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(struct inode *); 80 extern void nfs_fscache_clear_inode(struct inode *); 81 extern void nfs_fscache_open_file(struct inode *, struct file *); 82 83 extern void __nfs_fscache_invalidate_page(struct page *, struct inode *); 84 extern int nfs_fscache_release_page(struct page *, gfp_t); 85 86 extern int __nfs_readpage_from_fscache(struct nfs_open_context *, 87 struct inode *, struct page *); 88 extern int __nfs_readpages_from_fscache(struct nfs_open_context *, 89 struct inode *, struct address_space *, 90 struct list_head *, unsigned *); 91 extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int); 92 93 /* 94 * wait for a page to complete writing to the cache 95 */ 96 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 97 struct page *page) 98 { 99 if (PageFsCache(page)) 100 fscache_wait_on_page_write(nfsi->fscache, page); 101 } 102 103 /* 104 * release the caching state associated with a page if undergoing complete page 105 * invalidation 106 */ 107 static inline void nfs_fscache_invalidate_page(struct page *page, 108 struct inode *inode) 109 { 110 if (PageFsCache(page)) 111 __nfs_fscache_invalidate_page(page, inode); 112 } 113 114 /* 115 * Retrieve a page from an inode data storage object. 116 */ 117 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 118 struct inode *inode, 119 struct page *page) 120 { 121 if (NFS_I(inode)->fscache) 122 return __nfs_readpage_from_fscache(ctx, inode, page); 123 return -ENOBUFS; 124 } 125 126 /* 127 * Retrieve a set of pages from an inode data storage object. 128 */ 129 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 130 struct inode *inode, 131 struct address_space *mapping, 132 struct list_head *pages, 133 unsigned *nr_pages) 134 { 135 if (NFS_I(inode)->fscache) 136 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages, 137 nr_pages); 138 return -ENOBUFS; 139 } 140 141 /* 142 * Store a page newly fetched from the server in an inode data storage object 143 * in the cache. 144 */ 145 static inline void nfs_readpage_to_fscache(struct inode *inode, 146 struct page *page, 147 int sync) 148 { 149 if (PageFsCache(page)) 150 __nfs_readpage_to_fscache(inode, page, sync); 151 } 152 153 /* 154 * Invalidate the contents of fscache for this inode. This will not sleep. 155 */ 156 static inline void nfs_fscache_invalidate(struct inode *inode) 157 { 158 fscache_invalidate(NFS_I(inode)->fscache); 159 } 160 161 /* 162 * Wait for an object to finish being invalidated. 163 */ 164 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) 165 { 166 fscache_wait_on_invalidate(NFS_I(inode)->fscache); 167 } 168 169 /* 170 * indicate the client caching state as readable text 171 */ 172 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 173 { 174 if (server->fscache && (server->options & NFS_OPTION_FSCACHE)) 175 return "yes"; 176 return "no "; 177 } 178 179 #else /* CONFIG_NFS_FSCACHE */ 180 static inline int nfs_fscache_register(void) { return 0; } 181 static inline void nfs_fscache_unregister(void) {} 182 183 static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {} 184 static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {} 185 186 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} 187 188 static inline void nfs_fscache_init_inode(struct inode *inode) {} 189 static inline void nfs_fscache_clear_inode(struct inode *inode) {} 190 static inline void nfs_fscache_open_file(struct inode *inode, 191 struct file *filp) {} 192 193 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) 194 { 195 return 1; /* True: may release page */ 196 } 197 static inline void nfs_fscache_invalidate_page(struct page *page, 198 struct inode *inode) {} 199 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 200 struct page *page) {} 201 202 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 203 struct inode *inode, 204 struct page *page) 205 { 206 return -ENOBUFS; 207 } 208 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 209 struct inode *inode, 210 struct address_space *mapping, 211 struct list_head *pages, 212 unsigned *nr_pages) 213 { 214 return -ENOBUFS; 215 } 216 static inline void nfs_readpage_to_fscache(struct inode *inode, 217 struct page *page, int sync) {} 218 219 220 static inline void nfs_fscache_invalidate(struct inode *inode) {} 221 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {} 222 223 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 224 { 225 return "no "; 226 } 227 228 #endif /* CONFIG_NFS_FSCACHE */ 229 #endif /* _NFS_FSCACHE_H */ 230