xref: /linux/fs/f2fs/gc.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
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 		.one_time = false };
43 
44 	wait_ms = gc_th->min_sleep_time;
45 
46 	set_freezable();
47 	do {
48 		bool sync_mode, foreground = false, gc_boost = false;
49 
50 		wait_event_freezable_timeout(*wq,
51 				kthread_should_stop() ||
52 				waitqueue_active(fggc_wq) ||
53 				gc_th->gc_wake,
54 				msecs_to_jiffies(wait_ms));
55 
56 		if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq)) {
57 			foreground = true;
58 			gc_control.one_time = false;
59 		} else if (f2fs_sb_has_blkzoned(sbi)) {
60 			gc_control.one_time = true;
61 		}
62 
63 		/* give it a try one time */
64 		if (gc_th->gc_wake)
65 			gc_th->gc_wake = false;
66 
67 		if (f2fs_readonly(sbi->sb)) {
68 			stat_other_skip_bggc_count(sbi);
69 			continue;
70 		}
71 		if (kthread_should_stop())
72 			break;
73 
74 		if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
75 			increase_sleep_time(gc_th, &wait_ms);
76 			stat_other_skip_bggc_count(sbi);
77 			continue;
78 		}
79 
80 		if (time_to_inject(sbi, FAULT_CHECKPOINT))
81 			f2fs_stop_checkpoint(sbi, false,
82 					STOP_CP_REASON_FAULT_INJECT);
83 
84 		if (!sb_start_write_trylock(sbi->sb)) {
85 			stat_other_skip_bggc_count(sbi);
86 			continue;
87 		}
88 
89 		/*
90 		 * [GC triggering condition]
91 		 * 0. GC is not conducted currently.
92 		 * 1. There are enough dirty segments.
93 		 * 2. IO subsystem is idle by checking the # of writeback pages.
94 		 * 3. IO subsystem is idle by checking the # of requests in
95 		 *    bdev's request list.
96 		 *
97 		 * Note) We have to avoid triggering GCs frequently.
98 		 * Because it is possible that some segments can be
99 		 * invalidated soon after by user update or deletion.
100 		 * So, I'd like to wait some time to collect dirty segments.
101 		 */
102 		if (sbi->gc_mode == GC_URGENT_HIGH ||
103 				sbi->gc_mode == GC_URGENT_MID) {
104 			wait_ms = gc_th->urgent_sleep_time;
105 			f2fs_down_write_trace(&sbi->gc_lock, &gc_control.lc);
106 			goto do_gc;
107 		}
108 
109 		if (foreground) {
110 			f2fs_down_write_trace(&sbi->gc_lock, &gc_control.lc);
111 			goto do_gc;
112 		} else if (!f2fs_down_write_trylock_trace(&sbi->gc_lock,
113 							&gc_control.lc)) {
114 			stat_other_skip_bggc_count(sbi);
115 			goto next;
116 		}
117 
118 		if (!is_idle(sbi, GC_TIME)) {
119 			increase_sleep_time(gc_th, &wait_ms);
120 			f2fs_up_write_trace(&sbi->gc_lock, &gc_control.lc);
121 			stat_io_skip_bggc_count(sbi);
122 			goto next;
123 		}
124 
125 		if (f2fs_sb_has_blkzoned(sbi)) {
126 			if (has_enough_free_blocks(sbi,
127 				gc_th->no_zoned_gc_percent)) {
128 				wait_ms = gc_th->no_gc_sleep_time;
129 				f2fs_up_write_trace(&sbi->gc_lock,
130 							&gc_control.lc);
131 				goto next;
132 			}
133 			if (wait_ms == gc_th->no_gc_sleep_time)
134 				wait_ms = gc_th->max_sleep_time;
135 		}
136 
137 		if (need_to_boost_gc(sbi)) {
138 			decrease_sleep_time(gc_th, &wait_ms);
139 			if (f2fs_sb_has_blkzoned(sbi))
140 				gc_boost = true;
141 		} else {
142 			increase_sleep_time(gc_th, &wait_ms);
143 		}
144 do_gc:
145 		stat_inc_gc_call_count(sbi, foreground ?
146 					FOREGROUND : BACKGROUND);
147 
148 		sync_mode = (F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC) ||
149 			(gc_boost && gc_th->boost_gc_greedy);
150 
151 		/* foreground GC was been triggered via f2fs_balance_fs() */
152 		if (foreground && !f2fs_sb_has_blkzoned(sbi))
153 			sync_mode = false;
154 
155 		gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
156 		gc_control.no_bg_gc = foreground;
157 		gc_control.nr_free_secs = foreground ? 1 : 0;
158 
159 		/* if return value is not zero, no victim was selected */
160 		if (f2fs_gc(sbi, &gc_control)) {
161 			/* don't bother wait_ms by foreground gc */
162 			if (!foreground)
163 				wait_ms = gc_th->no_gc_sleep_time;
164 		} else {
165 			/* reset wait_ms to default sleep time */
166 			if (wait_ms == gc_th->no_gc_sleep_time)
167 				wait_ms = gc_th->min_sleep_time;
168 		}
169 
170 		if (foreground)
171 			wake_up_all(&gc_th->fggc_wq);
172 
173 		trace_f2fs_background_gc(sbi->sb, wait_ms,
174 				prefree_segments(sbi), free_segments(sbi));
175 
176 		/* balancing f2fs's metadata periodically */
177 		f2fs_balance_fs_bg(sbi, true);
178 next:
179 		if (sbi->gc_mode != GC_NORMAL) {
180 			spin_lock(&sbi->gc_remaining_trials_lock);
181 			if (sbi->gc_remaining_trials) {
182 				sbi->gc_remaining_trials--;
183 				if (!sbi->gc_remaining_trials)
184 					sbi->gc_mode = GC_NORMAL;
185 			}
186 			spin_unlock(&sbi->gc_remaining_trials_lock);
187 		}
188 		sb_end_write(sbi->sb);
189 
190 	} while (!kthread_should_stop());
191 	return 0;
192 }
193 
194 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
195 {
196 	struct f2fs_gc_kthread *gc_th = &sbi->gc_thread;
197 	dev_t dev = sbi->sb->s_bdev->bd_dev;
198 
199 	gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
200 	gc_th->valid_thresh_ratio = DEF_GC_THREAD_VALID_THRESH_RATIO;
201 	gc_th->boost_gc_multiple = BOOST_GC_MULTIPLE;
202 	gc_th->boost_gc_greedy = GC_GREEDY;
203 
204 	if (f2fs_sb_has_blkzoned(sbi)) {
205 		gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME_ZONED;
206 		gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME_ZONED;
207 		gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME_ZONED;
208 		gc_th->no_zoned_gc_percent = LIMIT_NO_ZONED_GC;
209 		gc_th->boost_zoned_gc_percent = LIMIT_BOOST_ZONED_GC;
210 	} else {
211 		gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
212 		gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
213 		gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
214 		gc_th->no_zoned_gc_percent = 0;
215 		gc_th->boost_zoned_gc_percent = 0;
216 	}
217 
218 	gc_th->gc_wake = false;
219 
220 	init_waitqueue_head(&gc_th->gc_wait_queue_head);
221 	init_waitqueue_head(&gc_th->fggc_wq);
222 	gc_th->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
223 			"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
224 	if (IS_ERR(gc_th->f2fs_gc_task)) {
225 		int err = PTR_ERR(gc_th->f2fs_gc_task);
226 
227 		gc_th->f2fs_gc_task = NULL;
228 		return err;
229 	}
230 
231 	set_user_nice(gc_th->f2fs_gc_task,
232 			PRIO_TO_NICE(sbi->critical_task_priority));
233 	return 0;
234 }
235 
236 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
237 {
238 	struct f2fs_gc_kthread *gc_th = &sbi->gc_thread;
239 
240 	if (!gc_th->f2fs_gc_task)
241 		return;
242 
243 	kthread_stop(gc_th->f2fs_gc_task);
244 	gc_th->f2fs_gc_task = NULL;
245 	wake_up_all(&gc_th->fggc_wq);
246 }
247 
248 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
249 {
250 	int gc_mode;
251 
252 	if (gc_type == BG_GC) {
253 		if (sbi->am.atgc_enabled)
254 			gc_mode = GC_AT;
255 		else
256 			gc_mode = GC_CB;
257 	} else {
258 		gc_mode = GC_GREEDY;
259 	}
260 
261 	switch (sbi->gc_mode) {
262 	case GC_IDLE_CB:
263 	case GC_URGENT_LOW:
264 	case GC_URGENT_MID:
265 		gc_mode = GC_CB;
266 		break;
267 	case GC_IDLE_GREEDY:
268 	case GC_URGENT_HIGH:
269 		gc_mode = GC_GREEDY;
270 		break;
271 	case GC_IDLE_AT:
272 		gc_mode = GC_AT;
273 		break;
274 	}
275 
276 	return gc_mode;
277 }
278 
279 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
280 			int type, struct victim_sel_policy *p)
281 {
282 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
283 
284 	if (p->alloc_mode == SSR || p->alloc_mode == AT_SSR) {
285 		p->gc_mode = GC_GREEDY;
286 		p->dirty_bitmap = dirty_i->dirty_segmap[type];
287 		p->max_search = dirty_i->nr_dirty[type];
288 		p->ofs_unit = 1;
289 	} else {
290 		p->gc_mode = select_gc_type(sbi, gc_type);
291 		p->ofs_unit = SEGS_PER_SEC(sbi);
292 		if (__is_large_section(sbi)) {
293 			p->dirty_bitmap = dirty_i->dirty_secmap;
294 			p->max_search = count_bits(p->dirty_bitmap,
295 						0, MAIN_SECS(sbi));
296 		} else {
297 			p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
298 			p->max_search = dirty_i->nr_dirty[DIRTY];
299 		}
300 	}
301 
302 	/*
303 	 * adjust candidates range, should select all dirty segments for
304 	 * foreground GC and urgent GC cases.
305 	 */
306 	if (gc_type != FG_GC &&
307 			(sbi->gc_mode != GC_URGENT_HIGH) &&
308 			(p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
309 			p->max_search > sbi->max_victim_search)
310 		p->max_search = sbi->max_victim_search;
311 
312 	/* let's select beginning hot/small space first. */
313 	if (f2fs_need_rand_seg_blk(sbi, type)) {
314 		p->offset = get_random_u32_below(MAIN_SECS(sbi) *
315 						SEGS_PER_SEC(sbi));
316 		SIT_I(sbi)->last_victim[p->gc_mode] = p->offset;
317 	} else if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
318 		p->offset = 0;
319 	else
320 		p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
321 }
322 
323 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
324 				struct victim_sel_policy *p)
325 {
326 	/* SSR allocates in a segment unit */
327 	if (p->alloc_mode == SSR)
328 		return BLKS_PER_SEG(sbi);
329 	else if (p->alloc_mode == AT_SSR)
330 		return UINT_MAX;
331 
332 	/* LFS */
333 	if (p->gc_mode == GC_GREEDY)
334 		return SEGS_TO_BLKS(sbi, 2 * p->ofs_unit);
335 	else if (p->gc_mode == GC_CB)
336 		return UINT_MAX;
337 	else if (p->gc_mode == GC_AT)
338 		return UINT_MAX;
339 	else /* No other gc_mode */
340 		return 0;
341 }
342 
343 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
344 {
345 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
346 	unsigned int secno;
347 
348 	/*
349 	 * If the gc_type is FG_GC, we can select victim segments
350 	 * selected by background GC before.
