fs/9p/cache.h

   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 #define _9P_CACHE_H
  25 #ifdef CONFIG_9P_FSCACHE
  26 #include <linux/fscache.h>
  27 #include <linux/spinlock.h>
  28
  29 extern struct fscache_netfs v9fs_cache_netfs;
  30 extern const struct fscache_cookie_def v9fs_cache_session_index_def;
  31 extern const struct fscache_cookie_def v9fs_cache_inode_index_def;
  32
  33 extern void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses);
  34 extern void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses);
  35
  36 extern void v9fs_cache_inode_get_cookie(struct inode *inode);
  37 extern void v9fs_cache_inode_put_cookie(struct inode *inode);
  38 extern void v9fs_cache_inode_flush_cookie(struct inode *inode);
  39 extern void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp);
  40 extern void v9fs_cache_inode_reset_cookie(struct inode *inode);
  41
  42 extern int __v9fs_cache_register(void);
  43 extern void __v9fs_cache_unregister(void);
  44
  45 extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp);
  46 extern void __v9fs_fscache_invalidate_page(struct page *page);
  47 extern int __v9fs_readpage_from_fscache(struct inode *inode,
  48                                         struct page *page);
  49 extern int __v9fs_readpages_from_fscache(struct inode *inode,
  50                                          struct address_space *mapping,
  51                                          struct list_head *pages,
  52                                          unsigned *nr_pages);
  53 extern void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page);
  54 extern void __v9fs_fscache_wait_on_page_write(struct inode *inode,
  55                                               struct page *page);
  56
  57 static inline int v9fs_fscache_release_page(struct page *page,
  58                                             gfp_t gfp)
  59 {
  60         return __v9fs_fscache_release_page(page, gfp);
  61 }
  62
  63 static inline void v9fs_fscache_invalidate_page(struct page *page)
  64 {
  65         __v9fs_fscache_invalidate_page(page);
  66 }
  67
  68 static inline int v9fs_readpage_from_fscache(struct inode *inode,
  69                                              struct page *page)
  70 {
  71         return __v9fs_readpage_from_fscache(inode, page);
  72 }
  73
  74 static inline int v9fs_readpages_from_fscache(struct inode *inode,
  75                                               struct address_space *mapping,
  76                                               struct list_head *pages,
  77                                               unsigned *nr_pages)
  78 {
  79         return __v9fs_readpages_from_fscache(inode, mapping, pages,
  80                                              nr_pages);
  81 }
  82
  83 static inline void v9fs_readpage_to_fscache(struct inode *inode,
  84                                             struct page *page)
  85 {
  86         if (PageFsCache(page))
  87                 __v9fs_readpage_to_fscache(inode, page);
  88 }
  89
  90 static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
  91 {
  92         struct v9fs_inode *v9inode = V9FS_I(inode);
  93         fscache_uncache_page(v9inode->fscache, page);
  94         BUG_ON(PageFsCache(page));
  95 }
  96
  97 static inline void v9fs_fscache_wait_on_page_write(struct inode *inode,
  98                                                    struct page *page)
  99 {
 100         return __v9fs_fscache_wait_on_page_write(inode, page);
 101 }
 102
 103 #else /* CONFIG_9P_FSCACHE */
 104
 105 static inline void v9fs_cache_inode_get_cookie(struct inode *inode)
 106 {
 107 }
 108
 109 static inline void v9fs_cache_inode_put_cookie(struct inode *inode)
 110 {
 111 }
 112
 113 static inline void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *file)
 114 {
 115 }
 116
 117 static inline int v9fs_fscache_release_page(struct page *page,
 118                                             gfp_t gfp) {
 119         return 1;
 120 }
 121
 122 static inline void v9fs_fscache_invalidate_page(struct page *page) {}
 123
 124 static inline int v9fs_readpage_from_fscache(struct inode *inode,
 125                                              struct page *page)
 126 {
 127         return -ENOBUFS;
 128 }
 129
 130 static inline int v9fs_readpages_from_fscache(struct inode *inode,
 131                                               struct address_space *mapping,
 132                                               struct list_head *pages,
 133                                               unsigned *nr_pages)
 134 {
 135         return -ENOBUFS;
 136 }
 137
 138 static inline void v9fs_readpage_to_fscache(struct inode *inode,
 139                                             struct page *page)
 140 {}
 141
 142 static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
 143 {}
 144
 145 static inline void v9fs_fscache_wait_on_page_write(struct inode *inode,
 146                                                    struct page *page)
 147 {
 148         return;
 149 }
 150
 151 #endif /* CONFIG_9P_FSCACHE */
 152 #endif /* _9P_CACHE_H */