1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _LINUX_CLEANCACHE_H
3*4882a593Smuzhiyun #define _LINUX_CLEANCACHE_H
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <linux/fs.h>
6*4882a593Smuzhiyun #include <linux/exportfs.h>
7*4882a593Smuzhiyun #include <linux/mm.h>
8*4882a593Smuzhiyun #include <linux/android_vendor.h>
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #define CLEANCACHE_NO_POOL -1
11*4882a593Smuzhiyun #define CLEANCACHE_NO_BACKEND -2
12*4882a593Smuzhiyun #define CLEANCACHE_NO_BACKEND_SHARED -3
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #define CLEANCACHE_KEY_MAX 6
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /*
17*4882a593Smuzhiyun * cleancache requires every file with a page in cleancache to have a
18*4882a593Smuzhiyun * unique key unless/until the file is removed/truncated. For some
19*4882a593Smuzhiyun * filesystems, the inode number is unique, but for "modern" filesystems
20*4882a593Smuzhiyun * an exportable filehandle is required (see exportfs.h)
21*4882a593Smuzhiyun */
22*4882a593Smuzhiyun struct cleancache_filekey {
23*4882a593Smuzhiyun union {
24*4882a593Smuzhiyun ino_t ino;
25*4882a593Smuzhiyun __u32 fh[CLEANCACHE_KEY_MAX];
26*4882a593Smuzhiyun u32 key[CLEANCACHE_KEY_MAX];
27*4882a593Smuzhiyun } u;
28*4882a593Smuzhiyun };
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun struct cleancache_ops {
31*4882a593Smuzhiyun int (*init_fs)(size_t);
32*4882a593Smuzhiyun int (*init_shared_fs)(uuid_t *uuid, size_t);
33*4882a593Smuzhiyun int (*get_page)(int, struct cleancache_filekey,
34*4882a593Smuzhiyun pgoff_t, struct page *);
35*4882a593Smuzhiyun void (*put_page)(int, struct cleancache_filekey,
36*4882a593Smuzhiyun pgoff_t, struct page *);
37*4882a593Smuzhiyun void (*invalidate_page)(int, struct cleancache_filekey, pgoff_t);
38*4882a593Smuzhiyun void (*invalidate_inode)(int, struct cleancache_filekey);
39*4882a593Smuzhiyun void (*invalidate_fs)(int);
40*4882a593Smuzhiyun ANDROID_OEM_DATA(1);
41*4882a593Smuzhiyun };
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun extern int cleancache_register_ops(const struct cleancache_ops *ops);
44*4882a593Smuzhiyun extern void __cleancache_init_fs(struct super_block *);
45*4882a593Smuzhiyun extern void __cleancache_init_shared_fs(struct super_block *);
46*4882a593Smuzhiyun extern int __cleancache_get_page(struct page *);
47*4882a593Smuzhiyun extern void __cleancache_put_page(struct page *);
48*4882a593Smuzhiyun extern void __cleancache_invalidate_page(struct address_space *, struct page *);
49*4882a593Smuzhiyun extern void __cleancache_invalidate_inode(struct address_space *);
50*4882a593Smuzhiyun extern void __cleancache_invalidate_fs(struct super_block *);
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun #ifdef CONFIG_CLEANCACHE
53*4882a593Smuzhiyun #define cleancache_enabled (1)
cleancache_fs_enabled_mapping(struct address_space * mapping)54*4882a593Smuzhiyun static inline bool cleancache_fs_enabled_mapping(struct address_space *mapping)
55*4882a593Smuzhiyun {
56*4882a593Smuzhiyun return mapping->host->i_sb->cleancache_poolid >= 0;
57*4882a593Smuzhiyun }
cleancache_fs_enabled(struct page * page)58*4882a593Smuzhiyun static inline bool cleancache_fs_enabled(struct page *page)
59*4882a593Smuzhiyun {
60*4882a593Smuzhiyun return cleancache_fs_enabled_mapping(page->mapping);
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun #else
63*4882a593Smuzhiyun #define cleancache_enabled (0)
64*4882a593Smuzhiyun #define cleancache_fs_enabled(_page) (0)
65*4882a593Smuzhiyun #define cleancache_fs_enabled_mapping(_page) (0)
66*4882a593Smuzhiyun #endif
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun /*
69*4882a593Smuzhiyun * The shim layer provided by these inline functions allows the compiler
70*4882a593Smuzhiyun * to reduce all cleancache hooks to nothingness if CONFIG_CLEANCACHE
71*4882a593Smuzhiyun * is disabled, to a single global variable check if CONFIG_CLEANCACHE
72*4882a593Smuzhiyun * is enabled but no cleancache "backend" has dynamically enabled it,
73*4882a593Smuzhiyun * and, for the most frequent cleancache ops, to a single global variable
74*4882a593Smuzhiyun * check plus a superblock element comparison if CONFIG_CLEANCACHE is enabled
75*4882a593Smuzhiyun * and a cleancache backend has dynamically enabled cleancache, but the
76*4882a593Smuzhiyun * filesystem referenced by that cleancache op has not enabled cleancache.
