3636 		clear_ret = clear_extent_bits(&inode->io_tree, entry_start,
3637 					      entry_end, EXTENT_QGROUP_RESERVED);
3638 		if (!ret && clear_ret < 0)
3639 			ret = clear_ret;
3640 
3641 		ulist_del(&reserved->range_changed, entry->val, entry->aux);
3642 		if (likely(reserved->bytes_changed >= entry_len)) {
3643 			reserved->bytes_changed -= entry_len;
3644 		} else {
3645 			WARN_ON(1);
3646 			reserved->bytes_changed = 0;
3647 		}
3648 	}
3649 
3650 	return ret;
3651 }
3652 
3653 /*
3654  * Try to free some space for qgroup.
3655  *
3656  * For qgroup, there are only 3 ways to free qgroup space:
3657  * - Flush nodatacow write
3658  *   Any nodatacow write will free its reserved data space at run_delalloc_range().
3659  *   In theory, we should only flush nodatacow inodes, but it's not yet
3660  *   possible, so we need to flush the whole root.
3661  *
3662  * - Wait for ordered extents
3663  *   When ordered extents are finished, their reserved metadata is finally
3664  *   converted to per_trans status, which can be freed by later commit
3665  *   transaction.
3666  *
3667  * - Commit transaction
3668  *   This would free the meta_per_trans space.
3669  *   In theory this shouldn't provide much space, but any more qgroup space
3670  *   is needed.
3671  */
try_flush_qgroup(struct btrfs_root * root)3672 static int try_flush_qgroup(struct btrfs_root *root)
3673 {
3674 	struct btrfs_trans_handle *trans;
3675 	int ret;
3676 	bool can_commit = true;
3677 
3678 	/*
3679 	 * If current process holds a transaction, we shouldn't flush, as we
3680 	 * assume all space reservation happens before a transaction handle is
3681 	 * held.
3682 	 *
3683 	 * But there are cases like btrfs_delayed_item_reserve_metadata() where
3684 	 * we try to reserve space with one transction handle already held.
3685 	 * In that case we can't commit transaction, but at least try to end it
3686 	 * and hope the started data writes can free some space.
3687 	 */
3688 	if (current->journal_info &&
3689 	    current->journal_info != BTRFS_SEND_TRANS_STUB)
3690 		can_commit = false;
3691 
3692 	/*
3693 	 * We don't want to run flush again and again, so if there is a running
3694 	 * one, we won't try to start a new flush, but exit directly.
3695 	 */
3696 	if (test_and_set_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)) {
3697 		/*
3698 		 * We are already holding a transaction, thus we can block other
3699 		 * threads from flushing.  So exit right now. This increases
3700 		 * the chance of EDQUOT for heavy load and near limit cases.
3701 		 * But we can argue that if we're already near limit, EDQUOT is
3702 		 * unavoidable anyway.