351 	 * Those segments guarantee they have small valid blocks.
352 	 */
353 	for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
354 		if (sec_usage_check(sbi, secno))
355 			continue;
356 		clear_bit(secno, dirty_i->victim_secmap);
357 		return GET_SEG_FROM_SEC(sbi, secno);
358 	}
359 	return NULL_SEGNO;
360 }
361 
362 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
363 {
364 	struct sit_info *sit_i = SIT_I(sbi);
365 	unsigned long long mtime = 0;
366 	unsigned int vblocks;
367 	unsigned char age = 0;
368 	unsigned char u;
369 	unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi);
370 
371 	mtime = f2fs_get_section_mtime(sbi, segno);
372 	f2fs_bug_on(sbi, mtime == INVALID_MTIME);
373 	vblocks = get_valid_blocks(sbi, segno, true);
374 	vblocks = div_u64(vblocks, usable_segs_per_sec);
375 
376 	u = BLKS_TO_SEGS(sbi, vblocks * 100);
377 
378 	/* Handle if the system time has changed by the user */
379 	if (mtime < sit_i->min_mtime)
380 		sit_i->min_mtime = mtime;
381 	if (mtime > sit_i->max_mtime)
382 		sit_i->max_mtime = mtime;
383 	if (sit_i->max_mtime != sit_i->min_mtime)
384 		age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
385 				sit_i->max_mtime - sit_i->min_mtime);
386 
387 	return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
388 }
389 
390 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
391 			unsigned int segno, struct victim_sel_policy *p,
392 			unsigned int valid_thresh_ratio)
393 {
394 	if (p->alloc_mode == SSR)
395 		return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
396 
397 	if (p->one_time_gc && (valid_thresh_ratio < 100) &&
398 			(get_valid_blocks(sbi, segno, true) >=
399 			CAP_BLKS_PER_SEC(sbi) * valid_thresh_ratio / 100))
400 		return UINT_MAX;
401 
402 	/* alloc_mode == LFS */
403 	if (p->gc_mode == GC_GREEDY)
404 		return get_valid_blocks(sbi, segno, true);
405 	else if (p->gc_mode == GC_CB)
406 		return get_cb_cost(sbi, segno);
407 
408 	f2fs_bug_on(sbi, 1);
409 	return 0;
410 }
411 
412 static unsigned int count_bits(const unsigned long *addr,
413 				unsigned int offset, unsigned int len)
414 {
415 	unsigned int end = offset + len, sum = 0;
416 
417 	while (offset < end) {
418 		if (test_bit(offset++, addr))
419 			++sum;
420 	}
421 	return sum;
422 }
423 
424 static bool f2fs_check_victim_tree(struct f2fs_sb_info *sbi,
425 				struct rb_root_cached *root)
426 {
427 #ifdef CONFIG_F2FS_CHECK_FS
428 	struct rb_node *cur = rb_first_cached(root), *next;
429 	struct victim_entry *cur_ve, *next_ve;
430 
431 	while (cur) {
432 		next = rb_next(cur);
433 		if (!next)
434 			return true;
435 
436 		cur_ve = rb_entry(cur, struct victim_entry, rb_node);
437 		next_ve = rb_entry(next, struct victim_entry, rb_node);
438 
439 		if (cur_ve->mtime > next_ve->mtime) {
440 			f2fs_info(sbi, "broken victim_rbtree, "
441 				"cur_mtime(%llu) next_mtime(%llu)",
442 				cur_ve->mtime, next_ve->mtime);
443 			return false;
444 		}
445 		cur = next;
446 	}
447 #endif
448 	return true;
449 }
450 
451 static struct victim_entry *__lookup_victim_entry(struct f2fs_sb_info *sbi,
452 					unsigned long long mtime)
453 {
454 	struct atgc_management *am = &sbi->am;
455 	struct rb_node *node = am->root.rb_root.rb_node;
456 	struct victim_entry *ve = NULL;
457 
458 	while (node) {
459 		ve = rb_entry(node, struct victim_entry, rb_node);
460 
461 		if (mtime < ve->mtime)
462 			node = node->rb_left;
463 		else
464 			node = node->rb_right;
465 	}
466 	return ve;
467 }
468 
469 static struct victim_entry *__create_victim_entry(struct f2fs_sb_info *sbi,
470 		unsigned long long mtime, unsigned int segno)
471 {
472 	struct atgc_management *am = &sbi->am;
473 	struct victim_entry *ve;
474 
475 	ve =  f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS, true, NULL);
476 
477 	ve->mtime = mtime;
478 	ve->segno = segno;
479 
480 	list_add_tail(&ve->list, &am->victim_list);
481 	am->victim_count++;
482 
483 	return ve;
484 }
485 
486 static void __insert_victim_entry(struct f2fs_sb_info *sbi,
487 				unsigned long long mtime, unsigned int segno)
488 {
489 	struct atgc_management *am = &sbi->am;
490 	struct rb_root_cached *root = &am->root;
491 	struct rb_node **p = &root->rb_root.rb_node;
492 	struct rb_node *parent = NULL;
493 	struct victim_entry *ve;
494 	bool left_most = true;
495 
496 	/* look up rb tree to find parent node */
497 	while (*p) {
498 		parent = *p;
499 		ve = rb_entry(parent, struct victim_entry, rb_node);
500 
501 		if (mtime < ve->mtime) {
502 			p = &(*p)->rb_left;
503 		} else {
504 			p = &(*p)->rb_right;
505 			left_most = false;
506 		}
507 	}
508 
509 	ve = __create_victim_entry(sbi, mtime, segno);
510 
511 	rb_link_node(&ve->rb_node, parent, p);
512 	rb_insert_color_cached(&ve->rb_node, root, left_most);
513 }
514 
515 static void add_victim_entry(struct f2fs_sb_info *sbi,
516 				struct victim_sel_policy *p, unsigned int segno)
517 {
518 	struct sit_info *sit_i = SIT_I(sbi);
519 	unsigned long long mtime = 0;
520 
521 	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
522 		if (p->gc_mode == GC_AT &&
523 			get_valid_blocks(sbi, segno, true) == 0)
524 			return;
525 	}
526 
527 	mtime = f2fs_get_section_mtime(sbi, segno);
528 	f2fs_bug_on(sbi, mtime == INVALID_MTIME);
529 
530 	/* Handle if the system time has changed by the user */
531 	if (mtime < sit_i->min_mtime)
532 		sit_i->min_mtime = mtime;
533 	if (mtime > sit_i->max_mtime)
534 		sit_i->max_mtime = mtime;
535 	if (mtime < sit_i->dirty_min_mtime)
536 		sit_i->dirty_min_mtime = mtime;
537 	if (mtime > sit_i->dirty_max_mtime)
538 		sit_i->dirty_max_mtime = mtime;
539 
540 	/* don't choose young section as candidate */
541 	if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
542 		return;
543 
544 	__insert_victim_entry(sbi, mtime, segno);
545 }
546 
547 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
548 						struct victim_sel_policy *p)
549 {
550 	struct sit_info *sit_i = SIT_I(sbi);
551 	struct atgc_management *am = &sbi->am;
552 	struct rb_root_cached *root = &am->root;
553 	struct rb_node *node;
554 	struct victim_entry *ve;
555 	unsigned long long total_time;
556 	unsigned long long age, u, accu;
557 	unsigned long long max_mtime = sit_i->dirty_max_mtime;
558 	unsigned long long min_mtime = sit_i->dirty_min_mtime;
559 	unsigned int sec_blocks = CAP_BLKS_PER_SEC(sbi);
560 	unsigned int vblocks;
561 	unsigned int dirty_threshold = max(am->max_candidate_count,
562 					am->candidate_ratio *
563 					am->victim_count / 100);
564 	unsigned int age_weight = am->age_weight;
565 	unsigned int cost;
566 	unsigned int iter = 0;
567 
568 	if (max_mtime < min_mtime)
569 		return;
570 
571 	max_mtime += 1;
572 	total_time = max_mtime - min_mtime;
573 
574 	accu = div64_u64(ULLONG_MAX, total_time);
575 	accu = min_t(unsigned long long, div_u64(accu, 100),
576 					DEFAULT_ACCURACY_CLASS);
577 
578 	node = rb_first_cached(root);
579 next:
580 	ve = rb_entry_safe(node, struct victim_entry, rb_node);
581 	if (!ve)
582 		return;
583 
584 	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
585 		goto skip;
586 
587 	/* age = 10000 * x% * 60 */
588 	age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
589 								age_weight;
590 
591 	vblocks = get_valid_blocks(sbi, ve->segno, true);
592 	f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
593 
594 	/* u = 10000 * x% * 40 */
595 	u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
596 							(100 - age_weight);
597 
598 	f2fs_bug_on(sbi, age + u >= UINT_MAX);
599 
600 	cost = UINT_MAX - (age + u);
601 	iter++;
602 
603 	if (cost < p->min_cost ||
604 			(cost == p->min_cost && age > p->oldest_age)) {
605 		p->min_cost = cost;
606 		p->oldest_age = age;
607 		p->min_segno = ve->segno;
608 	}
609 skip:
610 	if (iter < dirty_threshold) {
611 		node = rb_next(node);
612 		goto next;
613 	}
614 }
615 
616 /*
617  * select candidates around source section in range of
618  * [target - dirty_threshold, target + dirty_threshold]
619  */
620 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
621 						struct victim_sel_policy *p)
622 {
623 	struct sit_info *sit_i = SIT_I(sbi);
624 	struct atgc_management *am = &sbi->am;
625 	struct victim_entry *ve;
626 	unsigned long long age;
627 	unsigned long long max_mtime = sit_i->dirty_max_mtime;
628 	unsigned long long min_mtime = sit_i->dirty_min_mtime;
629 	unsigned int vblocks;
630 	unsigned int dirty_threshold = max(am->max_candidate_count,
631 					am->candidate_ratio *
632 					am->victim_count / 100);
633 	unsigned int cost, iter;
634 	int stage = 0;
635 
636 	if (max_mtime < min_mtime)
637 		return;
638 	max_mtime += 1;
639 next_stage:
640 	iter = 0;
641 	ve = __lookup_victim_entry(sbi, p->age);
642 next_node:
643 	if (!ve) {
644 		if (stage++ == 0)
645 			goto next_stage;
646 		return;
647 	}
648 
649 	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
650 		goto skip_node;
651 
652 	age = max_mtime - ve->mtime;
653 
654 	vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
655 	f2fs_bug_on(sbi, !vblocks);
656 
657 	/* rare case */
658 	if (vblocks == BLKS_PER_SEG(sbi))
659 		goto skip_node;
660 
661 	iter++;
662 
663 	age = max_mtime - abs(p->age - age);
664 	cost = UINT_MAX - vblocks;
665 
666 	if (cost < p->min_cost ||
667 			(cost == p->min_cost && age > p->oldest_age)) {
668 		p->min_cost = cost;
669 		p->oldest_age = age;
670 		p->min_segno = ve->segno;
671 	}
672 skip_node:
673 	if (iter < dirty_threshold) {
674 		ve = rb_entry(stage == 0 ? rb_prev(&ve->rb_node) :
675 					rb_next(&ve->rb_node),
676 					struct victim_entry, rb_node);
677 		goto next_node;
678 	}
679 
680 	if (stage++ == 0)
681 		goto next_stage;
682 }
683 
684 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
685 						struct victim_sel_policy *p)
686 {
687 	f2fs_bug_on(sbi, !f2fs_check_victim_tree(sbi, &sbi->am.root));
688 
689 	if (p->gc_mode == GC_AT)
690 		atgc_lookup_victim(sbi, p);
