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 * Definition of the auxiliary data attached to NFS inode storage objects 61 * within the cache. 62 * 63 * The contents of this struct are recorded in the on-disk local cache in the 64 * auxiliary data attached to the data storage object backing an inode. This 65 * permits coherency to be managed when a new inode binds to an already extant 66 * cache object. 67 */ 68 struct nfs_fscache_inode_auxdata { 69 struct timespec mtime; 70 struct timespec ctime; 71 u64 change_attr; 72 }; 73 74 /* 75 * fscache-index.c 76 */ 77 extern struct fscache_netfs nfs_fscache_netfs; 78 extern const struct fscache_cookie_def nfs_fscache_server_index_def; 79 extern const struct fscache_cookie_def nfs_fscache_super_index_def; 80 extern const struct fscache_cookie_def nfs_fscache_inode_object_def; 81 82 extern int nfs_fscache_register(void); 83 extern void nfs_fscache_unregister(void); 84 85 /* 86 * fscache.c 87 */ 88 extern void nfs_fscache_get_client_cookie(struct nfs_client *); 89 extern void nfs_fscache_release_client_cookie(struct nfs_client *); 90 91 extern void nfs_fscache_get_super_cookie(struct super_block *, const char *, int); 92 extern void nfs_fscache_release_super_cookie(struct super_block *); 93 94 extern void nfs_fscache_init_inode(struct inode *); 95 extern void nfs_fscache_clear_inode(struct inode *); 96 extern void nfs_fscache_open_file(struct inode *, struct file *); 97 98 extern void __nfs_fscache_invalidate_page(struct page *, struct inode *); 99 extern int nfs_fscache_release_page(struct page *, gfp_t); 100 101 extern int __nfs_readpage_from_fscache(struct nfs_open_context *, 102 struct inode *, struct page *); 103 extern int __nfs_readpages_from_fscache(struct nfs_open_context *, 104 struct inode *, struct address_space *, 105 struct list_head *, unsigned *); 106 extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int); 107 108 /* 109 * wait for a page to complete writing to the cache 110 */ 111 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 112 struct page *page) 113 { 114 if (PageFsCache(page)) 115 fscache_wait_on_page_write(nfsi->fscache, page); 116 } 117 118 /* 119 * release the caching state associated with a page if undergoing complete page 120 * invalidation 121 */ 122 static inline void nfs_fscache_invalidate_page(struct page *page, 123 struct inode *inode) 124 { 125 if (PageFsCache(page)) 126 __nfs_fscache_invalidate_page(page, inode); 127 } 128 129 /* 130 * Retrieve a page from an inode data storage object. 131 */ 132 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 133 struct inode *inode, 134 struct page *page) 135 { 136 if (NFS_I(inode)->fscache) 137 return __nfs_readpage_from_fscache(ctx, inode, page); 138 return -ENOBUFS; 139 } 140 141 /* 142 * Retrieve a set of pages from an inode data storage object. 143 */ 144 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 145 struct inode *inode, 146 struct address_space *mapping, 147 struct list_head *pages, 148 unsigned *nr_pages) 149 { 150 if (NFS_I(inode)->fscache) 151 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages, 152 nr_pages); 153 return -ENOBUFS; 154 } 155 156 /* 157 * Store a page newly fetched from the server in an inode data storage object 158 * in the cache. 159 */ 160 static inline void nfs_readpage_to_fscache(struct inode *inode, 161 struct page *page, 162 int sync) 163 { 164 if (PageFsCache(page)) 165 __nfs_readpage_to_fscache(inode, page, sync); 166 } 167 168 /* 169 * Invalidate the contents of fscache for this inode. This will not sleep. 170 */ 171 static inline void nfs_fscache_invalidate(struct inode *inode) 172 { 173 fscache_invalidate(NFS_I(inode)->fscache); 174 } 175 176 /* 177 * Wait for an object to finish being invalidated. 178 */ 179 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) 180 { 181 fscache_wait_on_invalidate(NFS_I(inode)->fscache); 182 } 183 184 /* 185 * indicate the client caching state as readable text 186 */ 187 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 188 { 189 if (server->fscache && (server->options & NFS_OPTION_FSCACHE)) 190 return "yes"; 191 return "no "; 192 } 193 194 #else /* CONFIG_NFS_FSCACHE */ 195 static inline int nfs_fscache_register(void) { return 0; } 196 static inline void nfs_fscache_unregister(void) {} 197 198 static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {} 199 static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {} 200 201 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} 202 203 static inline void nfs_fscache_init_inode(struct inode *inode) {} 204 static inline void nfs_fscache_clear_inode(struct inode *inode) {} 205 static inline void nfs_fscache_open_file(struct inode *inode, 206 struct file *filp) {} 207 208 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) 209 { 210 return 1; /* True: may release page */ 211 } 212 static inline void nfs_fscache_invalidate_page(struct page *page, 213 struct inode *inode) {} 214 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 215 struct page *page) {} 216 217 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 218 struct inode *inode, 219 struct page *page) 220 { 221 return -ENOBUFS; 222 } 223 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 224 struct inode *inode, 225 struct address_space *mapping, 226 struct list_head *pages, 227 unsigned *nr_pages) 228 { 229 return -ENOBUFS; 230 } 231 static inline void nfs_readpage_to_fscache(struct inode *inode, 232 struct page *page, int sync) {} 233 234 235 static inline void nfs_fscache_invalidate(struct inode *inode) {} 236 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {} 237 238 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 239 { 240 return "no "; 241 } 242 243 #endif /* CONFIG_NFS_FSCACHE */ 244 #endif /* _NFS_FSCACHE_H */ 245