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 
gc_thread_func(void * data)31 static int gc_thread_func(void *data)
32 {
33 	struct f2fs_sb_info *sbi = data;
34 	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
35 	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
36 	wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
37 	unsigned int wait_ms;
38 	struct f2fs_gc_control gc_control = {
39 		.victim_segno = NULL_SEGNO,
40 		.should_migrate_blocks = false,
41 		.err_gc_skipped = false };
42 
43 	wait_ms = gc_th->min_sleep_time;
44 
45 	set_freezable();
46 	do {
47 		bool sync_mode, foreground = false;
48 
49 		wait_event_interruptible_timeout(*wq,
50 				kthread_should_stop() || freezing(current) ||
51 				waitqueue_active(fggc_wq) ||
52 				gc_th->gc_wake,
53 				msecs_to_jiffies(wait_ms));
54 
55 		if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq))
56 			foreground = true;
57 
58 		/* give it a try one time */
59 		if (gc_th->gc_wake)
60 			gc_th->gc_wake = 0;
61 
62 		if (try_to_freeze()) {
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_show_injection_info(sbi, FAULT_CHECKPOINT);
77 			f2fs_stop_checkpoint(sbi, false);
78 		}
79 
80 		if (!sb_start_write_trylock(sbi->sb)) {
81 			stat_other_skip_bggc_count(sbi);
82 			continue;
83 		}
84 
85 		/*
86 		 * [GC triggering condition]
87 		 * 0. GC is not conducted currently.
88 		 * 1. There are enough dirty segments.
89 		 * 2. IO subsystem is idle by checking the # of writeback pages.
90 		 * 3. IO subsystem is idle by checking the # of requests in
91 		 *    bdev's request list.
92 		 *
93 		 * Note) We have to avoid triggering GCs frequently.
94 		 * Because it is possible that some segments can be
95 		 * invalidated soon after by user update or deletion.
96 		 * So, I'd like to wait some time to collect dirty segments.
97 		 */
98 		if (sbi->gc_mode == GC_URGENT_HIGH) {
99 			spin_lock(&sbi->gc_urgent_high_lock);
100 			if (sbi->gc_urgent_high_limited) {
101 				if (!sbi->gc_urgent_high_remaining) {
102 					sbi->gc_urgent_high_limited = false;
103 					spin_unlock(&sbi->gc_urgent_high_lock);
104 					sbi->gc_mode = GC_NORMAL;
105 					continue;
106 				}
107 				sbi->gc_urgent_high_remaining--;
108 			}
109 			spin_unlock(&sbi->gc_urgent_high_lock);
110 		}
111 
112 		if (sbi->gc_mode == GC_URGENT_HIGH ||
113 				sbi->gc_mode == GC_URGENT_MID) {
114 			wait_ms = gc_th->urgent_sleep_time;
115 			f2fs_down_write(&sbi->gc_lock);
116 			goto do_gc;
117 		}
118 
119 		if (foreground) {
120 			f2fs_down_write(&sbi->gc_lock);
121 			goto do_gc;
122 		} else if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
123 			stat_other_skip_bggc_count(sbi);
124 			goto next;
125 		}
126 
127 		if (!is_idle(sbi, GC_TIME)) {
128 			increase_sleep_time(gc_th, &wait_ms);
129 			f2fs_up_write(&sbi->gc_lock);
130 			stat_io_skip_bggc_count(sbi);
131 			goto next;
132 		}
133 
134 		if (has_enough_invalid_blocks(sbi))
135 			decrease_sleep_time(gc_th, &wait_ms);
136 		else
137 			increase_sleep_time(gc_th, &wait_ms);
138 do_gc:
139 		if (!foreground)
140 			stat_inc_bggc_count(sbi->stat_info);
141 
142 		sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
143 
144 		/* foreground GC was been triggered via f2fs_balance_fs() */
145 		if (foreground)
146 			sync_mode = false;
147 
148 		gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
149 		gc_control.no_bg_gc = foreground;
150 		gc_control.nr_free_secs = foreground ? 1 : 0;
151 
152 		/* if return value is not zero, no victim was selected */
153 		if (f2fs_gc(sbi, &gc_control))
154 			wait_ms = gc_th->no_gc_sleep_time;
155 
156 		if (foreground)
157 			wake_up_all(&gc_th->fggc_wq);
158 
159 		trace_f2fs_background_gc(sbi->sb, wait_ms,
160 				prefree_segments(sbi), free_segments(sbi));
161 
162 		/* balancing f2fs's metadata periodically */
163 		f2fs_balance_fs_bg(sbi, true);
164 next:
165 		sb_end_write(sbi->sb);
166 
167 	} while (!kthread_should_stop());
168 	return 0;
169 }
170 
f2fs_start_gc_thread(struct f2fs_sb_info * sbi)171 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
172 {
173 	struct f2fs_gc_kthread *gc_th;
174 	dev_t dev = sbi->sb->s_bdev->bd_dev;
175 	int err = 0;
176 
177 	gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
178 	if (!gc_th) {
179 		err = -ENOMEM;
180 		goto out;
181 	}
182 
183 	gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
184 	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
185 	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
186 	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
187 
188 	gc_th->gc_wake = 0;
189 
190 	sbi->gc_thread = gc_th;
191 	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
192 	init_waitqueue_head(&sbi->gc_thread->fggc_wq);
193 	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
194 			"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
195 	if (IS_ERR(gc_th->f2fs_gc_task)) {
196 		err = PTR_ERR(gc_th->f2fs_gc_task);
197 		kfree(gc_th);
198 		sbi->gc_thread = NULL;
199 	}
200 out:
201 	return err;
202 }
203 
f2fs_stop_gc_thread(struct f2fs_sb_info * sbi)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 
select_gc_type(struct f2fs_sb_info * sbi,int gc_type)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 
select_policy(struct f2fs_sb_info * sbi,int gc_type,int type,struct victim_sel_policy * p)245 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
246 			int type, struct victim_sel_policy *p)
247 {
248 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
249 
250 	if (p->alloc_mode == SSR) {
251 		p->gc_mode = GC_GREEDY;
252 		p->dirty_bitmap = dirty_i->dirty_segmap[type];
253 		p->max_search = dirty_i->nr_dirty[type];
254 		p->ofs_unit = 1;
255 	} else if (p->alloc_mode == AT_SSR) {
256 		p->gc_mode = GC_GREEDY;
257 		p->dirty_bitmap = dirty_i->dirty_segmap[type];
258 		p->max_search = dirty_i->nr_dirty[type];
259 		p->ofs_unit = 1;
260 	} else {
261 		p->gc_mode = select_gc_type(sbi, gc_type);
262 		p->ofs_unit = sbi->segs_per_sec;
263 		if (__is_large_section(sbi)) {
264 			p->dirty_bitmap = dirty_i->dirty_secmap;
265 			p->max_search = count_bits(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 in no_heap mode*/
284 	if (f2fs_need_rand_seg(sbi))
285 		p->offset = prandom_u32() % (MAIN_SECS(sbi) * sbi->segs_per_sec);
286 	else if (test_opt(sbi, NOHEAP) &&
287 		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
288 		p->offset = 0;
289 	else
290 		p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
291 }
292 
get_max_cost(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)293 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
294 				struct victim_sel_policy *p)
295 {
296 	/* SSR allocates in a segment unit */
297 	if (p->alloc_mode == SSR)
298 		return sbi->blocks_per_seg;
299 	else if (p->alloc_mode == AT_SSR)
300 		return UINT_MAX;
301 
302 	/* LFS */
303 	if (p->gc_mode == GC_GREEDY)
304 		return 2 * sbi->blocks_per_seg * p->ofs_unit;
305 	else if (p->gc_mode == GC_CB)
306 		return UINT_MAX;
307 	else if (p->gc_mode == GC_AT)
308 		return UINT_MAX;
309 	else /* No other gc_mode */
310 		return 0;
311 }
312 
check_bg_victims(struct f2fs_sb_info * sbi)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 
get_cb_cost(struct f2fs_sb_info * sbi,unsigned int segno)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 = (vblocks * 100) >> sbi->log_blocks_per_seg;
352 
353 	/* Handle if the system time has changed by the user */
354 	if (mtime < sit_i->min_mtime)
355 		sit_i->min_mtime = mtime;
356 	if (mtime > sit_i->max_mtime)
357 		sit_i->max_mtime = mtime;
358 	if (sit_i->max_mtime != sit_i->min_mtime)
359 		age = 100 - div64_u64(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 
get_gc_cost(struct f2fs_sb_info * sbi,unsigned int segno,struct victim_sel_policy * p)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 
count_bits(const unsigned long * addr,unsigned int offset,unsigned int len)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 
attach_victim_entry(struct f2fs_sb_info * sbi,unsigned long long mtime,unsigned int segno,struct rb_node * parent,struct rb_node ** p,bool left_most)393 static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
394 				unsigned long long mtime, unsigned int segno,
395 				struct rb_node *parent, struct rb_node **p,
396 				bool left_most)
397 {
398 	struct atgc_management *am = &sbi->am;
399 	struct victim_entry *ve;
400 
401 	ve =  f2fs_kmem_cache_alloc(victim_entry_slab,
402 				GFP_NOFS, true, NULL);
403 
404 	ve->mtime = mtime;
405 	ve->segno = segno;
406 
407 	rb_link_node(&ve->rb_node, parent, p);
408 	rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
409 
410 	list_add_tail(&ve->list, &am->victim_list);
411 
412 	am->victim_count++;
413 
414 	return ve;
415 }
416 
insert_victim_entry(struct f2fs_sb_info * sbi,unsigned long long mtime,unsigned int segno)417 static void insert_victim_entry(struct f2fs_sb_info *sbi,
418 				unsigned long long mtime, unsigned int segno)
419 {
420 	struct atgc_management *am = &sbi->am;
