1 /* NFS filesystem cache interface definitions 2 * 3 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public Licence 8 * as published by the Free Software Foundation; either version 9 * 2 of the Licence, or (at your option) any later version. 10 */ 11 12 #ifndef _NFS_FSCACHE_H 13 #define _NFS_FSCACHE_H 14 15 #include <linux/nfs_fs.h> 16 #include <linux/nfs_mount.h> 17 #include <linux/nfs4_mount.h> 18 #include <linux/fscache.h> 19 20 #ifdef CONFIG_NFS_FSCACHE 21 22 /* 23 * set of NFS FS-Cache objects that form a superblock key 24 */ 25 struct nfs_fscache_key { 26 struct rb_node node; 27 struct nfs_client *nfs_client; /* the server */ 28 29 /* the elements of the unique key - as used by nfs_compare_super() and 30 * nfs_compare_mount_options() to distinguish superblocks */ 31 struct { 32 struct { 33 unsigned long s_flags; /* various flags 34 * (& NFS_MS_MASK) */ 35 } super; 36 37 struct { 38 struct nfs_fsid fsid; 39 int flags; 40 unsigned int rsize; /* read size */ 41 unsigned int wsize; /* write size */ 42 unsigned int acregmin; /* attr cache timeouts */ 43 unsigned int acregmax; 44 unsigned int acdirmin; 45 unsigned int acdirmax; 46 } nfs_server; 47 48 struct { 49 rpc_authflavor_t au_flavor; 50 } rpc_auth; 51 52 /* uniquifier - can be used if nfs_server.flags includes 53 * NFS_MOUNT_UNSHARED */ 54 u8 uniq_len; 55 char uniquifier[0]; 56 } key; 57 }; 58 59 /* 60 * fscache-index.c 61 */ 62 extern struct fscache_netfs nfs_fscache_netfs; 63 extern const struct fscache_cookie_def nfs_fscache_server_index_def; 64 extern const struct fscache_cookie_def nfs_fscache_super_index_def; 65 extern const struct fscache_cookie_def nfs_fscache_inode_object_def; 66 67 extern int nfs_fscache_register(void); 68 extern void nfs_fscache_unregister(void); 69 70 /* 71 * fscache.c 72 */ 73 extern void nfs_fscache_get_client_cookie(struct nfs_client *); 74 extern void nfs_fscache_release_client_cookie(struct nfs_client *); 75 76 extern void nfs_fscache_get_super_cookie(struct super_block *, const char *, int); 77 extern void nfs_fscache_release_super_cookie(struct super_block *); 78 79 extern void nfs_fscache_init_inode_cookie(struct inode *); 80 extern void nfs_fscache_release_inode_cookie(struct inode *); 81 extern void nfs_fscache_zap_inode_cookie(struct inode *); 82 extern void nfs_fscache_set_inode_cookie(struct inode *, struct file *); 83 extern void nfs_fscache_reset_inode_cookie(struct inode *); 84 85 extern void __nfs_fscache_invalidate_page(struct page *, struct inode *); 86 extern int nfs_fscache_release_page(struct page *, gfp_t); 87 88 extern int __nfs_readpage_from_fscache(struct nfs_open_context *, 89 struct inode *, struct page *); 90 extern int __nfs_readpages_from_fscache(struct nfs_open_context *, 91 struct inode *, struct address_space *, 92 struct list_head *, unsigned *); 93 extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int); 94 95 /* 96 * wait for a page to complete writing to the cache 97 */ 98 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 99 struct page *page) 100 { 101 if (PageFsCache(page)) 102 fscache_wait_on_page_write(nfsi->fscache, page); 103 } 104 105 /* 106 * release the caching state associated with a page if undergoing complete page 107 * invalidation 108 */ 109 static inline void nfs_fscache_invalidate_page(struct page *page, 110 struct inode *inode) 111 { 112 if (PageFsCache(page)) 113 __nfs_fscache_invalidate_page(page, inode); 114 } 115 116 /* 117 * Retrieve a page from an inode data storage object. 118 */ 119 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 120 struct inode *inode, 121 struct page *page) 122 { 123 if (NFS_I(inode)->fscache) 124 return __nfs_readpage_from_fscache(ctx, inode, page); 125 return -ENOBUFS; 126 } 127 128 /* 129 * Retrieve a set of pages from an inode data storage object. 130 */ 131 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 132 struct inode *inode, 133 struct address_space *mapping, 134 struct list_head *pages, 135 unsigned *nr_pages) 136 { 137 if (NFS_I(inode)->fscache) 138 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages, 139 nr_pages); 140 return -ENOBUFS; 141 } 142 143 /* 144 * Store a page newly fetched from the server in an inode data storage object 145 * in the cache. 146 */ 147 static inline void nfs_readpage_to_fscache(struct inode *inode, 148 struct page *page, 149 int sync) 150 { 151 if (PageFsCache(page)) 152 __nfs_readpage_to_fscache(inode, page, sync); 153 } 154 155 /* 156 * indicate the client caching state as readable text 157 */ 158 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 159 { 160 if (server->fscache && (server->options & NFS_OPTION_FSCACHE)) 161 return "yes"; 162 return "no "; 163 } 164 165 166 #else /* CONFIG_NFS_FSCACHE */ 167 static inline int nfs_fscache_register(void) { return 0; } 168 static inline void nfs_fscache_unregister(void) {} 169 170 static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {} 171 static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {} 172 173 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} 174 175 static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {} 176 static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {} 177 static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {} 178 static inline void nfs_fscache_set_inode_cookie(struct inode *inode, 179 struct file *filp) {} 180 static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {} 181 182 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) 183 { 184 return 1; /* True: may release page */ 185 } 186 static inline void nfs_fscache_invalidate_page(struct page *page, 187 struct inode *inode) {} 188 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 189 struct page *page) {} 190 191 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 192 struct inode *inode, 193 struct page *page) 194 { 195 return -ENOBUFS; 196 } 197 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 198 struct inode *inode, 199 struct address_space *mapping, 200 struct list_head *pages, 201 unsigned *nr_pages) 202 { 203 return -ENOBUFS; 204 } 205 static inline void nfs_readpage_to_fscache(struct inode *inode, 206 struct page *page, int sync) {} 207 208 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 209 { 210 return "no "; 211 } 212 213 #endif /* CONFIG_NFS_FSCACHE */ 214 #endif /* _NFS_FSCACHE_H */ 215