1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* fs/f2fs/gc.c
4	*
5	* Copyright (c) 2012 Samsung Electronics Co., Ltd.
6	* http://www.samsung.com/
7	*/
8	#include <linux/fs.h>
9	#include <linux/module.h>
10	#include <linux/init.h>
11	#include <linux/f2fs_fs.h>
12	#include <linux/kthread.h>
13	#include <linux/delay.h>
14	#include <linux/freezer.h>
15	#include <linux/sched/signal.h>
16	#include <linux/random.h>
17	#include <linux/sched/mm.h>
18
19	#include "f2fs.h"
20	#include "node.h"
21	#include "segment.h"
22	#include "gc.h"
23	#include "iostat.h"
24	#include <trace/events/f2fs.h>
25
26	static struct kmem_cache *victim_entry_slab;
27
28	static unsigned int count_bits(const unsigned long *addr,
29	unsigned int offset, unsigned int len);
30
31	static int gc_thread_func(void *data)
32	{
33	struct f2fs_sb_info *sbi = data;
34	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
35	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
36	wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
37	unsigned int wait_ms;
38	struct f2fs_gc_control gc_control = {
39	.victim_segno = NULL_SEGNO,
40	.should_migrate_blocks = false,
41	.err_gc_skipped = false };
42
43	wait_ms = gc_th->min_sleep_time;
44
45	set_freezable();
46	do {
47	bool sync_mode, foreground = false;
48
49	wait_event_interruptible_timeout(*wq,
50	kthread_should_stop() || freezing(current) ||
51	waitqueue_active(fggc_wq) ||
52	gc_th->gc_wake,
53	msecs_to_jiffies(wait_ms));
54
55	if (test_opt(sbi, GC_MERGE) && waitqueue_active(wq_head: fggc_wq))
56	foreground = true;
57
58	/* give it a try one time */
59	if (gc_th->gc_wake)
60	gc_th->gc_wake = false;
61
62	if (try_to_freeze() || f2fs_readonly(sb: sbi->sb)) {
63	stat_other_skip_bggc_count(sbi);
64	continue;
65	}
66	if (kthread_should_stop())
67	break;
68
69	if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
70	increase_sleep_time(gc_th, wait: &wait_ms);
71	stat_other_skip_bggc_count(sbi);
72	continue;
73	}
74
75	if (time_to_inject(sbi, FAULT_CHECKPOINT))
76	f2fs_stop_checkpoint(sbi, end_io: false,
77	reason: STOP_CP_REASON_FAULT_INJECT);
78
79	if (!sb_start_write_trylock(sb: sbi->sb)) {
80	stat_other_skip_bggc_count(sbi);
81	continue;
82	}
83
84	/*
85	* [GC triggering condition]
86	* 0. GC is not conducted currently.
87	* 1. There are enough dirty segments.
88	* 2. IO subsystem is idle by checking the # of writeback pages.
89	* 3. IO subsystem is idle by checking the # of requests in
90	* bdev's request list.
91	*
92	* Note) We have to avoid triggering GCs frequently.
93	* Because it is possible that some segments can be
94	* invalidated soon after by user update or deletion.
95	* So, I'd like to wait some time to collect dirty segments.
96	*/
97	if (sbi->gc_mode == GC_URGENT_HIGH ||
98	sbi->gc_mode == GC_URGENT_MID) {
99	wait_ms = gc_th->urgent_sleep_time;
100	f2fs_down_write(sem: &sbi->gc_lock);
101	goto do_gc;
102	}
103
104	if (foreground) {
105	f2fs_down_write(sem: &sbi->gc_lock);
106	goto do_gc;
107	} else if (!f2fs_down_write_trylock(sem: &sbi->gc_lock)) {
108	stat_other_skip_bggc_count(sbi);
109	goto next;
110	}
111
112	if (!is_idle(sbi, type: GC_TIME)) {
113	increase_sleep_time(gc_th, wait: &wait_ms);
114	f2fs_up_write(sem: &sbi->gc_lock);
115	stat_io_skip_bggc_count(sbi);
116	goto next;
117	}
118
119	if (has_enough_invalid_blocks(sbi))
120	decrease_sleep_time(gc_th, wait: &wait_ms);
121	else
122	increase_sleep_time(gc_th, wait: &wait_ms);
123	do_gc:
124	stat_inc_gc_call_count(sbi, foreground ?
125	FOREGROUND : BACKGROUND);
126
127	sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
128
129	/* foreground GC was been triggered via f2fs_balance_fs() */
130	if (foreground)
131	sync_mode = false;
132
133	gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
134	gc_control.no_bg_gc = foreground;
135	gc_control.nr_free_secs = foreground ? 1 : 0;
136
137	/* if return value is not zero, no victim was selected */
138	if (f2fs_gc(sbi, gc_control: &gc_control)) {
139	/* don't bother wait_ms by foreground gc */
140	if (!foreground)
141	wait_ms = gc_th->no_gc_sleep_time;
142	} else {
143	/* reset wait_ms to default sleep time */
144	if (wait_ms == gc_th->no_gc_sleep_time)
145	wait_ms = gc_th->min_sleep_time;
146	}
147
148	if (foreground)
149	wake_up_all(&gc_th->fggc_wq);
150
151	trace_f2fs_background_gc(sb: sbi->sb, wait_ms,
152	prefree: prefree_segments(sbi), free: free_segments(sbi));
153
154	/* balancing f2fs's metadata periodically */
155	f2fs_balance_fs_bg(sbi, from_bg: true);
156	next:
157	if (sbi->gc_mode != GC_NORMAL) {
158	spin_lock(lock: &sbi->gc_remaining_trials_lock);
159	if (sbi->gc_remaining_trials) {
160	sbi->gc_remaining_trials--;
161	if (!sbi->gc_remaining_trials)
162	sbi->gc_mode = GC_NORMAL;
163	}
164	spin_unlock(lock: &sbi->gc_remaining_trials_lock);
165	}
166	sb_end_write(sb: sbi->sb);
167
168	} while (!kthread_should_stop());
169	return 0;
170	}
171
172	int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
173	{
174	struct f2fs_gc_kthread *gc_th;
175	dev_t dev = sbi->sb->s_bdev->bd_dev;
176
177	gc_th = f2fs_kmalloc(sbi, size: sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
178	if (!gc_th)
179	return -ENOMEM;
180
181	gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
182	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
183	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
184	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
185
186	gc_th->gc_wake = false;
187
188	sbi->gc_thread = gc_th;
189	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
190	init_waitqueue_head(&sbi->gc_thread->fggc_wq);
191	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
192	"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
193	if (IS_ERR(ptr: gc_th->f2fs_gc_task)) {
194	int err = PTR_ERR(ptr: gc_th->f2fs_gc_task);
195
196	kfree(objp: gc_th);
197	sbi->gc_thread = NULL;
198	return err;
199	}
200
201	return 0;
202	}
203
204	void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
205	{
206	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
207
208	if (!gc_th)
209	return;
210	kthread_stop(k: gc_th->f2fs_gc_task);
211	wake_up_all(&gc_th->fggc_wq);
212	kfree(objp: gc_th);
213	sbi->gc_thread = NULL;
214	}
215
216	static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
217	{
218	int gc_mode;
219
220	if (gc_type == BG_GC) {
221	if (sbi->am.atgc_enabled)
222	gc_mode = GC_AT;
223	else
224	gc_mode = GC_CB;
225	} else {
226	gc_mode = GC_GREEDY;
227	}
228
229	switch (sbi->gc_mode) {
230	case GC_IDLE_CB:
231	gc_mode = GC_CB;
232	break;
233	case GC_IDLE_GREEDY:
234	case GC_URGENT_HIGH:
235	gc_mode = GC_GREEDY;
236	break;
237	case GC_IDLE_AT:
238	gc_mode = GC_AT;
239	break;
240	}
241
242	return gc_mode;
243	}
244
245	static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
246	int type, struct victim_sel_policy *p)
247	{
248	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
249
250	if (p->alloc_mode == SSR) {
251	p->gc_mode = GC_GREEDY;
252	p->dirty_bitmap = dirty_i->dirty_segmap[type];
253	p->max_search = dirty_i->nr_dirty[type];
254	p->ofs_unit = 1;
255	} else if (p->alloc_mode == AT_SSR) {
256	p->gc_mode = GC_GREEDY;
257	p->dirty_bitmap = dirty_i->dirty_segmap[type];
258	p->max_search = dirty_i->nr_dirty[type];
259	p->ofs_unit = 1;
260	} else {
261	p->gc_mode = select_gc_type(sbi, gc_type);
262	p->ofs_unit = sbi->segs_per_sec;
263	if (__is_large_section(sbi)) {
264	p->dirty_bitmap = dirty_i->dirty_secmap;
265	p->max_search = count_bits(addr: p->dirty_bitmap,
266	offset: 0, MAIN_SECS(sbi));
267	} else {
268	p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
269	p->max_search = dirty_i->nr_dirty[DIRTY];
270	}
271	}
272
273	/*
274	* adjust candidates range, should select all dirty segments for
275	* foreground GC and urgent GC cases.
276	*/
277	if (gc_type != FG_GC &&
278	(sbi->gc_mode != GC_URGENT_HIGH) &&
279	(p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
280	p->max_search > sbi->max_victim_search)
281	p->max_search = sbi->max_victim_search;
282
283	/* let's select beginning hot/small space first in no_heap mode*/
284	if (f2fs_need_rand_seg(sbi))
285	p->offset = get_random_u32_below(MAIN_SECS(sbi) * sbi->segs_per_sec);
286	else if (test_opt(sbi, NOHEAP) &&
287	(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
288	p->offset = 0;
289	else
290	p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
291	}
292
293	static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
294	struct victim_sel_policy *p)
295	{
296	/* SSR allocates in a segment unit */
297	if (p->alloc_mode == SSR)
298	return sbi->blocks_per_seg;
299	else if (p->alloc_mode == AT_SSR)
300	return UINT_MAX;
301
302	/* LFS */
303	if (p->gc_mode == GC_GREEDY)
304	return 2 * sbi->blocks_per_seg * p->ofs_unit;
305	else if (p->gc_mode == GC_CB)
306	return UINT_MAX;
307	else if (p->gc_mode == GC_AT)
308	return UINT_MAX;
309	else /* No other gc_mode */
310	return 0;
311	}
312
313	static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
314	{
315	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
316	unsigned int secno;
317
318	/*
319	* If the gc_type is FG_GC, we can select victim segments
320	* selected by background GC before.
