xref: /openbmc/linux/fs/f2fs/gc.c (revision 7bd59381c82defe19875284c48b1ac9dacd16e8f)
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 
27 static struct kmem_cache *winode_slab;
28 
29 static 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 #ifdef CONFIG_F2FS_STAT_FS
81 		sbi->bg_gc++;
82 #endif
83 
84 		/* if return value is not zero, no victim was selected */
85 		if (f2fs_gc(sbi))
86 			wait_ms = gc_th->no_gc_sleep_time;
87 	} while (!kthread_should_stop());
88 	return 0;
89 }
90 
91 int start_gc_thread(struct f2fs_sb_info *sbi)
92 {
93 	struct f2fs_gc_kthread *gc_th;
94 	dev_t dev = sbi->sb->s_bdev->bd_dev;
95 	int err = 0;
96 
97 	if (!test_opt(sbi, BG_GC))
98 		goto out;
99 	gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
100 	if (!gc_th) {
101 		err = -ENOMEM;
102 		goto out;
103 	}
104 
105 	gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
106 	gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
107 	gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
108 
109 	gc_th->gc_idle = 0;
110 
111 	sbi->gc_thread = gc_th;
112 	init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
113 	sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
114 			"f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
115 	if (IS_ERR(gc_th->f2fs_gc_task)) {
116 		err = PTR_ERR(gc_th->f2fs_gc_task);
117 		kfree(gc_th);
118 		sbi->gc_thread = NULL;
119 	}
120 
121 out:
122 	return err;
123 }
124 
125 void stop_gc_thread(struct f2fs_sb_info *sbi)
126 {
127 	struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
128 	if (!gc_th)
129 		return;
130 	kthread_stop(gc_th->f2fs_gc_task);
131 	kfree(gc_th);
132 	sbi->gc_thread = NULL;
133 }
134 
135 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
136 {
137 	int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
138 
139 	if (gc_th && gc_th->gc_idle) {
140 		if (gc_th->gc_idle == 1)
141 			gc_mode = GC_CB;
142 		else if (gc_th->gc_idle == 2)
143 			gc_mode = GC_GREEDY;
144 	}
145 	return gc_mode;
146 }
147 
148 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
149 			int type, struct victim_sel_policy *p)
150 {
151 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
152 
153 	if (p->alloc_mode == SSR) {
154 		p->gc_mode = GC_GREEDY;
155 		p->dirty_segmap = dirty_i->dirty_segmap[type];
156 		p->max_search = dirty_i->nr_dirty[type];
157 		p->ofs_unit = 1;
158 	} else {
159 		p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
160 		p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
161 		p->max_search = dirty_i->nr_dirty[DIRTY];
162 		p->ofs_unit = sbi->segs_per_sec;
163 	}
164 
165 	if (p->max_search > MAX_VICTIM_SEARCH)
166 		p->max_search = MAX_VICTIM_SEARCH;
167 
168 	p->offset = sbi->last_victim[p->gc_mode];
169 }
170 
171 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
172 				struct victim_sel_policy *p)
173 {
174 	/* SSR allocates in a segment unit */
175 	if (p->alloc_mode == SSR)
176 		return 1 << sbi->log_blocks_per_seg;
177 	if (p->gc_mode == GC_GREEDY)
178 		return (1 << sbi->log_blocks_per_seg) * p->ofs_unit;
179 	else if (p->gc_mode == GC_CB)
180 		return UINT_MAX;
181 	else /* No other gc_mode */
182 		return 0;
183 }
184 
185 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
186 {
187 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
188 	unsigned int hint = 0;
189 	unsigned int secno;
190 
191 	/*
192 	 * If the gc_type is FG_GC, we can select victim segments
193 	 * selected by background GC before.
194 	 * Those segments guarantee they have small valid blocks.
