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