321	* Those segments guarantee they have small valid blocks.
322	*/
323	for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
324	if (sec_usage_check(sbi, secno))
325	continue;
326	clear_bit(nr: secno, addr: dirty_i->victim_secmap);
327	return GET_SEG_FROM_SEC(sbi, secno);
328	}
329	return NULL_SEGNO;
330	}
331
332	static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
333	{
334	struct sit_info *sit_i = SIT_I(sbi);
335	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
336	unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
337	unsigned long long mtime = 0;
338	unsigned int vblocks;
339	unsigned char age = 0;
340	unsigned char u;
341	unsigned int i;
342	unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
343
344	for (i = 0; i < usable_segs_per_sec; i++)
345	mtime += get_seg_entry(sbi, segno: start + i)->mtime;
346	vblocks = get_valid_blocks(sbi, segno, use_section: true);
347
348	mtime = div_u64(dividend: mtime, divisor: usable_segs_per_sec);
349	vblocks = div_u64(dividend: vblocks, divisor: usable_segs_per_sec);
350
351	u = (vblocks * 100) >> sbi->log_blocks_per_seg;
352
353	/* Handle if the system time has changed by the user */
354	if (mtime < sit_i->min_mtime)
355	sit_i->min_mtime = mtime;
356	if (mtime > sit_i->max_mtime)
357	sit_i->max_mtime = mtime;
358	if (sit_i->max_mtime != sit_i->min_mtime)
359	age = 100 - div64_u64(dividend: 100 * (mtime - sit_i->min_mtime),
360	divisor: sit_i->max_mtime - sit_i->min_mtime);
361
362	return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
363	}
364
365	static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
366	unsigned int segno, struct victim_sel_policy *p)
367	{
368	if (p->alloc_mode == SSR)
369	return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
370
371	/* alloc_mode == LFS */
372	if (p->gc_mode == GC_GREEDY)
373	return get_valid_blocks(sbi, segno, use_section: true);
374	else if (p->gc_mode == GC_CB)
375	return get_cb_cost(sbi, segno);
376
377	f2fs_bug_on(sbi, 1);
378	return 0;
379	}
380
381	static unsigned int count_bits(const unsigned long *addr,
382	unsigned int offset, unsigned int len)
383	{
384	unsigned int end = offset + len, sum = 0;
385
386	while (offset < end) {
387	if (test_bit(offset++, addr))
388	++sum;
389	}
390	return sum;
391	}
392
393	static bool f2fs_check_victim_tree(struct f2fs_sb_info *sbi,
394	struct rb_root_cached *root)
395	{
396	#ifdef CONFIG_F2FS_CHECK_FS
397	struct rb_node *cur = rb_first_cached(root), *next;
398	struct victim_entry *cur_ve, *next_ve;
399
400	while (cur) {
401	next = rb_next(cur);
402	if (!next)
403	return true;
404
405	cur_ve = rb_entry(cur, struct victim_entry, rb_node);
406	next_ve = rb_entry(next, struct victim_entry, rb_node);
407
408	if (cur_ve->mtime > next_ve->mtime) {
409	f2fs_info(sbi, "broken victim_rbtree, "
410	"cur_mtime(%llu) next_mtime(%llu)",
411	cur_ve->mtime, next_ve->mtime);
412	return false;
413	}
414	cur = next;
415	}
416	#endif
417	return true;
418	}
419
420	static struct victim_entry *__lookup_victim_entry(struct f2fs_sb_info *sbi,
421	unsigned long long mtime)
422	{
423	struct atgc_management *am = &sbi->am;
424	struct rb_node *node = am->root.rb_root.rb_node;
425	struct victim_entry *ve = NULL;
426
427	while (node) {
428	ve = rb_entry(node, struct victim_entry, rb_node);
429
430	if (mtime < ve->mtime)
431	node = node->rb_left;
432	else
433	node = node->rb_right;
434	}
435	return ve;
436	}
437
438	static struct victim_entry *__create_victim_entry(struct f2fs_sb_info *sbi,
439	unsigned long long mtime, unsigned int segno)
440	{
441	struct atgc_management *am = &sbi->am;
442	struct victim_entry *ve;
443
444	ve = f2fs_kmem_cache_alloc(cachep: victim_entry_slab, GFP_NOFS, nofail: true, NULL);
445
446	ve->mtime = mtime;
447	ve->segno = segno;
448
449	list_add_tail(new: &ve->list, head: &am->victim_list);
450	am->victim_count++;
451
452	return ve;
453	}
454
455	static void __insert_victim_entry(struct f2fs_sb_info *sbi,
456	unsigned long long mtime, unsigned int segno)
457	{
458	struct atgc_management *am = &sbi->am;
459	struct rb_root_cached *root = &am->root;
460	struct rb_node **p = &root->rb_root.rb_node;
461	struct rb_node *parent = NULL;
462	struct victim_entry *ve;
463	bool left_most = true;
464
465	/* look up rb tree to find parent node */
466	while (*p) {
467	parent = *p;
468	ve = rb_entry(parent, struct victim_entry, rb_node);
469
470	if (mtime < ve->mtime) {
471	p = &(*p)->rb_left;
472	} else {
473	p = &(*p)->rb_right;
474	left_most = false;
475	}
476	}
477
478	ve = __create_victim_entry(sbi, mtime, segno);
479
480	rb_link_node(node: &ve->rb_node, parent, rb_link: p);
481	rb_insert_color_cached(node: &ve->rb_node, root, leftmost: left_most);
482	}
483
484	static void add_victim_entry(struct f2fs_sb_info *sbi,
485	struct victim_sel_policy *p, unsigned int segno)
486	{
487	struct sit_info *sit_i = SIT_I(sbi);
488	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
489	unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
490	unsigned long long mtime = 0;
491	unsigned int i;
492
493	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
494	if (p->gc_mode == GC_AT &&
495	get_valid_blocks(sbi, segno, use_section: true) == 0)
496	return;
497	}
498
499	for (i = 0; i < sbi->segs_per_sec; i++)
500	mtime += get_seg_entry(sbi, segno: start + i)->mtime;
501	mtime = div_u64(dividend: mtime, divisor: sbi->segs_per_sec);
502
503	/* Handle if the system time has changed by the user */
504	if (mtime < sit_i->min_mtime)
505	sit_i->min_mtime = mtime;
506	if (mtime > sit_i->max_mtime)
507	sit_i->max_mtime = mtime;
508	if (mtime < sit_i->dirty_min_mtime)
509	sit_i->dirty_min_mtime = mtime;
510	if (mtime > sit_i->dirty_max_mtime)
511	sit_i->dirty_max_mtime = mtime;
512
513	/* don't choose young section as candidate */
514	if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
515	return;
516
517	__insert_victim_entry(sbi, mtime, segno);
518	}
519
520	static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
521	struct victim_sel_policy *p)
522	{
523	struct sit_info *sit_i = SIT_I(sbi);
524	struct atgc_management *am = &sbi->am;
525	struct rb_root_cached *root = &am->root;
526	struct rb_node *node;
527	struct victim_entry *ve;
528	unsigned long long total_time;
529	unsigned long long age, u, accu;
530	unsigned long long max_mtime = sit_i->dirty_max_mtime;
531	unsigned long long min_mtime = sit_i->dirty_min_mtime;
532	unsigned int sec_blocks = CAP_BLKS_PER_SEC(sbi);
533	unsigned int vblocks;
534	unsigned int dirty_threshold = max(am->max_candidate_count,
535	am->candidate_ratio *
536	am->victim_count / 100);
537	unsigned int age_weight = am->age_weight;
538	unsigned int cost;
539	unsigned int iter = 0;
540
541	if (max_mtime < min_mtime)
542	return;
543
544	max_mtime += 1;
545	total_time = max_mtime - min_mtime;
546
547	accu = div64_u64(ULLONG_MAX, divisor: total_time);
548	accu = min_t(unsigned long long, div_u64(accu, 100),
549	DEFAULT_ACCURACY_CLASS);
550
551	node = rb_first_cached(root);
552	next:
553	ve = rb_entry_safe(node, struct victim_entry, rb_node);
554	if (!ve)
555	return;
556
557	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
558	goto skip;
559
560	/* age = 10000 * x% * 60 */
561	age = div64_u64(dividend: accu * (max_mtime - ve->mtime), divisor: total_time) *
562	age_weight;
563
564	vblocks = get_valid_blocks(sbi, segno: ve->segno, use_section: true);
565	f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
566
567	/* u = 10000 * x% * 40 */
568	u = div64_u64(dividend: accu * (sec_blocks - vblocks), divisor: sec_blocks) *
569	(100 - age_weight);
570
571	f2fs_bug_on(sbi, age + u >= UINT_MAX);
572
573	cost = UINT_MAX - (age + u);
574	iter++;
575
576	if (cost < p->min_cost ||
577	(cost == p->min_cost && age > p->oldest_age)) {
578	p->min_cost = cost;
579	p->oldest_age = age;
580	p->min_segno = ve->segno;
581	}
582	skip:
583	if (iter < dirty_threshold) {
584	node = rb_next(node);
