123 lines
3.7 KiB
C
123 lines
3.7 KiB
C
#ifndef _LINUX_CLEANCACHE_H
|
|
#define _LINUX_CLEANCACHE_H
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/exportfs.h>
|
|
#include <linux/mm.h>
|
|
|
|
#define CLEANCACHE_KEY_MAX 6
|
|
|
|
/*
|
|
* cleancache requires every file with a page in cleancache to have a
|
|
* unique key unless/until the file is removed/truncated. For some
|
|
* filesystems, the inode number is unique, but for "modern" filesystems
|
|
* an exportable filehandle is required (see exportfs.h)
|
|
*/
|
|
struct cleancache_filekey {
|
|
union {
|
|
ino_t ino;
|
|
__u32 fh[CLEANCACHE_KEY_MAX];
|
|
u32 key[CLEANCACHE_KEY_MAX];
|
|
} u;
|
|
};
|
|
|
|
struct cleancache_ops {
|
|
int (*init_fs)(size_t);
|
|
int (*init_shared_fs)(char *uuid, size_t);
|
|
int (*get_page)(int, struct cleancache_filekey,
|
|
pgoff_t, struct page *);
|
|
void (*put_page)(int, struct cleancache_filekey,
|
|
pgoff_t, struct page *);
|
|
void (*flush_page)(int, struct cleancache_filekey, pgoff_t);
|
|
void (*flush_inode)(int, struct cleancache_filekey);
|
|
void (*flush_fs)(int);
|
|
};
|
|
|
|
extern struct cleancache_ops
|
|
cleancache_register_ops(struct cleancache_ops *ops);
|
|
extern void __cleancache_init_fs(struct super_block *);
|
|
extern void __cleancache_init_shared_fs(char *, struct super_block *);
|
|
extern int __cleancache_get_page(struct page *);
|
|
extern void __cleancache_put_page(struct page *);
|
|
extern void __cleancache_flush_page(struct address_space *, struct page *);
|
|
extern void __cleancache_flush_inode(struct address_space *);
|
|
extern void __cleancache_flush_fs(struct super_block *);
|
|
extern int cleancache_enabled;
|
|
|
|
#ifdef CONFIG_CLEANCACHE
|
|
static inline bool cleancache_fs_enabled(struct page *page)
|
|
{
|
|
return page->mapping->host->i_sb->cleancache_poolid >= 0;
|
|
}
|
|
static inline bool cleancache_fs_enabled_mapping(struct address_space *mapping)
|
|
{
|
|
return mapping->host->i_sb->cleancache_poolid >= 0;
|
|
}
|
|
#else
|
|
#define cleancache_enabled (0)
|
|
#define cleancache_fs_enabled(_page) (0)
|
|
#define cleancache_fs_enabled_mapping(_page) (0)
|
|
#endif
|
|
|
|
/*
|
|
* The shim layer provided by these inline functions allows the compiler
|
|
* to reduce all cleancache hooks to nothingness if CONFIG_CLEANCACHE
|
|
* is disabled, to a single global variable check if CONFIG_CLEANCACHE
|
|
* is enabled but no cleancache "backend" has dynamically enabled it,
|
|
* and, for the most frequent cleancache ops, to a single global variable
|
|
* check plus a superblock element comparison if CONFIG_CLEANCACHE is enabled
|
|
* and a cleancache backend has dynamically enabled cleancache, but the
|
|
* filesystem referenced by that cleancache op has not enabled cleancache.
|
|
* As a result, CONFIG_CLEANCACHE can be enabled by default with essentially
|
|
* no measurable performance impact.
|
|
*/
|
|
|
|
static inline void cleancache_init_fs(struct super_block *sb)
|
|
{
|
|
if (cleancache_enabled)
|
|
__cleancache_init_fs(sb);
|
|
}
|
|
|
|
static inline void cleancache_init_shared_fs(char *uuid, struct super_block *sb)
|
|
{
|
|
if (cleancache_enabled)
|
|
__cleancache_init_shared_fs(uuid, sb);
|
|
}
|
|
|
|
static inline int cleancache_get_page(struct page *page)
|
|
{
|
|
int ret = -1;
|
|
|
|
if (cleancache_enabled && cleancache_fs_enabled(page))
|
|
ret = __cleancache_get_page(page);
|
|
return ret;
|
|
}
|
|
|
|
static inline void cleancache_put_page(struct page *page)
|
|
{
|
|
if (cleancache_enabled && cleancache_fs_enabled(page))
|
|
__cleancache_put_page(page);
|
|
}
|
|
|
|
static inline void cleancache_flush_page(struct address_space *mapping,
|
|
struct page *page)
|
|
{
|
|
/* careful... page->mapping is NULL sometimes when this is called */
|
|
if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
|
|
__cleancache_flush_page(mapping, page);
|
|
}
|
|
|
|
static inline void cleancache_flush_inode(struct address_space *mapping)
|
|
{
|
|
if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
|
|
__cleancache_flush_inode(mapping);
|
|
}
|
|
|
|
static inline void cleancache_flush_fs(struct super_block *sb)
|
|
{
|
|
if (cleancache_enabled)
|
|
__cleancache_flush_fs(sb);
|
|
}
|
|
|
|
#endif /* _LINUX_CLEANCACHE_H */
|