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  1/*
  2 * fs/f2fs/gc.c
  3 *
  4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
  5 *             http://www.samsung.com/
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 */
 11#include <linux/fs.h>
 12#include <linux/module.h>
 13#include <linux/backing-dev.h>
 14#include <linux/init.h>
 15#include <linux/f2fs_fs.h>
 16#include <linux/kthread.h>
 17#include <linux/delay.h>
 18#include <linux/freezer.h>
 19#include <linux/blkdev.h>
 20
 21#include "f2fs.h"
 22#include "node.h"
 23#include "segment.h"
 24#include "gc.h"
 25#include <trace/events/f2fs.h>
 26
 27static struct kmem_cache *winode_slab;
 28
 29static int gc_thread_func(void *data)
 30{
 31	struct f2fs_sb_info *sbi = data;
 32	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 33	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
 34	long wait_ms;
 35
 36	wait_ms = gc_th->min_sleep_time;
 37
 38	do {
 39		if (try_to_freeze())
 40			continue;
 41		else
 42			wait_event_interruptible_timeout(*wq,
 43						kthread_should_stop(),
 44						msecs_to_jiffies(wait_ms));
 45		if (kthread_should_stop())
 46			break;
 47
 48		if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
 49			wait_ms = increase_sleep_time(gc_th, wait_ms);
 50			continue;
 51		}
 52
 53		/*
 54		 * [GC triggering condition]
 55		 * 0. GC is not conducted currently.
 56		 * 1. There are enough dirty segments.
 57		 * 2. IO subsystem is idle by checking the # of writeback pages.
 58		 * 3. IO subsystem is idle by checking the # of requests in
 59		 *    bdev's request list.
 60		 *
 61		 * Note) We have to avoid triggering GCs too much frequently.
 62		 * Because it is possible that some segments can be
 63		 * invalidated soon after by user update or deletion.
 64		 * So, I'd like to wait some time to collect dirty segments.
 65		 */
 66		if (!mutex_trylock(&sbi->gc_mutex))
 67			continue;
 68
 69		if (!is_idle(sbi)) {
 70			wait_ms = increase_sleep_time(gc_th, wait_ms);
 71			mutex_unlock(&sbi->gc_mutex);
 72			continue;
 73		}
 74
 75		if (has_enough_invalid_blocks(sbi))
 76			wait_ms = decrease_sleep_time(gc_th, wait_ms);
 77		else
 78			wait_ms = increase_sleep_time(gc_th, wait_ms);
 79
 80		stat_inc_bggc_count(sbi);
 81
 82		/* if return value is not zero, no victim was selected */
 83		if (f2fs_gc(sbi))
 84			wait_ms = gc_th->no_gc_sleep_time;
 85
 86		/* balancing f2fs's metadata periodically */
 87		f2fs_balance_fs_bg(sbi);
 88
 89	} while (!kthread_should_stop());
 90	return 0;
 91}
 92
 93int start_gc_thread(struct f2fs_sb_info *sbi)
 94{
 95	struct f2fs_gc_kthread *gc_th;
 96	dev_t dev = sbi->sb->s_bdev->bd_dev;
 97	int err = 0;
 98
 99	if (!test_opt(sbi, BG_GC))
100		goto out;
101	gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
102	if (!gc_th) {
103		err = -ENOMEM;
104		goto out;
105	}
106
107	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
108	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
109	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
110
111	gc_th->gc_idle = 0;
112
113	sbi->gc_thread = gc_th;
114	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
115	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
116			"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
117	if (IS_ERR(gc_th->f2fs_gc_task)) {
118		err = PTR_ERR(gc_th->f2fs_gc_task);
119		kfree(gc_th);
120		sbi->gc_thread = NULL;
121	}
122out:
123	return err;
124}
125
126void stop_gc_thread(struct f2fs_sb_info *sbi)
127{
128	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
129	if (!gc_th)
130		return;
131	kthread_stop(gc_th->f2fs_gc_task);
132	kfree(gc_th);
133	sbi->gc_thread = NULL;
134}
135
136static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
137{
138	int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
139
140	if (gc_th && gc_th->gc_idle) {
141		if (gc_th->gc_idle == 1)
142			gc_mode = GC_CB;
143		else if (gc_th->gc_idle == 2)
144			gc_mode = GC_GREEDY;
145	}
146	return gc_mode;
147}
148
149static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
150			int type, struct victim_sel_policy *p)
151{
152	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
153
154	if (p->alloc_mode == SSR) {
155		p->gc_mode = GC_GREEDY;
156		p->dirty_segmap = dirty_i->dirty_segmap[type];
157		p->max_search = dirty_i->nr_dirty[type];
158		p->ofs_unit = 1;
159	} else {
160		p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
161		p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
162		p->max_search = dirty_i->nr_dirty[DIRTY];
163		p->ofs_unit = sbi->segs_per_sec;
164	}
165
166	if (p->max_search > sbi->max_victim_search)
167		p->max_search = sbi->max_victim_search;
168
169	p->offset = sbi->last_victim[p->gc_mode];
170}
171
172static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
173				struct victim_sel_policy *p)
174{
175	/* SSR allocates in a segment unit */
176	if (p->alloc_mode == SSR)
177		return 1 << sbi->log_blocks_per_seg;
178	if (p->gc_mode == GC_GREEDY)
179		return (1 << sbi->log_blocks_per_seg) * p->ofs_unit;
180	else if (p->gc_mode == GC_CB)
181		return UINT_MAX;
182	else /* No other gc_mode */
183		return 0;
184}
185
186static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
187{
188	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
189	unsigned int hint = 0;
190	unsigned int secno;
191
192	/*
193	 * If the gc_type is FG_GC, we can select victim segments
194	 * selected by background GC before.