421 	struct rb_node **p;
422 	struct rb_node *parent = NULL;
423 	bool left_most = true;
424 
425 	p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
426 	attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
427 }
428 
add_victim_entry(struct f2fs_sb_info * sbi,struct victim_sel_policy * p,unsigned int segno)429 static void add_victim_entry(struct f2fs_sb_info *sbi,
430 				struct victim_sel_policy *p, unsigned int segno)
431 {
432 	struct sit_info *sit_i = SIT_I(sbi);
433 	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
434 	unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
435 	unsigned long long mtime = 0;
436 	unsigned int i;
437 
438 	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
439 		if (p->gc_mode == GC_AT &&
440 			get_valid_blocks(sbi, segno, true) == 0)
441 			return;
442 	}
443 
444 	for (i = 0; i < sbi->segs_per_sec; i++)
445 		mtime += get_seg_entry(sbi, start + i)->mtime;
446 	mtime = div_u64(mtime, sbi->segs_per_sec);
447 
448 	/* Handle if the system time has changed by the user */
449 	if (mtime < sit_i->min_mtime)
450 		sit_i->min_mtime = mtime;
451 	if (mtime > sit_i->max_mtime)
452 		sit_i->max_mtime = mtime;
453 	if (mtime < sit_i->dirty_min_mtime)
454 		sit_i->dirty_min_mtime = mtime;
455 	if (mtime > sit_i->dirty_max_mtime)
456 		sit_i->dirty_max_mtime = mtime;
457 
458 	/* don't choose young section as candidate */
459 	if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
460 		return;
461 
462 	insert_victim_entry(sbi, mtime, segno);
463 }
464 
lookup_central_victim(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)465 static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
466 						struct victim_sel_policy *p)
467 {
468 	struct atgc_management *am = &sbi->am;
469 	struct rb_node *parent = NULL;
470 	bool left_most;
471 
472 	f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
473 
474 	return parent;
475 }
476 
atgc_lookup_victim(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)477 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
478 						struct victim_sel_policy *p)
479 {
480 	struct sit_info *sit_i = SIT_I(sbi);
481 	struct atgc_management *am = &sbi->am;
482 	struct rb_root_cached *root = &am->root;
483 	struct rb_node *node;
484 	struct rb_entry *re;
485 	struct victim_entry *ve;
486 	unsigned long long total_time;
487 	unsigned long long age, u, accu;
488 	unsigned long long max_mtime = sit_i->dirty_max_mtime;
489 	unsigned long long min_mtime = sit_i->dirty_min_mtime;
490 	unsigned int sec_blocks = BLKS_PER_SEC(sbi);
491 	unsigned int vblocks;
492 	unsigned int dirty_threshold = max(am->max_candidate_count,
493 					am->candidate_ratio *
494 					am->victim_count / 100);
495 	unsigned int age_weight = am->age_weight;
496 	unsigned int cost;
497 	unsigned int iter = 0;
498 
499 	if (max_mtime < min_mtime)
500 		return;
501 
502 	max_mtime += 1;
503 	total_time = max_mtime - min_mtime;
504 
505 	accu = div64_u64(ULLONG_MAX, total_time);
506 	accu = min_t(unsigned long long, div_u64(accu, 100),
507 					DEFAULT_ACCURACY_CLASS);
508 
509 	node = rb_first_cached(root);
510 next:
511 	re = rb_entry_safe(node, struct rb_entry, rb_node);
512 	if (!re)
513 		return;
514 
515 	ve = (struct victim_entry *)re;
516 
517 	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
518 		goto skip;
519 
520 	/* age = 10000 * x% * 60 */
521 	age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
522 								age_weight;
523 
524 	vblocks = get_valid_blocks(sbi, ve->segno, true);
525 	f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
526 
527 	/* u = 10000 * x% * 40 */
528 	u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
529 							(100 - age_weight);
530 
531 	f2fs_bug_on(sbi, age + u >= UINT_MAX);
532 
533 	cost = UINT_MAX - (age + u);
534 	iter++;
535 
536 	if (cost < p->min_cost ||
537 			(cost == p->min_cost && age > p->oldest_age)) {
538 		p->min_cost = cost;
539 		p->oldest_age = age;
540 		p->min_segno = ve->segno;
541 	}
542 skip:
543 	if (iter < dirty_threshold) {
544 		node = rb_next(node);
545 		goto next;
546 	}
547 }
548 
549 /*
550  * select candidates around source section in range of
551  * [target - dirty_threshold, target + dirty_threshold]
552  */
atssr_lookup_victim(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)553 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
554 						struct victim_sel_policy *p)
555 {
556 	struct sit_info *sit_i = SIT_I(sbi);
557 	struct atgc_management *am = &sbi->am;
558 	struct rb_node *node;
559 	struct rb_entry *re;
560 	struct victim_entry *ve;
561 	unsigned long long age;
562 	unsigned long long max_mtime = sit_i->dirty_max_mtime;
563 	unsigned long long min_mtime = sit_i->dirty_min_mtime;
564 	unsigned int seg_blocks = sbi->blocks_per_seg;
565 	unsigned int vblocks;
566 	unsigned int dirty_threshold = max(am->max_candidate_count,
567 					am->candidate_ratio *
568 					am->victim_count / 100);
569 	unsigned int cost;
570 	unsigned int iter = 0;
571 	int stage = 0;
572 
573 	if (max_mtime < min_mtime)
574 		return;
575 	max_mtime += 1;
576 next_stage:
577 	node = lookup_central_victim(sbi, p);
578 next_node:
579 	re = rb_entry_safe(node, struct rb_entry, rb_node);
580 	if (!re) {
581 		if (stage == 0)
582 			goto skip_stage;
583 		return;
584 	}
585 
586 	ve = (struct victim_entry *)re;
587 
588 	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
589 		goto skip_node;
590 
591 	age = max_mtime - ve->mtime;
592 
593 	vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
594 	f2fs_bug_on(sbi, !vblocks);
595 
596 	/* rare case */
597 	if (vblocks == seg_blocks)
598 		goto skip_node;
599 
600 	iter++;
601 
602 	age = max_mtime - abs(p->age - age);
603 	cost = UINT_MAX - vblocks;
604 
605 	if (cost < p->min_cost ||
606 			(cost == p->min_cost && age > p->oldest_age)) {
607 		p->min_cost = cost;
608 		p->oldest_age = age;
609 		p->min_segno = ve->segno;
610 	}
611 skip_node:
612 	if (iter < dirty_threshold) {
613 		if (stage == 0)
614 			node = rb_prev(node);
615 		else if (stage == 1)
616 			node = rb_next(node);
617 		goto next_node;
618 	}
619 skip_stage:
620 	if (stage < 1) {
621 		stage++;
622 		iter = 0;
623 		goto next_stage;
624 	}
625 }
lookup_victim_by_age(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)626 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
627 						struct victim_sel_policy *p)
628 {
629 	f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
630 						&sbi->am.root, true));
631 
632 	if (p->gc_mode == GC_AT)
633 		atgc_lookup_victim(sbi, p);
634 	else if (p->alloc_mode == AT_SSR)
635 		atssr_lookup_victim(sbi, p);
636 	else
637 		f2fs_bug_on(sbi, 1);
638 }
639 
release_victim_entry(struct f2fs_sb_info * sbi)640 static void release_victim_entry(struct f2fs_sb_info *sbi)
641 {
642 	struct atgc_management *am = &sbi->am;
643 	struct victim_entry *ve, *tmp;
644 
645 	list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
646 		list_del(&ve->list);
647 		kmem_cache_free(victim_entry_slab, ve);
648 		am->victim_count--;
649 	}
650 
651 	am->root = RB_ROOT_CACHED;
652 
653 	f2fs_bug_on(sbi, am->victim_count);
654 	f2fs_bug_on(sbi, !list_empty(&am->victim_list));
655 }
656 
f2fs_pin_section(struct f2fs_sb_info * sbi,unsigned int segno)657 static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
658 {
659 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
660 	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
661 
662 	if (!dirty_i->enable_pin_section)
663 		return false;
664 	if (!test_and_set_bit(secno, dirty_i->pinned_secmap))
665 		dirty_i->pinned_secmap_cnt++;
666 	return true;
667 }
668 
f2fs_pinned_section_exists(struct dirty_seglist_info * dirty_i)669 static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
670 {
671 	return dirty_i->pinned_secmap_cnt;
672 }
673 
f2fs_section_is_pinned(struct dirty_seglist_info * dirty_i,unsigned int secno)674 static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
675 						unsigned int secno)
676 {
677 	return dirty_i->enable_pin_section &&
678 		f2fs_pinned_section_exists(dirty_i) &&
679 		test_bit(secno, dirty_i->pinned_secmap);
680 }
681 
f2fs_unpin_all_sections(struct f2fs_sb_info * sbi,bool enable)682 static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
683 {
684 	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
685 
686 	if (f2fs_pinned_section_exists(DIRTY_I(sbi))) {
687 		memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
688 		DIRTY_I(sbi)->pinned_secmap_cnt = 0;
689 	}
690 	DIRTY_I(sbi)->enable_pin_section = enable;
691 }
692 
f2fs_gc_pinned_control(struct inode * inode,int gc_type,unsigned int segno)693 static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
694 							unsigned int segno)
695 {
696 	if (!f2fs_is_pinned_file(inode))
697 		return 0;
698 	if (gc_type != FG_GC)
699 		return -EBUSY;
700 	if (!f2fs_pin_section(F2FS_I_SB(inode), segno))
701 		f2fs_pin_file_control(inode, true);
702 	return -EAGAIN;
703 }
704 
705 /*
706  * This function is called from two paths.
