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Dan Magenheimer077b1f82011-05-26 10:01:36 -06001#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
Vladimir Davydov3cb29d12015-04-14 15:46:48 -07008#define CLEANCACHE_NO_POOL -1
9#define CLEANCACHE_NO_BACKEND -2
10#define CLEANCACHE_NO_BACKEND_SHARED -3
11
Dan Magenheimer077b1f82011-05-26 10:01:36 -060012#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 */
20struct cleancache_filekey {
21 union {
22 ino_t ino;
23 __u32 fh[CLEANCACHE_KEY_MAX];
24 u32 key[CLEANCACHE_KEY_MAX];
25 } u;
26};
27
28struct 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 *);
Dan Magenheimer91c6cc92012-01-12 14:03:25 -050035 void (*invalidate_page)(int, struct cleancache_filekey, pgoff_t);
36 void (*invalidate_inode)(int, struct cleancache_filekey);
37 void (*invalidate_fs)(int);
Dan Magenheimer077b1f82011-05-26 10:01:36 -060038};
39
Vladimir Davydov53d85c92015-04-14 15:46:45 -070040extern int cleancache_register_ops(struct cleancache_ops *ops);
Dan Magenheimer077b1f82011-05-26 10:01:36 -060041extern void __cleancache_init_fs(struct super_block *);
Vladimir Davydov9de16262015-04-14 15:46:42 -070042extern void __cleancache_init_shared_fs(struct super_block *);
Dan Magenheimer077b1f82011-05-26 10:01:36 -060043extern int __cleancache_get_page(struct page *);
44extern void __cleancache_put_page(struct page *);
Dan Magenheimer31677602011-09-21 11:56:28 -040045extern void __cleancache_invalidate_page(struct address_space *, struct page *);
46extern void __cleancache_invalidate_inode(struct address_space *);
47extern void __cleancache_invalidate_fs(struct super_block *);
Dan Magenheimer077b1f82011-05-26 10:01:36 -060048
49#ifdef CONFIG_CLEANCACHE
Bob Liuff610a12013-04-30 15:26:58 -070050#define cleancache_enabled (1)
Dan Magenheimer077b1f82011-05-26 10:01:36 -060051static inline bool cleancache_fs_enabled(struct page *page)
52{
53 return page->mapping->host->i_sb->cleancache_poolid >= 0;
54}
55static inline bool cleancache_fs_enabled_mapping(struct address_space *mapping)
56{
57 return mapping->host->i_sb->cleancache_poolid >= 0;
58}
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
78static inline void cleancache_init_fs(struct super_block *sb)
79{
80 if (cleancache_enabled)
81 __cleancache_init_fs(sb);
82}
83
Vladimir Davydov9de16262015-04-14 15:46:42 -070084static inline void cleancache_init_shared_fs(struct super_block *sb)
Dan Magenheimer077b1f82011-05-26 10:01:36 -060085{
86 if (cleancache_enabled)
Vladimir Davydov9de16262015-04-14 15:46:42 -070087 __cleancache_init_shared_fs(sb);
Dan Magenheimer077b1f82011-05-26 10:01:36 -060088}
89
90static inline int cleancache_get_page(struct page *page)
91{
92 int ret = -1;
93
94 if (cleancache_enabled && cleancache_fs_enabled(page))
95 ret = __cleancache_get_page(page);
96 return ret;
97}
98
99static inline void cleancache_put_page(struct page *page)
100{
101 if (cleancache_enabled && cleancache_fs_enabled(page))
102 __cleancache_put_page(page);
103}
104
Dan Magenheimer31677602011-09-21 11:56:28 -0400105static inline void cleancache_invalidate_page(struct address_space *mapping,
Dan Magenheimer077b1f82011-05-26 10:01:36 -0600106 struct page *page)
107{
108 /* careful... page->mapping is NULL sometimes when this is called */
109 if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
Dan Magenheimer31677602011-09-21 11:56:28 -0400110 __cleancache_invalidate_page(mapping, page);
Dan Magenheimer077b1f82011-05-26 10:01:36 -0600111}
112
Dan Magenheimer31677602011-09-21 11:56:28 -0400113static inline void cleancache_invalidate_inode(struct address_space *mapping)
Dan Magenheimer077b1f82011-05-26 10:01:36 -0600114{
115 if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
Dan Magenheimer31677602011-09-21 11:56:28 -0400116 __cleancache_invalidate_inode(mapping);
Dan Magenheimer077b1f82011-05-26 10:01:36 -0600117}
118
Dan Magenheimer31677602011-09-21 11:56:28 -0400119static inline void cleancache_invalidate_fs(struct super_block *sb)
Dan Magenheimer077b1f82011-05-26 10:01:36 -0600120{
121 if (cleancache_enabled)
Dan Magenheimer31677602011-09-21 11:56:28 -0400122 __cleancache_invalidate_fs(sb);
Dan Magenheimer077b1f82011-05-26 10:01:36 -0600123}
124
125#endif /* _LINUX_CLEANCACHE_H */