691 	else if (p->alloc_mode == AT_SSR)
692 		atssr_lookup_victim(sbi, p);
693 	else
694 		f2fs_bug_on(sbi, 1);
695 }
696 
697 static void release_victim_entry(struct f2fs_sb_info *sbi)
698 {
699 	struct atgc_management *am = &sbi->am;
700 	struct victim_entry *ve, *tmp;
701 
702 	list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
703 		list_del(&ve->list);
704 		kmem_cache_free(victim_entry_slab, ve);
705 		am->victim_count--;
706 	}
707 
708 	am->root = RB_ROOT_CACHED;
709 
710 	f2fs_bug_on(sbi, am->victim_count);
711 	f2fs_bug_on(sbi, !list_empty(&am->victim_list));
712 }
713 
714 static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
715 {
716 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
717 	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
718 
719 	if (!dirty_i->enable_pin_section)
720 		return false;
721 	if (!test_and_set_bit(secno, dirty_i->pinned_secmap))
722 		dirty_i->pinned_secmap_cnt++;
723 	return true;
724 }
725 
726 static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
727 {
728 	return dirty_i->pinned_secmap_cnt;
729 }
730 
731 static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
732 						unsigned int secno)
733 {
734 	return dirty_i->enable_pin_section &&
735 		f2fs_pinned_section_exists(dirty_i) &&
736 		test_bit(secno, dirty_i->pinned_secmap);
737 }
738 
739 static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
740 {
741 	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
742 
743 	if (f2fs_pinned_section_exists(DIRTY_I(sbi))) {
744 		memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
745 		DIRTY_I(sbi)->pinned_secmap_cnt = 0;
746 	}
747 	DIRTY_I(sbi)->enable_pin_section = enable;
748 }
749 
750 static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
751 							unsigned int segno)
752 {
753 	if (!f2fs_is_pinned_file(inode))
754 		return 0;
755 	if (gc_type != FG_GC)
756 		return -EBUSY;
757 	if (!f2fs_pin_section(F2FS_I_SB(inode), segno))
758 		f2fs_pin_file_control(inode, true);
759 	return -EAGAIN;
760 }
761 
762 /*
763  * This function is called from two paths.
764  * One is garbage collection and the other is SSR segment selection.
765  * When it is called during GC, it just gets a victim segment
766  * and it does not remove it from dirty seglist.
767  * When it is called from SSR segment selection, it finds a segment
768  * which has minimum valid blocks and removes it from dirty seglist.
769  */
770 int f2fs_get_victim(struct f2fs_sb_info *sbi, unsigned int *result,
771 			int gc_type, int type, char alloc_mode,
772 			unsigned long long age, bool one_time)
773 {
774 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
775 	struct sit_info *sm = SIT_I(sbi);
776 	struct victim_sel_policy p = {0};
777 	unsigned int secno, last_victim;
778 	unsigned int last_segment;
779 	unsigned int nsearched;
780 	unsigned int valid_thresh_ratio = 100;
781 	bool is_atgc;
782 	int ret = 0;
783 
784 	mutex_lock(&dirty_i->seglist_lock);
785 	last_segment = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
786 
787 	p.alloc_mode = alloc_mode;
788 	p.age = age;
789 	p.age_threshold = sbi->am.age_threshold;
790 	if (one_time) {
791 		p.one_time_gc = one_time;
792 		if (has_enough_free_secs(sbi, 0, NR_PERSISTENT_LOG))
793 			valid_thresh_ratio = sbi->gc_thread.valid_thresh_ratio;
794 	}
795 
796 retry:
797 	select_policy(sbi, gc_type, type, &p);
798 	p.min_segno = NULL_SEGNO;
799 	p.oldest_age = 0;
800 	p.min_cost = get_max_cost(sbi, &p);
801 
802 	is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
803 	nsearched = 0;
804 
805 	if (is_atgc)
806 		SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
807 
808 	if (*result != NULL_SEGNO) {
809 		if (!get_valid_blocks(sbi, *result, false)) {
810 			ret = -ENODATA;
811 			goto out;
812 		}
813 
814 		if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result))) {
815 			ret = -EBUSY;
816 			goto out;
817 		}
818 		if (gc_type == FG_GC)
819 			clear_bit(GET_SEC_FROM_SEG(sbi, *result), dirty_i->victim_secmap);
820 		p.min_segno = *result;
821 		goto got_result;
822 	}
823 
824 	ret = -ENODATA;
825 	if (p.max_search == 0)
826 		goto out;
827 
828 	if (__is_large_section(sbi) && p.alloc_mode == LFS) {
829 		if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
830 			p.min_segno = sbi->next_victim_seg[BG_GC];
831 			*result = p.min_segno;
832 			sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
833 			goto got_result;
834 		}
835 		if (gc_type == FG_GC &&
836 				sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
837 			p.min_segno = sbi->next_victim_seg[FG_GC];
838 			*result = p.min_segno;
839 			sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
840 			goto got_result;
841 		}
842 	}
843 
844 	last_victim = sm->last_victim[p.gc_mode];
845 	if (p.alloc_mode == LFS && gc_type == FG_GC) {
846 		p.min_segno = check_bg_victims(sbi);
847 		if (p.min_segno != NULL_SEGNO)
848 			goto got_it;
849 	}
850 
851 	while (1) {
852 		unsigned long cost, *dirty_bitmap;
853 		unsigned int unit_no, segno;
854 
855 		dirty_bitmap = p.dirty_bitmap;
856 		unit_no = find_next_bit(dirty_bitmap,
857 				last_segment / p.ofs_unit,
858 				p.offset / p.ofs_unit);
859 		segno = unit_no * p.ofs_unit;
860 		if (segno >= last_segment) {
861 			if (sm->last_victim[p.gc_mode]) {
862 				last_segment =
863 					sm->last_victim[p.gc_mode];
864 				sm->last_victim[p.gc_mode] = 0;
865 				p.offset = 0;
866 				continue;
867 			}
868 			break;
869 		}
870 
871 		p.offset = segno + p.ofs_unit;
872 		nsearched++;
873 
874 #ifdef CONFIG_F2FS_CHECK_FS
875 		/*
876 		 * skip selecting the invalid segno (that is failed due to block
877 		 * validity check failure during GC) to avoid endless GC loop in
878 		 * such cases.
879 		 */
880 		if (test_bit(segno, sm->invalid_segmap))
881 			goto next;
882 #endif
883 
884 		secno = GET_SEC_FROM_SEG(sbi, segno);
885 
886 		if (sec_usage_check(sbi, secno))
887 			goto next;
888 
889 		/* Don't touch checkpointed data */
890 		if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
891 			if (p.alloc_mode == LFS) {
892 				/*
893 				 * LFS is set to find source section during GC.
894 				 * The victim should have no checkpointed data.
895 				 */
896 				if (get_ckpt_valid_blocks(sbi, segno, true))
897 					goto next;
898 			} else {
899 				/*
900 				 * SSR | AT_SSR are set to find target segment
901 				 * for writes which can be full by checkpointed
902 				 * and newly written blocks.
903 				 */
904 				if (!f2fs_segment_has_free_slot(sbi, segno))
905 					goto next;
906 			}
907 
908 			if (!get_valid_blocks(sbi, segno, true))
909 				goto next;
910 		}
911 
912 		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
913 			goto next;
914 
915 		if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
916 			goto next;
917 
918 		if (is_atgc) {
919 			add_victim_entry(sbi, &p, segno);
920 			goto next;
921 		}
922 
923 		cost = get_gc_cost(sbi, segno, &p, valid_thresh_ratio);
924 
925 		if (p.min_cost > cost) {
926 			p.min_segno = segno;
927 			p.min_cost = cost;
928 		}
929 next:
930 		if (nsearched >= p.max_search) {
931 			if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
932 				sm->last_victim[p.gc_mode] =
933 					last_victim + p.ofs_unit;
934 			else
935 				sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
936 			sm->last_victim[p.gc_mode] %=
937 				(MAIN_SECS(sbi) * SEGS_PER_SEC(sbi));
938 			break;
939 		}
940 	}
941 
942 	/* get victim for GC_AT/AT_SSR */
943 	if (is_atgc) {
944 		lookup_victim_by_age(sbi, &p);
945 		release_victim_entry(sbi);
946 	}
947 
948 	if (is_atgc && p.min_segno == NULL_SEGNO &&
949 			sm->elapsed_time < p.age_threshold) {
950 		p.age_threshold = 0;
951 		goto retry;
952 	}
953 
954 	if (p.min_segno != NULL_SEGNO) {
955 got_it:
956 		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
957 got_result:
958 		if (p.alloc_mode == LFS) {
959 			secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
960 			if (gc_type == FG_GC)
961 				sbi->cur_victim_sec = secno;
962 			else
963 				set_bit(secno, dirty_i->victim_secmap);
964 		}
965 		ret = 0;
966 
967 	}
968 out:
969 	if (p.min_segno != NULL_SEGNO)
970 		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
971 				sbi->cur_victim_sec,
972 				prefree_segments(sbi), free_segments(sbi));
973 	mutex_unlock(&dirty_i->seglist_lock);
974 
975 	return ret;
976 }
977 
978 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
979 {
980 	struct inode_entry *ie;
981 
982 	ie = radix_tree_lookup(&gc_list->iroot, ino);
983 	if (ie)
984 		return ie->inode;
985 	return NULL;
986 }
987 
988 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
989 {
990 	struct inode_entry *new_ie;
991 
992 	if (inode == find_gc_inode(gc_list, inode->i_ino)) {
993 		iput(inode);
994 		return;
995 	}
996 	new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
997 					GFP_NOFS, true, NULL);
998 	new_ie->inode = inode;
999 
1000 	f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
1001 	list_add_tail(&new_ie->list, &gc_list->ilist);
1002 }
1003 
1004 static void put_gc_inode(struct gc_inode_list *gc_list)
1005 {
1006 	struct inode_entry *ie, *next_ie;
1007 
1008 	list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
1009 		radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
1010 		iput(ie->inode);
1011 		list_del(&ie->list);
1012 		kmem_cache_free(f2fs_inode_entry_slab, ie);
1013 	}
1014 }
1015 
1016 static int check_valid_map(struct f2fs_sb_info *sbi,
1017 				unsigned int segno, int offset)
1018 {
1019 	struct sit_info *sit_i = SIT_I(sbi);
1020 	struct seg_entry *sentry;
1021 	int ret;
1022 
1023 	down_read(&sit_i->sentry_lock);
1024 	sentry = get_seg_entry(sbi, segno);
1025 	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
1026 	up_read(&sit_i->sentry_lock);
1027 	return ret;
1028 }
1029 
1030 /*
1031  * This function compares node address got in summary with that in NAT.
