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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/mount.h>
11 #include <linux/backing-dev.h>
12 #include <linux/init.h>
13 #include <linux/f2fs_fs.h>
14 #include <linux/kthread.h>
15 #include <linux/delay.h>
16 #include <linux/freezer.h>
17 #include <linux/sched/signal.h>
18 
19 #include "f2fs.h"
20 #include "node.h"
21 #include "segment.h"
22 #include "gc.h"
23 #include <trace/events/f2fs.h>
24 
25 static struct kmem_cache *victim_entry_slab;
26 
27 static unsigned int count_bits(const unsigned long *addr,
28 				unsigned int offset, unsigned int len);
29 
gc_thread_func(void * data)30 static int gc_thread_func(void *data)
31 {
32 	struct f2fs_sb_info *sbi = data;
33 	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
34 	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
35 	wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
36 	unsigned int wait_ms;
37 
38 	wait_ms = gc_th->min_sleep_time;
39 
40 	set_freezable();
41 	do {
42 		bool sync_mode, foreground = false;
43 
44 		wait_event_interruptible_timeout(*wq,
45 				kthread_should_stop() || freezing(current) ||
46 				waitqueue_active(fggc_wq) ||
47 				gc_th->gc_wake,
48 				msecs_to_jiffies(wait_ms));
49 
50 		if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq))
51 			foreground = true;
52 
53 		/* give it a try one time */
54 		if (gc_th->gc_wake)
55 			gc_th->gc_wake = 0;
56 
57 		if (try_to_freeze()) {
58 			stat_other_skip_bggc_count(sbi);
59 			continue;
60 		}
61 		if (kthread_should_stop())
62 			break;
63 
64 		if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
65 			increase_sleep_time(gc_th, &wait_ms);
66 			stat_other_skip_bggc_count(sbi);
67 			continue;
68 		}
69 
70 		if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
71 			f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
72 			f2fs_stop_checkpoint(sbi, false);
73 		}
74 
75 		if (!sb_start_write_trylock(sbi->sb)) {
76 			stat_other_skip_bggc_count(sbi);
77 			continue;
78 		}
79 
80 		/*
81 		 * [GC triggering condition]
82 		 * 0. GC is not conducted currently.
83 		 * 1. There are enough dirty segments.
84 		 * 2. IO subsystem is idle by checking the # of writeback pages.
85 		 * 3. IO subsystem is idle by checking the # of requests in
86 		 *    bdev's request list.
87 		 *
88 		 * Note) We have to avoid triggering GCs frequently.
89 		 * Because it is possible that some segments can be
90 		 * invalidated soon after by user update or deletion.
91 		 * So, I'd like to wait some time to collect dirty segments.
92 		 */
93 		if (sbi->gc_mode == GC_URGENT_HIGH) {
94 			wait_ms = gc_th->urgent_sleep_time;
95 			down_write(&sbi->gc_lock);
96 			goto do_gc;
97 		}
98 
99 		if (foreground) {
100 			down_write(&sbi->gc_lock);
101 			goto do_gc;
102 		} else if (!down_write_trylock(&sbi->gc_lock)) {
103 			stat_other_skip_bggc_count(sbi);
104 			goto next;
105 		}
106 
107 		if (!is_idle(sbi, GC_TIME)) {
108 			increase_sleep_time(gc_th, &wait_ms);
109 			up_write(&sbi->gc_lock);
110 			stat_io_skip_bggc_count(sbi);
111 			goto next;
112 		}
113 
114 		if (has_enough_invalid_blocks(sbi))
115 			decrease_sleep_time(gc_th, &wait_ms);
116 		else
117 			increase_sleep_time(gc_th, &wait_ms);
118 do_gc:
119 		if (!foreground)
120 			stat_inc_bggc_count(sbi->stat_info);
121 
122 		sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
123 
124 		/* foreground GC was been triggered via f2fs_balance_fs() */
125 		if (foreground)
126 			sync_mode = false;
127 
128 		/* if return value is not zero, no victim was selected */
129 		if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
130 			wait_ms = gc_th->no_gc_sleep_time;
131 
132 		if (foreground)
133 			wake_up_all(&gc_th->fggc_wq);
134 
135 		trace_f2fs_background_gc(sbi->sb, wait_ms,
136 				prefree_segments(sbi), free_segments(sbi));
137 
138 		/* balancing f2fs's metadata periodically */
139 		f2fs_balance_fs_bg(sbi, true);
140 next:
141 		sb_end_write(sbi->sb);
142 
143 	} while (!kthread_should_stop());
144 	return 0;
145 }
146 
f2fs_start_gc_thread(struct f2fs_sb_info * sbi)147 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
148 {
149 	struct f2fs_gc_kthread *gc_th;
150 	dev_t dev = sbi->sb->s_bdev->bd_dev;
151 	int err = 0;
152 
153 	gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
154 	if (!gc_th) {
155 		err = -ENOMEM;
156 		goto out;
157 	}
158 
159 	gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
160 	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
161 	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
162 	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
163 
164 	gc_th->gc_wake= 0;
165 
166 	sbi->gc_thread = gc_th;
167 	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
168 	init_waitqueue_head(&sbi->gc_thread->fggc_wq);
169 	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
170 			"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
171 	if (IS_ERR(gc_th->f2fs_gc_task)) {
172 		err = PTR_ERR(gc_th->f2fs_gc_task);
173 		kfree(gc_th);
174 		sbi->gc_thread = NULL;
175 	}
176 out:
177 	return err;
178 }
179 
f2fs_stop_gc_thread(struct f2fs_sb_info * sbi)180 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
181 {
182 	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
183 	if (!gc_th)
184 		return;
185 	kthread_stop(gc_th->f2fs_gc_task);
186 	wake_up_all(&gc_th->fggc_wq);
187 	kfree(gc_th);
188 	sbi->gc_thread = NULL;
189 }
190 
select_gc_type(struct f2fs_sb_info * sbi,int gc_type)191 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
192 {
193 	int gc_mode;
194 
195 	if (gc_type == BG_GC) {
196 		if (sbi->am.atgc_enabled)
197 			gc_mode = GC_AT;
198 		else
199 			gc_mode = GC_CB;
200 	} else {
201 		gc_mode = GC_GREEDY;
202 	}
203 
204 	switch (sbi->gc_mode) {
205 	case GC_IDLE_CB:
206 		gc_mode = GC_CB;
207 		break;
208 	case GC_IDLE_GREEDY:
209 	case GC_URGENT_HIGH:
210 		gc_mode = GC_GREEDY;
211 		break;
212 	case GC_IDLE_AT:
213 		gc_mode = GC_AT;
214 		break;
215 	}
216 
217 	return gc_mode;
218 }
219 
select_policy(struct f2fs_sb_info * sbi,int gc_type,int type,struct victim_sel_policy * p)220 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
221 			int type, struct victim_sel_policy *p)
222 {
223 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
224 
225 	if (p->alloc_mode == SSR) {
226 		p->gc_mode = GC_GREEDY;
227 		p->dirty_bitmap = dirty_i->dirty_segmap[type];
228 		p->max_search = dirty_i->nr_dirty[type];
229 		p->ofs_unit = 1;
230 	} else if (p->alloc_mode == AT_SSR) {
231 		p->gc_mode = GC_GREEDY;
232 		p->dirty_bitmap = dirty_i->dirty_segmap[type];
233 		p->max_search = dirty_i->nr_dirty[type];
234 		p->ofs_unit = 1;
235 	} else {
236 		p->gc_mode = select_gc_type(sbi, gc_type);
237 		p->ofs_unit = sbi->segs_per_sec;
238 		if (__is_large_section(sbi)) {
239 			p->dirty_bitmap = dirty_i->dirty_secmap;
240 			p->max_search = count_bits(p->dirty_bitmap,
241 						0, MAIN_SECS(sbi));
242 		} else {
243 			p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
244 			p->max_search = dirty_i->nr_dirty[DIRTY];
245 		}
246 	}
247 
248 	/*
249 	 * adjust candidates range, should select all dirty segments for
250 	 * foreground GC and urgent GC cases.
251 	 */
252 	if (gc_type != FG_GC &&
253 			(sbi->gc_mode != GC_URGENT_HIGH) &&
254 			(p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
255 			p->max_search > sbi->max_victim_search)
256 		p->max_search = sbi->max_victim_search;
257 
258 	/* let's select beginning hot/small space first in no_heap mode*/
259 	if (test_opt(sbi, NOHEAP) &&
260 		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
261 		p->offset = 0;
262 	else
263 		p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
264 }
265 
get_max_cost(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)266 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
267 				struct victim_sel_policy *p)
268 {
269 	/* SSR allocates in a segment unit */
270 	if (p->alloc_mode == SSR)
271 		return sbi->blocks_per_seg;
272 	else if (p->alloc_mode == AT_SSR)
273 		return UINT_MAX;
274 
275 	/* LFS */
276 	if (p->gc_mode == GC_GREEDY)
277 		return 2 * sbi->blocks_per_seg * p->ofs_unit;
278 	else if (p->gc_mode == GC_CB)
279 		return UINT_MAX;
280 	else if (p->gc_mode == GC_AT)
281 		return UINT_MAX;
282 	else /* No other gc_mode */
283 		return 0;
284 }
285 
check_bg_victims(struct f2fs_sb_info * sbi)286 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
287 {
288 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
289 	unsigned int secno;
290 
291 	/*
292 	 * If the gc_type is FG_GC, we can select victim segments
293 	 * selected by background GC before.
