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 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 */