3703 		 */
3704 		if (!can_commit)
3705 			return 0;
3706 
3707 		wait_event(root->qgroup_flush_wait,
3708 			!test_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state));
3709 		return 0;
3710 	}
3711 
3712 	ret = btrfs_start_delalloc_snapshot(root);
3713 	if (ret < 0)
3714 		goto out;
3715 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
3716 
3717 	trans = btrfs_join_transaction(root);
3718 	if (IS_ERR(trans)) {
3719 		ret = PTR_ERR(trans);
3720 		goto out;
3721 	}
3722 
3723 	if (can_commit)
3724 		ret = btrfs_commit_transaction(trans);
3725 	else
3726 		ret = btrfs_end_transaction(trans);
3727 out:
3728 	clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state);
3729 	wake_up(&root->qgroup_flush_wait);
3730 	return ret;
3731 }
3732 
qgroup_reserve_data(struct btrfs_inode * inode,struct extent_changeset ** reserved_ret,u64 start,u64 len)3733 static int qgroup_reserve_data(struct btrfs_inode *inode,
3734 			struct extent_changeset **reserved_ret, u64 start,
3735 			u64 len)
3736 {
3737 	struct btrfs_root *root = inode->root;
3738 	struct extent_changeset *reserved;
3739 	bool new_reserved = false;
3740 	u64 orig_reserved;
3741 	u64 to_reserve;
3742 	int ret;
3743 
3744 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &root->fs_info->flags) ||
3745 	    !is_fstree(root->root_key.objectid) || len == 0)
3746 		return 0;
3747 
3748 	/* @reserved parameter is mandatory for qgroup */
3749 	if (WARN_ON(!reserved_ret))
3750 		return -EINVAL;
3751 	if (!*reserved_ret) {
3752 		new_reserved = true;
3753 		*reserved_ret = extent_changeset_alloc();
3754 		if (!*reserved_ret)
3755 			return -ENOMEM;
3756 	}
3757 	reserved = *reserved_ret;
3758 	/* Record already reserved space */
3759 	orig_reserved = reserved->bytes_changed;
3760 	ret = set_record_extent_bits(&inode->io_tree, start,
3761 			start + len -1, EXTENT_QGROUP_RESERVED, reserved);
3762 
3763 	/* Newly reserved space */
3764 	to_reserve = reserved->bytes_changed - orig_reserved;
3765 	trace_btrfs_qgroup_reserve_data(&inode->vfs_inode, start, len,
3766 					to_reserve, QGROUP_RESERVE);
3767 	if (ret < 0)
3768 		goto out;
3769 	ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA);
3770 	if (ret < 0)
3771 		goto cleanup;
3772 
3773 	return ret;
3774 
3775 cleanup:
3776 	qgroup_unreserve_range(inode, reserved, start, len);
3777 out:
3778 	if (new_reserved) {
3779 		extent_changeset_release(reserved);
3780 		kfree(reserved);
3781 		*reserved_ret = NULL;
3782 	}
3783 	return ret;
3784 }
3785 
3786 /*
3787  * Reserve qgroup space for range [start, start + len).
3788  *
3789  * This function will either reserve space from related qgroups or do nothing
3790  * if the range is already reserved.
3791  *
3792  * Return 0 for successful reservation
3793  * Return <0 for error (including -EQUOT)
3794  *
3795  * NOTE: This function may sleep for memory allocation, dirty page flushing and
3796  *	 commit transaction. So caller should not hold any dirty page locked.
3797  */
btrfs_qgroup_reserve_data(struct btrfs_inode * inode,struct extent_changeset ** reserved_ret,u64 start,u64 len)3798 int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
3799 			struct extent_changeset **reserved_ret, u64 start,
3800 			u64 len)
3801 {
3802 	int ret;
3803 
3804 	ret = qgroup_reserve_data(inode, reserved_ret, start, len);
3805 	if (ret <= 0 && ret != -EDQUOT)
3806 		return ret;
3807 
3808 	ret = try_flush_qgroup(inode->root);
3809 	if (ret < 0)
3810 		return ret;
3811 	return qgroup_reserve_data(inode, reserved_ret, start, len);
3812 }
3813 
3814 /* Free ranges specified by @reserved, normally in error path */
qgroup_free_reserved_data(struct btrfs_inode * inode,struct extent_changeset * reserved,u64 start,u64 len)3815 static int qgroup_free_reserved_data(struct btrfs_inode *inode,
3816 			struct extent_changeset *reserved, u64 start, u64 len)
3817 {
3818 	struct btrfs_root *root = inode->root;
3819 	struct ulist_node *unode;
3820 	struct ulist_iterator uiter;
3821 	struct extent_changeset changeset;
3822 	int freed = 0;
3823 	int ret;
3824 
3825 	extent_changeset_init(&changeset);
3826 	len = round_up(start + len, root->fs_info->sectorsize);
3827 	start = round_down(start, root->fs_info->sectorsize);
3828 
3829 	ULIST_ITER_INIT(&uiter);
3830 	while ((unode = ulist_next(&reserved->range_changed, &uiter))) {
3831 		u64 range_start = unode->val;
3832 		/* unode->aux is the inclusive end */
3833 		u64 range_len = unode->aux - range_start + 1;
3834 		u64 free_start;
3835 		u64 free_len;
3836 
3837 		extent_changeset_release(&changeset);
3838 
3839 		/* Only free range in range [start, start + len) */
3840 		if (range_start >= start + len ||
3841 		    range_start + range_len <= start)
3842 			continue;
3843 		free_start = max(range_start, start);
3844 		free_len = min(start + len, range_start + range_len) -
3845 			   free_start;
3846 		/*
3847 		 * TODO: To also modify reserved->ranges_reserved to reflect
3848 		 * the modification.