294 	 * Those segments guarantee they have small valid blocks.
295 	 */
296 	for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
297 		if (sec_usage_check(sbi, secno))
298 			continue;
299 		clear_bit(secno, dirty_i->victim_secmap);
300 		return GET_SEG_FROM_SEC(sbi, secno);
301 	}
302 	return NULL_SEGNO;
303 }
304 
get_cb_cost(struct f2fs_sb_info * sbi,unsigned int segno)305 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
306 {
307 	struct sit_info *sit_i = SIT_I(sbi);
308 	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
309 	unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
310 	unsigned long long mtime = 0;
311 	unsigned int vblocks;
312 	unsigned char age = 0;
313 	unsigned char u;
314 	unsigned int i;
315 	unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
316 
317 	for (i = 0; i < usable_segs_per_sec; i++)
318 		mtime += get_seg_entry(sbi, start + i)->mtime;
319 	vblocks = get_valid_blocks(sbi, segno, true);
320 
321 	mtime = div_u64(mtime, usable_segs_per_sec);
322 	vblocks = div_u64(vblocks, usable_segs_per_sec);
323 
324 	u = (vblocks * 100) >> sbi->log_blocks_per_seg;
325 
326 	/* Handle if the system time has changed by the user */
327 	if (mtime < sit_i->min_mtime)
328 		sit_i->min_mtime = mtime;
329 	if (mtime > sit_i->max_mtime)
330 		sit_i->max_mtime = mtime;
331 	if (sit_i->max_mtime != sit_i->min_mtime)
332 		age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
333 				sit_i->max_mtime - sit_i->min_mtime);
334 
335 	return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
336 }
337 
get_gc_cost(struct f2fs_sb_info * sbi,unsigned int segno,struct victim_sel_policy * p)338 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
339 			unsigned int segno, struct victim_sel_policy *p)
340 {
341 	if (p->alloc_mode == SSR)
342 		return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
343 
344 	/* alloc_mode == LFS */
345 	if (p->gc_mode == GC_GREEDY)
346 		return get_valid_blocks(sbi, segno, true);
347 	else if (p->gc_mode == GC_CB)
348 		return get_cb_cost(sbi, segno);
349 
350 	f2fs_bug_on(sbi, 1);
351 	return 0;
352 }
353 
count_bits(const unsigned long * addr,unsigned int offset,unsigned int len)354 static unsigned int count_bits(const unsigned long *addr,
355 				unsigned int offset, unsigned int len)
356 {
357 	unsigned int end = offset + len, sum = 0;
358 
359 	while (offset < end) {
360 		if (test_bit(offset++, addr))
361 			++sum;
362 	}
363 	return sum;
364 }
365 
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)366 static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
367 				unsigned long long mtime, unsigned int segno,
368 				struct rb_node *parent, struct rb_node **p,
369 				bool left_most)
370 {
371 	struct atgc_management *am = &sbi->am;
372 	struct victim_entry *ve;
373 
374 	ve =  f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS);
375 
376 	ve->mtime = mtime;
377 	ve->segno = segno;
378 
379 	rb_link_node(&ve->rb_node, parent, p);
380 	rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
381 
382 	list_add_tail(&ve->list, &am->victim_list);
383 
384 	am->victim_count++;
385 
386 	return ve;
387 }
388 
insert_victim_entry(struct f2fs_sb_info * sbi,unsigned long long mtime,unsigned int segno)389 static void insert_victim_entry(struct f2fs_sb_info *sbi,
390 				unsigned long long mtime, unsigned int segno)
391 {
392 	struct atgc_management *am = &sbi->am;
393 	struct rb_node **p;
394 	struct rb_node *parent = NULL;
395 	bool left_most = true;
396 
397 	p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
398 	attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
399 }
400 
add_victim_entry(struct f2fs_sb_info * sbi,struct victim_sel_policy * p,unsigned int segno)401 static void add_victim_entry(struct f2fs_sb_info *sbi,
402 				struct victim_sel_policy *p, unsigned int segno)
403 {
404 	struct sit_info *sit_i = SIT_I(sbi);
405 	unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
406 	unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
407 	unsigned long long mtime = 0;
408 	unsigned int i;
409 
410 	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
411 		if (p->gc_mode == GC_AT &&
412 			get_valid_blocks(sbi, segno, true) == 0)
413 			return;
414 	}
415 
416 	for (i = 0; i < sbi->segs_per_sec; i++)
417 		mtime += get_seg_entry(sbi, start + i)->mtime;
418 	mtime = div_u64(mtime, sbi->segs_per_sec);
419 
420 	/* Handle if the system time has changed by the user */
421 	if (mtime < sit_i->min_mtime)
422 		sit_i->min_mtime = mtime;
423 	if (mtime > sit_i->max_mtime)
424 		sit_i->max_mtime = mtime;
425 	if (mtime < sit_i->dirty_min_mtime)
426 		sit_i->dirty_min_mtime = mtime;
427 	if (mtime > sit_i->dirty_max_mtime)
428 		sit_i->dirty_max_mtime = mtime;
429 
430 	/* don't choose young section as candidate */
431 	if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
432 		return;
433 
434 	insert_victim_entry(sbi, mtime, segno);
435 }
436 
lookup_central_victim(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)437 static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
438 						struct victim_sel_policy *p)
439 {
440 	struct atgc_management *am = &sbi->am;
441 	struct rb_node *parent = NULL;
442 	bool left_most;
443 
444 	f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
445 
446 	return parent;
447 }
448 
atgc_lookup_victim(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)449 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
450 						struct victim_sel_policy *p)
451 {
452 	struct sit_info *sit_i = SIT_I(sbi);
453 	struct atgc_management *am = &sbi->am;
454 	struct rb_root_cached *root = &am->root;
455 	struct rb_node *node;
456 	struct rb_entry *re;
457 	struct victim_entry *ve;
458 	unsigned long long total_time;
459 	unsigned long long age, u, accu;
460 	unsigned long long max_mtime = sit_i->dirty_max_mtime;
461 	unsigned long long min_mtime = sit_i->dirty_min_mtime;
462 	unsigned int sec_blocks = BLKS_PER_SEC(sbi);
463 	unsigned int vblocks;
464 	unsigned int dirty_threshold = max(am->max_candidate_count,
465 					am->candidate_ratio *
466 					am->victim_count / 100);
467 	unsigned int age_weight = am->age_weight;
468 	unsigned int cost;
469 	unsigned int iter = 0;
470 
471 	if (max_mtime < min_mtime)
472 		return;
473 
474 	max_mtime += 1;
475 	total_time = max_mtime - min_mtime;
476 
477 	accu = div64_u64(ULLONG_MAX, total_time);
478 	accu = min_t(unsigned long long, div_u64(accu, 100),
479 					DEFAULT_ACCURACY_CLASS);
480 
481 	node = rb_first_cached(root);
482 next:
483 	re = rb_entry_safe(node, struct rb_entry, rb_node);
484 	if (!re)
485 		return;
486 
487 	ve = (struct victim_entry *)re;
488 
489 	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
490 		goto skip;
491 
492 	/* age = 10000 * x% * 60 */
493 	age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
494 								age_weight;
495 
496 	vblocks = get_valid_blocks(sbi, ve->segno, true);
497 	f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
498 
499 	/* u = 10000 * x% * 40 */
500 	u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
501 							(100 - age_weight);
502 
503 	f2fs_bug_on(sbi, age + u >= UINT_MAX);
504 
505 	cost = UINT_MAX - (age + u);
506 	iter++;
507 
508 	if (cost < p->min_cost ||
509 			(cost == p->min_cost && age > p->oldest_age)) {
510 		p->min_cost = cost;
511 		p->oldest_age = age;
512 		p->min_segno = ve->segno;
