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 #ifdef CONFIG_9P_FSCACHE
  25 #include <linux/fscache.h>
  26 #include <linux/spinlock.h>
  27
  28 extern struct fscache_netfs v9fs_cache_netfs;
  29 extern const struct fscache_cookie_def v9fs_cache_session_index_def;
  30 extern const struct fscache_cookie_def v9fs_cache_inode_index_def;
  31
  32 extern void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses);
  33 extern void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses);
  34
  35 extern void v9fs_cache_inode_get_cookie(struct inode *inode);
  36 extern void v9fs_cache_inode_put_cookie(struct inode *inode);
  37 extern void v9fs_cache_inode_flush_cookie(struct inode *inode);
  38 extern void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp);
  39 extern void v9fs_cache_inode_reset_cookie(struct inode *inode);
  40
  41 extern int __v9fs_cache_register(void);
  42 extern void __v9fs_cache_unregister(void);
  43
  44 extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp);
  45 extern void __v9fs_fscache_invalidate_page(struct page *page);
  46 extern int __v9fs_readpage_from_fscache(struct inode *inode,
  47                                         struct page *page);
  48 extern int __v9fs_readpages_from_fscache(struct inode *inode,
  49                                          struct address_space *mapping,
  50                                          struct list_head *pages,
  51                                          unsigned *nr_pages);
  52 extern void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page);
  53 extern void __v9fs_fscache_wait_on_page_write(struct inode *inode,
  54                                               struct page *page);
  55
  56 static inline int v9fs_fscache_release_page(struct page *page,
  57                                             gfp_t gfp)
  58 {
  59         return __v9fs_fscache_release_page(page, gfp);
  60 }
  61
  62 static inline void v9fs_fscache_invalidate_page(struct page *page)
  63 {
  64         __v9fs_fscache_invalidate_page(page);
  65 }
  66
  67 static inline int v9fs_readpage_from_fscache(struct inode *inode,
  68                                              struct page *page)
  69 {
  70         return __v9fs_readpage_from_fscache(inode, page);
  71 }
  72
  73 static inline int v9fs_readpages_from_fscache(struct inode *inode,
  74                                               struct address_space *mapping,
  75                                               struct list_head *pages,
  76                                               unsigned *nr_pages)
  77 {
  78         return __v9fs_readpages_from_fscache(inode, mapping, pages,
  79                                              nr_pages);
  80 }
  81
  82 static inline void v9fs_readpage_to_fscache(struct inode *inode,
  83                                             struct page *page)
  84 {
  85         if (PageFsCache(page))
  86                 __v9fs_readpage_to_fscache(inode, page);
  87 }
  88
  89 static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
  90 {
  91         struct v9fs_inode *v9inode = V9FS_I(inode);
  92         fscache_uncache_page(v9inode->fscache, page);
  93         BUG_ON(PageFsCache(page));
  94 }
  95
  96 static inline void v9fs_fscache_set_key(struct inode *inode,
  97                                         struct p9_qid *qid)
  98 {
  99         struct v9fs_inode *v9inode = V9FS_I(inode);
 100         spin_lock(&v9inode->fscache_lock);
 101         v9inode->fscache_key = qid;
 102         spin_unlock(&v9inode->fscache_lock);
 103 }
 104
 105 static inline void v9fs_fscache_wait_on_page_write(struct inode *inode,
 106                                                    struct page *page)
 107 {
 108         return __v9fs_fscache_wait_on_page_write(inode, page);
 109 }
 110
 111 #else /* CONFIG_9P_FSCACHE */
 112
 113 static inline int v9fs_fscache_release_page(struct page *page,
 114                                             gfp_t gfp) {
 115         return 1;
 116 }
 117
 118 static inline void v9fs_fscache_invalidate_page(struct page *page) {}
 119
 120 static inline int v9fs_readpage_from_fscache(struct inode *inode,
 121                                              struct page *page)
 122 {
 123         return -ENOBUFS;
 124 }
 125
 126 static inline int v9fs_readpages_from_fscache(struct inode *inode,
 127                                               struct address_space *mapping,
 128                                               struct list_head *pages,
 129                                               unsigned *nr_pages)
 130 {
 131         return -ENOBUFS;
 132 }
 133
 134 static inline void v9fs_readpage_to_fscache(struct inode *inode,
 135                                             struct page *page)
 136 {}
 137
 138 static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
 139 {}
 140
 141 static inline void v9fs_fscache_wait_on_page_write(struct inode *inode,
 142                                                    struct page *page)
 143 {
 144         return;
 145 }
 146
 147 #endif /* CONFIG_9P_FSCACHE */
 148 #endif /* _9P_CACHE_H */