195	 * Those segments guarantee they have small valid blocks.
196	 */
197next:
198	secno = find_next_bit(dirty_i->victim_secmap, TOTAL_SECS(sbi), hint++);
199	if (secno < TOTAL_SECS(sbi)) {
200		if (sec_usage_check(sbi, secno))
201			goto next;
202		clear_bit(secno, dirty_i->victim_secmap);
203		return secno * sbi->segs_per_sec;
204	}
205	return NULL_SEGNO;
206}
207
208static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
209{
210	struct sit_info *sit_i = SIT_I(sbi);
211	unsigned int secno = GET_SECNO(sbi, segno);
212	unsigned int start = secno * sbi->segs_per_sec;
213	unsigned long long mtime = 0;
214	unsigned int vblocks;
215	unsigned char age = 0;
216	unsigned char u;
217	unsigned int i;
218
219	for (i = 0; i < sbi->segs_per_sec; i++)
220		mtime += get_seg_entry(sbi, start + i)->mtime;
221	vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
222
223	mtime = div_u64(mtime, sbi->segs_per_sec);
224	vblocks = div_u64(vblocks, sbi->segs_per_sec);
225
226	u = (vblocks * 100) >> sbi->log_blocks_per_seg;
227
228	/* Handle if the system time is changed by user */
229	if (mtime < sit_i->min_mtime)
230		sit_i->min_mtime = mtime;
231	if (mtime > sit_i->max_mtime)
232		sit_i->max_mtime = mtime;
233	if (sit_i->max_mtime != sit_i->min_mtime)
234		age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
235				sit_i->max_mtime - sit_i->min_mtime);
236
237	return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
238}
239
240static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
241			unsigned int segno, struct victim_sel_policy *p)
242{
243	if (p->alloc_mode == SSR)
244		return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
245
246	/* alloc_mode == LFS */
247	if (p->gc_mode == GC_GREEDY)
248		return get_valid_blocks(sbi, segno, sbi->segs_per_sec);
249	else
250		return get_cb_cost(sbi, segno);
251}
252
253/*
254 * This function is called from two paths.
255 * One is garbage collection and the other is SSR segment selection.
256 * When it is called during GC, it just gets a victim segment
257 * and it does not remove it from dirty seglist.
258 * When it is called from SSR segment selection, it finds a segment
259 * which has minimum valid blocks and removes it from dirty seglist.