513 	}
514 skip:
515 	if (iter < dirty_threshold) {
516 		node = rb_next(node);
517 		goto next;
518 	}
519 }
520 
521 /*
522  * select candidates around source section in range of
523  * [target - dirty_threshold, target + dirty_threshold]
524  */
atssr_lookup_victim(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)525 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
526 						struct victim_sel_policy *p)
527 {
528 	struct sit_info *sit_i = SIT_I(sbi);
529 	struct atgc_management *am = &sbi->am;
530 	struct rb_node *node;
531 	struct rb_entry *re;
532 	struct victim_entry *ve;
533 	unsigned long long age;
534 	unsigned long long max_mtime = sit_i->dirty_max_mtime;
535 	unsigned long long min_mtime = sit_i->dirty_min_mtime;
536 	unsigned int seg_blocks = sbi->blocks_per_seg;
537 	unsigned int vblocks;
538 	unsigned int dirty_threshold = max(am->max_candidate_count,
539 					am->candidate_ratio *
540 					am->victim_count / 100);
541 	unsigned int cost;
542 	unsigned int iter = 0;
543 	int stage = 0;
544 
545 	if (max_mtime < min_mtime)
546 		return;
547 	max_mtime += 1;
548 next_stage:
549 	node = lookup_central_victim(sbi, p);
550 next_node:
551 	re = rb_entry_safe(node, struct rb_entry, rb_node);
552 	if (!re) {
553 		if (stage == 0)
554 			goto skip_stage;
555 		return;
556 	}
557 
558 	ve = (struct victim_entry *)re;
559 
560 	if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
561 		goto skip_node;
562 
563 	age = max_mtime - ve->mtime;
564 
565 	vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
566 	f2fs_bug_on(sbi, !vblocks);
567 
568 	/* rare case */
569 	if (vblocks == seg_blocks)
570 		goto skip_node;
571 
572 	iter++;
573 
574 	age = max_mtime - abs(p->age - age);
575 	cost = UINT_MAX - vblocks;
576 
577 	if (cost < p->min_cost ||
578 			(cost == p->min_cost && age > p->oldest_age)) {
579 		p->min_cost = cost;
580 		p->oldest_age = age;
581 		p->min_segno = ve->segno;
582 	}
583 skip_node:
584 	if (iter < dirty_threshold) {
585 		if (stage == 0)
586 			node = rb_prev(node);
587 		else if (stage == 1)
588 			node = rb_next(node);
589 		goto next_node;
590 	}
591 skip_stage:
592 	if (stage < 1) {
593 		stage++;
594 		iter = 0;
595 		goto next_stage;
596 	}
597 }
lookup_victim_by_age(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)598 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
599 						struct victim_sel_policy *p)
600 {
601 	f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
602 						&sbi->am.root, true));
603 
604 	if (p->gc_mode == GC_AT)
605 		atgc_lookup_victim(sbi, p);
606 	else if (p->alloc_mode == AT_SSR)
607 		atssr_lookup_victim(sbi, p);
608 	else
609 		f2fs_bug_on(sbi, 1);
610 }
611 
release_victim_entry(struct f2fs_sb_info * sbi)612 static void release_victim_entry(struct f2fs_sb_info *sbi)
613 {
614 	struct atgc_management *am = &sbi->am;
615 	struct victim_entry *ve, *tmp;
616 
617 	list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
618 		list_del(&ve->list);
619 		kmem_cache_free(victim_entry_slab, ve);
620 		am->victim_count--;
621 	}
622 
623 	am->root = RB_ROOT_CACHED;
624 
625 	f2fs_bug_on(sbi, am->victim_count);
626 	f2fs_bug_on(sbi, !list_empty(&am->victim_list));
627 }
628 
629 /*
630  * This function is called from two paths.
631  * One is garbage collection and the other is SSR segment selection.
632  * When it is called during GC, it just gets a victim segment
633  * and it does not remove it from dirty seglist.
634  * When it is called from SSR segment selection, it finds a segment
635  * which has minimum valid blocks and removes it from dirty seglist.
636  */
get_victim_by_default(struct f2fs_sb_info * sbi,unsigned int * result,int gc_type,int type,char alloc_mode,unsigned long long age)637 static int get_victim_by_default(struct f2fs_sb_info *sbi,
638 			unsigned int *result, int gc_type, int type,
639 			char alloc_mode, unsigned long long age)
640 {
641 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
642 	struct sit_info *sm = SIT_I(sbi);
643 	struct victim_sel_policy p;
644 	unsigned int secno, last_victim;
645 	unsigned int last_segment;
646 	unsigned int nsearched;
647 	bool is_atgc;
648 	int ret = 0;
649 
650 	mutex_lock(&dirty_i->seglist_lock);
651 	last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
652 
653 	p.alloc_mode = alloc_mode;
654 	p.age = age;
655 	p.age_threshold = sbi->am.age_threshold;
656 
657 retry:
658 	select_policy(sbi, gc_type, type, &p);
659 	p.min_segno = NULL_SEGNO;
660 	p.oldest_age = 0;
661 	p.min_cost = get_max_cost(sbi, &p);
662 
663 	is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
664 	nsearched = 0;
665 
666 	if (is_atgc)
667 		SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
668 
669 	if (*result != NULL_SEGNO) {
670 		if (!get_valid_blocks(sbi, *result, false)) {
671 			ret = -ENODATA;
672 			goto out;
673 		}
674 
675 		if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
676 			ret = -EBUSY;
677 		else
678 			p.min_segno = *result;
679 		goto out;
680 	}
681 
682 	ret = -ENODATA;
683 	if (p.max_search == 0)
684 		goto out;
685 
686 	if (__is_large_section(sbi) && p.alloc_mode == LFS) {
687 		if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
688 			p.min_segno = sbi->next_victim_seg[BG_GC];
689 			*result = p.min_segno;
690 			sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
691 			goto got_result;
692 		}
693 		if (gc_type == FG_GC &&
694 				sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
695 			p.min_segno = sbi->next_victim_seg[FG_GC];
696 			*result = p.min_segno;
697 			sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
698 			goto got_result;
699 		}
700 	}
701 
702 	last_victim = sm->last_victim[p.gc_mode];
703 	if (p.alloc_mode == LFS && gc_type == FG_GC) {
704 		p.min_segno = check_bg_victims(sbi);
705 		if (p.min_segno != NULL_SEGNO)
706 			goto got_it;
707 	}
708 
709 	while (1) {
710 		unsigned long cost, *dirty_bitmap;
711 		unsigned int unit_no, segno;
712 
713 		dirty_bitmap = p.dirty_bitmap;
714 		unit_no = find_next_bit(dirty_bitmap,
715 				last_segment / p.ofs_unit,
716 				p.offset / p.ofs_unit);
717 		segno = unit_no * p.ofs_unit;
718 		if (segno >= last_segment) {
719 			if (sm->last_victim[p.gc_mode]) {
720 				last_segment =
721 					sm->last_victim[p.gc_mode];
722 				sm->last_victim[p.gc_mode] = 0;
723 				p.offset = 0;
724 				continue;
725 			}
726 			break;
727 		}
728 
729 		p.offset = segno + p.ofs_unit;
730 		nsearched++;
731 
732 #ifdef CONFIG_F2FS_CHECK_FS
733 		/*
734 		 * skip selecting the invalid segno (that is failed due to block
735 		 * validity check failure during GC) to avoid endless GC loop in
736 		 * such cases.
737 		 */
738 		if (test_bit(segno, sm->invalid_segmap))
739 			goto next;
740 #endif
741 
742 		secno = GET_SEC_FROM_SEG(sbi, segno);
743 
744 		if (sec_usage_check(sbi, secno))
745 			goto next;
746 
747 		/* Don't touch checkpointed data */
748 		if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
749 			if (p.alloc_mode == LFS) {
750 				/*
751 				 * LFS is set to find source section during GC.
752 				 * The victim should have no checkpointed data.
753 				 */
754 				if (get_ckpt_valid_blocks(sbi, segno, true))
755 					goto next;
756 			} else {
757 				/*
758 				 * SSR | AT_SSR are set to find target segment
759 				 * for writes which can be full by checkpointed
760 				 * and newly written blocks.
