1// SPDX-License-Identifier: GPL-2.0
2/*
3 * f2fs shrinker support
4 * the basic infra was copied from fs/ubifs/shrinker.c
5 *
6 * Copyright (c) 2015 Motorola Mobility
7 * Copyright (c) 2015 Jaegeuk Kim <jaegeuk@kernel.org>
8 */
9#include <linux/fs.h>
10#include <linux/f2fs_fs.h>
11
12#include "f2fs.h"
13#include "node.h"
14
15static LIST_HEAD(f2fs_list);
16static DEFINE_SPINLOCK(f2fs_list_lock);
17static unsigned int shrinker_run_no;
18
19static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
20{
21 return NM_I(sbi)->nat_cnt[RECLAIMABLE_NAT];
22}
23
24static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
25{
26 long count = NM_I(sbi)->nid_cnt[FREE_NID] - MAX_FREE_NIDS;
27
28 return count > 0 ? count : 0;
29}
30
31static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi,
32 enum extent_type type)
33{
34 struct extent_tree_info *eti = &sbi->extent_tree[type];
35
36 return atomic_read(v: &eti->total_zombie_tree) +
37 atomic_read(v: &eti->total_ext_node);
38}
39
40unsigned long f2fs_shrink_count(struct shrinker *shrink,
41 struct shrink_control *sc)
42{
43 struct f2fs_sb_info *sbi;
44 struct list_head *p;
45 unsigned long count = 0;
46
47 spin_lock(lock: &f2fs_list_lock);
48 p = f2fs_list.next;
49 while (p != &f2fs_list) {
50 sbi = list_entry(p, struct f2fs_sb_info, s_list);
51
52 /* stop f2fs_put_super */
53 if (!mutex_trylock(&sbi->umount_mutex)) {
54 p = p->next;
55 continue;
56 }
57 spin_unlock(lock: &f2fs_list_lock);
58
59 /* count read extent cache entries */
60 count += __count_extent_cache(sbi, type: EX_READ);
61
62 /* count block age extent cache entries */
63 count += __count_extent_cache(sbi, type: EX_BLOCK_AGE);
64
65 /* count clean nat cache entries */
66 count += __count_nat_entries(sbi);
67
68 /* count free nids cache entries */
69 count += __count_free_nids(sbi);
70
71 spin_lock(lock: &f2fs_list_lock);
72 p = p->next;
73 mutex_unlock(lock: &sbi->umount_mutex);
74 }
75 spin_unlock(lock: &f2fs_list_lock);
76 return count ?: SHRINK_EMPTY;
77}
78
79unsigned long f2fs_shrink_scan(struct shrinker *shrink,
80 struct shrink_control *sc)
81{
82 unsigned long nr = sc->nr_to_scan;
83 struct f2fs_sb_info *sbi;
84 struct list_head *p;
85 unsigned int run_no;
86 unsigned long freed = 0;
87
88 spin_lock(lock: &f2fs_list_lock);
89 do {
90 run_no = ++shrinker_run_no;
91 } while (run_no == 0);
92 p = f2fs_list.next;
93 while (p != &f2fs_list) {
94 sbi = list_entry(p, struct f2fs_sb_info, s_list);
95
96 if (sbi->shrinker_run_no == run_no)
97 break;
98
99 /* stop f2fs_put_super */
100 if (!mutex_trylock(&sbi->umount_mutex)) {
101 p = p->next;
102 continue;
103 }
104 spin_unlock(lock: &f2fs_list_lock);
105
106 sbi->shrinker_run_no = run_no;
107
108 /* shrink extent cache entries */
109 freed += f2fs_shrink_age_extent_tree(sbi, nr_shrink: nr >> 2);
110
111 /* shrink read extent cache entries */
112 freed += f2fs_shrink_read_extent_tree(sbi, nr_shrink: nr >> 2);
113
114 /* shrink clean nat cache entries */
115 if (freed < nr)
116 freed += f2fs_try_to_free_nats(sbi, nr_shrink: nr - freed);
117
118 /* shrink free nids cache entries */
119 if (freed < nr)
120 freed += f2fs_try_to_free_nids(sbi, nr_shrink: nr - freed);
121
122 spin_lock(lock: &f2fs_list_lock);
123 p = p->next;
124 list_move_tail(list: &sbi->s_list, head: &f2fs_list);
125 mutex_unlock(lock: &sbi->umount_mutex);
126 if (freed >= nr)
