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