761 				 */
762 				if (!f2fs_segment_has_free_slot(sbi, segno))
763 					goto next;
764 			}
765 		}
766 
767 		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
768 			goto next;
769 
770 		if (is_atgc) {
771 			add_victim_entry(sbi, &p, segno);
772 			goto next;
773 		}
774 
775 		cost = get_gc_cost(sbi, segno, &p);
776 
777 		if (p.min_cost > cost) {
778 			p.min_segno = segno;
779 			p.min_cost = cost;
780 		}
781 next:
782 		if (nsearched >= p.max_search) {
783 			if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
784 				sm->last_victim[p.gc_mode] =
785 					last_victim + p.ofs_unit;
786 			else
787 				sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
788 			sm->last_victim[p.gc_mode] %=
789 				(MAIN_SECS(sbi) * sbi->segs_per_sec);
790 			break;
791 		}
792 	}
793 
794 	/* get victim for GC_AT/AT_SSR */
795 	if (is_atgc) {
796 		lookup_victim_by_age(sbi, &p);
797 		release_victim_entry(sbi);
798 	}
799 
800 	if (is_atgc && p.min_segno == NULL_SEGNO &&
801 			sm->elapsed_time < p.age_threshold) {
802 		p.age_threshold = 0;
803 		goto retry;
804 	}
805 
806 	if (p.min_segno != NULL_SEGNO) {
807 got_it:
808 		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
809 got_result:
810 		if (p.alloc_mode == LFS) {
811 			secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
812 			if (gc_type == FG_GC)
813 				sbi->cur_victim_sec = secno;
814 			else
815 				set_bit(secno, dirty_i->victim_secmap);
816 		}
817 		ret = 0;
818 
819 	}
820 out:
821 	if (p.min_segno != NULL_SEGNO)
822 		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
823 				sbi->cur_victim_sec,
824 				prefree_segments(sbi), free_segments(sbi));
825 	mutex_unlock(&dirty_i->seglist_lock);
826 
827 	return ret;
828 }
829 
830 static const struct victim_selection default_v_ops = {
831 	.get_victim = get_victim_by_default,
832 };
833 
find_gc_inode(struct gc_inode_list * gc_list,nid_t ino)834 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
835 {
836 	struct inode_entry *ie;
837 
838 	ie = radix_tree_lookup(&gc_list->iroot, ino);
839 	if (ie)
840 		return ie->inode;
841 	return NULL;
842 }
843 
add_gc_inode(struct gc_inode_list * gc_list,struct inode * inode)844 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
845 {
846 	struct inode_entry *new_ie;
847 
848 	if (inode == find_gc_inode(gc_list, inode->i_ino)) {
849 		iput(inode);
850 		return;
851 	}
852 	new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
853 	new_ie->inode = inode;
854 
855 	f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
856 	list_add_tail(&new_ie->list, &gc_list->ilist);
857 }
858 
put_gc_inode(struct gc_inode_list * gc_list)859 static void put_gc_inode(struct gc_inode_list *gc_list)
860 {
861 	struct inode_entry *ie, *next_ie;
862 	list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
863 		radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
864 		iput(ie->inode);
865 		list_del(&ie->list);
866 		kmem_cache_free(f2fs_inode_entry_slab, ie);
867 	}
868 }
869 
check_valid_map(struct f2fs_sb_info * sbi,unsigned int segno,int offset)870 static int check_valid_map(struct f2fs_sb_info *sbi,
871 				unsigned int segno, int offset)
872 {
873 	struct sit_info *sit_i = SIT_I(sbi);
874 	struct seg_entry *sentry;
875 	int ret;
876 
877 	down_read(&sit_i->sentry_lock);
878 	sentry = get_seg_entry(sbi, segno);
879 	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
880 	up_read(&sit_i->sentry_lock);
881 	return ret;
882 }
883 
884 /*
885  * This function compares node address got in summary with that in NAT.
886  * On validity, copy that node with cold status, otherwise (invalid node)
887  * ignore that.
888  */
gc_node_segment(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,unsigned int segno,int gc_type)889 static int gc_node_segment(struct f2fs_sb_info *sbi,
890 		struct f2fs_summary *sum, unsigned int segno, int gc_type)
891 {
892 	struct f2fs_summary *entry;
893 	block_t start_addr;
894 	int off;
895 	int phase = 0;
896 	bool fggc = (gc_type == FG_GC);
897 	int submitted = 0;
898 	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
899 
900 	start_addr = START_BLOCK(sbi, segno);
901 
902 next_step:
903 	entry = sum;
904 
905 	if (fggc && phase == 2)
906 		atomic_inc(&sbi->wb_sync_req[NODE]);
907 
908 	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
909 		nid_t nid = le32_to_cpu(entry->nid);
910 		struct page *node_page;
911 		struct node_info ni;
912 		int err;
913 
914 		/* stop BG_GC if there is not enough free sections. */
915 		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
916 			return submitted;
917 
918 		if (check_valid_map(sbi, segno, off) == 0)
919 			continue;
920 
921 		if (phase == 0) {
922 			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
923 							META_NAT, true);
924 			continue;
925 		}
926 
927 		if (phase == 1) {
928 			f2fs_ra_node_page(sbi, nid);
929 			continue;
930 		}
931 
932 		/* phase == 2 */
933 		node_page = f2fs_get_node_page(sbi, nid);
934 		if (IS_ERR(node_page))
935 			continue;
936 
937 		/* block may become invalid during f2fs_get_node_page */
938 		if (check_valid_map(sbi, segno, off) == 0) {
939 			f2fs_put_page(node_page, 1);
940 			continue;
941 		}
942 
943 		if (f2fs_get_node_info(sbi, nid, &ni)) {
944 			f2fs_put_page(node_page, 1);
945 			continue;
946 		}
947 
948 		if (ni.blk_addr != start_addr + off) {
949 			f2fs_put_page(node_page, 1);
950 			continue;
951 		}
952 
953 		err = f2fs_move_node_page(node_page, gc_type);
954 		if (!err && gc_type == FG_GC)
955 			submitted++;
956 		stat_inc_node_blk_count(sbi, 1, gc_type);
957 	}
958 
959 	if (++phase < 3)
960 		goto next_step;
961 
962 	if (fggc)
963 		atomic_dec(&sbi->wb_sync_req[NODE]);
964 	return submitted;
965 }
966 
967 /*
968  * Calculate start block index indicating the given node offset.
969  * Be careful, caller should give this node offset only indicating direct node
970  * blocks. If any node offsets, which point the other types of node blocks such
971  * as indirect or double indirect node blocks, are given, it must be a caller's
972  * bug.
973  */
f2fs_start_bidx_of_node(unsigned int node_ofs,struct inode * inode)974 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
975 {
976 	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
977 	unsigned int bidx;
978 
979 	if (node_ofs == 0)
980 		return 0;
981 
982 	if (node_ofs <= 2) {
983 		bidx = node_ofs - 1;
984 	} else if (node_ofs <= indirect_blks) {
985 		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
986 		bidx = node_ofs - 2 - dec;
987 	} else {
988 		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
989 		bidx = node_ofs - 5 - dec;
990 	}
991 	return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
992 }
993 
is_alive(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,struct node_info * dni,block_t blkaddr,unsigned int * nofs)994 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
995 		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
996 {
997 	struct page *node_page;
998 	nid_t nid;
999 	unsigned int ofs_in_node, max_addrs, base;
1000 	block_t source_blkaddr;
1001 
1002 	nid = le32_to_cpu(sum->nid);
1003 	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1004 
1005 	node_page = f2fs_get_node_page(sbi, nid);
1006 	if (IS_ERR(node_page))
1007 		return false;
1008 
1009 	if (f2fs_get_node_info(sbi, nid, dni)) {
1010 		f2fs_put_page(node_page, 1);
1011 		return false;
1012 	}
1013 
1014 	if (sum->version != dni->version) {
1015 		f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1016 			  __func__);
1017 		set_sbi_flag(sbi, SBI_NEED_FSCK);
1018 	}
1019 
1020 	if (f2fs_check_nid_range(sbi, dni->ino)) {
1021 		f2fs_put_page(node_page, 1);
1022 		return false;
1023 	}
1024 
1025 	if (IS_INODE(node_page)) {
1026 		base = offset_in_addr(F2FS_INODE(node_page));
1027 		max_addrs = DEF_ADDRS_PER_INODE;
1028 	} else {
1029 		base = 0;
1030 		max_addrs = DEF_ADDRS_PER_BLOCK;
1031 	}
1032 
1033 	if (base + ofs_in_node >= max_addrs) {
1034 		f2fs_err(sbi, "Inconsistent blkaddr offset: base:%u, ofs_in_node:%u, max:%u, ino:%u, nid:%u",
1035 			base, ofs_in_node, max_addrs, dni->ino, dni->nid);
1036 		f2fs_put_page(node_page, 1);
1037 		return false;
1038 	}
1039 
1040 	*nofs = ofs_of_node(node_page);
1041 	source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1042 	f2fs_put_page(node_page, 1);
1043 
1044 	if (source_blkaddr != blkaddr) {
1045 #ifdef CONFIG_F2FS_CHECK_FS
1046 		unsigned int segno = GET_SEGNO(sbi, blkaddr);
1047 		unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1048 
1049 		if (unlikely(check_valid_map(sbi, segno, offset))) {
1050 			if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1051 				f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u\n",
1052 						blkaddr, source_blkaddr, segno);
1053 				set_sbi_flag(sbi, SBI_NEED_FSCK);
1054 			}
1055 		}
1056 #endif
1057 		return false;
1058 	}
1059 	return true;
1060 }
1061 
ra_data_block(struct inode * inode,pgoff_t index)1062 static int ra_data_block(struct inode *inode, pgoff_t index)
1063 {
1064 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1065 	struct address_space *mapping = inode->i_mapping;
1066 	struct dnode_of_data dn;
1067 	struct page *page;
1068 	struct extent_info ei = {0, 0, 0};
1069 	struct f2fs_io_info fio = {
1070 		.sbi = sbi,
1071 		.ino = inode->i_ino,
1072 		.type = DATA,
1073 		.temp = COLD,
1074 		.op = REQ_OP_READ,
1075 		.op_flags = 0,
1076 		.encrypted_page = NULL,
1077 		.in_list = false,
1078 		.retry = false,
1079 	};
1080 	int err;
1081 
1082 	page = f2fs_grab_cache_page(mapping, index, true);
1083 	if (!page)
1084 		return -ENOMEM;
1085 
1086 	if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1087 		dn.data_blkaddr = ei.blk + index - ei.fofs;
1088 		if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1089 						DATA_GENERIC_ENHANCE_READ))) {
1090 			err = -EFSCORRUPTED;
1091 			goto put_page;
1092 		}
1093 		goto got_it;
1094 	}
1095 
1096 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1097 	err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1098 	if (err)
1099 		goto put_page;
1100 	f2fs_put_dnode(&dn);
1101 
1102 	if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1103 		err = -ENOENT;
1104 		goto put_page;
1105 	}
1106 	if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1107 						DATA_GENERIC_ENHANCE))) {
1108 		err = -EFSCORRUPTED;
1109 		goto put_page;
1110 	}
1111 got_it:
1112 	/* read page */
1113 	fio.page = page;
1114 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1115 
1116 	/*
1117 	 * don't cache encrypted data into meta inode until previous dirty
1118 	 * data were writebacked to avoid racing between GC and flush.
