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 */ 25struct 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 */ 62extern struct fscache_netfs nfs_fscache_netfs; 63extern const struct fscache_cookie_def nfs_fscache_server_index_def; 64extern const struct fscache_cookie_def nfs_fscache_super_index_def; 65extern const struct fscache_cookie_def nfs_fscache_inode_object_def; 66 67extern int nfs_fscache_register(void); 68extern void nfs_fscache_unregister(void); 69 70/* 71 * fscache.c 72 */ 73extern void nfs_fscache_get_client_cookie(struct nfs_client *); 74extern void nfs_fscache_release_client_cookie(struct nfs_client *); 75 76extern void nfs_fscache_get_super_cookie(struct super_block *, 77 const char *, 78 struct nfs_clone_mount *); 79extern void nfs_fscache_release_super_cookie(struct super_block *); 80 81extern void nfs_fscache_init_inode_cookie(struct inode *); 82extern void nfs_fscache_release_inode_cookie(struct inode *); 83extern void nfs_fscache_zap_inode_cookie(struct inode *); 84extern void nfs_fscache_set_inode_cookie(struct inode *, struct file *); 85extern void nfs_fscache_reset_inode_cookie(struct inode *); 86 87extern void __nfs_fscache_invalidate_page(struct page *, struct inode *); 88extern int nfs_fscache_release_page(struct page *, gfp_t); 89 90extern int __nfs_readpage_from_fscache(struct nfs_open_context *, 91 struct inode *, struct page *); 92extern int __nfs_readpages_from_fscache(struct nfs_open_context *, 93 struct inode *, struct address_space *, 94 struct list_head *, unsigned *); 95extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int); 96 97/* 98 * wait for a page to complete writing to the cache 99 */ 100static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 101 struct page *page) 102{ 103 if (PageFsCache(page)) 104 fscache_wait_on_page_write(nfsi->fscache, page); 105} 106 107/* 108 * release the caching state associated with a page if undergoing complete page 109 * invalidation 110 */ 111static inline void nfs_fscache_invalidate_page(struct page *page, 112 struct inode *inode) 113{ 114 if (PageFsCache(page)) 115 __nfs_fscache_invalidate_page(page, inode); 116} 117 118/* 119 * Retrieve a page from an inode data storage object. 120 */ 121static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 122 struct inode *inode, 123 struct page *page) 124{ 125 if (NFS_I(inode)->fscache) 126 return __nfs_readpage_from_fscache(ctx, inode, page); 127 return -ENOBUFS; 128} 129 130/* 131 * Retrieve a set of pages from an inode data storage object. 132 */ 133static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 134 struct inode *inode, 135 struct address_space *mapping, 136 struct list_head *pages, 137 unsigned *nr_pages) 138{ 139 if (NFS_I(inode)->fscache) 140 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages, 141 nr_pages); 142 return -ENOBUFS; 143} 144 145/* 146 * Store a page newly fetched from the server in an inode data storage object 147 * in the cache. 148 */ 149static inline void nfs_readpage_to_fscache(struct inode *inode, 150 struct page *page, 151 int sync) 152{ 153 if (PageFsCache(page)) 154 __nfs_readpage_to_fscache(inode, page, sync); 155} 156 157/* 158 * indicate the client caching state as readable text 159 */ 160static inline const char *nfs_server_fscache_state(struct nfs_server *server) 161{ 162 if (server->fscache && (server->options & NFS_OPTION_FSCACHE)) 163 return "yes"; 164 return "no "; 165} 166 167 168#else /* CONFIG_NFS_FSCACHE */ 169static inline int nfs_fscache_register(void) { return 0; } 170static inline void nfs_fscache_unregister(void) {} 171 172static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {} 173static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {} 174 175static inline void nfs_fscache_get_super_cookie( 176 struct super_block *sb, 177 const char *uniq, 178 struct nfs_clone_mount *mntdata) 179{ 180} 181static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} 182 183static inline void nfs_fscache_init_inode_cookie(struct inode *inode) {} 184static inline void nfs_fscache_release_inode_cookie(struct inode *inode) {} 185static inline void nfs_fscache_zap_inode_cookie(struct inode *inode) {} 186static inline void nfs_fscache_set_inode_cookie(struct inode *inode, 187 struct file *filp) {} 188static inline void nfs_fscache_reset_inode_cookie(struct inode *inode) {} 189 190static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp) 191{ 192 return 1; /* True: may release page */ 193} 194static inline void nfs_fscache_invalidate_page(struct page *page, 195 struct inode *inode) {} 196static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi, 197 struct page *page) {} 198 199static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx, 200 struct inode *inode, 201 struct page *page) 202{ 203 return -ENOBUFS; 204} 205static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx, 206 struct inode *inode, 207 struct address_space *mapping, 208 struct list_head *pages, 209 unsigned *nr_pages) 210{ 211 return -ENOBUFS; 212} 213static inline void nfs_readpage_to_fscache(struct inode *inode, 214 struct page *page, int sync) {} 215 216static inline const char *nfs_server_fscache_state(struct nfs_server *server) 217{ 218 return "no "; 219} 220 221#endif /* CONFIG_NFS_FSCACHE */ 222#endif /* _NFS_FSCACHE_H */ 223