1032  * On validity, copy that node with cold status, otherwise (invalid node)
1033  * ignore that.
1034  */
1035 static int gc_node_segment(struct f2fs_sb_info *sbi,
1036 		struct f2fs_summary *sum, unsigned int segno, int gc_type,
1037 		struct blk_plug *plug)
1038 {
1039 	struct f2fs_summary *entry;
1040 	block_t start_addr;
1041 	int off;
1042 	int phase = 0;
1043 	bool fggc = (gc_type == FG_GC);
1044 	int submitted = 0;
1045 	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1046 
1047 	start_addr = START_BLOCK(sbi, segno);
1048 
1049 next_step:
1050 	entry = sum;
1051 
1052 	if (fggc && phase == 2)
1053 		atomic_inc(&sbi->wb_sync_req[NODE]);
1054 
1055 	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1056 		nid_t nid = le32_to_cpu(entry->nid);
1057 		struct folio *node_folio;
1058 		struct node_info ni;
1059 		int err;
1060 
1061 		/* stop BG_GC if there is not enough free sections. */
1062 		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
1063 			return submitted;
1064 
1065 		if (check_valid_map(sbi, segno, off) == 0)
1066 			continue;
1067 
1068 		if (phase == 0) {
1069 			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1070 							META_NAT, true);
1071 			continue;
1072 		}
1073 
1074 		if (phase == 1) {
1075 			f2fs_ra_node_page(sbi, nid);
1076 			continue;
1077 		}
1078 
1079 		/* phase == 2 */
1080 		node_folio = f2fs_get_node_folio(sbi, nid, NODE_TYPE_REGULAR);
1081 		if (IS_ERR(node_folio))
1082 			continue;
1083 
1084 		/* block may become invalid during f2fs_get_node_folio */
1085 		if (check_valid_map(sbi, segno, off) == 0) {
1086 			f2fs_folio_put(node_folio, true);
1087 			continue;
1088 		}
1089 
1090 		if (f2fs_get_node_info(sbi, nid, &ni, false)) {
1091 			f2fs_folio_put(node_folio, true);
1092 			continue;
1093 		}
1094 
1095 		if (ni.blk_addr != start_addr + off) {
1096 			f2fs_folio_put(node_folio, true);
1097 			continue;
1098 		}
1099 
1100 		err = f2fs_move_node_folio(node_folio, gc_type);
1101 		if (!err && gc_type == FG_GC)
1102 			submitted++;
1103 		stat_inc_node_blk_count(sbi, 1, gc_type);
1104 	}
1105 
1106 	if (++phase < 3) {
1107 		blk_finish_plug(plug);
1108 		blk_start_plug(plug);
1109 		goto next_step;
1110 	}
1111 
1112 	if (fggc)
1113 		atomic_dec(&sbi->wb_sync_req[NODE]);
1114 	return submitted;
1115 }
1116 
1117 /*
1118  * Calculate start block index indicating the given node offset.
1119  * Be careful, caller should give this node offset only indicating direct node
1120  * blocks. If any node offsets, which point the other types of node blocks such
1121  * as indirect or double indirect node blocks, are given, it must be a caller's
1122  * bug.
1123  */
1124 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1125 {
1126 	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1127 	unsigned int bidx;
1128 
1129 	if (node_ofs == 0)
1130 		return 0;
1131 
1132 	if (node_ofs <= 2) {
1133 		bidx = node_ofs - 1;
1134 	} else if (node_ofs <= indirect_blks) {
1135 		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1136 
1137 		bidx = node_ofs - 2 - dec;
1138 	} else {
1139 		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1140 
1141 		bidx = node_ofs - 5 - dec;
1142 	}
1143 	return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1144 }
1145 
1146 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1147 		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1148 {
1149 	struct folio *node_folio;
1150 	nid_t nid;
1151 	unsigned int ofs_in_node, max_addrs, base;
1152 	block_t source_blkaddr;
1153 
1154 	nid = le32_to_cpu(sum->nid);
1155 	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1156 
1157 	node_folio = f2fs_get_node_folio(sbi, nid, NODE_TYPE_REGULAR);
1158 	if (IS_ERR(node_folio))
1159 		return false;
1160 
1161 	if (f2fs_get_node_info(sbi, nid, dni, false)) {
1162 		f2fs_folio_put(node_folio, true);
1163 		return false;
1164 	}
1165 
1166 	if (sum->version != dni->version) {
1167 		f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1168 			  __func__);
1169 		set_sbi_flag(sbi, SBI_NEED_FSCK);
1170 	}
1171 
1172 	if (f2fs_check_nid_range(sbi, dni->ino)) {
1173 		f2fs_folio_put(node_folio, true);
1174 		return false;
1175 	}
1176 
1177 	if (IS_INODE(node_folio)) {
1178 		base = offset_in_addr(F2FS_INODE(node_folio));
1179 		max_addrs = DEF_ADDRS_PER_INODE;
1180 	} else {
1181 		base = 0;
1182 		max_addrs = DEF_ADDRS_PER_BLOCK;
1183 	}
1184 
1185 	if (base + ofs_in_node >= max_addrs) {
1186 		f2fs_err(sbi, "Inconsistent blkaddr offset: base:%u, ofs_in_node:%u, max:%u, ino:%u, nid:%u",
1187 			base, ofs_in_node, max_addrs, dni->ino, dni->nid);
1188 		f2fs_folio_put(node_folio, true);
1189 		return false;
1190 	}
1191 
1192 	*nofs = ofs_of_node(node_folio);
1193 	source_blkaddr = data_blkaddr(NULL, node_folio, ofs_in_node);
1194 	f2fs_folio_put(node_folio, true);
1195 
1196 	if (source_blkaddr != blkaddr) {
1197 #ifdef CONFIG_F2FS_CHECK_FS
1198 		unsigned int segno = GET_SEGNO(sbi, blkaddr);
1199 		unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1200 
1201 		if (unlikely(check_valid_map(sbi, segno, offset))) {
1202 			if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1203 				f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1204 					 blkaddr, source_blkaddr, segno);
1205 				set_sbi_flag(sbi, SBI_NEED_FSCK);
1206 			}
1207 		}
1208 #endif
1209 		return false;
1210 	}
1211 	return true;
1212 }
1213 
1214 static int ra_data_block(struct inode *inode, pgoff_t index)
1215 {
1216 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1217 	struct address_space *mapping = inode->i_mapping;
1218 	struct inode *atomic_inode = NULL;
1219 	struct dnode_of_data dn;
1220 	struct folio *folio, *efolio;
1221 	struct f2fs_io_info fio = {
1222 		.sbi = sbi,
1223 		.ino = inode->i_ino,
1224 		.type = DATA,
1225 		.temp = COLD,
1226 		.op = REQ_OP_READ,
1227 		.op_flags = 0,
1228 		.encrypted_page = NULL,
1229 		.in_list = 0,
1230 	};
1231 	int err = 0;
1232 
1233 	f2fs_down_read(&F2FS_I(inode)->i_sem);
1234 	if (f2fs_is_cow_file(inode)) {
1235 		atomic_inode = igrab(F2FS_I(inode)->atomic_inode);
1236 		if (!atomic_inode) {
1237 			f2fs_up_read(&F2FS_I(inode)->i_sem);
1238 			return -EBUSY;
1239 		}
1240 		mapping = atomic_inode->i_mapping;
1241 	}
1242 	f2fs_up_read(&F2FS_I(inode)->i_sem);
1243 
1244 	folio = f2fs_grab_cache_folio(mapping, index, true);
1245 	if (IS_ERR(folio)) {
1246 		err = PTR_ERR(folio);
1247 		goto out_iput;
1248 	}
1249 
1250 	if (f2fs_lookup_read_extent_cache_block(inode, index,
1251 						&dn.data_blkaddr)) {
1252 		if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1253 						DATA_GENERIC_ENHANCE_READ))) {
1254 			err = -EFSCORRUPTED;
1255 			goto put_folio;
1256 		}
1257 		goto got_it;
1258 	}
1259 
1260 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1261 	err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1262 	if (err)
1263 		goto put_folio;
1264 	f2fs_put_dnode(&dn);
1265 
1266 	if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1267 		err = -ENOENT;
1268 		goto put_folio;
1269 	}
1270 	if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1271 						DATA_GENERIC_ENHANCE))) {
1272 		err = -EFSCORRUPTED;
1273 		goto put_folio;
1274 	}
1275 got_it:
1276 	/* read folio */
1277 	fio.folio = folio;
1278 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1279 
1280 	/*
1281 	 * don't cache encrypted data into meta inode until previous dirty
1282 	 * data were writebacked to avoid racing between GC and flush.
1283 	 */
1284 	f2fs_folio_wait_writeback(folio, DATA, true, true);
1285 
1286 	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1287 
1288 	efolio = f2fs_filemap_get_folio(META_MAPPING(sbi), dn.data_blkaddr,
1289 					FGP_LOCK | FGP_CREAT, GFP_NOFS);
1290 	if (IS_ERR(efolio)) {
1291 		err = PTR_ERR(efolio);
1292 		goto put_folio;
1293 	}
1294 
1295 	fio.encrypted_page = &efolio->page;
1296 
1297 	if (folio_test_uptodate(efolio))
1298 		goto put_encrypted_page;
1299 
1300 	err = f2fs_submit_page_bio(&fio);
1301 	if (err)
1302 		goto put_encrypted_page;
1303 	f2fs_put_page(fio.encrypted_page, false);
1304 	f2fs_folio_put(folio, true);
1305 
1306 	f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE);
1307 	f2fs_update_iostat(sbi, NULL, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1308 
1309 	if (atomic_inode)
1310 		iput(atomic_inode);
1311 	return 0;
1312 put_encrypted_page:
1313 	f2fs_put_page(fio.encrypted_page, true);
1314 put_folio:
1315 	f2fs_folio_put(folio, true);
1316 out_iput:
1317 	if (atomic_inode)
1318 		iput(atomic_inode);
1319 	return err;
1320 }
1321 
1322 /*
1323  * Move data block via META_MAPPING while keeping locked data page.