707  * One is garbage collection and the other is SSR segment selection.
708  * When it is called during GC, it just gets a victim segment
709  * and it does not remove it from dirty seglist.
710  * When it is called from SSR segment selection, it finds a segment
711  * which has minimum valid blocks and removes it from dirty seglist.
712  */
get_victim_by_default(struct f2fs_sb_info * sbi,unsigned int * result,int gc_type,int type,char alloc_mode,unsigned long long age)713 static int get_victim_by_default(struct f2fs_sb_info *sbi,
714 			unsigned int *result, int gc_type, int type,
715 			char alloc_mode, unsigned long long age)
716 {
717 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
718 	struct sit_info *sm = SIT_I(sbi);
719 	struct victim_sel_policy p;
720 	unsigned int secno, last_victim;
721 	unsigned int last_segment;
722 	unsigned int nsearched;
723 	bool is_atgc;
724 	int ret = 0;
725 
726 	mutex_lock(&dirty_i->seglist_lock);
727 	last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
728 
729 	p.alloc_mode = alloc_mode;
730 	p.age = age;
731 	p.age_threshold = sbi->am.age_threshold;
732 
733 retry:
734 	select_policy(sbi, gc_type, type, &p);
735 	p.min_segno = NULL_SEGNO;
736 	p.oldest_age = 0;
737 	p.min_cost = get_max_cost(sbi, &p);
738 
739 	is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
740 	nsearched = 0;
741 
742 	if (is_atgc)
743 		SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
744 
745 	if (*result != NULL_SEGNO) {
746 		if (!get_valid_blocks(sbi, *result, false)) {
747 			ret = -ENODATA;
748 			goto out;
749 		}
750 
751 		if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
752 			ret = -EBUSY;
753 		else
754 			p.min_segno = *result;
755 		goto out;
756 	}
757 
758 	ret = -ENODATA;
759 	if (p.max_search == 0)
760 		goto out;
761 
762 	if (__is_large_section(sbi) && p.alloc_mode == LFS) {
763 		if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
764 			p.min_segno = sbi->next_victim_seg[BG_GC];
765 			*result = p.min_segno;
766 			sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
767 			goto got_result;
768 		}
769 		if (gc_type == FG_GC &&
770 				sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
771 			p.min_segno = sbi->next_victim_seg[FG_GC];
772 			*result = p.min_segno;
773 			sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
774 			goto got_result;
775 		}
776 	}
777 
778 	last_victim = sm->last_victim[p.gc_mode];
779 	if (p.alloc_mode == LFS && gc_type == FG_GC) {
780 		p.min_segno = check_bg_victims(sbi);
781 		if (p.min_segno != NULL_SEGNO)
782 			goto got_it;
783 	}
784 
785 	while (1) {
786 		unsigned long cost, *dirty_bitmap;
787 		unsigned int unit_no, segno;
788 
789 		dirty_bitmap = p.dirty_bitmap;
790 		unit_no = find_next_bit(dirty_bitmap,
791 				last_segment / p.ofs_unit,
792 				p.offset / p.ofs_unit);
793 		segno = unit_no * p.ofs_unit;
794 		if (segno >= last_segment) {
795 			if (sm->last_victim[p.gc_mode]) {
796 				last_segment =
797 					sm->last_victim[p.gc_mode];
798 				sm->last_victim[p.gc_mode] = 0;
799 				p.offset = 0;
800 				continue;
801 			}
802 			break;
803 		}
804 
805 		p.offset = segno + p.ofs_unit;
806 		nsearched++;
807 
808 #ifdef CONFIG_F2FS_CHECK_FS
809 		/*
810 		 * skip selecting the invalid segno (that is failed due to block
811 		 * validity check failure during GC) to avoid endless GC loop in
812 		 * such cases.
813 		 */
814 		if (test_bit(segno, sm->invalid_segmap))
815 			goto next;
816 #endif
817 
818 		secno = GET_SEC_FROM_SEG(sbi, segno);
819 
820 		if (sec_usage_check(sbi, secno))
821 			goto next;
822 
823 		/* Don't touch checkpointed data */
824 		if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
825 			if (p.alloc_mode == LFS) {
826 				/*
827 				 * LFS is set to find source section during GC.
828 				 * The victim should have no checkpointed data.
829 				 */
830 				if (get_ckpt_valid_blocks(sbi, segno, true))
831 					goto next;
832 			} else {
833 				/*
834 				 * SSR | AT_SSR are set to find target segment
835 				 * for writes which can be full by checkpointed
836 				 * and newly written blocks.
