1/*
2 * V9FS cache definitions.
3 *
4 *  Copyright (C) 2009 by Abhishek Kulkarni <adkulkar@umail.iu.edu>
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License version 2
8 *  as published by the Free Software Foundation.
9 *
10 *  This program is distributed in the hope that it will be useful,
11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 *  GNU General Public License for more details.
14 *
15 *  You should have received a copy of the GNU General Public License
16 *  along with this program; if not, write to:
17 *  Free Software Foundation
18 *  51 Franklin Street, Fifth Floor
19 *  Boston, MA  02111-1301  USA
20 *
21 */
22
23#ifndef _9P_CACHE_H
24#ifdef CONFIG_9P_FSCACHE
25#include <linux/fscache.h>
26#include <linux/spinlock.h>
27
28extern struct kmem_cache *vcookie_cache;
29
30struct v9fs_cookie {
31	spinlock_t lock;
32	struct inode inode;
33	struct fscache_cookie *fscache;
34	struct p9_qid *qid;
35};
36
37static inline struct v9fs_cookie *v9fs_inode2cookie(const struct inode *inode)
38{
39	return container_of(inode, struct v9fs_cookie, inode);
40}
41
42extern struct fscache_netfs v9fs_cache_netfs;
43extern const struct fscache_cookie_def v9fs_cache_session_index_def;
44extern const struct fscache_cookie_def v9fs_cache_inode_index_def;
45
46extern void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses);
47extern void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses);
48
49extern void v9fs_cache_inode_get_cookie(struct inode *inode);
50extern void v9fs_cache_inode_put_cookie(struct inode *inode);
51extern void v9fs_cache_inode_flush_cookie(struct inode *inode);
52extern void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp);
53extern void v9fs_cache_inode_reset_cookie(struct inode *inode);
54
55extern int __v9fs_cache_register(void);
56extern void __v9fs_cache_unregister(void);
57
58extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp);
59extern void __v9fs_fscache_invalidate_page(struct page *page);
60extern int __v9fs_readpage_from_fscache(struct inode *inode,
61					struct page *page);
62extern int __v9fs_readpages_from_fscache(struct inode *inode,
63					 struct address_space *mapping,
64					 struct list_head *pages,
65					 unsigned *nr_pages);
66extern void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page);
67
68
69/**
70 * v9fs_cache_register - Register v9fs file system with the cache
71 */
72static inline int v9fs_cache_register(void)
73{
74	return __v9fs_cache_register();
75}
76
77/**
78 * v9fs_cache_unregister - Unregister v9fs from the cache
79 */
80static inline void v9fs_cache_unregister(void)
81{
82	__v9fs_cache_unregister();
83}
84
85static inline int v9fs_fscache_release_page(struct page *page,
86					    gfp_t gfp)
87{
88	return __v9fs_fscache_release_page(page, gfp);
89}
90
91static inline void v9fs_fscache_invalidate_page(struct page *page)
92{
93	__v9fs_fscache_invalidate_page(page);
94}
95
96static inline int v9fs_readpage_from_fscache(struct inode *inode,
97					     struct page *page)
98{
99	return __v9fs_readpage_from_fscache(inode, page);
100}
101
102static inline int v9fs_readpages_from_fscache(struct inode *inode,
103					      struct address_space *mapping,
104					      struct list_head *pages,
105					      unsigned *nr_pages)
106{
107	return __v9fs_readpages_from_fscache(inode, mapping, pages,
108					     nr_pages);
109}
110
111static inline void v9fs_readpage_to_fscache(struct inode *inode,
112					    struct page *page)
113{
114	if (PageFsCache(page))
115		__v9fs_readpage_to_fscache(inode, page);
116}
117
118static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
119{
120	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
121	fscache_uncache_page(vcookie->fscache, page);
122	BUG_ON(PageFsCache(page));
123}
124
125static inline void v9fs_vcookie_set_qid(struct inode *inode,
126					struct p9_qid *qid)
127{
128	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
129	spin_lock(&vcookie->lock);
130	vcookie->qid = qid;
131	spin_unlock(&vcookie->lock);
132}
133
134#else /* CONFIG_9P_FSCACHE */
135
136static inline int v9fs_cache_register(void)
137{
138	return 1;
139}
140
141static inline void v9fs_cache_unregister(void) {}
142
143static inline int v9fs_fscache_release_page(struct page *page,
144					    gfp_t gfp) {
145	return 1;
146}
147
148static inline void v9fs_fscache_invalidate_page(struct page *page) {}
149
150static inline int v9fs_readpage_from_fscache(struct inode *inode,
151					     struct page *page)
152{
153	return -ENOBUFS;
154}
155
156static inline int v9fs_readpages_from_fscache(struct inode *inode,
157					      struct address_space *mapping,
158					      struct list_head *pages,
159					      unsigned *nr_pages)
160{
161	return -ENOBUFS;
162}
163
164static inline void v9fs_readpage_to_fscache(struct inode *inode,
165					    struct page *page)
166{}
167
168static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
169{}
170
171static inline void v9fs_vcookie_set_qid(struct inode *inode,
172					struct p9_qid *qid)
173{}
174
175#endif /* CONFIG_9P_FSCACHE */
176#endif /* _9P_CACHE_H */
177