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 *, 77 struct nfs_parsed_mount_data *); 78 extern void nfs_fscache_release_super_cookie(struct super_block *); 79 80 extern void nfs_fscache_init_inode_cookie(struct inode *); 81 extern void nfs_fscache_release_inode_cookie(struct inode *); 82 extern void nfs_fscache_zap_inode_cookie(struct inode *); 83 extern void nfs_fscache_set_inode_cookie(struct inode *, struct file *); 84 extern void nfs_fscache_reset_inode_cookie(struct inode *); 85 86 extern void __nfs_fscache_invalidate_page(struct page *, struct inode *); 87 extern int nfs_fscache_release_page(struct page *, gfp_t); 88 89 extern int __nfs_readpage_from_fscache(struct nfs_open_context *, 90 struct inode *, struct page *); 91 extern int __nfs_readpages_from_fscache(struct nfs_open_context *, 92 struct inode *, struct address_space *, 93 struct list_head *, unsigned *); 94 extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int); 95 96 /* 97 * wait for a page to complete writing to the cache 98 */ 99 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 100 struct page *page) 101 { 102 if (PageFsCache(page)) 103 fscache_wait_on_page_write(nfsi->fscache, page); 104 } 105 106 /* 107 * release the caching state associated with a page if undergoing complete page 108 * invalidation 109 */ 110 static inline void nfs_fscache_invalidate_page(struct page *page, 111 struct inode *inode) 112 { 113 if (PageFsCache(page)) 114 __nfs_fscache_invalidate_page(page, inode); 115 } 116 117 /* 118 * Retrieve a page from an inode data storage object. 119 */ 120 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 121 struct inode *inode, 122 struct page *page) 123 { 124 if (NFS_I(inode)->fscache) 125 return __nfs_readpage_from_fscache(ctx, inode, page); 126 return -ENOBUFS; 127 } 128 129 /* 130 * Retrieve a set of pages from an inode data storage object. 131 */ 132 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 133 struct inode *inode, 134 struct address_space *mapping, 135 struct list_head *pages, 136 unsigned *nr_pages) 137 { 138 if (NFS_I(inode)->fscache) 139 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages, 140 nr_pages); 141 return -ENOBUFS; 142 } 143 144 /* 145 * Store a page newly fetched from the server in an inode data storage object 146 * in the cache. 147 */ 148 static inline void nfs_readpage_to_fscache(struct inode *inode, 149 struct page *page, 150 int sync) 151 { 152 if (PageFsCache(page)) 153 __nfs_readpage_to_fscache(inode, page, sync); 154 } 155 156 /* 157 * indicate the client caching state as readable text 158 */ 159 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 160 { 161 if (server->fscache && (server->options & NFS_OPTION_FSCACHE)) 162 return "yes"; 163 return "no "; 164 } 165 166 167 #else /* CONFIG_NFS_FSCACHE */ 168 static inline int nfs_fscache_register(void) { return 0; } 169 static inline void nfs_fscache_unregister(void) {} 170 171 static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {} 172 static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {} 173 174 static inline void nfs_fscache_get_super_cookie( 175 struct super_block *sb, 176 struct nfs_parsed_mount_data *data) 177 { 178 } 179 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} 180 181 static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {} 182 static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {} 183 static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {} 184 static inline void nfs_fscache_set_inode_cookie(struct inode *inode, 185 struct file *filp) {} 186 static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {} 187 188 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) 189 { 190 return 1; /* True: may release page */ 191 } 192 static inline void nfs_fscache_invalidate_page(struct page *page, 193 struct inode *inode) {} 194 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 195 struct page *page) {} 196 197 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 198 struct inode *inode, 199 struct page *page) 200 { 201 return -ENOBUFS; 202 } 203 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 204 struct inode *inode, 205 struct address_space *mapping, 206 struct list_head *pages, 207 unsigned *nr_pages) 208 { 209 return -ENOBUFS; 210 } 211 static inline void nfs_readpage_to_fscache(struct inode *inode, 212 struct page *page, int sync) {} 213 214 static inline const char *nfs_server_fscache_state(struct nfs_server *server) 215 { 216 return "no "; 217 } 218 219 #endif /* CONFIG_NFS_FSCACHE */ 220 #endif /* _NFS_FSCACHE_H */ 221