837 				 */
838 				if (!f2fs_segment_has_free_slot(sbi, segno))
839 					goto next;
840 			}
841 		}
842 
843 		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
844 			goto next;
845 
846 		if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
847 			goto next;
848 
849 		if (is_atgc) {
850 			add_victim_entry(sbi, &p, segno);
851 			goto next;
852 		}
853 
854 		cost = get_gc_cost(sbi, segno, &p);
855 
856 		if (p.min_cost > cost) {
857 			p.min_segno = segno;
858 			p.min_cost = cost;
859 		}
860 next:
861 		if (nsearched >= p.max_search) {
862 			if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
863 				sm->last_victim[p.gc_mode] =
864 					last_victim + p.ofs_unit;
865 			else
866 				sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
867 			sm->last_victim[p.gc_mode] %=
868 				(MAIN_SECS(sbi) * sbi->segs_per_sec);
869 			break;
870 		}
871 	}
872 
873 	/* get victim for GC_AT/AT_SSR */
874 	if (is_atgc) {
875 		lookup_victim_by_age(sbi, &p);
876 		release_victim_entry(sbi);
877 	}
878 
879 	if (is_atgc && p.min_segno == NULL_SEGNO &&
880 			sm->elapsed_time < p.age_threshold) {
881 		p.age_threshold = 0;
882 		goto retry;
883 	}
884 
885 	if (p.min_segno != NULL_SEGNO) {
886 got_it:
887 		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
888 got_result:
889 		if (p.alloc_mode == LFS) {
890 			secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
891 			if (gc_type == FG_GC)
892 				sbi->cur_victim_sec = secno;
893 			else
894 				set_bit(secno, dirty_i->victim_secmap);
895 		}
896 		ret = 0;
897 
898 	}
899 out:
900 	if (p.min_segno != NULL_SEGNO)
901 		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
902 				sbi->cur_victim_sec,
903 				prefree_segments(sbi), free_segments(sbi));
904 	mutex_unlock(&dirty_i->seglist_lock);
905 
906 	return ret;
907 }
908 
909 static const struct victim_selection default_v_ops = {
910 	.get_victim = get_victim_by_default,
911 };
912 
find_gc_inode(struct gc_inode_list * gc_list,nid_t ino)913 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
914 {
915 	struct inode_entry *ie;
916 
917 	ie = radix_tree_lookup(&gc_list->iroot, ino);
918 	if (ie)
919 		return ie->inode;
920 	return NULL;
921 }
922 
add_gc_inode(struct gc_inode_list * gc_list,struct inode * inode)923 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
924 {
925 	struct inode_entry *new_ie;
926 
927 	if (inode == find_gc_inode(gc_list, inode->i_ino)) {
928 		iput(inode);
929 		return;
930 	}
931 	new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
932 					GFP_NOFS, true, NULL);
933 	new_ie->inode = inode;
934 
935 	f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
936 	list_add_tail(&new_ie->list, &gc_list->ilist);
937 }
938 
put_gc_inode(struct gc_inode_list * gc_list)939 static void put_gc_inode(struct gc_inode_list *gc_list)
940 {
941 	struct inode_entry *ie, *next_ie;
942 
943 	list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
944 		radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
945 		iput(ie->inode);
946 		list_del(&ie->list);
947 		kmem_cache_free(f2fs_inode_entry_slab, ie);
948 	}
949 }
950 
check_valid_map(struct f2fs_sb_info * sbi,unsigned int segno,int offset)951 static int check_valid_map(struct f2fs_sb_info *sbi,
952 				unsigned int segno, int offset)
953 {
954 	struct sit_info *sit_i = SIT_I(sbi);
955 	struct seg_entry *sentry;
956 	int ret;
957 
958 	down_read(&sit_i->sentry_lock);
959 	sentry = get_seg_entry(sbi, segno);
960 	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
961 	up_read(&sit_i->sentry_lock);
962 	return ret;
963 }
964 
965 /*
966  * This function compares node address got in summary with that in NAT.
967  * On validity, copy that node with cold status, otherwise (invalid node)
968  * ignore that.
969  */
gc_node_segment(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,unsigned int segno,int gc_type)970 static int gc_node_segment(struct f2fs_sb_info *sbi,
971 		struct f2fs_summary *sum, unsigned int segno, int gc_type)
972 {
973 	struct f2fs_summary *entry;
974 	block_t start_addr;
975 	int off;
976 	int phase = 0;
977 	bool fggc = (gc_type == FG_GC);
978 	int submitted = 0;
979 	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
980 
981 	start_addr = START_BLOCK(sbi, segno);
982 
983 next_step:
984 	entry = sum;
985 
986 	if (fggc && phase == 2)
987 		atomic_inc(&sbi->wb_sync_req[NODE]);
988 
989 	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
990 		nid_t nid = le32_to_cpu(entry->nid);
991 		struct page *node_page;
992 		struct node_info ni;
993 		int err;
994 
995 		/* stop BG_GC if there is not enough free sections. */
996 		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
997 			return submitted;
998 
999 		if (check_valid_map(sbi, segno, off) == 0)
1000 			continue;
1001 
1002 		if (phase == 0) {
1003 			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1004 							META_NAT, true);
1005 			continue;
1006 		}
1007 
1008 		if (phase == 1) {
1009 			f2fs_ra_node_page(sbi, nid);
1010 			continue;
1011 		}
1012 
1013 		/* phase == 2 */
1014 		node_page = f2fs_get_node_page(sbi, nid);
1015 		if (IS_ERR(node_page))
1016 			continue;
1017 
1018 		/* block may become invalid during f2fs_get_node_page */
1019 		if (check_valid_map(sbi, segno, off) == 0) {
1020 			f2fs_put_page(node_page, 1);
1021 			continue;
1022 		}
1023 
1024 		if (f2fs_get_node_info(sbi, nid, &ni, false)) {
1025 			f2fs_put_page(node_page, 1);
1026 			continue;
1027 		}
1028 
1029 		if (ni.blk_addr != start_addr + off) {
1030 			f2fs_put_page(node_page, 1);
1031 			continue;
1032 		}
1033 
1034 		err = f2fs_move_node_page(node_page, gc_type);
1035 		if (!err && gc_type == FG_GC)
1036 			submitted++;
1037 		stat_inc_node_blk_count(sbi, 1, gc_type);
1038 	}
1039 
1040 	if (++phase < 3)
1041 		goto next_step;
1042 
1043 	if (fggc)
1044 		atomic_dec(&sbi->wb_sync_req[NODE]);
1045 	return submitted;
1046 }
1047 
1048 /*
1049  * Calculate start block index indicating the given node offset.
1050  * Be careful, caller should give this node offset only indicating direct node
1051  * blocks. If any node offsets, which point the other types of node blocks such
1052  * as indirect or double indirect node blocks, are given, it must be a caller's
1053  * bug.
1054  */
f2fs_start_bidx_of_node(unsigned int node_ofs,struct inode * inode)1055 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1056 {
1057 	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1058 	unsigned int bidx;
1059 
1060 	if (node_ofs == 0)
1061 		return 0;
1062 
1063 	if (node_ofs <= 2) {
1064 		bidx = node_ofs - 1;
1065 	} else if (node_ofs <= indirect_blks) {
1066 		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1067 
1068 		bidx = node_ofs - 2 - dec;
1069 	} else {
1070 		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1071 
1072 		bidx = node_ofs - 5 - dec;
1073 	}
1074 	return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1075 }
1076 
is_alive(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,struct node_info * dni,block_t blkaddr,unsigned int * nofs)1077 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1078 		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1079 {
1080 	struct page *node_page;
1081 	nid_t nid;
1082 	unsigned int ofs_in_node;
1083 	block_t source_blkaddr;
1084 
1085 	nid = le32_to_cpu(sum->nid);
1086 	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1087 
1088 	node_page = f2fs_get_node_page(sbi, nid);
1089 	if (IS_ERR(node_page))
1090 		return false;
1091 
1092 	if (f2fs_get_node_info(sbi, nid, dni, false)) {
1093 		f2fs_put_page(node_page, 1);
1094 		return false;
1095 	}
1096 
1097 	if (sum->version != dni->version) {
1098 		f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1099 			  __func__);
1100 		set_sbi_flag(sbi, SBI_NEED_FSCK);
1101 	}
1102 
1103 	if (f2fs_check_nid_range(sbi, dni->ino)) {
1104 		f2fs_put_page(node_page, 1);
1105 		return false;
1106 	}
1107 
1108 	*nofs = ofs_of_node(node_page);
1109 	source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1110 	f2fs_put_page(node_page, 1);
1111 
1112 	if (source_blkaddr != blkaddr) {
1113 #ifdef CONFIG_F2FS_CHECK_FS
1114 		unsigned int segno = GET_SEGNO(sbi, blkaddr);
1115 		unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1116 
1117 		if (unlikely(check_valid_map(sbi, segno, offset))) {
1118 			if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1119 				f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1120 					 blkaddr, source_blkaddr, segno);
1121 				set_sbi_flag(sbi, SBI_NEED_FSCK);
1122 			}
1123 		}
1124 #endif
1125 		return false;
1126 	}
1127 	return true;
1128 }
1129 
ra_data_block(struct inode * inode,pgoff_t index)1130 static int ra_data_block(struct inode *inode, pgoff_t index)
1131 {
1132 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1133 	struct address_space *mapping = inode->i_mapping;
1134 	struct dnode_of_data dn;
1135 	struct page *page;
1136 	struct extent_info ei = {0, 0, 0};
1137 	struct f2fs_io_info fio = {
1138 		.sbi = sbi,
1139 		.ino = inode->i_ino,
1140 		.type = DATA,
1141 		.temp = COLD,
1142 		.op = REQ_OP_READ,
1143 		.op_flags = 0,
1144 		.encrypted_page = NULL,
1145 		.in_list = false,
1146 		.retry = false,
1147 	};
1148 	int err;
1149 
1150 	page = f2fs_grab_cache_page(mapping, index, true);
1151 	if (!page)
1152 		return -ENOMEM;
1153 
1154 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1155 		dn.data_blkaddr = ei.blk + index - ei.fofs;
1156 		if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1157 						DATA_GENERIC_ENHANCE_READ))) {
1158 			err = -EFSCORRUPTED;
1159 			goto put_page;
1160 		}
1161 		goto got_it;
1162 	}
1163 
1164 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1165 	err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1166 	if (err)
1167 		goto put_page;
1168 	f2fs_put_dnode(&dn);
1169 
1170 	if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1171 		err = -ENOENT;
1172 		goto put_page;
1173 	}
1174 	if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1175 						DATA_GENERIC_ENHANCE))) {
1176 		err = -EFSCORRUPTED;
1177 		goto put_page;
1178 	}
1179 got_it:
1180 	/* read page */
1181 	fio.page = page;
1182 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1183 
1184 	/*
1185 	 * don't cache encrypted data into meta inode until previous dirty
1186 	 * data were writebacked to avoid racing between GC and flush.