195 	 */
196 next:
197 	secno = find_next_bit(dirty_i->victim_secmap, TOTAL_SECS(sbi), hint++);
198 	if (secno < TOTAL_SECS(sbi)) {
199 		if (sec_usage_check(sbi, secno))
200 			goto next;
201 		clear_bit(secno, dirty_i->victim_secmap);
202 		return secno * sbi->segs_per_sec;
203 	}
204 	return NULL_SEGNO;
205 }
206 
207 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
208 {
209 	struct sit_info *sit_i = SIT_I(sbi);
210 	unsigned int secno = GET_SECNO(sbi, segno);
211 	unsigned int start = secno * sbi->segs_per_sec;
212 	unsigned long long mtime = 0;
213 	unsigned int vblocks;
214 	unsigned char age = 0;
215 	unsigned char u;
216 	unsigned int i;
217 
218 	for (i = 0; i < sbi->segs_per_sec; i++)
219 		mtime += get_seg_entry(sbi, start + i)->mtime;
220 	vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
221 
222 	mtime = div_u64(mtime, sbi->segs_per_sec);
223 	vblocks = div_u64(vblocks, sbi->segs_per_sec);
224 
225 	u = (vblocks * 100) >> sbi->log_blocks_per_seg;
226 
227 	/* Handle if the system time is changed by user */
228 	if (mtime < sit_i->min_mtime)
229 		sit_i->min_mtime = mtime;
230 	if (mtime > sit_i->max_mtime)
231 		sit_i->max_mtime = mtime;
232 	if (sit_i->max_mtime != sit_i->min_mtime)
233 		age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
234 				sit_i->max_mtime - sit_i->min_mtime);
235 
236 	return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
237 }
238 
239 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
240 			unsigned int segno, struct victim_sel_policy *p)
241 {
242 	if (p->alloc_mode == SSR)
243 		return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
244 
245 	/* alloc_mode == LFS */
246 	if (p->gc_mode == GC_GREEDY)
247 		return get_valid_blocks(sbi, segno, sbi->segs_per_sec);
248 	else
249 		return get_cb_cost(sbi, segno);
250 }
251 
252 /*
253  * This function is called from two paths.
254  * One is garbage collection and the other is SSR segment selection.
255  * When it is called during GC, it just gets a victim segment
256  * and it does not remove it from dirty seglist.
257  * When it is called from SSR segment selection, it finds a segment
258  * which has minimum valid blocks and removes it from dirty seglist.
259  */
260 static int get_victim_by_default(struct f2fs_sb_info *sbi,
261 		unsigned int *result, int gc_type, int type, char alloc_mode)
262 {
263 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
264 	struct victim_sel_policy p;
265 	unsigned int secno, max_cost;
266 	int nsearched = 0;
267 
268 	p.alloc_mode = alloc_mode;
269 	select_policy(sbi, gc_type, type, &p);
270 
271 	p.min_segno = NULL_SEGNO;
272 	p.min_cost = max_cost = get_max_cost(sbi, &p);
273 
274 	mutex_lock(&dirty_i->seglist_lock);
275 
276 	if (p.alloc_mode == LFS && gc_type == FG_GC) {
277 		p.min_segno = check_bg_victims(sbi);
278 		if (p.min_segno != NULL_SEGNO)
279 			goto got_it;
280 	}
281 
282 	while (1) {
283 		unsigned long cost;
284 		unsigned int segno;
285 
286 		segno = find_next_bit(p.dirty_segmap,
287 						TOTAL_SEGS(sbi), p.offset);
288 		if (segno >= TOTAL_SEGS(sbi)) {
289 			if (sbi->last_victim[p.gc_mode]) {
290 				sbi->last_victim[p.gc_mode] = 0;
291 				p.offset = 0;
292 				continue;
293 			}
294 			break;
295 		}
296 
297 		p.offset = segno + p.ofs_unit;
298 		if (p.ofs_unit > 1)
299 			p.offset -= segno % p.ofs_unit;
300 
301 		secno = GET_SECNO(sbi, segno);
302 
303 		if (sec_usage_check(sbi, secno))
304 			continue;
305 		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
306 			continue;
307 
308 		cost = get_gc_cost(sbi, segno, &p);
309 
310 		if (p.min_cost > cost) {
311 			p.min_segno = segno;
312 			p.min_cost = cost;
313 		} else if (unlikely(cost == max_cost)) {
314 			continue;
315 		}
316 
317 		if (nsearched++ >= p.max_search) {
318 			sbi->last_victim[p.gc_mode] = segno;
319 			break;
320 		}
321 	}
322 	if (p.min_segno != NULL_SEGNO) {
323 got_it:
324 		if (p.alloc_mode == LFS) {
325 			secno = GET_SECNO(sbi, p.min_segno);
