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2658e50d JK |
1 | /* |
2 | * f2fs shrinker support | |
3 | * the basic infra was copied from fs/ubifs/shrinker.c | |
4 | * | |
5 | * Copyright (c) 2015 Motorola Mobility | |
6 | * Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | #include <linux/fs.h> | |
13 | #include <linux/f2fs_fs.h> | |
14 | ||
15 | #include "f2fs.h" | |
16 | ||
17 | static LIST_HEAD(f2fs_list); | |
18 | static DEFINE_SPINLOCK(f2fs_list_lock); | |
19 | static unsigned int shrinker_run_no; | |
20 | ||
1b38dc8e JK |
21 | static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi) |
22 | { | |
23 | return NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt; | |
24 | } | |
25 | ||
31696580 CY |
26 | static unsigned long __count_free_nids(struct f2fs_sb_info *sbi) |
27 | { | |
28 | if (NM_I(sbi)->fcnt > NAT_ENTRY_PER_BLOCK) | |
29 | return NM_I(sbi)->fcnt - NAT_ENTRY_PER_BLOCK; | |
30 | return 0; | |
31 | } | |
32 | ||
554df79e JK |
33 | static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi) |
34 | { | |
74fd8d99 | 35 | return atomic_read(&sbi->total_zombie_tree) + |
7441ccef | 36 | atomic_read(&sbi->total_ext_node); |
554df79e JK |
37 | } |
38 | ||
2658e50d JK |
39 | unsigned long f2fs_shrink_count(struct shrinker *shrink, |
40 | struct shrink_control *sc) | |
41 | { | |
42 | struct f2fs_sb_info *sbi; | |
43 | struct list_head *p; | |
44 | unsigned long count = 0; | |
45 | ||
46 | spin_lock(&f2fs_list_lock); | |
47 | p = f2fs_list.next; | |
48 | while (p != &f2fs_list) { | |
49 | sbi = list_entry(p, struct f2fs_sb_info, s_list); | |
50 | ||
51 | /* stop f2fs_put_super */ | |
52 | if (!mutex_trylock(&sbi->umount_mutex)) { | |
53 | p = p->next; | |
54 | continue; | |
55 | } | |
56 | spin_unlock(&f2fs_list_lock); | |
57 | ||
554df79e JK |
58 | /* count extent cache entries */ |
59 | count += __count_extent_cache(sbi); | |
60 | ||
1b38dc8e JK |
61 | /* shrink clean nat cache entries */ |
62 | count += __count_nat_entries(sbi); | |
2658e50d | 63 | |
31696580 CY |
64 | /* count free nids cache entries */ |
65 | count += __count_free_nids(sbi); | |
66 | ||
2658e50d JK |
67 | spin_lock(&f2fs_list_lock); |
68 | p = p->next; | |
69 | mutex_unlock(&sbi->umount_mutex); | |
70 | } | |
71 | spin_unlock(&f2fs_list_lock); | |
72 | return count; | |
73 | } | |
74 | ||
75 | unsigned long f2fs_shrink_scan(struct shrinker *shrink, | |
76 | struct shrink_control *sc) | |
77 | { | |
78 | unsigned long nr = sc->nr_to_scan; | |
79 | struct f2fs_sb_info *sbi; | |
80 | struct list_head *p; | |
81 | unsigned int run_no; | |
82 | unsigned long freed = 0; | |
83 | ||
84 | spin_lock(&f2fs_list_lock); | |
85 | do { | |
86 | run_no = ++shrinker_run_no; | |
87 | } while (run_no == 0); | |
88 | p = f2fs_list.next; | |
89 | while (p != &f2fs_list) { | |
90 | sbi = list_entry(p, struct f2fs_sb_info, s_list); | |
91 | ||
92 | if (sbi->shrinker_run_no == run_no) | |
93 | break; | |
94 | ||
95 | /* stop f2fs_put_super */ | |
96 | if (!mutex_trylock(&sbi->umount_mutex)) { | |
97 | p = p->next; | |
98 | continue; | |
99 | } | |
100 | spin_unlock(&f2fs_list_lock); | |
101 | ||
102 | sbi->shrinker_run_no = run_no; | |
103 | ||
554df79e JK |
104 | /* shrink extent cache entries */ |
105 | freed += f2fs_shrink_extent_tree(sbi, nr >> 1); | |
106 | ||
1b38dc8e | 107 | /* shrink clean nat cache entries */ |
554df79e JK |
108 | if (freed < nr) |
109 | freed += try_to_free_nats(sbi, nr - freed); | |
2658e50d | 110 | |
31696580 CY |
111 | /* shrink free nids cache entries */ |
112 | if (freed < nr) | |
113 | freed += try_to_free_nids(sbi, nr - freed); | |
114 | ||
2658e50d JK |
115 | spin_lock(&f2fs_list_lock); |
116 | p = p->next; | |
117 | list_move_tail(&sbi->s_list, &f2fs_list); | |
118 | mutex_unlock(&sbi->umount_mutex); | |
119 | if (freed >= nr) | |
120 | break; | |
121 | } | |
122 | spin_unlock(&f2fs_list_lock); | |
123 | return freed; | |
124 | } | |
125 | ||
126 | void f2fs_join_shrinker(struct f2fs_sb_info *sbi) | |
127 | { | |
128 | spin_lock(&f2fs_list_lock); | |
129 | list_add_tail(&sbi->s_list, &f2fs_list); | |
130 | spin_unlock(&f2fs_list_lock); | |
131 | } | |
132 | ||
133 | void f2fs_leave_shrinker(struct f2fs_sb_info *sbi) | |
134 | { | |
3e72f721 JK |
135 | f2fs_shrink_extent_tree(sbi, __count_extent_cache(sbi)); |
136 | ||
2658e50d JK |
137 | spin_lock(&f2fs_list_lock); |
138 | list_del(&sbi->s_list); | |
139 | spin_unlock(&f2fs_list_lock); | |
140 | } |