xref: /linux/fs/f2fs/gc.c (revision a7aaa65f9c46b82051af490c93bc6398f11b94ce)
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_freezable_timeout(*wq,
50  				kthread_should_stop() ||
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(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 (f2fs_readonly(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_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, false,
77  					STOP_CP_REASON_FAULT_INJECT);
78  
79  		if (!sb_start_write_trylock(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(&sbi->gc_lock);
101  			goto do_gc;
102  		}
103  
104  		if (foreground) {
105  			f2fs_down_write(&sbi->gc_lock);
106  			goto do_gc;
107  		} else if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
108  			stat_other_skip_bggc_count(sbi);
109  			goto next;
110  		}
111  
112  		if (!is_idle(sbi, GC_TIME)) {
113  			increase_sleep_time(gc_th, &wait_ms);
114  			f2fs_up_write(&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_ms);
121  		else
122  			increase_sleep_time(gc_th, &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)) {
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(sbi->sb, wait_ms,
152  				prefree_segments(sbi), free_segments(sbi));
153  
154  		/* balancing f2fs's metadata periodically */
155  		f2fs_balance_fs_bg(sbi, true);
156  next:
157  		if (sbi->gc_mode != GC_NORMAL) {
158  			spin_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(&sbi->gc_remaining_trials_lock);
165  		}
166  		sb_end_write(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, 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(gc_th->f2fs_gc_task)) {
194  		int err = PTR_ERR(gc_th->f2fs_gc_task);
195  
196  		kfree(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(gc_th->f2fs_gc_task);
211  	wake_up_all(&gc_th->fggc_wq);
212  	kfree(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 = SEGS_PER_SEC(sbi);
263  		if (__is_large_section(sbi)) {
264  			p->dirty_bitmap = dirty_i->dirty_secmap;
265  			p->max_search = count_bits(p->dirty_bitmap,
266  						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. */
284  	if (f2fs_need_rand_seg(sbi))
285  		p->offset = get_random_u32_below(MAIN_SECS(sbi) *
286  						SEGS_PER_SEC(sbi));
287  	else if (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 BLKS_PER_SEG(sbi);
299  	else if (p->alloc_mode == AT_SSR)
300  		return UINT_MAX;
301  
302  	/* LFS */
303  	if (p->gc_mode == GC_GREEDY)
304  		return SEGS_TO_BLKS(sbi, 2 * 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(secno, 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, start + i)->mtime;
346  	vblocks = get_valid_blocks(sbi, segno, true);
347  
348  	mtime = div_u64(mtime, usable_segs_per_sec);
349  	vblocks = div_u64(vblocks, usable_segs_per_sec);
350  
351  	u = BLKS_TO_SEGS(sbi, vblocks * 100);
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(100 * (mtime - sit_i->min_mtime),
360  				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, 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(victim_entry_slab, GFP_NOFS, true, NULL);
445  
446  	ve->mtime = mtime;
447  	ve->segno = segno;
448  
449  	list_add_tail(&ve->list, &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(&ve->rb_node, parent, p);
481  	rb_insert_color_cached(&ve->rb_node, root, 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, true) == 0)
496  			return;
497  	}
498  
499  	for (i = 0; i < SEGS_PER_SEC(sbi); i++)
500  		mtime += get_seg_entry(sbi, start + i)->mtime;
501  	mtime = div_u64(mtime, SEGS_PER_SEC(sbi));
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, 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(accu * (max_mtime - ve->mtime), total_time) *
562  								age_weight;
563  
564  	vblocks = get_valid_blocks(sbi, ve->segno, true);
565  	f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
566  
567  	/* u = 10000 * x% * 40 */
568  	u = div64_u64(accu * (sec_blocks - vblocks), 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 vblocks;
603  	unsigned int dirty_threshold = max(am->max_candidate_count,
604  					am->candidate_ratio *
605  					am->victim_count / 100);
606  	unsigned int cost, iter;
607  	int stage = 0;
608  
609  	if (max_mtime < min_mtime)
610  		return;
611  	max_mtime += 1;
612  next_stage:
613  	iter = 0;
614  	ve = __lookup_victim_entry(sbi, p->age);
615  next_node:
616  	if (!ve) {
617  		if (stage++ == 0)
618  			goto next_stage;
619  		return;
620  	}
621  
622  	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
623  		goto skip_node;
624  
625  	age = max_mtime - ve->mtime;
626  
627  	vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
628  	f2fs_bug_on(sbi, !vblocks);
629  
630  	/* rare case */
631  	if (vblocks == BLKS_PER_SEG(sbi))
632  		goto skip_node;
633  
634  	iter++;
635  
636  	age = max_mtime - abs(p->age - age);
637  	cost = UINT_MAX - vblocks;
638  
639  	if (cost < p->min_cost ||
640  			(cost == p->min_cost && age > p->oldest_age)) {
641  		p->min_cost = cost;
642  		p->oldest_age = age;
643  		p->min_segno = ve->segno;
644  	}
645  skip_node:
646  	if (iter < dirty_threshold) {
647  		ve = rb_entry(stage == 0 ? rb_prev(&ve->rb_node) :
648  					rb_next(&ve->rb_node),
649  					struct victim_entry, rb_node);
650  		goto next_node;
651  	}
652  
653  	if (stage++ == 0)
654  		goto next_stage;
655  }
656  
657  static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
658  						struct victim_sel_policy *p)
659  {
660  	f2fs_bug_on(sbi, !f2fs_check_victim_tree(sbi, &sbi->am.root));
661  
662  	if (p->gc_mode == GC_AT)
663  		atgc_lookup_victim(sbi, p);
664  	else if (p->alloc_mode == AT_SSR)
665  		atssr_lookup_victim(sbi, p);
666  	else
667  		f2fs_bug_on(sbi, 1);
668  }
669  
670  static void release_victim_entry(struct f2fs_sb_info *sbi)
671  {
672  	struct atgc_management *am = &sbi->am;
673  	struct victim_entry *ve, *tmp;
674  
675  	list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
676  		list_del(&ve->list);
677  		kmem_cache_free(victim_entry_slab, ve);
678  		am->victim_count--;
679  	}
680  
681  	am->root = RB_ROOT_CACHED;
682  
683  	f2fs_bug_on(sbi, am->victim_count);
684  	f2fs_bug_on(sbi, !list_empty(&am->victim_list));
685  }
686  
687  static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
688  {
689  	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
690  	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
691  
692  	if (!dirty_i->enable_pin_section)
693  		return false;
694  	if (!test_and_set_bit(secno, dirty_i->pinned_secmap))
695  		dirty_i->pinned_secmap_cnt++;
696  	return true;
697  }
698  
699  static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
700  {
701  	return dirty_i->pinned_secmap_cnt;
702  }
703  
704  static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
705  						unsigned int secno)
706  {
707  	return dirty_i->enable_pin_section &&
708  		f2fs_pinned_section_exists(dirty_i) &&
709  		test_bit(secno, dirty_i->pinned_secmap);
710  }
711  
712  static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
713  {
714  	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
715  
716  	if (f2fs_pinned_section_exists(DIRTY_I(sbi))) {
717  		memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
718  		DIRTY_I(sbi)->pinned_secmap_cnt = 0;
719  	}
720  	DIRTY_I(sbi)->enable_pin_section = enable;
721  }
722  
723  static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
724  							unsigned int segno)
725  {
726  	if (!f2fs_is_pinned_file(inode))
727  		return 0;
728  	if (gc_type != FG_GC)
729  		return -EBUSY;
730  	if (!f2fs_pin_section(F2FS_I_SB(inode), segno))
731  		f2fs_pin_file_control(inode, true);
732  	return -EAGAIN;
733  }
734  
735  /*
736   * This function is called from two paths.
