2 * f2fs shrinker support
3 * the basic infra was copied from fs/ubifs/shrinker.c
5 * Copyright (c) 2015 Motorola Mobility
6 * Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
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.
13 #include <linux/f2fs_fs.h>
17 static LIST_HEAD(f2fs_list);
18 static DEFINE_SPINLOCK(f2fs_list_lock);
19 static unsigned int shrinker_run_no;
21 static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
23 return NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
26 static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
28 return sbi->total_ext_tree + atomic_read(&sbi->total_ext_node);
31 unsigned long f2fs_shrink_count(struct shrinker *shrink,
32 struct shrink_control *sc)
34 struct f2fs_sb_info *sbi;
36 unsigned long count = 0;
38 spin_lock(&f2fs_list_lock);
40 while (p != &f2fs_list) {
41 sbi = list_entry(p, struct f2fs_sb_info, s_list);
43 /* stop f2fs_put_super */
44 if (!mutex_trylock(&sbi->umount_mutex)) {
48 spin_unlock(&f2fs_list_lock);
50 /* count extent cache entries */
51 count += __count_extent_cache(sbi);
53 /* shrink clean nat cache entries */
54 count += __count_nat_entries(sbi);
56 spin_lock(&f2fs_list_lock);
58 mutex_unlock(&sbi->umount_mutex);
60 spin_unlock(&f2fs_list_lock);
64 unsigned long f2fs_shrink_scan(struct shrinker *shrink,
65 struct shrink_control *sc)
67 unsigned long nr = sc->nr_to_scan;
68 struct f2fs_sb_info *sbi;
71 unsigned long freed = 0;
73 spin_lock(&f2fs_list_lock);
75 run_no = ++shrinker_run_no;
76 } while (run_no == 0);
78 while (p != &f2fs_list) {
79 sbi = list_entry(p, struct f2fs_sb_info, s_list);
81 if (sbi->shrinker_run_no == run_no)
84 /* stop f2fs_put_super */
85 if (!mutex_trylock(&sbi->umount_mutex)) {
89 spin_unlock(&f2fs_list_lock);
91 sbi->shrinker_run_no = run_no;
93 /* shrink extent cache entries */
94 freed += f2fs_shrink_extent_tree(sbi, nr >> 1);
96 /* shrink clean nat cache entries */
98 freed += try_to_free_nats(sbi, nr - freed);
100 spin_lock(&f2fs_list_lock);
102 list_move_tail(&sbi->s_list, &f2fs_list);
103 mutex_unlock(&sbi->umount_mutex);
107 spin_unlock(&f2fs_list_lock);
111 void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
113 spin_lock(&f2fs_list_lock);
114 list_add_tail(&sbi->s_list, &f2fs_list);
115 spin_unlock(&f2fs_list_lock);
118 void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
120 f2fs_shrink_extent_tree(sbi, __count_extent_cache(sbi));
122 spin_lock(&f2fs_list_lock);
123 list_del(&sbi->s_list);
124 spin_unlock(&f2fs_list_lock);