1324  * This can be used to move blocks, aka LBAs, directly on disk.
1325  */
1326 static int move_data_block(struct inode *inode, block_t bidx,
1327 				int gc_type, unsigned int segno, int off)
1328 {
1329 	struct address_space *mapping = inode->i_mapping;
1330 	struct inode *atomic_inode = NULL;
1331 	struct f2fs_io_info fio = {
1332 		.sbi = F2FS_I_SB(inode),
1333 		.ino = inode->i_ino,
1334 		.type = DATA,
1335 		.temp = COLD,
1336 		.op = REQ_OP_READ,
1337 		.op_flags = 0,
1338 		.encrypted_page = NULL,
1339 		.in_list = 0,
1340 	};
1341 	struct dnode_of_data dn;
1342 	struct f2fs_summary sum;
1343 	struct node_info ni;
1344 	struct folio *folio, *mfolio, *efolio;
1345 	block_t newaddr;
1346 	int err = 0;
1347 	bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1348 	int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1349 				(fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1350 				CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1351 
1352 	f2fs_down_read(&F2FS_I(inode)->i_sem);
1353 	if (f2fs_is_cow_file(inode)) {
1354 		atomic_inode = igrab(F2FS_I(inode)->atomic_inode);
1355 		if (!atomic_inode) {
1356 			f2fs_up_read(&F2FS_I(inode)->i_sem);
1357 			return -EBUSY;
1358 		}
1359 		mapping = atomic_inode->i_mapping;
1360 	}
1361 	f2fs_up_read(&F2FS_I(inode)->i_sem);
1362 
1363 	/* do not read out */
1364 	folio = f2fs_grab_cache_folio(mapping, bidx, false);
1365 	if (IS_ERR(folio)) {
1366 		err = PTR_ERR(folio);
1367 		goto out_iput;
1368 	}
1369 
1370 	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1371 		err = -ENOENT;
1372 		goto out;
1373 	}
1374 
1375 	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1376 	if (err)
1377 		goto out;
1378 
1379 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1380 	err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1381 	if (err)
1382 		goto out;
1383 
1384 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1385 		folio_clear_uptodate(folio);
1386 		err = -ENOENT;
1387 		goto put_out;
1388 	}
1389 
1390 	/*
1391 	 * don't cache encrypted data into meta inode until previous dirty
1392 	 * data were writebacked to avoid racing between GC and flush.
1393 	 */
1394 	f2fs_folio_wait_writeback(folio, DATA, true, true);
1395 
1396 	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1397 
1398 	err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1399 	if (err)
1400 		goto put_out;
1401 
1402 	/* read page */
1403 	fio.folio = folio;
1404 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1405 
1406 	if (lfs_mode)
1407 		f2fs_down_write(&fio.sbi->io_order_lock);
1408 
1409 	mfolio = f2fs_grab_cache_folio(META_MAPPING(fio.sbi),
1410 					fio.old_blkaddr, false);
1411 	if (IS_ERR(mfolio)) {
1412 		err = PTR_ERR(mfolio);
1413 		goto up_out;
1414 	}
1415 
1416 	fio.encrypted_page = folio_file_page(mfolio, fio.old_blkaddr);
1417 
1418 	/* read source block in mfolio */
1419 	if (!folio_test_uptodate(mfolio)) {
1420 		err = f2fs_submit_page_bio(&fio);
1421 		if (err) {
1422 			f2fs_folio_put(mfolio, true);
1423 			goto up_out;
1424 		}
1425 
1426 		f2fs_update_iostat(fio.sbi, inode, FS_DATA_READ_IO,
1427 							F2FS_BLKSIZE);
1428 		f2fs_update_iostat(fio.sbi, NULL, FS_GDATA_READ_IO,
1429 							F2FS_BLKSIZE);
1430 
1431 		folio_lock(mfolio);
1432 		if (unlikely(!is_meta_folio(mfolio) ||
1433 			     !folio_test_uptodate(mfolio))) {
1434 			err = -EIO;
1435 			f2fs_folio_put(mfolio, true);
1436 			goto up_out;
1437 		}
1438 	}
1439 
1440 	set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1441 
1442 	/* allocate block address */
1443 	err = f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1444 				&sum, type, NULL);
1445 	if (err) {
1446 		f2fs_folio_put(mfolio, true);
1447 		/* filesystem should shutdown, no need to recovery block */
1448 		goto up_out;
1449 	}
1450 
1451 	efolio = f2fs_filemap_get_folio(META_MAPPING(fio.sbi), newaddr,
1452 					FGP_LOCK | FGP_CREAT, GFP_NOFS);
1453 	if (IS_ERR(efolio)) {
1454 		err = PTR_ERR(efolio);
1455 		f2fs_folio_put(mfolio, true);
1456 		goto recover_block;
1457 	}
1458 
1459 	fio.encrypted_page = &efolio->page;
1460 
1461 	/* write target block */
1462 	f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1463 	memcpy(page_address(fio.encrypted_page),
1464 				folio_address(mfolio), PAGE_SIZE);
1465 	f2fs_folio_put(mfolio, true);
1466 
1467 	f2fs_invalidate_internal_cache(fio.sbi, fio.old_blkaddr, 1);
1468 
1469 	set_page_dirty(fio.encrypted_page);
1470 	if (clear_page_dirty_for_io(fio.encrypted_page))
1471 		dec_page_count(fio.sbi, F2FS_DIRTY_META);
1472 
1473 	set_page_writeback(fio.encrypted_page);
1474 
1475 	fio.op = REQ_OP_WRITE;
1476 	fio.op_flags = REQ_SYNC;
1477 	fio.new_blkaddr = newaddr;
1478 	f2fs_submit_page_write(&fio);
1479 
1480 	f2fs_update_iostat(fio.sbi, NULL, FS_GC_DATA_IO, F2FS_BLKSIZE);
1481 
1482 	f2fs_update_data_blkaddr(&dn, newaddr);
1483 	set_inode_flag(inode, FI_APPEND_WRITE);
1484 
1485 	f2fs_put_page(fio.encrypted_page, true);
1486 recover_block:
1487 	if (err)
1488 		f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1489 							true, true, true);
1490 up_out:
1491 	if (lfs_mode)
1492 		f2fs_up_write(&fio.sbi->io_order_lock);
1493 put_out:
1494 	f2fs_put_dnode(&dn);
1495 out:
1496 	f2fs_folio_put(folio, true);
1497 out_iput:
1498 	if (atomic_inode)
1499 		iput(atomic_inode);
1500 	return err;
1501 }
1502 
1503 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1504 						unsigned int segno, int off)
1505 {
1506 	struct folio *folio;
1507 	int err = 0;
1508 
1509 	folio = f2fs_get_lock_data_folio(inode, bidx, true);
1510 	if (IS_ERR(folio))
1511 		return PTR_ERR(folio);
1512 
1513 	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1514 		err = -ENOENT;
1515 		goto out;
1516 	}
1517 
1518 	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1519 	if (err)
1520 		goto out;
1521 
1522 	if (gc_type == BG_GC) {
1523 		if (folio_test_writeback(folio)) {
1524 			err = -EAGAIN;
1525 			goto out;
1526 		}
1527 		folio_mark_dirty(folio);
1528 		folio_set_f2fs_gcing(folio);
1529 	} else {
1530 		struct f2fs_io_info fio = {
1531 			.sbi = F2FS_I_SB(inode),
1532 			.ino = inode->i_ino,
1533 			.type = DATA,
1534 			.temp = COLD,
1535 			.op = REQ_OP_WRITE,
1536 			.op_flags = REQ_SYNC,
1537 			.old_blkaddr = NULL_ADDR,
1538 			.folio = folio,
1539 			.encrypted_page = NULL,
1540 			.need_lock = LOCK_REQ,
1541 			.io_type = FS_GC_DATA_IO,
1542 		};
1543 		bool is_dirty = folio_test_dirty(folio);
1544 
1545 retry:
1546 		f2fs_folio_wait_writeback(folio, DATA, true, true);
1547 
1548 		folio_mark_dirty(folio);
1549 		if (folio_clear_dirty_for_io(folio)) {
1550 			inode_dec_dirty_pages(inode);
1551 			f2fs_remove_dirty_inode(inode);
1552 		}
1553 
1554 		folio_set_f2fs_gcing(folio);
1555 
1556 		err = f2fs_do_write_data_page(&fio);
1557 		if (err) {
1558 			folio_clear_f2fs_gcing(folio);
1559 			if (err == -ENOMEM) {
1560 				memalloc_retry_wait(GFP_NOFS);
1561 				goto retry;
1562 			}
1563 			if (is_dirty)
1564 				folio_mark_dirty(folio);
1565 		}
1566 	}
1567 out:
1568 	f2fs_folio_put(folio, true);
1569 	return err;
1570 }
1571 
1572 /*
1573  * This function tries to get parent node of victim data block, and identifies
1574  * data block validity. If the block is valid, copy that with cold status and
1575  * modify parent node.
1576  * If the parent node is not valid or the data block address is different,
1577  * the victim data block is ignored.
1578  */
1579 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1580 		struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1581 		bool force_migrate, struct blk_plug *plug)
1582 {
1583 	struct super_block *sb = sbi->sb;
1584 	struct f2fs_summary *entry;
1585 	block_t start_addr;
1586 	int off;
1587 	int phase = 0;
1588 	int submitted = 0;
1589 	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1590 
1591 	start_addr = START_BLOCK(sbi, segno);
1592 
1593 next_step:
1594 	entry = sum;
1595 
1596 	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1597 		struct inode *inode;
1598 		struct node_info dni; /* dnode info for the data */
1599 		unsigned int ofs_in_node, nofs;
1600 		block_t start_bidx;
1601 		nid_t nid = le32_to_cpu(entry->nid);
1602 
1603 		/*
1604 		 * stop BG_GC if there is not enough free sections.
1605 		 * Or, stop GC if the segment becomes fully valid caused by
1606 		 * race condition along with SSR block allocation.