737   * One is garbage collection and the other is SSR segment selection.
738   * When it is called during GC, it just gets a victim segment
739   * and it does not remove it from dirty seglist.
740   * When it is called from SSR segment selection, it finds a segment
741   * which has minimum valid blocks and removes it from dirty seglist.
742   */
743  int f2fs_get_victim(struct f2fs_sb_info *sbi, unsigned int *result,
744  			int gc_type, int type, char alloc_mode,
745  			unsigned long long age)
746  {
747  	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
748  	struct sit_info *sm = SIT_I(sbi);
749  	struct victim_sel_policy p;
750  	unsigned int secno, last_victim;
751  	unsigned int last_segment;
752  	unsigned int nsearched;
753  	bool is_atgc;
754  	int ret = 0;
755  
756  	mutex_lock(&dirty_i->seglist_lock);
757  	last_segment = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
758  
759  	p.alloc_mode = alloc_mode;
760  	p.age = age;
761  	p.age_threshold = sbi->am.age_threshold;
762  
763  retry:
764  	select_policy(sbi, gc_type, type, &p);
765  	p.min_segno = NULL_SEGNO;
766  	p.oldest_age = 0;
767  	p.min_cost = get_max_cost(sbi, &p);
768  
769  	is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
770  	nsearched = 0;
771  
772  	if (is_atgc)
773  		SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
774  
775  	if (*result != NULL_SEGNO) {
776  		if (!get_valid_blocks(sbi, *result, false)) {
777  			ret = -ENODATA;
778  			goto out;
779  		}
780  
781  		if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
782  			ret = -EBUSY;
783  		else
784  			p.min_segno = *result;
785  		goto out;
786  	}
787  
788  	ret = -ENODATA;
789  	if (p.max_search == 0)
790  		goto out;
791  
792  	if (__is_large_section(sbi) && p.alloc_mode == LFS) {
793  		if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
794  			p.min_segno = sbi->next_victim_seg[BG_GC];
795  			*result = p.min_segno;
796  			sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
797  			goto got_result;
798  		}
799  		if (gc_type == FG_GC &&
800  				sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
801  			p.min_segno = sbi->next_victim_seg[FG_GC];
802  			*result = p.min_segno;
803  			sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
804  			goto got_result;
805  		}
806  	}
807  
808  	last_victim = sm->last_victim[p.gc_mode];
809  	if (p.alloc_mode == LFS && gc_type == FG_GC) {
810  		p.min_segno = check_bg_victims(sbi);
811  		if (p.min_segno != NULL_SEGNO)
812  			goto got_it;
813  	}
814  
815  	while (1) {
816  		unsigned long cost, *dirty_bitmap;
817  		unsigned int unit_no, segno;
818  
819  		dirty_bitmap = p.dirty_bitmap;
820  		unit_no = find_next_bit(dirty_bitmap,
821  				last_segment / p.ofs_unit,
822  				p.offset / p.ofs_unit);
823  		segno = unit_no * p.ofs_unit;
824  		if (segno >= last_segment) {
825  			if (sm->last_victim[p.gc_mode]) {
826  				last_segment =
827  					sm->last_victim[p.gc_mode];
828  				sm->last_victim[p.gc_mode] = 0;
829  				p.offset = 0;
830  				continue;
831  			}
832  			break;
833  		}
834  
835  		p.offset = segno + p.ofs_unit;
836  		nsearched++;
837  
838  #ifdef CONFIG_F2FS_CHECK_FS
839  		/*
840  		 * skip selecting the invalid segno (that is failed due to block
841  		 * validity check failure during GC) to avoid endless GC loop in
842  		 * such cases.
843  		 */
844  		if (test_bit(segno, sm->invalid_segmap))
845  			goto next;
846  #endif
847  
848  		secno = GET_SEC_FROM_SEG(sbi, segno);
849  
850  		if (sec_usage_check(sbi, secno))
851  			goto next;
852  
853  		/* Don't touch checkpointed data */
854  		if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
855  			if (p.alloc_mode == LFS) {
856  				/*
857  				 * LFS is set to find source section during GC.
858  				 * The victim should have no checkpointed data.
859  				 */
860  				if (get_ckpt_valid_blocks(sbi, segno, true))
861  					goto next;
862  			} else {
863  				/*
864  				 * SSR | AT_SSR are set to find target segment
865  				 * for writes which can be full by checkpointed
866  				 * and newly written blocks.
867  				 */
868  				if (!f2fs_segment_has_free_slot(sbi, segno))
869  					goto next;
870  			}
871  		}
872  
873  		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
874  			goto next;
875  
876  		if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
877  			goto next;
878  
879  		if (is_atgc) {
880  			add_victim_entry(sbi, &p, segno);
881  			goto next;
882  		}
883  
884  		cost = get_gc_cost(sbi, segno, &p);
885  
886  		if (p.min_cost > cost) {
887  			p.min_segno = segno;
888  			p.min_cost = cost;
889  		}
890  next:
891  		if (nsearched >= p.max_search) {
892  			if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
893  				sm->last_victim[p.gc_mode] =
894  					last_victim + p.ofs_unit;
895  			else
896  				sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
897  			sm->last_victim[p.gc_mode] %=
898  				(MAIN_SECS(sbi) * SEGS_PER_SEC(sbi));
899  			break;
900  		}
901  	}
902  
903  	/* get victim for GC_AT/AT_SSR */
904  	if (is_atgc) {
905  		lookup_victim_by_age(sbi, &p);
906  		release_victim_entry(sbi);
907  	}
908  
909  	if (is_atgc && p.min_segno == NULL_SEGNO &&
910  			sm->elapsed_time < p.age_threshold) {
911  		p.age_threshold = 0;
912  		goto retry;
913  	}
914  
915  	if (p.min_segno != NULL_SEGNO) {
916  got_it:
917  		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
918  got_result:
919  		if (p.alloc_mode == LFS) {
920  			secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
921  			if (gc_type == FG_GC)
922  				sbi->cur_victim_sec = secno;
923  			else
924  				set_bit(secno, dirty_i->victim_secmap);
925  		}
926  		ret = 0;
927  
928  	}
929  out:
930  	if (p.min_segno != NULL_SEGNO)
931  		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
932  				sbi->cur_victim_sec,
933  				prefree_segments(sbi), free_segments(sbi));
934  	mutex_unlock(&dirty_i->seglist_lock);
935  
936  	return ret;
937  }
938  
939  static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
940  {
941  	struct inode_entry *ie;
942  
943  	ie = radix_tree_lookup(&gc_list->iroot, ino);
944  	if (ie)
945  		return ie->inode;
946  	return NULL;
947  }
948  
949  static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
950  {
951  	struct inode_entry *new_ie;
952  
953  	if (inode == find_gc_inode(gc_list, inode->i_ino)) {
954  		iput(inode);
955  		return;
956  	}
957  	new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
958  					GFP_NOFS, true, NULL);
959  	new_ie->inode = inode;
960  
961  	f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
962  	list_add_tail(&new_ie->list, &gc_list->ilist);
963  }
964  
965  static void put_gc_inode(struct gc_inode_list *gc_list)
966  {
967  	struct inode_entry *ie, *next_ie;
968  
969  	list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
970  		radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
971  		iput(ie->inode);
972  		list_del(&ie->list);
973  		kmem_cache_free(f2fs_inode_entry_slab, ie);
974  	}
975  }
976  
977  static int check_valid_map(struct f2fs_sb_info *sbi,
978  				unsigned int segno, int offset)
979  {
980  	struct sit_info *sit_i = SIT_I(sbi);
981  	struct seg_entry *sentry;
982  	int ret;
983  
984  	down_read(&sit_i->sentry_lock);
985  	sentry = get_seg_entry(sbi, segno);
986  	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
987  	up_read(&sit_i->sentry_lock);
988  	return ret;
989  }
990  
991  /*
992   * This function compares node address got in summary with that in NAT.
