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authorAbhishek Kulkarni <adkulkar@umail.iu.edu>2009-09-23 14:00:27 -0400
committerEric Van Hensbergen <ericvh@strongmad.austin.ibm.com>2009-09-23 14:03:46 -0400
commit60e78d2c993e58d890596d951fff77d5965adcd6 (patch)
tree3d53ed7254c613ef8d8de36fdceda25bc493f4f7 /fs/9p/cache.h
parent637d020a02cd734bf27acfc56c6d942cddd9eb80 (diff)
9p: Add fscache support to 9p
This patch adds a persistent, read-only caching facility for 9p clients using the FS-Cache caching backend. When the fscache facility is enabled, each inode is associated with a corresponding vcookie which is an index into the FS-Cache indexing tree. The FS-Cache indexing tree is indexed at 3 levels: - session object associated with each mount. - inode/vcookie - actual data (pages) A cache tag is chosen randomly for each session. These tags can be read off /sys/fs/9p/caches and can be passed as a mount-time parameter to re-attach to the specified caching session. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'fs/9p/cache.h')
-rw-r--r--fs/9p/cache.h176
1 files changed, 176 insertions, 0 deletions
diff --git a/fs/9p/cache.h b/fs/9p/cache.h
new file mode 100644
index 000000000000..a94192bfaee8
--- /dev/null
+++ b/fs/9p/cache.h
@@ -0,0 +1,176 @@
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 */
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-08 16:44:01 -0500