xref: /kernel/linux/linux-5.10/fs/cifs/fscache.h (revision 8c2ecf20)
1/*
2 *   fs/cifs/fscache.h - CIFS filesystem cache interface definitions
3 *
4 *   Copyright (c) 2010 Novell, Inc.
5 *   Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
6 *
7 *   This library is free software; you can redistribute it and/or modify
8 *   it under the terms of the GNU Lesser General Public License as published
9 *   by the Free Software Foundation; either version 2.1 of the License, or
10 *   (at your option) any later version.
11 *
12 *   This library is distributed in the hope that it will be useful,
13 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
15 *   the GNU Lesser General Public License for more details.
16 *
17 *   You should have received a copy of the GNU Lesser General Public License
18 *   along with this library; if not, write to the Free Software
19 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21#ifndef _CIFS_FSCACHE_H
22#define _CIFS_FSCACHE_H
23
24#include <linux/fscache.h>
25
26#include "cifsglob.h"
27
28#ifdef CONFIG_CIFS_FSCACHE
29
30/*
31 * Auxiliary data attached to CIFS superblock within the cache
32 */
33struct cifs_fscache_super_auxdata {
34	u64	resource_id;		/* unique server resource id */
35	__le64	vol_create_time;
36	u32	vol_serial_number;
37} __packed;
38
39/*
40 * Auxiliary data attached to CIFS inode within the cache
41 */
42struct cifs_fscache_inode_auxdata {
43	u64 last_write_time_sec;
44	u64 last_change_time_sec;
45	u32 last_write_time_nsec;
46	u32 last_change_time_nsec;
47	u64 eof;
48};
49
50/*
51 * cache.c
52 */
53extern struct fscache_netfs cifs_fscache_netfs;
54extern const struct fscache_cookie_def cifs_fscache_server_index_def;
55extern const struct fscache_cookie_def cifs_fscache_super_index_def;
56extern const struct fscache_cookie_def cifs_fscache_inode_object_def;
57
58extern int cifs_fscache_register(void);
59extern void cifs_fscache_unregister(void);
60extern char *extract_sharename(const char *);
61
62/*
63 * fscache.c
64 */
65extern void cifs_fscache_get_client_cookie(struct TCP_Server_Info *);
66extern void cifs_fscache_release_client_cookie(struct TCP_Server_Info *);
67extern void cifs_fscache_get_super_cookie(struct cifs_tcon *);
68extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);
69
70extern void cifs_fscache_release_inode_cookie(struct inode *);
71extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
72extern void cifs_fscache_reset_inode_cookie(struct inode *);
73
74extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
75extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
76extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
77extern int __cifs_readpages_from_fscache(struct inode *,
78					 struct address_space *,
79					 struct list_head *,
80					 unsigned *);
81extern void __cifs_fscache_readpages_cancel(struct inode *, struct list_head *);
82
83extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
84
85static inline void cifs_fscache_invalidate_page(struct page *page,
86					       struct inode *inode)
87{
88	if (PageFsCache(page))
89		__cifs_fscache_invalidate_page(page, inode);
90}
91
92static inline int cifs_readpage_from_fscache(struct inode *inode,
93					     struct page *page)
94{
95	if (CIFS_I(inode)->fscache)
96		return __cifs_readpage_from_fscache(inode, page);
97
98	return -ENOBUFS;
99}
100
101static inline int cifs_readpages_from_fscache(struct inode *inode,
102					      struct address_space *mapping,
103					      struct list_head *pages,
104					      unsigned *nr_pages)
105{
106	if (CIFS_I(inode)->fscache)
107		return __cifs_readpages_from_fscache(inode, mapping, pages,
108						     nr_pages);
109	return -ENOBUFS;
110}
111
112static inline void cifs_readpage_to_fscache(struct inode *inode,
113					    struct page *page)
114{
115	if (PageFsCache(page))
116		__cifs_readpage_to_fscache(inode, page);
117}
118
119static inline void cifs_fscache_readpages_cancel(struct inode *inode,
120						 struct list_head *pages)
121{
122	if (CIFS_I(inode)->fscache)
123		return __cifs_fscache_readpages_cancel(inode, pages);
124}
125
126#else /* CONFIG_CIFS_FSCACHE */
127static inline int cifs_fscache_register(void) { return 0; }
128static inline void cifs_fscache_unregister(void) {}
129
130static inline void
131cifs_fscache_get_client_cookie(struct TCP_Server_Info *server) {}
132static inline void
133cifs_fscache_release_client_cookie(struct TCP_Server_Info *server) {}
134static inline void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) {}
135static inline void
136cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}
137
138static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
139static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
140						 struct file *filp) {}
141static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
142static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)
143{
144	return 1; /* May release page */
145}
146
147static inline void cifs_fscache_invalidate_page(struct page *page,
148			struct inode *inode) {}
149static inline int
150cifs_readpage_from_fscache(struct inode *inode, struct page *page)
151{
152	return -ENOBUFS;
153}
154
155static inline int cifs_readpages_from_fscache(struct inode *inode,
156					      struct address_space *mapping,
157					      struct list_head *pages,
158					      unsigned *nr_pages)
159{
160	return -ENOBUFS;
161}
162
163static inline void cifs_readpage_to_fscache(struct inode *inode,
164			struct page *page) {}
165
166static inline void cifs_fscache_readpages_cancel(struct inode *inode,
167						 struct list_head *pages)
168{
169}
170
171#endif /* CONFIG_CIFS_FSCACHE */
172
173#endif /* _CIFS_FSCACHE_H */
174