993   * On validity, copy that node with cold status, otherwise (invalid node)
994   * ignore that.
995   */
996  static int gc_node_segment(struct f2fs_sb_info *sbi,
997  		struct f2fs_summary *sum, unsigned int segno, int gc_type)
998  {
999  	struct f2fs_summary *entry;
1000  	block_t start_addr;
1001  	int off;
1002  	int phase = 0;
1003  	bool fggc = (gc_type == FG_GC);
1004  	int submitted = 0;
1005  	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1006  
1007  	start_addr = START_BLOCK(sbi, segno);
1008  
1009  next_step:
1010  	entry = sum;
1011  
1012  	if (fggc && phase == 2)
1013  		atomic_inc(&sbi->wb_sync_req[NODE]);
1014  
1015  	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1016  		nid_t nid = le32_to_cpu(entry->nid);
1017  		struct page *node_page;
1018  		struct node_info ni;
1019  		int err;
1020  
1021  		/* stop BG_GC if there is not enough free sections. */
1022  		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
1023  			return submitted;
1024  
1025  		if (check_valid_map(sbi, segno, off) == 0)
1026  			continue;
1027  
1028  		if (phase == 0) {
1029  			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1030  							META_NAT, true);
1031  			continue;
1032  		}
1033  
1034  		if (phase == 1) {
1035  			f2fs_ra_node_page(sbi, nid);
1036  			continue;
1037  		}
1038  
1039  		/* phase == 2 */
1040  		node_page = f2fs_get_node_page(sbi, nid);
1041  		if (IS_ERR(node_page))
1042  			continue;
1043  
1044  		/* block may become invalid during f2fs_get_node_page */
1045  		if (check_valid_map(sbi, segno, off) == 0) {
1046  			f2fs_put_page(node_page, 1);
1047  			continue;
1048  		}
1049  
1050  		if (f2fs_get_node_info(sbi, nid, &ni, false)) {
1051  			f2fs_put_page(node_page, 1);
1052  			continue;
1053  		}
1054  
1055  		if (ni.blk_addr != start_addr + off) {
1056  			f2fs_put_page(node_page, 1);
1057  			continue;
1058  		}
1059  
1060  		err = f2fs_move_node_page(node_page, gc_type);
1061  		if (!err && gc_type == FG_GC)
1062  			submitted++;
1063  		stat_inc_node_blk_count(sbi, 1, gc_type);
1064  	}
1065  
1066  	if (++phase < 3)
1067  		goto next_step;
1068  
1069  	if (fggc)
1070  		atomic_dec(&sbi->wb_sync_req[NODE]);
1071  	return submitted;
1072  }
1073  
1074  /*
1075   * Calculate start block index indicating the given node offset.
1076   * Be careful, caller should give this node offset only indicating direct node
1077   * blocks. If any node offsets, which point the other types of node blocks such
1078   * as indirect or double indirect node blocks, are given, it must be a caller's
1079   * bug.
1080   */
1081  block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1082  {
1083  	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1084  	unsigned int bidx;
1085  
1086  	if (node_ofs == 0)
1087  		return 0;
1088  
1089  	if (node_ofs <= 2) {
1090  		bidx = node_ofs - 1;
1091  	} else if (node_ofs <= indirect_blks) {
1092  		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1093  
1094  		bidx = node_ofs - 2 - dec;
1095  	} else {
1096  		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1097  
1098  		bidx = node_ofs - 5 - dec;
1099  	}
1100  	return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1101  }
1102  
1103  static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1104  		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1105  {
1106  	struct page *node_page;
1107  	nid_t nid;
1108  	unsigned int ofs_in_node, max_addrs, base;
1109  	block_t source_blkaddr;
1110  
1111  	nid = le32_to_cpu(sum->nid);
1112  	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1113  
1114  	node_page = f2fs_get_node_page(sbi, nid);
1115  	if (IS_ERR(node_page))
1116  		return false;
1117  
1118  	if (f2fs_get_node_info(sbi, nid, dni, false)) {
1119  		f2fs_put_page(node_page, 1);
1120  		return false;
1121  	}
1122  
1123  	if (sum->version != dni->version) {
1124  		f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1125  			  __func__);
1126  		set_sbi_flag(sbi, SBI_NEED_FSCK);
1127  	}
1128  
1129  	if (f2fs_check_nid_range(sbi, dni->ino)) {
1130  		f2fs_put_page(node_page, 1);
1131  		return false;
1132  	}
1133  
1134  	if (IS_INODE(node_page)) {
1135  		base = offset_in_addr(F2FS_INODE(node_page));
1136  		max_addrs = DEF_ADDRS_PER_INODE;
1137  	} else {
1138  		base = 0;
1139  		max_addrs = DEF_ADDRS_PER_BLOCK;
1140  	}
1141  
1142  	if (base + ofs_in_node >= max_addrs) {
1143  		f2fs_err(sbi, "Inconsistent blkaddr offset: base:%u, ofs_in_node:%u, max:%u, ino:%u, nid:%u",
1144  			base, ofs_in_node, max_addrs, dni->ino, dni->nid);
1145  		f2fs_put_page(node_page, 1);
1146  		return false;
1147  	}
1148  
1149  	*nofs = ofs_of_node(node_page);
1150  	source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1151  	f2fs_put_page(node_page, 1);
1152  
1153  	if (source_blkaddr != blkaddr) {
1154  #ifdef CONFIG_F2FS_CHECK_FS
1155  		unsigned int segno = GET_SEGNO(sbi, blkaddr);
1156  		unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1157  
1158  		if (unlikely(check_valid_map(sbi, segno, offset))) {
1159  			if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1160  				f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1161  					 blkaddr, source_blkaddr, segno);
1162  				set_sbi_flag(sbi, SBI_NEED_FSCK);
1163  			}
1164  		}
1165  #endif
1166  		return false;
1167  	}
1168  	return true;
1169  }
1170  
1171  static int ra_data_block(struct inode *inode, pgoff_t index)
1172  {
1173  	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1174  	struct address_space *mapping = f2fs_is_cow_file(inode) ?
1175  				F2FS_I(inode)->atomic_inode->i_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  	};
1188  	int err;
1189  
1190  	page = f2fs_grab_cache_page(mapping, index, true);
1191  	if (!page)
1192  		return -ENOMEM;
1193  
1194  	if (f2fs_lookup_read_extent_cache_block(inode, index,
1195  						&dn.data_blkaddr)) {
1196  		if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1197  						DATA_GENERIC_ENHANCE_READ))) {
1198  			err = -EFSCORRUPTED;
1199  			goto put_page;
1200  		}
1201  		goto got_it;
1202  	}
1203  
1204  	set_new_dnode(&dn, inode, NULL, NULL, 0);
1205  	err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1206  	if (err)
1207  		goto put_page;
1208  	f2fs_put_dnode(&dn);
1209  
1210  	if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1211  		err = -ENOENT;
1212  		goto put_page;
1213  	}
1214  	if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1215  						DATA_GENERIC_ENHANCE))) {
1216  		err = -EFSCORRUPTED;
1217  		goto put_page;
1218  	}
1219  got_it:
1220  	/* read page */
1221  	fio.page = page;
1222  	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1223  
1224  	/*
1225  	 * don't cache encrypted data into meta inode until previous dirty
1226  	 * data were writebacked to avoid racing between GC and flush.
