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