1607 		 */
1608 		if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1609 			(!force_migrate && get_valid_blocks(sbi, segno, true) ==
1610 							CAP_BLKS_PER_SEC(sbi)))
1611 			return submitted;
1612 
1613 		if (check_valid_map(sbi, segno, off) == 0)
1614 			continue;
1615 
1616 		if (phase == 0) {
1617 			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1618 							META_NAT, true);
1619 			continue;
1620 		}
1621 
1622 		if (phase == 1) {
1623 			f2fs_ra_node_page(sbi, nid);
1624 			continue;
1625 		}
1626 
1627 		/* Get an inode by ino with checking validity */
1628 		if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1629 			continue;
1630 
1631 		if (phase == 2) {
1632 			f2fs_ra_node_page(sbi, dni.ino);
1633 			continue;
1634 		}
1635 
1636 		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1637 
1638 		if (phase == 3) {
1639 			struct folio *data_folio;
1640 			int err;
1641 
1642 			inode = f2fs_iget(sb, dni.ino);
1643 			if (IS_ERR(inode))
1644 				continue;
1645 
1646 			if (is_bad_inode(inode) ||
1647 					special_file(inode->i_mode)) {
1648 				iput(inode);
1649 				continue;
1650 			}
1651 
1652 			if (f2fs_has_inline_data(inode)) {
1653 				iput(inode);
1654 				set_sbi_flag(sbi, SBI_NEED_FSCK);
1655 				f2fs_err_ratelimited(sbi,
1656 					"inode %llu has both inline_data flag and "
1657 					"data block, nid=%u, ofs_in_node=%u",
1658 					inode->i_ino, dni.nid, ofs_in_node);
1659 				continue;
1660 			}
1661 
1662 			err = f2fs_gc_pinned_control(inode, gc_type, segno);
1663 			if (err == -EAGAIN) {
1664 				iput(inode);
1665 				return submitted;
1666 			}
1667 
1668 			if (!f2fs_down_write_trylock(
1669 				&F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1670 				iput(inode);
1671 				sbi->skipped_gc_rwsem++;
1672 				continue;
1673 			}
1674 
1675 			start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1676 								ofs_in_node;
1677 
1678 			if (f2fs_meta_inode_gc_required(inode)) {
1679 				int err = ra_data_block(inode, start_bidx);
1680 
1681 				f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1682 				if (err) {
1683 					iput(inode);
1684 					continue;
1685 				}
1686 				add_gc_inode(gc_list, inode);
1687 				continue;
1688 			}
1689 
1690 			data_folio = f2fs_get_read_data_folio(inode, start_bidx,
1691 							REQ_RAHEAD, true, NULL);
1692 			f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1693 			if (IS_ERR(data_folio)) {
1694 				iput(inode);
1695 				continue;
1696 			}
1697 
1698 			f2fs_folio_put(data_folio, false);
1699 			add_gc_inode(gc_list, inode);
1700 			continue;
1701 		}
1702 
1703 		/* phase 4 */
1704 		inode = find_gc_inode(gc_list, dni.ino);
1705 		if (inode) {
1706 			struct f2fs_inode_info *fi = F2FS_I(inode);
1707 			bool locked = false;
1708 			int err;
1709 
1710 			if (S_ISREG(inode->i_mode)) {
1711 				if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[WRITE])) {
1712 					sbi->skipped_gc_rwsem++;
1713 					continue;
1714 				}
1715 				if (!f2fs_down_write_trylock(
1716 						&fi->i_gc_rwsem[READ])) {
1717 					sbi->skipped_gc_rwsem++;
1718 					f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1719 					continue;
1720 				}
1721 				locked = true;
1722 
1723 				/* wait for all inflight aio data */
1724 				inode_dio_wait(inode);
1725 			}
1726 
1727 			start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1728 								+ ofs_in_node;
1729 			if (f2fs_meta_inode_gc_required(inode))
1730 				err = move_data_block(inode, start_bidx,
1731 							gc_type, segno, off);
1732 			else
1733 				err = move_data_page(inode, start_bidx, gc_type,
1734 								segno, off);
1735 
1736 			if (!err && (gc_type == FG_GC ||
1737 					f2fs_meta_inode_gc_required(inode)))
1738 				submitted++;
1739 
1740 			if (locked) {
1741 				f2fs_up_write(&fi->i_gc_rwsem[READ]);
1742 				f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1743 			}
1744 
1745 			stat_inc_data_blk_count(sbi, 1, gc_type);
1746 		}
1747 	}
1748 
1749 	if (++phase < 5) {
1750 		blk_finish_plug(plug);
1751 		blk_start_plug(plug);
1752 		goto next_step;
1753 	}
1754 
1755 	return submitted;
1756 }
1757 
1758 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1759 			int gc_type, bool one_time)
1760 {
1761 	struct sit_info *sit_i = SIT_I(sbi);
1762 	int ret;
1763 
1764 	down_write(&sit_i->sentry_lock);
1765 	ret = f2fs_get_victim(sbi, victim, gc_type, NO_CHECK_TYPE,
1766 			LFS, 0, one_time);
1767 	up_write(&sit_i->sentry_lock);
1768 	return ret;
1769 }
1770 
1771 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1772 				unsigned int start_segno,
1773 				struct gc_inode_list *gc_list, int gc_type,
1774 				bool force_migrate, bool one_time)
1775 {
1776 	struct blk_plug plug;
1777 	unsigned int segno = start_segno;
1778 	unsigned int end_segno = start_segno + SEGS_PER_SEC(sbi);
1779 	unsigned int sec_end_segno;
1780 	int seg_freed = 0, migrated = 0;
1781 	unsigned char type;
1782 	unsigned char data_type;
1783 	int submitted = 0, sum_blk_cnt;
1784 
1785 	if (__is_large_section(sbi)) {
1786 		sec_end_segno = rounddown(end_segno, SEGS_PER_SEC(sbi));
1787 
1788 		/*
1789 		 * zone-capacity can be less than zone-size in zoned devices,
1790 		 * resulting in less than expected usable segments in the zone,
1791 		 * calculate the end segno in the zone which can be garbage
1792 		 * collected
1793 		 */
1794 		if (f2fs_sb_has_blkzoned(sbi))
1795 			sec_end_segno -= SEGS_PER_SEC(sbi) -
1796 					f2fs_usable_segs_in_sec(sbi);
1797 
1798 		if (gc_type == BG_GC || one_time) {
1799 			unsigned int window_granularity =
1800 				sbi->migration_window_granularity;
1801 
1802 			if (f2fs_sb_has_blkzoned(sbi) &&
1803 					!has_enough_free_blocks(sbi,
1804 					sbi->gc_thread.boost_zoned_gc_percent))
1805 				window_granularity *=
1806 					sbi->gc_thread.boost_gc_multiple;
1807 
1808 			end_segno = start_segno + window_granularity;
1809 		}
1810 
1811 		if (end_segno > sec_end_segno)
1812 			end_segno = sec_end_segno;
1813 	}
1814 
1815 	sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1816 
1817 	segno = rounddown(segno, sbi->sums_per_block);
1818 	sum_blk_cnt = DIV_ROUND_UP(end_segno - segno, sbi->sums_per_block);
1819 	/* readahead multi ssa blocks those have contiguous address */
1820 	if (__is_large_section(sbi))
1821 		f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1822 					sum_blk_cnt, META_SSA, true);
1823 
1824 	/* reference all summary page */
1825 	while (segno < end_segno) {
1826 		struct folio *sum_folio = f2fs_get_sum_folio(sbi, segno);
1827 
1828 		segno += sbi->sums_per_block;
1829 		if (IS_ERR(sum_folio)) {
1830 			int err = PTR_ERR(sum_folio);
1831 
1832 			end_segno = segno - sbi->sums_per_block;
1833 			segno = rounddown(start_segno, sbi->sums_per_block);
1834 			while (segno < end_segno) {
1835 				sum_folio = filemap_get_folio(META_MAPPING(sbi),
1836 						GET_SUM_BLOCK(sbi, segno));
1837 				folio_put_refs(sum_folio, 2);
1838 				segno += sbi->sums_per_block;
1839 			}
1840 			return err;
1841 		}
1842 		folio_unlock(sum_folio);
1843 	}
1844 
1845 	blk_start_plug(&plug);
1846 
1847 	segno = start_segno;
1848 	while (segno < end_segno) {
1849 		unsigned int cur_segno;
1850 
1851 		/* find segment summary of victim */
1852 		struct folio *sum_folio = filemap_get_folio(META_MAPPING(sbi),
1853 					GET_SUM_BLOCK(sbi, segno));
1854 		unsigned int block_end_segno = rounddown(segno, sbi->sums_per_block)
1855 					+ sbi->sums_per_block;
1856 
1857 		if (block_end_segno > end_segno)
1858 			block_end_segno = end_segno;
1859 
1860 		if (is_cursec(sbi, GET_SEC_FROM_SEG(sbi, segno))) {
1861 			f2fs_err(sbi, "%s: segment %u is used by log",
1862 							__func__, segno);
1863 			f2fs_bug_on(sbi, 1);
1864 			goto next_block;
1865 		}
1866 
1867 		if (!folio_test_uptodate(sum_folio) ||
1868 		    unlikely(f2fs_cp_error(sbi)))
1869 			goto next_block;
1870 
1871 		for (cur_segno = segno; cur_segno < block_end_segno;
1872 				cur_segno++) {
1873 			struct f2fs_summary_block *sum;
1874 
1875 			if (get_valid_blocks(sbi, cur_segno, false) == 0)
1876 				goto freed;
1877 			if (gc_type == BG_GC && __is_large_section(sbi) &&
1878 					migrated >= sbi->migration_granularity)
1879 				continue;
1880 
1881 			if (migrated == 0) {
1882 				type = IS_DATASEG(get_seg_entry(sbi, cur_segno)->type) ?
1883 							SUM_TYPE_DATA : SUM_TYPE_NODE;
1884 				data_type = (type == SUM_TYPE_DATA) ? DATA : NODE;
1885 			}
1886 
1887 			sum = SUM_BLK_PAGE_ADDR(sbi, sum_folio, cur_segno);
1888 			if (type != GET_SUM_TYPE(sum_footer(sbi, sum))) {
1889 				f2fs_err(sbi, "Inconsistent segment (%u) type "
1890 						"[%d, %d] in SIT and SSA",
1891 						cur_segno, type,
1892 						GET_SUM_TYPE(
1893 						sum_footer(sbi, sum)));
1894 				f2fs_stop_checkpoint(sbi, false,
1895 						STOP_CP_REASON_CORRUPTED_SUMMARY);
1896 				continue;
1897 			}
1898 
1899 			/*
1900 			 * this is to avoid deadlock:
1901 			 *  - lock_page(sum_page)     - f2fs_replace_block
1902 			 *   - check_valid_map()        - down_write(sentry_lock)
1903 			 *    - down_read(sentry_lock) - change_curseg()
1904 			 *                               - lock_page(sum_page)
1905 			 */
1906 			if (type == SUM_TYPE_NODE)
1907 				submitted += gc_node_segment(sbi, sum->entries,
1908 						cur_segno, gc_type, &plug);
1909 			else
1910 				submitted += gc_data_segment(sbi, sum->entries,
1911 						gc_list, cur_segno,
1912 						gc_type, force_migrate, &plug);
1913 
1914 			stat_inc_gc_seg_count(sbi, data_type, gc_type);
1915 			sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1916 			migrated++;
1917 
1918 freed:
1919 			if (gc_type == FG_GC &&
1920 					get_valid_blocks(sbi, cur_segno, false) == 0)
1921 				seg_freed++;
1922 
1923 			if (__is_large_section(sbi))
1924 				sbi->next_victim_seg[gc_type] =
1925 					(cur_segno + 1 < sec_end_segno) ?