1227  	 */
1228  	f2fs_wait_on_page_writeback(page, DATA, true, true);
1229  
1230  	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1231  
1232  	fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1233  					dn.data_blkaddr,
1234  					FGP_LOCK | FGP_CREAT, GFP_NOFS);
1235  	if (!fio.encrypted_page) {
1236  		err = -ENOMEM;
1237  		goto put_page;
1238  	}
1239  
1240  	err = f2fs_submit_page_bio(&fio);
1241  	if (err)
1242  		goto put_encrypted_page;
1243  	f2fs_put_page(fio.encrypted_page, 0);
1244  	f2fs_put_page(page, 1);
1245  
1246  	f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE);
1247  	f2fs_update_iostat(sbi, NULL, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1248  
1249  	return 0;
1250  put_encrypted_page:
1251  	f2fs_put_page(fio.encrypted_page, 1);
1252  put_page:
1253  	f2fs_put_page(page, 1);
1254  	return err;
1255  }
1256  
1257  /*
1258   * Move data block via META_MAPPING while keeping locked data page.
1259   * This can be used to move blocks, aka LBAs, directly on disk.
1260   */
1261  static int move_data_block(struct inode *inode, block_t bidx,
1262  				int gc_type, unsigned int segno, int off)
1263  {
1264  	struct address_space *mapping = f2fs_is_cow_file(inode) ?
1265  				F2FS_I(inode)->atomic_inode->i_mapping : inode->i_mapping;
1266  	struct f2fs_io_info fio = {
1267  		.sbi = F2FS_I_SB(inode),
1268  		.ino = inode->i_ino,
1269  		.type = DATA,
1270  		.temp = COLD,
1271  		.op = REQ_OP_READ,
1272  		.op_flags = 0,
1273  		.encrypted_page = NULL,
1274  		.in_list = 0,
1275  	};
1276  	struct dnode_of_data dn;
1277  	struct f2fs_summary sum;
1278  	struct node_info ni;
1279  	struct page *page, *mpage;
1280  	block_t newaddr;
1281  	int err = 0;
1282  	bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1283  	int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1284  				(fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1285  				CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1286  
1287  	/* do not read out */
1288  	page = f2fs_grab_cache_page(mapping, bidx, false);
1289  	if (!page)
1290  		return -ENOMEM;
1291  
1292  	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1293  		err = -ENOENT;
1294  		goto out;
1295  	}
1296  
1297  	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1298  	if (err)
1299  		goto out;
1300  
1301  	set_new_dnode(&dn, inode, NULL, NULL, 0);
1302  	err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1303  	if (err)
1304  		goto out;
1305  
1306  	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1307  		ClearPageUptodate(page);
1308  		err = -ENOENT;
1309  		goto put_out;
1310  	}
1311  
1312  	/*
1313  	 * don't cache encrypted data into meta inode until previous dirty
1314  	 * data were writebacked to avoid racing between GC and flush.
1315  	 */
1316  	f2fs_wait_on_page_writeback(page, DATA, true, true);
1317  
1318  	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1319  
1320  	err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1321  	if (err)
1322  		goto put_out;
1323  
1324  	/* read page */
1325  	fio.page = page;
1326  	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1327  
1328  	if (lfs_mode)
1329  		f2fs_down_write(&fio.sbi->io_order_lock);
1330  
1331  	mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1332  					fio.old_blkaddr, false);
1333  	if (!mpage) {
1334  		err = -ENOMEM;
1335  		goto up_out;
1336  	}
1337  
1338  	fio.encrypted_page = mpage;
1339  
1340  	/* read source block in mpage */
1341  	if (!PageUptodate(mpage)) {
1342  		err = f2fs_submit_page_bio(&fio);
1343  		if (err) {
1344  			f2fs_put_page(mpage, 1);
1345  			goto up_out;
1346  		}
1347  
1348  		f2fs_update_iostat(fio.sbi, inode, FS_DATA_READ_IO,
1349  							F2FS_BLKSIZE);
1350  		f2fs_update_iostat(fio.sbi, NULL, FS_GDATA_READ_IO,
1351  							F2FS_BLKSIZE);
1352  
1353  		lock_page(mpage);
1354  		if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1355  						!PageUptodate(mpage))) {
1356  			err = -EIO;
1357  			f2fs_put_page(mpage, 1);
1358  			goto up_out;
1359  		}
1360  	}
1361  
1362  	set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1363  
1364  	/* allocate block address */
1365  	err = f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1366  				&sum, type, NULL);
1367  	if (err) {
1368  		f2fs_put_page(mpage, 1);
1369  		/* filesystem should shutdown, no need to recovery block */
1370  		goto up_out;
1371  	}
1372  
1373  	fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1374  				newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1375  	if (!fio.encrypted_page) {
1376  		err = -ENOMEM;
1377  		f2fs_put_page(mpage, 1);
1378  		goto recover_block;
1379  	}
1380  
1381  	/* write target block */
1382  	f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1383  	memcpy(page_address(fio.encrypted_page),
1384  				page_address(mpage), PAGE_SIZE);
1385  	f2fs_put_page(mpage, 1);
1386  
1387  	f2fs_invalidate_internal_cache(fio.sbi, fio.old_blkaddr);
1388  
1389  	set_page_dirty(fio.encrypted_page);
1390  	if (clear_page_dirty_for_io(fio.encrypted_page))
1391  		dec_page_count(fio.sbi, F2FS_DIRTY_META);
1392  
1393  	set_page_writeback(fio.encrypted_page);
1394  
1395  	fio.op = REQ_OP_WRITE;
1396  	fio.op_flags = REQ_SYNC;
1397  	fio.new_blkaddr = newaddr;
1398  	f2fs_submit_page_write(&fio);
1399  
1400  	f2fs_update_iostat(fio.sbi, NULL, FS_GC_DATA_IO, F2FS_BLKSIZE);
1401  
1402  	f2fs_update_data_blkaddr(&dn, newaddr);
1403  	set_inode_flag(inode, FI_APPEND_WRITE);
1404  
1405  	f2fs_put_page(fio.encrypted_page, 1);
1406  recover_block:
1407  	if (err)
1408  		f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1409  							true, true, true);
1410  up_out:
1411  	if (lfs_mode)
1412  		f2fs_up_write(&fio.sbi->io_order_lock);
1413  put_out:
1414  	f2fs_put_dnode(&dn);
1415  out:
1416  	f2fs_put_page(page, 1);
1417  	return err;
1418  }
1419  
1420  static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1421  							unsigned int segno, int off)
1422  {
1423  	struct page *page;
1424  	int err = 0;
1425  
1426  	page = f2fs_get_lock_data_page(inode, bidx, true);
1427  	if (IS_ERR(page))
1428  		return PTR_ERR(page);
1429  
1430  	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1431  		err = -ENOENT;
1432  		goto out;
1433  	}
1434  
1435  	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1436  	if (err)
1437  		goto out;
1438  
1439  	if (gc_type == BG_GC) {
1440  		if (folio_test_writeback(page_folio(page))) {
1441  			err = -EAGAIN;
1442  			goto out;
1443  		}
1444  		set_page_dirty(page);
1445  		set_page_private_gcing(page);
1446  	} else {
1447  		struct f2fs_io_info fio = {
1448  			.sbi = F2FS_I_SB(inode),
1449  			.ino = inode->i_ino,
1450  			.type = DATA,
1451  			.temp = COLD,
1452  			.op = REQ_OP_WRITE,
1453  			.op_flags = REQ_SYNC,
1454  			.old_blkaddr = NULL_ADDR,
1455  			.page = page,
1456  			.encrypted_page = NULL,
1457  			.need_lock = LOCK_REQ,
1458  			.io_type = FS_GC_DATA_IO,
1459  		};
1460  		bool is_dirty = PageDirty(page);
1461  
1462  retry:
1463  		f2fs_wait_on_page_writeback(page, DATA, true, true);
1464  
1465  		set_page_dirty(page);
1466  		if (clear_page_dirty_for_io(page)) {
1467  			inode_dec_dirty_pages(inode);
1468  			f2fs_remove_dirty_inode(inode);
1469  		}
1470  
1471  		set_page_private_gcing(page);
1472  
1473  		err = f2fs_do_write_data_page(&fio);
1474  		if (err) {
1475  			clear_page_private_gcing(page);
1476  			if (err == -ENOMEM) {
1477  				memalloc_retry_wait(GFP_NOFS);
1478  				goto retry;
1479  			}
1480  			if (is_dirty)
1481  				set_page_dirty(page);
1482  		}
1483  	}
1484  out:
1485  	f2fs_put_page(page, 1);
1486  	return err;
1487  }
1488  
1489  /*
1490   * This function tries to get parent node of victim data block, and identifies
1491   * data block validity. If the block is valid, copy that with cold status and
1492   * modify parent node.
