xref: /openbmc/linux/fs/9p/cache.h (revision d3ea9fa0)
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 
28 extern struct kmem_cache *vcookie_cache;
29 
30 struct v9fs_cookie {
31 	spinlock_t lock;
32 	struct inode inode;
33 	struct fscache_cookie *fscache;
34 	struct p9_qid *qid;
35 };
36 
37 static inline struct v9fs_cookie *v9fs_inode2cookie(const struct inode *inode)
38 {
39 	return container_of(inode, struct v9fs_cookie, inode);
40 }
41 
42 extern struct fscache_netfs v9fs_cache_netfs;
43 extern const struct fscache_cookie_def v9fs_cache_session_index_def;
44 extern const struct fscache_cookie_def v9fs_cache_inode_index_def;
45 
46 extern void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses);
47 extern void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses);
48 
49 extern void v9fs_cache_inode_get_cookie(struct inode *inode);
50 extern void v9fs_cache_inode_put_cookie(struct inode *inode);
51 extern void v9fs_cache_inode_flush_cookie(struct inode *inode);
52 extern void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp);
53 extern void v9fs_cache_inode_reset_cookie(struct inode *inode);
54 
55 extern int __v9fs_cache_register(void);
56 extern void __v9fs_cache_unregister(void);
57 
58 extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp);
59 extern void __v9fs_fscache_invalidate_page(struct page *page);
60 extern int __v9fs_readpage_from_fscache(struct inode *inode,
61 					struct page *page);
62 extern int __v9fs_readpages_from_fscache(struct inode *inode,
63 					 struct address_space *mapping,
64 					 struct list_head *pages,
65 					 unsigned *nr_pages);
66 extern 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  */
72 static 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  */
80 static inline void v9fs_cache_unregister(void)
81 {
82 	__v9fs_cache_unregister();
83 }
84 
85 static inline int v9fs_fscache_release_page(struct page *page,
86 					    gfp_t gfp)
87 {
88 	return __v9fs_fscache_release_page(page, gfp);
89 }
90 
91 static inline void v9fs_fscache_invalidate_page(struct page *page)
92 {
93 	__v9fs_fscache_invalidate_page(page);
94 }
95 
96 static inline int v9fs_readpage_from_fscache(struct inode *inode,
97 					     struct page *page)
98 {
99 	return __v9fs_readpage_from_fscache(inode, page);
100 }
101 
102 static 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 
111 static 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 
118 static 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 
125 static 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 
136 static inline int v9fs_cache_register(void)
137 {
138 	return 1;
139 }
140 
141 static inline void v9fs_cache_unregister(void) {}
142 
143 static inline int v9fs_fscache_release_page(struct page *page,
144 					    gfp_t gfp) {
145 	return 1;
146 }
147 
148 static inline void v9fs_fscache_invalidate_page(struct page *page) {}
149 
150 static inline int v9fs_readpage_from_fscache(struct inode *inode,
151 					     struct page *page)
152 {
153 	return -ENOBUFS;
154 }
155 
156 static 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 
164 static inline void v9fs_readpage_to_fscache(struct inode *inode,
165 					    struct page *page)
166 {}
167 
168 static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
169 {}
170 
171 static 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