260 */
261static int get_victim_by_default(struct f2fs_sb_info *sbi,
262		unsigned int *result, int gc_type, int type, char alloc_mode)
263{
264	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
265	struct victim_sel_policy p;
266	unsigned int secno, max_cost;
267	int nsearched = 0;
268
269	p.alloc_mode = alloc_mode;
270	select_policy(sbi, gc_type, type, &p);
271
272	p.min_segno = NULL_SEGNO;
273	p.min_cost = max_cost = get_max_cost(sbi, &p);
274
275	mutex_lock(&dirty_i->seglist_lock);
276
277	if (p.alloc_mode == LFS && gc_type == FG_GC) {
278		p.min_segno = check_bg_victims(sbi);
279		if (p.min_segno != NULL_SEGNO)
280			goto got_it;
281	}
282
283	while (1) {
284		unsigned long cost;
285		unsigned int segno;
286
287		segno = find_next_bit(p.dirty_segmap,
288						TOTAL_SEGS(sbi), p.offset);
289		if (segno >= TOTAL_SEGS(sbi)) {
290			if (sbi->last_victim[p.gc_mode]) {
291				sbi->last_victim[p.gc_mode] = 0;
292				p.offset = 0;
293				continue;
294			}
295			break;
296		}
297
298		p.offset = segno + p.ofs_unit;
299		if (p.ofs_unit > 1)
300			p.offset -= segno % p.ofs_unit;
301
302		secno = GET_SECNO(sbi, segno);
303
304		if (sec_usage_check(sbi, secno))
305			continue;
306		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
307			continue;
308
309		cost = get_gc_cost(sbi, segno, &p);
310
311		if (p.min_cost > cost) {
312			p.min_segno = segno;
313			p.min_cost = cost;
314		} else if (unlikely(cost == max_cost)) {
315			continue;
316		}
317
318		if (nsearched++ >= p.max_search) {
319			sbi->last_victim[p.gc_mode] = segno;
320			break;
321		}
322	}
323	if (p.min_segno != NULL_SEGNO) {
324got_it:
325		if (p.alloc_mode == LFS) {
326			secno = GET_SECNO(sbi, p.min_segno);
327			if (gc_type == FG_GC)
328				sbi->cur_victim_sec = secno;
329			else
330				set_bit(secno, dirty_i->victim_secmap);
331		}
332		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
333
334		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
335				sbi->cur_victim_sec,
336				prefree_segments(sbi), free_segments(sbi));
337	}
338	mutex_unlock(&dirty_i->seglist_lock);
339
340	return (p.min_segno == NULL_SEGNO) ? 0 : 1;
341}
342
343static const struct victim_selection default_v_ops = {
344	.get_victim = get_victim_by_default,
345};
346
347static struct inode *find_gc_inode(nid_t ino, struct list_head *ilist)
348{
349	struct inode_entry *ie;
350
351	list_for_each_entry(ie, ilist, list)
352		if (ie->inode->i_ino == ino)
353			return ie->inode;
354	return NULL;
355}
356
357static void add_gc_inode(struct inode *inode, struct list_head *ilist)
358{
359	struct inode_entry *new_ie;
360
361	if (inode == find_gc_inode(inode->i_ino, ilist)) {
362		iput(inode);
363		return;
364	}
365
366	new_ie = f2fs_kmem_cache_alloc(winode_slab, GFP_NOFS);
367	new_ie->inode = inode;
368	list_add_tail(&new_ie->list, ilist);
369}
370
371static void put_gc_inode(struct list_head *ilist)
372{
373	struct inode_entry *ie, *next_ie;
374	list_for_each_entry_safe(ie, next_ie, ilist, list) {
375		iput(ie->inode);
376		list_del(&ie->list);
377		kmem_cache_free(winode_slab, ie);
378	}
379}
380
381static int check_valid_map(struct f2fs_sb_info *sbi,
382				unsigned int segno, int offset)
383{
384	struct sit_info *sit_i = SIT_I(sbi);
385	struct seg_entry *sentry;
386	int ret;
387
388	mutex_lock(&sit_i->sentry_lock);
389	sentry = get_seg_entry(sbi, segno);
390	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
391	mutex_unlock(&sit_i->sentry_lock);
392	return ret;
393}
394
395/*
396 * This function compares node address got in summary with that in NAT.
397 * On validity, copy that node with cold status, otherwise (invalid node)
398 * ignore that.
399 */
400static void gc_node_segment(struct f2fs_sb_info *sbi,
401		struct f2fs_summary *sum, unsigned int segno, int gc_type)
402{
403	bool initial = true;
404	struct f2fs_summary *entry;
405	int off;
406
407next_step:
408	entry = sum;
409
410	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
411		nid_t nid = le32_to_cpu(entry->nid);
412		struct page *node_page;
413
414		/* stop BG_GC if there is not enough free sections. */
415		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
416			return;
417
418		if (check_valid_map(sbi, segno, off) == 0)
419			continue;
420
421		if (initial) {
422			ra_node_page(sbi, nid);
423			continue;
424		}
425		node_page = get_node_page(sbi, nid);
426		if (IS_ERR(node_page))
427			continue;
428
429		/* set page dirty and write it */
430		if (gc_type == FG_GC) {
431			f2fs_wait_on_page_writeback(node_page, NODE);
432			set_page_dirty(node_page);
433		} else {
434			if (!PageWriteback(node_page))
435				set_page_dirty(node_page);
436		}
437		f2fs_put_page(node_page, 1);
438		stat_inc_node_blk_count(sbi, 1);
439	}
440
441	if (initial) {
442		initial = false;
443		goto next_step;
444	}
445
446	if (gc_type == FG_GC) {
447		struct writeback_control wbc = {
448			.sync_mode = WB_SYNC_ALL,
449			.nr_to_write = LONG_MAX,
450			.for_reclaim = 0,
451		};
452		sync_node_pages(sbi, 0, &wbc);
453
454		/*
455		 * In the case of FG_GC, it'd be better to reclaim this victim
456		 * completely.