127 break;
128 }
129 spin_unlock(lock: &f2fs_list_lock);
130 return freed;
131}
132
133unsigned int f2fs_donate_files(void)
134{
135 struct f2fs_sb_info *sbi;
136 struct list_head *p;
137 unsigned int donate_files = 0;
138
139 spin_lock(lock: &f2fs_list_lock);
140 p = f2fs_list.next;
141 while (p != &f2fs_list) {
142 sbi = list_entry(p, struct f2fs_sb_info, s_list);
143
144 /* stop f2fs_put_super */
145 if (!mutex_trylock(&sbi->umount_mutex)) {
146 p = p->next;
147 continue;
148 }
149 spin_unlock(lock: &f2fs_list_lock);
150
151 donate_files += sbi->donate_files;
152
153 spin_lock(lock: &f2fs_list_lock);
154 p = p->next;
155 mutex_unlock(lock: &sbi->umount_mutex);
156 }
157 spin_unlock(lock: &f2fs_list_lock);
158
159 return donate_files;
160}
161
162static unsigned int do_reclaim_caches(struct f2fs_sb_info *sbi,
163 unsigned int reclaim_caches_kb)
164{
165 struct inode *inode;
166 struct f2fs_inode_info *fi;
167 unsigned int nfiles = sbi->donate_files;
168 pgoff_t npages = reclaim_caches_kb >> (PAGE_SHIFT - 10);
169
170 while (npages && nfiles--) {
171 pgoff_t len;
172
173 spin_lock(lock: &sbi->inode_lock[DONATE_INODE]);
174 if (list_empty(head: &sbi->inode_list[DONATE_INODE])) {
175 spin_unlock(lock: &sbi->inode_lock[DONATE_INODE]);
176 break;
177 }
178 fi = list_first_entry(&sbi->inode_list[DONATE_INODE],
179 struct f2fs_inode_info, gdonate_list);
180 list_move_tail(list: &fi->gdonate_list, head: &sbi->inode_list[DONATE_INODE]);
181 inode = igrab(&fi->vfs_inode);
182 spin_unlock(lock: &sbi->inode_lock[DONATE_INODE]);
183
184 if (!inode)
185 continue;
186
187 inode_lock(inode);
188 if (!is_inode_flag_set(inode, flag: FI_DONATE_FINISHED)) {
189 len = fi->donate_end - fi->donate_start + 1;
190 npages = npages < len ? 0 : npages - len;
191
192 invalidate_inode_pages2_range(mapping: inode->i_mapping,
193 start: fi->donate_start, end: fi->donate_end);
194 set_inode_flag(inode, flag: FI_DONATE_FINISHED);
195 }
196 inode_unlock(inode);
197
198 iput(inode);
199 cond_resched();
200 }
201 return npages << (PAGE_SHIFT - 10);
202}
203
204void f2fs_reclaim_caches(unsigned int reclaim_caches_kb)
205{
206 struct f2fs_sb_info *sbi;
207 struct list_head *p;
208
209 spin_lock(lock: &f2fs_list_lock);
210 p = f2fs_list.next;
211 while (p != &f2fs_list && reclaim_caches_kb) {
212 sbi = list_entry(p, struct f2fs_sb_info, s_list);
213
214 /* stop f2fs_put_super */
215 if (!mutex_trylock(&sbi->umount_mutex)) {
216 p = p->next;
217 continue;
218 }
219 spin_unlock(lock: &f2fs_list_lock);
220
221 reclaim_caches_kb = do_reclaim_caches(sbi, reclaim_caches_kb);
222
223 spin_lock(lock: &f2fs_list_lock);
224 p = p->next;
225 mutex_unlock(lock: &sbi->umount_mutex);
226 }
227 spin_unlock(lock: &f2fs_list_lock);
228}
229
230void f2fs_join_shrinker(struct f2fs_sb_info *sbi)
231{
232 spin_lock(lock: &f2fs_list_lock);
233 list_add_tail(new: &sbi->s_list, head: &f2fs_list);
234 spin_unlock(lock: &f2fs_list_lock);
235}
236
237void f2fs_leave_shrinker(struct f2fs_sb_info *sbi)
238{
239 f2fs_shrink_read_extent_tree(sbi, nr_shrink: __count_extent_cache(sbi, type: EX_READ));
240 f2fs_shrink_age_extent_tree(sbi,
241 nr_shrink: __count_extent_cache(sbi, type: EX_BLOCK_AGE));
242
243 spin_lock(lock: &f2fs_list_lock);
244 list_del_init(entry: &sbi->s_list);
245 spin_unlock(lock: &f2fs_list_lock);
246}
247

source code of linux/fs/f2fs/shrinker.c