326 			if (gc_type == FG_GC)
327 				sbi->cur_victim_sec = secno;
328 			else
329 				set_bit(secno, dirty_i->victim_secmap);
330 		}
331 		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
332 
333 		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
334 				sbi->cur_victim_sec,
335 				prefree_segments(sbi), free_segments(sbi));
336 	}
337 	mutex_unlock(&dirty_i->seglist_lock);
338 
339 	return (p.min_segno == NULL_SEGNO) ? 0 : 1;
340 }
341 
342 static const struct victim_selection default_v_ops = {
343 	.get_victim = get_victim_by_default,
344 };
345 
346 static struct inode *find_gc_inode(nid_t ino, struct list_head *ilist)
347 {
348 	struct inode_entry *ie;
349 
350 	list_for_each_entry(ie, ilist, list)
351 		if (ie->inode->i_ino == ino)
352 			return ie->inode;
353 	return NULL;
354 }
355 
356 static void add_gc_inode(struct inode *inode, struct list_head *ilist)
357 {
358 	struct inode_entry *new_ie;
359 
360 	if (inode == find_gc_inode(inode->i_ino, ilist)) {
361 		iput(inode);
362 		return;
363 	}
364 
365 	new_ie = f2fs_kmem_cache_alloc(winode_slab, GFP_NOFS);
366 	new_ie->inode = inode;
367 	list_add_tail(&new_ie->list, ilist);
368 }
369 
370 static void put_gc_inode(struct list_head *ilist)
371 {
372 	struct inode_entry *ie, *next_ie;
373 	list_for_each_entry_safe(ie, next_ie, ilist, list) {
374 		iput(ie->inode);
375 		list_del(&ie->list);
376 		kmem_cache_free(winode_slab, ie);
377 	}
378 }
379 
380 static int check_valid_map(struct f2fs_sb_info *sbi,
381 				unsigned int segno, int offset)
382 {
383 	struct sit_info *sit_i = SIT_I(sbi);
384 	struct seg_entry *sentry;
385 	int ret;
386 
387 	mutex_lock(&sit_i->sentry_lock);
388 	sentry = get_seg_entry(sbi, segno);
389 	ret = f2fs_test_bit(offset, sentry->cur_valid_map);
390 	mutex_unlock(&sit_i->sentry_lock);
391 	return ret;
392 }
393 
394 /*
395  * This function compares node address got in summary with that in NAT.
396  * On validity, copy that node with cold status, otherwise (invalid node)
397  * ignore that.
398  */
399 static void gc_node_segment(struct f2fs_sb_info *sbi,
400 		struct f2fs_summary *sum, unsigned int segno, int gc_type)
401 {
402 	bool initial = true;
403 	struct f2fs_summary *entry;
404 	int off;
405 
406 next_step:
407 	entry = sum;
408 
409 	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
410 		nid_t nid = le32_to_cpu(entry->nid);
411 		struct page *node_page;
412 
413 		/* stop BG_GC if there is not enough free sections. */
414 		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
415 			return;
416 
417 		if (check_valid_map(sbi, segno, off) == 0)
418 			continue;
419 
420 		if (initial) {
421 			ra_node_page(sbi, nid);
422 			continue;
423 		}
424 		node_page = get_node_page(sbi, nid);
425 		if (IS_ERR(node_page))
426 			continue;
427 
428 		/* set page dirty and write it */
429 		if (gc_type == FG_GC) {
430 			f2fs_wait_on_page_writeback(node_page, NODE, true);
431 			set_page_dirty(node_page);
432 		} else {
433 			if (!PageWriteback(node_page))
434 				set_page_dirty(node_page);
435 		}
436 		f2fs_put_page(node_page, 1);
437 		stat_inc_node_blk_count(sbi, 1);
438 	}
439 
440 	if (initial) {
441 		initial = false;
442 		goto next_step;
443 	}
444 
445 	if (gc_type == FG_GC) {
446 		struct writeback_control wbc = {
447 			.sync_mode = WB_SYNC_ALL,
448 			.nr_to_write = LONG_MAX,
449 			.for_reclaim = 0,
450 		};
451 		sync_node_pages(sbi, 0, &wbc);
452 
453 		/*
454 		 * In the case of FG_GC, it'd be better to reclaim this victim
455 		 * completely.
456 		 */
457 		if (get_valid_blocks(sbi, segno, 1) != 0)
458 			goto next_step;
459 	}
460 }
461 
462 /*
463  * Calculate start block index indicating the given node offset.
464  * Be careful, caller should give this node offset only indicating direct node
465  * blocks. If any node offsets, which point the other types of node blocks such
466  * as indirect or double indirect node blocks, are given, it must be a caller's
467  * bug.