585	goto next;
586	}
587	}
588
589	/*
590	* select candidates around source section in range of
591	* [target - dirty_threshold, target + dirty_threshold]
592	*/
593	static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
594	struct victim_sel_policy *p)
595	{
596	struct sit_info *sit_i = SIT_I(sbi);
597	struct atgc_management *am = &sbi->am;
598	struct victim_entry *ve;
599	unsigned long long age;
600	unsigned long long max_mtime = sit_i->dirty_max_mtime;
601	unsigned long long min_mtime = sit_i->dirty_min_mtime;
602	unsigned int seg_blocks = sbi->blocks_per_seg;
603	unsigned int vblocks;
604	unsigned int dirty_threshold = max(am->max_candidate_count,
605	am->candidate_ratio *
606	am->victim_count / 100);
607	unsigned int cost, iter;
608	int stage = 0;
609
610	if (max_mtime < min_mtime)
611	return;
612	max_mtime += 1;
613	next_stage:
614	iter = 0;
615	ve = __lookup_victim_entry(sbi, mtime: p->age);
616	next_node:
617	if (!ve) {
618	if (stage++ == 0)
619	goto next_stage;
620	return;
621	}
622
623	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
624	goto skip_node;
625
626	age = max_mtime - ve->mtime;
627
628	vblocks = get_seg_entry(sbi, segno: ve->segno)->ckpt_valid_blocks;
629	f2fs_bug_on(sbi, !vblocks);
630
631	/* rare case */
632	if (vblocks == seg_blocks)
633	goto skip_node;
634
635	iter++;
636
637	age = max_mtime - abs(p->age - age);
638	cost = UINT_MAX - vblocks;
639
640	if (cost < p->min_cost ||
641	(cost == p->min_cost && age > p->oldest_age)) {
642	p->min_cost = cost;
643	p->oldest_age = age;
644	p->min_segno = ve->segno;
645	}
646	skip_node:
647	if (iter < dirty_threshold) {
648	ve = rb_entry(stage == 0 ? rb_prev(&ve->rb_node) :
649	rb_next(&ve->rb_node),
650	struct victim_entry, rb_node);
651	goto next_node;
652	}
653
654	if (stage++ == 0)
655	goto next_stage;
656	}
657
658	static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
659	struct victim_sel_policy *p)
660	{
661	f2fs_bug_on(sbi, !f2fs_check_victim_tree(sbi, &sbi->am.root));
662
663	if (p->gc_mode == GC_AT)
664	atgc_lookup_victim(sbi, p);
665	else if (p->alloc_mode == AT_SSR)
666	atssr_lookup_victim(sbi, p);
667	else
668	f2fs_bug_on(sbi, 1);
669	}
670
671	static void release_victim_entry(struct f2fs_sb_info *sbi)
672	{
673	struct atgc_management *am = &sbi->am;
674	struct victim_entry *ve, *tmp;
675
676	list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
677	list_del(entry: &ve->list);
678	kmem_cache_free(s: victim_entry_slab, objp: ve);
679	am->victim_count--;
680	}
681
682	am->root = RB_ROOT_CACHED;
683
684	f2fs_bug_on(sbi, am->victim_count);
685	f2fs_bug_on(sbi, !list_empty(&am->victim_list));
686	}
687
688	static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
689	{
690	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
691	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
692
693	if (!dirty_i->enable_pin_section)
694	return false;
695	if (!test_and_set_bit(nr: secno, addr: dirty_i->pinned_secmap))
696	dirty_i->pinned_secmap_cnt++;
697	return true;
698	}
699
700	static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
701	{
702	return dirty_i->pinned_secmap_cnt;
703	}
704
705	static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
706	unsigned int secno)
707	{
708	return dirty_i->enable_pin_section &&
709	f2fs_pinned_section_exists(dirty_i) &&
710	test_bit(secno, dirty_i->pinned_secmap);
711	}
712
713	static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
714	{
715	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
716
717	if (f2fs_pinned_section_exists(dirty_i: DIRTY_I(sbi))) {
718	memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
719	DIRTY_I(sbi)->pinned_secmap_cnt = 0;
720	}
721	DIRTY_I(sbi)->enable_pin_section = enable;
722	}
723
724	static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
725	unsigned int segno)
726	{
727	if (!f2fs_is_pinned_file(inode))
728	return 0;
729	if (gc_type != FG_GC)
730	return -EBUSY;
731	if (!f2fs_pin_section(sbi: F2FS_I_SB(inode), segno))
732	f2fs_pin_file_control(inode, inc: true);
733	return -EAGAIN;
734	}
735
736	/*
737	* This function is called from two paths.
738	* One is garbage collection and the other is SSR segment selection.
739	* When it is called during GC, it just gets a victim segment
740	* and it does not remove it from dirty seglist.
741	* When it is called from SSR segment selection, it finds a segment
742	* which has minimum valid blocks and removes it from dirty seglist.
743	*/
744	int f2fs_get_victim(struct f2fs_sb_info *sbi, unsigned int *result,
745	int gc_type, int type, char alloc_mode,
746	unsigned long long age)
747	{
748	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
749	struct sit_info *sm = SIT_I(sbi);
750	struct victim_sel_policy p;
751	unsigned int secno, last_victim;
752	unsigned int last_segment;
753	unsigned int nsearched;
754	bool is_atgc;
755	int ret = 0;
756
757	mutex_lock(&dirty_i->seglist_lock);
758	last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
759
760	p.alloc_mode = alloc_mode;
761	p.age = age;
762	p.age_threshold = sbi->am.age_threshold;
763
764	retry:
765	select_policy(sbi, gc_type, type, p: &p);
766	p.min_segno = NULL_SEGNO;
767	p.oldest_age = 0;
768	p.min_cost = get_max_cost(sbi, p: &p);
769
770	is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
771	nsearched = 0;
772
773	if (is_atgc)
774	SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
775
776	if (*result != NULL_SEGNO) {
777	if (!get_valid_blocks(sbi, segno: *result, use_section: false)) {
778	ret = -ENODATA;
779	goto out;
780	}
781
782	if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
783	ret = -EBUSY;
784	else
785	p.min_segno = *result;
786	goto out;
787	}
788
789	ret = -ENODATA;
790	if (p.max_search == 0)
791	goto out;
792
793	if (__is_large_section(sbi) && p.alloc_mode == LFS) {
794	if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
795	p.min_segno = sbi->next_victim_seg[BG_GC];
796	*result = p.min_segno;
797	sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
798	goto got_result;
799	}
800	if (gc_type == FG_GC &&
801	sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
802	p.min_segno = sbi->next_victim_seg[FG_GC];
803	*result = p.min_segno;
804	sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
805	goto got_result;
806	}
807	}
808
809	last_victim = sm->last_victim[p.gc_mode];
810	if (p.alloc_mode == LFS && gc_type == FG_GC) {
811	p.min_segno = check_bg_victims(sbi);
812	if (p.min_segno != NULL_SEGNO)
813	goto got_it;
814	}
815
816	while (1) {
817	unsigned long cost, *dirty_bitmap;
818	unsigned int unit_no, segno;
819
820	dirty_bitmap = p.dirty_bitmap;
821	unit_no = find_next_bit(addr: dirty_bitmap,
822	size: last_segment / p.ofs_unit,
823	offset: p.offset / p.ofs_unit);
824	segno = unit_no * p.ofs_unit;
825	if (segno >= last_segment) {
826	if (sm->last_victim[p.gc_mode]) {
827	last_segment =
828	sm->last_victim[p.gc_mode];
829	sm->last_victim[p.gc_mode] = 0;
830	p.offset = 0;
831	continue;
832	}
833	break;
834	}
835
836	p.offset = segno + p.ofs_unit;
837	nsearched++;
838
839	#ifdef CONFIG_F2FS_CHECK_FS
840	/*
841	* skip selecting the invalid segno (that is failed due to block
842	* validity check failure during GC) to avoid endless GC loop in
843	* such cases.
844	*/
845	if (test_bit(segno, sm->invalid_segmap))
846	goto next;
847	#endif
848
849	secno = GET_SEC_FROM_SEG(sbi, segno);
850
851	if (sec_usage_check(sbi, secno))
852	goto next;
853
854	/* Don't touch checkpointed data */
855	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
856	if (p.alloc_mode == LFS) {
857	/*
858	* LFS is set to find source section during GC.
859	* The victim should have no checkpointed data.
860	*/
861	if (get_ckpt_valid_blocks(sbi, segno, use_section: true))
862	goto next;
863	} else {
864	/*
865	* SSR | AT_SSR are set to find target segment
866	* for writes which can be full by checkpointed
867	* and newly written blocks.
