tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 */
21struct 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 */
64struct nfs_fscache_inode_auxdata {
65 struct timespec mtime;
66 struct timespec ctime;
67 u64 change_attr;
68};
69
70/*
71 * fscache-index.c
72 */
73extern struct fscache_netfs nfs_fscache_netfs;
74extern const struct fscache_cookie_def nfs_fscache_server_index_def;
75extern const struct fscache_cookie_def nfs_fscache_super_index_def;
76extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
77
78extern int nfs_fscache_register(void);
79extern void nfs_fscache_unregister(void);
80
81/*
82 * fscache.c
83 */
84extern void nfs_fscache_get_client_cookie(struct nfs_client *);
85extern void nfs_fscache_release_client_cookie(struct nfs_client *);
86
87extern void nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
88extern void nfs_fscache_release_super_cookie(struct super_block *);
89
90extern void nfs_fscache_init_inode(struct inode *);
91extern void nfs_fscache_clear_inode(struct inode *);
92extern void nfs_fscache_open_file(struct inode *, struct file *);
93
94extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
95extern int nfs_fscache_release_page(struct page *, gfp_t);
96
97extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
98 struct inode *, struct page *);
99extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
100 struct inode *, struct address_space *,
101 struct list_head *, unsigned *);
102extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
103
104/*
105 * wait for a page to complete writing to the cache
106 */
107static 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 */
118static 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 */
128static 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 */
140static 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 */
156static 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 */
167static 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 */
175static 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 */
183static 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 */
191static inline int nfs_fscache_register(void) { return 0; }
192static inline void nfs_fscache_unregister(void) {}
193
194static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
195static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
196
197static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
198
199static inline void nfs_fscache_init_inode(struct inode *inode) {}
200static inline void nfs_fscache_clear_inode(struct inode *inode) {}
201static inline void nfs_fscache_open_file(struct inode *inode,
202 struct file *filp) {}
203
204static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
205{
206 return 1; /* True: may release page */
207}
208static inline void nfs_fscache_invalidate_page(struct page *page,
209 struct inode *inode) {}
210static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
211 struct page *page) {}
212
213static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
214 struct inode *inode,
215 struct page *page)
216{
217 return -ENOBUFS;
218}
219static 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}
227static inline void nfs_readpage_to_fscache(struct inode *inode,
228 struct page *page, int sync) {}
229
230
231static inline void nfs_fscache_invalidate(struct inode *inode) {}
232static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {}
233
234static 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 */