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
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