| Jaegeuk Kim | 2658e50 | 2015-06-19 12:01:21 -0700 | [diff] [blame^] | 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 | |
| 21 | unsigned long f2fs_shrink_count(struct shrinker *shrink, |
| 22 | struct shrink_control *sc) |
| 23 | { |
| 24 | struct f2fs_sb_info *sbi; |
| 25 | struct list_head *p; |
| 26 | unsigned long count = 0; |
| 27 | |
| 28 | spin_lock(&f2fs_list_lock); |
| 29 | p = f2fs_list.next; |
| 30 | while (p != &f2fs_list) { |
| 31 | sbi = list_entry(p, struct f2fs_sb_info, s_list); |
| 32 | |
| 33 | /* stop f2fs_put_super */ |
| 34 | if (!mutex_trylock(&sbi->umount_mutex)) { |
| 35 | p = p->next; |
| 36 | continue; |
| 37 | } |
| 38 | spin_unlock(&f2fs_list_lock); |
| 39 | |
| 40 | /* TODO: count # of objects */ |
| 41 | |
| 42 | spin_lock(&f2fs_list_lock); |
| 43 | p = p->next; |
| 44 | mutex_unlock(&sbi->umount_mutex); |
| 45 | } |
| 46 | spin_unlock(&f2fs_list_lock); |
| 47 | return count; |
| 48 | } |
| 49 | |
| 50 | unsigned long f2fs_shrink_scan(struct shrinker *shrink, |
| 51 | struct shrink_control *sc) |
| 52 | { |
| 53 | unsigned long nr = sc->nr_to_scan; |
| 54 | struct f2fs_sb_info *sbi; |
| 55 | struct list_head *p; |
| 56 | unsigned int run_no; |
| 57 | unsigned long freed = 0; |
| 58 | |
| 59 | spin_lock(&f2fs_list_lock); |
| 60 | do { |
| 61 | run_no = ++shrinker_run_no; |
| 62 | } while (run_no == 0); |
| 63 | p = f2fs_list.next; |
| 64 | while (p != &f2fs_list) { |
| 65 | sbi = list_entry(p, struct f2fs_sb_info, s_list); |
| 66 | |
| 67 | if (sbi->shrinker_run_no == run_no) |
| 68 | break; |
| 69 | |
| 70 | /* stop f2fs_put_super */ |
| 71 | if (!mutex_trylock(&sbi->umount_mutex)) { |
| 72 | p = p->next; |
| 73 | continue; |
| 74 | } |
| 75 | spin_unlock(&f2fs_list_lock); |
| 76 | |
| 77 | sbi->shrinker_run_no = run_no; |
| 78 | |
| 79 | /* TODO: shrink caches */ |
| 80 | |
| 81 | spin_lock(&f2fs_list_lock); |
| 82 | p = p->next; |
| 83 | list_move_tail(&sbi->s_list, &f2fs_list); |
| 84 | mutex_unlock(&sbi->umount_mutex); |
| 85 | if (freed >= nr) |
| 86 | break; |
| 87 | } |
| 88 | spin_unlock(&f2fs_list_lock); |
| 89 | return freed; |
| 90 | } |
| 91 | |
| 92 | void f2fs_join_shrinker(struct f2fs_sb_info *sbi) |
| 93 | { |
| 94 | spin_lock(&f2fs_list_lock); |
| 95 | list_add_tail(&sbi->s_list, &f2fs_list); |
| 96 | spin_unlock(&f2fs_list_lock); |
| 97 | } |
| 98 | |
| 99 | void f2fs_leave_shrinker(struct f2fs_sb_info *sbi) |
| 100 | { |
| 101 | spin_lock(&f2fs_list_lock); |
| 102 | list_del(&sbi->s_list); |
| 103 | spin_unlock(&f2fs_list_lock); |
| 104 | } |