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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_CLEANCACHE_H #define _LINUX_CLEANCACHE_H #include <linux/fs.h> #include <linux/exportfs.h> #include <linux/mm.h> #define CLEANCACHE_NO_POOL -1 #define CLEANCACHE_NO_BACKEND -2 #define CLEANCACHE_NO_BACKEND_SHARED -3 #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)(uuid_t *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 (*invalidate_page)(int, struct cleancache_filekey, pgoff_t); void (*invalidate_inode)(int, struct cleancache_filekey); void (*invalidate_fs)(int); }; extern int cleancache_register_ops(const struct cleancache_ops *ops); extern void __cleancache_init_fs(struct super_block *); extern void __cleancache_init_shared_fs(struct super_block *); extern int __cleancache_get_page(struct page *); extern void __cleancache_put_page(struct page *); extern void __cleancache_invalidate_page(struct address_space *, struct page *); extern void __cleancache_invalidate_inode(struct address_space *); extern void __cleancache_invalidate_fs(struct super_block *); #ifdef CONFIG_CLEANCACHE #define cleancache_enabled (1) static inline bool cleancache_fs_enabled_mapping(struct address_space *mapping) { return mapping->host->i_sb->cleancache_poolid >= 0; } static inline bool cleancache_fs_enabled(struct page *page) { return cleancache_fs_enabled_mapping(page->mapping); } #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(struct super_block *sb) { if (cleancache_enabled) __cleancache_init_shared_fs(sb); } static inline int cleancache_get_page(struct page *page) { if (cleancache_enabled && cleancache_fs_enabled(page)) return __cleancache_get_page(page); return -1; } static inline void cleancache_put_page(struct page *page) { if (cleancache_enabled && cleancache_fs_enabled(page)) __cleancache_put_page(page); } static inline void cleancache_invalidate_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_invalidate_page(mapping, page); } static inline void cleancache_invalidate_inode(struct address_space *mapping) { if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping)) __cleancache_invalidate_inode(mapping); } static inline void cleancache_invalidate_fs(struct super_block *sb) { if (cleancache_enabled) __cleancache_invalidate_fs(sb); } #endif /* _LINUX_CLEANCACHE_H */ |