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077b1f83 DM |
1 | #ifndef _LINUX_CLEANCACHE_H |
2 | #define _LINUX_CLEANCACHE_H | |
3 | ||
4 | #include <linux/fs.h> | |
5 | #include <linux/exportfs.h> | |
6 | #include <linux/mm.h> | |
7 | ||
3cb29d11 VD |
8 | #define CLEANCACHE_NO_POOL -1 |
9 | #define CLEANCACHE_NO_BACKEND -2 | |
10 | #define CLEANCACHE_NO_BACKEND_SHARED -3 | |
11 | ||
077b1f83 DM |
12 | #define CLEANCACHE_KEY_MAX 6 |
13 | ||
14 | /* | |
15 | * cleancache requires every file with a page in cleancache to have a | |
16 | * unique key unless/until the file is removed/truncated. For some | |
17 | * filesystems, the inode number is unique, but for "modern" filesystems | |
18 | * an exportable filehandle is required (see exportfs.h) | |
19 | */ | |
20 | struct cleancache_filekey { | |
21 | union { | |
22 | ino_t ino; | |
23 | __u32 fh[CLEANCACHE_KEY_MAX]; | |
24 | u32 key[CLEANCACHE_KEY_MAX]; | |
25 | } u; | |
26 | }; | |
27 | ||
28 | struct cleancache_ops { | |
29 | int (*init_fs)(size_t); | |
30 | int (*init_shared_fs)(char *uuid, size_t); | |
31 | int (*get_page)(int, struct cleancache_filekey, | |
32 | pgoff_t, struct page *); | |
33 | void (*put_page)(int, struct cleancache_filekey, | |
34 | pgoff_t, struct page *); | |
91c6cc9b DM |
35 | void (*invalidate_page)(int, struct cleancache_filekey, pgoff_t); |
36 | void (*invalidate_inode)(int, struct cleancache_filekey); | |
37 | void (*invalidate_fs)(int); | |
077b1f83 DM |
38 | }; |
39 | ||
b3c6de49 | 40 | extern int cleancache_register_ops(const struct cleancache_ops *ops); |
077b1f83 | 41 | extern void __cleancache_init_fs(struct super_block *); |
9de16262 | 42 | extern void __cleancache_init_shared_fs(struct super_block *); |
077b1f83 DM |
43 | extern int __cleancache_get_page(struct page *); |
44 | extern void __cleancache_put_page(struct page *); | |
3167760f DM |
45 | extern void __cleancache_invalidate_page(struct address_space *, struct page *); |
46 | extern void __cleancache_invalidate_inode(struct address_space *); | |
47 | extern void __cleancache_invalidate_fs(struct super_block *); | |
077b1f83 DM |
48 | |
49 | #ifdef CONFIG_CLEANCACHE | |
ff610a1d | 50 | #define cleancache_enabled (1) |
077b1f83 DM |
51 | static inline bool cleancache_fs_enabled_mapping(struct address_space *mapping) |
52 | { | |
53 | return mapping->host->i_sb->cleancache_poolid >= 0; | |
54 | } | |
a39bb9a0 CG |
55 | static inline bool cleancache_fs_enabled(struct page *page) |
56 | { | |
57 | return cleancache_fs_enabled_mapping(page->mapping); | |
58 | } | |
077b1f83 DM |
59 | #else |
60 | #define cleancache_enabled (0) | |
61 | #define cleancache_fs_enabled(_page) (0) | |
62 | #define cleancache_fs_enabled_mapping(_page) (0) | |
63 | #endif | |
64 | ||
65 | /* | |
66 | * The shim layer provided by these inline functions allows the compiler | |
67 | * to reduce all cleancache hooks to nothingness if CONFIG_CLEANCACHE | |
68 | * is disabled, to a single global variable check if CONFIG_CLEANCACHE | |
69 | * is enabled but no cleancache "backend" has dynamically enabled it, | |
70 | * and, for the most frequent cleancache ops, to a single global variable | |
71 | * check plus a superblock element comparison if CONFIG_CLEANCACHE is enabled | |
72 | * and a cleancache backend has dynamically enabled cleancache, but the | |
73 | * filesystem referenced by that cleancache op has not enabled cleancache. | |
74 | * As a result, CONFIG_CLEANCACHE can be enabled by default with essentially | |
75 | * no measurable performance impact. | |
76 | */ | |
77 | ||
78 | static inline void cleancache_init_fs(struct super_block *sb) | |
79 | { | |
80 | if (cleancache_enabled) | |
81 | __cleancache_init_fs(sb); | |
82 | } | |
83 | ||
9de16262 | 84 | static inline void cleancache_init_shared_fs(struct super_block *sb) |
077b1f83 DM |
85 | { |
86 | if (cleancache_enabled) | |
9de16262 | 87 | __cleancache_init_shared_fs(sb); |
077b1f83 DM |
88 | } |
89 | ||
90 | static inline int cleancache_get_page(struct page *page) | |
91 | { | |
077b1f83 | 92 | if (cleancache_enabled && cleancache_fs_enabled(page)) |
a39bb9a0 CG |
93 | return __cleancache_get_page(page); |
94 | return -1; | |
077b1f83 DM |
95 | } |
96 | ||
97 | static inline void cleancache_put_page(struct page *page) | |
98 | { | |
99 | if (cleancache_enabled && cleancache_fs_enabled(page)) | |
100 | __cleancache_put_page(page); | |
101 | } | |
102 | ||
3167760f | 103 | static inline void cleancache_invalidate_page(struct address_space *mapping, |
077b1f83 DM |
104 | struct page *page) |
105 | { | |
106 | /* careful... page->mapping is NULL sometimes when this is called */ | |
107 | if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping)) | |
3167760f | 108 | __cleancache_invalidate_page(mapping, page); |
077b1f83 DM |
109 | } |
110 | ||
3167760f | 111 | static inline void cleancache_invalidate_inode(struct address_space *mapping) |
077b1f83 DM |
112 | { |
113 | if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping)) | |
3167760f | 114 | __cleancache_invalidate_inode(mapping); |
077b1f83 DM |
115 | } |
116 | ||
3167760f | 117 | static inline void cleancache_invalidate_fs(struct super_block *sb) |
077b1f83 DM |
118 | { |
119 | if (cleancache_enabled) | |
3167760f | 120 | __cleancache_invalidate_fs(sb); |
077b1f83 DM |
121 | } |
122 | ||
123 | #endif /* _LINUX_CLEANCACHE_H */ |