1493   * If the parent node is not valid or the data block address is different,
1494   * the victim data block is ignored.
1495   */
1496  static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1497  		struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1498  		bool force_migrate)
1499  {
1500  	struct super_block *sb = sbi->sb;
1501  	struct f2fs_summary *entry;
1502  	block_t start_addr;
1503  	int off;
1504  	int phase = 0;
1505  	int submitted = 0;
1506  	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1507  
1508  	start_addr = START_BLOCK(sbi, segno);
1509  
1510  next_step:
1511  	entry = sum;
1512  
1513  	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1514  		struct page *data_page;
1515  		struct inode *inode;
1516  		struct node_info dni; /* dnode info for the data */
1517  		unsigned int ofs_in_node, nofs;
1518  		block_t start_bidx;
1519  		nid_t nid = le32_to_cpu(entry->nid);
1520  
1521  		/*
1522  		 * stop BG_GC if there is not enough free sections.
1523  		 * Or, stop GC if the segment becomes fully valid caused by
1524  		 * race condition along with SSR block allocation.
1525  		 */
1526  		if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1527  			(!force_migrate && get_valid_blocks(sbi, segno, true) ==
1528  							CAP_BLKS_PER_SEC(sbi)))
1529  			return submitted;
1530  
1531  		if (check_valid_map(sbi, segno, off) == 0)
1532  			continue;
1533  
1534  		if (phase == 0) {
1535  			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1536  							META_NAT, true);
1537  			continue;
1538  		}
1539  
1540  		if (phase == 1) {
1541  			f2fs_ra_node_page(sbi, nid);
1542  			continue;
1543  		}
1544  
1545  		/* Get an inode by ino with checking validity */
1546  		if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1547  			continue;
1548  
1549  		if (phase == 2) {
1550  			f2fs_ra_node_page(sbi, dni.ino);
1551  			continue;
1552  		}
1553  
1554  		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1555  
1556  		if (phase == 3) {
1557  			int err;
1558  
1559  			inode = f2fs_iget(sb, dni.ino);
1560  			if (IS_ERR(inode))
1561  				continue;
1562  
1563  			if (is_bad_inode(inode) ||
1564  					special_file(inode->i_mode)) {
1565  				iput(inode);
1566  				continue;
1567  			}
1568  
1569  			if (f2fs_has_inline_data(inode)) {
1570  				iput(inode);
1571  				set_sbi_flag(sbi, SBI_NEED_FSCK);
1572  				f2fs_err_ratelimited(sbi,
1573  					"inode %lx has both inline_data flag and "
1574  					"data block, nid=%u, ofs_in_node=%u",
1575  					inode->i_ino, dni.nid, ofs_in_node);
1576  				continue;
1577  			}
1578  
1579  			err = f2fs_gc_pinned_control(inode, gc_type, segno);
1580  			if (err == -EAGAIN) {
1581  				iput(inode);
1582  				return submitted;
1583  			}
1584  
1585  			if (!f2fs_down_write_trylock(
1586  				&F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1587  				iput(inode);
1588  				sbi->skipped_gc_rwsem++;
1589  				continue;
1590  			}
1591  
1592  			start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1593  								ofs_in_node;
1594  
1595  			if (f2fs_meta_inode_gc_required(inode)) {
1596  				int err = ra_data_block(inode, start_bidx);
1597  
1598  				f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1599  				if (err) {
1600  					iput(inode);
1601  					continue;
1602  				}
1603  				add_gc_inode(gc_list, inode);
1604  				continue;
1605  			}
1606  
1607  			data_page = f2fs_get_read_data_page(inode, start_bidx,
1608  							REQ_RAHEAD, true, NULL);
1609  			f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1610  			if (IS_ERR(data_page)) {
1611  				iput(inode);
1612  				continue;
1613  			}
1614  
1615  			f2fs_put_page(data_page, 0);
1616  			add_gc_inode(gc_list, inode);
1617  			continue;
1618  		}
1619  
1620  		/* phase 4 */
1621  		inode = find_gc_inode(gc_list, dni.ino);
1622  		if (inode) {
1623  			struct f2fs_inode_info *fi = F2FS_I(inode);
1624  			bool locked = false;
1625  			int err;
1626  
1627  			if (S_ISREG(inode->i_mode)) {
1628  				if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[WRITE])) {
1629  					sbi->skipped_gc_rwsem++;
1630  					continue;
1631  				}
1632  				if (!f2fs_down_write_trylock(
1633  						&fi->i_gc_rwsem[READ])) {
1634  					sbi->skipped_gc_rwsem++;
1635  					f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1636  					continue;
1637  				}
1638  				locked = true;
1639  
1640  				/* wait for all inflight aio data */
1641  				inode_dio_wait(inode);
1642  			}
1643  
1644  			start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1645  								+ ofs_in_node;
1646  			if (f2fs_meta_inode_gc_required(inode))
1647  				err = move_data_block(inode, start_bidx,
1648  							gc_type, segno, off);
1649  			else
1650  				err = move_data_page(inode, start_bidx, gc_type,
1651  								segno, off);
1652  
1653  			if (!err && (gc_type == FG_GC ||
1654  					f2fs_meta_inode_gc_required(inode)))
1655  				submitted++;
1656  
1657  			if (locked) {
1658  				f2fs_up_write(&fi->i_gc_rwsem[READ]);
1659  				f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1660  			}
1661  
1662  			stat_inc_data_blk_count(sbi, 1, gc_type);
1663  		}
1664  	}
1665  
1666  	if (++phase < 5)
1667  		goto next_step;
1668  
1669  	return submitted;
1670  }
1671  
1672  static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1673  			int gc_type)
1674  {
1675  	struct sit_info *sit_i = SIT_I(sbi);
1676  	int ret;
1677  
1678  	down_write(&sit_i->sentry_lock);
1679  	ret = f2fs_get_victim(sbi, victim, gc_type, NO_CHECK_TYPE, LFS, 0);
1680  	up_write(&sit_i->sentry_lock);
1681  	return ret;
1682  }
1683  
1684  static int do_garbage_collect(struct f2fs_sb_info *sbi,