1119 	 */
1120 	f2fs_wait_on_page_writeback(page, DATA, true, true);
1121 
1122 	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1123 
1124 	fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1125 					dn.data_blkaddr,
1126 					FGP_LOCK | FGP_CREAT, GFP_NOFS);
1127 	if (!fio.encrypted_page) {
1128 		err = -ENOMEM;
1129 		goto put_page;
1130 	}
1131 
1132 	err = f2fs_submit_page_bio(&fio);
1133 	if (err)
1134 		goto put_encrypted_page;
1135 	f2fs_put_page(fio.encrypted_page, 0);
1136 	f2fs_put_page(page, 1);
1137 
1138 	f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1139 	f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1140 
1141 	return 0;
1142 put_encrypted_page:
1143 	f2fs_put_page(fio.encrypted_page, 1);
1144 put_page:
1145 	f2fs_put_page(page, 1);
1146 	return err;
1147 }
1148 
1149 /*
1150  * Move data block via META_MAPPING while keeping locked data page.
1151  * This can be used to move blocks, aka LBAs, directly on disk.
1152  */
move_data_block(struct inode * inode,block_t bidx,int gc_type,unsigned int segno,int off)1153 static int move_data_block(struct inode *inode, block_t bidx,
1154 				int gc_type, unsigned int segno, int off)
1155 {
1156 	struct f2fs_io_info fio = {
1157 		.sbi = F2FS_I_SB(inode),
1158 		.ino = inode->i_ino,
1159 		.type = DATA,
1160 		.temp = COLD,
1161 		.op = REQ_OP_READ,
1162 		.op_flags = 0,
1163 		.encrypted_page = NULL,
1164 		.in_list = false,
1165 		.retry = false,
1166 	};
1167 	struct dnode_of_data dn;
1168 	struct f2fs_summary sum;
1169 	struct node_info ni;
1170 	struct page *page, *mpage;
1171 	block_t newaddr;
1172 	int err = 0;
1173 	bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1174 	int type = fio.sbi->am.atgc_enabled ?
1175 				CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1176 
1177 	/* do not read out */
1178 	page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1179 	if (!page)
1180 		return -ENOMEM;
1181 
1182 	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1183 		err = -ENOENT;
1184 		goto out;
1185 	}
1186 
1187 	if (f2fs_is_atomic_file(inode)) {
1188 		F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1189 		F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1190 		err = -EAGAIN;
1191 		goto out;
1192 	}
1193 
1194 	if (f2fs_is_pinned_file(inode)) {
1195 		if (gc_type == FG_GC)
1196 			f2fs_pin_file_control(inode, true);
1197 		err = -EAGAIN;
1198 		goto out;
1199 	}
1200 
1201 	set_new_dnode(&dn, inode, NULL, NULL, 0);
1202 	err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1203 	if (err)
1204 		goto out;
1205 
1206 	if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1207 		ClearPageUptodate(page);
1208 		err = -ENOENT;
1209 		goto put_out;
1210 	}
1211 
1212 	/*
1213 	 * don't cache encrypted data into meta inode until previous dirty
1214 	 * data were writebacked to avoid racing between GC and flush.
1215 	 */
1216 	f2fs_wait_on_page_writeback(page, DATA, true, true);
1217 
1218 	f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1219 
1220 	err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
1221 	if (err)
1222 		goto put_out;
1223 
1224 	set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1225 
1226 	/* read page */
1227 	fio.page = page;
1228 	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1229 
1230 	if (lfs_mode)
1231 		down_write(&fio.sbi->io_order_lock);
1232 
1233 	mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1234 					fio.old_blkaddr, false);
1235 	if (!mpage) {
1236 		err = -ENOMEM;
1237 		goto up_out;
1238 	}
1239 
1240 	fio.encrypted_page = mpage;
1241 
1242 	/* read source block in mpage */
1243 	if (!PageUptodate(mpage)) {
1244 		err = f2fs_submit_page_bio(&fio);
1245 		if (err) {
1246 			f2fs_put_page(mpage, 1);
1247 			goto up_out;
1248 		}
1249 
1250 		f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1251 		f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1252 
1253 		lock_page(mpage);
1254 		if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1255 						!PageUptodate(mpage))) {
1256 			err = -EIO;
1257 			f2fs_put_page(mpage, 1);
1258 			goto up_out;
1259 		}
1260 	}
1261 
1262 	f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1263 				&sum, type, NULL, SEQ_NONE);
1264 
1265 	fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1266 				newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1267 	if (!fio.encrypted_page) {
1268 		err = -ENOMEM;
1269 		f2fs_put_page(mpage, 1);
1270 		goto recover_block;
1271 	}
1272 
1273 	/* write target block */
1274 	f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1275 	memcpy(page_address(fio.encrypted_page),
1276 				page_address(mpage), PAGE_SIZE);
1277 	f2fs_put_page(mpage, 1);
1278 	invalidate_mapping_pages(META_MAPPING(fio.sbi),
1279 				fio.old_blkaddr, fio.old_blkaddr);
1280 
1281 	set_page_dirty(fio.encrypted_page);
1282 	if (clear_page_dirty_for_io(fio.encrypted_page))
1283 		dec_page_count(fio.sbi, F2FS_DIRTY_META);
1284 
1285 	set_page_writeback(fio.encrypted_page);
1286 	ClearPageError(page);
1287 
1288 	/* allocate block address */
1289 	f2fs_wait_on_page_writeback(dn.node_page, NODE, true, true);
1290 
1291 	fio.op = REQ_OP_WRITE;
1292 	fio.op_flags = REQ_SYNC;
1293 	fio.new_blkaddr = newaddr;
1294 	f2fs_submit_page_write(&fio);
1295 	if (fio.retry) {
1296 		err = -EAGAIN;
1297 		if (PageWriteback(fio.encrypted_page))
1298 			end_page_writeback(fio.encrypted_page);
1299 		goto put_page_out;
1300 	}
1301 
1302 	f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
1303 
1304 	f2fs_update_data_blkaddr(&dn, newaddr);
1305 	set_inode_flag(inode, FI_APPEND_WRITE);
1306 	if (page->index == 0)
1307 		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1308 put_page_out:
1309 	f2fs_put_page(fio.encrypted_page, 1);
1310 recover_block:
1311 	if (err)
1312 		f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1313 							true, true, true);
1314 up_out:
1315 	if (lfs_mode)
1316 		up_write(&fio.sbi->io_order_lock);
1317 put_out:
1318 	f2fs_put_dnode(&dn);
1319 out:
1320 	f2fs_put_page(page, 1);
1321 	return err;
1322 }
1323 
move_data_page(struct inode * inode,block_t bidx,int gc_type,unsigned int segno,int off)1324 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1325 							unsigned int segno, int off)
1326 {
1327 	struct page *page;
1328 	int err = 0;
1329 
1330 	page = f2fs_get_lock_data_page(inode, bidx, true);
1331 	if (IS_ERR(page))
1332 		return PTR_ERR(page);
1333 
1334 	if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1335 		err = -ENOENT;
1336 		goto out;
1337 	}
1338 
1339 	if (f2fs_is_atomic_file(inode)) {
1340 		F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1341 		F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1342 		err = -EAGAIN;
1343 		goto out;
1344 	}
1345 	if (f2fs_is_pinned_file(inode)) {
1346 		if (gc_type == FG_GC)
1347 			f2fs_pin_file_control(inode, true);
1348 		err = -EAGAIN;
1349 		goto out;
1350 	}
1351 
1352 	if (gc_type == BG_GC) {
1353 		if (PageWriteback(page)) {
1354 			err = -EAGAIN;
1355 			goto out;
1356 		}
1357 		set_page_dirty(page);
1358 		set_cold_data(page);
1359 	} else {
1360 		struct f2fs_io_info fio = {
1361 			.sbi = F2FS_I_SB(inode),
1362 			.ino = inode->i_ino,
1363 			.type = DATA,
1364 			.temp = COLD,
1365 			.op = REQ_OP_WRITE,
1366 			.op_flags = REQ_SYNC,
1367 			.old_blkaddr = NULL_ADDR,
1368 			.page = page,
1369 			.encrypted_page = NULL,
1370 			.need_lock = LOCK_REQ,
1371 			.io_type = FS_GC_DATA_IO,
1372 		};
1373 		bool is_dirty = PageDirty(page);
1374 
1375 retry:
1376 		f2fs_wait_on_page_writeback(page, DATA, true, true);
1377 
1378 		set_page_dirty(page);
1379 		if (clear_page_dirty_for_io(page)) {
1380 			inode_dec_dirty_pages(inode);
1381 			f2fs_remove_dirty_inode(inode);
1382 		}
1383 
1384 		set_cold_data(page);
1385 
1386 		err = f2fs_do_write_data_page(&fio);
1387 		if (err) {
1388 			clear_cold_data(page);
1389 			if (err == -ENOMEM) {
1390 				congestion_wait(BLK_RW_ASYNC,
1391 						DEFAULT_IO_TIMEOUT);
1392 				goto retry;
1393 			}
1394 			if (is_dirty)
1395 				set_page_dirty(page);
1396 		}
1397 	}
1398 out:
1399 	f2fs_put_page(page, 1);
1400 	return err;
1401 }
1402 
1403 /*
1404  * This function tries to get parent node of victim data block, and identifies
1405  * data block validity. If the block is valid, copy that with cold status and
1406  * modify parent node.