1187 	 */
1188 	f2fs_wait_on_page_writeback(page, DATA, true, true);
1189 
1190 	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1191 
1192 	fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1193 					dn.data_blkaddr,
1194 					FGP_LOCK | FGP_CREAT, GFP_NOFS);
1195 	if (!fio.encrypted_page) {
1196 		err = -ENOMEM;
1197 		goto put_page;
1198 	}
1199 
1200 	err = f2fs_submit_page_bio(&fio);
1201 	if (err)
1202 		goto put_encrypted_page;
1203 	f2fs_put_page(fio.encrypted_page, 0);
1204 	f2fs_put_page(page, 1);
1205 
1206 	f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1207 	f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1208 
1209 	return 0;
1210 put_encrypted_page:
1211 	f2fs_put_page(fio.encrypted_page, 1);
1212 put_page:
1213 	f2fs_put_page(page, 1);
1214 	return err;
1215 }
1216 
1217 /*
1218  * Move data block via META_MAPPING while keeping locked data page.
1219  * This can be used to move blocks, aka LBAs, directly on disk.
1220  */
move_data_block(struct inode * inode,block_t bidx,int gc_type,unsigned int segno,int off)1221 static int move_data_block(struct inode *inode, block_t bidx,
1222 				int gc_type, unsigned int segno, int off)
1223 {
1224 	struct f2fs_io_info fio = {
1225 		.sbi = F2FS_I_SB(inode),
1226 		.ino = inode->i_ino,
1227 		.type = DATA,
1228 		.temp = COLD,
1229 		.op = REQ_OP_READ,
1230 		.op_flags = 0,
1231 		.encrypted_page = NULL,
1232 		.in_list = false,
1233 		.retry = false,
1234 	};
1235 	struct dnode_of_data dn;
1236 	struct f2fs_summary sum;
1237 	struct node_info ni;
1238 	struct page *page, *mpage;
1239 	block_t newaddr;
1240 	int err = 0;
1241 	bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1242 	int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1243 				(fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1244 				CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1245 
1246 	/* do not read out */
1247 	page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1248 	if (!page)
1249 		return -ENOMEM;
1250 
1251 	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1252 		err = -ENOENT;
1253 		goto out;
1254 	}
1255 
1256 	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1257 	if (err)
1258 		goto out;
1259 
1260 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1261 	err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1262 	if (err)
1263 		goto out;
1264 
1265 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1266 		ClearPageUptodate(page);
1267 		err = -ENOENT;
1268 		goto put_out;
1269 	}
1270 
1271 	/*
1272 	 * don't cache encrypted data into meta inode until previous dirty
1273 	 * data were writebacked to avoid racing between GC and flush.
1274 	 */
1275 	f2fs_wait_on_page_writeback(page, DATA, true, true);
1276 
1277 	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1278 
1279 	err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1280 	if (err)
1281 		goto put_out;
1282 
1283 	/* read page */
1284 	fio.page = page;
1285 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1286 
1287 	if (lfs_mode)
1288 		f2fs_down_write(&fio.sbi->io_order_lock);
1289 
1290 	mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1291 					fio.old_blkaddr, false);
1292 	if (!mpage) {
1293 		err = -ENOMEM;
1294 		goto up_out;
1295 	}
1296 
1297 	fio.encrypted_page = mpage;
1298 
1299 	/* read source block in mpage */
1300 	if (!PageUptodate(mpage)) {
1301 		err = f2fs_submit_page_bio(&fio);
1302 		if (err) {
1303 			f2fs_put_page(mpage, 1);
1304 			goto up_out;
1305 		}
1306 
1307 		f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1308 		f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1309 
1310 		lock_page(mpage);
1311 		if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1312 						!PageUptodate(mpage))) {
1313 			err = -EIO;
1314 			f2fs_put_page(mpage, 1);
1315 			goto up_out;
1316 		}
1317 	}
1318 
1319 	set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1320 
1321 	/* allocate block address */
1322 	f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1323 				&sum, type, NULL);
1324 
1325 	fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1326 				newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1327 	if (!fio.encrypted_page) {
1328 		err = -ENOMEM;
1329 		f2fs_put_page(mpage, 1);
1330 		goto recover_block;
1331 	}
1332 
1333 	/* write target block */
1334 	f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1335 	memcpy(page_address(fio.encrypted_page),
1336 				page_address(mpage), PAGE_SIZE);
1337 	f2fs_put_page(mpage, 1);
1338 	invalidate_mapping_pages(META_MAPPING(fio.sbi),
1339 				fio.old_blkaddr, fio.old_blkaddr);
1340 	f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
1341 
1342 	set_page_dirty(fio.encrypted_page);
1343 	if (clear_page_dirty_for_io(fio.encrypted_page))
1344 		dec_page_count(fio.sbi, F2FS_DIRTY_META);
1345 
1346 	set_page_writeback(fio.encrypted_page);
1347 	ClearPageError(page);
1348 
1349 	fio.op = REQ_OP_WRITE;
1350 	fio.op_flags = REQ_SYNC;
1351 	fio.new_blkaddr = newaddr;
1352 	f2fs_submit_page_write(&fio);
1353 	if (fio.retry) {
1354 		err = -EAGAIN;
1355 		if (PageWriteback(fio.encrypted_page))
1356 			end_page_writeback(fio.encrypted_page);
1357 		goto put_page_out;
1358 	}
1359 
1360 	f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
1361 
1362 	f2fs_update_data_blkaddr(&dn, newaddr);
1363 	set_inode_flag(inode, FI_APPEND_WRITE);
1364 	if (page->index == 0)
1365 		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1366 put_page_out:
1367 	f2fs_put_page(fio.encrypted_page, 1);
1368 recover_block:
1369 	if (err)
1370 		f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1371 							true, true, true);
1372 up_out:
1373 	if (lfs_mode)
1374 		f2fs_up_write(&fio.sbi->io_order_lock);
1375 put_out:
1376 	f2fs_put_dnode(&dn);
1377 out:
1378 	f2fs_put_page(page, 1);
1379 	return err;
1380 }
1381 
move_data_page(struct inode * inode,block_t bidx,int gc_type,unsigned int segno,int off)1382 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1383 							unsigned int segno, int off)
1384 {
1385 	struct page *page;
1386 	int err = 0;
1387 
1388 	page = f2fs_get_lock_data_page(inode, bidx, true);
1389 	if (IS_ERR(page))
1390 		return PTR_ERR(page);
1391 
1392 	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1393 		err = -ENOENT;
1394 		goto out;
1395 	}
1396 
1397 	err = f2fs_gc_pinned_control(inode, gc_type, segno);
1398 	if (err)
1399 		goto out;
1400 
1401 	if (gc_type == BG_GC) {
1402 		if (PageWriteback(page)) {
1403 			err = -EAGAIN;
1404 			goto out;
1405 		}
1406 		set_page_dirty(page);
1407 		set_page_private_gcing(page);
1408 	} else {
1409 		struct f2fs_io_info fio = {
1410 			.sbi = F2FS_I_SB(inode),
1411 			.ino = inode->i_ino,
1412 			.type = DATA,
1413 			.temp = COLD,
1414 			.op = REQ_OP_WRITE,
1415 			.op_flags = REQ_SYNC,
1416 			.old_blkaddr = NULL_ADDR,
1417 			.page = page,
1418 			.encrypted_page = NULL,
1419 			.need_lock = LOCK_REQ,
1420 			.io_type = FS_GC_DATA_IO,
1421 		};
1422 		bool is_dirty = PageDirty(page);
1423 
1424 retry:
1425 		f2fs_wait_on_page_writeback(page, DATA, true, true);
1426 
1427 		set_page_dirty(page);
1428 		if (clear_page_dirty_for_io(page)) {
1429 			inode_dec_dirty_pages(inode);
1430 			f2fs_remove_dirty_inode(inode);
1431 		}
1432 
1433 		set_page_private_gcing(page);
1434 
1435 		err = f2fs_do_write_data_page(&fio);
1436 		if (err) {
1437 			clear_page_private_gcing(page);
1438 			if (err == -ENOMEM) {
1439 				memalloc_retry_wait(GFP_NOFS);
1440 				goto retry;
1441 			}
1442 			if (is_dirty)
1443 				set_page_dirty(page);
1444 		}
1445 	}
1446 out:
1447 	f2fs_put_page(page, 1);
1448 	return err;
1449 }
1450 
1451 /*
1452  * This function tries to get parent node of victim data block, and identifies
1453  * data block validity. If the block is valid, copy that with cold status and
1454  * modify parent node.