1685  				unsigned int start_segno,
1686  				struct gc_inode_list *gc_list, int gc_type,
1687  				bool force_migrate)
1688  {
1689  	struct page *sum_page;
1690  	struct f2fs_summary_block *sum;
1691  	struct blk_plug plug;
1692  	unsigned int segno = start_segno;
1693  	unsigned int end_segno = start_segno + SEGS_PER_SEC(sbi);
1694  	int seg_freed = 0, migrated = 0;
1695  	unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1696  						SUM_TYPE_DATA : SUM_TYPE_NODE;
1697  	unsigned char data_type = (type == SUM_TYPE_DATA) ? DATA : NODE;
1698  	int submitted = 0;
1699  
1700  	if (__is_large_section(sbi))
1701  		end_segno = rounddown(end_segno, SEGS_PER_SEC(sbi));
1702  
1703  	/*
1704  	 * zone-capacity can be less than zone-size in zoned devices,
1705  	 * resulting in less than expected usable segments in the zone,
1706  	 * calculate the end segno in the zone which can be garbage collected
1707  	 */
1708  	if (f2fs_sb_has_blkzoned(sbi))
1709  		end_segno -= SEGS_PER_SEC(sbi) -
1710  					f2fs_usable_segs_in_sec(sbi, segno);
1711  
1712  	sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1713  
1714  	/* readahead multi ssa blocks those have contiguous address */
1715  	if (__is_large_section(sbi))
1716  		f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1717  					end_segno - segno, META_SSA, true);
1718  
1719  	/* reference all summary page */
1720  	while (segno < end_segno) {
1721  		sum_page = f2fs_get_sum_page(sbi, segno++);
1722  		if (IS_ERR(sum_page)) {
1723  			int err = PTR_ERR(sum_page);
1724  
1725  			end_segno = segno - 1;
1726  			for (segno = start_segno; segno < end_segno; segno++) {
1727  				sum_page = find_get_page(META_MAPPING(sbi),
1728  						GET_SUM_BLOCK(sbi, segno));
1729  				f2fs_put_page(sum_page, 0);
1730  				f2fs_put_page(sum_page, 0);
1731  			}
1732  			return err;
1733  		}
1734  		unlock_page(sum_page);
1735  	}
1736  
1737  	blk_start_plug(&plug);
1738  
1739  	for (segno = start_segno; segno < end_segno; segno++) {
1740  
1741  		/* find segment summary of victim */
1742  		sum_page = find_get_page(META_MAPPING(sbi),
1743  					GET_SUM_BLOCK(sbi, segno));
1744  		f2fs_put_page(sum_page, 0);
1745  
1746  		if (get_valid_blocks(sbi, segno, false) == 0)
1747  			goto freed;
1748  		if (gc_type == BG_GC && __is_large_section(sbi) &&
1749  				migrated >= sbi->migration_granularity)
1750  			goto skip;
1751  		if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1752  			goto skip;
1753  
1754  		sum = page_address(sum_page);
1755  		if (type != GET_SUM_TYPE((&sum->footer))) {
1756  			f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1757  				 segno, type, GET_SUM_TYPE((&sum->footer)));
1758  			f2fs_stop_checkpoint(sbi, false,
1759  				STOP_CP_REASON_CORRUPTED_SUMMARY);
1760  			goto skip;
1761  		}
1762  
1763  		/*
1764  		 * this is to avoid deadlock:
1765  		 * - lock_page(sum_page)         - f2fs_replace_block
1766  		 *  - check_valid_map()            - down_write(sentry_lock)
1767  		 *   - down_read(sentry_lock)     - change_curseg()
1768  		 *                                  - lock_page(sum_page)
1769  		 */
1770  		if (type == SUM_TYPE_NODE)
1771  			submitted += gc_node_segment(sbi, sum->entries, segno,
1772  								gc_type);
1773  		else
1774  			submitted += gc_data_segment(sbi, sum->entries, gc_list,
1775  							segno, gc_type,
1776  							force_migrate);
1777  
1778  		stat_inc_gc_seg_count(sbi, data_type, gc_type);
1779  		sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1780  		migrated++;
1781  
1782  freed:
1783  		if (gc_type == FG_GC &&
1784  				get_valid_blocks(sbi, segno, false) == 0)
1785  			seg_freed++;
1786  
1787  		if (__is_large_section(sbi))
1788  			sbi->next_victim_seg[gc_type] =
1789  				(segno + 1 < end_segno) ? segno + 1 : NULL_SEGNO;
1790  skip:
1791  		f2fs_put_page(sum_page, 0);
1792  	}
1793  
1794  	if (submitted)
1795  		f2fs_submit_merged_write(sbi, data_type);
1796  
1797  	blk_finish_plug(&plug);
1798  
1799  	if (migrated)
1800  		stat_inc_gc_sec_count(sbi, data_type, gc_type);
1801  
1802  	return seg_freed;
1803  }
1804  
1805  int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1806  {
1807  	int gc_type = gc_control->init_gc_type;
1808  	unsigned int segno = gc_control->victim_segno;
1809  	int sec_freed = 0, seg_freed = 0, total_freed = 0, total_sec_freed = 0;
1810  	int ret = 0;
1811  	struct cp_control cpc;
1812  	struct gc_inode_list gc_list = {
1813  		.ilist = LIST_HEAD_INIT(gc_list.ilist),
1814  		.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1815  	};
1816  	unsigned int skipped_round = 0, round = 0;
1817  	unsigned int upper_secs;
1818  
1819  	trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
1820  				gc_control->nr_free_secs,
1821  				get_pages(sbi, F2FS_DIRTY_NODES),
1822  				get_pages(sbi, F2FS_DIRTY_DENTS),
1823  				get_pages(sbi, F2FS_DIRTY_IMETA),
1824  				free_sections(sbi),
1825  				free_segments(sbi),
1826  				reserved_segments(sbi),
1827  				prefree_segments(sbi));
1828  
1829  	cpc.reason = __get_cp_reason(sbi);
1830  gc_more:
1831  	sbi->skipped_gc_rwsem = 0;
1832  	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1833  		ret = -EINVAL;
1834  		goto stop;
1835  	}
1836  	if (unlikely(f2fs_cp_error(sbi))) {
1837  		ret = -EIO;
1838  		goto stop;
1839  	}
1840  
1841  	/* Let's run FG_GC, if we don't have enough space. */
1842  	if (has_not_enough_free_secs(sbi, 0, 0)) {
1843  		gc_type = FG_GC;
1844  
1845  		/*
1846  		 * For example, if there are many prefree_segments below given
1847  		 * threshold, we can make them free by checkpoint. Then, we
1848  		 * secure free segments which doesn't need fggc any more.