77*4882a593Smuzhiyun * As a result, CONFIG_CLEANCACHE can be enabled by default with essentially
78*4882a593Smuzhiyun * no measurable performance impact.
79*4882a593Smuzhiyun */
80*4882a593Smuzhiyun
cleancache_init_fs(struct super_block * sb)81*4882a593Smuzhiyun static inline void cleancache_init_fs(struct super_block *sb)
82*4882a593Smuzhiyun {
83*4882a593Smuzhiyun if (cleancache_enabled)
84*4882a593Smuzhiyun __cleancache_init_fs(sb);
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun
cleancache_init_shared_fs(struct super_block * sb)87*4882a593Smuzhiyun static inline void cleancache_init_shared_fs(struct super_block *sb)
88*4882a593Smuzhiyun {
89*4882a593Smuzhiyun if (cleancache_enabled)
90*4882a593Smuzhiyun __cleancache_init_shared_fs(sb);
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun
cleancache_get_page(struct page * page)93*4882a593Smuzhiyun static inline int cleancache_get_page(struct page *page)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun if (cleancache_enabled && cleancache_fs_enabled(page))
96*4882a593Smuzhiyun return __cleancache_get_page(page);
97*4882a593Smuzhiyun return -1;
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun
cleancache_put_page(struct page * page)100*4882a593Smuzhiyun static inline void cleancache_put_page(struct page *page)
101*4882a593Smuzhiyun {
102*4882a593Smuzhiyun if (cleancache_enabled && cleancache_fs_enabled(page))
103*4882a593Smuzhiyun __cleancache_put_page(page);
104*4882a593Smuzhiyun }
105*4882a593Smuzhiyun
cleancache_invalidate_page(struct address_space * mapping,struct page * page)106*4882a593Smuzhiyun static inline void cleancache_invalidate_page(struct address_space *mapping,
107*4882a593Smuzhiyun struct page *page)
108*4882a593Smuzhiyun {
109*4882a593Smuzhiyun /* careful... page->mapping is NULL sometimes when this is called */
110*4882a593Smuzhiyun if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
111*4882a593Smuzhiyun __cleancache_invalidate_page(mapping, page);
112*4882a593Smuzhiyun }
113*4882a593Smuzhiyun
cleancache_invalidate_inode(struct address_space * mapping)114*4882a593Smuzhiyun static inline void cleancache_invalidate_inode(struct address_space *mapping)
115*4882a593Smuzhiyun {
116*4882a593Smuzhiyun if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
117*4882a593Smuzhiyun __cleancache_invalidate_inode(mapping);
118*4882a593Smuzhiyun }
119*4882a593Smuzhiyun
cleancache_invalidate_fs(struct super_block * sb)120*4882a593Smuzhiyun static inline void cleancache_invalidate_fs(struct super_block *sb)
121*4882a593Smuzhiyun {
122*4882a593Smuzhiyun if (cleancache_enabled)
123*4882a593Smuzhiyun __cleancache_invalidate_fs(sb);
124*4882a593Smuzhiyun }
125*4882a593Smuzhiyun
126*4882a593Smuzhiyun #endif /* _LINUX_CLEANCACHE_H */
127