3849 		 *
3850 		 * However as long as we free qgroup reserved according to
3851 		 * EXTENT_QGROUP_RESERVED, we won't double free.
3852 		 * So not need to rush.
3853 		 */
3854 		ret = clear_record_extent_bits(&inode->io_tree, free_start,
3855 				free_start + free_len - 1,
3856 				EXTENT_QGROUP_RESERVED, &changeset);
3857 		if (ret < 0)
3858 			goto out;
3859 		freed += changeset.bytes_changed;
3860 	}
3861 	btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
3862 				  BTRFS_QGROUP_RSV_DATA);
3863 	ret = freed;
3864 out:
3865 	extent_changeset_release(&changeset);
3866 	return ret;
3867 }
3868 
__btrfs_qgroup_release_data(struct btrfs_inode * inode,struct extent_changeset * reserved,u64 start,u64 len,int free)3869 static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
3870 			struct extent_changeset *reserved, u64 start, u64 len,
3871 			int free)
3872 {
3873 	struct extent_changeset changeset;
3874 	int trace_op = QGROUP_RELEASE;
3875 	int ret;
3876 
3877 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &inode->root->fs_info->flags))
3878 		return 0;
3879 
3880 	/* In release case, we shouldn't have @reserved */
3881 	WARN_ON(!free && reserved);
3882 	if (free && reserved)
3883 		return qgroup_free_reserved_data(inode, reserved, start, len);
3884 	extent_changeset_init(&changeset);
3885 	ret = clear_record_extent_bits(&inode->io_tree, start, start + len -1,
3886 				       EXTENT_QGROUP_RESERVED, &changeset);
3887 	if (ret < 0)
3888 		goto out;
3889 
3890 	if (free)
3891 		trace_op = QGROUP_FREE;
3892 	trace_btrfs_qgroup_release_data(&inode->vfs_inode, start, len,
3893 					changeset.bytes_changed, trace_op);
3894 	if (free)
3895 		btrfs_qgroup_free_refroot(inode->root->fs_info,
3896 				inode->root->root_key.objectid,
3897 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
3898 	ret = changeset.bytes_changed;
3899 out:
3900 	extent_changeset_release(&changeset);
3901 	return ret;
3902 }
3903 
3904 /*
3905  * Free a reserved space range from io_tree and related qgroups
3906  *
3907  * Should be called when a range of pages get invalidated before reaching disk.
3908  * Or for error cleanup case.
3909  * if @reserved is given, only reserved range in [@start, @start + @len) will
3910  * be freed.
3911  *
3912  * For data written to disk, use btrfs_qgroup_release_data().
3913  *
3914  * NOTE: This function may sleep for memory allocation.
3915  */
btrfs_qgroup_free_data(struct btrfs_inode * inode,struct extent_changeset * reserved,u64 start,u64 len)3916 int btrfs_qgroup_free_data(struct btrfs_inode *inode,
3917 			struct extent_changeset *reserved, u64 start, u64 len)
3918 {
3919 	return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
3920 }
3921 
3922 /*
3923  * Release a reserved space range from io_tree only.
3924  *
3925  * Should be called when a range of pages get written to disk and corresponding
3926  * FILE_EXTENT is inserted into corresponding root.