1455  * If the parent node is not valid or the data block address is different,
1456  * the victim data block is ignored.
1457  */
gc_data_segment(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,struct gc_inode_list * gc_list,unsigned int segno,int gc_type,bool force_migrate)1458 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1459 		struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1460 		bool force_migrate)
1461 {
1462 	struct super_block *sb = sbi->sb;
1463 	struct f2fs_summary *entry;
1464 	block_t start_addr;
1465 	int off;
1466 	int phase = 0;
1467 	int submitted = 0;
1468 	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1469 
1470 	start_addr = START_BLOCK(sbi, segno);
1471 
1472 next_step:
1473 	entry = sum;
1474 
1475 	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1476 		struct page *data_page;
1477 		struct inode *inode;
1478 		struct node_info dni; /* dnode info for the data */
1479 		unsigned int ofs_in_node, nofs;
1480 		block_t start_bidx;
1481 		nid_t nid = le32_to_cpu(entry->nid);
1482 
1483 		/*
1484 		 * stop BG_GC if there is not enough free sections.
1485 		 * Or, stop GC if the segment becomes fully valid caused by
1486 		 * race condition along with SSR block allocation.
1487 		 */
1488 		if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1489 			(!force_migrate && get_valid_blocks(sbi, segno, true) ==
1490 							BLKS_PER_SEC(sbi)))
1491 			return submitted;
1492 
1493 		if (check_valid_map(sbi, segno, off) == 0)
1494 			continue;
1495 
1496 		if (phase == 0) {
1497 			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1498 							META_NAT, true);
1499 			continue;
1500 		}
1501 
1502 		if (phase == 1) {
1503 			f2fs_ra_node_page(sbi, nid);
1504 			continue;
1505 		}
1506 
1507 		/* Get an inode by ino with checking validity */
1508 		if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1509 			continue;
1510 
1511 		if (phase == 2) {
1512 			f2fs_ra_node_page(sbi, dni.ino);
1513 			continue;
1514 		}
1515 
1516 		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1517 
1518 		if (phase == 3) {
1519 			int err;
1520 
1521 			inode = f2fs_iget(sb, dni.ino);
1522 			if (IS_ERR(inode) || is_bad_inode(inode) ||
1523 					special_file(inode->i_mode))
1524 				continue;
1525 
1526 			err = f2fs_gc_pinned_control(inode, gc_type, segno);
1527 			if (err == -EAGAIN) {
1528 				iput(inode);
1529 				return submitted;
1530 			}
1531 
1532 			if (!f2fs_down_write_trylock(
1533 				&F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1534 				iput(inode);
1535 				sbi->skipped_gc_rwsem++;
1536 				continue;
1537 			}
1538 
1539 			start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1540 								ofs_in_node;
1541 
1542 			if (f2fs_post_read_required(inode)) {
1543 				int err = ra_data_block(inode, start_bidx);
1544 
1545 				f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1546 				if (err) {
1547 					iput(inode);
1548 					continue;
1549 				}
1550 				add_gc_inode(gc_list, inode);
1551 				continue;
1552 			}
1553 
1554 			data_page = f2fs_get_read_data_page(inode,
1555 						start_bidx, REQ_RAHEAD, true);
1556 			f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1557 			if (IS_ERR(data_page)) {
1558 				iput(inode);
1559 				continue;
1560 			}
1561 
1562 			f2fs_put_page(data_page, 0);
1563 			add_gc_inode(gc_list, inode);
1564 			continue;
1565 		}
1566 
1567 		/* phase 4 */
1568 		inode = find_gc_inode(gc_list, dni.ino);
1569 		if (inode) {
1570 			struct f2fs_inode_info *fi = F2FS_I(inode);
1571 			bool locked = false;
1572 			int err;
1573 
1574 			if (S_ISREG(inode->i_mode)) {
1575 				if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[READ])) {
1576 					sbi->skipped_gc_rwsem++;
1577 					continue;
1578 				}
1579 				if (!f2fs_down_write_trylock(
1580 						&fi->i_gc_rwsem[WRITE])) {
1581 					sbi->skipped_gc_rwsem++;
1582 					f2fs_up_write(&fi->i_gc_rwsem[READ]);
1583 					continue;
1584 				}
1585 				locked = true;
1586 
1587 				/* wait for all inflight aio data */
1588 				inode_dio_wait(inode);
1589 			}
1590 
1591 			start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1592 								+ ofs_in_node;
1593 			if (f2fs_post_read_required(inode))
1594 				err = move_data_block(inode, start_bidx,
1595 							gc_type, segno, off);
1596 			else
1597 				err = move_data_page(inode, start_bidx, gc_type,
1598 								segno, off);
1599 
1600 			if (!err && (gc_type == FG_GC ||
1601 					f2fs_post_read_required(inode)))
1602 				submitted++;
1603 
1604 			if (locked) {
1605 				f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1606 				f2fs_up_write(&fi->i_gc_rwsem[READ]);
1607 			}
1608 
1609 			stat_inc_data_blk_count(sbi, 1, gc_type);
1610 		}
1611 	}
1612 
1613 	if (++phase < 5)
1614 		goto next_step;
1615 
1616 	return submitted;
1617 }
1618 
__get_victim(struct f2fs_sb_info * sbi,unsigned int * victim,int gc_type)1619 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1620 			int gc_type)
1621 {
1622 	struct sit_info *sit_i = SIT_I(sbi);
1623 	int ret;
1624 
1625 	down_write(&sit_i->sentry_lock);
1626 	ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1627 					      NO_CHECK_TYPE, LFS, 0);
1628 	up_write(&sit_i->sentry_lock);
1629 	return ret;
1630 }
1631 
do_garbage_collect(struct f2fs_sb_info * sbi,unsigned int start_segno,struct gc_inode_list * gc_list,int gc_type,bool force_migrate)1632 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1633 				unsigned int start_segno,
1634 				struct gc_inode_list *gc_list, int gc_type,
1635 				bool force_migrate)
1636 {
1637 	struct page *sum_page;
1638 	struct f2fs_summary_block *sum;
1639 	struct blk_plug plug;
1640 	unsigned int segno = start_segno;
1641 	unsigned int end_segno = start_segno + sbi->segs_per_sec;
1642 	int seg_freed = 0, migrated = 0;
1643 	unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1644 						SUM_TYPE_DATA : SUM_TYPE_NODE;
1645 	int submitted = 0;
1646 
1647 	if (__is_large_section(sbi))
1648 		end_segno = rounddown(end_segno, sbi->segs_per_sec);
1649 
1650 	/*
1651 	 * zone-capacity can be less than zone-size in zoned devices,
1652 	 * resulting in less than expected usable segments in the zone,
1653 	 * calculate the end segno in the zone which can be garbage collected
1654 	 */
1655 	if (f2fs_sb_has_blkzoned(sbi))
1656 		end_segno -= sbi->segs_per_sec -
1657 					f2fs_usable_segs_in_sec(sbi, segno);
1658 
1659 	sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1660 
1661 	/* readahead multi ssa blocks those have contiguous address */
1662 	if (__is_large_section(sbi))
1663 		f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1664 					end_segno - segno, META_SSA, true);
1665 
1666 	/* reference all summary page */
1667 	while (segno < end_segno) {
1668 		sum_page = f2fs_get_sum_page(sbi, segno++);
1669 		if (IS_ERR(sum_page)) {
1670 			int err = PTR_ERR(sum_page);
1671 
1672 			end_segno = segno - 1;
1673 			for (segno = start_segno; segno < end_segno; segno++) {
1674 				sum_page = find_get_page(META_MAPPING(sbi),
1675 						GET_SUM_BLOCK(sbi, segno));
1676 				f2fs_put_page(sum_page, 0);
1677 				f2fs_put_page(sum_page, 0);
1678 			}
1679 			return err;
1680 		}
1681 		unlock_page(sum_page);
1682 	}
1683 
1684 	blk_start_plug(&plug);
1685 
1686 	for (segno = start_segno; segno < end_segno; segno++) {
1687 
1688 		/* find segment summary of victim */
1689 		sum_page = find_get_page(META_MAPPING(sbi),
1690 					GET_SUM_BLOCK(sbi, segno));
1691 		f2fs_put_page(sum_page, 0);
1692 
1693 		if (get_valid_blocks(sbi, segno, false) == 0)
1694 			goto freed;
1695 		if (gc_type == BG_GC && __is_large_section(sbi) &&
1696 				migrated >= sbi->migration_granularity)
1697 			goto skip;
1698 		if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1699 			goto skip;