468  */
469 block_t start_bidx_of_node(unsigned int node_ofs, struct f2fs_inode_info *fi)
470 {
471 	unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
472 	unsigned int bidx;
473 
474 	if (node_ofs == 0)
475 		return 0;
476 
477 	if (node_ofs <= 2) {
478 		bidx = node_ofs - 1;
479 	} else if (node_ofs <= indirect_blks) {
480 		int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
481 		bidx = node_ofs - 2 - dec;
482 	} else {
483 		int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
484 		bidx = node_ofs - 5 - dec;
485 	}
486 	return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi);
487 }
488 
489 static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
490 		struct node_info *dni, block_t blkaddr, unsigned int *nofs)
491 {
492 	struct page *node_page;
493 	nid_t nid;
494 	unsigned int ofs_in_node;
495 	block_t source_blkaddr;
496 
497 	nid = le32_to_cpu(sum->nid);
498 	ofs_in_node = le16_to_cpu(sum->ofs_in_node);
499 
500 	node_page = get_node_page(sbi, nid);
501 	if (IS_ERR(node_page))
502 		return 0;
503 
504 	get_node_info(sbi, nid, dni);
505 
506 	if (sum->version != dni->version) {
507 		f2fs_put_page(node_page, 1);
508 		return 0;
509 	}
510 
511 	*nofs = ofs_of_node(node_page);
512 	source_blkaddr = datablock_addr(node_page, ofs_in_node);
513 	f2fs_put_page(node_page, 1);
514 
515 	if (source_blkaddr != blkaddr)
516 		return 0;
517 	return 1;
518 }
519 
520 static void move_data_page(struct inode *inode, struct page *page, int gc_type)
521 {
522 	if (gc_type == BG_GC) {
523 		if (PageWriteback(page))
524 			goto out;
525 		set_page_dirty(page);
526 		set_cold_data(page);
527 	} else {
528 		struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
529 
530 		f2fs_wait_on_page_writeback(page, DATA, true);
531 
532 		if (clear_page_dirty_for_io(page) &&
533 			S_ISDIR(inode->i_mode)) {
534 			dec_page_count(sbi, F2FS_DIRTY_DENTS);
535 			inode_dec_dirty_dents(inode);
536 		}
537 		set_cold_data(page);
538 		do_write_data_page(page);
539 		clear_cold_data(page);
540 	}
541 out:
542 	f2fs_put_page(page, 1);
543 }
544 
545 /*
546  * This function tries to get parent node of victim data block, and identifies
547  * data block validity. If the block is valid, copy that with cold status and
548  * modify parent node.
549  * If the parent node is not valid or the data block address is different,
550  * the victim data block is ignored.
551  */
552 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
553 		struct list_head *ilist, unsigned int segno, int gc_type)
554 {
555 	struct super_block *sb = sbi->sb;
556 	struct f2fs_summary *entry;
557 	block_t start_addr;
558 	int off;
559 	int phase = 0;
560 
561 	start_addr = START_BLOCK(sbi, segno);
562 
563 next_step:
564 	entry = sum;
565 
566 	for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
567 		struct page *data_page;
568 		struct inode *inode;
569 		struct node_info dni; /* dnode info for the data */
570 		unsigned int ofs_in_node, nofs;
571 		block_t start_bidx;
572 
573 		/* stop BG_GC if there is not enough free sections. */
574 		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
575 			return;
576 
577 		if (check_valid_map(sbi, segno, off) == 0)
578 			continue;
579 
580 		if (phase == 0) {
581 			ra_node_page(sbi, le32_to_cpu(entry->nid));
582 			continue;
583 		}
584 
585 		/* Get an inode by ino with checking validity */
586 		if (check_dnode(sbi, entry, &dni, start_addr + off, &nofs) == 0)
587 			continue;
588 
589 		if (phase == 1) {
590 			ra_node_page(sbi, dni.ino);
591 			continue;
592 		}
593 
594 		ofs_in_node = le16_to_cpu(entry->ofs_in_node);
595 
596 		if (phase == 2) {
597 			inode = f2fs_iget(sb, dni.ino);
598 			if (IS_ERR(inode))
599 				continue;
600 
601 			start_bidx = start_bidx_of_node(nofs, F2FS_I(inode));
602 
603 			data_page = find_data_page(inode,
604 					start_bidx + ofs_in_node, false);
605 			if (IS_ERR(data_page))
606 				goto next_iput;
607 
608 			f2fs_put_page(data_page, 0);
609 			add_gc_inode(inode, ilist);
610 		} else {
611 			inode = find_gc_inode(dni.ino, ilist);
612 			if (inode) {
613 				start_bidx = start_bidx_of_node(nofs,
614 								F2FS_I(inode));
615 				data_page = get_lock_data_page(inode,
616 						start_bidx + ofs_in_node);
617 				if (IS_ERR(data_page))
618 					continue;
619 				move_data_page(inode, data_page, gc_type);
620 				stat_inc_data_blk_count(sbi, 1);
621 			}
622 		}
623 		continue;
624 next_iput:
625 		iput(inode);
626 	}
627 
628 	if (++phase < 4)
629 		goto next_step;
630 
631 	if (gc_type == FG_GC) {
632 		f2fs_submit_bio(sbi, DATA, true);
633 
634 		/*
635 		 * In the case of FG_GC, it'd be better to reclaim this victim
636 		 * completely.