3927  *
3928  * Since new qgroup accounting framework will only update qgroup numbers at
3929  * commit_transaction() time, its reserved space shouldn't be freed from
3930  * related qgroups.
3931  *
3932  * But we should release the range from io_tree, to allow further write to be
3933  * COWed.
3934  *
3935  * NOTE: This function may sleep for memory allocation.
3936  */
btrfs_qgroup_release_data(struct btrfs_inode * inode,u64 start,u64 len)3937 int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len)
3938 {
3939 	return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
3940 }
3941 
add_root_meta_rsv(struct btrfs_root * root,int num_bytes,enum btrfs_qgroup_rsv_type type)3942 static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3943 			      enum btrfs_qgroup_rsv_type type)
3944 {
3945 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3946 	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3947 		return;
3948 	if (num_bytes == 0)
3949 		return;
3950 
3951 	spin_lock(&root->qgroup_meta_rsv_lock);
3952 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC)
3953 		root->qgroup_meta_rsv_prealloc += num_bytes;
3954 	else
3955 		root->qgroup_meta_rsv_pertrans += num_bytes;
3956 	spin_unlock(&root->qgroup_meta_rsv_lock);
3957 }
3958 
sub_root_meta_rsv(struct btrfs_root * root,int num_bytes,enum btrfs_qgroup_rsv_type type)3959 static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes,
3960 			     enum btrfs_qgroup_rsv_type type)
3961 {
3962 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC &&
3963 	    type != BTRFS_QGROUP_RSV_META_PERTRANS)
3964 		return 0;
3965 	if (num_bytes == 0)
3966 		return 0;
3967 
3968 	spin_lock(&root->qgroup_meta_rsv_lock);
3969 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) {
3970 		num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc,
3971 				  num_bytes);
3972 		root->qgroup_meta_rsv_prealloc -= num_bytes;
3973 	} else {
3974 		num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans,
3975 				  num_bytes);
3976 		root->qgroup_meta_rsv_pertrans -= num_bytes;
3977 	}
3978 	spin_unlock(&root->qgroup_meta_rsv_lock);
3979 	return num_bytes;
3980 }
3981 
btrfs_qgroup_reserve_meta(struct btrfs_root * root,int num_bytes,enum btrfs_qgroup_rsv_type type,bool enforce)3982 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
3983 			      enum btrfs_qgroup_rsv_type type, bool enforce)
3984 {
3985 	struct btrfs_fs_info *fs_info = root->fs_info;
3986 	int ret;
3987 
3988 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
3989 	    !is_fstree(root->root_key.objectid) || num_bytes == 0)
3990 		return 0;
3991 
3992 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
3993 	trace_qgroup_meta_reserve(root, (s64)num_bytes, type);
3994 	ret = qgroup_reserve(root, num_bytes, enforce, type);
3995 	if (ret < 0)
3996 		return ret;
3997 	/*
3998 	 * Record what we have reserved into root.
3999 	 *
4000 	 * To avoid quota disabled->enabled underflow.
4001 	 * In that case, we may try to free space we haven't reserved
4002 	 * (since quota was disabled), so record what we reserved into root.
4003 	 * And ensure later release won't underflow this number.
