summaryrefslogtreecommitdiff
path: root/fs/f2fs/shrinker.c
blob: 83d6fb97dcae0f84ff6bd76ad389198a5660a5c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
// SPDX-License-Identifier: GPL-2.0
/*
 * f2fs shrinker support
 *   the basic infra was copied from fs/ubifs/shrinker.c
 *
 * Copyright (c) 2015 Motorola Mobility
 * Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
 */
#include <linux/fs.h>
#include <linux/f2fs_fs.h>

#include "f2fs.h"
#include "node.h"

static LIST_HEAD(f2fs_list);
static DEFINE_SPINLOCK(f2fs_list_lock);
static unsigned int shrinker_run_no;

static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
{
	return NM_I(sbi)->nat_cnt[RECLAIMABLE_NAT];
}

static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
{
	long count = NM_I(sbi)->nid_cnt[FREE_NID] - MAX_FREE_NIDS;

	return count > 0 ? count : 0;
}

static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi,
					enum extent_type type)
{
	struct extent_tree_info *eti = &sbi->extent_tree[type];

	return atomic_read(&eti->total_zombie_tree) +
				atomic_read(&eti->total_ext_node);
}

unsigned long f2fs_shrink_count(struct shrinker *shrink,
				struct shrink_control *sc)
{
	struct f2fs_sb_info *sbi;
	struct list_head *p;
	unsigned long count = 0;

	spin_lock(&f2fs_list_lock);
	p = f2fs_list.next;
	while (p != &f2fs_list) {
		sbi = list_entry(p, struct f2fs_sb_info, s_list);

		/* stop f2fs_put_super */
		if (!mutex_trylock(&sbi->umount_mutex)) {
			p = p->next;
			continue;
		}
		spin_unlock(&f2fs_list_lock);

		/* count read extent cache entries */
		count += __count_extent_cache(sbi, EX_READ);

		/* count block age extent cache entries */
		count += __count_extent_cache(sbi, EX_BLOCK_AGE);

		/* count clean nat cache entries */
		count += __count_nat_entries(sbi);

		/* count free nids cache entries */
		count += __count_free_nids(sbi);

		spin_lock(&f2fs_list_lock);
		p = p->next;
		mutex_unlock(&sbi->umount_mutex);
	}
	spin_unlock(&f2fs_list_lock);
	return count;
}

unsigned long f2fs_shrink_scan(struct shrinker *shrink,
				struct shrink_control *sc)
{
	unsigned long nr = sc->nr_to_scan;
	struct f2fs_sb_info *sbi;
	struct list_head *p;
	unsigned int run_no;
	unsigned long freed = 0;

	spin_lock(&f2fs_list_lock);
	do {
		run_no = ++shrinker_run_no;
	} while (run_no == 0);
	p = f2fs_list.next;
	while (p != &f2fs_list) {
		sbi = list_entry(p, struct f2fs_sb_info, s_list);

		if (sbi->shrinker_run_no == run_no)
			break;

		/* stop f2fs_put_super */
		if (!mutex_trylock(&sbi->umount_mutex)) {
			p = p->next;
			continue;
		}
		spin_unlock(&f2fs_list_lock);

		sbi->shrinker_run_no = run_no;

		/* shrink extent cache entries */
		freed += f2fs_shrink_age_extent_tree(sbi, nr >> 2);

		/* shrink read extent cache entries */
		freed += f2fs_shrink_read_extent_tree(sbi, nr >> 2);

		/* shrink clean nat cache entries */
		if (freed < nr)
			freed += f2fs_try_to_free_nats(sbi, nr - freed);

		/* shrink free nids cache entries */
		if (freed < nr)
			freed += f2fs_try_to_free_nids(sbi, nr - freed);

		spin_lock(&f2fs_list_lock);
		p = p->next;
		list_move_tail(&sbi->s_list, &f2fs_list);
		mutex_unlock(&sbi->umount_mutex);
		if (freed >= nr)
			break;
	}
	spin_unlock(&f2fs_list_lock);
	return freed;
}

void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
{
	spin_lock(&f2fs_list_lock);
	list_add_tail(&sbi->s_list, &f2fs_list);
	spin_unlock(&f2fs_list_lock);
}

void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
{
	f2fs_shrink_read_extent_tree(sbi, __count_extent_cache(sbi, EX_READ));
	f2fs_shrink_age_extent_tree(sbi,
				__count_extent_cache(sbi, EX_BLOCK_AGE));

	spin_lock(&f2fs_list_lock);
	list_del_init(&sbi->s_list);
	spin_unlock(&f2fs_list_lock);
}