1849  		 */
1850  		if (prefree_segments(sbi)) {
1851  			stat_inc_cp_call_count(sbi, TOTAL_CALL);
1852  			ret = f2fs_write_checkpoint(sbi, &cpc);
1853  			if (ret)
1854  				goto stop;
1855  			/* Reset due to checkpoint */
1856  			sec_freed = 0;
1857  		}
1858  	}
1859  
1860  	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1861  	if (gc_type == BG_GC && gc_control->no_bg_gc) {
1862  		ret = -EINVAL;
1863  		goto stop;
1864  	}
1865  retry:
1866  	ret = __get_victim(sbi, &segno, gc_type);
1867  	if (ret) {
1868  		/* allow to search victim from sections has pinned data */
1869  		if (ret == -ENODATA && gc_type == FG_GC &&
1870  				f2fs_pinned_section_exists(DIRTY_I(sbi))) {
1871  			f2fs_unpin_all_sections(sbi, false);
1872  			goto retry;
1873  		}
1874  		goto stop;
1875  	}
1876  
1877  	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
1878  				gc_control->should_migrate_blocks);
1879  	if (seg_freed < 0)
1880  		goto stop;
1881  
1882  	total_freed += seg_freed;
1883  
1884  	if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno)) {
1885  		sec_freed++;
1886  		total_sec_freed++;
1887  	}
1888  
1889  	if (gc_type == FG_GC) {
1890  		sbi->cur_victim_sec = NULL_SEGNO;
1891  
1892  		if (has_enough_free_secs(sbi, sec_freed, 0)) {
1893  			if (!gc_control->no_bg_gc &&
1894  			    total_sec_freed < gc_control->nr_free_secs)
1895  				goto go_gc_more;
1896  			goto stop;
1897  		}
1898  		if (sbi->skipped_gc_rwsem)
1899  			skipped_round++;
1900  		round++;
1901  		if (skipped_round > MAX_SKIP_GC_COUNT &&
1902  				skipped_round * 2 >= round) {
1903  			stat_inc_cp_call_count(sbi, TOTAL_CALL);
1904  			ret = f2fs_write_checkpoint(sbi, &cpc);
1905  			goto stop;
1906  		}
1907  	} else if (has_enough_free_secs(sbi, 0, 0)) {
1908  		goto stop;
1909  	}
1910  
1911  	__get_secs_required(sbi, NULL, &upper_secs, NULL);
1912  
1913  	/*
1914  	 * Write checkpoint to reclaim prefree segments.
1915  	 * We need more three extra sections for writer's data/node/dentry.
1916  	 */
1917  	if (free_sections(sbi) <= upper_secs + NR_GC_CHECKPOINT_SECS &&
1918  				prefree_segments(sbi)) {
1919  		stat_inc_cp_call_count(sbi, TOTAL_CALL);
1920  		ret = f2fs_write_checkpoint(sbi, &cpc);
1921  		if (ret)
1922  			goto stop;
1923  		/* Reset due to checkpoint */
1924  		sec_freed = 0;
1925  	}
1926  go_gc_more:
1927  	segno = NULL_SEGNO;
1928  	goto gc_more;
1929  
1930  stop:
1931  	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1932  	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
1933  
1934  	if (gc_type == FG_GC)
1935  		f2fs_unpin_all_sections(sbi, true);
1936  
1937  	trace_f2fs_gc_end(sbi->sb, ret, total_freed, total_sec_freed,
1938  				get_pages(sbi, F2FS_DIRTY_NODES),
1939  				get_pages(sbi, F2FS_DIRTY_DENTS),
1940  				get_pages(sbi, F2FS_DIRTY_IMETA),
1941  				free_sections(sbi),
1942  				free_segments(sbi),
1943  				reserved_segments(sbi),
1944  				prefree_segments(sbi));
1945  
1946  	f2fs_up_write(&sbi->gc_lock);
1947  
1948  	put_gc_inode(&gc_list);
1949  
1950  	if (gc_control->err_gc_skipped && !ret)
1951  		ret = total_sec_freed ? 0 : -EAGAIN;
1952  	return ret;
1953  }
1954  
1955  int __init f2fs_create_garbage_collection_cache(void)
1956  {
1957  	victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1958  					sizeof(struct victim_entry));
1959  	return victim_entry_slab ? 0 : -ENOMEM;
1960  }
1961  
1962  void f2fs_destroy_garbage_collection_cache(void)
1963  {
1964  	kmem_cache_destroy(victim_entry_slab);
1965  }
1966  
1967  static void init_atgc_management(struct f2fs_sb_info *sbi)
1968  {
1969  	struct atgc_management *am = &sbi->am;
1970  
1971  	if (test_opt(sbi, ATGC) &&
1972  		SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1973  		am->atgc_enabled = true;
1974  
1975  	am->root = RB_ROOT_CACHED;
1976  	INIT_LIST_HEAD(&am->victim_list);
1977  	am->victim_count = 0;
1978  
1979  	am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1980  	am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1981  	am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1982  	am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1983  }
1984  
1985  void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1986  {
1987  	sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1988  
1989  	/* give warm/cold data area from slower device */
1990  	if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1991  		SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1992  				GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1993  
1994  	init_atgc_management(sbi);
1995  }
1996  
1997  int f2fs_gc_range(struct f2fs_sb_info *sbi,
1998  		unsigned int start_seg, unsigned int end_seg,
1999  		bool dry_run, unsigned int dry_run_sections)
2000  {
2001  	unsigned int segno;
2002  	unsigned int gc_secs = dry_run_sections;
2003  
2004  	if (unlikely(f2fs_cp_error(sbi)))
2005  		return -EIO;
2006  
2007  	for (segno = start_seg; segno <= end_seg; segno += SEGS_PER_SEC(sbi)) {
2008  		struct gc_inode_list gc_list = {
2009  			.ilist = LIST_HEAD_INIT(gc_list.ilist),
2010  			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
2011  		};
2012  
2013  		do_garbage_collect(sbi, segno, &gc_list, FG_GC,
2014  						dry_run_sections == 0);
2015  		put_gc_inode(&gc_list);
2016  
2017  		if (!dry_run && get_valid_blocks(sbi, segno, true))
2018  			return -EAGAIN;
2019  		if (dry_run && dry_run_sections &&
2020  		    !get_valid_blocks(sbi, segno, true) && --gc_secs == 0)
2021  			break;
2022  
2023  		if (fatal_signal_pending(current))
2024  			return -ERESTARTSYS;
2025  	}
2026  
2027  	return 0;
2028  }
2029  
2030  static int free_segment_range(struct f2fs_sb_info *sbi,
2031  				unsigned int secs, bool dry_run)
2032  {
2033  	unsigned int next_inuse, start, end;
2034  	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2035  	int gc_mode, gc_type;
2036  	int err = 0;
2037  	int type;
2038  
2039  	/* Force block allocation for GC */
2040  	MAIN_SECS(sbi) -= secs;
2041  	start = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
2042  	end = MAIN_SEGS(sbi) - 1;
2043  
2044  	mutex_lock(&DIRTY_I(sbi)->seglist_lock);
2045  	for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
2046  		if (SIT_I(sbi)->last_victim[gc_mode] >= start)
2047  			SIT_I(sbi)->last_victim[gc_mode] = 0;
2048  
2049  	for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
2050  		if (sbi->next_victim_seg[gc_type] >= start)
2051  			sbi->next_victim_seg[gc_type] = NULL_SEGNO;
2052  	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
2053  
2054  	/* Move out cursegs from the target range */
2055  	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++) {
2056  		err = f2fs_allocate_segment_for_resize(sbi, type, start, end);
2057  		if (err)
2058  			goto out;
2059  	}
2060  
2061  	/* do GC to move out valid blocks in the range */
2062  	err = f2fs_gc_range(sbi, start, end, dry_run, 0);
2063  	if (err || dry_run)
2064  		goto out;
2065  
2066  	stat_inc_cp_call_count(sbi, TOTAL_CALL);