4004 	 */
4005 	add_root_meta_rsv(root, num_bytes, type);
4006 	return ret;
4007 }
4008 
__btrfs_qgroup_reserve_meta(struct btrfs_root * root,int num_bytes,enum btrfs_qgroup_rsv_type type,bool enforce)4009 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
4010 				enum btrfs_qgroup_rsv_type type, bool enforce)
4011 {
4012 	int ret;
4013 
4014 	ret = btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4015 	if (ret <= 0 && ret != -EDQUOT)
4016 		return ret;
4017 
4018 	ret = try_flush_qgroup(root);
4019 	if (ret < 0)
4020 		return ret;
4021 	return btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce);
4022 }
4023 
btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root * root)4024 void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root)
4025 {
4026 	struct btrfs_fs_info *fs_info = root->fs_info;
4027 
4028 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4029 	    !is_fstree(root->root_key.objectid))
4030 		return;
4031 
4032 	/* TODO: Update trace point to handle such free */
4033 	trace_qgroup_meta_free_all_pertrans(root);
4034 	/* Special value -1 means to free all reserved space */
4035 	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid, (u64)-1,
4036 				  BTRFS_QGROUP_RSV_META_PERTRANS);
4037 }
4038 
__btrfs_qgroup_free_meta(struct btrfs_root * root,int num_bytes,enum btrfs_qgroup_rsv_type type)4039 void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes,
4040 			      enum btrfs_qgroup_rsv_type type)
4041 {
4042 	struct btrfs_fs_info *fs_info = root->fs_info;
4043 
4044 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4045 	    !is_fstree(root->root_key.objectid))
4046 		return;
4047 
4048 	/*
4049 	 * reservation for META_PREALLOC can happen before quota is enabled,
4050 	 * which can lead to underflow.
4051 	 * Here ensure we will only free what we really have reserved.
4052 	 */
4053 	num_bytes = sub_root_meta_rsv(root, num_bytes, type);
4054 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize));
4055 	trace_qgroup_meta_reserve(root, -(s64)num_bytes, type);
4056 	btrfs_qgroup_free_refroot(fs_info, root->root_key.objectid,
4057 				  num_bytes, type);
4058 }
4059 
qgroup_convert_meta(struct btrfs_fs_info * fs_info,u64 ref_root,int num_bytes)4060 static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root,
4061 				int num_bytes)
4062 {
4063 	struct btrfs_qgroup *qgroup;
4064 	struct ulist_node *unode;
4065 	struct ulist_iterator uiter;
4066 	int ret = 0;
4067 
4068 	if (num_bytes == 0)
4069 		return;
4070 	if (!fs_info->quota_root)
4071 		return;
4072 
4073 	spin_lock(&fs_info->qgroup_lock);
4074 	qgroup = find_qgroup_rb(fs_info, ref_root);
4075 	if (!qgroup)
4076 		goto out;
4077 	ulist_reinit(fs_info->qgroup_ulist);
4078 	ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid,
4079 		       qgroup_to_aux(qgroup), GFP_ATOMIC);
4080 	if (ret < 0)
4081 		goto out;
4082 	ULIST_ITER_INIT(&uiter);
4083 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
4084 		struct btrfs_qgroup *qg;
4085 		struct btrfs_qgroup_list *glist;
4086 
4087 		qg = unode_aux_to_qgroup(unode);
4088 
4089 		qgroup_rsv_release(fs_info, qg, num_bytes,
4090 				BTRFS_QGROUP_RSV_META_PREALLOC);
4091 		qgroup_rsv_add(fs_info, qg, num_bytes,
4092 				BTRFS_QGROUP_RSV_META_PERTRANS);
4093 		list_for_each_entry(glist, &qg->groups, next_group) {
4094 			ret = ulist_add(fs_info->qgroup_ulist,
4095 					glist->group->qgroupid,
