1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* NFS filesystem cache interface definitions
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 #ifndef _NFS_FSCACHE_H
9 #define _NFS_FSCACHE_H
10
11 #include <linux/nfs_fs.h>
12 #include <linux/nfs_mount.h>
13 #include <linux/nfs4_mount.h>
14 #include <linux/fscache.h>
15
16 #ifdef CONFIG_NFS_FSCACHE
17
18 /*
19 * set of NFS FS-Cache objects that form a superblock key
20 */
21 struct nfs_fscache_key {
22 struct rb_node node;
23 struct nfs_client *nfs_client; /* the server */
24
25 /* the elements of the unique key - as used by nfs_compare_super() and
26 * nfs_compare_mount_options() to distinguish superblocks */
27 struct {
28 struct {
29 unsigned long s_flags; /* various flags
30 * (& NFS_MS_MASK) */
31 } super;
32
33 struct {
34 struct nfs_fsid fsid;
35 int flags;
36 unsigned int rsize; /* read size */
37 unsigned int wsize; /* write size */
38 unsigned int acregmin; /* attr cache timeouts */
39 unsigned int acregmax;
40 unsigned int acdirmin;
41 unsigned int acdirmax;
42 } nfs_server;
43
44 struct {
45 rpc_authflavor_t au_flavor;
46 } rpc_auth;
47
48 /* uniquifier - can be used if nfs_server.flags includes
49 * NFS_MOUNT_UNSHARED */
50 u8 uniq_len;
51 char uniquifier[0];
52 } key;
53 };
54
55 /*
56 * Definition of the auxiliary data attached to NFS inode storage objects
57 * within the cache.
58 *
59 * The contents of this struct are recorded in the on-disk local cache in the
60 * auxiliary data attached to the data storage object backing an inode. This
61 * permits coherency to be managed when a new inode binds to an already extant
62 * cache object.
63 */
64 struct nfs_fscache_inode_auxdata {
65 struct timespec mtime;
66 struct timespec ctime;
67 u64 change_attr;
68 };
69
70 /*
71 * fscache-index.c
72 */
73 extern struct fscache_netfs nfs_fscache_netfs;
74 extern const struct fscache_cookie_def nfs_fscache_server_index_def;
75 extern const struct fscache_cookie_def nfs_fscache_super_index_def;
76 extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
77
78 extern int nfs_fscache_register(void);
79 extern void nfs_fscache_unregister(void);
80
81 /*
82 * fscache.c
83 */
84 extern void nfs_fscache_get_client_cookie(struct nfs_client *);
85 extern void nfs_fscache_release_client_cookie(struct nfs_client *);
86
87 extern void nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
88 extern void nfs_fscache_release_super_cookie(struct super_block *);
89
90 extern void nfs_fscache_init_inode(struct inode *);
91 extern void nfs_fscache_clear_inode(struct inode *);
92 extern void nfs_fscache_open_file(struct inode *, struct file *);
93
94 extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
95 extern int nfs_fscache_release_page(struct page *, gfp_t);
96
97 extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
98 struct inode *, struct page *);
99 extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
100 struct inode *, struct address_space *,
101 struct list_head *, unsigned *);
102 extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
103
104 /*
105 * wait for a page to complete writing to the cache
106 */
nfs_fscache_wait_on_page_write(struct nfs_inode * nfsi,struct page * page)107 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
108 struct page *page)
109 {
110 if (PageFsCache(page))
111 fscache_wait_on_page_write(nfsi->fscache, page);
112 }
113
114 /*
115 * release the caching state associated with a page if undergoing complete page
116 * invalidation
117 */
nfs_fscache_invalidate_page(struct page * page,struct inode * inode)118 static inline void nfs_fscache_invalidate_page(struct page *page,
119 struct inode *inode)
120 {
121 if (PageFsCache(page))
122 __nfs_fscache_invalidate_page(page, inode);
123 }
124
125 /*
126 * Retrieve a page from an inode data storage object.
127 */
nfs_readpage_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct page * page)128 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
129 struct inode *inode,
130 struct page *page)
131 {
132 if (NFS_I(inode)->fscache)
133 return __nfs_readpage_from_fscache(ctx, inode, page);
134 return -ENOBUFS;
135 }
136
137 /*
138 * Retrieve a set of pages from an inode data storage object.
