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 s64 mtime_sec;
66 s64 mtime_nsec;
67 s64 ctime_sec;
68 s64 ctime_nsec;
69 u64 change_attr;
70 };
71
72 /*
73 * fscache-index.c
74 */
75 extern struct fscache_netfs nfs_fscache_netfs;
76 extern const struct fscache_cookie_def nfs_fscache_server_index_def;
77 extern const struct fscache_cookie_def nfs_fscache_super_index_def;
78 extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
79
80 extern int nfs_fscache_register(void);
81 extern void nfs_fscache_unregister(void);
82
83 /*
84 * fscache.c
85 */
86 extern void nfs_fscache_get_client_cookie(struct nfs_client *);
87 extern void nfs_fscache_release_client_cookie(struct nfs_client *);
88
89 extern void nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
90 extern void nfs_fscache_release_super_cookie(struct super_block *);
91
92 extern void nfs_fscache_init_inode(struct inode *);
93 extern void nfs_fscache_clear_inode(struct inode *);
94 extern void nfs_fscache_open_file(struct inode *, struct file *);
95
96 extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
97 extern int nfs_fscache_release_page(struct page *, gfp_t);
98
99 extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
100 struct inode *, struct page *);
101 extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
102 struct inode *, struct address_space *,
103 struct list_head *, unsigned *);
104 extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
105
106 /*
107 * wait for a page to complete writing to the cache
108 */
nfs_fscache_wait_on_page_write(struct nfs_inode * nfsi,struct page * page)109 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
110 struct page *page)
111 {
112 if (PageFsCache(page))
113 fscache_wait_on_page_write(nfsi->fscache, page);
114 }
115
116 /*
117 * release the caching state associated with a page if undergoing complete page
118 * invalidation
119 */
nfs_fscache_invalidate_page(struct page * page,struct inode * inode)120 static inline void nfs_fscache_invalidate_page(struct page *page,
121 struct inode *inode)
122 {
123 if (PageFsCache(page))
124 __nfs_fscache_invalidate_page(page, inode);
125 }
126
127 /*
128 * Retrieve a page from an inode data storage object.
129 */
nfs_readpage_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct page * page)130 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
131 struct inode *inode,
132 struct page *page)
133 {
134 if (NFS_I(inode)->fscache)
135 return __nfs_readpage_from_fscache(ctx, inode, page);
136 return -ENOBUFS;
137 }
138
139 /*
140 * Retrieve a set of pages from an inode data storage object.
141 */
nfs_readpages_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct address_space * mapping,struct list_head * pages,unsigned * nr_pages)142 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
143 struct inode *inode,
144 struct address_space *mapping,
145 struct list_head *pages,
146 unsigned *nr_pages)
147 {
148 if (NFS_I(inode)->fscache)
149 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
150 nr_pages);
151 return -ENOBUFS;
152 }
153
154 /*
155 * Store a page newly fetched from the server in an inode data storage object
156 * in the cache.
157 */
nfs_readpage_to_fscache(struct inode * inode,struct page * page,int sync)158 static inline void nfs_readpage_to_fscache(struct inode *inode,
159 struct page *page,
160 int sync)
161 {
162 if (PageFsCache(page))
163 __nfs_readpage_to_fscache(inode, page, sync);
164 }
165
166 /*
167 * Invalidate the contents of fscache for this inode. This will not sleep.
168 */
nfs_fscache_invalidate(struct inode * inode)169 static inline void nfs_fscache_invalidate(struct inode *inode)
170 {
171 fscache_invalidate(NFS_I(inode)->fscache);
172 }
173
174 /*
175 * Wait for an object to finish being invalidated.
176 */
nfs_fscache_wait_on_invalidate(struct inode * inode)177 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode)
178 {
179 fscache_wait_on_invalidate(NFS_I(inode)->fscache);
180 }
181
182 /*
183 * indicate the client caching state as readable text
184 */
nfs_server_fscache_state(struct nfs_server * server)185 static inline const char *nfs_server_fscache_state(struct nfs_server *server)
186 {
187 if (server->fscache)
188 return "yes";
189 return "no ";
190 }
191
192 #else /* CONFIG_NFS_FSCACHE */
nfs_fscache_register(void)193 static inline int nfs_fscache_register(void) { return 0; }
nfs_fscache_unregister(void)194 static inline void nfs_fscache_unregister(void) {}
195
nfs_fscache_get_client_cookie(struct nfs_client * clp)196 static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
nfs_fscache_release_client_cookie(struct nfs_client * clp)197 static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
198
nfs_fscache_release_super_cookie(struct super_block * sb)199 static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
200
nfs_fscache_init_inode(struct inode * inode)201 static inline void nfs_fscache_init_inode(struct inode *inode) {}
nfs_fscache_clear_inode(struct inode * inode)202 static inline void nfs_fscache_clear_inode(struct inode *inode) {}
nfs_fscache_open_file(struct inode * inode,struct file * filp)203 static inline void nfs_fscache_open_file(struct inode *inode,
204 struct file *filp) {}
205
nfs_fscache_release_page(struct page * page,gfp_t gfp)206 static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
207 {
208 return 1; /* True: may release page */
209 }
nfs_fscache_invalidate_page(struct page * page,struct inode * inode)210 static inline void nfs_fscache_invalidate_page(struct page *page,
211 struct inode *inode) {}
nfs_fscache_wait_on_page_write(struct nfs_inode * nfsi,struct page * page)212 static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
213 struct page *page) {}
214
nfs_readpage_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct page * page)215 static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
216 struct inode *inode,
217 struct page *page)
218 {
219 return -ENOBUFS;
220 }
nfs_readpages_from_fscache(struct nfs_open_context * ctx,struct inode * inode,struct address_space * mapping,struct list_head * pages,unsigned * nr_pages)221 static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
222 struct inode *inode,
223 struct address_space *mapping,
224 struct list_head *pages,
225 unsigned *nr_pages)
226 {
227 return -ENOBUFS;
228 }
nfs_readpage_to_fscache(struct inode * inode,struct page * page,int sync)229 static inline void nfs_readpage_to_fscache(struct inode *inode,
230 struct page *page, int sync) {}
231
232
nfs_fscache_invalidate(struct inode * inode)233 static inline void nfs_fscache_invalidate(struct inode *inode) {}
nfs_fscache_wait_on_invalidate(struct inode * inode)234 static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {}
235
nfs_server_fscache_state(struct nfs_server * server)236 static inline const char *nfs_server_fscache_state(struct nfs_server *server)
237 {
238 return "no ";
239 }
240
241 #endif /* CONFIG_NFS_FSCACHE */
242 #endif /* _NFS_FSCACHE_H */
243