4096 					qgroup_to_aux(glist->group), GFP_ATOMIC);
4097 			if (ret < 0)
4098 				goto out;
4099 		}
4100 	}
4101 out:
4102 	spin_unlock(&fs_info->qgroup_lock);
4103 }
4104 
btrfs_qgroup_convert_reserved_meta(struct btrfs_root * root,int num_bytes)4105 void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes)
4106 {
4107 	struct btrfs_fs_info *fs_info = root->fs_info;
4108 
4109 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) ||
4110 	    !is_fstree(root->root_key.objectid))
4111 		return;
4112 	/* Same as btrfs_qgroup_free_meta_prealloc() */
4113 	num_bytes = sub_root_meta_rsv(root, num_bytes,
4114 				      BTRFS_QGROUP_RSV_META_PREALLOC);
4115 	trace_qgroup_meta_convert(root, num_bytes);
4116 	qgroup_convert_meta(fs_info, root->root_key.objectid, num_bytes);
4117 }
4118 
4119 /*
4120  * Check qgroup reserved space leaking, normally at destroy inode
4121  * time
4122  */
btrfs_qgroup_check_reserved_leak(struct btrfs_inode * inode)4123 void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode)
4124 {
4125 	struct extent_changeset changeset;
4126 	struct ulist_node *unode;
4127 	struct ulist_iterator iter;
4128 	int ret;
4129 
4130 	extent_changeset_init(&changeset);
4131 	ret = clear_record_extent_bits(&inode->io_tree, 0, (u64)-1,
4132 			EXTENT_QGROUP_RESERVED, &changeset);
4133 
4134 	WARN_ON(ret < 0);
4135 	if (WARN_ON(changeset.bytes_changed)) {
4136 		ULIST_ITER_INIT(&iter);
4137 		while ((unode = ulist_next(&changeset.range_changed, &iter))) {
4138 			btrfs_warn(inode->root->fs_info,
4139 		"leaking qgroup reserved space, ino: %llu, start: %llu, end: %llu",
4140 				btrfs_ino(inode), unode->val, unode->aux);
4141 		}
4142 		btrfs_qgroup_free_refroot(inode->root->fs_info,
4143 				inode->root->root_key.objectid,
4144 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
4145 
4146 	}
4147 	extent_changeset_release(&changeset);
4148 }
4149 
btrfs_qgroup_init_swapped_blocks(struct btrfs_qgroup_swapped_blocks * swapped_blocks)4150 void btrfs_qgroup_init_swapped_blocks(
4151 	struct btrfs_qgroup_swapped_blocks *swapped_blocks)
4152 {
4153 	int i;
4154 
4155 	spin_lock_init(&swapped_blocks->lock);
4156 	for (i = 0; i < BTRFS_MAX_LEVEL; i++)
4157 		swapped_blocks->blocks[i] = RB_ROOT;
4158 	swapped_blocks->swapped = false;
4159 }
4160 
4161 /*
4162  * Delete all swapped blocks record of @root.
4163  * Every record here means we skipped a full subtree scan for qgroup.
4164  *
4165  * Gets called when committing one transaction.
4166  */
btrfs_qgroup_clean_swapped_blocks(struct btrfs_root * root)4167 void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root)
4168 {
4169 	struct btrfs_qgroup_swapped_blocks *swapped_blocks;
4170 	int i;
4171 
4172 	swapped_blocks = &root->swapped_blocks;
4173 
4174 	spin_lock(&swapped_blocks->lock);
4175 	if (!swapped_blocks->swapped)
4176 		goto out;
4177 	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4178 		struct rb_root *cur_root = &swapped_blocks->blocks[i];
4179 		struct btrfs_qgroup_swapped_block *entry;
4180 		struct btrfs_qgroup_swapped_block *next;
4181 
4182 		rbtree_postorder_for_each_entry_safe(entry, next, cur_root,
4183 						     node)
4184 			kfree(entry);
4185 		swapped_blocks->blocks[i] = RB_ROOT;
4186 	}
4187 	swapped_blocks->swapped = false;
4188 out:
4189 	spin_unlock(&swapped_blocks->lock);
4190 }
4191 
4192 /*
4193  * Add subtree roots record into @subvol_root.