868	*/
869	if (!f2fs_segment_has_free_slot(sbi, segno))
870	goto next;
871	}
872	}
873
874	if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
875	goto next;
876
877	if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
878	goto next;
879
880	if (is_atgc) {
881	add_victim_entry(sbi, p: &p, segno);
882	goto next;
883	}
884
885	cost = get_gc_cost(sbi, segno, p: &p);
886
887	if (p.min_cost > cost) {
888	p.min_segno = segno;
889	p.min_cost = cost;
890	}
891	next:
892	if (nsearched >= p.max_search) {
893	if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
894	sm->last_victim[p.gc_mode] =
895	last_victim + p.ofs_unit;
896	else
897	sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
898	sm->last_victim[p.gc_mode] %=
899	(MAIN_SECS(sbi) * sbi->segs_per_sec);
900	break;
901	}
902	}
903
904	/* get victim for GC_AT/AT_SSR */
905	if (is_atgc) {
906	lookup_victim_by_age(sbi, p: &p);
907	release_victim_entry(sbi);
908	}
909
910	if (is_atgc && p.min_segno == NULL_SEGNO &&
911	sm->elapsed_time < p.age_threshold) {
912	p.age_threshold = 0;
913	goto retry;
914	}
915
916	if (p.min_segno != NULL_SEGNO) {
917	got_it:
918	*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
919	got_result:
920	if (p.alloc_mode == LFS) {
921	secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
922	if (gc_type == FG_GC)
923	sbi->cur_victim_sec = secno;
924	else
925	set_bit(nr: secno, addr: dirty_i->victim_secmap);
926	}
927	ret = 0;
928
929	}
930	out:
931	if (p.min_segno != NULL_SEGNO)
932	trace_f2fs_get_victim(sb: sbi->sb, type, gc_type, p: &p,
933	pre_victim: sbi->cur_victim_sec,
934	prefree: prefree_segments(sbi), free: free_segments(sbi));
935	mutex_unlock(lock: &dirty_i->seglist_lock);
936
937	return ret;
938	}
939
940	static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
941	{
942	struct inode_entry *ie;
943
944	ie = radix_tree_lookup(&gc_list->iroot, ino);
945	if (ie)
946	return ie->inode;
947	return NULL;
948	}
949
950	static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
951	{
952	struct inode_entry *new_ie;
953
954	if (inode == find_gc_inode(gc_list, ino: inode->i_ino)) {
955	iput(inode);
956	return;
957	}
958	new_ie = f2fs_kmem_cache_alloc(cachep: f2fs_inode_entry_slab,
959	GFP_NOFS, nofail: true, NULL);
960	new_ie->inode = inode;
961
962	f2fs_radix_tree_insert(root: &gc_list->iroot, index: inode->i_ino, item: new_ie);
963	list_add_tail(new: &new_ie->list, head: &gc_list->ilist);
964	}
965
966	static void put_gc_inode(struct gc_inode_list *gc_list)
967	{
968	struct inode_entry *ie, *next_ie;
969
970	list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
971	radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
972	iput(ie->inode);
973	list_del(entry: &ie->list);
974	kmem_cache_free(s: f2fs_inode_entry_slab, objp: ie);
975	}
976	}
977
978	static int check_valid_map(struct f2fs_sb_info *sbi,
979	unsigned int segno, int offset)
980	{
981	struct sit_info *sit_i = SIT_I(sbi);
982	struct seg_entry *sentry;
983	int ret;
984
985	down_read(sem: &sit_i->sentry_lock);
986	sentry = get_seg_entry(sbi, segno);
987	ret = f2fs_test_bit(nr: offset, addr: sentry->cur_valid_map);
988	up_read(sem: &sit_i->sentry_lock);
989	return ret;
990	}
991
992	/*
993	* This function compares node address got in summary with that in NAT.
994	* On validity, copy that node with cold status, otherwise (invalid node)
995	* ignore that.
996	*/
997	static int gc_node_segment(struct f2fs_sb_info *sbi,
998	struct f2fs_summary *sum, unsigned int segno, int gc_type)
999	{
1000	struct f2fs_summary *entry;
1001	block_t start_addr;
1002	int off;
1003	int phase = 0;
1004	bool fggc = (gc_type == FG_GC);
1005	int submitted = 0;
1006	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1007
1008	start_addr = START_BLOCK(sbi, segno);
1009
1010	next_step:
1011	entry = sum;
1012
1013	if (fggc && phase == 2)
1014	atomic_inc(v: &sbi->wb_sync_req[NODE]);
1015
1016	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1017	nid_t nid = le32_to_cpu(entry->nid);
1018	struct page *node_page;
1019	struct node_info ni;
1020	int err;
1021
1022	/* stop BG_GC if there is not enough free sections. */
1023	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, freed: 0, needed: 0))
1024	return submitted;
1025
1026	if (check_valid_map(sbi, segno, offset: off) == 0)
1027	continue;
1028
1029	if (phase == 0) {
1030	f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), nrpages: 1,
1031	type: META_NAT, sync: true);
1032	continue;
1033	}
1034
1035	if (phase == 1) {
1036	f2fs_ra_node_page(sbi, nid);
1037	continue;
1038	}
1039
1040	/* phase == 2 */
1041	node_page = f2fs_get_node_page(sbi, nid);
1042	if (IS_ERR(ptr: node_page))
1043	continue;
1044
1045	/* block may become invalid during f2fs_get_node_page */
1046	if (check_valid_map(sbi, segno, offset: off) == 0) {
1047	f2fs_put_page(page: node_page, unlock: 1);
1048	continue;
1049	}
1050
1051	if (f2fs_get_node_info(sbi, nid, ni: &ni, checkpoint_context: false)) {
1052	f2fs_put_page(page: node_page, unlock: 1);
1053	continue;
1054	}
1055
1056	if (ni.blk_addr != start_addr + off) {
1057	f2fs_put_page(page: node_page, unlock: 1);
1058	continue;
1059	}
1060
1061	err = f2fs_move_node_page(node_page, gc_type);
1062	if (!err && gc_type == FG_GC)
1063	submitted++;
1064	stat_inc_node_blk_count(sbi, 1, gc_type);
1065	}
1066
1067	if (++phase < 3)
1068	goto next_step;
1069
1070	if (fggc)
1071	atomic_dec(v: &sbi->wb_sync_req[NODE]);
1072	return submitted;
1073	}
1074
1075	/*
1076	* Calculate start block index indicating the given node offset.
1077	* Be careful, caller should give this node offset only indicating direct node
1078	* blocks. If any node offsets, which point the other types of node blocks such
1079	* as indirect or double indirect node blocks, are given, it must be a caller's
1080	* bug.
1081	*/
1082	block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1083	{
1084	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1085	unsigned int bidx;
1086
1087	if (node_ofs == 0)
1088	return 0;
1089
1090	if (node_ofs <= 2) {
1091	bidx = node_ofs - 1;
1092	} else if (node_ofs <= indirect_blks) {
1093	int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1094
1095	bidx = node_ofs - 2 - dec;
1096	} else {
1097	int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1098
1099	bidx = node_ofs - 5 - dec;
1100	}
1101	return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1102	}
1103
1104	static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1105	struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1106	{
1107	struct page *node_page;
1108	nid_t nid;
1109	unsigned int ofs_in_node, max_addrs, base;
1110	block_t source_blkaddr;
1111
1112	nid = le32_to_cpu(sum->nid);
1113	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1114
1115	node_page = f2fs_get_node_page(sbi, nid);
1116	if (IS_ERR(ptr: node_page))
1117	return false;
1118
1119	if (f2fs_get_node_info(sbi, nid, ni: dni, checkpoint_context: false)) {
1120	f2fs_put_page(page: node_page, unlock: 1);
1121	return false;
1122	}
1123
1124	if (sum->version != dni->version) {
1125	f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1126	__func__);
1127	set_sbi_flag(sbi, type: SBI_NEED_FSCK);
1128	}
1129
1130	if (f2fs_check_nid_range(sbi, nid: dni->ino)) {
1131	f2fs_put_page(page: node_page, unlock: 1);
1132	return false;
1133	}
1134
1135	if (IS_INODE(page: node_page)) {
1136	base = offset_in_addr(i: F2FS_INODE(page: node_page));
1137	max_addrs = DEF_ADDRS_PER_INODE;
1138	} else {
1139	base = 0;
1140	max_addrs = DEF_ADDRS_PER_BLOCK;
1141	}
1142
1143	if (base + ofs_in_node >= max_addrs) {
1144	f2fs_err(sbi, "Inconsistent blkaddr offset: base:%u, ofs_in_node:%u, max:%u, ino:%u, nid:%u",
1145	base, ofs_in_node, max_addrs, dni->ino, dni->nid);
1146	f2fs_put_page(page: node_page, unlock: 1);
1147	return false;
1148	}
1149
1150	*nofs = ofs_of_node(node_page);
1151	source_blkaddr = data_blkaddr(NULL, node_page, offset: ofs_in_node);
1152	f2fs_put_page(page: node_page, unlock: 1);
1153
1154	if (source_blkaddr != blkaddr) {
1155	#ifdef CONFIG_F2FS_CHECK_FS
1156	unsigned int segno = GET_SEGNO(sbi, blkaddr);
1157	unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1158
1159	if (unlikely(check_valid_map(sbi, segno, offset))) {
1160	if (!test_and_set_bit(nr: segno, addr: SIT_I(sbi)->invalid_segmap)) {
1161	f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1162	blkaddr, source_blkaddr, segno);
1163	set_sbi_flag(sbi, type: SBI_NEED_FSCK);
1164	}
1165	}
1166	#endif
1167	return false;
1168	}
1169	return true;
1170	}
1171
1172	static int ra_data_block(struct inode *inode, pgoff_t index)
1173	{
1174	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1175	struct address_space *mapping = inode->i_mapping;
1176	struct dnode_of_data dn;
1177	struct page *page;
1178	struct f2fs_io_info fio = {
1179	.sbi = sbi,
1180	.ino = inode->i_ino,
1181	.type = DATA,
1182	.temp = COLD,
1183	.op = REQ_OP_READ,
1184	.op_flags = 0,
1185	.encrypted_page = NULL,
1186	.in_list = 0,
1187	.retry = 0,
1188	};
1189	int err;
1190
1191	page = f2fs_grab_cache_page(mapping, index, for_write: true);
1192	if (!page)
1193	return -ENOMEM;
1194
1195	if (f2fs_lookup_read_extent_cache_block(inode, index,
1196	blkaddr: &dn.data_blkaddr)) {
1197	if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1198	DATA_GENERIC_ENHANCE_READ))) {
1199	err = -EFSCORRUPTED;
1200	f2fs_handle_error(sbi, error: ERROR_INVALID_BLKADDR);
1201	goto put_page;
1202	}
1203	goto got_it;
1204	}
1205
1206	set_new_dnode(dn: &dn, inode, NULL, NULL, nid: 0);
1207	err = f2fs_get_dnode_of_data(dn: &dn, index, mode: LOOKUP_NODE);
1208	if (err)
1209	goto put_page;
1210	f2fs_put_dnode(dn: &dn);
1211
1212	if (!__is_valid_data_blkaddr(blkaddr: dn.data_blkaddr)) {
1213	err = -ENOENT;
1214	goto put_page;
1215	}
1216	if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1217	DATA_GENERIC_ENHANCE))) {
1218	err = -EFSCORRUPTED;
1219	f2fs_handle_error(sbi, error: ERROR_INVALID_BLKADDR);
1220	goto put_page;
1221	}
1222	got_it:
1223	/* read page */
1224	fio.page = page;
1225	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1226
1227	/*
1228	* don't cache encrypted data into meta inode until previous dirty
1229	* data were writebacked to avoid racing between GC and flush.