637 		 */
638 		if (get_valid_blocks(sbi, segno, 1) != 0) {
639 			phase = 2;
640 			goto next_step;
641 		}
642 	}
643 }
644 
645 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
646 						int gc_type, int type)
647 {
648 	struct sit_info *sit_i = SIT_I(sbi);
649 	int ret;
650 	mutex_lock(&sit_i->sentry_lock);
651 	ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, type, LFS);
652 	mutex_unlock(&sit_i->sentry_lock);
653 	return ret;
654 }
655 
656 static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
657 				struct list_head *ilist, int gc_type)
658 {
659 	struct page *sum_page;
660 	struct f2fs_summary_block *sum;
661 	struct blk_plug plug;
662 
663 	/* read segment summary of victim */
664 	sum_page = get_sum_page(sbi, segno);
665 	if (IS_ERR(sum_page))
666 		return;
667 
668 	blk_start_plug(&plug);
669 
670 	sum = page_address(sum_page);
671 
672 	switch (GET_SUM_TYPE((&sum->footer))) {
673 	case SUM_TYPE_NODE:
674 		gc_node_segment(sbi, sum->entries, segno, gc_type);
675 		break;
676 	case SUM_TYPE_DATA:
677 		gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
678 		break;
679 	}
680 	blk_finish_plug(&plug);
681 
682 	stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
683 	stat_inc_call_count(sbi->stat_info);
684 
685 	f2fs_put_page(sum_page, 1);
686 }
687 
688 int f2fs_gc(struct f2fs_sb_info *sbi)
689 {
690 	struct list_head ilist;
691 	unsigned int segno, i;
692 	int gc_type = BG_GC;
693 	int nfree = 0;
694 	int ret = -1;
695 
696 	INIT_LIST_HEAD(&ilist);
697 gc_more:
698 	if (!(sbi->sb->s_flags & MS_ACTIVE))
699 		goto stop;
700 
701 	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) {
702 		gc_type = FG_GC;
703 		write_checkpoint(sbi, false);
704 	}
705 
706 	if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
707 		goto stop;
708 	ret = 0;
709 
710 	for (i = 0; i < sbi->segs_per_sec; i++)
711 		do_garbage_collect(sbi, segno + i, &ilist, gc_type);
712 
713 	if (gc_type == FG_GC) {
714 		sbi->cur_victim_sec = NULL_SEGNO;
715 		nfree++;
716 		WARN_ON(get_valid_blocks(sbi, segno, sbi->segs_per_sec));
717 	}
718 
719 	if (has_not_enough_free_secs(sbi, nfree))
720 		goto gc_more;
721 
722 	if (gc_type == FG_GC)
723 		write_checkpoint(sbi, false);
724 stop:
725 	mutex_unlock(&sbi->gc_mutex);
726 
727 	put_gc_inode(&ilist);
728 	return ret;
729 }
730 
731 void build_gc_manager(struct f2fs_sb_info *sbi)
732 {
733 	DIRTY_I(sbi)->v_ops = &default_v_ops;
734 }
735 
736 int __init create_gc_caches(void)
737 {
738 	winode_slab = f2fs_kmem_cache_create("f2fs_gc_inodes",
739 			sizeof(struct inode_entry), NULL);
740 	if (!winode_slab)
741 		return -ENOMEM;
742 	return 0;
743 }
744 
745 void destroy_gc_caches(void)
746 {
747 	kmem_cache_destroy(winode_slab);
748 }
749