4194  *
4195  * @subvol_root:	tree root of the subvolume tree get swapped
4196  * @bg:			block group under balance
4197  * @subvol_parent/slot:	pointer to the subtree root in subvolume tree
4198  * @reloc_parent/slot:	pointer to the subtree root in reloc tree
4199  *			BOTH POINTERS ARE BEFORE TREE SWAP
4200  * @last_snapshot:	last snapshot generation of the subvolume tree
4201  */
btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle * trans,struct btrfs_root * subvol_root,struct btrfs_block_group * bg,struct extent_buffer * subvol_parent,int subvol_slot,struct extent_buffer * reloc_parent,int reloc_slot,u64 last_snapshot)4202 int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
4203 		struct btrfs_root *subvol_root,
4204 		struct btrfs_block_group *bg,
4205 		struct extent_buffer *subvol_parent, int subvol_slot,
4206 		struct extent_buffer *reloc_parent, int reloc_slot,
4207 		u64 last_snapshot)
4208 {
4209 	struct btrfs_fs_info *fs_info = subvol_root->fs_info;
4210 	struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks;
4211 	struct btrfs_qgroup_swapped_block *block;
4212 	struct rb_node **cur;
4213 	struct rb_node *parent = NULL;
4214 	int level = btrfs_header_level(subvol_parent) - 1;
4215 	int ret = 0;
4216 
4217 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4218 		return 0;
4219 
4220 	if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) >
4221 	    btrfs_node_ptr_generation(reloc_parent, reloc_slot)) {
4222 		btrfs_err_rl(fs_info,
4223 		"%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu",
4224 			__func__,
4225 			btrfs_node_ptr_generation(subvol_parent, subvol_slot),
4226 			btrfs_node_ptr_generation(reloc_parent, reloc_slot));
4227 		return -EUCLEAN;
4228 	}
4229 
4230 	block = kmalloc(sizeof(*block), GFP_NOFS);
4231 	if (!block) {
4232 		ret = -ENOMEM;
4233 		goto out;
4234 	}
4235 
4236 	/*
4237 	 * @reloc_parent/slot is still before swap, while @block is going to
4238 	 * record the bytenr after swap, so we do the swap here.
4239 	 */
4240 	block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot);
4241 	block->subvol_generation = btrfs_node_ptr_generation(reloc_parent,
4242 							     reloc_slot);
4243 	block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot);
4244 	block->reloc_generation = btrfs_node_ptr_generation(subvol_parent,
4245 							    subvol_slot);
4246 	block->last_snapshot = last_snapshot;
4247 	block->level = level;
4248 
4249 	/*
4250 	 * If we have bg == NULL, we're called from btrfs_recover_relocation(),
4251 	 * no one else can modify tree blocks thus we qgroup will not change
4252 	 * no matter the value of trace_leaf.
4253 	 */
4254 	if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA)
4255 		block->trace_leaf = true;
4256 	else
4257 		block->trace_leaf = false;
4258 	btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot);
4259 
4260 	/* Insert @block into @blocks */
4261 	spin_lock(&blocks->lock);
4262 	cur = &blocks->blocks[level].rb_node;
4263 	while (*cur) {
4264 		struct btrfs_qgroup_swapped_block *entry;
4265 
4266 		parent = *cur;
4267 		entry = rb_entry(parent, struct btrfs_qgroup_swapped_block,
4268 				 node);
4269 
4270 		if (entry->subvol_bytenr < block->subvol_bytenr) {
4271 			cur = &(*cur)->rb_left;
4272 		} else if (entry->subvol_bytenr > block->subvol_bytenr) {
4273 			cur = &(*cur)->rb_right;
4274 		} else {
4275 			if (entry->subvol_generation !=
4276 					block->subvol_generation ||
4277 			    entry->reloc_bytenr != block->reloc_bytenr ||
4278 			    entry->reloc_generation !=
4279 					block->reloc_generation) {
4280 				/*
4281 				 * Duplicated but mismatch entry found.
4282 				 * Shouldn't happen.
4283 				 *
4284 				 * Marking qgroup inconsistent should be enough
4285 				 * for end users.
4286 				 */
4287 				WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
4288 				ret = -EEXIST;
4289 			}
4290 			kfree(block);
4291 			goto out_unlock;
4292 		}
4293 	}
4294 	rb_link_node(&block->node, parent, cur);
4295 	rb_insert_color(&block->node, &blocks->blocks[level]);
4296 	blocks->swapped = true;
4297 out_unlock:
4298 	spin_unlock(&blocks->lock);
4299 out:
4300 	if (ret < 0)
4301 		fs_info->qgroup_flags |=
4302 			BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
4303 	return ret;
4304 }
4305 
4306 /*
4307  * Check if the tree block is a subtree root, and if so do the needed
4308  * delayed subtree trace for qgroup.