1230	*/
1231	f2fs_wait_on_page_writeback(page, type: DATA, ordered: true, locked: true);
1232
1233	f2fs_wait_on_block_writeback(inode, blkaddr: dn.data_blkaddr);
1234
1235	fio.encrypted_page = f2fs_pagecache_get_page(mapping: META_MAPPING(sbi),
1236	index: dn.data_blkaddr,
1237	FGP_LOCK | FGP_CREAT, GFP_NOFS);
1238	if (!fio.encrypted_page) {
1239	err = -ENOMEM;
1240	goto put_page;
1241	}
1242
1243	err = f2fs_submit_page_bio(fio: &fio);
1244	if (err)
1245	goto put_encrypted_page;
1246	f2fs_put_page(page: fio.encrypted_page, unlock: 0);
1247	f2fs_put_page(page, unlock: 1);
1248
1249	f2fs_update_iostat(sbi, inode, type: FS_DATA_READ_IO, F2FS_BLKSIZE);
1250	f2fs_update_iostat(sbi, NULL, type: FS_GDATA_READ_IO, F2FS_BLKSIZE);
1251
1252	return 0;
1253	put_encrypted_page:
1254	f2fs_put_page(page: fio.encrypted_page, unlock: 1);
1255	put_page:
1256	f2fs_put_page(page, unlock: 1);
1257	return err;
1258	}
1259
1260	/*
1261	* Move data block via META_MAPPING while keeping locked data page.
1262	* This can be used to move blocks, aka LBAs, directly on disk.
1263	*/
1264	static int move_data_block(struct inode *inode, block_t bidx,
1265	int gc_type, unsigned int segno, int off)
1266	{
1267	struct f2fs_io_info fio = {
1268	.sbi = F2FS_I_SB(inode),
1269	.ino = inode->i_ino,
1270	.type = DATA,
1271	.temp = COLD,
1272	.op = REQ_OP_READ,
1273	.op_flags = 0,
1274	.encrypted_page = NULL,
1275	.in_list = 0,
1276	.retry = 0,
1277	};
1278	struct dnode_of_data dn;
1279	struct f2fs_summary sum;
1280	struct node_info ni;
1281	struct page *page, *mpage;
1282	block_t newaddr;
1283	int err = 0;
1284	bool lfs_mode = f2fs_lfs_mode(sbi: fio.sbi);
1285	int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1286	(fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1287	CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1288
1289	/* do not read out */
1290	page = f2fs_grab_cache_page(mapping: inode->i_mapping, index: bidx, for_write: false);
1291	if (!page)
1292	return -ENOMEM;
1293
1294	if (!check_valid_map(sbi: F2FS_I_SB(inode), segno, offset: off)) {
1295	err = -ENOENT;
1296	goto out;
1297	}
1298
1299	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1300	if (err)
1301	goto out;
1302
1303	set_new_dnode(dn: &dn, inode, NULL, NULL, nid: 0);
1304	err = f2fs_get_dnode_of_data(dn: &dn, index: bidx, mode: LOOKUP_NODE);
1305	if (err)
1306	goto out;
1307
1308	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1309	ClearPageUptodate(page);
1310	err = -ENOENT;
1311	goto put_out;
1312	}
1313
1314	/*
1315	* don't cache encrypted data into meta inode until previous dirty
1316	* data were writebacked to avoid racing between GC and flush.
1317	*/
1318	f2fs_wait_on_page_writeback(page, type: DATA, ordered: true, locked: true);
1319
1320	f2fs_wait_on_block_writeback(inode, blkaddr: dn.data_blkaddr);
1321
1322	err = f2fs_get_node_info(sbi: fio.sbi, nid: dn.nid, ni: &ni, checkpoint_context: false);
1323	if (err)
1324	goto put_out;
1325
1326	/* read page */
1327	fio.page = page;
1328	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1329
1330	if (lfs_mode)
1331	f2fs_down_write(sem: &fio.sbi->io_order_lock);
1332
1333	mpage = f2fs_grab_cache_page(mapping: META_MAPPING(sbi: fio.sbi),
1334	index: fio.old_blkaddr, for_write: false);
1335	if (!mpage) {
1336	err = -ENOMEM;
1337	goto up_out;
1338	}
1339
1340	fio.encrypted_page = mpage;
1341
1342	/* read source block in mpage */
1343	if (!PageUptodate(page: mpage)) {
1344	err = f2fs_submit_page_bio(fio: &fio);
1345	if (err) {
1346	f2fs_put_page(page: mpage, unlock: 1);
1347	goto up_out;
1348	}
1349
1350	f2fs_update_iostat(sbi: fio.sbi, inode, type: FS_DATA_READ_IO,
1351	F2FS_BLKSIZE);
1352	f2fs_update_iostat(sbi: fio.sbi, NULL, type: FS_GDATA_READ_IO,
1353	F2FS_BLKSIZE);
1354
1355	lock_page(page: mpage);
1356	if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1357	!PageUptodate(mpage))) {
1358	err = -EIO;
1359	f2fs_put_page(page: mpage, unlock: 1);
1360	goto up_out;
1361	}
1362	}
1363
1364	set_summary(sum: &sum, nid: dn.nid, ofs_in_node: dn.ofs_in_node, version: ni.version);
1365
1366	/* allocate block address */
1367	f2fs_allocate_data_block(sbi: fio.sbi, NULL, old_blkaddr: fio.old_blkaddr, new_blkaddr: &newaddr,
1368	sum: &sum, type, NULL);
1369
1370	fio.encrypted_page = f2fs_pagecache_get_page(mapping: META_MAPPING(sbi: fio.sbi),
1371	index: newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1372	if (!fio.encrypted_page) {
1373	err = -ENOMEM;
1374	f2fs_put_page(page: mpage, unlock: 1);
1375	goto recover_block;
1376	}
1377
1378	/* write target block */
1379	f2fs_wait_on_page_writeback(page: fio.encrypted_page, type: DATA, ordered: true, locked: true);
1380	memcpy(page_address(fio.encrypted_page),
1381	page_address(mpage), PAGE_SIZE);
1382	f2fs_put_page(page: mpage, unlock: 1);
1383	invalidate_mapping_pages(mapping: META_MAPPING(sbi: fio.sbi),
1384	start: fio.old_blkaddr, end: fio.old_blkaddr);
1385	f2fs_invalidate_compress_page(sbi: fio.sbi, blkaddr: fio.old_blkaddr);
1386
1387	set_page_dirty(fio.encrypted_page);
1388	if (clear_page_dirty_for_io(page: fio.encrypted_page))
1389	dec_page_count(sbi: fio.sbi, count_type: F2FS_DIRTY_META);
1390
1391	set_page_writeback(fio.encrypted_page);
1392
1393	fio.op = REQ_OP_WRITE;
1394	fio.op_flags = REQ_SYNC;
1395	fio.new_blkaddr = newaddr;
1396	f2fs_submit_page_write(fio: &fio);
1397	if (fio.retry) {
1398	err = -EAGAIN;
1399	if (PageWriteback(page: fio.encrypted_page))
1400	end_page_writeback(page: fio.encrypted_page);
1401	goto put_page_out;
1402	}
1403
1404	f2fs_update_iostat(sbi: fio.sbi, NULL, type: FS_GC_DATA_IO, F2FS_BLKSIZE);
1405
1406	f2fs_update_data_blkaddr(dn: &dn, blkaddr: newaddr);
1407	set_inode_flag(inode, flag: FI_APPEND_WRITE);
1408	if (page->index == 0)
1409	set_inode_flag(inode, flag: FI_FIRST_BLOCK_WRITTEN);
1410	put_page_out:
1411	f2fs_put_page(page: fio.encrypted_page, unlock: 1);
1412	recover_block:
1413	if (err)
1414	f2fs_do_replace_block(sbi: fio.sbi, sum: &sum, old_blkaddr: newaddr, new_blkaddr: fio.old_blkaddr,
1415	recover_curseg: true, recover_newaddr: true, from_gc: true);
1416	up_out:
1417	if (lfs_mode)
1418	f2fs_up_write(sem: &fio.sbi->io_order_lock);
1419	put_out:
1420	f2fs_put_dnode(dn: &dn);
1421	out:
1422	f2fs_put_page(page, unlock: 1);
1423	return err;
1424	}
1425
1426	static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1427	unsigned int segno, int off)
1428	{
1429	struct page *page;
1430	int err = 0;
1431
1432	page = f2fs_get_lock_data_page(inode, index: bidx, for_write: true);
1433	if (IS_ERR(ptr: page))
1434	return PTR_ERR(ptr: page);
1435
1436	if (!check_valid_map(sbi: F2FS_I_SB(inode), segno, offset: off)) {
1437	err = -ENOENT;
1438	goto out;
1439	}
1440
1441	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1442	if (err)
1443	goto out;
1444
1445	if (gc_type == BG_GC) {
1446	if (PageWriteback(page)) {
1447	err = -EAGAIN;
1448	goto out;
1449	}
1450	set_page_dirty(page);
1451	set_page_private_gcing(page);
1452	} else {
1453	struct f2fs_io_info fio = {
1454	.sbi = F2FS_I_SB(inode),
1455	.ino = inode->i_ino,
1456	.type = DATA,
1457	.temp = COLD,
1458	.op = REQ_OP_WRITE,
1459	.op_flags = REQ_SYNC,
1460	.old_blkaddr = NULL_ADDR,
1461	.page = page,
1462	.encrypted_page = NULL,
1463	.need_lock = LOCK_REQ,
1464	.io_type = FS_GC_DATA_IO,
1465	};
1466	bool is_dirty = PageDirty(page);
1467
1468	retry:
1469	f2fs_wait_on_page_writeback(page, type: DATA, ordered: true, locked: true);
1470
1471	set_page_dirty(page);
1472	if (clear_page_dirty_for_io(page)) {
1473	inode_dec_dirty_pages(inode);
1474	f2fs_remove_dirty_inode(inode);
1475	}
1476
1477	set_page_private_gcing(page);
1478
1479	err = f2fs_do_write_data_page(fio: &fio);
1480	if (err) {
1481	clear_page_private_gcing(page);
1482	if (err == -ENOMEM) {
1483	memalloc_retry_wait(GFP_NOFS);
1484	goto retry;
1485	}
1486	if (is_dirty)
1487	set_page_dirty(page);
1488	}
1489	}
1490	out:
1491	f2fs_put_page(page, unlock: 1);
1492	return err;
1493	}
1494
1495	/*
1496	* This function tries to get parent node of victim data block, and identifies
1497	* data block validity. If the block is valid, copy that with cold status and
1498	* modify parent node.