139 */
nfs_readpages_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct address_space * mapping,struct list_head * pages,unsigned * nr_pages)140 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
141 struct inode *inode,
142 struct address_space *mapping,
143 struct list_head *pages,
144 unsigned *nr_pages)
145 {
146 if (NFS_I(inode)->fscache)
147 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
148 nr_pages);
149 return -ENOBUFS;
150 }
151
152 /*
153 * Store a page newly fetched from the server in an inode data storage object
154 * in the cache.
155 */
nfs_readpage_to_fscache(struct inode * inode,struct page * page,int sync)156 static inline void nfs_readpage_to_fscache(struct inode *inode,
157 struct page *page,
158 int sync)
159 {
160 if (PageFsCache(page))
161 __nfs_readpage_to_fscache(inode, page, sync);
162 }
163
164 /*
165 * Invalidate the contents of fscache for this inode. This will not sleep.
166 */
nfs_fscache_invalidate(struct inode * inode)167 static inline void nfs_fscache_invalidate(struct inode *inode)
168 {
169 fscache_invalidate(NFS_I(inode)->fscache);
170 }
171
172 /*
173 * Wait for an object to finish being invalidated.
174 */
nfs_fscache_wait_on_invalidate(struct inode * inode)175 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode)
176 {
177 fscache_wait_on_invalidate(NFS_I(inode)->fscache);
178 }
179
180 /*
181 * indicate the client caching state as readable text
182 */
nfs_server_fscache_state(struct nfs_server * server)183 static inline const char *nfs_server_fscache_state(struct nfs_server *server)
184 {
185 if (server->fscache)
186 return "yes";
187 return "no ";
188 }
189
190 #else /* CONFIG_NFS_FSCACHE */
nfs_fscache_register(void)191 static inline int nfs_fscache_register(void) { return 0; }
nfs_fscache_unregister(void)192 static inline void nfs_fscache_unregister(void) {}
193
nfs_fscache_get_client_cookie(struct nfs_client * clp)194 static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
nfs_fscache_release_client_cookie(struct nfs_client * clp)195 static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
196
nfs_fscache_release_super_cookie(struct super_block * sb)197 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
198
nfs_fscache_init_inode(struct inode * inode)199 static inline void nfs_fscache_init_inode(struct inode *inode) {}
nfs_fscache_clear_inode(struct inode * inode)200 static inline void nfs_fscache_clear_inode(struct inode *inode) {}
nfs_fscache_open_file(struct inode * inode,struct file * filp)201 static inline void nfs_fscache_open_file(struct inode *inode,
202 struct file *filp) {}
203
nfs_fscache_release_page(struct page * page,gfp_t gfp)204 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
205 {
206 return 1; /* True: may release page */
207 }
nfs_fscache_invalidate_page(struct page * page,struct inode * inode)208 static inline void nfs_fscache_invalidate_page(struct page *page,
209 struct inode *inode) {}
nfs_fscache_wait_on_page_write(struct nfs_inode * nfsi,struct page * page)210 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
211 struct page *page) {}
212
nfs_readpage_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct page * page)213 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
214 struct inode *inode,
215 struct page *page)
216 {
217 return -ENOBUFS;
218 }
nfs_readpages_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct address_space * mapping,struct list_head * pages,unsigned * nr_pages)219 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
220 struct inode *inode,
221 struct address_space *mapping,
222 struct list_head *pages,
223 unsigned *nr_pages)
224 {
225 return -ENOBUFS;
226 }
nfs_readpage_to_fscache(struct inode * inode,struct page * page,int sync)227 static inline void nfs_readpage_to_fscache(struct inode *inode,
228 struct page *page, int sync) {}
229
230
nfs_fscache_invalidate(struct inode * inode)231 static inline void nfs_fscache_invalidate(struct inode *inode) {}
nfs_fscache_wait_on_invalidate(struct inode * inode)232 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {}
233
nfs_server_fscache_state(struct nfs_server * server)234 static inline const char *nfs_server_fscache_state(struct nfs_server *server)
235 {
236 return "no ";
237 }
238
239 #endif /* CONFIG_NFS_FSCACHE */
240 #endif /* _NFS_FSCACHE_H */
241