457		 */
458		if (get_valid_blocks(sbi, segno, 1) != 0)
459			goto next_step;
460	}
461}
462
463/*
464 * Calculate start block index indicating the given node offset.
465 * Be careful, caller should give this node offset only indicating direct node
466 * blocks. If any node offsets, which point the other types of node blocks such
467 * as indirect or double indirect node blocks, are given, it must be a caller's
468 * bug.
469 */
470block_t start_bidx_of_node(unsigned int node_ofs, struct f2fs_inode_info *fi)
471{
472	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
473	unsigned int bidx;
474
475	if (node_ofs == 0)
476		return 0;
477
478	if (node_ofs <= 2) {
479		bidx = node_ofs - 1;
480	} else if (node_ofs <= indirect_blks) {
481		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
482		bidx = node_ofs - 2 - dec;
483	} else {
484		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
485		bidx = node_ofs - 5 - dec;
486	}
487	return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi);
488}
489
490static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
491		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
492{
493	struct page *node_page;
494	nid_t nid;
495	unsigned int ofs_in_node;
496	block_t source_blkaddr;
497
498	nid = le32_to_cpu(sum->nid);
499	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
500
501	node_page = get_node_page(sbi, nid);
502	if (IS_ERR(node_page))
503		return 0;
504
505	get_node_info(sbi, nid, dni);
506
507	if (sum->version != dni->version) {
508		f2fs_put_page(node_page, 1);
509		return 0;
510	}
511
512	*nofs = ofs_of_node(node_page);
513	source_blkaddr = datablock_addr(node_page, ofs_in_node);
514	f2fs_put_page(node_page, 1);
515
516	if (source_blkaddr != blkaddr)
517		return 0;
518	return 1;
519}
520
521static void move_data_page(struct inode *inode, struct page *page, int gc_type)
522{
523	struct f2fs_io_info fio = {
524		.type = DATA,
525		.rw = WRITE_SYNC,
526	};
527
528	if (gc_type == BG_GC) {
529		if (PageWriteback(page))
530			goto out;
531		set_page_dirty(page);
532		set_cold_data(page);
533	} else {
534		f2fs_wait_on_page_writeback(page, DATA);
535
536		if (clear_page_dirty_for_io(page))
537			inode_dec_dirty_dents(inode);
538		set_cold_data(page);
539		do_write_data_page(page, &fio);
540		clear_cold_data(page);
541	}
542out:
543	f2fs_put_page(page, 1);
544}
545
546/*
547 * This function tries to get parent node of victim data block, and identifies
548 * data block validity. If the block is valid, copy that with cold status and
549 * modify parent node.
550 * If the parent node is not valid or the data block address is different,
551 * the victim data block is ignored.