1499	* If the parent node is not valid or the data block address is different,
1500	* the victim data block is ignored.
1501	*/
1502	static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1503	struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1504	bool force_migrate)
1505	{
1506	struct super_block *sb = sbi->sb;
1507	struct f2fs_summary *entry;
1508	block_t start_addr;
1509	int off;
1510	int phase = 0;
1511	int submitted = 0;
1512	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1513
1514	start_addr = START_BLOCK(sbi, segno);
1515
1516	next_step:
1517	entry = sum;
1518
1519	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1520	struct page *data_page;
1521	struct inode *inode;
1522	struct node_info dni; /* dnode info for the data */
1523	unsigned int ofs_in_node, nofs;
1524	block_t start_bidx;
1525	nid_t nid = le32_to_cpu(entry->nid);
1526
1527	/*
1528	* stop BG_GC if there is not enough free sections.
1529	* Or, stop GC if the segment becomes fully valid caused by
1530	* race condition along with SSR block allocation.
1531	*/
1532	if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, freed: 0, needed: 0)) ||
1533	(!force_migrate && get_valid_blocks(sbi, segno, use_section: true) ==
1534	CAP_BLKS_PER_SEC(sbi)))
1535	return submitted;
1536
1537	if (check_valid_map(sbi, segno, offset: off) == 0)
1538	continue;
1539
1540	if (phase == 0) {
1541	f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), nrpages: 1,
1542	type: META_NAT, sync: true);
1543	continue;
1544	}
1545
1546	if (phase == 1) {
1547	f2fs_ra_node_page(sbi, nid);
1548	continue;
1549	}
1550
1551	/* Get an inode by ino with checking validity */
1552	if (!is_alive(sbi, sum: entry, dni: &dni, blkaddr: start_addr + off, nofs: &nofs))
1553	continue;
1554
1555	if (phase == 2) {
1556	f2fs_ra_node_page(sbi, nid: dni.ino);
1557	continue;
1558	}
1559
1560	ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1561
1562	if (phase == 3) {
1563	int err;
1564
1565	inode = f2fs_iget(sb, ino: dni.ino);
1566	if (IS_ERR(ptr: inode) || is_bad_inode(inode) ||
1567	special_file(inode->i_mode))
1568	continue;
1569
1570	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1571	if (err == -EAGAIN) {
1572	iput(inode);
1573	return submitted;
1574	}
1575
1576	if (!f2fs_down_write_trylock(
1577	sem: &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1578	iput(inode);
1579	sbi->skipped_gc_rwsem++;
1580	continue;
1581	}
1582
1583	start_bidx = f2fs_start_bidx_of_node(node_ofs: nofs, inode) +
1584	ofs_in_node;
1585
1586	if (f2fs_post_read_required(inode)) {
1587	int err = ra_data_block(inode, index: start_bidx);
1588
1589	f2fs_up_write(sem: &F2FS_I(inode)->i_gc_rwsem[WRITE]);
1590	if (err) {
1591	iput(inode);
1592	continue;
1593	}
1594	add_gc_inode(gc_list, inode);
1595	continue;
1596	}
1597
1598	data_page = f2fs_get_read_data_page(inode, index: start_bidx,
1599	REQ_RAHEAD, for_write: true, NULL);
1600	f2fs_up_write(sem: &F2FS_I(inode)->i_gc_rwsem[WRITE]);
1601	if (IS_ERR(ptr: data_page)) {
1602	iput(inode);
1603	continue;
1604	}
1605
1606	f2fs_put_page(page: data_page, unlock: 0);
1607	add_gc_inode(gc_list, inode);
1608	continue;
1609	}
1610
1611	/* phase 4 */
1612	inode = find_gc_inode(gc_list, ino: dni.ino);
1613	if (inode) {
1614	struct f2fs_inode_info *fi = F2FS_I(inode);
1615	bool locked = false;
1616	int err;
1617
1618	if (S_ISREG(inode->i_mode)) {
1619	if (!f2fs_down_write_trylock(sem: &fi->i_gc_rwsem[WRITE])) {
1620	sbi->skipped_gc_rwsem++;
1621	continue;
1622	}
1623	if (!f2fs_down_write_trylock(
1624	sem: &fi->i_gc_rwsem[READ])) {
1625	sbi->skipped_gc_rwsem++;
1626	f2fs_up_write(sem: &fi->i_gc_rwsem[WRITE]);
1627	continue;
1628	}
1629	locked = true;
1630
1631	/* wait for all inflight aio data */
1632	inode_dio_wait(inode);
1633	}
1634
1635	start_bidx = f2fs_start_bidx_of_node(node_ofs: nofs, inode)
1636	+ ofs_in_node;
1637	if (f2fs_post_read_required(inode))
1638	err = move_data_block(inode, bidx: start_bidx,
1639	gc_type, segno, off);
1640	else
1641	err = move_data_page(inode, bidx: start_bidx, gc_type,
1642	segno, off);
1643
1644	if (!err && (gc_type == FG_GC ||
1645	f2fs_post_read_required(inode)))
1646	submitted++;
1647
1648	if (locked) {
1649	f2fs_up_write(sem: &fi->i_gc_rwsem[READ]);
1650	f2fs_up_write(sem: &fi->i_gc_rwsem[WRITE]);
1651	}
1652
1653	stat_inc_data_blk_count(sbi, 1, gc_type);
1654	}
1655	}
1656
1657	if (++phase < 5)
1658	goto next_step;
1659
1660	return submitted;
1661	}
1662
1663	static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1664	int gc_type)
1665	{
1666	struct sit_info *sit_i = SIT_I(sbi);
1667	int ret;
1668
1669	down_write(sem: &sit_i->sentry_lock);
1670	ret = f2fs_get_victim(sbi, result: victim, gc_type, type: NO_CHECK_TYPE, alloc_mode: LFS, age: 0);
1671	up_write(sem: &sit_i->sentry_lock);
1672	return ret;
1673	}
1674
1675	static int do_garbage_collect(struct f2fs_sb_info *sbi,
1676	unsigned int start_segno,
1677	struct gc_inode_list *gc_list, int gc_type,
1678	bool force_migrate)
1679	{
1680	struct page *sum_page;
1681	struct f2fs_summary_block *sum;
1682	struct blk_plug plug;
1683	unsigned int segno = start_segno;
1684	unsigned int end_segno = start_segno + sbi->segs_per_sec;
1685	int seg_freed = 0, migrated = 0;
1686	unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1687	SUM_TYPE_DATA : SUM_TYPE_NODE;
1688	unsigned char data_type = (type == SUM_TYPE_DATA) ? DATA : NODE;
1689	int submitted = 0;
1690
1691	if (__is_large_section(sbi))
1692	end_segno = rounddown(end_segno, sbi->segs_per_sec);
1693
1694	/*
1695	* zone-capacity can be less than zone-size in zoned devices,
1696	* resulting in less than expected usable segments in the zone,
1697	* calculate the end segno in the zone which can be garbage collected
1698	*/
1699	if (f2fs_sb_has_blkzoned(sbi))
1700	end_segno -= sbi->segs_per_sec -
1701	f2fs_usable_segs_in_sec(sbi, segno);
1702
1703	sanity_check_seg_type(sbi, seg_type: get_seg_entry(sbi, segno)->type);
1704
1705	/* readahead multi ssa blocks those have contiguous address */
1706	if (__is_large_section(sbi))
1707	f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1708	nrpages: end_segno - segno, type: META_SSA, sync: true);
1709
1710	/* reference all summary page */
1711	while (segno < end_segno) {
1712	sum_page = f2fs_get_sum_page(sbi, segno: segno++);
1713	if (IS_ERR(ptr: sum_page)) {
1714	int err = PTR_ERR(ptr: sum_page);
1715
1716	end_segno = segno - 1;
1717	for (segno = start_segno; segno < end_segno; segno++) {
1718	sum_page = find_get_page(mapping: META_MAPPING(sbi),
1719	GET_SUM_BLOCK(sbi, segno));
1720	f2fs_put_page(page: sum_page, unlock: 0);
1721	f2fs_put_page(page: sum_page, unlock: 0);
1722	}
1723	return err;
1724	}
1725	unlock_page(page: sum_page);
1726	}
1727
1728	blk_start_plug(&plug);
1729
1730	for (segno = start_segno; segno < end_segno; segno++) {
1731
1732	/* find segment summary of victim */
1733	sum_page = find_get_page(mapping: META_MAPPING(sbi),
1734	GET_SUM_BLOCK(sbi, segno));
1735	f2fs_put_page(page: sum_page, unlock: 0);
1736
1737	if (get_valid_blocks(sbi, segno, use_section: false) == 0)
1738	goto freed;
1739	if (gc_type == BG_GC && __is_large_section(sbi) &&
1740	migrated >= sbi->migration_granularity)
1741	goto skip;
1742	if (!PageUptodate(page: sum_page) || unlikely(f2fs_cp_error(sbi)))
1743	goto skip;
1744
1745	sum = page_address(sum_page);
1746	if (type != GET_SUM_TYPE((&sum->footer))) {
1747	f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1748	segno, type, GET_SUM_TYPE((&sum->footer)));
1749	set_sbi_flag(sbi, type: SBI_NEED_FSCK);
1750	f2fs_stop_checkpoint(sbi, end_io: false,
1751	reason: STOP_CP_REASON_CORRUPTED_SUMMARY);
1752	goto skip;
1753	}
1754
1755	/*
1756	* this is to avoid deadlock:
1757	* - lock_page(sum_page) - f2fs_replace_block
1758	* - check_valid_map() - down_write(sentry_lock)