1926 					cur_segno + 1 : NULL_SEGNO;
1927 
1928 			if (unlikely(freezing(current))) {
1929 				folio_put_refs(sum_folio, 2);
1930 				goto stop;
1931 			}
1932 		}
1933 next_block:
1934 		folio_put_refs(sum_folio, 2);
1935 		segno = block_end_segno;
1936 	}
1937 
1938 stop:
1939 	if (submitted)
1940 		f2fs_submit_merged_write(sbi, data_type);
1941 
1942 	blk_finish_plug(&plug);
1943 
1944 	if (migrated)
1945 		stat_inc_gc_sec_count(sbi, data_type, gc_type);
1946 
1947 	return seg_freed;
1948 }
1949 
1950 int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1951 {
1952 	int gc_type = gc_control->init_gc_type;
1953 	unsigned int segno = gc_control->victim_segno;
1954 	int sec_freed = 0, seg_freed = 0, total_freed = 0, total_sec_freed = 0;
1955 	int ret = 0;
1956 	struct cp_control cpc;
1957 	struct gc_inode_list gc_list = {
1958 		.ilist = LIST_HEAD_INIT(gc_list.ilist),
1959 		.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1960 	};
1961 	unsigned int skipped_round = 0, round = 0;
1962 	unsigned int upper_secs;
1963 
1964 	trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
1965 				gc_control->nr_free_secs,
1966 				get_pages(sbi, F2FS_DIRTY_NODES),
1967 				get_pages(sbi, F2FS_DIRTY_DENTS),
1968 				get_pages(sbi, F2FS_DIRTY_IMETA),
1969 				free_sections(sbi),
1970 				free_segments(sbi),
1971 				reserved_segments(sbi),
1972 				prefree_segments(sbi));
1973 
1974 	cpc.reason = __get_cp_reason(sbi);
1975 gc_more:
1976 	sbi->skipped_gc_rwsem = 0;
1977 	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1978 		ret = -EINVAL;
1979 		goto stop;
1980 	}
1981 	if (unlikely(f2fs_cp_error(sbi))) {
1982 		ret = -EIO;
1983 		goto stop;
1984 	}
1985 
1986 	/* Let's run FG_GC, if we don't have enough space. */
1987 	if (has_not_enough_free_secs(sbi, 0, 0)) {
1988 		gc_type = FG_GC;
1989 		gc_control->one_time = false;
1990 
1991 		/*
1992 		 * For example, if there are many prefree_segments below given
1993 		 * threshold, we can make them free by checkpoint. Then, we
1994 		 * secure free segments which doesn't need fggc any more.
1995 		 */
1996 		if (prefree_segments(sbi)) {
1997 			stat_inc_cp_call_count(sbi, TOTAL_CALL);
1998 			ret = f2fs_write_checkpoint(sbi, &cpc);
1999 			if (ret)
2000 				goto stop;
2001 			/* Reset due to checkpoint */
2002 			sec_freed = 0;
2003 		}
2004 	}
2005 
2006 	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
2007 	if (gc_type == BG_GC && gc_control->no_bg_gc) {
2008 		ret = -EINVAL;
2009 		goto stop;
2010 	}
2011 retry:
2012 	if (unlikely(freezing(current))) {
2013 		ret = 0;
2014 		goto stop;
2015 	}
2016 	ret = __get_victim(sbi, &segno, gc_type, gc_control->one_time);
2017 	if (ret) {
2018 		/* allow to search victim from sections has pinned data */
2019 		if (ret == -ENODATA && gc_type == FG_GC &&
2020 				f2fs_pinned_section_exists(DIRTY_I(sbi))) {
2021 			f2fs_unpin_all_sections(sbi, false);
2022 			goto retry;
2023 		}
2024 		goto stop;
2025 	}
2026 
2027 	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
2028 				gc_control->should_migrate_blocks,
2029 				gc_control->one_time);
2030 	if (seg_freed < 0)
2031 		goto stop;
2032 
2033 	total_freed += seg_freed;
2034 
2035 	if (seg_freed == f2fs_usable_segs_in_sec(sbi)) {
2036 		sec_freed++;
2037 		total_sec_freed++;
2038 	}
2039 
2040 	if (gc_control->one_time)
2041 		goto stop;
2042 
2043 	if (gc_type == FG_GC) {
2044 		sbi->cur_victim_sec = NULL_SEGNO;
2045 
2046 		if (has_enough_free_secs(sbi, sec_freed, 0)) {
2047 			if (!gc_control->no_bg_gc &&
2048 			    total_sec_freed < gc_control->nr_free_secs)
2049 				goto go_gc_more;
2050 			goto stop;
2051 		}
2052 		if (sbi->skipped_gc_rwsem)
2053 			skipped_round++;
2054 		round++;
2055 		if (skipped_round > MAX_SKIP_GC_COUNT &&
2056 				skipped_round * 2 >= round) {
2057 			stat_inc_cp_call_count(sbi, TOTAL_CALL);
2058 			ret = f2fs_write_checkpoint(sbi, &cpc);
2059 			goto stop;
2060 		}
2061 	} else if (has_enough_free_secs(sbi, 0, 0)) {
2062 		goto stop;
2063 	}
2064 
2065 	upper_secs = __get_secs_required(sbi);
2066 
2067 	/*
2068 	 * Write checkpoint to reclaim prefree segments.
2069 	 * We need more three extra sections for writer's data/node/dentry.
2070 	 */
2071 	if (free_sections(sbi) <= upper_secs + NR_GC_CHECKPOINT_SECS &&
2072 				prefree_segments(sbi)) {
2073 		stat_inc_cp_call_count(sbi, TOTAL_CALL);
2074 		ret = f2fs_write_checkpoint(sbi, &cpc);
2075 		if (ret)
2076 			goto stop;
2077 		/* Reset due to checkpoint */
2078 		sec_freed = 0;
2079 	}
2080 go_gc_more:
2081 	segno = NULL_SEGNO;
2082 	goto gc_more;
2083 
2084 stop:
2085 	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
2086 	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
2087 
2088 	if (gc_type == FG_GC)
2089 		f2fs_unpin_all_sections(sbi, true);
2090 
2091 	trace_f2fs_gc_end(sbi->sb, ret, total_freed, total_sec_freed,
2092 				get_pages(sbi, F2FS_DIRTY_NODES),
2093 				get_pages(sbi, F2FS_DIRTY_DENTS),
2094 				get_pages(sbi, F2FS_DIRTY_IMETA),
2095 				free_sections(sbi),
2096 				free_segments(sbi),
2097 				reserved_segments(sbi),
2098 				prefree_segments(sbi));
2099 
2100 	f2fs_up_write_trace(&sbi->gc_lock, &gc_control->lc);
2101 
2102 	put_gc_inode(&gc_list);
2103 
2104 	if (gc_control->err_gc_skipped && !ret)
2105 		ret = total_sec_freed ? 0 : -EAGAIN;
2106 	return ret;
2107 }
2108 
2109 int __init f2fs_create_garbage_collection_cache(void)
2110 {
2111 	victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
2112 					sizeof(struct victim_entry));
2113 	return victim_entry_slab ? 0 : -ENOMEM;
2114 }
2115 
2116 void f2fs_destroy_garbage_collection_cache(void)
2117 {
2118 	kmem_cache_destroy(victim_entry_slab);
2119 }
2120 
2121 static void init_atgc_management(struct f2fs_sb_info *sbi)
2122 {
2123 	struct atgc_management *am = &sbi->am;
2124 
2125 	if (test_opt(sbi, ATGC) &&
2126 		SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
2127 		am->atgc_enabled = true;
2128 
2129 	am->root = RB_ROOT_CACHED;
2130 	INIT_LIST_HEAD(&am->victim_list);
2131 	am->victim_count = 0;
2132 
2133 	am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
2134 	am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
2135 	am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
2136 	am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
2137 }
2138 
2139 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
2140 {
2141 	sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
2142 
2143 	/* give warm/cold data area from slower device */
2144 	if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
2145 		SIT_I(sbi)->last_victim[ALLOC_NEXT] =
2146 				GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
2147 
2148 	init_atgc_management(sbi);
2149 }
2150 
2151 int f2fs_gc_range(struct f2fs_sb_info *sbi,
2152 		unsigned int start_seg, unsigned int end_seg,
2153 		bool dry_run, unsigned int dry_run_sections, bool lock)
2154 {
2155 	struct f2fs_lock_context lc;
2156 	unsigned int segno;
2157 	unsigned int gc_secs = dry_run_sections;
2158 
2159 	if (unlikely(f2fs_cp_error(sbi)))
2160 		return -EIO;
2161 
2162 	stat_inc_gc_call_count(sbi, FOREGROUND);
2163 	for (segno = start_seg; segno <= end_seg; segno += SEGS_PER_SEC(sbi)) {
2164 		struct gc_inode_list gc_list = {
2165 			.ilist = LIST_HEAD_INIT(gc_list.ilist),
2166 			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
2167 		};
2168 		int err = 0;
2169 
2170 		if (lock)
2171 			f2fs_down_write_trace(&sbi->gc_lock, &lc);
2172 
2173 		/*
2174 		 * avoid migrating empty section, as it can be allocated by
2175 		 * log in parallel.