1407  * If the parent node is not valid or the data block address is different,
1408  * the victim data block is ignored.
1409  */
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)1410 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1411 		struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1412 		bool force_migrate)
1413 {
1414 	struct super_block *sb = sbi->sb;
1415 	struct f2fs_summary *entry;
1416 	block_t start_addr;
1417 	int off;
1418 	int phase = 0;
1419 	int submitted = 0;
1420 	unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1421 
1422 	start_addr = START_BLOCK(sbi, segno);
1423 
1424 next_step:
1425 	entry = sum;
1426 
1427 	for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1428 		struct page *data_page;
1429 		struct inode *inode;
1430 		struct node_info dni; /* dnode info for the data */
1431 		unsigned int ofs_in_node, nofs;
1432 		block_t start_bidx;
1433 		nid_t nid = le32_to_cpu(entry->nid);
1434 
1435 		/*
1436 		 * stop BG_GC if there is not enough free sections.
1437 		 * Or, stop GC if the segment becomes fully valid caused by
1438 		 * race condition along with SSR block allocation.
1439 		 */
1440 		if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1441 			(!force_migrate && get_valid_blocks(sbi, segno, true) ==
1442 							BLKS_PER_SEC(sbi)))
1443 			return submitted;
1444 
1445 		if (check_valid_map(sbi, segno, off) == 0)
1446 			continue;
1447 
1448 		if (phase == 0) {
1449 			f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1450 							META_NAT, true);
1451 			continue;
1452 		}
1453 
1454 		if (phase == 1) {
1455 			f2fs_ra_node_page(sbi, nid);
1456 			continue;
1457 		}
1458 
1459 		/* Get an inode by ino with checking validity */
1460 		if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1461 			continue;
1462 
1463 		if (phase == 2) {
1464 			f2fs_ra_node_page(sbi, dni.ino);
1465 			continue;
1466 		}
1467 
1468 		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1469 
1470 		if (phase == 3) {
1471 			inode = f2fs_iget(sb, dni.ino);
1472 			if (IS_ERR(inode) || is_bad_inode(inode) ||
1473 					special_file(inode->i_mode)) {
1474 				set_sbi_flag(sbi, SBI_NEED_FSCK);
1475 				continue;
1476 			}
1477 
1478 			if (!down_write_trylock(
1479 				&F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1480 				iput(inode);
1481 				sbi->skipped_gc_rwsem++;
1482 				continue;
1483 			}
1484 
1485 			start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1486 								ofs_in_node;
1487 
1488 			if (f2fs_post_read_required(inode)) {
1489 				int err = ra_data_block(inode, start_bidx);
1490 
1491 				up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1492 				if (err) {
1493 					iput(inode);
1494 					continue;
1495 				}
1496 				add_gc_inode(gc_list, inode);
1497 				continue;
1498 			}
1499 
1500 			data_page = f2fs_get_read_data_page(inode,
1501 						start_bidx, REQ_RAHEAD, true);
1502 			up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1503 			if (IS_ERR(data_page)) {
1504 				iput(inode);
1505 				continue;
1506 			}
1507 
1508 			f2fs_put_page(data_page, 0);
1509 			add_gc_inode(gc_list, inode);
1510 			continue;
1511 		}
1512 
1513 		/* phase 4 */
1514 		inode = find_gc_inode(gc_list, dni.ino);
1515 		if (inode) {
1516 			struct f2fs_inode_info *fi = F2FS_I(inode);
1517 			bool locked = false;
1518 			int err;
1519 
1520 			if (S_ISREG(inode->i_mode)) {
1521 				if (!down_write_trylock(&fi->i_gc_rwsem[READ])) {
1522 					sbi->skipped_gc_rwsem++;
1523 					continue;
1524 				}
1525 				if (!down_write_trylock(
1526 						&fi->i_gc_rwsem[WRITE])) {
1527 					sbi->skipped_gc_rwsem++;
1528 					up_write(&fi->i_gc_rwsem[READ]);
1529 					continue;
1530 				}
1531 				locked = true;
1532 
1533 				/* wait for all inflight aio data */
1534 				inode_dio_wait(inode);
1535 			}
1536 
1537 			start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1538 								+ ofs_in_node;
1539 			if (f2fs_post_read_required(inode))
1540 				err = move_data_block(inode, start_bidx,
1541 							gc_type, segno, off);
1542 			else
1543 				err = move_data_page(inode, start_bidx, gc_type,
1544 								segno, off);
1545 
1546 			if (!err && (gc_type == FG_GC ||
1547 					f2fs_post_read_required(inode)))
1548 				submitted++;
1549 
1550 			if (locked) {
1551 				up_write(&fi->i_gc_rwsem[WRITE]);
1552 				up_write(&fi->i_gc_rwsem[READ]);
1553 			}
1554 
1555 			stat_inc_data_blk_count(sbi, 1, gc_type);
1556 		}
1557 	}
1558 
1559 	if (++phase < 5)
1560 		goto next_step;
1561 
1562 	return submitted;
1563 }
1564 
__get_victim(struct f2fs_sb_info * sbi,unsigned int * victim,int gc_type)1565 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1566 			int gc_type)
1567 {
1568 	struct sit_info *sit_i = SIT_I(sbi);
1569 	int ret;
1570 
1571 	down_write(&sit_i->sentry_lock);
1572 	ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1573 					      NO_CHECK_TYPE, LFS, 0);
1574 	up_write(&sit_i->sentry_lock);
1575 	return ret;
1576 }
1577 
do_garbage_collect(struct f2fs_sb_info * sbi,unsigned int start_segno,struct gc_inode_list * gc_list,int gc_type,bool force_migrate)1578 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1579 				unsigned int start_segno,
1580 				struct gc_inode_list *gc_list, int gc_type,
1581 				bool force_migrate)
1582 {
1583 	struct page *sum_page;
1584 	struct f2fs_summary_block *sum;
1585 	struct blk_plug plug;
1586 	unsigned int segno = start_segno;
1587 	unsigned int end_segno = start_segno + sbi->segs_per_sec;
1588 	int seg_freed = 0, migrated = 0;
1589 	unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1590 						SUM_TYPE_DATA : SUM_TYPE_NODE;
1591 	int submitted = 0;
1592 
1593 	if (__is_large_section(sbi))
1594 		end_segno = rounddown(end_segno, sbi->segs_per_sec);
1595 
1596 	/*
1597 	 * zone-capacity can be less than zone-size in zoned devices,
1598 	 * resulting in less than expected usable segments in the zone,
1599 	 * calculate the end segno in the zone which can be garbage collected
1600 	 */
1601 	if (f2fs_sb_has_blkzoned(sbi))
1602 		end_segno -= sbi->segs_per_sec -
1603 					f2fs_usable_segs_in_sec(sbi, segno);
1604 
1605 	sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1606 
1607 	/* readahead multi ssa blocks those have contiguous address */
1608 	if (__is_large_section(sbi))
1609 		f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1610 					end_segno - segno, META_SSA, true);
1611 
1612 	/* reference all summary page */
1613 	while (segno < end_segno) {
1614 		sum_page = f2fs_get_sum_page(sbi, segno++);
1615 		if (IS_ERR(sum_page)) {
1616 			int err = PTR_ERR(sum_page);
1617 
1618 			end_segno = segno - 1;
1619 			for (segno = start_segno; segno < end_segno; segno++) {
1620 				sum_page = find_get_page(META_MAPPING(sbi),
1621 						GET_SUM_BLOCK(sbi, segno));
1622 				f2fs_put_page(sum_page, 0);
1623 				f2fs_put_page(sum_page, 0);
1624 			}
1625 			return err;
1626 		}
1627 		unlock_page(sum_page);
1628 	}
1629 
1630 	blk_start_plug(&plug);
1631 
1632 	for (segno = start_segno; segno < end_segno; segno++) {
1633 
1634 		/* find segment summary of victim */
1635 		sum_page = find_get_page(META_MAPPING(sbi),
1636 					GET_SUM_BLOCK(sbi, segno));
1637 		f2fs_put_page(sum_page, 0);
1638 
1639 		if (get_valid_blocks(sbi, segno, false) == 0)
1640 			goto freed;
1641 		if (gc_type == BG_GC && __is_large_section(sbi) &&
1642 				migrated >= sbi->migration_granularity)
1643 			goto skip;
1644 		if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1645 			goto skip;
1646 
1647 		sum = page_address(sum_page);
1648 		if (type != GET_SUM_TYPE((&sum->footer))) {
1649 			f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1650 				 segno, type, GET_SUM_TYPE((&sum->footer)));
1651 			set_sbi_flag(sbi, SBI_NEED_FSCK);
1652 			f2fs_stop_checkpoint(sbi, false);