552 */
553static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
554		struct list_head *ilist, unsigned int segno, int gc_type)
555{
556	struct super_block *sb = sbi->sb;
557	struct f2fs_summary *entry;
558	block_t start_addr;
559	int off;
560	int phase = 0;
561
562	start_addr = START_BLOCK(sbi, segno);
563
564next_step:
565	entry = sum;
566
567	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
568		struct page *data_page;
569		struct inode *inode;
570		struct node_info dni; /* dnode info for the data */
571		unsigned int ofs_in_node, nofs;
572		block_t start_bidx;
573
574		/* stop BG_GC if there is not enough free sections. */
575		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
576			return;
577
578		if (check_valid_map(sbi, segno, off) == 0)
579			continue;
580
581		if (phase == 0) {
582			ra_node_page(sbi, le32_to_cpu(entry->nid));
583			continue;
584		}
585
586		/* Get an inode by ino with checking validity */
587		if (check_dnode(sbi, entry, &dni, start_addr + off, &nofs) == 0)
588			continue;
589
590		if (phase == 1) {
591			ra_node_page(sbi, dni.ino);
592			continue;
593		}
594
595		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
596
597		if (phase == 2) {
598			inode = f2fs_iget(sb, dni.ino);
599			if (IS_ERR(inode))
600				continue;
601
602			start_bidx = start_bidx_of_node(nofs, F2FS_I(inode));
603
604			data_page = find_data_page(inode,
605					start_bidx + ofs_in_node, false);
606			if (IS_ERR(data_page))
607				goto next_iput;
608
609			f2fs_put_page(data_page, 0);
610			add_gc_inode(inode, ilist);
611		} else {
612			inode = find_gc_inode(dni.ino, ilist);
613			if (inode) {
614				start_bidx = start_bidx_of_node(nofs,
615								F2FS_I(inode));
616				data_page = get_lock_data_page(inode,
617						start_bidx + ofs_in_node);
618				if (IS_ERR(data_page))
619					continue;
620				move_data_page(inode, data_page, gc_type);
621				stat_inc_data_blk_count(sbi, 1);
622			}
623		}
624		continue;
625next_iput:
626		iput(inode);
627	}
628
629	if (++phase < 4)
630		goto next_step;
631
632	if (gc_type == FG_GC) {
633		f2fs_submit_merged_bio(sbi, DATA, WRITE);
634
635		/*
636		 * In the case of FG_GC, it'd be better to reclaim this victim
637		 * completely.
638		 */
639		if (get_valid_blocks(sbi, segno, 1) != 0) {
640			phase = 2;
641			goto next_step;
642		}
643	}
644}
645
646static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
647						int gc_type, int type)
648{
649	struct sit_info *sit_i = SIT_I(sbi);
650	int ret;
651	mutex_lock(&sit_i->sentry_lock);
652	ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, type, LFS);
653	mutex_unlock(&sit_i->sentry_lock);
654	return ret;
655}
656
657static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
658				struct list_head *ilist, int gc_type)
659{
660	struct page *sum_page;
661	struct f2fs_summary_block *sum;
662	struct blk_plug plug;
663
664	/* read segment summary of victim */
665	sum_page = get_sum_page(sbi, segno);
666
667	blk_start_plug(&plug);
668
669	sum = page_address(sum_page);
670
671	switch (GET_SUM_TYPE((&sum->footer))) {
672	case SUM_TYPE_NODE:
673		gc_node_segment(sbi, sum->entries, segno, gc_type);
674		break;
675	case SUM_TYPE_DATA:
676		gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
677		break;
678	}
679	blk_finish_plug(&plug);
680
681	stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
682	stat_inc_call_count(sbi->stat_info);
683
684	f2fs_put_page(sum_page, 1);
685}
686
687int f2fs_gc(struct f2fs_sb_info *sbi)
688{
689	struct list_head ilist;
690	unsigned int segno, i;
691	int gc_type = BG_GC;
692	int nfree = 0;
693	int ret = -1;
694
695	INIT_LIST_HEAD(&ilist);
696gc_more:
697	if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE)))
698		goto stop;
699	if (unlikely(is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)))
700		goto stop;
701
702	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) {
703		gc_type = FG_GC;
704		write_checkpoint(sbi, false);
705	}
706
707	if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
708		goto stop;
709	ret = 0;
710
711	/* readahead multi ssa blocks those have contiguous address */
712	if (sbi->segs_per_sec > 1)
713		ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), sbi->segs_per_sec,
714								META_SSA);
715
716	for (i = 0; i < sbi->segs_per_sec; i++)
717		do_garbage_collect(sbi, segno + i, &ilist, gc_type);
718
719	if (gc_type == FG_GC) {
720		sbi->cur_victim_sec = NULL_SEGNO;
721		nfree++;
722		WARN_ON(get_valid_blocks(sbi, segno, sbi->segs_per_sec));
723	}
724
725	if (has_not_enough_free_secs(sbi, nfree))
726		goto gc_more;
727
728	if (gc_type == FG_GC)
729		write_checkpoint(sbi, false);
730stop:
731	mutex_unlock(&sbi->gc_mutex);
732
733	put_gc_inode(&ilist);
734	return ret;
735}
736
737void build_gc_manager(struct f2fs_sb_info *sbi)
738{
739	DIRTY_I(sbi)->v_ops = &default_v_ops;
740}
741
742int __init create_gc_caches(void)
743{
744	winode_slab = f2fs_kmem_cache_create("f2fs_gc_inodes",
745			sizeof(struct inode_entry));
746	if (!winode_slab)
747		return -ENOMEM;
748	return 0;
749}
750
751void destroy_gc_caches(void)
752{
753	kmem_cache_destroy(winode_slab);
754}