1 // SPDX-License-Identifier: GPL-2.0
3 * f2fs shrinker support
4 * the basic infra was copied from fs/ubifs/shrinker.c
6 * Copyright (c) 2015 Motorola Mobility
7 * Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
10 #include <linux/f2fs_fs.h>
15 static LIST_HEAD(f2fs_list);
16 static DEFINE_SPINLOCK(f2fs_list_lock);
17 static unsigned int shrinker_run_no;
19 static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
21 return NM_I(sbi)->nat_cnt[RECLAIMABLE_NAT];
24 static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
26 long count = NM_I(sbi)->nid_cnt[FREE_NID] - MAX_FREE_NIDS;
28 return count > 0 ? count : 0;
31 static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi,
32 enum extent_type type)
34 struct extent_tree_info *eti = &sbi->extent_tree[type];
36 return atomic_read(&eti->total_zombie_tree) +
37 atomic_read(&eti->total_ext_node);
40 unsigned long f2fs_shrink_count(struct shrinker *shrink,
41 struct shrink_control *sc)
43 struct f2fs_sb_info *sbi;
45 unsigned long count = 0;
47 spin_lock(&f2fs_list_lock);
49 while (p != &f2fs_list) {
50 sbi = list_entry(p, struct f2fs_sb_info, s_list);
52 /* stop f2fs_put_super */
53 if (!mutex_trylock(&sbi->umount_mutex)) {
57 spin_unlock(&f2fs_list_lock);
59 /* count read extent cache entries */
60 count += __count_extent_cache(sbi, EX_READ);
62 /* count clean nat cache entries */
63 count += __count_nat_entries(sbi);
65 /* count free nids cache entries */
66 count += __count_free_nids(sbi);
68 spin_lock(&f2fs_list_lock);
70 mutex_unlock(&sbi->umount_mutex);
72 spin_unlock(&f2fs_list_lock);
76 unsigned long f2fs_shrink_scan(struct shrinker *shrink,
77 struct shrink_control *sc)
79 unsigned long nr = sc->nr_to_scan;
80 struct f2fs_sb_info *sbi;
83 unsigned long freed = 0;
85 spin_lock(&f2fs_list_lock);
87 run_no = ++shrinker_run_no;
88 } while (run_no == 0);
90 while (p != &f2fs_list) {
91 sbi = list_entry(p, struct f2fs_sb_info, s_list);
93 if (sbi->shrinker_run_no == run_no)
96 /* stop f2fs_put_super */
97 if (!mutex_trylock(&sbi->umount_mutex)) {
101 spin_unlock(&f2fs_list_lock);
103 sbi->shrinker_run_no = run_no;
105 /* shrink read extent cache entries */
106 freed += f2fs_shrink_read_extent_tree(sbi, nr >> 1);
108 /* shrink clean nat cache entries */
110 freed += f2fs_try_to_free_nats(sbi, nr - freed);
112 /* shrink free nids cache entries */
114 freed += f2fs_try_to_free_nids(sbi, nr - freed);
116 spin_lock(&f2fs_list_lock);
118 list_move_tail(&sbi->s_list, &f2fs_list);
119 mutex_unlock(&sbi->umount_mutex);
123 spin_unlock(&f2fs_list_lock);
127 void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
129 spin_lock(&f2fs_list_lock);
130 list_add_tail(&sbi->s_list, &f2fs_list);
131 spin_unlock(&f2fs_list_lock);
134 void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
136 f2fs_shrink_read_extent_tree(sbi, __count_extent_cache(sbi, EX_READ));
138 spin_lock(&f2fs_list_lock);
139 list_del_init(&sbi->s_list);
140 spin_unlock(&f2fs_list_lock);