1653 			goto skip;
1654 		}
1655 
1656 		/*
1657 		 * this is to avoid deadlock:
1658 		 * - lock_page(sum_page)         - f2fs_replace_block
1659 		 *  - check_valid_map()            - down_write(sentry_lock)
1660 		 *   - down_read(sentry_lock)     - change_curseg()
1661 		 *                                  - lock_page(sum_page)
1662 		 */
1663 		if (type == SUM_TYPE_NODE)
1664 			submitted += gc_node_segment(sbi, sum->entries, segno,
1665 								gc_type);
1666 		else
1667 			submitted += gc_data_segment(sbi, sum->entries, gc_list,
1668 							segno, gc_type,
1669 							force_migrate);
1670 
1671 		stat_inc_seg_count(sbi, type, gc_type);
1672 		migrated++;
1673 
1674 freed:
1675 		if (gc_type == FG_GC &&
1676 				get_valid_blocks(sbi, segno, false) == 0)
1677 			seg_freed++;
1678 
1679 		if (__is_large_section(sbi))
1680 			sbi->next_victim_seg[gc_type] =
1681 				(segno + 1 < end_segno) ? segno + 1 : NULL_SEGNO;
1682 skip:
1683 		f2fs_put_page(sum_page, 0);
1684 	}
1685 
1686 	if (submitted)
1687 		f2fs_submit_merged_write(sbi,
1688 				(type == SUM_TYPE_NODE) ? NODE : DATA);
1689 
1690 	blk_finish_plug(&plug);
1691 
1692 	stat_inc_call_count(sbi->stat_info);
1693 
1694 	return seg_freed;
1695 }
1696 
f2fs_gc(struct f2fs_sb_info * sbi,bool sync,bool background,bool force,unsigned int segno)1697 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1698 			bool background, bool force, unsigned int segno)
1699 {
1700 	int gc_type = sync ? FG_GC : BG_GC;
1701 	int sec_freed = 0, seg_freed = 0, total_freed = 0;
1702 	int ret = 0;
1703 	struct cp_control cpc;
1704 	unsigned int init_segno = segno;
1705 	struct gc_inode_list gc_list = {
1706 		.ilist = LIST_HEAD_INIT(gc_list.ilist),
1707 		.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1708 	};
1709 	unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1710 	unsigned long long first_skipped;
1711 	unsigned int skipped_round = 0, round = 0;
1712 
1713 	trace_f2fs_gc_begin(sbi->sb, sync, background,
1714 				get_pages(sbi, F2FS_DIRTY_NODES),
1715 				get_pages(sbi, F2FS_DIRTY_DENTS),
1716 				get_pages(sbi, F2FS_DIRTY_IMETA),
1717 				free_sections(sbi),
1718 				free_segments(sbi),
1719 				reserved_segments(sbi),
1720 				prefree_segments(sbi));
1721 
1722 	cpc.reason = __get_cp_reason(sbi);
1723 	sbi->skipped_gc_rwsem = 0;
1724 	first_skipped = last_skipped;
1725 gc_more:
1726 	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1727 		ret = -EINVAL;
1728 		goto stop;
1729 	}
1730 	if (unlikely(f2fs_cp_error(sbi))) {
1731 		ret = -EIO;
1732 		goto stop;
1733 	}
1734 
1735 	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1736 		/*
1737 		 * For example, if there are many prefree_segments below given
1738 		 * threshold, we can make them free by checkpoint. Then, we
1739 		 * secure free segments which doesn't need fggc any more.
1740 		 */
1741 		if (prefree_segments(sbi) &&
1742 				!is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1743 			ret = f2fs_write_checkpoint(sbi, &cpc);
1744 			if (ret)
1745 				goto stop;
1746 		}
1747 		if (has_not_enough_free_secs(sbi, 0, 0))
1748 			gc_type = FG_GC;
1749 	}
1750 
1751 	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1752 	if (gc_type == BG_GC && !background) {
1753 		ret = -EINVAL;
1754 		goto stop;
1755 	}
1756 	ret = __get_victim(sbi, &segno, gc_type);
1757 	if (ret)
1758 		goto stop;
1759 
1760 	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
1761 	if (gc_type == FG_GC &&
1762 		seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1763 		sec_freed++;
1764 	total_freed += seg_freed;
1765 
1766 	if (gc_type == FG_GC) {
1767 		if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1768 						sbi->skipped_gc_rwsem)
1769 			skipped_round++;
1770 		last_skipped = sbi->skipped_atomic_files[FG_GC];
1771 		round++;
1772 	}
1773 
1774 	if (gc_type == FG_GC && seg_freed)
1775 		sbi->cur_victim_sec = NULL_SEGNO;
1776 
1777 	if (sync)
1778 		goto stop;
1779 
1780 	if (!has_not_enough_free_secs(sbi, sec_freed, 0))
1781 		goto stop;
1782 
1783 	if (skipped_round <= MAX_SKIP_GC_COUNT || skipped_round * 2 < round) {
1784 
1785 		/* Write checkpoint to reclaim prefree segments */
1786 		if (free_sections(sbi) < NR_CURSEG_PERSIST_TYPE &&
1787 				prefree_segments(sbi) &&
1788 				!is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1789 			ret = f2fs_write_checkpoint(sbi, &cpc);
1790 			if (ret)
1791 				goto stop;
1792 		}
1793 		segno = NULL_SEGNO;
1794 		goto gc_more;
1795 	}
1796 	if (first_skipped < last_skipped &&
1797 			(last_skipped - first_skipped) >
1798 					sbi->skipped_gc_rwsem) {
1799 		f2fs_drop_inmem_pages_all(sbi, true);
1800 		segno = NULL_SEGNO;
1801 		goto gc_more;
1802 	}
1803 	if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1804 		ret = f2fs_write_checkpoint(sbi, &cpc);
1805 stop:
1806 	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1807 	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1808 
1809 	trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1810 				get_pages(sbi, F2FS_DIRTY_NODES),
1811 				get_pages(sbi, F2FS_DIRTY_DENTS),
1812 				get_pages(sbi, F2FS_DIRTY_IMETA),
1813 				free_sections(sbi),
1814 				free_segments(sbi),
1815 				reserved_segments(sbi),
1816 				prefree_segments(sbi));
1817 
1818 	up_write(&sbi->gc_lock);
1819 
1820 	put_gc_inode(&gc_list);
1821 
1822 	if (sync && !ret)
1823 		ret = sec_freed ? 0 : -EAGAIN;
1824 	return ret;
1825 }
1826 
f2fs_create_garbage_collection_cache(void)1827 int __init f2fs_create_garbage_collection_cache(void)
1828 {
1829 	victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1830 					sizeof(struct victim_entry));
1831 	if (!victim_entry_slab)
1832 		return -ENOMEM;
1833 	return 0;
1834 }
1835 
f2fs_destroy_garbage_collection_cache(void)1836 void f2fs_destroy_garbage_collection_cache(void)
1837 {
1838 	kmem_cache_destroy(victim_entry_slab);
1839 }
1840 
init_atgc_management(struct f2fs_sb_info * sbi)1841 static void init_atgc_management(struct f2fs_sb_info *sbi)
1842 {
1843 	struct atgc_management *am = &sbi->am;
1844 
1845 	if (test_opt(sbi, ATGC) &&
1846 		SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1847 		am->atgc_enabled = true;
1848 
1849 	am->root = RB_ROOT_CACHED;
1850 	INIT_LIST_HEAD(&am->victim_list);
1851 	am->victim_count = 0;
1852 
1853 	am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1854 	am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1855 	am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1856 	am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1857 }
1858 
f2fs_build_gc_manager(struct f2fs_sb_info * sbi)1859 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1860 {
1861 	DIRTY_I(sbi)->v_ops = &default_v_ops;
1862 
1863 	sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1864 
1865 	/* give warm/cold data area from slower device */
1866 	if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1867 		SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1868 				GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1869 
1870 	init_atgc_management(sbi);
1871 }
1872 
free_segment_range(struct f2fs_sb_info * sbi,unsigned int secs,bool gc_only)1873 static int free_segment_range(struct f2fs_sb_info *sbi,
1874 				unsigned int secs, bool gc_only)
1875 {
1876 	unsigned int segno, next_inuse, start, end;
1877 	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1878 	int gc_mode, gc_type;
1879 	int err = 0;
1880 	int type;
1881 
1882 	/* Force block allocation for GC */
1883 	MAIN_SECS(sbi) -= secs;
1884 	start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1885 	end = MAIN_SEGS(sbi) - 1;
1886 
1887 	mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1888 	for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1889 		if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1890 			SIT_I(sbi)->last_victim[gc_mode] = 0;