1700 
1701 		sum = page_address(sum_page);
1702 		if (type != GET_SUM_TYPE((&sum->footer))) {
1703 			f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1704 				 segno, type, GET_SUM_TYPE((&sum->footer)));
1705 			set_sbi_flag(sbi, SBI_NEED_FSCK);
1706 			f2fs_stop_checkpoint(sbi, false);
1707 			goto skip;
1708 		}
1709 
1710 		/*
1711 		 * this is to avoid deadlock:
1712 		 * - lock_page(sum_page)         - f2fs_replace_block
1713 		 *  - check_valid_map()            - down_write(sentry_lock)
1714 		 *   - down_read(sentry_lock)     - change_curseg()
1715 		 *                                  - lock_page(sum_page)
1716 		 */
1717 		if (type == SUM_TYPE_NODE)
1718 			submitted += gc_node_segment(sbi, sum->entries, segno,
1719 								gc_type);
1720 		else
1721 			submitted += gc_data_segment(sbi, sum->entries, gc_list,
1722 							segno, gc_type,
1723 							force_migrate);
1724 
1725 		stat_inc_seg_count(sbi, type, gc_type);
1726 		sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1727 		migrated++;
1728 
1729 freed:
1730 		if (gc_type == FG_GC &&
1731 				get_valid_blocks(sbi, segno, false) == 0)
1732 			seg_freed++;
1733 
1734 		if (__is_large_section(sbi) && segno + 1 < end_segno)
1735 			sbi->next_victim_seg[gc_type] = segno + 1;
1736 skip:
1737 		f2fs_put_page(sum_page, 0);
1738 	}
1739 
1740 	if (submitted)
1741 		f2fs_submit_merged_write(sbi,
1742 				(type == SUM_TYPE_NODE) ? NODE : DATA);
1743 
1744 	blk_finish_plug(&plug);
1745 
1746 	stat_inc_call_count(sbi->stat_info);
1747 
1748 	return seg_freed;
1749 }
1750 
f2fs_gc(struct f2fs_sb_info * sbi,struct f2fs_gc_control * gc_control)1751 int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1752 {
1753 	int gc_type = gc_control->init_gc_type;
1754 	unsigned int segno = gc_control->victim_segno;
1755 	int sec_freed = 0, seg_freed = 0, total_freed = 0;
1756 	int ret = 0;
1757 	struct cp_control cpc;
1758 	struct gc_inode_list gc_list = {
1759 		.ilist = LIST_HEAD_INIT(gc_list.ilist),
1760 		.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1761 	};
1762 	unsigned int skipped_round = 0, round = 0;
1763 
1764 	trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
1765 				gc_control->nr_free_secs,
1766 				get_pages(sbi, F2FS_DIRTY_NODES),
1767 				get_pages(sbi, F2FS_DIRTY_DENTS),
1768 				get_pages(sbi, F2FS_DIRTY_IMETA),
1769 				free_sections(sbi),
1770 				free_segments(sbi),
1771 				reserved_segments(sbi),
1772 				prefree_segments(sbi));
1773 
1774 	cpc.reason = __get_cp_reason(sbi);
1775 	sbi->skipped_gc_rwsem = 0;
1776 gc_more:
1777 	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1778 		ret = -EINVAL;
1779 		goto stop;
1780 	}
1781 	if (unlikely(f2fs_cp_error(sbi))) {
1782 		ret = -EIO;
1783 		goto stop;
1784 	}
1785 
1786 	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1787 		/*
1788 		 * For example, if there are many prefree_segments below given
1789 		 * threshold, we can make them free by checkpoint. Then, we
1790 		 * secure free segments which doesn't need fggc any more.
1791 		 */
1792 		if (prefree_segments(sbi)) {
1793 			ret = f2fs_write_checkpoint(sbi, &cpc);
1794 			if (ret)
1795 				goto stop;
1796 		}
1797 		if (has_not_enough_free_secs(sbi, 0, 0))
1798 			gc_type = FG_GC;
1799 	}
1800 
1801 	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1802 	if (gc_type == BG_GC && gc_control->no_bg_gc) {
1803 		ret = -EINVAL;
1804 		goto stop;
1805 	}
1806 retry:
1807 	ret = __get_victim(sbi, &segno, gc_type);
1808 	if (ret) {
1809 		/* allow to search victim from sections has pinned data */
1810 		if (ret == -ENODATA && gc_type == FG_GC &&
1811 				f2fs_pinned_section_exists(DIRTY_I(sbi))) {
1812 			f2fs_unpin_all_sections(sbi, false);
1813 			goto retry;
1814 		}
1815 		goto stop;
1816 	}
1817 
1818 	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
1819 				gc_control->should_migrate_blocks);
1820 	total_freed += seg_freed;
1821 
1822 	if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1823 		sec_freed++;
1824 
1825 	if (gc_type == FG_GC)
1826 		sbi->cur_victim_sec = NULL_SEGNO;
1827 
1828 	if (gc_control->init_gc_type == FG_GC ||
1829 	    !has_not_enough_free_secs(sbi,
1830 				(gc_type == FG_GC) ? sec_freed : 0, 0)) {
1831 		if (gc_type == FG_GC && sec_freed < gc_control->nr_free_secs)
1832 			goto go_gc_more;
1833 		goto stop;
1834 	}
1835 
1836 	/* FG_GC stops GC by skip_count */
1837 	if (gc_type == FG_GC) {
1838 		if (sbi->skipped_gc_rwsem)
1839 			skipped_round++;
1840 		round++;
1841 		if (skipped_round > MAX_SKIP_GC_COUNT &&
1842 				skipped_round * 2 >= round) {
1843 			ret = f2fs_write_checkpoint(sbi, &cpc);
1844 			goto stop;
1845 		}
1846 	}
1847 
1848 	/* Write checkpoint to reclaim prefree segments */
1849 	if (free_sections(sbi) < NR_CURSEG_PERSIST_TYPE &&
1850 				prefree_segments(sbi)) {
1851 		ret = f2fs_write_checkpoint(sbi, &cpc);
1852 		if (ret)
1853 			goto stop;
1854 	}
1855 go_gc_more:
1856 	segno = NULL_SEGNO;
1857 	goto gc_more;
1858 
1859 stop:
1860 	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1861 	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
1862 
1863 	if (gc_type == FG_GC)
1864 		f2fs_unpin_all_sections(sbi, true);
1865 
1866 	trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1867 				get_pages(sbi, F2FS_DIRTY_NODES),
1868 				get_pages(sbi, F2FS_DIRTY_DENTS),
1869 				get_pages(sbi, F2FS_DIRTY_IMETA),
1870 				free_sections(sbi),
1871 				free_segments(sbi),
1872 				reserved_segments(sbi),
1873 				prefree_segments(sbi));
1874 
1875 	f2fs_up_write(&sbi->gc_lock);
1876 
1877 	put_gc_inode(&gc_list);
1878 
1879 	if (gc_control->err_gc_skipped && !ret)
1880 		ret = sec_freed ? 0 : -EAGAIN;
1881 	return ret;
1882 }
1883 
f2fs_create_garbage_collection_cache(void)1884 int __init f2fs_create_garbage_collection_cache(void)
1885 {
1886 	victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1887 					sizeof(struct victim_entry));
1888 	if (!victim_entry_slab)
1889 		return -ENOMEM;
1890 	return 0;
1891 }
1892 
f2fs_destroy_garbage_collection_cache(void)1893 void f2fs_destroy_garbage_collection_cache(void)
1894 {
1895 	kmem_cache_destroy(victim_entry_slab);
1896 }
1897 
init_atgc_management(struct f2fs_sb_info * sbi)1898 static void init_atgc_management(struct f2fs_sb_info *sbi)
1899 {
1900 	struct atgc_management *am = &sbi->am;
1901 
1902 	if (test_opt(sbi, ATGC) &&
1903 		SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1904 		am->atgc_enabled = true;
1905 
1906 	am->root = RB_ROOT_CACHED;
1907 	INIT_LIST_HEAD(&am->victim_list);
1908 	am->victim_count = 0;
1909 
1910 	am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1911 	am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1912 	am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1913 	am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1914 }
1915 
f2fs_build_gc_manager(struct f2fs_sb_info * sbi)1916 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1917 {
1918 	DIRTY_I(sbi)->v_ops = &default_v_ops;
1919 
1920 	sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1921 
1922 	/* give warm/cold data area from slower device */
1923 	if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1924 		SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1925 				GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1926 
1927 	init_atgc_management(sbi);
1928 }
1929 
free_segment_range(struct f2fs_sb_info * sbi,unsigned int secs,bool gc_only)1930 static int free_segment_range(struct f2fs_sb_info *sbi,
1931 				unsigned int secs, bool gc_only)
1932 {
1933 	unsigned int segno, next_inuse, start, end;
1934 	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1935 	int gc_mode, gc_type;
1936 	int err = 0;
1937 	int type;
1938 
1939 	/* Force block allocation for GC */
1940 	MAIN_SECS(sbi) -= secs;