2176 		 */
2177 		if (!get_valid_blocks(sbi, segno, true))
2178 			goto next;
2179 
2180 		if (is_cursec(sbi, GET_SEC_FROM_SEG(sbi, segno)))
2181 			goto next;
2182 
2183 		do_garbage_collect(sbi, segno, &gc_list, FG_GC, true, false);
2184 		put_gc_inode(&gc_list);
2185 
2186 		/* reset all pinned status during fggc */
2187 		f2fs_unpin_all_sections(sbi, true);
2188 
2189 		if (!dry_run && get_valid_blocks(sbi, segno, true)) {
2190 			err = -EAGAIN;
2191 			goto next;
2192 		}
2193 		if (dry_run && dry_run_sections &&
2194 			!get_valid_blocks(sbi, segno, true)) {
2195 			--gc_secs;
2196 			goto next;
2197 		}
2198 
2199 		if (fatal_signal_pending(current))
2200 			err = -ERESTARTSYS;
2201 next:
2202 		if (lock)
2203 			f2fs_up_write_trace(&sbi->gc_lock, &lc);
2204 		if (err)
2205 			return err;
2206 		if (dry_run && dry_run_sections && !gc_secs)
2207 			return 0;
2208 	}
2209 
2210 	return 0;
2211 }
2212 
2213 void f2fs_reset_gc_victim_resource(struct f2fs_sb_info *sbi,
2214 			unsigned int start, unsigned int end)
2215 {
2216 	int i;
2217 
2218 	mutex_lock(&DIRTY_I(sbi)->seglist_lock);
2219 	for (i = 0; i < MAX_GC_POLICY; i++)
2220 		if (SIT_I(sbi)->last_victim[i] >= start &&
2221 			SIT_I(sbi)->last_victim[i] <= end)
2222 			SIT_I(sbi)->last_victim[i] = 0;
2223 
2224 	for (i = BG_GC; i <= FG_GC; i++)
2225 		if (sbi->next_victim_seg[i] >= start &&
2226 			sbi->next_victim_seg[i] <= end)
2227 			sbi->next_victim_seg[i] = NULL_SEGNO;
2228 	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
2229 }
2230 
2231 static int free_segment_range(struct f2fs_sb_info *sbi,
2232 				unsigned int secs, bool dry_run)
2233 {
2234 	unsigned int secno, next_inuse, start, end, end_secno;
2235 	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2236 	unsigned int freed_secs = 0;
2237 	int err = 0;
2238 	int type;
2239 
2240 	MAIN_SECS(sbi) -= secs;
2241 	start = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
2242 	end = MAIN_SEGS(sbi) - 1;
2243 	end_secno = GET_SEC_FROM_SEG(sbi, end);
2244 
2245 	f2fs_reset_gc_victim_resource(sbi, start, end);
2246 
2247 	spin_lock(&FREE_I(sbi)->segmap_lock);
2248 	for (secno = MAIN_SECS(sbi); secno <= end_secno; secno++) {
2249 		if (!test_bit(secno, FREE_I(sbi)->free_secmap))
2250 			freed_secs++;
2251 	}
2252 	FREE_I(sbi)->free_sections -= freed_secs;
2253 	spin_unlock(&FREE_I(sbi)->segmap_lock);
2254 
2255 	/* Move out cursegs from the target range */
2256 	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++) {
2257 		err = f2fs_allocate_segment_for_resize(sbi, type, start, end);
2258 		if (err)
2259 			goto out;
2260 	}
2261 
2262 	/* do GC to move out valid blocks in the range */
2263 	err = f2fs_gc_range(sbi, start, end, dry_run, 0, false);
2264 	if (err || dry_run)
2265 		goto out;
2266 
2267 	stat_inc_cp_call_count(sbi, TOTAL_CALL);
2268 	err = f2fs_write_checkpoint(sbi, &cpc);
2269 	if (err)
2270 		goto out;
2271 
2272 	next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
2273 	if (next_inuse <= end) {
2274 		f2fs_err(sbi, "segno %u should be free but still inuse!",
2275 			 next_inuse);
2276 		f2fs_bug_on(sbi, 1);
2277 	}
2278 out:
2279 	spin_lock(&FREE_I(sbi)->segmap_lock);
2280 	FREE_I(sbi)->free_sections += freed_secs;
2281 	spin_unlock(&FREE_I(sbi)->segmap_lock);
2282 	MAIN_SECS(sbi) += secs;
2283 	return err;
2284 }
2285 
2286 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
2287 {
2288 	struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
2289 	int section_count;
2290 	int segment_count;
2291 	int segment_count_main;
2292 	long long block_count;
2293 	int segs = secs * SEGS_PER_SEC(sbi);
2294 
2295 	f2fs_down_write(&sbi->sb_lock);
2296 
2297 	section_count = le32_to_cpu(raw_sb->section_count);
2298 	segment_count = le32_to_cpu(raw_sb->segment_count);
2299 	segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2300 	block_count = le64_to_cpu(raw_sb->block_count);
2301 
2302 	raw_sb->section_count = cpu_to_le32(section_count + secs);
2303 	raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2304 	raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2305 	raw_sb->block_count = cpu_to_le64(block_count +
2306 			(long long)SEGS_TO_BLKS(sbi, segs));
2307 	if (f2fs_is_multi_device(sbi)) {
2308 		int last_dev = sbi->s_ndevs - 1;
2309 		int dev_segs =
2310 			le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2311 
2312 		raw_sb->devs[last_dev].total_segments =
2313 						cpu_to_le32(dev_segs + segs);
2314 	}
2315 
2316 	f2fs_up_write(&sbi->sb_lock);
2317 }
2318 
2319 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2320 {
2321 	int segs = secs * SEGS_PER_SEC(sbi);
2322 	long long blks = SEGS_TO_BLKS(sbi, segs);
2323 	long long user_block_count =
2324 				le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2325 
2326 	SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2327 	MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2328 	MAIN_SECS(sbi) += secs;
2329 	if (sbi->allocate_section_hint > MAIN_SECS(sbi))
2330 		sbi->allocate_section_hint = MAIN_SECS(sbi);
2331 	FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2332 	FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2333 	F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2334 
2335 	if (f2fs_is_multi_device(sbi)) {
2336 		int last_dev = sbi->s_ndevs - 1;
2337 
2338 		sbi->allocate_section_hint = FDEV(0).total_segments /
2339 					SEGS_PER_SEC(sbi);
2340 
2341 		FDEV(last_dev).total_segments =
2342 				(int)FDEV(last_dev).total_segments + segs;
2343 		FDEV(last_dev).end_blk =
2344 				(long long)FDEV(last_dev).end_blk + blks;
2345 #ifdef CONFIG_BLK_DEV_ZONED
2346 		FDEV(last_dev).nr_blkz = FDEV(last_dev).nr_blkz +
2347 					div_u64(blks, sbi->blocks_per_blkz);
2348 #endif
2349 	}
2350 }
2351 
2352 int f2fs_resize_fs(struct file *filp, __u64 block_count)
2353 {
2354 	struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
2355 	__u64 old_block_count, shrunk_blocks;
2356 	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2357 	struct f2fs_lock_context lc;
2358 	struct f2fs_lock_context glc;
2359 	struct f2fs_lock_context clc;
2360 	unsigned int secs;
2361 	int err = 0;
2362 	__u32 rem;
2363 
2364 	old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2365 	if (block_count > old_block_count)
2366 		return -EINVAL;
2367 
2368 	if (f2fs_is_multi_device(sbi)) {
2369 		int last_dev = sbi->s_ndevs - 1;
2370 		__u64 last_segs = FDEV(last_dev).total_segments;
2371 
2372 		if (block_count + SEGS_TO_BLKS(sbi, last_segs) <=
2373 								old_block_count)
2374 			return -EINVAL;
2375 	}
2376 
2377 	/* new fs size should align to section size */
2378 	div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2379 	if (rem)
2380 		return -EINVAL;
2381 
2382 	if (block_count == old_block_count)
2383 		return 0;
2384 
2385 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2386 		f2fs_err(sbi, "Should run fsck to repair first.");
2387 		return -EFSCORRUPTED;
2388 	}
2389 
2390 	if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2391 		f2fs_err(sbi, "Checkpoint should be enabled.");
2392 		return -EINVAL;
2393 	}
2394 
2395 	err = mnt_want_write_file(filp);
2396 	if (err)
2397 		return err;
2398 
2399 	shrunk_blocks = old_block_count - block_count;
2400 	secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2401 
2402 	/* stop other GC */
2403 	if (!f2fs_down_write_trylock_trace(&sbi->gc_lock, &glc)) {
2404 		err = -EAGAIN;
2405 		goto out_drop_write;
2406 	}
2407 
2408 	/* stop CP to protect MAIN_SEC in free_segment_range */
2409 	f2fs_lock_op(sbi, &lc);
2410 
2411 	spin_lock(&sbi->stat_lock);
2412 	if (shrunk_blocks + valid_user_blocks(sbi) +
2413 		sbi->current_reserved_blocks + sbi->unusable_block_count +
2414 		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2415 		err = -ENOSPC;
2416 	spin_unlock(&sbi->stat_lock);
2417 
2418 	if (err)
2419 		goto out_unlock;
2420 
2421 	err = free_segment_range(sbi, secs, true);
2422 
2423 out_unlock:
2424 	f2fs_unlock_op(sbi, &lc);
2425 	f2fs_up_write_trace(&sbi->gc_lock, &glc);
2426 out_drop_write:
2427 	mnt_drop_write_file(filp);
2428 	if (err)
2429 		return err;
2430 
2431 	err = freeze_super(sbi->sb, FREEZE_HOLDER_KERNEL, NULL);
2432 	if (err)
2433 		return err;
2434 
2435 	if (f2fs_readonly(sbi->sb)) {
2436 		err = thaw_super(sbi->sb, FREEZE_HOLDER_KERNEL, NULL);
2437 		if (err)
2438 			return err;
2439 		return -EROFS;
2440 	}
2441 
2442 	f2fs_down_write_trace(&sbi->gc_lock, &glc);
2443 	f2fs_down_write_trace(&sbi->cp_global_sem, &clc);
2444 
2445 	spin_lock(&sbi->stat_lock);
2446 	if (shrunk_blocks + valid_user_blocks(sbi) +
2447 		sbi->current_reserved_blocks + sbi->unusable_block_count +
2448 		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2449 		err = -ENOSPC;
2450 	else
2451 		sbi->user_block_count -= shrunk_blocks;
2452 	spin_unlock(&sbi->stat_lock);
2453 	if (err)
2454 		goto out_err;
2455 
2456 	set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2457 	err = free_segment_range(sbi, secs, false);
2458 	if (err)
2459 		goto recover_user_blocks;
2460 
2461 	update_sb_metadata(sbi, -secs);
2462 
2463 	err = f2fs_commit_super(sbi, false);
2464 	if (err) {
2465 		update_sb_metadata(sbi, secs);
2466 		goto recover_out;
2467 	}
2468 
2469 	update_fs_metadata(sbi, -secs);
2470 	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2471 	set_sbi_flag(sbi, SBI_IS_DIRTY);
2472 
2473 	stat_inc_cp_call_count(sbi, TOTAL_CALL);
2474 	err = f2fs_write_checkpoint(sbi, &cpc);
2475 	if (err) {
2476 		update_fs_metadata(sbi, secs);
2477 		update_sb_metadata(sbi, secs);
2478 		f2fs_commit_super(sbi, false);
2479 	}
2480 recover_out:
2481 	if (err) {
2482 		f2fs_bug_on(sbi, err == -EAGAIN);
2483 		set_sbi_flag(sbi, SBI_NEED_FSCK);
2484 		f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2485 	}
2486 recover_user_blocks:
2487 	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2488 	if (err) {
2489 		spin_lock(&sbi->stat_lock);
2490 		sbi->user_block_count += shrunk_blocks;
2491 		spin_unlock(&sbi->stat_lock);
2492 	}
2493 out_err:
2494 	f2fs_up_write_trace(&sbi->cp_global_sem, &clc);
2495 	f2fs_up_write_trace(&sbi->gc_lock, &glc);
2496 	thaw_super(sbi->sb, FREEZE_HOLDER_KERNEL, NULL);
2497 	return err;
2498 }
2499