2067  	err = f2fs_write_checkpoint(sbi, &cpc);
2068  	if (err)
2069  		goto out;
2070  
2071  	next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
2072  	if (next_inuse <= end) {
2073  		f2fs_err(sbi, "segno %u should be free but still inuse!",
2074  			 next_inuse);
2075  		f2fs_bug_on(sbi, 1);
2076  	}
2077  out:
2078  	MAIN_SECS(sbi) += secs;
2079  	return err;
2080  }
2081  
2082  static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
2083  {
2084  	struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
2085  	int section_count;
2086  	int segment_count;
2087  	int segment_count_main;
2088  	long long block_count;
2089  	int segs = secs * SEGS_PER_SEC(sbi);
2090  
2091  	f2fs_down_write(&sbi->sb_lock);
2092  
2093  	section_count = le32_to_cpu(raw_sb->section_count);
2094  	segment_count = le32_to_cpu(raw_sb->segment_count);
2095  	segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2096  	block_count = le64_to_cpu(raw_sb->block_count);
2097  
2098  	raw_sb->section_count = cpu_to_le32(section_count + secs);
2099  	raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2100  	raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2101  	raw_sb->block_count = cpu_to_le64(block_count +
2102  			(long long)SEGS_TO_BLKS(sbi, segs));
2103  	if (f2fs_is_multi_device(sbi)) {
2104  		int last_dev = sbi->s_ndevs - 1;
2105  		int dev_segs =
2106  			le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2107  
2108  		raw_sb->devs[last_dev].total_segments =
2109  						cpu_to_le32(dev_segs + segs);
2110  	}
2111  
2112  	f2fs_up_write(&sbi->sb_lock);
2113  }
2114  
2115  static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2116  {
2117  	int segs = secs * SEGS_PER_SEC(sbi);
2118  	long long blks = SEGS_TO_BLKS(sbi, segs);
2119  	long long user_block_count =
2120  				le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2121  
2122  	SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2123  	MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2124  	MAIN_SECS(sbi) += secs;
2125  	FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2126  	FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2127  	F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2128  
2129  	if (f2fs_is_multi_device(sbi)) {
2130  		int last_dev = sbi->s_ndevs - 1;
2131  
2132  		FDEV(last_dev).total_segments =
2133  				(int)FDEV(last_dev).total_segments + segs;
2134  		FDEV(last_dev).end_blk =
2135  				(long long)FDEV(last_dev).end_blk + blks;
2136  #ifdef CONFIG_BLK_DEV_ZONED
2137  		FDEV(last_dev).nr_blkz = FDEV(last_dev).nr_blkz +
2138  					div_u64(blks, sbi->blocks_per_blkz);
2139  #endif
2140  	}
2141  }
2142  
2143  int f2fs_resize_fs(struct file *filp, __u64 block_count)
2144  {
2145  	struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
2146  	__u64 old_block_count, shrunk_blocks;
2147  	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2148  	unsigned int secs;
2149  	int err = 0;
2150  	__u32 rem;
2151  
2152  	old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2153  	if (block_count > old_block_count)
2154  		return -EINVAL;
2155  
2156  	if (f2fs_is_multi_device(sbi)) {
2157  		int last_dev = sbi->s_ndevs - 1;
2158  		__u64 last_segs = FDEV(last_dev).total_segments;
2159  
2160  		if (block_count + SEGS_TO_BLKS(sbi, last_segs) <=
2161  								old_block_count)
2162  			return -EINVAL;
2163  	}
2164  
2165  	/* new fs size should align to section size */
2166  	div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2167  	if (rem)
2168  		return -EINVAL;
2169  
2170  	if (block_count == old_block_count)
2171  		return 0;
2172  
2173  	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2174  		f2fs_err(sbi, "Should run fsck to repair first.");
2175  		return -EFSCORRUPTED;
2176  	}
2177  
2178  	if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2179  		f2fs_err(sbi, "Checkpoint should be enabled.");
2180  		return -EINVAL;
2181  	}
2182  
2183  	err = mnt_want_write_file(filp);
2184  	if (err)
2185  		return err;
2186  
2187  	shrunk_blocks = old_block_count - block_count;
2188  	secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2189  
2190  	/* stop other GC */
2191  	if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
2192  		err = -EAGAIN;
2193  		goto out_drop_write;
2194  	}
2195  
2196  	/* stop CP to protect MAIN_SEC in free_segment_range */
2197  	f2fs_lock_op(sbi);
2198  
2199  	spin_lock(&sbi->stat_lock);
2200  	if (shrunk_blocks + valid_user_blocks(sbi) +
2201  		sbi->current_reserved_blocks + sbi->unusable_block_count +
2202  		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2203  		err = -ENOSPC;
2204  	spin_unlock(&sbi->stat_lock);
2205  
2206  	if (err)
2207  		goto out_unlock;
2208  
2209  	err = free_segment_range(sbi, secs, true);
2210  
2211  out_unlock:
2212  	f2fs_unlock_op(sbi);
2213  	f2fs_up_write(&sbi->gc_lock);
2214  out_drop_write:
2215  	mnt_drop_write_file(filp);
2216  	if (err)
2217  		return err;
2218  
2219  	err = freeze_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2220  	if (err)
2221  		return err;
2222  
2223  	if (f2fs_readonly(sbi->sb)) {
2224  		err = thaw_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2225  		if (err)
2226  			return err;
2227  		return -EROFS;
2228  	}
2229  
2230  	f2fs_down_write(&sbi->gc_lock);
2231  	f2fs_down_write(&sbi->cp_global_sem);
2232  
2233  	spin_lock(&sbi->stat_lock);
2234  	if (shrunk_blocks + valid_user_blocks(sbi) +
2235  		sbi->current_reserved_blocks + sbi->unusable_block_count +
2236  		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2237  		err = -ENOSPC;
2238  	else
2239  		sbi->user_block_count -= shrunk_blocks;
2240  	spin_unlock(&sbi->stat_lock);
2241  	if (err)
2242  		goto out_err;
2243  
2244  	set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2245  	err = free_segment_range(sbi, secs, false);
2246  	if (err)
2247  		goto recover_out;
2248  
2249  	update_sb_metadata(sbi, -secs);
2250  
2251  	err = f2fs_commit_super(sbi, false);
2252  	if (err) {
2253  		update_sb_metadata(sbi, secs);
2254  		goto recover_out;
2255  	}
2256  
2257  	update_fs_metadata(sbi, -secs);
2258  	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2259  	set_sbi_flag(sbi, SBI_IS_DIRTY);
2260  
2261  	stat_inc_cp_call_count(sbi, TOTAL_CALL);
2262  	err = f2fs_write_checkpoint(sbi, &cpc);
2263  	if (err) {
2264  		update_fs_metadata(sbi, secs);
2265  		update_sb_metadata(sbi, secs);
2266  		f2fs_commit_super(sbi, false);
2267  	}
2268  recover_out:
2269  	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2270  	if (err) {
2271  		set_sbi_flag(sbi, SBI_NEED_FSCK);
2272  		f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2273  
2274  		spin_lock(&sbi->stat_lock);
2275  		sbi->user_block_count += shrunk_blocks;
2276  		spin_unlock(&sbi->stat_lock);
2277  	}
2278  out_err:
2279  	f2fs_up_write(&sbi->cp_global_sem);
2280  	f2fs_up_write(&sbi->gc_lock);
2281  	thaw_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2282  	return err;
2283  }
2284