4309  *
4310  * This is called during btrfs_cow_block().
4311  */
btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct extent_buffer * subvol_eb)4312 int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
4313 					 struct btrfs_root *root,
4314 					 struct extent_buffer *subvol_eb)
4315 {
4316 	struct btrfs_fs_info *fs_info = root->fs_info;
4317 	struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
4318 	struct btrfs_qgroup_swapped_block *block;
4319 	struct extent_buffer *reloc_eb = NULL;
4320 	struct rb_node *node;
4321 	bool found = false;
4322 	bool swapped = false;
4323 	int level = btrfs_header_level(subvol_eb);
4324 	int ret = 0;
4325 	int i;
4326 
4327 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
4328 		return 0;
4329 	if (!is_fstree(root->root_key.objectid) || !root->reloc_root)
4330 		return 0;
4331 
4332 	spin_lock(&blocks->lock);
4333 	if (!blocks->swapped) {
4334 		spin_unlock(&blocks->lock);
4335 		return 0;
4336 	}
4337 	node = blocks->blocks[level].rb_node;
4338 
4339 	while (node) {
4340 		block = rb_entry(node, struct btrfs_qgroup_swapped_block, node);
4341 		if (block->subvol_bytenr < subvol_eb->start) {
4342 			node = node->rb_left;
4343 		} else if (block->subvol_bytenr > subvol_eb->start) {
4344 			node = node->rb_right;
4345 		} else {
4346 			found = true;
4347 			break;
4348 		}
4349 	}
4350 	if (!found) {
4351 		spin_unlock(&blocks->lock);
4352 		goto out;
4353 	}
4354 	/* Found one, remove it from @blocks first and update blocks->swapped */
4355 	rb_erase(&block->node, &blocks->blocks[level]);
4356 	for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
4357 		if (RB_EMPTY_ROOT(&blocks->blocks[i])) {
4358 			swapped = true;
4359 			break;
4360 		}
4361 	}
4362 	blocks->swapped = swapped;
4363 	spin_unlock(&blocks->lock);
4364 
4365 	/* Read out reloc subtree root */
4366 	reloc_eb = read_tree_block(fs_info, block->reloc_bytenr,
4367 				   block->reloc_generation, block->level,
4368 				   &block->first_key);
4369 	if (IS_ERR(reloc_eb)) {
4370 		ret = PTR_ERR(reloc_eb);
4371 		reloc_eb = NULL;
4372 		goto free_out;
4373 	}
4374 	if (!extent_buffer_uptodate(reloc_eb)) {
4375 		ret = -EIO;
4376 		goto free_out;
4377 	}
4378 
4379 	ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
4380 			block->last_snapshot, block->trace_leaf);
4381 free_out:
4382 	kfree(block);
4383 	free_extent_buffer(reloc_eb);
4384 out:
4385 	if (ret < 0) {
4386 		btrfs_err_rl(fs_info,
4387 			     "failed to account subtree at bytenr %llu: %d",
4388 			     subvol_eb->start, ret);
4389 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
4390 	}
4391 	return ret;
4392 }
4393 
btrfs_qgroup_destroy_extent_records(struct btrfs_transaction * trans)4394 void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans)
4395 {
4396 	struct btrfs_qgroup_extent_record *entry;
4397 	struct btrfs_qgroup_extent_record *next;
4398 	struct rb_root *root;
4399 
4400 	root = &trans->delayed_refs.dirty_extent_root;
4401 	rbtree_postorder_for_each_entry_safe(entry, next, root, node) {
4402 		ulist_free(entry->old_roots);
4403 		kfree(entry);
4404 	}
4405 	*root = RB_ROOT;
4406 }
4407