1759	* - down_read(sentry_lock) - change_curseg()
1760	* - lock_page(sum_page)
1761	*/
1762	if (type == SUM_TYPE_NODE)
1763	submitted += gc_node_segment(sbi, sum: sum->entries, segno,
1764	gc_type);
1765	else
1766	submitted += gc_data_segment(sbi, sum: sum->entries, gc_list,
1767	segno, gc_type,
1768	force_migrate);
1769
1770	stat_inc_gc_seg_count(sbi, data_type, gc_type);
1771	sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1772	migrated++;
1773
1774	freed:
1775	if (gc_type == FG_GC &&
1776	get_valid_blocks(sbi, segno, use_section: false) == 0)
1777	seg_freed++;
1778
1779	if (__is_large_section(sbi))
1780	sbi->next_victim_seg[gc_type] =
1781	(segno + 1 < end_segno) ? segno + 1 : NULL_SEGNO;
1782	skip:
1783	f2fs_put_page(page: sum_page, unlock: 0);
1784	}
1785
1786	if (submitted)
1787	f2fs_submit_merged_write(sbi, type: data_type);
1788
1789	blk_finish_plug(&plug);
1790
1791	if (migrated)
1792	stat_inc_gc_sec_count(sbi, data_type, gc_type);
1793
1794	return seg_freed;
1795	}
1796
1797	int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1798	{
1799	int gc_type = gc_control->init_gc_type;
1800	unsigned int segno = gc_control->victim_segno;
1801	int sec_freed = 0, seg_freed = 0, total_freed = 0, total_sec_freed = 0;
1802	int ret = 0;
1803	struct cp_control cpc;
1804	struct gc_inode_list gc_list = {
1805	.ilist = LIST_HEAD_INIT(gc_list.ilist),
1806	.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1807	};
1808	unsigned int skipped_round = 0, round = 0;
1809	unsigned int upper_secs;
1810
1811	trace_f2fs_gc_begin(sb: sbi->sb, gc_type, no_bg_gc: gc_control->no_bg_gc,
1812	nr_free_secs: gc_control->nr_free_secs,
1813	dirty_nodes: get_pages(sbi, count_type: F2FS_DIRTY_NODES),
1814	dirty_dents: get_pages(sbi, count_type: F2FS_DIRTY_DENTS),
1815	dirty_imeta: get_pages(sbi, count_type: F2FS_DIRTY_IMETA),
1816	free_sec: free_sections(sbi),
1817	free_seg: free_segments(sbi),
1818	reserved_seg: reserved_segments(sbi),
1819	prefree_seg: prefree_segments(sbi));
1820
1821	cpc.reason = __get_cp_reason(sbi);
1822	gc_more:
1823	sbi->skipped_gc_rwsem = 0;
1824	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1825	ret = -EINVAL;
1826	goto stop;
1827	}
1828	if (unlikely(f2fs_cp_error(sbi))) {
1829	ret = -EIO;
1830	goto stop;
1831	}
1832
1833	/* Let's run FG_GC, if we don't have enough space. */
1834	if (has_not_enough_free_secs(sbi, freed: 0, needed: 0)) {
1835	gc_type = FG_GC;
1836
1837	/*
1838	* For example, if there are many prefree_segments below given
1839	* threshold, we can make them free by checkpoint. Then, we
1840	* secure free segments which doesn't need fggc any more.
1841	*/
1842	if (prefree_segments(sbi)) {
1843	stat_inc_cp_call_count(sbi, TOTAL_CALL);
1844	ret = f2fs_write_checkpoint(sbi, cpc: &cpc);
1845	if (ret)
1846	goto stop;
1847	/* Reset due to checkpoint */
1848	sec_freed = 0;
1849	}
1850	}
1851
1852	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1853	if (gc_type == BG_GC && gc_control->no_bg_gc) {
1854	ret = -EINVAL;
1855	goto stop;
1856	}
1857	retry:
1858	ret = __get_victim(sbi, victim: &segno, gc_type);
1859	if (ret) {
1860	/* allow to search victim from sections has pinned data */
1861	if (ret == -ENODATA && gc_type == FG_GC &&
1862	f2fs_pinned_section_exists(dirty_i: DIRTY_I(sbi))) {
1863	f2fs_unpin_all_sections(sbi, enable: false);
1864	goto retry;
1865	}
1866	goto stop;
1867	}
1868
1869	seg_freed = do_garbage_collect(sbi, start_segno: segno, gc_list: &gc_list, gc_type,
1870	force_migrate: gc_control->should_migrate_blocks);
1871	total_freed += seg_freed;
1872
1873	if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno)) {
1874	sec_freed++;
1875	total_sec_freed++;
1876	}
1877
1878	if (gc_type == FG_GC) {
1879	sbi->cur_victim_sec = NULL_SEGNO;
1880
1881	if (has_enough_free_secs(sbi, freed: sec_freed, needed: 0)) {
1882	if (!gc_control->no_bg_gc &&
1883	total_sec_freed < gc_control->nr_free_secs)
1884	goto go_gc_more;
1885	goto stop;
1886	}
1887	if (sbi->skipped_gc_rwsem)
1888	skipped_round++;
1889	round++;
1890	if (skipped_round > MAX_SKIP_GC_COUNT &&
1891	skipped_round * 2 >= round) {
1892	stat_inc_cp_call_count(sbi, TOTAL_CALL);
1893	ret = f2fs_write_checkpoint(sbi, cpc: &cpc);
1894	goto stop;
1895	}
1896	} else if (has_enough_free_secs(sbi, freed: 0, needed: 0)) {
1897	goto stop;
1898	}
1899
1900	__get_secs_required(sbi, NULL, upper_p: &upper_secs, NULL);
1901
1902	/*
1903	* Write checkpoint to reclaim prefree segments.
1904	* We need more three extra sections for writer's data/node/dentry.
1905	*/
1906	if (free_sections(sbi) <= upper_secs + NR_GC_CHECKPOINT_SECS &&
1907	prefree_segments(sbi)) {
1908	stat_inc_cp_call_count(sbi, TOTAL_CALL);
1909	ret = f2fs_write_checkpoint(sbi, cpc: &cpc);
1910	if (ret)
1911	goto stop;
1912	/* Reset due to checkpoint */
1913	sec_freed = 0;
1914	}
1915	go_gc_more:
1916	segno = NULL_SEGNO;
1917	goto gc_more;
1918
1919	stop:
1920	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1921	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
1922
1923	if (gc_type == FG_GC)
1924	f2fs_unpin_all_sections(sbi, enable: true);
1925
1926	trace_f2fs_gc_end(sb: sbi->sb, ret, seg_freed: total_freed, sec_freed: total_sec_freed,
1927	dirty_nodes: get_pages(sbi, count_type: F2FS_DIRTY_NODES),
1928	dirty_dents: get_pages(sbi, count_type: F2FS_DIRTY_DENTS),
1929	dirty_imeta: get_pages(sbi, count_type: F2FS_DIRTY_IMETA),
1930	free_sec: free_sections(sbi),
1931	free_seg: free_segments(sbi),
1932	reserved_seg: reserved_segments(sbi),
1933	prefree_seg: prefree_segments(sbi));
1934
1935	f2fs_up_write(sem: &sbi->gc_lock);
1936
1937	put_gc_inode(gc_list: &gc_list);
1938
1939	if (gc_control->err_gc_skipped && !ret)
1940	ret = total_sec_freed ? 0 : -EAGAIN;
1941	return ret;
1942	}
1943
1944	int __init f2fs_create_garbage_collection_cache(void)
1945	{
1946	victim_entry_slab = f2fs_kmem_cache_create(name: "f2fs_victim_entry",
1947	size: sizeof(struct victim_entry));
1948	return victim_entry_slab ? 0 : -ENOMEM;
1949	}
1950
1951	void f2fs_destroy_garbage_collection_cache(void)
1952	{
1953	kmem_cache_destroy(s: victim_entry_slab);
1954	}
1955
1956	static void init_atgc_management(struct f2fs_sb_info *sbi)
1957	{
1958	struct atgc_management *am = &sbi->am;
1959
1960	if (test_opt(sbi, ATGC) &&
1961	SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1962	am->atgc_enabled = true;
1963
1964	am->root = RB_ROOT_CACHED;
1965	INIT_LIST_HEAD(list: &am->victim_list);
1966	am->victim_count = 0;
1967
1968	am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1969	am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1970	am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1971	am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1972	}
1973
1974	void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1975	{
1976	sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1977
1978	/* give warm/cold data area from slower device */
1979	if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1980	SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1981	GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1982
1983	init_atgc_management(sbi);
1984	}
1985
1986	static int free_segment_range(struct f2fs_sb_info *sbi,
1987	unsigned int secs, bool gc_only)
1988	{
1989	unsigned int segno, next_inuse, start, end;
1990	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1991	int gc_mode, gc_type;
1992	int err = 0;
1993	int type;
1994
1995	/* Force block allocation for GC */
1996	MAIN_SECS(sbi) -= secs;
1997	start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1998	end = MAIN_SEGS(sbi) - 1;
1999
2000	mutex_lock(&DIRTY_I(sbi)->seglist_lock);
2001	for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
2002	if (SIT_I(sbi)->last_victim[gc_mode] >= start)
2003	SIT_I(sbi)->last_victim[gc_mode] = 0;
2004
2005	for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
