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192.168.1.100 / T103 / 13eb6a97dabf274443d07c46a6ec8b3392553f08 / . / src / kernel / linux / v4.14 / fs / nfs / fscache.h
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rjw1f884582022-01-06 17:20:42 +0800[diff] [blame]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(struct inode *);
80extern void nfs_fscache_clear_inode(struct inode *);
81extern void nfs_fscache_open_file(struct inode *, struct file *);
82
83extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
84extern int nfs_fscache_release_page(struct page *, gfp_t);
85
86extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
87 struct inode *, struct page *);
88extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
89 struct inode *, struct address_space *,
90 struct list_head *, unsigned *);
91extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
92
93/*
94 * wait for a page to complete writing to the cache
95 */
96static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
97 struct page *page)
98{
99 if (PageFsCache(page))
100 fscache_wait_on_page_write(nfsi->fscache, page);
101}
102
103/*
104 * release the caching state associated with a page if undergoing complete page
105 * invalidation
106 */
107static inline void nfs_fscache_invalidate_page(struct page *page,
108 struct inode *inode)
109{
110 if (PageFsCache(page))
111 __nfs_fscache_invalidate_page(page, inode);
112}
113
114/*
115 * Retrieve a page from an inode data storage object.
116 */
117static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
118 struct inode *inode,
119 struct page *page)
120{
121 if (NFS_I(inode)->fscache)
122 return __nfs_readpage_from_fscache(ctx, inode, page);
123 return -ENOBUFS;
124}
125
126/*
127 * Retrieve a set of pages from an inode data storage object.
128 */
129static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
130 struct inode *inode,
131 struct address_space *mapping,
132 struct list_head *pages,
133 unsigned *nr_pages)
134{
135 if (NFS_I(inode)->fscache)
136 return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
137 nr_pages);
138 return -ENOBUFS;
139}
140
141/*
142 * Store a page newly fetched from the server in an inode data storage object
143 * in the cache.
144 */
145static inline void nfs_readpage_to_fscache(struct inode *inode,
146 struct page *page,
147 int sync)
148{
149 if (PageFsCache(page))
150 __nfs_readpage_to_fscache(inode, page, sync);
151}
152
153/*
154 * Invalidate the contents of fscache for this inode. This will not sleep.
155 */
156static inline void nfs_fscache_invalidate(struct inode *inode)
157{
158 fscache_invalidate(NFS_I(inode)->fscache);
159}
160
161/*
162 * Wait for an object to finish being invalidated.
163 */
164static inline void nfs_fscache_wait_on_invalidate(struct inode *inode)
165{
166 fscache_wait_on_invalidate(NFS_I(inode)->fscache);
167}
168
169/*
170 * indicate the client caching state as readable text
171 */
172static inline const char *nfs_server_fscache_state(struct nfs_server *server)
173{
174 if (server->fscache && (server->options & NFS_OPTION_FSCACHE))
175 return "yes";
176 return "no ";
177}
178
179#else /* CONFIG_NFS_FSCACHE */
180static inline int nfs_fscache_register(void) { return 0; }
181static inline void nfs_fscache_unregister(void) {}
182
183static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
184static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
185
186static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
187
188static inline void nfs_fscache_init_inode(struct inode *inode) {}
189static inline void nfs_fscache_clear_inode(struct inode *inode) {}
190static inline void nfs_fscache_open_file(struct inode *inode,
191 struct file *filp) {}
192
193static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
194{
195 return 1; /* True: may release page */
196}
197static inline void nfs_fscache_invalidate_page(struct page *page,
198 struct inode *inode) {}
199static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
200 struct page *page) {}
201
202static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
203 struct inode *inode,
204 struct page *page)
205{
206 return -ENOBUFS;
207}
208static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
209 struct inode *inode,
210 struct address_space *mapping,
211 struct list_head *pages,
212 unsigned *nr_pages)
213{
214 return -ENOBUFS;
215}
216static inline void nfs_readpage_to_fscache(struct inode *inode,
217 struct page *page, int sync) {}
218
219
220static inline void nfs_fscache_invalidate(struct inode *inode) {}
221static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {}
222
223static inline const char *nfs_server_fscache_state(struct nfs_server *server)
224{
225 return "no ";
226}
227
228#endif /* CONFIG_NFS_FSCACHE */
229#endif /* _NFS_FSCACHE_H */