1891 
1892 	for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1893 		if (sbi->next_victim_seg[gc_type] >= start)
1894 			sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1895 	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1896 
1897 	/* Move out cursegs from the target range */
1898 	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1899 		f2fs_allocate_segment_for_resize(sbi, type, start, end);
1900 
1901 	/* do GC to move out valid blocks in the range */
1902 	for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1903 		struct gc_inode_list gc_list = {
1904 			.ilist = LIST_HEAD_INIT(gc_list.ilist),
1905 			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1906 		};
1907 
1908 		do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1909 		put_gc_inode(&gc_list);
1910 
1911 		if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1912 			err = -EAGAIN;
1913 			goto out;
1914 		}
1915 		if (fatal_signal_pending(current)) {
1916 			err = -ERESTARTSYS;
1917 			goto out;
1918 		}
1919 	}
1920 	if (gc_only)
1921 		goto out;
1922 
1923 	err = f2fs_write_checkpoint(sbi, &cpc);
1924 	if (err)
1925 		goto out;
1926 
1927 	next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1928 	if (next_inuse <= end) {
1929 		f2fs_err(sbi, "segno %u should be free but still inuse!",
1930 			 next_inuse);
1931 		f2fs_bug_on(sbi, 1);
1932 	}
1933 out:
1934 	MAIN_SECS(sbi) += secs;
1935 	return err;
1936 }
1937 
update_sb_metadata(struct f2fs_sb_info * sbi,int secs)1938 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1939 {
1940 	struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1941 	int section_count;
1942 	int segment_count;
1943 	int segment_count_main;
1944 	long long block_count;
1945 	int segs = secs * sbi->segs_per_sec;
1946 
1947 	down_write(&sbi->sb_lock);
1948 
1949 	section_count = le32_to_cpu(raw_sb->section_count);
1950 	segment_count = le32_to_cpu(raw_sb->segment_count);
1951 	segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1952 	block_count = le64_to_cpu(raw_sb->block_count);
1953 
1954 	raw_sb->section_count = cpu_to_le32(section_count + secs);
1955 	raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1956 	raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1957 	raw_sb->block_count = cpu_to_le64(block_count +
1958 					(long long)segs * sbi->blocks_per_seg);
1959 	if (f2fs_is_multi_device(sbi)) {
1960 		int last_dev = sbi->s_ndevs - 1;
1961 		int dev_segs =
1962 			le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1963 
1964 		raw_sb->devs[last_dev].total_segments =
1965 						cpu_to_le32(dev_segs + segs);
1966 	}
1967 
1968 	up_write(&sbi->sb_lock);
1969 }
1970 
update_fs_metadata(struct f2fs_sb_info * sbi,int secs)1971 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1972 {
1973 	int segs = secs * sbi->segs_per_sec;
1974 	long long blks = (long long)segs * sbi->blocks_per_seg;
1975 	long long user_block_count =
1976 				le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1977 
1978 	SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1979 	MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1980 	MAIN_SECS(sbi) += secs;
1981 	FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1982 	FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1983 	F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1984 
1985 	if (f2fs_is_multi_device(sbi)) {
1986 		int last_dev = sbi->s_ndevs - 1;
1987 
1988 		FDEV(last_dev).total_segments =
1989 				(int)FDEV(last_dev).total_segments + segs;
1990 		FDEV(last_dev).end_blk =
1991 				(long long)FDEV(last_dev).end_blk + blks;
1992 #ifdef CONFIG_BLK_DEV_ZONED
1993 		FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1994 					(int)(blks >> sbi->log_blocks_per_blkz);
1995 #endif
1996 	}
1997 }
1998 
f2fs_resize_fs(struct file * filp,__u64 block_count)1999 int f2fs_resize_fs(struct file *filp, __u64 block_count)
2000 {
2001 	struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
2002 	__u64 old_block_count, shrunk_blocks;
2003 	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2004 	unsigned int secs;
2005 	int err = 0;
2006 	__u32 rem;
2007 
2008 	old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2009 	if (block_count > old_block_count)
2010 		return -EINVAL;
2011 
2012 	if (f2fs_is_multi_device(sbi)) {
2013 		int last_dev = sbi->s_ndevs - 1;
2014 		__u64 last_segs = FDEV(last_dev).total_segments;
2015 
2016 		if (block_count + last_segs * sbi->blocks_per_seg <=
2017 								old_block_count)
2018 			return -EINVAL;
2019 	}
2020 
2021 	/* new fs size should align to section size */
2022 	div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2023 	if (rem)
2024 		return -EINVAL;
2025 
2026 	if (block_count == old_block_count)
2027 		return 0;
2028 
2029 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2030 		f2fs_err(sbi, "Should run fsck to repair first.");
2031 		return -EFSCORRUPTED;
2032 	}
2033 
2034 	if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2035 		f2fs_err(sbi, "Checkpoint should be enabled.");
2036 		return -EINVAL;
2037 	}
2038 
2039 	err = mnt_want_write_file(filp);
2040 	if (err)
2041 		return err;
2042 
2043 	shrunk_blocks = old_block_count - block_count;
2044 	secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2045 
2046 	/* stop other GC */
2047 	if (!down_write_trylock(&sbi->gc_lock)) {
2048 		err = -EAGAIN;
2049 		goto out_drop_write;
2050 	}
2051 
2052 	/* stop CP to protect MAIN_SEC in free_segment_range */
2053 	f2fs_lock_op(sbi);
2054 
2055 	spin_lock(&sbi->stat_lock);
2056 	if (shrunk_blocks + valid_user_blocks(sbi) +
2057 		sbi->current_reserved_blocks + sbi->unusable_block_count +
2058 		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2059 		err = -ENOSPC;
2060 	spin_unlock(&sbi->stat_lock);
2061 
2062 	if (err)
2063 		goto out_unlock;
2064 
2065 	err = free_segment_range(sbi, secs, true);
2066 
2067 out_unlock:
2068 	f2fs_unlock_op(sbi);
2069 	up_write(&sbi->gc_lock);
2070 out_drop_write:
2071 	mnt_drop_write_file(filp);
2072 	if (err)
2073 		return err;
2074 
2075 	freeze_super(sbi->sb);
2076 
2077 	if (f2fs_readonly(sbi->sb)) {
2078 		thaw_super(sbi->sb);
2079 		return -EROFS;
2080 	}
2081 
2082 	down_write(&sbi->gc_lock);
2083 	mutex_lock(&sbi->cp_mutex);
2084 
2085 	spin_lock(&sbi->stat_lock);
2086 	if (shrunk_blocks + valid_user_blocks(sbi) +
2087 		sbi->current_reserved_blocks + sbi->unusable_block_count +
2088 		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2089 		err = -ENOSPC;
2090 	else
2091 		sbi->user_block_count -= shrunk_blocks;
2092 	spin_unlock(&sbi->stat_lock);
2093 	if (err)
2094 		goto out_err;
2095 
2096 	set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2097 	err = free_segment_range(sbi, secs, false);
2098 	if (err)
2099 		goto recover_out;
2100 
2101 	update_sb_metadata(sbi, -secs);
2102 
2103 	err = f2fs_commit_super(sbi, false);
2104 	if (err) {
2105 		update_sb_metadata(sbi, secs);
2106 		goto recover_out;
2107 	}
2108 
2109 	update_fs_metadata(sbi, -secs);
2110 	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2111 	set_sbi_flag(sbi, SBI_IS_DIRTY);
2112 
2113 	err = f2fs_write_checkpoint(sbi, &cpc);
2114 	if (err) {
2115 		update_fs_metadata(sbi, secs);
2116 		update_sb_metadata(sbi, secs);
2117 		f2fs_commit_super(sbi, false);
2118 	}
2119 recover_out:
2120 	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2121 	if (err) {
2122 		set_sbi_flag(sbi, SBI_NEED_FSCK);
2123 		f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2124 
2125 		spin_lock(&sbi->stat_lock);
2126 		sbi->user_block_count += shrunk_blocks;
2127 		spin_unlock(&sbi->stat_lock);
2128 	}
2129 out_err:
2130 	mutex_unlock(&sbi->cp_mutex);
2131 	up_write(&sbi->gc_lock);
2132 	thaw_super(sbi->sb);
2133 	return err;
2134 }
2135