1941 	start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1942 	end = MAIN_SEGS(sbi) - 1;
1943 
1944 	mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1945 	for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1946 		if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1947 			SIT_I(sbi)->last_victim[gc_mode] = 0;
1948 
1949 	for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1950 		if (sbi->next_victim_seg[gc_type] >= start)
1951 			sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1952 	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1953 
1954 	/* Move out cursegs from the target range */
1955 	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1956 		f2fs_allocate_segment_for_resize(sbi, type, start, end);
1957 
1958 	/* do GC to move out valid blocks in the range */
1959 	for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1960 		struct gc_inode_list gc_list = {
1961 			.ilist = LIST_HEAD_INIT(gc_list.ilist),
1962 			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1963 		};
1964 
1965 		do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1966 		put_gc_inode(&gc_list);
1967 
1968 		if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1969 			err = -EAGAIN;
1970 			goto out;
1971 		}
1972 		if (fatal_signal_pending(current)) {
1973 			err = -ERESTARTSYS;
1974 			goto out;
1975 		}
1976 	}
1977 	if (gc_only)
1978 		goto out;
1979 
1980 	err = f2fs_write_checkpoint(sbi, &cpc);
1981 	if (err)
1982 		goto out;
1983 
1984 	next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1985 	if (next_inuse <= end) {
1986 		f2fs_err(sbi, "segno %u should be free but still inuse!",
1987 			 next_inuse);
1988 		f2fs_bug_on(sbi, 1);
1989 	}
1990 out:
1991 	MAIN_SECS(sbi) += secs;
1992 	return err;
1993 }
1994 
update_sb_metadata(struct f2fs_sb_info * sbi,int secs)1995 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1996 {
1997 	struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1998 	int section_count;
1999 	int segment_count;
2000 	int segment_count_main;
2001 	long long block_count;
2002 	int segs = secs * sbi->segs_per_sec;
2003 
2004 	f2fs_down_write(&sbi->sb_lock);
2005 
2006 	section_count = le32_to_cpu(raw_sb->section_count);
2007 	segment_count = le32_to_cpu(raw_sb->segment_count);
2008 	segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2009 	block_count = le64_to_cpu(raw_sb->block_count);
2010 
2011 	raw_sb->section_count = cpu_to_le32(section_count + secs);
2012 	raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2013 	raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2014 	raw_sb->block_count = cpu_to_le64(block_count +
2015 					(long long)segs * sbi->blocks_per_seg);
2016 	if (f2fs_is_multi_device(sbi)) {
2017 		int last_dev = sbi->s_ndevs - 1;
2018 		int dev_segs =
2019 			le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2020 
2021 		raw_sb->devs[last_dev].total_segments =
2022 						cpu_to_le32(dev_segs + segs);
2023 	}
2024 
2025 	f2fs_up_write(&sbi->sb_lock);
2026 }
2027 
update_fs_metadata(struct f2fs_sb_info * sbi,int secs)2028 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2029 {
2030 	int segs = secs * sbi->segs_per_sec;
2031 	long long blks = (long long)segs * sbi->blocks_per_seg;
2032 	long long user_block_count =
2033 				le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2034 
2035 	SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2036 	MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2037 	MAIN_SECS(sbi) += secs;
2038 	FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2039 	FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2040 	F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2041 
2042 	if (f2fs_is_multi_device(sbi)) {
2043 		int last_dev = sbi->s_ndevs - 1;
2044 
2045 		FDEV(last_dev).total_segments =
2046 				(int)FDEV(last_dev).total_segments + segs;
2047 		FDEV(last_dev).end_blk =
2048 				(long long)FDEV(last_dev).end_blk + blks;
2049 #ifdef CONFIG_BLK_DEV_ZONED
2050 		FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
2051 					(int)(blks >> sbi->log_blocks_per_blkz);
2052 #endif
2053 	}
2054 }
2055 
f2fs_resize_fs(struct f2fs_sb_info * sbi,__u64 block_count)2056 int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
2057 {
2058 	__u64 old_block_count, shrunk_blocks;
2059 	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2060 	unsigned int secs;
2061 	int err = 0;
2062 	__u32 rem;
2063 
2064 	old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2065 	if (block_count > old_block_count)
2066 		return -EINVAL;
2067 
2068 	if (f2fs_is_multi_device(sbi)) {
2069 		int last_dev = sbi->s_ndevs - 1;
2070 		__u64 last_segs = FDEV(last_dev).total_segments;
2071 
2072 		if (block_count + last_segs * sbi->blocks_per_seg <=
2073 								old_block_count)
2074 			return -EINVAL;
2075 	}
2076 
2077 	/* new fs size should align to section size */
2078 	div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2079 	if (rem)
2080 		return -EINVAL;
2081 
2082 	if (block_count == old_block_count)
2083 		return 0;
2084 
2085 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2086 		f2fs_err(sbi, "Should run fsck to repair first.");
2087 		return -EFSCORRUPTED;
2088 	}
2089 
2090 	if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2091 		f2fs_err(sbi, "Checkpoint should be enabled.");
2092 		return -EINVAL;
2093 	}
2094 
2095 	shrunk_blocks = old_block_count - block_count;
2096 	secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2097 
2098 	/* stop other GC */
2099 	if (!f2fs_down_write_trylock(&sbi->gc_lock))
2100 		return -EAGAIN;
2101 
2102 	/* stop CP to protect MAIN_SEC in free_segment_range */
2103 	f2fs_lock_op(sbi);
2104 
2105 	spin_lock(&sbi->stat_lock);
2106 	if (shrunk_blocks + valid_user_blocks(sbi) +
2107 		sbi->current_reserved_blocks + sbi->unusable_block_count +
2108 		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2109 		err = -ENOSPC;
2110 	spin_unlock(&sbi->stat_lock);
2111 
2112 	if (err)
2113 		goto out_unlock;
2114 
2115 	err = free_segment_range(sbi, secs, true);
2116 
2117 out_unlock:
2118 	f2fs_unlock_op(sbi);
2119 	f2fs_up_write(&sbi->gc_lock);
2120 	if (err)
2121 		return err;
2122 
2123 	set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2124 
2125 	freeze_super(sbi->sb);
2126 	f2fs_down_write(&sbi->gc_lock);
2127 	f2fs_down_write(&sbi->cp_global_sem);
2128 
2129 	spin_lock(&sbi->stat_lock);
2130 	if (shrunk_blocks + valid_user_blocks(sbi) +
2131 		sbi->current_reserved_blocks + sbi->unusable_block_count +
2132 		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2133 		err = -ENOSPC;
2134 	else
2135 		sbi->user_block_count -= shrunk_blocks;
2136 	spin_unlock(&sbi->stat_lock);
2137 	if (err)
2138 		goto out_err;
2139 
2140 	err = free_segment_range(sbi, secs, false);
2141 	if (err)
2142 		goto recover_out;
2143 
2144 	update_sb_metadata(sbi, -secs);
2145 
2146 	err = f2fs_commit_super(sbi, false);
2147 	if (err) {
2148 		update_sb_metadata(sbi, secs);
2149 		goto recover_out;
2150 	}
2151 
2152 	update_fs_metadata(sbi, -secs);
2153 	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2154 	set_sbi_flag(sbi, SBI_IS_DIRTY);
2155 
2156 	err = f2fs_write_checkpoint(sbi, &cpc);
2157 	if (err) {
2158 		update_fs_metadata(sbi, secs);
2159 		update_sb_metadata(sbi, secs);
2160 		f2fs_commit_super(sbi, false);
2161 	}
2162 recover_out:
2163 	if (err) {
2164 		set_sbi_flag(sbi, SBI_NEED_FSCK);
2165 		f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2166 
2167 		spin_lock(&sbi->stat_lock);
2168 		sbi->user_block_count += shrunk_blocks;
2169 		spin_unlock(&sbi->stat_lock);
2170 	}
2171 out_err:
2172 	f2fs_up_write(&sbi->cp_global_sem);
2173 	f2fs_up_write(&sbi->gc_lock);
2174 	thaw_super(sbi->sb);
2175 	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2176 	return err;
2177 }
2178