2006	if (sbi->next_victim_seg[gc_type] >= start)
2007	sbi->next_victim_seg[gc_type] = NULL_SEGNO;
2008	mutex_unlock(lock: &DIRTY_I(sbi)->seglist_lock);
2009
2010	/* Move out cursegs from the target range */
2011	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
2012	f2fs_allocate_segment_for_resize(sbi, type, start, end);
2013
2014	/* do GC to move out valid blocks in the range */
2015	for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
2016	struct gc_inode_list gc_list = {
2017	.ilist = LIST_HEAD_INIT(gc_list.ilist),
2018	.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
2019	};
2020
2021	do_garbage_collect(sbi, start_segno: segno, gc_list: &gc_list, gc_type: FG_GC, force_migrate: true);
2022	put_gc_inode(gc_list: &gc_list);
2023
2024	if (!gc_only && get_valid_blocks(sbi, segno, use_section: true)) {
2025	err = -EAGAIN;
2026	goto out;
2027	}
2028	if (fatal_signal_pending(current)) {
2029	err = -ERESTARTSYS;
2030	goto out;
2031	}
2032	}
2033	if (gc_only)
2034	goto out;
2035
2036	stat_inc_cp_call_count(sbi, TOTAL_CALL);
2037	err = f2fs_write_checkpoint(sbi, cpc: &cpc);
2038	if (err)
2039	goto out;
2040
2041	next_inuse = find_next_inuse(free_i: FREE_I(sbi), max: end + 1, segno: start);
2042	if (next_inuse <= end) {
2043	f2fs_err(sbi, "segno %u should be free but still inuse!",
2044	next_inuse);
2045	f2fs_bug_on(sbi, 1);
2046	}
2047	out:
2048	MAIN_SECS(sbi) += secs;
2049	return err;
2050	}
2051
2052	static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
2053	{
2054	struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
2055	int section_count;
2056	int segment_count;
2057	int segment_count_main;
2058	long long block_count;
2059	int segs = secs * sbi->segs_per_sec;
2060
2061	f2fs_down_write(sem: &sbi->sb_lock);
2062
2063	section_count = le32_to_cpu(raw_sb->section_count);
2064	segment_count = le32_to_cpu(raw_sb->segment_count);
2065	segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2066	block_count = le64_to_cpu(raw_sb->block_count);
2067
2068	raw_sb->section_count = cpu_to_le32(section_count + secs);
2069	raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2070	raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2071	raw_sb->block_count = cpu_to_le64(block_count +
2072	(long long)segs * sbi->blocks_per_seg);
2073	if (f2fs_is_multi_device(sbi)) {
2074	int last_dev = sbi->s_ndevs - 1;
2075	int dev_segs =
2076	le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2077
2078	raw_sb->devs[last_dev].total_segments =
2079	cpu_to_le32(dev_segs + segs);
2080	}
2081
2082	f2fs_up_write(sem: &sbi->sb_lock);
2083	}
2084
2085	static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2086	{
2087	int segs = secs * sbi->segs_per_sec;
2088	long long blks = (long long)segs * sbi->blocks_per_seg;
2089	long long user_block_count =
2090	le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2091
2092	SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2093	MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2094	MAIN_SECS(sbi) += secs;
2095	FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2096	FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2097	F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2098
2099	if (f2fs_is_multi_device(sbi)) {
2100	int last_dev = sbi->s_ndevs - 1;
2101
2102	FDEV(last_dev).total_segments =
2103	(int)FDEV(last_dev).total_segments + segs;
2104	FDEV(last_dev).end_blk =
2105	(long long)FDEV(last_dev).end_blk + blks;
2106	#ifdef CONFIG_BLK_DEV_ZONED
2107	FDEV(last_dev).nr_blkz = FDEV(last_dev).nr_blkz +
2108	div_u64(dividend: blks, divisor: sbi->blocks_per_blkz);
2109	#endif
2110	}
2111	}
2112
2113	int f2fs_resize_fs(struct file *filp, __u64 block_count)
2114	{
2115	struct f2fs_sb_info *sbi = F2FS_I_SB(inode: file_inode(f: filp));
2116	__u64 old_block_count, shrunk_blocks;
2117	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2118	unsigned int secs;
2119	int err = 0;
2120	__u32 rem;
2121
2122	old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2123	if (block_count > old_block_count)
2124	return -EINVAL;
2125
2126	if (f2fs_is_multi_device(sbi)) {
2127	int last_dev = sbi->s_ndevs - 1;
2128	__u64 last_segs = FDEV(last_dev).total_segments;
2129
2130	if (block_count + last_segs * sbi->blocks_per_seg <=
2131	old_block_count)
2132	return -EINVAL;
2133	}
2134
2135	/* new fs size should align to section size */
2136	div_u64_rem(dividend: block_count, BLKS_PER_SEC(sbi), remainder: &rem);
2137	if (rem)
2138	return -EINVAL;
2139
2140	if (block_count == old_block_count)
2141	return 0;
2142
2143	if (is_sbi_flag_set(sbi, type: SBI_NEED_FSCK)) {
2144	f2fs_err(sbi, "Should run fsck to repair first.");
2145	return -EFSCORRUPTED;
2146	}
2147
2148	if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2149	f2fs_err(sbi, "Checkpoint should be enabled.");
2150	return -EINVAL;
2151	}
2152
2153	err = mnt_want_write_file(file: filp);
2154	if (err)
2155	return err;
2156
2157	shrunk_blocks = old_block_count - block_count;
2158	secs = div_u64(dividend: shrunk_blocks, BLKS_PER_SEC(sbi));
2159
2160	/* stop other GC */
2161	if (!f2fs_down_write_trylock(sem: &sbi->gc_lock)) {
2162	err = -EAGAIN;
2163	goto out_drop_write;
2164	}
2165
2166	/* stop CP to protect MAIN_SEC in free_segment_range */
2167	f2fs_lock_op(sbi);
2168
2169	spin_lock(lock: &sbi->stat_lock);
2170	if (shrunk_blocks + valid_user_blocks(sbi) +
2171	sbi->current_reserved_blocks + sbi->unusable_block_count +
2172	F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2173	err = -ENOSPC;
2174	spin_unlock(lock: &sbi->stat_lock);
2175
2176	if (err)
2177	goto out_unlock;
2178
2179	err = free_segment_range(sbi, secs, gc_only: true);
2180
2181	out_unlock:
2182	f2fs_unlock_op(sbi);
2183	f2fs_up_write(sem: &sbi->gc_lock);
2184	out_drop_write:
2185	mnt_drop_write_file(file: filp);
2186	if (err)
2187	return err;
2188
2189	err = freeze_super(super: sbi->sb, who: FREEZE_HOLDER_USERSPACE);
2190	if (err)
2191	return err;
2192
2193	if (f2fs_readonly(sb: sbi->sb)) {
2194	err = thaw_super(super: sbi->sb, who: FREEZE_HOLDER_USERSPACE);
2195	if (err)
2196	return err;
2197	return -EROFS;
2198	}
2199
2200	f2fs_down_write(sem: &sbi->gc_lock);
2201	f2fs_down_write(sem: &sbi->cp_global_sem);
2202
2203	spin_lock(lock: &sbi->stat_lock);
2204	if (shrunk_blocks + valid_user_blocks(sbi) +
2205	sbi->current_reserved_blocks + sbi->unusable_block_count +
2206	F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2207	err = -ENOSPC;
2208	else
2209	sbi->user_block_count -= shrunk_blocks;
2210	spin_unlock(lock: &sbi->stat_lock);
2211	if (err)
2212	goto out_err;
2213
2214	set_sbi_flag(sbi, type: SBI_IS_RESIZEFS);
2215	err = free_segment_range(sbi, secs, gc_only: false);
2216	if (err)
2217	goto recover_out;
2218
2219	update_sb_metadata(sbi, secs: -secs);
2220
2221	err = f2fs_commit_super(sbi, recover: false);
2222	if (err) {
2223	update_sb_metadata(sbi, secs);
2224	goto recover_out;
2225	}
2226
2227	update_fs_metadata(sbi, secs: -secs);
2228	clear_sbi_flag(sbi, type: SBI_IS_RESIZEFS);
2229	set_sbi_flag(sbi, type: SBI_IS_DIRTY);
2230
2231	stat_inc_cp_call_count(sbi, TOTAL_CALL);
2232	err = f2fs_write_checkpoint(sbi, cpc: &cpc);
2233	if (err) {
2234	update_fs_metadata(sbi, secs);
2235	update_sb_metadata(sbi, secs);
2236	f2fs_commit_super(sbi, recover: false);
2237	}
2238	recover_out:
2239	clear_sbi_flag(sbi, type: SBI_IS_RESIZEFS);
2240	if (err) {
2241	set_sbi_flag(sbi, type: SBI_NEED_FSCK);
2242	f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2243
2244	spin_lock(lock: &sbi->stat_lock);
2245	sbi->user_block_count += shrunk_blocks;
2246	spin_unlock(lock: &sbi->stat_lock);
2247	}
2248	out_err:
2249	f2fs_up_write(sem: &sbi->cp_global_sem);
2250	f2fs_up_write(sem: &sbi->gc_lock);
2251	thaw_super(super: sbi->sb, who: FREEZE_HOLDER_USERSPACE);
2252	return err;
2253	}
2254